WO2007095541A2

WO2007095541A2 - Plural lumen gastrostomy tube insert for placement into the duodenum and method of monitoring and managing feeding

Info

Publication number: WO2007095541A2
Application number: PCT/US2007/062071
Authority: WO
Inventors: Gerald Moss
Original assignee: Gerald Moss
Priority date: 2006-02-13
Filing date: 2007-02-13
Publication date: 2007-08-23
Also published as: WO2007095541A3

Abstract

A feeding tube assembly for feeding in the gastrointestinal tract of a patient continuously aspirates and feeds at a rate commensurate with the ability of the intestines to absorb nutrients. The feeding tube assembly aspirates air to reduce the likelihood of distension in response to air and excess fluids in the gastrointestinal tract. Digestive juices and nutrients that are aspirated are refed together with unused feeding material into the gastrointestinal tract at a location that more efficiently moves and digests the food. The assembly includes two aspirate reservoirs to and from which aspirate is alternatingly transferred. To provide the continuous and alternating flow, a solenoid valve and timer switch device is provided.

Description

PLURAL LUMEN GASTROSTOMY TUBE INSERT FOR PLACEMENT

INTO THE DUODENUM AND METHOD OF MONITORING

AND MANAGING FEEDING

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of patent application serial No. 11/197,703, filed August 3, 2005, and entitled "METHOD AND APPARATUS FOR SUCTIONING AND REFEEDING GASTRIC JUICES", which is a continuation-in-part of U.S. patent application serial No. 10/419,036, filed April 18, 2003, entitled CONTINUOUS FEEDING AND DECOMPRESSING DEVICE AND METHOD, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

[0002] This invention generally relates to medical devices, such as feeding and aspiration devices.

Description of the Related Art

[0003] Frequently, hospital patients are unable to consume food normally. In these situations, it is often necessary to use a feeding tube to provide nutrition, fluids, and/or medicine. Such a tube is inserted into a patient's gastro-intestinal tract through the nose (nasogastric or nasoenteric tubes) or surgically by means of a gastrostomy tube or jejunostomy tube. Because adequate nutritional intake facilitates recovery, the proper use of a feeding tube and an associated device for feeding through the feeding tube can greatly benefit a patient .

[0004] However, the feeding tubes and the associated devices and methods also pose some discomfort, and even some potential risks, to patients. A number of commercially available feeding tubes exist. Unfortunately, all presently available feeding tube devices and methods for feeding through the tubes suffer from a variety of deficiencies. One common problem is that a feeding tube may deliver the fluids (which include liquid nutrition, hydrating fluids, and medicine to the patient) at a rate exceeding the ability of the gastro-intestinal tract to absorb such fluids. This results in an accumulation of fluid within the intestine. In particularly bad cases, accumulation of fluid causes distension of the intestine that leads to the temporary loss of all residual intestinal function. In rare cases, this intestinal distention may induce fatal vagal reflex circulatory changes. Approximately 1 in 1000 patients that are fed through a jejunal tube die of bowel necrosis, a complication that may be related to the lack of safety of the devices and methods of feeding directly into the gastro-intestinal tract. Severely ill, malnourished patients are most at risk for developing complications associated with overfeeding. Aside from being at high risk, these patients are also most in need of the earliest optimum nutrition. In any case, when a patient's intestine is not operating fully, then the amount of nutrition the patient can receive is limited. However, adequate nutrition is obviously a critical part of anyone's health and is necessary in order to provide optimum recovery for a patient. It is thus desirable to deliver as much nutrition to a patient as can be absorbed safely by the patient's impaired gastro-intestinal tract. Devices and methods of the past are deficient in providing this maximum feeding in a safe, prompt, and effective way to patients in need.

[0005] It is not desirable to simply deliver a maximum amount of nutrition into a patient's intestine. The reason for this is that overfeeding, which is delivering feedings at a rate exceeding the ability of the patient's gastrointestinal tract to absorb its own secretions plus the added nutrition, itself presents serious hazards to a patient. Overfeeding a patient leads to an accumulation of fluid, which distends the intestine. This intestinal distension can lead to fatal circulatory changes, as set forth above. More commonly, complications from overfeeding include the temporary further impairment of intestinal function, with nausea and vomiting, which at a minimum causes discomfort and delays recovery. A common and more severe related complication is impaired ability to breathe deeply and cough because of abdominal distention, resulting in atelectasis and pneumonia.

[0006] A patient's impaired digestive system may also produce too many digestive secretions for the patient to reabsorb immediately. A typical person secretes seven to eight liters of fluid per day, starting with saliva. All secretions normally are reabsorbed by the intestine, without net loss or gain of fluid for the body. Unfortunately, during recovery from surgery the level of secretions remains relatively constant or decreases, while the intestine's ability to absorb secretions is typically impaired, sometimes severely. The result can be a build up of fluid in the intestine, with the same detrimental side effects as found with over-feeding. The problem of digestive secretions can be exacerbated by feeding. [0007] When concentrated nutrition is delivered to a patient's gastro-intestinal tract, the body's natural response is to produce digestive secretions to dilute the feedings and break down the complex nutrients for absorption by the intestine. However, if a patient's gastro-intestinal function is severely impaired only a portion of the total fluid may be absorbed. By way of example, for 2 ml of nutrition delivered to the gastrointestinal tract, 10 ml of digestive secretions may be provided in response. The intestine may temporarily be capable of absorbing only 2 ml of fluid, resulting in a net increase of 10 ml to the volume of fluid in the gastrointestinal tract. Thus, nutrition delivered to the intestine may be competing with digestive secretions for absorption by the intestine. This problem may worsen as feedings continue, causing progressive intestinal distension which, in turn, further impairs intestinal function and reduces the amount of nutrient actually being absorbed. To avoid problems of overfeeding or excessive secretion build up during recovery, a patient's gastrointestinal tract may be aspirated to remove excessive fluid. However, any secretions removed in this way will cause a net loss of fluids and dehydration of the patient. Past solutions to this problem include providing replacement fluids in the form of an intravenous saline solution. However, this method of fluid replacement does not conserve nutrients and digestive juices that may have otherwise been used.

[0008] Another problem that has not adequately been solved is that the very presence of a nasal feeding tube stimulates swallowing by the patient, introducing additional air into the intestine. The presence of air within the gastro-intestinal tract interferes with the propulsion and absorption of nutrition and can be quite uncomfortable or painful to a patient. The use of an aspirating tube to remove air from the gastro-intestinal tract has been used to combat this problem. As set forth above, aspirating introduces additional problems of increased risks of dehydration and removal of potentially beneficial nutrients.

[0009] Unfortunately, the use of a second tube for aspiration presents new problems. The introduction of a second tube only adds to the pain and discomfort experienced by a patient. Furthermore, if a separate second tube is used, it may be difficult to effectively locate it proximate to the feeding tube, thereby preventing it from aspirating excessive food present in the gastro-intestinal tract .

[0010] In conjunction with systems of the past that have been used for feeding and aspirating, tubes with more than one lumen integrated in a single tube have been used. These tubes are typically manufactured with a plurality of lumens that are permanently formed as part of the tubes. Thus, the feeding tubes of the past are deficient enabling assembly and disassembly after the time of manufacture. Furthermore, the manufacturing process used to make feeding and aspirating tubes having a plurality of permanent lumens is relatively expensive and intricate.

BRIEF SUMMARY OF THE INVENTION

[0011] The present invention relates to a feeding tube assembly for providing nutrients to a patient's gastrointestinal tract with a reduced likelihood of overfeeding. The feeding tube assembly improves the efficiency of absorption in the gastro-intestinal tract by removing gas therefrom and by stepping a feeding material forward to a location in which reflux is inhibited and greater peristaltic activity promotes greater absorption and flow. The device and method further reduce the tendency toward dehydration of past devices and methods.

[0012] In one aspect, the invention comprises a feeding and decompression device for feeding into and aspirating from an intestinal tract. The device includes a first aspirate reservoir and a second aspirate reservoir each connected to an aspiration channel. A vacuum source is alternatingly fluidly connected to the first and the second aspirate reservoirs and induces a flow of an aspirate from the aspiration channel to at least one of the reservoirs at a time.

[0013] To facilitate the switching between the reservoirs, the device may include a solenoid valve connected to the first and second aspirate reservoirs and to the vacuum source. A timer switch may connect a power source to the solenoid valve so that the timer switch and solenoid valve alternatingly fluidly connect the first and second aspirate reservoirs with the vacuum source. Furthermore, the timer switch and the solenoid valve may connect the reservoir that is not connected to the vacuum source to a vent. Specifically, the first and second reservoirs can be continuously switched back and forth between being connected to the vacuum source and the vent so that one reservoir is always connected to the vacuum source and one is always connected to the vent. [0014] The device may simply comprise a solenoid valve and timer device for alternating valves of the device between positions. In this aspect, the device may include a solenoid and a valve housing having at least four connection points for connecting a plurality of fluid lines. The valve housing may be connected to the solenoid such that the solenoid operatively controls at least two valves within the housing. The solenoid and timer device may have an adjustable timer that meters time for a cycle of a predetermined period of the time. The adjustable timer may be connected to the solenoid and to a switch so that the switch alternates between an open and a closed state for predetermined portions of the cycle. This cycle can be repeated indefinitely. A source of power may be connected to the solenoid by a circuit that includes the switch. Thus, the switch may be alternatingly closed and opened by the timer, whereby power from the power source may be correspondingly applied to and removed from the solenoid. The power being repeatedly turned on and off in this manner will cause the solenoid to simultaneously move the at least two valves between a first position and a second position.

[0015] The power can actuate any number of valves by any number of members. However, the at least two valves can be provided by a single motive member. The single motive member can provide a rotary valve. Alternatively, the motive member can include a piston member.

[0016] The timer can be provided as a mechanical or electro-mechanical timer. The timer can be provided by a microcircuit . In this regard, it is contemplated that at least a portion of the switch can also be provided by the microcircuit .

[0017] The invention has a feeding and decompression device providing substantially constant aspiration during feeding yet does not require a solenoid valve and a timer. In this aspect, the invention incorporates a single aspirate reservoir and provides constant aspiration and feeding by a means other than switching between two or more such reservoirs. In this aspect, a feeding and decompression device may include at least one aspirate reservoir having an aspiration port and a feeding port. An aspiration channel may be connected to the aspirate reservoir via the aspiration port. A feeding channel may be connected to the aspirate reservoir via the feeding port. A vacuum source may be connected to the aspiration channel for drawing aspirate toward the aspirate reservoir. The vacuum source in this aspect of the invention can be provided by an electric pump fluidly connected directly to the aspiration channel. [0018] The invention includes a method of feeding and decompressing in a gastro-intestinal tract. The method includes initial steps of placing a distal end of a feeding channel at a first position and a distal end of an aspiration channel at a second position that is spaced proximally relative to the first position. In accordance with the method, digestive juices and any nutrient or feeding material therein may be continuously aspirated via the aspiration channel. In accordance with one aspect of the method, the step of continuously aspirating may further comprise substantially collapsing a portion of the duodenum at the second position. The method may further comprise continuously feeding via the feeding channel.

[0019] The steps of continuously aspirating and continuously feeding may further include aspirating into at least one of a plurality of aspirate reservoirs at a time through the aspiration channel. In accordance with the method, the aspiration channel can be common to all of the aspirate reservoirs.

[0020] The step of continuously feeding may include feeding from one of the plurality of aspirate reservoirs into which nothing is being aspirated. That is, aspirate can be directed into other (s) of the plurality of aspirate reservoirs simultaneously with the step of feeding from the one aspirate reservoir into the feeding channel. The method may further include supplying the feeding channel with feeding material from an unused feeding material line and from at least one refeeding line connected to another of the aspirate reservoirs.

[0021] The step of continuously feeding may further comprise returning at least a portion of digestive juices and feeding material to the first position that were previously aspirated at the second position. This return of digestive juices actually steps the digestive juices and feeding material forward in the digestive tract reduces the tendencies of gastric reflux and dehydration in a patient. The return of the feeding material reduces waste of the material. However, this refeeding and feeding must be accomplished in a way that avoids physiological harm and discomfort. Therefore, the method of feeding and decompressing may further include inhibiting distending of the gastro-intestinal tract. This is achieved by limiting an amount of aspirate that is fed and refed into the feeding channel during a certain period of time. [0022] The method not only includes simultaneously impeding overfeeding, distending, and dehydration, but also facilitates obtaining direct feedback regarding absorption of a feeding material in the gastro-intestinal tract. This feedback can be in the form of observing a volume of aspirate that is greater than a predetermined amount. Thus, the method can also include adjusting the pressure or the flow resistance in the feeding channel so that a volume of aspirated fluid during a period of time is substantially equal to or less than the volume absorbed during the same period of time.

[0023] A method of feeding and decompressing in a gastrointestinal tract in accordance with the present invention includes feeding through a feeding channel into a duodenum and aspirating through an aspiration channel from portions of a stomach and/or duodenum. The step of feeding includes refeeding aspirate that has been removed from the stomach and/or duodenum in the step of aspirating. [0024] The method of feeding and decompressing includes placing a distal end of a feeding channel at a first position in a duodenum, placing a distal end of an aspiration channel at a second position in the duodenum, and aspirating via the aspiration channel. The method of feeding and decompressing, further may include the steps of placing a distal end of an aspiration channel at a position in the duodenum spaced proximally relative to the first position, and continuously aspirating and substantially collapsing a portion of a duodenum at the second position. It is to be understood that the step of feeding and the step of aspirating may include feeding and aspirating from separate tubes forming separate channels. Alternatively or additionally, the step of feeding and the step of aspirating may include feeding and aspirating through a single composite line having plural channels. It is to be understood that inner tubes of a composite line may be removable for withdrawal from within outer tube(s) while the outer tube(s) remain in place extending into the duodenum, for example.

[0025] Other advantageous aspects of the method include improving an efficiency of digestion and absorption by removing gases from a gastro-intestinal tract and by stepping a feeding material forward in the gastrointestinal tract to a location where greater peristaltic activity facilitates absorption. The efficiency can be improved to a case specific and time dependent maximum by the steps of observing and adjusting as set forth above. To this end, the volume of aspirate returned plus the unused feeding material to be fed can be made to be substantially equal to the volume absorbed. As long as the sum of the fluid to be fed is not greater than the fluid being absorbed, overfeeding will be avoided.

[0026] The method of feeding and decompressing in a gastrointestinal tract may include inhibiting gastric reflux without permanently removing natural gastric juices. The method may include reducing one or more of dehydration, loss of natural antibodies, and lose of enzymes. The step of feeding may include refeeding a feeding material removed during the step of aspirating. The method may include filtering an aspirate from the stomach to a maximum particle size in a range from one quarter of a millimeter to one millimeter. [0027] The combination feeding and decompression or aspiration tube can be formed as a feeding tube assembly that overcomes deficiencies of past devices and provides a readily assembleable unit that can be put together by a doctor or an assistant in a hospital. Thus, the expensive plural-lumen feeding and aspirating tubes of the past can be replaced by a simple combination of an inner and an outer tube assembled together to form the feeding tube of the present invention. In particular, this feeding tube may be a jejunal or a duodenal feeding and aspirating tube for the several reasons and specific advantages set forth herein .

[0028] The feeding and aspirating tube assembly may include a first outer aspirating tube and a second inner feeding tube. The second inner feeding tube may be removably disposed inside the first outer aspirating tube. The outer tube may have a branch portion having at least two branches. One of the branches can be selectively used to guide the inner tube through an external opening and into an interior of the outer tube. The other of the branches can be connected to a vacuum or pump source for aspirating through the outer tube. This aspiration may be accomplished with the inner tube in the interior of the outer tube or with the inner tube removed.

[0029] The inner tube or feeding tube may be preassembled within the outer tube. A third tube may be formed by one or more short spacing tubes or spacing beads extending between a distal end of the outer tube and a distal end of the inner tube. A distal end of the third tube, the distal spacing tube, or the distal spacing bead may be removably fixed to the distal end of the inner tube. In this way, the distal spacing tube or distal spacing bead is a nut for securing the rest of the spacing tubes or spacing beads on the inner tube. Thus, the tube(s) or bead(s) form spacers that separate the distal end of the outer tube from the distal end of the inner tube. In this way, the third tube, spacing tube(s) or spacing bead(s) may advantageously space a distal end of the feeding tube from the aspiration channel of the outer tube so that aspiration occurs at a position at least slightly upstream in the digestive tract relative to a position of feeding. [0030] In the system for aspirating from and feeding into the gastro-intestinal tract, as applied to feeding into the duodenum, the feeding tube assembly is connected to at least one aspirate reservoir. The system includes at least one filter and at least one one-way valve each fluidly connected to the aspirate reservoir by an aspirate line. At least one feeding line may be fluidly connected to the aspirate reservoir. The aspirate line may be at least one of a nasogastric, nasoenteric, gastrostomy, and jejunostomy tube having aspirating openings in the aspirate line along a length of the aspirate line in a range from approximately eight inches to approximately twelve inches. [0031] The feeding tube assembly includes a third tube removably supported on the first outer aspirating tube and the second inner feeding tube. The second inner feeding tube may be removably disposed inside the first outer aspirating tube and inside the third tube. The outer tube may fit loosely around the inner tube to permit aspiration through the outer tube between the inner and the outer tubes while the inner tube is disposed inside the outer tube. A distal end of the inner tube may be supported by the third tube at a location in a range from approximately three fourths inch to approximately ten inches from a distal end of the outer tube when the feeding tube assembly is in an assembled state.

[0032] The third tube of the feeding tube assembly includes a one or more spacing beads threaded or slidably guided onto the inner tube. When the third tube comprises a plurality of spacing beads threaded on the inner tube, the spacing beads abutting each other and a distal end of the aspirating tube. The third tube may further include a nut, which may be a distal most spacing bead, removably attached to a distal end of the inner tube and abutting a distal most one of the rest of the plurality of spacing beads .

[0033] The outer tube of the feeding tube assembly further includes a plurality of aspiration openings through a wall of the outer tube. These openings are formed by the material of outer tube wall and extend completely through the thickness of the wall. The plurality of aspiration openings may be located in spaced relation to each other along a length of the outer tube adjacent to the distal end of the outer tube. The plurality of aspiration openings may be located at alternatingly more proximal locations on opposite sides of the outer tube wall relative to each other. The plurality of aspiration openings may include openings of a first large size and openings of a second small size smaller than the first large size. The openings of the first large size may be located opposite to respective openings of the second small size in a direction generally perpendicular to a length direction of the outer tube .

[0034] The length of the outer tube that includes the aspiration openings may be defined as extending from the distal end of the outer tube to a most proximally located one of the plurality of aspirate openings. Thus defined, the length may be in a range from approximately three inches to approximately fifteen inches. This length may be any magnitude inside or outside this range. For example, this length may be approximately ten inches.

[0035] For the feeding tube assembly as applied to duodenal applications, a greater size differential between the outer and the inner tubes may be advantageously implemented. For this reason, the outer diameter of the outer tube may be in a range from approximately six millimeters to approximately nine millimeters. The outer diameter of the inner tube may be in a range from approximately one millimeter to approximately three millimeters. Thus a range of differences is possible. Furthermore, it may be possible to implement the invention with even larger outer tube diameters and smaller inner tube diameters. Also, a wall thickness of the inner tube may be very thin, such as approximately one twentieth of an inch in thickness, for improved flow advantages. It is to be understood that at least some of the advantages that the increased size differential and thinner inner tube walls provide may apply to feeding in the jejunum or stomach. [0036] By surrounding a distal end of the feeding tube with tube(s) or beads, the feeding tube may be strengthened so that a much thinner wall for the feeding tube may be incorporated. A thinner wall for the feeding tube provided as the inner tube provides a greater cross sectional area forming the aspiration channel through which aspirate may pass between the outer and inner tubes. This improves aspiration capacity of the system in which these features are incorporated. At the same time, the tube(s) or beads will support the distal end of the inner tube so that the distal end of the inner tube reaches a position that is positively spaced from the distal end of the aspiration channel. Then, after a period of protected feeding and aspiration, the inner tube may be withdrawn by exerting a pulling force on the inner tube. Under a predetermined pulling force, the distal end of the inner tube will slip out of a distal most tube(s) or bead(s) and the inner tube may be completely removed from within the outer tube. The tube(s) or bead(s) will then be free to harmlessly move through the digestive tract and out of the patient's body in a natural way. [0037] Many of the aspects of the present invention provide the advantage of enabling feeding of a fine feeding material and closely monitoring a patient and the amount of feeding material being absorbed in the early stages after an operation. Subsequent to this feeding and monitoring period, when a patient's gastro-intestinal tract is capable of consistently absorbing more feeding material, the fine feeding material can be replaced by a coarser feeding material and the combination feeding and aspirating tube can be replaced by a subset of the feeding and aspirating tube combination. That is, the feeding tube can be withdrawn from within the outer aspirating tube and the aspirating tube can be used for both feeding courser feeding material and for aspirating if needed. Alternatively, a separate feeding tube can be used to feed the courser material.

[0038] The system may further include a combination feeding and aspirate line connected to the aspirate reservoir at one end. The combination feeding and aspirate line may also be connected to each of the aspirating and feeding lines. The aspirating line may include at least one of a nasogastric, nasoenteric, gastrostomy, and jejunostomy tube having aspirating openings adapted for aspiration from the stomach and/or duodenum.

[0039] The foregoing and other features and advantages of the present invention will be apparent from the following more detailed description of the particular embodiments of the invention, as illustrated in the accompanying drawings .

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG. 1 is a diagrammatic view of a system according to a first embodiment of the present invention, depicting a use for feeding and decompressing in a gastrointestinal region of a patient.

[0041] FIG. 2 is an enlarged diagrammatic view of a device of the system shown in FIG. 1.

[0042] FIG. 3 is a schematic representation of the solenoid valve and switch device that may be included in the device of FIGS. 1 and 2.

[0043] FIG. 4 is a diagrammatic view of part of a system according to a second embodiment of the invention. [0044] FIG. 5 is a diagrammatic view of the system of FIGS. 1-2 and incorporating a particular feeding tube assembly in accordance with one aspect of the invention. [0045] FIG. 6 is an exploded perspective view of the feeding tube assembly of FIG. 5.

[0046] FIG. 7 is sectional view of an encircled portion indicated at 7 in FIG. 5.

[0047] FIG. 8 is a partial sectional view of another feeding tube assembly.

[0048] FIG. 9 is a detailed partial sectional view of portion IX of the feeding tube assembly of FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

[0049] The present invention incorporates the principles of the Applicant's prior inventions disclosed in U.S. Patent No. 6,447,472, filed October 19, 2000, and issued September 10, 2002, the disclosure of which is incorporated herein by reference. The present invention has many added features, structural differences, and utilizes distinct methods. The new aspects safely provide continuous aspiration and continuous feeding and other advantages that have not been adequately addressed by devices and methods of the past. [0050] It should be noted that the devices and methods of the present invention are not limited to use in human patients, but may be used in veterinarian applications or even in other non-medical applications. Furthermore, it is to be understood that while the devices are specifically applicable in the gastro-intestinal tract of a body, the devices may also be useful in other organs or systems of the human. Therefore, the disclosure directed specifically to the application of the devices and methods for feeding and decompressing in the gastro-intestinal tract is to be considered exemplary and not restrictive. The limitations of the devices and methods are to be interpreted in accordance with the appended claims.

[0051] As shown in FIG. 1, an aspirate storing and refeeding device 10 is used to feed and decompress in a gastro-intestinal tract 15 of a patient 20. To this end, a combination feeding and aspirating tube 25 may be inserted into the gastro-intestinal tract 15 through a gastrostomy port 27 of a percutaneous enteric gastrostomy (PEG) or through the nose and esophagus for a nasoenteric access as shown in dashed lines in FIG. 1. Other ways of accessing the gastro-intestinal tract include inserting the tube through the abdominal wall directly into the jejunum, or directly into the stomach and intraluminally to the jejunum. As can be appreciated from FIG. 1, the combination feeding and aspirating tube 25 may be a double lumen tube and may include an aspiration channel 30 and a feeding channel 35 for handling flow in opposite respective directions. Combining these channels 30, 35 into a single composite tube 25 has the advantage of reducing bulk and complexity in the inserted portion of the channels 30, 35. As shown, the feeding channel may be supplied with one or more of a non-aspirated fine feeding material from an unused feeding material line 37 and an aspirate from a refeeding line 39. These two lines joint in a Y to form the feeding channel 35 and the composite feeding and aspirating line 25, as shown. However, a separate aspiration channel may be inserted through the abdominal wall, or through the nasal passages and esophagus. When a separate aspiration channel is implemented, the feeding line may be a dedicated feeding line.

[0052] As shown in the detailed partial sectional views of FIGS. 8 and 9, the aspiration channel 30 has a distal end 40 including an opening 45 for feeding and/or aspirating fluids including digestive juices and feeding material after a protected feeding period as will be described below. Additional openings 47 and 48 may be located at intervals spaced proximally from the distal end 40 along the aspiration channel 30, as shown in FIGS. 1, 8, and 9. This has the effect of aspirating along a greater length of the gastrointestinal tract as indicated by the collapsed region 49 of the duodenum, as shown in FIG. 1. The feeding channel 35 may have a distal end 50 extending distally beyond the distal end 40 of the aspiration channel 30. The distal end 50 of the feeding channel 35 may have an opening 55 for delivering feeding material and other fluids as will be described below. The distal end 50 and the opening 55 of the feeding channel 35 may be spaced distally from the distal end 40 and opening 45 of the aspiration channel 30 by approximately three inches. Depending on the particulars of the cite at which the channels are placed, the separation of the most distal openings 45, 55 of respective aspiration and feeding channels may be in the range from 1/4 inch to 12 inches. In most cases, the separation of the distal openings 45, 55 of the aspirating and feeding channels 30, 35 will not exceed approximately 6 inches.

[0053] To assure that the spacing is maintained, the feeding and aspirating tube 25 may have a third tube 56 formed of one or more spacing tubes or beads 57. These tube(s) or beads 57 may have through holes that may be threaded onto an inner tube 58 that forms the feeding channel 35, as may be appreciated from the illustrations of FIGS. 1, 8, and 9. A most proximal one of the tube(s) or beads 57 will abut the distal end 40 of the aspiration channel 30, and distally adjacent tube(s) or beads 57 will abut each other. An end nut 59 having an opening that snugly and frictionally receives the distal end 50 of the inner tube 58 of the feeding channel 35 will abut the distal most one of the tube(s) or beads 57 and hold the one or more tube(s) or beads 57 in a substantially rigid state when a slight pulling force is maintained on the inner tube 58. Thus, a distal segment of the inner tube 58 underlying the spacing tube(s) or beads 57 is held in a stiff or rigid condition while the pulling force is maintained. Therefore, the feeding channel may be controllably inserted through the stomach and into the duodenum without undesirable buckling of the feeding channel 35 or mis- positioning of the distal end 50 of the feeding channel 35. [0054] In one embodiment shown in FIG. 2, the device 10 may include a first aspirate reservoir 60 and a second aspirate reservoir 65. The reservoirs 60, 65 can be provided in the form of burettes having single lumen combination feeding and aspirating lines 70, 75 for handling both aspiration and refeeding of aspirate to and from the reservoirs 60, 65, respectively. The combination feeding and aspirating lines 70, 75 generally handle flow in only one direction at a time, either toward or away from the reservoirs 60, 65. However, flow in one of the combination feeding lines is generally in an opposite direction relative to flow in the other of the combination feeding and aspirating lines 70, 75. Thus, there is an alternating pattern of aspirating into the first reservoir 60 for a first half of a cycle and then aspirating into the second reservoir 65 for a second half of the cycle. Meanwhile, the second reservoir 65 refeeds aspirate for the first half of the cycle and the first reservoir 60 refeeds aspirate for the second half of the cycle. This alternating pattern can be repeated indefinitely during feeding. It is to be understood that refeeding need not be continuous during all of the half cycles. Likewise, aspiration flow may cease at any point during each of the half cycles. Additionally, the cycles need not be divided into halves. Rather any alternating pattern of time is considered to be within the scope of the invention. [0055] In order to effectuate the alternating pattern of aspirating and refeeding, the device 10 may include a system of lines 80, 85, 90, 95, one-way valves 100, and a solenoid valve 105 for alternatingly connecting the reservoirs to a vacuum source 107. The one-way valves 100 permit flow in the lines 80, 85, 90, and 95 only in the directions indicated by the arrows in FIG. 2. Thus, when the solenoid valve 105 connects either of the reservoirs 60, 65 with the vacuum source 107, only flow through the aspirating lines 80 and 90 is induced, which in turn induces flow from the aspiration channel 30. When the vacuum source 107 is disconnected from one of the reservoirs 60, 65, the contents of that reservoir are permitted to flow out through one of the feeding lines 85, 95 under the influence of gravity, for example. Alternatively, a pump or vacuum source 107 could be connected to the feeding channel 35 to draw and refeed the aspirate into the feeding channel 35. A filter 108 can also be placed in the aspiration channel 30 or between the aspiration channel 30 and the aspirating lines 80, 90 as shown in FIG . 2.

[0056] As shown, the device 10 may be in addition to a feeding system that is typically used in hospitals. As such, the unused feeding material may be provided in a feeding bag 110. The feeding bag may be connected to the feeding channel by the unused feeding material line 37. The flow of the feeding material into the feeding channel 35 is affected by the capacity of the feeding channel 35, the pressure at which the feeding material is fed from the feeding bag 110, (such as by a pump), and the flow rate of the aspirate that is being refed into the feeding channel 35. These and other factors can be adjusted to adjust the flow of feeding material into the feeding channel 35. The flow from the feeding bag 110 can be reduced in proportion to a flow of aspirate that is refed. Thus, waste of unused feeding material can be avoided. Furthermore, nutrients and digestive juices that typically have been discarded in the past can be reintroduced and absorbed with little or no loss of fluids and nutrients to the patient.

[0057] The device 10 also enables the aspiration to be applied continuously. That is, vacuum from the vacuum source can be applied substantially constantly. Flow of the aspirate may not be constant or continuous due to a presence or a lack of presence of fluids in the portion of the gastrointestinal tract being aspirated. However, continuous and/or constant aspiration has the advantage of continuously removing gases from the gastrointestinal tract as there is no interval without suction during which gas may be propelled by peristalsis distal to the most distal aspiration orifice. Removing these gases has the advantages set forth above. Furthermore, removing the gases continuously or constantly has the advantage of preventing distending of the intestines due to build up of these gases.

[0058] When the length of the half cycles are set properly, both the refeeding flow and aspiration flow is driven to a constant flow value and can be continuous. With more constant and/or continuous the flow in the feeding channel, the less the fluctuation of flow into the gastrointestinal tract will be. By providing less fluctuation in the flow into the intestines, distending can further be inhibited or prevented. Furthermore, nutrients and fluids will be more constantly available for absorption by the intestines.

[0059] A predetermined volume of aspirate to be retained in the reservoirs 60, 65 can be selected and set. This volume also affects the "head" or pressure due to gravitational forces that causes the flow of aspirate out of the reservoirs 60, 65. Preferably, a maximum predetermined volume to be retained in each reservoir 60, 65 during each half cycle is in the range from 10 to 15 cc. This reduces the chance for overfeeding, for example when the half cycle is kept to approximately V2 minute. Perhaps a maximum adjustable volume could be as much as 35 cc. Adjustment of the predetermined volume is achieved by adjusting the depth 120 of a lower end 125 of a first draw tube 130 in the first aspirate reservoir 60. Similarly, the maximum volume of aspirate to be retained in the second aspirate reservoir 65 can be adjusted by adjusting a depth 120 of a lower end 135 of a similar second draw tube 140. [0060] The draw tubes 130, 140 connect the aspirate reservoirs 60, 65 to first and second overflow chambers 145, 150. These tubes may also provide fluid communication between an interior of each of the reservoirs 60, 65 and the solenoid valve 105. Thus, draw tubes 130, 140 may connect the aspirate reservoirs to the vacuum source 107 in an alternating pattern, as will be described in further detail below. The draw tubes 130, 140 may thus act to remove aspirate in excess of the predetermined maximum volume and draw the excess aspirate into respective overflow chambers 145, 150. The overflow chambers 145, 150 may have any reasonable volume. Preferably, the volume of each overflow chamber is in the range from 200-4000 cc, with 1000 cc being a fairly standard capacity. Once removed, the excess aspirate can be discarded or refed later when the flow of aspirate in the aspiration channel 30 has decreased. [0061] The first and second overflow chambers 145, 150 are connected to the solenoid valve by first and second valve connection lines 155, 160. Thus, the overflow chambers 145, 150 are fluidly connected to the solenoid valve 105 and to the reservoirs 60, 65 via the draw tubes 130, 140. The solenoid valve preferably comprises a single motive member 165 contained within a solenoid housing 170. The motive member 165 provides at least two (2), two-way valves for connection between at least four ports 175, 180, 185, and 190. The motive member may have first and second channels 195 and 197. The first channel 195 may connect the first valve connection line 155 from the first aspirate reservoir 60 to the vacuum source 107 through a vacuum line 200 or to an ambient pressure volume through a vent hose 205. The second channel of the motive member 165 may connect the second valve connection line 160 to the ambient pressure volume through the vent line 205 or to the vacuum source 107 through the vacuum line 200. In one configuration of the solenoid valve, the motive member 165 is a rotary member that rotates under the influence of a solenoid through a range of approximately ninety degrees to exclusively connect either the first aspirate reservoir 60 or the second aspirate reservoir 65 to the vacuum source 107 as shown in FIG. 2. Alternatively stated, the first channel either connects the first reservoir 60 to the vacuum line 200 or to the vent line 205. Likewise, the second channel 197 of the motive member 165 either connects the second aspirate reservoir 65 to the vent line 205 or to the vacuum line. Only one of the reservoirs 60, 65 is connected to the vacuum source 107 at a time. The other reservoir is connected to ambient air through the vent line 205. By way of example and not by way of limitation, this is efficiently achieved by a single motive member that rotates or moves linearly between only two operating positions . [0062] The connections to the vacuum source 107 and vent 205 are alternated back and forth so that one of the aspirate reservoirs 60, 65 is connected to the vacuum source 107 and the other is connected to the vent at all times. Preferably, this is achieved by a switch connected to the solenoid valve 105, and wherein the solenoid valve is in a first position when the switch is closed and in a second position when the switch is opened. That is, applying power to the solenoid valve places it in a first position and removing power from the solenoid valve places it in a second position indicated by the dashed arrows in FIG. 2. Preferably, the switch is provided by a timer switch 210 in a circuit connected to a power source 215 as shown in FIG. 3. The timer switch 210 can be adjusted to actuate its switch at a predetermined interval corresponding to a half cycle. Thus, the switch 210 will be turned on or off after each half cycle and the motive member 165 will be moved to its first or second position. [0063] The solenoid could be replaced by a different solenoid valve. For example, the solenoid valve may comprise a piston member and more than four ports. The solenoid valve can connect the aspirate reservoirs to respective sources of vacuum and/or to respective vent lines. Further alternatively, the device could be manually operated. That is, instead of employing a timer switch, a switch could be operated by hand. Further alternatively, manually operated valves could be provided so that a person would be required to switch the connections to the reservoirs back and forth between vacuum and vent. [0064] As indicated above, the amount of aspirate received into the reservoirs 60 and 65 is optimally equal to or slightly less than the amount refed during a half cycle of the device. However, the amount refed varies during feeding and over the course of recuperation. Therefore, there will be periods of time during some half cycles when the aspiration is being applied, but little or no aspirate is flowing. Likewise, there will be periods when the aspirate being refed is completely withdrawn from a reservoir before a current half cycle has ended. Since a reservoir is connected to ambient during feeding from that reservoir, there is a potential for drawing air from the ambient into the feeding channel and eventually into the gastrointestinal tract. To prevent this from happening, a check valve is provided in each reservoir 60, 65 by a ball 220. As shown, the ball 220 is buoyant and is thus positioned by the aspirate at a first level 225. When the aspirate reaches a maximum level, the ball floats at the maximum aspirate level as indicated at 230. However, when the aspirate completely leaves the reservoirs 60, 65, the ball 220 seats in a sealed position as shown at 235. With aspirate refeed being induced by gravity, this type of check valve will normally be sufficient to prevent air from being drawn into the feeding channel 35. On the other hand, if a positive pressure pump is employed to draw and refeed the aspirate, a more positive shutoff valve may be necessary .

[0065] As can be appreciated, the device 10 may include a solenoid valve and timer device 240 as shown in FIG. 3. Furthermore, the solenoid valve and timer device 240 has special characteristics that are particularly beneficial when used with the overall device 10 described above. Specifically, the solenoid valve 105 could be made automatic by an electrical circuit including a timer switch 210. The timer switch can comprise electronics that includes a timer. The timer switch 210 can further include low voltage switch actuation that opens and closes the circuit connected to the power source 215. Alternatively, the timer switch can be made up of discrete electrical components or discrete mechanical components that accomplish the same alternating timing function. Further alternatively, the timer switch can include a combination of electrical and mechanical elements that achieve the same alternating timing function.

[0066] FIG. 4 is a diagrammatic view of a device 245 according to a second embodiment of the invention. This device 245 differs from the device 10 described above in that the previously described device had two aspirate reservoirs whereas the device 245 has only one aspirate reservoir 250. The aspirate reservoir 250 in this case has a capacity equal to a maximum volume of aspirate to be retained in the reservoir. Any excess aspirate will spill into an overflow chamber 255. A further difference is that the line connected to the reservoir 250 for refeeding aspirate does not also function to conduct aspirate to the reservoir 250. That is, the aspirate channel 30 is connected to the reservoir by an aspirating line 260 and the feeding channel 35 is connected to the reservoir 250 by an aspirate refeeding line 265. As such, aspiration and refeeding can occur simultaneously from the same reservoir 245. However, aspiration cannot be effectuated by a vacuum source in fluid communication with the aspiration channel via the reservoir 245. If so, refeeding in the refeeding line 265 would be impeded. Therefore, a positive pressure pump 270 is provided in the aspirating line to draw aspirate toward the reservoir 245. Aspirate can be refed by a gravitational force. However, a pressure source such as a pump could be substituted. To assure flow in the right direction, a one way valve 275 is also placed in the aspirating line 260. As in the previous embodiment a filter 280 is also preferably placed in the aspirating line 260, or between the aspirating line 260 and the aspiration channel 30. A check valve including a ball 220 like that described in the embodiment above is provided in the reservoir 250 of the device 245. This check valve functions substantially the same as that described above. Typically, the reservoir is open to the ambient air so that aspirate can be refed by gravity. Like the previous embodiment, the device is intended to be used in addition to a supply of an unused feeding material that can be fed from a feeding bag 285 by a pump or gravity.

[0067] The device 245 of FIG. 4 is similar to the previously described embodiment in that it advantageously provides for continuous or constant aspiration and refeeding of aspirate. While the device 245 requires a positive pressure source 270, device 245 does not require the solenoid and timer device 240 of the previously described embodiment of FIGS. 1-3.

[0068] FIG. 5 shows a particular feeding tube assembly 305 that can be used with the device 10 of FIGS. 1 and 2 or with the device 245 of FIG. 4. The feeding tube assembly 305 can also be used with other feeding and aspirating devices. For example, the feeding tube assembly 305 can be used together with the single burette system of my U.S. Patent No. 6,447,472 issued September 10, 2002, which is incorporated herein by reference. The feeding tube assembly 305 has a combination feeding and aspirating tube 310 that is connected to the feeding and aspirating device 10 by a separate aspirating line 315 and a separate feeding line 320. The feeding tube assembly 310 includes a branched section 325 that includes at least a first branch 327 and a second branch 329. As shown in FIG. 5, the first branch 327 can be selected for connection with the separate aspirating line 315, and the second branch 329 can be selected for connection with the separate feeding line 320. [0069] FIG. 6 shows the feeding tube assembly 305 in greater detail. A first outer tube 330 is connected to the branched section 325, which in this case is in the form of a "Y". The first outer tube 330 is connected to the branched section by a sealed joint 332. A second inner tube 335 is selectively inserted into the outer tube 330 via the branched section 325. Respective lengths of the inner tube 335 and the outer tube 330 are selected to provide a distally protruding portion 337 of the inner tube 335 when the inner tube is inserted completely through the outer tube 330 as shown in FIG. 5. This relationship provides for a distally located position of the feeding portion of the feeding and aspirating tube 310 relative to the aspirating portion as will be described in greater detail below.

[0070] It is to be understood that when the inner tube 335 is inserted to its assembled state within the outer tube 330, an adapter 339 on the inner tube 335 is received in the second branch 329 in a hermitically sealed relation. Thus, no aspirate or feeding material can move in or out of the second branch 329 except through the inner tube 335. For this purpose, the adapter 339 has an input opening 342 on a proximal end thereof for receiving and passing a feeding material into the inner tube 335. A cap 345 connected to the adapter 339 by a flexible connector 347 can be used to close the input opening 342 when the inner feeding tube 335 is not in use. The inner tube 335 has a rounded distal end 350 to aid in passing the inner tube 335 through the outer tube 330 and to reduce the chance of injury to an intestinal tract of a patient. The inner tube 335 has feeding openings 352 slightly proximately located relative to the rounded distal end 350 and spaced along the inner tube 335 in an alternating pattern as shown in FIG. 6.

[0071] The outer tube 330 has a distal portion 356 including a distal tip 359 that has an aspirating opening 362 therethrough. Additional aspirating openings 365 are spaced along the outer tube 330 in an alternating relation as shown in FIG. 6. FIG. 7 is a sectional view of a portion of the feeding tube 310 shown as in an encircled region shown at 7 in FIG. 5. This figure shows how the feeding openings 352 can be spaced along the inner tube 335. Likewise, the aspirating openings 365 can be spaced along the outer tube 330. As described with regard to the embodiments above, the feeding openings need to be located distally relative to the aspirating openings 365. This provides the advantage of feeding at a location downstream in the gastrointestinal tract from a location at which excess gastrointestinal fluids and feeding material are aspirated. Thus, the feeding material and any medication in the inner tube 335 is less likely to be withdrawn during aspiration. This is especially so when the feeding tube is placed in the jejunum as described above.

[0072] In this particular embodiment of the feeding and aspirating tube combination 310, the feeding openings 352 are located at distal positions within a particular range of distances from the most distal aspirating opening 362 of the aspirating outer tube 330. As shown in FIG. 7, a distal most feeding opening 352 is located in a range from approximately 2 cm to approximately 3 cm from the distal opening 362 of the outer aspiration tube 330. The feeding opening 352 that is most proximal is located in a range from approximately Vz cm to approximately 2 cm from the distal opening 362 of the outer tube 330.

[0073] The relative sizes of the inner tube 335 and the outer tube 330 are important in determining the resistance to flow between the inner tube 335 and the outer tube 330. For example, if the inner tube 335 is too large, then the flow of aspirate between the inner tube 335 and the outer tube 330 will be adversely restricted. Thus an outer diameter 370 of the outer aspirating tube 330 should have a dimension in a range from approximately 10 French-18 French. In more common units, the outside diameter 370 of the outer aspirating tube 330 can be in a range from approximately 3 mm to approximately 6 mm. The outer diameter 375 of the inner tube 335 may be in a range from approximately 4 French to approximately 8 French. Likewise, in more common units the outer diameter 375 of the inner tube 335 can be in a range from approximately 1 mm to approximately 3 mm. In one particular configuration, the outer diameter 375 of the inner tube 335 is approximately 6.5 French and the outer diameter 370 of the outer tube 330 is approximately 14 French.

[0074] While the inner tube 335 and the outer tube 330 are in their assembled state the relationship between the inner tube 335 and the outer tube 330 can be considered generally coaxial. This is the case even when the outer tube 330 fits loosely around the inner tube 335 to permit aspiration through the outer tube 330 while the inner tube 335 is disposed inside the outer tube 330. Advantageously, the inner tube is removable from the outer tube. Thus, the inner tube 335 and the outer tube 330 form the assembly 305 that can be joined together as a combination feeding and aspirating tube 310 by an end user such as a surgeon or an assistant in a hospital or other facility. As such, a method of feeding and aspirating with a feeding tube of the present invention includes the step of inserting an inner tube 335 through an outer tube 330. The method further includes sealing an external end of the inner tube relative to an external end of the outer tube. The method may also include placing the combination inner and outer tubes in the jejunum of the patient. This placement of the combination feeding and aspirating tube can be performed in any of the various manners set forth above. However, it is to be understood that a small amount of feeding material can be fed during insertion in order to prevent clogging of the inner tube by clotted blood or large particles from the gastro intestinal tract. The method may also include aspirating through the outer tube.

[0075] Although the description associated with FIGS. 5- 7 has been directed to a specific embodiment of the feeding tube assembly 305, it is to be understood that any and all of the elements and features described may be selectively applied to the embodiment of the feeding tube assembly 25 shown and described with reference to FIG. 1 above. The feeding tube assembly 25 shown in FIG. 1 may include an aspiration tube or outer tube 380 that forms the aspirating channel 30, the feeding tube or inner tube 58, the third tube 56 formed by one or more spacing bead(s) 57, and the nut 59. Similarly, any and all of the elements and features of the embodiment of the feeding tube assembly 25 of FIG. 1 may be applied to the feeding tube assembly 305 of FIGS. 5-7. Some of the features are common to both embodiments and are considered to be inherent since they are required for the assemblies to function properly. For example, the external or proximal ends of the feeding and aspirating tubes must be isolated from each other and sealed against fluid communication between the feeding tube and the aspirating tube, and between the tubes and the atmosphere in order to function properly during use. [0076] Both embodiments of the feeding tube assembly have removable feeding or inner tubes 58, 335. On one hand, the feeding tube assembly 305 of FIGS. 5-7 does not have the third tube 56 formed of one or more spacing tube(s) or spacing beads 57. However, the spacing beads 57 and nut of the assembly 25 of FIG. 1 may be applied to the assembly 305 of FIGS. 5-7. Similarly, the exemplary illustration of FIG. 5 shows the aspiration openings located in the jejunum. The feeding tube assembly 25 of FIG. 1 may be applied to the jejunum instead of to the stomach and/or the duodenum, and the assembly 305 of FIGS. 5-7 may be selectively applied in the duodenum for the respective advantages of each.

[0077] FIG. 8 is a detailed partial sectional view of the feeding tube assembly 25 of FIG. 1. As shown in FIG. 1, the feeding tube assembly 25 may be provided in any length to accommodate applications via nasoenteric or PEG port 27 insertion. The two most standard lengths for the assembly 25 corresponding to these two methods of insertion may be in a range from approximately eighteen to twenty inches for the PEG insertion and from approximately thirty- six inches to forty-two inches for the nasoenteric insertion. For different size patients or for accessing different portions of the GI tract, the length of the assembly 25 may be customized to have lengths inside or outside these ranges. With reference to a normal adult size patient, the inner tube 58 may extend approximately three inches beyond a distal end of the outer tube 380. [0078] To hold the distal end 50 of the inner tube 58 in a spaced relation to the distal end 40 of the outer tube 380, one or more of the spacing tubes or spacing beads 57 may be threaded onto the inner tube 58. The spacing beads 57 may have a through opening formed by an inner wall 382 having a dimension that is at least slightly larger than an outer dimension 385 of the inner tube 58 so that the beads 57 may easily slide on and off the inner tube 58. These beads 57 may be held in mutually abutting relation with each other and in abutment with a distal end 40 of the outer tube by the nut 59.

[0079] The term "dimension" as used herein may refer to a major or a minor dimension of a height, width, length or depth of a feature having any shape, for example. However, it may also refer to a diameter when the feature being described is round.

[0080] The nut 59 may have a bullet or otherwise rounded tip to protect the inner walls of the GI tract during insertion of the assembly 25. The nut 59 may have a hole formed by an inner wall 390 that may extend partially or completely through the nut 59. The inner wall 390 may have a slightly smaller dimension than an outer dimension 385 of the inner tube 58, as shown in FIG. 9. In this way, the inner tube 58 may be forced into the through opening of the nut 59 for a friction fit.

[0081] With the nut 59 secured to the inner tube 58, a slight force may be applied and/or maintained on the inner tube 58 in a direction of arrow 395, as shown in FIG. 9. Once a period of protected feeding has lapsed, then the inner tube may be pulled with a greater predetermined force to overcome the friction fit with the nut 59. In response, the nut 59 and spacing beads 57 will be released into the GI tract. The spacing beads 57 may have a similar outer dimension to that of the outer tube 380 so that the third tube 56 of the beads 57 and the nut 59 may have the same outer dimension as the outer tube 380, and may generally form a continuation of the outer tube 380. This continuation or third tube 56 may extend to the distal end 50 of the inner tube 58 during insertion and the period of protected feeding. The length of the spacing beads 57 may be approximately one-half inch so that they will be readily moved by natural processes through the GI track and passed out of the tract with bodily waste. Thus, an elegant and harmless way of spacing the distal end 50 of the inner tube 58 from the distal end 40 of the outer tube 380 is provided. At the same time, the spacing beads 57 also surround and stiffen or strengthen the feeding tube or inner tube 58.

[0082] As shown in FIGS. 8 and 9, five one-half inch spacing beads 57 and the nut 59 may provide the spacing of approximately three inches between distal ends of the inner tube 58 and the outer tube 380. As shown by dashed line 399 in FIG. 9, the distal end of the inner tube 58 may be trimmed to be flush with a distal face of the nut 59. Other spacing dimensions may be provided by varying the number or length of the spacing beads 57. For example, a number of beads 57 may range between four and eight. Other numbers of beads 57 may be incorporated in order to achieve any spacing inside or outside the ranges described herein. [0083] Placing the feeding tube assembly 25 in the GI tract through a PEG port 27 may be especially beneficial because the length of the assembly may be kept short. This is especially the case for an assembly 25 configured to reach into the stomach and/or duodenum as shown in FIG. 1. [0084] In use, the feeding tube assembly 25 may be inserted so that the distal end of the feeding or inner tube 58 is located in the duodenum as shown in FIG. 1. The third tube 56 formed by the spacing beads remains flexible although it is strengthened and stiffened by the beads 57 thus aiding in guidance of the feeding tube assembly 25 through the stomach and into the intestine. The feeding tube assembly 25 may remain in the position shown in FIG. 1 for feeding a fine material into the duodenum for a first protected feeding period, which may last up to several days. A protected feeding period of a few days is more typical. However, the sooner the patient's body can accept the greater quantities, the sooner that patient will receive the benefits of more nutrition at a faster rate. A major benefit of the present invention is that it enables the patient to receive a maximum possible amount of nutrition at a maximum rate through continuous monitoring, aspiration of excess, and refeeding as much as the GI tract can absorb.

[0085] To this end, the feeding tube assembly 25 may be placed so that approximately three aspiration openings 47 are located in the stomach and another six aspiration openings are in the duodenum. This placement still locates the third tube 56 for discharge of unfed feeding material 402 from the inner tube 58 in the duodenum, as shown in FIG. 1 since the duodenum is approximately ten inches long. The feeding tube assembly 25 may remain in this position and the feeding, aspirating, and monitoring may be implemented as described above during the protected feeding period. Once the GI tract is absorbing the feeding material well, the inner tube 58 may be withdrawn and courser feeding material may be fed through the outer tube 380. This may be accomplished by applying the predetermined greater pulling force to the inner tube 58 in the direction of arrow 395 as described above. Once the GI tract is absorbing the feeding material well, it is safe to cease monitoring and start feeding the patient greater quantities and courser feeding materials that can only be accommodated through the larger diameter outer tube 380. To inhibit the possibility or tendency toward gastric reflux, the outer tube 380 may be advanced through the PEG port 27 or nasal passages by approximately three to four inches so that the aspiration openings 47 advance out of the stomach and into the duodenum. As shown, the outer tube 380 will then extend into the duodenum generally to where the third tube 56 was during the protected feeding period or slightly beyond so that the feeding material continues to be fed into the duodenum.

[0086] FIG. 8 shows general lengths of the third tube 56 and the portion of the feeding tube assembly 25 that has aspiration openings 47, 48. As shown, the third tube 56 may have a length 405 in a range from approximately one- half inch to approximately ten inches. The length 405 of the third tube 56 may be from approximately two inches to approximately four inches. The third tube 56 may have a length 405 of approximately three inches. Proximally located and adjacent to the third tube 56, a perforated portion 410 of the outer tube may include one or more openings that permit fluid communication between an inside and an outside of the outer tube 380. The openings may be of any shape or size as shown in FIGS. 8 and 9. As shown in FIG. 1, the openings may be formed through opposite sides of the outer tube 380. That is, the openings may be alternatingly located at one hundred eighty degrees from each other along a length 415 of the perforated portion 410. The length 415 of the perforated portion 410 may be in a range from approximately one inch to approximately twelve inches. However, since the openings 47, 48 may be used to feed after a protected feeding period, the perforated portion may be kept to a length that will not extend into the stomach when the outer tube 380 is advanced after the protected feeding period. Thus, the length 415 of the perforated portion may be approximately 10 inches long. On the other hand a longer length could be used for applications intended to extend the perforated portion into the jejunum as well as in the duodenum for feeding. [0087] FIGS. 8 and 9 show an example of a pattern of openings 47 and 48 that include large oval openings 47 and small round openings 48. As shown, the large and small openings 47, 48 may be alternated on a line along a wall of the outer tube 380. The small and large openings 48, 47 may also be alternated on a line along an opposite wall of the outer tube 380. The openings may be positioned so that the small openings 48 are exactly opposite the large openings 47. The large openings 47 generally weaken the wall of the outer tube 380 in an area surrounding the large openings 47 more than do the small opening 48 in a region surrounding the small openings 48. Even though the large openings 47 have the advantage of enabling greater flow of aspirate and/or feeding material than do the small openings 48, the small openings enable greater flow that if they were completely omitted. By placing the small openings 48 directly opposite the large openings 47 a needed level of strength in the regions corresponding to each pair of opposite openings is maintained. At the same time, an increased amount of flow is enabled.

[0088] Also apparent from FIGS. 8 and 9, the inner tube 58 may have a size that is relatively small as compared with the outer tube 380. This difference in size has the benefit of providing a larger cross sectional area of flow between the inner and outer tubes 58, 380, and thus enabling greater rates of flow for aspirate during the protected feeding period. The outer tube 380 may have a diameter in a range from approximately eighteen French to approximately 28 French. This range is a dimension 420 from approximately six millimeters to approximately nine millimeters across the outer tube 380. The outer diameter 385 of the inner tube 58 may be in a range from approximately four French to approximately eight French. Likewise, in more common units the outer diameter 385 of the inner tube 85 can be in a range from approximately one millimeter to approximately three millimeters. Additionally, the strengthening aspects of the spacing beads 57 and nut 59 enable use of a very thin walled inner tube 58. For example, the inner tube 58 may have a wall thickness of approximately one twentieth of an inch, or paper thin. The thin wall of the inner tube 58 enables a greater cross section of flow for a given outer diameter of the inner tube 58. This advantage also translates into enabling use of smaller diameter inner tubes 58 than is possible with thicker walls. The result is that the difference in the diameters of the inner tube 58 and the outer tube 380 may be increased so that the cross section of flow between the outer and inner tubes 380, 58 is greater during aspiration.

[0089] In another aspect of the invention, the method includes feeding for a first predetermined period of time after an operation. After the first predetermined period of time has lapsed, the inner tube is removed. Feeding can subsequently be provided through the outer tube or through another separate feeding tube that is larger than the inner tube. The first predetermined period of time can correspond to a period of time in which the patient recovers sufficiently for the gastrointestinal tract to be capable of accepting larger quantities of feeding material, and perhaps a courser feeding material. After the operation and before the first predetermined period of time has lapsed, feeding must be monitored closely in order to avoid overfeeding. Once the gastrointestinal tract function is capable of consistently absorbing the feedings, then the monitoring can be lessened or stopped. Once the feedings are being readily absorbed and monitoring has been stopped, the more costly two-reservoir system is no longer needed. Also, as the gastrointestinal tract becomes more capable of handling courser feedings, expensive predigested feedings are no longer required. Therefore, less expensive feeding material may be fed and constant monitoring is no longer required.

[0090] A method in accordance with the present invention may include feeding into a distal portion of the duodenum, aspirating in a proximal portion of the duodenum, and/or aspirating in the stomach. In particular, the present invention may include aspirating from both the stomach and a proximal end of the duodenum during a period of protected feeding. That is, the method may include straddling a junction between the stomach and the duodenum with a length of the aspiration line having aspiration openings, and aspirating in both the stomach and the duodenum through the aspiration openings. The method may also include ceasing a period of protected feeding, withdrawing an inner tube or a feeding tube, and advancing an outer tube so that none of the aspiration openings are in the stomach. The method may also include feeding a larger quantity of feeding material, (which may be a course feeding material), through the outer tube, and/or through the aspiration openings that were originally used to aspirate.

[0091] The method may include extending a feeding tube or inner tube approximately two to three inches beyond a distal end of an aspiration tube. The step of extending may include strengthening the feeding tube or inner tube by one or more structural elements. A length of two to three inches of thin walled feeding or inner tube may be strengthened by surrounding the inner tube with the structural element (s), which may take the form of spacing tube(s) or spacing bead(s). The method may include releasing the structural element (s) into the GI tract after a period of feeding through the feeding tube or inner tube. Thus, the method may include passing the structural element (s) out of the patient's body naturally, such as by a bowel movement.

[0092] With the devices and methods for monitoring feeding and protecting a patient during early stages after surgery when the patient's GI tract is functioning only at a minimal level, the present invention has additional advantages. For example, feeding into the duodenum instead of into the jejunum has the advantage of providing the digestion that occurs in the duodenum. Thus, less expensive courser material may be fed into the duodenum than into the jejunum while maintaining the advantages of stepping the nutrients forward and aspirating proximally of the feeding during early stages. By moving the outer tube forward after the protected period, a larger quantity may be fed more quickly and still avoid feeding into the stomach, which could cause gastric reflux.

[0093] It is to be understood that the term "positive pressure source" generally refers to a pump or an equivalent, such as a syringe or pressurized receptacle. The term "positive" refers to an "active" as opposed to a passive pressure means, such as a gravitational pressure means. It is also to be understood that vacuum source refers to any number of equivalents such as a pump, an aspirating syringe, or a negative pressure receptacle. One common vacuum source is that typically provided by a hospital or other facility and piped throughout the facility to the various stations including patients' rooms. [0094] The embodiments and examples set forth herein were presented in order to best explain the present invention and its practical application and to thereby enable those of ordinary skill in the art to make and use the invention. However, those of ordinary skill in the art will recognize that the foregoing description and examples have been presented for the purposes of illustration and example only. The description as set forth is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the teachings above without departing from the spirit and scope of the forthcoming claims. [0095] The embodiments of the invention described herein are exemplary and numerous modifications, variations and rearrangements can be readily envisioned to achieve substantially equivalent results, all of which are intended to be embraced within the spirit and scope of the invention .

Claims

1. A method of feeding and decompressing in a gastrointestinal tract, the method comprising: feeding through a feeding channel into a duodenum; and aspirating through an aspiration channel from at least one of a stomach and the duodenum.

2. The method of claim 1, wherein the step of aspirating comprises aspirating from the stomach and the duodenum.

3. The method of claim 1, further comprising: placing a distal end of a feeding channel at a first position in the duodenum; placing a distal end of an aspiration channel at a second position in the duodenum; and aspirating via the aspiration channel.

4. The method of claim 1, further comprising the steps of: placing a distal end of an aspiration channel proximate to the distal end of the feeding channel; and continuously aspirating and substantially collapsing a portion of a duodenum adjacent to the distal end of an aspiration channel.

5. The method of claim 1, wherein the step of feeding and the step of aspirating comprise feeding and aspirating through a single composite line having plural channels .

6. The method of claim 1, wherein the step of feeding comprises refeeding aspirate that has been removed from the stomach and/or duodenum in the step of aspirating.

7. The method of claim 1, wherein the steps of feeding and aspirating further comprise feeding and decompressing in a gastrointestinal tract, comprising the steps of: continuously feeding via the feeding channel; and continuously aspirating via the aspiration channel ; wherein the steps of continuously aspirating and continuously feeding further comprise alternatingly aspirating into a plurality of aspirate reservoirs in a repeated cycle.

8. The method of claim 7, wherein the step of continuously aspirating further comprises: aspirating an amount of aspirate greater than a predetermined maximum into a first overflow chamber connected to the first reservoir during a first part of a cycle; and aspirating an amount of aspirate greater than the predetermined maximum into a second overflow chamber connected to the second reservoir during a second part of the cycle.

9. The method of claim 1, further comprising filtering an aspirate from the at least one of the stomach and duodenum to a particle size in a range from one quarter of a millimeter to one millimeter.

10. The method of claim 1, further comprising maximizing feeding while preventing overfeeding by: observing a volume of aspirate collected during aspiration; and adjusting the pressure or the flow resistance in the feeding channel so that the volume aspirated during a period of time is substantially equal to or less than a volume absorbed during the same period of time.

11. The method of claim 1, further comprising the preliminary steps of forming a feeding tube assembly by: inserting an inner tube through an outer tube; and sealing an external end of the inner tube relative an external end of the outer tube; wherein the steps of placing comprise placing the feeding tube assembly in the duodenum of a patient; wherein the step of feeding comprises feeding from externally of the patient through the inner tube to the duodenum of the patient; and wherein the step of aspirating comprises aspirating from the at least one of the stomach and the duodenum through the outer tube.

12. The method of claim 1, wherein: the step of feeding comprises feeding for a first predetermined period of time after an operation; removing the inner tube from the outer tube after the first predetermined period of time; and feeding through one of the outer tube after the first predetermined period of time.

13. A system for aspirating from and feeding into the gastro-intestinal tract, comprising: at least one aspirate reservoir; an aspirate line; at least one aspirate filter in the aspirate line and fluidly connected to the aspirate reservoir; at least one one-way valve in the aspirate line; and at least one feeding line fluidly connected to the aspirate reservoir; wherein the aspirate line comprises at least one of a nasogastric, nasoenteric, gastrostomy, and jejunostomy tube having aspirating openings in the aspirate line along a length of the aspirate line in a range from approximately eight inches to approximately twelve inches.

14. A feeding tube assembly comprising: a first outer aspirating tube; and a second inner feeding tube; and a third tube removably supported on the first outer aspirating tube and the second inner feeding tube; wherein the second inner feeding tube is removably disposed inside the first outer aspirating tube and inside the third tube.

15. The assembly of claim 14, wherein the outer tube fits around the inner tube to allow aspiration therebetween .

16. The assembly of claim 14, wherein a distal end of the inner tube is supported by the third tube at a location in a range from approximately three fourths inch to approximately ten inches from a distal end of the outer tube when the feeding tube assembly is in an assembled state .

17. The assembly of claim 16, wherein the third tube comprises one or more spacing beads threaded onto the inner tube .

18. The assembly of claim 16, wherein the third tube comprises a plurality of spacing beads threaded on the inner tube, the spacing beads abutting each other and a distal end of the aspirating tube.

19. The assembly of claim 18, wherein the third tube further comprises a nut removably attached to a distal end of the inner tube and abutting a distal most one of the plurality of spacing beads.

20. The assembly of claim 14, wherein the outer tube further comprises: a plurality of aspiration openings through a wall of the outer tube; and wherein the plurality of aspiration openings are located in spaced relation to each other along a length of the outer tube adjacent to the distal end of the outer tube .

21. The assembly of claim 20, wherein the plurality of aspiration openings are located at alternatingly more proximal locations on opposite sides of the outer tube relative to each other.

22. The assembly of claim 20, wherein: the plurality of aspiration openings comprises openings of a first size and openings of a second size smaller than the first size; the openings of the first large size being located opposite to respective openings of the second small size in a direction generally perpendicular to a length direction of the outer tube.

23. The assembly of claim 20, wherein the length extends from the distal end of the outer tube to a proximally located aspirate opening, the length being in a range from approximately three inches to approximately fifteen inches.

24. The assembly of claim 18, wherein the outer diameter of the outer tube is in a range from approximately six millimeters to approximately nine millimeters.

25. The assembly of claim 18, wherein the outer diameter of the inner tube is in a range from approximately one millimeter to approximately three millimeters.