WO2013140422A1

WO2013140422A1 - Anvil for a chirurgical mechanical circular stapler

Info

Publication number: WO2013140422A1
Application number: PCT/IT2012/000079
Authority: WO
Inventors: Lino POLESE; Lorenzo NORBERTO
Original assignee: Universita' Degli Studi Di Padova
Priority date: 2012-03-21
Filing date: 2012-03-21
Publication date: 2013-09-26

Abstract

The present invention relates to an anvil for a surgical mechanical circular stapler, comprising: - a head; a stem 3 associated to the head; - a terminal element 4, having a tapered head portion 4a and associated to the stem. The terminal element comprises means 5 for associating it to a threadlike element 8. The anvil 1 may comprise an elongated extension element 7, preferably more flexible than the stem and the terminal element, positioned between the stem and the terminal element. The present invention also relates to a surgical kit and to a mechanical circular stapler.

Description

ANVIL FOR A CHIRURGICAL MECHANICAL CIRCULAR STAPLER

FIELD OF APPLICATION

[0001] . The present invention relates to an anvil for a surgical mechanical circular stapler and a mechanical circular stapler.

[0002] . The anvil for a stapler and the stapler according to the present invention are destined in particular for use in mini-invasive surgery, in areas to be operated on not directly accessible from the outside.

STATE OF THE ART

[0003] . Over recent years minimally invasive surgery, aimed at continuously reducing the number and size of surgical wounds, has developed considerably.

[0004] . With specific reference to abdominal surgery, as well as the already well-known laparoscope, new surgical approaches, such as SILS (single incision laparoscopic surgery) and NOTES (natural orifice translumenal endoscopic surgery) are therefore being developed.

[0005] . In abdominal surgery, mechanical circular staplers have been in use for some years now. The use of these devices makes viscero-visceral anastomosis possible in anatomical sites which would otherwise be inconvenient for performing a manual anastomosis (such as in lower rectal or oesophageal surgery) .

[0006] . Staplers for internal use draw the tissues close together by means of open U-shaped metal staples which are closed in the shape of a B. When the instrument is closed, the legs of the staples are guided through the tissues and then closed by drawing them together and bending them by means of an anvil present on the opposite side of the instrument. The B configuration thereby achieved permits the transit of small capillary vessels. It is to be noted therefore that this type of suture is not in itself entirely haemostatic. The pressure applied to the tissues amounts^' to 8g/mm², such as to promote a spontaneous haemostasis and also prevent the dehiscence of the sutured tissue.

[0007] . This type of technical solution has been carefully studied to permit correct revascularisation of the resection margins, an essential condition for a rapid henosis process. Any slight residual bleeding can easily be controlled by electro-coagulation or with ligature.

[0008] . The internal use staplers known as "circular" form a double row of metal staples in a circular configuration. When the instrument is closed, a circular blade contemporaneously sections the tissues inside the suture line.

[0009] . Operatively, as will be explained further below, the head of the instrument is inserted in the lumen of the organ to be anastomised through a short section of its wall or, in the case of lower anterior rectal resections, through the anus. Anastomoses are performed with heads of differing size to adapt to the lumen of viscera with different diameters. They are used for termino-terminal or termino-lateral anastomoses through the gastrointestinal tract, from the oesophagus to the rectum. They are particularly useful when the operating site is cramped or deep for anatomical reasons, as in esophagojejunal anastomosis after total gastrectomy or in colo-rectal anastomoses after anterior resection of the distal rectum.

[0010] . Nowadays mechanical sutures often take the place of manual ones. While on the one hand they entail considerably high costs, on the other they offer well- known advantages to surgeons, making them irreplaceable. They enable for example reproducibility of the procedure assuring calibrated and equidistant stitches and a reduction of surgery time, as well as offering the chance to perform sutures in positions and on organs difficult to reach manually.

[0011] . One of the staplers most widely used to perform intestinal anastomoses is the E.E.A. stapler (End to End Anastomosis) . In detail, as shown schematically in Figures 1 to 4, an E.E.A. stapler comprises: [0012] . - a long, rectilinear or curved cylindrical rod A which has a grip fitted with a lever L (with safety catch) at one end that triggers the section and suture mechanism contained in a loader C, which is situated at the other end of the rod and contains a cutting blade D and the staples G arranged in two circular rows;

[0013] . - a head T, which is connected to the loader C by a pin P and on the surface facing the loader contains recesses which the staples (C-shaped) are struck against to close (in a B-shape) ;

[0014] . - a knob M situated at the beginning of the rod and which when rotated progressively brings the head closer to the loader.

[0015] . An operation requiring sewing of an anastomosis is briefly described below with reference to Figures 5a to 5d.

[0016] . The segment of diseased intestine which must be removed is isolated. It is then closed, at safety distance, with two bowel clamps (forceps which gently compress in a non-traumatic manner) to prevent the escape of the intestinal contents. The diseased tract is removed, also closed by bowel clamps. The two intestinal stumps to be anastomised remain. A tobacco pouch suture is sewn on the proximal stump manually or using ASP-50 forceps. The same is done to the distal segment (see Figure 5a) . In the distal segment, several centimetres from the sectioned point, a transversal counter-opening is made sufficient to introduce the rod of the stapler containing the closed head-loader group. The instrument is made to progress delicately until the head and the loader come out of the stump. At this point by rotating the knob the head is distanced from the loader remaining connected to it by the pin only. The head is inserted in the proximal stump where it remains encapsulated once the tobacco pouch is closed. On the other segment the closure of the pouch encapsulates the loader (see Figure 5b) . The knob is turned the other way so that progressively the head is drawn closer to the loader. This makes the two intestinal stumps come into contact. After making sure that the. two segments have been closed with the right tension and so as to fit together perfectly, the safety catch situated on the grip is removed and the lever is pressed decisively. This triggers the blade and the two rows of circular staples which cut and suture the intestine closed around the pin contemporaneously. The knob is then counter-rotated again to distance the head, from the loader and enable the delicate extraction of the stapler through the breach used to introduce it (Figure 5c) . The operation is terminated by closing the breach, sutured so as not to cause stenosis of the viscera (see Figure 5d) . [0017] . In most mechanical staplers the aforesaid head T has a stem which is able to couple to the rod of the loader. Once the two components have coupled, the stapler can be closed. The mechanical suture takes place between the two anatomical structures interposed between the head and the loader.

With the development of minimally invasive laparoscopic, trans-orifice surgery (NOTES: natural orifice translumenal endoscopic surgery) and hybrid NOTES- laparoscopic surgery, the need may arise in some situations to bring the stem of the anvil of a circular stapler through one or two visceral walls, avoiding having to open the loop and sew a tobacco pouch.

PRESENTATION OF THE INVENTION

[0018]. The purpose- of the present invention is to make available an anvil for a surgical mechanical circular stapler which can be placed with the stem through the wall of a viscera without the need to sew a tobacco pouch.

[0019] . A further purpose of the present invention is to make available an anvil for a surgical mechanical circular stapler, which can be placed in the seat of the anastomosis without the need to operate directly in the seat of the anastomosis itself.

[0020] . A further purpose of the present invention is to make available an anvil for a surgical mechanical circular stapler, which can be placed with the stem through the wall of a viscera reducing the risk of trauma to the structure it passes through to a minimum.

[0021] . A further purpose of the present invention is to make available an anvil for a surgical mechanical circular stapler, which can be placed in the anastomosis site reducing the risks of contamination related to opening of the viscera, to a minimum.

[0022] . A further purpose of the present invention is to make available an anvil for a surgical mechanical circular stapler which is effective and safe to use.

[0023] . A further purpose of the present invention is to make available an anvil for a surgical mechanical circular stapler, which is simple and economical to make.

[0024] . A further purpose of the present invention is to make available a surgical mechanical circular stapler, which can be guided in the anatomical area to be anastomised in a mechanical manner without the need for direct visual control.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] . The technical characteristics of the invention, according to the aforesaid purposes, can be seen clearly from the contents of the following claims and the advantages of the same will be more clearly comprehensible from the detailed description below, made with reference to the attached drawings, showing one or more embodiments by way of non-limiting examples, wherein:

[0026] . - figure 1 shows a schematic view of a circular mechanical stapler of the traditional type;

[0027] . - figure 2 shows a detailed schematic view of the stapler in figure 1 with a head separated from a loader;

[0028] . - Figure 3 shows an orthogonal view of the head in figure 2 from the side facing the loader;

[0029] . - Figure 4 shows an orthogonal view of the loader in figure 2 from the side facing the head;

[0030] . - Figures 5a to 5d show in sequence four steps of an anastomosis with the use of the traditional stapler in figure 1;

[0031] . - Figure 6 shows a schematic view of an anvil according to a first embodiment of the invention, already positioned in the anastomosis site of two viscera VI and V2;

[0032] . - Figure 7 shows a schematic view of an anvil for a stapler according to a first embodiment of the invention;

[0033] . - Figure 8 shows a schematic view partially in cross-section of a mechanical stapler according to a preferred embodiment of the invention;

[0034] . - Figures 9 and 10 shows two views of a detail of an anvil according to one embodiment of the invention, relative to a terminal element with tapered head portion..

DETAILED DESCRIPTION

[0035] . With reference to the appended drawings, the anvil for a mechanical circular stapler according to the present invention has been globally denoted by reference numeral 1, while the stapler according to the invention has been globally denoted by reference numeral 10.

[0036] . According to a general embodiment of the invention, the anvil 1 comprises:

[0037] . - a head 2, destined to receive in abutment the staples of the loader 12 of a stapler 10;

[0038] . - a stem 3 associated to the head at a first end 3' .

[0039] . Advantageously, the stem 3 can be connected to the head 2 by means of an articulation, so as to vary the orientation of the head in relation to such stem.

[0040] . The stem 3 is destined to engage in a movable manner in an axial direction in the stapler 10 at the end bearing a loader 12.

[0041] . According to such general embodiment, the anvil 1 comprises a terminal element 4, associated to a second end 3" of the stem 3, opposite the first.

[0042] . Such terminal element 4 has a tapered head portion 4a. The tapered shape (that is to say with a decreasing cross-section) of the head portion 4a enables the terminal element 4 to engage a hole previously created in a visceral wall for the passage of a thread and thus to pass through (widening such hole) one or more visceral walls, if it is pulled by a thread or traction system which has already passed through the wall/walls, as will be explained further in the rest of the description.

[0043] . Operatively, such terminal element 4 is destined to engage axially with a mechanical stapler at the end bearing the loader, in a similar way to the stem of the anvil it is associated to, or such terminal element 4 may be detached from the stem of the anvil (after it has passed through the visceral wall or walls with the stem) enabling the same stem to couple to the stapler.

[0044] . Preferably, to such purpose, the terminal element 4 has a maximum diameter equivalent to that of the stem 3 of the anvil 1.

[0045] . The aforesaid terminal element 4 comprises in turn means 5 for associating it to a threadlike element 8. Preferably, as shown in the appended drawings, such means of association 5 consist of a hole, made in the head portion 4a of the terminal element, inside which the thread 8 may be made to pass. Alternatively to the hole a projecting eyelet may be envisaged.

[0046] . Thanks to the presence of the terminal element 4, the anvil may be made to pass through one or two visceral walls (for example intestinal) with its stem 3 if subjected to a force of traction by means of the aforesaid threadlike element 8.

[0047] . By using the anvil 1 according to the invention it is possible in particular to carry out the procedure for the anastomosis of two viscera VI and V2, described below with reference to Fig. 6. The head 2 of the anvil 1 is fitted on a loop of viscera to be anastomised VI, closed with a tobacco pouch. A thread 8 is made to pass through the wall of the other viscera V2 to be anastomised, . in a minimally invasive manner (for example endoscopically with an endoscopic needle) . The thread is connected from the extraluminal end to the terminal element 4 (with tapered head 4a) and the latter to the stem 3 of the anvil 1. By pulling the thread F from the intraluminal side or natural orifice of the second viscera V2, the portion of tapered head 4a engages the transit hole of the thread on the wall of the viscera, widens it and then brings the stem 3 of the anvil 1 inside the lumen of the second viscera V2, while the head 2 remains inside the first viscera VI. The first viscera which contain the head of the anvil is brought next to the wall of the second viscera V2 to be anastomised. At this point, if necessary after releasing the terminal element 4 from the stem 3, it is possible to connect the stem 3 to the stapler 10. Operation of the stapler will then lead to completion of the anastomosis.

[0048] . All this makes it possible to connect the anvil to the body of the mechanical circular stapler, after the stem of the anvil has already passed through the two visceral walls to be anastomised. This way the connection between the anvil and the body of the stapler occurs inside viscera or trans-orifice, without the need to prepare the tobacco pouch on the second viscera V2.

[0049] . Thank to the anvil 1 according to the invention a similar procedure to that just described may be performed (in which preparing the tobacco pouch may be avoided) even on the first viscera to be anastomised, that is to say on the viscera where the head of the anvil is to be fitted. Once the thread (threadlike element 8) has been made to pass through as described above, if it is attached to the terminal element connected to the stem of the anvil externally to the orifice of the first viscera to be anastomised, pulling the thread from the other end will bring the stem of the anvil to pass through the viscera, while the head of the anvil remains inside the viscera. In this case the stem of the anvil may be connected to a stapler which has passed through and perforated the other viscera to be anastomised, preferably after having released the terminal element.

[0050] . According to one embodiment of the invention, the terminal element 4 is associated as a single body to the second end 3" of the stem or by non-detachable connection means.

[0051] . According to a preferred embodiment, the terminal element 4 is associated in a detachable manner to the second end 3" of the stem, that is by connection means 6, of the detachable type.

[0052] . Operatively, thanks to such connection means, of the detachable type, the terminal element can be released from the stem 3 of the anvil 1 even after the latter has been brought next to the wall of viscera to anastomise, while the stem has passed through said wall of the viscera. The terminal element 4 can be released from the stem of the anvil when desired by the operator for the subsequent insertion of the stapler.

[0053] . According to a preferred embodiment shown in Figure 7, the anvil 1 comprises an elongated extension element 7, positioned between the second end 3" of the stem and the terminal element 4. Such elongated element 7 is associated to the terminal element 4 at a first end T and to the stem 3 at a second end 7", opposite the first.

[0054] . Preferably., such elongated extension element 7 has a diameter equivalent to the maximum diameter of the terminal element 4 and the stem 3 of the anvil. _; In particular, the stem, the elongated extension element and the terminal element have equivalent diameters, at least in the junction areas to prevent discontinuities.

[0055] . Advantageously, the elongated element 7 is more flexible than the stem 3 and than the terminal element, so as to slide inside the viscera or peritoneal cavity, reducing the risk of trauma, until it brings the terminal element and the stem with the associated head to the zone to be anastomised.

[0056] . In particular, the elongated extension element 7 is made from flexible polymeric material, such as silicone .

[0057 ] . In particular, the elongated extension element 7 may be a tubular element, in particular hollow.

[0058] . Advantageously, the connection means 6, preferably of the detachable type, are positioned between the stem 3 and the elongated extension element 7, so as to permit the release of the stem 3 also from such elongated element 7 to which the terminal element 4 is associated.

[0059] . In particular, the terminal element 4 may be attached to the elongated extension element 7 in a non- detachable manner. An alternative solution may however be envisaged in which the terminal element 4 is attached to the elongated extension element in a detachable manner. [0060] . Preferably, the anvil 1 comprises a retractable covering (not shown in the appended drawings) positioned so as to protect the terminal element.

[0061] . More specifically, such retractable covering is movable from a covering position, in which it completely covers at least the head portion 4a of the terminal element, to an exposed position, in which it is distanced from the head portion 4a leaving it at least partially uncovered.

[0062] . In particular, the aforesaid covering is slidingly associated with the terminal element 4 in a tapering direction X of the head portion 4a and moves from the covered position to the exposed position when the covering is subjected to a stress in the tapering direction X. This way the head portion 4a is exposed only if it encounters a perpendicular obstacle, such as the wall to be anastomised.

[0063] . Advantageously, the head portion 4a has a pointed shape, i.e. has a tip, which may be rounded or not.

[0064] . According to a first embodiment, illustrated for example in Figure 6, the head portion 4a has a pointed shape and has, in particular, a conical shape. With this configuration the head portion 4a is able to engage the hole previously made in the wall of the viscera starting from its tip only. The penetration of the head portion may therefore take place in a facilitated manner only if the tapered head portion 4a is positioned orthogonally to the viscera wall.

[0065] . A non-orthogonal positioning of the head portion in relation to the visceral wall would make the penetration operation difficult. The dimensions of the anvil 1 are substantially comparable to the diameter of an intestinal viscera. The head 2 may have a diameter of 21 to 34 mm, while the stem 3 has a length of not less than 1 cm and often of several centimetres. Generally, the diameter of the small intestine is around 3-4cm, that of the colon about 3 to 7cm. Bearing in mind the dimensions of the anvil 1, the orthogonal disposition of the head portion 4a in relation to the visceral wall is difficult to achieve on account of the dimensions and weight of the head 2 and of the dimensions of the anvil stem, unless strong pressure is exerted on the visceral walls (exploiting their elasticity) . By operating thus it may however happen that under the effect of the traction exerted by the threadlike element 8, the tapered head portion 4a, initially obstructed and blocked, suddenly penetrates the hole- with a sudden movement - and the head 3 of the anvil violently collides with the visceral wall, with the risk of tearing it. It may also happen that the tapered head portion 4a takes the wrong path in relation to the threadlike element guide, separating 2 or more layers of the visceral wall.

[0066] . Advantageously, to simplify the operation of positioning the head portion 4a and reduce the risk of trauma it is preferable to utilise an anvil 1 provided with the aforementioned extension element 7 (more flexible than the stem 3 and the terminal element 4) . Such elongated element - thanks to its flexibility- enables the terminal element 4, and in particular the head portion 4a, to position itself on the visceral wall under the traction of the thread-like element 8 separately from the stem 3 and from the head 2 of the anvil 1, without being obstructed in its movement of orientation by the surrounding visceral walls. In fact the elongated element 7 follows the movements of the terminal element 4 without obstructing it in any way. Thanks to the elongated flexible element 7 the head portion may, therefore, orient itself orthogonally to the visceral wall (pulled by the thread 8) in a much more simple and rapid manner, without the need to exert pressure on the surrounding viscera, thereby reducing to a minimum the risk of trauma to the structure it passes through.

[0067] . Similar effects may be achieved even in the absence of the elongated extension element 7, using a terminal element 4 in which the tapered head 4a has at least one cutting edge 9. Thanks to the cutting edge 9 the tapered head portion 4a is able to widen the hole cutting the visceral wall, when the edge (and therefore no longer a tip, but a plurality of tips) is brought into contact with the visceral wall.

[0068] . It is therefore not necessary for the tapered head portion 4a to engage the hole with the tip (at a single point) oriented orthogonally to the visceral wall. It is sufficient for the tapered head portion 4a to come into contact with the visceral wall with the cutting edge 9 next, to the hole, regardless of its orientation.

[0069] . Preferably, the head portion 4a may comprise at least two cutting edges 9, positioned on opposite sides to the tapering direction X. Thanks to this configuration (with one or more cutting edges) , the tapered head portion succeeds in penetrating inside the hole, by cutting the visceral wall regardless of its spatial disposition in relation to said wall.

[0070] . According to the embodiment shown in Figure 6 and 9 to 10, the terminal element 4 has a flattened, tapered head portion 4a, in the shape of. a wedge. The wedge has a profile with a tip 4a' (in particular rounded, but it could also be pointed) , at which tip the two cutting profiles 9 join. Such latter extend on opposite sides to the tapering direction X.

[0071] . The present invention relates to a surgical kit for a mechanical circular stapler. According to a general embodiment, such kit comprises:

[0072] . - an anvil 1 for a stapler, having a head 2, a stem 3 associated to the head at a first end 3' , and a terminal element 4, having a tapered head portion 4a, which can be associated by connection means 6 to a second end 3" of the stem 3, opposite the first; and

[0073]. - a threadlike element 8.

[0074] . The terminal element 4 of the anvil 1 comprises means 5 for associating it to said threadlike element 8.

[0075] . In particular, the threadlike element 8 may be a coloured nylon thread (in particular) of such a diameter as to be introduced through the wall of viscera by means of an endoscopic diathermic needle (for example 0.8mm in diameter) . Preferably such thread is resistant, has a sufficiently small diameter and colour which facilitates its identification (blue for example) .

[0076] . Advantageously, the kit comprises an elongated extension element 7, destined to be positioned between the second end 3" of the stem and the terminal element 4 to connect the terminal element 4 to the stem 3. Preferably, the elongated element 7 is more flexible than the stem 3 and the terminal element 4. [0077 ] . Advantageously, the kit comprises means 6 (preferably of the detachable type) of associating the terminal element 4 and/or the elongated extension element 7 to the stem 3.

[0078] . In particular, the anvil 1 for a mechanical circular stapler of the surgical kit is an anvil according to the present invention, in particular as described above. The anvil 1 may therefore have a tapered head portion, in the various embodiments described above.

[0079] . The creation of a gastrojejunal by-pass with the hybrid NOTES technique using an anvil 1 according to the invention is described briefly below.

[0080] . A gastroscope is inserted in the stomach, insufflating. After transillumination the stomach is pierced with^' a percutaneous cannula and the end of a thread is inserted in the stomach through the cannula, then seized by an endoscopic forceps from the inside and brought out though the mouth, while the other end remains transcutaneous. After positioning a Hasson trocar in left hypochondrium/epigastrium, a sterile gastroscope in inserted in the trocar and, after peritoneoscopy, the stomach is pierced with an endoscopic diathermic needle from the peritoneal side of the wall, in a point several centimetres distal (about 6) to the previous, inserting the end of a second thread which is also seized with the gastroscope and extracted outside the oral cavity. The two ends coming out of the oral cavity are tied. Pulling on the transcutaneous ends brings the knot as far as the inner side of the gastric wall. At this point it is as if a single thread passed through the stomach from one side to the other. The sterile gastroscope is inserted once again through the trocar, the jejunal loop to be anastomised to the stomach is seized and exteriorised, after enlarging the incision of the trocar and removing the trocar. The head 2 of a circular mechanical stapler is inserted in the jejunal loop, closed with a tobacco pouch. The stem 3 of the anvil 1 is connected to the terminal element 4 with the elongated extension element 7 interposed and the thread coming out most distally from the gastric wall is then tied to the loop of the terminal element. The jejunal loop containing the head and, connected to it, the stem, the elongated extension element 7 and the terminal element 4 are returned to the abdomen. The other thread is pulled until the terminal element has brought the stem of the anvil inside the stomach, drawing the jejunal loop containing the head towards the gastric wall, in the point destined for anastomosis. After gastrotomy the stem 3 of the anvil situated inside the stomach is seized with a curved forceps and the elongated extension element 7 and terminal element 4 are released. The mechanical stapler is inserted through the gastrotomy, connected to the stem 3 and fired, sewing the gastroje unal anastomosis. The gastrotomy and mini- service laparotomy are closed. In this case the anvil 1 with tapered terminal element 4 and extension element 7 makes it possible to bring the stem of the head coming out of the jejunal loop which the head of the anvil has been fitted in, through the gastric wall, inside the stomach. The head, rather, remains in the jejunal loop, next to the gastric wall. This way both the visceral parts to be anastomised are already between the head and the portion of stem to be coupled to the mechanical stapler. In the case in point this manoeuvre makes it possible to perform the anastomosis without having to operate directly in such site. In fact, the operator pulls the thread, connected to the terminal element, operating outside the abdominal wall, then performs a gastrotomy in another site (closer to the abdominal wall) from that of the anastomosis, and seizes the stem of the anvil from the endoluminal side. The connection between the stem and the stapler therefore occurs inside the gastric lumen. This way the operator need not necessarily work on the point of the gastric wall where the anastomosis will be sewn nor must he/she visually monitor such site, since the passage of the anvil stem takes place guided by the- thread previously positioned endoscopically . Ultimately this makes it possible to perform the gastrojejunal by-pas operation in a minimally invasive manner by making a single incision in the wall of about 3cm. Such procedure is rendered possible thanks to the anvil 1 with terminal element 4 and elongated extension element 7. The elongated extension element 7 positions itself between the element 4 and the element 3, interrupting the^' rigid part of the system and thereby making it possible to insert the head fitted on the loop with its stem 3 and the terminal element 4, inside the peritoneal cavity at two different moments through the breach of the abdominal wall. Consequently the breach in the wall may be smaller than would be necessary if the elements 3 and 4 were directly connected, constituting a single rigid structure.

[0081] . The creation of a Roux gastrojejunal by-pass with the hybrid NOTES technique using an anvil 1 according to the invention is described briefly below.

[0082] . A Hasson trocar is positioned in the left hypochondrium/epigastrium. A sterile gastroscope in inserted in the same. The gastric wall is pierced with a diathermic needle in the site destined for gastrojejunal anastomosis. A thread is inserted in the stomach through the needle. The inner end is then seized by another gastroscope and pulled outwards from the mouth. A jejunal loop is then seized with the sterile gastroscope inserted through the trocar after marking a tract (proximal or distal) of the loop and is exteriorised, widening as needed the breach previously made to position the trocar, which is removed. The loop is interrupted and the tract proximal to the bottom of the distal tract at the bottom of the loop is anastomised, to create a Y-shaped gastrojejunal anastomosis. The terminal element 4 of the anvil 1 is connected to the end of the previously positioned thread coming out of the mouth. The head 2 is kept bent in relation to the stem 3 .until the moment of the anastomosis by means of an articulation between the head and stem. The opposite end of the thread is retracted until the terminal element is brought to perforate the gastric wall and the stem 3 of the anvil passes through the aforesaid breach, while the head 2 remains inside the stomach. The head 2 is straightened and the terminal element 4 removed. At this point the mechanical stapler is inserted in the open tract of the jejunal loop, the stem of the stapler is made to come out in a point not far away and connected to the stem of the anvil protruding from the gastric wall, the stapler is fired, creating a gastrojejunal anastomosis. The cul-de- sac of the jejunal loop is then closed with a mechanical or manual suture. The use of the anvil 1 therefore makes it possible to perforate the gastric wall guided by the thread previously inserted. The terminal element 4, thanks to the elongated extension element 7, or thanks to the cutting edges 9, crosses the gastric wall on the guide thread with a minimal risk of traumatism or contamination. It is therefore not necessary to open the gastric wall from the outside to position the head of the stapler and sew a tobacco pouch, nor is it necessary to open the gastric wall to manually or instrumentally recuperate the stem of the head or whatever system is connected to it.

[0083] . The anvil 1 according to the invention may be used with circular mechanical staplers of the traditional type (as described in the applicative examples above) or, advantageously, with staplers 10 according to the invention as will be described now.

[0084] . A surgical mechanical circular stapler 10 according to the invention will therefore now be described. The elements in common with the anvil 1 have been retained for clarity of explanation.

[0085] . According to a general embodiment schematically illustrated in Figure 8, the surgical mechanical circular stapler 10 comprises a hollow tubular support structure 11 which at a first end 11' bears an associated loader 12.

[0086] . In particular, the loader 12 comprises a plurality of staples positioned in one or more concentric circular rows and a concentric cutting system. The loader is operated by means of a loader operating system positioned at a second end 11" of the hollow structure, opposite the first.

[0087] . According to the aforesaid general embodiment, the stapler 10 comprises an anvil 1, comprising in turn a striking head 2 and a stem 3.

[0088] . The stem 3 is connected to the head 2 at a first end 3' and is destined to engage in a mobile manner in an axial direction the loader 12 at the end bearing the loader 12, to draw together or distance the head 2 from said loader 12.

[0089] . According to such general embodiment, the anvil 1 comprises a guide element 7, 8 with a mainly longitudinal extension, associated, directly or indirectly, to the second end 3" of the stem. Such guide element 7, 8 will be described further below.

[0090] . The hollow tubular support structure 11 comprises within it a through passage 13, which extends from one end 11' to the other 11" of the hollow support structure 11 and is open at both ends.

[0091] . As illustrated in Figure 8, the guide element 7,8 of the anvil 1 is destined to cross the hollow support structure 12 in an axial direction inside the through passage 13, guiding the hollow structure 12 in a movement bringing it closer to the anvil 1 already blocked in position in a viscera to be anastomised.

[0092] . Advantageously, the anvil 1 is an anvil according to the present invention, in particular as described above. The anvil 1 may therefore have a tapered head portion, in the various embodiments described above.

[ 0093] . More specifically, the anvil 1 may comprise a terminal element 4 associated to the second end 3" of the stem and provided with means 5 for associating it to a threadlike element 8.

[0094 ] . Advantageously, the terminal element 4 may be associated to the stem 3 by an elongated extension element 7, as described above. Preferably, such elongated extension element 7 is more flexible than the stem 3 and the terminal element 4.

[0095] . In particular, when the anvil is of the type according to the invention, and therefore provided with a terminal element 4, the aforesaid guide element may consist in particular of the threadlike element 8 only, of the elongated extension element 7 or of both. Advantageously, the guide element may also comprise other elements, besides the threadlike element and the elongated extension element. In particular, if the anvil is of the traditional type and therefore lacking a terminal element 4, the guide element may consist of a hollow tubular element connected at one end to the anvil stem.

[0096] . The hollow structure 11 of the stapler may be rigid like the anvil stem.

[0097] . Advantageously, the hollow support structure 11 may be flexible at least in its longitudinal portion, preferably the end portion bearing the loader 12. According to a particular embodiment, the hollow support structure advantageously comprises two longitudinal portions, of which the portion bearing the associated loader is more flexible than the other portion. In other words, at .least one part of the hollow structure of the stapler is flexible similarly to the elongated extension element of the anvil, so as to slide inside the viscera, adapting to their conformation, until it reaches the area to be anastomised.

[0098] . Preferably, the through passage 13 is positioned axially inside the hollow tubular support structure.

[0099] . Advantageously, the through passage 13 may have - at the end which the loader is placed in -a portion able to couple to the stem 3 once this is brought inside it.

[00100] . Advantageously, the stapler 10 may be provided with means (not shown) to audibly signal the coupling of the stem 3 inside the through passage 13 (for example by means of a metallic sound such as a "click") .

[00101] . Advantageously, the stapler 10 may be provided with means (not shown) to visually signal the arrival of the stem 3 inside the through passage 13 at the end 11", such as a marker placed on the guide element 7, 8.

[00102] . Advantageously, achievement of the distance between the head and loader needed to operate the system for application of staples and blade is signalled on the guide element 7,8 or in one of the stapler elements 10 placed at the end 11".

[00103] . The creation of an ilea-rectal by-pass with the hybrid NOTES technique using an anvil 1 and a mechanical stapler 10 is described briefly below. The stapler 10 may be with a hollow support structure either of the rigid type, or at least partially flexible.

[00104] . A peri-umbilical Hasson trocar is positioned. A sterile gastroscope in then inserted in the trocar, and a peritoneoscopy is performed. Another endoscope is inserted through the anus and the rectum is perforated with a diathermic needle above the peritoneal reflection, monitoring the procedure from the intraperitoneal side. A thread is then inserted through the diathermic needle, which is seized using endoscopic forceps by the gastroscope inserted in the peritoneum and pulled to the outside. This way one end comes out the anus and the other, passing through the intestinal wall, comes out through the percutaneous trocar. The loop of the terminal ileum to be used for the by-pass is identified with the gastroscope. The loop is extracted and the head 2 of an anvil 1, closed with a tobacco pouch, is positioned. The stem 3 of the anvil 1 is connected with the terminal element 4 and with the elongated extension element 7, and the terminal element to the transcutaneous end of the aforesaid thread. The loop with the head, the elongated extension element 7 and the terminal element 4 are returned to the abdomen. The thread is pulled from the trans-anal end and the hollow stapler able to host the terminal element is inserted along the same. Once a position of adherence has been achieved between the head and stapler, the stapler is fired sewing the ilea-rectal anastomosis .

[00105] . The anvil 1 and the stapler 10 thereby permit an operation to be performed with a single cutaneous incision, in particular the coupling of the anvil and stapler occurs inside the lumen, without the need to manoeuvre the anvil manually or with instruments as . with traditional staplers.

[00106] . The creation of a gastrojejunal by-pass with single trocar and stapler inserted through the mouth, using an anvil 1 and a mechanical stapler 10 of the flexible type is described briefly below.

[00107] . A Hasson trocar is placed in the desired site (for example periumbilical) . A sterile gastroscope in then inserted through the same and a peritoneoscopy is performed. The stomach wall is pierced in the desired anastomosis site with a diathermic needle and a thread inserted in the same. The thread is seized from the endoluminal gastric side with another gastroscope and pulled out of the oral cavity. With the gastroscope in the peritoneum the jejunal loop to be anastomised to the stomach is identified, seized and exteriorised. The head 2 of an anvil 1 is placed in the loop on the tobacco pouch. The stem 3 of the head is then connected to the elongated extension element 7 and the terminal element 4, and the latter to the transcutaneous end of the thread by association means 5. The ileal loop with the head fitted and the terminal element 4 with the extension 7 connected to the stem 3 are then returned to the abdomen. The rigid zones of this system are the head of the anvil 2 and its stem 3 on the one side, and the terminal element 4 on the other. The two rigid structures are interrupted by the elongated extension element 7 (less rigid) , which permits the insertion of the system in the peritoneal cavity through a small hole. The trans-oral end of the thread is pulled, bringing the stem of the anvil through the gastric wall inside the gastric lumen and the hollow stapler 10 of the flexible type is inserted along the same, again from the oral cavity. Once a position of adherence has been achieved between the head and stapler, the stapler is fired sewing the gastrojejunal anastomosis. In this case too, the union of the anvil with the stapler may take place without the need for direct visual monitoring and without the need to manoeuvre the anvil inside the abdominal cavity with instruments. This makes it possible to perform the technique described without the need to position further trocars for the insertion of forceps or other instruments making the anvil couple to the stapler, as would occur with traditional staplers.

[00108] . The creation of a colo-colic anastomosis above the promontory using an anvil 1 and a mechanical stapler 10 of the flexible type is described briefly below.

[00109] . Traditionally, when a mechanical colo-rectal anastomosis needs to be performed with a circular stapler, the introduction of the rigid stapler may reach as far as the sacral promontory, while the introduction of the stapler further is more difficult and injurious.

[00110] . Thanks to the stapler 10 with flexible portion according to the present invention, it is possible to overcome this problem, leaving unvaried the type of anastomosis with introduction of the stapler through the anus. The stem 3 of the anvil 1 is connected to the terminal element 4, after fitting the anvil on the upstream loop. The terminal element 4 is connected with a thread made to pass through the wall of the rectal- stump on the point to be anatomised and which comes out on the other side, from the anus. Pulling the thread brings the head 2 with the colic loop towards the rectum and the stem 3 through the rectal wall. The hollow stapler with flexible portion inserted through the anus is inserted along the thread and the terminal element and the anastomosis is sewn.

[00111] . The invention permits numerous advantages to be achieved, some of which already highlighted above.

[00112] . The anvil 1 for a surgical mechanical circular stapler according to the invention may be placed with the stem through the wall of viscera without the need to sew a tobacco pouch. In particular, it may be connected to a stapler directly inside the viscera without having to open said viscera and sew a tobacco pouch.

[00113] . The anvil 1 may be placed in the anastomosis site without the need to operate directly in the anastomosis site itself. The anvil may in fact be brought into position by pulling a thread connected to it and previously made to pass through the anastomosis site.

[00114]. The anvil 1 (in the embodiment with flexible elongated extension element and/or with cutting head portion) may, in addition, be placed with the stem through the wall of viscera, reducing to a minimum the risk of trauma to the structure crossed.

[00115] . The anvil may in addition be placed in the anastomosis site reducing to a minimum the risks of contamination related to opening of the viscera. The positioning of the anvil in fact requires only the preventive aperture of a small hole for the passage of a thread. Such hole is considerably smaller than the apertures which need to be adopted for anvils of the traditional type. This considerably reduces the risk of contamination .

[00116] . The anvil 1 is efficient and safe to use, in part thanks to the retractable covering.

[00117] . The anvil 1 is simple and economical to make, thanks to its non-complex structure which may use components in part already present on the market (such as the head and the stem for example) .

[00118] . The stapler 10 according to the invention can be guided in the anatomical area to be anastomised in a mechanical manner without the need for direct visual control .

[00119] . The invention thus conceived thereby achieves the purposes set out.

Claims

1. Anvil for a surgical mechanical circular stapler, of the type comprising a loader with staples, comprising:

- a head (2), destined to receive in abutment the staples of the loader (12) of a stapler (10);

- a stem (3) associated to the head at a first end (3'), said stem (3) being destined to engage movably in an axial direction in the stapler (10) at the end bearing the loader (12) .

characterised by the fact of comprising a terminal element

(4) , having a tapered head portion (4a) and associated to a second end (3") of the stem (3) , opposite the first, and by the fact that said terminal element (4) comprises means

(5) for associating it to a threadlike element (8).

2. Anvil according to claim 1, wherein said terminal element (4) is associated to the second end (3") of the stem by connection means (6) .

3. Anvil according to claim 1 or 2, comprising an elongated extension element (7), positioned between the second end (3") of the stem and the terminal element (4), said elongated element (7) being associated at its two ends (7',7") respectively to the terminal element (4) and to the stem (3) .

4. Anvil according to claim 3, wherein said elongated element (7) is more flexible than the stem (3) and the terminal element (4) .

5. Anvil according to claim 3 or 4, wherein said elongated extension element (7) is made from flexible polymeric material .

6. Anvil according to one or more of the claims from 3 to 5, wherein the elongated extension element (7) is a tubular element, in particular hollow.

7. Anvil according to claim 2 and to one or more of the claims from 3 to 6, wherein said connection means (6) are positioned between the stem (3) and the elongated extension element (7).

8. Anvil according to claim 7, wherein the terminal element (4) is attached to the elongated extension element (7) in a non-detachable manner.

9. Anvil according to one or more of the claims from 2 to 8, wherein said connection means (6) are of the detachable type.

10. Anvil according to one or more of the previous claims, comprising a retractable covering positioned so as to protect the head portion (4a) of the terminal element.

11. Anvil according to claim 10, wherein said retractable covering is movable from a covering position, in which it completely covers at least the head portion (4a) of the terminal element, to an exposed position, in which it is distanced from the head portion (4a) leaving it at least partially uncovered.

12. Anvil according to claim 11, wherein said covering is slidingly associated with the terminal element in a tapering direction (X) of the head portion (4a) and moves from the covered position to the exposed position when the covering is subjected to a stress in the tapering direction (X) .

13. Anvil according to one or more of the previous, claims, wherein the head portion (4a) has a pointed shape.

14. Anvil according to claim 13, wherein the head portion (4a) has a conical shape.

15. Anvil according to one or more of the previous claims, wherein the head portion (4a) has at least one cutting edge.

16. Anvil according to claim 15, wherein the head portion (4a) comprises at least two cutting edges, positioned on opposite sides to the tapering direction (X) .

17. Surgical kit for a mechanical circular stapler, comprising :

- an anvil (1) according to one or more of the previous claims, having a head (2), a stem (3) associated to the head at a first end (3'),_. and a terminal element (4), having a tapered head portion (4a), associable by means of connection means (6) to a second end (3") of the stem (3) , opposite the first; and - a threadlike element (8) .

the terminal element (4) comprising means (5) for associating it to said threadlike element (8) .

18. Kit according to claim 17,. comprising an elongated extension element (7), destined to be positioned between the second end (3") of the stem and the terminal element (4) to connect the terminal element (4) to the stem (3), preferably the elongated element (7) being more flexible than the stem (3) and the terminal element (4).

19. Kit according to claim 17 or 18, wherein the head portion (4a) has a pointed shape.

20. Kit according to one or more of the claims from 17 to

19, wherein the head portion (4a) has at least one cutting edge .

21. Kit according to claim 20, wherein the head portion (4a) comprises at least two cutting edges, positioned on opposite sides to the tapering direction (X) of the head portion ( 4a) .

22. Surgical mechanical circular stapler, comprising:

- a hollow tubular support structure (11) which at a first end (11') bears an associated loader (12) for staples;

- an anvil (1), comprising a striking head (2) and a stem (3), which at a first end (3' ) is connected to the head (2) and is destined to engage in a mobile manner in an axial direction in the hollow tubular structure (11) at the end bearing the loader (12) to draw together or distance the head (2) from the loader (12) ;

characterised by the fact that the anvil (1) comprises a guide · element (7,8) with a mainly longitudinal extension, associated, directly or indirectly, to the second end (3") of the stem,

and by the fact that the hollow tubular support structure (11) comprises within it a through passage (13), which extends from one end (11') to the other (11") of the hollow support structure and is open at both ends, the guide element (7,8) of the anvil (1) being destined to cross the hollow support structure (11) in an axial direction inside the through passage (13) guiding the hollow structure (11) in a movement bringing it closer to the anvil (1) .

23. Stapler according to claim 22, wherein the anvil comprises a terminal element (4), which is associated to the second end (3") of the stem, said guide element (7,8)) being associated to said terminal element (4).

24. Stapler according to claim 23, wherein the terminal element (4) is provided with means for associating it to a threadlike element (8), said guide element comprising said threadlike element (8) .

25. Stapler according to claim 23 or 24, wherein the terminal element (4) is associated to the stem (3) by an elongated extension element (7), said guide element comprising said elongated extension element (7) .

26. Stapler according to claim 25, wherein the elongated extension element (7) is more flexible than the stem (3) and the terminal element (4) .

27. Stapler according to one or more of the claims from 23 to 26, wherein said terminal element (4) comprises a tapered head portion (4a) .

28. Stapler according to claim 27, wherein the head portion (4a) has a pointed shape.

29. Stapler according to claim 27 or 28, wherein the head portion (4a) has at least one cutting edge.

30. Stapler according to claim 29, wherein the head portion (4a) comprises at least two cutting edges, positioned on opposite sides to the tapering direction (X) of the head portion (4a) .

31. Stapler according to one or more of the claims from 22 to 30, wherein the hollow support structure is flexible at least in one of its longitudinal portions, preferably the end portion bearing the loader.

32. Stapler according to one or more of the claims from 22 to 30, wherein the through passage (13) is positioned axially inside the hollow tubular support structure (11).