RU2289854C1 - System for estimating functional characteristics of end loop anastomoses under experimental conditions - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: system has silicon catheters implantable above and below anastomosis, probe having inflatable cuff for setting boundary between gastric and esophageal lumen, silicon tube to be introduced into proximal region of efferent intestine below the anastomosis. Probe with cuff and efferent tube are connected to roller pump for supplying physiologic saline or colloid solution into the system. The silicon catheters are connected to electronic transducer unit for measuring hydrodynamic pressure in the system.

EFFECT: high quality of anastomosis characteristics estimates.

1 dwg

Description

The present invention relates to medicine, namely to medical instruments, and can be used in an experiment to study new designs of anastomoses.

According to the literature, the postoperative loss of such functional structures of the digestive canal as the cardia, antrum, pylorus, and baugini damper, against the background of simple anastomotic designs, increases the frequency and diversity of postoperative diseases (S.V. Volkov, 1996; G.K.Zherlov et al. ., 1996; B.N. Zyryanov et al., 1998; U. Eichfeld et aL, 1994). Reflux gastritis, reflux esophagitis and dumping syndrome are the most common complications of surgical interventions on the stomach performed according to classical methods (A.F. Chernousov, S.A. Polikarpov, M.E. Voronov, 2004).

In this regard, the development of surgery of the gastrointestinal tract in recent years is characterized by a desire to develop anastomotic designs that allow the creation of conditions for the normal movement of food along the digestive tract and restore the areflux function of the lost valve apparatus. The emergence of new designs of anastomoses dictates the need to create methods for their adequate research. In a traditional clinical study of the operation of the anastomosis, an assessment is made not so much of the function of the anastomosis itself as of the functional state of the gastroduodenal complex as a whole, which is determined by many factors that are difficult to account for and often completely independent of the specific surgical design. The experimental assessment of anastomoses in most works provides only an assessment of the viability of the joints using pneumatic or hydropressive methods.

The only analogue we have identified is the use of a device that provides pneumatic compression for assessing the areflux properties of a gastrostomy and jejunostoma in an experiment (G.K. Zherlov, M.I. Vasilchenko, D.V. Zykov. Areflux gastrostomy and jejunostoma. - Tomsk. - 1997, - p. 79-81). The pneumopressure test is carried out as follows: after removing the organocomplex with the gastrostomy, the esophagus is ligated, a rubber tube is inserted into the pyloric stomach, around which the stomach is tightly tied with a ligature. A spring manometer of the Riva-Rochi apparatus is attached to the distal end of the rubber tube to register the generated intragastric pressure. Using a pressure gauge bulb, air is injected into the jejunum up to 100-110 mm Hg. Areflux properties are evaluated by the pressure level at which air appears from the external opening of the stoma.

Disadvantages.

Conducting functional studies of the anastomosis on a drug extracted from the body by blowing air through the anastomosis or stoma is not physiological.

The use of the pneumatic compression method to assess the anastomotic obturator mechanism based on a single passage of air with a certain pressure in the cavity of the organocomplex under study, which is measured only at the inlet, does not adequately reflect the functional properties of the anastomosis or stoma, compared to natural conditions.

Tasks.

1. To develop a system for modeling anastomoses and evaluating their functional characteristics in the experiment, which allows to exclude the influence of environmental factors not related to the anastomosis, and to provide an objective characteristic of the function of the anastomosis;

2. Using the developed system, study the functional characteristics of end-loop gastroenteroanastomosis, namely, the provision of free emptying of the gastric stump and the obstruction of retrograde reflux of intestinal contents into the stump of the stomach.

The technical result.

The developed system allows the model to give an objective functional characteristic of new anastomosis designs developed and introduced into the clinic on the gastrointestinal tract. The experimental conditions for the study of new anastomoses can be easily changed in a wide range according to the properties studied and the tasks set. The proposed system for studying the properties of the anastomosis is largely universal and suitable for comparing different designs of anastomoses with each other. Experimental studies make it possible to justify the choice of anastomosis and the introduction of a pre-tested anastomosis design in the clinic, ensuring the prevention of diseases and syndromes associated with the loss of such functional structures as the cardia, antrum, pylorus, bauginia damper, which will improve the quality of life of patients, restore their working capacity, avoid repeated reconstructive operations.

The essence of the proposal is the creation of a system for modeling anastomoses and evaluating their functional characteristics in an experiment, which includes silicone catheters implanted above and below the anastomosis, a probe with an inflatable cuff, delimiting the lumen of the stomach and esophagus, a silicone tube in the proximal lumen of the intestine below the anastomosis moreover, a probe with a cuff and a discharge tube are connected to a roller pump for supplying physiological and colloidal solutions to the system, and silicone legs ry sensors connected to an electronic unit for measuring the hydrodynamic pressure in the system.

The system for a better understanding is shown in figure 1 where:

1. A container of liquid for feeding into the system.

2. The roller pump.

3. A probe for supplying fluid with an inflatable cuff, delimiting the lumen of the stomach and esophagus.

4. 2 silicone catheters connected to pressure sensors above the anastomosis zone.

5. 2 silicone catheters connected to pressure sensors below the anastomotic zone.

6. A line of pressure sensors manufactured by Synectics (England) for recording indicators and a multi-channel electronic unit.

7. An IBM PC computer with the Windows'95 operating system, equipped with the L-264 ADC (L-Card CJSC).

8. The outlet tube in the proximal lumen of the outlet intestine.

9. The esophagus.

10. Stump of the stomach.

11. End loop gastroenteroanastomosis.

12. The abducting intestine.

The work of our proposed system was carried out on an experimental model, including distal gastrectomy with the formation of end loop gastroenteroanastomosis (drawing, position 11). The system is used as follows: after isolating the anastomotic zone into the lumen of the stomach and the lumen of the loop of the small intestine above and below the gastroenteroanastomosis, silicone catheters with a diameter of 1 mm are implanted connected to pressure sensors (positions 5, 6, 7, 10, 11). A probe with an inflatable cuff is installed through the esophagus into the cardia region, which, after inflating the cuff and pulling it, hermetically delimits the cavity of the esophagus and stomach (positions 4, 9). The intestine below the gastroenteroanastomosis is crossed and a silicone tube is inserted into the lumen of its proximal end, which is hermetically fixed (position 1). A probe with an inflatable cuff and a discharge tube are connected to a roller pump for supplying physiological and colloidal solutions to the system. In this way, the system “gastric stump - gastroenteroanastomosis - abduction” is isolated. The liquid from the tank (physiological saline or colloidal solution, comparable in physical properties to the chyme) in the system is fed using a roller pump through a tube with an inflatable cuff into the cavity of the stomach stump. Then the fluid follows through the anastomosis into the discharge intestine and returns to the pump via the silicone tube (positions 1, 2, 8, 11, 12). The volumetric flow rates of the fluid used by the roller pump are 50, 200, 600 ml / min. Using open catheters, hydrodynamic pressure is measured in the lumen of the digestive tube. To record indicators, a multi-channel electronic unit, a line of pressure sensors manufactured by Synectics (England), an IBM PC with Windows'95 operating system equipped with an L-264 ADC (L-Card CJSC) are used. The signal is recorded in the form of a curve using the original program (Fig.1-7, 8). Similar measurements are carried out during the retrograde passage, when the fluid is fed into the discharge intestine. In this way, pressure gradients in the digestive tube are determined at various levels relative to the gastroenteroanastomosis at different speeds and the direction of supply of various fluids created by the roller pump. Then, short-term pressure changes are proximal and distal to the anastomosis, similar to those created by the gastric motility and the abducting intestine. The transmission of phase changes in intraluminal pressure to adjacent segments of the system “stomach - gastroenteroanastomosis - abduction” is estimated.

The dynamics of pressure changes depended both on the feed rate, its direction, and the viscosity of the liquids used. The use of a colloidal solution in the system "stomach - gastroenteroanastomosis - abduction" showed that the increase in resistance is directly dependent on its viscosity.

In animals (outbred dogs) with end-loop gastroenteroanastomosis with antegrade fluid delivery at low speed, the pressure in the stomach exceeds the pressure in the intestine by 9.1 ± 0.27 and 18.0 ± 0.58 cm aq. depending on the density of the liquid, and the main pressure gradient was created directly in the area of the anastomosis. The resistance created by the end loop gastroenteroanastomosis to supply the contents from the stomach to the intestine seems comparable to that of the intact pylorus, since the pressure gradient between the stomach and the duodenum, determined normally, is 5-15 cm aq. This resistance characterized the ability of the anastomosis to provide gradual and free emptying of the stomach.

The ability of the anastomosis to impede a constant retrograde fluid flow was 1.6 (for physiological saline) and 3 times (for colloidal solution) higher than for antegrade fluid flow. A study of the hydrodynamics of the system with short-term high-amplitude pressure rises similar to those occurring with intestinal motility revealed the ability of the anastomosis to reduce these pressure rises from 10 times to full areflux: the maximum pressure gradient between the intestinal loop and the stomach during passage of saline was up to 250 cm of water. Thus, under conditions close to natural, the anastomosis manifested itself as areflux. Thus, the hydrodynamic assessment of the function of the gastrointestinal anastomosis performed by us under the conditions of the experiment showed that this anastomosis design provides a metered obstacle to antegrade fluid delivery of different viscosities, which implies the provision of gradual and free emptying of the stomach stump, and also has pronounced areflux properties.

Claims (1)

A system for evaluating the functional characteristics of end loop anastomoses in an experiment, including means for creating and means for measuring pressure in the anastomosis zone, characterized in that it includes silicone catheters for implantation above and below the anastomosis, a probe with an inflatable cuff to distinguish between the lumen of the stomach and esophagus and a silicone discharge a tube for insertion into the proximal section of the abdominal gut below the anastomosis, the probe with a cuff and the outlet tube connected to a roller pump, made with the possibility Strongly change feed rates for feeding in physiological or colloidal solutions, and silicone catheters are connected to the pressure measuring means are designed as an electronic sensor unit for measuring the hydrodynamic pressure.