Colorectal Anastomoses and Intramural Blood Flow Disorders

The dissertation is dedicated to studying the patterns of reparative regeneration of colorectal anastomoses under conditions of impaired intramural blood flow. The relevance of the research is due to the high rate of anastomosis insufficiency and associated severe postoperative complications, such as fecal peritonitis. The work analyzes the influence of the architecture of intramural arteries of the intestinal wall, specifically the system of short and long straight arteries, on the reliability of anastomosis formation. The research aims to develop optimal variants of intestinal suture topography taking into account individual features of colon blood supply.

Relevance of the problem

Improvement in the techniques of surgical interventions on the colon, achievements in pharmacological prevention and treatment of purulent-septic complications in operative proctology have significantly improved the results of surgical treatment of colon diseases. However, until now, one of the main problems of colorectal surgery remains a rather high rate of colorectal anastomosis insufficiency leading to the development of severe fecal peritonitis and fatal outcomes [21, 46, 99].

According to literature data, the rate of colorectal anastomosis insufficiency ranges from 1.1% to 32% [42, 68, 182, 190, 191]. When performing anastomoses with suture apparatuss of various constructions, the probability of anastomosis insufficiency amounts to 2.7-8.6% [81, 104, 158, 159, 161, 165]. Fecal peritonitis complicating colorectal anastomosis insufficiency is characterized by extremely high mortality reaching 50% [32, 58, 148, 166, 172, 185].

The sigmoid intestine occupies a special position as an object of surgical intervention. Its size, intraperitoneal position in the abdominal cavity, and mobility allow for the performance of intra-abdominal resections, which are distinguished by a smaller volume of intervention and less trauma compared to hemicolectomy. The latter is especially important in the older age group and in patients with an unfavorable premorbid background. The feasibility of resections in a number of pathological processes of the sigmoid intestine, and in oncology this is up to 65% of tumor localization in the left half of the colon [2, 670], is determined by typical and individual features of the arterial and venous bed of the organ.

The features of the vascular architecture of the left half of the colon are a key moment in most current problems of operative proctology. The success of widely spread operations in Russia and abroad related to the mobilization and lowering of the sigmoid colon and adjacent sections is largely discredited by a number of complications associated with anastomosis insufficiency, marginal necrosis, peritonitis, and fecal fistulas [142, 155,213].

When studying the blood supply of this section of the gastrointestinal tract, a number of authors attached special importance to the forms of division of the inferior mesenteric artery [44] and the forms of arcs of the sigmoid intestine [2, 155].

The vascular architecture of the left half of the colon has been the subject of numerous studies [71, 143]. The main attention in most works was paid to studying the possibility of using the left half of the colon as an autotransplantate for esophagus replacement or lowering the colon during abdominoperineal resection of the rectum. The main object of study in this regard were anatomical variants of the inferior mesenteric artery.

There is no unanimous opinion in the literature regarding the degree of participation of the branches of the inferior mesenteric artery in the formation of the Riolan arc and the blood supply of various sections of the left half of the colon. Hence the differences in determining the level of ligation of the inferior mesenteric artery and the proximal boundary of colon resection.

The study of the state of hemimicrocirculation in the intestine to understand the causes of postoperative complications remains relevant [83, 87, 102]. There is no unified representation of microcirculatory changes in the wall of the colon preceding its destruction in the anastomosis zone [15, 113]. It is precisely the violation of intraorgan blood supply of the colon wall in the area of the anastomosis after operations that some authors consider the cause of the high percentage of anastomosis suture insufficiency [33, 50, 68].

There is a lot of data on the significance of hemodynamic disorders (local and general) preceding colorectal anastomosis insufficiency [39, 79]. Disturbance of blood flow is one of the main pathological links in the occurrence of postoperative complications [24, 26, 34, 108, 153]. Study of the nature of hemodynamic microcirculatory intraorgan disorders [122], as well as the conditions of their occurrence, is one of the relevant tasks of operative colon surgery and has great practical and theoretical significance. With a positive result, there is a probability of opening new possibilities and conditions for ensuring the reliability of colorectal anastomoses.

Until now, there are no precise practical recommendations for choosing and applying the most optimal variants of anastomosis techniques in conditions of impaired intramural blood flow, especially since in this area clinical works largely precede fundamental research.

The presented literature data argue the goal of the present dissertation research.

Goal of the work

The goal of the work is to improve the quality of forming colorectal anastomoses by taking into account individual features of the architecture of intramural arteries of the intestinal wall.

Tasks of the research

In accordance with the goal of the present research, the tasks of the research were determined:

1. To study the features of colorectal anastomosis regeneration in conditions of intramural blood flow disorder of the short straight arteries system.

2. To study the features of colorectal anastomosis regeneration in conditions of intramural blood flow disorder of the long straight arteries system.

3. To study in the experiment the most significant factors of colorectal anastomosis reliability depending on the topography of interintestinal sutures relative to straight arteries.

4. Based on the obtained data, to implement in practical activity the optimal variants of the technique for forming colorectal anastomoses depending on individual features of intramural blood flow of the colon.

Scientific novelty of the work

For the first time, the features of regeneration and vascularization of colorectal anastomoses in conditions of critical ischemia of intramural blood flow of the short and long straight arteries systems have been studied. In the work, for the first time in a comparative aspect, the most optimal variant of forming a colorectal anastomosis depending on the topographic relationship of anastomosis sutures and intramural magistrales of straight arteries was studied and developed. A Russian Federation patent for invention No. 2291496 dated 10.01.2007 "Method for creating a model of chronic ischemia of the colon" was obtained.

Practical significance of the work

Based on a thorough study and analysis of the features of the structure of extraorgan blood supply of the inferior mesenteric artery system and the features of intramural blood flow of the sigmoid intestine, optimal variants of the technology for forming colorectal anastomoses have been developed.

Basic provisions put forward for defense

1. One of the most frequent and usually fatal complications of colon resection is anastomosis suture insufficiency and peritonitis, which are observed with varying frequency when using different methods of forming colorectal anastomoses.

2. Resection or capturing in the suture of intramural magistrales of straight arteries inevitably leads to critical ischemia of the "suture strip", anastomosis suture insufficiency, and peritonitis.

3. Optimal variants of forming colorectal anastomoses are directly dependent on the topographic relationships of anastomosis sutures and intramural magistrales of straight arteries.

Presentation of the work. The basic provisions of the dissertation were presented and discussed at the Scientific Coordination Council of RostGMU (Rostov-on-Don, 2000), the scientific conference "Questions of Applied Anatomy and Surgery" (Saint Petersburg, 2000), the scientific conference "Questions of Applied Anatomy and Surgery" (Saint Petersburg, 2001), the scientific conference "Morphological Foundations of Histogenesis and Tissue Regeneration" (Saint Petersburg, 2001), the V All-Russian Conference with International Participation "Actual Problems of Proctology" (Rostov-on-Don, 2001), the III All-Russian Conference with International Participation "Actual Questions of Clinical Anatomy and Operative Surgery" (Saint Petersburg, 2003), the Scientific and Practical Conference "Actual Problems of Surgery" (Rostov-on-Don, 2007), the I Congress of Surgeons of the Southern Federal District (Rostov-on-Don, 2007).

Publications

8 scientific works have been published on the topic of the dissertation.

Implementation in practice

The main results of the work have been implemented in the clinical practice of the surgery department of MLPU GB No. 7 and the department of surgical diseases No. 3 of the State Educational Institution of Higher Professional Education "Rostov State Medical University" of the Ministry of Health. The basic provisions of the dissertation are used when reading lectures and conducting practical classes at the department of surgical diseases No. 3 and the department of topographic anatomy and operative surgery of the State Educational Institution of Higher Professional Education "Rostov State Medical University".

Volume and structure of the dissertation. The dissertation is presented on 112 pages of typed text and is illustrated with 8 tables and 32 figures. The work consists of an introduction, an analytical literature review, five chapters of own research, conclusion, conclusions, practical recommendations, a list of literature including 223 sources, including 156 domestic and 67