On the assessment of surgical tactics in obstructive large-bowel obstruction

The dissertation is devoted to the analysis of surgical tactics in obstructive large-bowel obstruction of tumor origin. The study examines the epidemiology, etiology, and pathogenesis of this complication of colon cancer, as well as existing approaches to surgical treatment — ranging from multi-stage procedures involving the formation of decompressing colostomies to primarily radical operations. Particular attention is paid to the significance of intra-abdominal hypertension, the systemic inflammatory response, and the plasma levels of pro-inflammatory cytokines and tumor markers as factors that determine the severity of the patients' condition and the prognosis of the disease. The aim of the work is to improve the outcomes of treatment of patients with obstructive large-bowel obstruction by optimizing the timing and extent of surgical intervention with regard to the age and clinical characteristics of the patients.

Obstructive large-bowel obstruction (OLBO) is the most frequent complication of the tumor process affecting the colon. According to data from various authors, its frequency ranges from 15 to 85% (Aleksandrov N.N. et al., 1980; Efimov G.A. et al., 1984; Bondar' G.V. et al., 1990; Kukosh V.I. et al., 2003; Mokhov Ye.M. et al., 2003; Razzadorin S.S. et al., 2003; Yaitskiy N.A. et al., 2004; Nikitin N.A. et al., 2007; Nadvikova Ye.A. et al., 2008).

Over recent decades, a steady increase in the incidence of colorectal cancer (CRC) has been recorded throughout the world. At present, colon cancer is one of the most widespread oncological diseases, as evidenced by published data. Every year in the world, CRC is diagnosed in 500,000–600,000 patients (Martynyuk V.V., 2000; Belyayev A.M. et al., 2008). Malignant tumors of this localization occur most frequently in economically developed countries. For example, in the United States in 1968, 73,000 cases were detected (Curamings K. et al., 1985), whereas at present approximately 150,000 new cases are registered annually, about 55,000–60,000 patients die, and only lung cancer produces a higher mortality.

It is noteworthy that patients with this pathology are predominantly representatives of older age groups (mean age of patients 65±3 years), and the number of elderly and senile patients is steadily increasing (Aliyev S.A., 1998; Belov S.G. et al., 2000; Petrov V.P. et al., 2002; Pakhomova G.V. et al., 2007; Dvoretskiy S.Yu. et al., 2007; Maskin S.S. et al., 2008; Mikhaylov A.P. et al., 2008). Considering the age characteristics of patients with this pathology, it should be noted that virtually all patients are burdened with multiple comorbidities.

In parallel with the increase in the incidence of CRC, despite considerable improvement of diagnostic methods, the number of complicated forms is growing. According to V.L. Vasyutkov and co-authors (2004), in 30–35% of patients with colon cancer and in 20–25% of those with rectal cancer, the course of the disease is complicated by obstructive large-bowel obstruction (OLBO).

Intestinal obstruction is often the first manifestation of the oncological process, and among newly identified patients, persons with "advanced intestinal obstruction," in which the small intestine is already involved in the process, constitute 88–92% (Aliyev S.A., 1998; Pakhomova G.V. et al., 2007; Meshkov A.V. et al., 2008; Kukosh M.V. et al., 2008; Mikhaylov A.P. et al., 2008).

The combination of obstructive intestinal obstruction with other complications of the tumor process (perforation of the colonic wall, paracolic abscess, intestinal hemorrhage, etc.), localization of the malignant tumor in the left half of the colon, stage IIIB–IV of cancer, various comorbidities, and the elderly or senile age of the patients are factors that allow this group of patients to be assigned to the category of "increased operative risk" (Aliyev S.A., 1998; Anisimov A.Yu. et al., 2000; Petrov V.P. et al., 2002; Rogan V.Ya. et al., 2003; Borota A.V. et al., 2005; Dvoretskiy S.Yu. et al., 2007; Manikhas G.M. et al., 2008).

Patients with complications of the tumor process affecting the colon are admitted to general surgical hospitals rather than to specialized oncological institutions. Consequently, it is surgeons who must address all the complex issues of treating complicated colon cancer (Aliyev S.A., 1998; Mokhov Ye.M. et al., 2003; Yaitskiy N.A. et al., 2004; Afendulov S.A. et al., 2007; Pakhomova G.V. et al., 2008).

The available data indicate the absence of a single, pathogenetically grounded approach to the choice of surgical tactics for patients with complicated tumor of the colon.

For intestinal obstruction, some authors recommend multi-stage operations with preliminary formation of decompressing colostomies followed by radical procedures (Belyy V.Ya. et al., 1996; Makarov A.A. et al., 1998; Belov S.G., 2000; Vorobyev G.I. et al., 1996; Chumakov A.A. et al., 2003; Karachintsev I.E. et al., 2003; Kitayev A.V. et al., 2004; Safronov D.V. et al., 2004; Kovalev A.I., 2008; Pugayev A.V. et al., 2008).

Other surgeons recommend performing primarily radical operations, finishing them with the formation of a colostomy or by primary restoration of the intestinal tube (Totikov V.Z., 1993; Fyodorov V.D. et al., 1994; Ektov V.N., 1995; Aliyev S.A., 1999; Briskin B.S. et al., 1999; M. Csiky et al., 1997; B. Formoni et al., 1998; H. Tzu-Chi, 1998; Lupaltsov V.I. et al., 2003; Pakhomova G.V. et al., 2003; Verzhanskiy A.P., 2003; Vorobyev G.I. et al., 2005; Andreyev G.N. et al., 2007; Glukhov A.A. et al., 2008; Vasilyev S.V. et al., 2008).

The current scientific and technological progress has had a positive impact on the results of treatment of this category of patients. However, the mortality rate in complicated tumor of the colon unfortunately remains high, reaching 23–52% (Vasilyev S.V. et al., 1996; Aliyev S.A., 1998; Briskin B.S. et al., 1999; Petrenko S.L. et al., 2000; Kh. Stoianov et al., 1996; Karachintsev I.E. et al., 2002; Mikhaylov A.P. et al., 2003; Korotkevich A.G. et al., 2003; Khanevich M.D. et al., 2004; Bokarev M.I. et al., 2008; Belyayev A.M. et al., 2008; Babkov O.V. et al., 2008).

Thus, the steady worldwide increase in the incidence of colon cancer, the absence of a unified view on the surgical tactics for complicated cancer of the left half of the colon, frequent postoperative complications, and, most importantly, the high mortality rate have designated this problem as one of the most pressing not only in medical but also in social terms.

The foregoing points have served as the starting points for the present study.

Aim of the study.

To improve the results of treatment of patients with obstructive large-bowel obstruction.

Objectives of the study.

1. To study the causes and features of clinical manifestations of obstructive large-bowel obstruction.

2. To study the significance of the intra-abdominal hypertension syndrome, cytokines, and tumor markers in blood plasma in this pathology.

3. To study the influence of the timing and extent of surgical intervention on the course of the postoperative period and the mortality rate.

Scientific novelty.

1. It has been established that the progression of obstructive large-bowel obstruction is accompanied by an increase in intra-abdominal hypertension, in the frequency of systemic inflammatory response and multiple organ failure, and in the plasma concentrations of pro-inflammatory interleukins and tumor necrosis factor.

2. It has been shown that the plasma levels of carcinoembryonic antigen and vascular endothelial growth factor are determined by the stage of the oncological process and the morphological structure of the tumor. When the obstruction is resolved without removal of the tumor, their concentrations increase.

3. It has been revealed that after emergency and planned operations with removal of the tumor, the clinical effect is, to a certain extent, associated with normalization of cytokines in the blood plasma. This is manifested by a decrease in the frequency of postoperative complications and in the mortality rate.

Practical significance.

It has been established that the principal cause of obstructive large-bowel obstruction is a tumor of the colon. Most often the tumor is localized in its left half.

It has been shown that the degree of tumor differentiation does not exert a substantial influence on the course of intestinal obstruction.

It has been revealed that the proportion of elderly and senile patients with this pathology exceeds 80%. In these cases the tumor is predominantly localized in the distal part of the colon.

The significance of intra-abdominal hypertension and the systemic inflammatory response, as well as their influence on the outcome of the disease, has been determined.

The influence of the extent of the surgical intervention on the plasma levels of cytokines and tumor markers in the early postoperative period has been shown.

The mechanisms of the favorable course of the postoperative period after emergency operations with removal of the tumor, in comparison with symptomatic ones, have been revealed.

Main propositions defended.

1. In obstructive large-bowel obstruction the tumor is most often localized in the left half of the colon, particularly in patients older than 75 years. The progression of the obstruction is accompanied by an increase in the frequency of systemic inflammatory response, multiple organ dysfunction, intra-abdominal hypertension, and shock index.

2. The performance of planned and emergency operations with removal of the colonic tumor, compared with symptomatic operations, leads in the early postoperative period to normalization of the plasma levels of pro-inflammatory cytokines and tumor markers. Resolution of the obstruction is accompanied by elimination of intra-abdominal hypertension.

3. The outcome of the disease in obstructive large-bowel obstruction is determined by its severity, the stage of the oncological process, and the age of the patients. With removal of the tumor, the frequency of postoperative complications and the mortality rate decrease.