Diagnosis and Treatment of Diastatic Perforations of the Colon in Obstructive Colorectal Cancer

The dissertation is dedicated to the study of diastatic perforations of the colon as a severe complication of obstructive colorectal cancer. The research is based on clinical observations of 58 patients and includes a retrospective analysis of their medical records. The author developed clinico-radiological signs allowing suspicion of diastatic perforation before surgery, evaluated the applicability of the Manheim scale and CTES index for assessing the severity of peritonitis. Principles for selecting the volume of surgical intervention based on operative risk factors were identified, and the necessity of thorough revision of all segments of the colon when bowel diameter exceeds 10 cm was substantiated.

Диссертация посвящена изучению диастатических разрывов ободочной кишки как тяжелого осложнения опухолевой толстокишечной непроходимости при колоректальном раке. Исследование основано на клинических наблюдениях 58 больных и включает ретроспективный анализ их историй болезни. Автором разработаны клинико-рентгенологические признаки, позволяющие заподозрить диастатическую перфорацию до операции, оценена применимость шкалы Манхаймера и индекса CTES для оценки тяжести перитонита. Выделены принципы выбора объема хирургического пособия в зависимости от факторов операционного риска, обоснована необходимость тщательной ревизии всех отделов ободочной кишки при диаметре кишечника более 10 см.

Colorectal cancer is a prevalent disease and, in many countries worldwide, has moved to second or third place in frequency among malignant neoplasms (Martynuk V.V., 2000; 2004). More than 190,000 patients with this localization die annually in Europe (Borovac N., 2003). In Russia, colorectal cancer ranks third (10.9%) in the structure of mortality from malignant neoplasms, after lung and stomach tumors (Axel E.M. et al., 2001). Over the last 15 years in Saint Petersburg, the standardized mortality rate from colon cancer has increased by more than 30% (Martynuk V.V., 2004).

Despite the advancement of colorectal cancer diagnostic methods in our country, practically every fourth patient with a first-established diagnosis of colon cancer belongs to clinical stage IV, and in some regions this indicator reaches 50% (Melnikov R.A. et al., 1987). In Western European and American countries, despite attempts to implement a screening system, 25% of patients are found to have metastases of colorectal cancer at initial diagnosis (Borovac N., 2003). Meanwhile, complicated forms of this disease are observed in 60–90% of patients (Pakhomova G.V., Podlovchenko T.G., 2003).

The most frequent complication of colon cancer is acute obstructive large bowel obstruction, which occurs in 20–40% of patients with colon cancer (Zinevich V.P., Babkin V.Ya., 1991). According to M.V. Grinev et al. (2004), up to 70–96.5% of these patients are hospitalized at stages III–IV of the disease with localization of the tumor process in the left half of the large intestine.

One of the relatively rare but extremely severe complications of colon cancer is perforation. Its frequency, according to various authors, ranges widely from 2.3% to 22.3% (Viaycki I.V., 1993; Repse S. et al., 1999; Freeman H.P., Alshafie T.A., 2002), while postoperative mortality reaches 23–88.9% (Yilmazlar T. et al., 1999; Alcobendas F. et al., 2000; Ceriati F. et al., 2002). As a rule, this complication also occurs more frequently with tumor localization in the left half of the colon, which is observed in 75–82% of cases (Dmitriev M.O. et al., 2004; Borovac N., 2003).

Diastatic perforation of the colon occurs much less frequently — approximately in 26–35% of perforation cases (Viaycki I.V., 1993; Aliev S.A., 1999; Gullino D. et al., 1999) or in 3.4–8.9% of cases of obstructive large bowel obstruction (Manov E.N., 2003; Susla P.A. et al., 2003). As a rule, it is associated with obstructive tumor-related large bowel obstruction.

The number of cases of diastatic perforations of the large intestine described in the literature by domestic and foreign authors is small and rarely exceeds 20, while, as a rule, high mortality is noted, which ranges, according to various authors, from 29% to 85.7% (Aleksandrov N.N. et al., 1980; Aliev S.A., 1999; Napalkov A.N. et al., 2004; Renoux V. et al., 1986; Carraro P.G. et al., 1998; Chen H.S., Sheen-Chen S.M., 2000; Biondo S. et al., 2002). The main causes of fatal outcomes are cancer intoxication, progressive peritonitis, as well as septic and thromboembolic complications (Solovev I.E., 2000; Napalkov A.N. et al., 2004; Kriwanek S. et al., 1996; Mandava N., 1996; Biondo S. et al., 2002).

Diastatic perforation of the large intestine is distinguished by polymorphism of the clinical picture; therefore, most authors note significant difficulties in diagnosing this complication, mainly due to the subtlety of clinical manifestations of peritonitis in patients whose severity of condition is aggravated by the presence of a malignant tumor (Aleksandrov N.N. et al., 1980; Aliev S.A., 1999; Divilin V.Ya. et al., 2004). Therefore, most such patients are admitted to the hospital with a referral diagnosis of acute abdomen, intestinal obstruction, acute appendicitis, perforative ulcer, no earlier than 6–7 hours after the onset of the disease (Kutyakov M.G. et al., 1987; Shalkov Yu.L., 2003).

Treatment of diastatic perforation of the colon is a difficult task. Only timely and adequate surgical intervention with subsequent intensive therapy can save the patient's life. However, until now, primarily due to the small number of such observations by domestic and foreign authors, no consensus has yet been reached regarding optimal diagnostic measures, choice of type and volume of surgical treatment for this complex category of patients.

The aim of the study — based on own clinical observations and retrospective analysis of medical records of patients with diastatic perforations of the colon — is to establish the necessary volume of diagnostic measures allowing timely suspicion of this complication of colorectal cancer, and to determine the optimal volume of surgical intervention.

Tasks of the study:

1. To study the features of clinical manifestations of diastatic perforations of the colon in colorectal cancer and the necessary volume of diagnostic measures in the development of this complication.

2. To analyze the immediate results of surgical treatment of patients with colon cancer complicated by diastatic perforations, depending on the time of their occurrence, localization, extent of the tumor process, degree of morphological changes, severity of peritonitis, volume and type of surgical intervention performed.

3. To study the outcomes of various types of operations in colorectal cancer complicated by diastatic perforations, and depending on the presence of risk factors to determine the most rational methods of surgical intervention.

4. To evaluate the effectiveness of assessment of peritonitis severity by the Manheim scale and the choice of volume of surgical intervention by the CTES index in diastatic perforations of the colon.

Scientific novelty:

Clinico-radiological signs were described that allow suspicion of this complication even before surgery. The possibility of applying the Manheim scale and CTES index in this patient cohort was evaluated. Nine variants of operations performed in this patient cohort for the primary disease and three variants — directly for diastatic perforations of the colon — were studied. Principles for selecting the optimal volume of surgical intervention in diastatic perforations of the colon depending on identified operative risk factors were developed.

Practical significance of the work:

The data presented in the dissertation expand the knowledge of practicing surgeons about the etiology, pathogenesis, clinical features, and diagnosis of diastatic perforations of the colon in colorectal cancer. The necessary minimum of diagnostic measures for earlier detection of this rare complication was determined. Clinico-laboratory risk factors for performing extended surgical interventions in colon cancer complicated by diastatic perforations were identified. The necessity of thorough revision of all segments of the colon during surgery for large bowel obstruction when its diameter exceeds 10 cm, regardless of tumor localization, for detection and elimination of probable diastatic perforations was substantiated. It was found that performing single-stage decompression of the dilated colon against the background of obstructive large bowel obstruction does not guarantee protection from development of diastatic perforation in the early postoperative period; in such cases, cecostomy and nasointestinal intubation must be performed. It was established that the tumor causing intestinal obstruction must be removed in all cases where this is technically feasible, except in situations where peritoneal carcinomatosis, terminal phase of intra-abdominal infection, or endotoxic shock are diagnosed — then colostomy should be limited. Diastatic perforations of the colon may be removed together with the tumor or sutured with possible extraperitonealization. Decompression of the intestine must be an obligatory stage of the operation.

Propositions for defense:

1. Diastatic perforations of the colon are one of the most severe complications of obstructive large bowel obstruction and are accompanied by postoperative mortality of 63.8%. The main cause of death is multiple organ insufficiency against the background of intoxication of mixed etiology.

2. Diagnosis of diastatic perforations of the colon is extremely difficult, as their clinical picture is distinguished by polymorphism. Diastatic perforations manifest as three groups of signs identified by us.

3. In colorectal cancer complicated by obstructive obstruction and diastatic perforations of the colon, one should strive not only to eliminate complications but also to perform a primary radical operation in which the tumor and diastatic perforation are removed, except in situations where peritoneal carcinomatosis, terminal phase of intra-abdominal infection, or endotoxic shock are diagnosed — then colostomy should be limited.

Reliability of research results:

Information about all 58 patients was recorded in special statistical cards and also entered into a specially created computer database. The sample of medical records was produced according to 147 parameters.

Necessary statistical processing of the obtained data was performed using variance statistics with the Microsoft® Office Excel 2003 package. In this process, calculation of arithmetic mean (X), standard deviation (σ), standard error of the arithmetic mean (t), confidence interval for the true mean (μ) in the studied sample at 95% probability (p=0.05) was conducted. The reliability of differences between compared values was determined by Student's t-criterion and reliable probability (p). A difference between mean indicator values was considered reliable at p<0.05.

Validation and implementation of research results:

The proposed methods of diagnosis and surgical treatment of patients with diastatic perforations of the colon in colorectal cancer are used in practical work at clinical bases of the 2nd department (advanced training in surgery) of the S.M. Kirov Military Medical Academy, St. George's Hospital, and also at the Saint Petersburg Research Institute of Emergency Medicine named after I.I. Janelidze.

Research results are used in the educational process at the 2nd department (advanced training in surgery).

Ten scientific papers on the dissertation topic have been published, including in the central journal "Emergency Medical Aid" (2004), the collection of scientific works "Actual Questions of Clinical Surgery" (St. Petersburg, 2004). The research results were reported at the international forum "Emergency Medicine in a Megapolis" (Moscow, 2004), the all-Russian surgeons' conference dedicated to the 80th anniversary of Professor Petrov V.P. (Krasnogorsk, 2004), the scientific-practical conference "Emergency Medical Aid: State, Problems, Prospects of Development" (Moscow, 2004), and others.

Structure and volume of the dissertation:

The dissertation is presented on 133 pages of typed text and consists of an introduction, a literature review, 3 chapters with the results of the author's research.