RU2803009C1 - Method of choosing the tactics of surgical treatment of rectal tumors - Google Patents

Abstract

FIELD: surgery; oncoproctology.

SUBSTANCE: in a patient with a tumor of the rectum before surgery, the level of preoperative hemoglobin, the volume of the tumor, the presence or absence of diabetes mellitus, the presence or absence of excess body mass index (BMI) is determined. The risk of colorectal anastomosis failure (p) is calculated according to the original formula. When the value of p is less than 0.14, surgical treatment of a tumor of the rectum is completed with the formation of a colorectal anastomosis using a circular stapler; if p is greater than or equal to 0.14, the surgical treatment of the rectal tumor is completed with the formation of a colorectal anastomosis with a circular stapler, followed by the imposition of a preventive intestinal stoma.

EFFECT: method makes it possible to preliminarily assess the risk of colorectal anastomosis failure, to select adequate surgical tactics at the preoperative stage and to reduce postoperative complications in patients at high risk of colorectal anastomosis failure, and thereby increase the effectiveness of treatment.

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Description

The invention relates to surgery, in particular to oncoproctology, and can be used to select tactics for surgical treatment of rectal tumors.

Surgical treatment of rectal tumors is a complex task in modern oncology, requiring not only appropriate equipment, but also a qualified surgeon. Preservation of the anal sphincter during surgical treatment of rectal tumors without compromising oncological radicalism is a priority goal for both the patient and the surgeon (Park J.S., Choi G.S., Kim S.H., et al. Multicenter analysis of risk factors for anastomotic leakage after laparoscopic rectal cancer excision : the Korean laparoscopic colorectal surgery study group // Ann. Surg. - 2013. - No. 257. - P. 665-71). Failure of the colorectal anastomosis (HKA) after its application is one of the most severe complications and occurs in 7.5 to 25% of cases, and the associated postoperative mortality reaches 6.0-39.3% (Popov D.E. Risk factors failure of colorectal anastomoses in patients with rectal cancer // Coloproctology. - 2014. - No. 2 (48). - P. 48-56). One of the key points in the prevention of complications is the correct choice of tactics for surgical treatment of rectal tumors. The solution to this problem is based on a full and comprehensive study of risk factors for NCA. Thus, if there is a high risk of anastomotic failure and in order to avoid severe complications, surgical treatment of a rectal tumor must be completed with various measures to prevent complications, namely: the imposition of a preventive intestinal stoma, additional strengthening of the anastomotic area, transanal drainage, etc. Most often, surgeons use a preventive intestinal stoma. Published scientific works, both in domestic and foreign literature, on methods for predicting ICA and choosing surgical treatment tactics are very contradictory and require further study. (Hirst N.A., Tiernan J.P., Millner P.A. et al. Systematic review of methods to predict and detect anastomotic leakage in colorectal surgery // Colorectal Disease. - 2014; 16 (2): 95-109).

Dissatisfaction with the results of modern methods for choosing tactics for surgical treatment of rectal tumors requires the development of new highly effective methods for treating this disease.

By searching the scientific and patent literature, we found different methods for choosing tactics for surgical treatment of rectal tumors.

There is a known method for choosing tactics for surgical treatment of rectal tumors, described in the work of Zheng N. et al. (Zheng N., Wu Z., Wu Y. et al. Laparoscopic surgery may decrease the risk of clinical anastomotic leakage and a nomogram to predict anastomotic leakage after anterior resection for rectal cancer. Int J Colorectal Dis 2019; 34 (2): 319-28. DOI: 10.1007/s00384-018-3199-z). Risk factors for the development of colorectal anastomotic leakage are determined: gender of the patient; distance from tumor to anus; tumor size; duration of the operation; presence or absence of diabetes mellitus; type of operation - laparoscopic or open; the presence or absence of bleeding from the anastomosis. Each factor is assigned a certain number of points. With a score above 120, the risk of developing colorectal anastomotic failure was predicted; therefore, the operation was completed with the formation of a preventive intestinal stoma.

The disadvantages of the method are: 1. insufficient efficiency of the model, since the sensitivity of the method was 93%, which in some cases the formation of preventive intestinal stomas was unfounded.

2. The method is labor-intensive, since it is necessary to take into account a large number of risk factors.

There is a known method for selecting tactics for surgical treatment of rectal tumors, including resection of the rectum with the tumor and the imposition of a colorectal anastomosis, in which, to select the tactics for imposing anastomosis, the length of the distal part of the rectum is measured from the external opening of the anal canal to the level of the anastomosis (L1), characterized in that , that in addition, before surgical intervention, determine the zone of maximum pressure in the anal canal at rest and measure the length of the rectum from the external opening of the anal canal to the zone of maximum pressure in the anal canal (L2), then calculate the difference L1-L2 and if its value is more than 2 cm, an anastomosis is applied as an “end-to-end” or “side-to-end” type, and if the L1-L2 value is 2 cm or less, an anastomosis is applied only as a “side-to-end” type (RF patent No. 2319456, published . 2008.03.20)

This method does not make it possible for each individual patient, taking into account his anatomical and functional characteristics, to clarify the indications for applying one or another type of colorectal anastomosis and thereby reduce the number of colorectal anastomosis failures.

The closest technical solution taken as a prototype is the “Method for choosing tactics for surgical treatment of rectal tumors”, described in the work of Penna M., et al. (Penna M., Hompes R., Arnold S. et al. Incidence and risk factors for anastomotic failure in 1594 patients treated by transanal total mesorectal excision: results from the International TaTME Registry. Ann Surg 2019;269(4):700- 11. DOI: 10.1097/ SLA.0000000000002653). Risk factors for the development of early NCA are determined: patient gender, body mass index, smoking, presence or absence of diabetes mellitus, tumor size. Each factor is assigned a certain number of points. After this, the risk of developing early failure of the colorectal anastomosis is determined by summing the scores. With a score ranging from 0 to 6, the risk of developing UCA is predicted to be from 6.3% to 50.0%, and the operation is completed with the formation of a colorectal anastomosis and the imposition of a preventive stoma.

The disadvantage of this method, according to the authors themselves, is that a statistical assessment of the quality of the model for predicting the development of NCA has not been performed, and therefore there are no clear recommendations on the choice of tactics for surgical treatment of rectal tumors.

The objective of the invention is to develop a highly effective method for choosing tactics for surgical treatment of rectal tumors, allowing to reduce the number of colorectal anastomotic leaks.

The problem is solved by determining the level of preoperative hemoglobin, tumor volume, the presence or absence of diabetes mellitus, the presence or absence of excess body mass index (BMI) before surgery; after which the risk of predicting failure of the colorectal anastomosis is calculated using the formula:

p - risk of predicting failure of colorectal anastomosis,

e - Euler number (constant) equal to 2.71828;

z=0.639-0.078*X ₁ +0.157*X ₂ +2.844*X ₃ +1.525*X ₄ , where

X1 - indicator of the level of preoperative hemoglobin, in g/l;

X2 is an indicator of tumor volume, cm ³ ;

X3 - indicator of the presence or absence of diabetes mellitus (yes =1, no =0);

X4 - indicator of the presence or absence of excess body mass index (yes = 1, no = 0);

the indicated indicators in absolute values are substituted into the formula for calculating p and, if the condition is met when the risk of predicting failure of the colorectal anastomosis (CFA) p is less than 0.14 - surgical treatment of the rectal tumor is completed with the formation of a colorectal anastomosis using a circular stapler; if p is greater than or equal to 0.14, surgical treatment of a rectal tumor is completed with the formation of a colorectal anastomosis using a circular stapler, followed by the imposition of a preventive intestinal stoma.

The technical result of the proposed method, which manifests itself during its implementation, is to increase the accuracy and reliability of choosing the most effective tactics for surgical treatment of rectal tumors, which makes it possible to reduce postoperative complications of patients who are at high risk of developing colorectal anastomotic failure and, thereby, increase the effectiveness of treatment.

Thus, the technical result is achieved if p is less than 0.14 - surgical treatment of a rectal tumor is completed by forming a colorectal anastomosis using a circular stapler; if p is greater than or equal to 0.14, surgical treatment of a rectal tumor is completed with the formation of a colorectal anastomosis using a circular stapler, followed by the imposition of a preventive intestinal stoma.

Our studies have shown that, based on the values of regression coefficients, the factors “tumor volume”, “presence of diabetes mellitus” and “exceeding BMI” have a direct relationship with the likelihood of developing colorectal anastomotic leakage. The factor “hemoglobin before surgery” has an inverse relationship with the likelihood of developing colorectal anastomotic failure. A decrease in “hemoglobin on admission” by 1 g/l will lead to an increase in the chance of developing colorectal anastomotic leakage by 1.1 times.

An increase in the “tumor volume” indicator by 1 cm ³ will increase the chance of developing colorectal anastomotic leakage by 1.17 times.

The presence of the “diabetes mellitus” factor will increase the chance of developing colorectal anastomotic failure by 17.1 times.

The presence of the indicator “exceeding BMI” will lead to an increase in the chance of developing colorectal anastomotic leakage by 4.6 times.

The resulting regression model is statistically significant (p<0.0001). The sensitivity of the model was 98.4%. Corresponds to the percentage of correct predictions about the presence of an outcome (presence of colorectal anastomotic leakage).

The specificity of the model was 93.6%. Corresponds to the percentage of correct predictions about the absence of an outcome (no colorectal anastomotic leak).

The diagnostic efficiency of the model was 97.2%. Corresponds to the percentage of correct predictions for both the presence and absence of an outcome (NCA).

Based on the value of the Nigelkirk coefficient of determination R2, the model took into account 92% of the factors influencing the probability of NCA.

The threshold value of the logistic function p was 0.14 (14%). P values <0.14 (14%) predicted a low risk of colorectal anastomotic leakage. With p values ≥0.14 (14%) there is a high risk of developing colorectal anastomotic failure. This made it possible to reasonably choose adequate surgical tactics for treating rectal tumors.

If there is no risk of colorectal anastomotic failure, surgical treatment of a rectal tumor is completed with the formation of a colorectal anastomosis using a circular stapler.

If the risk of colorectal anastomotic failure is predicted, surgical treatment of the rectal tumor is completed with the formation of a colorectal anastomosis using a circular stapler, followed by the imposition of a preventive intestinal stoma.

A comparative analysis of the proposed solution with the above methods revealed a difference in the method of choosing tactics for surgical treatment of rectal tumors by assessing the likelihood of the risk of developing colorectal anastomosis.

Previously, the use of these factors had not been described, and a mathematical model based on these factors had not been developed to assess the likelihood of the risk of colorectal anastomosis failure. Based on this, we can conclude that the proposed method meets the “inventive step” criterion.

The authors did not identify cases of a combination of these factors and the presence of similar mathematical models for assessing the likelihood of the risk of colorectal anastomosis failure. Thus, the proposed technical solution meets the invention criterion of “novelty”.

This method can be used by surgeons, oncologists, and proctologists to select tactics for surgical treatment of rectal tumors by assessing the likelihood of the risk of developing colorectal anastomotic failure, which meets the “industrial applicability” criterion.

Detailed description of the method and examples of its clinical implementation.

Upon admission to the department, before surgical treatment of a rectal tumor, the patient is examined. Based on the examination results, statistically significant factors are determined before surgery that influence the choice of tactics for surgical treatment of rectal tumors, namely: preoperative hemoglobin level (g/l), tumor volume (cm ³ ), presence (1) or absence (0) patient with diabetes mellitus, presence (1) or absence (0) of excess body mass index. The obtained indicators are assigned the following designation: indicator of preoperative hemoglobin level (X1), indicator of tumor volume (X2), indicator of the presence or absence of diabetes mellitus (X3), indicator of the presence or absence of excess body mass index (X4).

The blood hemoglobin level before surgery is determined according to the method described in the work “Clinical laboratory diagnostics. Textbook, M., FGBOU DPO RMANPO - 2016. - P. 476.”

The volume of the tumor is determined by measuring its size according to the results of magnetic resonance imaging of the pelvis performed before surgery.

The presence or absence of diabetes mellitus is determined before surgery by interviewing the patient and examining blood glucose levels according to the method described in the work “Clinical laboratory diagnostics. Textbook, M., FGBOU DPO RMANPO - 2016. - P. 541-545.” If the patient does not have diabetes mellitus, the CV value is assigned a numerical value (0); in the presence of diabetes mellitus, a numerical value (1) is assigned.

The patient’s BMI is determined by measuring his height using a stadiometer and his weight on a scale with an accuracy of 0.01 kg. BMI is calculated using the formula: weight (kg) / height ² (m ² ), described in the work “Anthropometric Reference Data for Children and Adults: United States. CDC DHHS (2012).” If the patient’s body mass index is not exceeded, the X4 value is assigned a numerical value (0); if BMI is exceeded, a numerical value (1) is assigned.

The indicated indicators in absolute values are substituted into the formula and the risk of predicting (p) failure of the colorectal anastomosis is calculated using the formula:

p - risk of predicting failure of colorectal anastomosis,

e - Euler number (constant) equal to 2.71828;

z=0.639-0.078*X ₁ +0.157*X ₂ +2.844*X ₃ +1.525*X ₄ , where

X1 - indicator of the level of preoperative hemoglobin, in g/l;

X2 is an indicator of tumor volume, cm ³ ;

X3 - indicator of the presence or absence of diabetes mellitus (yes =1, no =0);

X4 - indicator of the presence or absence of excess body mass index (yes = 1, no = 0);

the indicated indicators in absolute values are substituted into the formula for calculating p and, if the condition is met that the risk of predicting failure of the colorectal anastomosis p is less than 0.14 surgical treatment of the rectal tumor is completed with the formation of a colorectal anastomosis by inserting a circular stapler “EEA circular stapler” through the anus for application colorectal anastomosis with a diameter of 31 mm (made in the USA); if p is greater than or equal to 0.14, surgical treatment of a rectal tumor is completed with the formation of a colorectal anastomosis by inserting a circular stapler such as an “EEA circular stapler” through the anus to apply a colorectal anastomosis with a diameter of 31 mm (made in the USA), followed by the imposition of a preventive intestinal stoma (ileostomy) ).

The EEA circular stapler using Tri-Staple technology applies a circular suture from 3 rows of staggered titanium staples and cuts off excess tissue, forming a circular anastomosis. One-time mechanism for stitching and cutting fabrics. The diameter of the staple seam is determined by the size of the selected tool: 33 mm, 31 mm, 28 mm.

The performance of the proposed method is confirmed by the following clinical examples:

Example 1.

Patient N-ev, 77 years old, was admitted to the department with a diagnosis of malignant neoplasm of the rectum T3N0M0 stage II, clinical group 2, when collecting anamnesis and the results of clinical studies at the preoperative stage, he had: hemoglobin level upon admission X1 = 99 g/l, volume tumor X2=16 cm ³ . Presence of diabetes mellitus X3=1, no BMI exceeded: according to the established data for 77 years old, the norm is BMI 24-29, the patient has a BMI=24, which corresponds to the age norm X4=0.

To assess the risk of predicting failure of the colorectal anastomosis, in order to select tactics for surgical treatment of rectal tumors, we substituted the obtained values into the mathematical model we developed, obtained p = 0.15, this value is higher than the critical p = 0.14, and therefore, according to the claimed method, this patient may develop NCA. In this regard, the tactics of surgical treatment of a rectal tumor with the formation of a colorectal anastomosis was chosen by inserting a circular stapler “EEA circular stapler” through the anus to apply a colorectal anastomosis with a diameter of 31 mm, followed by the application of a preventive intestinal stoma (ileostomy). The postoperative period passed without complications. This made it possible to reduce the patient’s stay in the hospital and increase the efficiency of treatment.

Example 2.

Patient B-va, 63 years old, was admitted to the department with a diagnosis of stage II malignant neoplasm of the rectum T4N0M0, clinical group 2, when collecting anamnesis and the results of clinical studies, revealed that she had: hemoglobin level on admission X1=112 g/l, tumor volume X2= 12 cm ³ . Presence of diabetes mellitus X3=1, excess BMI: the patient had BMI=30.2, which was higher than the age norm, which means X4=1.

To assess the risk of predicting failure of the colorectal anastomosis and in order to select tactics for surgical treatment of rectal tumors, we substituted the obtained values into the mathematical model we developed, obtained p = 0.14, this value is equal to the critical p = 0.14, which means that according to the claimed method, this The patient may have failed colorectal anastomosis, and we classified her as a risk group. In this regard, the tactics of surgical treatment of the rectal tumor were chosen by inserting a circular stapler “EEA circular stapler” through the anus to create a colorectal anastomosis with a diameter of 31 mm, followed by the application of a preventive intestinal stoma (ileostomy). The postoperative period passed without complications. This made it possible to reduce the patient’s stay in the hospital and increase the efficiency of treatment.

Example 3.

Patient O-ev, 67 years old, was admitted to the department with a diagnosis of malignant neoplasm of the rectum T2N0M0 stage II, clinical group 2. When collecting anamnesis and the results of clinical studies, he was found to have: hemoglobin level on admission X1=97 g/l, tumor volume X2 =4 cm ³ . Presence of diabetes mellitus X3=1, excess BMI X4=1: the patient has a BMI=33.2, which is higher than the norm for the age of 65 years.

To assess the risk of predicting failure of the colorectal anastomosis, in order to select tactics for surgical treatment of rectal tumors, we substituted the obtained values into the mathematical model we developed, obtained p = 0.13, this value is less than the critical one (p = 0.14), which means that according to the claimed method, this patient will not experience colorectal anastomotic leakage, that is, the patient was classified as a group with a low risk of developing ICA. The chosen tactics for surgical treatment of a rectal tumor in this patient included completing the formation of a colorectal anastomosis by inserting a circular stapler “EEA circular stapler” through the anus to apply a colorectal anastomosis with a diameter of 31 mm. After surgery, the patient did not experience any development of colorectal anastomotic leakage. The postoperative period passed without complications. This made it possible to reduce the patient’s stay in the hospital and increase the efficiency of treatment.

The proposed method was used in the department of abdominal oncology of the Rostov State Medical University clinic in 50 patients to select tactics for surgical treatment of rectal tumors. 50 patients were examined according to the claimed method, the above statistically significant indicators were determined, and the coefficient for choosing tactics for surgical treatment of rectal tumors was calculated using the original formula. Depending on the coefficient (p), the tactics of surgical treatment of rectal tumor were determined. In 47 cases there was a low probability of developing NCA; surgical treatment of the rectal tumor was completed with the formation of a colorectal anastomosis using a circular stapler. It was subsequently confirmed that none of the 47 people developed NCA. In 3 cases, a high risk of developing ICA was predicted; surgical treatment of the rectal tumor was completed with the formation of a colorectal anastomosis using a circular stapler, followed by the imposition of a preventive intestinal stoma. No NCA was recorded in the postoperative period.

Thus, compared with the prototype, the proposed method makes it possible to increase the reliability of the choice of tactics for surgical treatment of rectal tumors.

The method was tested on 215 patients who were treated at the clinic of the Federal State Budgetary Educational Institution of Higher Education Rostov State Medical University of the Ministry of Health of Russia, Department of Abdominal Oncology (patients with rectal cancer). The number of patients with the risk of colorectal anastomosis failure was 24 people (11.2%), who were allocated to observation group 1, and 191 people (88.8%) were included in the 2nd group of people without the risk of colorectal anastomosis failure.

After the surgical treatment, stage II of data analysis was carried out in order to determine statistically significant factors influencing the development of colorectal anastomotic failure. At the next stage, a mathematical model was developed to assess the probability of colorectal anastomosis failure using binary logistic regression.

Databases were generated using Microsoft Office Excel 16 (2015, Microsoft, USA). Statistical processing of the obtained data was carried out using Microsoft Office Excel 16 (2015, Microsoft, USA) and Statistica 16.0 (StatSoft, USA), SPSS Statistic 26.0 (IBM, USA).

Advantages of the proposed method

The proposed method for choosing tactics for surgical treatment of rectal tumors allows you to choose a pathogenetically based treatment tactic that prevents the development of complications by assessing the likelihood of colorectal anastomosis failure in each specific patient with this pathology.

The advantage of the proposed method is that it allows you to assess in advance the likelihood of the risk of colorectal anastomotic leakage, at the preoperative stage, select adequate surgical tactics and reduce postoperative complications in patients who are at high risk of developing colorectal anastomotic leakage and, thereby, increase the effectiveness of treatment .

The method has been tested on large clinical material and can be recommended for widespread use by oncologists, surgeons, and proctologists in clinical practice.

Claims (10)

A method for choosing tactics for surgical treatment of a rectal tumor, including examining the patient, determining body mass index (BMI), the presence of diabetes mellitus, characterized in that before surgery the hemoglobin level and tumor volume are determined, after which the risk of developing colorectal anastomotic failure is calculated using the formula p - risk of developing colorectal anastomosis failure, e - Euler number - a constant equal to 2.71828; z=0.639-0.078*X1+0.157*X2+2.844*X3+1.525*X4, where X1 is the hemoglobin level before surgery, in g/l; X2 - tumor volume, cm ³ ; X3 - presence of diabetes mellitus = 1, no = 0; X4 - excess body mass index yes = 1, no = 0; when p is less than 0.14, surgical treatment of a rectal tumor is completed with the formation of a colorectal anastomosis using a circular stapler; when p is greater than or equal to 0.14, surgical treatment of a rectal tumor is completed with the formation of a colorectal anastomosis using a circular stapler, followed by the imposition of a preventive intestinal stoma.