RU2290070C2 - Method for presurgical detection of distal boundary of resection at rectal cancer - Google Patents

Abstract

FIELD: medicine, oncology.

SUBSTANCE: detection should be carried out at applying an optic coherent tomograph equipped with an optic microprobe, and a rectoscope. The optic microprobe should be introduced into rectoscope's canal, press the optic microprobe at right angle towards rectal wall in area of visual tumor boundary to obtain here the first image of rectal wall. Then it is necessary to shift the optic microprobe distally and at spaces of 2 mm one should have pictures of rectal wall. As for distal boundary of rectal resection, it should be determined according to abrupt alteration of regular stratified tissue structure for homogeneous structure-free mass. With the help of electrocoagulator one should put a label at mucosa in area of true tumor boundary. During surgical interference one should conduct distal line of rectal resection due to applying a reference point by the label.

EFFECT: higher accuracy of detection.

1 cl, 1 ex

Description

The present invention relates to medicine, namely to surgery, and can be used for preoperative diagnosis of intramural prevalence of colorectal cancer and a clear definition of the distal border of the rectum resection.

Despite the success in the diagnosis and treatment of colorectal cancer, the problem of local relapses remains relevant. According to different authors, they are found in 21% -36.7% of cases. To reduce them, accurate preoperative diagnosis of the intramural prevalence of the pathological process is especially important, especially since the possibility of performing a sphincter-preserving operation depends on it.

Currently, the most common methods for assessing the true border of a tumor are visual assessment, intracavitary ultrasound, and morphological examination. The visual border of the tumor often does not coincide with the true one due to tumor invasion along the intestinal wall (V.D. Fedorov, Clinical and operative coloproctology. M .: SSC Proctology, 1994. - 432 p.). Intracavitary ultrasound of the rectum allows a high degree of certainty to establish the depth of tumor infiltration of the intestinal wall and surrounding tissues, that is, to determine the lateral border of the tumor, but is not used to determine the distal border (G.I. Vorobyov. Diagnosis and treatment of colon cancer / breast cancer. - 1998. - T. 6, No. 19. - S.1244-1257).

The distal edge of the resection is usually selected by indenting 3-4 cm from the visible edge of the tumor (V.D. Fedorov. Clinical and operative coloproctology. M .: SSC Proctology, 1994. - 432 p.). Of great importance in assessing the distal edge of the resection is the morphological study of the intestinal resection line. But performing multiple preoperative biopsies with the capture of the submucosal layer of the rectum is traumatic, as it violates the integrity of the intestinal wall in the area of the supposed inter-intestinal anastomosis, therefore it is performed only after the operation in the form of “morphological confirmation of the purity of the resection” (G.I. Vorobyov. The distal edge of the resection in surgery colorectal cancer / Annals of surgery. - 2001. - No. 4. - P.22-26).

In fact, at present, in surgical practice, only one method is used to determine the distal border of the rectum resection in colorectal cancer. This method consists in the fact that the border of the resection is determined by indenting 3-4 cm distal to the visible borders of the neoplasm (V.D. Fedorov. Clinical and operative coloproctology. M .: SSC Proctology, 1994. - 432 p.). It is applicable for any type of surgical intervention, but it is more often used when performing an anterior (abdominal) resection of the rectum, since it is with this type of operation that the deficit of the length of the rectum is most significant. To do this, the rectum is mobilized 3-4 cm distal to the visible edge of the tumor and a L-shaped clamp is placed on it, below which the intestine is resected. A circular hardware or manual sigmorectal anastomosis is performed.

The disadvantages of the method:

1. The distal border of the resection is determined by indenting 3-4 cm from the visible edge of the tumor. Since the visible border of the tumor does not correspond to its true border, the real indentation is often smaller.

2. Determination of the distal border of the resection is carried out in the process of mobilization of the intestine, when it is in an extended state, which does not allow to accurately measure the distance from the edge of the tumor to the edge of the resection. On the drug, this distance is often different.

3. Visual assessment is carried out from the muscular membrane of the mobilized intestine, while small tumors growing within the mucous membrane and submucosal layer are not accessible to palpation and visual control. The resection line must be chosen intuitively.

4. An indent of 3-4 cm is proposed for all types of tumors without taking into account the degree of differentiation and the nature of growth. This approach does not allow taking into account the individual characteristics of each particular case and can entail both excessive radicalism and unjustified refusal to perform sphincter-preserving surgery, on the one hand, and underestimation of latent intramural tumor invasion and leaving cancer cells along the resection border, on the other.

The objective of the invention is:

- optimization of the selection and labeling of the distal border of the rectum resection in cancer using an effective method of preoperative diagnosis of intramural spread of rectal cancer;

- improving the accuracy of determining the border of the tumor due to the objectification of this definition;

- increasing the accuracy of the determination by providing the ability to conduct this determination on the unstretched intestine, before surgery;

- providing the ability to determine the border of the tumor in case of inaccessibility of palpation and visual control;

- creating conditions for increasing the number of sphincter-preserving operations.

The implementation in the proposed method of all these advantages is a new technical result.

The task is achieved in that the determination is carried out using an optical coherent tomograph equipped with an optical microprobe and a rectoscope, while the optical microprobe is inserted into the biopsy channel of the rectoscope, the optical microprobe is pressed at a right angle to the wall of the rectum in the area of the visual border of the tumor and the first image of the intestinal wall, then step by step shift the optical microprobe distally and with an interval of 2 mm take an image of the intestinal wall, all images are saved on a computer analyze the true border of the tumor, which determines the distal border of the rectum resection, determine by a sharp change in the regular layered tissue structure to a homogeneous, structureless mass, then with the help of an electrocoagulator put a mark on the mucous membrane in the region of the true border of the tumor, in the place where the unchanged rectal wall structure is observed , followed by during the surgical intervention of the distal line of intestinal resection using a landmark on the label;

the fact that they use an optical coherent tomograph with probing radiation of near-infrared light with a wavelength of 1270 nm or 830 nm, a radiation power of 1.5 mW, having a resolution of 10-20 microns.

The proposed method is as follows. On the eve of the operation, rectoscopy is performed. Measure the distance from the visible edge of the tumor to the anus. The distal border of the resection is determined using an optical coherence tomograph - a high-resolution (10-15 μm) device for obtaining images of the internal microstructure of tissues in cross section, using near-infrared light as probe radiation. All optical and electronic parts of the OCT device are located inside the housing. An exception is an optical probe, consisting of a fiber optic and electric cable in a flexible tube, as well as a scanner with a lens system at its distal end. The OCT devices used in our work use low-coherent radiation with a wavelength of 1270 nm or 830 nm (depending on the required depth of investigation) and a radiation power of 1.5 mW on the sample, have a resolution of 10-20 μm. The penetration depth of the probe radiation is 1-2 mm, the image acquisition time is 1.5 seconds. The device is combined with a computer, on the screen of which the image is displayed. The OCT device used in our research was equipped with a microprobe with an external diameter of 2 mm and compatible with the working channels of standard endoscopes. The quartz window at the distal end of the probe is sealed, making it accessible for sterilization. A microprobe is inserted into the rectoscopy biopsy channel, which is pressed at a right angle to the wall of the rectum in the area of the visual border of the tumor, where the first image of the intestinal wall is taken. Then the microprobe is displaced stepwise distally and images of the intestinal wall are taken at intervals of 2 mm. All images are stored on a computer and analyzed. The rectal wall unchanged by the pathological process is presented on the tomograms as a regular layered structure. The area of the intestine affected by the tumor looks like a homogeneous, structureless mass. The true border of the tumor, spreading along the submucosal layer of the rectum and often differing from the visual border by 0.5-1 cm, is visible as a sharp loss of tissue structure. This allows you to use it to assess the prevalence of adenocarcinoma along the rectum, which makes it possible to preoperatively plan the level of resection. In the place where the device clearly shows the unchanged structure of the rectal wall, with the help of an electrocoagulator, they mark the mucous membrane. A radical operation is performed as follows: mobilize the intestine 3-4 cm distal to the tumor, dissect the front wall of the rectum, find a mark on the mucous membrane and draw a distal line of intestinal resection, guided by the label.

An example of a specific implementation of the method.

Patient Z., 72 years old, medical history No. 01598, was treated with a diagnosis of Colorectal cancer T2N0M0 with 10 cm from the anus. The diagnosis was established based on the results of previous rectoscopy with a biopsy, histologically - moderately differentiated adenocarcinoma. On the eve of the operation, the patient underwent rectoscopy with optical coherence tomography of the distal border of the tumor. It was revealed that the tomographic border of the tumor is located 1 cm distal to the visual border in the submucosal layer of the rectum. Marked tomographic border using an electrocoagulator. The next day the patient underwent anterior resection of the rectum, the distal line of resection is made taking into account the marked border. A morphological study of the surgical material confirmed the spread of the tumor along the submucosal layer 1 cm distal to the visual border, and the absence of cancer cells along the rectum resection line was histologically observed. The patient was examined after 2 years, tumor recurrence was not detected.

Using preoperative OCT, 22 rectum resections were performed, the distance of the resection line from the tumor ranged from 2 to 4 cm. A morphological study of the edges of the resection never revealed adenocarcinoma cells, and two-year follow-up revealed only one extraintestinal local relapse, no intraintestinal relapses .

The advantages of this method

1. The distal border of the resection is determined by focusing not on the visual, but on the tomographic border of the tumor, corresponding to the true border.

2. Determination of the distal border of the resection is carried out before surgery on the unstretched colon, which increases the accuracy of the study.

3. A visual assessment is carried out from the mucous membrane of the rectum, even small tumors growing within the mucous membrane and submucosal layer, not accessible by palpation and visual control from the outside, are clearly visible. The optimal line of resection is selected.

4. The line of resection is selected taking into account the individual characteristics of each particular case. This allows you to increase the number of sphincter-preserving operations without compromising radicalism.

Claims (2)

1. The method of preoperative determination of the distal border of rectum resection in colorectal cancer, characterized in that the determination is carried out using an optical coherent tomograph equipped with an optical microprobe and a rectoscope, while the optical microprobe is introduced into the rectoscope channel, the optical microprobe is pressed at right angles to the rectal wall in the area of the visual border of the tumor and the first image of the intestinal wall is taken here, then the optical microprobe is displaced step by step and at intervals of 2 mm an image of the intestinal wall is taken, all images are saved on a computer and analyzed, the true border of the tumor, which determines the distal border, resection of the rectum, is determined by a sharp change in the regular layered tissue structure to a homogeneous structureless mass, then with the help of an electrocoagulator a mark is placed on the mucous membrane in the region of the true border tumors, in the place where the invariable structure of the rectal wall is observed, followed by the distal line of resection of the ki during surgery ki using on the label guide. 2. The method according to claim 1, characterized in that they use an optical coherent tomograph with probing light of the near infrared range with a wavelength of 1270 or 830 nm, a radiation power of 1.5 mW, having a resolution of 10-20 μm.