Ординатура / Хирургия / @xirurgi_2025 / @xirurgi_2025 - 855 - файл

GIST are rare tumors arising from Cajal cells. Rectal GIST account for 5% of all GIST [2]. The incidence of GIST is higher in the fth to sixth decade of life. Symptoms may be nonspecic as with TGC, with pelvic or anal pain, gastrointesti­nal bleeding, anemia or weight loss, or be absent. Contrast-enhanced computed tomography (CT) is the imaging modality of choice for the diagnosis of GIST. Fluorodeoxyglucose-positron emission tomography (FDG-PET) has good specicity and sensitivity for assessing tumor response after imatinib mesylate treatment. Approximately only 30% of GIST are malignant. Rectal GIST are classi­ed by the National Institutes of Health (NIH) as “very low”, “low”, “intermediate”, or “high” risk tumors, depending on location, mitotic index and size [3]. Diagnosis of a rectal GIST has been associated with a poor overall prognosis. One reason for the poor prognosis of rectal GIST is that the rate of tumor rupture is more than four times that of non-rectal GIST, and perforation is associated with a high-risk progno­sis [4]. Radical resection with en-bloc excision of the mass is the standard rst-line treatment for all localized GIST.Local excision, low anterior resection, abdomino­perineal excision of the rectum (APER), and pelvic exenteration might be needed. The primary goal of surgery is to obtain negative microscopic margins without causing bleeding or rupture of the pseudocapsule [5]. Transanal resection is one of the most minimally invasive methods but is limited by the distance from the dentate line [6]. Transcoccygeal excision is adequate for lower rectal GIST but has high postoperative morbidity, with stulae occurring in 21% of patients [7]. For small rectal GIST, local resection may be safe [8]. Treatment of advanced rectal GIST requires a multimodal therapy with imatinib mesylate and is indicated for rst-line treatment of metastatic or unresectable GIST.

The patient is placed in a Trendelenburg position and tilted on the right side. The small intestine and the greater omentum are manually displaced toward the upper abdomen. Adhesiolysis is performed if needed.

With the tip-up forceps in R1, the sigmoid colon is retracted cranially and laterally to expose the sacral promontory (Fig.23.2a). Further countertraction can be provided with a laparoscopic grasper from the assistant port. Dissection begins anterior to the sacral promontory and continues to the right border of the mesorectum or pararectal groove (Fig.23.2b). Care must be taken to clearly identify and protect the left common iliac vein, median sacral vessels, right hypogastric nerve, and both ureters. The tip-up grasper is repositioned continuously to allow for adequate traction (Fig. 23.2c–d). Careful dissection is performed in the mesorectal plane, allowing right-sided mobiliza­tion of the rectum down to the pelvic oor and adequate exposure of the perineal body.