[Feasibility of a three-sided encapsulation procedure based on fascia anatomy in laparoscopic lateral lymph node dissection for middle and low rectal cancer].

Objective: To explore the feasibility and value of performing a three-sided encapsulation procedure based on fascia anatomy in laparoscopic lateral lymph node dissection (LLND) for middle and low rectal cancer. Methods: This was a retrospective review. The study cohort comprised patients who met the diagnostic criteria for rectal cancer according to the Chinese Guidelines for the Diagnosis and Treatment of Colorectal Cancer, had a short lymph node diameter of >5 mm on the lateral side within the 15 days before surgery, were evaluated as feasible candidates for laparoscopic total mesorectal excision+LLND surgery, had been diagnosed with low or intermediate level rectal cancer, and whose tumor was less than 8 cm away from the anal verge according to pathological examination of the operative specimen. Patients with a history of other malignant tumors of the abdomen or with incomplete follow-up data were excluded. Forty-two patients with middle and low rectal cancer who had undergone lateral lymph node dissection in diagnosis and treatment center of Gastrointestinal Cancer of Guangdong Hospital of Chinese Medicine from Jan.2018 to Dec.2022 were enrolled. There were 24 men (57.1%) and 18 women (42.9%) aged 58.4±11.8 years and the median BMI was 22.5 (19.3-24.1) kg/m2. The main point of the three-sided encapsulation procedure is to expand the external side medial to the external iliac artery and vein, narrowing the range of exterior side dissection. The anterior-medial side is designed to expand the vesical fascia to define the range of anterior-medial side extension. The internal side is fully extended to the ureterohypogastric nerve fascia; the distal point of the caudal extension reaches the level of the Alcock canal and the bottom reaches the piriformis, enabling dissection of the obturator nerve and No.283 lymph nodes. No.263D lymph nodes are dissected by exposing the internal iliac artery and its branches, dissecting the group No.263P lymph nodes, and severing the inferior vesical artery. Finally, the lateral lymphatic tissue is completely resected. Relevant variables were recorded, including the number of lateral lymph nodes detected, the rate of lymph node metastasis, operation duration, intraoperative blood loss, postoperative complications, postoperative hospital stay, and 3-year overall survival rate. Results: Laparoscopic surgery was successfully completed in all patients with no conversions to open surgery and no intraoperative complications. Twenty-seven (64.3%) of the study patients underwent left-sided LLND, 10 (23.8%) right-sided LLND, and five (11.9%) bilateral LLND, with lymph nodes cleared on both sides. All patients' lymph nodes were examined pathologically. A median of 17.0 (11.7, 26.0) lymph nodes was detected, the median of lateral lymph nodes being 5.0 (2.0, 10.2). The median operation time was 254.5 (199.0, 325.2) minutes. The median intra-operative blood loss was 50.0 (30.0, 100.0) mL. All patients were diagnosed with adenocarcinoma by pathological examination of the operative specimen. Two patients developed postoperative intestinal obstruction, one lymphatic leakage, and one a perineal incision infection. There were no cases of anastomotic leakage. The median postoperative hospital stay was 6.0 (5.0, 7.0) days and the median follow-up time 23.5 (9.0, 36.7) months. During follow-up, three patients (7.1%) died of tumor recurrence and metastasis. Two (4.8%) experienced mild urinary dysfunction, and one (2.4%) had moderate postoperative erectile dysfunction. One patient (2.4%) was found to have prostate and lung metastases 3 month after surgery. The 3-year overall survival rate was 74.4%. Conclusions: Three sided encapsulation is a safe and feasible procedure for LLND, achieving accurate and complete clearance of lateral lymphatic tissue.目的： 探讨基于膜解剖的“三面包抄式”的侧方淋巴结清扫（LLND）关键技术在中低位直肠癌腹腔镜LLND中的可行性和应用价值。 方法： 采用观察性研究方法。纳入符合中国结直肠癌诊疗规范中直肠癌诊断标准、术前15 d内经影像学检查提示侧方淋巴结短径>5 mm、经评估可行腹腔镜下全直肠系膜切除术+LLND手术且经术后病理明确诊断为中低位直肠癌，肿瘤距肛缘<8 cm的患者；排除既往腹部其他恶性肿瘤史或随访资料不完整者。根据上述指标，回顾性纳入2018年1月至2022年12月期间，于广东省中医院胃肠肿瘤诊治中心施行LLND的42例中低位直肠癌患者，男性24例（57.1%），女性18例（42.9%），年龄（58.4±11.8）岁，中位体质指数22.5（19.3~24.1）kg/m2。“三面包抄式”技术要点是在髂外血管内侧拓展“外侧面”，缩小外侧面清扫范围；在膀胱筋膜处拓展“前内侧面”，明确前侧拓展范围；在输尿管腹下筋膜处充分拓展“内侧面”；尾侧最远点拓展到达Alcock管水平，底部到达梨状肌水平，裸化游离闭孔神经，清扫No.283淋巴结；裸化髂内动脉清扫No.263P淋巴结，结扎膀胱下动脉并清扫No.263D淋巴结；最后整块切除侧方淋巴组织。观察侧方淋巴结送检数、淋巴结转移率、手术时长、术中出血量、术后并发症、术后住院时间及3年生存率等临床指标。 结果： 所有患者均顺利完成腹腔镜手术，术中无中转开腹，术中均未发生副损伤。其中，27例（64.3%）行左侧LLND，10例（23.8%）行右侧LLND，5例（11.9%）行双侧LLND，侧方淋巴结均清扫完整。全部患者均送检淋巴结，总淋巴结送检中位数17.0（11.7，26.0）枚，侧方淋巴结送检中位数5.0（2.0，10.2）枚，中位手术时间254.5（199.0，325.2）min，中位术中出血量50.0（30.0，100.0）ml。术后病理分型均为腺癌。术后2例（4.8%）发生肠梗阻，1例（2.4%）发生淋巴漏，1例（2.4%）会阴部切口感染，未有吻合口漏发生。中位术后住院时间6.0（5.0，7.0）d。中位随访时间23.5（9.0，36.7）个月，3例（7.1%）因肿瘤复发转移死亡，2例（4.8%）出现轻度排尿功能异常，1例（2.4%）男性术后中度勃起功能障碍，1例（2.4%）患者出现前列腺及肺部转移（术后3个月）。全组患者的3年总生存率为74.4%。 结论： “三面包抄式”技术应用于LLND可精准并全面完整清扫侧方淋巴组织，安全可行。.