探讨改良抵钉座置入法在腹腔镜低位直肠癌经肛门外翻切除标本的腹部无辅助切口手术（NOSES Ⅰ式B法）中的应用价值。

连续纳入2021年1月至2023年9月郑州大学第一附属医院结直肠肛门外科接受两种抵钉座置入方式NOSES Ⅰ式B法手术的低位直肠癌病例60例，剔除资料不全者4例后纳入56例，按照采用抵钉座置入方式分为观察组（改良抵钉座体外置入法，29例）和对照组（传统抵钉座体内置入法，27例）。观察组参照本团队前期改良抵钉座置入法：完成全直肠系膜切除及近端乙状结肠充分游离后，经肛门外翻直肠断端并在直视下完成远端切断；将近端乙状结肠经肛门拉出体外，在直视下置入抵钉座并行荷包缝合固定，再将其送回腹腔完成圆形吻合器吻合。对照组采用体内切开近端乙状结肠残端置入抵钉座的方法。比较两组抵钉座置入耗时、围手术期相关指标、30 d并发症发生率、病理学相关指标及肿瘤学随访结果。

观察组术后总并发症发生率为3.4%（1/29），低于对照组的22.2%（6/27），差异有统计学意义（P=0.048）。观察组抵钉座置入耗时为4.7（2.0，6.0）min，短于对照组的8.0（5.0，10.0）min（Z=4.89，P＜0.01），差异有统计学意义；两组手术时间（157.0 vs. 173.0 min）和术中出血量（50.0 vs. 50.0 mL）差异均无统计学意义。两组首次排气、排便、进食及下床活动时间差异均无统计学意义。两组淋巴结清扫数、切缘及标本完整性差异均无统计学意义；中位随访时间为42.2个月，两组3年总生存率分别为93.1%和88.9%，3年无病生存率分别为96.6%和92.6%，差异均无统计学意义。

改良抵钉座体外置入法在经选择的低位直肠癌NOSES Ⅰ式B法患者中显示出一定的操作便捷性；本研究观察到其抵钉座置入及固定耗时较短、术后30 d总并发症发生率较低，但其安全性及潜在获益仍需前瞻性、多中心、大样本研究进一步验证。

To evaluate the clinical utility of a modified anvil placement technique in laparoscopic resection of low rectal cancer with transanal eversion and specimen extraction without an auxiliary abdominal incision (NOSES type Ⅰ, technique B).

Consecutive patients with low rectal cancer who underwent NOSES type I, procedure B, using either of two anvil placement techniques at the Department of Colorectal and Anal Surgery, the First Affiliated Hospital of Zhengzhou University, between January 2021 and September 2023 were retrospectively identified. Of the 60 patients screened, 4 were excluded because of incomplete data, leaving 56 patients for analysis. Patients were categorized according to the anvil placement technique used into an observation group (modified extracorporeal anvil placement, n=29) and a control group (conventional intracorporeal anvil placement, n=27). In the modified group, the technique previously developed by our team was performed as follows: after total mesorectal excision and adequate mobilization of the proximal sigmoid colon, the rectal stump was everted through the anus, and distal transection was performed under direct vision. The proximal sigmoid colon was then exteriorized transanally, allowing anvil insertion and fixation with a purse-string suture under direct vision. The colon was subsequently returned to the abdominal cavity, and a circular stapled anastomosis was completed. In the conventional group, the anvil was inserted intracorporeally through an incision in the proximal sigmoid stump. Anvil placement time, perioperative outcomes, 30-day complications, pathological outcomes, and oncological follow-up outcomes were compared between groups.

The overall postoperative complication rate was significantly lower in the modified group than in the conventional group [3.4% (1/29) vs. 22.2% (6/27); P=0.048]. Anvil placement time was also significantly shorter in the modified group [4.7 (2.0, 6.0) vs. 8.0 (5.0, 10.0) min; Z=4.89, P＜0.01]. Operative time (157.0 vs. 173.0 min) and intraoperative blood loss (50.0 vs. 50.0 mL) did not differ significantly between groups. No significant differences were observed in time to first flatus, first bowel movement, resumption of oral intake, or ambulation. Lymph node yield, resection margins, and specimen integrity were comparable between groups. At a median follow-up of 42.2 months, the 3-year overall survival rates were 93.1% and 88.9%, and the 3-year disease-free survival rates were 96.6% and 92.6% in the modified and conventional groups, respectively; neither difference was statistically significant.

In selected patients with low rectal cancer undergoing NOSES type Ⅰ technique B, modified extracorporeal anvil placement showed technical convenience and was associated with a shorter anvil placement/fixation time and a lower 30-day postoperative complication rate in this study. Its safety and potential benefits require confirmation in prospective, multicenter studies with larger samples.