建议预防性放置网片以预防造口旁疝。支持这种做法的证据是相互矛盾的。为了确定漏斗形永久性合成造口旁补片在预防造口旁疝方面是否有效且安全。烟囱试验是一项随机单盲多中心试验，从 2 月份开始在芬兰 4 家医院和瑞典 1 家医院进行2019 年和 2021 年 9 月。在 439 名接受腹腔镜或机器人辅助腹会阴切除术或 Hartmann 手术的直肠腺癌患者中，143 名患者参加了试验，135 名患者接受了分配的干预措施，121 名患者在 12 个月的随访中进行了分析。分析了 2023 年 12 月至 2024 年 5 月的数据。在干预组中，使用漏斗形腹膜内网片进行永久性结肠造口，并与没有网片的造口的对照组进行比较。主要终点是计算机断层扫描的发生率术后 12 个月 (CT) 确诊造口旁疝。有 68 名患者（平均 [SD] 年龄，68.7 [11.6] 岁；36 名 [53% 男性和 32 名 [47%] 女性）接受了网格中的预期分配组和 67 名（平均 [SD] 年龄，66.4 [11.7] 岁；48 [72%] 男性和 19 [28%] 女性）在对照组中接受了预期分配。在 12 个月的随访中，网片组的 58 名患者和对照组的 59 名患者进行了 CT 扫描。 CT 扫描证实网片组 58 名患者中有 6 名 (10%) 存在造口旁疝，而对照组 59 名患者中有 22 名 (37%) 存在造口旁疝（差异，27%；95% CI，12-41；P < .001 ）。网片组 60 名患者中有 1 名 (2%) 记录了临床造口旁疝作为次要结局，而对照组 61 名患者中 27 名 (43%) 记录了临床造口旁疝（差异，41%；95% CI，29-55；P < .001)。网状组中 Clavien-Dindo II 级肠梗阻患者人数为 23 名 (35%)，而对照组为 11 名 (17%)（差异，18%；95% CI，3-32；P = .006 ）。各组之间在其他造口相关并发症、再入院、手术时间、手术部位感染、再次手术和生活质量方面仅检测到轻微差异。在这项研究中，漏斗形造口旁网预防了大量造口旁疝，且没有使患者产生诱发因素。 12 个月的随访期间与网片或造口相关的并发症。这项研究的结果表明，漏斗形网片是预防造口旁疝的可行选择。ClinicalTrials.gov 标识符：NCT03799939。

Prophylactic placement of a mesh has been suggested to prevent parastomal hernia. Evidence to support this practice is contradictory.To determine whether funnel-shaped permanent synthetic parastomal mesh is effective and safe in parastomal hernia prevention.The Chimney Trial was a randomized single-blinded multicenter trial conducted in 4 hospitals in Finland and 1 in Sweden from February 2019 and September 2021. Of 439 patients with rectal adenocarcinoma undergoing either laparoscopic or robotic-assisted abdominoperineal resection or the Hartmann procedure, 143 were enrolled in the trial, 135 received their allocated intervention, and 121 were analyzed at 12-month follow-up. Data were analyzed from December 2023 to May 2024.In the intervention group, a permanent colostomy was created with a funnel-shaped intraperitoneal mesh and compared to a control group with a stoma without the mesh.The primary end point was the incidence of computed tomography (CT)-confirmed parastomal hernia 12 months after surgery.There were 68 patients (mean [SD] age, 68.7 [11.6] years; 36 [53% male and 32 [47%] female) who received the intended allocation in the mesh group and 67 (mean [SD] age, 66.4 [11.7] years; 48 [72%] male and 19 [28%] female) who received the intended allocation in the control group. CT scans were available for 58 patients in the mesh group and 59 patients in the control group at the 12-month follow-up. CT scans confirmed parastomal hernia in 6 of 58 patients (10%) in the mesh group compared to 22 of 59 patients (37%) in the control group (difference, 27%; 95% CI, 12-41; P < .001). Clinical parastomal hernia as a secondary outcome was recorded in 1 of 60 patients (2%) in the mesh group compared to 27 of 61 (43%) in the control group (difference, 41%; 95% CI, 29-55; P < .001). The number of patients with Clavien-Dindo class II ileus was 23 (35%) in the mesh group compared to 11 (17%) in the control group (difference, 18%; 95% CI, 3-32; P = .006). Only slight differences between the groups were detected in other stoma-related complications, readmissions, operative time, surgical site infections, reoperations, and quality of life.In this study, funnel-shaped parastomal mesh prevented a significant number of parastomal hernias without predisposing patients to mesh- or stoma-related complications during 12-month follow-up. The results of this study suggest the funnel-shaped mesh is a feasible option to prevent parastomal hernia.ClinicalTrials.gov Identifier: NCT03799939.