Development and validation of a prognostic prediction model for patients with stage Ⅰ to Ⅲ colon cancer incorporating high-risk pathological features / 中华外科杂志

Objective: To examine a predictive model that incorporating high risk pathological factors for the prognosis of stage Ⅰ to Ⅲ colon cancer. Methods: This study retrospectively collected clinicopathological information and survival outcomes of stage Ⅰ~Ⅲ colon cancer patients who underwent curative surgery in 7 tertiary hospitals in China from January 1, 2016 to December 31, 2017. A total of 1 650 patients were enrolled, aged (M(IQR)) 62 (18)years (range: 14 to 100). There were 963 males and 687 females. The median follow-up period was 51 months. The Cox proportional hazardous regression model was utilized to select high-risk pathological factors, establish the nomogram and scoring system. The Bootstrap resampling method was utilized for internal validation of the model, the concordance index (C-index) was used to assess discrimination and calibration curves were presented to assess model calibration. The Kaplan-Meier method was used to plot survival curves after risk grouping, and Cox regression was used to compare disease-free survival between subgroups. Results: Age (HR=1.020, 95%CI: 1.008 to 1.033,P=0.001), T stage (T3:HR=1.995,95%CI:1.062 to 3.750,P=0.032;T4:HR=4.196, 95%CI: 2.188 to 8.045, P<0.01), N stage (N1: HR=1.834, 95%CI: 1.307 to 2.574, P<0.01; N2: HR=3.970, 95%CI: 2.724 to 5.787, P<0.01) and number of lymph nodes examined (≥36: HR=0.438, 95%CI: 0.242 to 0.790, P=0.006) were independently associated with disease-free survival. The C-index of the scoring model (model 1) based on age, T stage, N stage, and dichotomous variables of the lymph nodes examined (<12 and ≥12) was 0.723, and the C-index of the scoring model (model 2) based on age, T stage, N stage, and multi-categorical variables of the lymph nodes examined (<12, 12 to <24, 24 to <36, and ≥36) was 0.726. A scoring system was established based on age, T stage, N stage, and multi-categorical variables of lymph nodes examined, the 3-year DFS of the low-risk (≤1), middle-risk (2 to 4) and high-risk (≥5) group were 96.3%(n=711), 89.0%(n=626) and 71.4%(n=313), respectively. Statistically significant difference was observed among groups (P<0.01). Conclusions: The number of lymph nodes examined was an independent prognostic factor for disease-free survival after curative surgery in patients with stage Ⅰ to Ⅲ colon cancer. Incorporating the number of lymph nodes examined as a multi-categorical variable into the T and N staging system could improve prognostic predictive validity.

Research progress and future development prospect of transanal total mesorectal excision / 中华胃肠外科杂志

Transanal total mesorectal excision (taTME) is one of the hotspots in colorectal surgery in recent years. Although most studies confirm that taTME is safe and feasible, some studies still showed that the morbidity of complication and local recurrence rate of taTME were higher than traditional laparoscopic surgery. This article reviews and analyzes the short-term and long-term outcomes of taTME and the related progress of postoperative function. The results showed that there were no significant differences in the main short-term and long-term efficacy between taTME and traditional laparoscopic TME, but taTME had potential advantages in postoperative functional recovery. The results of case study after passing the learning curve suggested that taTME had better short-term and long-term efficacy. Moreover, with the maturity of taTME technology, transanal endoscopic surgery has gradually shown its advantages in the treatment of complex pelvic diseases. In the future, the application of single-port robot will further promote the development of natural orifice transluminal endoscopic colorectal surgery.

Efficacy of transanal hand-sewn reinforcement in low rectal stapled anastomosis in preventing anastomotic leak after transanal total mesorectal excision / 中华胃肠外科杂志

Objective: To explore the efficacy and feasibility of transanal hand-sewn reinforcement of low stapled anastomosis in preventing anastomotic leak after transanal total mesorectal excision (taTME). Methods: A descriptive cohort study was conducted. Clinical data of 51 patients with rectal cancer who underwent taTME with transanal hand-sewn reinforcement of low stapled anastomosis at Department of Colorectal Surgery, the Sixth Affiliated Hospital of Sun Yat-sen University from January 2019 to December 2020 were retrospectively collected. Inclusion criteria: (1) age >18 years old; (2) rectal cancer confirmed by preoperative pathology; (3) distance from tumor to anal verge ≤ 8 cm according to pelvic MR; (4) the lesion was evaluated to be resectable before operation; (5) with or without neoadjuvant chemotherapy and radiotherapy; (6) taTME, end-to-end stapled anastomosis, and reinforcement in the anastomosis with absorbable thread intermittently were performed, and the distance between anastomosis and anal verge was ≤ 5 cm. Exclusion criteria: (1) previous history of colorectal cancer surgery; (2) emergency surgery due to intestinal obstruction, bleeding or perforation; (3) patients with local recurrence or distant metastasis; (4) the period of postoperative follow-up less than 3 months. The procedure of transanal hand-sewn reinforcement was as follows: firstly, no sign of bleeding was confirmed after checking the anastomosis. Then, the anastomosis was reinforced by suturing the muscle layer of rectum intermittently in a figure-of-eight manner using 3-0 single Vicryl. The entry site of the next suture was close next to the exit site of the last one. Any weak point of the anastomosis could also be reinforced according to the specimen from the circular stapler. The primary outcome were the incidence of anastomotic leak, methods of the secondary operation, anastomotic infection, anastomotic stricture, and conditions of Intraoperative and postoperative. Results: All the 51 enrolled patients completed surgery successfully without any conversion to open surgery. The median operative time was 169 (109-337) minutes, and the median intraoperative blood loss was 50 (10-600) ml. The median postoperative hospital stay was 8 (5-16) days. The mssorectum was complete and distal resection margin was negative in all patients. Postive circumferential resection margin was observed in 1 patients (2.0%). Twelve (23.5%) patients underwent prophylactic ileostomy. One patient developed anastomosis stricture which was cured by digital dilatation of the anastomosis. ISREC grade C anastomotic leak was observed in 3 (5.9%) male patients, of whom 2 cases did not received prophylactic ileostomy during the operation, and were cured by a second operation with the ileostomy and anastomotic repair. The other one healed by transanal repair of the anastomosis and anti-infection therapy. One (2.0%) patient suffered from perianal infection and healed by sitz bath and anti-infection therapy. No death was reported within 30 days after operation. Conclusion: Transanal hand-sewn reinforcement in low rectal stapled anastomosis in preventing anastomotic leak after taTME is safe and feasible.