Time Interval Between the End of Neoadjuvant Therapy and Elective Resection of Locally Advanced Rectal Cancer in the CRONOS Study.

Importance: The treatment for extraperitoneal locally advanced rectal cancer (LARC) is neoadjuvant therapy (NAT) followed by total mesorectal excision (TME). Robust evidence on the optimal time interval between NAT completion and surgery is lacking. Objective: To assess the association of time interval between NAT completion and TME with short- and long-term outcomes. It was hypothesized that longer intervals increase the pathologic complete response (pCR) rate without increasing perioperative morbidity. Design, Setting, and Participants: This cohort study included patients with LARC from 6 referral centers who completed NAT and underwent TME between January 2005 and December 2020. The cohort was divided into 3 groups depending on the time interval between NAT completion and surgery: short (≤8 weeks), intermediate (>8 and ≤12 weeks), and long (>12 weeks). The median follow-up duration was 33 months. Data analyses were conducted from May 1, 2021, to May 31, 2022. The inverse probability of treatment weighting method was used to homogenize the analysis groups. Exposure: Long-course chemoradiotherapy or short-course radiotherapy with delayed surgery. Main outcome and Measures: The primary outcome was pCR. Other histopathologic results, perioperative events, and survival outcomes constituted the secondary outcomes. Results: Among the 1506 patients, 908 were male (60.3%), and the median (IQR) age was 68.8 (59.4-76.5) years. The short-, intermediate-, and long-interval groups included 511 patients (33.9%), 797 patients (52.9%), and 198 patients (13.1%), respectively. The overall pCR was 17.2% (259 of 1506 patients; 95% CI, 15.4%-19.2%). When compared with the intermediate-interval group, no association was observed between time intervals and pCR in short-interval (odds ratio [OR], 0.74; 95% CI, 0.55-1.01) and long-interval (OR, 1.07; 95% CI, 0.73-1.61) groups. The long-interval group was significantly associated with lower risk of bad response (tumor regression grade [TRG] 2-3; OR, 0.47; 95% CI, 0.24-0.91), systemic recurrence (hazard ratio, 0.59; 95% CI, 0.36-0.96), higher conversion risk (OR, 3.14; 95% CI, 1.62-6.07), minor postoperative complications (OR, 1.43; 95% CI, 1.04-1.97), and incomplete mesorectum (OR, 1.89; 95% CI, 1.02-3.50) when compared with the intermediate-interval group. Conclusions and Relevance: Time intervals longer than 12 weeks were associated with improved TRG and systemic recurrence but may increase surgical complexity and minor morbidity.

Mechanical Reinforced Terminolateral Ileo-Transverse Anastomosis: An Option After Right Hemicolectomy-A 452 Patients Study.

INTRODUCTION: Bowel reconstruction techniques after right hemicolectomy has currently been objective of review, due to the high rate of anastomotic leak. The aim of this study is to analyse our results of the mechanical reinforced terminolateral ileo-transverse anastomosis. MATERIALS AND METHODS: A prospective and descriptive study of a consecutive series of right colonic cancer cases that underwent right hemicolectomy. Mechanical reinforced terminolateral ileo-transverse anastomosis technique was carried out in all patients. Demographics, emergency or elective surgery, surgical management, postoperative complications, rate of anastomotic leak, need for surgical procedure after complication, average stay, and mortality were analysed. RESULTS: A total of 452 patients underwent surgery between 2010 and 2017. Of those, 40.6% were female and 59.4% were male. The average age and body mass index (BMI) was 72±11.3 years old, and 26±7.1, respectively. Elective surgery was carried out in 405 (89.6%) patients. Laparoscopic approach was used in 250 patients (61.7%) and 6% needed conversion. Only 41 patients (10.6%) had major complications (Clavien-Dindo III-IV). The rate of postoperative paralytic ileus reach was up to 13.9%. Reintervention was needed in five patients (1.1%) due to anastomotic leak and three (0.7%) of them from the elective surgery subgroup. There were 10 patients (2.2%) with postoperative gastrointestinal bleeding. The average stay was 8.2±2.8 days and late postoperative mortality in the first 30 days was 2%. CONCLUSIONS: Mechanical reinforced terminolateral ileo-colic anastomosis is a safe technique with a low anastomotic leak rate. Although our results using this approach seem promising, postoperative paralytic ileus is still a high-rate complication.