Analysis of conversion factors in robotic-assisted rectal cancer surgery

Predictors of operative difficulty in robotic low anterior resection for rectal cancer

AIM

This study evaluates the relationship of tumour and anatomical features with operative difficulty in robotic low anterior resection performed by four experienced surgeons in a high-volume colorectal cancer practice.

METHODS

Data from 382 patients who underwent robotic low anterior resection by four expert surgeons between January 2016 and June 2019 were included in the analysis. Operating time was used as a measure of operative difficulty. Univariate and multivariate mixed models were used to identify associations between baseline characteristics and operating time, with surgeon as a random effect, thereby controlling for variability in surgeon speed and proficiency. In an exploratory analysis, operative difficulty was defined as conversion to laparotomy, a positive margin or an incomplete mesorectum.

RESULTS

Median operating time was 4.28 h (range 1.95-11.33 h) but varied by surgeon from 3.45 h (1.95-6.10 h) to 5.93 h (3.33-11.33 h) (P < 0.001). Predictors of longer operating time in multivariate analysis were male sex, higher body mass index, neoadjuvant radiotherapy, low tumour height, greater sacral height and larger mesorectal area at the S5 vertebral level. Conversion occurred in two cases (0.5%), and incomplete mesorectum and positive margins were found in nine (2.4%) and 19 (5.0%) patients, respectively. Neoadjuvant radiotherapy and larger pelvic outlet were the only characteristics associated with the exploratory measure of difficulty.

CONCLUSION

Predicting operative difficulty based on easy to identify, preoperative radiological and clinical variables is feasible in robotic anterior resection.

Is the interval from surgery to ileostomy closure a risk factor for low anterior resection syndrome?

AIM

Low anterior resection syndrome (LARS) comprises a collection of symptoms affecting patients after restorative surgery for rectal cancer. The aim of the present study was to analyse the incidence of LARS in patients undergoing rectal cancer surgery with and without subsequent ileostomy and to determine whether the interval to ileostomy closure is a factor associated with its occurrence.

METHOD

All patients undergoing curative anterior resection for rectal cancer from 2008 to 2012 in our institution were included in the study. They were divided into two groups according to whether or not a defunctioning ileostomy had been performed. Patients were assessed for LARS at a median interval of 23.60 ± 16.73 (12-48) months from anterior resection in those who did not have an ileostomy and at an interval of 11.31 ± 14.24 (12-60) months from closure of the ileostomy in those who did. They underwent a structured telephone interview based on a validated LARS score questionnaire. Univariate and multivariate analysis was carried out to assess possible associations between LARS and the variables studied.

RESULTS

There were 150 patients (93 men) of whom 54.7% had no evidence of LARS, 17.3% had minor symptoms and 28% major symptoms of LARS. Univariate analysis showed that male gender, the presence of a temporary ileostomy and neoadjuvant therapy were predisposing factors for LARS. The interval from construction of the ileostomy to its closure did not appear to be a factor associated with LARS. In multivariate analysis, male gender and preoperative neoadjuvant therapy were significant predisposing factors for LARS.

CONCLUSION

Male gender and preoperative neoadjuvant therapy are risk factors for LARS. The presence of ileostomy or time to ileostomy closure is not associated with the development of this syndrome.