Introduction

Surgeons' estimates for their surgical times can be accurately predicted with feedback and knowledge of the key variables. Our study aimed to utilize the International robotic cystectomy consortium (IRCC) database of robot-assisted radical cystectomy (RARC) to determine patient and institutional variables of importance in scheduling the procedure.

Methods

2686 RARCs performed at 23 institutions from 12 countries were utilized from the IRCC database. Variables used for prediction of surgical times were: institutional RARC volume, age at RARC, gender, BMI, ASA Score, history of prior abdominal surgery and radiation, clinical stage of disease, administration of neoadjuvant chemotherapy, approach, and type of diversion. A conditional inference tree method was used to fit a binary decision tree predicting operative time. Permutation tests were performed to determine the variables having the strongest association with RARC surgical time. The data was split at the value of this variable resulting in the largest difference in means for the surgical time across the split. This process was repeated separately on the resultant data sets until the permutation tests showed no significant association.

Results

2136 procedures were included in the analysis. The most important determinant of surgical time was the type of diversion (Ileal conduits - 69 minutes shorter than Neobladders, p<0.001). Among patients who received neobladders, BMI was also an important determinant of surgical time (higher BMI—longer by 50 minutes, p<0.001). Among the Ileal conduit patients, institutional RARC volume was an important factor (44 minutes, p<0.001). In the following regression tree, the box plots show the median, interquartile deviation, and ranges of surgical times for each node.

Conclusions

We developed a methodology to predict operative time for RARC based on patient, disease characteristics and Institutional experience. This model can be used to improve OR efficiency.

Funding

Vattikuti Foundation Collective Quality Initiative and Roswell Park Cancer Institute Alliance Foundation