Analysis of conversion factors in robotic-assisted rectal cancer surgery.

BACKGROUND: Robotic surgical management of rectal cancer has a series of advantages which might facilitate the surgical approach to the pelvic cavity and reduce conversion rates. The aim of the present study is to identify independent factors for conversion during robotic rectal cancer surgery. METHODS: A total of 67 patients underwent preoperative CT scan in order to obtain a three-dimensional image of the pelvis, the tumour and prostate. We measured maximum and minimum ilio-iliac, sacral promontory-pubis, coccyx-pubis diameters and maximum lateral axis. Further variables under consideration were age, BMI and use of neoadjuvant therapy. We recorded short-term follow-up outcomes of the resected tumour. RESULTS: The present study included 67 patients (39 males) with an average age of 65.11 ± 10.30 years and a BMI of 27.70 ± 3.97 kg/m(2). Operative procedures included nine abdominoperineal resections and 58 low anterior resections. There were 15 (22.38 %) conversions. Mean operating time was 192.2 ± 42.73 min. Minimum ilio-iliac, maximum ilio-iliac, promontory-pubic and coccyx-pubis diameter as well as maximum lateral axis were 100.38 ± 7.65, 107.10 ± 10.01, 109.97 ± 9.20, 105.61 ± 9.27 and 129.01 ± 9.94 mm, respectively. Mean tumour volume was 37.06 ± 44.08 cc; mean prostate volume was 42.07 ± 17.49 cc. The univariate analysis of the variables showed a correlation between conversion and BMI and minimum ilio-iliac and coccyx-pubis diameters (p = 0.004, 0.047, 0.046). In the multivariate analysis, the only independent predictive factor for conversion was the BMI (p = 0.004).No correlation was found between conversion and sex, age, tumour volume or the rest of pelvic diameters. CONCLUSION: BMI is an independent factor for conversion in robotic-assisted rectal cancer surgery.

Learning curve for robotic-assisted laparoscopic rectal cancer surgery.

INTRODUCTION: One of the main uses of robotic assisted abdominal surgery is the mesorectal excision in patients with rectal cancer. The aim of the present study is to analyse the learning curve for robotic assisted laparoscopic resection of rectal cancer. PATIENTS AND METHODS: We included in our study 43 consecutive rectal cancer resections (16 females and 27 males) performed from January 2008 through December 2010. Mean age of patients was 66 ± 9.0 years. Surgical procedures included both abdomino-perineal and anterior resections. We analysed the following parameters: demographic data of the patients included in the study, intra- and postoperative data, time taking to set up the robot for operations (set-up or docking time), operative time, intra- and postoperative complications, conversion rates and pathological specimen features. The learning curve was analysed using cumulative sum (CUSUM) methodology. RESULTS: The procedures understudied included seven abdomino-perineal resections and 36 anterior resections. In our series of patients, mean robotic set-up time was 62.9 ± 24.6 min, and the mean operative time was 197.4 ± 44.3 min. Once we applied CUSUM methodology, we obtained two graphs for CUSUM values (operating time and success), both of them showing three well-differentiated phases: phase 1 (the initial 9-11 cases), phase 2 (the middle 12 cases) and phase 3 (the remaining 20-22 cases). Phase 1 represents initial learning; phase 2 plateau represents increased competence in the use of the robotic system, and finally, phase 3 represents the period of highest skill or mastery with a reduction in docking time (p = 0.000), but a slight increase in operative time (p = 0.007). CONCLUSION: The CUSUM curve shows three phases in the learning and use of robotic assisted rectal cancer surgery which correspond to the phases of initial learning of the technique, consolidation and higher expertise or mastery. The data obtained suggest that the estimated learning curve for robotic assisted rectal cancer surgery is achieved after 21-23 cases.

[Prospective randomised study: robotic-assisted versus conventional laparoscopic surgery in colorectal cancer resection]. / Estudio prospectivo, aleatorizado: cirugía laparoscópica con asistencia robótica versus cirugía laparoscópica convencional en la resección del cáncer colorrectal.

INTRODUCTION: Robotic-assisted surgery is playing an increasingly important role in the last few years in the treatment of colorectal oncological disease. However, there are still no studies that objectively demonstrate the advantages of this type of surgery. We present a prospective randomised study in order to compare the short-term results between colorectal robotic surgery and laparoscopic surgery. MATERIAL AND METHOD: A total of 56 patients diagnosed with colorectal cancer between January 2008 and January 2009, were randomised and assigned to the robotic or laparoscopic group. Age, body mass index, tumour location, conversions in each group, complications during and after surgery, and histological characteristics of the specimens obtained, were all compared. RESULTS: There were no significant differences between age (P=.055), body mass index (P=.12), or tumour location (P=.91). Only one patient in the robotic group required a transfusion and none in the laparoscopic group. The percentage of conversions was the same in both groups, however, the preparation times and operating times were significantly longer in patients intervened using the robotic device (P=.0001 and P=.017, respectively). There were no differences as regards the rate of complications or in the percentage of re-interventions (14.2% and 7.1%). The mean hospital stay of the patients was 9.3 (8.1) days in the robotic group and 9.2 (6.8) days in the laparoscopic (P=.79). The distal resection margin was greater in the specimen obtained using robotic surgery (P =.003) as well as the number of lymph nodes obtained in the specimen (P =.23). CONCLUSION: Robotic colorectal was performed safely and effectively, and with similar clinical results. International Trial Number for this study is: ISRCTN60866560.