The Learning Curve of Retroperitoneoscopic Urologic Surgery: A Systematic Review

Abstract

Introduction: Retroperitoneal laparoscopic (RPL) urologic surgery offers comparable surgical and functional outcomes to the traditional transperitoneal approach, with the advantage of circumventing the need to enter the intraabdominal space. This precludes the necessity to encounter small intestinal and colonic segments, encounter abdominal adhesions, and mobilize adjacent organs, translating to better peri-operative and post-operative conditions. However, RPL demands a strong knowledge of the retroperitoneal anatomy coupled with a level of laparoscopic dexterity, this results in a steep learning curve. Unfortunately, the evidence on the learning curve for RPL is diverse and scarce. The aim of this systematic review was to consolidate the available literature and determine the minimum required number of cases to efficiently and safely perform RPL.

Methods: This is a systematic review of the literature via PubMed, EBSCO and Science Direct of all studies published since 2000 to 2019. The search was conducted by combining the following terms, “Retroperitoneoscopy”, “Retroperitoneoscopic”, “posterior laparoscopy”, “Learning”, “Nephrectomy”, “Adrenalectomy”, and “Ureterolithotomy”. Outcomes of interest were learning curve, mean operative time, mean intra-operative blood loss and mean hospital stay.

Results: After the screening phase and application of the eligibility and exclusion criteria, the review included a total of 6 studies on the learning curve for RPL. The learning curve for retroperitoneoscopic adrenalectomy was 40 cases and 24 to 42 cases, based on the evidence from Uitert, et al. (2016) and Vrielink, et al. (2017), respectively. For retroperitoneoscopic nephrectomy, the minimum required number of cases is 30 – 70, based on the studies by Pal, et al. (2017), Zhu, et al. (2018) and Tokodai, et al. (2013). Ercil, et al. (2014) demonstrated the learning curve for retroperitoneoscpic ureterolithotomy to be at 30 cases. Review of each literature showed that completion of the learning curves translated to better peri-operative and post-operative conditions (i.e. shorter operative time, lesser intra-operative blood loss, shorter hospital stay). Overall, the evidence in this review suggests that for posterior retroperitoneal laparoscopy, a mean learning curve of 31 to 56 cases is required to safely and efficiently perform the procedure.

Conclusion: Retroperitoneal laparoscopic surgery is a valid alternative to the traditional transperitoneal approach. It offers comparable anatomic and functional results, albeit better peri-operative and post-operative outcomes. However, its performance requires a strong knowledge and familiarity of working within the retroperitoneum which can be achieved through progressive experience in RPL. The evidence consolidated by this review suggests a learning curve of 31 to 56 cases prior to effectively performing the procedure.