Is robotic-assisted surgery a step in the right direction for routine inguinal hernia repair?

© Laparoscopic Surgery. All rights reserved. Laparosc Surg 2021 | http://dx.doi.org/10.21037/ls-20-113 Until now, the latest technical novelty in inguinal hernia surgery, robotic-assisted repair, has spread without any evidence of its efficacy or safety from randomized clinical trials. In March 2020, however, Prabhu and colleagues (1) from the Cleveland Clinic in the US published the results of what they call a randomized pilot study. The reason for describing it as a “pilot” study was a lack of reliable data for the expected outcome of robotic-assisted surgery compared to conventional laparoscopic inguinal hernia repair. Nevertheless, they designed a multicenter single-blinded protocol conforming to most CONSORT criteria including a total of 102 patients (54 in the conventional laparoscopic arm and 48 in the robotic-assisted arm). Thus, with a strict study design and surgeons experienced in both methods, as applied by the Cleveland group, one can assume that most clinically relevant differences would become manifest in the outcome measures. Another obvious reason for describing this trial as a pilot study is the difficulty in choosing an appropriate main outcome variable that would reveal a significant and clinically relevant improvement in results. This is underlined in an editorial by Jacob Rosenberg (2) published in this Journal in December 2019, commenting on a Chinese observational comparative study on conventional laparoscopic and robotic-assisted rectal resection surgery (3). No relevant advantage regarding complications or conversion rates could be identified for robotic-assisted surgery in that study. With this in mind, it is relevant to spend a few minutes on recapitulating the history of inguinal hernia surgery research on quality improvement, and subsequent changes in main outcome parameters over the past three decades. Inguinal hernia may be regarded as a chronic disorder with surgery being the only cure. In the beginning, repeated recurrence was the expected course after surgery. However, consequent standardization and quality control has reduced the recurrence rates. According to data from the Swedish and Danish national hernia databases the 2-year cumulative recurrence rates were less than 2% (4,5). Improved surgical quality and individual audit of surgeons, as well as the introduction of reinforcement mesh (i.e., the Lichtenstein technique) contributed to this development. A consequence of these low recurrence rates was that studies on hernia repair with recurrence as the main outcome variable became difficult to design and carry out. Such studies required the inclusion of thousands of patients to achieve acceptable power. This led to a paradigm shift where randomized trials adopted new main outcome variables. Long-term pain has become one of the most common of these. Depending on the definition of pain and when its estimation is performed, up to 30% of patients claim some degree of pain the past week and more than 5% suffer from pain that interferes with daily activities (6). Several instruments for standardized measurement of pain such as the Inguinal Pain Questionnaire (7) and Carolinas Editorial Commentary