A Study Evaluating the Feasibility of a Peri-Operative Rehabilitation Program for Inguinal Hernia Repair Surgery to Reduce Risk of Post-Surgical Pain

Inguinal hernia repair is one of the most common surgeries performed globally, with more than 20 million performed each year. Not only does this huge number of surgeries have a substantial direct economic burden on healthcare systems, there is also indirect impact from time off work and decreased productivity due ongoing post-surgical pain requiring extended time spent on modified duties. It is estimated that approximately 15% of patients undergoing inguinal hernia repair will experience persistent post-surgical pain that could last months to years. Furthermore, current clinical guidelines for return to work and activity after inguinal hernia repair are inconsistently informed by evidence, highly variable, and outdated. Forbes et al (2012) found that the average patient undergoing inguinal hernia repair experiences more than 40 days of short-term disability despite indications that earlier return to activity is safe (i.e. will not lead to repair failure) and likely beneficial for reducing chronic pain and disability.

Evidence from related procedures indicates that better surgical preparation through pre-operative exercise and education (i.e. Prehabilitation) followed by ongoing post-surgical rehabilitation leads to more rapid recovery, return to activities and lower likelihood of persistent post-surgical pain. Prehabilitation was first described in the 1940's when the British Army developed a prehabilitation program as part of an experiment to increase the quality of recruits. The concept of prehabilitation gained traction within the medical community when Topp et. al. and Ditmyer et. al. promoted a theoretical model of prehabilitation, positing that patients who participate in presurgical exercise with the goal of improving functional capacity may experience more rapid postoperative recovery than patients who remain physically inactive through the preoperative period. Prehab has also been shown to increase self-efficacy, a moderator of pain catastrophizing and fear avoidance beliefs, that are important factors linked to the pain experience of those with persistent pain. The investigators propose that this theoretical model can be extrapolated to inguinal hernia repair and theorize that prehabilitation will increase patients' preoperative self-efficacy, allowing them to more rapidly regain abilities, subsequently shortening duration of modified duties and decreasing likelihood of persistent post-surgical pain.

Little information is available regarding the use of prehabilitation in the context of inguinal hernia repair. There have been numerous studies looking at prehabilitation in orthopedics, cardiovascular surgery, and prior to major abdominal surgeries, but limited studies for inguinal hernia repair. A randomized control study by Liang et. al. examined the impact of prehabilitation on ventral hernia recurrence and post-operative complications. They concluded that patients undergoing prehabilitation have a higher likelihood of being hernia-free and complication-free 30 days postoperatively. Notably, this study is limited in that only obese patients were included, and outcomes only included recurrence and complications. No studies were located examining the impact of prehabilitation on recovery time, post-surgical pain, and return to activity after inguinal hernia repair. However psychosocial factors such as pain catastrophizing appear to be important predictors. Typical practice guidelines often recommend limiting activity for at least 3 months to avoid re-rupture. However, these guidelines are based on expert opinion due to a lack of quality research and can pose a risk in building unhelpful beliefs about pain, fear of movement and poor coping strategies. Research is needed to inform practice guidelines and return-to-activity recommendations.