[Chronic Pain After Outpatient Inguinal Hernioplasty: Retrospective Cohort Study].

Introduction: Chronic postoperative pain is the most frequent late complication of inguinal hernia repair surgery. The aim of this study is to evaluate the incidence of chronic post-hernioplasty pain in outpatient care at Centro Hospitalar do Porto, describe it, analyse its relation with other variables defined in the literature and study its functional interference.
Material and Methods: We performed a retrospective cohort study between February and May 2016, using a structured telephone interview composed of questions from the authors and sections of published questionnaires, two of which are validated for the Portuguese language and culture. We included men who underwent ambulatory inguinal hernioplasty, by laparotomy or laparoscopy, at Centro Hospitalar do Porto, between January 2011 and October 2015.
Results: In a final sample of 829 surgeries, the incidence of chronic post-hernioplasty pain was 24.0% [confidence interval: 21.2 - 27.1]. The development of chronic post-hernioplasty pain was higher in patients with pre-surgical pain and younger age and was related with the presence of pain during the first month after surgery. No relationship was found between surgical technique and the development of chronic post-hernioplasty pain. Of the individuals with chronic pain, 65.0% mentioned moderate-severe 'pain on the average' and 37.7% presented descriptors suggestive of neuropathic pain. The only parameter evaluated with which chronic post-hernioplasty pain 'did not interfere completely' was sleep.
Discussion: The prevalence found for chronic posthernioplasty pain with significant functional interference is in line with data retrieved from literature. The predictive potential of pre-surgical pain and young age for the development of chronic posthernioplasty pain is also in agreement with previous studies. Limitations were found to this study given its retrospective nature.
Conclusion: The high prevalence of chronic post-hernioplasty pain raises the urgent need for raising awareness regarding this issue among health care professionals. The main areas for improvement are diagnosis, follow-up and treatment of pain.