Smaller inguinal hernias are associated with a greater risk of chronic postoperative inguinal pain than larger hernias, according to a study published in Annals of Surgery.

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Open hernia surgery

Researchers used data from the European Herniamed registry to look at 1-year outcomes in 57,999 male patients who underwent primary unilateral inguinal hernia repair.

While patients with larger hernias showed significantly longer operation times and had a significantly larger body mass index, those with smaller hernias had significantly higher rates of pain at rest or on exertion, and chronic pain requiring treatment.

Individuals with smaller hernias (EHS I) had a 35% higher odds of pain at rest, compared with those with medium-sized hernias (EHS II), and 84% higher odds, compared with individuals with large hernias (EHS III). Smaller hernias were also associated with a 100% higher odds of pain on exertion and greater than 100% higher odds of chronic postoperative pain requiring treatment, compared with large hernias.

“CPIP [chronic postoperative inguinal pain] has become one of the most important surgical quality parameters after elective inguinal hernia repair with significant consequences affecting patient productivity, employment, and quality of life,” wrote Henry Hoffmann, MD, of the clinic for visceral surgery at the University Hospital Basel in Switzerland, and his coauthors. “With our findings we contribute to the important discussion of prevention, risk factors, and treatment of CPIP identifying smaller inguinal hernias [EHS I-II] as a new independent, patient-related risk factor for the development of CPIP.”

Noting that an association between smaller hernias and increased postoperative pain seems counterintuitive, the authors suggested that patients’ expectations of outcomes may be higher in those with smaller hernias than in patients with larger hernias. While larger hernias are likely more bothersome rather than painful or uncomfortable, smaller hernias may be associated more with pain and discomfort. As such, patients with smaller hernias may have higher hopes for relief from surgery, and therefore may be more likely to experience disappointment.

“Based on a cognitive information processing model it has been suggested that a greater discrepancy between expected and actual pain after surgery leads to significant postoperative distress,” the authors wrote.

The study also found patients aged younger than 55 years were also at greater risk of pain at rest, pain on exertion, and chronic pain requiring treatment.

Overall, around half the patients in the study underwent transabdominal preperitoneal repair, 35.6% underwent totally extraperitoneal repair, 10.1% had Lichtenstein repair, and 3.8% had Shouldice repair.

Lichtenstein was associated with more postoperative pain at rest and on exertion, compared with other surgical methods, and there was a trend toward an increased odds for developing pain requiring treatment in patients with smaller hernias.

The Herniamed Registry is supported by Johnson & Johnson, Karl Storz, pfm medical Cologne, Dahlhausen Cologne, B. Braun Tuttlingen, MenkeMed, and Bard. No conflicts of interest were reported.

SOURCE: Hoffmann H et al. Ann Surg. 2018 Oct 10. doi: 10.1097/SLA.0000000000003065.