Analysis of post-surgical pain after inguinal hernia repair : a prospective study of 1,440 operations

Background: Pain remains a significant clinical problem after inguinal hernia repair. We prospectively assessed post-surgical pain following herniorrhaphy in 1,440 operations with the aim of describing the characteristics and identifying predisposing factors for pain. Methods: Pain quality was assessed with the short-form McGill Pain Questionnaire (SF-MPQ); pain character was estimated as either nociceptive or neuropathic in nature. Results: A total of 38.3% of replies reported pain (acute or chronic), and 18.7% reported chronic pain. Independent risk factors for pain were young age, BMI >25, day surgery, and use of Radomesh. In patients with chronic pain, independent risk factors were young age, BMI >25 and use of Radomesh. Analysis of the SF-MPQ revealed that the pain reported by most patients was sensory-discriminative in quality. The most common descriptors were tender and aching. Patients with chronic pain reported more intense pain and used sensory descriptors of greater mean intensity than patients with acute pain. A total of 73.9% of replies used descriptors typical of nociceptive pain, 6.5% used descriptors typical of neuropathic pain and 19.6% used nociceptive plus neuropathic descriptors. Patients considered to have nociceptive pain used significantly more sensory descriptors than those considered to have neuropathic pain. By contrast patients with neuropathic pain used more affective descriptors than those with nociceptive pain. Neuropathic pain was reported as more difficult to treat with analgesics than nociceptive pain and neuropathic plus nociceptive pain. Conclusions: Our study confirms that herniorrhaphy frequently produces chronic pain, which can reduce quality of life. The SF-MPQ is a useful instrument to administer to all patients and provides important information about qualitative properties of the pain.