Ultrasound-guided Nerve Blocks for Post-hernia Repair Pain

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Chronic pain is the most frequent long-term complication of treating inguinal hernia. It may restrict the patient's daily activities for several years postoperatively. Onset of post-hernia repair pain usually occurs immediately after surgery [1], and predictive factors include repair of recurrent hernia, preoperative pain, severe early post-operative pain, younger age, psychological vulnerability or psychiatric disorder, and workers' compensation [1,2]. There are two predominant types of post-hernia repair pain: no-ciceptive pain, due predominantly to inflammation, and neuropathic pain, due to nerve injury. The most common type of postoperative pain is nociceptive pain presenting with tenderness along the inguinal ligament and radiation to the thigh. Nociceptive pain after hernia repair, commonly characterized as tender, gnawing, or pounding, is mostly due to tissue damage by sutures or mesh fixation devices. The suggested underlying pathomechanism is chronic inflammation resulting from tissue injury [3]. Neuro-pathic pain is typically a result of surgical injury to a specific nerve(s) such as the ilioinguinal, iliohypogastric, the genital branch of the genitofemoral or lateral femoral cu-taneous nerve. Nerve injury may be caused by partial or complete nerve sectioning, entrapment by sutures and mesh fixation devices, or unintended trauma (e.g., con-tusion, electrocautery), subsequently causing irritation and compression by foreign material and scar tissue. Neuro-pathic pain is characterized by a transient electrical stabbing or burning pain that occurs either spontaneously or after provocation test. Treatments include medical treatment , injection of local anesthetics with or without ste-roids, cryotherapy, and behavioral therapy [1-3]. Chemical neurolysis or surgical revision with radical neurectomy may be required for some patients [4,5]. The following actual case illustrates one potential pitfall of ultrasound-guided nerve blocks for diagnosis and treatment of neuralgic pain following laparoscopic inguinal hernia repair. A 44-year-old woman was referred to our pain clinic for management of persistent right inguinal area pain after laparoscopic right herniorrhaphy performed 5 days previously. She was diagnosed with right in-guinal hernia and chronic cholecystitis. She had undergone laparoscopic right herniorrhaphy with placement of mesh by autosuture and cholecystectomy at our general surgery department. Immediately following the procedure, the patient experienced severe right inguinal pain radiating to the medial and lateral area of her right thigh. Pain was exacerbated by walking, leg raising and …