Ilioinguinal nerve block may be performed for either diagnosis of nerve entrapment in patients with chronic pelvic pain (1) or as part of regional anesthesia/analgesia when surgery of the inguinal area is contemplated. In many patients complaining of chronic orchialgia, the source of pain may be elusive, despite extensive diagnostic work-up (2). In this case, a local anesthetic block of the ilioinguinal nerve was helpful in the diagnosis of referred testicular pain. Reported herein is a case of a small, retroperitoneal pelvic hematoma after the performance of this block.
A 40-yr-old male presented to the pain clinic with an 8-mo history of left-sided testicular pain. The pain was intermittent and worse with sitting, standing, and sexual intercourse. It was relieved by bedrest. The visual analog score was 8/10, and the patient described the pain as having a burning, dysesthetic character. He denied any trauma, recent surgeries, diabetes mellitus, fever, back pain, or penile discharge. He worked full time. He had a history of a gunshot wound at age 18, for which he underwent a laparotomy and received a blood transfusion. As a result of this, he tested positive for hepatitis C, but remained otherwise asymptomatic. He denied smoking, drinking alcohol, or consuming illicit drugs. His urologic work-up, including a scrotal ultrasound and blood tests, was unrevealing. A trial of antibiotics, nonsteroidal antiinflammatory drugs, antidepressants, and anticonvulsants did not improve his symptoms. At the time of the visit he was not taking any medications. Physical examination revealed a pleasant, oriented gentleman, in no apparent distress and with normal vital signs. His weight was 200 lb. He had an old, nontender keloid scar over the epigastric area. There was no evidence of varicocele, hydrocele, local erythema, or hernia. Testicular size was normal. He had some mild tenderness over the left testicle and left inguinal area. There was no lymphadenopathy. Neurologic examination was normal.
An ilioinguinal nerve block was performed, following the technique described by Moore (3). The injection was made using a 3.5-in., 22-gauge spinal needle. Ten milliliters of 1% plain lidocaine was slowly injected as the needle was felt to pass through the fascia of the external oblique muscle, the internal oblique muscle, and the transversalis muscle. Careful repeated negative aspiration was performed. Recorded vital signs were stable. The patient reported immediate resolution of pain and subsequently he was discharged home. Three hours later he called the office, complaining of nausea, dizzy spells, and worsening of the abdominal discomfort. At this point, the differential diagnosis included bowel puncture, hemoperitoneum, and localized reaction to the injection accompanied by pain. He was instructed to go to the emergency room where vital signs were found to be stable. He had increased tenderness over the lower left abdominal quadrant but no guarding or rebound. His white blood cell count was 15,200. A consultant surgeon advised a computed tomography scan of the abdomen, blood cultures, hydration, broad antibiotic coverage, and admission to the hospital. The computed tomography scan (Fig. 1) revealed a left pelvic hematoma above the dome of the bladder, tracking along the iliac vessels and the lowest aspect of the left colonic gutter. Its volume was approximately 20 mL. Eventually, his symptoms improved with conservative management, and he was discharged home after 2 days.
A case of pelvic hematoma after a single ilioinguinal nerve block is reported. This specific complication has not been previously reported in the literature. The clinical course was benign, but required hospital admission. This complication occurred even though the patient was not taking any aspirin, nonsteroidal antiinflammatory drugs, or anticoagulants.
Although this is considered to be a simple procedure, various complications have been reported, including colonic puncture (4) and transient quadriceps paresis in children (5). For patients with chronic inguinal pain symptoms, to avoid multiple punctures, placement of an indwelling catheter and fluoroscopic verification has been suggested (6). In this case, fluoroscopy was not used because multiple injections were not contemplated.
Because this patient underwent previous abdominal surgery, risks beyond those normally associated with ilioinguinal block, such as viscus and blood vessel perforation, should have been considered and discussed with the patient. Abnormal scar tissue may be present and thus distort the normal anatomy, predisposing to unusual complications, despite appropriate needle depth. In this subgroup of patients, needle placement should be slightly different than the usual classic approach, as the tip of the needle should lay between the internal and external oblique muscles. This will allow enough local anesthetic spread along the ilioinguinal and iliohypogastric nerves, thus eliminating the risk for peritoneal perforation when the needle is advanced deep beyond the fascia of the transversus muscle. Conceivably, trauma to an iliac artery branch can also produce a small pelvic hematoma, without a true puncture of the peritoneum, because blood can track laterally behind the peritoneum. In this case, primary etiology of the bleeding could be established only by angiography.
In conclusion, this is a case of a small pelvic hematoma after ilioinguinal nerve block in a patient who had a history of a previous laparotomy.
1. Sippo WC, Burghardt A, Gomez AC, et al. Nerve entrapment after Pfannenstiel incision. Am J Obstet Gynecol 1987; 157: 420–1.
2. Davis BE, Noble MJ, Weigel JW. Analysis and management of chronic testicular pain. J Urol 1990; 143: 936–9.
3. Moore DC. Block of the inguinal region. In: Thomas CC, House B, eds. Regional nerve block. 4th ed. Springfield, IL: CC Thomas, 1965: 167–71.
4. Johr M, Sossai R. Colonic puncture during ilioinguinal nerve block in a child. Anesth Analg 1999; 78: 314–6.
5. Roy-Shapira A, Amoury RA, Ashcraft KW, et al. Transient quadriceps paresis following local inguinal block for postoperative pain control. J Pediatr Surg 1985; 20: 554–5.
6. Ghia JN, Blank BW, McAdams CG. A new interabdominis approach to inguinal region block for the management of chronic pain. Reg Anesth 1991; 16: 72–8.