Cryoanalgesia versus sham treatment was applied to the ilioinguinal and iliohypogastric nerves after mesh repair of an inguinal hernia under local anesthesia in 48 male patients in a prospective, randomized, and observer- and patient-blinded trial. Pain was scored daily during rest, while coughing, and during mobilization to the sitting position for 1 wk and weekly for 8 wk on a four-point verbal rank scale. Use of supplementary analgesics and sensory disturbances were recorded. Assessments were made for allodynia, hyperalgesia, and mechanical pain detection thresholds 8 wk postoperatively. Cumulative pain scores for the first postoperative week were equal in the two groups, as was the use of analgesics. Eight weeks postoperatively, three cases of hyperalgesia to pinprick were detected in the cryoanalgesia group, and 10 patients in the cryoanalgesia group versus 5 in the sham-treatment group reported disturbed sensibility. We conclude that cryoanalgesia of the iliohypogastrical and ilioinguinal nerve does not decrease postherniorrhaphy pain.
Implications: Does freezing of sensory nerves in the groin reduce pain after hernia repair? Extreme cold (-60 degrees C) was applied in a double-blind, randomized study. No difference in pain scores was found. Sensory disturbances were seen in treatment and control patients. Freezing cannot be recommended for pain relief after hernia repair.