Lateral Internal Sphincterotomy under Local Anesthesia: a Randomized Clinical Trial

Background: Nowadays there is an attempt to perform lateral internal sphincterotomy (LIS) operation on an ambulatory basis under local anesthesia. This study aimed to compare postoperative outcome in local anesthesia with spinal anesthesia. Methods: A randomized, double blinded, controlled trial was performed on 62 patients divided into group A (Local Anesthesia) and Group B (Spinal Anesthesia) with n=31 equally. To achieve adequate anesthesia a cocktail, 6 of Lidocaine 2% and Marcaine 0.5% with the addition of some bicarbonate was injected into subcutaneous tissue and 20 cc of this was injected into the intersphincteric space before LIS. Postoperative pain was assessed by a 10 cm VAS. Results: Needle pain scores in group A and B were: 2.29±1.40 vs. 16.1±0.88 but pain scores, 6 hours after LIS, before leaving hospital and at the first week after the operation were significantly lower in group A than B (1.90±1.07 vs. 3.77±1.25, 0.90±0.47 vs. 1.65±0.75, 0.71±0.46 vs.1.06±0.51 respectively). Need of opioid and codeine in the first 24 hours after the operation in group A was significantly less than the other group. Also nausea and vomiting in group A was significantly lower than group B. Conclusion: The study showed that LIS under local anesthesia is a less painful technique in office surgery. MJIRI, Vol. 20, No.1, 37-40, 2006.