Analgesic efficacy and impact of caudal block on surgical complications of hypospadias repair: a systematic review and meta-analysis

Abstract

Background and objectivesis commonly used for children undergoing hypospadias repair. However, the safety of caudal block for hypospadias repair in children is controversial in terms of surgical complications such as urethrocutaneous fistula and glans dehiscence. We sought to perform a meta-analysis to estimate the analgesic efficacy and relative complications of caudal block for hypospadias repair in children.MethodsWe identified comparative studies of caudal block versus peripheral nerve block or no caudal block; studies were published or presented through 1 January 2018, and reports of analgesic efficacy or surgical complications of hypospadias repair in children were identified. Peripheral nerve block includes dorsal nerve penile block and pudendal nerve block. Data were abstracted from studies comparing caudal block with peripheral nerve block or no caudal block; original source data were used when available. We prespecified separate assessments of randomized controlled trials (RCTs) and observational studies given the inherent differences between types of study designs. Data from 298 patients in four RCTs and from 1726 patients in seven observational studies were included. RCT and observational data were analyzed separately.ResultsIn RCTs, caudal blocks (compared with peripheral nerve blocks) showed no detectable differences in terms of need for additional analgesia within 24 hours after the surgery (OR 10.49; 95% CI 0.32 to 343.24; p=0.19), but limited data showed lower pain scores 24 hours after the surgery (standardized mean difference (SMD) 1.57; 95% CI 0.29 to 2.84; p=0.02), a significantly shorter duration of analgesia (SMD −3.33; 95% CI −4.18 to −2.48; p<0.0001) and analgesics consumption. No significant differences were observed in terms of postoperative nausea and vomiting (OR 3.08; 95% CI 0.12 to 77.80; p=0.50) or motor weakness (OR 0.01; 95% CI −0.03 to 0.05; p=0.56). Only one randomized study showed that caudal blocks (compared with peripheral nerve blocks) were associated with detectable differences in urethrocutaneous fistula rate (OR 25.27; 95% CI 1.37 to 465.01; p=0.03) and parental satisfaction rate (OR 0.07; 95% CI 0.02 to 0.21; p<0.00001). In observational studies, caudal block was not associated with surgical complications in all types of primary hypospadias repair (OR 1.83; 95% CI 0.80 to 4.16; p=0.15). To adjust for confounding factors and to eliminate potential selection bias involving caudal block indication, we performed subgroup analysis including only patients with distal hypospadias. This analysis revealed similar complication rates in children who received a caudal block and in children not receiving caudal block (OR 1.02; 95% CI, 0.39 to 2.65; p=0.96). This result further confirmed that caudal block was not a risk factor for surgical complications in hypospadias repair. The direction of outcomes in all the other subgroup analyses did not change, suggesting stability of our results.ConclusionsIn RCTs, only limited data showed peripheral nerve blocks providing better analgesic qua...

Response to ‘Hypospadias repair and caudal analgesia: biases and myths hinder meaningful meta-analysis’ by Haydar and Freed

“…Thank you for the opportunity to respond to Dr Haydar’s1 letter. We appreciated that Dr Haydar and his coauthors found our paper2 of interest. He brought up several points, which we agree are worth clarifying.…”

Response to the letter from Dr Yifeng Renet al

“…We appreciated that Dr Niu and his co-authors found our paper1 2 of interest. He brought up several points, which we agree are worth clarifying.…”

Hypospadias repair and caudal analgesia: biases and myths hinder meaningful meta-analysis

“…We read with interest the meta-analysis of caudal block for hypospadias repair by Zhu and colleagues 1. Their work helps to improve understanding about the relative efficacy of different analgesic techniques, but unfortunately perpetuates a baseless myth and overlooks important deficiencies in the works they cite regarding surgical complications.…”