title: Cause and Effect versus Confounding-Is There a True Association between Caudal Blocks and Tubularized Incised Plate Repair Complications?
abstract: We studied the impact of caudal block vs dorsal penile block on the rate of urethrocutaneous fistula and glans dehiscence in children who underwent hypospadias repair.
  
  
  
  We retrospectively reviewed the records of 849 consecutive patients who underwent tubularized incised plate repair between 2004 and 2015. A total of 331 cases with incomplete medical records, other techniques and redo repair were excluded. The preference for caudal block was based on anesthesiologist discretion. Age at surgery, meatal location, preoperative testosterone stimulation, type of regional anesthesia (caudal block vs dorsal penile block), degree of ventral curvature, surgeon expertise and complications (urethrocutaneous fistula/glans dehiscence) were captured. Univariate and multivariable analyses were done of risk factors for complications.
  
  
  
  Median age at surgery was 18 months and median followup was 6 months. Of 518 patients 405 (78%) had distal and 113 (22%) had mid shaft/proximal defects. Complications developed in 37 cases (7%), including urethrocutaneous fistula in 21 (19 with a caudal block and 2 with a dorsal penile block) and glans dehiscence in 16 (13 with a caudal block and 3 with a dorsal penile block). On univariate analysis preoperative testosterone stimulation vs no preoperative testosterone stimulation (13.0% vs 6.2% of cases, p = 0.04), mid shaft/proximal vs distal defects (15.9% vs 4.7%, p <0.01) and caudal block (8.7% vs 3.3%, p = 0.03) were significantly associated with more complications. However, on multivariable analysis the associations of preoperative testosterone stimulation (OR 1.2, 95% CI 0.4-3.7) and caudal block (OR 2.4, 95% CI 0.9-6.4) with complications did not hold. Only the combination of meatal location/ventral curvature remained as an independent risk factor for urethrocutaneous fistula/glans dehiscence (OR 2.4, 95% CI 1.1-5.7, p = 0.04).
  
  
  
  Our data indicate that hypospadias severity and not the type of regional anesthesia was the only risk factor significantly associated with postoperative complications. To confirm these findings and provide strong and definitive evidence on this topic a well powered, randomized, controlled trial is clearly required.
authors: Clinical Urology Research Enterprise Program, McMaster Children's Hospital, Hamilton, Ontario, Canada. Electronic address: braga@mcmaster.ca.
authors: Luis H
authors: LH
authors: Braga
authors: McMaster Pediatric Surgery Research Collaborative, McMaster University, Hamilton, Ontario, Canada; Clinical Urology Research Enterprise Program, McMaster Children's Hospital, Hamilton, Ontario, Canada.
authors: Kizanee
authors: K
authors: Jegatheeswaran
authors: McMaster Pediatric Surgery Research Collaborative, McMaster University, Hamilton, Ontario, Canada; Clinical Urology Research Enterprise Program, McMaster Children's Hospital, Hamilton, Ontario, Canada.
authors: Melissa
authors: M
authors: McGrath
authors: McMaster Pediatric Surgery Research Collaborative, McMaster University, Hamilton, Ontario, Canada; Clinical Urology Research Enterprise Program, McMaster Children's Hospital, Hamilton, Ontario, Canada.
authors: Bethany
authors: B
authors: Easterbrook
authors: Clinical Urology Research Enterprise Program, McMaster Children's Hospital, Hamilton, Ontario, Canada.
authors: Mandy
authors: M
authors: Rickard
authors: Division of Urology, Department of Surgery, McMaster University, Hamilton, Ontario, Canada; Clinical Urology Research Enterprise Program, McMaster Children's Hospital, Hamilton, Ontario, Canada.
authors: Jorge
authors: J
authors: DeMaria
authors: Division of Urology, Hospital for Sick Children, Toronto, Ontario, Canada.
authors: Armando J
authors: AJ
authors: Lorenzo
mesh_terms: D000293:Adolescent; D000763:Anesthesia, Caudal; D002648:Child; D002675:Child, Preschool; D015986:Confounding Factors, Epidemiologic; D017577:Cutaneous Fistula / Q000453:epidemiology*; D006801:Humans; D007021:Hypospadias / Q000601:surgery*; D007223:Infant; D008297:Male; D009407:Nerve Block / Q000379:methods*; D011183:Postoperative Complications / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013529:Surgical Wound Dehiscence / Q000453:epidemiology*; D014522:Urethral Diseases / Q000453:epidemiology*; D014548:Urinary Fistula / Q000453:epidemiology*; D013521:Urologic Surgical Procedures, Male / Q000379:methods
keywords: anesthesia; caudal; fistula; hypospadias; penis; postoperative complications