Timing of Inguinal Hernia Repair in Premature Neonates Jordan Gale, R3 10/6/2011

JC 4mo former 26 week premature infant – Hospitalized x 3 months – Discharged 2 weeks ago Bilateral inguinal hernias Irritability and swelling in right groin for 12 hours and 1 episode of emesis that morning

JC Incarcerated right inguinal hernia diagnosed in ED 5.9kgs, afebrile, WBC 13,200 Reduced without sedation On exam reducable RIH and left scrotal hydrocele

JC Operative findings: – Amyand hernia – Bilateral herniorrhaphies with high ligations – Incidental appendectomy – Left vas inadvertantly transected and vasovasorrhaphy performed

Epidemiology of Inguinal Hernias in Children 1-5% of all newborns Most common procedure in children M:F 6:1 60% Right sided 9-11% of premature neonates Inverse relationship between birth weight/gestational age and risk for developing a hernia g: 30-42% g: 10% g: 3%

Embryology Processes vaginalis (PV) forms during 3 rd month At 7-9 months testes descend through ring PV closes within – 2 months in 40% – 2 years in 60% ½ of remaining babies with open PV develop a hernia

Pathophysiology Inguinal canal short and straight Premature neonates at high risk – processes vaginalis may have not closed – Mechanical ventilation/increased intra-abdominal pressure

Complications Incarceration – 14-31% – Female: 17%; Male 12%

Complicating Factors Surgical: – Fragile hernia sac and spermatic cord Medical: – RDS – NEC/sepsis – cardiac issues

Delayed Repair Reasons of delay: – Technically challenging – Co-morbid conditions – Anesthetic complications (prolong or re- intubations)

Early Repair Reasons for early surgery 1.Risk of incarceration 2.Risk of incarceration 3.Risk of incarceration Bowel, testicle or ovary strangulation Testicular atrophy Increased scarring (repeated incarceration)

KID Database 3% overall incidence of IH 16% incarceration in house (176/1123) – 36 to 39 weeks = 9% – <36 weeks = 11% – >40 weeks = 21% Risk factors: male, gestational age, birth weight, prolonged mechanical ventilation

KID Database Timing of repair: – Incarcerated = 76.7 days – Reducible = 67.8 days 16% incarceration noted during initial hospitalization – vs 28% of premature/term infants admitted within 1 year for repair

Proponents of early operation Possible complicating factors with delayed repair: – Growing hernia sac – Thickening sac – More adhesions Uemura 1999: 40 children One case: – 29 weeks, 850g with several episodes of incarceration until surgery at 8 weeks – Bilateral testicular necrosis – Op time = 240 minutes – Recurrent hernia at POD #8 with strangulation and bowel necrosis

Additional Case Reports 2 premature neonates Incarcerated hernias complicated by bowel perforation Suggest that hernias should be repaired upon diagnosis

Time and Weight Vaos 2010: – Surgery within 1 week of diagnosis vs delayed – Incarceration: 12% vs 56% – Recurrence: – Testicular atrophy: Davies 2003: – Hernia repair in <3kg babies – Increased recurrence, testicular atrophy and hydocele

Trends in Preference Repair prior to NICU discharge – 1993: 71% – 2005: 63% – 2006 KID database study: 56%

Conclusions Manual reduction is usually successful Daily examination of known hernias – And intervention if incarceration occurs Delaying surgery has significant advantages Incarceration rate in premature neonates may not be an higher than term infants

Sources Coren, M., Madden, N., Haddad, M. and Lissauer, T. (2001), Incarcerated inguinal hernia in premature babies- a report of two cases. Acta Paediatrica, 90: 453–454. Harper, et al. Inguinal Hernias in Premature Infants Operated on Before Discharge From the Neonatal Intensive Care Unit Arch Surg 1985; 120: Lautz, TB et al. Does Timing Matter? A National Perspective on the Risk of Incarceration in Premature Neonates with Inguinal Hernia. Journal of Pediatrics, 2011; 158: Vaos G, et al. Optimal timing for repair of an inguinal hernia in premature infants. Pediatr Surg Int 2010; 26: Davies BW, et al. A prospective study of neonatal inguinal herniotomy: the problem of the postoperative hydrocele. Pediatr Surg Int 203; 19: Umeura S, et al. Early repair of inguinal hernia in premature babies. Pediatr Surg Int 1999; 15: Ramsook, C and Endom, E. Overview of inguinal hernia in children. uptodate.com. Accessed 10/5/2011