Pediatric Inguinal Hernia Repair: The Controversies Emanuel Nearing, II, MD

Why does it matter?  Inguinal hernias are common  3-5% in term infants  13% in infants born <33 weeks  Optimal timing for repair remains debatable  Multiple techniques for repair  Open  Laparoscopic  Combination of both

The basics  Goal of pediatric inguinal hernia repair is complete ligation of patent processus vaginalis  Normally, obliteration occurs in “the last weeks of gestation”  Left processus closes prior to the right  Right side hernias more common  Failure to close leads to hernia and hydrocele

Why do repairs fail?  Ligation of sac not high enough  Injury to the floor of inguinal canal  Failure to close inguinal ring (girls)  Wound infections or hematoma

Laparoscopic Inguinal Hernia Repair  Benefits  Excellent visualization  Minimal dissection  Better cosmesis  Faster recovery?  Less post operative pain  Simultaneous control of contralateral patent processes vaginalis  Faster if contralateral side repaired

Laparoscopic Inguinal Hernia Repair  Drawbacks  Cost  Not gold standard  Infertility risk  Length of surgery?  8 papers reviewed and this is the extent of the cons!

Open Inguinal Herniorrhaphy  Gold standard  Most commonly performed  79% of surgeons favor this approach for first time, unilateral hernias  Only 17% of surgeons reported favoring laparoscopic approach for first time, unilateral hernias

Yang et al. (2011)  Meta analysis of Open versus Lap (7 studies)  3 RCTs and 4 OCSs (1543 patients)  Findings--there were no statistical differences:  Operative time (with experienced surgeons)  Hospital stay  Time to resume full activity  Recurrence  Post operative CMIH  Complications  Infertility not addressed

Possible in premature neonates!  Does earlier repair favor open technique?  Chan et al. (2013): 79 premature neonates  Patients born prior to 37 weeks  Laparoscopic repair offered at 2.5 kg  One patient with incarceration (didn’t convert to open)  No incidents of apnea

Contralateral Evaluation What do we do about patients presenting with unilateral hernia?  Is there a Contralateral Patent Processus Vaginalis (CPPV)?  Development of Contralateral Metachronous Inguinal Hernia (CMIH)?

Contralateral Patent Processus Vaginalis (CPPV)  Open tunnel without identifiable termination to the peritoneal sac in the inguinal canal  Fear that this will lead to CMIH  Risk of incarceration  Evaluation via laparoscopy: transumbilical versus transinguinal  Does every CPPV become a clinically apparent hernia?  Risks of evaluation: testicular atrophy, vas deferens injury, even infertility

CPPV cont.  Clinically undetected CPPV incidence: 20-50%  7% risk of hernia development

Contralateral Metachronous Inguinal Hernia (CMIH) Definition varies:  Clinically detected inguinal hernia on the side with negative findings of CPPV on initial laparoscopy and subsequent confirmation of patent processus vaginalis in second surgery  Open tunnel into the contralateral inguinal region  Swelling or palpable crepitus under pneumoperitoneum pressure in the contralateral groin or scrotum  Bubbles or fluid expressed by palpation over the contralateral inguinal canal o scrotum  Incidence: 2.5% of children following negative evaluation for CPPV by transingunal laparoscopy

Evaluation  Laparoscopic evaluation for CPPV in 1992 via separate umbilical incision during open repair  Transinguinal approach developed shortly afterward  Literature “favors” transinguinal laparoscopy for CPPV investigation  Transumbilical “has become routine” during laparoscopic repair of clinically apparent unilateral hernias

Evaluation continued  Transumbilical laparoscopy:  Sensitive (99.4%) and specific (99.5%)  Zhong (2013) Meta Analysis of 23 studies:  13 studies favored inguinal approach  6 studies favored laparoscopic approach  4 combined approach  Various visible angle laparoscopes (30º – 120º and flexible scopes)  Pneumoperitoneum pressure 6-15 mm Hg

Evaluation continued  Umbilical laparoscopy: better visualization  Transinguinal  Higher incidence when higher angle scope used  Lower incidence with pneumoperitoneum pressure of >8 mm Hg

Bigger Question!  What does a CPPV mean clinically?  Natural history is still unknown  1-31% range for CMIH in literature  Does this warrant evaluation at time of initial surgery?  The jury is still out…

Issues related to timing of IH repair  Prematurity  Risk of incarceration or strangulation  Development of apnea  Repair prior to discharge from NICU versus electively as outpatient  Balance potential risks of hernia with anesthetic and technical risks

Early versus late repair Why is there debate?  No consensus in the literature regarding optimal timing in asymptomatic patients  Studies providing insight dated

Prematurity and Hernia  Estimated incidence of 13% in infants born <32 weeks, and 30% in infants born <1 kg  Risks:  Male sex  Prolonged mechanical ventilation  Lower gestational age  Extremely low birth weight

Prematurity and Hernia  Rate of incarceration (Lautz, 2011)  14.6% prior to 1 month  11.9 at 1-2 months  15.6% at 2-3 months  18.2% for repair after 3 months of life  Repair after 40 weeks post conception was associated with a 2 fold risk of incarceration (20.6%) compared with repair between weeks (9%)  Repair before 36 weeks (11.3%)

Prematurity  Within the initial hospitalization, interval from birth to repair had no significant bearing on the risk of incarceration  Delay past 40 weeks post conceptual age increases the risk 2 fold  Survey by American Academy of Pediatrics, Section on Surgery: 63% would perform inguinal herniorrhaphy just before discharge from NICU

Post conception age (PCA)  Trigger for admission for observation  Risk of apnea nearly absent by 44 weeks PCA (does risk extend out to 60 weeks?)  Cote et al. (1995) incidence of apnea significantly reduced at weeks and was <1% at 54 weeks PCA

Incarceration  Will occur in 15-35% of all infants <1 year of age  Risk for individual patient is 4.6%  No question as to potential severity here!

Apnea  Apnea rate in former premature infants as high as 49% (5% more realistic?)  2.6% risk in full term infants  Inversely related to gestational age and PCA  Risk continued at home

Apnea cont.  Multiple definitions (6 in my review)  Time between breaths from secs  Oxygen desaturations  Visual absence of respiration  Decreased risk with modern anesthetic agents

Apnea cont.  High percentage of premature infants have a rocky course in recovery but that doesn’t translate into overnight events  Longer PACU monitoring?  Would 4-6 hrs (up to 12 hrs) be sufficient  Ozdemir found mean time to apnea event  <45 weeks: 8.6 hrs  >45 weeks: 4 hrs  Laituri (2011) had no apnea events in 300+ pts over 45 weeks

Lee et al. (2010)  172 patients mean age 30.7 weeks  No patient with known inguinal hernia incarcerated prior to elective repair  35 discharged from NICU with known hernia  127 repaired electively as outpatient  Longer overall hospitalization in patients who had hernia repair prior to discharge from NICU  13 pts required prolonged intubation >48 hrs  Former premature infants with post conception age between weeks can safely undergo outpatient herniorrhaphy if there is no history of lung disease or apnea

Ozdemir (2013)  May be able to reduce timing of surgery as outpatient down to PCA of 45 weeks  Book the patient as first case so that there can be 6 hrs of PACU monitoring prior to discharge

Conclusion  Laparoscopic hernia repair is safe  I would not specifically look for CPPV: just deal with the CMIH if and when it develops  The debate will continue!  I have more questions than when I started…

Citations  Chan, I., et al. (2013). Laparoscopic Inguinal Hernia Repair in Premature Neonates: Is It Safe? Pediatric Surgery International, 29:  Esposito, C., et al. (2012). Laparoscopic Inguinal Hernia Repair in Premature Babies Weighing 3 kg or Less. Pediatric Surgery International, 28:  Laituri, C., et al. ( 2012). Overnight Observation in Former Premature Infants Undergoing Inguinal Hernia Repair. Journal of Pediatric Surgery,2012; 47:  Lautz, T., Raval, M., et al. (2011). Does Timing Matter? A National Perspective on the Risk of Incarceration in Premature Neonates with Inguinal Hernia. The Journal of Pediatrics, 158 (4)  Lee, S., Gleason, J., et al. ( 2011). A Critical Review of Premature Infants with Inguinal Hernias: Optimal timing of repair, incarceration risk, and postoperative apnea. Journal of Pediatric Surgery, 2011; 46:  Ozdemir, T., Arikan, A. (2013). Postoperative Apnea After Inguinal Hernia Repair in Formerly Premature Infants: impacts of gestational age, postconceptional age and comorbidities. Pediatric Surgery International, 29:  Shalaby, R., et al. (2012). Laparoscopic Hernia Repair versus open Herniotomy in Children: A Controlled Randomised Study. Minimally Invasive Surgery, 2012; 2012:  Tam, Y., et al. ( 2012). Simple maneuvers to reduce the incidence of false-negative findings for contralateral patent processus vaginalis during laparoscopic hernia repair in children: a comparitive study between 2 cohorts. Journal of Pediatric Surgery,2013; 48:  Tam, Y., et al. ( 2014). Unexpected Metachronous Hernia Development in Children Following Laparoscopic Unilateral Hernia Repair with Negative Evaluation for Contralateral Patent Processus Vaginalis. Journal of Laparoendoscopic and Advanced Surgical Techniques, 24 (2):  Wang, K. (2012)Assessment and Management of Inguinal Hernia in Infants. American Acadamy of Pediatrics, 130:  Yang, C., et al. (2011). Laparoscopic vs Open Herniorrhaphy in the Management of Pediatric Inguinal Hernia: A systematic review and meta-analysis. Journal of Pediatric Surgery, 46:  Zani, A., et al. (2013). Management of Pediatric Inguinal Hernias in the Era of Laparoscopy: Results of an International Survey. Eur J Pediarti Surg, 2014; 24:9-13.  Zhong, H., Wang, F. ( 2014). Contralateram Metachronous Hernia Following Negative Laparoscopic Evaluation for Contralateral Patent Processus Vaginalis: A meta-analysis. Journal of Laparoendoscopic and Advanced Surgical Techniques, 24 (2):