Grant bolsters inguinal hernia repair

Martin Blakely, M.D., M.S., has been awarded a $3 million federal grant for a multi-center, multi-disciplinary study to examine the safety outcomes of early versus later inguinal hernia repair for premature infants.

An inguinal hernia is an internal opening in the abdomen near the groin called the inguinal canal in which intestines or other intra-abdominal structures can become trapped, and potentially damaged. Currently, depending on providers’ preferences at various institutions, the hernia in premature infants is repaired either prior to discharge from the neonatal intensive care unit or after a variable waiting period beyond discharge (usually 4-5 months). There are significant risks associated with either of these treatment options.

But little scientific evidence is available to help surgeons, neonatologists and parents pick the best method based on outcomes or to determine if anesthesia exposure earlier rather than later poses any developmental risks.

The five-year Hernia in Premies (HIP) trial will in part determine which of the two treatment strategies is safer for premature infants, as measured by the significant adverse event rate. This is one of very few federally-funded randomized trials focusing on a neonatal surgical treatment. Randomized clinical trials for pediatric surgeries in general are fairly rare.

So far, 20 centers have signed on to participate in the HIP trial, though as many as 30 sites will likely be involved. Researchers plan to enroll 600 infants. They will be randomly divided into two treatment groups: early IH repair (prior to NICU discharge, at approximately 38 weeks post-conceptual age [weeks of gestation plus weeks of age since birth]) or later IH repair (after NICU discharge and after 55 weeks post conceptual age.)

“The required treatment is always inguinal hernia repair, but the risk to the infant associated with the timing of repair is what is very controversial,” said Blakely, associate professor of Pediatrics in the Department of Pediatric Surgery at Monroe Carell Jr. Children’s Hospital at Vanderbilt. “Often, the decision is based on provider preference and training, rather than being evidence based.”

Risks exist for repairing the hernia in both instances—before NICU discharge as well as after. Unrepaired hernias can result in an incarcerated hernia, in which the intestines or other intra-abdominal organs get trapped in the hernia, requiring emergency surgery. Surgery in a premature infant in the NICU can also result in adverse events which include need for a ventilator after the operation, apneas and bradycardia.

“We hypothesize that the effectiveness of the repair is the same in either group. So really, it comes down to safety,” said Blakely. “What we hope is that after the 600 babies that we enroll at about 30 sites around the country, we can have a much more informed discussion with neonatologists and families and we will be able to use evidence from the trial to provide safer surgical care to these vulnerable infants.”

As principal investigator, Blakely will lead a multi-disciplinary team of Vanderbilt pediatric researchers from various disciplines, which include anesthesia, informatics, neonatology, urology, patient safety and neurodevelopmental experts.

While the study’s primary purpose is to look at risks correlated to the timing of the repair, researchers will also, as a secondary objective, look at neurodevelopmental outcomes of the infants at age 2, using the Bayley Scales of Infant Development, to determine if anesthesia exposure earlier versus later carries any developmental risks.

The five-year grant was awarded from the Eunice Kennedy Shriver National Institute of Child Health & Human Development at the National Institutes of Health under grant number 1R01HD076733.

– by Christina Echegaray