Towards a model of biliary atresia - Pilot feasibility study in newborn piglets

Biliary atresia (BA) is a rare congenital liver disease with unknown etiology, and it is the most common indication for liver transplantation in children. As BA infants suffer from intestinal malabsorption and neurodevelopmental deficits, it is necessary to identify optimal medical and nutritional strategies using appropriate neonatal animal models. We aim to determine the feasibility of using newborn piglets with surgically induced cholestasis (bile duct ligation (BDL)) to mimic clinical features of BA. Six piglets were subjected to abdominal surgery on day 4 after birth. The bile ducts were ligated, and the piglet were followed for up to 12 days. On day 12 the piglets were subjected to a hepatobiliary scintigraphy using the tracer radiolabeled Technetium(99m-tc)-mebrofenin, and blood samples were collected for biochemical profiling. Of the six piglets, hepatobiliary scintigraphy verified that two piglets (BDL) had no excretion of bile into the duodenum, i.e. full cholestasis with a hepatic extraction fraction of 84-87% and clearance time of 230-318 min. One piglet (SHAM) had bile excretion to the duodenum. In accordance with this, the BDL piglets had steatorrhea, and increased levels of bilirubin and gammaglutamyl transferase (GGT). The last three piglets were euthanized due to bile leakage or poor growth. Surgically induced cholestasis in young piglets, may offer an animal model that displays clinical characteristics of biliary atresia, including malabsorption, hyperbilirubinaemia, increased GGT and reduced hepatic excretory function. Following refinement, this animal model may be used to optimize feeding strategies to secure optimal nutrition and neurodevelopment for neonatal cholestasis/BA patients.

Laparoscopy to Assist Surgical Decisions Related to Necrotizing Enterocolitis in Preterm Neonates

Aim of the Study: Necrotizing enterocolitis (NEC) is a devastating intestinal disease that mainly affects preterm infants. Despite advancements in neonatal care, mortality of NEC remains high and controversies exist regarding the most appropriate time for surgical intervention and challenging of diagnosing NEC. Using a pig model of NEC, we aimed to examine if laparoscopy is feasible for diagnosis of NEC. Methods: Preterm caesarean-delivered piglets (n = 42) were fed with increasing amounts of infant formula up to 5 days to induce NEC. On days 3-5, we examined the intestine by laparoscopy under general anesthesia. The bowel was examined by tilting the pigs from supine position to the left and right side. Macroscopic NEC lesions were identified and graded according to a macroscopic scoring system, then a laparotomy was performed to rule out any organ injury and missed NEC lesions. Results: Visible NEC lesions (scores 4-6) were found in 26% (11/42) of the piglets. A positive predictive value of 100% was found for laparoscopy as a diagnostic marker of NEC in both colon and the small intestine. One piglet had a higher NEC score in the small intestine found at laparotomy, than at laparoscopy, resulting in a sensitivity of 67%, and a specificity of 100% for the small intestine. Conversely, both the sensitivity and specificity for colon was 100%. Acceptable levels of agreement was found, with minimal proportional bias in both colon and the small intestine for laparoscopy and laparotomy. Ultrasound examination had a lower sensitivity of 67% and specificity of 63%. All piglets were respiratory and circulatory stable during the procedure. Conclusions: In preterm piglets, laparoscopy is a feasible tool to diagnose NEC with a high positive predictive value and a high specificity.