A 38 year-old mother of three, presented in 2015 with recurrent, predominantly meal-related hypoglycaemia, 6 months after Roux-en-Y gastric bypass surgery.
Roux-en-Y surgery had been performed for persistent abdominal pain, bloating and weight loss occurring on a background of a vertical banded gastroplasty for obesity in 1993, and gastrostomy in 2013 for symptomatic gastric stomal stenosis.
Mixed meal testing elicited a pronounced insulin surge 30 minutes post meal ingestion resulting in hypoglycaemia at 120 minutes. A 72 hour fast excluded a fasting hyperinsulinaemic state.
GLP-1 Ga-68 PET imaging was consistent with diffuse islet cell hyperplasia/nesidioblastosis.
Trials of Diazoxide, Verapamil SR, Octreotide, Acarbose, Exenatide and Prednisolone were eventually inefficacious or not tolerated, and the patient continued to experience debilitating severe hypoglycaemia with declining awareness.
A subtotal 80% pancreatectomy initially resulted in symptomatic improvement and reduction in hypoglycaemia frequency, however after 6 months recurrent hypoglycaemia was again encountered. Repeat mixed meal testing was consistent with recurrent nesidioblastosis, albeit with a milder insulin surge.
Refractory to Octreotide, care proceeded to a trial of Pasireotide 600 micrograms twice daily. This was up-titrated to 900 micrograms twice daily after 1 week. This was then changed to 600 micrograms three times a day, which eventually proved ineffective.
A completion total pancreatectomy was then performed with a reduction in hypoglycaemia events and improvement in hypoglycaemia awareness. She has however, developed brittle diabetes requiring subcutaneous insulin, with wide swings in blood sugar readings as well as complications of pancreatic exocrine insufficiency.
NIPHS, a rare disease entity in its own right, is being increasingly recognised as a complication of gastric bypass procedures. There are limited effective non-operative management strategies. Although the novel somatostatin analogue Pasireotide has had some recent success with sustained control in some cases, in our patient it proved ineffective, ultimately necessitating a completion total pancreatectomy.