The value of cystoscopically‐directed biopsy in human pancreaticoduodenal transplantation

Currently in pancreas transplantation, only indirect evidence of graft dysfunction is used as the mainstay of diagnosing a rejection episode. However, histologic specimens obtained by open surgical procedures are required for diagnostic dilemmas. After demonstrating the safety and efficacy of a cystoscopically‐directed biopsy technique to obtain adequate histologic specimens in a canine pancreaticoduodenal allograft model, we began using a similar technique in our human recipients. Between December 1987 and January 1989, 16 patients received a pancreaticoduodenal allograft with a duodenocystostomy at the Mayo Clinic. Cystoscopically‐directed needle biopsy specimens of the pancreas were obtained at the time of graft dysfunction (hypoamylasuria) and at 10 days after transplantation. The biopsy procedure consisted of obtaining pancreatic core tissue specimens with an 18‐gauge Menghini biopsy needle introduced through a rigid side‐viewing néphroscope that had been inserted transurethrally through the urinary bladder into the transplanted duodenal segment. The specimens were identified to be adequate histologically if acinar tissue was present. Each biopsy procedure was followed closely by clinical and ultrasonic examinations and serum amylase determinations. In 12 recipients, we performed 23 cystoscopically‐directed biopsies and 14 specimens (61%) were adequate. However, of our last 13 biopsy specimens, 12 (92%) were adequate. The follow‐up time per biopsy was an average of 103 d (range, 4 to 290 d). We had only two complications. Both were episodes of moderate hematuria that resolved with less than 24 hours of urinary catheter drainage. No fistulae, pseudocysts, hematomas, episodes of pancreatitis, or infections related to the biopsy procedure were documented. We have demonstrated that the cystoscopically‐directed biopsy technique is a safe procedure in human pancreaticoduodenal transplantation. This procedure can be used to differentiate the many causes of graft dysfunction.