A cystoscopically directed biopsy technique developed in canine pancreaticoduodenal transplantation.

Present methods of monitoring for allograft dysfunction in pancreaticoduodenal transplantation (urinary amylase, scintigraphy) give indirect evidence and do not consistently allow recognition of early, potentially reversible rejection from other causes of allograft dysfunction. For better diagnosis of allograft dysfunction, adequate tissue specimens must be obtained without trauma to the allograft. We devised a cystoscopically directed needle biopsy technique to obtain tissue from the canine pancreaticoduodenal allograft. This technique is made feasible by a duodenocystostomy similar to that in human pancreaticoduodenal transplantation. The duodenum acts as a port of entry for the biopsy instruments, providing access to the pancreas. A 24F side-viewing nephroscope is used to view the duodenum. The tissue specimen is obtained with an 18-gauge, 350 mm Menghini aspiration needle inserted by way of the nephroscope through the duodenum and into the pancreas. Pancreaticoduodenal allotransplantation with a duodenocystostomy for exocrine drainage was performed in 18 dogs. Of 59 serial biopsy specimens obtained, 41 (69.5%) were adequate for pathologic evaluation. The principal complication associated with the technique was minimal bleeding at the biopsy site, occurring in 22 of the 59 biopsy procedures. This cystoscopically directed biopsy technique appears to be safe, often obtains adequate tissue for diagnosis, and may be directly applicable for distinguishing causes of allograft dysfunction in human pancreaticoduodenal transplantation.