Postoperative CT in pancreas transplantation

Early detection of complications in pancreas transplants by microdialysis catheters, an observational feasibility study

Background

Despite advances in immunosuppression and surgical technique, pancreas transplantation is encumbered with a high rate of complication and graft losses. Particularly, venous graft thrombi occur relatively frequently and are rarely detected before the transplant is irreversibly damaged.

Methods

To detect complications early, when the grafts are potentially salvageable, we placed microdialysis catheters anteriorly and posteriorly to the graft in a cohort of 34 consecutive patients. Glucose, lactate, pyruvate, and glycerol were measured at the bedside every 1–2 hours.

Results

Nine patients with graft venous thrombosis had significant lactate and lactate–to-pyruvate-ratio increases without concomitant rise in blood glucose or clinical symptoms. The median lactate in these patients was significantly higher in both catheters compared to non-events (n = 15). Out of the nine thrombi, four grafts underwent successful angiographic extraction, one did not require intervention and four grafts were irreversibly damaged and explanted. Four patients with enteric anastomosis leakages had significantly higher glycerol measurements compared to non-events. As with the venous thrombi, lactate and lactate-to-pyruvate ratio were also increased in six patients with graft surrounding hematomas.

Conclusions

Bedside monitoring with microdialysis catheters is a promising surveillance modality of pancreatic grafts, but differentiating between the various pathologies proves challenging.

Multi-Modality Imaging Evaluation of the Whole-Organ Pancreas Transplant

Pancreas transplants are an important treatment options for patients with severe diabetes mellitus and other medical conditions. Multiple-imaging modalities, including computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound (US) are available to evaluate the pancreas transplants and their vascular supply, with the graft having a characteristic appearance on each modality. Complications of the graft and its vascular supply present interesting challenges to the clinicians and radiologists caring for this patient population. Being able to identify the imaging appearance of normal and abnormal pancreas transplants, it is necessary to ensure these patients are provided optimal care.

Duodenal graft complications requiring duodenectomy after pancreas and pancreas-kidney transplantation

Duodenal graft complications are poorly reported complications of pancreas transplantation that can result in graft loss. Excluding patients with early graft failure, after a median follow-up period of 126 months (range 23-198) duodenectomy was required in 14 of 312 pancreas transplants (4.5%). All patients were insulin-independent at the time of diagnosis. Reasons for duodenectomy included delayed duodenal graft perforation (n = 10, 71.5%) and refractory duodenal graft bleeding (n = 4, 28.5%). In patients with duodenal graft bleeding, a total duodenectomy was performed. In patients with duodenal graft perforation, preservation of a duodenal segment was possible in five patients but completion duodenectomy was necessary in one patient. After total duodenectomy, immediate enteric duct drainage was feasible in seven patients. In two patients, a pancreaticocutaneous fistula was created that was subsequently converted to enteric drainage in one patient. In the other patient, enteric fistulization occurred as a consequence of silent pressure perforation of the draining catheter on the ascending colon. After a mean follow-up period of 52 months (21-125), all patients were alive, well, and insulin-independent. An aggressive and timely surgical approach may permit graft rescue in patients with severe duodenal graft complications occurring after pancreas transplantation. Generalization of these results remains to be established.

Techniques of pancreas graft salvage/indications for allograft pancreatectomy

PURPOSE OF REVIEW

Despite improvements in pancreas allograft outcome, graft complications remain a significant cause of morbidity and mortality. This review analyses the issues involved in the management of conditions that may require graft pancreatectomy, including the indications and techniques for graft salvage.

RECENT FINDINGS

With early recognition of graft complications, liberal use of radiological interventions, improved infection control, access to critical care and innovative surgical techniques, graft salvage is now feasible in many circumstances where graft pancreatectomy would previously have been necessary.

SUMMARY

The outcome of pancreas transplantation continues to improve with advances in the management of graft-threatening complications.