Pancreas transplant graft evaluation using the MIBI scan--a useful tool

Vascular complications of pancreas transplantation

OBJECTIVE

The purpose of our study was to focus on the early diagnosis and treatment of vascular complications after simultaneous pancreas-kidney (SPK) transplantation. Description of the technique for salvage of the graft after venous thrombosis (VT) is also provided.

METHODS

From July 1994 to December 2002, 14 patients of 206 SPK transplant recipients had partial VT. Partial splenic VT (PSVT) was documented in 10 patients (4.8%), two had complete thrombosis of the splenic vein, one partial superior mesenteric thrombosis, and one developed partial thrombosis of the splenic and superior mesenteric vein. Four patients developed complete VT of the pancreas allograft and one superior mesenteric artery thrombosis. Our experience with four arteriovenous fistulae is also reported. The immunosuppression included tacrolimus, steroids, and monoclonal antibody to the IL-2 receptor. Thymoglobulin was introduced in June 2000 in our protocol combined with rapamycin or mycophenolate mofetil. These cases were identified following the intravenous (iv) use of tacrolimus with or without anti-IL-2R therapy. One case of complete VT is also reported one month following transplantation in a recipient with high rapamycin levels. Diagnosis was established during routine color Doppler ultrasonography.

RESULTS

Partial VT was effectively treated with anticoagulation. Complete VT required surgical thrombectomy. In our series, the pancreas was salvaged successfully in all patients with the technique described here.

CONCLUSION

Early diagnosis of vascular complications after pancreas transplantation is of paramount importance for the appropriate treatment with organ salvage. Based on our experience, we suggest that VT can be effectively treated with anticoagulation. Aspirin is sufficient for PSVT.

Partial venous thrombosis of the pancreatic allografts after simultaneous pancreas-kidney transplantation

Despite new advances in transplantation, complete venous thrombosis (VT) of the pancreas after simultaneous pancreas kidney (SPK) transplantation usually results in graft loss. Data are limited regarding the outcome and treatment of partial VT of the pancreas allograft. From July 1994 to December 1999, 126 patients with IDDM/end-stage renal disease underwent SPK with systemic bladder drainage at the University of Miami. We retrospectively reviewed our experience regarding the outcome and treatment options of partial VT of the pancreas allografts. From July 1994 to April 1997, partial VT was not seen in the first 66 SPK patients induced with anti-CD3 rnAb and oral or intravenous (i.v.) tacrolimus (TAC) in the operating room. From May 1997 to June 1999, 14 (29%) out of 48 patients had VT. These cases were identified following the i.v. use of TAC with anti-IL-2R antibody-induction therapy (7/15) or without (7/33). Partial thrombosis of the splenic vein (PTSV) was documented in 10 patients, 2 had complete thrombosis of the splenic vein (CTSV), 1 had partial thrombosis of the superior mesenteric vein (PTSMV), and 1 patient had PTSV and PTSMV. These were identified incidentally during routine color Doppler ultrasonography (CDU). None of these SPK recipients demonstrates a change in clinical parameters. The first 8 patients were systemically heparinized, followed by oral anticoagulation, except 1 patient with CTSV. He progressed to complete thrombosis of the pancreas allograft and was treated with percutaneous thrombectomy and urokinase infusion, followed by heparinization and oral anticoagulation. One patient required exploration for bleeding. In an attempt to reduce the morbidity of heparinization, we treated the next 6 patients with PTSV with aspirin followed by serial CDU. All 14 patients had preservation of the endocrine and exocrine pancreatic functions. CDU showed resolution with recanalization of the thrombosed vein(s). From July 1999 to December 1999, 12 SPK recipients were administered TAC orally with or without induction therapy with anti-IL-2R antibody. So far, in this group, VT has not been identified. In summary, a total of 14 out of 126 patients (11%) had isolated VT with a mean follow-up of 36.4 months. Based on our experience, we suggest that extensive VT after pancreas transplantation, including splenic and superior mesenteric VT, be treated with heparin and subsequent oral anticoagulation for 3 months. For more limited, partial splenic VT, aspirin may be sufficient. Follow-up CDU is critical for a successful outcome. The i.v. use of TAC appears to be a risk factor for the increased incidence of VT. Currently, using IL-2rmAb as induction, TAC is started orally on postoperative days 3 or 4 and aspirin on postoperative day 2.