Venous graft thrombosis in clinical pancreas transplantation: options for a rescue treatment

Salvage Endovascular Thrombectomy for Splenic Vein Thrombosis After Pancreas Transplantation: A Single-Center Experience and Systematic Literature Review

OBJECTIVES

Technical graft loss, usually thrombotic in nature, accounts for most of the pancreas grafts that are removed early after transplant. Although arterial and venous thrombosis can occur, the vein is predominantly affected, with estimated overall rate of thrombosis of 6% to 33%. In late diagnosis, the graft will need to be removed because thrombectomy will not restore its functionality. However, in early diagnosis, a salvage procedure should be attempted.

MATERIALS AND METHODS

We conducted a retrospective, descriptive analysis of a prospective database of patients who underwent pancreas transplant from April 2008 to June 2020 at a single center. We evaluated post-transplant clinical glucose levels, imaging, treatment, and outcomes. We also performed a systematic review of publications for endovascular treatment of vascular graft thrombosis in pancreas transplant.

RESULTS

In 67 pancreas transplants analyzed, 13 (19%) were diagnosed with venous thrombus. In 7 of 13 patients (54%), systemic anticoagulation was prescribed because of a non-occlusive thromboses, resulting in complete resolution for all 7 patients. Six patients (46%) required endovascular thrombectomy because of the presence of complete occlusive thrombosis; 4 of these patients (67%) needed a second procedure because of recurrence of the thrombosis. One of the 6 patients (17%) required a surgical approach, resulting in successful removal of the recurrent clot. Twelve of the 13 grafts (92%) were rescued. Graft survival at 1 year was 84%; graft survival at 3, 5, and 10 years remained at 70%.

CONCLUSIONS

Pancreas vein thrombosis represents a frequent surgical complication and remains as a challenging problem. In our experience, early diagnoses and an endovascular approach combined with aggressive medical treatment and follow-up can be used for successful treatment and reduce graft loss.

Pancreas transplants venous graft thrombosis: endovascular thrombolysis for graft rescue

PURPOSE

To retrospectively assess the efficacy and safety of percutaneous endovascular treatment in patients with pancreas venous graft thrombosis (PVGT).

MATERIALS AND METHODS

Between 2001 and 2009, 206 pancreas transplants were performed at our institution. A retrospective review of pancreas graft recipients who underwent endovascular therapy for PVGT was performed. The study group included 17 patients (10 men, 7 women; mean age 38 years) with PVGT (<60 % [9 patients]; 30-60 % [8 patients]) 6.6 ± 5.7 days after grafting. The angiographic studies, type of endovascular procedure, endovascular procedural and postprocedural effectiveness, and patient and graft outcomes were assessed.

RESULTS

In 16 of 17 cases (94 %), significant (87.5 %) or partial (12.5 %) lysis of thrombi was achieved. One patient had external compression of the portal vein due to a hematoma, which hindered mechanical removal of the thrombi. This patient required graft pancreatectomy for extensive areas of parenchymal necrosis 2 days after the endovascular procedure. No complications related to endovascular treatment were observed. Postprocedural bleeding episodes related to anticoagulation were observed in five patients. Patient and pancreas graft survival rates at 12 months were 94 and 76 %, respectively.

CONCLUSION

Catheter-directed thrombectomy is an effective treatment for patients with PVGT. Percutaneous thrombectomy, followed by anticoagulation, appears to be an effective therapy to remove the thrombus and is associated with a low complication rate.

Prevention and management of graft thrombosis in pancreatic transplant

Pancreatic transplant effectively cures type 1 diabetes mellitus and maintains consistent long-term euglycemia. However, technical failure, and in particular graft thrombosis, accounts for the vast majority of transplants lost in the early postoperative period. The pancreas' inherently low microvascular flow state makes it vulnerable to vascular complications, as does the hypercoagulable blood of diabetic patients. Ultimately, the phenomenon is most definitely multifactorial. Prevention, as opposed to treatment, is key and should focus on reducing these multiple risk factors. This will involve tactical donor selection, optimal surgical technique and some form of anticoagulation. Close monitoring and early intervention will be crucial when treating thrombosis once preventative methods have failed. This may be achieved by further anticoagulation, graft salvage, or pancreatectomy with retransplant. This article will explore the multiple factors contributing to graft thrombus formation and the ways in which they may be addressed to firstly prevent, or more likely, reduce thrombosis. Secondly, we will consider the management strategies which can be implemented once thrombosis has occurred.

Pancreatic graft survival despite partial vascular graft thrombosis due to splenocephalic anastomoses

Thrombotic complications following pancreas transplantation are still the most common cause of nonimmunologic graft loss. The aim of this study was to analyze pancreatic graft function after partial arterial graft thrombosis and the investigation of the pancreatic arterial anatomy with regard to intraparenchymal anastomoses. We retrospectively analyzed the data for 175 consecutive pancreas transplants performed between January 2002 and October 2007. Selective Y-graft angiography was performed in 10 and rubber-milk injection in 5 fresh pancreas specimens. Thrombosis of one leg of the Y-graft was diagnosed in 18 (10.3%) patients. Only one of these patients with thrombosis of the splenic artery required exogenous insulin. Sufficient graft perfusion was demonstrated in all of the remaining grafts. One graft was lost due to acute rejection. In all specimens angiography showed an excellent perfusion of the pancreaticoduodenal arcade, even after selective cannulation of the splenic artery. Arterial collaterals between the gastroduodenal, splenic artery and the superior mesenteric artery were demonstrated. Our results demonstrate that global perfusion of the pancreatic graft and sufficient graft function is sustained after the thrombotic occlusion of one branch of the Y-graft by a complex system of intraparenchymal anastomoses. These anatomical findings may have consequences for resection strategies in pancreas surgery.

Complications after pancreas transplantation

PURPOSE OF REVIEW

The history of transplantation of the pancreas, unlike that of transplantation of other abdominal organs, has largely been shaped by the associated surgical complications. After more than three decades of progress, surgical-technical pancreas graft failure rates have decreased to approximately 8%. The most recent developments in this area are systematically reviewed in this article.

RECENT FINDINGS

Vascular graft thrombosis remains, by far, the most common cause of technical graft failure. Recent reports suggested that pancreas preservation with histidine-tryptophan-ketoglutarate solution (HTK) might be a risk factor for reperfusion pancreatitis, graft thrombosis and decreased short- and long-term graft survival. It remains unclear whether these results are, at least in part, related to HTK flush volumes and extended preservation (e.g.,>12 h). For selected thrombosed pancreas grafts, there has been renewed interest in pharmacological, interventional, and surgical salvage. For selected recipients with early pancreas graft thrombosis not amenable to a salvage intervention, transplant pancreatectomy in conjunction with immediate retransplantation has emerged as a viable option. For graft thrombosis prevention, the enhanced backtable pancreas vascular reconstruction techniques (e.g., gastroduodenal artery revascularization) proposed by some authors await more formal study. For prevention of native vascular complications in high-risk recipients, several technical modifications have been reported. Developments with respect to other surgical complications (wound infection, pancreatitis, leak, and bleeding) have been more incremental.

CONCLUSION

Recent evidence underscores the importance of judicious donor and recipient selection and of optimization of preservation and surgical factors for excellent short- and long-term pancreas transplant outcomes.

Intensivtherapie nach Organtransplantation

Nach langen Diskussionen bietet das Transplantationsgesetz, das seit 01.12.1997 in Kraft ist, Rechtssicherheit. Das Gesetz dient dem Schutz des Spenders und des Empfängers, und es bietet Rechtssicherheit für alle in der Transplantationsmedizin Tätigen. Das Gesetz legt die Rechte und Verpflichtungen der Beteiligten und die Wege der Organspende und -vermittlung fest. Das Gesetz unterscheidet zwischen der Organentnahme bei Lebenden und bei Verstorbenen und legt die Rahmenbedingungen fest. Die Umsetzung der Todesbestimmung soll nach den Erkenntnissen der medizinischen Wissenschaft erfolgen und ist in den Richtlinien der Bundesärztekammer (3. Fortschreibung 1997) festgelegt worden.

Prothrombotic disorders in uremic type-1 diabetics undergoing simultaneous pancreas and kidney transplantation

BACKGROUND

Although prothrombotic disorders (PTD) are known to increase the risk of graft failure in kidney transplantation only, there are no data on PTD in simultaneous pancreas and kidney transplantation (SPK).

METHODS

Forty-seven SPK performed between September 2000 and July 2002 underwent routine screening for PTD. Data were retrospectively analyzed in view of complications (relaparotomy, graft thrombosis, pancreatitis, rejection) and graft function (HbA1c, serum creatinine) 3 months posttransplantation.

RESULTS

Twenty-five of forty-seven (53.2%) patients had 30 PTDs. Homozygous mutations of the MTHFR gene (C677T) were found in six, factor-V Leiden mutation (homo- or heterozygous G1691A) in seven, and prothrombin mutation (20210A) in one patient (group 1). Group 2 consists of deficiencies of protein C (n=1), of protein S (n=12), of antithrombin (n=1), and antiphospholipid syndromes (n=2). Overall, PTD had no influence on graft thrombosis (P=0.36) or rejection (P=0.56). In patients with homozygous mutations, relaparotomies were more often necessary than in patients without mutations (42.9% vs. 11.8%, P=0.046). In group 1, there was a trend toward a higher incidence of graft pancreatitis than in patients without mutations (38.5% vs. 14.7%, P=0.075). Three months posttransplantation, HbA1c was 6.0% in patients with and 5.5% in patients without PTD (P=0.023). With regard to serum creatinine, no significant differences were observed.

CONCLUSION

PTD are frequent in type-1 diabetics receiving SPK and may have a role in relaparotomies, graft pancreatitis, and pancreas graft function.

Successful surgical salvage of partial pancreatic allograft thrombosis

BACKGROUND

Venous thrombosis remains an important cause of pancreatic graft loss. Nevertheless, reports are scarce of treatment alternatives to complete graft removal. We describe a case of surgical salvage of a partial pancreatic graft thrombosis.

METHODS

We used descriptive retrospective analysis.

RESULTS

A 36-year-old patient with juvenile-onset diabetes mellitus and previous living related renal transplant received a cadaveric pancreas transplant in the right iliac fossa with enteric exocrine drainage and standard vascular anastomosis. Two days after discharge from the hospital, he presented with severe right upper quadrant pain, nausea, vomiting, fever, and leukocytosis. He was taken to the operating room for exploration. The tail of the pancreas, which was kinked under the gallbladder, was necrotic and excised. The remainder of the pancreas looked normal. The patient recovered well from surgery and was discharged home 7 days later.

CONCLUSIONS

Partial pancreatectomy is an acceptable surgical alternative for incomplete graft thrombosis.

Treatment and outcome of pancreatic venous graft thrombosis after kidney--pancreas transplantation

BACKGROUND

Pancreas venous graft thrombosis after transplantation is the main non-immunological cause of graft failure and usually results in pancreatectomy. Duplex Doppler ultrasonography is the primary imaging technique for monitoring vascular patency after pancreas transplantation. This study reports the results of rescue treatments for pancreas graft thrombosis after simultaneous pancreas--kidney transplantation.

METHODS

One hundred and ninety-six patients with insulin-dependent diabetes mellitus received a simultaneous pancreas--kidney transplantation. Venous graft thrombosis was diagnosed in 25 of these patients based on Doppler ultrasonographic findings.

RESULTS

Total venous graft thrombosis was diagnosed in 20 symptomatic patients, of whom 14 required graft pancreatectomy. Surgical thrombectomy was attempted in six patients with preserved arterial supply and was successful in four. Partial venous graft thrombosis was diagnosed in five asymptomatic patients; one also had partial splenic artery thrombosis. Rescue graft procedures included systemic anticoagulation (one patient), arterial thrombolysis (one) and venous thrombolysis and/or mechanical venous thrombectomy (four episodes in three patients). Graft rescue was achieved in three patients treated by venous thrombolysis/thrombectomy.

CONCLUSION

Doppler ultrasonography allows the appropriate selection of rescue treatment based on the findings of total or partial thrombosis.

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.