Outcome after splenic vein thrombosis in the pancreas allograft

Salvage of Pancreas Transplant After Successful Splenic Artery Thrombectomy

Primary nonfunction due to thrombosis after pancreas transplant is still the leading cause of nonimmunologic graft failure. Early identification of pancreatic graft arterial thrombus and prompt surgical intervention are effective for rescue of graft perfusion and its associated complications. Here, we report a case of successful surgical thrombectomy of the splenic artery, with particular emphasis on clinical presentation, diagnosis, and surgical technique.

Endovascular Stenting of Portal Vein for Graft Rescue after a Pancreas Transplant Venous Graft Thrombosis: A Case Report

Venous thrombosis of pancreas transplant allografts often leads to graft loss. It is an worrisome complication and difficult to treat, forming the most common nonimmunological cause of graft loss. Multiple risk factors have been implicated in the development of venous thrombosis of pancreas transplant. Color Doppler ultrasonography enables early diagnosis of venous thrombosis, thus increasing the possibility of graft-rescue treatments. Endovascular management of pancreatic transplant vascular complications is scant and in the form of case reports. We report a case of early detection of pancreatic graft venous thrombosis that was treated successfully by catheter-directed thrombolysis mechanical thrombectomy, percutaneous transluminal angioplasty, and stenting of portal vein.

Endovascular Management for the Treatment of Pancreas Transplant Venous Thrombosis: A Single-Center Experience

PURPOSE

To investigate the safety and efficacy of mechanical thrombectomy used as a tool for graft rescue in patients with pancreas graft venous thrombosis (PGVT).

MATERIALS AND METHODS

Graft venous thrombosis was discovered in 36 (33%) of 110 patients who underwent pancreas transplantation. Percutaneous aspiration thrombectomy was performed in seven patients (mean age, 31 y; range, 15-36 y) who had complete or severe thrombosis of the splenic vein or superior mesenteric vein seen on postoperative computed tomography.

RESULTS

Successful evacuation of PGVT was possible in six of seven patients; the thrombus was partially evacuated in one patient. In this patient, subsequent anticoagulation salvaged the graft, rendering primary and secondary technical success rates as 86% and 100%, respectively. As pancreas grafts were successfully functioning in all seven patients within 1 month after endovascular treatment, the clinical success rate was 100%. There were no procedure-related complications. At the last follow-up evaluation, all seven patients were alive with no graft loss (mean follow-up time, 9.4 mo; range, 3.6-22.2 mo).

CONCLUSIONS

Endovascular treatment may be considered in patients with severe PGVT to prevent early 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.

Pancreas graft thrombosis: causes, prevention, diagnosis, and intervention

PURPOSE OF REVIEW

Pancreas graft thrombosis remains one of the most common reasons for pancreas transplant loss. Patients with a history of thrombotic events should be identified and evaluated for thrombophilia to identify transplant candidates at highest risk.

RECENT FINDINGS

Early after transplant, vascular thrombosis is multifactorial, but beyond 2 weeks, inflammation or acute rejection predominate as the cause of thrombosis. Most pancreas transplant centers utilize some form of anticoagulation following transplantation. Aspirin is highly recommended. Unfractionated or low-molecular-weight heparin is often administered, but some centers use heparin selectively and typically at low dose to avoid postoperative bleeding. Warfarin is less frequently given and its use should probably be limited to patients with thrombophilia.

SUMMARY

Thrombectomy, either surgical or percutaneous, may salvage the pancreas graft if performed early after the occurrence of thrombosis.

Current status of organ transplantation in Japan and worldwide

Recent advances in immunosuppressant therapy have dramatically reduced the frequency of acute rejection of organ transplants. Subsequently, the short-term graft survival rate has been improved, and ABO blood type-incompatible and existing anti-HLA antibody-positive kidney transplantation has been enabled, which has increased the availability of living kidney donors. Japan has a unique history and strategies of liver transplantation (LT) for various liver diseases. The outcomes of living donor liver transplantation (LDLT) in Japan is comparable to that of deceased donor liver transplantation (DDLT) in Western countries despite the relatively short history of LT. The main disadvantage of LT in Japan is donor shortage mainly due to the small number of available deceased donors. There are some disadvantages with LDLT in autoimmune liver diseases because of the dependence on blood relative donors. The first brain-dead pancreas transplantation (PTx) was performed in 2000. Since that time, 42 brain-dead PTx, 2 non-heart beating PTx, and 14 living donor PTx had been performed by the end of 2007. One of the 44 recipients of deceased donor PTx died of unknown causes 11 months after transplantation. Although most of the deceased donors in Japan were marginal and their condition was not favorable, the results of these cases were comparable to those of Western countries. Fourteen intestinal transplantations (ITx) had been performed by the end of 2007 in four transplant centers. There were 3 deceased donor and 11 live donor transplants. The original diseases included short bowel syndrome (n = 6), intestinal function disorder (n = 6), and retransplantation (n = 2). The graft and patient survival rate are 60% and 69%, respectively. Eight recipients survived and stopped parenteral nutrition with full-functioning grafts. Amendment of the Japanese law for the utilization of deceased donors should increase the number available donors in the future.

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.

Role of color Doppler sonography in post-transplant surveillance of vascular complications involving pancreatic allografts()

PURPOSE

To evaluate the role of color Doppler ultrasonography in the postoperative surveillance of the vascular complications involving pancreas allografts.

METHODS

A retrospective analysis of a consecutive series of 223 pancreas transplantations was performed. All recipients received antithrombotic prophylaxis, which was tailored to the individual's estimated risk of thrombosis. All patients were monitored with daily color Doppler ultrasonography during the first post-transplant week and thereafter whenever clinically indicated. Vascular complications were defined as all thrombotic events requiring: increased anticoagulant therapy, angiography with fibrinolytic therapy, or repeat surgery.

RESULTS

The overall patient survival rates at one, three, and five years after transplantation were 94.7%, 93.3%, and 91%, respectively. The overall graft survival rates at the same time points were 87.4%, 79.6%, and 75.6%, respectively. In 28 of the 223 cases (12.5%) graft thromboses were diagnosed with Doppler ultrasound within the first 10 days after transplantation. In 3 cases, graft pancreatectomies were performed because of a complete loss of blood flow in the parenchyma. An attempt to rescue the graft was made in 18 patients. Fourteen of these grafts were saved and are still functioning (77.7%); and 4 rescue attempts failed and the grafts were subsequently explanted (32.3%).

CONCLUSION

Color Doppler ultrasound is a suitable tool for postoperative surveillance of pancreas transplant recipients. Its use can lead to early diagnosis and timely treatment of vascular complications.

Surveillance and rescue of pancreas grafts

BACKGROUND

Technical failure rates are higher for pancreas allografts (PA) compared with other solid organs. Posttransplant surveillance and prompt availability of rescue teams with multidisciplinary expertise both contribute to improve this result. We herein report a single institution's experience with posttransplant surveillance and rescue of PA.

METHODS

A retrospective survey was performed of a consecutive series of 177 whole organ pancreas transplants in 173 patients. Antithrombotic prophylaxis was used in all recipients and tailored on anticipated individual risk of thrombosis. During the first posttransplant week, all PA were monitored with daily Doppler ultrasonography. Surgical complications were defined as all adverse events requiring relaparotomy during the initial hospital stay or the first 3 posttransplant months.

RESULTS

A total of 26 relaparotomies were performed in 25 patients (14.7%). One recipient needed two relaparotomies (0.6%). Graft rescue was attempted in patients without permanent parenchymal damage at repeat surgery and in 12 recipients diagnosed with nonocclusive vascular thrombosis. Overall 25 grafts (96.3%) were rescued and one was lost. One-year recipient and graft survivals in patients with versus without complications potentially leading to allograft loss were 92.6% and 63.0% versus 94.4% and 94.3%, respectively. Excluding complications for which graft rescue was not possible, 1-year graft survival rate increased to 78.7%.

CONCLUSIONS

Close posttransplant surveillance can allow rescue of a relevant proportion of PA developing nonocclusive venous thrombosis or other surgical complications. Further improvement awaits better understanding of biological reasons for posttransplant complications jeopardizing PA survival and the development of more effective preventive measures.

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.

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.

Pancreas transplantation: the histologic morphology of graft loss and clinical correlations

BACKGROUND

Graft losses due to leaks, bleeding, thrombosis, infections, and early pancreatitis are grouped together under the category of technical failure. Among these complications, massive vascular thrombosis continues to be the most important cause of early graft loss due to technical failure. Pathological evaluation of most allografts lost early in the posttransplantation period shows vascular thrombosis with associated proportional parenchymal necrosis. The morphological findings in allografts that are considered to be lost due to technical failure has not been systematically addressed. In particular, the role of acute rejection in early graft loss has not been well studied.

METHODS

Seventy-four consecutive pancreas graft pancreatectomies were studied histologically to evaluate for thrombosis (recent versus organized), type of vessel involved by thrombosis (arteries, veins, or both), acute rejection grade, chronic rejection grade, endotheliitis, transplant arteritis, coagulation necrosis, acute pancreatitis, presence of infectious organisms, transplant (obliterative) arteriopathy, neoplasia, relative proportions of alpha and beta islet cells, and immunoglobulin and complement deposition. The histological findings were correlated with donor and recipient data as well as clinical presentation.

RESULTS

In 23 out of 39 grafts lost in the first 4 weeks posttransplantation, the only pathological changes found were vascular thrombosis and bland ischemic parenchymal necrosis. In these cases, no underlying vascular pathology or any other specific histological change was identified. Most of these grafts (78%) were lost in less than 48 hr and all in the first 2 weeks posttransplantation. Massive vascular thrombosis occurring in an otherwise histologically normal pancreas was the most common cause of graft loss in the first 4 weeks posttransplantation (59%). In most of the remaining cases (33%), although the clinical presentation suggested technical failure, there was clear histological evidence that the massive thrombosis resulted from vascular injury due to immune damage (acute and hyperacute rejection). Increased incidence of early graft thrombosis was seen in grafts from older donors and longer cold ischemia times. After the first month posttransplantation, graft pancreatectomies revealed a wider variety of pathological processes that included severe acute rejection, combined acute and chronic rejection, chronic rejection, and infections. Acute and chronic vascular thrombosis in large and small vessels was commonly seen at all times posttransplantation; chronic, organized thrombosis was strongly associated with chronic rejection.

CONCLUSIONS

(a) Early acute thrombosis occurring in a histologically normal pancreas defines a true technical failure. This study showed that acute rejection leading to massive thrombosis, which clinically simulates technical failure, results in a significant proportion of early graft losses. (b) Systematic histological evaluation of failed grafts is absolutely necessary for the accurate classification of the cause of graft loss. (c) There is morphological evidence that chronically ongoing thrombosis is an important, common, contributing factor for late graft loss.

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.