Pancreas graft thrombosis: is there a role for trypsin

Early protocol computer tomography and endovascular interventions in pancreas transplantation

BACKGROUND

Early vascular complications following pancreatic transplantation are not uncommon (3%-8%). Typically, cross-sectional imaging is requested in response to clinical change. We instituted a change in protocol to request imaging pre-emptively to identify patients with thrombotic complications.

METHODS

In 2013, protocol computer tomography angiography (CTA) at days 3-5 and day 10 following pancreas transplantation was introduced. A retrospective analysis of all pancreas transplants performed at our institution from January 2001 to May 2019 was undertaken.

RESULTS

A total of 115 patients received pancreas transplants during this time period. A total of 78 received pancreas transplant without routine CTA and 37 patients with the new protocol. Following the change in protocol, we detected a high number of subclinical thromboses (41.7%). There was a significant decrease in invasive intervention for thrombosis (78.6% before vs 30.8% after, p = .02), and graft survival was significantly higher (61.5% before vs 86.1% after, p = .04). There was also a significant reduction in the number of graft failures (all-cause) where thrombosis was present (23.4% before vs 5.6% after, p = .02). Patient survival was unaffected (p = .48).

CONCLUSIONS

Implementation of early protocol CTA identifies a large number of patients with subclinical graft thromboses that are more amenable to conservative management and significantly reduces the requirement for invasive intervention.

Inferior Vena Cava-Duodenal Drainage in Pancreas Alone Transplantation for Chronic Pancreatitis: A Case Report

Enteric drainage has been the main trend in solitary pancreas transplantation. Compared with bladder drainage, it does not cause metabolic or urologic complications, but there is no way to perform immunologic monitoring, except by graft pancreas biopsy. Additionally, although portal drainage of the graft vein is considered physiological drainage, it has more of a risk for surgical complications. To overcome these disadvantages, we successfully performed inferior vena cava (IVC)-duodenal drainage in pancreas alone transplantation. A 44-year-old man underwent pancreas alone transplantation. He had insulin-dependent diabetes because of chronic pancreatitis, thus he had taken a pancreatic enzyme. After right-sided medial visceral rotation, the IVC was dissected for anastomosis with a graft portal vein. The right common iliac artery was anastomosed with a Y-graft in the pancreas graft. The graft duodenum was anastomosed with recipient duodenum using the side-to-side manner. Postoperatively, he underwent protocol biopsies of the graft duodenum through endoscopy two times. There was no evidence of graft thrombosis or rejection. He had a normal glucose level without any diabetic drugs, and he required no pancreatic enzyme for digestion. The IVC-duodenum drainage procedure was a feasible method for preventing thrombosis and providing an opportunity for direct graft monitoring through endoscopy.

Formation of Collateral Veins in a Graft Pancreas After a Simultaneous Pancreas and Kidney Transplantation: A Case Report

A graft vein thrombosis is the main cause of early graft failure after pancreas transplantation. We report a case of formation of collateral veins in a graft pancreas after transplant. A 30-year-old woman underwent simultaneous pancreas and kidney transplantation. She was discharged 16 days after the operation with good pancreas and kidney function. A total occlusion of the portal vein was discovered on computed tomography (CT) performed at an outpatient clinic. She had no symptoms or signs of hyperglycemia. Venography was attempted for vein thrombectomy but failed. After 2 weeks of heparinization therapy, the edema disappeared and perfusion of the graft pancreas improved. However, the thrombotic occlusion was not resolved on CT. Arteriography of the Y-graft revealed collateral veins. She was discharged with warfarin. She is currently doing well without any symptoms or signs. This is the first reported case of collateral vein formation in a grafted pancreas after pancreas transplantation.

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.

Early pancreas allograft thrombosis

OBJECTIVES

To determine factors associated with early pancreatic allograft thrombosis (EPAT). Thrombosis is the leading non-immunological cause of early pancreatic allograft failure. Multiple risk factors have been postulated. We hypothesized that recipient perioperative hypotension was a major risk factor and evaluated the correlation of this and other parameters with EPAT.

METHODS

We retrospectively reviewed the records of the 118 patients who received a pancreatic allograft at our center between October 1992 and January 2010. Multiple donor and recipient parameters were analyzed as associates of EPAT by univariate and multivariate analysis.

RESULTS

There were 12 episodes of EPAT, resulting in an incidence of 10.2%. On univariate analysis, EPAT was associated with perioperative hypotension, vasopressor use, and neuropathy in the recipient (p ≤ 0.04 for all). On multivariate analysis corrected for age, sex, and peripheral vascular disease, only vasopressor use retained a significant association with EPAT with a hazard ratio of 8.74 (CI 1.11-68.9, p = 0.04). Factors associated with vasopressor use included recipient ischemic heart disease, peripheral vascular disease, retinopathy or neuropathy, and any surgical complication.

CONCLUSIONS

Significant hypotension, measured by the need for perioperative vasopressor use was associated with EPAT, suggesting that maintenance of higher perfusion pressures may avoid this complication.

Pancreas transplantation: a single-institution experience in Japan

Purpose

We herein report our experience with pancreas transplantation in 26 patients at a single institution in Japan between August 2001 and December 2011.

Methods

We reviewed the medical records of 26 pancreas transplantations performed in our institute.

Results

The early complications (within 2 weeks) included one graft venous thrombosis, one arterial thrombosis, and two reoperations for bleeding. Of the 26 pancreas transplant recipients, five lost pancreas graft function. Of 24 simultaneous pancreas–kidney recipients, three lost kidney graft function due to noncompliance. The patient, pancreas, and kidney survival rates were 100, 96 and 93 % at 1 year; 100, 80 and 93 % at 5 years; and 100, 67 and 68 % at 10 years, respectively. Of all these complications, venous thrombosis after pancreas transplantation was the most critical.

Conclusions

As the largest series of pancreas transplantations in a single institution in Japan, our series yielded better results than the worldwide data recorded by the International Pancreas Transplant Registry. Routine postoperative anticoagulation therapy is not necessary for the prevention of graft thrombosis if sufficient fluid infusion is strictly controlled and the graft blood flow is frequently monitored. When graft thrombosis occurs, both early detection and appropriate intervention are extremely important if the pancreas graft is to survive.

How to avoid graft thrombosis requiring graftectomy: immediate posttransplant CT angiography in pancreas transplantation

BACKGROUND

Graft thrombosis immediately after surgery remains a problem for successful pancreas transplantation. The present study evaluated the efficacy of computed tomography (CT) angiography for monitoring of graft patency in the immediate postoperative period.

METHODS

The study involved 119 patients who underwent pancreas transplantation between July 1992 and December 2009 in a single center. The anticoagulation strategy was heparin during and after transplantation and then oral warfarin for 1 to 6 months. Graft thrombosis was monitored using color Doppler ultrasonography until July 2005 (group A) and, thereafter, using CT angiography (group B). We retrospectively analyzed the efficacy of diagnosis of graft thrombosis in two groups. Graft survival was assessed using Kaplan-Meier analysis.

RESULTS

Group A comprised 51 patients, and group B comprised 68 patients. Total vascular thrombosis was diagnosed in three (5.9%) group A and one (1.4%) group B patients, and partial venous thrombosis was diagnosed in 1 (2.0%) group A and 19 (31.6%) group B patients. Eighteen of the 19 grafts with partial thrombosis in group B were successfully treated using heparin-based anticoagulant therapy. There were no CT contrast media-related complications in group B. In group B, graft survival rates were the same for grafts with partial thrombosis and grafts without thrombosis.

CONCLUSIONS

CT angiography was safe and effective for evaluating graft patency after pancreas transplantation. Partial vascular thrombosis in the immediate posttransplantation period showed no effect on graft survival under intensive anticoagulation and monitoring by CT angiography.

Pancreas allograft thrombosis

Thrombosis of the transplanted pancreas is a common and often catastrophic event. Predisposing factors include the hypercoagulable state of many patients with diabetic renal failure, preservation-related graft endothelial injury, and low-velocity venous flow. Clinical management includes optimization of modifiable risk factors, controlled anticoagulation, graft monitoring, and early therapeutic intervention.

Induction of heme oxygenase-1 improves the survival of pancreas grafts by prevention of pancreatitis after transplantation

BACKGROUND

Ischemia/reperfusion (I/R) injury after pancreas transplantation might result in graft pancreatitis. The role of heme oxygenase-1 (HO-1) in pancreas transplantation and prevention of graft pancreatitis is unknown.

METHOD

We studied the impact of HO-1 induction with cobalt protoporphyrin (CoPP) in experimental pancreas transplantation with moderate (6 hr) and prolonged (20 hr) cold ischemic time (CIT). Donor animals received CoPP 5 mg/kg intraperitoneal at 48 hr or intraperitoneal saline injections in the corresponding control groups before procurement. Harvested grafts were perfused with HTK solution and stored at 4 degrees C.

RESULTS

After prolonged CIT, graft survival was 100% with CoPP pretreatment in contrast to only 37.5% without pretreatment. CoPP-pretreated grafts demonstrated an unimpaired endocrine graft function at moderate and prolonged CIT. Serum lipase activity as a sign of exocrine preservation was significantly lower. In addition, morphological architecture was well preserved. CoPP pretreatment markedly increased HO-1 gene expression in donor pancreas (130-fold increase) by means of quantitative reverse transcriptase -polymerase chain reaction. Immunohistochemical examinations showed that the increase of HO-1 on the protein level was related to HO-1-positive donor macrophages in the pancreas grafts. HO-1 overexpression was accompanied by significant decrease of proinflammatory cytokines such as tumor necrosis factor-alpha, interleukin (IL)-2, IL-6, interferon-y, and by significant increase of the anti-inflammatory cytokine IL-10 and less expression of adhesion molecules such as e- and p-selectins.

CONCLUSIONS

HO-1 is highly inducible in the allograft rat pancreas and associated with a survival benefit and good graft function after transplantation. This study contributes to the beneficial potentials of HO-1 for the prevention of graft pancreatitis.

Outcome and morbidity of pancreas transplantation in a single Spanish institution

BACKGROUND

Pancreas transplantation is nowadays the only treatment to reestablish normal blood glucose in diabetic patients. Moreover, transplantation may also prevent and possibly even revert diabetes-related complications. We present our results with the first 4 years of a pancreas transplantation program.

MATERIALS AND METHODS

From February 2000 to June 2004, we performed 43 pancreas transplants in 42 recipients. In all cases the technique was enteric drainage of the exocrine secretions and systemic venous derivation to the inferior vena cava for endocrine secretions.

RESULTS

A simultaneous pancreas-kidney transplant was performed in 37 (88.1%) patients, a pancreas after kidney in 4 (9.5%) patients, and a retransplant in 1 (2.4%) patient. Glycosylated hemoglobin and C peptide returned to normal values in all cases. Patient and graft survivals were 91% and 84%, respectively, after a median follow-up of 19 months. The rate of reoperations was 31% with an overall 16% graft loss.

CONCLUSIONS

Our results were comparable to those of larger series.

Single-shot antithrombin in human pancreas-kidney transplantation: reduction of reperfusion pancreatitis and prevention of graft thrombosis*

Reperfusion pancreatitis and graft thrombosis often induce early graft loss in simultaneous pancreas-kidney (SPK) transplantation. Antithrombin (AT) is a coagulatory inhibitor with pleiotropic activities that reduces experimental ischemia/reperfusion injury. This study retrospectively analyses prophylactic high-dose AT application in patients with first SPK. In an university transplantation center, 53 consecutive patients with SPK were studied without randomization. In one group, 3000 IU of AT was given intravenously before pancreatic reperfusion (AT, n = 24). Patients receiving standard therapy including postoperative AT supplementation (controls, n = 29) served as controls. Daily blood sampling was performed as a part of the clinical routine during four postoperative days. There were no differences in demographic and laboratory parameters [donor/recipient age, ischemia time, perfusion solution, body weight, mismatches] between both groups. Baseline creatinine values were lower in the control group versus AT group (P < 0.05). Coagulatory parameters and bleeding incidence were not influenced by AT, while incidence of graft thrombosis was reduced (control: 7/29; AT: 4/24; relative reduction of risk: -33%; P < 0.05). Single-shot AT application during SPK modulated serum lipase activity on postoperative days 2 and 3, and minimized risk for graft thromboses without increasing perioperative bleeding. This new concept should deserve testing in a prospective clinical trial.

Ciclosporin aggravates tissue damage in ischemia reperfusion-induced acute pancreatitis

OBJECTIVES

Ischemia reperfusion (I/R)-associated early graft pancreatitis is a major complication after pancreas transplantation. The influence of immunosuppressants on graft pancreatitis remains unclear. The aim of this study was to evaluate ciclosporin and tacrolimus in experimental pancreatic I/R.

METHODS

Moderate pancreatitis was induced in rats by I/R injury. Animals were assigned to 4 groups: (1) control without I/R, (2) I/R without therapy, (3) I/R + ciclosporin, or (4) I/R + tacrolimus. After 24 hours, pancreatic damage was evaluated by amylase, endothelin 1, thromboxane A2, and histology. Additionally, microcirculation was evaluated 12 hours after reperfusion by intravital microscopy.

RESULTS

I/R significantly increased amylase compared with controls, with maximum levels after ciclosporin treatment. Histology showed comparable tissue injury in control and tacrolimus-treated animals. Ciclosporin-treated animals developed significantly (P < 0.05) more inflammation and necrosis compared with the other groups. Erythrocyte velocity evaluated by intravital microscopy was reduced in all animals after I/R. This was significantly pronounced after ciclosporin application. There was a significant increase of adherent leukocytes and platelets in ciclosporin-treated animals compared with both other groups.

CONCLUSIONS

Tacrolimus does not negatively influence I/R-induced pancreatitis, whereas ciclosporin aggravates pancreatic tissue damage after I/R. These effects should be evaluated in the clinical setting of pancreas transplantation.

Trasplante de páncreas: resultados del grupo Málaga

INTRODUCTION

Pancreatic transplantation is currently the only therapeutic alternative able to restore normal blood glucose levels in diabetic patients. Moreover, this procedure can halt or even reverse diabetes-related complications. The aim of this study was to present our experience and the results of the first 4 years of a pancreatic transplantation program in our center.

MATERIAL AND METHOD

From February 2000 to June 2004, 43 pancreatic transplantations were performed in 42 recipients in the Carlos Haya Regional Hospital in Malaga (Spain). In all patients, the technique of enteric drainage of exocrine pancreatic secretions and systemic venous shunting of endocrine secretions (to the inferior vena cava) was used.

RESULTS

There were 37 (88.1%) simultaneous pancreas-kidney transplantations, 4 (9.5%) in patients with prior kidney transplantation and 1 retransplantation (2.4%). In all patients, glycosylated hemoglobin and C-peptide levels returned to normal. Patient and pancreatic graft survival were 91% and 84%, respectively, with a median follow-up of 19 months. The reintervation rate was 31%, with an overall rate of graft loss of 16%.

CONCLUSIONS

The results obtained in our series are similar to those reported for large series.