Incidence of pancreas graft thrombosis using low-molecular-weight heparin

Pancreatic Allograft Thrombosis: Implementation of the CPAT-Grading System in a Retrospective Series of Simultaneous Pancreas-Kidney Transplantation

Pancreatic graft thrombosis (PAT) is a major surgical complication, potentially leading to graft loss. The recently proposed Cambridge Pancreas Allograft Thrombosis (CPAT) grading system provides diagnostic, prognostic and therapeutic recommendations. The aim of the present study was to retrospectively assess computed tomography angiography (CTA) examinations performed routinely in simultaneous pancreas-kidney (SPK) recipients to implement the CPAT grading system and to study its association with the recipients' outcomes. We retrospectively studied 319 SPK transplant recipients, who underwent a routine CTA within the first 7 postoperative days. Analysis of the CTA scans revealed PAT in 215 patients (106 grade 1, 85 grade 2, 24 grade 3), while 104 showed no signs. Demographic data of the patients with and without PAT (thrombosis and non-thrombosis group) were not significantly different, except for the higher number of male donors in the thrombosis group. Pancreatic graft survival was significantly shorter in the thrombosis group. Graft loss due to PAT was significantly associated with grade 2 and 3 thrombosis, while it did not differ for recipients with grade 0 or grade 1 thrombosis. In conclusion, the CPAT grading system was successfully implemented in a large series of SPK transplant recipients and proved applicable in clinical practice.

Heparin Thromboprophylaxis in Simultaneous Pancreas-Kidney Transplantation: A Systematic Review and Meta-Analysis of Observational Studies

Thrombosis is a leading causes of pancreas graft loss after simultaneous pancreas kidney (SPK), pancreas after kidney (PAK), and pancreas transplant alone (PTA). There remains no standardized thromboprophylaxis protocol. The aim of this systematic review and meta-analysis is to evaluate the impact of heparin thromboprophylaxis on the incidence of pancreas thrombosis, pancreas graft loss, bleeding, and secondary outcomes in SPK, PAK, and PTA. Following PRISMA guidelines, we systematically searched BIOSIS®, PubMed®, Cochrane Library®, EMBASE®, MEDLINE®, and Web of Science® on April 21, 2021. Primary peer-reviewed studies that met inclusion criteria were included. Two methods of quantitative synthesis were performed to account for comparative and non-comparative studies. We included 11 studies, comprising of 1,122 patients in the heparin group and 236 patients in the no-heparin group. When compared to the no-heparin control, prophylactic heparinization significantly decreased the risk of early pancreas thrombosis and pancreas loss for SPK, PAK and PTA without increasing the incidence of bleeding or acute return to the operating room. Heparin thromboprophylaxis yields an approximate two-fold reduction in both pancreas thrombosis and pancreas loss for SPK, PAK and PTA. We report the dosage, frequency, and duration of heparin administration to consolidate the available evidence.

First World Consensus Conference on pancreas transplantation: Part II - recommendations

The First World Consensus Conference on Pancreas Transplantation provided 49 jury deliberations regarding the impact of pancreas transplantation on the treatment of diabetic patients, and 110 experts' recommendations for the practice of pancreas transplantation. The main message from this consensus conference is that both simultaneous pancreas-kidney transplantation (SPK) and pancreas transplantation alone can improve long-term patient survival, and all types of pancreas transplantation dramatically improve the quality of life of recipients. Pancreas transplantation may also improve the course of chronic complications of diabetes, depending on their severity. Therefore, the advantages of pancreas transplantation appear to clearly surpass potential disadvantages. Pancreas after kidney transplantation increases the risk of mortality only in the early period after transplantation, but is associated with improved life expectancy thereafter. Additionally, preemptive SPK, when compared to SPK performed in patients undergoing dialysis, appears to be associated with improved outcomes. Time on dialysis has negative prognostic implications in SPK recipients. Increased long-term survival, improvement in the course of diabetic complications, and amelioration of quality of life justify preferential allocation of kidney grafts to SPK recipients. Audience discussions and live voting are available online at the following URL address: http://mediaeventi.unipi.it/category/1st-world-consensus-conference-of-pancreas-transplantation/246.

Impact of Histidine-Tryptophan-Ketoglutarate Versus University of Wisconsin Solution on the Outcome of Pancreas Transplant With Cold Ischemic Time ≥12 Hours: A Retrospective Study

OBJECTIVES

Histidine-tryptophan-ketoglutarate and University of Wisconsin solutions are currently used for pancreas graft preservation. Our hypothesis was whether the use of histidine-tryptophan-ketoglutarate solution is associated with worse pancreas graft survival than University of Wisconsin solution, in general and after prolonged cold ischemic time of ≥12 hours.

MATERIALS AND METHODS

This retrospective study investigated the impact of static cold storage in histidine-tryptophan-ketoglutarate (n = 133) versus University of Wisconsin (n = 107) solution on outcomes of 240 pancreas transplant procedures. Patient and graft survival rates were compared after 1, 3, and 5 years in both groups. Serum lipase, amylase, and C-reactive protein levels and incidence of surgical complications were evaluated at postoperative week 1. A subgroup analysis of 96 grafts (52 with histidine-tryptophanketoglutarate/44 with University of Wisconsin) with pancreas graft cold ischemic time ≥12 hours was also performed.

RESULTS

At mean follow-up of 75.2 ± 9.9 months, both groups demonstrated comparable short- and long-term patient survival. Overall, pancreas graft survival was slightly better in the histidine-tryptophan-ketoglutarate group (Kaplan-Meier analysis, log-rank P = .013). However, the subgroup analysis of grafts with cold ischemic time ≥12 hours showed slightly better pancreatic graft survival in the University of Wisconsin group, although not significantly (log-rank P = .95). Serum lipase and C-reactive protein levels at postoperative week 1 were higher in the histidinetryptophan-ketoglutarate group. Surgical complications were comparable. Multivariable Cox regression analysis identified neither solution as a risk factor affecting patient and graft survival.

CONCLUSIONS

Although a direct comparison between histidine-tryptophan-ketoglutarate and University of Wisconsin showed better pancreas graft survival with histidine-tryptophan-ketoglutarate, the multivariable analysis showed that the perfusion solution does not significantly influence patient and graft survival. However, in the analysis of transplants with cold ischemic time ≥12 hours, pancreas graft survival was slightly better in the University of Wisconsin group, although not significantly.

The Value of Graft Implantation Sequence in Simultaneous Pancreas-Kidney Transplantation on the Outcome and Graft Survival

BACKGROUND/OBJECTIVES

The sequence of graft implantation in simultaneous pancreas-kidney transplantation (SPKT) warrants additional study and more targeted focus, since little is known about the short- and long-term effects on the outcome and graft survival after transplantation.

MATERIAL AND METHODS

103 patients receiving SPKT in our department between 1999 and 2015 were included in the study. Patients were divided according to the sequence of graft implantation into pancreas-first (PF, n = 61) and kidney-first (KF, n = 42) groups. Clinicopathological characteristics, outcome and survival were reviewed retrospectively.

RESULTS

Donor and recipient characteristics were similar. Rates of post-operative complications and graft dysfunction were significantly higher in the PF group compared with the KF group (episodes of acute rejection within the first year after SPKT: 11 (18%) versus 2 (4.8%); graft pancreatitis: 18 (18%) versus 2 (4.8%), p = 0.04; vascular thrombosis of the pancreas: 9 (14.8%) versus 1 (2.4%), p = 0.03; and delayed graft function of the kidney: 12 (19.6%) versus 2 (4.8%), p = 0.019). The three-month pancreas graft survival was significantly higher in the KF group (PF: 77% versus KF: 92.1%; p = 0.037). No significant difference was observed in pancreas graft survival five years after transplantation (PF: 71.6% versus KF: 84.8%; p = 0.104). Kidney graft survival was similar between the two groups. Multivariate analysis revealed order of graft implantation as an independent prognostic factor for graft survival three months after SPKT (HR 2.6, 1.3-17.1, p = 0.026) and five years (HR 3.7, 2.1-23.4, p = 0.040).

CONCLUSION

Our data indicates that implantation of the pancreas prior to the kidney during SPKT has an influence especially on the early-post-operative outcome and survival rate of pancreas grafts.

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.

Applicability and reproducibility of the CPAT-grading system for pancreas allograft thrombosis

PURPOSE

Although pancreas allograft thrombosis (PAT) incidence has progressively decreased, it remains the most common cause of early graft failure. Currently, there is no consensus on documentation of PAT, which has resulted in a great variability in reporting. The Cambridge Pancreas Allograft Thrombosis (CPAT) grading system has recently been developed for classification of PAT. In this study we aimed to assess the applicability and validate the reproducibility of the CPAT grading system.

METHODS

This study is a retrospective cohort study. Selected for this study were all 177 pancreas transplantations performed at our center between January 1 st, 2008 and September 1 st, 2018 were included.

RESULTS

A total of 318 Computed Tomography (CT) images was reevaluated according the CPAT system by two local radiologists. Inter-rater agreement expressed in Cohen's kappa was 0.403 for arterial and 0.537 for venous thrombosis. Inter-rater agreement, expressed in the Fleiss' kappa, within clinically relevant thrombosis categories was 0.626 for Grade 2 and 0.781 for Grade 3 venous thrombosis.

CONCLUSIONS

Although not perfect, we believe that implementation of the CPAT system would improve current documentation on PAT. However, it is questionable whether identification of a small Grade 1 thrombosis would be relevant in clinical practice. Furthermore, a good quality CT scan, including adequate phasing, is essential to accurately identify potential thrombus and extend after pancreas transplantation.

Anticoagulation in simultaneous pancreas kidney transplantation - On what basis?

BACKGROUND

Despite technical refinements, early pancreas graft loss due to thrombosis continues to occur. Conventional coagulation tests (CCT) do not detect hypercoagulability and hence the hypercoagulable state due to diabetes is left untreated. Thromboelastogram (TEG) is an in-vitro diagnostic test which is used in liver transplantation, and in various intensive care settings to guide anticoagulation. TEG is better than CCT because it is dynamic and provides a global hemostatic profile including fibrinolysis.

AIM

To compare the outcomes between TEG and CCT (prothrombin time, activated partial thromboplastin time and international normalized ratio) directed anticoagulation in simultaneous pancreas and kidney (SPK) transplant recipients.

METHODS

A single center retrospective analysis comparing the outcomes between TEG and CCT-directed anticoagulation in SPK recipients, who were matched for donor age and graft type (donors after brainstem death and donors after circulatory death). Anticoagulation consisted of intravenous (IV) heparin titrated up to a maximum of 500 IU/h based on CCT in conjunction with various clinical parameters or directed by TEG results. Graft loss due to thrombosis, anticoagulation related bleeding, radiological incidence of partial thrombi in the pancreas graft, thrombus resolution rate after anticoagulation dose escalation, length of the hospital stays and, 1-year pancreas and kidney graft survival between the two groups were compared.

RESULTS

Seventeen patients who received TEG-directed anticoagulation were compared against 51 contemporaneous SPK recipients (ratio of 1: 3) who were anticoagulated based on CCT. No graft losses occurred in the TEG group, whereas 11 grafts (7 pancreases and 4 kidneys) were lost due to thrombosis in the CCT group (P = 0.06, Fisher’s exact test). The overall incidence of anticoagulation related bleeding (hematoma/ gastrointestinal bleeding/ hematuria/ nose bleeding/ re-exploration for bleeding/ post-operative blood transfusion) was 17.65% in the TEG group and 45.10% in the CCT group (P = 0.05, Fisher’s exact test). The incidence of radiologically confirmed partial thrombus in pancreas allograft was 41.18% in the TEG and 25.50% in the CCT group (P = 0.23, Fisher’s exact test). All recipients with partial thrombi detected in computed tomography (CT) scan had an anticoagulation dose escalation. The thrombus resolution rates in subsequent scan were 85.71% and 63.64% in the TEG group vs the CCT group (P = 0.59, Fisher’s exact test). The TEG group had reduced blood product usage {10 packed red blood cell (PRBC) and 2 fresh frozen plasma (FFP)} compared to the CCT group (71 PRBC/ 10 FFP/ 2 cryoprecipitate and 2 platelets). The proportion of patients requiring transfusion in the TEG group was 17.65% vs 39.25% in the CCT group (P = 0.14, Fisher’s exact test). The median length of hospital stay was 18 days in the TEG group vs 31 days in the CCT group (P = 0.03, Mann Whitney test). The 1-year pancreas graft survival was 100% in the TEG group vs 82.35% in the CCT group (P = 0.07, log rank test) and, the 1-year kidney graft survival was 100% in the TEG group vs 92.15% in the CCT group (P = 0.23, log tank test).

CONCLUSION

TEG is a promising tool in guiding judicious use of anticoagulation with concomitant prevention of graft loss due to thrombosis, and reduces the length of hospital stay.

Susceptibility-directed anticoagulation after pancreas transplantation: A single-center retrospective study

Pancreas transplant achieves consistent long-term euglycemia in type 1 diabetes. Allograft thrombosis (AT) causes the majority of early graft failure. We compared outcomes of four anticoagulation regimens administered to 95 simultaneous kidney-pancreas or isolated pancreas transplanted between 1/1/2015 and 11/20/2018. Early postoperative anticoagulation regimens included the following: none, subcutaneous heparin/aspirin, with or without dextran, and heparin infusion. The regimens were empirically selected based on each surgeon's assessment of hemostasis of the operative field and personal preference. A sonographic-based global scoring system of AT is presented. The 47-month recipients and graft survival were 95% and 86%, respectively. Recipients with or without AT had similar survival. Five and four grafts were lost due to death and AT, respectively. Outcomes of prophylaxis regimens correlated with intensity of anticoagulation. Compared with no anticoagulation, an increase in hemorrhagic complications occurred exclusively with iv heparin. The higher arterial AT score found in regimens lacking antiplatelet therapy highlights the importance of early antiaggregants therapy. Abnormal fibrinolysis was associated with an increase in AT score. Platelet dysfunction, warm ischemia time, and enteric drainage were predictive of AT and, along with other known risk factors, were incorporated into an algorithm that matches intensity of early postoperative anticoagulation to the thrombotic risk.

Paired Analysis of Outcomes After Kidney Transplantation in Peritoneal and Hemodialysis Patients

BACKGROUND

The impact of dialysis modality before kidney transplantation (hemodialysis or peritoneal dialysis) on outcomes is not clear. In this study we retrospectively analyzed the impact of dialysis modality on posttransplant follow-up.

METHODS

To minimize donor bias, a paired kidney analysis was applied. One hundred thirty-three pairs of peritoneal dialysis (PD) and hemodialysis (HD) patients were transplanted at our center between 1994 and 2016. Those who received kidneys from the same donor were included in the study. HD patients were significantly older (44 vs 48 years), but the Charlson Comorbidity Index was similar (3.12 vs 3.46) in both groups. The groups did not differ significantly with respect to immunosuppressive protocols and number of mismatches (2.96 vs 2.95).

RESULTS

One-year patient (98% vs 96%) and graft (90% vs 93%) survival was similar in the PD and HD patient groups. The Kaplan-Meier curves of the patients and graft survival did not differ significantly. Delayed graft function (DGF) and acute rejection (AR) occurred significantly more often in the HD recipients. Graft vessel thrombosis resulting in graft loss occurred in 9 PD (6.7%) and 4 HD (3%) patients (P > .05). Serum creatinine concentration and estimated glomerular filtration rate (using the Modification of Diet in Renal Disease guidelines) showed no difference at 1 month, 1 year, and at final visit. On multivariate analysis, factors significantly associated with graft loss were graft vessel thrombosis, DGF, and graft function 1 month after transplantation. On univariate analysis, age, coronary heart disease, and graft loss were associated with death. Among these factors, only coronary heart disease (model 1) and graft loss were significant predictors of death on multivariate analysis.

CONCLUSION

The long-term outcome for renal transplantation is similar in patients with PD and HD. These groups differ in some aspects, however, such as susceptibility to vascular thrombosis in PD patients, and to DGF and AR in HD patients.

Pancreatic allograft thrombosis: Suggestion for a CT grading system and management algorithm

Pancreatic allograft thrombosis (PAT) remains the leading cause of nonimmunologic graft failure. Here, we propose a new computed tomography (CT) grading system of PAT to identify risk factors for allograft loss and outline a management algorithm by retrospective review of consecutive pancreatic transplantations between 2009 and 2014. Triple-phase CT scans were graded independently by 2 radiologists as grade 0, no thrombosis; grade 1, peripheral thrombosis; grade 2, intermediate non-occlusive thrombosis; and grade 3, central occlusive thrombosis. Twenty-four (23.3%) of 103 recipients were diagnosed with PAT (including grade 1). Three (2.9%) grafts were lost due to portal vein thrombosis. On multivariate analysis, pancreas after simultaneous pancreas-kidney transplantation/solitary pancreatic transplantation, acute rejection, and CT findings of peripancreatic edema and/or inflammatory change were significant risk factors for PAT. Retrospective review of CT scans revealed more grade 1 and 2 thromboses than were initially reported. There was no significant difference in graft or patient survival, postoperative stay, or morbidity of recipients with grade 1 or 2 thrombosis who were or were not anticoagulated. Our data suggest that therapeutic anticoagulation is not necessary for grade 1 and 2 arterial and grade 1 venous thrombosis. The proposed grading system can assist clinicians in decision-making and provide standardized reporting for future studies.

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.

Splenic Vein Thrombosis Following Pancreas Transplantation: Identification of Factors That Support Conservative Management

Prophylaxis for graft portal/splenic venous thrombosis following pancreas transplant varies between institutions. Similarly, treatment of venous thrombosis ranges from early re-exploration to conservative management with anticoagulation. We wished to determine the prevalence of graft splenic vein (SV) thrombosis, as well as the clinical significance of non-occlusive thrombus observed on routine imaging. Records of 112 pancreas transplant recipients over a 5-year period at a single center were reviewed. Venous thrombosis was defined as absence of flow or presence of thrombus identified in any part of the graft SV on ultrasound. Thirty patients (27%) had some degree of thrombus or absence of flow in the SV on postoperative ultrasound. There were 5 graft losses in this group. Four were due to venous thrombosis, and occurred within 20 days of transplant. All patients with non-occlusive partial SV thrombus but normal arterial signal on Doppler ultrasound were successfully treated with IV heparin followed by warfarin for 3-6 months, and remained insulin independent. Findings of arterial signal abnormalities, such as absence or reversal of diastolic flow within the graft, require urgent operative intervention since this finding can be associated with more extensive thrombus that may lead to graft loss.

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.

Heparin infusion in simultaneous pancreas and kidney transplantation reduces graft thrombosis and improves graft survival

INTRODUCTION

Thrombosis of the pancreas after transplantation is the most common cause of relaparotomy and resultant graft loss. There is currently no standard protocol consistently proven to prevent thrombosis following transplantation. Our objective was to determine whether our protocol of post-operative low-dose intravenous (IV) heparin infusion would prevent graft thrombosis without additional complications in our patients.

METHODS

A total of 66 simultaneous pancreas kidney (SPK) transplants were performed at our institution from 2004 to 2014. Patients were divided into 2 retrospective cohort groups. Group 1 patients received only acetylsalicylic acid (ASA) 81 mg/d started on post-operative day 1. Group 2 patients received IV heparin infusion beginning in the recovery room at a rate of 500 IU/h for the first 24 hours, reduced by 100 IU/h every day to stop on day 5, and then received ASA 81 mg/d afterward. Outcome and complication rates were compared between the two groups for 5 years post-transplant.

RESULTS

We observed a significant reduction in graft thrombosis and graft loss with (0/29) patients in the heparin group vs (7/33) 25.7% from the non-heparin (P<.01) with no differences in complication rates.

CONCLUSIONS

We present a heparin infusion protocol which may help prevent graft thrombosis and graft loss in SPK transplantation.

US Findings in Patients at Risk for Pancreas Transplant Failure

Purpose To determine if ultrasonographic (US) findings, including Doppler US findings, are associated with subsequent pancreas transplant failure. Materials and Methods A cohort of adult patients who underwent pancreas transplantation at a tertiary institution over the course of 10 years (from 2003 to 2012) was retrospectively evaluated for failure, which was defined as return to insulin therapy or surgical graft removal. The institutional review board provided a waiver of informed consent. All US images obtained within the 1st postoperative year were reviewed for three findings: arterial flow (presence or absence of intraparenchymal forward diastole flow), splenic vein thrombus, and edema. These findings were correlated with pancreas graft failure within 1-year after surgery by using Cox proportional hazards models and hazard ratios. Results A total of 228 transplants were included (mean patient age, 41.6 years; range, 19-57 years; 122 men, 106 women). Absent or reversed arterial diastolic flow was identified in nine of 20 failed transplants (sensitivity, 45%; 95% confidence interval [CI]: 23, 68) and in 15 of 208 transplants that survived (specificity, 93% [193 of 208]; 95% CI: 89, 96). The Cox proportional hazard ratio was 6.2 (95% CI: 3.1, 12.4). Splenic vein thrombus was identified in 10 of 20 failed transplants (sensitivity, 50%; 95% CI: 27, 73) and in 25 of 208 transplants that survived (specificity, 88% [183 of 208]; 95% CI: 83, 92). The Cox proportional hazard ratio was 4.2 (95% CI: 2.4, 7.4). Edema had the lowest specificity (Cox proportional hazard ratio, 2.0; 95% CI: 1.3, 2.9). In the multivariate analysis, only absent or reversed arterial diastolic flow remained significantly associated with transplant failure (adjusted hazard ratio, 3.6; 95% CI: 1.0, 12.8; P = .045). Conclusion Absent or reversed diastolic arterial Doppler flow has a stronger association with transplant failure than does splenic vein thrombus or edema. (©) RSNA, 2016.

Pancreas-Kidney transplantation: Impact of dialysis modality on the outcome

It remains controversial whether dialysis modality prior to SPKT (simultaneous pancreas-kidney transplantation) affects the outcome. We analyzed outcomes in type 1 diabetic patients undergoing SPKT, comparing peritoneal dialysis (PD) and hemodialysis (HD) groups: 119 had been on HD; 39 on PD. They were comparable except regarding dialysis time, higher in HD patients (30 ± 23 vs. 21 ± 15 months, P = 0.003). Thrombosis-driven relaparotomy was more frequent in PD patients (12.8% vs. 1.7%, P = 0.014). Pancreas loss due to infection was higher in PD patients (12.8% vs. 3.4%, P = 0.042). Thrombosis-related kidney loss was more frequent in PD patients (5.1%, vs. 0% in HD patients, P = 0.058). Thirteen deaths occurred, more within the PD group (17.9% vs. 5%; P = 0.011), being infection the leading cause (13.5%, vs. 1.7% in HD patients, P = 0.010). Patient survival was inferior in PD patients. Besides PD, cardiovascular disease and graft failure were independent predictors of patient death. In conclusion, PD patients more frequently complicated with intra-abominal infection leading to pancreatic loss and with renal thrombosis, with adverse impact on survival. As a PD first strategy in end-stage renal disease patients is generally associated with good outcomes, these gloomier results after SPKT urge for careful adjustment of infection and thrombosis prophylactic protocols in PD patients.

Clinical outcomes associated with the early postoperative use of heparin in pancreas transplantation

BACKGROUND

Graft thrombosis following pancreas transplantation is the leading non-immunologic cause of graft loss. Routine systemic anticoagulation is controversial because of an increased bleeding risk.

METHODS

This was a retrospective, single-center analysis including all pancreas transplants performed over 9 years evaluating the use of low-dose heparin in the early postoperative period. Clinical outcomes were partial and complete graft thrombosis within 30 days, bleeding events, relaparotomy rates, and 30-day graft and patient survival. Multivariate regression analysis was performed to identify risk factors for early graft loss resulting from thrombosis.

RESULTS

One hundred fifty-two patients were included, 52 in the heparin group. The overall complete thrombosis rate was 13.1%, 10% in those who received heparin, and 15% in those who did not. Partial thrombosis was higher in the heparin group (10% vs. 3%). Higher relaparotomy rates were seen in the heparin group (29% vs. 22%); however, bleeding events were similar between groups. Graft and patient survival at 30 days were similar between groups; however, there was a trend toward higher graft survival in the heparin group. Heparin showed a trend toward a protective benefit for early graft loss resulting from thrombosis in all multivariate regression models.

CONCLUSION

These data suggest low-dose heparin early in the postoperative period may provide a protective benefit in the prevention of early graft loss resulting from thrombosis, without an increased risk of bleeding.

125 Cases of duodenoduodenostomy in pancreas transplantation: a single-centre experience of an alternative enteric drainage

Several exocrine drainage procedures have been successfully developed to perform pancreas transplantation (PT). Retroperitoneal graft placement allows exocrine drainage via direct duodenoduodenostomy (DD). This technique provides easy access for endoscopic surveillance and biopsy. A total of 241 PT procedures were performed in our centre between 2002 and 2012. DD was performed in 125 patients, and duodenojejunostomy (DJ) in 116 patients. We retrospectively compared our experience with these two types of enteric drainage, focusing on graft and patient survivals, as well as postoperative complications. With a mean follow-up of 59 months, both groups demonstrated comparable patient and graft survivals. 14 (11%) of 125 cases in the DD group and 21 (18%) of 116 cases in the DJ group had pancreatic graft loss (P = 0.142). Graft thrombosis [5 (4%) vs. 18 (16%) P = 0.002], anastomotic insufficiency [2 (1.6%) vs. 8 (7%) P = 0.052] and relaparotomy [52 (41%) vs. 56 (48%) P = 0.29] occurred more frequently in the DJ group, whereas gastrointestinal bleeding [14 (11%) vs. 4 (3%) P = 0.026] occurred more often in the DD group. DD is a feasible and safe technique in PT, with no increase in enteric complications. It is equivalent to other established techniques and extends the feasibility of anastomotic sites, especially in recipients who have undergone a second transplantation.

Surgical Morbidity of Simultaneous Kidney and Pancreas Transplantation: A Single-Centre Experience in the Tacrolimus Era

Introduction. Simultaneous pancreas and kidney (SPK) transplantation is performed to restore normoglycaemia and renal function in patients with Type I diabetes mellitus and end-stage renal failure. We aimed to evaluate the impact of major postoperative complications to patient and graft survival outcomes. Method. Using a prospectively collected database over a 10-year period, major postoperative complications requiring return to operating theatre as well as patient and graft survival outcomes were analysed retrospectively. Results. Between January 2001 and May 2010, 165 patients underwent first-time SPK transplantation. Median age of recipients was 39.8 years (range, 16.9–53.2). Enteric drainage was used in 149 patients, and bladder drainage was used in 16. Median follow-up time was 5.2 years (range 1.1–10.3). Fifty-six patients (34%) returned to operating theatre at least once. Pancreatic allograft loss secondary to vascular thrombosis occurred in 12 patients (7%), and 2 patients (1.2%) required transplant pancreatectomy due to debilitating pancreatic enzyme leaks. At 1 and 5 years, patient survival was 98% and 94%; pancreas graft survival, 86% and 77%; kidney graft survival 96% and 89%, respectively. Conclusion. SPK is a safe and effective treatment for Type I diabetes mellitus and end-stage renal failure although surgical reintervention is required in approximately one-third of patients. Preventing vascular thrombosis remains a major challenge.

Impact of blood amylase peak over vascular graft thrombosis in pancreas transplantation

BACKGROUND

Vascular graft thrombosis (VGT) is still the achuilles heel in pancreas transplantation (PT); it is the main cause of nonimmunologic graft loss. Early diagnosis is essential to avoid transplantectomy. The aim of our study was to analyze the peak amylase during the first 3 days after PT as risk factor for VGT.

METHODS

This retrospective study included 58 pancreas transplants in 55 patients from January 2007 to November 2011. They underwent an anticoagulation protocol based on unfractionated heparin and low-molecular-weight heparin. The technique consisted of enteric drainage and systemic venous drainage. The primary endpoint was VGT with consideration of multiple relevant variables. The maximum amylase level was determined during the first 3 days after transplantation. A receiver operating characteristic analysis was performed to establish a cutoff point as (mean plus one standard deviation; 745 mg/dL), calculating the sensitivity, specificity, and predictive values.

RESULTS

Recipient characteristics were 71% males with an overall mean age of 39 years (range, 23-55) and body mass index 24 (range, 19-36). The donor sex was similar. Mean donor age was 32 years with occurrences of hypotension in 9%, cerebrovascular brain death in 46%. Mean ischemia time was 10 hours and 45 minutes. Mean blood amylase peak was 395 mg/dL. Seven VGT cases were diagnosed during the postoperative period including six with complete thrombosis requring transplantectomy. Bivariate analysis showed the group of subjects with amylase levels above 745 mg/dL to display on eight-fold greater risk for VGT (odds ratio = 8.6; P = .032). The area under the curve of blood amylase peak during the first 3 days to detect VGT was 0.630 (95% confidence interval 0.41-0.84).

CONCLUSIONS

A blood amylase peak above 745 mg/dL in the first 3 days after transplantation was associated with risk for VGT.

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.

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.

Donor-dependent risk factors for early surgical complications after simultaneous pancreas-kidney transplantation

INTRODUCTION

The success of simultaneous pancreas-kidney transplantation (SPK) depends in a large degree on avoidance of surgical complications in the early postoperative period. The aim of the study was to analyze the Pre-procurement Pancreas Allocation Suitability Score (P-PASS) and the deceased donor parameters included within it as risk factors for early surgical complications after SPK.

MATERIAL AND METHODS

Forty-six consecutive donors whose kidney and pancreas were simultaneously transplanted were included in the study.

RESULTS

Donor age was older among recipients who lost their pancreatic grafts: 30.4±6.9 versus 24.1±6.9 years. Donor age was also older among recipients who lost their pancreatic grafts or died compared with those discharged with a functioning graft: 29.3±5.7 versus 24.0±6.9 years. Donor body mass index (BMI) was higher among patients who died compared with those who were discharged: 25.3±1.1 versus 23.2±2.5 kg/m2. P-PASS was higher in patients who lost their pancreatic grafts (17.6±2.1 vs 15.2±1.8) or died (15.3±1.9 vs 17.2±1.9), or lost pancreatic graft or died (15.2±1.8 vs 17.0±2.2) or with intra-abdominal infections (IAI; 17.1±1.7 vs 15.0±1.8). The incidence of donors≥30 years old was higher among recipients with IAI (45.4% vs 14.3%; P=.04). An higher rate of donors with P-PASS>16 was revealed among patients who lost their pancreatic grafts (26.7% vs 3.2%), died (26.7% vs 3.2%), lost the pancreatic graft or died (33.3% vs 6.4%), or experienced IAI (46.7% vs 9.7%). Multivariate logistic regression analysis revealed P-PASS (odds ratio 2.57; P=.014) and serum sodium (odds ration, 0.91; P=.048) to be important predictors of IAI development.

CONCLUSION

Older age and higher BMI among deceased donors increased the risk of IAI, pancreatic graft loss, or recipient death after SPK. Transplantation of a pancreas from a donor with a low P-PASS score was associated with a lower risk of surgical complications after SPK.

Current status of pancreas transplantation

Pancreas transplantation has emerged as the treatment of choice for patients with end-stage diabetes mellitus. Over the last four decades, many improvements have been made in the surgical techniques and immunosuppressive regimens, which contributed to increased number of indications and improved allograft survival. Pancreas transplantation can be justified on the basis that patients replace daily injections of insulin with an improved quality of life but at the expense of a major surgical procedure with a relatively higher complication rate, and lifelong immunosuppression. Therefore, efforts to develop more minimally invasive techniques for endocrine replacement therapy such as islet transplantation have been in progress. This article summarizes the current understanding of pancreas transplantation-associated indications, donor selection, surgical techniques, immunosuppression, and rejection.

Pancreas transplantation: does age increase morbidity?

Introduction. Pancreas transplantation (PTx) is the only definitive intervention for type 1 diabetes. Medical advancements in diabetes care have led to an aging PTx candidate pool. We report our experience with patients ≥50 years of age undergoing PTx. Methods. We reviewed 136 consecutive PTx patients at our institution from 1996–2010; 17 were ≥50 years of age. We evaluated demographics, surgical complications, acute rejection (AR) rates, nonsurgical infections, and survival outcomes. Results. Demographic data was similar (P > .05) between groups, excluding age. The two groups had comparable major and minor surgical complication rates (P = .10 and P = .25, resp.). The older group had a lower 1-year and overall AR rate (P = .04 and P = .03, resp.). The incidence of non-surgical infections and overall patient and graft survival was similar between groups (P > .05). Conclusion. Older patients with type 1 diabetes are feasible candidates for PTx, as surgical morbidity, incidence of infections, and AR rates are low.

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.

Preprocurement pancreas allocation suitability score does not correlate with long-term pancreas graft survival

BACKGROUND

Within recent years, more marginal donors have been offered to Eurotransplant. To help identify suitable pancreas donors, the Eurotransplant Pancreas Advisory Committee introduced a donor score system (P-PASS). Little is known about the influence of P-PASS on long-term pancreas graft survival.

METHODS

From June 1994 to September 2009, we performed 405 pancreas transplantations. In a retrospective study we analyzed P-PASS in 318 cases. Pancreas grafts from donors with P-PASS < 17 (n = 146) analyzed for graft and patient survival as well as for surgical complications were compared with donors of a PASS > or = 17 (n = 172). The mean follow-up was 7.2 +/- 4.3 years.

RESULTS

Recipient characteristics were comparable in both groups. Mean P-PASS was 16.7 +/- 2.7 for both groups: 14.3 +/- 1.5 for P-PASS < 17 and 18.8 +/- 1.6 for P-PASS > or = 17. Pancreas graft survival rates for 1, 5, and 10 years were 85%, 77%, and 73% among P-PASS < 17 and 81%, 73%, and 64% among P-PASS > or = 17 groups (P = .12). There were 12 (8.2%) cases of venous thrombosis in the <17 group and 22 (12.7%) in the > or =17 group (P < .05). The relaparotomy rate was significant higher (38.7% vs 28.7%) and duration of hospital treatment longer (40.2 vs 32 days) in the P-PASS > or = 17 group (P < .05). There was no significant difference in patient or kidney graft survival between groups.

CONCLUSIONS

The data demonstrated that utilization of pancreas grafts from donors with a P-PASS > or = 17 resulted in good overall outcomes and could expand the organ donor pool. There was no correlation between P-PASS and long-term patient or graft outcome. Complications requiring relaparotomy were more frequent among patients after transplantation from donors with higher P-PASS.