Early reexploration for suspected thrombosis after pancreas transplantation. Transplantation. 2011;91:902-907. [PMID: 21301398 DOI: 10.1097/tp.0b013e3182106069]

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.

Medical and Surgical Management of the Failed Pancreas Transplant

Despite the continued improvements in pancreas transplant outcomes in recent decades, a subset of recipients experience graft failure and can experience substantial morbidity and mortality. Here, we summarize what is known about the failed pancreas allograft and what factors are important for consideration of retransplantation. The current definition of pancreas allograft failure and its challenges for the transplant community are explored. The impacts of a failed pancreas allograft are presented, including patient survival and resultant morbidities. The signs, symptoms, and medical and surgical management of a failed pancreas allograft are described, whereas the options and consequences of immunosuppression withdrawal are reviewed. Medical and surgical factors necessary for successful retransplant candidacy are detailed with emphasis on how well-selected patients may achieve excellent retransplant outcomes. To achieve substantial medical mitigation and even pancreas retransplantation, patients with a failed pancreas allograft warrant special attention to their residual renal, cardiovascular, and pulmonary function. Future studies of the failed pancreas allograft will require improved reporting of graft failure from transplant centers and continued investigation from experienced centers.

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.

Distal allograft pancreatectomy for graft salvage after pancreas transplantation

Early pancreas allograft failure most commonly results from vascular thrombosis. Immediate surgical intervention may permit pancreas allograft salvage, typically requiring thrombectomy. In cases of partial allograft necrosis secondary to splenic arterial thrombosis, distal allograft pancreatectomy may allow salvage of at least half of the pancreas allograft with retention of function. We retrospectively reviewed four cases of simultaneous pancreas and kidney recipients who required distal allograft pancreatectomy for splenic artery thrombosis with necrosis of the distal pancreas. Three of the four maintained long-term allograft function with euglycemia independent of insulin at six months to six years of follow-up, and all patients continue to maintain normal renal allograft function. Early diagnosis and early intervention are essential in order to salvage the pancreas allograft in the case of thrombosis. Distal allograft pancreatectomy can be performed safely and result in excellent long-term outcomes in select patients.

Immediate post-operative complications (I): Post-operative bleeding; vascular origin: Thrombosis pancreatitis

Simultaneous pancreas-kidney transplantation is the treatment of choice for insulin-dependent diabetes that associates end-stage diabetic nephropathy, since it achieves not only a clear improvement in the quality of life, but also provides a long-term survival advantage over isolated kidney transplant. However, pancreas transplantation still has the highest rate of surgical complications among organ transplants. More than 70% of early graft losses are attributed to technical failures, that is, to a non-immunological cause. The so-called technical failures include graft thrombosis, bleeding, infection, pancreatitis, anastomotic leak and pancreatic fistula. Pancreatic graft thrombosis leads these technical complications as the most frequent cause of early graft loss. Currently most recipients receive postoperative anticoagulation with the aim of reducing the rate of thrombosis. Hemoperitoneum in the early postoperative period is a frequent cause of relaparotomy, but it is not usually associated with graft loss. The incidence of hemoperitoneum is clearly related to the use of anticoagulation in the postoperative period. Post-transplant pancreatitis is another cause of early postoperative complications, less frequent than the previous. In this review, we analyze the most common surgical complications that determine pancreatic graft losses.

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.

Contrast-Enhanced Ultrasound Versus Doppler Ultrasound for Detection of Early Vascular Complications of Pancreas Grafts

OBJECTIVE. The purpose of this study is to compare conventional duplex ultrasound and contrast-enhanced ultrasound (CEUS) for identifying vascular abnormalities in pancreas allografts in the immediate posttransplant setting. Identification of pancreas allografts at risk of failure may impact patient care because early intervention for vascular insufficiency can lead to graft salvage. MATERIALS AND METHODS. Two radiologists who were blinded to patient outcomes performed a retrospective analysis of the postoperative Doppler ultrasound and CEUS images of 34 pancreas grafts from transplants performed between 2017 and 2019. A total of 28 patients who did not require surgical reexploration were considered the control group. Six patients had surgically proven arterial or venous abnormalities on surgical reexploration. Each radiologist scored grafts as having normal or abnormal vascularity on the basis of image sets obtained using Doppler ultrasound only and CEUS only. Comparisons of both the diagnostic performance of each modality and interobserver agreement were performed. RESULTS. Both readers showed that CEUS had increased sensitivity for detecting vascular abnormalities (83.3% for both readers) compared with Doppler ultrasound (66.7% and 50.0%). For both readers, the specificity of CEUS was similar to that of Doppler imaging (81.6% and 78.9% for reader 1 and reader 2 versus 76.3% and 84.2% for reader 1 and reader 2). For both readers, the negative predictive value of CEUS was higher than that of Doppler ultrasound (96.9% and 96.8% for reader 1 and reader 2 versus 93.5% and 91.4% for reader 1 and reader 2). Interobserver agreement was higher for CEUS than for Doppler ultrasound (κ = 0.54 vs κ = 0.28). CONCLUSION. CEUS may provide radiologists and surgeons with a means of timely and effective evaluation of pancreas graft perfusion after surgery, and it may help identify grafts that could benefit from surgical salvage.

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.

Management of vascular and nonvascular complications following pancreas transplantation with interventional radiology

Pancreas transplantation exposes to high rates of complications, either vascular (thrombosis, stenosis, pseudoaneurysm, arteriovenous fistula) or nonvascular (fluid collection, graft rejection). With advances in percutaneous and endovascular techniques, interventional radiologists are increasingly involved in the management of these complications. In this article, we review the anatomical considerations relevant to pancreas transplantation, the techniques used for image-guided interventions for vascular and nonvascular complications, and the expected outcomes of these interventions.

Sonographic Detection and Evaluation of Thrombosis in a Patient With Recent Pancreas Transplant

Simultaneous pancreas and kidney transplants are most commonly evaluated with sonography. Thorough understanding of the variety of surgical techniques, postoperative anatomy, and potential complications is necessary for proper diagnosis. A common complication following pancreas transplant surgery is venous thrombosis. In the presented case, sonography was able to demonstrate portosplenic thrombosis, and computed tomography angiography was used as a secondary means of imaging. Following treatment, sonography was used to follow the resolution of the thrombus, which facilitated survival of the pancreas graft.

Gray-scale, Doppler and contrast-enhanced ultrasound in pancreatic allograft surveillance: A systematic literature review

BACKGROUND

Gray scale ultrasound (US), Doppler and Contrast Enhanced Ultrasound (CEUS) represent important surveillance tools in the early post-operative period after pancreas transplantation (PTx), when complications are more common. This review summarizes the available evidence on their clinical application in this setting.

METHODS

We searched the Pub-Med database from inception to October 2018 for English literature on the clinical use of US, Doppler and CEUS in the post-PTx surveillance. Article selection was carried out according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses criteria (PRISMA).

RESULTS

Twenty-nine articles concerning the clinical applications of US, Doppler and CEUS were identified, 13 of which, involving 264 patients, were focused on the sonographic findings in immunologic rejection, whereas 11 studies reporting on 887 patients were focused on post-PTx vascular complications. The remaining five articles, involving a total of 196 patients, described US or CEUS applied in the study of pancreatic morphology and texture to diagnose peri-graft fluids collections or to obtain experimental data on allograft endocrine function.

CONCLUSIONS

US, Doppler and CEUS have proven to be valuable assets in post-PTx follow up, thanks to the combination of their non-invasiveness with a high accuracy in the detection of early abnormalities, in particular regarding vascular complications. Preliminary experiences are directing towards functional research; however, future prospective trials are necessary to precisely correlate organ perfusion, early abnormalities and allograft function.

The successful salvage of a thrombosed pancreatic graft at the early postoperative period of a simultaneous pancreas and kidney transplantation

INTRODUCTION

Simultaneous kidney and pancreas transplant is the preferred treatment option for end-stage renal disease due to type 1 diabetic nephropathy. Vascular complications are detrimental to graft survival and can lead to graft loss in the early postoperative phase of transplantation. Generally, duplex Doppler ultrasound is used for vascular patency monitoring and pancreatectomy followed by re-transplantation is required in the majority of cases. Recently, pancreatic graft salvage with non-operative management, including medical anticoagulation and endovascular thrombectomy, in the early postoperative period has been described with success.

PRESENTATION OF CASE

We report a case of early detection of pancreas venous graft thrombosis via clinical suspicion and radiological methods, and early intervention with endovascular thrombolysis. As a result, the pancreatic graft was successfully salvaged.

DISCUSSION

A limited number of studies had showed successful graft salvage in only 30-45% of thrombosed pancreatic graft with surgical thrombectomy. Our patient also had bleeding from the vascular access site and ultimately required blood transfusion, however she recovered well after procedure.

CONCLUSION

Given the complexity and significance of PVGT, urgent and prompt treatment is necessary. Interpreting outcomes from our case and other small studies, it appears that endovascular pharmacomechanical thrombectomy can be a vital tool to salvage graft organs in those receiving SPK.

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.

Simultaneous Kidney-Pancreas Transplantation With an Original "Transverse Pancreas" Technique: Initial 9 Years' Experience With 56 Cases

An innovative technique for pancreas transplantation is described. The main aspect consists of the horizontal positioning of the pancreas, which allows a better venous outflow, thus preventing thrombosis and graft loss. The program of pancreas transplantation in this national reference center for pancreatic and liver surgery was started in 2007; the initial results were considered poor, resulting in the loss of half of the grafts due to venous thrombosis. After analyzing the possible causes, this technique was proposed and successfully implemented, reducing the postoperative complications, particularly the problem of venous thrombosis. A detailed description of the new surgical technique is provided. The main clinical and demographic characteristics of the 56 patients who underwent the surgery are analyzed. The incidence of venous thrombosis was 5.3% (3 patients) and graft loss was 3.5% (2 patients). Due to the good results, this technique became the standard surgery for transplantation of the pancreas in our center. The technique proved to be safe and successful. Due to the unique pancreas graft implantation, we called it "transverse pancreas surgery."

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.

Clinical Experience with Pancreas Graft Rescue From Severe Thrombus After Simultaneous Pancreas-Kidney Transplantation by Early Detection with Doppler Ultrasound: A Case Report

Patient: Female, 41

Final Diagnosis: Graft thrombosis

Symptoms: None

Medication: —

Clinical Procedure: Doppler ultrasound

Specialty: Transplantology

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.

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.

A registry analysis of damage to the deceased donor pancreas during procurement

Surgical injury to the pancreas is thought to occur commonly during procurement. The UK Transplant Registry was analyzed to determine the frequency of pancreatic injuries, identify factors associated with damage, and assess the impact of injuries on graft survival. Twelve hundred ninety-six pancreata were procured from donation after brain death donors, with 314 (19.5%) from donation after circulatory death donors. More than 50% of recovered pancreata had at least one injury, most commonly a short portal vein (21.5%). Liver donation, procurement team origin, hepatic artery (HA) arising from the superior mesenteric artery (SMA), and increasing donor BMI were associated with increased rates of pancreas damage on univariate analyses; on multivariate analysis only the presence of an HA from the SMA remained significant (p = 0.02). Six hundred forty solid organ pancreas transplants were performed; 238 had some form of damage. Overall, there was no difference in graft survival between damaged and undamaged organs (p = 0.28); however, graft loss was significantly more frequent in pancreata with arterial damage (p = 0.04) and in those with parenchymal damage (p = 0.05). Damage to the pancreas during organ recovery is more common than other organs, and meticulous surgical technique and awareness of damage risk factors are essential to reduce rates of procurement-related injuries.

Short and long-term outcomes of systemic drainage to IVC: a new technique for pancreas transplantation

Ninety-eight percent of the whole pancreas does not serve the purpose of pancreatic transplantation and it is a major cause of surgical complications. Up to 30% of pancreas transplant recipients experience surgical complications and require reoperation. Graft thrombosis and pancreatitis are the most common complications of pancreas transplantation (PT). Thus, different surgical techniques have been described to overcome the surgical hurdles and reduce surgical complications. In this study, for the first time, we report short- and long-term outcomes of PT with inferior vena cava (IVC) venous drainage. Forty-five PTs (22 simultaneous pancreas and kidney [SPK] transplantations and 23 pancreas after kidney [PAK] transplantations) were performed with this technique in our center. Sixty-eight percent of the donors were imported from outside of our area after they were declined by their local transplantation center. Patient and graft survival rates were 100% at 1 year. No graft thrombosis or pancreatitis occurred with this technique. Six patients (13.3%) required reoperation (3 bleeding, 2 anastomotic leak, and 1 small bowel perforation). No patient or graft loss occurred due to surgical complications. We conclude that this technique provides fast and easy dissection of the venous drainage of the PT without the need of complete occlusion of venous outflow. Surgical complication rates were lower with this technique compared with other reported techniques.

Allograft Pancreatectomy: Indications and Outcomes

This study evaluated the indications, surgical techniques, and outcomes of allograft pancreatectomy based on a single center experience. Between 2003 and 2013, 47 patients developed pancreas allograft failure, excluding mortality with a functioning pancreas allograft. Early graft loss (within 14 days) occurred in 16, and late graft loss in 31. All patients with early graft loss eventually required allograft pancreatectomy. Nineteen of 31 patients (61%) with late graft loss underwent allograft pancreatectomy. The main indication for early allograft pancreatectomy included vascular thrombosis with or without severe pancreatitis, whereas one recipient required urgent allograft pancreatectomy for gastrointestinal hemorrhage secondary to an arterioenteric fistula. In cases of late allograft pancreatectomy, graft failure with clinical symptoms such as abdominal discomfort, pain, and nausea were the main indications (13/19 [68%]), simultaneous retransplantation without clinical symptoms in 3 (16%), and vascular catastrophes including pseudoaneurysm and enteric arterial fistula in 3 (16%). Postoperative morbidity included one case each of pulmonary embolism leading to mortality, formation of pseudoaneurysm requiring placement of covered stent, and postoperative bleeding requiring relaparotomy eventually leading to femoro-femoral bypass surgery 2 years after allograftectomy. Allograft pancreatectomy can be performed safely, does not preclude subsequent retransplantation, and may be lifesaving in certain instances.

Functioning pancreas graft with thromboses of splenic and superior mesenteric arteries after simultaneous pancreas-kidney transplantation: a case report

Graft thrombosis is the most common cause of early graft loss after pancreas transplantation. The grafted pancreas is difficult to salvage after complete thrombosis, especially arterial thrombosis, and graft pancreatectomy is required. We describe a patient presenting with a functioning pancreas graft with thromboses of the splenic artery (SA) and superior mesenteric artery (SMA) after simultaneous pancreas-kidney transplantation (SPK). A 37-year-old woman with a 20-year history of type 1 diabetes mellitus underwent SPK. The pancreaticoduodenal graft was implanted in the right iliac fossa with enteric drainage. A Carrel patch was anastomosed to the recipient's right common iliac artery, and the graft gastroduodenal artery was anastomosed to the common hepatic artery using an arterial I-graft. The donor portal vein was anastomosed to the recipient's inferior vena cava. Four days after surgery, graft thromboses were detected by Doppler ultrasound without increases in the serum amylase and blood glucose levels. Contrast enhanced computed tomography revealed thromboses in the SA, splenic vein and SMA. Selective angiography showed that blood flow was interrupted in the SA and SMA. However, pancreatic graft perfusion was maintained by the I-graft in the head of the pancreas and the transverse pancreatic artery in the body and tail of the pancreas. We performed percutaneous direct thrombolysis and adjuvant thrombolytic therapy. However, we had to stop the thrombolytic therapy because of gastrointestinal hemorrhage. Thereafter, the postoperative course was uneventful and the pancreas graft was functioning with a fasting blood glucose level of 75 mg/dL, HbA1c of 5.1%, and serum C-peptide level of 1.9 ng/mL at 30 months post-transplantation.

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.

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.