Late complications of pancreas transplant

Comprehensive review of imaging in pancreas transplantation: a primer for radiologists

Pancreas transplantation is a complex surgical procedure performed to restore normoglycemia in patients with type 1 diabetes and includes whole/segmental organ transplant and islet cell transplantation (ICT). In the United States, simultaneous pancreas-kidney transplant (SPK) is most commonly performed due to the higher occurrence of end-stage renal disease in diabetic patients. Understanding the surgical technique and postoperative anatomy is imperative for effective and accurate surveillance following transplantation. Imaging plays an essential role in patients with pancreatic transplants and is often used to evaluate viability, vascular and parenchymal anatomy, and identify potential complications. Imaging techniques such as ultrasound, color and spectral Doppler, computed tomography (CT), magnetic resonance imaging (MRI), and angiography have a complementary role in the postoperative evaluation following a pancreas transplant. The common complications after a whole organ pancreas transplant include vascular thrombosis, graft rejection, pancreatitis, and infections. Complications can be classified into vascular (partial or complete venous thrombosis, arterial thrombosis, stenosis or pseudoaneurysm), parenchymal (pancreatitis, graft rejection), and bowel-related or miscellaneous causes (bowel obstruction, anastomotic leak, and peripancreatic fluid collections). Islet cell transplantation is an innovative therapy for patients with type 1 diabetes. It involves isolating insulin-producing islet cells from donor pancreas and transplanting into recipients, to provide long-term insulin independence or significantly reduce insulin requirements. In recent years, isolation techniques, immunosuppressive regimens, and post-transplant monitoring advancements have propelled ICT as a viable therapeutic option. This comprehensive review aims to provide insights into the current state-of-the-art imaging techniques discussing both normal and abnormal features following pancreas transplantation.

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.

A Prospective Study of the Effect of Gastroduodenal Artery Reconstruction on Duodenal Oxygenation and Enzyme Content After Pancreas Transplantation

BACKGROUND

Whole pancreas transplantation provides durable glycemic control and can improve survival rate; however, it can carry an increased risk of surgical complications. One devastating complication is a duodenal leak at the site of enteroenteric anastomosis. The gastroduodenal artery (GDA) supplies blood to the donor duodenum and pancreas but is commonly ligated during procurement. Since we have not had expressive changes in pancreatic back table surgical techniques in the recent decades, we hypothesized whether back table GDA reconstruction, improving perfusion of the donor duodenum and head of the pancreas, could lead to fewer surgical complications in simultaneous pancreas-kidney (SPK) transplants.

MATERIAL AND METHODS

Between 2017 and 2021, we evaluated demographic information, postoperative complications, intraoperative donor duodenum, recipient bowel O2 tissue saturation, and patient morbidity through the Comprehensive Complication Index (CCI®).

RESULTS

A total of 26 patients were included: 13 underwent GDA reconstruction (GDA-R), and 13 had GDA ligation (GDA-L). There were no pancreatic leaks in the GR group compared to 38% (5/13) in the GDA-L group (p = 0.03913). Intraoperative tissue oxygen saturation was higher in the GDA-R group than in the GDA-L (95.18 vs.76.88%, p < 0,001). We observed an increase in transfusion rate in GDA-R (p < 0.05), which did not result in a higher rate of exploration (p = 0.38). CCI® patient morbidity was also significantly lower in the GDA-R group (s < 0.05).

CONCLUSIONS

This study identified improved intraoperative duodenal tissue oxygen saturation in the GDA-R group with an associated reduction in pancreatic leaks and CCI® morbidity risk. A larger prospective multicenter study comparing the two methods is warranted.

Ultrasound of pancreatic transplant complications: a primer for radiologists

Pancreatic transplantation is an established treatment for patients with type 1 diabetes patients and select type 2 diabetes patients, with excellent survival rates as graft health is evaluated through regular imaging and early detection of complications. Amongst the various imaging methods that may aid in diagnosis of pancreatic transplant complications, ultrasound is a widely available, quick, portable, and cost-effective technique, often used as the sole method to assess for pancreatic transplant complications. When assessing a patient with a pancreatic transplant, the radiologist should be methodical in assessing the vasculature, the pancreatic parenchyma, and the peripancreatic regions. Complications can be categorised based on time from transplant and type of complications, and include vascular, parenchymal, and enteric/anastomotic complications. Doppler has a major role in the diagnosis of vascular complications including arterial and venous thrombosis, arterial stenosis, pseudoaneurysms, and haematomas. Pancreatic complications include rejections and pancreatitis, and are often diagnosed through a combination of clinical, laboratory, and imaging findings, such as pancreatic heterogeneity or the presence of pancreatic pseudocysts. Enteric/anastomotic complications include leaks and bowel obstructions, and may require cross-sectional imaging in addition to ultrasound. This review covers the most common and high-impact vascular, parenchymal, and enteric/anastomotic complications that should be considered in every radiologist's search pattern when assessing a pancreatic graft, as well as their respective postoperative timeframes.

Simultaneous pancreas-kidney transplantation: which graft warns the most?

BACKGROUND

Simultaneous pancreas-kidney transplantation (SPK) is still characterized by high rates of postoperative complications. This study aims to offer an in-depth characterization of early, medium-term, and late complications following SPK to derive insights for postoperative management and follow-up.

METHODS

Consecutive SPK transplantations were analysed. Pancreatic graft (P-graft)- and kidney graft (K-graft)-related complications were analysed separately. The global postoperative course was assessed in three timeframes (early, medium-term, and late) using the comprehensive complication index (CCI). Predictors of complications and early graft loss were explored.

RESULTS

Complications occurred in 61.2% of patients, and the 90-day mortality was 3.9%. The overall burden of complications was significantly high during admission (CCI 22.4 ± 21.1) and decreased gradually afterwards. P-graft-related complications burdened the most in the early postoperative course (CCI 11.6 ± 13.8); postoperative ileus and perigraft fluid collection were the most frequent complications, and pseudoaneurysms, haemorrhages, and bowel leaks were the major concerns. K-related complications were milder but represented the largest proportion of the CCI in the late postoperative timeframe (CCI 7.6 ± 13.6). No predictors of P-graft- or K-graft-related complications were found.

CONCLUSION

Pancreas graft-related complications represent the largest part of the clinical burden in the early postoperative timeframe but are negligible after 3 months. Kidney grafts have a relevant impact in the long term. The multidisciplinary approach to SPK recipients should be driven based on all graft-specific complications and tailored on a time-dependent basis.

Appraising pancreatic fistula in pancreas transplantation: A comprehensive complication index based analysis of postoperative outcomes and predictors of graft survival

BACKGROUND

A definition of pancreatic fistula specifically addressing pancreas transplantation (PT) is lacking. This study sought to characterize pancreatic fistula in this setting and to define its clinical relevance on the postoperative course and long-term graft survival (GS).

METHODS

Consecutive simultaneous pancreas and kidney transplantations were analysed. The global postoperative course was assessed through the comprehensive complication index (CCI). PF was defined according to the original International Study Group for Pancreatic Surgery (ISGPS) definition. Predictors of poor postoperative course and GS were explored.

RESULTS

Seventy-eight patients were analysed. Surgical morbidity was 48.7%, with severe complications occurring in 39.7%. Ninety-day mortality was 2.6%. PF occurred in 56.6% of patients, although its average clinical burden was low and did not correlate with either early or long-term outcomes. Peri-graft fluid collections, postoperative day (POD) 1 drain fluid amylase (DFA) ≥ 2200 U/L, and POD 5 DFA/serum amylase ratio ≥7.0 independently correlated with poor postoperative course. Perigraft fluid collections were associated with reduced GS.

CONCLUSION

Conventionally defined pancreatic fistula is frequent following PT, although its clinical impact is negligible. To define clinically relevant PF, novel cut-offs for DFA might be pondered in a future series, while perigraft fluid collections should be strongly considered.

Human cytomegalovirus: a survey of end-organ diseases and diagnostic challenges in solid organ transplant recipients

PURPOSE OF REVIEW

Human cytomegalovirus (CMV) infection is one of the most important infectious complications in solid organ transplant (SOT) recipients, leading to significant morbidity and mortality. Therefore, early detection and prompt treatment are imperative to improve transplant outcomes. This article highlights the clinical characteristics of the most common CMV end-organ diseases in SOT recipients and their diagnostic modalities and challenges.

RECENT FINDINGS

CMV can cause a variety of end-organ diseases in SOT recipients. Although CMV nucleic acid amplification by polymerase chain reaction (PCR) is frequently employed to detect CMV reactivation or infection, its predictive value for various CMV end-organ diseases remains uncertain. Given the limitation of PCR or other noninvasive tests, confirmation of CMV end-organ disease may require tissue biopsy, which may not be feasible or available, or may cause untoward complications.

SUMMARY

The utility of PCR to diagnose CMV end-organ disease is limited. As CMV can infect any organ system(s), clinicians caring for SOT recipients need to maintain vigilance for any signs and symptoms of end-organ disease to allow early recognition and prompt treatment. Invasive procedures might be needed to confirm the diagnosis and minimize the empirical use of antiviral therapy that may have substantial drug toxicities.

Vascular Complications After Simultaneous Pancreas and Kidney Transplantation: A Case Report

A 51-year-old patient with type I diabetes and end-stage renal disease was qualified for a simultaneous kidney and pancreas transplant. The procedure was performed in a typical manner: arterial anastomosis to the right common iliac artery, the graft's portal vein with inferior vena cava, and side-to-side duodenal intestinal anastomosis. The kidney was implanted retroperitoneally. Six months after the transplant, the patient reported pain in the right lower abdomen, and imaging examinations revealed arterial anastomosis. Reconstruction of the right common iliac artery was performed with a Gore-Tex prosthesis and the pancreatic artery reanastomosed to the right external iliac artery. After the surgery, the function of the transplanted pancreas deteriorated, the level of C-peptide was decreased, and the patient required low doses of insulin. After another 8 months, the imaging studies revealed an aneurysm located in the bifurcation of the aorta up to the anastomosis of the pancreatic graft artery with the iliac artery. The patient was qualified for the implantation of an endovascular of 2 prosthesis, which improved the graft's function. After another 2 months, the presence of an aneurysm at the endovascular prosthesis was found again. The patient was requalified for endovascular prosthesis implantation. Currently, there is no aneurysm but the function of the pancreas graft is impaired, though the kidney graft function is good. Patients after simultaneous kidney and pancreas transplant are a group of patients with an increased risk of vascular complications. Treatment should take place in a multidisciplinary center.

Endovascular management of giant common iliac artery pseudoaneurysm after complications in simultaneous pancreas-kidney transplant: a case report

Background

Pancreatic transplantation is a definitive treatment for selected patients with insulin-dependent diabetes. It is a technically challenging surgery, and vascular complications are the most common cause of pancreatic graft failure. Although rare, pancreas transplants present higher rates of pseudoaneurysms at the vascular anastomosis than other visceral transplants. We present a case of a simultaneous pancreas–kidney transplant complicated with graft failure and common iliac artery pseudoaneurysm that was successfully treated through endovascular techniques.

Case presentation

A 34-year-old White woman presented with abdominal pain and a history of type 1 diabetes mellitus, end-stage renal disease, and two previous pancreas transplantation failures. The first was a simultaneous pancreas–kidney transplantation performed 7 months prior that was complicated by pancreas graft thrombosis within 1 month and required graft resection. Five months later, she underwent a second pancreas transplantation with another pancreatic graft thrombosis requiring graft resection. Abdominal angiotomography revealed a pseudoaneurysm in the right common iliac artery at the point of the previous graft anastomosis. The patient was successfully treated endovascularly with a covered stent in the common iliac artery.

Conclusion

Stent graft implantation for the treatment of common iliac artery pseudoaneurysm as a complication of simultaneous pancreas–kidney transplantation is a safe and feasible procedure.