Vascular complications of transplantation: part 2: pancreatic transplants

Interventional Radiology Approaches for Managing Postpancreatic Transplant Complications and Type 1 Diabetes Mellitus

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disorder characterized by the destruction of insulin-secreting beta cells in the pancreas, resulting in metabolic disturbances and long-term complications. While subcutaneous insulin remains the primary approach for achieving normoglycemia, pancreatic transplantation has emerged as an effective intervention for long-standing T1DM, providing insulin independence and normalized glycosylated hemoglobin levels. However, complications associated with pancreatic transplantation are frequent, necessitating thorough evaluation using diverse imaging modalities. This manuscript presents an overview of complications encountered with pancreatic transplantation, including vascular complications such as arterial and venous graft thrombosis, vessel stenosis, pseudoaneurysm, arterio-enteric fistula, and arteriovenous malformations. Additionally, the manuscript discusses other associated complications such as pancreatitis, pseudocyst formation, fistulas, pseudo-thrombosis of the iliac vein, post-transplantation lymphoproliferative disorder, and fluid collections. The integration of various imaging modalities plays a crucial role in diagnosing and managing these complications, with interventional radiologists assuming a vital role in employing image-guided procedures. Moreover, the manuscript explores pancreatic islet cell transplantation as a promising cellular-based therapy for T1DM, offering stable long-term glycemic control and decreased reliance on exogenous insulin in a significant proportion of recipients. This minimally invasive procedure involves the image-guided transcatheter infusion of islet cells obtained from deceased donors into the recipient's liver. The importance of interventional radiologists in managing complications related to pancreatic transplantation is underscored, with endovascular or image-guided approaches being utilized to address the diverse spectrum of encountered complications. Furthermore, the potential of islet cell transplantation as a minimally invasive alternative to traditional pancreatic transplantation is emphasized, as it offers the prospect of preventing many associated complications.

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.

Recurrent Renal Allograft Torsion After Simultaneous Kidney and Pancreas Transplantation: Is it Still Possible to Salvage the Graft? A Case Report

BACKGROUND

Kidney allograft torsion (KAT) is defined as a rotation of the renal allograft around its vascular pedicle. It is a rare complication with high rate of graft loss. The nonspecific presentation and inability to provide a definitive diagnosis by imaging, mainly in cases of partial torsion, often delay the diagnosis and treatment. We report a case of recurrent complete torsion of the renal allograft after simultaneous kidney and pancreas transplantation, requiring 2 emergency exploratory laparotomies.

CASE REPORT

A 38-year-old woman with a history of intraperitoneal simultaneous kidney and pancreas transplantation underwent 2 separate emergency exploratory laparotomies secondary to complete renal allograft torsion, respectively, 7 and 11 months after the transplant. In both episodes, no adhesions were encountered. During the first operation, nephropexy was performed. During the second operation, an abdominal wall mesh was placed and fixed to the abdominal wall. Acute kidney injury related to KAT recovered in both occasions with a creatinine of 1.3 mg/dL at 4 months follow-up.

CONCLUSIONS

Renal torsion always should be suspected in intraperitoneally placed kidneys presenting with nonspecific symptoms, abdominal pain, oliguria, and worsening kidney function. Surgical exploration should be considered to salvage the renal graft. This case illustrates the reversibility of a severe injury related to this vascular complication with an adequate return to baseline kidney function even when diagnosis and surgical treatment of KAT might be delayed secondary to its misleading clinical presentation.

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.

Novel surgical technique and efficacy analysis of donor pancreas preparation without vascular reconstruction in pancreas transplantation

Objective

Because of the complicated blood supply and vascular structure of the pancreas, blood vessel reconstruction and reshaping are generally required during pancreas transplantation. We modified the vascular preparation procedure for the donor pancreas (i.e., no vascular reconstruction was performed) based on experiences in our department and in other domestic and international transplantation centers.

Methods

Twelve donor pancreas preparations without vascular reconstruction were performed. The patch (Carrel patch), celiac trunk, and superior mesenteric artery were preserved as arterial inflow channels for the donor pancreas. The common hepatic artery and the gastroduodenal artery were transected at a site 0.5 cm away from the bifurcation. The bifurcated portion was preserved for the donor liver. The stumps of the gastroduodenal artery and common hepatic artery were then ligated. The portal vein was transected in the middle of the hepatoduodenal ligament during separation of the liver and pancreas. The partial portal vein preserved with the pancreas was used as the outflow channel of the donor pancreas.

Results

The transplanted pancreas functioned well in the recipients, and no vascular complications were reported.

Conclusion

The overall efficacy of pancreas transplantation without vascular reconstruction has been improved.

Treatment of Visceral Transplant Pseudoaneurysms Using Physician-Modified Fenestrated Stent Grafts: Initial Experience

Pseudoaneurysms after visceral transplantation represent a significant risk to patients. We report the successful treatment of three transplant (pancreas, liver and kidney) artery anastomotic pseudoaneurysms using physician-modified fenestrated endovascular stent grafts. In all cases, surgical repair was considered high risk and would have compromised the arterial supply to the graft. The endovascular approach in all cases obviated the need for surgical intervention and maintained graft arterial supply.

Iatrogenic-related transplant injuries: the role of the interventional radiologist

As advances in surgical techniques and postoperative care continue to improve outcomes, the use of solid organ transplants as a treatment for end-stage organ disease is increasing. With the growing population of transplant patients, there is an increasing need for radiologic diagnosis and minimally invasive procedures for the management of posttransplant complications. Typical complications may be vascular or nonvascular. Vascular complications include arterial stenosis, graft thrombosis, and development of fistulae. Common nonvascular complications consist of leaks, abscess formation, and stricture development. The use of interventional radiology in the management of these problems has led to better graft survival and lower patient morbidity and mortality. An understanding of surgical techniques, postoperative anatomy, radiologic findings, and management options for complications is critical for proficient management of complex transplant cases. This article reviews these factors for kidney, liver, pancreas, islet cell, lung, and small bowel transplants.