Surveillance and rescue of pancreas grafts

Contrast enhanced ultrasound for the diagnosis of bilateral renal lymphangiectasia: literature review and contrast enhanced ultrasound findings

Renal lymphangiectasia (RLmp) is a rare benign lymphatic malformation which should be distinguished from other more common pathologies. Ultrasound (US) examination can define the first diagnostic suspicion, but the definitive diagnosis is usually reached with a second level imaging such as computed tomography (CT) or magnetic resonance imaging (MRI). We herein describe for the first time in literature, the use of the contrast enhanced ultrasound (CEUS) in disclosing the nature of peri-renal anechoic lesions in a 27-years old woman, that were initially confused with parenchymal cysts at B-Mode US. The diagnosis of RLmp may be particularly demanding due to its rarity and different clinical presentations. We suggest a possible role of CEUS as a real time, cost saving and easily accessible second level diagnostic tool, that can represent an appealing alternative in the diagnostic work up of suspected RLmp, respect to other imaging modalities.

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.

Retrospective study on detection, treatment, and clinical outcome of graft thrombosis following pancreas transplantation

Complete graft thrombosis is the leading cause of early graft loss following pancreas transplantation. Partial thrombosis is usually subclinical and discovered on routine imaging. Treatment options may vary in such cases. We describe the incidence and relevance of partial graft thrombosis in a large transplant center. All consecutive pancreas transplantation at our center (2004–2015) were included in this study. Radiological follow‐up, type and quantity of thrombosis prophylaxis, complications and, graft and patient survival were collected. Partial thrombosis and follow‐up were also studied. All 230 pancreas transplantations were included in the analysis. Computed tomography was performed in most cases (89.1%). Early graft failure occurred in 23 patients (13/23 due to graft thrombosis, 3/23 bleeding, 1/23 anastomotic leakage, 6/23 secondary to antibody mediated rejection). There was evidence of partial thrombosis in 59 cases (26%), of which the majority was treated with heparin and a vitamin K antagonist with graft preservation in 57/59 patients (97%). Thrombosis is the leading cause of early graft loss following pancreas transplantation. Computed tomography allows for early detection of partial thrombosis, which is usually subclinical. Partial graft thrombosis occurs in about 25% of all cases. In this series, treatment with anticoagulant therapy (heparin and vitamin K antagonist) resulted in graft preservation in almost all cases.

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.

Pancreas transplantation: Advantages of a retroperitoneal graft position

INTRODUCTION

In the 50 years since the first pancreas transplant performed at the University of Minnesota, the surgical techniques employed have undergone many modifications. Techniques such as retroperitoneal graft placement have further improved the ability to reproduce the physiology of the «native» pancreas. We herein present our experience of a modified technique for pancreatic transplant, with the organ placed into a fully retroperitoneal position with systemic venous and enteric drainage of the graft by duodeno-duodenostomy.

METHODS

All pancreas transplantations performed between May 2016 and January 2017 were prospectively entered into our transplant database and retrospectively analyzed.

RESULTS

A total of 10 transplants were performed using the retroperitoneal technique (6 men: median age of 41 years [IQR 36-54]). Median cold ischemia times was 10,30h [IQR 5,30-12,10]. The preservation solution used was Celsior (n=7), IGL-1 (n=2), and UW (n=1). No complications related to the new surgical technique were identified. In one patient, transplantectomy at 12h was performed due to graft thrombosis, probably related to ischemic conditions from a donor with prolonged cardio-respiratory arrest. Another procedure was aborted without completing the graft implant due to an intraoperative immediate arterial thrombosis in a patient with severe iliac atheromatosis. No primary pancreas non-function occurred in the remaining 8patients. The median hospital stay was 13,50 days [IQR 10-27].

CONCLUSIONS

Retroperitoneal graft placement appears feasible with easy access for dissection the vascular site; comfortable technical vascular reconstruction; and a decreased risk of intestinal obstruction by separation of the small bowel from the pancreas graft.

Multi detector computed tomography (MDCT) for the diagnosis of early complications after pancreas transplantation

PURPOSE

Solitary Pancreas (SPT) and simultaneous kidney-pancreas (SPKT) transplants carry a high risk of surgical complications that may lead to the loss of the pancreas graft and impact later kidney function. The purpose of this study was to investigate the role of MDCT in the diagnosis of early complications and its impact on kidney function.

METHODS

All patients receiving SPT or SPKT over 5 years were retrospectively included. Complications that occurred within the first 15 days were registered and MDCT data analyzed. Data regarding donor, transplant, and recipient characteristics as well as transplantation procedures were analyzed according to the occurrence of early complications. Kidney function at day 3 following MDCT was evaluated.

RESULTS

One hundred and forty-one patients were included (85 men, 56 women; mean age 40.1 years, SD 7.7) with 119 SPKT and 22 SPT. Sixty-four complications were registered in 50 patients. Partial (P-) or complete venous thrombosis (C-VT) occurred in 12.1 % (n = 17), arterial thrombosis (AT) in 1.4 % (n = 2), and hemorrhage in 8.5 % (n = 12) of all patients. For venous thrombosis, the predominant risk factor was body mass index (BMI) for either recipients (P < 0.05) or donors (P < 0.01). Median time for venous thrombosis diagnosis with MDCT was 4 days. Kidney function was not altered following MDCT. Fourteen pancreatectomies were necessary. All patients with C-VT and AT had to undergo graftectomy.

CONCLUSION

Vascular complications occurred early following grafting. Systematic early-enhanced MDCT at day 2-3 should be adequate to detect early thrombosis, especially if risk factors have been identified, without induced kidney function alteration.

Early reexploration for suspected thrombosis after pancreas transplantation

BACKGROUND

Graft thrombosis is the most common cause of early graft loss after pancreas transplantation. Early reexploration may permit salvage or timely removal of the thrombosed graft.

METHODS

This was a retrospective review of 345 pancreas transplants performed at a single center between January 2003 and December 2009. Early reexploration was defined as within 1 week of pancreas transplantation.

RESULTS

Of the 345 transplants, there were 35 early reexplorations. The graft was compromised in 20 cases (57%): 10 venous thromboses, 3 arterial thromboses, 2 combined arterial and venous thrombosis, 2 thromboses secondary to allograft pancreatitis, and 3 cases of positional ischemia without thrombosis. Of these allografts, three reperfused once repositioned and six were successfully thrombectomized for a graft salvage rate of 45%. One of the thrombectomized grafts remained perfused but never functioned and was removed at retransplantation. The 10 remaining compromised grafts that were deemed unsalvageable and required allograft pancreatectomy. Nine of these recipients were retransplanted (eight within 2 weeks) and one was not a retransplantation candidate.

CONCLUSIONS

Reexploration for suspected graft thrombosis after pancreas transplantation resulted in a negative laparotomy rate of 43%, but permitted graft salvage in 45% of compromised grafts.

Contribution of contrast-enhanced ultrasonography to nonoperative management of segmental ischemia of the head of a pancreas graft

A 32-year-old recipient of a pancreas transplant (PTx) alone was diagnosed with segmental graft ischemia, involving the head of the pancreas graft (HPG), based on color Doppler ultrasonography (CDU) and computed tomography (CT) angiography. For investigational purposes, graft supply was further checked by contrast-enhanced ultrasonography (CEU). Surprisingly, CEU showed collateral blood supply to the HPG starting from 40 s after contrast injection and resulting in homogenous parenchymography at 90 s. Full-dose heparin infusion, followed by long-term oral anticoagulation, allowed graft salvage without reoperation. At the longest follow-up of 18 months, the patient is insulin independent. This case report shows that CEU may be employed in PTx recipients suspected to harbor vascular complications. To the best of our knowledge, this is the first description of the use of CEU in PTx and the first description of graft salvage, without partial pancreatectomy after CDU and CT diagnosis of segmental graft ischemia.

[Intensive care treatment following transplant surgery]

Transplant-related intensive care treatment after transplantation of visceral organs, in Germany traditionally headed by transplant surgeons, is an integral part of postoperative therapy after liver, pancreas, intestinal, and combined organ transplantation, i.e. pancreas-kidney, liver-kidney, and multivisceral transplantation. Apart from adjustment and monitoring of immunosuppressive therapy, as well as common intensive care issues such as cardiopulmonary disease and complications, the avoidance, early detection, and rigorous treatment of transplant-related problems are the focus of surgical intensive care treatment of transplant patients. In the following article, its role after visceral organ transplantation is described regarding the most frequent transplant-related complications such as technical failure, various kinds of infection, and graft failure with different etiologies.