Transplantation Reports最新文献

Background

The small intestine is one of the most sensitive organs to ischemia. L-arginine has been shown to reduce damage from ischemia and reperfusion injury. We hypothesize that explanted intestinal segments from rats will demonstrate reduced susceptibility to ischemic injury when perfused with l-arginine.

Methods

45 small intestinal segments were harvested from male Sprague-Dawley rats and connected to an ex vivo intestinal perfusion device. Ischemic damage was induced by perfusing the extraluminal side with Ringer-HEPES buffer saturated with 100% N2. All segments were then perfused intraluminally with and without l-arginine. We conducted a set of experiments with intraluminal perfusion with both l-arginine and N-nitroarginine methyl ester (L-NAME), an inhibitor of the nitric oxide – arginine pathway. Control segments were perfused extraluminally under non-ischemic conditions and intraluminally with and without l-arginine. The intraluminal perfusate contained FITC-inulin, and the fluorescence signal of FITC-inulin was measured to calculate average fluid secretion, which directly corresponds to the extent of ischemic injury.

Results

Intestinal segments perfused with l-arginine had significantly decreased secretion over time in comparison to intestinal segments perfused without l-arginine (p<0.0001). Perfusion with L-NAME abrogated the protective effect of l-arginine.

Conclusion

Intraluminal perfusion with l-arginine reduced ischemic damage to harvested intestine.

Introduction

During brain death, several events occur, including hormonal. metabolic and systemic changes. This systematic review aims to find the role of hormone therapy in cadaver donors and its impact on graft function and/or survival following solid organ transplantation.

Method and materials

Randomized clinical trials were reviewed to investigate the effects of hormone therapy on graft survival amongst brain death cases. studies from Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) were identified and reviewed for this current work. Two reviewers independently rated the quality of the study. As a result, 18 studies met inclusion criteria and were included in this study.

Results

Over 2235 titles were retrieved from various search sources and 16 full papers were identified for possible inclusion. Trial sample sizes varied widely from 25 to 12,333 patients. Multiple therapy schemes were developed and applied for brain death donors. The first scheme simply involved applying Triiodothyronine, Dopamine, Immunosuppressive, Vasopressin and Desmopressin separately. The second scheme consisted of applying double hormone therapy using Methylprednisolone and Vasopressin simultaneously. Finally, triple hormone therapy was applied which included Methylprednisolone, Triiodothyronine and Arginine vasopressin.

Conclusions

Results from this systematic study indicated no significant effects on overall organ survival in recipients who received brain death hormone therapy. Thus, the potential effects of hormone therapy in brain death scenarios are still unknown and need further investigation.

Introduction

Lethal symptoms due to graft rejection warrant rapid removal of the transplanted graft to save the patient's life. We report a case of massive pancreas graft bleeding due to chronic rejection that necessitated graft removal after hemostasis by stent graft insertion.

Case presentation

A 39-year-old woman underwent simultaneous pancreas-kidney transplantation for type I diabetes and chronic renal failure nine years ago. She suffered irreversible kidney damage from severe chronic rejection due to drug non-compliance. She was admitted to the emergency department for abdominal pain and bloody stools. She presented with signs of shock based on her vitals due to massive bleeding in the stool a day after hospitalization and required systemic management in the intensive care unit (ICU). Enhanced computed tomography (CT) scan revealed active bleeding from the duodenal portion of the pancreas graft. Hemostasis was achieved by inserting a stent graft into the right external iliac artery. The respiratory and circulatory status of the patient improved after the intervention, and she was transported to our hospital day after treatment. The graft was removed along with the part of the anastomosed intestine, which was reconstructed with a functional end-to-end anastomosis.

Conclusion

We encountered a patient with hemorrhagic shock due to bleeding from a rejected pancreas graft. The patient was successfully treated and saved using stent-graft hemostasis followed by graft removal. Clinicians and surgeons should be mindful of chronic rejection, which could lead to life-threatening hemodynamic complications.

Background

: Anemia is known to impact quality of life and survival in both renal and non-renal patients. End stage kidney disease (ESKD) patient's survival substantially improves post transplantation. Observational studies have reported better patients and graft outcomes in non anemic renal transplant recipients. Anemia of chronic kidney disease (CKD) is frequently linked to erythropoietin deficiency. Patients with post-transplant anemia (PTA) represent a distinct subset of CKD population. The benefit of using erythropoietin stimulating agents (ESA) in PTA is not clearly defined.

Aim

: The aim of this extended literature review is to define the role of ESA use in improving hemoglobin (Hb) level and graft survival in patients with PTA.

Methods

: An extended literature review was done to identify randomized controlled trials (RCTs) with patients with PTA as the study population, the use of erythropoietin stimulating agents as the intervention, and the renal function and Hb level as the outcomes. The aim of this literature review is to delineate the role of using ESA in PTA. Medline, Google scholar, Scopus, and CINHAL data bases were searched and papers meeting the pre-set inclusion criteria were identified.

Results

: A total of 163 papers were identified. After screening the results, four papers met the inclusion criteria and were included for review. 2/4 papers recruited patients with early PTA, while 2/4 papers recruited patients with late PTA. The early PTA papers were not consistent in reporting the effect of ESA in improving renal outcomes. Both studies showed that using ESA had no additional benefit in anemia treatment. 2/4 studies looked at late PTA. The study designs were similar and the follow up period was 2-3 years. Both studies showed a better graft survival in the higher Hb group.

Conclusion

: In the case of early PTA, the benefit of using ESA is not clear. The two RCTs studying the effect of ESA in patients with late PTA showed that targeting higher Hb levels was associated with better graft function. The optimal Hb target and the utility of intravenous iron need further clarifications.

Background

BK polyomavirus (BKPyV) is the most important polyomavirus affecting renal transplant recipients. BKPyV associated nephropathy (BKVAN) is seen in about 5% of renal transplant patients and can lead to graft loss in up to 50% of cases. Monitoring of specific immunity combined with viral load could be used to individually assess the risk of viral reactivation. However, cellular immunity and targeting the immune system have also the potential to be used in therapy development. Consequently, we performed a rapid review about cellular immune responses to summarize the evidence for planning new research on treatment. Additionally, we present an immunologically interesting case of BKVAN.

Methods

We performed a rapid review with a search in MEDLINE from 1971 to 2021. Additionally, we present an immunological interesting case of BKVAN.

Results

The literature search for original studies yielded 92 results. Finally, nine studies were considered, two of them were experimental studies, three retrospective case series and four prospective clinical trials. On the whole, there is evidence that virus-specific T cells could be used for monitoring of BKVAN, but also for therapy.

Conclusions

Cellular immune response to BKVAN is complex, but further prospective clinical studies, especially in virus-specific T cells are necessary.

Elevations in dd-cfDNA at the time of kidney allograft dysfunction are associated with an increased risk of rejection. The utility of such measurements in a stable allograft is unknown. Herein we present a case utilizing routine surveillance dd-cfDNA to detect subclinical active BANFF rejection with persistent elevations and biopsy evidence of ongoing injury despite treatments. Due to treatment failure she developed chronic allograft nephropathy within six months of transplantation. Surveillance and post treatment monitoring of dd-cfDNA may be useful early detection and monitoring of rejection in kidney transplant recipients and as a marker in future studies.

The utilization of venovenous bypass in liver transplantation (LT) has become less frequent and more center dependent over time. Unfortunately, this has left many transplant surgeons, particularly younger trainees, unfamiliar with the techniques and indications for its utilization. We present a case of LT in a patient with complete superior vena cava (SVC) occlusion prohibiting direct vascular access. A multi-disciplinary approach involving interventional radiology, anesthesiology, cardiac surgery, and transplant surgery, was used to diagnose, evaluate, and develop an operative plan for successful LT. In doing so, a novel approach to portosystemic bypass was utilized involving a right mini-thoracotomy with direct cannulation of the right atrium to gain central venous access and optimize venous return during LT. As a center that does not routinely use venovenous bypass, this multidisciplinary approach was crucial identifying the need for a rarely used technique for vascular access and performance of a successful LT.