A single center experience of abdominal wall graft rejection after combined intestinal and abdominal wall transplantation

Acute Rejection Rates in Vascularized Composite Allografts: A Systematic Review of Case Reports

INTRODUCTION

Vascularized Composite Allografts (VCA) are usually performed in a full major histocompatibility complex mismatch setting, with a risk of acute rejection depending on factors such as the type of immunosuppression therapy and the quality of graft preservation. In this systematic review, we present the different immunosuppression protocols used in VCA and point out relationships between acute rejection rates and possible factors that might influence it.

METHODS

This systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We systematically searched Medline (PubMed), Embase, and The Cochrane Library between November 2022 and February 2023, using following Mesh Terms: Transplant, Transplantation, Hand, Face, Uterus, Penis, Abdominal Wall, Larynx, and Composite Tissue Allografts. All VCA case reports and reviews describing multiple case reports were included.

RESULTS

We discovered 211 VCA cases reported. The preferred treatment was a combination of antithymocyte globulins, mycophenolate mofetil (MMF), tacrolimus, and steroids; and a combination of MMF, tacrolimus, and steroids for induction and maintenance treatment, respectively. Burn patients showed a higher acute rejection rate (P = 0.073) and were administered higher MMF doses (P = 0.020).

CONCLUSIONS

In contrast to previous statements, the field of VCA is not rapidly evolving, as it has encountered challenges in addressing immune-related concerns. This is highlighted by the absence of a standardized immunosuppression regimen. Consequently, more substantial data are required to draw more conclusive results regarding the immunogenicity of VCAs and the potential superiority of one immunosuppressive treatment over another. Future efforts should be made to report the VCA surgeries comprehensively, and muti-institutional long-term prospective follow-up studies should be performed to compare the number of acute rejections with influencing factors.

Abdominal Wall Vascularized Composite Allotransplantation: A Scoping Review

BACKGROUND

 Abdominal wall vascularized composite allotransplantation (AW-VCA) is a novel reconstructive technique used for large abdominal wall defects in combination with intestinal transplantation (ITx) or multivisceral abdominal transplantation (MVTx). Since the introduction of this procedure, several studies have been published reporting their experience. This study aims to present a scoping review looking at all available evidence-based medicine information to understand the most current surgical techniques and clinical outcomes.

METHODS

 This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) extension for scoping reviews checklist. A comprehensive research strategy of several databases was conducted.

RESULTS

 A total of 31 studies were included in this review, which comprised animal, cadaveric, and human studies. In human studies, four surgical techniques with high flap survival rates and low complication rates were found. In cadaveric studies, it was shown that the use of iliofemoral cuff-based flaps provided adequate tissue perfusion to the abdominal wall graft. Also, the use of thoracolumbar nerves have been described to provide functionality to the AW-VCA and prevent long-term muscle atrophy.

CONCLUSION

 AW-VCA is a safe and efficient alternative for patients with large and complex abdominal wall defects. The future holds a promising evolution of a functional AW-VCA, though surgeons must face and overcome the challenge of distorted anatomy frequently present in this population. Forthcoming studies with a better level of evidence are required to evaluate functionality and differences between surgical techniques.

Abdominal Wall Transplantation: Indications and Outcomes

Purpose of Review

This article aims to review published outcomes associated with full-thickness vascularized abdominal wall transplantation, with particular emphasis on advances in the field in the last 3 years.

Recent Findings

Forty-six full-thickness vascularized abdominal wall transplants have been performed in 44 patients worldwide. Approximately 35% of abdominal wall transplant recipients will experience at least one episode of acute rejection in the first year after transplant, compared with rejection rates of 87.8% and 72.7% for hand and face transplant respectively. Recent evidence suggests that combining a skin containing abdominal wall transplant with an intestinal transplant does not appear to increase sensitization or de novo donor-specific antibody formation.

Summary

Published data suggests that abdominal wall transplantation is an effective safe solution to achieve primary closure of the abdomen after intestinal or multivisceral transplant. However, better data is needed to confirm observations made and to determine long-term outcomes, requiring standardized data collection and reporting and collaboration between the small number of active transplant centres around the world.

Indications of Intestinal Transplantation

"The intestinal transplantation is reserved for patients with life-threatening complications of permanent intestinal failure or underlying gastrointestinal disease. The choice of the allograft for a particular patient depends on several factors and the presence of concurrent organ failure, and availability of the donor organs, and specialized care. Combined liver and intestinal transplant allows for patients who have parenteral nutrition-associated liver disease a possibility of improved quality of life and nutrition as well as survival. Intestinal transplantation has made giant strides over the past few decades to the present era where current graft survivals are comparable with other solid organ transplants."

Abdominal wall transplantation in organ transplantation: Our experience

Abdominal wall transplantation has been consolidated as an alternative to primary abdominal wall closure in intestinal and multiple organ transplant recipients. Given that it is feasible to obtain the visceral graft and the abdominal wall graft from the same donor, abdominal wall transplantation could offer satisfactory outcomes and be easily coordinated. Non-vascularized fascia is one of the alternatives for abdominal wall closure in transplantation. We report two cases of non-vascularized fascia transplantation in intestinal and multivisceral transplants, respectively. Both donors were young (23 and 18 years old). Both recipients had endured multiple previous surgeries, and no surgical alternatives for primary wall repair could be offered. In both cases, a complete abdominal wall flap was retrieved from the donor, however, due to the characteristics of the recipient's abdominal wall defect, only non-vascularized fascia was used after removing skin and subcutaneous cellular tissue from the graft. Abdominal wall transplantation is an option to consider for abdominal wall closure in patients with multiple previous surgeries and no alternatives for primary wall repair.

Abdominal Wall Transplant Surgery

The evolution and success of intestinal and multi-visceral transplantation over the past 20 years have raised the issue of difficult or even impossible abdominal closure, a topic rarely encountered in other fields of transplantation. Different techniques have been proposed to address this topic. The choice depends on the transplant team's expertise and/or the availability of a plastic surgery service. Abdominal wall transplant is a type of composite tissue allograft that can be utilized to reconstitute the abdominal domains of patients who undergo intestinal transplant, and the results are encouraging. It is an effective option to achieve primary abdominal closure after intestinal transplant. In its full-thickness form, it may be useful for monitoring rejection or viability of visceral organs. Our aim is to review the role of abdominal wall transplant in achieving tension-free closure of the abdomen.

Abdominal wall allotransplantation

Allotransplantation of vascularized composite tissue is a new field of transplantation surgery. One application of this technique is abdominal wall transplantation used as a supplementary procedure to the transplantation of visceral organs in patients with abdominal compartment deficits. As abdominal wall closure problems are experienced in around 30-40% of such patients, peer reviewed conclusions on the viability of various options, are important for an informed choice of possible procedures. This review focuses on the abdominal wall allotransplantion procedure. Our search provided 35 appropriate references which we used to support our findings as follows: abdominal wall transplantation was performed in 33 patients at seven centres. Of these, 30 had a full thickness abdominal wall transplanted from the same donor, 3 from a second donor. Three had visceral organ transplants and in addition, the posterior sheet of the rectus muscle fascia. In summary, our findings were that abdominal wall allotransplantation does not jeopardize the outcome of visceral organs transplantation. There is no higher risk of complications or rejection of the visceral organs. There have been no fatalities as a direct result of complications due to abdominal wall transplantation. Finally, the transplanted abdominal wall may provide an early warning of rejection before diagnostic tests on the bowel are symptomatic.

The abdominal wall transplant as a sentinel skin graft

PURPOSE OF REVIEW

Abdominal wall transplantation is a technique used to achieve abdominal closure after intestinal and multivisceral transplantation. This review focuses on whether there are additional benefits for the skin component as an immune-monitoring tool.

RECENT FINDINGS

The largest series of abdominal wall transplants has recently been published. Alongside the physiological advantage gained in abdominal closure, the authors describe the immunological insight that the skin component can provide and how this contributes to the management of patients. The skin appears to develop a rash with early rejection, which facilitates early systemic treatment before significant visceral rejection occurs. It can also help in cases in which there is diagnostic doubt regarding the cause of bowel dysfunction such as in instances of intestinal infection. Despite the additional immunological burden of donor tissue, there appears to be no requirement for increased immunosuppressive therapy.

SUMMARY

The technical and immunological feasibility of abdominal wall transplantation has now been demonstrated by several centres. Skin transplanted as part of the abdominal wall or as a separate vascularized sentinel skin flap may aid in the diagnosis of rejection. This has the potential to improve graft survival and reduce immunosuppressive morbidity.

Role of “reduced-size” liver/bowel grafts in the “abdominal wall transplantation” era

The evolution of multi-visceral and isolated intestinal transplant techniques over the last 3 decades has highlighted the technical challenges related to the closure of the abdomen at the end of the procedure. Two key factors that contribute to this challenge include: (1) Volume/edema of donor graft; and (2) loss of abdominal domain in the recipient. Not being able to close the abdominal wall leads to a variety of complications and morbidity that range from complex ventral hernias to bowel perforation. At the end of the 90’s this challenge was overcome by graft reduction during the donor operation or bench table procedure (especially reducing liver and small intestine), as well as techniques to increase the volume of abdominal cavity by pre-operative expansion devices. Recent reports from a few groups have demonstrated the ability of transplanting a full-thickness, vascularized abdominal wall from the same donor. Thus, a spectrum of techniques have co-evolved with multi-visceral and intestinal transplantation, ranging from graft reduction to enlarging the volume of the abdominal cavity. None of these techniques are free from complications, however in large-volume centers the combinations of both (graft reduction and abdominal widening, sometimes used in the same patient) could decrease the adverse events related to recipient’s closure, allowing a faster recovery. The quest for a solution to this unique challenge has led to the proposal and implementation of innovative solutions to enlarge the abdominal cavity.

Intestinal transplantation: a review

PURPOSE OF REVIEW

The purpose of this article is to review the existing literature on the current indications, surgical techniques, immunosuppressive therapy and outcomes following intestinal transplantation (ITx).

RECENT FINDINGS

Over recent years, ITx has become a more common operation with approximately 2500 procedures carried out worldwide by 2014. It is reserved for patients with intestinal failure and who have developed complications of home parenteral nutrition or who have a high risk of dying from their underlying disease. Recent advances such as the improvement in survival rates, not only for isolated small bowel transplants but also following inclusion of a liver graft in combined liver-small bowel transplant, and the utility of citrulline as a noninvasive biomarker to appreciate acute rejection herald an exciting shift in the field of ITx.

SUMMARY

With advancements in immunosuppressive drugs, induction regimens, standardization of surgical techniques and improved postoperative care, survival is increasing. In due course, it will most likely become as good as remaining on home parenteral nutrition and as such could become a viable first-line option.

Current state of abdominal wall transplantation

PURPOSE OF REVIEW

Primary closure of the abdominal wall remains one of the early challenges of intestinal transplantation. Our aim is to review the role of abdominal wall transplantation in achieving tension-free closure of the abdomen.

RECENT FINDINGS

In total, 38 full-thickness vascularized abdominal wall transplants, six partial-thickness vascularized and 17 partial-thickness nonvascularized rectus facia grafts have been reported worldwide. Different techniques have been described. The most popular choice seems to be the full-thickness vascularized abdominal wall allograft, where the anastomosis is performed either in a micro- or macrovascular fashion. Temporary 'remote' revascularisation of the allograft has been performed in some cases onto the recipient's forearm vessels when there is a long anticipated cold ischaemia time (>5 h). Preliminary data suggest that the abdominal wall skin rejection might be an early predictor of intestinal rejection. Vascularized and nonvascularized rectus fascia may be effective when there is inadequate healthy muscle/fascia but sufficient skin cover.

SUMMARY

Several centres have already proved the technical and immunologic feasibility of partial or full-thickness abdominal wall transplantation. It is an effective option to achieve primary abdominal closure following intestinal transplantation and in its full-thickness form, it may be useful for monitoring rejection in visceral organs.

Abdominal Wall Transplantation: Skin as a Sentinel Marker for Rejection

Abdominal wall transplantation (AWTX) has revolutionized difficult abdominal closure after intestinal transplantation (ITX). More important, the skin of the transplanted abdominal wall (AW) may serve as an immunological tool for differential diagnosis of bowel dysfunction after transplant. Between August 2008 and October 2014, 29 small bowel transplantations were performed in 28 patients (16 male, 12 female; aged 41 ± 13 years). Two groups were identified: the solid organ transplant (SOT) group (n = 15; 12 ITX and 3 modified multivisceral transplantation [MMVTX]) and the SOT-AWTX group (n = 14; 12 ITX and 2 MMVTX), with the latter including one ITX-AWTX retransplantation. Two doses of alemtuzumab were used for induction (30 mg, 6 and 24 h after reperfusion), and tacrolimus (trough levels 8-12 ng/mL) was used for maintenance immunosuppression. Patient survival was similar in both groups (67% vs. 61%); however, the SOT-AWTX group showed faster posttransplant recovery, better intestinal graft survival (79% vs. 60%), a lower intestinal rejection rate (7% vs. 27%) and a lower rate of misdiagnoses in which viral infection was mistaken and treated as rejection (14% vs. 33%). The skin component of the AW may serve as an immune modulator and sentinel marker for immunological activity in the host. This can be a vital tool for timely prevention of intestinal graft rejection and, more important, avoidance of overimmunosuppression in cases of bowel dysfunction not related to graft rejection.

Scleromatous Changes in an Abdominal Wall Graft: Graft-Versus-Graft Disease, or Chronic Graft Rejection?

Abdominal wall transplants are relatively new procedures that are frequently performed in conjunction with multivisceral transplants. The skin of the abdominal wall transplant is often the first site for graft rejection to manifest itself. Prompt recognition can lead to appropriate treatment before the involvement of the underlying viscera. However, the signs of graft rejection are nonspecific and can overlap with other entities. We present a case of a patient who received a multivisceral and abdominal wall transplant from 2 different donors, who presented with acute and eventually chronic graft rejection of the abdominal wall graft. Serial biopsies performed during the course of her treatment demonstrated progressive sclerotic changes in the dermis. Because these changes were confined to the abdominal wall graft, they could represent either chronic graft rejection or graft-versus-graft disease. To date, graft-versus-graft disease has not been documented in these patients. This case illustrates the possibility that patients with multidonor transplants may be at an increased risk for graft failure secondary to multiple potential etiologies.

Skype clinics after intestinal transplantation - follow-up beyond post codes

The follow-up after intestinal transplantation (ITX) is complex and limited to specialized centers. ITX recipients often travel all over the country to be seen in the outpatient clinic of specialized centers which is costly and time-consuming. Videoconferences through Skype have been implemented to eliminate travel time, costs, and to improve patient compliance without jeopardizing safety. Eighteen of 19 patients followed up after ITX or modified multivisceral transplantation (MMVTX) in conventional outpatient clinics in Oxford agreed to attend additional Skype clinics. All patients who were followed up through Skype clinics after ITX/MMVTX received a questionnaire to measure their satisfaction with methods and technical aspects of videoconferencing as well as time/mode of traveling, travel expenses/costs, waiting time in outpatient clinic and patients' satisfaction. Mean travel distance to Oxford was 236 ± 168 miles, mean travel time was 277 ± 175 min, and mean travel cost was 200 ± 56 Great Britain Pounds. A total of 56% had to take time off work and/or find child/family care for the time spent in travel. These patients reported a satisfaction score of 4.38 ± 0.77 of 5 points as opposed to 2.88 ± 0.90 for attending the conventional outpatient clinic. Skype clinics have been proven successful and feasible in highly specialized fields like ITX in eligible patients.

Current understanding of alloimmunity of the intestinal graft

PURPOSE OF REVIEW

This review focuses on the known mechanisms of alloimmunity that occur after transplantation and what is being done in order to improve graft and patient survival, particularly in the long term.

RECENT FINDINGS

The presence of mismatched antigens and epitopes might relate directly to the development of de-novo donor-specific antibodies (DSA), and thus, rejection. In an abdominal wall transplant, the skin graft could be the first to show signs of rejection. The epithelial or endothelial cells are the main targets in acute and chronic rejection, respectively. Possible therapeutical targets are gut homing T cells and cells of the innate immune system. Chimerism development might mostly occur in isolated lymph nodes, but also in the epithelium, particularly after transplantation of bone marrow mesenchymal stromal cells.

SUMMARY

Ischemia-reperfusion, surgical injury, and bacterial translocation trigger the innate immune system, starting acute rejection. Interaction between donor and recipient immune cells generate injury and tolerance, which occur mostly in secondary lymphoid organs, lamina propria, and epithelium. Chronic rejection mostly affects the endothelial cells, generating graft dysfunction. DSA increase the risk of graft rejection both acutely and chronically, and the liver protects against their effects. Induction therapies deplete lymphocytes prior to implantation, and maintenance therapies inhibit T-cell expansion. Rejection rates are the lowest when depleting drugs and a combination of interleukin 2 receptor blockade, inhibition of T-cell expansion, and steroids are used as maintenance therapy. Chimerism and tolerogenic regiments that induce Tregs and prevent the development of DSA are important treatment goals for the future.

Modified liver-free multivisceral transplantation for a metastatic small bowel neuroendocrine tumor: a case report

Neuroendocrine tumors originating from the small bowel frequently metastasize to the lymph nodes and/or liver. Although surgical extirpation of the primary tumor and locoregional metastases epitomizes the management of patients with such tumors, this is not always possible with conventional surgical techniques. Nonresectable, slow-growing tumors involving the mesenteric root represent a generally accepted indication for deceased donor intestinal and multivisceral transplantation. Furthermore, vascularized sentinel forearm flaps offer opportunities for monitoring graft rejection and tailoring immunosuppression regimens. Here, we report the first documented case of modified liver-free multivisceral transplantation preceded by neoadjuvant 177-lutetium peptide receptor radionuclide therapy in a patient with a small bowel neuroendocrine tumor and extensive lymph node metastases in the mesenterium. At a follow-up of 21 months the patient is biochemically and radiologically disease-free.

The use of bi-planar tissue expanders to augment abdominal domain in a pediatric intestinal transplant recipient

Intestinal transplantation is a well-accepted treatment for SBS. However, patients with SBS often have decreased abdominal capacity, which makes size-matching of donor organs more difficult, thus decreasing organ availability. Reported approaches for addressing this problem include surgically reducing the graft size, leaving an open abdomen for a prolonged period, and cotransplanting rectus fascia as a non-vascularized allograft. Each approach has significant disadvantages. There has been one previous report of tissue expanders used intra-abdominally and two reports of subcutaneous use to increase intra-abdominal capacity prior to transplantation. We report the first use of bi-planar expander placement for this purpose. In our case, a two-yr-old male child with SBS due to malrotation was treated with tissue expanders 10 months prior to intestinal transplantation, thus allowing transplantation of a larger graft with the ability to close the abdomen safely. There were no complications, and the patient is now doing well and tolerating diet off PN. The use of tissue expanders prior to intestinal transplantation is a promising approach for such patients and avoids the morbidity associated with other approaches. This approach requires a multidisciplinary effort by gastroenterology, transplant surgery, and plastic surgery teams.