The role of osmotic self-inflatable tissue expanders in intestinal transplant candidates

Multilevel Analysis of the Neovascularization and Integration Process of a Nonvascularized Rectus Fascia Transplantation

Background

Failure to close the abdominal wall after intestinal transplantation (ITx) or multivisceral Tx remains a surgical challenge. An attractive method is the use of nonvascularized rectus fascia (NVRF) in which both layers of the donor abdominal rectus fascia are used as an inlay patch without vascular anastomosis. How this graft integrates over time remains unknown. The study aims to provide a multilevel analysis of the neovascularization and integration process of the NVRF.

Methods

Three NVRF-Tx were performed after ITx. Clinical, radiological, histological, and immunological data were analyzed to get insights into the neovascularization and integration process of the NVRF. Moreover, cryogenic contrast-enhanced microfocus computed tomography (microCT) analysis was used for detailed reconstruction of the vasculature in and around the NVRF (3-dimensional histology).

Results

Two men (31- and 51-y-old) and 1 woman (49-y-old) underwent 2 multivisceral Tx and 1 combined liver-ITx, respectively. A CT scan showed contrast enhancement around the fascia graft at 5 days post-Tx. At 6 weeks, newly formed blood vessels were visualized around the graft with Doppler ultrasound. Biopsies at 2 weeks post-Tx revealed inflammation around the NVRF and early fibrosis. At 6 months, classical 2-dimensional histological analysis of a biopsy confirmed integration of the fascia graft with strong fibrotic reaction without signs of rejection. A cryogenic contrast-enhanced microCT scan of the same biopsy revealed the presence of microvasculature, enveloping and penetrating the donor fascia.

Conclusions

We showed clinical, histological, and microCT evidence of the neovascularization and integration process of the NVRF after Tx.

Abdominal Wall Closure in Intestinal and Multivisceral Transplantation: A State-Of-The-Art Review of Vascularized Abdominal Wall and Nonvascularized Rectus Fascia Transplantation

Failure to close the abdomen after intestinal or multivisceral transplantation (Tx) remains a frequently occurring problem. Two attractive reconstruction methods, especially in large abdominal wall defects, are full-thickness abdominal wall vascularized composite allograft (AW-VCA) and nonvascularized rectus fascia (NVRF) Tx. This review compares surgical technique, immunology, integration, clinical experience, and indications of both techniques. In AW-VCA Tx, vascular anastomosis is required and the graft undergoes hypotrophy post-Tx. Furthermore, it has immunologic benefits and good clinical outcome. NVRF Tx is an easy technique without the need for vascular anastomosis. Moreover, a rapid integration and neovascularization occurs with excellent clinical outcome.

Outcome After Intestinal Transplantation From Living Versus Deceased Donors: A Propensity-matched Cohort Analysis of the International Intestinal Transplant Registry

OBJECTIVE

To describe the worldwide experience with living donation (LD) in intestinal transplantation (ITx) and compare short-term and long-term outcomes to a propensity-matched cohort of deceased donors.

BACKGROUND

ITx is a rare life-saving procedure for patients with complicated intestinal failure (IF). Living donation (LD)-ITx has been performed with success, but no direct comparison with deceased donation (DD) has been performed. The Intestinal Transplant Registry (ITR) was created in 1985 by the Intestinal Transplant Association to capture the worldwide activity and promote center's collaborations.

METHODS

Based on the ITR, 4156 ITx were performed between January 1987 and April 2019, of which 76 (1.8%) were LD, including 5 combined liver-ITx, 7 ITx-colon, and 64 isolated ITx. They were matched with 186 DD-ITx for recipient age/sex, weight, region, IF-cause, retransplant, pretransplant status, ABO compatibility, immunosuppression, and transplant date. Primary endpoints were acute rejection and 1-/5-year patient/graft survival.

RESULTS

Most LDs were performed in North America (61%), followed by Asia (29%). The mean recipient age was: 22 years; body mass index: 19kg/m²; and female/male ratio: 1/1.4. Volvulus (N=17) and ischemia (N=17) were the most frequent IF-causes. Fifty-two percent of patients were at home at the time of transplant. One-/5-year patient survival for LD and DD was 74.2/49.8% versus 80.3/48.1%, respectively ( P =0.826). One-/5-year graft survival was 60.3/40.6% versus 69.2/36.1%, respectively ( P =0.956). Acute rejection was diagnosed in 47% of LD versus 51% of DD ( P =0.723).

CONCLUSION

Worldwide, LD-ITx has been rarely performed. This retrospective matched ITR analysis revealed no difference in rejection and in patient/graft survival between LD and DD-ITx.

Potential options to expand the intestinal donor pool: a comprehensive review

PURPOSE OF REVIEW

Intestinal donation is currently restricted to 'perfect' donors, as the intestine is extremely vulnerable to ischemia. With generally deteriorating donor quality and increasing indications for intestinal transplantation (ITx), the potential to safely increase the donor pool should be evaluated.

RECENT FINDINGS

Increasing awareness on intestinal donation (often forgotten) and cautiously broadening the strict donor criteria (increasing age, resuscitation time and ICU stay) could expand the potential donor pool. Donors after circulatory death (DCD) have so far not been considered for ITx, due to the particularly detrimental effect of warm ischemia on the intestine. However, normothermic regional perfusion might be a well tolerated strategy to render the use of DCD intestinal grafts feasible. Furthermore, machine perfusion is under continuous development and might improve preservation of the intestine and potentially offer a platform to modulate the intestinal graft. Lastly, living donation currently represents only a minority of all ITxs performed worldwide. Various studies and registry analysis show that it can be performed safely for the donor and successfully in the recipient.

SUMMARY

Several potential strategies are available to expand the current intestinal donor pool. Most of them require further investigation or technical developments before they can be implemented in the clinical routine.

Allotransplantation of donor rectus fascia for abdominal wall closure in transplant patients: A systematic review

BACKGROUND

Abdominal wall closure after intestinal, multivisceral or liver transplantation can be a major challenge. Different surgical techniques have been described to close complex abdominal wall defects, but results remain variable. Two promising transplant techniques have been developed using either non-vascularized or vascularized donor rectus fascia. This systematic review aimed to evaluate the feasibility, safety, and effectiveness of the two techniques.

METHODS

A systematic review was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Human studies published between January 2000 and April 2020 were included. Methodological quality appraisal was done using an adapted 10-item standardized checklist.

RESULTS

The search resulted in 9 articles including 74 patients. Both techniques proved to be feasible and had similar results. After non-vascularized rectus fascia allotransplantation, there was a slightly higher rate of surgical site infections in the earlier reports. Overall, there were few complications, no fascial graft related rejections or deaths. The included articles scored low on quality appraisal, mostly due to the small number of cases and scarcely reported outcome parameters.

CONCLUSIONS

This systematic literature review reports two emerging new techniques for complex abdominal wall closure in transplant patients, with promising results. Standardized data collection in a prospective manner could give us more detailed information about short- and long-term outcomes. Preclinical animal studies are necessary for a thorough investigation of the mechanisms of graft integration, the risk of hernia development and the alloimmune response against the graft.

Role of tissue expansion in abdominal wall reconstruction: A systematic evidence-based review

BACKGROUND

Tissue expanders (TEs) can be used to assist primary closure of complicated hernias and large abdominal wall defects. However, there is no consensus regarding the optimal technique, use, or associated risk of TE in abdominal wall reconstruction.

METHODS

A systematic search of PubMed and Embase databases was conducted to identify articles reporting abdominal wall reconstruction with TE techniques. English articles published between 1980 and 2016 were included on the basis of the following inclusion criteria: two-stage TE surgical technique, >3 cases, reporting of postoperative complications, hernia recurrence, and patient-based clinical data.

RESULTS

Fourteen studies containing 103 patients (85 adults and 18 children) were identified for analysis. Most patients presented with a skin-grafted ventral hernia (n = 86). The etiology of the hernia was from trauma or prior abdominal surgery. The remaining patients had TE placed before organ transplantation (n = 12) or for congenital abdominal wall defects (n = 5). The location for expander placement was subcutaneous (n = 74), between the internal and external obliques (n = 26), posterior to the rectus sheath (n = 2), and intra-peritoneal (n = 1). Postoperative infections and implant-related problems were the most commonly reported complications after Stage I. The most common complication after Stage II was recurrent hernia, which was observed in 12 patients (11.7%). Five patients with TE died. Complications and mortality were more prevalent in children, immunosuppressed patients, and those with chronic illnesses.

CONCLUSIONS

Tissue expansion for abdominal wall reconstruction can be successfully used for a variety of carefully selected patients with an acceptable complication and risk profile.