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.

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

Intestinal transplantation (ITx) is often associated with decreased abdominal domain, rendering abdominal closure difficult. Pre-transplant placement of tissue expanders (TE) can overcome this challenge; however it can be associated with life-threatening complications. This review aimed to comprehensively summarize all available literature on TE in ITx candidates and include the technical details of osmotic, self-inflatable TE -a technique undescribed before. PubMed, EMBASE and CCTR were searched until April 30, 2016. Based on structured data abstraction and detailed analysis, eighteen cases of TE (inflatable) in ITx candidates were found. Localisation of placement was: subcutaneously in 11; intraperitoneally in 4; 1 patient had 1 TE placed retromuscularly and 1 intraperitoneally; 1 patient had biplanar TE (intraperitoneally placed and extending retromuscularly) and in 1 localisation was unreported. Complication rate was high (61%), injection- or intraperitoneal-related, resulting in life-threatening infections/hematoma. With successful expansion, physiological graft protection -by skin+/-fascia- was always achieved. In completion of this review, we describe our own experience with two patients (7.5-, 34-year-old females), in whom osmotic TE were placed subcutaneously pre-ITx. No TE-related complications occurred and both patients underwent uncomplicated ITx with respectively primary skin and skin + fascia closure. The pros and cons of each TE type and placement are discussed, resulting in the overall conclusions that TE offer an important benefit in graft-protection following ITx. Osmotic TE are safer than conventional prostheses by avoiding percutaneous injections. Subcutaneous placement seems to be safer and more reliable.