Early tissue modifications observed in a non immunosuppressed rat model of Abdominal Rectus Fascia Transplant

JEREMÍAS E. MOREIRA; PABLO STRINGA ; PEDRO MARTIN; VERÓNICA MILESI; CONSTANZA ARRIOLA-BENITEZ; IVANA IVANOFF; ARACELI CASTRO; RUMBO, MARTÍN; GABRIEL E GONDOLESI; GENTILINI MARIA VIRGINIA

Congreso; 18th Congress of the Intestinal Rehabilitation and Transplant Association, CIRTA,; 2023

ORAL ABSTRACTS AND POSTER OF DISTINCTION: ADVANCES IN INTESTINAL BIOENGINEERING: STEM CELL BIOLOGY, TISSUE ENGINEERING AND PERSONALIZED MEDICINE42: Early tissue modifications observed in a non immunosuppressed rat model of Abdominal Rectus Fascia TransplantMoreira, Jeremías PhD student1; Stringa, Pablo PhD2,3; Gentilini, María Virginia PhD1; Martín, Pedro PhD2; Milesi, Verónica PhD2; Arriola-Benitez, Constanza PhD1; Ivanoff, Ivana PhD student2; Castro, CPA Araceli Tec1; Rumbo, Martín PhD2; Gondolesi, Gabriel PhD1,4Author InformationTransplantation 107(7S):p 23, July 2023. | DOI: 10.1097/01.tp.0000945624.64477.23FREEMetricsIntroduction: The impossibility of performing an adequate closure of the abdominal wall after an intestinal or multivisceral transplant increases the occurrence of complications and post-surgical death. The use of synthetic meshes can predispose to infections and fistulas, high costs and low availability on the market. Within the clinic, the use of different abdominal wall transplantation techniques has been proposed, however, many immunological phenomena are still unknown, the reason why further studies are necessary. Our aim was to characterize a new experimental model of rectus fascia transplantation.Methods: The technique was developed by reproducing the technical aspects of “the Miami procedure” for avascular abdominal rectus fascia transplantation (TxARF) for humans in rats. Eighteen TxARF were performed, 9 were isogenic and 9 allogeneic transplants. Sprague Dawley and Wistar rats were used. Recipients were sacrificed on day 30 post-surgery and graft samples were taken for elasticity measurement, histopathological evaluation by Weigert analysis for elastic fibers, Trichromic to stain collagenous connective tissue fibers, and immunohistochemistry for CD3+ cells. Six non-implanted fascias were taken as a control group (Ct). Relative amounts of CD4+ and CD8+ Tcells was determined by flow cytometry. Turnover of hematopoietic cells in the graft was analyzed by flow cytometry using GFP+Wistar rats as recipients.Results: In the TxARF group, the 30 day survival was 100%; no adhesions between the intestines and the grafts were observed. The presence of neo-vascularization has been observed in all grafts. Isogenic and allogeneic grafts on day 30 presented less elasticity compared to the Ct (p=0.003), although no differences were observed in terms of the number of elastic fibers observed in TxARF grafts and Ct. The mean percentage of collagen fibers stained was more than 10 times higher in the TxARF allogeneic and isogenic groups than in the Ct (p