Histologic evaluation of organ preservation injury and correlation with cold ischemia time in 13 intestinal grafts

Abstract

Lesions produced in the graft mucosa due to harvesting, storage, and implantation must be graduated to assess the subsequent protocolized biopsy specimens. The aim is to identify type and intensity of graft mucosal lesions observed immediately after implantation. Congestion, hemorrhage, microthrombi, neutrophilic infiltrates, shortening of villi, epithelial detachment, erosion, and crypt loss were separately evaluated by two pathologists in mucosal biopsy specimens from 13 grafts. Each change was assessed as normal, mild, moderate, or severe and by splintering the summation of points a global score was designed. Cold ischemia time was registered. Correlation between the pathologists' evaluations and between final preservation injury degree and cold ischemia time was determined using the "index of correlation rho (ρ)" (Spearman's test). The same changes were assessed in 19 biopsy specimens from day 2 to day 6 (3.6 ± 1.1) to determine their evolution. Congestion was found in 7 biopsy specimens, microthrombi in 2, hemorrhage in 4, neutrophils in 6, villous atrophy in 8, epithelial detachment in 9, erosions in 2 and/or crypt loss in 2. The maximum degree of preservation injury was expressed as intense congestion and hemorrhage associated with epithelial detachment and villous atrophy. The global preservation score was grade 3 in 2 cases, grade 2 in 5, grade 1 in 2, and grade 0 in 4. There was positive correlation (ρ = 0.915) in the evaluation between pathologists (P < .01), total agreement in 9 biopsy specimens, and partial agreement (only 1 point disagreement) in 4. Mean cold ischemia time was 327 ± 101 min. (135-480). There was positive correlation (ρ = 0.694) between preservation score and cold ischemia time (P < .01). In the follow-up biopsy procedures, histological injury decreased by at least one grade in every case. Additionally, karyorrhexis was observed in 3 grafts and very occasional apoptosis in 2 others. This scale achieves good reproducibility and allows graduate preservation injury in intestinal transplantation.