Hannah B Baker, PhD, Adam Young, PhD, Thomas Gilbert, PhD. ACell Inc.
The utility of biologically derived surgical meshes relies on their capacity to integrate with host tissue and remodel over time. However, development of mesh attachment to viscera after intraperitoneal placement must be minimized to limit risk of bowel obstruction and intestinal fistula. Herein, the utility of surgical grafts derived from urinary bladder matrix (UBM) and small intestine submucosa (SIS) to minimize tissue attachments was investigated in a rabbit model of intraperitoneal tissue attachment.
The rabbit model entailed excision of the peritoneum and abrasion of the cecum to induce the formation of tissue attachment between the bowel and peritoneum (n=6 per treatment and time point). Commercially available UBM and SIS grafts (3 variable thickness UBM grafts and 1 SIS graft) were placed intraperitoneally and sutured to the peritoneum to reinforce the midline repair. Animals with non-reinforced repairs were used as controls. At 14 and 90 days, the number and severity of tissue attachments between the device and the surrounding viscera were assessed and tissues were processed for histology.
At both time points, all three UBM groups had fewer animals with tissue attachments (Fig.1) and lower average severity scores than the SIS group. When compared to controls, the UBM groups had fewer and/or smaller tissue attachments (single vs multifocal) and lower attachment severity scores at both time points. At 14 days, all devices remained largely non-resorbed while at 90 days moderate device degradation was observed across all groups, with the thinnest UBM devices appearing substantially degraded. Histologic evaluation revealed closure of the midline defect and granulation tissue deposition for all groups, with appreciable differences in semi-quantitative histological assessments for certain cell types. At 14 days, all surgical meshes showed increased numbers of macrophages compared to control animals. Lymphocytes were also more readily apparent in UBM compared to SIS devices. At 90 days there were increased numbers of multinucleated giant cells for SIS compared to UBM.
This study evaluated the ability of biologically-derived surgical meshes to minimize tissue attachments in a preclinical model in which adhesion formation would normally be expected. UBM devices all showed performance that was similar to or better than SIS devices with respect to limiting tissue attachment formation when the devices are placed intraperitoneally. The results of this study support the use of UBM-based devices for intraperitoneal repair reinforcement as well as laparoscopic deployment of biologically derived surgical meshes.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 92693
Program Number: P552
Presentation Session: Poster Session (Non CME)
Presentation Type: Poster