Allogenic dehydrated human pericardium patch graft (Tutoplast): A novel use for reconstruction in orbital implant exposure

Purpose: Exposure of orbital implant post enucleation or evisceration remains one of the common complications irrespective of the type of implant used. Dermis fat graft and temporalis fascia have been used to repair the implant exposure in anophthalmic sockets. Tutoplast® pericardium, gamma sterilised dehydrated human pericardium, has been used as a scleral patch graft for glaucoma drainage device exposure and scleral thinning post squint surgery. We report the novel use of Tutoplast® patch graft to repair orbital implant exposure in this case series. Methods: The case notes of three patients who received Tutoplast® pericardium patch graft to repair implant exposure were reviewed. Data regarding presenting symptoms, implant type, time to exposure from primary surgery, post-operative complications and length of follow up post Tutoplast® pericardium patch graft were collected. Results: Three patients presented with implant exposure following evisceration. The presenting symptoms were recurrent infection, discharging socket and discomfort in all three patients. One patient had a Medpore implant, two had silicone implants. Total follow-up ranged from 9 to 22 months. In all three cases, there was relief from symptoms and the graft had incorporated fully into the surrounding orbital tissue with no recurrent exposure noted during the follow-up period. Conclusion: Tutoplast® pericardium has demonstrated a good safety profile and is a suitable material to use as a patch graft for orbital implant exposure.

Modification of Human Pericardium by Chemical Crosslinking

Autologous and allogenic human pericardia used as biomaterials for cardiovascular surgery are traditionally crosslinked with glutaraldehyde. In this work, we have evaluated the resistivity to collagenase digestion and the cytotoxicity of human pericardium crosslinked with various concentrations of glutaraldehyde in comparison with pericardium crosslinked by genipin, nordihydroguaiaretic acid, tannic acid, and in comparison with unmodified pericardium. Crosslinking retained the wavy-like morphology of native pericardium visualized by second harmonic generation microscopy. The collagenase digestion products were analyzed using SDS-PAGE, capillary electrophoresis, and a hydroxyproline assay. Glutaraldehyde and genipin crosslinking protected the native pericardium efficiently against digestion with collagenase III. Only low protection was provided by the other crosslinking agents. The cytotoxicity of crosslinked pericardium was evaluated using xCELLigence by monitoring the viability of porcine valve interstitial cells cultured in eluates from crosslinked pericardium. The highest cell index, reflecting both the number and the shape of the monitored cells was observed in eluates from genipin. Crosslinking pericardium grafts with genipin therefore seems to be a promising alternative procedure to the traditional crosslinking with glutaraldehyde, because it provides similarly high protection against degradation with collagenase, without cytotoxic effects.