The use of a "horizontal centrifugation protocol" to prepare autologous platelet-rich fibrin membranes for corneal reconstruction surgery in dogs with complicated corneal ulcerations: A case series.

OBJECTIVE: The purpose of this case series was to describe the effect of autologous PRF membrane for corneal reconstruction surgery in dogs. PRF membranes made from two healthy dogs unrelated to the current case series were used for PRF histologic analyses. ANIMALS: Seven dogs with complicated corneal ulcerations. PROCEDURE: A complete ophthalmic examination, hematology, and fibrinogen analysis were performed pre-surgery. A PRF clot was made from autologous blood in a serum tube after centrifugation in a horizontal Bio-PRF® Centrifuge at 700 × g for 8 min. The PRF clot was processed in a PRF-Box® into a PRF membrane. The PRF membrane was sutured to the corneal ulcer bed. Each dog had a follow-up at days 5-7, 12-14, and 30-40 post-surgery. A final long-term follow-up was performed as well. RESULTS: A positive outcome with healing and a "good" quality PRF membrane was seen in six out of seven dogs. One dog had a fibrinogen level below normal range and the PRF membrane was of "poor" quality. This dog developed a descemetocele 13 days post-surgery and needed rescue surgery. Mean healing time for all dogs was 9 ± 5.5 days. Minimal scarring, corneal pigmentation, and vascularization were observed at the final long-term follow-up 288 ± 44 days post-surgery. CONCLUSION: PRF membrane was successful as graft material for corneal ulceration reconstruction surgery. Low fibrinogen appeared to have negative effect on the quality of the PRF membrane, showing the importance for the surgeon to evaluate the quality of the PRF membrane prior to surgery.

Implementation of the ISTH classification of non-overt DIC in a thromboplastin induced rabbit model.

Validation of animal models of disseminated intravascular coagulation (DIC) to human DIC is crucial in order to translate findings in research models to treatment modalities for DIC in humans. ISTH classifications of overt and non-overt human DIC have proven to have a high diagnostic accuracy, but the scoring systems have rarely been applied to animal models of DIC. In this study, we use rabbit brain thromboplastin (thromboplastin) to induce DIC in a rabbit model and test the applicability of the ISTH criteria for standardized diagnosis of DIC. Cardiovascular and haematological parameters from rabbits, either saline-injected or administered 0.625, 1.25, 2.5 or 5 mg thromboplastin/kg as a single bolus, were collected at four timepoints over a 90 minute period. All groups of rabbits were scored at each time point according to the ISTH diagnostic criteria for non-overt DIC. Injection of 5 mg thromboplastin/kg was lethal. For the remaining groups, a dose dependent decrease in blood pressure, platelet count and fibrinogen level together with a dose dependent increase in prothrombin time, activated partial thromboplastin time, level of thrombin-antithrombin complexes, fibrin degradation products and number of thrombi in lung vasculature was seen. The administration of a bolus of 1.25 - 2.5 mg thromboplastin/kg to rabbits induced a reproducible dose dependent model of non-overt DIC according to the ISTH diagnostic criteria. We conclude that the non-overt ISTH score can be applied to evaluate severity and progression of DIC in a standardized manner in this thromboplastin induced rabbit model.