Initial Histological Evaluation of a Novel Dura Mater Graft Based on Capsule Granulation Harvested From Subcutaneous Tissue: Experimental Model.

INTRODUCTION: Autografts are useful but unfortunately are limited in big dural defects, in such cases, synthetic implants have been recommended. Extensive evidence in the literature suggests that sometimes synthetic implants had high rates of complications like infections. This paper aims to present a novel dura matter graft based on capsule granulation tissue harvested from subcutaneous space as a dura substitute and its histological findings. MATERIALS AND METHODS: Wistar rats between 240 and 430 grams of both genders were included. First stage procedure introducing silicon spheres in the subcutaneous tissue. Second stage procedure 4 weeks later harvested de capsule granulation tissue that contain them. Then a craniectomy was performed to create a dura mater defect. This defect was reconstructed with the granulation tissue was placed onlay the defect. After another 4 weeks the subjects were euthanized and sent to an external pathology unit for analysis with validated integration scales. RESULTS: A total of 5 subjects were included (3 males and 2 females) with weight between 240 and 430 grams. Only 2 outcome out of 6 scales had significance difference between the samples: adhesions P = 0.011 and integration P = 0.006. CONCLUSIONS: The histological findings shown that capsule granulation graft is a compatible, autologous compatible substitute for dura mater. It has a great potential of full integration and an acceptable grade of adhesions.

Evaluation of Predictive Values of an Automatic Device Measuring Oximetry in Free Flaps.

Free-flap monitoring is challenging to perform in some centers. It requires the availability of trained health care personnel for 24 hours a day and seven days a week. Many methods had been proposed for flap monitoring, and none of them are superior to clinical evaluation. This study aimed to present a murine model to evaluate the accuracy (sensitivity, specificity, and the positive or negative predictive values) of a device. Wistar rats weighing 240-490 g were included for intervention and data collection. A murine model of left inferior epigastric vessel flaps was implemented. Intermittent pedicle clamping was performed to calculate the accuracy of the device that detects flow obstruction. The general variables studied were age, weight, and gender. The sensitivity, specificity, and negative or predictive values were calculated. The results showed a sensitivity of 97%, a specificity of 95% with a positive predictive value of 95%, and negative predictive value of 97%. The sensitivity and specificity showed excellent results within the range of clinical security. We require more data to analyze the multiparameter monitoring to see if it is feasible and cost-effective.