The impact of occlusive vs non-occlusive application of 5-aminolevulinic acid (BF-200 ALA) on the efficacy and tolerability of photodynamic therapy for actinic keratosis on the scalp and face: A prospective within-patient comparison trial.

BACKGROUND: Photodynamic therapy (PDT) is an effective treatment for actinic keratoses (AK). PDT is usually performed with occlusion of the photosensitizer prior to subsequent illumination. OBJECTIVES: This study aimed to compare the efficacy and tolerability of occlusive versus non-occlusive application of a 5-aminolevulinic gel (BT-200 ALA) for PDT of multiple AK on the scalp or face. METHODS: Prospective, investigator-blinded, within-patient comparison study on 45 patients. PDT with occlusion of ALA was performed in a target area on one randomized side of the scalp or face. One week later a contralateral target area received the same treatment except that no occlusion of the ALA gel was performed. 3 and 6 months after PDT, the clearance rate of a predetermined target lesion and the total clearance rate of all AK within the treated areas were determined. PDT-induced pain and skin phototoxicity and cosmetic outcome were also recorded. RESULTS: Clearance rate of the target AK and total AK clearance rate at 3 months after PDT was 88.4% and 90.6% for occlusive PDT and 58.1% (P = .001) and 70.4% (P = .04) for non-occlusive PDT. The corresponding values at 6 months after PDT were 69.7% and 72.1% for occlusive PDT and 30.2% (P < .001) and 35.6% (P = .001) for non-occlusive PDT. Pain score and skin phototoxicity were significantly higher after occlusive ALA application. No difference was observed with respect to cosmetic outcome. CONCLUSIONS: Occlusive application of ALA significantly improves the efficacy of PDT but is associated with more pain and increased phototoxicity.

Biologic hernia implants in experimental intraperitoneal onlay mesh plasty repair: the impact of proprietary collagen processing methods and fibrin sealant application on tissue integration.

BACKGROUND: Biologic implants have been recommended for reinforcement in routine and challenging hernia repair. However, experimental and clinical studies have reported adverse effects (e.g., slow implant integration and pronounced foreign body reaction). To evaluate the impact of different material processing methods (cross-linking vs. non-cross-linking of collagen) and implant design, four different biologic hernia implants were compared directly in experimental intraperitoneal onlay mesh plasty (IPOM). Tissue integration, shrinkage, and foreign body reaction were primary outcome parameters. METHODS: In this study, 48 Sprague-Dawley rats were randomized to four treatment groups. Open IPOM repair was performed. One peritoneal defect per animal was covered with 2 × 2 cm patches of cross-linked or non-cross-linked implants including CollaMend (n = 12), Peripatch (n = 12), Surgisis (n = 12), and Tutomesh (n = 12). In half of the animals, fibrin sealant was applied for additional fixation and to cover sutures. The observation period was 60 days. The primary outcome parameters were implant integration, shrinkage, and foreign body reaction. Macroscopic and histologic assessments were performed. RESULTS: The integration of implants was insufficient in all the groups. The implants could be detached easily from the underlying tissue, and the penetration of fibroblasts and vessels was limited to the perforations. Foreign body reaction was pronounced with CollaMend and Surgisis, leading to persistent granulomatous inflammation. Shrinkage was excessive with Surgisis, whereas Tutomesh and Peripatch yielded sufficient anti-adhesion and elicited no foreign body reaction. CONCLUSION: At 2 months, cross-linked and non-cross-linked biologic hernia implants were poorly integrated. Cross-linking led to a more pronounced foreign body reaction. Less inflammatory response may reduce local complications, but did not enhance implant integration in this study.