Microscopic Findings of Sheet-Type Collagen Applied to Air Leaks after Pulmonary Resection

Purpose: It has been reported that Integran (R), a sheet-type absorbable topical collagen hemostat, is feasible for preventing pulmonary fistula after lung surgery. The most favorable aspect of Integran (R) is that it contains no blood products. However, the microscopic findings of post-surgery application of Integran (R) to the lung are not known. We identified 2 such cases of Integran (R) application, which were carried out a few years earlier, and described the microscopic findings. Method: In case 1, a 53-year-old man underwent video-assisted left upper lobectomy for primary lung cancer. Integran (R) was applied to the left lower lobe. Completion left pneumonectomy was performed after 2 years and 1 month due to recurrence. In case 2, a 77-year-old woman underwent video-assisted right middle lobectomy for primary lung cancer. Integran (R) was applied to the right upper lobe. Completion right upper lobectomy was performed after 1 year and 8 months due to recurrence. Results: The repaired visceral pleura of the 2 patients were covered with proliferated collagen fibers. However, there was little infiltration of inflammatory cells and fibroblasts. Conclusion: The microscopic findings revealed that the ability of Integran (R) to generate inflammation or adhesion is weak, but it has the ability to repair damaged visceral pleura.