Microscopic findings of sheet-type collagen applied to air leaks after pulmonary resection.

PURPOSE It has been reported that Integran(®), a sheet-type absorbable topical collagen hemostat, is feasible for preventing pulmonary fistula after lung surgery. The most favorable aspect of Integran(®) is that it contains no blood products. However, the microscopic findings of post-surgery application of Integran(®) to the lung are not known. We identified 2 such cases of Integran(®) 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(®) 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(®) 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(®) to generate inflammation or adhesion is weak, but it has the ability to repair damaged visceral pleura.