Technical pearls for swine lung transplantation.

BACKGROUND: Since the advent of ex vivo lung perfusion (EVLP), there has been increased focus on swine models of lung transplantation; however, the anatomic differences between human and swine lungs and the technical challenges in performing porcine lung transplantation are not well described in the surgical literature. METHODS: Surgically important anatomic variations are described, and the technical measures taken to address them during harvest and transplantation are introduced. RESULTS: There are three surgically important anatomic variations in pigs. First, the right cranial lobe bronchus arises directly from the trachea, which makes right lung transplantation technically challenging if not prohibitive. Second, the left hemi-azygos vein is fully developed and courses upward through the posterior mediastinum, where it crosses the left pulmonary hilum and drains directly into the coronary sinus. During transplantation, this vein is ligated and dissected away to expose the underlying left pulmonary hilar structures. Third, the right inferior pulmonary vein crosses the midline to drain into the left atrium immediately adjacent to the left inferior pulmonary vein. During donor lung preparation, the right inferior pulmonary vein is ligated distally from the left atrium, which leaves an adequate atrial cuff around the left sided pulmonary veins for later anastomosis. CONCLUSION: Experimental porcine lung transplantation is technically demanding. We have found recognition of the above described anatomical differences and technical nuances facilitate transplantation and provide reproducible results.

A novel method for low load friction testing on living cells.

A low load tribology technique for studying the effects of friction on living cells was developed. Results show a direct relationship between the coefficient of friction (COF) and the extent of cell damage. The COF, mu, for a glass pin on an intact layer of human corneal epithelial cells is determined to be on the order of mu = 0.05 +/- 0.02 (n = 16). The correlations between applied normal load and extent of cell damage, as well as between number of reciprocation cycles and cell damage, are reported. It is also found that cell damage can occur when a loading force as low as 0.5 mN is applied, although the cells appear to be intact.