Faculty Bibliography

Bronchial anastomotic complications in lung transplantation in man remain a major cause of failure. To study this problem in a canine model, we varied the length of the distal bronchial component in three groups of dogs that underwent hilar stripping, bronchial transection, and reanastomosis, The distal bronchial component was thus analogous to the donor in a transplanted lung. Anastomoses were performed, respectively, at the level of the main carina (long single anastomosis), at the midpoint between the main carina and the bifurcation of the left main-stem bronchus (short single anastomosis), and just distal to the bifurcation of the left main-stem bronchus (lobar anastomosis). Bronchial anastomotic damage and necrosis were evaluated by periodic examination with a fiberoptic bronchoscope and by gross and microscopic examination at sacrifice on the seventh postoperative day. The long single anastomoses demonstrated the most necrosis, and the labor anastomoses showed the least. The short single anastomoses showed an intermediate degree of damage. These findings support the hypothesis that shortening the distal or donor bronchial component reduces anastomotic damage, probably because of better pulmonary-to-bronchial collateral blood supply. This study provides a canine model by which to examine bronchial anastomotic complicatons and demonstrates the feasibility of performing labor anastomoses as a means for decreasing bronchial anastomotic problems in lung transplantation

As part of an evaluation of the effects of left lung transplantation in dogs with papain emphysema of the right lung, differential lung blood flows were estimated by in vivo scintiscan of 99Mc-macroaggregated albumin (99mTc-MAA) and, after sacrifice, by direct counting of isotopically labeled carbonized microspheres. In six dogs, percentage flow to the right lung was calculated at the following four times: before and after induction of papain emphysema and 2 and 6 weeks after left lung autotransplantation. After the induction of right lung emphysema, the right lung in four of six animals continued to receive more than 50 percent of the total pulmonary blood flow. No correlation could be established between right lung blood flow determined by carbonized microsphere distribution (true right lung blood flow) and the flow determined by anterior and posterior scintiscans (apparent right lung blood flow). This discrepancy was caused by gross distortion of the right, emphysematous lungs, which had herniated into the left hemithoraces. This herniation was demonstrated by coronal slices taken through the thoraces of two additional dogs with right lung emphysema that were given radiolabeled carbonized microspheres and 99Tc-MAA and frozen after sacrifice. These results indicate that external scintiscans for which the particulate distribution technique are used are invalid in circumstances of altered lung geometry