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The selective arterialization of coronary veins as a surgical therapy for diffuse coronary arteriosclerosis was studied in canine and sheep experiments. The arterialized blood can be delivered promptly to the selected region of the myocardium and an adequate runoff exists for this mode of revascularization, so that myocardial edema and hemorrhage do not occur. The retrograde blood flow through an anastomosis between the internal mammary artery (IMA) and great cardiac vein (GCV) is excellent, with a predominantly diastolic flow pattern. Follow-up studies indicate significant but partial protection of the myocardium against diffuse LAD occlusion. The size of infarcts is decreased. However, the focal or small transmural infarcts observed are usually located near the apex of the heart. The studies with radioactive microspheres (15 ± 5 μ diameter) revealed that the degree of capillary trapping of microspheres is very much less when the microspheres are injected retrograde into the vein than when injected into the artery. This may indicate that significant “shunt” blood flow exists when the coronary vein is arterialized. Thus this study demonstrates both the potential and the limitation of the selective arterialization of coronary veins in revascularizing patients suffering from diffuse coronary arteriosclerosis.

Tracheobronchial mucociliary function in dogs that underwent left upper sleeve lobectomy was compared with that of dogs that underwent left lung autotransplantation or allotransplantation (n = 5 each). Proximal airway clearance was measured by observing the movement of carbon particles through a bronchoscope. Preoperative and postoperative clearance rates for the right lungs in these dogs were unchanged. Although preoperative clearance rates in the transplanted left lungs were comparable with those of the right lungs, these left lungs were unable to clear the carbon particles during a 15-minute observation period 3 weeks postoperatively. In contrast, preoperative and postoperative clearance rates for the dogs that underwent sleeve resection were unchanged for both lungs. Mucus rigidity was studied by microrheometry and was found to be significantly increased postoperatively for samples collected from the autotransplanted and allotransplanted lungs than for samples collected from the untreated right lungs. These changes in mucus were noted for forces representing both normal ciliary beat and coughing. Viscoelastic properties of mucus were not significantly altered after sleeve lobectomy. Microscopic study showed squamous cell metaplasia and relative disappearance of bronchial glands distal to the anastomosis in all transplanted lungs. These changes were less pronounced in the sleeve resected bronchi. We conclude that changes in rheologic characteristics of mucus can impair mucociliary clearance and may be related to denervation after lung transplantation. Bronchial devascularization may have an additional effect of altering mucosal structures and function in the early postoperative period after lung transplantation. These effects are avoided by preserving peribronchial tissue in sleeve resection.