Myocardial revascularization using the "no-touch" technique, with mild systemic hypothermia, in patients with a calcified ascending aorta.

Modifications in the standard technique for coronary artery bypass grafting are recommended in presence of a calcified ascending aorta, to avoid clamp injury or atheroembolism. Between January 1991 and August 1994, we used a "no-touch" technique in 18 patients undergoing myocardial revascularization, who had a heavily calcified and atherosclerotic ascending aorta. Their mean age was 76.1 years (range 63 to 82 years). Cardiopulmonary bypass with mild systemic hypothermia (32 degrees C) was employed in 16 patients; 2 other patients were operated upon without cardiopulmonary bypass. The "no-touch" technique avoids all types of clamps in the aorta. No cardioplegia was given, and no grafts were anastomosed to the aorta. Fifty-two distal anastomoses (mean: 2.9 per patient) were performed, using 37 pedicled arterial grafts (22 internal mammary and 15 gastroepiploic arteries), and 15 free grafts, which were anastomosed proximally to the internal mammary artery. There were no postoperative cerebrovascular accidents. Three patients died (16.7% overall mortality): 1 died of pneumonia, one patient with a large left ventricular aneurysm died in congestive heart failure, and one patient with associated aortic insufficiency died in low cardiac output. Our experience suggests that using pedicled arterial grafts for myocardial revascularization is safe and effective to avoid clamp injury or atheroembolism in patients with a calcified aorta. Deep hypothermia is not necessary when using the "no-touch" technique.

Edema development and recovery in neurogenic pulmonary edema.

We determined the time course of changes in extravascular lung water (EVLW) that occur after massive sympathetic activation produced by intracisternal veratrine administration in chloralose-anesthetized dogs. Three groups of dogs were studied. In the first group (n = 9), acute increases in EVLW (occurring within minutes) were determined both by measuring extravascular thermal volume and by gravimetric analysis. In the second (n = 6) and third (n = 7) groups, changes in EVLW were followed for 2-3 h after veratrine administration. Extravascular thermal volume was measured in the second group. In the third group, right atrial injections of a vascular indicator (125I-labeled serum albumin) and an extravascular indicator (3HOH) were made while blood was sampled from the pulmonary artery (PA) and left atrium, and EVLW was determined by deconvolution of the left atrial and PA concentration-time curves. Indicator-dilution and gravimetric EVLW increased acutely only in dogs in which PA pressure exceeded 60 Torr, with two- to four-fold increases in EVLW being observed in dogs that developed the highest PA pressures (maximum 94 Torr). Thus, severe edema can develop rapidly after massive sympathetic nervous system activation but requires extreme degrees of pulmonary hypertension. In several dogs after the acute increase in EVLW associated with the pulmonary hypertension, the indicator-dilution EVLW decreased with time. These decreases appear to effect clearance of edema fluid rather than alterations in perfusion.