Spontaneous rupture of the thoracic descending aorta is rare, and uniformly fatal without surgery. We report herein the case of a man in whom such a rupture was successfully treated with emergency surgery. We believe that the rupture in this patient was most likely associated with perforation through an atherosclerotic plaque of the descending aorta and was induced by sudden hypertension.

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are excellent conduits and should be used if there is any question regarding adequate length.My second comment is in regard to the use of the electrocautery in the skeletonization technique of ITA dissection. In their article comparing the effects of monopolar and bipolar cauterization on skeletonized ITA's, Yoshida and associates 3 go into detail describing the damaging effects of the two cauterization techniques on these relatively fragile arteries. I suggest that the arteries would sustain far less damage and hemostasis would be immediate and secure if hemoclips, rather than cautery, are used on the ITA branches. As described in our article, 2 thermal trauma to the ITA is thus specifically avoided. If meticulous clip application techniques are used and scrupulous attention is paid to the details of the dissection, fewer than 1% of skeletonized ITAs are unsuitable conduits.One of the main advantages to the use of arterial conduits is their longevity. I therefore propose that conduit life will remain optimum if we do our best to use harvesting techniques that keep arterial wall and intimal trauma to an absolute minimum.

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Twenty-one dogs (group 1) had retrograde brain perfusion for 90 minutes through the sagittal sinus and superior vena cava with pressure-regulated cardiopulmonary bypass, and 10 dogs (group 2) had 60 minutes of circulatory arrest with an additional 30-minute evaluation of brain slices, both at 20 degrees C. In group 1, cerebral blood flow determined by laser flowmetry was 8.98 +/- 2.02 ml/100 gm/min with a driving pressure of 29.69 +/- 9.92 mm Hg during the retrograde perfusion, whereas it was 0.85 ml/100 gm/min during solitary perfusion through the superior vena cava. Retrograde cerebral vascular resistance was slightly higher than the antegrade resistance. Neutral red stain was given intraperitoneally as an intracellular pH indicator. Regional intracellular pH was calculated from photoabsorption at 440 and 535 nm with the use of color transparency photographs of the brain and spinal cord slices taken after retrograde cerebral perfusion in group 1 and after circulatory arrest in group 2. The pH mapping showed that the retrograde brain perfusion maintained the pH within 6.77 to 7.14, whereas the cerebral pH decreased to 6.24 to 6.43 at 60 minutes of circulatory arrest and further decreased to 5.81 to 6.22 at 90 minutes. The pH after the retrograde brain perfusion was significantly higher than the pH after circulatory arrest in the entire brain and the spinal cord. We conclude that the brain is protected when perfused retrogradely beyond the venous valves with a driving pressure above 20 mm Hg.