Seiichi Sumino

Angiographic and angioscopic observations of the arterial luminal changes induced by vasospasm

Angiography and angioscopy were used to examine arterial luminal changes induced by experimental vasospasm. The right common carotid artery of the dog was perfused with Krebs-Henseleit solution at a constant pressure, 3,4-diaminopyridine (DAP), a selective potassium channel blocker was applied on the adventitia, and the luminal changes were observed with angiography and angioscopy. Angiographically vasospasm (defined as a reduction in the internal diameter to less than 50% of the control value) was always induced by the topical application of 5 X 10(-1) mol/L DAP. The internal diameter decreased to 25% +/- 7% (mean +/- standard error, n = 6) 15 minutes after the application. The vasospasms propagated 2.7 +/- 0.6 and 1.1 +/- 0.3 cm downstream and upstream, respectively. Angioscopy showed that the lumen narrowed gradually and concentrically. Perfusion of the artery during vasospasm for 15 minutes with a backflow of blood from the contralateral artery resulted in thrombosis at the spastic segment. The results indicate that carotid vasospasm can be constantly induced by DAP, thrombosis occurs in the spastic artery, and angioscopy is useful for serial observation of the luminal changes induced by vasospasm.

The Size of Kidney with Renovascular Hypertension in Patients with Aortitis Syndrome

Renal atrophy due to the renal artery stenosis associated with aortitis syn drome was studied in seven patients. Severe hypertension, high plasma renin activity and normal overall renal functions were present in all. The luminal diameter of the stenosed renal artery seen on the angiogram was less than 1.5 mm at the maximum area of stenosis in all patients. The size of the kidney with renal artery stenosis was diminished, ranging from 8.0 to 14.0 cm in longitudi nal diameter on the nephrogram. Histological findings of the small kidney re vealed ischemic atrophy. Although the rate of progression of the arterial stenosis was uncertain, the collateral circulation was found to be rich. Renal atrophy was not frequent and not marked even in the presence of high grade renal stenosis or obstruction in case of renovascular hypertension secondary to the arteritis.