Hemodynamics of erection in the monkey.

Being able to induce controlled erection in dogs and monkeys, we investigated the hemodynamics and mechanism of penile erection. 'Chronic' monkey models, having had electrodes implanted around the cavernous nerves for electroerection, were studied to evaluate the details of the hemodynamic changes. The studies included: 1) arterial blood flow, 2) corporeal pressure, 3) blood gases, 4) venous flow and 5) radiography. Tumescence of the corpora cavernosa was found to be a result of: 1) active relaxation of the sinusoidal spaces, 2) active arteriolar dilatation and 3) active venous outflow constriction. At full erection there is adequate but reduced blood flow into and out of the corpora cavernosa for metabolic exchange.

Incidence of radiographically evident bone disease, nephrocalcinosis, and nephrolithiasis in various types of renal tubular acidosis.

The syndrome of renal tubular acidosis has been categorized into three physiologic types that have different clinical findings and prognostic and therapeutic implications. We reviewed radiographs of the skeleton and kidneys in 92 patients (56 children and 36 adults) with renal tubular acidosis in order to determine whether the radiologic findings could be related to the type of syndrome. Forty-four patients had Type 1 renal tubular acidosis, 18 had Type 2, and 30 had Type 4. Evidence of skeletal abnormalities was uncommon (17 per cent) and was confined to patients who had the Type 2 disorder or azotemia. The children with Type 2 and skeletal abnormalities had rickets; the adults had osteopenia without pseudofractures. Nephrocalcinosis was evident in approximately one fourth of the group (29 per cent) and was restricted to patients with the Type 1 syndrome. In patients with Type 4, osteopenia was evident in 12 per cent, all of whom were azotemic. Our observations indicate that the radiographic manifestations of renal tubular acidosis are influenced by the physiologic type of renal tubular acidosis.

Segmental kidney resection in children with small, hypertension-producing intrarenal vascular lesions.

Renal angiography is indispensable in the study of children with suspected renal hypertension. Main or segmental renal artery stenoses are usually well-demonstrated by midstream abdominal aortography, but small intrarenal vascular abnormalities can be easily overlooked when such a nonselective method is used. Such tiny abnormalities, however, can be the cause for, or indication of focally increased renin production and consequent hypertension. The most common primary intrarenal lesions (stenoses, focal occlusions) may be readily apparent on good arteriograms. Quite often, however, they are angiographically occult, and their presence is indicated indirectly by tortuous or "corkscrew" intrarenal collaterals. The need for selective renal arteriograms and segmental renal vein renin assays in the work-up of such patients is stressed, and the effectiveness of treatment by segmental renal resection rather than nephrectomy in patients with such lesions is illustrated.

CT evaluation of invasive lesions of the bladder.

The role of computed tomography (CT) in defining the extent of local tumor invasion was reviewed retrospectively in 22 patients with biopsy proven malignant lesions of the bladder. These included 14 cases of primary bladder carcinoma and 8 cases of pelvic malignancies with secondary invasion of the bladder. Computed tomography proved accurate in detecting lymph node enlargement, obvious extravesical masses, and relatively small mural of mucosal lesions of the bladder. However, CT was not able to reliably predict microscopic invasion of either the serosal surface of the bladder by pelvic malignancies or microscopic invasion of the perivesical fat by intrinsic bladder carcinoma. These factors, in addition to the inability of CT to detect metastases in normal sized lymph nodes, appear to limit the overall accuracy of CT in the evaluation of locally invasive pelvic malignancies. Nevertheless, CT appears to be a useful noninvasive screening technique to avoid needless radical surgery in advanced lesions with bladder invasion.

Localization of functioning pheochromocytomas by venous sampling and radioenzymatic analysis.

The authors describe a sensitive radioenzymatic technique for determining blood catecholamines which is very effective in localizing occult functioning pheochromocytomas. It appears to be more consistent than any other technique in demonstrating theirapproximate location. Combined with other noninvasive studies such as CT, it should greatly facilitate demonstration of extra-adrenal pheochromocytomas, thereby reducing the need for more invasive procedures such as arteriography.

Results and significance of angiography in potential kidney donors.

Multiple renal arteries originating from the aortoiliac vessels were identified angiographically in 44% of 444 prospective renal donors. Bilateral multiple renal arteries were identified in 12%. With good immunological donor-recipient matching, 17 kidneys with multiple renal arteries were transplanted with excellent results; therefore, presence of multiple renal arteries should not be considered a contraindication to kidney transplantation. A high proportion (17%) of the prospective donors, acceptable by all other means of evaluation, had abnormmal angiographic findings that led to reconsideration of their acceptance. In addition to multiple renal arteries, neither renovascular atherosclerosis nor fibromuscular dysplasia proved to be an absolute contraindication to transplantation.

Nonoperative diagnosis of pyelocalyceal deformity due to venous impressions.

Two patients with filling defects on films of the upper urinary tract caused by venous impressions are reported. To date, the literature includes 22 other cases. These cases are frequently associated with hematuria, flank or abdominal pain; the filling defect might be found incidentally during the evaluation of another problem. The two most frequent causes are varices--of renal vein, renal pelvic vein, ureteral veins, and normal renal vessels. Generally, the lesions were not diagnosed without surgical intervention. The filling defects of our cases were caused by other types of lesions. Their diagnosis was made nonoperatively through the use of intravenous pyelography, renal arteriography, and retrograde phlebography. Filling defects caused by venous impressions on the upper urinary tract should be diagnosed by the use of these three studies rather than surgically.

Arterial-portal venous shunting in cavernous hemangioma of the liver.

Arterial-portal venous shunting was found to occur in a focal cavernous hemangioma of the liver. This occurrence stresses the lack of specificity of this finding in differentiating benign from malignant lesions.

The spotted nephrogram of renal scleroderma.

The renal angiographic findings in our two patients with scleroderma and recent onset of hypertension included minor changes in the distal interlobar and arcuate arteries and a nephrogram displaying diffuse, spotty lucencies. Although the spotted nephrogram is occasionally seen in cases of severe nephrosclerosis, we believe that, in the absence of major arterial changes in the arcuate and distal interlobar arteries, it is virtually diagnostic of renal scleroderma.

Renal arteriography in the evaluation of unexplained hypertension in children and adolescents.

Arteriography demonstrated renal artery stenosis in 24% of 101 selected patients whose hypertension was first diagnosed before the age of 20 years. Arteriographic findings were normal in 58%. The prevalence of RAS was greater in the younger than in the older age groups. An abdominal bruit and urographic abnormalities were frequently observed in association with RAS. Adequate follow-up information was available for 16 patients who underwent vascular repair or nephrectomy for RAS. In 14 of the 16, the hypertension was eliminated (81%) or definitely reduced (6%).

Bifurcation of the portal vein appearing as a focal defect on the liver image.

A focal defect was seen on a gamma camera image of the liver in 2 patients, a 52-year-old woman with abdominal pain and a 46-year-old woman with pancytopenia. Liver function was normal, and no tumor stain was seen. Angiography revealed that the "defect" was in reality the bifurcation of the portal vein. These findings re-emphasize the importance of visceral angiography as a complement to radionuclide imaging in the study of liver disease.