Accuracy of magnetic resonance imaging compared to computerized tomography and renal selective angiography in preoperatively staging renal cell carcinoma.

During 1986 and 1987, 47 patients with renal cell carcinoma were evaluated preoperatively with CT, angiography and MRI. The preoperative tumor stage (T), lymph node metastases and venous involvement determined with the three methods were compared to the operative and histopathological findings. For T stage, angiography proved less accurate (54%) than CT (64%) or MRI (63%). MRI was found to be superior to CT in assessing lymph nodes, with an overall accuracy of 89% and sensitivity of 100% compared to 77 and 60%, respectively, of CT. For venous involvement CT was overall more accurate (74%) than angiography (65%) or MRI (63%). All three methods expressed a low sensitivity (between 31 and 41%) and a high specificity (between 95 and 100%) for detecting venous involvement. The minimal advantages of MRI compared to its high cost do not justify its routine use. CT remains the method of choice in staging preoperatively renal cell carcinoma.

Acute (nonprogressive) alcoholic pancreatitis: prospective longitudinal study of 144 patients with recurrent alcoholic pancreatitis.

Over the last 10 years, a series of 144 consecutive patients with alcoholic recurrent pancreatitis have been studied prospectively at regular intervals with particular regard to exocrine function, calcifications, pancreatographic ductal changes, and histopathology of the pancreas. Based upon the long-term course, the patients were classified into two groups; group A (n = 95), those with chronic pancreatitis (78 of them with calcifications); and group B (n = 49), those with acute (nonprogressive) pancreatitis. The duration of disease from onset was 2-19 years (median, 9.7 and 8.3 years, respectively, in group A and B). The two groups were comparable at onset of the disease in age, sex, number of episodes of pancreatitis, and number of pseudocysts. In group A, all 95 cases fulfilled the strict diagnostic criteria of chronic pancreatitis within the period of observation (e.g., progressive exocrine insufficiency and/or typical morphological changes, particularly calcifications). In group B, the exocrine function remained normal over the entire period of observation. No histologic evidence of chronic pancreatitis was detected in five of seven large pancreatic specimens. Marked to moderate ductal changes were found in 10 of 16 patients in group B (despite normal exocrine function). Our data suggest that about one third of patients of the present series with alcoholic (recurrent) pancreatitis did not progress toward chronic (progressive) pancreatitis, although some demonstrated morphological alterations (except calcifications) in association with normally preserved exocrine function (residual scars?). The pathogenetic factor(s) responsible for progression (or nonprogression) of alcoholic (recurrent) pancreatitis to chronic pancreatitis remain(s) to be elucidated.

Transluminal angioplasty evaluated by electron microscopy.

To gain more understanding about the changes that follow balloon angioplasty, an electron and light microscopic study was carried out in normal canine arteries. Thirty-five arterial segments were dilated with balloon catheters. Early changes consisted of denudation of the intima with widespread necrosis of myocytes and dehiscence of collagen fibers. After three days, myocytes had disappeared leaving empty spaces and edematous ground substance. After two weeks, reendothelization occurred and there was evidence of intimal hyperplasia persisting up to two months. Repair of the dilated arterial segments occurred by proliferation of myocytes, formation of intima, and proliferation of collagen. In two to three months, repair of the intima and media was completed. After six months, dilated segments were characterized by persistent intimal hyperplasia and increased collagen content in the media.

Percutaneous transluminal angioplasty of the aorta. Light and electron microscopic observations in normal and atherosclerotic rabbits.

Histological changes which developed after percutaneous transluminal angioplasty in normal and atherosclerotic rabbit aortas were correlated with balloon size and inflation time. In normal rabbits, progressive changes were observed in the intima and media with increasing balloon size and inflation time. The atherosclerotic aortas exhibited unpredictable fragility, with limited correlation between histological changes, balloon size, and inflation time, attributable mainly to the distribution and thickness of plaques. In atherosclerotic vessels, the mechanism of angioplasty consisted of plaque dehiscence and fracture, followed by overstretching of the plaque-free wall segments. No plaque compression was observed.