The effect of electromagnetically produced shock waves on calcified, stenosed aortic valves

To determine if electromagnetically generated shock-wave lithotripsy has potential application for treatment of stenotic, calcified aortic valves, 38 cusps of surgically excised human aortic valves were studied. Valves were weighed, photographed, and calcium deposition was determined by x-ray. Stiffness was determined by palpation and by measuring the pressure gradient generated in a perfusion system. Valves were exposed to shock waves at 16 or 18 kV with 200 or 400 impulses each. Twenty valves reacted to exposure to shock waves with a reduction in pressure gradient of 1.9 +/- 2 cm H2O. Calcified valve area was reduced by 3.5 +/- 1.3 mm2. Valves without changes in pressure gradient showed a reduction of 7.1 +/- 2 mm2 of calcified valve area. There was no significant difference in weight loss. Using a small focus (4 mm) there was a significant reduction in pressure gradient and calcified valve area, but not in weight; with a large focus (8 mm) reduction in calcified valve area, gradient, and weight was significant (p less than 0.05). Changes in valve stiffness were independent of weight loss and reduction in calcified valve area. In conclusion, shock-wave lithotripsy is capable of reducing stiffness of calcified aortic valves, presumably by fragmentation of tissue calcium deposits.     

Low-speed rotational angioplasty in chronic peripheral artery occlusions: experience in 83 patients. Work in progress

Between December 1986 and October 1988, 83 patients with chronic peripheral artery occlusions were treated with a new technique. In 56 patients, the superficial femoral artery was completely occluded; in 21 patients, the popliteal artery; and in six patients, the iliac artery. The length of occlusion ranged from 5 to 35 cm (mean, 12.5 cm). The duration, estimated by history, was 5-48 months (mean, 16.5 months). In seven patients, durations of 6-36 months were documented angiographically. A flexible, blunt, motor-driven rotating catheter was introduced through an 8-F sheath, and rotational angioplasty was performed at low speed (up to 200 rpm). In 49 of 60 (82%) patients in whom this new technique was used as the primary intervention, the occlusions were successfully reopened. In 23 patients in whom conventional methods had failed more than 4 weeks earlier, the success rate for rotational angioplasty was 67% (12 of 18 patients); when the time interval was less than 4 weeks, only one of five patients was treated successfully. In none of the 83 patients did a perforation occur. This new technique can reopen chronic artery occlusions with a high degree of success and without the danger of vessel-wall perforation, even after failure of conventional techniques.     

Regional ventricular function before and after sublingual administration of nitroglycerin in patients with recent myocardial infarction in the subacute and chronic stage

Seven patients with a recent myocardial infarction and mostly normal left ventricular end-diastolic pressure were investigated by radionuclide ventriculography after 3-4 days and three weeks before and after 1.6 mg nitroglycerin. Between day 3-4 and the third week global ejection fraction (EF) rose insignificantly (p greater than 0.05) from 31 +/- 4 to 37 +/- 6 percent. The regional EF in the non infarcted area remained nearly stable (74 +/- 5 to 85 +/- 13 relative percent, p greater than 0.05). However, the EF in the infarcted area rose from 22 +/- 9 to 38 +/- 11 relative percent (p less than 0.05 percent). On day 3-4 nitroglycerin induced a clear increase of the EF in the infarcted area from 22 +/- 9 to 35 +/- 11 relative percent (p less than 0.05). The global EF and the EF in the non infarcted area remained nearly constant (global EF from 31 +/- 4 to 34 +/- 5 percent, EF in the non infarcted area from 74 +/- 5 to 77 +/- 7 relative percent; p greater than 0.05). Three weeks after myocardial infarction 1.6 mg nitroglycerin did not produce a significant alteration of the ejection fraction (slight increase of the global EF from 37 +/- 6 to 40 +/- 6, the regional EF in the infarcted area from 38 +/- 11 to 48 +/- 11 relative percent and from 85 +/- 13 to 90 +/- 11 relative percent in the non infarcted area; p greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of the calcium antagonist nisoldipine on coronary circulation and myocardial ischemia in temporary coronary occlusion

Sixteen patients undergoing PTCA of a significant lesion of the left anterior descending coronary artery received either 0.3 mg nisoldipine or placebo intravenously. Immediately before and during balloon inflation the following parameters were measured: aortic pressure, post-stenotic pressure, coronary occlusion pressure, diastolic pulmonary artery pressure, coronary sinus flow (thermodilution), and intracoronary ECG. After placebo there were no statistically significant changes. Nisoldipine led to a decrease in aortic pressure from 109 +/- 12 to 93 +/- 11 mm Hg (p less than 0.05) before, and from 103 +/- 14 to 92 +/- 8 mm Hg (NS) during balloon inflation. In contrast, coronary occlusion pressure remained unchanged. Heart rate increased from 80 +/- 13 to 96 +/- 16/min before (p less than 0.05), and from 87 +/- 18 to 97 +/- 17/min during balloon inflation (NS). Coronary sinus flow was increased from 95 +/- 16 to 116 +/- 13 ml/min before balloon inflation (p less than 0.01), and from 70 +/- 25 to 86 +/- 26 ml/min during balloon inflation (NS). ST-segment depression or elevation, severity of angina pectoris, and the diastolic pulmonary artery pressure remained unchanged. Thus, 0.3 mg nisoldipine led to a peripheral vasodilatation. While the aortic pressure decreased, coronary occlusion pressure remained unaffected. This could be explained by a marked dilatation of collateral vessels due to nisoldipine. However, myocardial ischemia remained unaffected as a result of the constant coronary occlusion pressure.     

Nutritional anemias in elderly patients

Nutritional deficiencies cause one third of the cases of anemia in the elderly. The urgency of anemia management in elderly patients depends on tolerance and repercussions, rather than only on the hemoglobin level. Iron, vitamin B12 and folate are the most common deficiencies, and their levels should be tested. Chronic gastrointestinal bleeding is the principal cause of iron-deficiency anemia. Management is based on supplementation combined with effective etiological treatment.     

Differences in the production of methemoglobin during high-dose treatment with isosorbide dinitrate or isosorbide 5-mononitrate

12 patients with coronary heart disease were studied to see whether high doses of isosorbide dinitrate (ISDN, Corovliss) or isosorbide 5-mononitrate (IS-5-MN, Ismo) increase the erythrocyte methemoglobin production in an acute experiment and after 4 days of medication. The patients were divided into two groups. Group 1 (6 patients) was given a single dose of 80 mg ISDN on the morning of day 1 and Group 2 (6 patients) was given 80 mg IS-5-MN as a single oral dose. Under the influence of the IS-5-MN no change was observed from the initial methemoglobin (met-Hb) value (0.81% of the total Hb) at measurements performed 1 and 2 h after the administration of the drug. In Group 1 (ISDN) the initial met-Hb value was 0.58% of the total Hb, a slight increase to 0.70% being observed after 1 h and to 0.77% after 2 h (p less than 0.05). The patients were then treated as follows for a further 4 days: Group 1 480 mg ISDN/d, Group 2 480 mg IS-5-MN/d. On day 5 the initial met-Hb values in both groups were unchanged compared to day 1. The patients were then given first 80 mg ISDN (Group 1) or 80 mg IS-5-MN (Group 2) and 4 h later a single dose of 160 mg of the appropriate substance. In Group 2 (IS-5-MN) the met-Hb content remained unaffected. In Group 1 a slight increase of the met-Hb to 0.79% occurred 1 h after 80 mg ISDN and to 0.9% after 2 h (p less than 0.05). The dose of 160 mg ISDN gave rise to a further slight increase to 1.00% (after 1 h) and 1.13% (after 2 h) (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Histologic and molecular analyses of colonic perineurial-like proliferations in serrated polyps: perineurial-like stromal proliferations are seen in sessile serrated adenomas

Colonic perineuriomas are recently described benign mucosal polyps that are composed of a bland spindle cell proliferation surrounding crypts that often demonstrate hyperplastic/serrated epithelial changes. However, the origin of this unique stromal proliferation is still unclear, and the association with serrated polyps, including sessile serrated adenomas, has not been fully described. We evaluated the pathologic and molecular features of colonic polyps associated with perineurial-like proliferations in 2 retrospective cohorts: (1) a series of 198 consecutive sessile serrated adenomas and (2) 20 colonic polyps diagnosed as a perineurioma irrespective of the presence of serrated colonic crypts. Thirteen of 198 (6.5%) sessile serrated adenomas demonstrated a perineurial-like stromal proliferation, with most (12 of 13, 92%) involving the right (9 cases) and transverse colon (3 cases). In all 13 cases, the perineurial-like proliferation surrounded serrated colonic crypts and typically involved only a small area of the sessile serrated adenoma (average 9% of polyp size; range, 2% to 19%). All 11 polyps evaluated for epithelial membrane antigen (EMA) expression demonstrated stromal EMA staining limited to the perineurial-like proliferation. Twelve of 13 (92%) sessile serrated adenomas with perineurial-like proliferations demonstrated a pV600E BRAF mutation. Of the 20 colonic polyps diagnosed as a perineurioma, 18 (90%) demonstrated serrated crypts intimately associated with the perineurial-like proliferation. In 13 of 18 polyps with associated serrated crypts, all serrated crypts were invested with the perineurial proliferation. In 5 cases, serrated crypts were seen away from the perineurial proliferation. Of these 18 polyps, the majority (16 of 18, 89%) were microvesicular hyperplastic polyps involving the left colon. However, 2 (11%) polyps in the right colon demonstrated histologic features diagnostic of sessile serrated adenoma. All 18 polyps with serrated crypts demonstrated a pV600E BRAF mutation. In contrast, the 2 polyps not associated with serrated crypts were negative for a BRAF mutation. Our results show for the first time that perineurial-like stromal proliferations frequently occur in sessile serrated adenomas. The presence of focal perineurial-like stromal proliferations in sessile serrated adenomas and the common finding of serrated crypts in colonic perineuriomas are likely indicative of an epithelial-stromal interaction, possibly related to some factor elaborated by the serrated epithelium.