Self-expanding nitinol stents in canine vertebral arteries: hemodynamics and tissue response.

PURPOSETo evaluate the hemodynamics and tissue response associated with stent placement in low-flow-velocity arteries.METHODSSix self-expanding nitinol stents (5.5 mm caliber) were implanted transfemorally within the proximal segments of vertebral arteries (2.5 mm diameter) in six adult dogs during anticoagulative protection.RESULTSControl angiograms demonstrated patency and 20% dilatation of all stented arteries. One artery was partially thrombosed 1 week later and subsequently showed a 50% stenosis. Throughout the observation period (4 to 9 months after stenting), the other five arteries remained patent without significant narrowing (< or = 15%). Small cervical muscle branches originating from the vertebral arteries within the stented segments remained patent. No major branch occlusions of the vertebrobasilar system were detected. Stent migration or kinking did not occur. MR studies of the brain 4 months after implantation revealed no infarcted areas. These findings were confirmed with brain sections. Stented artery specimens showed delayed stent dilatation. A comparison of the total mean thickness of intima covering the five 30- to 40-mm stents removed at 4, 6, and 9 months showed no significant difference (338, 332, and 389 microns, respectively). Histologic findings verified the macroscopic impression of a thicker intima at the inner curve of the stented artery segments and at the junctions of the stent filaments. The shortest (10 mm) stent had the thinnest neointimal growth (155 microns). Stented vessels showed compression of the media with atrophy, but without necrosis or perforation. Scanning electron photomicrographs revealed intact endothelial cell linings with typical elongated cells.CONCLUSIONSNo significant risk of thromboembolic events exists after implanting these nitinol stents in nonatherosclerotic vertebral arteries in dogs. Thicker neointimal growth after stenting may result from either low wall shear stress with possible flow separation or from changes in the shape and size of the stent, or both.     

Antiulcer activity of Tinospora cordifolia Miers and Centella asiatica linn extracts

The ethanol extracts of the roots of T. cordifolia Miers and C. asiatica Linn were observed to induce a marked protective action against an 8 h restraint stress induced ulcerization, the activity being comparable to that of diazepam.     

Health actions and disease patterns related to coronary heart disease in the coloured population of the Cape Peninsula

The health-related behaviour of the Cape Peninsula coloured population, which has been shown to have an adverse coronary heart disease (CHD) risk factor profile, is reported. Private medical services were used most often by participants: 54.1% and 51.6% of males and females respectively had made use of these services during the preceding year. Only 17.9% and 21.8% of males and females respectively had attended day hospitals during the year. Blood pressures were measured in 43.8% and 57.1% of male and female participants respectively during the year preceding the study. The results indicated the need for the measurement of blood pressure to determine the true prevalence of hypertension, since patient reporting of the condition was inaccurate. Attempts to give up smoking had been made by 44.4% of male and 47.1% of female smokers. About 75% of the participants were found to have hypercholesterolaemia, yet their knowledge of the prudent diet was poor and few reported appropriate dietary modifications to protect against CHD. Frequent reporting of hypercholesterolaemia, hypertension and constipation by the study population highlights the need for dietary education. Mortality rates (MRs) for CHD and cerebrovascular disease (CVD) for the coloured and the white populations were compared. In all age groups white males had higher MRs for CHD than coloured males, while coloured females older than 34 years had higher rates than their white counterparts. The coloured population had MRs for CVD that were higher than those of whites.     

Serpentine aneurysm of the posterior circulation: report of two cases

Giant serpentine aneurysms form a subgroup of giant intracranial aneurysms with specific radiological and surgical features. Previous reports have stressed the predilection of these lesions for the carotid circulation, particularly the middle cerebral artery. Two cases of serpentine aneurysm affecting the posterior circulation are reported and the problems of diagnosis and treatment of this lesion are discussed.     

A dosage study of the effect of the 21-aminosteroid U74006F on chronic cerebral vasospasm in a primate model

The efficacy of the 21-aminosteroid U74006F was investigated using different dosages in a restricted, randomized, placebo-controlled trial. Forty cynomolgous monkeys were divided into five groups of eight. There were two groups given treatment with placebos, one being saline and the other the vehicle in which U74006F was delivered. There were three U74006F treatment dosage groups: 0.3, 1.0, and 3.0 mg/kg. Each monkey underwent baseline cerebral angiography followed by right-sided craniectomy and subarachnoid placement of a clot around the middle cerebral artery (MCA). Treatment was administered intravenously every 8 hours for 6 days. Seven days after experimental subarachnoid hemorrhage, angiography was repeated, and the animals were killed. In both saline or vehicle placebo treatment groups, significant vasospasm (VSP) occurred on the clot side in the extradural internal carotid artery (C3), the intradural internal carotid artery, the precommunicating segment of the anterior cerebral artery (A1,) and the MCA (P less than 0.01). After U74006F treatment, significantly less VSP developed in the A1 on the clot side (0.3 mg/kg U74006F treatment group) and the MCA (all U74006F treatment groups, P less than 0.05). When the percentages of change from the baseline for the vessel diameters on the clot side were compared, VSP was attenuated in the A1 (P less than 0.05) and MCA (P less than 0.001) of all U74006F treatment groups as compared with the placebo treatment groups. Only 0.3 mg/kg of U74006F significantly prevented VSP in C3 (P less than 0.01). Although the 0.3 mg/kg dosage appeared to have the most favorable effect, no significant differences were observed among the three dosage groups. Electron microscopy of the MCA on the clot side in the animals treated with U74006F still showed luminal convolutions and morphological changes in the endothelial cells. These changes appeared less prominent in those MCAs with milder VSP. If these results in primates are applicable to humans, U74006F would be useful in reducing VSP after aneurysmal subarachnoid hemorrhage.     

A giant renal artery aneurysm diagnosed post partum

We report a case of a 5.8 cm. right renal artery aneurysm diagnosed intact 8 weeks post partum. Rupture of a renal arterial aneurysm during pregnancy is a rare but well described catastrophic event. There are no previous reports of an intact renal artery aneurysm diagnosed either ante partum or post partum. To our knowledge, this also represents the largest reported renal artery aneurysm. The aneurysm was repaired successfully with kidney salvage and closure of the fistulous connection to the renal vein.     

The ileal neobladder: experience and results of more than 100 consecutive cases

The ileal neobladder produces a completely detubularized, low pressure, high capacity reservoir constructed from ileum without any valves. From April 1986 through May 1989, 113 patients underwent this procedure at our institution. Of these patients 99 underwent simultaneous radical cystectomy for bladder cancer and 14 underwent bladder augmentation. The mean postoperative followup was 14.4 months, with a range of 1 to 36 months. There was no perioperative mortality. However, 7 patients died more than 2 months postoperatively: 5 of tumor progression, 1 of pneumonia and severe metabolic acidosis, and 1 of septicemia of unknown cause. Reoperation was necessary in only 13 patients; 10 patients required urethrotomy or dilation of urethral strictures. Day and night continence was preserved in 82.1% of all patients. Stress incontinence, which must be corrected by an artificial sphincter, was found in 4 patients (4.2%) and night-time incontinence that required an external device occurred in 5 (5.3%). Eight patients (8.4%) with mild stress incontinence required no further treatment. Pressure waves exceeding 22 cm. water seldom occurred and then only at maximum capacity. Our experience with this relatively simple system without a nipple is an overwhelming success. The need for reoperation is extraordinarily low and the high reservoir capacity results in continence from the beginning in most patients. The concept is sound and offers a genuine alternative to any form of cutaneous urinary diversion with an incidence of complications not higher than after standard supravesical urinary diversion.     

Comparative evaluation of thermographic and radiothermometric methods of examination during mass screening of women with dyshormonal hyperplasia of the breast

The article deals with the results of prehospital appraisal of hyperplasia of the mammary glands in 364 females by means of infrared thermovision techniques and UHF-radiothermometry. The thermovision and radiothermometric signs of this pathological condition are described. Examination conducted in the course of the disease twice in 52% and 3 to 4 times in 30% of cases showed radiothermometry to be highly informative in optimization of the management of patients with mastopathy. The feature of the thermal metabolic process in cancer was revealed. The proposed radiothermometric method may be used as an auxiliary criterion for appraising the condition of the mammary tissues.     

Ultrasonic vascular scanning in the diagnosis of acute arterial obstruction

In thrombosis of the aorta and major arteries (52 cases), postthrombotic occlusion (26), arterial embolism (14), the ultrasound vascular scanning++ was performed. The method permits to define the presence and location of arterial occlusion, differentiate thrombosis and embolism, atherosclerotic and autoimmune diseases of the vessels and as well to assess the outcome of restorative and reconstructive operations in acute arterial obstruction.     

Endoscopic alternatives in the management of colonic strictures

A 10-year review of our experience with all patients with symptoms of colonic narrowing (n = 61) revealed 14 patients who were treated endoscopically. The site of narrowing was the sigmoid colon in 12 patients and the rectum in two patients. The strictures occurred after anastomosis in seven patients, with carcinoma in four patients, and with inflammatory disease, external compression, and idiopathy in one patient each. Although combinations of endoscopic techniques were occasionally used, the predominant method responsible for successful management of the narrowing was bouginage in four patients, endoscopy with a prototype dilating endoscope in four patients, balloon dilatation in three patients, and electrocautery and laser surgery in one patient each. There were no perforations or bleeding complications. Repeated treatments were usually needed. As less invasive methods evolve to treat colonic narrowing, appropriate matching of available techniques with the underlying disease becomes easier. We have found that dilation with a bougie, balloon, or a prototype dilating endoscope can provide especially beneficial results when used on patients with strictures resulting from inflammatory disease or external compression. Cutting and ablating tools such as the electrocautery and laser tools are more suited for management of strictures that result from carcinoma and anastomotic webs. Appropriate matching of endoscopic technique to underlying colonic pathology will allow increasingly successful and safer management of colonic narrowing without operation.