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Biomedical subjects

A M Imparato

Publications and source records attributed to A M Imparato.

At least 19 recordsLinked to original sources
PubMed1992

Silent myocardial ischemia monitoring predicts late as well as perioperative cardiac events in patients undergoing vascular surgery.

In a previous study we have shown that perioperative monitoring for silent myocardial ischemia can noninvasively identify those patients undergoing peripheral vascular surgery who are at significantly increased risk for perioperative myocardial infarction. In the present study a group of 385 patients undergoing peripheral vascular surgery was studied long-term as well as short-term to determine whether perioperative monitoring for silent ischemia can identify those patients who are at significantly increased risk of late cardiac death or late cardiac complications as well as those patients at increased risk of perioperative myocardial infarction. All patients were monitored before, during, and after operation and were divided into two groups on the basis of results of monitoring: patients whose total duration of silent ischemia as a percentage of the total duration of perioperative monitoring was 1% or greater (group I, n = 120) and those for whom this value was less than 1% (group II, n = 265). Among patients in group I 13.3% (16 of 120) suffered a perioperative myocardial infarction in contrast to only 1.1% (3 of 265) patients in group II (p less than 0.001). Multivariate logistic regression analysis of preoperative and perioperative characteristics showed that the presence of a total perioperative percent time ischemic 1% or greater and age were the only significant predictors of perioperative myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Vertebral artery angioplasty in patients younger than 55 years: long-term follow-up.

Since 1964 we have performed 136 vertebral artery reconstructions representing 4% of all operations on extracranial cerebral arteries by our staff. Fifteen of our patients were under age 55 years and had symptoms of dizziness, bilateral visual disturbances, ataxia, presyncopal episodes, and occasionally localized extremity weakness. Dizziness, often severe and incapacitating, has been the most common and consistent symptom. The diagnosis of vertebral artery lesions was made using aortic arch four-vessel cerebral arteriography. Operations were performed for severely obstructing bilateral vertebral artery lesions and included only unilateral vertebral vein patch angioplasty with or without suture plication of the artery in 13 patients. Unilateral carotid vertebral bypass was performed in one patient and unilateral vertebral reimplantation to the carotid in another. Follow-up averaged 8.9 years, ranging from ten months to 20 years. Eleven of 15 patients have remained asymptomatic and without strokes. Recurrent dizziness was present in three, two of whom had vertebral arteriography showing patent vertebral reconstructions. Another had a stroke related to the anterior circulation in follow-up at nine years. Atherosclerotic obstruction of vertebral arteries does occur in patients in the preatherosclerotic age group. Even atypical symptoms suggestive of vertebrobasilar insufficiency may be associated with isolated correctable bilateral flow-impeding vertebral lesions. These symptoms warrant evaluation with cardiac neurological and cerebrovascular studies. Vertebral angioplasty relieves symptoms and the incidence of stroke during follow-up is low.

Arteriosclerosis↗
PubMed1991

Redo endarterectomy for recurrent carotid artery stenosis.

From a registry of 2406 carotid endarterectomies performed on 1818 patients over a 19-year period, 29 patients (1.6%) underwent reoperations for recurrent stenosis. Reoperations were performed for symptomatic stenosis for 23 and asymptomatic greater than 80% stenosis for six patients. Compared to the entire series, there was no difference in the incidence of restenosis for men and women. The pathologic findings were myointimal hyperplasia in 27%, atherosclerosis in 53%, thrombus with vessel dilatation in 17% and extrinsic scar in 3%. Redo endarterectomy with patch angioplasty was used for reconstruction in 27 patients and patch angioplasty alone in two. There were no operative deaths or strokes. Late follow-up (mean 50 months) revealed only one stroke and six other deaths. Although 21 (75%) were alive and stroke-free, follow-up studies suggest a high incidence (21%) of tertiary lesions among patients who have undergone redo endarterectomy for recurrent stenosis.

Aged↗
PubMed1990

Rupture of the vein patch: a rare complication of carotid endarterectomy.

Vein patch closure after carotid endarterectomy has been used to reduce the incidence of residual and recurrent stenosis at the carotid bifurcation. A rare but potential serious complication is rupture of the vein patch during the early postoperative period. In our experience of 2359 carotid operations performed from 1962 through 1986, saphenous vein was used for closure in 2275 (96.5%) operations. In three patients out of 75 in whom the vein patch had been harvested from the ankle, rupture of the patch occurred 2 to 5 days after uneventful carotid surgery. At emergency reoperation, the central portion of the vein was necrotic, with no evidence of infection. In each case the carotid artery was closed again with fresh thigh saphenous vein, and recovery was uneventful. The use of ankle vein was discontinued in December 1983 in favor of groin saphenous vein, and similar complications have not occurred in more than 600 carotid endarterectomies performed since. Early noninfectious ruptures of the saphenous vein patches have been mentioned in other reported series of carotid operations and have often been related to the use of ankle vein, but they remain unexplained.

Carotid Arteries↗
PubMed1989

Beta blockade to decrease silent myocardial ischemia during peripheral vascular surgery.

The incidence and duration of intraoperative silent myocardial ischemia have been shown to be significantly correlated with the incidence of perioperative myocardial infarction in patients undergoing peripheral vascular surgery. To assess the effectiveness of intraoperative beta blockade in limiting such silent myocardial ischemia, a group of 48 patients was treated with oral metoprolol immediately prior to peripheral vascular surgery. The total duration of intraoperative silent myocardial ischemia, the percentage of intraoperative time silent myocardial ischemia was present, the number of intraoperative episodes of silent myocardial ischemia, and the intraoperative heart rate in the treated patients were compared with those in 152 similar but untreated peripheral vascular surgery patients. The patients treated with oral metoprolol had significantly less intraoperative silent ischemia with respect to relative duration and frequency of episodes, a significantly lower intraoperative heart rate, and less intraoperative silent myocardial ischemia in terms of total absolute duration. These results suggest that beta-adrenergic activation may play a major role in the pathogenesis of silent myocardial ischemia during peripheral vascular surgery.

Adrenergic beta-Antagonists↗
PubMed1989

The value of silent myocardial ischemia monitoring in the prediction of perioperative myocardial infarction in patients undergoing peripheral vascular surgery.

Real-time electrocardiographic monitoring for silent myocardial ischemia was performed on 200 patients undergoing peripheral vascular surgery to try to better define those at high risk of perioperative myocardial infarction. The patients were divided into those undergoing abdominal aortic aneurysm or lower extremity revascularization procedures (group I, n = 120) and those undergoing carotid artery endarterectomy (group II, n = 80). Silent ischemia was detected during the preoperative, intraoperative, or post-operative periods in 60.8% of group I and 67.5% of group II patients. Six group I and three group II patients suffered an acute perioperative myocardial infarction with two cardiac deaths. In both groups I and II a variety of parameters based on monitoring of silent myocardial ischemia were compared between the subgroups of patients who had myocardial infarction and those who did not. The results show that in both groups there was a significantly (p less than or equal to 0.05) greater total duration of perioperative ischemic time, total number of perioperative ischemic episodes, and total duration of perioperative ischemic time as a percent of total monitoring time in patients who suffered a perioperative myocardial infarction compared to those who did not. Multivariate logistic regression analysis of preoperative characteristics in all 200 patients showed the occurrence of preoperative silent myocardial ischemia and angina at rest to be the only significant predictors of perioperative myocardial infarction. Thus perioperative monitoring for silent myocardial ischemia might noninvasively identify those patients undergoing peripheral vascular surgery who are at increased risk for perioperative myocardial infarction, permitting implementation of timely preventive measures in selected patients.

Aged↗
PubMed1989

Is duplex scanning sufficient evaluation before carotid endarterectomy?

Recent reports have suggested that cerebral angiography may not be necessary before carotid endarterectomy is performed in selected patients. To determine if arteriography provides additional information that might influence the decision to operate or the conduct of the operation, a retrospective review was performed of 100 consecutive patients undergoing cerebral angiography and carotid duplex scanning. Eighty of the 100 patients subsequently underwent carotid endarterectomy for neurologic symptoms or asymptomatic stenosis greater than 80%. Among the 20 patients not operated on, three would have undergone unnecessary surgery for mistaken diagnoses had the arteriogram not been obtained. Two other patients in this group of 20 would have had carotid endarterectomy for asymptomatic stenosis in the presence of an equally stenotic tandem lesion. Among the 80 patients operated on, an additional three had the operative procedure altered because arteriographic studies revealed pathologic findings outside the area of duplex scan examination. Thus the use of arteriography altered the management of eight (8%) patients in this group of 100.

Aged↗
PubMed1988

Revascularization of the external carotid artery.

Numerous reports describe the relative effectiveness of external carotid artery (ECA) revascularization in patients with ipsilateral internal carotid artery occlusion. Most, however, suffer from small numbers of patients or lack of detailed follow-up data. In addition, controversy persists regarding the safety with which this procedure can be performed. Twenty-two patients underwent a total of 27 ECA revascularizations. There were no perioperative strokes or deaths. During a mean follow-up period of 46 months, no strokes occurred and only two patients suffered transient ischemic attacks. Revascularization of the ECA is an effective means of treating the patient with ipsilateral internal carotid artery occlusion and may be performed with minimal morbidity and mortality.

Adult↗
PubMed1988

Intracranial hemorrhage after carotid endarterectomy.

Among 1500 carotid endarterectomies performed between 1975 and 1984, 11 ipsilateral intracranial hemorrhages (IH) occurred between the first and tenth postoperative days for an incidence of 0.7%. The mortality rate among these patients was 36%. The only recognizable predisposing factor was relief of high-grade carotid stenosis (greater than 90%) whereas other factors such as age (58 to 81 years), preoperative hypertension (systolic blood pressure 120 to 160 mm Hg), preoperative head CT scans showing recent infarction (only one in five positive), and preoperative cerebral infarction (only 1 of 11 patients) did not play a role. All patients had normal coagulation studies. No patient required a shunt because all tolerated cross-clamping of the carotid artery. Postoperative systolic blood pressures were 200 to 240 mm Hg in 6 of 11 patients. The time of occurrence of IH extended from the immediate postoperative period to the tenth postoperative day (mean interval 3.3 days). Treatment consisted of craniotomy in five patients; four survived and one recovered completely. Of the six patients treated nonoperatively, three survived and two completely recovered. IH shares equal incidence with recurrent thrombosis, cross-clamping ischemia, and embolization as a cause of perioperative stroke. Although all except IH can be prevented by current practice, the means of preventing IH are not apparent; however, careful monitoring of blood pressure to prevent uncontrolled hypertension deserves consideration.

Aged↗
PubMed1987

Surgical management of the patient with bilateral internal carotid artery occlusion.

The patient with bilateral internal carotid artery occlusion is at high risk for development of stroke. Medical management and extracranial-intracranial bypass do not appear to offer these patients any protection from symptoms of cerebrovascular insufficiency. Our initial treatment in 11 of 12 patients who had this pattern of extracranial arterial occlusion has been external carotid artery revascularization. Nineteen procedures were performed for symptomatic lesions in all cases except one. There were no perioperative strokes or deaths. During a mean follow-up of 44.7 months, no new strokes occurred. Among 10 patients undergoing external carotid artery revascularization alone, only one transient ischemic attack occurred in follow-up. Seven of the eight surviving patients are presently asymptomatic. External carotid artery revascularization may be an effective and durable treatment for the patient with bilateral internal carotid artery occlusion.

Adult↗
PubMed1987

Surgical therapy for the patient with internal carotid artery occlusion and contralateral stenosis.

With demonstration of the failure of extracranial-intracranial (EC-IC) bypass to reduce the incidence of stroke in patients with internal carotid artery (ICA) occlusion, controversy continues regarding the best method of stroke prevention in these high-risk persons. One approach, endarterectomy of stenotic lesions of the contralateral carotid bifurcation, has been used for 145 patients with ICA occlusion during the past 25 years. Presenting symptoms included focal transient ischemic attacks (TIAs) in 62 patients, stroke (CVA) in 57, and nonfocal TIAs in 16. Ten patients were asymptomatic. Nine patients (6.2%) sustained perioperative strokes, only three of which were ipsilateral to the endarterectomy. There were three perioperative deaths (2.1%). During the follow-up period (mean 4 years) there were 13 new strokes (9.2%), four of which were fatal. These late results compare favorably with patients from the cooperative study of EC-IC bypass with occlusion of one ICA, whether they received surgical treatment or were managed nonoperatively. With the exception of select situations where an occluded ICA may be reopened, we conclude that the best current therapy for these patients is close observation of the nonoccluded ICA and endarterectomy once a stenotic lesion is encountered.

Adult↗