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Biomedical subjects

E G Beven

Publications and source records attributed to E G Beven.

At least 55 records · Page 3Linked to original sources
PubMed1987

Simultaneous aortic reconstruction and renal revascularization: risk factors and late results in eighty-nine patients.

From 1973 through 1984, graft replacement of infrarenal aortic aneurysms (N = 56) or occlusive disease (N = 33) was performed in conjunction with simultaneous renal revascularization in 89 patients. Isolated renal artery stenosis was corrected by unilateral reconstruction in 56 patients (63%), but the remaining 33 (37%) had diffuse involvement that required either bilateral renal artery grafts or unilateral revascularization of solitary kidneys. The incidence of hypertension (greater than 180/90 mm Hg) refractory to preoperative medical therapy (88%), severe coronary disease documented by angiography (40%), and postoperative azotemia (33%) or oliguric renal failure (15%) was significantly higher among patients with bilateral renal artery disease (p less than 0.05). In addition, this group had twice the early mortality rate (15%) of patients having unilateral renal artery lesions (7.1%). During a mean follow-up interval of 37 months, medical control of hypertension was enhanced in 46 of the 80 operative survivors (58%), and renal function improved or remained stable in 63 survivors (79%). Five-year actuarial survival presently is 65% for the entire series, with a cumulative mortality rate of 38% among patients who underwent aneurysm resection (mean age 64 years) in comparison to 15% (p = 0.03) for those patients with aortoiliac occlusive disease (mean age 60 years).

Aged↗
PubMed1987

Late results of coronary bypass in patients with infrarenal aortic aneurysms. The Cleveland Clinic Study.

Cardiac catheterization was performed in a prospective series of 1000 patients under consideration for elective peripheral vascular reconstruction at the Cleveland Clinic from 1978-1982. Of these, 246 patients (mean age: 68 years) presented primarily because of infrarenal abdominal aortic aneurysms (AAA) and are eligible for subsequent evaluation 3-7 years (mean: 4.6 years) after entrance into the study. Severe, surgically correctable coronary artery disease (CAD) was documented in 78 patients (32%) in the AAA group, and 70 patients (28%) received myocardial revascularization with four fatal complications (5.7%). A total of 56 patients in this subset had staged aneurysm resection, usually during the same hospital admission after coronary bypass, with a single death (1.8%) caused by cerebral infarction. The overall operative mortality rate for 126 coronary and AAA procedures was 4%. A total of 59 additional patients (25%) died during the late follow-up interval, including 14 patients (5.9%) with cardiac events and eight patients (3.4%) with ruptured aneurysms. The cumulative 5-year survival rate (75%) and cardiac mortality rate (5%) after coronary bypass reflected traditional parameters (preoperative ventricular function, completeness of revascularization) and are nearly identical to the results calculated for patients having normal coronary arteries or only mild to moderate CAD. In comparison, the cumulative survival and cardiac mortality rates in a small subset of patients with severe, uncorrected coronary involvement currently are 29% (p = 0.0001) and 34%, respectively. These data support the conclusion that selected patients who require elective resection of AAA also warrant myocardial revascularization to enhance perioperative risk and late survival.

Age Factors↗
PubMed1987

A prospective study of vein patch angioplasty during carotid endarterectomy. Three-year results for 801 patients and 917 operations.

From 1983 through 1985, 801 consecutive patients (mean age: 66 years) underwent 917 primary carotid endarterectomies at the Cleveland Clinic. Conventional arteriotomy closure was performed during 483 operations, while patch angioplasty using a distal segment of saphenous vein was employed in 434. Preoperative risk factors, surgical management, and antiplatelet therapy were equivalent in the vein patch (VP) and nonpatch (NP) groups. Early results were evaluated by intravenous angiography (DSA) in 715 patients (89%), and 332 reconstructions (36%) have been reassessed by objective imaging during a mean follow-up interval of 21 months. Ischemic strokes occurred after 18 (1.9%) of the 917 procedures (0.7% VP, 3.1% NP; p = 0.0084), and symptomatic (N = 9) or unsuspected (N = 8) thrombosis of the internal carotid artery was confirmed by neck exploration or routine DSA after 1.9% of all operations (0.5% VP, 3.1% NP; p = 0.0027). Only ten patients (1.2%) have required reoperations for severe recurrent lesions, but the cumulative 3-year incidence of new defects (greater than or equal to 30% stenosis) documented by objective studies in the VP and NP groups was 9% and 31%, respectively (p = 0.0066). These results strongly suggest that VP angioplasty enhances the safety and durability of carotid endarterectomy.

Adult↗
PubMed1987

Treatment of deep vein thrombosis and pulmonary emboli in patients with primary and metastatic brain tumors. Anticoagulants or inferior vena cava filter?

There is a common belief that administration of anticoagulants to patients with brain tumors is contraindicated. Between 1982 and 1986, 50 patients with deep venous thrombosis and pulmonary emboli and brain tumors were examined and treated. Twenty-four patients received an inferior vena cava Greenfield filter and 25 patients were treated with anticoagulants. One patient was terminal and received no therapy. Patients in each group were similar with regard to age, sex, primary tumor, computed tomographic findings, and ultimate outcome. At the time of diagnosis, all patients had residual tumor and most had significant cerebral edema and midline shift. There were no complications in the group receiving Greenfield filters. One patient had a pulmonary embolus after the filter was placed and later required anticoagulant therapy. In the group receiving anticoagulants, one patient had focal intraventricular bleeding observed incidentally on computed tomographic scan one month after beginning anticoagulant therapy and was totally asymptomatic. One patient had gastrointestinal tract bleeding five days after beginning anticoagulant therapy with heparin sodium, and the therapy was therefore discontinued. No other patient had significant bleeding. In view of these findings, a reevaluation of anticoagulant therapy in patients with central nervous system tumors is warranted.

Anticoagulants↗
PubMed1986

Coronary artery disease in patients with aortic aneurysm: a classification of 302 coronary angiograms and results of surgical management.

In an attempt to reduce early and late mortality caused by myocardial infarction in patients with aortic aneurysms, coronary arteriography and, when indicated, myocardial revascularization were performed prior to elective aortic reconstruction in 302 patients with infrarenal (289) or thoracoabdominal (13) aortic aneurysms. Severe correctable coronary artery disease (CAD) was identified in 31% of the entire series, whereas severe inoperable CAD was seen in another 5%. Severe, correctable CAD was documented in 42% of patients suspected to have CAD by standard clinical criteria and in 19% of those in whom CAD was not suspected. The overall mortality for 89 cardiac and 227 infrarenal aortic surgical procedures was 4,4%. Fatal complications after infrarenal aneurysm resection occurred in only one (1.6%) of 61 patients who had had preliminary myocardial revascularization.

Aged↗
PubMed1986

Peripheral artery and bypass graft thrombolysis with recombinant human tissue-type plasminogen activator.

Recombinant tissue-type plasminogen activator (t-PA) is a DNA-synthesized thrombolytic agent recently approved for clinical trials. We present the results of t-PA infusions in 18 patients with thrombosed peripheral arteries (12 patients) and peripheral bypass grafts (six patients). The duration of occlusion ranged from 1 to 21 days (mean, 6.8 days). Infusions of t-PA were done by way of an intra-arterial approach at a dose of 0.1 mg/kg/hr. All patients demonstrated thrombus lysis angiographically. Fifteen of 18 (83%) had clinical as well as angiographic improvement. Secondary procedures to maintain patency of the arterial segment were required in seven patients. No complications occurred that were related to the t-PA infusion. No significant prolongation of the prothrombin, thrombin, or activated partial thromboplastin times occurred. At the end of t-PA infusion, the mean circulating fibrinogen level was 59% of the starting value. The therapeutic use of t-PA is still in its preliminary stages and the efficacy and safety of this promising agent need to be further established. From our early experience with t-PA, it appears to be safe as well as effective.

Adult↗
PubMed1986

Routine coronary angiography in patients undergoing surgery for abdominal aortic aneurysm and lower extremity occlusive disease.

Between 1978 and 1982, 1000 patients under consideration for peripheral vascular reconstruction underwent coronary angiography. Normal coronary arteries were found in 8%; mild to moderate coronary artery disease (CAD), in 32%; advanced but compensated CAD, in 29%; severe correctable CAD, in 25%; and inoperable CAD, in 6%. Severe correctable CAD was demonstrated in 14% of patients who had no indications of CAD on clinical criteria. Patients with severe correctable CAD were advised to undergo myocardial revascularization before the vascular operation. Under this protocol, a total of 1292 cardiac and peripheral vascular reconstructions were performed with an overall mortality rate of 2.6% (5.2% for myocardial revascularization and 2% for vascular operation). Only one death (0.8%) occurred after peripheral vascular reconstruction in 130 patients who had preliminary myocardial revascularization. These results indicate that approximately 30% of all patients who require vascular reconstruction have severe, but surgically correctable, CAD and that preliminary myocardial revascularization appears to add a margin of safety to the subsequent vascular operation.

Aorta, Abdominal↗
PubMed1986

Surgical versus nonoperative treatment of symptomatic carotid stenosis. 211 patients documented by intravenous angiography.

From 1980 through 1982, intravenous extracranial digital subtraction angiography (DSA) was performed in 6684 patients at the Cleveland Clinic. Of these, 211 previously unoperated patients had prior transient ischemic attacks (TIA) or strokes in conjunction with greater than 50% carotid stenosis on unequivocal DSA studies. Nonoperative management was employed in 126 patients, including 120 (84%) who received antiplatelet therapy or formal anticoagulation. The remaining 85 patients underwent carotid endarterectomy. During a mean follow-up interval of 36 months, there was no overall difference in survival, late TIA, or stroke between the nonoperated and surgical cohorts. However, parity was maintained in these groups only because of the prevalence of intermediate (50-69%) stenotic lesions and stable internal carotid occlusions in the nonoperated group. Carotid endarterectomy provided superior stroke prevention for patients with greater than 70% unilateral stenosis (p = 0.04), for those with greater than 50% bilateral stenosis (p = 0.004), and for those with internal carotid occlusions associated with greater than 50% contralateral stenosis (p = 0.03). The special risk of such discrete subsets should be recognized in order to plan appropriate treatment at the present time, as well as to conduct safe clinical trials in the future.

Adolescent↗
PubMed1986

Surgical versus nonoperative treatment of asymptomatic carotid stenosis. 290 patients documented by intravenous angiography.

From 1980 through 1982, intravenous extracranial digital subtraction angiography (DSA) was performed in 6684 patients at the Cleveland Clinic. Of these, 290 previously unoperated patients had asymptomatic carotid stenosis exceeding 50% of lumen diameter on unequivocal DSA studies. Either the presence or the absence of carotid bruits substantially misrepresented the severity of angiographic stenosis on approximately 30% of sides. Nonoperative management was employed in 195 patients, including 104 (53%) who received antiplatelet therapy, while another group of 95 patients underwent prophylactic carotid endarterectomy. During mean follow-up intervals of 33-38 months, surgical treatment significantly reduced the cumulative incidence of subsequent neurologic events in men (p = 0.05). Statistically unconfirmed trends also suggested that carotid endarterectomy tended to prevent late strokes in subsets of patients with greater than 70% stenosis or bilateral carotid lesions. The overall stroke rate for women was higher in the surgical group (p = 0.03), in part because of their unusual risk for perioperative complications (9%) in this particular series.

Adult↗
PubMed1986

Surgical management of popliteal aneurysms. Trends in presentation, treatment, and results from 1952 to 1984.

Graft replacement was performed for 123 (77%) of 160 popliteal aneurysms evaluated at The Cleveland Clinic from 1952 to 1984, employing autogenous saphenous vein in 58 (36%), polytetrafluoroethylene in 19 (12%), and of historic interest, Dacron (12%) or arterial homograft (16%) in 46. The 10-year cumulative patency (CP) rate was 56% and the limb salvage (LS) rate was 83% following graft replacement, but late results were superior in patients who received vein bypass (CP, 94%; LS, 98%), in those who underwent revascularization before ischemic complications had occurred (CP, 92%; LS, 96%), and in those who recovered both pedal pulses (CP, 64%; LS, 96%). Long-term asymptomatic limbs were restored in 96%, 92%, and 89% of these subsets, respectively, compared with 65% of those receiving other graft materials (p = 0.00003), 59% of those with preoperative ischemic symptoms (p = 0.00001) and 68% of those regaining only an isolated popliteal pulse (p = 0.0326). These data indicate that popliteal aneurysms should be corrected by vein bypass to a patent tibioperoneal segment before spontaneous thrombosis or embolization eliminates the critical outflow bed.

Actuarial Analysis↗
PubMed1986

Thrombolysis with recombinant human tissue-type plasminogen activator in patients with peripheral artery and bypass graft occlusions.

Thirty-three patients with thrombosed peripheral arteries and bypass grafts, as confirmed by angiography, were treated with recombinant human tissue-type plasminogen activator (rt-PA). Twenty-six patients were treated with a dose of 0.1 mg/kg/hr and seven patients with 0.05 mg/kg/hr. Thrombus lysis and clinical improvement occurred in 22 of 26 (85%) patients in the 0.1 mg/kg/hr group. In seven of seven (100%) patients in the 0.05 mg/kg/hr group angiographic as well as clinical improvement were observed. Fifteen of the 33 patients required anticoagulation to maintain patency. Sixteen required secondary procedures to maintain patency. One (3%) patient required a blood transfusion for a hematoma at the catheter entry site. Three other patients developed small hematomas that were controlled without transfusion or intervention. Sixty-one percent of patients treated with the 0.01 mg/kg/hr dose and 86% of patients treated with the 0.05 mg/kg/hr dose maintained fibrinogen levels greater than 50% of their initial values. Infusion durations ranged from 1 to 6 hr (mean 3.9 hr). rt-PA appears to be a potent and selective thrombolytic agent that rapidly and safely lyses thrombi in peripheral arteries and occluded bypass grafts.

Adult↗
PubMed1986

Surgical management of infected abdominal aortic grafts: review of a 25-year experience.

Eighty-four patients with infected abdominal aortic grafts managed from 1961 through February 1985 were reviewed. Thirty-three patients had associated aortoenteric fistula formation. Twenty-eight infections (33%) and 13 aortoenteric fistulas (39%) originated at The Cleveland Clinic, yielding an incidence of aortic graft infection of 0.77% (28 of 3652 grafts) and aortoenteric fistula formation of 0.36% (13 of 3652 grafts) at this center. Staphylococcus organisms alone or in combination with other organisms were isolated from 34% of the series. Management consisted of graft removal and extra-anatomic bypass in 54 patients (64%), graft removal alone in 14 (17%) patients, partial graft removal and extra-anatomic bypass in seven (8%) patients, and miscellaneous operations in nine (11%) patients. Twenty-three patients (27%) required major amputations, nine of which were bilateral. Life-table analysis yielded 30-day and 1-year survival rates of 72% and 42%, respectively. Thirty-day survival of the aortoenteric fistula subset (49%) was less than that (86%) of the nonaortoenteric fistula subset (p = 0.003). One-year survival of patients treated since 1980 (54%) was superior to that of patients treated before 1980 (31%, p = 0.035). No difference in operative or 1-year survival was demonstrated between the group treated with extra-anatomic bypass and subsequent graft removal and another in which both procedures were performed simultaneously, although the staged group experienced substantially fewer (p = 0.04) amputations (7%) than the combined group (41%).

Actuarial Analysis↗
PubMed1985

Superior mesenterorenal bypass for renal revascularization with infrarenal aortic occlusion.

The technique of renal revascularization using a saphenous vein bypass graft from the superior mesenteric artery is described. This operation has been performed for the correction of renal artery stenosis in 4 patients with atherosclerotic aortic occlusion. When the requisite conditions are present, mesenterorenal bypass offers a safe and effective method of renal revascularization, and is preferable to aortic replacement in selected patients.

Aorta, Abdominal↗
PubMed1985

Medial agenesis associated with multiple extracranial peripheral and visceral arterial aneurysms.

Developmental abnormalities consisting of focal absence of the arterial media have been implicated in the formation of the arterial aneurysms commonly observed in the intracranial cerebrovascular system. However, this observation has rarely been associated with visceral or peripheral arterial aneurysm formation. This article describes the experience with two patients having multiple peripheral and visceral arterial aneurysms with histologic findings previously observed only in intracranial, saccular berry aneurysms and in one patient with an isolated common carotid artery aneurysm. The two patients described herein had no clinical or angiographic evidence of cerebrovascular aneurysm formation. Light and electron microscopic histologic studies revealed complete focal absence of the arterial media in the region of aneurysm formation. No clinical or laboratory evidence of associated collagen-vascular disease was demonstrated. The patients were successfully managed with segmental resection and grafting of symptomatic, expanding, or large aneurysms. The necessity for an aggressive search for associated aneurysms as well as the need for long-term follow-up when histologic evidence of medial agenesis is demonstrated in association with arterial aneurysm formation are emphasized.

Aneurysm↗
PubMed1985

Local thrombolysis in the treatment of thrombosed arteries, bypass grafts, and arteriovenous fistulas.

We reviewed the results, systemic effects, and complications associated with the selective infusion of low-dose streptokinase in 151 patients. Successful thrombus lysis was achieved in 78% of atherosclerotic thrombotic occlusions less than 30 days old, in 81% of post-procedural occlusions less than 14 days old, and in 87% of patients with thrombosed arteriovenous fistulas no more than 4 days old. During the first 12 hours of treatment 81% to 84% of patients had greater than 50% decrease in plasma fibrinogen levels and 100% showed the same decline after 24 hours of treatment. The thrombin time was prolonged to at least 1 1/2 times the control thrombin time in 33% to 42% of patients measured at 4 hours of therapy and in 93% to 97% of patients measured at 24 hours of treatment. Fifteen patients (9.9%) had major complications. Eleven of these had hemorrhagic complications, two had significant distal emboli, one had a thrombosed brachial artery, and one had a false aneurysm at the catheter entry site. We have found that selective low-dose streptokinase is effective in the treatment of acute and chronic thrombotic occlusions and is a useful adjuvant to vascular reconstruction or percutaneous transluminal angioplasty. Although the local infusion dose is substantially lower than the usual systemic dose, a systemic lytic effect was seen in all patients. Hemorrhagic complications occurred despite customary precautions.

Aged↗
PubMed1985

Recurrent carotid stenosis. A five-year series of 65 reoperations.

From 1979 to 1983, 1726 carotid endarterectomies were performed at the Cleveland Clinic. During this period, 39 men (mean age, 60 years) and 22 women (mean age, 63 years) required 65 reoperations (3.8%) for correction of recurrent carotid stenosis occurring 3 to 194 months (mean, 42 months) after previous endarterectomy at this center (N = 43) or elsewhere (N = 22). Remedial procedures were necessary because of restenosis demonstrated by routine noninvasive testing in 32 asymptomatic lesions and because of neurologic symptoms in 33 others. The mean recurrence interval was 57 postoperative months for atherosclerosis (N = 37) in comparison to 21 months (p = 0.0007) for myointimal hyperplasia (N = 28), and was 48 months for men in comparison to 31 months for women (p = NS). Hypercholesterolemia appeared to be associated with late atherosclerotic recurrence (p = 0.05), but was not a feature of myointimal hyperplasia. Patch angioplasty (N = 59) or graft replacement (N = 3) was employed during 62 of the 65 reoperations, with a total of two operative deaths (3.1%), one nonfatal stroke (1.5%), and six transient cranial nerve injuries (9.2%). Three unrelated late deaths have occurred within a mean follow-up period of 23 months, but only three patients have experienced subsequent neurologic symptoms.

Adult↗
PubMed1985

Extracranial carotid aneurysms: report of six cases and review of the literature.

Ligation of atherosclerotic extracranial carotid aneurysms was described nearly 200 years ago, but resection and direct reconstruction of these unusual lesions currently are associated with less risk for perioperative neurologic complications as well as with durable late results. During an interval in which carotid endarterectomy was performed in over 1500 patients at The Cleveland Clinic, only six patients underwent surgical management of cervical carotid aneurysms. Aneurysm resection was performed in conjunction with reanastomosis of the internal carotid artery in two patients but required saphenous vein interposition grafts in four others. A temporary carotid shunt was employed routinely and was threaded through the harvested vein before its insertion whenever graft replacement was necessary. Although one vein graft required revision because of early thrombosis, no operative deaths or permanent strokes occurred in this small series. Each patient has remained asymptomatic throughout a maximum follow-up period of 6 years postoperatively.

Adult↗