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Biomedical subjects

C A Bucknam

Publications and source records attributed to C A Bucknam.

14 recordsLinked to original sources
PubMed1988

Benefit of external carotid endarterectomy in patients with advanced cerebrovascular disease.

The external carotid artery and its branches may serve as critical collateral pathways to the cerebral hemisphere when the internal carotid artery is occluded. In this setting, a stenotic lesion of the external carotid artery can result in hypoperfusion as well as lead to embolic phenomena via enlarged collaterals. This is a report of an experience with six external carotid endarterectomies in five patients from April 1983 to March 1986. All five of the patients had an internal carotid artery occlusion ipsilateral to a significant external carotid artery stenosis. Each patient had symptomatic cerebrovascular insufficiency with four of the five patients demonstrating clear cut symptoms, which lateralized to the side with external carotid stenosis and internal carotid occlusion. These symptoms included amaurosis fugax in four patients and transient extremity weakness in two patients. Four out of five patients were completely relieved of their symptoms after external carotid endarterectomy with follow up periods ranging from 6 months to 2 and one half years. There were no perioperative neurological deficits or complications. The duplex scan was useful in identifying possible candidates for this operation. Important technical details include use of an arterial shunt and closure of the internal carotid artery stump, which may be a source of further emboli. It is concluded that with appropriate patient selection, external carotid endarterectomy can be safely employed with gratifying results in patients with advanced cerebrovascular disease.

Aged↗
PubMed1987

Recent experience with the asymptomatic cervical bruit.

To document our recent experience with asymptomatic cervical bruit, we reviewed the records of 418 patients referred to the noninvasive vascular laboratory. Mean follow-up of 23.7 months was obtained for 370 patients by record review or telephone. In a group of 313 patients not operated on, transient ischemic attacks occurred in 14 and stroke in seven (6.7%). The risk of neurologic morbidity was highest in patients with advanced carotid stenosis. Carotid endarterectomy was performed 62 times in 57 patients, with one stroke (1.6%). If carotid endarterectomy is performed with low morbidity, identification of selected surgical candidates with advanced carotid stenosis is reasonable.

Auscultation↗
PubMed1986

Intra-arterial fibrinolytic therapy. Efficacy of streptokinase vs urokinase.

This study is a retrospective comparison of the results in 25 low-dose, intra-arterial streptokinase and 12 low-dose intra-arterial urokinase infusions for thromboembolic disease. Intra-arterial streptokinase was successful in 50% of infusions and was marked by significant abnormalities in the coagulation criteria. There was a high incidence of major and minor bleeding (48% overall), which could be attributed to systemic effects of the drug. Urokinase was successful in 100% of infusions, and showed no significant effects on systemic coagulation criteria. There were also fewer complications during urokinase infusion. The average pharmacy cost for a course of intra-arterial streptokinase was $165, while urokinase cost $1142. Despite the significant difference in expense, the increased efficacy and safety of urokinase make it the preferred agent for intra-arterial infusion. Theoretical reasons for the increased effectiveness of urokinase are discussed.

Adult↗
PubMed1986

Axillofemoral bypass: a tool with a limited role.

Axillofemoral bypass (AXB) was performed on 100 patients who had claudication (19), pain at rest (42), gangrene or ulcer (22), aortic sepsis (14), or unresectable abdominal aneurysm (3). Unilateral (27 grafts), double unilateral (1), or axillobifemoral (72) grafts with Dacron (58), polytetrafluoroethylene (PTFE) (28), ring-supported Dacron or PTFE (12), or other material (2) were performed by 13 surgeons. Eight patients died within 30 days and three major amputations were necessary. Fifty-two (57%) of the 92 survivors had a total of 92 graft complications during a mean follow-up period of 21.5 months. Thirty-two patients underwent 57 reoperations of various types, incurring an additional three deaths and three amputations. Sixty (65%) of the original 92 survivors of AXB avoided reoperation. The 89 patients who survived the original and repeat procedures were followed up through the end of 1984 (62 patients), to late death (23), or to late graft removal (4), whichever occurred first. At these end points, 83 of the 89 (93%) patients had patent grafts. The graft patency rate of the original 100 AXBs by life table was 54% at 36 months; but with reoperation, it was 72%. Among those patients who left the hospital after AXB, the survival rate at 36 months was 69%. Statistically insignificant trends toward improved early patency were noted with bilateral femoral anastomoses, total iliac occlusion, and less severe ischemia. AXB provided safe palliation of severe arterial disease, with overall graft patency exceeding postoperative patient survival according to life-table analysis. However, the safety of AXB was tempered by frequent complications and the necessity for many reoperations to provide maximum efficacy.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1985

Combined oculopneumoplethysmography and duplex scan. Use in the noninvasive cerebrovascular laboratory examination.

To determine the relative merits of oculopneumoplethysmography (OPG) (Gee) and duplex scanning of the carotid arteries, a retrospective analysis was made of 93 patients in a 12-month period who underwent noninvasive carotid studies followed by carotid angiography. The results for the duplex scan were 91% sensitivity, 86% specificity, and 89% overall accuracy in evaluation of 184 arteries. The OPG results were 59% sensitivity, 90% specificity, and 74% accuracy when applied to individual arteries. The sensitivity of OPG increased to 77% when applied to disease in the patient rather than in individual arteries. Analysis of cases in which the duplex scan and OPG were in agreement and disagreement suggested an important role for the OPG test despite its inferior accuracy compared with the duplex scan alone. The predictive value of an abnormal duplex scan result was 98% when the OPG was also abnormal, whereas it was 81% when the OPG was normal. The predictive value of a normal duplex scan result was 93% when the OPG was also normal, whereas it was 60% in those cases where the OPG was abnormal. We believe that the duplex scan should be the basic noninvasive evaluation of cerebrovascular disease, although the OPG continues to provide important information.

Arterial Occlusive Diseases↗
PubMed1985

Role of computerized tomography in assessment of the mediastinum in patients with lung carcinoma.

Over a 28 months period, 75 patients with pathologically confirmed lung carcinoma had computerized tomographic scanning of the mediastinum as a staging procedure. The scan had a sensitivity of 85 percent and a specificity of 89 percent for mediastinal lymph node metastases, making routine mediastinoscopy unnecessary. Tissue confirmation of most positive scans is advisable since false-positive results can deny some patients potentially curative resection. Invasive staging should also be employed in the face of negative scans in selected patients. Computerized tomographic scanning provides anatomic information that is helpful in directing these invasive staging procedures.

Adult↗
PubMed1985

Factors affecting survival after ruptured abdominal aortic aneurysm.

To identify the factors affecting the high mortality rates associated with ruptured abdominal aortic aneurysm (AAA), a review was made of the records of 81 patients treated surgically between 1972 and 1983. Correlation of data with survival and predictive value of preoperative findings were studied. The mortality rate was 43.2%; there was a 29.2% mortality rate among those surviving the day of surgery. Patient-determined variables associated with deaths included age more than 76 years, hematocrit less than 30% and acute abnormality detected by ECG at admission, and suprarenal extension or free rupture of the AAA. Survival could be predicted with only 70% accuracy with a computerized discriminant function based on age and hematocrit and blood pressure values determined at admission. Events following admission associated with death were precipitous fall or persistently low level of preoperative blood pressure, technical complications, and postoperative organ failure. Although the patient's ultimate outcome after ruptured AAA is partly determined before intervention of the physician, efforts to address events resulting in death after admission by improving rapid diagnosis, early resuscitation, and prompt flawless surgery can increase survival.

Aged↗
PubMed1984

Early experience with in situ saphenous vein grafts for severe ischemia of the lower extremity.

Based upon this group of 35 patients with a variety of vascular lesions, it would appear that the in situ saphenous vein technique is certainly, at least, a viable alternative to standard bypass techniques. It has been applied with equally encouraging results by several surgeons in a variety of clinical settings, all using the procedure for the first time in a learning phase. This technique may become the procedure of choice for the treatment of occlusive disease of the lower extremity in this difficult and challenging group of patients.

Blood Vessel Prosthesis↗