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Biomedical subjects

L M Taylor

Publications and source records attributed to L M Taylor.

At least 19 recordsLinked to original sources
PubMed1992

Neurologic deficits following noncarotid vascular surgery.

Neurologic events following noncarotid vascular surgery (NCVS) are considered unpredictable. To test this hypothesis, we reviewed our vascular registry for a 3-year period and identified all patients with new postoperative focal neurologic events (stroke, hemispheric transient ischemic attack [TIA]) within 2 weeks of a category I or II vascular procedure as defined by the American Board of Surgery, exclusive of carotid surgery and arterial trauma. Thirteen of 1,390 NCVS procedures (0.9%) in 13 patients were associated with focal neurologic events. There were 2 TIAs, 10 anterior circulation strokes, and 1 posterior circulation stroke. Twenty-seven percent of strokes were fatal. The neurologic deficit developed in the immediate postoperative period in 31%, more than 4 hours but less than 72 hours postoperatively in 54%, and within 3 to 14 days postoperatively in 15%. Patients with anterior circulation events (group A, n = 12) were compared for variables potentially influencing postoperative stroke with case controls who were selected using a table of random numbers (group B, n = 12). Controls were derived from a pool of all category I or II NCVS procedures recorded in our vascular registry sequentially during the same time period and who were without new neurologic deficits postoperatively. Using Fisher's exact test, comparisons between groups A and B revealed that new anterior circulation neurologic events in vascular surgical patients tended to be associated with intra-abdominal procedures (p less than 0.05), perioperative hypotension (p less than 0.05), and the presence of a greater than or equal to 50% internal carotid artery stenosis ipsilateral to the neurologic event (p less than 0.001). Such information may prove useful in the management of selected patients prior to arterial reconstruction and in operated NCVS patients with postoperative neurologic events.

Aged↗
PubMed1992

The incidence of perioperative myocardial infarction in general vascular surgery.

In a 1-year period all patients undergoing general vascular surgery (491 patients, 534 procedures) underwent monitoring by creatine phosphokinase isoenzymes and electrocardiograms (ECG) to detect perioperative myocardial infarction. Only those patients with severe symptomatic coronary artery disease (31 patients, 5.8%) characterized by unstable angina pectoris, uncontrolled arrhythmia, or severe congestive heart failure had any testing for coronary artery disease beyond history, physical examination, and ECG. Only three patients (0.5%) had prophylactic coronary artery bypass performed before general vascular procedures. Twenty-one (3.9%) myocardial infarctions (five asymptomatic, detected by enzymes only, and 16 symptomatic, four of which were fatal) were associated with the 534 procedures (aorta 105, carotid 87, infrainguinal bypass 207, extraanatomic 51, other 84). Eight noncardiac perioperative deaths occurred. All operative deaths (12 of 534, 2.2%) including all four fatal myocardial infarctions occurred associated with surgery on an urgent or emergency basis (12 of 249 procedures, urgent/emergent operative mortality rate 4.8%). No operative deaths and no fatal myocardial infarctions associated with the 285 elective procedures occurred. Nine of the 17 nonfatal myocardial infarctions (53%) also occurred after urgent/emergent procedures. The rate of perioperative myocardial infarctions (eight of 285, 2.8%) after elective surgery in this patient series is no different from that reported by multiple recent authors advocating widespread screening for and prophylactic treatment of coronary artery disease before general vascular surgery. Our experience confirms the therapeutic approach that expensive and invasive coronary screening programs in patients to undergo vascular operations should be limited to carefully selected patients with severely symptomatic coronary disease.

Adult↗
PubMed1992

Surgical management of severe acute lower extremity ischemia.

Seventy-four patients (70 men [95%], 4 women [5%], mean age, 63 years) with severe, acute lower limb ischemia (acute clinical deterioration and absent pedal Doppler signals) caused by either arterial thrombosis (n = 68) or embolism (n = 6) underwent urgent surgical management consisting of operative revascularization with or without amputation in 67 patients (91%) and primary amputation alone in 7 patients (9%). Sixty-one patients (82%) had severely threatened limb viability, and 13 (18%) had major irreversible ischemic limb changes at presentation. Eighty-six percent of patients were initially anticoagulated with heparin. Seventy percent underwent preoperative angiography. Surgical revascularization included 42 inflow and 20 outflow arterial reconstructions and 9 thrombectomy or embolectomy procedures. Mean follow-up was 17 months (range, 0 to 64). Life-table primary patency at 36 months for arterial reconstructions was 81% for inflow and 78% for outflow procedures. Cumulative limb salvage was 70% at 1 month and 68% at 36 months. Patient survival was 85% at 1 month and 51% at 36 months. No death was directly attributable to complications related to limb reperfusion, and no patient required dialysis for myoglobinuria. We conclude that management of severe, acute lower limb ischemia with early amputation of nonviable limbs and heparinization, angiography, and prompt operative revascularization for threatened but viable extremities minimizes morbidity and mortality rates, while maximizing limb salvage. These results may be useful for comparison with comparable groups of patients treated with thrombolytic or endovascular modalities.

Acute Disease↗
PubMed1992

Upper extremity arterial bypass distal to the wrist.

Seventeen arterial bypass procedures distal to the wrist have been performed in 13 men and two women at the Oregon Health Sciences University during the past 9 years. Ten patients had traumatic true or false aneurysms of the ulnar artery with digital embolization. Five patients with end-stage renal disease had severe hand and finger ischemia manifested by rest pain or digital ulceration resulting from widespread forearm and hand arterial occlusions. Patients with aneurysms of the ulnar artery underwent excision and reversed autogenous vein grafting (n = 11) from the distal ulnar artery in the forearm to the superficial palmar arch. All the patients with end-stage renal disease had severe occlusive disease of the forearm and hand arteries and underwent a variety of procedures including radial-radial bypass (n = 2), ulnar-ulnar bypass (n = 2), radial-radial bypass with takedown of a Brescia-Cimino fistula (n = 1), and brachial-radial bypass (n = 1). High-quality upper extremity and magnification hand arteriography was essential for operative planning and was available on all patients. Distal saphenous vein from the ankle or foot was the graft source in 16 procedures and basilic vein the source in one procedure. All operations were performed with headlight illumination, optical loupes, fine sutures, and microvascular instruments. There were no operative deaths or major complications. The mean follow-up period was 14 months. Of the 17 grafts, 16 remained patent by clinical and vascular lab criteria. The single occlusion occurred in an ulnar aneurysm bypass and was accompanied only by mild intolerance to cold.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Limb salvage vs amputation for critical ischemia. The role of vascular surgery.

Since 1980, 498 patients with 627 critically ischemic legs (rest pain, gangrene, ischemic ulcer, and ankle-brachial pressure index less than 0.40) were treated with revascularization regardless of operative risk or anticipated operative difficulty. Primary amputation was performed only when no graftable distal vessels were present (14 primary amputations [2.8%]) or in neurologically impaired, hopelessly nonambulatory patients. The mortality for revascularization was 2.3%, and the median hospital stay was 11 days. During follow-up, 41 limbs (7%) required amputation, 31 after failure of revascularization and 10 despite patent revascularizations. Renal failure had an adverse influence on limb salvage (67%) because of a significantly increased requirement for amputation despite patent revascularizations. We conclude aggressive limb revascularization in patients with critical lower-extremity ischemia results in low operative morbidity and mortality and excellent long-term limb salvage. Patients with critical leg ischemia and renal failure are at higher risk for limb loss than patients without renal failure.

Adult↗
PubMed1991

The association of elevated plasma homocyst(e)ine with progression of symptomatic peripheral arterial disease.

Plasma homocyst(e)ine (the sum of free and bound homocysteine, homocystine, and the mixed disulfide homocysteine-cysteine, expressed as homocysteine) levels were determined by high performance liquid chromatography in 214 patients with symptomatic (claudication, rest pain, gangrene, amputation) lower extremity arterial occlusive disease and/or symptomatic (stroke, cerebral transient ischemic attacks) cerebral vascular disease and in 103 control persons. Mean plasma homocyst(e)ine was significantly higher in patients than in controls (14.37 +/- 6.89 nmol/ml vs 10.10 +/- 2.16, p less than 0.05). Thirty-nine percent of patients (83 of 214) had plasma homocyst(e)ine values greater than control mean + 2 standard deviations. Plasma homocyst(e)ine values were contrasted to age, male sex, diabetes, hypertension, smoking, renal failure, and plasma cholesterol. No difference was found in the incidence and/or level of any of these risk factors when patients with normal plasma homocyst(e)ine were compared to those with elevated plasma homocyst(e)ine, both by univariate and multivariate analysis. Patients with elevated plasma homocyst(e)ine were more likely to demonstrate clinical progression of lower extremity disease and of coronary artery disease, but not of cerebral vascular disease than were patients with normal plasma homocyst(e)ine, and the rate of progression was more rapid (p = 0.002). Progression of lower extremity disease as assessed in the vascular laboratory was also more common in patients with elevated plasma homocyst(e)ine (p = 0.01). We conclude that elevated plasma homocyst(e)ine is an independent risk factor for symptomatic lower extremity disease or cerebral vascular disease or both. Symptomatic patients with lower extremity disease and with elevated plasma homocyst(e)ine also appear to have more rapid progression of disease.

Age Factors↗
PubMed1991

Vascular contractions to serotonin are augmented by cooling.

Human saphenous veins (HSV; n = 17) were obtained at surgery and assayed immediately. The veins were cut into rings, suspended in organ chambers and connected to force transducers for the recording of isometric tension. Tail arteries (RTA) from male Sprague-Dawley rats were similarly prepared. In quiescent rings, cooling from 37 to 24 degrees C had no significant effect. In the presence of alpha-adrenoceptor blockade, potassium chloride (KCl, 10-80 mM) caused concentration-dependent contractions that were inhibited slightly by cooling. Serotonin (5-HT, 10(-8)-10(-5) M) elicited concentration-dependent contractions in both the HSV and RTA with EC50's (-log concentration required to induce contractions 50% of maximal) of 6.31 +/- 0.03 and 6.55 +/- 0.06, respectively. These contractions were subject to blockade with the S2-selective 5-HT antagonist, ketanserin. When either HSVs or RTAs were contracted with 5-HT and cooled, a potent augmentation of the contractions ensued. The data indicate that, while acute moderate cooling does not significantly augment either resting tone or KCl-induced contractions of HSV or RTA, S2-receptor-mediated events are enhanced, yielding potent augmentations of the vascular response to the platelet-derived compound, serotonin. The relationship between temperature and serotonergic receptor responsiveness may be of clinical importance as a mechanism contributing to cold-induced vasospasm.

Animals↗
PubMed1991

Simultaneous operative repair of multilevel lower extremity occlusive disease.

Sixty-two patients (39 men (63%), 23 women (27%), mean age 68 years) with multilevel lower extremity arterial occlusive disease underwent simultaneous inflow and outflow operative arterial repair consisting of aortofemoral bypass in 22 (35%), axillofemoral bypass in 17 (28%), femorofemoral bypass in 15 (24%), iliac endarterectomy in 7 (11%), and unilateral aortoiliac bypass in 1 (2%), combined with 69 outflow procedures (unilateral in 55 patients, 89%), including above-knee femoropopliteal in 12 (17%), below-knee femoropopliteal in 35 (51%), femoroinfrapopliteal in 20 (29%), popliteal tibial in 1 (1%), and femoropedal bypass in 1 (1%). Multiple criteria were used to identify patients with multilevel disease likely to benefit from multilevel procedures. The operations were performed by two operating teams in a median time of 240 minutes. Prosthetic grafts were used for eight (13%) distal bypasses, the remainder were autogenous vein. There was one operative death (1.8%). The mortality rate, morbidity rate, and operative time were not significantly different from a group of patients who underwent concurrent, isolated inflow operations (aortofemoral, axillobifemoral, femorofemoral bypass or iliac endarterectomy). Mean follow-up was 14.9 months (range, 0 to 120). The life-table primary patency for the inflow procedures was 92.6% at 24 months, the outflow was 94.9% at 24 months. Cumulative limb salvage was 90.9% at 48-month follow-up. All patients with claudication were relieved of their symptoms. We conclude that complete correction of multilevel disease can be accomplished with operative time, morbidity rate, and patency equal to that of single level repair. Multilevel procedures provide complete relief of symptoms in a higher percentage of patients than has been reported after single level repair.

Adult↗
PubMed1991

Clinical and anatomic considerations for surgery in femoropopliteal disease and the results of surgery.

From 1980 to 1988 we performed 288 femoropopliteal bypass operations in 231 patients at the Oregon Health Sciences University. The indication for the procedure was claudication in 31% and the relief of limb-threatening ischemia in 64%. Operative mortality occurred after four of these operations (1.4%), including three deaths from myocardial infarction and one death from stroke. The femoropopliteal bypass patients were divided into groups for patency analysis, including those undergoing bypass surgery with a good quality greater saphenous vein versus alternate bypass conduits and patients undergoing primary limb bypass versus those undergoing repeat bypass after prior bypass failure. Our overall primary graft patency for all femoropopliteal grafts was 79% at 5 years. Patients undergoing bypass with a good quality greater saphenous vein had primary graft patency of 85% at 5 years. Patients undergoing bypass using a conduit other than greater saphenous vein had a 5-year patency of 73%. Patients undergoing repeat bypass after a prior failed bypass had a 5-year patency of 57%.

Arteriosclerosis↗
PubMed1991

Fifteen-year results of ambulatory compression therapy for chronic venous ulcers.

A nonoperative approach to venous stasis ulceration of the lower extremity, consisting of initial bedrest, ulcer cleansing, dressing changes, and ambulatory elastic compression stocking therapy, has been maintained for over 15 years. All patients had class III, severe chronic venous insufficiency. One hundred five of 113 patients (93%) experienced complete ulcer healing in a mean of 5.3 months. One hundred two patients were compliant with elastic compression stockings, and 11 patients were noncompliant. Complete ulcer healing occurred in 99 of 102 patients (97%) who were compliant versus six of 11 patients (55%) who were noncompliant (p less than 0.0001). The influence of noncompliance, previous venous ulceration, previous venous surgery, previous known deep venous thrombosis, peripheral arterial insufficiency (ankle brachial systolic blood pressure index less than or equal to 0.60), pretreatment ulcer duration, ulcer size, age, sex, diabetes, smoking, and photoplethysmography venous refill time on ulcer healing was determined by logistic regression analysis. Only noncompliance with elastic compression stockings (p less than 0.0001) and a pretreatment ulcer duration of more than 9 months (p = 0.02) significantly decreased initial ulcer healing. Posthealing follow-up was available in 73 patients for a mean of 30 months. Fifty-eight patients (79%) continued to be compliant with stockings; 15 patients were noncompliant. Total ulcer recurrence in patients who were compliant was 16%. Five-year lifetable recurrence was 29%. All patients who were noncompliant had recurrent ulceration by 36 months. Previous ulceration, previous venous surgery, and peripheral arterial insufficiency had no effect on ulcer recurrence (p greater than 0.05).

Adult↗
PubMed1990

Improving survival and limb salvage in patients with aortic graft infection.

A 15-year experience with 38 aortic graft infections, including 15 patients with graft enteric fistulas, is reviewed in order to analyze modern-day surgical results utilizing extra-anatomic bypass and aortic graft excision. Perioperative mortality was 14% during the most recent 7-year interval, which was a notable improvement compared with the earlier time interval (p = 0.06). Extended follow-up of the perioperative survivors demonstrated a 77% cumulative 5-year survival and a 76% cumulative 5-year limb salvage rate. Subsequent axillofemoral graft infection occurred in 22% of survivors and resulted in a significantly higher amputation rate compared with those patients with no axillofemoral graft infection (p less than 0.001). The results suggest good perioperative and long-term survival in patients with aortic graft infection, with excellent limb salvage if subsequent axillofemoral graft infection can be avoided.

Aged↗
PubMed1990

Surgical treatment of distal ulnar artery aneurysm.

In the past 7 years, we have encountered six patients with finger ischemia as a result of digital artery occlusion associated with seven distal ulnar artery aneurysms. Our experience with the management of these patients forms the basis of this report. All patients were men, with a mean age of 29 years, and all experienced repetitive trauma to the involved upper extremity. Each patient presented with the acute onset of cool and painful digits, with no previous history of cold sensitivity or Raynaud's syndrome. None of the patients had any serologic or clinical evidence of autoimmune disease. Angiography revealed occlusion of the ulnar artery on the affected side in two patients and patent ulnar artery aneurysms in the remaining five patients. There was occlusion of multiple common and proper digital arteries in all patients. One patient with bilateral ulnar artery aneurysms underwent operative repair consisting of aneurysm excision and replacement with autogenous vein grafts from the lower extremity. All patients have improved symptoms, and the grafts remained patent over a mean follow-up of 24 months (range: 13 to 57 months). Based on these results, we recommend that excision and grafting be considered for patients with symptomatic patent ulnar artery aneurysms. Selected patients with thrombosed aneurysms with ongoing digital ischemia may also benefit from surgical intervention.

Adolescent↗