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Biomedical subjects

L M Taylor

Publications and source records attributed to L M Taylor.

At least 145 records · Page 8Linked to original sources

Reversed vein bypass to infrapopliteal arteries. Modern results are superior to or equivalent to in-situ bypass for patency and for vein utilization.

In recent years many reports have attributed improved patency and improved vein utilization with lower extremity arterial bypass to infrapopliteal arteries to the use of the in-situ vein graft technique (ISVB). This report describes 110 reversed vein bypasses (RVB) to infrapopliteal arteries performed from 1980-1986. Thirty-three per cent of these patients did not have an intact ipsilateral greater saphenous vein. One hundred per cent of patients had autogenous RVB performed using a variety of techniques, including vein splicing, use of arm veins, lesser saphenous veins, branch veins, and use of graft origins distal to the common femoral artery. The life table patency figures for these grafts are 90%, 85%, and 85% at 1 year, 3 years, and 5 years, respectively. The life table limb salvage at 5 years is 93%. These figures for patency, vein utilization, and limb salvage for modern RVB to infrapopliteal arteries are clearly equal to or superior to any reported figures for ISVB. Results for RVB are greatly improved when compared with historic controls, as are results for ISVB. There is no evidence to date demonstrating superiority of one technique versus another.

Adult↗

Digital ischemia as a manifestation of malignancy.

The association of malignancy with thrombotic disorders of the arterial and venous systems is well described. To date, however, there are only 23 published case reports of digital gangrene associated with malignancy. During a prospective evaluation of over 700 patients with finger ischemia, there were five patients with finger gangrene associated with malignancy. Detailed clinical and laboratory evaluation, including detailed immunologic survey and hand angiography, allowed establishment of the precise mechanisms responsible for vascular occlusions in each patient. Three mechanisms were identified: arteritis, hyperviscosity, and hypercoagulability. Digital gangrene associated with malignancy is a rare condition, the mechanism for which can be deduced by careful diagnostic evaluation.

Adult↗

Upper extremity ischemia caused by small artery disease.

One hundred patients with ischemic finger ulceration had detailed prospective evaluation to determine the incidence of associated diseases, response to treatment, and natural history of the condition. A potentially serious associated disease was detected in each patient including autoimmune disease in 54%, Buerger's disease in 9%, arteriosclerosis obliterans in 9%, hypersensitivity angiitis in 22%, and miscellaneous diseases in 6%. Conservative treatment with soap and water scrubs, antibiotics, and local resection/debridement resulted in long-term healing without recurrence in 88% of patients. Most recurrences occurred in patients with autoimmune disease, usually scleroderma or CRST.

Angiography↗

Alpha 2-adrenergic receptor levels in obstructive and spastic Raynaud's syndrome.

The present study examines the hypothesis that alterations in the activity of alpha 2-adrenergic receptors (A2R) may underlie the clinical vasospasm seen in patients with Raynaud's syndrome. Platelets were isolated from 13 normal subjects, from 50 patients with vasospastic Raynaud's syndrome, and from 20 patients with obstructive Raynaud's syndrome and A2R levels measured. Binding capacity as determined in femtomoles per milligram of protein (fmol/mg of protein) and affinity were measured by Scatchard plot analysis. In a separate experiment normal human platelets were incubated with either buffer, normal serum, or serum from patients with spastic Raynaud's syndrome and A2R levels were measured. A2R levels in normal subjects averaged 112 +/- 18 fmol/mg; in the patients with spastic Raynaud's syndrome, 191 +/- 14 fmol/mg, p less than 0.01; and in the patients with obstructive Raynaud's syndrome, 164 +/- 31 fmol/mg, p greater than 0.05 (ns). Of the patients with spastic Raynaud's syndrome, 26% had values that were less than the mean value of the normal subjects (69 +/- 7 fmol/mg, p less than 0.05). The A2R levels decreased after incubation with serum from patients who had spastic Raynaud's syndrome by 17.4 +/- 3.1 fmol/mg (p less than 0.05). These results indicate that most patients with vasospastic Raynaud's syndrome have increased platelet A2R levels, which may constitute a primary pathophysiologic abnormality underlying this condition. The presence of subnormal A2R levels in a portion of the patients and the finding of a decrease in measurable A2R levels after incubation in serum from patients with spastic Raynaud's syndrome suggests the possibility of receptor modulation as a mechanism for increased cellular receptor synthesis.

Blood Platelets↗

The clinical course of diabetics who require emergent foot surgery because of infection or ischemia.

For the past 15 years at our institution, all acute diabetic foot problems have been treated on the vascular surgery service. The treatment approach has emphasized aggressive local foot surgery and frequent use of revascularization to avoid amputation. A total of 212 urgent or emergent foot operations were performed on 138 limbs in 114 diabetic patients for indications of infection, gangrene, or infected neurotrophic ulcers. The average number of operations per limb was 1.5 (range one to six) and per patients was 1.9 (range one to nine). Ischemia was sufficiently severe to require concurrent lower extremity revascularization in 48 limbs in 43 patients. Follow-up ranged from 1 month to 11 years (mean 3 years). Ultimately 36 major lower extremity amputations were required in 33 patients at time intervals ranging from zero to 86 months (mean 7 months) after the initial operation on the affected limb. These data indicate that an aggressive program of surgical treatment of diabetic foot problems combined with liberal use of lower extremity revascularization resulted in long-term salvage of 73% of threatened limbs in these high-risk patients. These results form the basis for our recommendation that major lower extremity amputations be considered only as a last resort in diabetic patients with limbs threatened by foot infection or localized gangrene.

Adult↗

Supraceliac aortofemoral bypass.

Increasing numbers of patients with aortoiliac disease are seen with contraindications to standard infrarenal aortofemoral reconstruction. Although axillofemoral bypass is possible in these patients, the decreased patency rate associated with this operation makes alternate procedures desirable. This report details our experience with prosthetic bypass from the supraceliac aorta to the femoral arteries in seven patients with limb-threatening ischemia of the lower extremity, all of whom had undergone multiple previous aortic operations. The operations were performed through thoracoabdominal or flank incision, and the preferred graft configuration consisted of a single Dacron tube from the aorta to the left groin with a standard subcutaneous femorofemoral graft to the right groin. No surgical deaths occurred. At 3 1/2 years' mean follow-up, there has been one graft limb occlusion that resulted in amputation for an overall life table patency and limb salvage rate of 93%. We conclude that supraceliac to femoral artery bypass is a useful procedure for the treatment of patients who have had multiple previous aortic reconstructions fail.

Adult↗

Extraperitoneal iliac endarterectomy in the treatment of multilevel lower extremity arterial occlusive disease.

The traditional approach to the surgical correction of lower extremity ischemia resulting from combined aortoiliac and femoropopliteal disease has consisted of aortofemoral bypass as the initial step. This operation is of considerable magnitude, mandates the use of prosthetic material, and may not adequately relieve distal ischemia. Extraperitoneal iliac endarterectomy is an operation of lesser magnitude and does not require the use of prosthetic material. When applied to selected patients with multilevel disease, it can be conveniently and expeditiously combined with distal bypass and deep femoral repair, femorofemoral bypass, or both for the simultaneous and complete correction of multilevel disease. In the past 10 years, 65 patients underwent simultaneous extraperitoneal iliac endarterectomy in combination with an outflow procedure for the correction of multilevel lower extremity arterial occlusive disease. Using a two-team approach, operative time averaged 3 hours. Operative mortality was 5 percent. The procedure was combined with femoral endarterectomy in 60 patients, with femoropopliteal-to-tibial bypass in 30 patients, and with femorofemoral bypass in 10 patients. The life table patency for iliac endarterectomy was 100 percent at 6 years, whereas patency for the associated outflow procedures was 87 percent at 6 years. These results indicate that extraperitoneal iliac endarterectomy is uniquely suited for combination with distal procedures to permit the simultaneous repair of combined aortoiliac and femoropopliteal disease in a single operation of reasonable magnitude.

Adult↗

Long-term hemodynamic and clinical sequelae of lower extremity deep vein thrombosis.

Forty-seven patients with phlebographically confirmed lower extremity deep vein thrombosis (DVT) were reexamined 5 to 10 years (mean, 7 years) after the thrombotic event. Clinical symptoms were recorded and the following noninvasive venous vascular laboratory tests were performed: Doppler examination to determine venous valve competence and photoplethysmography to measure ambulatory venous pressure and venous recovery time. Twenty-eight control subjects underwent similar examination. Although only 10 of 47 patients (21%) were asymptomatic, venous ulceration had developed in only two patients. The symptomatic patients had varying degrees of edema, pigmentation, and varicosities. Eighty-three percent of DVT patients had abnormal vascular laboratory findings. Both the severity of clinical symptoms and the magnitude of the hemodynamic abnormalities generally correlated with the extent of the initial thrombus. However, only 47% of patients whose initial thrombus appeared limited to the calf were asymptomatic, and only 25% of this group had normal venous hemodynamic findings. This study indicates that 5 to 10 years after lower extremity DVT 80% of patients will have both symptoms and abnormal venous hemodynamics regardless of the initial site of the thrombosis.

Female↗

Present status of reversed vein bypass for lower extremity revascularization.

During the past 4 years we have performed 239 reversed vein bypasses for leg ischemia in 196 patients including 45 to the above-knee popliteal artery, 118 to the below-knee popliteal artery, and 76 to infrapopliteal arteries. The cumulative primary patency results by the life-table method through 24 months are 97% at 6 months, 91% at 1 year, and 88% at 2 years. No difference was evident in patency rates with respect to site of distal anastomosis or reason for graft performance (i.e., for claudication [31%] or for limb salvage [69%]). Twenty-two percent of these patients did not have an intact ipsilateral greater saphenous vein. By a variety of techniques including the use of cephalic and lesser saphenous veins, vein splicing, and proximal superficial femoral endarterectomy, we have been able to perform autogenous vein bypass in 94% of all patients who require lower extremity revascularization. The patency of bypasses made from conduits other than greater saphenous vein does not differ from that of the entire series. Both the graft patency and vein utilization rates in the present report are equal to those of recently published series of in situ saphenous vein bypasses and are clearly better than the published results with reversed vein bypass a decade and more ago. We conclude that, although in situ saphenous vein bypass is a good procedure, it is not superior to reversed vein bypass performed in the same time period. This report again emphasizes the hazards of evaluating any new treatment by use of historic controls.

Actuarial Analysis↗

Thrombolytic therapy followed by first rib resection for spontaneous ("effort") subclavian vein thrombosis.

Spontaneous (effort) subclavian vein thrombosis in young persons has historically produced long-term disability from arm swelling and exercise limitation because of failure of the occluded vein to recanalize. Several investigators have speculated that the use of thrombolytic therapy to produce clot dissolution followed by resection of the first rib to prevent recurrence might be ideal management of this condition. Our recent experience with treatment of two such patients formed the basis for this report. Two young men were seen within 24 hours of onset of acute arm swelling, found by venography to be caused by acute thrombosis of the subclavian vein at the level of the first rib. They were treated with systemic thrombolytic therapy with intravenous streptokinase. Both had prompt resolution of all signs and symptoms, confirmed by repeat venography to be accompanied by recanalization of the occluded veins. Both were then anticoagulated with heparin followed by warfarin and underwent elective first rib resection, after which anticoagulation was discontinued. Both patients have remained asymptomatic. Persistent venous patency has been confirmed by repeat venography. Thrombolytic therapy to recanalized spontaneous (effort) subclavian vein thrombosis followed by first rib resection appears to be an advance in the treatment of this condition and may avoid the long-term disability with which it has historically been associated.

Adolescent↗

Current status of thrombolytic therapy.

The optimal role of thrombolytic therapy in clinical practice has not been defined precisely. A review of available information indicates that such therapy may be useful in a small number of carefully selected patients with deep vein thrombosis and/or pulmonary emboli. The superiority of thrombolytic therapy over conventional surgery for arterial thrombi has not been convincingly demonstrated. Available evidence suggests such therapy should be reserved for those conditions in which surgery may be expected to have a poor outcome or be associated with a high incidence of complications. Preliminary information suggests thrombolytic therapy may be of benefit in selected patients with acute myocardial infarction.

Adult↗

Binding characteristics of anti-Rh0(D) antibodies to Rh0(D)-positive and Du red cells.

The relation of human erythrocyte Rh0(D) to Du sites is an important unresolved question in the field of immunohematology. To compare the immunological reactivity of Rh0(D)-positive and Du erythrocytes, the binding characteristics of two anti-Rh0(D) antisera to human Rh0(D)-positive and Du ("low-grade") erythrocytes were studied. 14C-Protein A and direct antibody-labeled techniques were used to generate binding curves and to derive double-reciprocal plots. The results show that the number of antigen sites differ by a factor of 10 to 15 between the Rh0(D)-positive and Du red cells, but that the dissociation constants between anti-Rh0(D) and the Rh0(D) and Du antigens are indistinguishable when studied by the two labeling methods and two different anti-Rh0(D) antibodies. The extent of binding to 112 different Du samples showed a normal distribution and was independent of apparent phenotype. These data suggest immunologic identity of Rh0(D) and Du ("low-grade") sites and that the difference between the antigens of Rh0(D) and Du cells is quantitative only. The data are incompatible with the "missing mosaic" and gene interaction theories of mechanism.

Antigen-Antibody Reactions↗

Intraarterial streptokinase infusion for acute popliteal and tibial artery occlusion.

Eight consecutive patients with acute thrombotic or embolic occlusion of the popliteal or tibial artery were treated with low-dose intraarterial streptokinase followed by arterial reconstructive surgery where appropriate. Three patients had acute thrombosis of a popliteal aneurysm with limb-threatening ischemia. All three were relieved of their acute ischemia by streptokinase infusion accompanied by lysis of clots in the popliteal artery outflow tract. Each patient then underwent elective popliteal aneurysm bypass. Four patients had acute embolic popliteal or tibial artery occlusion. Each was relieved of ischemic symptoms. One required surgery to remove residual clot. One patient with thrombosis of the tibioperoneal trunk did not have a decrease in symptoms with streptokinase infusion, but did experience sufficient outflow tract thrombolysis to permit construction of a tibial bypass with resultant restoration of normal circulation. Low-dose intraarterial streptokinase may be the treatment of choice for selected patients who present with thrombosis of a popliteal aneurysm with tibial vessel involvement or with embolic popliteal or tibial artery occlusion.

Acute Disease↗

Treatment of chronic visceral ischemia.

Herein, we have described the surgical management of 23 patients with chronic intestinal ischemia. The patients presented most commonly with postprandial pain and weight loss. Diagnosis was confirmed by angiography, including lateral aortography. Surgery included bypass with Dacron being the most common graft material. As many vessels as possible were revascularized using an infrarenal graft origin. Two patients died postoperatively from acute myocardial infarction. There were two graft failures in this group. At the present time, 19 of the 21 surviving patients are asymptomatic or greatly improved.

Adult↗