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Biomedical subjects

F W LoGerfo

Publications and source records attributed to F W LoGerfo.

At least 127 records · Page 7Linked to original sources
PubMed1981

Atherosclerotic aneurysms of the superficial femoral artery: a literature review and report of six additional cases.

Six patients with seven superficial femoral artery aneurysms are described, and additional cases in the literature are reviewed. Superficial femoral artery aneurysms are found in elderly patients with advanced atherosclerosis. These patients usually present with signs and symptoms of a high mass, often with local expansion and rupture. Proximal and distal ligation with vein bypass grafting was, for the authors, a satisfactory method of treatment. Patients with this lesion should be screened for possible abdominal aortic aneurysms, present in 33% of the authors' patients, and for other peripheral aneurysms, present in 50% of the authors' patients. Superficial femoral artery aneurysms should be surgically repaired, because when untreated, they tend to rupture and occasionally serve as a source of emboli.

Aged↗
PubMed1981

An improved technique for preservation of endothelial morphology in vein grafts.

Scanning electron microscopy was performed on 29 canine and two human veins prepared for vein grafting by means of various techniques. Endothelial morphology was best preserved when veins were pretreated with papaverine before excision, when a warm solution was used for dilatation, when the grafts were stored up to 1 hour either in a warm, nutritive medium (Dulbecco's modified eagles) or a cold, nonnutritive solution (saline), and when the grafts were maintained in the distended state. Distending pressure up to 500 mm Hg did not cause injury to veins prepared by these techniques. The use of cold solutions to distend veins was especially harmful.

Animals↗
PubMed1980

Clinical experience with the Mobin-Uddin vena cava umbrella filter.

The Mobin-Uddin vena cava filter has been used at Boston University Medical Center since 1971. The umbrella filter has been placed in 128 high-risk patients with a mean age of 60 years, 42% of whom had malignancies. The operative morbidity consists of five wound hematomas, one misplaced umbrella, one retroperitoneal hematoma, and one acute vena cava occlusion, with a total operative morbidity of 6.2%. No patients died of the actual pacement, and the 30-day hospital mortality was 7.0%. Late sequaelae included an incidence of mild edema of 6% and severe edema of 16%. We know of no patients in our series who had recurrent pulmonary embolism. In our experience, the Mobin-Uddin vena cava umbrella filter is a safe, effective method of vena cava interruption in a high-risk population with a low operative morbidity and a low 30-day mortality.

Female↗
PubMed1980

Flow disturbance at the distal end-to-side anastomosis. Effect of patency of the proximal outflow segment and angle of anastomosis.

We investigated the flow disturbance that occurs at the distal end-to-side anastomosis. Clear plastic model end-to-side anastomoses were constructed with inlet angles of 15 degrees and 45 degrees. Flow patterns were visualized with steady and pulsatile flow using a dye-injection technique. Multiple lateral pressure measurements were made in the region of the anastomosis. A laser Doppler anemometer was used to measure near-wall velocity. Flow disturbance was minimal when the inlet angle was low and the proximal outflow segment occluded. Patency of the proximal outflow segment or a high inlet angle may result in areas of boundary-layer separation, with corresponding adverse pressure gradients at the anastomosis. These separation regions are characterized by low near-wall velocity, which may contribute to anastomotic hyperplasia.

Blood Circulation↗
PubMed1979

Boundary layer separation in models of side-to-end arterial anastomoses.

We performed an investigation of boundary layer separation in models of side-to-end anastomoses, used clinically in axillofemoral and femorofemoral grafting. Boundary layer separation occurs when momentum causes a fluid to flow against a local pressure gradient. Models of side-to-end anastomoses were constructed from Dacron grafting material and from clear plastic blocks and tubing. Fluid energy loss across the anastomosis was small and physiologically insignificant. Local adverse pressure gradients were demonstrated near the anastomosis. Flow visualization studies demonstrated characteristic areas of boundary layer separation in the region of the adverse pressure gradients. The separation region involved both the main limb and the side arm. The separation forms a shell or ring of slow-moving fluid around the mainstream. Preliminary studies with pulsatile flow and with blood demonstrate that boundary layer separation occurs under clinical flow conditions. Boundary layer separation may play a role in the development of anastomotic hyperplasia and atherosclerotic deposits in the vicinity of surgical anastomoses.

Arteriosclerosis↗
PubMed1978

Doppler ankle systolic blood pressure. Prognostic value in vein bypass grafts of the lower extremity.

The prognostic value of Doppler-derived ankle systolic pressure indices for predicting the patency of vein bypass grafts in the lower extremity was analyzed in 126 vein bypass grafts performed for limb salvage. Early or late graft failure was not found to correlate with the preoperative ankle systolic pressure index (ASPI). Intraoperative blood flow measurements did not correlate with the preoperative ASPI. An intraoperative graft flow of less than 0.7 at 24 to 48 hours, or an increase in ASPI of less than 0.4 were prognostic signs of early vein graft failure.

Adult↗
PubMed1978

Transposed basilic vein-brachial arteriovenous fistula. A reliable secondary-access procedure.

Over a two-year period, 25 transposed basilic vein-brachial arteriovenous fistulas were created as secondary vascular access procedures in patients undergoing chronic hemodialysis. The operative technique is described in detail. One-year patency rate by life-table analysis was 85%. There were two minor complications. The procedure is advocated as a reliable secondary-access procedure when a radial-cephalic arteriovenous fistula cannot be constructed or has failed.

Arteriovenous Shunt, Surgical↗
PubMed1978

Management of the upper extremity with absent pulses after cardiac catheterization.

Thirty-one patients had a delayed loss of brachial artery and radial artery pulse after cardiac catheterization; eleven of the patients had early embolectomy or a vein patch graft and 82% of these had immediate restoration of pulse and remained asymptomatic. Early surgery failed in two patients, requiring late vein bypass grafting for claudication. Twenty patients did not have early surgery, eleven (55%) remaining asymptomatic and nine (45%) developing ischemic symptoms. Five of these nine patients (25%) required late vein bypass grafting for severe claudication. Of the fifteen patients who lost their pulse and did not undergo surgery, the average Doppler forearm pressure immediately following the occlusion was 50 mm Hg (pressure index=0.46). The average Doppler pressure measured at the time of follow-up was 80 mm Hg (pressure index = 0.61). Early local surgery is highly successful in patients who lose their radial artery pulse after cardiac catheterization. Conservative nonoperative therapy may be successful but often results in late ischemic symptoms that may require late vein bypass grafting.

Arm↗
PubMed1977

Improved results with femoropopliteal vein grafts for limb salvage.

Over a ten-year period from 1966 to 1975, 154 femoropopliteal vein grafts were performed for limb salvage in 139 patients, including 42 diabetics. The average patient age was 70 years. The one-month operative mortality was 2.9% (four patients). Average preoperative Doppler ankle pressure was 46 mm Hg, with an average ankle-arm systolic blood pressure index (ASPI) of 0.33. The average postoperative Doppler ankle pressure was 96 mm Hg, with an ASPI of 0.76. Five-year vein graft patency was 72%. Poor quality of vein was a statistically significant cause of graft failure (P less than .015). Small saphenous veins of good quality and arm veins gave satisfactory results. Diabetics had a lower, but not statistically significantly decreased, five-year patency. Because of this high success rate and low operative mortality, we recommend an attempt at limb salvage by femoropopliteal vein grafting in patients threatened with limb loss because of atherosclerotic occlusive disease of the femoropopliteal segment.

Aged↗
PubMed1977

Reversal of vertebral artery blood flow demonstrated by Doppler ultrasound.

Vertebral artery blood flow was studied by a Doppler ultrasound technique in two patients with the subclavian steal syndrome. The Doppler probe was positioned in the region of the Chassaignac tubercle. The direction of vertebral artery flow corresponded with the angiographic flow direction preoperatively. Postoperatively, the technique was used to confirm the patency of a carotid-subclavian graft, and also to study the hemodynamic effects of axillary-axillary grafting. Reversal of vertebral flow direction was easily demonstrated by this technique, which is simpler to perform than previously described methods.

Aged↗
PubMed1977

Assessment of myocardial performance and optimal volume loading during elective abdominal aortic aneurysm resection.

Myocardial depression has been suggested as a cause of declamping hypotension. To investigate and manage this problem, thermal dilution catheters were placed in 22 elderly, high-risk patients (mean age 71 years) who underwent elective abdominal aortic aneurysm resection. There were no deaths. Myocardial performance curves (MPC) were determined preoperatively, following induction of anesthesia, during aortic clamping, following declamping, and 12 to 48 hours postoperatively. The slope of this curve was taken as an index of myocardial performance. Preoperative cardiac index at a pulmonary artery wedge pressure of 10 mm Hg (CI10) decreased significantly following induction of anesthesia (P less than .002) and persisted during aortic cross-clamping. Following declamping, CI10 rose to preoperative levels. The slope of the MPC followed this same pattern. There was no significant change in blood pressure with the aorta clamped or following declamping. Myocardial performance is depressed following induction of anesthesia but declamping hypotension can be minimized or prevented by optimum volume loading as guided by Starling's myocardial performance curves.

Aged↗
PubMed1977

A comparison of the late patency rates of axillobilateral femoral and axillounilateral femoral grafts.

A total of 130 axillofemoral grafts were peformed in 120 patients from 1966 to present; 66 were axillobilateral femoral moral and 64 were axillounilateral femoral grafts. The average patient age was 66 years. The indications for operation were occlusive disease with rest pain or gangrene in 102 patients, severe claudication four, and bypass of a thoracic aneurysm in one. The one month operative mortality rate was 8 percent (ten patients). Four deaths occurred in elderly patients operated upon as emergencies with acute aortic occlusion. In the 126 elective cases, there were six postoperative deaths (4.7 percent). Twenty thrombectomies were performed in 15 axillobilateral femoral grafts of which 15 (75 percent) were successful. In the unilateral grafts there were 25 thrombectomies in 22 grafts, of which only eight (32 percent) were successful. The 5 year patency rate by the life-table method was 74 percent for axillobilateral femoral grafts and 37 percent for axillounilateral femoral grafts. This difference in patency rates is statistically significant (p < 0.01). Average flow measured by electromagnetic flow meter in six axillobilateral femoral grafts was 621 c.c. per minute and in 11 unilateral femoral grafts was 273 c.c. per minute. We attribute the higher patency rate in axillobilateral femoral grafts to this increased flow. These data indicate that axillobilateral femoral grafts may be performed with anticipation of a 5 year patency rate comparable to that with conventional aortoiliac reconstruction and that axillobilateral femoral grafts should be performed in preference to axillounilateral femoral grafts in poor-risk patients requiring extra-anatomic bypass for aortoiliac occlusive disease.

Aged↗
PubMed1976

Gunshot wounds of the suprarenal abdominal aorta.

A review of recent series of penetrating aortic injuries is presented. The highest mortality rates were found with injuries of the suprarenal abdominal aorta. Five patients with this injury, four of whom survived, are presented. Factors preventing rapid exsanguination in some patients are explained. Surgical management, including the controversy of arterial debridement, is discussed. The possibility of missing an aortic perforation at operation with five examples from the literature is pointed out.

Adolescent↗
PubMed1976

Quantitative ultrasonic blood flow measurement in Dacron grafts.

A quantitative directional Doppler system was used to determine blood flow in 8 mm. aortoaortic Dacron grafts in dogs. The Doppler was calibrated with frequency standards and the output was integrated for one minute intervals. With the probe held at an angle of 60 degrees to the flow axis, the average frequency of the Doppler shift was determined. Frequency was converted to velocity with the Doppler equation. Volume flow was calculated from the product of velocity and cross-sectional area of the graft. When compared with an electromagnetic flowmeter, the Doppler system was highly accurate with flow rates up to 900 c.c per minute. At flow rates above 900 c.c. per minute, there was a significant decrease in Doppler output which probably is due to the effects of turbulence and background noise on the Doppler signal.

Blood Flow Velocity↗