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Biomedical subjects

F J Veith

Publications and source records attributed to F J Veith.

At least 181 records · Page 10Linked to original sources
PubMed1992

A twelve-year experience with the popliteal-to-distal artery bypass: the significance and management of proximal disease.

The value of the popliteal-to-distal artery bypass in limb salvage is well documented. However, the influence of progression of disease in the superficial femoral artery or proximal popliteal artery, and the role of percutaneous transluminal angioplasty of these vessels before bypass have not been adequately assessed. To evaluate these and other factors, we reviewed our experience with 153 nonsequential popliteal-to-distal artery bypasses performed over a 12-year period. Limb salvage was the indication for all procedures, and 87% of the patients were diabetic. The 5-year primary and secondary graft patency rates were 55% and 60%, respectively, and the limb salvage rate was 73%. Preoperative arteriograms were evaluated for stenosis in the superficial femoral artery or popliteal artery proximal to the graft. Fifty-six grafts with a proximal stenosis 20% or less were identified and had primary graft patency of 77% at 2 years, similar to the 70% patency for the 20 grafts placed distal to a 21% to 35% stenosis. The 18 grafts placed distal to a stenosis greater than 35% had 53% 2-year primary graft patency (p = 0.25). Percutaneous transluminal angioplasty of a superficial femoral artery or popliteal artery stenosis (24% to 85% luminal narrowing) in 19 limbs resulted in 68% 2-year graft patency, not significantly lower than grafts with 35% or less proximal stenosis (75%, p = 0.25). Other factors associated with significant decreases in graft patency included a vein graft diameter less than 3.0 mm, a dorsalis pedis outflow site, and poor quality outflow. Thus the popliteal-to-distal bypass is a durable procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Early experience with the smart laser in the treatment of atherosclerotic occlusions.

A dual-laser system (helium-cadmium and pulsed dye) capable of continuous computer analysis of spectroscopic characteristics of tissue fluorescence, which can distinguish atherosclerotic plaque from components of normal arterial wall, was used to deliver laser energy to ablate plaque. During a 1-year period this system was used to facilitate balloon angioplasty of short (3 to 17 cm) total occlusions of the superficial femoral or popliteal arteries only when standard angioplasty techniques were ineffective. During the year of the study, in one institution 415 patients were subjected to arteriography of the lower extremities for leg ischemia (397 for limb salvage indications). Standard angioplasty techniques were used in 94 of these patients; 218 patients were unsuitable for standard angioplasty, did not fulfill criteria for "smart" laser treatment, and underwent standard bypass operations. Only 11 patients (plus six others in the second institution) requiring treatment fulfilled the criteria for use of the "smart" laser. In 10 patients the occluding lesion was traversed by the laser wire (diameter 0.021 inch), and luminal patency was effectively restored by balloon angioplasty to greater than or equal to 70% of the most normal-appearing segment of that artery. Satisfactory luminal patency has persisted for 2 to 12 months (mean 6 months) in nine patients; the lesion in the tenth patient restenosed at 3 months. The laser procedure was unsuccessful in all three patients with occlusions greater than 10 cm and in four others. Although there were three microperforations with the laser wire, there were no clinically significant complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Unilateral aortofemoral bypass: a safe and effective option for the treatment of unilateral limb-threatening ischemia.

To determine whether unilateral aortofemoral (AUF) bypass is a safe and effective option for the treatment of unilateral limb-threatening ischemia in patients with aortic or bilateral iliac occlusive disease, we reviewed the results of 42 AUF bypasses performed using polytetrafluoroethylene grafts in patients operated on for limb salvage; 11 (26%) of the patients also underwent femoropopliteal or femorodistal (FP/D) bypasses. The indications for surgery were tissue necrosis or ulceration in 18 (43%) patients and rest pain in 17 (40%) patients. The 5-year primary graft patency and limb salvage rates for AUF bypass were 74% and 84%, respectively. The perioperative mortality rate was 5%. There were no significant differences in the primary graft patency or limb salvage rates in patients who underwent AUF bypass with or without FP/D bypass. Only 3 of 41 (7%) AUF bypass patients required subsequent femorofemoral bypass. We conclude that: (1) AUF bypass is a safe and effective surgical option in patients with unilateral limb-threatening ischemia and aortic or bilateral iliac occlusive disease; (2) the routine performance of an aortobifemoral or axillobifemoral bypass in patients with unilateral limb-threatening ischemia may be unnecessary; and (3) AUF bypass facilitates the combined inflow and infrainguinal operations that are frequently required for limb salvage in these patients.

Adult↗
PubMed1991

Value and limitations of secondary femoropopliteal bypasses with polytetrafluoroethylene.

Secondary femoropopliteal bypasses with polytetrafluoroethylene (PTFE) grafts are widely regarded to be of questionable value. This has prompted some to abandon all attempts at secondary revascularization with PTFE and others to recommend that primary femoropopliteal bypasses be performed preferentially with PTFE grafts so that vein may be used for secondary procedures. Because we questioned both of these views, we reviewed all femoropopliteal bypasses done at our institution in the past 12 years and identified 73 secondary PTFE femoropopliteal procedures performed after a failed ipsilateral infrainguinal bypass (69 failed femoropopliteal; 4 failed femorodistal). Seventy (96%) secondary bypasses were performed for limb salvage and 3 (4%) for severe disabling claudication. Insertion of grafts to the popliteal artery was above the knee in 26 (36%) and below the knee in 47 (64%). Primary life-table graft patency at 4 years was only 38%. Forty-eight reinterventions in 34 limbs were required to restore or maintain graft patency in thrombosed or failing grafts. For thrombosed grafts, 20 interventions consisted of 9 simple thrombectomies and 11 thrombectomies with additional revision procedures (5 distal or proximal extensions, 6 patch angioplasties). Twenty-eight lesions threatening graft patency were treated by percutaneous transluminal angioplasty in 3, proximal or distal extensions in 20, and patch angioplasty in 5. As a result of these reinterventions, the overall secondary patency rate was 55% at 4 years, and the limb salvage rate was 74% at 4 years. Although aggressive follow-up and reintervention may be required, the use of secondary PTFE conduits in the femoropopliteal position is a viable option in patients undergoing limb salvage procedures who are at high risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Epidural versus general anesthesia for infrainguinal arterial reconstruction.

A prospective evaluation of 213 consecutive infrainguinal bypass procedures was performed to determine the effect of anesthesia technique on the postoperative complication rate. Limb salvage was the indication for surgery in 92% of cases. No significant differences were observed in age, sex, indication for surgery, presence of cardiovascular and pulmonary risk factors, American Society of Anesthesiologists classification, or Goldman scores between patients receiving epidural anesthesia and those receiving general endotracheal anesthesia. Epidural anesthesia was used for 96 procedures and general endotracheal anesthesia was used in 117 cases. Cardiac complications for the epidural anesthesia and general endotracheal anesthesia groups, respectively, included a mortality rate of 5% versus 3%, nonfatal infarctions in 6% versus 7%, and reversible cardiac events in 14% versus 16%. A high-risk subgroup of 69 patients (American Surgical Association classes IV and V or Goldman score greater than 10 points) also had no significant difference in outcome between epidural anesthesia and general endotracheal anesthesia. Major noncardiac complications occurred in an additional 8% of each group. Regional and general anesthesia therefore produce equivalent cardiovascular risk for infrainguinal arterial reconstruction. These results suggest that indicated operations should not be postponed or avoided for patients either requiring or requesting general anesthesia. Furthermore, other investigations of cardiac risk in vascular surgery do not require a uniform anesthetic technique for valid interpretation of results.

Aged↗
PubMed1991

A ten-year experience with one hundred fifty failing or threatened vein and polytetrafluoroethylene arterial bypass grafts.

Between Jan. 1, 1980, and Dec. 31, 1989, 2187 infrainguinal revascularization procedures were performed. In 130 of these cases with patent bypasses, hemodynamic deterioration was suspected, and urgent arteriography was performed. Twenty additional patients with aortofemoral, femorofemoral, or axillofemoral bypasses demonstrated hemodynamic deterioration. In 93% of failing grafts the condition was suspected because of recurrent symptoms or changes in the pulse examination. Two hundred eighty-five high-grade stenotic or occlusive lesions were identified in inflow arteries, outflow arteries, within the graft, or at proximal or distal anastomoses associated with these 150 grafts. One hundred sixty-one (57%) of these lesions were in patients with failing vein grafts; 115 (40%) were in patients with failing polytetrafluoroethylene (PTFE) grafts; and 9 (3%) were associated with failing composite vein/PTFE grafts. Stenotic lesions less than 5 cm in length were initially treated with percutaneous transluminal balloon angioplasty (PTA). Occlusive lesions, stenoses greater than 5 cm in length, and PTA failures were treated surgically. The overall 6-year cumulative secondary patency rate for failing grafts was 65%, and the limb salvage rate was 75%. The extended patency rate after the first intervention in the failing state was 56% at 5 years. The 5-year secondary patency rate for grafts initially treated with PTA (58%) was not significantly different (p = 0.25) from that for grafts treated initially with surgery (71%). Percutaneous transluminal angioplasty was effective for inflow stenoses of the iliac, femoral, and popliteal arteries and for some outflow lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1991

Translumbar arch aortography: a retrospective controlled study of usefulness, technique, and safety.

Subclavian and axillary artery stenoses may lead to axillofemoral bypass graft failure. These arteries were assessed preoperatively with arch aortography performed after conventional high translumbar peripheral aortography by exchanging the initial 16-gauge sheath for a 5-F pigtail catheter. Thirty-two diagnostic translumbar runoff and arch (TLR-arch) aortograms were obtained in 30 patients with advanced lower extremity ischemia. In six patients (20%), the results of the arch study influenced the choice of an inflow site. These patients were compared with 70 control subjects who underwent conventional translumbar aortography without arch studies. In the TLR-arch group, two major complications occurred in one patient, while in the control group 11 major complications occurred in 10 patients. One retroperitoneal hematoma occurred in the TLR-arch group; two occurred in the control group. The mean change in hematocrit for the TLR-arch group was -3.81% (-0.0381), and for the control group it was -4.17% (-0.0417). This difference was not statistically significant. Arch aortography is a valuable adjunct to the translumbar aortofemoral study. It can be simply performed without increasing the morbidity of the peripheral study.

Aged↗
PubMed1991

[The influence of left atrial cuff rejection on pulmonary hemodynamics after canine lung allotransplantation].

Several factors influence pulmonary hemodynamics after lung transplantation: reimplantation response, lung rejection reaction and imperfect anastomosis technique. In this experiment, five cases presented marked elevation of mean pulmonary artery pressure at the time or right pulmonary artery occlusion test performed two weeks postoperatively. Left atrial cuff rejection reaction arose in one case in which edema and stenosis of the pulmonary vein outflow tract were evidenced. This finding demonstrated that the changes in pulmonary hemodynamics after transplant suggest the possibility of inducement by left atrial cuff rejection reaction.

Animals↗
PubMed1991

Impact of nonoperative therapy on the clinical management of peripheral arterial disease.

Nonoperative therapy includes conservative noninterventional modalities and the endovascular interventional modalities of percutaneous transluminal angioplasty and a variety of laser systems and atherectomy devices. The role and impact of all nonoperative treatments are considered in the perspectives of the natural history of lower-extremity arteriosclerosis and its present surgical (operative) treatment. Nonoperative treatments may replace and/or facilitate surgical treatment in operative candidates. Nonoperative methods may also justify treatment in patients who cannot or should not be subjected to surgery. Facts and opinions relating to these uses of nonoperative treatments are presented, and the qualifications and credentialing of individuals who should be treating patients with lower-extremity ischemia resulting from peripheral arteriosclerosis are discussed.

Angioplasty, Balloon↗
PubMed1991

Late results of two hundred seventeen femoropopliteal bypasses to isolated popliteal artery segments.

A 10-year-experience of 217 femoropopliteal bypasses to isolated popliteal artery segments in 207 patients is reported. Thirty-three femoropopliteal bypasses (15%) were performed with reversed saphenous vein and 184 (85%) with polytetrafluoroethylene grafts. Operative indications were gangrene in 121 (56%), nonhealing ulceration in 40 (18%), ischemic rest pain in 51 (24%), and claudication in 5 (2%) cases. The 5-year primary graft patency rate of these bypasses was 59% (reversed saphenous vein, 74%; polytetrafluoroethylene, 55%; p less than 0.05), the secondary 5-year graft patency rate was 61% (reversed saphenous vein, 79%; polytetrafluoroethylene, 56%; p less than 0.05), and the 5-year limb salvage rate was 78% (reversed saphenous vein, 78%; polytetrafluoroethylene, 78%). The 30-day operative mortality rate was 10%, and the 5-year patient survival rate was 38%. Eleven patients (5%) required lower extremity amputation because of progressive gangrene or extensive infection despite a patent bypass to an isolated popliteal artery segment. We conclude that femoropopliteal bypasses to isolated popliteal artery segments (1) have acceptable 5-year graft patency and limb salvage rates; (2) should be performed with reversed saphenous vein grafts when possible; (3) may be performed with polytetrafluoroethylene grafts if necessary, with a resulting limb salvage rate equal to that of reversed saphenous vein grafts; and (4) require sequential extension to an infrapopliteal artery in up to 20% of patients. In addition, the presence of an isolated popliteal artery segment is associated with a high operative mortality rate and limited life expectancy because of coronary artery disease.

Adult↗
PubMed1991

Diagnosis and management of infected prosthetic aortic grafts.

Infection of an aortic prosthetic graft represents one of the most difficult diagnostic and therapeutic challenges to the vascular surgeon. The presentation of this complication, the degree of ischemia of the lower extremities, and the overall medical status of the patient determine the urgency and optimal treatment to maximize limb salvage and survival. Although partial or total graft preservation can be a treatment option if the infection is localized to the distal limb of an aortofemoral graft and all anastomoses are intact, treatment of an infected aortic prosthetic graft often requires total graft excision, preferably preceded by revascularization of the lower extremities through lateral uninfected routes. Careful selection of the many time-honored and newly developed diagnostic and treatment modalities is necessary to lower morbidity and mortality rates in patients with this complication.

Aorta↗
PubMed1991

Prospective, randomized comparison of ringed and nonringed polytetrafluoroethylene femoropopliteal bypass grafts: a preliminary report.

Kinking and compression with knee flexion are thought to be one cause of failure of below-knee polytetrafluoroethylene femoropopliteal bypass. To prevent this problem polytetrafluoroethylene grafts externally supported with rigid rings have been developed. The present randomized, prospective study compared ringed and nonringed polytetrafluoroethylene grafts in 122 patients who underwent femoropopliteal bypass for severe limb ischemia. Patients were well matched for surgical indications and risk factors. There was no significant difference in the 3-year graft patency rate of ringed versus nonringed polytetrafluoroethylene femoropopliteal bypasses (74% vs 68%, p = 0.5). Similarly, no significant differences were found in the 3-year graft patency rates of ringed versus non-ringed above-knee (82% vs 74%, p = 0.5) or below-knee polytetrafluoroethylene femoropopliteal bypasses (68% vs 59%, p = 0.5). The 3-year graft patency rate of all above-knee polytetrafluoroethylene femoropopliteal bypasses was slightly greater than that of below-knee polytetrafluoroethylene femoropopliteal bypasses (76% vs 62%), but this difference was not statistically significant (p = 0.25). The 3-year limb salvage rate with ringed polytetrafluoroethylene grafts was 92% compared with 79% for nonringed polytetrafluoroethylene grafts, but this difference was not statistically significant (p = 0.25). Data to date from this study fail to support the recommendation that ringed polytetrafluoroethylene grafts be used preferentially over conventional polytetrafluoroethylene grafts in patients who require femoropopliteal bypass with a synthetic graft.

Adult↗
PubMed1991

Prospective randomized multicenter comparison of in situ and reversed vein infrapopliteal bypasses.

We have performed a prospective, randomized, multicenter study to compare in situ and reversed vein grafts for long limb salvage bypasses from the proximal thigh to an infrapopliteal artery. Three hundred eighty-four patients required an infrapopliteal bypass for critical lower extremity ischemia. Of these, 259 were excluded because a short vein bypass was performed or because the vein was considered inadequate. The remaining 125 patients had a randomized vein bypass, 63 reversed, 62 in situ. The two groups were similar with regard to risk factors, indications, graft dimensions, and outflow. Secondary patency at 30 months was similar for both techniques: reversed 67% +/- 9% (+/- SE); in situ 69% +/- 8%. For veins less than or equal to 3.0 mm in minimum distended diameter 24-month patency rates were 61% +/- 22% for 12 in situ veins and 37% +/- 29% for 10 reversed veins (p greater than 0.05). Angiographic evaluation of failing grafts revealed lesions similar in type and frequency in both types of grafts. These included focal (in situ, n = 4; reversed, n = 7) and diffuse vein hyperplasia (in situ, n = 2; reversed, n = 1), and inflow and outflow stenoses (in situ, n = 4; reversed, n = 3). The incidence of wound complications and the mortality rate were similar for the two groups. These data show no significant difference in overall patency rates for the two types of vein grafts at 2 1/2 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

The need for quality assurance in vascular surgery.

The need for quality assurance in vascular surgery can be deduced from the variability in unruptured abdominal aneurysm operative death rates in a group of patients large enough that factors influencing mortality rates other than quality of care can be controlled. Operative mortality rate for 3570 patients undergoing unruptured abdominal aortic aneurysm repair was determined for all non-Veterans Administration surgeons and hospitals in New York State from 1985 to 1987. The average annual number of aneurysm operations per surgeon was 3.6, and per hospital it was 10.2. Unruptured aneurysm repair mortality for surgeons performing 1 to 5 aneurysm operations per year was 10% whereas for surgeons performing more than 26 aneurysm operations per year it was 6% (p less than 0.0001). Unruptured aneurysm repair mortality for hospitals performing 1 to 5 aneurysm operations per year was 14% and for hospitals performing more than 38 aneurysm operations per year it was 5% (p less than 0.0001). Even when these mortality rates were adjusted for differences in patient age, severity of illness, secondary diagnoses and admission status, significant mortality rate differences persisted: 9% versus 4% for low and high volume surgeons, respectively (p less than 0.001), and 12% versus 5% for low and high volume hospitals, respectively (p less than 0.001). Surgeons who performed more than 7 aneurysm operations per year devoted more of their practice to aortic (11%) and vascular operations (52%) than did surgeons who performed 7 or fewer aneurysm operations per year (2% and 19%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta, Abdominal↗
PubMed1991

A new provocative test for chronic mesenteric ischemia.

A new provocative test for chronic mesenteric ischemia is described, based upon the demonstration of a fall in the intramural pH of the small bowel after introduction of a test meal into the stomach. Intramural pH (pHI) is determined indirectly by tonometry, utilizing a tonometer passed per os. Postoperative assessment of revascularization procedures is also possible by the same technique. Application of the test in an 84-yr-old woman showed good correlation between a preoperative fall in jejunal intramural pH and abdominal pain, and the absence of a fall postoperatively after successful revascularization.

Aged↗
PubMed1990

Improved strategies for secondary operations on infrainguinal arteries.

Secondary interventions play an important role in achieving the ultimate goal of limb salvage after primary infrainguinal interventions fail. By employing the described strategies and principles for secondary arterial reconstructions below the inguinal ligament, good results in terms of patency of the reoperated primary reconstruction or the secondary reconstruction can be obtained with significantly augmented limb salvage at a low cost in operative morbidity and mortality. These results mandate that vascular surgeons maintain an aggressive attitude toward the use of these secondary operations when a primary procedure fails to achieve or maintain its intended goal and a patient is faced with imminent limb loss because of distal ischemia.

Blood Vessel Prosthesis↗
PubMed1990

Use of a piezoelectric film sensor for monitoring vascular grafts.

Detection of failing arterial reconstructions requires intensive surveillance by frequent physical examination and noninvasive laboratory testing. However, many grafts fail during the intervals between these examinations. For this reason, we have developed an implantable miniaturized piezoelectric flow detection device whose function can be monitored externally by radiotransmission across the skin. Sensors were constructed from ultrathin polyvinylidene fluoride (PVF2) with piezoelectric activity and attached with silicone fixative to 6-mm polytetrafluoroethylene grafts. Ten of these grafts were placed in mongrel dogs as iliofemoral bypasses. Real time data were acquired from the sensors at a rate of 200 Hz, using a DATAQ A/D data acquisition board and CODAS data acquisition software, while simultaneous blood flow (using an electromagnetic flowmeter) and intraluminal pressure were processed by using separate channels of the same data acquisition board. The data were stored on computer storage media and analyzed by the ASYST software, which allows simultaneous signal curves to be compared using regression analysis. In the resting state, the mean blood flow was 123 +/- 16 mL and the mean intraluminal pressure was 124/78 mm Hg, and there was perfect correlation between the PVF2 sensor and the flowmeter and between the sensor and the intraluminal pressure (correlation coefficient, r greater than or equal to 0.99 and r greater than or equal to 0.93, respectively). A tourniquet was applied to the iliac artery proximal to the graft to reduce the flow to approximately half of the resting state (mean flow after tourniquet: 66 +/- 6 mL/minute). Signal tracings from the three sources showed a remarkable similarity with a very high correlation coefficient (r greater than or equal to 0.99 between sensor and flowmeter and r greater than or equal to 0.92 between sensor and the pressure signal). These preliminary results show that the sensors made from low-profile and low-mass PVF2 material have the potential of being implanted around grafts for long-term, continuous monitoring of graft function. Further studies involving long-term implantation to assess the effect of tissue ingrowth and loss of compliance are necessary before this device can be used clinically.

Animals↗