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Biomedical subjects

W H Pearce

Publications and source records attributed to W H Pearce.

At least 91 records · Page 5Linked to original sources
PubMed1993

Upper extremity bypass grafting. A 15-year experience.

OBJECTIVE: To analyze the perioperative morbidity and mortality, long-term patient survival, and patency characteristics of arterial bypass related to upper extremity ischemia. DESIGN: This is a retrospective review of sequential patients undergoing upper extremity arterial bypass during a 15-year period at a single tertiary-care teaching hospital. Data are expressed in a 5-year life-table format and interpreted using log-rank analysis. PATIENTS: Seventy-four patients with upper extremity ischemia undergoing arterial bypass, which included 95 separate operations. MAIN OUTCOME MEASURES: Operative morbidity and mortality, life-table survival, life-table bypass graft patency, and limb salvage are reported. RESULTS: There was no operative mortality, and there was a single major amputation. Survival rate was 86% at 5 years, and overall patency rate was 61.2% at 5 years, with autogenous conduits superior at all sites compared with prosthesis (70.9% vs 37.7%). Secondary operation was inferior to primary bypass (66% vs 48%) and associated with higher morbidity (22% vs 5%). All far distal forearm prosthetic bypass grafts failed within 1 year. CONCLUSIONS: Primary upper extremity bypass with venous conduit is a safe, durable procedure, after which prolonged patient survival can be expected.

Adolescent↗
PubMed1993

Limb-threatening ischemia complicated by perigenicular infection.

When graft infection or infection of the medial leg or popliteal fossa precludes a standard approach to revascularization of the ischemic leg, the literature suggests amputation may be the most prudent course because of excessive perioperative mortality and morbidity of attempts to reestablish axial flow. The purpose of this study is to define the outcome of revascularization when limb-threatening ischemia is complicated by perigenicular infection. Of 1020 infrainguinal reconstructions performed since 1984, nine (0.9%) presented with limb-threatening ischemia and graft or wound infections involving the popliteal fossa (6) or medial thigh or calf wounds (3) which precluded standard revascularization in the five women and four men. Risk factors for infection included diabetes mellitus (5/9), wound hematoma at initial operation (2/9), and intravenous drug abuse (1/9); Staphylococcus aureus was the predominant organism in all infected wounds and two popliteal fossa infections. The other deep infections grew group D streptococci, Enterococcus, and Salmonella. Extra-anatomic reconstruction was performed from the femoral (7) and iliac vessels (2) extending to the below-knee popliteal (2), the anterior tibial (4) and the peroneal (3) arteries using vein (5), and PTFE (4) in a lateral tunnel which avoiding the plane of the infection. Postoperative complications included MI (1), early graft thrombosis (2), and osteomyelitis of the femur (1); there were no deaths. With a mean follow-up of 19 months (3-57 months), primary graft patency was 66% and secondary patency was 78%, resulting in salvage of 66% of extremities at risk. These data demonstrate the safety and efficacy of extra-anatomic reconstruction for maintaining axial flow when limb-threatening ischemia is complicated by perigenicular infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Carotid endarterectomy with an occluded contralateral carotid artery.

Five hundred twenty-six patients who underwent carotid endarterectomy were separated by reviewing those 81 (15%) patients with an occluded contralateral carotid artery and those 445 (85%) with nonocclusion. The population characteristics and surgical indications were similar between the occluded and nonoccluded groups. Ipsilateral plus contralateral perioperative stroke occurred during 11 of 445 operations (2.5%) in which the contralateral carotid was patent, and during which no patient was hemorrhagic. Those patients with contralateral artery occlusion had ipsilateral plus contralateral stroke in 4 of 81 cases of (4.9%) (NS). Intracerebral hemorrhage was responsible for two of four strokes after carotid endarterectomy with contralateral occlusion (p = 0.001). Restenosis to greater than 50% by duplex scanning was more rapid in the occluded group with primary closure (no patch) (p = 0.025) and for men (p = 0.025). Although perioperative safety is comparable, patients with contralateral carotid occlusion may have a greater risk of intracranial hemorrhage and a more rapid rate of restenosis in some subgroups.

Aged↗
PubMed1993

Increased ICAM-1 expression in aortic disease.

PURPOSE: In this investigation we evaluated the expression of vascular adhesion molecules: intercellular adhesion molecule-1 (ICAM-1), E-selectin, and vascular cell adhesion molecule-1 (VCAM-1) in normal and diseased aorta. METHODS: Aortic tissue was obtained during operations for abdominal aortic aneurysms (AAA) (inflammatory, n = 3, noninflammatory, n = 6), aortic occlusive disease (AOD) (n = 6), or from fresh cadavers (NL) (n = 5). The tissue was stained with the avidin-biotin complex with the following primary antibodies: anti-ICAM-1-AA6, anti-E-selectin-BB11, and anti-VCAM-1-4B9. The slides were assigned an inflammatory score of 0 to 3, and the percentage of each cell type staining, 0% to 100%. RESULTS: A trend towards a higher inflammatory score was found in the vessel wall in AAA (2.4 +/- 1.8) as compared with AOD (1 +/- 0.37) or NL (0.2 +/- 0.2). There was no statistical difference. A significant elevation in ICAM-1 expression (p < or = 0.06), however, was demonstrated in the adventitial endothelial cells of AAA (85.8% +/- 7.8%), and AOD (80.0% +/- 11.1%), as compared with NL (30.8% +/- 12.2%). Both E-selectin and VCAM-1 were expressed in all groups, but no statistical difference was demonstrated. CONCLUSIONS: Patients with AAA and AOD display a significant upregulation of the expression of ICAM-1, suggesting a role for this protein in the initiation or maintenance of degenerative aortic diseases.

Aged↗
PubMed1993

Aortic diameter as a function of age, gender, and body surface area.

BACKGROUND: An aortic aneurysm is defined as a 50% or greater increase in diameter compared with normal levels or the level of the left renal vein. However, normal diameters for many aortic segments are not known, and the aortic segment at the left renal vein may be enlarged. The purpose of this study was to determine normal diameters of the thoracic and abdominal aortas in relationship to age, gender, and body size. METHODS: Aortic diameters (ADs) were determined at four anatomic levels: thoracic aorta, abdominal aorta at the celiac axis, renal arteries, and midway between the renal arteries and the bifurcation. ADs were determined with the use of a video analyzer and an electronic caliper. Computed tomographic scans (n = 389) obtained for nonvascular diagnoses were analyzed according to gender, age, height, weight, and body surface area (BSA). RESULTS: At all levels and in each decade the AD is significantly greater in men than in women (p < 0.0001). BSA is a better predictor of size than height or weight. AD increased with age at all levels, and there was a positive correlation between the AD and BSA and gender. Expected ADs for each aortic segment may be calculated according to regression equations. Age-, gender-, and BSA-matched patients with abdominal aortic aneurysms revealed significant enlargements in all proximal aortic segments. CONCLUSIONS: AD at a given level is a function of gender, age, and BSA. When these variables are known, it is possible to calculate an expected AD. The AD is greater at all levels in patients with abdominal aortic aneurysms and in men compared with women.

Adolescent↗
PubMed1993

Prognosis after graft replacement operation for abdominal aortic aneurysm.

We analyze findings on the long-term survival of patients undergoing elective graft replacement operations for abdominal aortic aneurysm. We review the principal surgical case series published in peer-reviewed, English-language journals over the past 15 years. Preoperative mortality was 4.0%, and 5-year survival was 69% in 16 reviewed studies encompassing 4,288 patients. Articles on late survival have largely focused on the preoperative assessment of coronary artery disease in patients who are candidates for aortic resection. The influence of other recognized risk factors, such as advanced age, hypertension, cerebrovascular disease, congestive heart failure, diabetes mellitus, and multiple aneurysms, is often not well specified in these studies. As a greater number of older patients with abdominal aortic aneurysm are seen with serious associated disease, knowledge about the expected survival of patients with surgically treated aneurysms is becoming more important to both primary care physicians and vascular surgeons when eliciting patient preferences for surgical treatment.

Age Factors↗
PubMed1993

Popliteal venous aneurysms.

Popliteal venous aneurysms are rarely reported but represent a potentially life-threatening condition requiring accurate diagnosis and surgical resection. Newer techniques including magnetic resonance imaging, computed tomography, and color flow duplex imaging offer new noninvasive methods to define popliteal fossa venous abnormalities. Excision of the aneurysm with venous reconstruction removes the embolic source and maintains prograde venous flow. A posterior surgical approach to the popliteal fossa is recommended to facilitate exposure. Early control of venous outflow is needed to avoid thromboembolism. This report describes the diagnosis and treatment of popliteal venous aneurysms in three patients with a review of the English-language literature.

Adolescent↗
PubMed1993

Management of sudden profuse bleeding from varicose veins.

Varicose vein bleeding of the lower extremities is an unusual but pressing indication for treatment and can be lethal. This series reviews operative and injection treatment of such veins in patients with bleeding. During a 49-month period 14 patients (eight men and six women) with a mean age of 62.1 years (range, 23 to 93 years) were seen after venous bleeding related to varicosities of the lower extremity. They described between one and five episodes of bleeding (mean, 2.4), but only one patient required transfusion. The site of bleeding was the lower calf or foot in 11 and affected the thigh in three patients. One was in the third trimester of pregnancy. Nine patients had lesions involving clustered small 1 mm or less diameter varicose veins, whereas five had large diffuse varicose vein formation. None had evidence of coagulopathy, and the inciting episode was either unknown or related to minor trauma. Treatment of eight patients with small-diameter veins was instituted with 0.2% sodium tetradecyl injection with a 30-gauge needle, thrombosing veins within 5 cm of the bleeding focus. A total of 13 ml solution (1.0 to 27 ml) per patient was used during two or three treatment periods (mean, 2.5 treatment periods) spaced 2 weeks apart. Six patients were treated by means of standard vein-stripping techniques or local branch removal at the bleeding site. Effective thrombosis was achieved in all eight patients with small (less than 1 mm) varicose veins treated with sclerosis. In five patients who underwent surgery there was effective resolution of the hemorrhage. One patient with small-diameter varicose veins clustered about the ankle underwent operative treatment and had venous stasis ulceration requiring compression dressings for healing. In all 14 cases control of bleeding was obtained, with follow-up to 49 months (mean, 21.3 months); one had rebleeding from a site 32 cm remote from the original injected area 11 months after treatment. Bleeding from small-diameter varicose veins of the lower extremity can be controlled effectively by sclerosing techniques with sodium tetradecyl. Larger veins are managed with operative removal. Combining these techniques provides efficient management of often-elderly patients, many in an outpatient setting.

Adult↗
PubMed1993

Descending thoracic aorta-to-femoral artery bypass: ten years' experience with a durable procedure.

PURPOSE: Arterial bypass from the descending thoracic aorta to the femoral system provides successful perfusion when an approach to the abdominal aorta is undesirable. This review of a large series with a decade of experience was conducted to better define patency data and the natural history of patients after this operation. METHODS: During a 10-year period, 21 patients, 18 men and 3 women (mean age 57 years), underwent descending thoracic aorta to left femoral artery bypass with femorofemoral bypass. These were placed to convert axillopopliteal or axillofemoral grafts (12 patients) to a more permanent inflow source. The axillary bypasses had been previously placed to allow removal of infected aortic grafts and had undergone a total of 14 revisions or thrombectomies before conversion. In addition, patients had this procedure after multiple failed attempts (at least two) at intraabdominal aortic repair (five patients) or to avoid exploration of the abdomen after extensive retroperitoneal dissection or radiation (four patients). Surgical technique involved a seventh interspace thoracotomy with a transdiaphragmatic retroperitoneal anterior axillary line tunnel to the left groin. RESULTS: There was no perioperative mortality. The mean hospital visit was 15.1 days and intensive care stay 4.3 days. There was no perioperative myocardial infarction, stroke, or renal failure that necessitated dialysis. With a follow-up period of 1 to 121 months (mean 44), the 4-year patency rate was 100%. A single graft failed at 49 months but was renewed by thrombectomy and femorofemoral bypass. Thus the extended patency rate was 86%, but the secondary patency rate remained 100% throughout. Since the thoracic operations, patients have required five femoropopliteal, three femorotibial, two profunda, and two femorofemoral operations. CONCLUSIONS: Descending thoracic aorta-to-femoral artery grafting is a safe, extremely durable arterial bypass configuration. It is an excellent reconstruction for survivors of aortic graft infection, those who have had multiple failures of aortic grafts, and patients for whom abdominal exploration would be hazardous.

Aged↗
PubMed1993

Enhanced production of the chemotactic cytokines interleukin-8 and monocyte chemoattractant protein-1 in human abdominal aortic aneurysms.

Inflammatory leukocytes play a central role in the pathogenesis of human atherosclerotic disease, from early atherogenesis to the late stages of atherosclerosis, such as aneurysm formation. We have shown previously that human abdominal aortic aneurysms are characterized by the presence of numerous chronic inflammatory cells throughout the vessel wall (Am J Pathol 1990, 137: 1199-1213). The signals that attract lymphocytes and monocytes into the aortic wall in aneurysmal disease remain to be precisely defined. We have studied the production of the chemotactic cytokines interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) by aortic tissues obtained from 47 subjects. We compared the antigenic production of these cytokines by explants of: 1) human abdominal aneurysmal tissue, 2) occlusive (atherosclerotic) aortas, and 3) normal aortas. IL-8, which is chemotactic for neutrophils, lymphocytes, and endothelial cells was liberated in greater quantities by abdominal aortic aneurysms than by occlusive or normal aortas. Using immunohistochemistry, macrophages, and to a lesser degree endothelial cells, were found to be positive for the expression of antigenic IL-8. Similarly, MCP-1, a potent chemotactic cytokine for monocytes/macrophages, was released by explants from abdominal aortic aneurysms in greater quantities than by explants from occlusive or normal aortas. Using immunohistochemistry, the predominant MCP-1 antigen-positive cells were macrophages and to a lesser extent smooth muscle cells. Our results indicate that human abdominal aortic aneurysms produce IL-8 and MCP-1, both of which may serve to recruit additional inflammatory cells into the abdominal aortic wall, hence perpetuating the inflammatory reaction that may result in the pathology of vessel wall destruction and aortic aneurysm formation.

Aortic Aneurysm, Abdominal↗
PubMed1992

Antiphospholipid antibodies and arterial thrombosis. Case reports and a review of the literature.

Antiphospholipid antibodies are a relatively heterogeneous mix of immunoglobulins with binding specificities for negatively charged or neutral phospholipids. Currently, the most commonly detected antiphospholipid antibodies include the anticardiolipin antibody, the lupus anticoagulant, and an antibody implicated in false-positive VDRL testing. Recently, a clinical syndrome of vaso-occlusive disorders associated with antiphospholipid antibodies has been identified and may result from immune-mediated disruption of endothelial function. This clinical syndrome encompasses arterial and venous thrombosis, recurrent fetal loss, neurologic dysfunction (eg, migraine, chorea, and encephalopathy), systemic and pulmonary arterial hypertension, and endocardial disease. Although most commonly associated with systemic lupus erythematosus, the antiphospholipid antibody syndrome also has been identified in patients with vaso-occlusive disease without systemic lupus erythematosus. Recently, identification of antiphospholipid antibodies has been facilitated by the development of a more sensitive assay for anticardiolipin antibody. In this article, case histories of three patients with arterial thrombosis and associated anticardiolipin antibodies, including the first associated case of terminal aortic thrombosis, are reviewed and the subject of the antiphospholipid antibody syndrome is discussed.

Adult↗
PubMed1992

Axillary-popliteal artery bypass provides successful limb salvage after removal of infected aortofemoral grafts.

Axillary-popliteal artery bypasses were placed to revascularize 28 extremities for 17 patients who were undergoing removal of infected aortofemoral grafts. Polytetrafluoroethylene (PTFE [polytef]) material was anastomosed to the above-knee popliteal artery in 22 cases and to the below-knee popliteal artery in six limbs. All but one patient had axillary-popliteal grafts in place before excision of the aortic graft. In 12 groins, vein-patch angioplasty was performed after removal of the infected aortic graft to provide retrograde pelvic perfusion and maintain femoral patency for future reconstruction. Three patients (18%) died of septic-related, multisystem organ failure. With a mean follow-up of 25 months, primary patency was 75% at 1 year and 43% at 2 years. Secondary patency, maintained by thrombectomy (n = 7), revision (n = 3), and conversion to warfarin sodium (Coumadin) therapy (n = 6) was 100% at 2 years, and limb salvage was achieved for all surviving patients.

Anastomosis, Surgical↗
PubMed1992

Long-term evaluation of composite sequential bypass for limb-threatening ischemia.

When sufficient vein for a completely autogenous femorotibial artery bypass is not available, composite sequential grafting by using vein combined with polytetrafluoroethylene material is a surgical option. This study reviews what is currently the largest collection of these grafts and focuses on technical aspects and long-term patency characteristics. During a 7-year period 67 composite sequential bypasses were used to manage rest pain (38), ulcer (18), or gangrene (11) in 62 patients (mean age, 66 years). Fifty-two percent were men, and 51% had diabetes. This method was used as a primary reconstruction in 30, a second bypass in 16, and in 21 it was used after multiple other failed bypasses. Femoral to above-knee popliteal (44) and below-knee popliteal (23) 6 mm polytetrafluoroethylene grafts were placed. Then extensions of greater saphenous (57) or lesser saphenous (10) vein were anastomosed to the anterior tibial (19), posterior tibial (26), or peroneal (22) arteries. Fifty-three percent were maintained on long-term warfarin (Coumadin) anticoagulation, and 33% were maintained on aspirin. No deaths occurred in the perioperative period. Bypass patency was ascertained by a Doppler pressure and waveform analysis, with mean follow-up of patency or to the time of graft failure of 33 months (1 to 91 months). Three-year patient survival was 72%. Cumulative life-table primary patency of 72% (1-year), 64% (2-year), and 48% (3-year) was calculated. Two grafts are functioning 7 years after placement. Limb salvage was 84% at 2 years and 70% at 4 years. At the time of failure, five grafts retained a patent venous bypass segment, which allowed prompt reconstruction of the proximal portion. In a comparison of grafts with early failure and those with long-term patency, the SVS/ISCVS runoff score, vein diameter, tibial artery diameter, and coagulation status were similar. However, patients with the popliteal anastomosis above the knee had 2-year patency of 72% compared with 46% for those with below-knee anastomoses. This technique, when possible, appears preferable to an all prosthetic tibial bypass.

Adult↗
PubMed1992

Interleukin-1 beta and tumor necrosis factor-alpha release in normal and diseased human infrarenal aortas.

The presence of chronic inflammatory cells in the adventitia and media of abdominal aortic aneurysms and aortic occlusive disease suggest an immunologic response. The purpose of this study is to determine whether normal or diseased infrarenal aortas liberate the inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta). Twenty-six infrarenal aortic biopsies (5 aortic occlusive disease, 15 abdominal aortic aneurysms, and 6 cadaveric donors) were weighed, minced into small pieces, and incubated in media for 48 hours. Conditioned media was harvested at 48 hours and assayed for IL-1 beta or TNF-alpha with use of an ELISA assay. Comparison of groups was performed with a one-way analysis of variance. The constitutive IL-1 beta produced by abdominal aortic aneurysms was significantly different than that in cadaveric donors (908 +/- 194 pg/ml [SE] vs 100 +2- 30 pg/ml). There was no statistically significant difference between abdominal aortic aneurysms and aortic occlusive disease (908 +/- 194 pg/ml vs 604 +/- 256 pg/ml) or aortic occlusive disease and cadaveric donor (604 +/- 256 vs 100 +/- 30). In time-course studies for the release of IL-1 beta, abdominal aortic aneurysms demonstrated maximal release at 48 hours. IL-1 beta release was augmented by lipopolysaccharide in all categories. A dose response curve demonstrated maximal IL-1 beta release on stimulation with 5 micrograms/ml LPS. Constitutive TNF-alpha production was low, ranging from 13 +/- 1.5 pg/ml in cadaveric donor, to 20 pg/ml in aortic occlusive disease, and 24 +/- 11 pg/ml in abdominal aortic aneurysms. There was no augmentation in TNF-alpha with lipopolysaccharide.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Elastin content, cross-links, and mRNA in normal and aneurysmal human aorta.

Although elastin depletion is thought to be an etiologic factor in abdominal aortic aneurysm, little is known about its transcription and posttranslational modification in normal and diseased human aorta. Our objectives were to quantify total elastin and elastin cross-links (desmosine/isodesmosine [DID]) and to determine if elastin mRNA was detectable in the disease-prone infrarenal aorta from patients with abdominal aortic aneurysm and a comparative group with no aneurysmal diseases. After preliminary extraction and thermolysin digestion, content of DID and the elastin tetrapeptide, valine-alanine-proline-glycine (VAPG), were determined by high-performance liquid chromatography. Tissue mRNA was studied by Northern blot analysis. Mean values (+/- SE) were compared by Student's t test. The proportion of insoluble elastin was markedly decreased in abdominal aortic aneurysm tissue (1.3% +/- 0.04% vs 12% +/- -2.8%; p less than 0.001). There was no difference in the small percentage of elastin solubilized during extraction in abdominal aortic aneurysm (5.3% +/- 1%) and no aneurysmal disease (6.0% +/- 1.2%; p = 0.71) tissues. The DID concentration of insoluble elastin was not different for abdominal aortic aneurysm and no aneurysmal disease tissue (0.18% +/- 0.07 vs 0.18 +/- 0.05 nm DID/nm VAPG; p = 0.97). On the basis of VAPG content, only 26% +/- 4% of the sodium hydroxide insoluble residue from abdominal aortic aneurysm was elastin; the predominate protein(s) was high in polar amino acids. Elastin mRNA was detectable in all tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Fibromuscular dysplasia of the brachial artery: a case report and review of the literature.

Fibromuscular dysplasia is a nonatherosclerotic, noninflammatory vascular disease that involves primarily medium-sized and small arteries. Fibromuscular dysplasia is characterized by medical fibrosis with or without smooth muscle cell hyperplasia and may produce luminal impingement with severe turbulence. Secondary aneurysmal deformity with or without thrombosis may also contribute to the obstruction. Fibromuscular dysplasia most commonly involves the renal and carotid arteries, with upper-extremity disease rarely reported. This case report describes a patient with digital embolization from brachial artery fibromuscular dysplasia. Angiography demonstrated significant narrowing and irregularity with a characteristic "string-of-beads" appearance of the right midbrachial artery. The abnormal segment was resected and reconstructed with a reversed saphenous vein graft. Histologic studies revealed disruption of the internal elastic lamina and disorientation of the hyperplastic medial smooth muscle cells characteristic of fibromuscular dysplasia.

Aged↗
PubMed1992

Collagen and elastin gene expression in aortic aneurysms.

BACKGROUND: The decreased elastin concentration found in abdominal aortic aneurysms (AAAs) may result from a differential synthetic response wherein elastin gene expression fails to increase in parallel with type I procollagen (COL I) gene expression. The purpose of this study is to determine tissue mRNA levels for elastin and COL I in AAAs compared with levels in normal, age-matched aorta and to determine the relationship between aging and COL I gene expression. METHODS: Total RNA exacted from normal infrarenal aortic tissue (n = 7) and AAA (n = 10) tissue was subjected to Northern analysis. Mean values for COL I, elastin, and alpha-tubulin mRNA levels were compared by use of the Student t test. Age and COL I mRNA levels were analyzed by regression analysis. RESULTS: COL I mRNA was increased significantly in AAAs (1.18 +/- 0.13) compared with normal aortas (0.14 +/- 0.05). A commensurate increase in elastin mRNA (AAAs, 0.11 +/- 0.02, vs normal aortas, 0.39 +/- 0.2) was absent. There was no correlation between age and COL gene expression. CONCLUSIONS: The decreased elastin concentration relative to collagen in AAAs may be explained, in part, by the changes in message level of elastin and collagen. The enhanced COL I gene expression in AAAs is unrelated to age.

Aging↗