Biomedical subjects

Mary C Proctor

Publications and source records attributed to Mary C Proctor.

10 recordsLinked to original sources

PubMed2004

Patients undergoing infrainguinal bypass to treat atherosclerotic vascular disease are underprescribed cardioprotective medications: effect on graft patency, limb salvage, and mortality.

INTRODUCTION: Established American Heart Association guidelines recommend the use of statin drugs, angiotensin converting enzyme (ACE) inhibitors, and antiplatelet agents in patients with systemic atherosclerosis, such as those undergoing operative intervention to treat peripheral atherosclerotic disease. Many of these patients have not received treatment of coronary heart disease and have not been prescribed these medications. Whether statin drugs and ACE inhibitors confer an improvement in graft patency, limb salvage, and operative mortality is unknown. METHODS: Consecutive patients who underwent infrainguinal bypass between 1997 and 2002 were evaluated for demographic data, comorbid disease, medication use, as well as cumulative graft patency, limb salvage, and mortality. Univariate, multivariate logistical regression, and Kaplan-Meier analyses were performed. P <.05 was considered significant. RESULTS: Two hundred ninety-three patients (mean age, 64 years; 67% men) underwent 338 infrainguinal bypass procedures with autologous vein (n = 218), prosthetic grafts (n = 88), or composite prosthetic-vein grafts (n = 32). Limb salvage was the operative indication in 75% of procedures. Coexisting diseases included hypertension (70%), diabetes (52%), hyperlipidemia (37%), coronary heart disease (51%), congestive heart failure (14%), and active tobacco use (30%). Statin drugs were taken by 56% of patients, ACE inhibitors by 54% of patients, and antiplatelet agents or warfarin sodium (Coumadin) by 93% of patients. Postoperative graft surveillance was done in 39% of patients. Cumulative graft patency was 73%, limb salvage was 85%, and mortality was 9%, with a mean follow-up of 17 months. Factors independently associated with increased graft patency included statin drug use (odds ratio [OR], 3.7; 95% confidence interval [CI], 2.1-6.4), male sex (OR, 2.8; 95% CI, 1.6-5.0), and graft surveillance (OR, 2.4; 95% CI, 1.3-4.5). Factors associated with decreased amputation rate were statin drug use (OR, 0.34; 95% CI, 6.15-0.77) and graft surveillance (OR, 0.23; 95% CI, 6.1-0.63). Factors associated with decreased mortality included graft surveillance (OR, 0.18; 95% CI, 0.1-0.56), whereas congestive heart failure (OR, 6.5; 95% CI, 2.5-17) and hemodialysis-dependent renal failure (OR, 29; 95% CI, 6.1-140) were associated with increased mortality. Kaplan-Meier analysis showed that only ACE inhibitors were associated with lower mortality (P =.05) CONCLUSIONS: Patients undergoing infrainguinal bypass are undertreated with respect to cardioprotective medications. ACE inhibitor use is associated with lower mortality, and statin drug use is associated with improved graft patency and limb salvage. Institution of consensus guidelines concerning these medications should be considered by all vascular specialists, including vascular surgeons.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2003

Vena caval filter use in patients with sepsis: results in 175 patients.

BACKGROUND: Septic patients are at risk of thromboembolism. However, the Food and Drug Administration guidance for intravascular filters states that "filters should not be implanted in patients with risk of septic embolism." The purpose of this study is to evaluate this restriction. HYPOTHESIS: There is no difference in outcomes following filter placement in patients with and without septicemia. DATA SOURCES: A registry of vena caval filter experiences containing information regarding filter placement and annual examinations of more than 2600 patients obtained during a 15-year period was reviewed. We conducted a MEDLINE search of publications reporting clinical sequelae of filter placement in septic patients. DATA EXTRACTION: The registry was searched for patients with a diagnosis of sepsis at filter placement; survival rates, adverse events, and recurrent sepsis or thromboembolism were noted. The MEDLINE search joined results from 7 MeSH headings (vena cava filter,sepsis, septic thromboembolism, vena caval filter contraindication, and filter adverse events) related to filters and sepsis. DATA SYNTHESIS: One-hundred seventy-five patients (6.7%) met the criteria and received Greenfield filters. None of the adverse events were related to sepsis, and no filter was removed. Follow-up data were available for 56 patients, with a combined recurrent pulmonary embolism and caval occlusion rate of 1.7%. The 30-day mortality rate was 33%. We noted a significant difference in survival related to the use of anticoagulation therapy (P =.001) and to age (P =.004). The MEDLINE search did not identify any clinical reports of septic filters or the need to remove a filter because of sepsis. CONCLUSIONS: Based on our review, the Greenfield filter is a safe method of prophylaxis for septic patients. Rescinding the restriction for use of vena caval filters in septic patients should be considered by regulatory bodies.

Adolescent↗

PubMed2003

Development and evaluation of investigational vena caval filters: the complementary roles of in vitro and in vivo studies.

BACKGROUND: The use of animals in medical research raises both ethical and economic concerns. Validated in vitro models allow extensive device testing prior to in vivo studies which limits the numbers of animals required to reach conclusions regarding efficacy and safety. MATERIALS AND METHODS: In vitro studies were conducted in a vena caval simulator (ECU) to evaluate characteristics of filter performance: ability to capture emboli, resistance to vertical movement from lateral forces, resistance to vertical movement from mass impact, and ability to maintain caval flow. These tests are used to select candidate filters for in vivo studies. In vivo filter studies are conducted in an ovine model with filters placed into the vena cava from a jugular or femoral vein approach. At intervals, the animals are sacrificed and both cava and device are evaluated for thrombogenicity, thrombus resolution, and mechanical integrity. Radiographs, intravascular ultrasound, and histology are used to determine outcome. RESULTS: During the 6-year period from 1993 to 1999, 11 vena caval filter types were evaluated. In each case, it was possible to select a single prototype for in vivo study on the basis of four tests. An investigational device was developed that was comparable to the marketed devices with respect to clot capture (P = 0.001), superior to the Greenfield in resistance to movement (P = 0.001), and superior to the VenaTech and Simon Nitinol relative to volume loading (P = 0.01). Problems with metal fatigue prevented clinical development. CONCLUSION: An integrative system of in vitro and in vivo studies allows efficient evaluation of IVC filters and identifies design characteristics associated with clinical functioning. Evaluation over time is essential to determine safety as well as efficacy.

Animals↗

PubMed2003

Clinical relevance of peripheral vascular occlusive disease in patients with rheumatoid arthritis and systemic lupus erythematosus.

INTRODUCTION: Peripheral vascular occlusive disease (PVOD) and rheumatologic disease (RD) are common in older patients. The effect that coexistence of these diseases may have on patient health has not been rigorously investigated. The present study was undertaken in an attempt to characterize patients with PVOD plus RD in terms of inflammatory serologic disorders, medications, and procedures, and their relation to limb salvage. METHODS: Medical records were reviewed retrospectively for all patients with diagnosed coexistent PVOD and non-arteritis RD treated over 15 years at the University of Michigan Hospital. Demographics, operative and medical therapies, and serologic studies were analyzed. Univariate and multivariate analysis and the Kaplan-Meier method were used to assess these variables in relation to limb salvage. RESULTS: Forty-one patients (34 women, 7 men), with mean age of 67 years, were studied. Mean antinuclear antibody titer was 274, C-reactive protein concentration was 3.1 mg/mL, and sedimentation rate was 49. Twenty-nine percent of patients had claudication, 49% had rest pain, and 32% had tissue loss. Mean ankle brachial index was 0.55. Medications included nonsteroidal anti-inflammatory drugs (67% of patients), corticosteroids (54%), and specific immunosuppressive agents (27%). Operative therapy included aortofemoral bypass grafting (n = 4), infrainguinal bypass grafting (n = 14), embolectomy (n = 4), and primary amputation (n = 7). Overall 5-year limb salvage rate was 70% in patients undergoing bypass surgery. Comparison of surgical with nonsurgical patients showed no significant differences in baseline risk factors, serologic disorders, or anatomic location of vascular disease. Multivariate analysis revealed that rest pain and lack of immunosuppression were significantly predictive of need for revascularization or amputation (P <.05). CONCLUSION: Patients with RD should receive treatment on the basis of standard criteria for limb ischemia, in that surgical revascularization outcomes are satisfactory. Immunosuppressive agents may confer a protective effect against progression of PVOD.

Aged↗

PubMed2003

Factors associated with recurrent venous thromboembolism in patients with malignant disease.

PURPOSE: The role of prophylactic vena cava filters (VCF) in patients with cancer is debated. Although VCF are often placed in patients with cancer after recurrence of venous thromboembolic events (VTE), identification of this subset of patients has not been well-defined. This study was undertaken to assess factors associated with increased risk for recurrent VTE. METHODS: All patients with a history of thromboembolism or malignant disease and who required a VCF because of failure of or contraindication to anticoagulation therapy were abstracted from the Michigan Filter Registry. Univariate analysis of potential risk factors for recurrent VTE and logistic regression models were used to identify associations between these variables and recurrent VTE. RESULTS: Ninety-nine patients (49 men, 50 women) with a mean age of 58 years were included in the study. New metastases occurred in 55% of patients, and 12% of patients had a history of VTE before cancer diagnosis. Corticosteroid agents were used during therapy in 48% of patients. Acute VTE was present in 52% of patients at cancer diagnosis, and in 34% of patients VTE was associated with new metastases. Recurrent VTE occurred in 40% of patients, and significant risk factors included presence of new metastases (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.16-9.09; P =.02) and history of VTE (OR, 10.6; CI, 1.98-57.2; P =.006). Whereas a single episode of neutropenia did not reach significance (OR, 1.1; CI, 0.97-1.35; P =.11), multiple neutropenic episodes were significantly associated with recurrent VTE (P =.04). Smoking, hormone replacement therapy, decreased mobility, post-surgical state, and obesity were not independently associated with increased risk. Mean survival in this series was 30 months, and was significantly worse in patients with VTE at cancer diagnosis and with inability to tolerate anticoagulant therapy in conjunction with VCF. CONCLUSION: Patients with malignant disease may be at increased risk for recurrent VTE after development of new metastases or multiple episodes of neutropenia, especially those patients with a history of VTE. VCF may be a reasonable alternative to long-term anticoagulation therapy in this subgroup of patients at high risk patients, provided their quality of life is reasonable.

Adolescent↗

PubMed2003

Predictors of severe morbidity and death after elective abdominal aortic aneurysmectomy in patients with chronic obstructive pulmonary disease.

OBJECTIVE: This study sought to identify risk factors associated with an unfavorable outcome after elective abdominal aortic aneurysm (AAA) repair in patients with chronic obstructive pulmonary disease (COPD). METHODS: The clinical records of 158 patients who underwent elective open AAA repair with COPD determined from preadmission International Classification of Diseases-ninth revision codes during a 12-year period at the University of Michigan were reviewed. Patients with uncomplicated outcomes (group I) were compared with those with unfavorable postoperative outcomes (group II). The unfavorable outcomes were defined as myocardial infarction, acute renal failure, worsening respiratory insufficiency necessitating tracheostomy, or death within 30 days of surgery. Logistic regression analyses of variables that were identified as being statistically significant in the univariate analysis were used to develop a predictive model of these events. RESULTS: Group I included 133 patients (77 men, 56 women) with a mean age of 70.1 years, and group II included 25 patients (13 men, 12 women) with a mean age of 71.4 years. Preoperative factors statistically related (P =.002) to an unfavorable outcome in group II patients included: suboptimal COPD management (fewer prescribed inhalers), lower hematocrit, preoperative renal insufficiency, and coronary artery disease. Importantly, abnormal preoperative spirometry and arterial blood gases were not predictive of a poor outcome. Univariate analysis also revealed increased hospital (25 versus 13 days; P =.0001) and intensive care unit (14 versus 4 days; P =.001) length of stays and a greater need for prolonged ventilation (8 versus 1 day; P =.039) for group II patients compared with group I patients. The 30-day mortality rate in the entire experience was 3.2% (5/158). No specific variables associated with mortality were identified. CONCLUSION: Fewer prescribed inhalers, lower hematocrit, renal insufficiency, and coronary artery disease are preoperative factors associated with unfavorable outcomes after open elective surgical repair of AAA in patients with COPD. Intensive management of these factors may reduce the hazards of AAA operations in these patients. COPD alone should not be considered a deterrent to the surgical treatment of AAAs.

Acute Kidney Injury↗

PubMed2003

A national and single institutional experience in the contemporary treatment of acute lower extremity ischemia.

OBJECTIVE: To determine the contemporary clinical relevance of acute lower extremity ischemia and the factors associated with amputation and in-hospital mortality. SUMMARY BACKGROUND DATA: Acute lower extremity ischemia is considered limb- and life-threatening and usually requires therapy within 24 hours. The equivalency of thrombolytic therapy and surgery for the treatment of subacute limb ischemia up to 14 days duration is accepted fact. However, little information exists with regards to the long-term clinical course and therapeutic outcomes in these patients. METHODS: Two databases formed the basis for this study. The first was the National Inpatient Sample (NIS) from 1992 to 2000 of all patients (N = 23,268) with a primary discharge diagnosis of acute embolism and thrombosis of the lower extremities. The second was a retrospective University of Michigan experience from 1995 to 2002 of matched ICD-9-CM coded patients (N = 105). Demographic factors, atherosclerotic risk factors, the need for amputation, and in-hospital mortality were assessed by univariate and multivariate logistic regression analysis. RESULTS: In the NIS, the mean patient age was 71 years, and 54% were female. The average length of stay (LOS) was 9.4 days, and inflation-adjusted cost per admission was $25,916. The amputation rate was 12.7%, and mortality was 9%. Decreased amputation rates accompanied: female sex (0.90, 0.81-0.99), age less than 63 years (0.47, 0.41-0.54), angioplasty (0.46, 0.38-0.55), and embolectomy (0.39, 0.35-0.44). Decreased mortality accompanied: angioplasty (0.79, 0.64-0.96), heparin administration (0.50, 0.29-0.86), and age less than 63 years(0.27, 0.23-0.33). The University of Michigan patients' mean age was 62 years, and 57% were men. The LOS was 11 days, with a 14% amputation rate and a mortality of 12%. Prior vascular bypasses existed in 23% of patients, and heparin use was documented in 16%. Embolectomy was associated with decreased amputation rates (0.054, 0.01-0.27) and mortality (0.07, 0.01-0.57). CONCLUSIONS: In patients with acute limb ischemia, the more widespread use of heparin anticoagulation and, in select patients, performance of embolectomy rather than pursuing thrombolysis may improve patient outcomes.

Acute Disease↗

PubMed2002

Compression stockings and venous function.

HYPOTHESIS: Surgical compression stockings measurably improve venous physiologic mechanisms, and stocking brands do not differ from one another. METHODS: Eleven patients, (8 men and 3 women [mean age, 53 years]), were included. Six patients had primary venous insufficiency and 5 patients had secondary venous insufficiency; 5 patients were in CEAP class 4 and 6 were in CEAP class 5. Patients were randomly assigned to a sequence of 4 brands of knee-high, open-toe, 30- to 40-mm Hg stockings. Each patient wore a stocking for a 1-month equilibration period, then a different stocking monthly for 4 months in a row. Air plethysmography examinations were performed with and without stockings before and after each month of wear. Patients filled out a daily stocking record log and a monthly satisfaction survey. Stockings underwent compression testing after use. RESULTS: Stockings controlled reflux better than they improved calf muscle pump function. With stockings on, patients in CEAP 4 benefited more than those in CEAP 5 in decreasing reflux, while patients in CEAP 5 benefited more than those in CEAP 4 in improving calf muscle pump function. Changes in residual volume fraction were improved in patients in CEAP 5 wearing stockings but not in patients in CEAP 4. Patients with primary disease had greater volumes of reflux and calf ejection than with secondary disease. There were no hemodynamic differences between stocking brands but there were differences in patient compliance and acceptance. CONCLUSIONS: Surgical support stockings seem to be more effective in controlling reflux than in improving calf muscle pump function. All stocking brands function equally as measured by air plethysmography.

Bandages↗

PubMed2002

Tissue loss, early primary graft occlusion, female gender, and a prohibitive failure rate of secondary infrainguinal arterial reconstruction.

PURPOSE: This study tested the hypothesis that a subset of secondary infrainguinal arterial reconstructions show prohibitive failure rates. METHODS: Records of 79 consecutive patients, 44 men and 35 women, with a mean age of 60 years, who underwent secondary infrainguinal bypass from 1992 to 2000 at the University of Michigan Hospital, were reviewed. Data were analyzed with life-table analysis, logistic regression, and descriptive statistics. RESULTS: Secondary infrainguinal reconstructions were performed in patients who had undergone earlier ipsilateral bypasses once (n = 35) or twice (n = 44). Among the prior procedures, 68% (n = 54) were done at an institution other than the authors'. Comorbidities included coronary artery disease (72%), tobacco use (77%), and diabetes mellitus (34%), but no patient had hemodialysis-dependent renal failure. Disabling claudication, with average ankle brachial index of 0.48, had been the indication for the primary operation in 77% of cases. Femoral-popliteal bypass was the primary procedure in 67%, with a prosthetic graft used in 62%. The mean patency duration of these earlier bypasses was 25 months. The indication for the final bypass was rest pain or tissue loss in 51% of patients, with an average ankle brachial index of 0.37. The most common procedure was a femoral-distal bypass with autologous vein (63%). Mean patency duration of the secondary bypasses was 30 months. Graft failure within 30 days of operation occurred in 22 patients (28%), and amputation was necessitated in 86% of these patients. The presence of rest pain or tissue loss, when accompanied with a history of early prior graft thrombosis in female patients, correlated with worse mean patency rates, recurrent graft failure (P </=.05), and a 94% amputation rate. Men in a similar setting incurred a 57% amputation rate. No association of final patency existed with regard to age, number of prior bypasses, conduit types, tobacco use, or diabetes. CONCLUSION: Secondary infrainguinal bypasses are associated with an increased rate of graft failure and significant limb loss, particularly in those with a history of rest pain or tissue loss, female gender, and early prior graft failure. More appropriate initial operations in carefully selected patients and aggressive postoperative graft surveillance is speculated to improve these outcomes.

Arterial Occlusive Diseases↗

PubMed2002

Operative mortality rate for elective abdominal aortic aneurysm repair is not increased by the presence of a previous or concurrent thoracic or thoracoabdominal aortic dissection.

BACKGROUND: The objective of this study was to determine the likelihood of mortality after abdominal aortic aneurysm (AAA) repair in patients with thoracic or thoracoabdominal aortic dissection. METHODS: Fourteen patients (11 men, three women) with known thoracic or thoracoabdominal aortic dissections underwent elective AAA repair from 1986 to 2001, including three patients with acute dissections (less than 14 days) and 11 patients with chronic dissections (14 days or longer). All 14 patients had type III aortic dissections. Stent graft exclusion of the aortic dissection was performed in one patient before AAA repair. Preoperative patient characteristics, intraoperative events, perioperative complications, and 30-day and 1-year mortality rates were assessed. RESULTS: Elective AAA repair in the setting of thoracic or thoracoabdominal aortic dissection in this series was associated with no 30-day mortality and a 1-year mortality rate of 7.1%. Furthermore, preoperative patient characteristics, intraoperative events, and perioperative complications did not appear to be associated with late, 1-year, mortality. CONCLUSION: Elective AAA repair in the setting of acute or chronic aortic dissection is associated with mortality rates similar to those generally attributed to elective AAA repair without accompanying aortic dissection. Nevertheless, the conduct of the operation is usually complex, especially in the setting of an acute aortic dissection.

Acute Disease↗