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Biomedical subjects

C A Athanasoulis

Publications and source records attributed to C A Athanasoulis.

At least 19 recordsLinked to original sources
PubMed2000

Inferior vena caval filters: review of a 26-year single-center clinical experience.

PURPOSE: To review a 26-year single-center clinical experience with inferior vena caval filters. MATERIALS AND METHODS: During 1973-1998, 1,765 filters were implanted in 1,731 patients. Hospital files were reviewed, and data were collected about the indications, safety, effectiveness, numbers, and types of caval filters. Fatal post-filter pulmonary embolism (PE) was considered the primary outcome. Morbidity and mortality were determined as secondary outcomes. Survival and morbidity-free survival curves were calculated. RESULTS: The prevalence of observed post-filter PE was 5.6%. It was fatal in 3.7% of patients. In most patients, fatal PE occurred soon after filter insertion (median, 4.0 days; 95% CI: 2.2, 5.8 days). Major complications occurred in 0.3% of procedures. The prevalence of observed post-filter caval thrombosis was 2.7%. The 30-day mortality rate was 17.0% overall, higher among patients with neoplasms (19.5%) as compared with those without neoplasms (14.3%; P =.004). Filter efficacy and associated morbidity were not different in 46 patients with suprarenal filters. The rate of filters placed for prophylaxis was 4.7% overall and increased to 16.4% in 1998. From 1980 to 1996, there was a fivefold increase in the number of caval filter implants. In recent years, more filters were implanted in younger patients. CONCLUSION: Inferior vena caval filters provide protection from life-threatening PE, with minimal morbidity.

Adolescent↗
PubMed2000

Preoperative imaging of the carotid bifurcation. Current trends.

BACKGROUND: There is disagreement about the most appropriate imaging examination necessary for the preoperative assessment of the carotid bifurcation. Our objective was to find out the preferences of clinicians on this issue in one large hospital. And to determine whether and how these preferences have changed over time. METHODS STUDY DESIGN: Observational, retrospective study. SETTING: Large metropolitan and university affiliated hospital. Numbers of patients per year who underwent carotid endarterectomy during 1990-1998. Numbers of patients per year who had conventional catheter carotid angiography during the same period. Assessment of the nature of preoperative carotid imaging in a sample of 400 patients (100 each in 1990, 1993, 1996 and 1998). Analysis of the types of imaging examinations by year and determination of underlying trends. MEASURES: Number of carotid angiograms expressed as a percentage of carotid endarterectomies performed each year. Types of preoperative imaging examinations of the carotids and changes over time. RESULTS: The number of preoperative conventional catheter angiograms decreased over time. In 1990 angiography was performed in 86% of carotid endarterectomies. In 1998 the proportion decreased to 16% (p<0.05). Conversely, the proportion of endarterectomies carried out based solely on ultrasonography increased from 6% in 1990 to 56% in 1998 (p<0.05). The proportion of endarterectomies performed based on the combined findings of ultrasound and magnetic resonance angiography increased from 3% in 1990 to 56% in 1996 and to 26% in 1998. Computed tomoangiography has not become popular. The observed reduction in the number of preoperative conventional carotid angiograms was independent of the presence/absence of symptoms, the level of serum creatinine, the subspecialty of the surgeon (vascular surgery vs neurosurgery) and the individual surgeon involved. CONCLUSIONS: In one large university affiliated hospital the trend in the preoperative imaging of the carotid arteries is moving away from conventional catheter angiography. There is increasing application of ultrasound combined with magnetic resonance angiography and a more pronounced trend towards the performance of carotid endarterectomy based only on ultrasonography.

Adult↗
PubMed1999

The Friday afternoon pulmonary angiogram: temporal relationship between onset of symptoms and requests for angiography.

BACKGROUND: To determine if pulmonary embolism symptoms and pulmonary angiography have a proclivity for a particular day of the week, month or season (Part I) and to assess the length of time elapsing between the appearance of symptoms and requests for pulmonary angiography (Part II). DESIGN: Prospective (in part) collection of data and retrospective review of clinical records. SETTING: Large metropolitan, university affiliated hospital. METHODS: Part I: 2,969 consecutive pulmonary angiograms performed over 17 years, were collected according to the day of the week, month and season of their performance. Relevant rates were calculated. Part II: A study of the time interval between the onset of pulmonary embolism symptoms and requests for and performance of angiography was conducted in 128 patients. Results. Part 1. In the course of 17 years, more pulmonary angiograms were performed on Fridays (mean 37.2, SE 1.8), than on any other day of the week (p <.001). No proclivity for a particular month or season was observed. Part II. The mean time elapsed between the onset of symptoms and requests for angiography was 24 hours (range 0.2-162, SE 4.3) for inpatients, and 45 hours (range 3-358, SE 7.8) for outpatients. The angiogram was completed urgently, within two hours of the onset of symptoms, only in 2.4%. CONCLUSIONS: Pulmonary angiography has a proclivity for Fridays. Pulmonary embolism symptoms and consequent angiograms do not favour a specific day, month or season. In most cases the time elapsing between the onset of symptoms and requests for angiography is too long to be consistent with urgency. The frequent Friday pulmonary angiogram reflects a tendency to "mop up" unfinished business prior to the week's end.

Angiography↗
PubMed1998

Acute pulmonary embolism: assessment of helical CT for diagnosis.

PURPOSE: To determine the sensitivity and specificity of helical computed tomography (CT) for the diagnosis of acute pulmonary embolism. MATERIALS AND METHODS: This prospective study included 47 patients who underwent pulmonary arteriography for evaluation for possible acute pulmonary embolism. Tailored helical CT and pulmonary arteriography were performed within 24 hours of each other. Each CT scan was interpreted by two chest radiologists, blinded to arteriographic results, at two institutions. CT scan interpretations were compared with findings on bilateral selective pulmonary arteriograms interpreted by two vascular radiologists at one institution. RESULTS: Fifteen (32%) of 47 patients had angiographically proved pulmonary embolism. For the readers at the first institution, helical CT had 60% sensitivity, 81% specificity, 60% positive predictive value, 81% negative predictive value, and 75% overall accuracy. For the readers at the second institution, helical CT had 53% sensitivity, 97% specificity, 89% positive predictive value, 82% negative predictive value, and 83% accuracy. CONCLUSION: Detection of pulmonary embolism with helical CT may be less accurate than previously reported. Given its high specificity but relatively low sensitivity, helical CT may not have the ideal attributes of a first-line imaging study for the diagnosis of pulmonary embolism.

Acute Disease↗
PubMed1995

Controversies in vascular imaging and intervention: a panel discussion.

PURPOSE: To express for educational purposes, different and often opposing views on controversial topics of current interest in vascular radiology. And to explore whether or not consensus can be reached on any of these controversial issues. METHOD: Panel discussion among experts in the field. With the help of a moderator, controversial topics were introduced for discussion. For each topic the moderator underscored the principal issue and asked relevant questions. All panelists were asked to express their views on all issues. The following issues were discussed: Atherectomy vs balloon angioplasty; Balloon angioplasty vs stents; Digital vs analog Imaging; TIPS as an emergency procedure; Regional thrombolysis; MRA vs conventional angiography; Laser angioplasty; Carbon dioxide angiography; Lymphangiography vs CT; The training of surgeons in angiography. The panelists were urged to avoid extensive references to the literature but rather to express their own personal opinions based on experience and practice. For each topic an attempt was made to arrive at consensus. RESULTS: Ten issues were presented for debate and discussion. Despite divergent opinions it was possible and relatively painless to reach consensus on seven controversies. On the remaining issues the panelists agreed to disagree. However even when there was disagreement certain trends became apparent. Local considerations and resource availability accounted for varied approaches to the solution of certain controversies. CONCLUSIONS: A panel discussion among experts may be a useful way to address controversies for educational purposes. Despite divergence of opinions consensus may be reached, or in absence of consensus general trends may become apparent.

Angioplasty, Balloon↗
PubMed1992

A prospective investigation of pulmonary embolism in women and men.

OBJECTIVE: The aim of this study was to compare, in women and men suspected of pulmonary embolism, the frequency, risk factors, diagnosis, and presentation of pulmonary embolism as well as the accuracy of the ventilation/perfusion scan (V/Q scan) as a diagnostic tool. DESIGN: Data were collected during a prospective study (the Prospective Investigation of Pulmonary Embolism Diagnosis) to establish the accuracy of the V/Q scan compared with pulmonary angiograms. SETTING: Six tertiary medical centers in Massachusetts, Michigan, Connecticut, Pennsylvania, and North Carolina. PARTICIPANTS: Patients suspected of pulmonary embolism for whom a request was made for a V/Q scan or pulmonary angiogram (496 women and 406 men). RESULTS: Women 50 years old and under had a decreased frequency of pulmonary embolism compared with men of that age (16% vs 32%), but there was no difference in patients over 50 years old (Breslow-Day test, P less than .01). Risk factors for pulmonary embolism, the usefulness of the V/Q scan, and 1-year mortality were not different for women and men. Estrogen use in women was not associated with an increased frequency of pulmonary embolism, except in women using oral contraceptives who had undergone surgery within 3 months; four of five (80%) had emboli compared with four of 28 (14%) age-matched surgical patients not using estrogens (P less than .01). CONCLUSION: Women 50 years old and under (even young women using oral contraceptives) who were suspected of having pulmonary emboli and were enrolled in the Prospective Investigation of Pulmonary Embolism Diagnosis study had a smaller frequency of pulmonary embolism than men of that age, The risk factors for pulmonary embolism were the same for women and men, except that women using oral contraceptives had an increased risk of pulmonary embolism following surgery. Although the V/Q scan was a useful tool in the preliminary evaluation for pulmonary embolism in these women, a pulmonary angiogram was often needed for accurate diagnosis.

Adolescent↗
PubMed1990

Penetrating aortic ulcers: diagnosis with MR imaging.

The authors studied seven patients with penetrating aortic ulcers with use of magnetic resonance (MR) imaging. All patients were evaluated for acute chest symptoms, and the presence of aortic ulcers was confirmed by means of angiography in all seven patients. Five patients also underwent computed tomography (CT). Three patients underwent surgical repair of the thoracic aorta. MR findings included intramural hematoma and focal aortic wall ulceration in four patients, focal ulceration in one, focal intramural hematoma in one, and focal intramural hematoma with rupture in one. The diagnosis of intramural hematoma was made by the detection of increased signal intensity on T1- and T2-weighted MR images. MR imaging was superior to angiography in depicting the extent of intramural thrombus, although one ulceration diagnosed at angiography was missed at MR imaging. MR imaging was superior to CT in differentiating acute intramural hematoma from atherosclerotic plaque and chronic intraluminal thrombus, although it did not depict displaced intimal calcification in one patient with extensive intramural hematoma.

Aged↗
PubMed1989

Long-term results of combined iliac balloon angioplasty and distal surgical revascularization.

Long-term results of combined use of iliac artery percutaneous transluminal angioplasty (PTA) and distal surgical revascularization for the management of multilevel occlusive disease were evaluated over a 12-year period. A total of 79 combined procedures were performed in 75 patients. All patients had tandem occlusive disease, with the inflow lesion felt to preclude a distal revascularization procedure alone. Revascularization was performed for incapacitating claudication in 17 (22%) and limb salvage indications in 62 (78%) cases. A mean resting iliac artery pressure gradient of 29 +/- 11 mmHg pre-PTA was reduced to 0.9 +/- 0.4 post-PTA. Major complications of PTA occurred in five (6%) cases, but four were successfully corrected at the time of the distal surgical procedure without alteration of the operative plan. Infrainguinal operations included 55 femoropopliteal or tibial bypass grafts, 18 femorofemoral grafts, and 6 profundaplasties. Mean follow-up was 43 months. By life table analysis, the 5-year primary patency rate of the distal surgical procedures was 76%; a secondary patency of 88% at 5 years was achieved by various means of reintervention. Mean pretreatment ankle/brachial index of 0.31 +/- 0.14 increased to 0.80 +/- 0.16 after operation (p less than 0.0001). The 5-year limb salvage rate was 90%. There were no operative deaths. We conclude that in carefully selected patients, combined use of iliac PTA and distal surgical reconstruction is effective and durable, safely reducing the extent of surgical intervention while reliably increasing the comprehensiveness of revascularization.

Actuarial Analysis↗
PubMed1989

Simon nitinol inferior vena cava filter: initial clinical experience. Work in progress.

The Simon nitinol filter for percutaneous interruption of the vena cava to prevent pulmonary embolism is currently undergoing a multicenter clinical trial. Preliminary clinical results are reported as work in progress. The results in 44 patients at two centers are analyzed in detail, and major events are reported from 103 patients in 17 centers in the United States during a 10-month period. The filter was successfully inserted via the femoral or jugular route in all patients through a 9-F catheter. The placement procedure was easy and without significant complications. Follow-up studies included plain radiography, ultrasonography, magnetic resonance (MR) imaging, and clinical evaluation. No filter migration or perforation occurred among the 103 patients. Symptomatic occlusions occurred in 7%-9%, comparable to other series, and some asymptomatic occlusions were detected with MR imaging only. The implications of occlusion of the filter are discussed.

Adult↗
PubMed1989

Regional infusion of urokinase into occluded lower-extremity bypass grafts: long-term clinical results.

The initial outcome, long-term patency rate, and rate of limb salvage were studied in patients after regional urokinase infusion for treatment of thrombosed lower-extremity grafts. Seventy-one infusions were performed in 53 patients. Complete clot lysis occurred in 75% of grafts, with establishment of antegrade blood flow in 66%. Variables that favorably influenced clot lysis and the reestablishment of antegrade blood flow through the graft were a short duration of occlusion and a suprainguinal graft position. The median duration of patency after infusion and adjunctive therapy was 162 days, with 75% limb salvage at 301 days. No statistically significant variables that influenced the length of patency were identified. These long-term patency results are inferior to the reported results in suprainguinal grafts after reoperation. They appear similar to reported results for occluded infrainguinal grafts treated with thrombectomy and patch grafting.

Female↗
PubMed1989

Standards of radiology practice: an approach to development.

Assessment and accountability will be issues shaping the health care system in the United States during the next decade. Qualitative and, more important, quantitative information will be essential elements in the process. This information will need to be viewed in the light of the expectations of radiologists. These expectations may be referred to as guidelines, standards, or practice parameters. If radiologists wish to be active participants in the process rather than passive observers, they need to develop their own standards of practice. For the development of standards, the authors propose a unifying approach based on the concept of components of radiology service and the service as a whole. The concept provides a flexible framework for building a list of standards. This list may be shortened or expanded in response to available resources and changing practice patterns.

Humans↗