Search

In a (negative) multicenter randomized trial on management for inoperable critical lower limb ischemia, comparing spinal cord stimulation and best medical treatment, a number of pre-defined factors were analyzed for prognostic value. We included a radiological arterial disease score, modified from the SVS/ISCVS runoff score. The purpose of this analysis was to evaluate clinical factors and commonly used circulatory measurements for prognostic modeling in patients with critical lower limb ischemia. We determined the incidence of amputation and its relation to various pre-defined risk factors. A total of 120 patients with critical limb ischemia were included in the study. The integrity of circulation in the affected limb was evaluated on five levels: suprainguinal, infrainguinal, popliteal, infrapopliteal and pedal. A total radiological arterial disease score was calculated from 1 (full integrity of circulation) to 20 (maximally compromised state). We used Cox regression analysis to quantify prognostic effects and differential treatment (predictive) effects. Major amputation occurred in 33% of the patients at 6 months and in 51% at 2 years. The presence of ischemic skin lesions and the radiological arterial disease score were independent prognostic factors for amputation. Patients with ulcerations or gangrene had a higher amputation risk (hazard ratio 2.38, p = 0.018 and 2.30, p = 0.036 respectively) as well as patients with a higher radiological arterial disease score (hazard ratio 1.17 per increment, p = 0.003). We did not observe significant interactions between prognostic factors and the effect of spinal cord stimulation. In conclusion, in patients with critical lower limb ischemia, the presence of ischemic skin lesions and the described radiological arterial disease score can be used to estimate amputation risk.

BACKGROUND: Adverse cardiac events are common after vascular surgery. We hypothesized that perioperative statin therapy would improve postoperative outcomes. METHODS: In this double-blind, placebo-con

OBJECTIVE: To evaluate the discriminatory value and compare the predictive performance of six non-invasive tests used for perioperative cardiac risk stratification in patients undergoing major vascular surgery. DESIGN: Meta-analysis of published reports. METHODS: Eight studies on ambulatory electrocardiography, seven on exercise electrocardiography, eight on radionuclide ventriculography, 23 on myocardial perfusion scintigraphy, eight on dobutamine stress echocardiography, and four on dipyridamole stress echocardiography were selected, using a systematic review of published reports on preoperative non-invasive tests from the Medline database (January 1975 and April 2001). Random effects models were used to calculate weighted sensitivity and specificity from the published results. Summary receiver operating characteristic (SROC) curve analysis was used to evaluate and compare the prognostic accuracy of each test. The relative diagnostic odds ratio was used to study the differences in diagnostic performance of the tests. RESULTS: In all, 8119 patients participated in the studies selected. Dobutamine stress echocardiography had the highest weighted sensitivity of 85% (95% confidence interval (CI) 74% to 97%) and a reasonable specificity of 70% (95% CI 62% to 79%) for predicting perioperative cardiac death and non-fatal myocardial infarction. On SROC analysis, there was a trend for dobutamine stress echocardiography to perform better than the other tests, but this only reached significance against myocardial perfusion scintigraphy (relative diagnostic odds ratio 5.5, 95% CI 2.0 to 14.9). CONCLUSIONS: On meta-analysis of six non-invasive tests, dobutamine stress echocardiography showed a positive trend towards better diagnostic performance than the other tests, but this was only significant in the comparison with myocardial perfusion scintigraphy. However, dobutamine stress echocardiography may be the favoured test in situations where there is valvar or left ventricular

PURPOSE: Recently, familial paraganglioma (PGL) was shown to be caused bymutations in the gene encoding succinate dehydrogenase subunit D (SDHD). However, the prevalence of SDHD mutations in apparently sporadic PGL is unknown. We studied the frequency and spectrum of germ-line and somatic SDHD mutations in patients with parasympathetic PGL. EXPERIMENTAL DESIGH: We studied 57 unselected patients who developed parasympathetic PGLs (n = 105 tumors) and who were treated between 1987 and 1999 at the Erasmus MC (Rotterdam, the Netherlands). Thirty-eight (67%) of these patients (n = 51 tumors) lacked a family history of parasympathetic PGL. We used conformation-dependent gel electrophoresis and sequence determination analysis of germ-line and tumor DNA to identify SDHD mutations. We compared the clinical and molecular characteristics of sporadic and hereditary PGLs. RESULTS: Three different SDHD germ-line mutations were identified in 32 of the 57 (56%) patients. These included 19 of 19 (100%) patients with familial PGL and also 13 of 38 (34%) patients with apparently sporadic PGL. All three mutations were characterized as missense mutations (D92Y, L95P, and L139P) in highly conserved regions of the SDHD gene and were not observed in 200 control alleles. No somatic mutations were found. CONCLUSIONS: Germ-line mutations of the SDHD gene are present in a significant number of patients with apparently sporadic parasympathetic PGL. Somatic SDHD mutations do not play a significant role in the sporadic form of this tumor. Genetic testing for SDHD germ-line mutations should be considered for every patient presenting with this tumor, even if a personal or family history of PGL is absent, to allow appropriate clinical management.

Background: Balloon injury (BI) of the rat carotid artery (CCA) is widely used to study intimal hyperplasia (IH) and decrease in lumen diameter (LD), but CCA's small diameter impedes the evaluation of endovascular therapies. Therefore, we validated BI in the aorta (AA) and iliac artery (CIA) to compare it with CCA. Methods: Rats underwent BI or a sham procedure (control). Light microscopic evaluation was performed either directly or at 1, 2, 3, 4 and 16 weeks follow-up. The area of IH and the change in LD (LD at 16 weeks minus LD post BI) were compared. Results: In the BI-groups the area of IH increased to 0.14 ± 0.08 mm2 (CCA), 0.14 ± 0.03 mm2 (CIA) and 0.12 ± 0.04 mm2 (AA) at 16 weeks (NS). The LD decreased with 0.49 ± 0.07 mm (CCA), compared to 0.22 ± 0.07 mm (CIA and 0.07 ± 0.10 mm (AA) at 16 weeks (p < 0.05). The constrictive vascular remodelling (CVR = wall circumference loss combined with a decrease in LD) was -0.17 ± 0.05 mm in CIA but absent in CCA and AA. No IH, no decrease in LD and no CVR was seen in the control groups. Conclusions: BI resulted in: (1.) a decrease in LD in CCA due to IH, (2.) a decrease in LD in CIA due to IH and CVR, (3.) no change in LD in AA, (4.) Comparable IH development in all arteries, (5.) CCA has no vasa vasorum compared to CIA and AA, (6.) The CIA model combines good access for 2 F endovascular catheters with a decrease in LD due to IH and CVR after BI.

BACKGROUND: Balloon injury (BI) of the rat carotid artery (CCA) is widely used to study intimal hyperplasia (IH) and decrease in lumen diameter (LD), but CCA's small diameter impedes the evaluation of endovascular therapies. Therefore, we validated BI in the aorta (AA) and iliac artery (CIA) to compare it with CCA. METHODS: Rats underwent BI or a sham procedure (control). Light microscopic evaluation was performed either directly or at 1, 2, 3, 4 and 16 weeks follow-up. The area of IH and the change in LD (LD at 16 weeks minus LD post BI) were compared. RESULTS: In the BI-groups the area of IH increased to 0.14 +/- 0.08 mm2 (CCA), 0.14 +/- 0.03 mm2 (CIA) and 0.12 +/- 0.04 mm2 (AA) at 16 weeks (NS). The LD decreased with 0.49 +/- 0.07 mm (CCA), compared to 0.22 +/- 0.07 mm (CIA) and 0.07 +/- 0.10 mm (AA) at 16 weeks (p < 0.05). The constrictive vascular remodelling (CVR = wall circumference loss combined with a decrease in LD) was -0.17 +/- 0.05 mm in CIA but absent in CCA and AA. No IH, no decrease in LD and no CVR was seen in the control groups. CONCLUSIONS: BI resulted in: (1.) a decrease in LD in CCA due to IH, (2.) a decrease in LD in CIA due to IH and CVR, (3.) no change in LD in AA, (4.) Comparable IH development in all arteries, (5.) CCA has no vasa vasorum compared to CIA and AA, (6.) The CIA model combines good access for 2 F endovascular catheters with a decrease in LD due to IH and CVR after BI.

CONTEXT: Patients who undergo major vascular surgery are at increased risk of perioperative cardiac complications. High-risk patients can be identified by clinical factors and noninvasive cardiac testing, such as dobutamine stress echocardiography (DSE); however, such noninvasive imaging techniques carry significant disadvantages. A recent study found that perioperative beta-blocker therapy reduces complication rates in high-risk individuals. OBJECTIVE: To examine the relationship of clinical characteristics, DSE results, beta-blocker therapy, and cardiac events in patients undergoing major vascular surgery. DESIGN AND SETTING: Cohort study conducted in 1996-1999 in the following 8 centers: Erasmus Medical Centre and Sint Clara Ziekenhuis, Rotterdam, Twee Steden Ziekenhuis, Tilburg, Academisch Ziekenhuis Utrecht, Utrecht, and Medisch Centrum Alkmaar, Alkmaar, the Netherlands; Ziekenhuis Middelheim, Antwerp, Belgium; and San Gerardo Hospital, Monza, Istituto di Ricovero e Cura a Carattere Scientifico, San Giovanni Rotondo, Italy. PATIENTS: A total of 1351 consecutive patients scheduled for major vascular surgery; DSE was performed in 1097 patients (81%), and 360 (27%) received beta-blocker therapy. MAIN OUTCOME MEASURE: Cardiac death or nonfatal myocardial infarction within 30 days after surgery, compared by clinical characteristics, DSE results, and beta-blocker use. RESULTS: Forty-five patients (3.3%) had perioperative cardiac death or nonfatal myocardial infarction. In multivariable analysis, important clinical determinants of adverse outcome were age 70 years or older; current or prior angina pectoris; and prior myocardial infarction, heart failure, or cerebrovascular accident. Eighty-three percent of patients had less than 3 clinical risk factors. Among this subgroup, patients receiving beta-blockers had a lower risk of cardiac complications (0.8% [2/263]) than those not receiving beta-blockers (2.3% [20/855]), and DSE had minimal additional prognostic value. In

BACKGROUND: We studied whether the effectiveness of ultrasound screening for abdominal aortic aneurysms could be increased by preselecting high-risk subjects, based on the presence of risk indicators for the disease. METHODS: In a population-based screening programme for abdominal aortic aneurysms among 5328 subjects living in Rotterdam, The Netherlands, we studied four different strategies to select subjects for ultrasound screening of the abdominal aorta, based on risk indicators for abdominal aortic aneurysm disease. Risk indicators used in each strategy were entered in a logistic regression model to predict the probability of an individual having an abdominal aortic aneurysm. Using several cutoff values for the probability of a subject having an aneurysm for each strategy, we estimated the proportion of subjects that should be referred for ultrasound screening and the proportion of aneurysms that would be diagnosed by each strategy (sensitivity). RESULTS: When a probability of 1.5% of having an aneurysm is chosen as the cutoff point above which ultrasound screening is indicated, the proportion of subjects that would be referred for screening ranged from 36% (first strategy) to approximately 50% (other strategies), while 80% (first strategy) to approximately 94% (other three strategies) of all aneurysms would be detected. CONCLUSION: Effectiveness in screening for abdominal aortic aneurysms can be increased by selecting subjects by means of a short medical questionnaire, filled out by the screening candidates, including questions on medical history.

Objectives: The 'closed' in situ bypass results in a reduction of wound complications compared to the 'open' technique. This advantage is partly diminished by extra costs for the 'closed' procedure and a larger percentage of residual arteriovenous (AV)-fistulae. This aim of this study was to analyse costs related to 'closed' and 'open' procedures. Methods: The cost affecting parameters: (1) duration of operation; (2) length of hospital stay; and (3) number of treated residual AV-fistulae, were analysed in a randomised group of 73 patients (35 'closed' and 38 'open') in two centres. In addition, costs of the operation, nursing care and treatment of AV-fistulae were analysed. Results: The 'closed' and 'open' group showed a median duration of operation of 210 min (range 105-570) and 154 min (range 90-355) (p < 0.05), length of hospital stay of 16 days (range 5-51) and 25 days (range 12-65) (p < 0.01), and a percentage of patients treated for residual AV-fistulae of 40% and 5%, respectively (p < 0.01). The median 'closed' operation was US$ 798 more expensive than the 'open'. Median postoperative care was US$ 2664 less for the 'closed' group. Mean estimated costs for treatment of AV-fistulae was US$ 9 in the 'open' and US$ 167 in the 'closed' group. Conclusion: The 'closed' in situ vein bypass technique is cost-effective in comparison with the 'open' technique.

Objective: The aim of this study was to test pre-operative ultrasound mapping for the detection of duplications and narrow vein segments of the greater saphenous vein (GSV) used as bypass for occlusive arterial disease surgery. Patients and methods: In 44 patients pre-operative ultrasound findings of duplications and lumen assessment of the GSV were compared to the per-operative findings. Results: In nine patients (20%) the pre-operative ultrasound examination showed a duplication. Pre-operative ultrasound had missed a duplication in two cases but had instead shown a narrow segment in both. The pre-operative ultrasound assessment of lumen diameter showed a narrow lumen segment in 10 of the 44 patients. In one patient a per-operatively narrow lumen had not been seen on pre-operative ultrasound. Conclusion: Pre-operative ultrasound mapping of the GSV is a sensitive tool for detection of duplications and narrow vein segments. Since these anatomical variations provide important information for the vascular surgeon, before performing a 'closed' in situ bypass operation, pre-operative vein mapping should be considered when planning such a procedure.

Objectives: This study sought to optimize preoperative cardiac risk stratification in a large group of consecutive candidates for vascular surgery by combining clinical risk assessment and semiquantitative dobutamine-atropine stress echocardiography. Background: Dobutamine-atropine stress echocardiography has been used for the prediction of perioperative cardiac risk in a small group of patients scheduled for elective major vascular surgery on the basis of the presence or absence of stress-induced regional left ventricular wall motion abnormalities. Methods: Clinical risk assessment and dobutamine-atropine stress echocardiography were performed in 302 consecutive patients presenting for major vascular surgery. The extent and severity of stress wall motion abnormalities and the heart rate at which they occurred, in addition to the presence of wall motion abnormalities at rest, were assessed. Results: The absence of clinical risk factors (angina, diabetes, Q waves on the electrocardiogram, symptomatic ventricular tachyarrhythmias, age >70 years) identified a low risk group of 100 patients with a 1% cardiac event rate (unstable angina). Dobutamine-atropine stress echocardiographic findings were positive in 72 patients. Twenty-seven patients had a perioperative cardiac event (cardiac death in 5, nonfatal infarction in 12, unstable angina pectoris in 10); all 27 patients had positive stress test results (positive predictive value 38%, negative predictive value 100%). The semiquantitative asses

With current 30-MHz intravascular ultrasound systems, flowing blood may cause considerable backscatter which in real-time images is characterized by dynamic speckle. However, in a single intravascular ultrasound image (still-frame) the discrimination between arterial lumen and wall may be difficult due to the frozen intraluminal speckle, particularly in the presence of dissections. We compared subtraction, averaging and saline flush as methods to improve the discrimination between arterial lumen and wall in a single image. The real-time images served as gold standard. In 22 patients who underwent peripheral balloon angioplasty, ultrasound images obtained from 84 sites were examined. The sensitivity and specificity of detecting dissections were in the subtraction image 85% and 100%, in the averaged image 57% and 96%, and in the saline flush image 58% and 86%, respectively. Subtraction is a promising method to outline the irregular lumen in a single image.

Quantitative analysis of arterial dimensions from high frequency intravascular ultrasound images (30 MHz) may be hampered by strong blood scattering. Replacement of blood by saline is one method to provide a clear view of the arterial lumen; another method is that of temporal averaging of successive ultrasound images. The accuracy of this latter method was tested by comparing the lumen area measurements on the temporal-averaged image, with the data of the same cross-section obtained from the single-frame and saline-filled images. The mean lumen area measured on the temporal-averaged images was similar to that measured on the single-frame images (mean difference: −0.02 ± 1.16 mm2; p = ns). The mean lumen ar