H. van Urk

Dobutamine stress echocardiography for assessment of perioperative cardiac risk in patients undergoing major vascular surgery.

BackgroundThe purpose of this study was to determine the predictive value of dobutamine stress echocardiography for perioperative cardiac events in patients scheduled for elective major noncardiac vascular surgery. Methods and ResultsPatients (N = 136; mean age, 68 years) unable to exercise underwent a dobutamine stress test before surgery (incremental dobutamine infusion [10-40 μg. kg-1. min-1] continued with atropine [0.25-1 mg i.v.] if necessary to achieve 85% of the age-predicted maximal heart rate without symptoms or signs of ischemia). The clinical risk profile was evaluated by Detskys modification Goldmans risk factor analysis. Echocardiographic images were evaluated by two observers blinded to the clinical data of the patients, and results of the test were not used for clinical decision making. Technically adequate images were obtained in 134 of 136 patients, one major complication occurred (ventricular fibrillation), and three tests were discontinued prematurely because of side effects. Finally, data from 131 patients were analyzed with univariate and multivariate methods. The dobutamine stress test was positive (new or worsened wall motion abnormality) in 35 of 131 patients. In the postoperative period, five patients died of myocardial infarction, nine patients had unstable angina, and one patient developed pulmonary edema. All patients with cardiac complications (15 patients) had a positive dobutamine stress test. cardiac events occurred in patients with negative tests. Five patients with a technically inadequate prematurely stopped test were operated on without complications. By multivariate analysis (logistic regression), only age >70 years and new wall motion abnormalities during the dobutamine test were significant predictors of perioperative cardiac events. ConclusionsDobutamine stress echocardiography is a feasible, safe, and useful method for identifying patients at high or low risk of perioperative cardiac events. The test yields additional information, beyond that provided by clinical variables, in patients who are scheduled for major noncardiac vascular surgery.

A meta-analysis comparing the prognostic accuracy of six diagnostic tests for predicting perioperative cardiac risk in patients undergoing major vascular surgery

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 dysfunction.

Effect of balloon angioplasty on femoral artery evaluated with intravascular ultrasound imaging.

BackgroundIntravascular ultrasound was used to assess the immediate effect of balloon angioplasty on the superficial femoral artery. Methods and Results. In 16 consecutive patients, corresponding ultrasonic cross sections (n = 72) before and after balloon angioplasty were qualitatively and quantitatively analyzed. The qualitative data were compared with angiographic findings. Before intervention, the angiographically demonstrated obstructive lesions were confirmed by intravascular ultrasound. Ultrasound enabled discrimination between soft (n = 43) and hard (n = 29) lesions, as well as between eccentric (n = 57) and concentric (n = 15) lesions. After balloon angioplasty, the presence of a dissection assessed angiographically in 14 patients was confirmed by intravascular ultrasound. Additional morphological information provided by ultrasound included plaque rupture in 14 patients and internal lamina rupture in six patients. Quantitative ultrasound data revealed an increase in free lumen area from 9.7±4.7 to 18.3±7.0 mm2 (p ≤ 0.01), an increase in minimal lumen diameter from 2.8±0.7 to 3.6±1.2 mm (p ≤ 0.01), and an increase in media-bounded area from 21.7±5.4 to 28.3±5.8 mm2 (p ≤ 0.01). The lesion area for the majority of cases (n = 32) remained unchanged (13.0±4.9 mm2 versus 12.9±4.6 mm 2), or the lesion disappeared partially (from 9.1±0.9 to 4.3±1.4 mm2, n = 4, p.0.01) or totally (from 10.1±4.2 to 0 mm2, n = 6). Stretching of the arterial wall was further evidenced by medial thinning from 0.55±0.19 to 0.34±0.11 mm (p ≤ 0.01). ConclusionsLuminal enlargement by balloon dilatation is achieved primarily by overstretching the arterial wall, with the lesion volume remaining practically unchanged. Overstretching is accompanied almost always by dissection and plaque rupture and occasionally by an internal lamina rupture.

Subfascial endoscopic ligation in the treatment of incompetent perforating veins

OBJECTIVES To assess the technique of subfascial endoscopic ligation of incompetent perforatory veins by use of a mediastinoscope. DESIGN Prospective open clinic study. SETTING Two Departments of Surgery. MATERIALS AND METHODS Thirty-eight consecutive patients (40 legs) with recurrent or protracted venous ulceration of the lower leg were treated. Through a short, transverse incision of the skin and fascia in the proximal 1/3 of the lower leg a mediastinoscope (length 18 cm, diameter 12 mm) is inserted after which the perforating veins are ligated by haemoclips under direct vision. MAIN RESULTS All legs showed signs of incompetent perforating veins by clinical examination, confirmed with continuous wave ultrasonography and in 31 legs there was associated deep vein incompetence. Sixteen patients had active ulceration at the moment of operation and 22 had a history of recent or recurrent ulceration. One patient developed an inflammatory reaction at the wound and in two legs a subfascial infection occurred, necessitating surgical drainage. No postoperative mortality was seen. All 16 ulcers healed within 2 months (mean: 34 days; range: 21-55 days). During a mean follow-up of 3.9 (range: 2-5) years only one out of 38 patients (2.5%) developed a recurrent ulcer. CONCLUSIONS Subfascial endoscopic ligation of incompetent perforating veins by use of a mediastinoscope is a relatively simple technique with a low postoperative complication rate and a low recurrent ulcer rate which makes it a valuable method for treating incompetent perforating veins.

Intravascular ultrasonic imaging: histologic and echographic correlation.

The feasibility of assessing arterial wall characteristics with an intravascular 40 MHz ultrasonic imaging device was determined in vitro. Ten autopsy specimens of human arteries, with and without atherosclerosis, were studied. A close relationship was observed between the histologic section and the corresponding ultrasonic cross-section with regard to the location, maximum plaque thickness and extent of the atherosclerotic lesion along the circumference of the vessel wall. Based on echogenicity of the atherosclerotic lesion, ultrasound could distinguish four basic types of atherosclerotic plaque components: 1. hypoechoic: a reflection of lipid deposits; 2. soft echoes: reflective of fibromuscular tissue; 3. bright echoes: representative of fibrous tissue; 4. bright echoes with shadowing behind the lesion: representative of calcium deposits. It is anticipated that development of such a catheter-tip imaging system combined with recanalisation methods will be of immense benefit for the precise localisation and identification of vessel wall pathology, precise positioning of a recanalisation instrument (laser device, atherectomy catheter) and subsequent use of this recanalisation procedure and for assessing the effect of recanalisation.

Technical Data and Complications of Spinal Cord Stimulation: Data from a Randomized Trial on Critical Limb Ischemia

This study was done to evaluate the effect of spinal cord stimulation (SCS) on critical limb ischemia and to report technical problems and complications. One hundred and twenty patients with critical limb ischemia were eligible for randomization between medical treatment and medical treatment plus SCS. Sixty received a spinal cord stimulator (Itrel II; Medtronic, Minneapolis, Minn., USA). Primary outcome measures were limb salvage and pain relief. The mean pain reduction in both treatment groups was 50% (from 5 to 2.5 on the visual analog scale). The 2-year limb survival was 52% (SCS) versus 46% (standard treatment; p = 0.47). The number of patients undergoing major amputations in the SCS group with intermediate TcpO2 values was half of that in the standard group (14 vs. 28; 24 vs. 48%; p = 0.17). Implantation was successful in 51 patients. Technical problems such as loss of stimulation due to lead displacement occurred in 13 patients (22%), local infection at the site of implantation occurred in 3 patients (5%), resulting in a total complication rate of 27%. Prematue depletion of the battery occurred within 2 years in 3 patients (5%). There were no lead fractures, epidural infections, hematoma or cerebrospinal fluid leakage. Training of physicians and better reliability of the hardware should reduce the frequency of technical problems. Lead displacement remains the major technical problem. The search for prognostic factors of limb salvage is important. One microcirculatory measurement (TcpO2) seems to have a prognostic value, which remains to be described more precisely.

Comparison between serum creatinine and creatinine clearance for the prediction of postoperative mortality in patients undergoing major vascular surgery.

BACKGROUND Poor renal function prior to surgery is associated with increased risk for mortality in patients undergoing major vascular surgery. Traditionally, this function is assessed by serum creatinine concentration (SeCreat). However, SeCreat is also influenced by age, gender and body weight. Hence, creatinine clearance (C(Cr)) is considered to be a better reflection of renal function. This study was undertaken to explore the prognostic value of preoperative calculated Cc, compared to SeCreat for the prediction of postoperative mortality. PATIENTS AND METHODS The study group comprised 852 consecutive patients who underwent elective major vascular surgery at the Erasmus Medical Center, Rotterdam. Preoperative C(Cr) was calculated based on the Cockroft-Gault equation using preoperative SeCreat, age, body weight and gender. Univariable logistic regression analyses were used to study the relation between preoperative SeCreat, C(Cr) and postoperative mortality. Furthermore, multivariable logistic regression analysis was applied to evaluate the additional predictive value of age, body weight and gender additional to SeCreat. The receiver operating characteristic (ROC) curve was determined to evaluate the predictive power of several regression models for perioperative mortality. RESULTS Postoperative mortality was 5.9% (50/852) within 30 days of surgery. In a univariable analysis, 10 micromol/l increment of SeCreat were associated with a 20% increased risk of postoperative mortality (OR = 1.2, 95% CI, 1.1-1.3) with an area under the ROC curve of 0.64 (95% CI, 0.56-0.71). If age, gender and body weight were added, the area under the ROC curve increased to 0.70 (95% CI, 0.63-0.77; p < 0.001), indicating that these risk factors had additional prognostic value. Indeed, in a separate regression analysis 10 ml/min decrease in C(Cr) was associated with a 40% increased risk of postoperative mortality (OR = 1.4,95% CI, 1.2-1.5; ROC area: 0.70, 95% CI, 0.63-0.76). ROC curve analysis showed that the cut-off value of 64 ml/min for C(Cr) yielded the highest sensitivity/specificity to predict postoperative mortality. CONCLUSION Preoperative SeCreat was strongly associated with postoperative mortality, and adding age, gender, and body weight to the model showed improved predictive power indicating that preoperative C(Cr) calculated with these data has additional prognostic value.

Advantages of limited thoracoscopic sympathectomy

AbstractBackground: Thoracoscopic resection of the first through the fourth thoracic sympathetic ganglion for palmary and axillary hyperhidrosis and Raynauds syndrome is associated with a high initial success rate. However, the reported incidence of compensatory hyperhidrosis of the trunk and legs and Horners syndrome are high. This study assesses the results of thoracoscopic sympathectomy limited to transection of the interganglionic trunk or resection of one or two thoracic ganglia. Methods: Twenty-eight thoracoscopic sympathectomies were done for dystrophy of the hand (n=9), palmar and axillary hyperhidrosis (n=6), and Raynauds syndrome (n=4). The extent of sympathectomy varied from interganglionic division between the second and third ganglion (n=12), to resection of the third ganglion (n=12), to resection of the second and third ganglion (n=4). Results: Sympathectomy resulted initially in relief of symptoms in all cases. Horners syndrome did not occur. Conclusions: After a median follow-up of 11 months, two of nine patients with dystrophy judged the result of operation as good. All patients with hyperhidrosis and Raynauds syndrome judged the result of sympathectomy as good. Compensatory hyperhidrosis was experienced by two patients with dystrophy of the hand who had removal of the second and third sympathetic ganglion.

Epidemiology of Abdominal Aortic Aneurysms

Aneurysms of the abdominal aorta (AAA) are a common cause of death. Ruptured AAA accounts for 1.3% of the deaths in men over 65 years of age. 1 In principle, most of these deaths are preventable because an asymptomatic AAA can be treated surgically. In 1952, Dubost 2 was the first to replace an abdominal aortic aneurysm with a graft. Since then the prognosis of the aneurysm of the abdominal aorta has changed dramatically. Nowadays the elective perioperative mortality is less than 5% 3 and a patient surviving aortic grafting has a life expectancy similar to that of men and women of the same age category. 4 In the case of ruptured AAA only one patient in three reaches the hospital alive. The reported mortality rates for emergency surgery for ruptured AAA vary from 30 to 63%.4-7 Despite the importance of aneurysms of the abdominal aorta, little is known about its prevalence, incidence, risk indicators and prognostic factors. Studies dealing with the epidemiology of AAA have only recently been performed. This may be related to the development of ultrasound diagnosis in the midseventies, a technique which provides an easy, inexpensive and accurate method to detect AAA. In this article the available literature on etiology, diagnosis, prevalence, incidence, risk indicators, and prognosis of AAA is reviewed. The objective of this review is to detect gaps in the knowledge on the epidemiology of the aneurysm of the abdominal aorta and to make suggestions as to the direction of future research in the light of the question as to whether screening of the general population for aneurysms of the abdominal aorta should be advocated. Three theories of the aetiology of AAA have emerged: 13 the genetic theory; the proteolytic enzyme theory; and the trace metal theory. Aneurysms of the abdominal aorta were first thought to be atherosclerotic in origin, s-ll Martin 12 was the first to question this concept, suggesting that atherosclerosis may not be the cause but rather the consequence of aortic degeneration. Sterpetti and co-workers 13 proposed the existence of two types of abdominal aneurysms: the first type associated with atherosclerotic occlusive disease and the other not. In their study of 526 patients undergoing aneurysmal resection, 25% were believed to be non-atherosclerotic. There were significantly more ruptures in this group, compared to the atherosclerotic group. A positive family history of AAA was also reported more frequently in the group of the non-atherosclerotic patients. Other differences between atherosclerotic and non-atherosclerotic patients with AAA suggest a generalised weakness of the aortic wall in the non-atherosclerotic type AAA. This may explain the higher risk of rupture and the increased incidence of false aneurysms after operative repair in these patients. They also appear to have a higher risk of aneurysms at other sites of the arterial tree. The finding that men with a first degree relative with AAA experience a 10-fold increased risk of developing an AAA, 14-2° provides a strong argument for a genetic component. Genetic variation on chromosome 16 in patients with AAA has been reported. 21 This has been related to an increased activity of alpha-2 haptaglobulin leading to an acceleration of the hydrolysis of elastin fibres by elastase.

Design Issues of a Randomised Controlled Clinical Trial on Spinal Cord Stimulation in Critical Limb Ischaemia

OBJECTIVES Review of the design of a clinical study to evaluate of the efficacy of epidural spinal cord electrical stimulation (ESES) as compared to best medical treatment in patients with nonreconstructible critical limb ischaemia. DESIGN Randomised controlled clinical trial of pragmatic type, which will be analysed according to the intention-to-treat principle. The treatment strategies are ESES, in addition to best medical treatment, and best medical treatment alone. Patients are followed-up for at least 18 months. SETTING The ESES-trial is an ongoing multicentre trial in 17 hospitals in The Netherlands. PATIENTS Patients with critical limb ischaemia, nonsuitable for either primary intervention or reintervention after failing reconstructions. CHIEF OUTCOME MEASURES Limb survival, patient survival, quality of life and cost-effectiveness. MAIN RESULTS From November 1991 until May 1994 120 patients had been enrolled. Using life-table analysis, at one year 76% of these randomised patients were alive: 41% without amputation and 35% with amputation. Quality of life of the trial patients was low, even compared to other severely ill patient groups, such as liver and heart transplant candidates. CONCLUSIONS Considering the high incidence of death and amputation, 18 months of follow-up seems adequate to detect a clinically relevant outcome improvement from ESES-treatment, if present. We hope to present the results of this study at the end of 1995.