Early postoperative detection of tissue necrosis in amputation stumps with indocyanine green fluorescence angiography

OBJECTIVE

Amputations of the lower extremity due to irreversible ischemic tissue loss are performed as distally as possible. Therefore, oftentimes wound-healing disorders develop, requiring additional surgical treatment.

METHODS

The amputations stumps of 10 patients with irreversible ischemic tissue loss due to arteriosclerosis were investigated within 72 hours postoperatively with indocyanine green (ICG) fluorescence.

RESULTS

For 6 of the investigated stumps, no perfusion deficit could be seen through fluorescence angiography. All stumps displayed primary healing. In the fluorescence angiography of 3 amputations, stump perfusions deficits predicted later tissue necrosis and had to be amputated again in a second operation. One amputation wound showed a small ICG perfusion deficit that represented a blood clot.

CONCLUSION

Indocyanine green fluorescence angiography allows a perfusion analysis of amputation stumps and therefore a prediction of the expected tissue necrosis. This tool may allow reliable prediction of amputation level.

Multiple biological predictors for vulnerable carotid lesions

BACKGROUND

In this study a multiscore analysis of various biomarkers including matrix metalloproteinases (MMPs), inflammatory factors and other clinical parameters was performed to establish a set of reliable biomarkers for improved detection of plaque instability in patients with advanced carotid stenosis.

METHODS

Study patients (n = 101) were classified as histologically stable (n = 37) or unstable (n = 64). Serum levels of MMP-1, -2, -3, -7, -8, -9, MMP inhibitors TIMP-1, -2, and inflammatory factors such as tumor necrosis factor (TNF-alpha), interleukin (IL)-1beta, -6, -8, -10, and -12 were measured by ELISA assays. Multiscore analysis was performed using multiple receiver operating characteristics analysis and determination of appropriate cutoff values.

RESULTS

Circulating levels of MMP-1, -7, TIMP-1, TNF-alpha, and IL-8 were significantly enhanced in patients with unstable plaques compared to individuals with stable lesions, mean differences being 1.2 (p = 0.032), 2.5 (p = 0.004), 30.0 (p = 0.014), 1.3 (p = 0.047), and 2.2 (p = 0.033), respectively. The combination of MMP-1, -7, TIMP-1 and IL-8 demonstrated the highest positive predictive value of 89.4% and negative predictive value of 60.1% for patients correctly classified as individuals with unstable and stable carotid lesions by means of blood sample analysis.

CONCLUSIONS

Multiple relevant biomarkers that play a decisive role in plaque instability can improve the correct determination of vulnerable carotid plaques in patients with advanced carotid artery stenosis.

Ultrasonographic screening for the detection of abdominal aortic aneurysms

BACKGROUND

The prevalence of abdominal aortic aneurysms (AAA) with a maximal diameter of 3 cm or more is age-dependent; among persons over age 65, it lies between 4% and 8% in men and between 0.5% and 1.5% in women. About 10% of all AAAs have a maximum diameter of 5 cm or more. The prognosis of ruptured AAA (rAAA) is dismal, with an overall mortality of at least 80%. Ultrasonography of the abdominal aorta is a safe and technically simple method of detecting AAAs.

METHODS

Evaluation of population-based, randomized studies of ultrasonographic screening for the detection of AAA, based on a selective review of the literature.

RESULTS

A meta-analysis of four randomized controlled studies showed that ultrasonographic screening was associated with a significant lowering of AAA-related mortality in men aged 65 to 80 after it had been performed for 3-5 years (risk reduction 44%, odds ratio [OR] 0.56, 95% confidence interval [CI] 0.44-0.72) and after it had been performed for 7-15 years (risk reduction 53%, OR 0.47, 95% CI 0.25-0.90). AAA screening was also associated with a significant lowering of the overall mortality after 7-15 years, but not in the first 5 years. Ultrasonographic screening led to a significant increase in the number of elective AAA operations performed and to a 50% reduction of the number of emergency operations for rAAA.

CONCLUSION

Ultrasonographic screening for AAA is a technically simple diagnostic test that is associated with a major reduction of AAA-related mortality. In view of the higher prevalence of AAA among the elderly, it is recommended that all men aged 65 or older and all men and women with a family history of AAA should be systematically screened. A national ultrasound screening program should be urgently implemented in Germany in order to bring about a major reduction in AAA-associated mortality.

Floating caval thrombus arising from the ovarian vein

We describe the case of a 37-year-old pregnant woman, who was admitted to hospital for suspicion of chorioamnionitis. An emergency C-section was performed. Four days later, the patient suffered from abdominal pain and fever. Computed tomographic scanning demonstrated only a thrombosis of the right ovarian vein. Anticoagulation and antibiotic therapy was started immediately. Color duplex imaging performed 3 days later revealed a free-floating caval thrombus reaching the confluence of hepatic veins while the patient was fully anticoagulated. Emergency thrombectomy was performed by laparotomy, and the thrombus was removed by caval incision during suprahepatic clamping of the inferior vena cava. The patient recovered rapidly from surgery and was discharged on the tenth postoperative day.

Association between carotid diameter and the advanced glycation end product N-epsilon-carboxymethyllysine (CML)

Background

N^ε-Carboxymethyllysine (CML) is the major non-cross linking advanced glycation end product (AGE). CML is elevated in diabetic patients and apparent in atherosclerotic lesions. AGEs are associated with hypertension and arterial stiffness potentially by qualitative changes of elastic fibers. We investigated whether CML affects carotid and aortic properties in normoglycemic subjects.

Methods

Hundred-two subjects (age 48.2 ± 11.3 years) of the FLEMENGHO study were stratified according to the median of the plasma CML level (200.8 ng/ml; 25^th percentile: 181.6 ng/ml, 75^th percentile: 226.1 ng/ml) into "high CML" versus "low CML" as determined by ELISA. Local carotid artery properties, carotid intima media thickness (IMT), aortic pulse wave velocity (PWV), blood pressure and fetuin-A were analyzed. In 26 patients after carotidectomy, CML was visualized using immunohistochemistry.

Results

According to the CML median, groups were similar for anthropometric and biochemical data. Carotid diameter was enlarged in the "high" CML group (485.7 ± 122.2 versus 421.2 ± 133.2 μm; P < 0.05), in particular in participants with elevated blood pressure and with "high" CML ("low" CML: 377.9 ± 122.2 μm and "high" CML: 514.5 ± 151.6 μm; P < 0.001). CML was associated fetuin-A as marker of vascular inflammation in the whole cohort (r = 0.28; P < 0.01) and with carotid diameter in hypertensive subjects (r = 0.42; P < 0.01). CML level had no effect on aortic stiffness. CML was detected in the subendothelial space of human carotid arteries.

Conclusion

In normoglycemic subjects CML was associated with carotid diameter without adaptive changes of elastic properties and with fetuin-A as vascular inflammation marker, in particular in subjects with elevated blood pressure. This may suggest qualitative changes of elastic fibers resulting in a defective mechanotransduction, in particular as CML is present in human carotid arteries.

Evaluation of serum matrix metalloproteinases as biomarkers for detection of neurological symptoms in carotid artery disease

OBJECTIVE

Relevant soluble matrix metalloproteinases (MMPs), their inhibitors, tissue inhibitor of metalloproteinases (TIMPs), and serological factors were analyzed as possible biomarkers for neurological symptoms in patients with carotid artery stenosis.

METHODS AND RESULTS

Asymptomatic (n = 76) and symptomatic (n = 69) patients were evaluated. Serum levels of collagenases (MMP-1, -8), gelatinases (MMP-2, -9), stromelysin (MMP-3), matrilysin (MMP-7), and TIMP-1, -2 were determined by enzyme-linked immunosorbant assay (ELISA). Furthermore, fibrinogen, C-reactive protein (CRP), leukocytes, and further serological parameters were measured. Circulating MMP-7, -8, -9, and TIMP-1 were significantly enhanced in symptomatic individuals with P < .001 for MMP-7 and P < .05 for MMP-8, -9, and TIMP-1. Significant correlations were found between various MMPs with highest correlation coefficient of r = .749 between MMP-8 and -9. In addition, MMP-1, -3, -7, -9 correlated significantly with leukocytes, MMP-1, and TIMP-1 with thrombocytes, MMP-8 with fibrinogen, and MMP-7 with creatinine. Combination of more than one biomarker led to significantly enhanced positive predictive value (PPV) for neurological symptom compared to single MMP (MMP-7 + MMP-9: PPV = 73.1%, MMP-7 + MMP-8 + MMP-9: PPV = 73.8% vs. PPV = 62.5%; P < .001).

CONCLUSIONS

Thus, using appropriate analytical approaches, we showed for the first time the possibility to use set of relevant biomarkers as predictors of neurological symptoms. Such biomarkers together with current diagnostic techniques may further contribute to recognize vulnerable lesions to define patients at risk.

Long-term results of balloon-expandable LifePath endografts in abdominal aortic aneurysm: a single-center experience

OBJECTIVE

This retrospective single-center study analyzed long-term results after LifePath (Edwards Lifesciences LLC, Irvine, Calif) endoprosthesis implantation for abdominal aortic aneurysm (AAA), primarily focusing on the wire form fracture issue and consecutive endoleak rate.

METHODS

Between 1999 and 2004, all consecutive patients with LifePath AAA devices in our institution were included in the retrospective analysis. All patients had computed tomography angiography (CTA) imaging preoperatively and image postprocessing. The follow-up using CTA imaging specifically addressed material fatigue (wire form fractures) resulting in migrations and type I endoleaks.

RESULTS

During the 6-year study period, which included the 1-year withdrawal and redesign of the device, 51 patients were treated with LifePath AAA endografts. The 30-day mortality was 0%. The perioperative 30-day morbidity was 9.8%. One patient required a primary conversion due to misdeployment of the iliac limbs within the graft main body. The primary endoleak rate was 20.56% (type I, 2%; type II, 19.6%). During the mean follow-up of 40.7 months, 12 patients died, six were lost to follow-up, and 32 underwent subsequent CTA imaging. Eight patients (25%) demonstrated a proximal type I endoleak, seven (22%) had a type II endoleak, and three had a type III endoleak (9%). In nine patients (28.1%), wire form fractures could be detected at image postprocessing. Four patients required a secondary conversion due to endoleak and aneurysm growth (2 type I endoleaks and 2 type III endoleaks).

CONCLUSION

Wire form fracture is the major structural problem in the LifePath balloon-expandable endograft device, resulting in a significant endoleak rate. We must caution those patients with a LifePath device in-situ that careful follow-up must be performed due to material fatigue and they should consider secondary conversion.

Complex Abdominal Aortic Pathologies: Operative and Midterm Results after Pararenal Aortic Aneurysm and Type IV Thoracoabdominal Aneurysm Repair

The aim of the study was to describe the clinical outcome of pararenal aortic aneurysm (PAAA) and type IV thoracoabdominal aneurysm (TAAA) repair, with special consideration placed on disease-related complications and midterm follow-up. Data were collected retrospectively between 1997 and 2004 for patients with PAAA or type IV TAAA repair. Comorbidities, operative details, and early and late outcome were analyzed to predict disease-related complications. During the study period, 63 patients (33 PAAAs, 30 type IV TAAAs) underwent aortic repair. The 30-day mortality rate of 7.9% was acceptable for complex aortic entities compared with other series. The morbidity for cardiac events was 3.2%, for pulmonary complications 17.5%, and the need for reoperation was 14.3%. With regard to disease-related complications, two patients (3.2%) required dialysis and one patient (1.6%) developed paraplegia (spinal cord ischemia) after type IV TAAA repair. Complex aortic repair for PAAAs and type IV TAAAs showed acceptable perioperative mortality, morbidity, and midterm survival rates. Patients with type IV TAAAs suffered more major complications, such as postoperative dialysis or spinal cord ischemia.

Prestressing in finite deformation abdominal aortic aneurysm simulation

In abdominal aortic aneurysm (AAA) simulation the patient-specific geometry of the object of interest is very often reconstructed from in vivo medical imaging such as CT scans. Such geometries represent a deformed configuration stressed by typical in vivo conditions. However, commonly, such structures are considered stress-free in simulation. In this contribution we sketch and compare two methods to introduce a physically meaningful stress/strain state to the obtained geometry for simulations in the finite strain regime and demonstrate the necessity of such prestressing techniques. One method is based on an inverse design analysis to calculate a stress-free reference configuration. The other method developed here is based on a modified updated Lagrangian formulation. Formulation of both methods is provided. Applicability and accurateness of both approaches are compared and evaluated utilizing fully three-dimensional patient-specific AAA structures in the finite strain regime.

Middle mesenteric artery arising from an inflammatory infrarenal aortic aneurysm

We report of a patient with an inflammatory infrarenal aortic aneurysm with a diameter of 6.5 cm, a middle mesenteric artery (MMA) arising from the aneurysm, and a review of the literature. The patient underwent successful surgical treatment by using an interposition tube graft (Dacron graft, 18 mm) with replantation of the MMA. Reports about a MMA arising separately from the aorta are extremely rare, especially in combination with an infrarenal aortic aneurysm. In our case, it arose from the anterior aspect of the abdominal aorta, 6 cm below the superior mesenteric artery (SMA) and 1.2 cm above the inferior mesenteric artery (IMA). The MMA gave branches to the ileum and distal jejunum and supplied the iliocolic and middle colic artery branch as well as the left colic artery branch. It is of extreme clinical importance for the surgical procedure to have a detailed knowledge of the different anatomical variations and anomalies.

Novel role of the CXC chemokine receptor 3 in inflammatory response to arterial injury: involvement of mTORC1

Atherosclerosis, restenosis, and posttransplant graft atherosclerosis are characterized by endothelial damage, infiltration of inflammatory cells, and proliferation of smooth muscle cells. The CXCR3-activating chemokines interferon-gamma inducible protein 10 (IP10) and MIG (monokine induced by interferon-gamma) have been implicated in vascular repair and remodeling. The underlying molecular mechanisms, however, remain elusive. Here, we show that wire-mediated arterial injury induced local and systemic expression of IP10 and MIG, resulting in enhanced recruitment of CXCR3(+) leukocytes and hematopoietic progenitor cells. This was accompanied by profound activation of mammalian target of rapamycin complex (mTORC)1, increased reactive oxygen species production, apoptosis, and intimal hyperplasia. Genetic and pharmacological inactivation of CXCR3 signaling not only suppressed recruitment of inflammatory cells but also abolished mTORC1 activation, reduced reactive oxygen species generation, and blocked apoptosis of vascular cells, resulting in significant reduction of intimal hyperplasia in vivo. In vitro, stimulation of T cells with IP10 directly activated mTORC1 and induced generation of reactive oxygen species and apoptosis in an mTORC1-dependent manner. These results strongly indicate that CXCR3-dependent activation of mTORC1 directly links stimulation of the Th1 immune system with the proliferative response of intimal cells in vascular remodeling.

Improvement of microcirculation after percutaneous transluminal angioplasty in the lower limb with prostaglandin E1

OBJECTIVE

The aim of the study was to investigate prospectively the microcirculation after angioplasty and its improvement with additional Prostaglandin E1 (PGE1) therapy assessed by transcutaneous pressure of oxygen.

PATIENTS AND METHODS

45 patients with intermittent claudication eligible for angioplasty were enrolled in a prospective randomised controlled clinical trial. Patients received either intra-arterial bolus of 40 microg PGE1 in addition to angioplasty or a 40 microg PGE1 intravenous infusion. Control group received no trial medication. Additional 15 patients undergoing intra-arterial angiography were also investigated. tcpO(2) values were recorded distal to the PTA region before, during the intervention, 24h, 2 and 4 weeks after intervention. Clinical endpoint was the change of tcpO(2) values 4 weeks after intervention.

RESULTS

During the 4 week follow-up tcpO(2) values decreased in patients treated with angioplasty. At the same time tcpO(2) increased significantly in those patients additionally treated with intra-arterial PGE1 bolus injection as well as with intravenous PGE1 infusion.

CONCLUSIONS

Impaired microcirculation after angioplasty can be improved with additional intravenous as well as intra-arterial PGE1 administration.

Results of the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) study to treat symptomatic stenoses at 2 years: a multinational, prospective, randomised trial

BACKGROUND

The SPACE trial is a multinational, prospective, randomised study to test the hypothesis that carotid artery stenting is not inferior to carotid endarterectomy for treating patients with severe symptomatic carotid artery stenosis. We did not prove non-inferiority of carotid artery stenting compared with carotid endarterectomy for the 30-day complication rate, and we now report the results at 2 years.

METHODS

Between March, 2001, and February, 2006, patients with symptomatic, severe (>or=70%) carotid artery stenosis were recruited to this non-inferiority trial and randomly assigned with a block randomisation design to have carotid artery angioplasty with stenting or carotid artery endarterectomy. 2-year endpoints include several clinical endpoints and the incidence of recurrent carotid stenosis of at least 70%. Clinical and vascular follow-up was done by a certified neurologist. Analyses were by intention to treat and per protocol. This trial is registered with ISRCTN, number 57874028.12.

FINDINGS

1 214 patients were randomly assigned (613 were randomly assigned to carotid angioplasty with stenting and 601 were randomly assigned to carotid endarterectomy). In both the intention-to-treat and per-protocol analyses the Kaplan-Meier estimates of ipsilateral ischaemic strokes up to 2 years after the procedure and any periprocedural stroke or death do not differ between the carotid artery stenting and the carotid endarterectomy groups (intention to treat 9.5%vs 8.8%; hazard ratio (HR) 1.10, 95%CI 0.75 to 1.61; log-rank p=0.62; per protocol 9.4%vs 7.8%; HR 1.23, 95%CI 0.82 to 1.83; log-rank p=0.31). In both the intention-to-treat and per-protocol populations, recurrent stenosis of 70% or more is significantly more frequent in the carotid artery stenting group compared with the carotid endarterectomy group, with a life-table estimate of 10.7% versus 4.6% (p=0.0009) and 11.1% versus 4.6% (p=0.0007), respectively. Only two incidences of recurrent stenoses after carotid artery stenting led to neurological symptoms.

INTERPRETATION

After 2 years' follow-up, the rate of recurrent ipsilateral ischaemic strokes reported in the SPACE trial is similar for both treatment groups. The incidence of recurrent carotid stenosis at 2 years, as defined by ultrasound, is significantly higher after carotid artery stenting. However, it cannot be excluded that the degree of in-stent stenosis is slightly overestimated by conventional ultrasound criteria.

Increased 18F-fluorodeoxyglucose uptake in abdominal aortic aneurysms in positron emission/computed tomography is associated with inflammation, aortic wall instability, and acute symptoms

OBJECTIVE

With the established computed tomographic (CT)- morphologic parameters, only the relative, but not the individual rupture risk of abdominal aortic aneurysm (AAA), can be determined. So far, increased aortic 18F-fluorodeoxyglucose (FDG) metabolism measured by positron emission tomography (PET) has been reported in AAA with increased rupture risk. The aim of the study was to analyze the histopathologic changes in AAA wall correlated with increased FDG uptake for further implications on aortic wall stability and AAA rupture risk.

METHODS

Fifteen patients with asymptomatic (n = 12) and symptomatic (n = 3) AAA underwent FDG-PET/CT, followed by open AAA repair. FDG-PET/CT was used for precise localization of maximum FDG uptake, and the maximum standard uptake values (SUV(max)) were calculated. Biopsies of the AAA wall were operatively collected from areas with maximum FDG uptake, immunohistologically stained, and semiquantitatively analyzed for inflammatory infiltrates, vascular smooth muscle cells (VSMC), matrix metalloproteinase (MMP)-2 and -9 expression, as well as for elastin and collagenous fibers.

RESULTS

Symptomatic AAA showed significantly increased FDG uptake compared with asymptomatic AAA (SUV(max), 3.5 +/- 0.6 vs 7.5 +/- 3; P < .001). Thus, increased FDG uptake was correlated with higher densities of inflammatory infiltrates (r = +0.87, P < .01) and macrophage and T-cell infiltrations (r = +0.95, P < .01 and r = +0.66, P < .05), with higher MMP-9 expressions (r = +0.86; P < .01), and with reduction of collagen fiber (r = -0.76; P < .01) and VSMCs (r = -0.71; P < .01). Consecutive correlations were found for total inflammatory infiltrates, T lymphocytes, and macrophages with MMP-9 expression (r = +0.79, +0.79 and +0.74; P < .01). Moreover, MMP-9 expression was correlated with decreasing collagen fiber content (r = -0.53, P < .05) and VSMC density (r = -0.57, P < .05).

CONCLUSIONS

Maximum aortic FDG uptake correlated significantly with inflammation, followed by increased MMP expression and histopathologic characteristics of aneurysm wall instability and clinical symptoms. Therefore, FDG-PET/CT might be a new diagnostic technique to study AAA disease in vivo and may contribute to improve prediction of individual AAA rupture risk.

[General surgery under discussion. From the viewpoint of vascular surgery]

Vascular diseases are common and their frequency is rising. Statistics show that 15% of the German population over 65 display some kind of peripheral arterial pathology. Even aneurysmatic degeneration and cardiac and visceral perfusion disorders are being observed more frequently, while peak age is dropping. Therapeutic surgical options are accordingly being continually advanced and refined. Additionally the range of interventional therapies and new conservative options has substantially increased vascular surgeons' armamentarium. Updates in surgical training have responded to this increase in such disorders, and the diversification of therapeutic modalities has resulted in the elevation of vascular surgery from specialized techniques to a fully accredited specialty equal in standing to the other seven surgical disciplines. Controversy exists however about the new accredition, beginning with the question of advancement from basic surgical training while excluding important elements of general surgery. Since those training for this specialty will branch off immediately after 2 years of basic surgical training, their final accreditation in the new classification would exclude essential skills that remain part of the training as general surgeons.

Clinical and angiographic risk factors for stroke and death within 30 days after carotid endarterectomy and stent-protected angioplasty: a subanalysis of the SPACE study

BACKGROUND

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are used to prevent ischaemic stroke in patients with stenosis of the internal carotid artery. Better knowledge of risk factors could improve assignment of patients to these procedures and reduce overall risk. We aimed to assess the risk of stroke or death associated with CEA and CAS in patients with different risk factors.

METHODS

We analysed data from 1196 patients randomised to CAS or CEA in the Stent-Protected Angioplasty versus Carotid Endarterectomy in Symptomatic Patients (SPACE) trial. The primary outcome event was death or ipsilateral stroke (ischaemic or haemorrhagic) with symptoms that lasted more than 24 h between randomisation and 30 days after therapy. Six predefined variables were assessed as potential risk factors for this outcome: age, sex, type of qualifying event, side of intervention, degree of stenosis, and presence of high-grade contralateral stenosis or occlusion. The SPACE trial is registered at Current Controlled Trials, with the international standard randomised controlled trial number ISRCTN57874028.

FINDINGS

Risk of ipsilateral stroke or death increased significantly with age in the CAS group (p=0.001) but not in the CEA group (p=0.534). Classification and regression tree analysis showed that the age that gave the greatest separation between high-risk and low-risk populations who had CAS was 68 years: the rate of primary outcome events was 2.7% (8/293) in patients who were 68 years old or younger and 10.8% (34/314) in older patients. Other variables did not differ between the CEA and CAS groups.

INTERPRETATION

Of the predefined covariates, only age was significantly associated with the risk of stroke and death. The lower risk after CAS versus CEA in patients up to 68 years of age was not detectable in older patients. This finding should be interpreted with caution because of the drawbacks of post-hoc analyses.

Transcutaneous oximetry compared to ankle-brachial-index measurement in the evaluation of percutaneous transluminal angioplasty

OBJECTIVE

To investigate transcutaneous oximetry as parameter of the microcirculation is correlated to ankle-brachial-index as parameter of the macrocirculation after peripheral angioplasty procedures.

DESIGN

Prospective study.

MATERIALS AND METHODS

60 patients suffering from intermittent claudication were scheduled for angioplasty treatment. 45 patients were considered as eligible for angioplasty after angiographic evaluation, 15 patients underwent angiography only. Transcutaneous oximetry measurements were performed before the procedure, at the end of intervention, 24h as well as 2 and 4 weeks after percutaneous transluminal angioplasty. Ankle-brachial-indices were obtained before intervention, 24h as well as 2 and 4 weeks later.

RESULTS

Ankle-brachial-indices increased significantly at 24h after angioplasty in patients being treated with angioplasty. Transcutaneous oximetry values dropped significantly at the end of the procedure and returned close to the baseline levels at 2 and 4 weeks after angioplasty. Ankle-brachial-indices and transcutaneous oximetry were positively correlated before (r=0.3833, p=0.009) as well as 4 weeks after angioplasty (r=0.4596, p=0.001). Immediately after radiological interventions, ankle-brachial-indices and transcutaneous oximetry are not positively correlated. In patients undergoing angiography only, transcutaneous oximetry levels drop significantly immediately after angiography and remain at decreased levels even at 4 weeks after intervention.

CONCLUSION

Transcutaneous oximetry as parameter of the microcirculation is positively correlated with ankle-brachial-index as parameter of the macrocirculation before and at 4 weeks after angioplasty. Intraarterial angiography leads to a sudden decrease in skin microcirculation without affecting macrocirculation. As indicated by a lack of recovery in transcutaneous oximetry levels after 4 weeks, angiography alone results in a prolonged impaired microcirculation which may reflect endothelial dysfunction caused by contrast material. The recovery of transcutaneous oximetry levels following angioplasty is counterbalanced by the adverse effects of the contrast material. Ankle-brachial-indices remains the most favourable parameter in evaluating the success of angioplasty procedures while transcutaneous oximetry serves as an indirect method in assessing endothelial dysfunction caused by contrast material.

Aneurysmen und Dissektionen der thorakalen und abdominellen Aorta

One to four per cent of all deaths in patients over 65 are caused by aneurysmatic diseases of the abdominal or thoracic aorta. For elective surgery in abdominal aneurysms, open surgery and endovascular treatment both demonstrate brilliant overall results. In the thoracic aorta, new endovascular procedures have led to considerable reductions of postoperative morbidity and mortality. Nevertheless, in view of the endovascular procedure's high cost and the still unclear long-term behaviour of the stent device, a second opinion from a specialised centre is an absolute necessity.

American Society of Anesthesiology and Rankin as Predictive Parameters for the Outcome of Carotid Endarterectomy Within 28 Days After an Ischemic Stroke

OBJECTIVE

Recent studies suggest that carotid endarterectomy (CEA) is more effective when performed closer to an ischemic event than after an arbitrary 4- to 6-week delay. Factors need to be identified to evaluate potential perioperative complications after early CEA.

METHODS

We investigated the influence of several clinical and morphological variables on the perioperative combined stroke and mortality rate and their influence on the modified Rankin-scale (mRS). In order to increase the statistical power, we combined data from three clinical studies (one multicenter and two single center trials) concerning the CEA after a waiting period of no more than 28 days. A perioperative stroke was defined as an important of at least 1 score in the mRS. Statistical analysis included univariate and multivariate analysis.

RESULTS

A total of 226 patients (167 male), aged between 30 and 87 years (median 65.05 years) underwent CEA following an ischemic stroke within a period of no more than 28 days (median 12 days). The majority (>90%) showed severe stenosis of the internal carotid artery (>/=70%), 149 patients (66%) were ranked Rankin </=2, 91 (42%) ASA </=2. The perioperative stroke and mortality rate was 8.4%; 10 patients (4.4%) suffered a nondisabling stroke and 8 patients (3.5%) a disabling second ischemic event. One patient died due to a myocardial infarction. The degree of stenosis, use of a shunt, timing of surgery, or demographic data did not significantly influence the perioperative outcome. Only the preoperative ASA classification could be shown to be a significant predictor (ASA >2, P = .0245) for a deterioration of the postoperative neurological status of at least 1 Rankin grade. There was also a trend concerning the Rankin scale at admission (Rankin >2, P = .0658). The logistic regression analysis showed that patients with an ASA classification >2 and a preoperative Rankin >2 that were treated within 12 days after the initial ischemic event had the greatest risk for a perioperative deterioration of their neurological symptoms (odds ratio: 4.4, 1.48-13.0; P = .01).

CONCLUSION

The ASA classification and the neurological status measured by the Rankin scale are predictive variables for the clinical perioperative outcome in patients treated within 28 days after an ischemic stroke. Patients ranked ASA </=2 and/or Rankin </=2 can safely undergo the CEA within a shorter waiting period. In contrast, patients with a more severe neurological deficit and a higher number of comorbidities are at a greater risk if treated too close to the ischemic event.

Do workshops improved the technical skill of vascular surgical trainees?

AIMS

Adjuncts to conventional surgical training are needed in order to address the reduction in working hours. This purpose of this study was to objectively assess the efficacy of workshop training on simulators.

METHODS

Fifteen consecutive participants of the European Vascular Workshop in 2003 and 2004 were recruited to this study. Participants performed a proximal anastomosis on a commercially available abdominal aortic aneurysm simulator, were then given intensive training on sophisticated models for 3 days and re-assessed. Pre- and post-course procedures were videotaped and independently reviewed by three assessors (tapes were blinded and in random order). The operative end product was similarly assessed. Four measures of technical skill were used: generic skill, procedural skill; a five point technical rating of the anastomosis (assessed using validated rating scales) and procedure time. Non-parametric tests were used in the statistical analysis.

RESULTS

The video assessment scores for aneurysm repair increased significantly following completion of the course (p=0.006 and p=0.004 for generic and procedural skill, respectively). End product assessment scores increased significantly post-course (p=0.001) and participants performed aneurysm repair faster following the course (p<0.05). Inter-observer reliability ranged from alpha=0.84-0.98 for the three rating scales pre- and post-course.

CONCLUSION

Objective improvements in technical performance follow intensive workshop training. Participants' perform better, faster, and with an improved end product following the course. Such adjuncts to training play an important part in a focused integrated programme that addresses reduced work hours.

Microembolic Signals Detected by Transcranial Doppler Sonography During Carotid Endarterectomy and Correlation With Serial Diffusion-Weighted Imaging

BACKGROUND AND PURPOSE

Embolic events are a major cause for procedure-related strokes after carotid endarterectomy (CEA). Transcranial Doppler sonography can reveal embolic events as microembolic signals (MES) during CEA. MES during declamping and shunting are frequently detected. MES during shunting are rare and known to be correlated with the neurological outcome of the patient. In the present study, we analyzed the occurrence of MES within different stages of CEA and whether MES within those stages were correlated with cerebral ischemia, as detected by diffusion-weighted imaging (DWI), and brain infarction, as detected by contrast-enhanced MRI.

METHODS

Thirty-three patients were monitored intraoperatively for MES using transcranial Doppler sonography. DWI was performed within 24 hours before and after surgery. Positive postoperative DWI led to reexamination with contrast-enhanced T1-MRI 7 to 10 days after CEA for detection of cerebral infarction.

RESULTS

MES were detected in 32 of 33 patients. The highest number of MES was found during shunting and declamping. A significant correlation was found between MES and DWI-lesions during dissection. A significant correlation was found between MES during dissection and shunting, and nonsignificant correlation was found between MES and the occurrence of cerebral infarction.

CONCLUSIONS

MES could be regularly detected during CEA. Dissection and shunting seem to be the most vulnerable stages of the procedure.

Operative Therapie extrakranieller Karotisstenosen

The surgical therapy for severe stenosis of the carotid provides a highly effective prophylaxis for carotid dependent ischemic strokes. After carrying out prospective, randomised studies, evidence based indications for carotid thromboarterectomy are available. Here, it is necesary to take into account the degree of stenosis, an initial clinical symptom (amaurosis fugax, TIA, stroke), and postoperative risk. This can not exceed 3% by asymptomatic and 6% by symptomatic stenoses in order not to endanger the carotid thromboarterectomy. Stenting of carotid stenoses provides a possible alternative to surgery. Until the prospective, randomised studies are completed, carotid stenting offers a clinical possibility which can only be carried out through interdisciplinary cooperation.

The Carotid Surgery for Ischemic Stroke trial: a prospective observational study on carotid endarterectomy in the early period after ischemic stroke

OBJECTIVE

The purpose of this study was to examine the safety of carotid endarterectomy (CEA) within 6 weeks after a nondisabling carotid-related ischemic stroke. Endpoints were the perioperative stroke or mortality rate and the incidence rate of cerebral bleedings.

METHODS

This prospective observational multicenter trial was performed in community and university centers. One hundred sixty-four hospitalized patients with nondisabling carotid-related ischemic stroke were included. The patients were identified clinically with the modified Rankin scale (initial neurologic deficit grade >/= 2, n = 160). Four patients with evidence of ischemic territorial infarction on cerebral computed tomographic (CT) scan but no persisting functional deficit were also included. CEA was performed within 6 weeks after stroke. Neurologic examinations were performed initially, before surgery, 3 days after surgery, and 6 weeks after CEA. Worsening of more than 1 grade on the Rankin scale was considered as a new stroke or stroke extension. Unenhanced CT scans of the brain were performed before and after surgery. CT scans were evaluated blind to clinical patient data. Statistical analysis included univariate and multivariate analysis.

RESULTS

The combined stroke or mortality rate within 30 days after CEA was 6.7%. Ten patients had a new ipsilateral stroke or stroke extension, and one patient died after surgery of a myocardial infarction. One patient (0.6%) had parenchymatous cerebral bleeding, and in 10 patients, hemorrhagic transformation within the preexisting ischemic infarction was detected but no infarct extension was observed. In the multivariate analysis, American Society of Anesthesiology (ASA) grades III and IV and decreasing age were significant predictors for an increased perioperative risk. Patients with a higher risk profile (ASA classification grades III and IV) had a high perioperative risk when CEA was performed within the first 3 weeks (14.6% versus 4.8% beyond 3 weeks). Patients without severe concomitant diseases (ASA grades I/II) had a low perioperative risk of 3.4% if CEA was performed within the first 3 weeks.

CONCLUSION

Early CEA within 6 weeks after a carotid-related ischemic stroke can be performed with a perioperative stroke or mortality rate comparable with the results reported in the European Carotid Surgery Trial and the North American Symptomatic Carotid Endarterectomy Trial. The risk of parenchymatous bleeding is low. ASA grades III and IV and decreasing age were predictive of an increased perioperative risk, especially if CEA was performed within the first 3 weeks. Patients at low risk can undergo operation safely within the first 3 weeks. Individual patient selection in an interdisciplinary approach between neurologists, anesthesiologists, and vascular surgeons remains mandatory in these patients.

[Outcome quality in vascular surgery]

INTRODUCTION

For the assessment of outcome quality, the acquisition and evaluation of internal and external treatment data is necessary. Vascular surgery is characterized in main topics of treatment such as carotid stenoses, aortic aneurysms, peripheral arterial disease, and varicose veins by clearly defined outcome indicators. Nevertheless, the determination of the quality of outcome is difficult because of the differing standards.

METHODS

For an external, comparative quality assurance, the quality assurance commission of the German Society for Vascular Surgery has established a program, "Quality Management for the carotid TEA and the BAA" according to section 137 SGB V, and has developed a questionnaire for recording the quality of treatment of varicose veins.

RESULTS

The evaluation of all the questionnaires submitted to an independent institute enables the participating departments to have a comprehensive evaluation of their own quality of outcome and provides a tool to compare it with defined quality levels (benchmarking).

CONCLUSION

For every physician, the perception of his own quality of outcome represents a fundamental requirement, which continues to gain importance within the context of future health policies.

Perfusion-weighted magnetic resonance imaging in patients with carotid artery disease before and after carotid endarterectomy

OBJECTIVE

The purpose of this study was to investigate the potential of perfusion-weighted magnetic resonance imaging for preoperative and postoperative evaluation of cerebral hemodynamics in patients undergoing carotid endarterectomy for carotid artery stenosis.

METHODS

We examined 26 patients with angiographically proven stenoses (60%-99%) of the internal carotid artery preoperatively. Perfusion imaging studies were performed by bolus-tracking of a dosage of 0.2 mmol/kg body weight of gadolinium diethylenetriaminepentaacetic acid on a 1.5-T scanner using a T2*-weighted fast low-angle shot sequence. The observed signal intensities were converted pixel by pixel into concentration-time curves. In each patient, the hemispheres were compared and the difference between the normalized first moments (NFMs) and the percentage changes of the regional cerebral blood volume (CBV) were calculated. Three months postoperatively, perfusion-weighted magnetic resonance imaging was performed in 13 patients.

RESULTS

In patients with <80% stenosis (n = 10), there was no significant alteration of NFM and regional CBV compared with the contralateral hemisphere (-0.16 +/- 0.7 s, +5.9 +/- 24.6%). In patients with stenoses >or=80% (n = 16), we found an increase in NFM ipsilateral to the stenosis of 1.2 +/- 0.92 s (P < .001) and an increase of CBV of 16.8 +/- 15.2% (P < .005). Three months postoperatively, perfusion parameters were normal in all 13 patients examined.

CONCLUSIONS

Perfusion-weighted magnetic resonance imaging is well suited to evaluate the preoperative and postoperative hemodynamic changes in patients with carotid artery stenosis. This noninvasive, semiquantitative magnetic resonance technique could prove to be a valuable adjunct in identification of patients who might benefit from carotid endarterectomy.

Immunophenotypic characterisation of carotid plaque: increased amount of inflammatory cells as an independent predictor for ischaemic symptoms

OBJECTIVES

To investigate the inflammatory response within intact carotid plaques from carotid eversion endarterectomy (CEE) to determine the relationship between immunohistological plaque morphology and ischaemic cerebrovascular symptoms.

MATERIAL AND METHODS

Intact CEE plaques from 71 patients with high-grade (>70%) stenosis undergoing CEE (group I, symptomatic, n=42; group II, asymptomatic, n =29) and 12 normal postmortem arteries (control group) were analysed with specific antibodies to inflammatory cells (T-Lymphocytes (CD3, CD4), cytotoxic T-cells (CD8), B-lymphocytes (CD20), natural killer cells (CD57), macrophages (CD68)), endothelial adhesion molecules (ICAM-1 (CD54), P-selectin (CD62P), E-selectin (CD62E), VCAM-1 (CD106) and T-lymphocyte co-stimulatory molecule (CD40)) and procoagulatory modulators (thrombomodulin (CD141), tissue factor (CD142)). Both groups were matched for gender, age, risk factors, degree of carotid artery stenosis. Plaques were measured using a semiquantitative score system in a blinded fashion by two observers. Statistical analysis of the group differences were performed by using the Kruskal-Wallis test and the Multitest Procedure with Permutation-Testing. Significance was taken as a p<0.05.

RESULTS

There were significantly more inflammatory cells, an overexpression of P-selectin and the procoagulatory markers thrombomodulin and tissue factor in symptomatic compared to both asymptomatic plaques and the ones of the control group. In both groups there was no significance for ICAM-1, VCAM-1, macrophages and co-stimulatory molecule CD40. There was also no significance for any factor between the asymptomatic and the control group. However, the differences between the symptomatic and the asymptomatic group were highly significant for all factors.

CONCLUSION

These data suggest that structural changes and inflammatory damage within the individual plaque seems to be a critical step in promoting plaque rupture with embolic sequelae.

Grading of Internal Carotid Artery Stenosis: Validation of Doppler/Duplex Ultrasound Criteria and Angiography Against Endarterectomy Specimen

OBJECTIVES

duplex ultrasound has replaced angiography prior to carotid endarterectomy (CEA) in many institutions. However, the indications for CEA are based on angiographically controlled studies and widely accepted ultrasound criteria do not exist. Consequently, the reliability of Doppler and/or duplex ultrasound to predict a high-grade ICA stenosis has to be proven.

DESIGN

prospective validation study.

MATERIALS

one hundred and fifty carotid bifurcations assessed by ultrasound and selective angiography and 68 acrylat outcasts of carotid specimen after eversion CEA.

METHODS

ICA stenosis was measured angiographically according to the ECST criteria. Combined Doppler acoustic standard criteria (CDASC), peak systolic frequency (PSF), peak systolic velocity (PSV) and end-diastolic velocity (EDV) served as criteria for the ultrasound assessment. These criteria and the results of angiography were compared to the degree of ICA stenosis determined by specimen measurements.

RESULTS

the median degree of ICA stenosis as assessed by angiography (82%, range 56-97%) and CDASC (83%, range 50-99%) corresponded well to the specimen measurements (80%, range 50-95%). The sensitivity of angiography and CDASC to predict a 70-90% ICA stenosis (ECST criteria) compared to the specimen measurements was 88% and 95%, respectively. The positive predictive value (PPV) reached 92% and 96%, respectively. CDASC were equivalent to angiography and were superior to the best single frequency or velocity parameters. If CDASC do not indicate a >/=70% ICA stenosis in spite of a PSV >/=180 cm/s and/or an EDV >/=50 cm/s, angiography may detect patients with a >70% ICA stenosis.

CONCLUSIONS

CDASC are valid in the quantification of high-grade ICA stenosis. They are more reliable than single velocity and/or frequency measurements. However, if velocity criteria and CDASC do not agree, angiography should be performed.

[Carotid surgery in patients 80 years old or older]

BACKGROUND AND OBJECTIVE

Because of their high age and markedly increased co-morbidity, physicians and geriatricians are often cautious in their indications for carotid thromboendarterectomy (TEA) in patients 80 years or older. However, it is these very patients who are subject to an exponentially increased risk of ischaemic cerebral vascular accidents (CVA). This study examined the morbidity and mortality rates of TEA in patients of this age group at one institution.

PATIENTS AND METHODS

Between 1994 and 1998, among a total of 912 TEAs, 46 had been performed in patients 80 years or older (15 women, 31 men): indications, diagnosis and associated diseases as well as perioperative complications were entered prospectively into a data-bank.

RESULTS

Only one patient (2.2%) sustained a perioperative CVA and no patient died. Three patients (6.5%) developed transitory neurological deficits. One patient had to have an emergency reoperation because of a postoperative carotid artery thrombosis. One patient had an intraoperative asystole due to a hypersensitive carotid sinus. There were no other serious cardiovascular or pulmonary complications. One patient sustained some oral muscle weakness as a result of intraoperative retractor pull on a branch of the facial muscle.

CONCLUSION

These results indicate that even in patients of this age group carotid TEA can be performed with great safety.

[Urgent and emergency carotid TEA]

Restoration of blood flow to reperfuse ischemic but not infarcted areas of the brain (ischemic penumbra) and the removal of an ongoing embolic source are the therapeutic aims of emergency and urgent carotid endarterectomy (CEA), both in patients with an acute or progressive ischemic stroke and in patients in the early period after a carotid-related stroke. Based on poor results in the 60ies and 70ies, many centers traditionally perform CEA four to six weeks after a carotid-related stroke at the earliest interval. Since natural history is associated with a high risk of an disabling and/or recurrent stroke in several subgroups of patients, some reports were able to show that urgent and emergency CEA could be worthwhile in well-selected patients.

[Measurement of local oxygen parameters for detection of cerebral ischemia. The significance of cerebral near-infrared spectroscopy and transconjunctival oxygen partial pressure in carotid surgery]

The principle of, "selective shunting" during carotid endarterectomy requires a special concept to monitor neuronal function. The valence of the oxymetric methods, "near-infrared" spectroscopy (NIRS) and conjunctival oxygen tension (pcjO2) was determined with the reference method somatosensory evoked potentials (SEP).

METHODS

In 41 patients undergoing reconstructive surgery on the internal carotid artery, recordings of the different methods were obtained under control, during carotid occlusion and during reperfusion. Cerebral ischemia was assumed if a complete loss of SEP appeared and an intraluminal shunt was placed. Conjunctival oxygen tension was measured continuously and simultaneously on the ipsi- and contralateral eye.

RESULTS

In comparison to the reference method (SEP) the sensitivity and specificity of NIRS was 80% and 94%, respectively. The occlusion induced reduction of NIRS appeared 6.5 +/- 3.2 min earlier than the corresponding loss of SEP. Biocular determination of conjunctival oxygen tension was not able to detect hypoperfusion dependent ischemia during carotid occlusion.

CONCLUSION

During carotid endarterectomy the measurement of conjunctival oxygen tension is not useful to detect cerebral ischemia. The use of NIRS as a single neuronal monitor is not appropriate to perform, "selective shunting". In contrast to SEP, however, NIRS is characterized by its rapid changes immediately following carotid occlusion. This non invasive method is likely to complete the standard method SEP in a modified monitoring concept of neuronal function during carotid endarterectomy.

Emergency carotid endarterectomy

OBJECTIVE

Evaluation of the therapeutical efficacy of emergency carotid endarterectomy (CEA) in neurologically unstable patients.

PATIENTS AND METHODS

Three groups of a consecutive series of 71 emergency CEAs performed from 1980 to July 1998 were classified: (1) acute onset of severe stroke (n = 16), (2) progressive stroke/stroke in evolution (n = 34), and (3) crescendo transient ischemic attacks (n = 21). Cerebral coma, cerebral haemorrhage, and major ischemic stroke established in cranial computed tomography scans were contraindications for surgery. The neurological outcome was assessed by the modified Rankin scale. Long-term survival and long-term stroke recurrences were analyzed.

RESULTS

The recovery/minor stroke rates (Rankin 0-3) in acute stroke, progressive stroke, and crescendo transient ischemic attacks were 56.3, 76.4 and 80.9%, respectively; the combined major stroke/mortality rates (Rankin 4-6) were 43.7, 23.6 and 19.1%, respectively. Intraoperative angiography in 39 patients detected early carotid reocclusions in 2 and intracranial embolism in 7 patients. Local application of thrombolytic agents (n = 5) may contribute to a better neurological outcome in emergency CEA. Life table probabilities of major strokefree survival were 74.5, 71.6, and 53.7% after 1, 2, and 5 years, respectively (including perioperative strokes). Life table probabilities to suffer no stroke recurrence during follow-up were 96.7, 96.7 and 85.3%, respectively (perioperative strokes excluded).

CONCLUSIONS

Emergency CEA may be worthwhile in selected patients. Completion angiography is mandatory. Emergency CEA should be included in therapeutic strategies for ischemic stroke.

[Endovascular prostheses: evolution, state-of-the-art and perspectives of a new technology]

The treatment of infrarenal aortic aneurysms by means of transluminally placed endovascular prostheses reflects significant progress in the field of vascular surgery. In the case of infrarenal aortic aneurysm it is possible to achieve technically successful implantation of such a prosthesis in well over 90 % of cases. The rate of clinical success, meaning lasting effective exclusion of the aortic aneurysm, cannot (yet) be definitively determined, since no long-term results are so far available. Secondary leaks are observed in at least 10 % of all patients, making a further therapy necessary (endorepair, conversion, embolization). Further development of endovascular prostheses will include optimization of the aortal/iliac attachment of the prostheses, a better configuration and the development of long-lasting materials that can be used for endovascular prostheses.

Adenosine: a sensitive indicator of cerebral ischemia during carotid endarterectomy

BACKGROUND

For the human brain, there are no data available concerning the significance of adenosine and its metabolites as biochemical indicators of cerebral ischemia. Since adenosine may counteract key pathogenetic mechanisms during cerebral ischemia, its sensitivity and specificity as a marker of cerebral ischemia was investigated in relation to hypoxanthine and lactate.

METHODS

Arterial and jugular venous concentration changes of adenosine, hypoxanthine, and lactate were studied in 41 patients undergoing carotid endarterectomy. Cerebral tissue oxygenation was monitored continuously by somatosensory-evoked potentials. A carotid artery shunt (n = 6) was placed only after complete loss of somatosensory-evoked potentials.

RESULTS

Before carotid artery clamping jugular venous concentrations of adenosine, hypoxanthine, and lactate in subsequently shunted patients were 229+/-88 nM, 1105+/-116 nM, and 0.85+/-0.52 mM, respectively (mean +/- SD). In patients who required shunting, carotid artery clamping induced a significant increase in jugular venous adenosine (389+/-114 nM) and jugular venous hypoxanthine (1444+/-168 nM). In contrast, the increase in jugular venous lactate (0.91+/-0.48 mM) did not reach statistical significance. Focal cerebral ischemia was indicated by jugular venous adenosine with a sensitivity and specificity of 0.83 and 0.71, respectively.

CONCLUSIONS

Carotid artery clamping induced significant increases in jugular venous adenosine and hypoxanthine in patients with inadequate collateral blood flow. In addition, focal cerebral ischemia was reflected by changes in adenosine concentrations.

[Carotid surgery for prophylaxis of ischemic stroke]

Every year more than 250,000 patients suffer from ischemic (80%) or hemorragic (20%) stroke. Some 40,000 of these strokes are induced by stenosis or occlusion of the extracranial carotid artery. Several randomized studies (NASCET, ECST, ACAS, etc.) have proved that operative removal of high-grade carotid stenoses is an effective method in the primary and secondary prophylaxis of ischemic stroke. Operative therapy is significantly better than medical therapy with thrombocyte aggregation inhibitors. The prerequisite for effective operative prophylaxis is a low perioperative stroke rate. Even though the prophylactic value of carotid thrombarterectomy (TEA) is obvious, only about 5% of all carotid-related strokes are prevented by this operation. Essential conditions for increased efficiency in carotid surgery are close cooperation with the neurologist and the internist, screening of patients with a high risk for ischemic stroke, sophisticated, mainly non-invasive diagnostics, and more operative capacity. Interventional methods (stent, PTA) have not yet been proved safe and effective. These methods should be employed only in special cases after interdisciplinary discussions or in randomized studies.

Carotid endarterectomy and intracranial thrombolysis: simultaneous and staged procedures in ischemic stroke

PURPOSE

The feasibility and safety of combining carotid surgery and thrombolysis for occlusions of the internal carotid artery (ICA) and the middle cerebral artery (MCA), either as a simultaneous or as a staged procedure in acute ischemic strokes, was studied.

METHODS

A nonrandomized clinical pilot study, which included patients who had severe hemispheric carotid-related ischemic strokes and acute occlusions of the MCA, was performed between January 1994 and January 1998. Exclusion criteria were cerebral coma and major infarction established by means of cerebral computed tomography scan. Clinical outcome was assessed with the modified Rankin scale.

RESULTS

Carotid reconstruction and thrombolysis was performed in 14 of 845 patients (1.7%). The ICA was occluded in 11 patients; occlusions of the MCA (mainstem/major branches/distal branch) or the anterior cerebral artery (ACA) were found in 14 patients. In three of the 14 patients, thrombolysis was performed first, followed by carotid enarterectomy (CEA) after clinical improvement (6 to 21 days). In 11 of 14 patients, 0.15 to 1 mIU urokinase was administered intraoperatively, ie, emergency CEA for acute ischemic stroke (n = 5) or surgical reexploration after elective CEA complicated by perioperative intracerebral embolism (n = 6). Thirteen of 14 intracranial embolic occlusions and 10 of 11 ICA occlusions were recanalized successfully (confirmed with angiography or transcranial Doppler studies). Four patients recovered completely (Rankin 0), six patients sustained a minor stroke (Rankin 2/3), two patients had a major stroke (Rankin 4/5), and two patients died. In one patient, hemorrhagic transformation of an ischemic infarction was detectable postoperatively.

CONCLUSION

Combining carotid surgery with thrombolysis (simultaneous or staged procedure) offers a new therapeutic approach in the emergency management of an acute carotid-related stroke. Its efficacy should be evaluated in interdisciplinary studies.

[Computer-based training exemplified by the carotid artery]

The purpose of computer-based training (CBT) is interactive use of multimedia components, such as text, graphics, animation, sound, digital slide shows, and videos. This CD-ROM illuminates different aspects of carotid surgery: cerebrovascular insufficiency, sonographic and neuroradiological diagnostics, indications and results of carotid surgery in the literature, perioperative complications and new developments such as interventional procedures. Digital imaging (60 minutes of video sequences and 250 graphics) especially focus on operative standard procedures (conventional and eversion technique) and alternative methods. CBT is an evolving supplement to improve education programs in vascular surgery.