Ultrasound Coded-Excitation Imaging for Endoleak Detection After Complex Endovascular Aortic Repair

OBJECTIVES

Several imaging modalities have been suggested for surveillance after fenestrated endovascular aortic repair in general and endoleak detection in specific. In the present project a coded excitation-based ultrasound (B-Flow) was investigated for endoleak detection after complex endovascular aortic repair.

METHODS

Patients post complex endovascular aortic repair (FEVAR or T/FEVAR) undergoing follow-up appointments including ultrasonography of the aorta at a vascular and endovascular surgery outpatient center were included in the study. B-Flow was compared with computed tomography angiography (CTA), Duplex ultrasound (DUS), and contrast-enhanced ultrasound (CEUS) regarding agreement and reliability for endoleak detection and characterization.

RESULTS

In total, 47 follow-ups were included. They accumulated in a total of 149 imaging investigations. Endoleaks were discovered in 44.7% of B-Flow studies and a majority of these endoleaks were classified as type II. Agreement between B-Flow and other imaging modalities was good (>80.0%) in general. However, with B-Flow 6 and 2 endoleaks would have been missed compared with CEUS and CTA, respectively. Regarding endoleak classification, B-Flow had a strong agreement (94.5%) with CEUS in detected cases. Furthermore, in a limited subset analysis, imaging findings were externally validated using findings from angiography.

CONCLUSIONS

Ultrasonography allows for endoleak detection and characterization without an invasive procedure or the use of potentially nephrotoxic contrast medium and can reduce radiation exposure. While CEUS mitigates issues of radiation and nephrotoxicity it still requires the intravenous application of contrast enhancers. Ultrasound coded-excitation imaging such as B-Flow could therefore further simplify endoleak surveillance after fenestrated endovascular aortic repair.

Remote training and evaluation of a simulator-based training course for complex endovascular procedures

Background

Intimate knowledge of the materials used in endovascular aortic interventions is essential for trainees and supporting staff taking part in an endovascular intervention. Training courses can help to familiarize trainees with the equipment. However, the pandemic has changed the landscape of hands-on training courses significantly. Therefore, we developed a training course including an educational recording of the procedure to transfer knowledge about the materials used during endovascular interventions and radiation exposure reduction.

Methods

We produced a video depicting cannulation of the left renal artery in a silicon cast of an aorta and its major side branches under C‑arm fluoroscopy. A presentation using the video was given to the trainees. The trainees were randomized into a control and an intervention group. Their performance was filmed and rated on a standardized five-point scale in the style of the OSATS global rating scale. The intervention group was remeasured after additional training time.

Results

In total, 23 trainees participated in the training and agreed to have their performance recorded. The control and intervention groups showed no difference in the assessed performance metrics during their initial attempt. However, after receiving additional training, the intervention group significantly improved in all evaluated metrics.

Conclusion

Our data add to the growing evidence that simulator-based training can help to increase trainees' understanding and performance of relevant skills. A standardized and evidence-based validation process for simulators could improve their acceptance in the medical field.

Exclusion of complex aortic aneurysm with chimney endovascular aortic repair is applicable in a minority of patients treated with fenestrated endografts

OBJECTIVES

The Medtronic Endurant II stent graft has recently received Conformité Européenne (CE) approval for the use in chimney endovascular aortic repair (ChEVAR) for the treatment for juxtarenal aortic aneurysms. The aim of this study was to assess the percentage of patients treated by fenestrated endovascular repair who would have been alternatively suitable for the treatment by the CE approved Medtronic ChEVAR.

METHODS

Preoperative computed tomography scans of 100 patients who underwent fenestrated endovascular aortic repair (FEVAR) between April 2013 and February 2017 were retrospectively assessed for the applicability of the ChEVAR technique according to the Medtronic instructions for use. Eligibility criteria included an aortic neck diameter of 19-30 mm, a minimum infrarenal neck length of 2 mm, a total proximal sealing zone of at least 15 mm, thrombus in the aortic neck in ˂25% of the circumference, and maximum aortic angulations of 60° in the infrarenal, 45° in the suprarenal segment and ˂45° above the superior mesenteric artery.

RESULTS

According to CE-approved inclusion criteria, 19 individuals (19%) would have been eligible for ChEVAR. In 81 patients, at least 1 measure was found outside instructions for use: (i) excluding factor was detected in 26 patients, (ii) incongruous measures in 28 patients and in 27 patients, 3-5 measures were outside the instructions for use. The most frequently identified excluding factor was an insufficient infrarenal neck at ˂2 mm length (n = 63; 63%).

CONCLUSIONS

Patients with juxta- or pararenal aneurysm treated by FEVAR are in 19% of the cases alternatively suitable for the treatment by ChEVAR within CE-approved instructions for use. While ChEVAR is suitable in many emergency cases, FEVAR offers a broader applicability in an elective setting.

Decrease of peripheral resistance after intraoperative administration of iloprost in patients with and without type 2 diabetes mellitus and with peripheral arterial occlusive disease

BACKGROUND

In many cases, Ilomedin^® infusions are applied as part of a perioperative measure in patients with peripheral arterial occlusive disease because it makes a relevant vasodilatatory effect in patients with type 2 diabetes mellitus and with/without peripheral neuropathy.

AIMS

A prospective case-control study was performed to investigate the effect of prostanoids on peripheral resistance in patients with type 2 diabetes mellitus and patients without type 2 diabetes mellitus, as well as the role of peripheral neuropathy in patients undergoing arterial reconstruction.

METHODS

Sixty patients undergoing arterial reconstruction were enrolled. Sufficient data were collected on 38 patients. Prior to surgery, peripheral nerve conduction velocity was measured. Blood flow volume at the common femoral artery was assessed intraoperatively using a Doppler flowmeter at four time points: at baseline before arterial reconstruction (T0), after reconstruction (T1), after 5 (T2) and 10 min (T3) after intra-arterial application of 3000 ng of Ilomedin. Peripheral resistance units were calculated as a function of mean arterial pressure and flow volume using the following formula: peripheral resistance unit = mean arterial pressure (mm Hg) / flow volume (mL/min).

RESULTS

Ilomedin produced an immediate and significant drop of peripheral resistance in patients without type 2 diabetes mellitus as well as in patients with type 2 diabetes mellitus. Patients with peripheral neuropathy showed a less pronounced effect to Ilomedin compared to individuals with normal nerve conduction velocity.

Assessment of Pull-out Forces in TEVAR and ANACONDA FEVAR Combination and Early Clinical Results: Creation of a Proximal Landing Zone for FEVAR in Patients with Extent I and Extent IV TAAAs

BACKGROUND

Although recent data on the treatment of thoracoabdominal aortic aneurysms (TAAAs) are promising, in some cases, the paravisceral segment of the aorta may not be suitable for a branched endograft due to space restrictions. A combination of a fenestrated aneurysm repair (FEVAR) with a thoracic aneurysm repair (TEVAR) may represent a feasible treatment option. The current investigation was performed to assess the stability of a fenestrated Anaconda device implanted into a set of thoracic endografts from different manufacturers. We then assessed our clinical results with the FEVAR/TEVAR combination.

METHODS

Pull-out forces were measured in vitro after docking a fenestrated Anaconda graft within the distal end of different TEVAR devices. Anaconda devices were implanted in 28- or 30-mm thoracic tube grafts (oversizing of at least 2 mm: 13.3-21.4; minimum overlap of 15 mm). Continuously increasing longitudinal pull forces of up to 100 N were applied on an Instron Tensile Tester. Initial break point and damage to the endografts were documented. Clinical results of patients treated with such an FEVAR/TEVAR combination at our institution are presented as a second part of this study.

RESULTS

Median pull-out forces ranged from 2.38 N to 55.0 N. The highest stability was achieved with 34-mm Anaconda devices in 28-mm thoracic tube grafts. Grafts with either thinner Dacron material or those featuring a polytetrafluorethylene membrane seemed especially vulnerable to punctures and tears caused by the downward-looking hooks of the Anaconda device. Between April 1, 2013 and December 31, 2018, in 28 of 172 patients treated with a fenestrated Anaconda device, prior implantation of a thoracic tube graft was necessary to create a sufficient proximal landing zone. In 25 cases (89.3%), the aneurysm was successfully treated. Although the 30-day reintervention rate in this subgroup was relatively high at 28.6%, none of these was due to a failure of the FEVAR/TEVAR combination. Upon an average follow-up of 15 months, no failure of the graft connection and no type III endoleak due to membrane damage were observed.

CONCLUSIONS

The combination of a thoracic tube graft and a fenestrated Anaconda device is a viable option for the treatment of patients with Extent I or IV TAAAs with no adequate landing zone above the celiac trunk. Although pull-out testing has shown good stability with most assessed grafts, the thoracic devices with thicker Dacron membranes seemed to be especially suitable.

Endograft Infection Due to Secondary Aortoenteric Fistula Treated With Custom-Made Bovine In Situ Aortic Bifurcation Graft

Purpose:

To increase awareness of the clinical presentation, diagnostic workup, and treatment options for endograft infections.

Case Report:

A 75-year-old male patient was admitted with suspected endograft infection 4 years after endovascular aortic aneurysm repair (EVAR). Although preoperative diagnostics showed no definitive signs of endograft infection, eventual surgical exposure of the endograft revealed signs of advanced inflammation, including the unexpected finding of an aortoduodenal fistula.

Conclusion:

A detailed evaluation of patient history and clinical examination, performed as a part of routine follow-ups, may be beneficial in identifying possible severe complications after EVAR early on. Regarding options for aortic reconstruction in case of endograft infection, bovine pericardium deserves consideration as a promising, feasible, and easily available graft material.

Successful percutaneous access for endovascular aneurysm repair is significantly cheaper than femoral cutdown in a prospective randomized trial

OBJECTIVE

Because of its minimally invasive nature, percutaneous femoral access for endovascular aneurysm repair (pEVAR) is currently undergoing rapid popularization. Compared with surgical cutdown for femoral access (cEVAR), it offers the advantage of faster recovery after surgery as well as a reduction in wound complications. Despite proposed advantages, the method is largely considered uneconomical because of its reliance on costly closure devices.

METHODS

There were 50 patients undergoing EVAR who were enrolled in this randomized prospective single-center trial. Each patient randomly received percutaneous access in one groin and surgical access in the other. The primary end points were access duration and cost. Secondary end points were wound complications and the postoperative pain levels.

RESULTS

Surgery was performed per protocol in 44 patients. Mean access times for pEVAR and cEVAR were 11.5 ± 3.4 minutes and 24.8 ± 12.1 minutes (P < .001), respectively. Total access costs were €559.65 ± €112.69 for pEVAR and €674.85 ± €289.55 for cEVAR (P = .016). Eight complications in six patients were attributed to cutdown, none to pEVAR (P = .02). The percutaneously accessed groin was significantly less painful at day 1 and day 5 after surgery (P < .001). An intention-to-treat analysis (N = 50 patients) included six cases of pEVAR conversion due to technical failure in three patients (6%) and change of the operative strategy in another three patients (eg, aortouni-iliac stent graft followed by crossover bypass). The intention-to-treat analysis showed shorter mean overall access time for pEVAR (pEVAR, 14.65 ± 10.20 minutes; cEVAR, 25.12 ± 11.77 minutes; P < .001) and no cost difference between the two methods (pEVAR, €651.29 ± €313.49; cEVAR, €625.53 ± €238.29; P = .65).

CONCLUSIONS

Our data confirm proposed potential benefits attributable to the minimally invasive nature of pEVAR while demonstrating cost-effectiveness despite the additional cost of closure devices. Taking into account pEVAR failures still does not increase pEVAR costs over cEVAR. Further considering reduced postoperative pain and wound complications, the technique deserves consideration in suitable patients.

[Aortofemoral vascular graft infections and their prevention]

Vascular prosthesis infections are potentially severe adverse events following vascular reconstruction. They are often associated with a high morbidity and mortality, especially in the aortofemoral region. The present article outlines the diagnosis, prevention and treatment of vascular graft infections in a clinical setting. The clinical presentation, inflammatory markers, microbiological work-up and imaging studies can contribute to diagnosing a prosthesis infection. Regarding the bacterial spectrum involved in the etiology of prosthesis infections, single organism infections (monoinfections) have become less significant over the past years, whereas infections with multiple organisms now constitute the most abundant microbiological constellation. Also, infections with resistant bacterial strains have been increasing in number over the past years and deserve special consideration. It remains unclear whether both aspects are due to a true epidemiological change or are the result of advanced molecular microbiological diagnostic methods. While during the past decades perioperative antibiotic prophylaxis was regarded as the most important measure for preventing prosthesis infections in vascular surgery, other primary preventive hygiene strategies have been increasingly explored and grouped together in the sense of preventive bundles. In most cases of deep postoperative infections involving a prosthetic device in the aortofemoral region, explantation of the prosthesis will be required. In situ and extra-anatomical reconstructions are often performed in such cases and the decision process to develop an optimal treatment plan must consider several individual factors. In select patients, palliative preservation of the prosthesis despite surrounding infection (i.e. graft salvage) and best conservative management in combination with local surgical measures, such as incision and drainage and vacuum therapy, deserve consideration as a treatment option for patients with a high surgical risk.

Prognostic relevance of ischemia-modified albumin and NT-proBNP in patients with peripheral arterial occlusive disease

BACKGROUND

Cardiovascular morbidity is high among patients with peripheral arterial occlusive disease (PAOD). The aim of this study was to evaluate the ability of ischemia-modified albumin (IMA), N-terminal proBNP (NT-proBNP), and high-sensitive cardiac Troponin T (hs-cTnT) to predict cardiovascular complications in male patients with Fontaine stage II PAOD.

METHODS

68 men with stage II PAOD underwent treadmill testing. NT-proBNP, IMA and hs-cTnT were measured before and after exercise. Patients were followed up prospectively and complete follow-up data were available for 66 individuals.

RESULTS

Median follow-up time was 43.0months. 12 (18.2%) patients had suffered from a major adverse cardiac event (MACE). IMA and NT-proBNP baseline concentrations were significantly higher in patients who developed MACE during follow-up: IMA: 110.6±2.4kU/L vs. 102.5±0.9kU/L (p<0.001); NT-proBNP: 270.5±295.9ng/L vs. 84.6±15.4ng/L (p=0.007). In multivariable regression models only IMA was significantly associated with the primary endpoint (HR=1.07, CI 1.01-1.13; p=0.029).

CONCLUSION

In the present study, a serum concentration of >103.9kU/L of IMA was a better independent predictor of MACE than NT-proBNP or hs-cTnT. IMA might be a valuable tool for risk stratification in PAOD patients.

Antiphospholipid antibodies predict progression of abdominal aortic aneurysms

Antiphospholipid antibodies (aPLs) frequently occur in autoimmune and cardiovascular diseases and correlate with a worse clinical outcome. In the present study, we evaluated the association between antiphospholipid antibodies (aPLs), markers of inflammation, disease progression and the presence of an intra-aneurysmal thrombus in abdominal aortic aneurysm (AAA) patients.

APLs ELISAs were performed in frozen serum samples of 96 consecutive AAA patients and 48 healthy controls yielding positive test results in 13 patients (13.5%) and 3 controls (6.3%; n.s.). Nine of the 13 aPL-positive AAA patients underwent a second antibody testing >12 weeks apart revealing a positive result in 6 cases. APL-positive patients had increased levels of inflammatory markers compared to aPL-negative patients. Disease progression was defined as an increase of the AAA diameter >0.5 cm/year measured by sonography. Follow-up was performed in 69 patients identifying 41 (59.4%) patients with progressive disease. Performing multipredictor logistic regression analysis adjusting for classical AAA risk factors as confounders, the presence of aPLs at baseline revealed an odds ratio of 9.4 (95% CI 1.0–86.8, p = 0.049) to predict AAA progression. Fifty-five patients underwent a computed tomography in addition to ultrasound assessment indicating intra-aneurysmal thrombus formation in 82.3%. Median thrombus volume was 46.7 cm³ (1.9–377.5). AAA diameter correlated with the size of the intra-aneurysmal thrombus (corr_coeff = 0.721, p<0.001), however neither the presence nor the size of the intra-aneurysmal thrombus were related to the presence of aPLs.

In conclusion, the presence of aPLs is associated with elevated levels of inflammatory markers and is an independent predictor of progressive disease in AAA patients.

The influence of gender on patency rates after iliac artery stenting

OBJECTIVE

The purpose of this study was to investigate the influence of gender on the long-term outcome after iliac artery stenting and to assess gender-specific differences of the influence of risk factors on treatment success and patency rates.

METHODS

Between January 2000 and December 2006, 404 percutaneous transluminal angioplasties with primary stent deployment for symptomatic iliac artery occlusive disease were performed at our center. These included 128 interventions in women and 276 interventions in men.

RESULTS

Whereas average age was significantly higher (65.9 ± 12.9 years; P = .007) and arterial hypertension more frequent (60.9% vs 49.3%; P = .032) in women, hyperuricemia (7.0% vs 14.1%; P = .047) and a positive smoking status (61.7% vs 74.3%; P = .014) were more frequently observed in men. Fontaine stage was more advanced (stages III and IV) in women than in men (P = .028; P < .001). Technical success was 97.7% in women and 99.3% in men. Overall complication rate was higher in women compared with men (P = .002), mostly caused by access site hematomas (4.7% vs 0.4%) and pseudoaneurysms (8.6% vs 2.5%). Patients were followed up for 45.0 ± 33.3 months. Restenosis developed in 16.8% of cases in women and in 14.6% of cases in men and was treated in 73.7% by an endovascular approach. Primary patency rates at 1, 3, 5, and 7 years were 90.3%, 77.2%, 60.2%, and 46.4% in women and 89.9%, 71.5%, 63.6%, and 59.7% in men, respectively (P = .524; log-rank, .406). Secondary patency rates were 97.2%, 91%, 81.5%, and 70.3% in women and 97.1%, 89.1%, 82.6%, and 78% in men, respectively (P = .959; log-rank, .003). Multivariate analysis identified lower age as the only independent risk factor for recurrent disease in both groups. Age-defined subgroup analysis showed a restenosis/reocclusion rate of 23.9% in men and 22.1% in women older than 63.5 years (P = .861) but 32.1% in men and 49.1% in women younger than that (P = .034).

CONCLUSIONS

Our data suggest that although women are older and present with a more advanced stage of peripheral arterial occlusive disease, endovascular therapy is equally effective irrespective of gender. Surprisingly, the subgroup of young female patients had a specifically poor outcome.

Homocysteine improves risk stratification in patients undergoing endarterectomy for asymptomatic internal carotid artery stenosis

BACKGROUND AND PURPOSE

A limited life expectancy reduces the benefit from carotid endarterectomy (CEA) for treatment of asymptomatic internal carotid artery stenosis. The aim of this study was to assess homocysteine as stratifying biomarker to improve prediction of postoperative survival.

METHODS

This was a prospective, nonrandomized case series from 2003 to 2012. Two hundred and fourteen consecutive patients (<75 years, n=130; ≥75 years, n=84) undergoing CEA for their asymptomatic internal carotid artery stenosis were observed for 8.5 years for the occurrence of death after CEA as primary end point (EC-nr: 04-067-0604). Homocysteine and major cardiovascular risk factors were used for computation of prognostic indices. Cumulative survival of prognostic indices-based quintiles was estimated by Kaplan-Meier curves.

RESULTS

Total homocysteine had a significant effect on postoperative survival (P<0.0001). Total homocysteine-based quintiles of prognostic indices showed a better prediction of the survival of the patients than age alone. This caused reclassification of 17 patients (20.2%)>75 years as fit for surgery, but also indicated a high risk for 19 patients (14.6%)<75 years. In the majority (79.8%) of patients aged>75 years, statistically, CEA could not be advised because of a significantly reduced 5-year survival rate.

CONCLUSIONS

High plasma homocysteine levels suggest that older patients with asymptomatic carotid stenosis might rather benefit from intensive medical therapy than from CEA.

Austrian national carotid intervention numbers prompt improvement in secondary stroke prevention

BACKGROUND

As recent data suggest a variable benefit of carotid endarterectomy (CEA) or stenting (CAS), a careful selection of patients is mandatory for efficient stroke prevention. This retrospective study analyzed carotid intervention rates from 1999-2008 in Austria. The aim was to assess whether interventions for carotid stenosis were performed with respect to epidemiological trends and published data taking into account intervention type, age and gender.

METHODS

Intervention numbers for internal carotid artery (ICA)-stenosis from a 10 years period (1999 to 2008) were retrieved from the national Austrian registry for hospital funding. Patients were grouped by gender, age (0-64, 65-74, older than 75 years) and intervention type.

RESULTS

CEA rates amounted to 32.2±1.4 per 100000 persons annually (female: 22.1±0.7, male: 43.0±2.3). Each year 9.1 CAS±1.6 per 100000 Austrians were performed (female: 9.3±1.8, male 8.9±1.7). CAS numbers increased (P<0.05), whereas CEA numbers stagnated, especially in older age groups. Women were more likely to undergo CAS than CEA compared to men.

CONCLUSION

Relative intervention rates for carotid stenosis have rather stagnated, although stroke incidence increases continuously in an overaging society. Despite controversial data, CAS rates have been rising constantly in elderly women. Secondary stroke prevention in Austria can be improved by a careful selection of future patients, especially with regard to female gender and type of intervention.

Indications and techniques for emergency carotid interventions

Mutual understanding exists among specialists of neurology, interventional radiology and vascular surgery concerning the need of interventional treatment for patients with symptomatic carotid artery stenosis. However, identification of individuals that will most likely benefit from treatment, timing of the intervention and selection of treatment mode continue to be a matter of intense debate. The aim of this manuscript was to discuss the changing attitude to this high-risk population and present evidence that points towards a resolute, fast-track approach.

Segmental disruption of the internal elastic lamina as a potential pathogenetic mechanism of a true posttraumatic femoral artery aneurysm, years after single blunt trauma

We present an unusual case of a true posttraumatic aneurysm of the superficial femoral artery (SFAA) 7 years after a motorcycle accident including blunt trauma to the thigh. Surgical reconstruction was accomplished without any complications by aneurysm resection and interposition of an autologous reversed saphenous vein. Histopathological examination revealed a true aneurysm with segmental disruption and fragmentation of the internal elastic lamina (IEL) in van Gieson's stain. This is a first-time finding in context with SFAA and may represent the pathogenetic explanation for the rare formation of posttraumatic true aneurysms.

Elevated baseline hs-cTnT levels predict exercise-induced myocardial ischemia in patients with peripheral arterial disease

INTRODUCTION

Due to the systemic nature of atherosclerosis, the prevalence of coronary artery disease (CAD) is high in patients with peripheral arterial disease (PAD). A biochemical assay for assessing cardiac risk might improve clinical evaluation of PAD patients. The aim of this study was to investigate whether a new high-sensitivity cardiac Troponin T (hs-cTnT) assay can predict exercise-induced myocardial ischemia in PAD patients without clinical signs of CAD.

METHODS

Sixty-eight ambulatory patients with Fontaine stage II PAD underwent treadmill stress testing to maximum walking distance. Myocardial ischemia was assessed using a 2-lead Holter ECG and ST-segment depression of ≥ 0.2 mV was considered significant. Hs-cTnT was measured from serum samples taken at baseline as well as 5, 10 and 30 min after exercise.

RESULTS

Hs-cTnT baseline levels were significantly higher (19.3 ng/L (5.0; 20.2 ng/L) vs. 6.6 ng/L (4.4; 9.4 ng/L); p=0.037) and increase of serum levels 5 min after cessation of exercise was more pronounced (1.09 ng/L (0.23; 1.80 ng/L) vs. 0.22 ng/L (-0.1; 0.65 ng/L), p=0.032) in ECG positive patients compared to individuals with normal ECG. Logistic regression analysis identified the baseline hs-cTnT serum level as an independent risk factor for developing significant exercise-induced ST-segment depression (odds ratio 1.2 per 1-unit increase, p=0.015).

CONCLUSIONS

In patients with PAD, exercise-induced myocardial ischemia is associated with elevated baseline levels and a significant early increase of hs-cTnT serum levels.

Reliability of constant-load treadmill testing in patients with intermittent claudication

AIM

Constant-load treadmill testing is frequently used to estimate walking ability of patients with peripheral arterial disease and to assess changes in functional capacity following therapeutic interventions or through disease progression. The value of this test has frequently been disputed based on doubts concerning its reproducibility. The aim of this study was to investigate the reliability of treadmill testing at a speed of 3 km/h and a constant inclination of 12%.

METHODS

Sixty-eight patients with stable peripheral arterial disease who were familiar with treadmill testing underwent two sessions of walking exercise at 3 km/h and 12% inclination within three weeks. Initial claudication distance (ICD) and maximum walking distance (MWD) on the treadmill as well as reported walking distances on level ground at individual speed were recorded.

RESULTS

Correlation coefficients of 0.8 and within-subject variation coefficients of 15% for ICD and 13% for MWD demonstrated low variability of walking distances between visits. No learning effects were observed. Intra-class correlation coefficients of 0.78 for ICD and 0.83 for MWD proved good reproducibility of treadmill testing. Correlation of measured and reported walking distances was poor.

CONCLUSION

Constant-load treadmill testing at 3km/h and 12% inclination is a well reproducible method to investigate walking capacity of patients with stable intermittent claudication who are familiar with this test method. From treadmill walking distances, no conclusions should be drawn concerning the actual walking range of the patient.

Local anesthesia and exposure for carotid endarterectomy: background and technical realization

While carotid endarterectomy is an established method for the treatment of symptomatic as well as high-grade asymptomatic carotid artery stenoses, there is a considerable variation concerning the kind of anesthesia used as well as technical details of the operation. In the present article differing arguments on local versus general anesthesia as well as a transverse versus a longitudinal skin incision will be discussed. Furthermore, possible access routes to the carotid bifurcation, the retrojugular compared to the ventrojugular approach, will be presented in detail.

Percutaneous protective coil occlusion of the proximal inferior mesenteric artery before N-butyl cyanoacrylate embolization of type II endoleaks after endovascular repair of abdominal aortic aneurysms

Bowel ischemia can complicate treatment of type II endoleak with liquid or semiliquid agents such as n-butyl cyanoacrylate (NBCA) if nontarget embolization of the inferior mesenteric artery (IMA) occurs. The current report describes four cases of type II endoleak in which the IMA was the main outflow vessel and was prophylactically occluded with embolization coils before NBCA injection into the endoleak nidus. The purpose was to prevent unintentional embolization of the NBCA into IMA branches. If feasible, protective IMA coil occlusion should be considered in type II endoleaks with IMA outflow in cases of NBCA embolization.

Lack of seasonal variation in flow-mediated dilatation of the brachial artery in women with primary Raynaud's phenomenon and healthy controls

BACKGROUND

The aim of this study was to examine endothelium function and seasonal variations of endothelium function in women with primary Raynaud's phenomenon (RP) and healthy controls.

PATIENTS AND METHODS

After a fast of at least 8 hours we studied 21 patients with primary RP (mean age 31.1 years, mean duration of RP 9.1 years) and 22 controls (mean age 27.8 years) by use of high resolution brachial artery sonography in winter (December/January 2000) and summer (July/August 2001). To exclude circadian variations all examinations were performed in the late afternoon only. All subjects were non-smokers. Confounding factors like serum glucose, HbAlc, and lipid concentrations were analyzed immediately before the investigations. Nicotine contamination was randomly analyzed in hair samples in 8 subjects of each study group. Flow mediated dilatation (FMD%) and nitroglycerin induced dilatation (NID%) were calculated by putting the basal vessel diameter as 100%.

RESULTS

Basal, flow-mediated, and nitroglycerin-induced absolute diameters of the brachial artery did not differ significantly between the study groups (p = 0.85). The test conditions (basal, postocclusive, nitroglycerin-induced) always let to the same vessel response in winter and summer (p = 0.61) and there was no significant influence between these test conditions and the study groups (p = 0.07). Compared to patients FMD% was slightly reduced in controls in summer (p = 0.09). Analysis of variance excluded a significant relation between study group and season (p = 0.43). For NID% too, no statistically significant differences were found.

CONCLUSIONS

We were not able to show impaired or seasonally variant flow-mediated or nitroglycerin-induced dilatation of the brachial artery in patients with primary RP. Our results argue against the presence of a more generalized endothelium dysfunction detectable with high resolution ultrasound of the brachial artery in patients with primary RP.

Cardiac troponin and beta-type myosin heavy chain concentrations in patients with polymyositis or dermatomyositis

Cardiac troponin T (cTnT), cardiac troponin I (cTnI), myosin heavy chains (MHC), myoglobin, creatine kinase (CK), and creatine kinase isoenzyme MB (CKMB), were measured in blood samples from 39 polymyositis (PM) or dermatomyositis (DM) patients without clinical evidence for cardiac involvement to evaluate their clinical usefulness in this patient population. MHC, myoglobin, and CKMB were frequently elevated and correlated with each other and with disease severity. Undetectable cTnI in all but one patient indicated that MHC was released from skeletal muscle, thereby providing the first laboratory evidence of frequent slow-twitch muscle fibre-necrosis in patients with PM or DM. CKMB was elevated in 51%, cTnT in 41%, and cTnI in only 2.5% of patients. cTnI did not correlate with other markers or with disease severity scores. The close correlations found between cTnT and skeletal muscle damage markers and the relationship between cTnT with disease severity without clinical evidence for myocardial damage suggest a release of cTnT from skeletal muscle. The relationship of cTnT with disease severity indicates a possible role of the marker for risk stratification. However, the prognostic values of cardiac troponins and other muscle damage markers in PM/DM patients remain to be compared in prospective outcome trials.

Myocardial damage after minimally invasive coronary artery bypass grafting on the beating heart

BACKGROUND

In conventional coronary artery bypass grafting, the rate of perioperative myocardial infarction is reported in the 2% to 6% range; however, significantly higher rates are observed if sensitive myocardial marker proteins are used to detect perioperative myocardial damage. For minimally invasive direct coronary artery bypass grafting, few data are available concerning myocardial marker protein release.

METHODS

Fifteen consecutive patients (11 male, 4 female; mean age, 59.6 +/- 8.5 years) received minimally invasive direct coronary artery bypass grafting procedures via minithoracotomy on the beating heart. Electrocardiography and transesophageal and transthoracic echocardiography as well as determination of creatine kinase-MB mass concentration and cardiac troponin I level were used for ischemic monitoring.

RESULTS

One patient had a perioperative myocardial infarction according to standard criteria and died despite mechanical circulatory support. Determination of cardiac troponin I level showed small but definitive ischemic damage in 4 of 9 patients (44%) who presented transient ischemic signs intraoperatively or postoperatively. In 2 of these 4 patients pathologic findings could be detected on angiographic restudies.

CONCLUSIONS

Subclinical myocardial injury is a common event in minimally invasive coronary artery bypass grafting on the beating heart. Cardiac troponin I could serve as an adequate diagnostic tool for diagnosis of perioperative myocardial infarction in minimally invasive direct coronary artery bypass grafting.

Different intracellular compartmentations of cardiac troponins and myosin heavy chains: a causal connection to their different early release after myocardial damage

We investigated the net myocardial release of creatine kinase isoenzyme MB (CKMB), myoglobin, cardiac troponin T (cTnT), cardiac troponin I (cTnI), and cardiac beta-type myosin heavy chain (beta-MHC) into the coronary circulation after cardioplegic cardiac arrest in humans. Cardiac markers were measured in paired arterial, central venous, and coronary sinus blood in 19 patients undergoing elective coronary artery bypass grafting (CABG) before aortic cross-clamping and 1, 5, 10, and 20 min after aortic declamping. cTnT and cTnI were released into the coronary sinus in parallel to each other and almost simultaneously to myoglobin and CKMB within 20 min of reperfusion. In contrast, no beta-MHC was released in the same patients during the study period. The average soluble cTnT and cTnI pools in right atrial appendages of 11 patients with right atrial and right ventricular pressures within reference values were comparable and were approximately 8% of total myocardial troponin content. The soluble beta-MHC pool was <0.1% in all patients. Our results demonstrate the impact of the different intracellular compartmention of regulatory and contractile proteins on their early release from damaged myocardium.

No release of cardiac troponin I during major orthopedic surgery after acute normovolemic hemodilution

BACKGROUND

Normovolemic hemodilution is a well-accepted method for intraoperative blood salvage. However, some controversy exists concerning the possible risk of myocardial fiber injury as consequence of the reduced oxygen content. Laboratory diagnosis of perioperative myocardial fiber injury is difficult, since biochemical markers are elevated postoperatively due to the surgical trauma. Cardiac troponin I (cTnI) is a new, highly sensitive and specific marker for the detection of myocardial injury. The aim of our study was to investigate whether normovolemic hemodilution in patients with major orthopedic surgery (13 hemodiluted patients, 15 control) induces a release of cTnI.

METHODS

cTnI as a highly specific and sensitive cardiac parameter, as well as total creatine kinase (CK), creatine kinase isoenzyme MB mass (CKMB mass) and myoglobin were measured after induction of anesthesia, after normovolemic hemodilution, prior to retransfusion of blood components, 3 h after surgery, and on the first and third postoperative days.

RESULTS

Prior to retransfusion of blood components the hematocrit was decreased to 25.4 +/- 1.2% (mean +/- SEM; range: 18%-34%) in the control group and to 20.2 +/- 0.8% (mean +/- SEM; range: 17%-24%) in the hemodilution group. Total CK, CKMB mass as well as myoglobin concentration increased significantly in both groups, reaching their maxima within the first day of surgery. In contrast, cTnI was below the detection limit of assay (< 0.5 micrograms/L) at any time.

CONCLUSIONS

We suggest that pre- and intraoperative hemodilution to a hematocrit of approximately 20% by maintaining normovolemia does not induce myocardial fiber injury in patients without preexisting cardiac diseases.