Individualizing Surveillance after Endovascular Aortic Repair Using a Modular Imaging Algorithm.

OBJECTIVES: Surveillance after endovascular aortic repair (EVAR) and fenestrated EVAR (FEVAR) is mainly directed by one-size-fits-all approaches instead of personalized decision making, even though treatment strategies and often endografts themselves are tailor-made to adjust for individual patients. We propose a modular imaging algorithm that escalates surveillance imaging based on invasiveness and need. MATERIALS AND METHODS: In this retrospective observational study of single-center data, results of a modular imaging algorithm were analyzed. The algorithm is characterized by initiating the examination with standard B-mode then transitioning to Duplex ultrasound, B-Flow, and CEUS. Additional CT(A) studies are conducted where required. The study population included both patients receiving EVAR or FEVAR. A comparative analysis was conducted regarding endoleak detection. RESULTS: The study population included 28 patients receiving EVAR and 40 patients receiving FEVAR. They accounted for 101 follow-up visits, which led to 431 distinct imaging studies. CEUS has the highest endoleak detection rate, followed by CTA and B-Flow. Duplex ultrasound and B-Flow resulted in 0 and 1 false positive cases, respectively, considering CEUS the reference standard. In a select group of six patients, CEUS was omitted after endoleaks were displayed by Duplex ultrasound or B-Flow, leading to a successful type II coiling and no aneurysm-related adverse events. CONCLUSIONS: The proposed modular algorithm showed great potential to incorporate principles of personalized medicine in surveillance after endovascular aortic treatment. Since Duplex ultrasound and B-Flow rarely cause false positive endoleaks, more resource-intensive and invasive imaging studies such as CEUS and CTA can be omitted after positive identification.

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.

Endoleak Detection after Endovascular Aortic Repair via Coded-Excitation Ultrasound-A Feasibility Study.

Endoleaks are the most common complication after endovascular aortic repair (EVAR). Their correct identification is one of the main objectives of surveillance protocols after EVAR. So far, computed tomography angiography (CTA), contrast-enhanced (CEUS) and Duplex ultrasound (DUS), as well as magnetic resonance angiography, have been investigated for their ability to detect endoleaks. In general, all technologies have distinct benefits and disadvantages, with CTA and CEUS emerging as the reference standard for surveillance after EVAR. However, they are both contrast-enhancer-dependent, and CTA additionally exposes patients to ionizing radiation. In the present study, we investigated B-Flow, a type of coded-excitation ultrasound that was specifically designed to optimize the visualization of blood flow, for its ability to detect endoleaks, and compared its performance to CEUS, CTA, and DUS. In total, 34 patients were included in the analysis that accumulated in 43 distinct B-Flow investigations. They underwent a total of 132 imaging investigations. Agreement between B-Flow and other imaging modalities was high (>80.0%), while inter-method reliability can be interpreted as good. However, with B-Flow, six and one endoleaks would have been missed compared to CEUS and CTA, respectively. Regarding endoleak classification, all metrics were lower but retained an adequate level of comparison. In a subset of patients requiring intervention, B-Flow had 100% accuracy regarding both endoleak detection and classification. Ultrasonography enables endoleak detection and classification without the need for pharmaceutical contrast enhancement or radiation. Ultrasound coded-excitation imaging in the application of B-Flow could further simplify surveillance after EVAR by offering adequate accuracy without requiring intravenous contrast enhancement. Our findings may promote subsequent investigations of coded-excitation imaging for endoleak detection and classification in the surveillance after EVAR.

Clinical Applications of B-Flow Ultrasound: A Scoping Review of the Literature.

Coded excitation ultrasound investigations have the potential to augment the resolution, increase the efficiency, and expand the possibilities of noninvasive diagnostic imaging. B-Flow ultrasound, a type of digitally encoded imaging, was developed more than 20 years ago with the aim to optimize the visualization of blood flow. It has been investigated for a plethora of applications so far. A scoping review regarding its clinical applications was conducted based on a systematic literature research. B-Flow has been investigated in various anatomic locations and pathologies. However, previous research is limited by small sample sizes, the rare occurrence of elaborate study designs, the reliance on subjective reports and qualitative data, as well as several potential biases. While results are in general promising, it should therefore still be considered an emerging technology. Nevertheless, the limitations can be addressed in future research and the potential to expand its applications make B-Flow an interesting candidate for further investigations.

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.

Stent-induced flow disturbances in the ipsilateral external carotid artery following internal carotid artery stenting: a temporary cause of jaw claudication.

BACKGROUND: We hypothesize that stenting of the internal carotid artery can immediately impede blood flow to the external carotid artery by either plaque shift or stent coverage of the ostium, and thereby cause ischemic symptoms like ipsilateral jaw claudication. METHODS: Thirty-three patients with high-grade asymptomatic stenosis of the internal carotid artery who underwent endovascular treatment were examined by ultrasound of the external carotid artery and performed an exercise test by chewing chewing gum synchronously to an electronic metronome for 3 min. Tests were performed before, the day after, and 1 week after the stenting procedure. Claudication time was defined as the timespan until occurrence of pain of the masseter muscle and/or chewing dyssynchrony to the metronome for more than 15 s. Ten patients with an isolated, atherosclerotic stenosis of the external carotid artery served as controls. RESULTS: A significantly reduced claudication time (in seconds) was recorded in patients who underwent carotid artery stenting compared to baseline values; median 89 (interquartile range, IQR, 57 to 124) vs. median 180 (IQR 153 to 180; p < 0.001). By categorization of the flow velocity at the external carotid artery into faster or slower as 200 cm/sec, the effect was even accentuated. Stenting values showed improvement 1 week after but did not return to baseline levels. No respective changes were found in controls. CONCLUSION: Stenting of the internal carotid artery lead to ipsilateral flow deterioration at the external carotid artery resulting in temporary jaw claudication. This impairment attenuated over the time and was significantly reduced after 1 week.

Vascular puncture site complications - diagnosis, therapy, and prognosis.

The numbers of endovascular procedures have been noted to substantially increase over the past two decades. Besides all the technical advances and the increasing skills of more and more trained interventionists, the vascular access site still offers the possibilities and carries the risk of access site complications, which have not been changed dramatically over the past years. Guidelines on the vascular puncture procedure itself are lacking. Complications at different vascular access sites presentclinically different, require different diagnostic work up and therapy. The aim of the following review is to systematically list the most likely vascular access site complications their diagnosis and if necessary the proper treatment.

Percutaneous instillation of physiological saline solution for the treatment of femoral pseudoaneuryms.

OBJECTIVE: To investigate the efficacy of para-aneurysmal saline injection for closure of postcatheterization pseudo-aneurysm (PA) at the vascular access site. METHODS: Fifty-one consecutive patients with postcatheterization PA at the vascular access site were included to undergo percutaneous para-aneurysmal saline injection. In case of technical failure the day after, PA were treated by bovine thrombin injection. Anatomical properties of the PA were recorded as were details to injection. RESULTS: Initially all patients exhibited success which was reduced to 43 % at day one. A saline volume of median 7 ml (interquartile range 6-8 ml) has been injected. The amount of injected saline was not different in patients with and without treatment success at day one (P = 0.6). Several anatomical properties of the PA exhibited marked differences in patients with or without success. The length (10.3 mm (7.8-12.0) vs. 12.5 mm (10.3-15.0); P = 0.009) and the angulation (110° (100-118) vs. 140° (129-146); P < 0.001) of the fistula/vessel axis was statistically different between groups. The peak systolic velocity failed to show significance with a tendency to higher values in the ineffective study group (P = 0.07). No peripheral complications occurred. CONCLUSION: Para-aneurysmal saline injection may be a therapeutic alternative to percutaneous thrombin injection in patients exhibiting favorable anatomical properties.

Auricular electroacupuncture reduces frequency and severity of Raynaud attacks.

BACKGROUND: Acupuncture has been shown to influence skin perfusion and the subjective cold perception threshold. Therefore, we hypothesized that auricular electroacupuncture (EA) might reduce symptoms in primary Raynaud's phenomenon (PRP). METHODS: Twenty-six patients with PRP received 6 cycles of auricular EA. After 3, 6 and 24 weeks attack frequency and severity were reevaluated using standardized questionnaires and a visual analogue scale (VAS). Skin temperature was assessed by infrared thermography and laser Doppler perfusion imaging was used to determine skin perfusion. RESULTS: Compared to baseline we found a significant reduction of attack frequency after 3 (p = 0.001) and 6 weeks (p < 0.001) of auricular EA. This improvement sustained following cessation of EA, after 24 weeks (p < 0.001). Furthermore, attack associated pain was reduced after 3 (p = 0.003), 6 (p = 0.003) and 24 weeks (p = 0.001) of treatment, while skin temperature and skin perfusion did not change significantly throughout the study period. CONCLUSIONS: Auricular EA reduces symptoms by means of frequency and severity of attacks in PRP but has no influence on skin perfusion and skin temperature.

Improvement of neurocognitive function after protected carotid artery stenting.

OBJECTIVE: To investigate the effect of protected carotid artery stenting on neurocognitive function with particular consideration of the angiographic filling of the ipsilateral anterior cerebral artery (ACA). BACKGROUND: An improved inflow to the supply area of the anterior cerebral artery after revascularisation of severe carotid artery stenosis may beneficially affect frontal lobe cognitive functions. METHODS: We prospectively included 71 consecutive patients who underwent carotid artery stenting (CAS) due to high grade carotid artery stenosis. Intracranial angiograms and filling status of the ACA pre- and post-stenting were analyzed and a battery of 5 selected neuropsychological tests for frontal lobe function were applied prior to and 6 months after CAS. Patients with improvement in at least two tests were defined as having improved neurocognitive function. RESULTS: Compared to baseline, we found a significant improvement of the Trail-Making Test A (median 6% improved change-score; P = 0.01), the test of supermarket items showed a trend towards significant improvement (median 3.7% improved change-score; P = 0.09). In 32 patients (45%) an improvement of at least 2 neurocognitive tests was observed. Neuropsychological improvement was found more frequently in patients with a contrasted ipsilateral ACA after CAS (88%, 95% CI 77 to 99) compared to patients without angiographic filling of the ipsilateral ACA post CAS (13%, 95% CI 1 to 25), respectively (P < 0.01). CONCLUSION: Carotid artery stenting improves neurocognitive function in a considerable proportion of patients. A contrasted ipsilateral anterior cerebral artery after CAS is associated with improved neurocognitive function, presumably due to amelioration of frontal lobe perfusion.

Quality of life after balloon angioplasty versus stent implantation in the superficial femoral artery: findings from a randomized controlled trial.

PURPOSE: To investigate whether primary nitinol stenting in the superficial femoral artery (SFA) is beneficial to patients' quality of life (QoL). METHODS: One hundred four patients (55 men; mean age 66+/-19 years) with chronic limb ischemia and SFA disease were randomly assigned to primary stent implantation (n=51) or balloon angioplasty (n=53) with optional stenting for a suboptimal angioplasty result (17 of 53). QoL was measured by the SF-36 questionnaire at baseline and at 3, 6, and 12 months post intervention. RESULTS: QoL was significantly improved post intervention and up to 12 months in both treatment groups. Significant inverse associations were observed between QoL parameters and restenosis. Comparing primary stenting (n=51) versus balloon angioplasty with optional stenting (n=53) by the intention to treat, no significant differences in QoL were observed. Analyses of stented patients (n=68) versus balloon angioplasty (n=36) patients, however, demonstrated significantly improved measures of QoL after stenting. CONCLUSION: Endovascular revascularization of SFA disease improves QoL, and restenosis negatively affects QoL outcomes. After stent implantation, whether primary or secondary, QoL was significantly ameliorated compared to balloon angioplasty alone. However, it remains to be proven in larger cohorts whether primary stenting yields a QoL benefit compared to balloon angioplasty with optional secondary stenting.

Prediction of iatrogenic pseudoaneurysm after percutaneous endovascular procedures.

PURPOSE: To prospectively evaluate the accuracy of using physical examination to identify puncture-related groin pseudoaneurysms, as assessed by using duplex ultrasonography (US), after percutaneous transluminal procedures and to prospectively evaluate the association between preinterventional platelet count, antiplatelet medication, and the occurrence of pseudoaneurysms. MATERIALS AND METHODS: This study was approved by the local ethics committee, and informed consent was obtained from all patients. The study prospectively included 273 consecutive patients (161 men, 112 women; age range, 34-90 years) who were referred for duplex US evaluation of the inguinal arterial puncture site 1 day after endovascular procedures. Prior to duplex US, all patients underwent physical examination of the groin. In addition, clinical characteristics and preinterventional laboratory parameters were assessed. Statistical significance was determined by using chi2 tests, the Fischer exact test, and unpaired t tests. RESULTS: Twenty-three pseudoaneurysms were found in 273 patients by using duplex US. Pulsatile groin masses that were detected at physical examination were used to correctly identify all pseudoaneurysms (positive predictive value, 100%; negative predictive value, 100%). Painful pulse palpation had a slightly lower predictive power (positive predictive value, 92% [95% confidence interval: 81%, 100%]; negative predictive value, 100% [95% confidence interval: 100%, 100%]). Other clinical parameters, such as the presence of superficial hematomas, systolic bruits, or nonpulsatile groin masses, had no adequate predictive properties. Interobserver agreement was excellent between observers (97% agreement [95% confidence interval: 92%, 100%]). All patients with pseudoaneurysms had a preprocedural platelet count of less than 200 x 10(9)/L. No subacute complications were observed at the access site in patients with a platelet count of more than 200 x 10(9)/L. CONCLUSION: Physical examination revealed sufficient predictive capability in facilitating the identification of iatrogenic pseudoaneurysms after percutaneous vascular procedures. A platelet count of less than 200 x 10(9)/L was associated with high predictive capability, thereby warranting further assessment in a larger series of patient.

Is there improvement of "vascular depression" after carotid artery stent placement?

PURPOSE: To prospectively evaluate if high-grade (> or = 80% luminal narrowing) internal carotid artery stenosis is associated with depressive symptoms and if carotid artery stent placement (CAS) potentially improves depressive symptoms. MATERIALS AND METHODS: The study was approved by the local ethics committee, and informed consent was obtained from all subjects. One hundred forty-three patients (91 men, 52 women; interquartile range, 63-76 years) undergoing CAS because of asymptomatic high-grade (> or = 80% luminal narrowing) carotid artery stenosis and 102 control subjects (64 men, 38 women; interquartile range, 63-73 years) with advanced peripheral artery disease and without carotid artery stenosis undergoing lower-limb percutaneous transluminal angioplasty were included. Substantial depressive symptoms (defined as a Beck Depression Inventory score of 10 or higher) were recorded at baseline and at 4 weeks (follow-up) after the percutaneous procedures. The chi2 test, Mann-Whitney U test, McNemar test, Wilcoxon rank sum test, and two-group t test were used to check for statistical significance. RESULTS: A significantly higher prevalence of depressive symptoms was found in patients with carotid artery stenosis than in control subjects with peripheral artery disease at baseline (33.6% vs 16.7%, P = .003). At follow-up, a significant reduction of depressive symptoms was found in patients who underwent CAS (33.6% vs 9.8%, P < .001). The frequency of depressive symptoms remained unaffected in control subjects (16.7% vs 13.0%, P = .1). CONCLUSION: High-grade carotid artery stenosis is associated with depressive symptoms in patients with atherosclerosis. CAS seems to exert beneficial effects on the course of depressive symptoms in these patients.

Cognitive functions in patients with cerebrovascular disease: potential impact of revascularization.

The purpose of this review is to assess the impact of luminal restoring of carotid artery stenosis on cognitive functions. Therefore, papers dealing with the neuropsychological influence of carotid artery stenosis and studies comparing the neuropsychological course after respective recanalization have been included.

Abciximab reduces monocyte tissue factor in carotid angioplasty and stenting.

BACKGROUND AND PURPOSE: Abciximab, a nonselective glycoprotein IIb/IIIa inhibitor, was shown to reduce peri-interventional stroke rate in carotid stenting. We evaluated the effect of adjunct abciximab therapy on monocyte-platelet cross talk and neurological deficit in unprotected carotid stenting and compared its efficacy with distal filter protection. METHODS: Fifty patients were randomized to either standard antithrombotic therapy (n=30) consisting of aspirin, clopidogrel, and heparin or adjunct bolus (0.25 mg/kg) and 12-hour infusion (0.125 microg x kg(-1) x min(-1)) of abciximab (n=20). A third cohort of patients was stented with filter protection (n=30). Monocyte-platelet aggregate formation and monocyte tissue factor expression were determined by whole blood flow cytometry, and F1.2 generation and soluble CD40 ligand (sCD40L) were determined by immunoassay. RESULTS: The incidence of peri-interventional ischemic episodes (23% versus 10%; P=0.2) and the number of de novo ischemic lesions detected by diffusion-weighted MRI (47% versus 30%; P=0.17) were not significantly different between standard antithrombotic therapy and adjunct abciximab but were reduced with filter protection (P=0.023). However, the number of transient ischemic attacks was lower (P=0.05) and the National Institutes of Health Stroke Score rapidly decreased in patients with adjunct abciximab. This clinical improvement was paralleled by a reduction in the postinterventional percentage of activated monocyte-platelet aggregates (CD62P+/CD14+; P=0.018) and the number of tissue factor-positive monocytes (TF+/CD14+; P=0.005). Both abciximab and filter protection suppressed F1.2 generation and significantly reduced sCD40L. CONCLUSIONS: Abciximab limits thrombus propagation and thrombus stabilization after carotid stenting by reducing monocyte-platelet cross talk and sCD40L. Although abciximab seems inferior to filter devices in peri-interventional cerebral protection, it may be considered in patients who do not allow placement of protection devices.