Upside-down positioning of a peri-interventional cava filter during endovascular thrombectomy of a septic superior vena cava thrombosis

A 43-year-old male patient with advanced colon carcinoma presented with disseminated staphylococcus aureus bacteremia and central venous catheter associated septic thrombosis of the superior vena cava. Despite appropriate antimicrobial therapy and surgical debridement of distant foci, bacteremia persisted, so an endovascular thrombectomy was performed. Contrary to the usual application, the Capturex® peri-interventional cava filter was positioned upside down, in the direction of the blood flow, in the superior vena cava to prevent septic embolism during mechanical thrombectomy. The wall-adherent septic thrombus was mechanically detached using a RAT fragmentation basket® followed by Aspirex® rotational thrombectomy. Final phlebography showed complete thrombus removal. Small thrombus fragments could be demonstrated in the filter after retrieval. The adapted technique of a reverse positioning of the Capturex® filter in the superior vena cava seems feasible and effective.

Sex-Specific Risks of Major Cardiovascular and Limb Events in Patients With Symptomatic Peripheral Artery Disease

BACKGROUND

Patients with peripheral artery disease (PAD) have a higher risk of major adverse cardiovascular events (MACE) compared with those without PAD.

OBJECTIVES

The aim of this post hoc analysis was to evaluate sex-specific differences in MACE and limb events in the EUCLID (Examining Use of Ticagrelor in PAD) trial.

METHODS

Cox proportional hazards models were used to compare time-to-event outcomes stratified by sex. Covariates were introduced after adjusted model selection.

RESULTS

EUCLID enrolled 13,885 patients with PAD (28% women [n = 3,888]). PAD severity and medical treatment were comparable between sexes, whereas prior lower extremity revascularization was reported less frequently in women (54.8% vs. 57.3%; p = 0.006). Women were older (mean ± SD age: 67.8 ± 8.9 vs. 66.1 ± 8.2 years; p < 0.001) and more likely to have diabetes mellitus (p = 0.004), hypertension, hyperlipidemia, and chronic kidney disease (all p < 0.001). Over a mean follow-up of 30 months, women had a lower risk of MACE (9.5% vs. 11.2%; adjusted hazard ratio: 0.77; 95% confidence interval: 0.68 to 0.88; p < 0.001) and all-cause-mortality (7.6% vs. 9.7%; adjusted hazard ratio: 0.61; 95% confidence interval: 0.53 to 0.71; p < 0.001). In contrast, risk for major adverse limb events (2.6% vs. 3.0%) and hospitalization for acute limb ischemia (1.6% vs. 1.7%) were not different by sex.

CONCLUSIONS

Although women with PAD are at lower risk for MACE and all-cause mortality, risk for limb events was similar between sexes over a mean follow-up of 30 months. Understanding sex-specific differences and dissociation between baseline cardiovascular risk and subsequent cardiovascular events requires further investigation. (A Study Comparing Cardiovascular Effects of Ticagrelor and Clopidogrel in Patients With Peripheral Artery Disease [EUCLID]; NCT01732822).

Capillary-venule malformation is a microfistulous variant of arteriovenous malformation

OBJECTIVE

To describe typical clinical presentation of patients with microfistular, capillary-venule (CV) malformation as a variant form of arteriovenous malformations (AVM).

METHODS

A retrospective clinical analysis of 15 patients with CV-AVM confirmed by a computational flow model enrolled in a prospective database of patients with congenital vascular malformation between January 2008 and May 2018.

RESULTS

The mean age of the patients at first time of presentation was 30 years with balanced sex ratio. Presentation was dominated by soft tissue hypertrophy (n = 12 [80.0%]) and atypical varicose veins (n = 11 [73.3%]). The anatomic location of enlarged varicose veins gave no uniform pattern and did not correspond with the typical picture of primary varicose vein disease. Most often, symptomatic CV-AVM was found at the lower extremities in this series of unselected patients. The most frequent compartment affected was the subcutis (n = 14 [93.3%]), involvement of muscle was recorded in one-third and cutis in one-fourth of patients.

CONCLUSIONS

A high grade of clinical suspicion is needed to recognize CV-AVM and to prevent inadequate therapy owing to missed diagnosis.

Angioarchitecture and hemodynamics of microvascular arterio-venous malformations

Introduction

Arteriovenous malformations (AVMs) are characterized by pathological high flow, low resistance connections between arteries and veins. Treatment is critically dependent on correct interpretation of angioarchitectural features. However, some microfistular AVMs do not match the characteristics described in current AVM classification systems. Therefore, we propose a new subgroup of microfistular AVMs, composed of enlarged, fistulous paths on the venous half of capillaries and/or dilated draining venules (hyperdynamic, capillary-venulous malformation [CV-AVM]). CV-AVMs still ensure arterial flow to the periphery and fistulous venous drainage is less pronounced than in classical AVMs such that these lesions are often misinterpreted as venous malformations.

Materials and methods

We developed a computational model to study the effects of microvascular anomalies on local hemodynamics, as well as their impact on angiographic contrast propagation. Flow rates and pressures were computed with a lumped parameter description, while contrast propagation was determined by solving the 1D advection-diffusion equation.

Results and conclusions

For the newly proposed CV-AVM angioarchitecture, the computational model predicts increased arterio-venous contrast agent transit times and highly dispersive transport characteristics, compared to microfistular, interstitial type IV AVMs and high flow type II and III AVMs. We related these findings to time-contrast intensity curves sampled from clinical angiographies and found that there is strong evidence for the existence of CV-AVM.

Patency of the arterial pedal-plantar arch in patients with chronic kidney disease or diabetes mellitus

BACKGROUND

Patency of the pedal-plantar arch limits risk of amputation in peripheral artery disease (PAD). We examined patients without chronic kidney disease (CKD)/diabetes mellits (DM) [PAD-control], those with DM without CKD, and those with CKD without DM.

METHOD

Uni- and multivariate logistic regression was used to assess association of CKD with loss of patency of the pedal-plantar arch and presence of tibial or peroneal vessel occlusion. Multivariate models adjusted for age, sex, hypertension, hyperlipidemia and smoking.

RESULTS

A total of 419 patients were included [age 75.2 ± 10.3 years, 288 (69%) male]. CKD nearly doubled the unadjusted odds ratio (OR) for loss of patency of the pedal-plantar arch. After adjustment, association remained significant for severe CKD [estimated glomerular filtration rate (eGFR) ≤ 29 ml/min compared with eGFR ≥ 60 ml/min, adjusted (adj.) OR 8.24 (95% confidence interval {CI} 0.99-68.36, p = 0.05)]. CKD was not related to risk of tibial or peroneal artery occlusion [PAD-control versus CKD, adj. OR 1.09 (95% CI 0.49-2.44, p = 0.83)] in contrast to DM [PAD-control versus DM, adj. OR 2.41 (95% CI 1.23-4.72, p = 0.01), CKD versus DM, adj. OR 2.21 (95% CI 0.93-5.22); p = 0.07)].

CONCLUSIONS

Below the knee (BTK) vascular pattern differs in patients with either DM or CKD alone. Severe CKD is a risk factor for loss of patency of the pedal-plantar arch.

Efficacy Outcomes of Endovascular Versus Surgical Revascularization in Critical Limb Ischemia: Results From a Prospective Cohort Study

Data on efficacy outcomes of endovascular versus surgical revascularization in patients with critical limb ischemia (CLI) in contemporary practice are limited. In this prospective cohort study, 353 consecutive patients with CLI were enrolled and allocated to endovascular (PTA [percutaneous transluminal angioplasty]), surgical (SURG), or no revascularization (No REVASC) after interdisciplinary consensus. Outcome measures were sustained primary clinical success (sPCS; survival without major amputation, repeated target extremity revascularization, and freedom from CLI), limb salvage, and amputation-free survival. Propensity-matched Kaplan-Meier analyses and stratified log-rank tests were performed. The PTA, SURG, and No REVASC groups consisted of 264, 62, and 27 patients, respectively. Compared to SURG patients, PTA patients were significantly older, had more risk factors, and more often had ischemic lesions. Propensity score-adjusted analyses showed no significant differences: sPCS was 51.3%/52.2%, limb salvage rate 91.5%/93.7%, and major amputation-free survival 90.5%/87.2% at 12 months for PTA and SURG, respectively. Amputation-free survival for the No REVASC group was 69% at 12 months. In conclusion, endovascular and surgical revascularization in CLI has comparable efficacy outcomes after 12 months. Contemporary overall outcome of patients with CLI is considerably better compared to earlier studies.

Early clinical outcomes of a novel rheolytic directional thrombectomy technique for patients with iliofemoral deep vein thrombosis

BACKGROUND

Rheolytic thrombectomy (RT) for acute iliofemoral deep vein thrombosis (DVT) with first-generation techniques is often incomplete and adjunctive conventional catheter-directed thrombolysis (CDT) is required in more than half of patients to achieve venous patency.

PATIENTS AND METHODS

From the prospective Bern Venous Stent Registry, we investigated rates of primary treatment success, primary patency, and post-thrombotic syndrome (PTS) from 40 consecutive patients (mean age 51 ± 19 years, 45 % women) with acute iliofemoral DVT, treated with a novel directional RT technology and stent placement. Overall, 24 patients were treated for native-vessel iliofemoral DVT (11 with single-session RT, 13 with bail-out RT after failed CDT) and 16 for iliofemoral stent thrombosis. Pulse-spray thrombolysis (r-tPA 10 mg) was performed in 29 (73 %) patients. The mean follow-up duration was 193 ± 132 days (minimum 90 days).

RESULTS

Overall, primary treatment success of RT was 95 %; only two patients required adjunctive CDT to restore patency. In 24 patients with native-vessel DVT, six-month primary patency was 92 % (95 %CI 75-99 %), and 23 patients (96 %) were free from the PTS according to the Villalta score. In 16 patients with stent thrombosis, six-month primary patency was 63 % (95 %CI 35-85 %) and 50 % were free from PTS. Except for transient macroscopic haemoglobinuria in all patients, no other side effects were recorded.

CONCLUSIONS

In patients with iliofemoral DVT of native or stented vessels, RT followed by stent placement appears to be effective and safe. The novel technique enables single-session DVT treatment in the majority of patients without the need for prolonged CDT.

Ultrasound-assisted versus conventional catheter-directed thrombolysis for acute iliofemoral deep vein thrombosis: 1-year follow-up data of a randomized-controlled trial

Essentials Acute iliofemoral deep vein thrombosis can be treated with catheter-directed thrombolysis (CDT). We performed a randomized trial comparing conventional CDT versus ultrasound-assisted CDT (USAT). Clinical and duplex sonographic outcomes at 12 months were similar in the CDT and USAT groups. In both groups, incidence of postthrombotic syndrome was very low with good quality of life.

SUMMARY

Background In patients with acute iliofemoral deep vein thrombosis (IFDVT), catheter-directed thrombolysis (CDT) aims to prevent the postthrombotic syndrome (PTS). Adding intravascular high-frequency, low-power ultrasound energy to CDT does not seem to improve the immediate thrombolysis results but its impact on clinical outcomes at 12 months is not known. Patients/Methods In this randomized-controlled trial, 48 patients (mean age 50 ± 21 years; 52% women) with acute IFDVT were randomized to conventional CDT (n = 24) or ultrasound-assisted CDT (USAT; n = 24). In both groups, a fixed-dose thrombolysis regimen (20 mg r-tPA over 15 h) was used, followed by routine stenting of residual venous obstruction. At 12 months, PTS and venous disease severity (Villalta score and revised Venous Clinical Severity Score [rVCSS]), disease-specific quality of live (QOL; CIVIQ-20) and duplex-sonographic outcomes were assessed. Results Among the 45 surviving patients, 40 (89%; 95% confidence interval [CI] 76-96%) patients were free from PTS (defined as Villalta score < 5 points; 83%, 95% CI 61-95% in the USAT and 96%, 95% CI 77-100% in the CDT group), with a similar mean total Villalta score of 2.3 ± 2.9 vs. 1.7 ± 1.6, and a mean total rVCSS of 3.0 ± 3.5 vs. 2.7 ± 2.9 in the USAT and the CDT groups, respectively. Both groups had good disease-specific QOL with a CIVIQ-20 score of 29.4 ± 11.8 vs. 26.1 ± 7.8, respectively. Primary (100% vs. 92%) and secondary (100% vs. 96%) iliofemoral patency rates and presence of femoro-popliteal venous reflux (39% vs. 33%) were similar in both groups. Conclusion The addition of intravascular ultrasound energy to conventional CDT for the treatment of acute IFDVT did not have any impact on relevant clinical or duplex sonographic outcomes, which were favorable in both study groups. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier:NCT01482273.

Hemodynamic Characterization of Peripheral Arterio-venous Malformations

Peripheral arterio-venous malformations (pAVMs) are congenital vascular anomalies that require treatment, due to their severe clinical consequences. The complexity of lesions often leads to misdiagnosis and ill-planned treatments. To improve disease management, we developed a computational model to quantify the hemodynamic effects of key angioarchitectural features of pAVMs. Hemodynamic results were used to predict the transport of contrast agent (CA), which allowed us to compare our findings to digital subtraction angiography (DSA) recordings of patients. The model is based on typical pAVM morphologies and a generic vessel network that represents realistic vascular feeding and draining components related to lesions. A lumped-parameter description of the vessel network was employed to compute blood pressure and flow rates. CA-transport was determined by coupling the model to a 1D advection-diffusion equation. Results show that the extent of hemodynamic effects of pAVMs, such as arterial steal and venous hypertension, strongly depends on the lesion type and its vascular architecture. Dimensions of shunting vessels strongly influence hemodynamic parameters. Our results underline the importance of the dynamics of CA-transport in diagnostic DSA images. In this context, we identified a set of temporal CA-transport parameters, which are indicative of the presence and specific morphology of pAVMs.

Feasibility of stereotactic MRI-based image guidance for the treatment of vascular malformations: a phantom study

PURPOSE

Treatment of vascular malformations requires the placement of a needle within vessels which may be as small as 1 mm, with the current state of the art relying exclusively on two-dimensional fluoroscopy images for guidance. We hypothesize that the combination of stereotactic image guidance with existing targeting methods will result in faster and more reproducible needle placements, as well as reduced radiationexposure, when compared to standard methods based on fluoroscopy alone.

METHODS

The proposed navigation approach was evaluated in a phantom experiment designed to allow direct comparison with the conventional method. An anatomical phantom of the left forearm was constructed, including an independent control mechanism to indicate the attainment of the target position. Three interventionalists (one inexperienced, two of them frequently practice the conventional fluoroscopic technique) performed 45 targeting attempts utilizing the combined and 45 targeting attempts utilizing the standard approaches.

RESULTS

In all 45 attempts, the users were able to reach the target when utilizing the combined approach. In two cases, targeting was stopped after 15 min without reaching the target when utilizing only the C-arm. The inexperienced user was faster when utilizing the combined approach and applied significantly less radiation than when utilizing the conventional approach. Conversely, both experienced users were faster when using the conventional approach, in one case significantly so, with no significant difference in radiation dose when compared to the combined approach.

CONCLUSIONS

This work presents an initial evaluation of a combined navigation fluoroscopy targeting technique in a phantom study. The results suggest that, especially for inexperienced interventionalists, navigation may help to reduce the time and the radiation dose. Future work will focus on the improvement and clinical evaluation of the proposed method.

FTIR analysis of the phase content in low-density polyethylene

The phase content of a low-density polyethylene was studied by analysis of the CH2 rocking vibrations in non-oriented films prepared from the press (P-films) or from solution (S-films). Spectral simulations of the transmission spectra give the mass fractions of the orthorhombic phase αortho and of two noncrystalline phases (monoclinic-like and amorphous). The values of αortho (IR) are compared to αortho (i) where (i) stands for the X-ray diffraction, density, and DSC techniques. New results are obtained concerning the orthorhombic order and the change of phase content with aging. A two-phase analysis is justified for non-aged films containing a small amount of the monoclinic-like phase. The values of αortho (IR) are larger than αortho (i), the difference ranging between 0.12 and 0.43. The difference is a measure of the short-range order. αortho (IR) can reach 0.73 for the S-films. The stability of the short-range order phase is investigated. The sample is also analyzed using the trace of slow calorimetry. The difference between αortho by DSC and by slow calorimetry is a measure of strainable order. During aging, the variation in the phase content is large for the noncrystalline phases (in content and frequency) and small for the orthorhombic. The increase of the monoclinic-like phase during aging suggests that it is a precursor of the more stable orthorhombic organization. The quantification of two noncrystalline phases on fresh and aged films clarifies some ambiguity found in the literature about the monoclinic-like phase and the localization of bands in the rocking region for sample characterization. Analysis of other regions of the spectrum is needed to confirm the present results. Key words: low-density PE, phase content, FTIR, network phase, slow calorimetry.