Blunt microdissection for endovascular treatment of infrainguinal chronic total occlusions

Design, Optimization, and Modeling of a Hydraulic Soft Robot for Chronic Total Occlusions

Chronic total occlusion (CTO) is one of the most severe and sophisticated vascular stenosis because of complete blockage, greater operation difficulty, and lower procedural success rate. This study proposes a hydraulic-driven soft robot imitating the earthworm's locomotion to assist doctors or operators in actively opening thrombi in coronary or peripheral artery vessels. Firstly, a three-actuator bionic soft robot is developed based on earthworms' physiological structure. The soft robot's locomotion gait inspired by the earthworm's mechanism is designed. Secondly, the influence of structure parameters on actuator deformation, stress, and strain is explored, which can help us determine the soft actuators' optimal structure parameters. Thirdly, the relationship between hydraulic pressure and actuator deformation is investigated by performing finite element analysis using the bidirectional fluid-structure interaction (FSI) method. The kinematic models of the soft actuators are established to provide a valuable reference for the soft actuators' motion control.

Femoropopliteal Artery Stent Thrombosis: Report From the Excellence in Peripheral Artery Disease Registry

BACKGROUND

There are limited data on femoropopliteal artery stent thrombosis (ST), which is a serious adverse outcome of peripheral artery interventions.

METHODS AND RESULTS

Index procedures resulting in femoropopliteal ST were compared with stent procedures without subsequent ST in the Excellence in Peripheral Artery Disease registry. The study data had a total of 724 cases of stent procedures and 604 unique patients. Femoropopliteal ST occurred in 26 of 604 patients (4.3%) over a median follow-up of 6 months post procedure. ST was more likely to occur in men (96.3% versus 82.2%; P=0.026) and to have an initial intervention for chronic total occlusions (88.5% versus 64.0%; P=0.01). There was no significant difference in ST between drug-coated and bare-metal stents (4.4% versus 3.4%; P=0.55), but the rate of ST was significantly higher with self-expanding covered stent grafts compared with bare-metal stents (10.6% versus 3.4%; P=0.02). ST was significantly associated with an increased risk of 12-month major adverse limb events (hazard ratio, 4.99; 95% confidence interval, 2.31-10.77; P<0.001) compared with no ST. On multivariate analysis, treatment of chronic total occlusion lesions (odds ratio, 3.46; 95% confidence interval, 0.98-12.20; P=0.05) and in-stent restenosis lesions (odds ratio, 5.30; 95% confidence interval, 1.83-15.32; P=0.002) were independently associated with an increased risk of ST.

CONCLUSIONS

In a multicenter peripheral interventional registry, femoropopliteal ST occurred in 4.3% of patients who underwent stent procedures, and it was associated with treatment of chronic total occlusions and in-stent restenosis lesions, and had higher 12-month major adverse limb events.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01904851.

Comparative Assessment of Guidewire and Microcatheter vs a Crossing Device-Based Strategy to Traverse Infrainguinal Peripheral Artery Chronic Total Occlusions

PURPOSE

To compare success rates of a guidewire and microcatheter strategy vs the use of specialized crossing devices to traverse infrainguinal peripheral artery chronic total occlusions (CTOs).

METHODS

For this analysis, data on 438 consecutive infrainguinal CTO interventions in 438 patients (mean age 63.2 years; 402 men) performed between August 2006 and May 2014 were extracted from the multicenter Excellence in Peripheral Artery Disease (XLPAD) database (ClinicalTrials.gov; identifier NCT01904851). Primary technical success constituted placement of a guidewire in the true lumen, past the distal CTO cap, with the initial crossing strategy.

RESULTS

A wire-catheter strategy was used in 295 (67.4%) and a specialized CTO crossing device in 143 (32.6%) patients (p<0.001). Primary crossing technical success was higher with CTO devices (72.1% vs 51.9%, p<0.001). The primary wire-catheter arm used significantly more secondary CTO devices (28.1% vs 17.5%) and/or provisional re-entry devices (26.7% vs 4.9%) compared with the primary CTO device arm (both p<0.001). Secondary crossing technical success (defined as crossing with an alternate strategy: 67.5% vs 71.4%, p=1.000), provisional crossing technical success (defined as use of a re-entry device: 84.2% vs 87.5%, p=0.768), and procedure success (93.6% vs 90.9%, p=0.332) were similar between the wire-catheter and CTO device strategies, respectively. No differences were observed in periprocedural complications or 30-day adverse events; however, at 12 months, there was a significantly higher surgical revascularization rate in the primary wire-catheter arm (8.8% vs 2.8%, p=0.025).

CONCLUSION

Infrainguinal peripheral artery CTO crossing is frequently attempted with a wire-catheter technique; however, an initial CTO crossing device approach is associated with higher primary technical success. Overall procedure success is similar with both strategies.

Revascularization of lower extremity chronic total occlusions with a novel intraluminal recanalization device: results of the ReOpen study

PURPOSE

To report outcomes of a multicenter, nonrandomized study evaluating the safety and effectiveness of a guidewire-mounted mechanical recanalization device with a rotating distal tip (TruePath) in facilitating the crossing of infrainguinal chronic total occlusions (CTOs).

METHODS

Eligible patients had lower extremity ischemia and an angiographically confirmed occlusion, with no antegrade flow for at least 30 days, in an infrainguinal artery. Enrollment occurred when a previous or concurrent attempt to cross the CTO with a conventional guidewire had failed. A total of 85 patients with 85 lesions were enrolled; 61 (71.8%) target lesions were in the superficial femoral artery and 68 (80%) were considered moderately or heavily calcified. Clinical evaluations were assessed immediately post procedure and at 30-day follow-up.

RESULTS

Freedom from clinical perforation at the time of the procedure was achieved in 98.8% of patients. The device facilitated CTO crossing into the distal true lumen (technical success) in 68 (80.0%) patients, with subsequent distal guidewire positioning in 65 (76.5%). The average ABI (n=58) improved from 0.65 (range 0.35-1.20) at baseline to 1.00 (range 0.50-2.00) through 30-day follow-up. Symptoms improved in 70 (82.4%) patients upon treatment, and improvement was maintained in 57/70 (81.4%) through 30 days.

CONCLUSION

The ReOpen Study demonstrated that the TruePath device is safe and effective for facilitating crossing of CTOs resistant to conventional guidewire maneuvers.