Evaluation of robotic endovascular catheters for arch vessel cannulation

OBJECTIVE

Conventional catheter instability and embolization risk limits the adoption of endovascular therapy in patients with challenging arch anatomy. This study investigated whether arch vessel cannulation can be enhanced by a remotely steerable robotic catheter system.

METHODS

Seventeen clinicians with varying endovascular experience cannulated all arch vessels within two computed tomography-reconstructed pulsatile flow phantoms (bovine type I and type III aortic arches), under fluoroscopic guidance, using conventional and robotic techniques. Quantitative (catheterization times, catheter tip movements, vessel wall hits, catheter deflection) and qualitative metrics (Imperial College Complex Endovascular Cannulation Scoring Tool [IC3ST]) performance scores were compared.

RESULTS

Robotic catheterization techniques resulted in a significant reduction in median carotid artery cannulation times and the median number of catheter tip movements for all vessels. Vessel wall contact with the aortic arch wall was reduced to a median of zero with robotic catheters. During stiff guidewire exchanges, robotic catheters maintained stability with zero deflection, independent of the distance the catheter was introduced into the carotid vessels. Overall IC3ST performance scores (interquartile range) were significantly improved using the robotic system: Type I arch score was 26/35 (20-30.8) vs 33/35 (31-34; P = .001), and type III arch score was 20.5/35 (16.5-28.5) vs 26.5/35 (23.5-28.8; P = .001). Low- and medium-volume interventionalists demonstrated an improvement in performance with robotic cannulation techniques. The high-volume intervention group did not show statistically significant improvement, but cannulation times, movements, and vessel wall hits were significantly reduced.

CONCLUSION

Robotic technology has the potential to reduce the time, risk of embolization and catheter dislodgement, radiation exposure, and the manual skill required for carotid and arch vessel cannulation, while improving overall performance scores.

Advanced catheter technology: is this the answer to overcoming the long learning curve in complex endovascular procedures

INTRODUCTION

Advanced endovascular procedures require a high degree of skill with a long learning curve. We aimed to identify differential increases in endovascular skill acquisition in novices using conventional (CC), manually steerable (MSC) and robotic endovascular catheters (RC).

MATERIALS/METHODS

10 novices cannulated all vessels within a CT-reconstructed pulsatile-flow arch phantom in the Simulated Endovascular Suite. Subjects were randomly assigned to conventional/manually-steerable/robotic techniques as the first procedure undertaken. The operators repeated the task weekly for 5 weeks. Quantitative (cannulation times, wire/catheter-tip movements, vessel wall hits) and qualitative metrics (validated rating scale (IC3ST)) were compared.

RESULTS

Subjects exhibited statistically significant differences when comparing initial to final performance for total procedure times and catheter-tip movements with all catheter types. Sequential non-parametric comparisons identified learning curve plateau levels at weeks 2 or 3(RCs, MSCs), and at week 4(CCs) for the majority of metrics. There were significantly fewer catheter-tip movements using advanced catheter technology after training (Week 5: CC 74 IQR(59-89) versus MSC 62(44-81); p = 0.028, and RC 33 (28-44); p = 0.012). RCs virtually eliminated wall hits at the arch (CC 29(28-76) versus RC 8(6-9); p = 0.005) and produced significantly higher overall performance scores (p < 0.02).

CONCLUSION

Advanced endovascular catheters, although more intricate, do not seem to take longer to master and in some areas offer clear advantages with regards to positional control, at a faster rate. RCs seem to be the most intuitive and advanced skill acquisition occurs with minimal training. Robotic endovascular technology may have a significantly shorter path to proficiency allowing an increased number of trainees to attempt more complex endovascular procedures earlier and with a greater degree of safety.

Stent-assisted Percutaneous Angioplasty for Extra-cranial Carotid Disease: Experience at Singapore General Hospital

Introduction: This study aims to analyse the results of carotid stenting in a tertiary referral centre in Singapore. Materials and Methods: Retrospective analysis of all carotid artery stenting (CAS) cases in a single centre from March 1997 to December 2008 was performed. Sixty successful procedures were performed in 61 patients, with bilateral stenting in 1 patient, and 2 failed procedures. The majority were Chinese (78.7%) and males (77.0%), with a high proportion having hypertension (82.0%) and hypercholesterolaemia (78.7%). The majority (91.8%) of patients were high surgical risk candidates, primarily due to cardiac risk factors. Ten patients (16.4%) had prior neck irradiation for nasopharyngeal carcinoma, and 3 patients each (4.9%) had previous endarterectomy and contralateral occlusion. A distal embolic protection device was used in 71.7% of cases. Results: Technical success was 96.8%. The 30-day stroke and death rate was 13.8%, comparable to reported results for this high surgical risk population. Conclusion: CAS is a technically feasible and a relatively safe alternative to endarterectomy to treat extracranial carotid stenosis, especially in patients who are inoperable orat high surgical risk. Keywords: Carotid stenting, High surgical risk