Development of a new thrombectomy technical difficulty index: TTDI

Aim: Multiple recent trials have proven the efficacy of thrombectomy in large vessel occlusive stroke and earlier reperfusion correlates with improved outcomes. We developed a thrombectomy technical difficulty index (TTDI) to predict the expected procedural difficulty as an aid to operator decision making for the achievement of a fast and successful recanalization.Materials and Methods: Key thrombectomy factors were used to grade predicted difficulty of thrombectomy on a 3-point scale, from minimal, mild to moderate to severe. Thirty patients that underwent thrombectomy had their computed tomography angiograms scans analysed by seven neurointerventionists using the TTDI to predict level of difficulty to establish its reliability (intra-class correlation, ICC) and validity.Results: An almost perfect level of agreement on TTDI scores between the 7 neurointerventionists was reported (ICC = 0.89, 95% CI = 0.81 to 0.94), and an expert INR opinion of case difficulty using the TTDI (ICC = 0.861, 95% CI = 0.77 to 0.93). Validity analysis showed that that length of procedure was shorter for minimal compared to mild to moderate difficultly cases as assessed with TTDI.Conclusion: The TTDI is a promising tool to assess predicted thrombectomy case difficulty, allowing operator to consider potential problems and inform decisions about whether a modification to technique, including access, equipment and anaesthesia, should be considered. Larger prospective studies evaluating the TTDI are warranted.