Ramsey Al-Hakim

Inferior Vena Cava Filter Retrieval: Effectiveness and Complications of Routine and Advanced Techniques

PURPOSE To investigate the success and safety of routine versus advanced inferior vena cava (IVC) filter retrieval techniques. MATERIALS AND METHODS A retrospective review was performed of patients who underwent IVC filter placement and/or a retrieval attempt over a 10-year period. Retrieval technique(s), preretrieval computed tomography, preretrieval venography, and clinical/imaging follow-up for 30 days after retrieval were analyzed. Mean filter dwell time was 134 days (range, 0-2,475 d). RESULTS Filter retrieval was attempted 231 times in 217 patients (39% female, 61% male; mean age, 50.7 y), with success rates of 73.2% (169 of 231) and 94.7% (54 of 57) for routine and advanced filter retrieval techniques, respectively. The overall filter retrieval complication rate was 1.7% (four of 231); complications in four patients (with multiple complications in some cases) included IVC dissection, IVC intussusception, IVC thrombus/stenosis, filter fracture with embedded strut, IVC injury with hemorrhage, and vascular injury from complicated venous access. The rate of complications associated with filter retrievals that required advanced technique was significantly higher than seen with routine technique (5.3% vs 0.4%; P < .05). Longer dwell time, more transverse tilt, and presence of an embedded hook were associated with significantly increased rates of failed retrieval via routine technique (P < .05). CONCLUSIONS IVC filters can be retrieved with a high overall success rate (98.2%) and a low complication rate (1.7%) by using advanced techniques when the routine approach has failed; however, the use of advanced techniques is associated with a significantly higher complication rate.

Radiation-Induced Cataractogenesis: A Critical Literature Review for the Interventional Radiologist

Extensive research supports an association between radiation exposure and cataractogenesis. New data suggests that radiation-induced cataracts may form stochastically, without a threshold and at low radiation doses. We first review data linking cataractogenesis with interventional work. We then analyze the lens dose typical of various procedures, factors modulating dose, and predicted annual dosages. We conclude by critically evaluating the literature describing techniques for lens protection, finding that leaded eyeglasses may offer inadequate protection and exploring the available data on alternative strategies for cataract prevention.

The Hangman Technique: A Modified Loop Snare Technique for the Retrieval of Inferior Vena Cava Filters with Embedded Hooks

The loop snare technique is a method for inferior vena cava (IVC) filter retrieval that creates a wire loop between the filter legs; this technique may fail in cases with an embedded hook. This report describes the hangman technique, a modified loop snare technique for filter retrieval that creates a wire loop between the filter neck and IVC wall for release of embedded filter hooks. The hangman technique was attempted in 11 cases complicated by tilt (mean tilt, 13.3 degrees ± 3.9) and an embedded hook (mean dwell time, 194.5 d) with a retrieval success rate of 81.8% (9 of 11 cases) and no associated complications.

Early Experience with AngioVac Aspiration in the Pulmonary Arteries

Five consecutive cases in which the AngioVac aspiration cannula was used for the management of pulmonary embolism (PE) were retrospectively reviewed. Four cases (80%) presented with massive PE, and two (40%) were technically successful (reduction in Miller index ≥ 5). Four patients (80%) died at a mean of 7.3 days after the procedure, including one death related to right ventricular free wall perforation. Although the AngioVac aspiration cannula has shown clinical promise in a variety of clinical applications, early experience in the pulmonary arteries has shown limited success, and further study and careful patient selection are required.

Removal of Caval and Right Atrial Thrombi and Masses Using the AngioVac Device: Initial Operative Experience

PURPOSE To describe initial single-center experience with a thrombectomy device in managing right atrial and caval thrombi, tumors, and vegetations. MATERIALS AND METHODS A retrospective analysis of AngioVac thrombectomy performed in 16 patients (mean age 53 y ± 13; 8 men, 8 women) between August 2013 and August 2015 was performed. Indications included right atrial mass/thrombus (6/16; 37.5%) and iliocaval thrombus (10/16; 62.5%). Procedural success was defined as aspiration of > 70% volume of atrial mass/thrombus or restoration of antegrade caval flow. RESULTS Procedural success was achieved in 4/6 (67%) right atrial masses/thrombi and 10/10 (100%) caval thrombi. All patients (8/8; 100%) with caval thrombus presenting with swelling/edema had improvement or resolution of symptoms. There were no procedural or periprocedural mortalities; complications included one major (6.3%; intraprocedural pulmonary embolus) and one minor (6.3%; access site hematoma not requiring transfusion) complication. Of 16 patients, 14 (87.5%) survived to discharge at a mean of 10 days ± 8 (range, 1-23 d), and 12 patients (75%) were alive at last known follow-up at a mean of 385 days ± 267 (range, 63-730 d). At a mean of 194 days ± 177 (range, 41-372 d), 4/16 (25%) patients were dead; no death was related to AngioVac thrombectomy. At a mean of 66 days ± 21 (range, 49-90 d) after intervention, 3/14 (21.4%) cases with procedural success had local recurrence of mass/thrombus. CONCLUSIONS AngioVac thrombectomy can be performed with high procedural success with clinical benefit in patients with right atrial and caval masses/thrombi.

Techniques and Devices for Catheter-Directed Therapy in Pulmonary Embolism

The clinical presentation of a patient with acute pulmonary embolism (PE) can be classified into 3 categories: low-risk, submassive (presence of right heart strain), and massive (hemodynamic compromise). Massive PE is associated with high morbidity or mortality and typically treated with systemic intravenous thrombolysis. Over the last 2 decades, however, catheter-directed techniques have become an increasingly popular treatment modality for patients with a contraindication to systemic thrombolysis or without clinical improvement after systemic thrombolysis. Furthermore, endovascular treatment for patients with submassive PE has been of great interest due to the significantly increased mortality associated with right heart strain, and prospective clinical trials have demonstrated catheter-directed thrombolysis to decrease right heart strain earlier than systemic anticoagulation alone. This article describes available devices and endovascular techniques used to treat patients with massive and submassive acute PE.

Defining New Metrics in Microwave Ablation of Pulmonary Tumors: Ablation Work and Ablation Resistance Score

PURPOSE To investigate pulmonary microwave ablation metrics including ablation work, ablation resistance score, and involution. MATERIALS AND METHODS Retrospective review was performed of 98 pulmonary tumor ablations using the NeuWave Certus Microwave Ablation System (NeuWave Medical, Madison, Wisconsin) in 71 patients (32 men and 39 women; mean age, 64.7 y ± 11.5). Ablation work was defined as sum of (power) * (time) * (number of antennas) for all phases during an ablation procedure. Ablation zone was measured on CT at 3 time points: after procedure, 1-3 months (mean 47 d), and 3-12 months (mean 292 d). Ablation zones were scored based on location for pulmonary lobe (upper = 1, middle/lingula = 2, lower = 3) and region (peripheral = 1, parenchymal = 2, central = 3), and the 2 were summed for ablation resistance score. RESULTS Ablation zone on CT at 1-3 months was significantly smaller in regions with higher ablation resistance score (P < .05). There was a significant correlation between ablation work and ablation zone measured on CT performed after procedure (P < .001), at 1-3 months (P < .001), and at 3-12 months (P < .05). Ablation zone significantly decreased from after procedure to 1-3 months (P < .001) and from 1-3 months to 3-12 months (P < .001), with change from after procedure to 1-3 months significantly greater (P < .01). CONCLUSIONS Pulmonary microwave ablation zone is significantly smaller in regions with higher ablation resistance score. Ablation work correlates to ablation zone with a nonlinear involution pattern in the first year and may be useful for planning before the procedure.