JVIR breaks its record for the most number of submission..... again

JVIR hits record-breaking number of submissions, exceeding 1200 in 2015—the highest in its 25-year history. Submit your cutting-edge research to JVIR to provide the base for future research like no other medical discipline can. Keep your eyes on us for a number of innovations and new features in JVIR this year!

Risk factors for thromboembolic occlusions and efficacy of aspiration thrombectomy

A recent study from researchers at Shanghai Jiao Tong University has evaluated the predictive factors behind thromboembolic occlusions occurring during endovascular revascularization (EVR) and the success rate of percutaneous aspiration thrombectomy. A total of 260 patients underwent EVR. EVR was done using intraluminal and/or subintimal recanalization with 4000U heparin given prior to angioplasty. Uncovered self-expandable stents were placed in patients with flow-limiting dissections or residual stenosis. Of the 260 patients, 237 patients had restoration of flow without thromboembolic occlusion. 23 patients had EVR with subsequent thromboembolic occlusion. In patients with thromboembolic occlusion, a 5F or 6F guiding catheter was introduced and passed though the thromboembolic segment. A 20- or 50-mL syringe was connected to the guiding catheter after removal of the guide wire. After confirming adequate clot removal, 250,000–500,000 U urokinase was diluted in 50 mL saline solution and gradually infused into the treated artery to dissolve any remaining clots in all cases, even though no clots were present angiographically. Technical success was defined as <30% residual stenosis. Investigators report a technical success rate of 95.7% in the aspiration thrombectomy group. Interestingly, there were no significant differences in the clinical outcomes of the two groups including ABI, maximum walking distance, ulcer healing, restenosis/occlusion, and limb salvage rates. Further, there were few factors that could be cited as significant risk factors for thromboembolic occlusion during EVR including stenosis >90% and intraluminal angioplasty. The authors concluded that aspiration thrombectomy is an effective therapy for acute thromboembolic occlusion and may be considered primary treatment when this event occurs during infrainguinal arterial EVR.

Commentary:

This manuscript is interesting and noteworthy for the simple methods used to both perform revascularization and to treat a thromboembolic complication. While this study is limited due to the small sample size of thromboembolic occlusions (n=23), the small number of variables strengthen the results. All patients were treated initially with either PTA or self-expanding stent. If there was an occlusion, it was treated with aspiration thrombectomy using a 5F or 6F catheter and a syringe. The low thromboembolic occlusion rate (6.6%) and high likelihood of success after aspiration thrombectomy argue against the added cost and complexity of a distal embolic protection device. However, more research is needed to determine the risk in interventions with limited runoff vessels and more complex revascularization techniques.

Figure 3. Arterial thrombosis in the left SFA in a 78-year-old man with severe claudication for 3 weeks. (a,b) Long-segment occlusion is detected in the left SFA on contrast-enhanced MR angiography and DSA (arrows, aand b), and severe arterial thrombosis after stent placement is observed in the SFA (arrows, c). PAT was performed and arterial thrombotic material was aspirated out (d). (e) Final angiogram shows good SFA patency. 

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Wei L, Zhu Y, Liu F, et al. Infrainguinal endovascular recanalization: risk factors for arterial thromboembolic occlusions and efficacy of percutaneous aspiration thrombectomy. J Vasc Interv Radiol 2016; 10.1016/j.jvir.2015.11.025

Post Author:
Luke R. Wilkins, MD

Bland Embolization as a Bridge to Transplantation

In the latest issue of JVIR, researchers from Duke evaluated the effectiveness of bland embolization as a bridge to transplantation in 117 patients with HCC that underwent treatment while within Milan criteria. Superselective embolization was performed in 128 of 181 procedures. PVA particles were the most common embolic used (132 of 181) with sizes ranging from 150-250 µm (n=111), 45-150 µm (n=16), and 250-355 µm (n=1). 40 µm embozene and 100-300 µm embospheres were also used in some procedures. Follow-up imaging was evaluated to determine if patients progressed beyond Milan criteria in an intent-to-transplant analysis. They found that post-embolization, 87% and 78% of patients still fell within Milan criteria at 6 and 12 months respectively. The median time to disease progression beyond Milan criteria was 22.6 months (95% confidence interval, 16.2-29 mo). 34 of 117 (29%) had eventual transplant at a median of 3.3 mo (range, 0.5 – 20.9 mo). The authors concluded that bland embolization has a comparable efficacy versus other embolotherapies as a bridging strategy to maintain HCC within Milan criteria.

Commentary:

A large portion of centers use TACE as the preferred noncurative locoregional treatment when surgical resection or locally ablative therapies are not feasible or as a bridge to transplantation. This manuscript is yet in another series of papers showing that there is a lack of evidence of superiority of chemoembolization versus bland embolization in prolonging survival. There is a significant increase in rate of adverse events when perform TACE versus TAE in addition to an increase in overall cost of the procedure. Given these factors, an article supporting bland embolization as a bridge to transplantation is noteworthy. While there are several limitations of the current study (multiple different embolic agents, no defined criteria for using TAE versus TACE, and a small number of patients going on to receive transplant)​ the results are an argument for bland embolization even if reserved for patients thought likely to receive a transplant if kept within Milan criteria.

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Hodavance MS, Vikingstad EM, Griffin AS, Pabon-Ramos WM, Berg CL, Suhocki PV, Kim CY. Effectiveness of transarterial embolization of hepatocellular carcinoma as a bridge to transplantation. J Vasc Interv Radiol 2016; 27:39-45.

Post Author:
Luke R. Wilkins