Use of Wallstent device as an embolic protection device during stenting of aortic thrombus.

Blue toe syndrome can occur due to distal embolization from proximal lesions such as an aortic thrombus. We describe the case of a patient who presented with chronic limb threatening ischemia due to a flow-limiting infrarenal aortic thrombus, with gangrene from distal embolization to the left fifth toe, and was successfully treated with endovascular aortic stent graft insertion. Distal embolization during instrumentation was successfully prevented by using a partially deployed Wallstent (Boston Scientific) as an embolic protection device. The reconstrainable Wallstent device can be considered for distal thromboembolic protection during aortic stenting, in particular, when distal embolization is a concern and commercial devices are not readily available.

The Utility of Ultrasound Guidance to Improve the Safety of Closure of Antegrade Common Femoral Artery Access after Lower Limb Revascularization.

This study aimed to investigate the feasibility of ultrasound (US)-guidance in reducing adverse event (AE) rates when using Angioseal device during antegrade lower limb angioplasty via common femoral artery access. From December 2016 to November 2022, 1,322 patients were identified, including 1,131 (85.6%) patients who underwent US-guided closure and 191 (14.4%) who underwent non-US-guided closure. Moderate AEs were encountered in 10 (5.2%) patients in the non-US-guided closure group compared to 38 (3.4%) patients in the US-guided closure group (P = .208). Severe AEs were encountered in 4 (2.1%) patients in the non-US-guided closure group compared to 3 (0.3%) patients in the US-guided closure group (P = .010). Overall AEs occurred in 14 (7.3%) patients in the non-US-guided closure group compared to 41 (3.6%) patients in the US-guided closure group (P = .029). Binary logistic regression showed that only non-US guidance was an independent risk factor for the occurrence of severe AEs (P = .008).

Single-centre experience with endovascular rotational thrombectomy for single session salvage of thrombosed arteriovenous fistulas and grafts.

OBJECTIVES: This paper documents our experience and outcomes of using a relatively new endovascular rotational thrombectomy device for salvage of thrombosed vascular access. METHODOLOGY: A retrospective study reviewing patients with thrombosed native AVF or AVG who underwent endovascular declotting using a rotational thrombectomy device between November 2018 and May 2020 at a tertiary university hospital in Southeast Asia. We evaluated demographics, procedural data, technical and procedural success, patency rates and complications. RESULTS: A total of 40 patients underwent single session endovascular declotting of thrombosed vascular access. The mean follow-up period was 21.6 months (range 13.4-31 months). The technical success was 92.5% and clinical success was 80%. About 50% of patients had concomitant thrombolysis for pharmacomechanical thrombectomy. One patient had a myocardial infarction during the post-operative period. There were no other major complications within 30 days. The primary patency was 45.5% at 6 months and 22.7% at 12 months. Assisted primary patency was 68.1% at 6 months and 61.6% at 12 months, which was maintained up to 2 years. The secondary patency was 84.1% at 6 and 12 months. CONCLUSION: Our study shows that rotational thrombectomy device for single session thrombectomy of thrombosed arteriovenous fistulas and grafts is safe and effective. A high technical and clinical success rate was achieved, with low complication rates and specific advantages compared to other techniques, including reduced length of hospital stay. Our reported mid-term outcomes are reasonable with an assisted primary patency of 62% at 12 and 24 months. The use of newer techniques and novel dedicated thrombectomy devices show promise.

Endovascular repair of mycotic aortic aneurysms confers good medium-term outcomes and aneurysmal sac resolution.

INTRODUCTION: Mycotic aortic aneurysm (MAA) is a life-threatening condition. Endovascular repair (EVAR) of aortic aneurysms has been found to be a safe and effective alternative to open repair. We aimed to present the short- to medium-term outcomes for EVAR of MAA in our cohort. METHODS: We conducted a retrospective study of 23 consecutive patients with MAA who underwent EVAR in our hospital from January 2008 to July 2017. RESULTS: The mean age of our study population was 62 years. The mean aneurysmal size was 3.2 cm. Abdominal MAAs (n = 16, 70%) were the most common, followed by thoracic MAAs (n = 4, 17%). There was no 30-day mortality in our cohort. Endoleak (Types 1, 3, 4) was detected in 3 (13%) cases. At the one-month surveillance computed tomography aortogram, all patients had a reduction in aneurysmal size and 5 (22%) had complete aneurysmal sac resolution. 7 (30%) patients had sac resolution at six months and 8 (35%) patients, at 12 months. The overall survival was 91%, 80% and 61% at one, 12 and 60 months, respectively. CONCLUSION: EVAR is a feasible and durable method for the repair of MAA, with a five-year overall survival of 61%. All patients in our study had a reduction in aneurysmal size at one month, with 65% having complete aneurysmal sac resolution by 12 months.

Percutaneous Ablation of Metastatic Lymph Nodes: An Insight from the Comparison of Efficacy and Safety Between Cryoablation and Radiofrequency Ablation.

PURPOSE: To retrospectively compare efficacy and safety of computed tomography (CT)-guided percutaneous ablation of metastatic lymph nodes (LN) between cryoablation (CA) and radiofrequency ablation (RFA). MATERIALS AND METHODS: A bi-central institutional database research identified 28 patients (42 metastatic LNs) who underwent percutaneous CT-guided ablation. RFA group included 18 patients/26 tumors; CA group included 10 patients/16 tumors. Contrast-enhanced CT or MRI was used for post-ablation follow-up. Patient and tumor characteristics, technical and clinical success on a per tumor and a per patient basis and complication rates were recorded, evaluated and compared between the 2 groups. RESULTS: Both RFA and CA groups had the same median tumor size (2.00 vs. 2.20 cm, p = 0.257), the same median follow-up time (20.50 vs. 20.00 months, p = 0.923) and the same median length of hospital stay (1.00 vs. 1.00 days, p = 0.283). CA group had a higher median procedure time (110.50 vs. 52.00 min, p = 0.001). On a per lesion basis, the overall complete response post-ablation was 88.46% (23/26 lesions) in the RFA and 93.75% (15/16 lesions) in the CA group; no association was revealed between local tumor control and ablation technique (p = 0.709). No complications were recorded in both Groups. On a per patient basis, CA had a longer disease-free interval (24.00 vs. 14.50, p = 0.012) which, however, did not affect the overall survival between the two techniques (26.0 vs. 22.0, p = 0.099 for CA and RFA respectively). CONCLUSION: Our limited data suggest that CT-guided RFA and CA are equally effective on terms of efficacy and safety for the treatment of metastatic lymph nodes.

Intravascular ultrasound correlation of unenhanced magnetic resonance venography in the context of pelvic deep venous disease.

OBJECTIVE: In the present retrospective, assessor-blinded cross-sectional study, we compared the diagnostic efficacy of the relaxation-enhanced angiography without contrast and triggering (REACT) protocol for magnetic resonance venography (MRV) and intravascular ultrasound (IVUS). METHODS: All patients without prior lower limb vascular stenting who had undergone MRV with the REACT protocol and IVUS at our institution from January 2018 to May 2020 were included. The REACT protocol for MRV comprises three main phases: the adiabatic-based T2-preparation module, the non-volume-selective short tau inversion recovery pulse sequence, and the three-dimensional, modified two-point chemical-shift water-fat separated turbo-field echo pulse sequence. The IVUS findings served as the reference standard for stenosis and were used in the diagnostic efficacy analysis of the REACT protocol for MRV. The REACT protocol MRV images were reviewed by three board-certified interventional radiologists, and an interrater analysis was performed. RESULTS: A total of 33 patients (110 segments with IVUS correlation; 18 men [54.5%] and 15 women [45.5%]) were included. Most patients were Chinese (63.6%), and 24 had had bilateral deep venous disease (72.7%). The mean patient age was 59.0 years (range, 26.0-79.5 years). Moderate agreement was found between the three radiologists' diagnoses of iliac vein pathology using the REACT protocol for MRV (κ = 0.524; 95% confidence interval [CI], 0.426-0.623; P < .001). Compared with IVUS, REACT protocol MRV achieved a sensitivity of 96.10% (95% CI, 89.03%-99.19%), specificity of 78.79% (95% CI, 61.09%-91.02%), positive predictive value of 91.36% (95% CI, 84.54%-95.33%), and negative predictive value of 89.66% (95% CI, 73.81%-96.38%). Overall, 78.5% agreement was noted between the REACT protocol MRV and IVUS findings. Good agreement between the index test and reference standard was noted (κ = 0.779; 95% CI, 0.645-0.907; P ≤ .05). CONCLUSIONS: REACT protocol MRV has the potential to be a highly sensitive and specific screening tool to diagnose deep venous disease.

Randomized Controlled Trial Comparing Drug-coated Balloon Angioplasty versus Conventional Balloon Angioplasty for Treating Below-the-Knee Arteries in Critical Limb Ischemia: The SINGA-PACLI Trial.

Background There is a paucity of randomized trials demonstrating superior efficacy of drug-coated balloon angioplasty (DCBA) compared with conventional percutaneous transluminal angioplasty (PTA) for below-the-knee arterial disease in patients with -critical limb ischemia. Purpose To compare DCBA versus PTA for below-the-knee lesions in participants with critical limb ischemia through 12 months. Materials and Methods In this prospective, randomized, two-center, double-blind superiority study, participants with critical limb ischemia with rest pain or tissue loss with atherosclerotic disease in the native below-the-knee arteries were randomly assigned (in a one-to-one ratio) to DCBA or PTA after stratification for diabetes and renal failure between November 2013 and October 2017. The primary efficacy end point was angiographic primary patency at 6 months analyzed on an intention-to-treat basis. Secondary end points through 12 months were composed of major adverse events including death and major amputations, wound healing, limb salvage, clinically driven target-lesion revascularization, and amputation-free survival. Primary and binary secondary end points, analyzed by using generalized-linear model and time-to-event analyses, were estimated with Kaplan-Meier survival curves and hazard ratios (Cox regression). Results Seventy participants (mean age, 61 years ± 10 [standard deviation]; 43 men) in the DCBA group and 68 (mean age, 64 years ± 10; 50 men) in the PTA group were evaluated. The percentage of patients with angiographic primary patency at 6 months was 43% (30 of 70) in the DCBA group and 38% (26 of 68) in the PTA group (P = .48). Through 12 months, the percentage of deaths was similar: 21% in the DCBA group and 16% in the PTA group (P = .43). Amputation-free survival rate assessed with Kaplan-Meier curves differed through 12 months: 59% (41 of 70) in the DCBA group compared with 78% (53 of 68) in the PTA group (P = .01). Conclusion In participants with critical limb ischemia, the drug-coated balloon angioplasty group and the conventional percutaneous transluminal angioplasty group had similar primary patency rates at 6 months after treatment of below-the-knee arteries. Amputation-free survival rates through 12 months were higher in the percutaneous transluminal angioplasty group. © RSNA, 2021 Online supplemental material is available for this article.

Combined Biopsy and Imaging-Guided Microwave Ablation by Using a Coaxial Guiding Needle.

This article demonstrates the technique of using a coaxial guiding needle to perform combined percutaneous biopsy and microwave ablation via a single tract. From May 2019 to July 2020, 14 patients underwent combined biopsy and microwave ablation by using a coaxial guiding cannula. Tumors were in the kidney of six patients (43%), the liver of six patients (43%), and the lung in two patients (14%). The diagnostic yield of biopsy was 86% (12/14). Ablation technical success rate was 100%. In conclusion, using a coaxial guiding needle in microwave ablation and biopsy is safe and effective.

Single-Setting Superior Vena Cava Biopsy and Stenting Utilizing Cone Beam Computed Tomography as an Additional Tool.

BACKGROUND Malignant disease is a common etiology of superior vena cava syndrome (SVCS). Being a medical emergency, it often requires rapid diagnostic evaluation and therapy. Transcaval biopsy and endovascular stenting in a single-setting has been described, but only in a handful of cases. These cases utilized intra-operative venograms. In this study, we also used intra-operative cone beam computed tomography (CBCT) to increase the safety and efficacy of such single-setting procedures. CASE REPORT From January 2017 to July 2019, there were 5 patients with malignant SVCS who underwent single-setting superior vena cava biopsy and endovascular stenting utilizing intra-operative CBCT as an adjunct. Demographic data, clinical presentation, investigation results, procedural details, and patient outcomes were recorded. CBCT was utilized in all cases to optimize sampling of biopsies, visualize subsequent stent positioning, and for early detection of procedure-related complications. Transcaval biopsy was diagnostic in 4 of the 5 patients. Endovascular stents were deployed successfully in all cases, with post-stenting venogram demonstrating relief of prior obstructed segments. One patient had a complication of an apical pneumothorax, with no associated long-term pneumothorax-related morbidity or mortality. CONCLUSIONS This study demonstrates that single-setting transcaval biopsy and stenting in the context of malignant SVCS is a cost-efficient, safe, and feasible approach. In addition, the additional use of intra-operative CBCT is a useful tool to increase procedure efficacy and safety.

Percutaneous Management of Recurrent Head and Neck Cancer: Current Role and Evolving Principles in the Multidisciplinary Setting.

PURPOSE OF REVIEW: In this review, we will outline the role of percutaneous interventional radiological management of recurrent head and neck (H&N) cancer in the context of a multidisciplinary setting which consists of surgery, radiation therapy, as well as established and evolving systemic therapies that may impact current practice. RECENT FINDINGS: Management of recurrent H&N cancer is complex, with attention to the preservation of function and minimal treatment-related morbidity. The favored treatment modalities in local recurrence previously treated with radiotherapy are surgical resection, and if unresectable, for chemotherapy as definitive treatment, or as a prelude to resection if there is good tumor response. Unfortunately, some of these patients are too frail for major surgery or to withstand the toxicity of chemotherapy. There is a gap for effective local therapy without the morbidity of surgery, toxicity of re-irradiation, and systemic side effects of chemotherapy. Percutaneous interventions have the potential to bridge that gap as well as provide palliative symptomatic treatment for patients that have exhausted all treatment options. In the multidisciplinary setting involving the treatment of complex recurrent H&N cancer, percutaneous management now plays a viable and effective role with a foothold in this team-based approach.

Outcomes of Catheter-Directed Thrombolysis for Arteriovenous Fistula Thrombosis in Singapore: Is It Still Relevant Today?

Objective: To review the outcomes of catheter-directed thrombolysis (CDT) for salvage of thrombosed arteriovenous fistula (AVF) in a single centre in Southeast Asia. Methods: A retrospective study of CDT in AVF between January 2015 and July 2018 at a tertiary university hospital was carried out. Results: Within the study period, 85 patients underwent CDT for AVF thrombosis. Of these patients, 78% underwent CDT for 24 h and 12% required CDT for 48 h. Moreover, 14% of patients had bleeding during CDT and hence required a decrease in dosing or complete cessation. Incidence of intracranial haemorrhage was 1%, and technical success was 92%. Post CDT, primary patency rates at 12, 24 and 36 months were 87%, 62% and 36%, respectively; assisted primary patency rates at 12, 24 and 36 months were 96%, 82% and 69%, respectively; and secondary patency rates at 12, 24 and 36 months were 99%, 93% and 86%, respectively. Multivariate analysis did not identify any predictive factors for patency post CDT. Conclusion: Within our study population, CDT for AVF salvage conferred good technical results with low rates of complications. There was good primary patency at 12 months, and the results were sustained up to 36 months. It remains a useful modality for fistula salvage, avoiding surgical intervention.

Transradial access for arteriovenous fistuloplasty in Singapore.

BACKGROUND: Endovascular balloon angioplasty is standard therapy for dysfunctional arteriovenous fistula in end-stage renal failure patients on hemodialysis. Venous antegrade or retrograde puncture of the fistula is typically performed to gain access for fistuloplasty. Transradial approach for brachiocephalic or brachiobasilic arteriovenous fistulas offers an alternative method of access with the advantage of addressing multi-focal juxta-anastomotic and venous stenosis from the same approach. We aim to review the efficacy, outcomes and complication rates of transradial access for arteriovenous fistuloplasty among patients in Singapore. METHODS: A retrospective review of 195 endovascular fistuloplasties from September 2017 to August 2019, at a tertiary university hospital Vascular Surgery unit. RESULTS: Of 195 fistuloplasties, 43 (22%) were transradial approach (23 brachiocephalic arteriovenous fistulas, 20 brachiobasilic arteriovenous fistulas) in 33 patients (67% male and mean age = 65 years). Of these 43 procedures, 11 (26%) were performed as balloon-assisted maturation fistuloplasties while 32 (74%) were performed for mature arteriovenous fistulas with multi-focal juxta-anastomosis and venous stenosis. Technical success rate was 95% with mean procedure duration at 43.5 ± 14.6 min. Mean pre- and post-fistuloplasty dialysis access flow rates increased from 502 to 952 ml/min (p < 0.001). Post-intervention primary patency was 100%, 66% and 20% at 1, 6 and 12 months, respectively. There were four patients with non-limb-threatening radial artery thrombosis (9.3%) while there was no radial artery pseudoaneurysm or post-procedural bleeding. CONCLUSION: Transradial approach for arteriovenous fistuloplasty is a safe and feasible option in patients requiring balloon-assisted maturation or with multi-focal juxta-anastomotic and venous stenosis.

Iliac vein pathology and short-term stenting outcomes in a South-East Asian population: A single-centre experience.

OBJECTIVE: Current literature regarding iliofemoral intervention and stenting is mostly based on Western populations. We present our experience of iliofemoral stenting for chronic venous disease within a South-East Asian population. METHODS: This is a single-centre retrospective review of a prospectively collected registry. Seventy-one patients with 105 limbs underwent iliac vein IVUS and stenting between 2016 and 2019. All patients underwent pre-procedure ultrasound venous scan and MRI venogram. Pre- and post-operative CEAP classification, Villalta score and Venous Clinical Severity Score (VCSS), technical results, stent patency rates and complication rates are documented. RESULTS: Seventy-six per cent of the cases are non-thrombotic iliac vein lesion, and 68% of patients have C4 to C6 disease. Ten percentage of patients had acute thrombosis on presentation. There was 100% technical success. A 6- and 7-point reduction in the mean VCSS and Villalta score, respectively, were noted post-stenting (baseline of 10 points and P < 0.001 in both categories). Post-stenting ulcer healing rate was 91% at 6 and 12 months. One-year ulcer recurrence and cellulites recurrence were at 8% and 7%, respectively. One unplanned 30-day readmission (not related to procedure) and no 30-day mortality were noted. Bleeding complication from anticoagulation was 3%. There was 10% in-stent non-flow limiting stenosis on surveillance. One-year primary patency was 91%, and secondary patency was 100%. CONCLUSION: Within our series, iliofemoral stenting has 100% technical success, with statistically significant reduction in VCSS and Villalta score, good wound healing rates, low ulcer and cellulites recurrence and good primary and secondary patency rates at 1 year.

Radiofrequency ablation of benign thyroid nodules: recommendations from the Asian Conference on Tumor Ablation Task Force.

Radiofrequency ablation (RFA) is a thermal ablation technique widely used for the management of benign thyroid nodules. To date, five academic societies in various countries have reported clinical practice guidelines, opinion statements, or recommendations regarding the use of thyroid RFA. However, despite some similarities, there are also differences among the guidelines, and a consensus is required regarding safe and effective treatment in Asian countries. Therefore, a task force was organized by the guideline committee of the Asian Conference on Tumor Ablation with the goal of devising recommendations for the clinical use of thyroid RFA. The recommendations in this article are based on a comprehensive analysis of the current literature and the consensus opinion of the task force members.

Intravascular Ultrasound-Guided Revascularization of Chronic Juxtarenal Aortoiliac Occlusion.

Chronic juxtarenal aortoiliac occlusion (JRO) represents the most severe form of aortoiliac occlusive disease, classified under Trans-Atlantic Inter-Society Consensus (TASC II) as a TASC II D lesion with surgical treatment as the main recommendation. Although endovascular revascularization of other TASC II D lesions are routinely performed, JRO is often considered a contraindication for endovascular treatment due to the extensive nature, extending from the level of the renal arteries down to the iliac arteries. We hereby illustrate an intravascular ultrasound-guided re-entry based technique to facilitate endovascular reconstruction of a JRO. A 58-year-old man with JRO presented with an infected nonhealing forefoot ulcer. A transradial pigtail catheter was positioned at the level of the occlusion as an imaging catheter and landmark for re-entry. Subintimal wiring was performed through bilateral groin accesses to the level of the pigtail catheter. Intravascular-guided re-entry catheter was used to identify the true lumen guide firing of the needle catheter, allowing passage for a guidewire into the true lumen of the suprarenal aorta. The intimal fenestration was dilated using a 4-mm angioplasty balloon which allowed passage of the contralateral guidewire. Kissing stent grafts were deployed bilaterally, extending from the level of the infrarenal aorta down to the level of the distal external iliac arteries in overlapping fashion. Completion angiography showed brisk flow from the aorta through the stented portion into the femoral arteries. The patient underwent forefoot amputation 2 days later with successful wound healing and limb salvage at 6 months.

Microwave ablation of the liver in a live porcine model: the impact of power, time and total energy on ablation zone size and shape.

Objective: To explore various microwave (MW) time/power combinations to achieve maximum single-probe system performance in a live pig liver model.Methods: Fifty-one microwave ablations performed in 12 female pigs using the following time/power combinations: 65 W for 10 min (65W 10MIN), ramped from 20 to 65 W (RAMPED), 95 W pulses with cooling periods (95W PULSED), 40 W for 16 min 15 s (LOW POWER), 1 min 95 W pulse then 8 min 65 W then a second 1 min 95 W pulse (BOOKEND 95W) and 65 W for 15 min (65W 15MIN). Temperatures 1.5 cm from the antenna were measured. Livers were excised, and ablations were measured and compared.Results: At fixed overall energy, LOW POWER produced ablation zones with the smallest volume compared to 65W 10MIN, RAMPED and 95W PULSED. At a fixed time of 10-min, BOOKEND 95W protocol achieved wider and larger ablation zones than 65W 10MIN (p = 0.038, p = 0.008) and 95W PULSED (p = 0.049, p = 0.004). The 65W 15MIN combination had significantly larger diameters (p = 0.026), larger lengths (p = 0.014) and larger volumes (p = 0.005) versus 65W 10MIN. Maximum temperatures were highest with BOOKEND 95W (62.9 °C) and 65 W 15 MIN (63.0 °C) and lowest with LOW POWER (45.9 °C), p = 0.009.Conclusions: Low power ablations, even if controlled for total energy delivery, create small ablation zones. High peak powers are associated with larger ablation zones and high margin temperatures if cooling pauses are avoided. Ramping and pulsing protocols with interleaved cooling appear to be of no benefit versus continuous 65 W for creating large ablation zones.