The Role of Drug-Coated Balloon in Haemodialysis Arteriovenous Fistula Stenosis Management.

Arteriovenous fistula (AVF) stenosis is a common problem leading to dialysis access dysfunction. The conventional balloon (CB) is the most commonly used device during angioplasty but suffers from poor durability of results due to neointimal hyperplasia-mediated recurrence. The drug-coated balloon (DCB) is an adjunct to balloon angioplasty that reduces neointimal hyperplasia, thereby improving post-angioplasty patency. Despite the heterogeneity of DCB clinical trials to date, the evidence suggests that DCBs of different brands are not necessarily equal, and that patient selection, adequate lesion preparation and proper DCB procedural technique are important to realize the benefit of DCB angioplasty.

Recurrent Stenoses in Arteriovenous Fistula (AVF) for Dialysis Access: cuttIng ballooN angioplaSTy combined wITh paclitaxel drUg-coaTed balloon angioplasty, an observatIONal study (INSTITUTION Study).

PURPOSE: To study the safety and efficacy of cutting balloon angioplasty (CBA) followed by paclitaxel drug-coated balloon (PCB) angioplasty for recurrent venous lesions in arteriovenous fistulas (AVFs). MATERIALS AND METHODS: We conducted a prospective single-arm cohort study of CBA followed by PCB angioplasty for recurrent AVF stenoses between September 2017 and April 2019. In total, 44 participants were recruited. Target lesions were included if they had recurred within 12 months post-angioplasty, were > = 0.5 cm upstream from the arteriovenous anastomosis, and did not involve the central veins. Up to two non-target lesions per circuit/participant with the same definition were allowed. Lesions were considered separate when there was an intervening 2-cm segment of normal vessel. Technical success was defined as complete lesion effacement on angioplasty. End-points of target and circuit patency were evaluated clinically at 3, 6, and 12 months post-procedure. RESULT: Technical success was 96% (42/44): Two participants were excluded from analysis due to the need for high-pressure balloon angioplasty as the target lesions did not efface with CBA. The median follow-up duration was 337.5 days. Mean stenosis pre- and post-angioplasty was 69.0% (51.6-84.8) and 20.8% (0-44.8), respectively. The target lesion primary, primary assisted and circuit patency for the entire study population (n = 42) were 61.6 ± 7.8%, 92.7 ± 4.0%, and 54.7 ± 7.9%, respectively, at 12 months. For participants without non-target lesions (n = 22), the rates were 77.3 ± 8.9%, 90.9 ± 6.1%, and 60.7 ± 11.0%, respectively, at 12 months. CONCLUSION: CBA followed by PCB angioplasty appears safe and feasible for treatment of recurrent venous lesions in dysfunctional AVFs.

Hepatic venous-portal gradient (HVPG) measurement: pearls and pitfalls.

Hepatic venous pressure gradient (HVPG) is the gold-standard for measurement of portal hypertension, a common cause for life-threatening conditions such as variceal bleeding and hepatic encephalopathy. HVPG also plays a crucial role in risk stratification, treatment selection and assessment of treatment response. Thus recognition of common pitfalls and unusual hepatic venous conditions is crucial. This article aims to provide a radiographical and clinical guide to HVPG with representative clinical cases.

Perfluorobutane contrast-enhanced ultrasonography: a new standard for ultrasonography-guided thermal ablation of sonographically occult liver tumours?

INTRODUCTION: Image-guided thermal ablation, preferably with ultrasonography (US), is increasingly used for treatment of small liver tumours. Perfluorobutane-contrast-enhanced US (pCEUS) is a promising tool that may allow for targeting of tumours that are otherwise imperceptible on greyscale US. Although pCEUS has been reported to be effective, the literature has been limited outside of Japan and South Korea. We aimed to provide data that supports the use of pCEUS in the thermal ablation of sonographically occult liver tumours. METHODS: We conducted a retrospective single-centre study of 35 consecutive patients who underwent pCEUS-guided ablation of 48 liver tumours with a median size of 1.2 cm. Periprocedural, one-month post-treatment and relevant follow-up imaging studies were reviewed. Electronic records were also obtained, with long-term follow-up data of 12-28 months being available for 32 patients. RESULTS: 36 (75%) tumours that were imperceptible on greyscale US became visible with pCEUS. Overall, complete tumour ablation at one month was 89%. 1 (3%) patient developed a major complication following treatment, while 6 (17%) had minor post-treatment complaints. The local tumour progression rate was 17%, with a median time of 14 months. CONCLUSION: pCEUS has a role in US-guided thermal ablation of liver tumours, offering a high technical success rate that is comparable to reported data. Additional benefits may include improved procedural time and freedom from ionising radiation.

Management of arterial dissections in 12 patients during transarterial chemoembolization and yttrium-90 selective internal radiotherapy for primary and secondary liver tumours.

OBJECTIVE: To describe rates and management strategies of arterial dissections in transarterial chemoembolization (TACE) and Yttrium-90 selective internal radiotherapy (90Y SIRT) for primary and secondary liver tumours. MATERIALS AND METHODS: This retrospective review included 1377 hepatic angiographies between May 2010 and June 2015 in a single centre for TACE and 90Y SIRT of liver tumours. The angiogram results, management, treatment outcomes and follow-up angiography/imaging findings were recorded. RESULTS AND DISCUSSION: Twelve cases of arterial dissections (12/1377, 0.87%) were documented. Three dissections (3/633, 0.47%) occurred during TACE, seven (7/449, 1.56%) during pre-treatment planning angiographies (PTPA) for 90Y SIRT, and two (2/249, 0.80%) during the treatment procedure of 90Y SIRT. The preferred management strategy was to manoeuvre past the dissection and complete the procedure, which was achieved in six patients (50%). Angioplasty with stenting was performed in one patient. In three patients, the procedure was held off for up to 3 months to allow the dissection to heal before repeating the procedure. A dissection that occurred during PTPA was detected only when the patient returned for 90Y SIRT. PTPA was immediately repeated for this patient. The last patient opted for sorafenib. Residual 50% stenosis was seen in one patient on follow-up hepatic angiography, but he was otherwise asymptomatic. In the remaining patients, no residual dissection or clinical sequelae was observed on follow-up. CONCLUSION: Arterial dissection is a rare but important complication of transarterial locoregional therapy. Where possible, attempts should be made at completing the therapy. Deferring treatment can be considered as dissections usually heal within 3 months. LEVEL OF EVIDENCE: Level 4, case series.

Mid-Term Outcomes of Patients with Central Venous Occlusive Disease Undergoing Surveillance Venography and Intervention.

INTRODUCTION: To evaluate the mid-term outcomes of regular surveillance venography with or without percutaneous transluminal angioplasty (PTA) in haemodialysis patients presenting with central venous occlusive disease. MATERIALS AND METHODS: A single-centre retrospective analysis of haemodialysis patients who presented with central vein occlusion (CVO) and central vein stenosis (CVS) between January 2008 and December 2011 was performed. CVO and significant CVS were defined as 100% and >50% luminal narrowing, respectively. Upon successful angioplasty on first presentation, patients were followed up with regular surveillance venography within 3-6 months of the intervention and were re-treated when a significant stenosis or occlusion was demonstrated. Data on patient's demographics, comorbidities, presenting symptoms, type of upper limb dialysis access, lesion characteristics and complications were collected. Technical success, primary patency and primary assisted patency were analysed. RESULTS: Thirty-five patients with CVO and 77 patients with CVS were enrolled. The technical success of initial PTA was 77% and 73% for the CVO and CVS groups, respectively. The primary patency at 3 months was 65% and 55% for the CVO group and CVS group, respectively (P = 0.32). The primary assisted patency at 1 year was 88% and 99% for the CVO group and CVS group, respectively (P = 0.009). At 2 years, the primary assisted patency were 77% and 90%, respectively (P = 0.07). There was significant difference in the overall primary assisted patency (P = 0.048) between the CVO and CVS groups. CONCLUSION: CVOs are more difficult to treat than CVS. High primary assisted patency rates can be achieved with surveillance venography, albeit at the expense of increased number of interventions. Further cost effectiveness studies need to be performed to study the true benefit of our surveillance programme.

Type 2 Endoleaks: Common and Hard to Eradicate yet Benign?

PURPOSE: The exact significance of type 2 endoleaks (T2ELs) and the indication and efficacy of treatment are widely debated. We report our experience with managing T2ELs in a tertiary Asian centre. MATERIALS AND METHODS: This was a retrospective study of patients who underwent endovascular abdominal aortic aneurysm repair (EVAR) between February 2006 and December 2016. Patients with T2ELs were identified, and their data were analysed. RESULTS: A total of 156 patients underwent EVAR, of which 67 (42.9%) developed T2ELs. Seven were lost to follow-up. The remaining 60 patients had a mean follow-up period of 50.3 ± 33.9 months-34 (56.7%) experienced T2ELs early and the rest (43.3%) had late T2ELs. Forty-one patients had isolated T2EL, whilst 19 had concomitant T1EL and/or T3EL. Spontaneous resolution occurred in 25 patients (41.7%). All T2ELs with stable sac size were on continued surveillance. Amongst those with persistent T2ELs associated with sac growth (n = 17), 14 underwent intervention, of which 7 (50%) received > 1 embolisation procedure. A total of 16 transarterial embolisation and 8 translumbar embolisation procedures were performed. Technical success rate was 75%. In the intervention group, 5 (35.7%) had complete and sustained resolution, 7 had persistent/recurrent T2ELs but stable sac size, and 2 had progressive sac expansion. Overall mortality due to sac rupture occurred in 2 patients with concomitant T2EL and T1EL/T3EL. CONCLUSION: T2ELs are common, albeit mostly benign if occurring in isolation and not in association with sac growth. Achieving complete T2EL resolution with embolisation is difficult even with reinterventions. LEVEL OF EVIDENCE: Level 2B, retrospective study.

Outcome and Distal Access Patency in Subintimal Arterial Flossing with Antegrade-Retrograde Intervention for Chronic Total Occlusions in Lower Extremity Critical Limb Ischemia.

PURPOSE: To report the outcome and distal access patency of the Subintimal Arterial Flossing with Antegrade-Retrograde Intervention (SAFARI) technique for chronic total occlusion (CTO) in critical limb ischemia (CLI). MATERIALS AND METHODS: From January 2009 to June 2015, 220 SAFARI procedures were performed for 200 limbs in 191 patients (108 males [56.5%]; median age, 70 years old; range, 36 to 97 years old) with CLI (9.4% were Fontaine classification 3; and 90.6% were Fontaine classification 4). Distal access was obtained from the distal superficial femoral artery (n = 6), popliteal artery (n = 49), anterior tibial artery (n = 56), dorsalis pedis (n = 51), peroneal artery (n = 12), posterior tibial artery (n = 45), and lateral plantar artery (n = 1). Distal access hemostasis was obtained with internal balloon tamponade in 71.4% (n = 157). Outcome measurements were technical success, freedom from major amputation and complications. Preprocedural angiograms of clinically driven repeat interventions were reviewed in 73 cases for distal access patency. RESULTS: Technical success was achieved in 80.5% (n = 177). Reasons for technical failure include inability to obtain distal access (n = 3), cross the occlusion retrogradely (n = 16), re-enter the true lumen (n = 9), and achieve antegrade blood flow after the procedure (n = 15). Freedom from major amputation for technically successful procedures was 84.7%, 82.9%, and 81.9% at 6, 12, and 24 months, respectively. There were 3 cases of distal access bleeding with 1case that required coil embolization. The distal access remained patent in 80.8% of observable cases with repeated endovascular intervention. CONCLUSIONS: Distal retrograde arterial access (SAFARI) technique is safe and effective in the treatment of CTOs in the context of CLI, after failure of antegrade revascularization.

Catheter-Directed Computed Tomography Hepatic Angiography for Yttrium-90 Selective Internal Radiotherapy of Hepatocellular Carcinoma Reduces Prophylactic Embolization of Extrahepatic Vessels.

OBJECTIVES: To determine the rate of prophylactic embolization of extrahepatic vessels in patients undergoing yttrium-90 selective internal radiotherapy (90Y SIRT) for hepatocellular carcinoma (HCC) with the use of catheter-directed computed tomography hepatic angiography (CD-CTHA). MATERIALS AND METHODS: This retrospective study included 186 HCC patients who received 90Y SIRT from May 2010 to June 2015 in a single institution. All procedures were performed in a hybrid angiography-CT suite equipped with digital subtraction angiography (DSA) and CD-CTHA capabilities. CD-CTHA was performed during pre-treatment hepatic angiography. 90Y SIRT was administered approximately 2 weeks later. Selective prophylactic embolization of extrahepatic vessels was performed if extrahepatic enhancement was seen on CD-CTHA or if an extrahepatic vessel opacified on DSA/CD-CTHA despite the final microcatheter position for 90Y microsphere delivery being beyond the origin of this vessel. RESULTS: Thirty-five patients (18.8%) required selective embolization of extrahepatic vessels. Technical success of 90Y SIRT was 99.5%. Two patients (1.1%) developed radiation-induced gastrointestinal ulceration, and one (0.54%) developed radiation-induced pneumonitis. Extrahepatic uptake of 90Y microspheres was seen in the gallbladder of one patient without significant complications. CONCLUSION: The use of CD-CTHA in 90Y SIRT of HCC was associated with a low rate of prophylactic embolization of extrahepatic vessels while maintaining a high technical success rate of treatment and low rate of complications. LEVEL OF EVIDENCE: Level 4, case series.

Homemade Candy Plug Using a Zenith Alpha Thoracic Stent-Graft for False Lumen Distal Occlusion in Acute-on-Chronic Type B Aortic Dissection.

Purpose: To report a candy-plug technique using a Zenith Alpha stent-graft to occlude the distal false lumen in a patient with a complicated chronic type B aortic dissection. Case Report: A 50-year-old male smoker presented with chest pain due to rapidly growing complicated chronic type B aortic dissection. Computed tomography angiography (CTA) showed the dissection extending from distal to the origin of the left subclavian artery (LSA) down to the left femoral artery. There was fusiform aneurysmal dilatation of the proximal descending aorta measuring up to 5.8 cm in diameter. He underwent left carotid-subclavian artery bypass, thoracic endovascular aortic repair with a Zenith Alpha stent-graft, a left common carotid artery chimney, and embolization of the proximal LSA. Serial CTA showed persistent false lumen flow. A decision was made to occlude the distal large false lumen using the candy-plug technique. A 44×125-mm Zenith Alpha stent-graft was used to prepare the candy plug. A gutter leak and a type Ia endoleak were embolized via a left brachial artery approach. At 2.5 years, imaging showed the candy plug in position, no endoleak, and the thrombosed false lumen in the thoracic aorta reduced in size. Conclusion: The candy-plug technique is useful in facilitating complete occlusion of the false lumen in chronic aortic dissection, which avoids an open procedure and the risk of higher morbidity.

Single-centre retrospective review of risk factors for local tumour progression and complications in radiofrequency ablation of 555 hepatic lesions.

INTRODUCTION: This study aimed to assess safety, local tumour progression (LTP) and risk factors for LTP after radiofrequency ablation (RFA) of liver tumours in a single centre. METHODS: All consecutive patients treated with RFA for liver tumours between January 2009 and October 2012 were included. Previously treated lesions that progressed were excluded. Using electronic medical records, the following data was captured: patient demographics, pre-procedural laboratory results, Child-Pugh status, tumour characteristics, development of tumoral seeding, RFA complications and LTP. Possible risk factors for LTP were identified using Cox regression. RESULTS: In total, 555 liver tumours were treated in 337 patients. 483 (87.0%) hepatocellular carcinomas, 52 (9.4%) colorectal metastases and 20 (3.6%) other tumour types were treated. Mean tumour size was 2.1 ± 1.1 (range 0.4-6.8) cm. Mean follow-up duration was 387 days. 416 (75.0%) lesions had no LTP at the last imaging. 70 (12.6%) patients had minor complications requiring observation, while 7 (1.3%) patients had significant complications requiring prolonged hospitalisation or further interventions. Only one case of tumour seeding was detected. Using multivariate Cox regression, the following factors were statistically significant in predicting LTP: hilar location (relative ratio [RR] 3.988), colorectal metastases (RR 2.075), size (RR 1.290) and younger age (RR 0.982). CONCLUSION: RFA of liver tumours is safe and effective, with a low significant complication rate of 1.3%. Hilar lesions are most prone to LTP, followed by lesions that were larger in size and colorectal metastases. 75.0% of patients showed no LTP at the last follow-up.

Use of Expression Profiles of HBV-DNA Integrated Into Genomes of Hepatocellular Carcinoma Cells to Select T Cells for Immunotherapy.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is often associated with hepatitis B virus (HBV) infection. Cells of most HBV-related HCCs contain HBV-DNA fragments that do not encode entire HBV antigens. We investigated whether these integrated HBV-DNA fragments encode epitopes that are recognized by T cells and whether their presence in HCCs can be used to select HBV-specific T-cell receptors (TCRs) for immunotherapy. METHODS: HCC cells negative for HBV antigens, based on immunohistochemistry, were analyzed for the presence of HBV messenger RNAs (mRNAs) by real-time polymerase chain reaction, sequencing, and Nanostring approaches. We tested the ability of HBV mRNA-positive HCC cells to generate epitopes that are recognized by T cells using HBV-specific T cells and TCR-like antibodies. We then analyzed HBV gene expression profiles of primary HCCs and metastases from 2 patients with HCC recurrence after liver transplantation. Using the HBV-transcript profiles, we selected, from a library of TCRs previously characterized from patients with self-limited HBV infection, the TCR specific for the HBV epitope encoded by the detected HBV mRNA. Autologous T cells were engineered to express the selected TCRs, through electroporation of mRNA into cells, and these TCR T cells were adoptively transferred to the patients in increasing numbers (1 × 104-10 × 106 TCR+ T cells/kg) weekly for 112 days or 1 year. We monitored patients' liver function, serum levels of cytokines, and standard blood parameters. Antitumor efficacy was assessed based on serum levels of alpha fetoprotein and computed tomography of metastases. RESULTS: HCC cells that did not express whole HBV antigens contained short HBV mRNAs, which encode epitopes that are recognized by and activate HBV-specific T cells. Autologous T cells engineered to express TCRs specific for epitopes expressed from HBV-DNA in patients' metastases were given to 2 patients without notable adverse events. The cells did not affect liver function over a 1-year period. In 1 patient, 5 of 6 pulmonary metastases decreased in volume during the 1-year period of T-cell administration. CONCLUSIONS: HCC cells contain short segments of integrated HBV-DNA that encodes epitopes that are recognized by and activate T cells. HBV transcriptomes of these cells could be used to engineer T cells for personalized immunotherapy. This approach might be used to treat a wider population of patients with HBV-associated HCC.

Hemodialysis Arteriovenous Fistula and Graft Stenoses: Randomized Trial Comparing Drug-eluting Balloon Angioplasty with Conventional Angioplasty.

Purpose To compare lesion primary patency and restenosis rates between drug-eluting balloon (DEB) percutaneous transluminal angioplasty (PTA) and conventional balloon PTA (cPTA) in the treatment of arteriovenous fistula (AVF) and arteriovenous graft (AVG) stenosis. Materials and Methods In this prospective study, 119 participants (mean age, 59.2 years; 79 men, 40 women) with failing AVFs (n = 98) or AVGs (n = 21) were randomly assigned to undergo either DEB PTA (n = 59) or cPTA (n = 60) from January 2012 to May 2013. Primary end points were lesion primary patency and restenosis rates at 6 months; secondary outcomes were anatomic and clinical success after PTA, circuit primary patency at 6 months and 1 year, and lesion primary patency at 1 year. Statistical analysis was performed by using the Kaplan-Meier product limit estimator, and hazard ratio was calculated by using Cox proportional hazards regression. Complication rates were assessed in both groups. Results Estimated lesion primary patency in the DEB PTA and cPTA arms was 0.81 and 0.61, respectively, at 6 months (P = .03) and 0.51 and 0.34, respectively, at 1 year (P = .04). Estimated circuit primary patency in the DEB PTA and cPTA arms was 0.76 and 0.56, respectively, at 6 months (P = .048) and 0.45 and 0.32, respectively, at 1 year (P = .16). Restenosis rate was 34.0% (16 of 47) for DEB PTA and 62.9% (22 of 35) for cPTA at 6 months (P = .01). No major complications were noted. Conclusion Drug-eluting balloon angioplasty was effective in prolonging lesion primary patency of dialysis access stenoses at 6 months and 1 year. © RSNA, 2018.

Catheter-directed thrombolysis versus percutaneous mechanical thrombectomy in the management of acute limb ischemia: a single center review.

BACKGROUND: Acute limb ischemia is associated with significant mortality and amputation rate. Early restoration of flow can be obtained by various treatment methods that include catheter-directed thrombolysis (CDT) and percutaneous mechanical thrombectomy (PMT). These treatments have been shown to be effective but associated with various complications. There is lack of data comparing these two treatments. We aim to review our experience in the treatment of acute limb ischemia (ALI) and compare CDT with PMT. RESULTS: A total of 94 patients [mean age 65 years, 67% male (n = 63)] presented with ALI between 2006 and 2015 and were treated with either CDT or PMT. Outcomes were retrospectively reviewed. Primary outcomes were technical and clinical success; secondary outcomes were amputation rate at 30 days, duration of hospitalization and 30-day mortality. A total of 117 procedures were performed in 94 patients: 27 surgical bypass grafts, 31 previously stented arteries and 59 native vessels. Twenty eight procedures (24%) were performed with PMT, and 89 (76%) procedures were performed with CDT. Higher technical success was achieved in the PMT group (68%, 19/28) compared to the CDT group (47%, 42/89), p = 0.056. Clinical success was similar in both groups (75%, 21/28 in the PMT group and 73%, 65/89) in the CDT group (p = 0.837). There was no statistically significant difference in 30-day mortality between the PMT vs CDT groups (4% vs 8%, p = 0.425). The length of post-procedural hospital stay was shorter in patients with PMT (6.0 vs 12.6 days, p = 0.001). The absence of end-stage renal failure appears to be a predictor for clinical succes (HR 3.3, 95% CI 0.809-13.592). CONCLUSION: PMT is associated with higher technical success and significantly shorter length of stay compared to CDT; however, clinical success is similar across both treatment entities. The safety profile is comparable.