A. Fischman

Preoperative Inferior Mesenteric Artery Embolization before Endovascular Aneurysm Repair: Decreased Incidence of Type II Endoleak and Aneurysm Sac Enlargement with 24-month Follow-up

PURPOSE To review the effect of preoperative embolization of the inferior mesenteric artery (IMA) before endovascular aneurysm repair (EVAR) on subsequent endoleaks and aneurysm growth. MATERIALS AND METHODS Between August 2002 and May 2010, 108 patients underwent IMA embolization before EVAR. Coil embolization was performed in all patients in whom the IMA was successfully visualized and accessed during preoperative conventional angiography. In this cohort, the incidences of type II endoleak, aneurysm sac volume enlargement at 24 months, and repeat intervention were compared with a group of 158 consecutive patients with a patent IMA on preoperative computed tomography angiography but not on conventional angiography, who therefore did not undergo preoperative embolization. RESULTS The incidence of type II endoleak was significantly higher in patients not treated with embolization (49.4% [78 of 158] vs 34.3% [37 of 108]; P = .015). The incidence of secondary intervention for type II endoleak embolization was also significantly higher in those who did not undergo embolization (7.6% [12 of 158] vs 0.9% [one of 108]; P = .013). At 24 months, an increase in aneurysm sac volume was observed in 47% of patients in the nonembolized cohort (21 of 45), compared with 26% of patients in the embolized cohort (13 of 51; P = .03). No aneurysm ruptures or aneurysm-related deaths were observed in either group. One patient in the embolization group developed mesenteric ischemia and ultimately died. CONCLUSIONS Preoperative embolization of the IMA was associated with reduced incidences of type II endoleak, aneurysm sac volume enlargement at 24 months, and secondary intervention.

Balloon-Occluded Retrograde Transvenous Obliteration of Gastric Varices

OBJECTIVE The purpose of this review is to describe the clinical factors related to balloon-occluded retrograde transvenous obliteration, including the preparation needed, the technique and challenges, and the outcomes. CONCLUSION Although the procedure can be performed when transjugular intrahepatic portosystemic shunt is contraindicated or when endoscopic management fails, balloon-occluded retrograde transvenous obliteration is successful as a first-line or second-line therapy. Gastric variceal rebleeding rates are low and serious complications are rare. Randomized controlled trials are required to evaluate the superiority of this procedure over other methods of treating gastric varices and to determine which sclerosant should be used. In the near future, this procedure may play a larger role in emergency care and in the management of nongastric varices.

Uterine artery embolization using a transradial approach: initial experience and technique

This study investigates the feasibility of performing uterine artery embolization (UAE) via transradial access (TRA). Growing evidence demonstrates significant benefits of TRA versus standard transfemoral access during percutaneous coronary intervention, now making it the preferred approach at many centers worldwide. At a single institution from March 2013 to October 2013, 29 consecutive patients were treated by transradial UAE. Technical success rate was 100%, with no immediate major or minor complications. The radial artery was patent at 1-month follow-up evaluation in all cases. These preliminary data suggest that transradial UAE is feasible and safe.

Single-Center Experience with Elective Transcatheter Coil Embolization of Splenic Artery Aneurysms: Technique and Midterm Follow-up

PURPOSE To review a single-center experience with elective coil embolization of splenic artery aneurysm (SAA) and analyze efficacy of the technique at midterm follow-up. MATERIALS AND METHODS From 2002 through 2011, 50 patients (28 women, 22 men; age range, 24-89 y; mean age, 53.5 y ± 13.6) underwent transcatheter coil embolization for treatment of SAAs. Pseudoaneurysms and ruptured aneurysms were excluded. A total of 63 SAAs were treated (size, 13-97 mm; mean, 29 mm). Ninety-eight percent of aneurysms were treated with coils alone. Regular follow-up consisted of an office visit and imaging. Patient medical records were reviewed for aneurysm location, procedural approach, and technical and clinical outcomes. RESULTS Ninety-eight percent of procedures were technically successful at thrombosing the aneurysm at the time of procedure. Repeat intervention was performed in four of 47 patients (9%) because of continued aneurysm perfusion at follow-up. Mean time to repeat intervention was 125 days (range, 42-245 d). All repeat interventions were technically successful. Neither aneurysm growth nor aneurysm rupture was observed in any patient during the follow-up period (mean, 78 weeks; range, 9 d to 7.1 y). There were no major adverse events. Major splenic infarction occurred in three of 33 patients (9%) with no underlying liver disease and normal splenic volume and in seven of 14 patients (50%) with portal hypertension. CONCLUSIONS Percutaneous transcatheter coil embolization is a safe, effective, and minimally invasive treatment for SAAs as evidenced by high rates of technical success and freedom from aneurysm rupture.

A Technical Guide Describing the Use of Transradial Access Technique for Endovascular Interventions

Transradial arterial access (TRA) has been employed for transcatheter coronary procedures for more than 25 years, with numerous studies demonstrating improved patient safety as compared with transfemoral arterial access. However, TRA remains underused by the interventional radiology and vascular surgery communities. Advantages of TRA over transfemoral arterial access include easier accomplishment of postprocedure hemostasis, decreased risk of hemorrhagic complications, shorter patient recovery leading to immediate ambulation and decreased procedure-related costs, and increased patient satisfaction. In particular, TRA may be advantageous in the population of patients with obesity. The primary patient selection factor to consider before attempting TRA is whether the patient has adequate collateral perfusion to the hand; this is assessed using the Barbeau test. Limitations of TRA may include operator unfamiliarity or learning curve and unavailability of adequate length catheters. The most common complication, although still rare, is localized access site hematoma, which is often asymptomatic. Radial artery occlusion is rare and rarely symptomatic owing to collateral perfusion to the hand. Theoretical increased risk of cerebral embolism during TRA may be minimized by preferentially accessing the left wrist during below-diaphragm procedures, which limits transcatheter manipulation of the aortic arch. Transulnar artery access is under investigation for use in patients who cannot undergo TRA. Providing patients the option of TRA can lead to improved outcomes, potentially increasing safety and patient satisfaction while decreasing procedure costs.

Outcomes of Radioembolization in the Treatment of Hepatocellular Carcinoma with Portal Vein Invasion: Resin versus Glass Microspheres

PURPOSE To compare outcomes of yttrium-90 radioembolization performed with resin-based ((90)Y-resin) and glass-based ((90)Y-glass) microspheres in the treatment of hepatocellular carcinoma (HCC) with associated portal vein invasion. MATERIALS AND METHODS A single-center retrospective review (January 2005-September 2014) identified 90 patients ((90)Y-resin, 21; (90)Y-glass, 69) with HCC and ipsilateral portal vein thrombosis (PVT). Patients were stratified according to age, sex, ethnicity, Child-Pugh class, Eastern Cooperative Oncology Group status, α-fetoprotein > 400 ng/mL, extent of PVT, tumor burden, and sorafenib therapy. Outcome variables included clinical and laboratory toxicities (Common Terminology Criteria Adverse Events, Version 4.03), imaging response (modified Response Evaluation Criteria in Solid Tumors), time to progression (TTP), and overall survival (OS). RESULTS Grade 3/4 bilirubin and aspartate aminotransferase toxicities developed at a 2.8-fold (95% confidence interval [CI], 1.3-6.1) and 2.6-fold (95% CI, 1.1-6.1) greater rate in the (90)Y-resin group. The disease control rate was 37.5% in the (90)Y-resin group and 54.5% in the (90)Y-glass group (P = .39). The median (95% CI) TTP was 2.8 (1.9-4.3) months in the (90)Y-resin group and 5.9 (4.2-9.1) months in the (90)Y-glass group (P = .48). Median (95% CI) survival was 3.7 (2.3-6.0) months in the (90)Y-resin group and 9.4 (7.6-15.0) months in the (90)Y-glass group (hazard ratio, 2.6; 95% CI, 1.5-4.3, P < .001). Additional multivariate predictors of improved OS included age < 65 years, Eastern Cooperative Oncology Group status < 1, α-fetoprotein ≤ 400 ng/mL, and unilobar tumor distribution. CONCLUSIONS Imaging response of (90)Y treatment in patients with HCC and PVT was not significantly different between (90)Y-glass and (90)Y-resin groups. Lower toxicity and improved OS were observed in the (90)Y-glass group.

Prospective, Randomized Study of Coil Embolization versus Surefire Infusion System during Yttrium-90 Radioembolization with Resin Microspheres

PURPOSE To compare standard coil embolization versus the use of an antireflux microcatheter (ARM) in patients undergoing planning angiography before selective internal radiation therapy (SIRT). MATERIALS AND METHODS A prospective, single-center trial was performed in which 30 patients were randomly assigned to undergo SIRT with coil embolization or the use of an ARM. The coil group underwent detachable coil embolization of nontarget vessels, and the ARM group underwent infusion of macroaggregated albumin with use of an ARM system, without coil embolization. Single-photon emission computed tomography (CT)/CT was then performed to assess for nontarget distribution. The primary endpoint was fluoroscopy time during planning angiography. Secondary endpoints included deployment time, total procedure time, radiation dose-area product, contrast agent used, and adverse events. Endpoints were evaluated during planning angiography and SIRT. RESULTS Over a 9-month period, 30 consecutive patients were randomized at a 1:1 ratio between coil embolization and ARM groups. Technical success rates were 100% in both groups. Mean fluoroscopy time was significantly reduced in the ARM group versus the coil embolization group (1.8 min [range, 0.4-4.9 min] vs 6.0 min [range, 1.9-15.7 min]; P = .002). The planning procedure time (P < .001), deployment time (P < .001), dose-area product (P = .04), and amount of contrast agent used (P < .001) were also significantly less in the ARM group than in the coil embolization group. No nontarget distribution was detected in either group. There was no difference between groups in dose delivered on the day of SIRT (P = .71). There were no major or minor adverse events at 30 days. CONCLUSIONS The use of an ARM during planning angiography can significantly reduce fluoroscopy time, procedure time, and radiation dose.

Tailoring the Endovascular Management of Transplant Renal Artery Stenosis

In this study we analyze the different types of endovascular interventions (EVIs) in de novo transplant renal artery stenosis (TRAS) and its anatomical subtypes to examine any variation in recovery of allograft function, blood pressure control, EVI patency and allograft survival with respect to EVI type (DES: drug‐eluting stent, BMS: bare‐metal stent, PTA: percutaneous transluminal angioplasty). Forty‐five patients underwent a total of 50 primary EVIs (DES: 18, BMS: 26, PTA: 6). Patients were stratified according to medical co‐morbidities, graft characteristics, biopsy results, clinical presentation and TRAS anatomic subtypes (anastomotic: 26, postanastomotic: 17, bend‐kink: 2). There was significant improvement in allograft function and mean arterial blood pressure (MAP) control across all interventions (pre‐EVI‐creatinine [CR]: 2.8 ± 1.4, post‐EVI‐Cr: 2.1 ± 0.7, p < 0.001; pre‐EVI‐MAP: 117 ± 16, post‐EVI‐MAP: 112 ± 17, p = 0.03) with no significant difference among EVI types. There was no significant difference in allograft survival with respect to EVI type. Patency was significantly higher in EVIs performed with DES and BMS compared to PTA (p = 0.001). In the postanastomotic TRAS subtype, patency rates were significantly higher in DES compared to BMS (p = 0.012) in vessels of comparable reference diameter (≤5 mm).

Portal Vein Embolization before Right Hepatectomy or Extended Right Hepatectomy Using Sodium Tetradecyl Sulfate Foam: Technique and Initial Results

PURPOSE To evaluate the safety and efficacy of portal vein embolization (PVE) with sodium tetradecyl sulfate (STS) foam. MATERIALS AND METHODS A single-center retrospective review of 35 patients (27 men and 8 women; mean age, 61 y) who underwent PVE with STS foam was performed. The technical success rate, rate of PVE at producing adequate future liver remnant (FLR) hypertrophy, and rate of disease progression precluding resection after PVE were analyzed. Complications of PVE and liver resection after PVE were recorded. RESULTS PVE was performed on 35 patients before right hepatic resection for both primary and secondary hepatic malignancies (22 hepatocellular carcinoma, 10 metastasis, 2 cholangiocarcinoma, 1 invasive gallbladder carcinoma). Technical success was achieved in 97.1% (34 of 35) of patients. Mean FLR of the total estimated liver volume increased from 24.5% (SD, 7.7%) to 36.5% (SD, 14.5%), a mean percentage increase of 48.8% (SD, 34.3%). PVE produced adequate FLR hypertrophy in 31 of 35 patients (88.6%). Proposed right hepatectomy was subsequently performed in 27 patients (77.1%). One patient remains scheduled for surgery, two had peritoneal spread at surgery and resection was aborted, two had disease progression on imaging after PVE, and three had inadequate FLR hypertrophy with no surgery. One major complication was observed related to PVE that involved nontarget embolization to segment III, which was managed conservatively. CONCLUSIONS Preoperative PVE with STS foam is a safe and effective method to induce hypertrophy of the FLR.

Percutaneous Microwave Ablation of Renal Tumors Using a Gas-Cooled 2.4-GHz Probe: Technique and Initial Results

The feasibility, safety, and preliminary effectiveness of microwave ablation (MWA) in the treatment of renal tumors using a high-powered, carbon dioxide-cooled probe were evaluated. There were 15 tumors treated in 14 patients. Computed tomography was performed immediately after MWA, and follow-up imaging was performed to evaluate for recurrence. Immediate technical effectiveness was 100%. One complication involved the formation of a renal artery pseudoaneurysm. At follow-up (mean interval, 12.5 wk) evaluation, 14 of 15 (93.3%) tumors demonstrated complete necrosis. MWA is a safe, effective treatment modality; larger studies are warranted to demonstrate long-term oncologic outcomes.