Percutaneous Intraportal Application of Adipose Tissue–derived Mesenchymal Stem Cells Using a Balloon Occlusion Catheter in a Porcine Model of Liver Fibrosis

PurposeTo investigate the safety and effectiveness of a novel endovascular approach for therapeutic cell delivery using a balloon occlusion catheter in a large animal model of liver fibrosis.Materials and MethodsTranscatheter arterial embolization with ethiodized oil (Ethiodol) and ethanol was used to induce liver damage in 11 pigs. Mesenchymal stem cells (MSCs) were harvested from adipose tissue and engineered to express green fluorescent protein (GFP). A balloon occlusion catheter was positioned in the bilateral first-order portal vein branches 2 weeks after embolization to allow intraportal application of MSCs in six experimental animals. MSCs were allowed to dwell for 10 minutes using prolonged balloon inflation. Five control animals received a sham injection of normal saline in a similar fashion. Hepatic venous pressure gradient (HVPG) was measured immediately before necropsy. Specimens from all accessible lobes were obtained with ultrasound-guided percutaneous 18-gauge biopsy 2 hours after cell application. All animals were euthanized within 4 weeks. Fluorescent microscopy was used to assess the presence and distribution of cells.ResultsLiver injury and fibrosis were successfully induced in all animals. MSCs (6–10 × 10⁷) were successfully delivered into the portal vein in the six experimental animals. Cell application was not associated with vascular complications. HVPG showed no instances of portal hypertension. GFP-expressing MSCs were visualized in biopsy specimens and were distributed primarily within the sinusoidal spaces; however, 4 weeks after implantation, MSCs could not be identified in histologic specimens.ConclusionsA percutaneous endovascular approach for cell delivery using a balloon occlusion catheter proved safe for intraportal MSC application in a large animal model of liver fibrosis.     

Targeting and Recanalization after Embolization with Calibrated Resorbable Microspheres versus Hand-cut Gelatin Sponge Particles in a Porcine Kidney Model

PurposeTo report on polyethylene glycol hydrogel-based resorbable embolization microspheres (REM) that were synthesized to resorb in < 24 hours, before inflammation and vascular remodeling, to achieve a complete arterial recanalization and to compare targeting and recanalization of REM of 300–500 µm, 500–700 µm, and 700–900 µm with hand-cut gelatin sponge particles (GSP).Materials and MethodsEight pigs underwent polar renal artery embolization with REM or GSP. Angiograms were obtained before embolization and 10 minutes and 7 days after embolization before pigs were sacrificed to determine the occlusion level, the percentage of occlusion, and the recanalization rate for each product. The distribution of embolic material was assessed in pathology, and infarction rate of the kidneys was measured.ResultsREM of 300–500 µm occluded more distal vessels than REM of 500–700 µm and 700–900 µm. At day 7, the recanalization rate was complete for the larger REM, whereas it was about 60% for the two smaller sizes. REM were completely degraded, with no residual material or inflammation. GSP occluded more proximal arteries than REM of 700–900 µm, were partly degraded at day 7, and were accompanied by a foreign body reaction in proximal and distal arteries. GSP recanalized at 79%. The infarction rate was higher with the two smaller sizes of REM and with GSP than with the largest REM.ConclusionsREM of different sizes targeted different occlusion levels in kidney arteries. GSP provided an extended occlusion level without actual targeting. Regardless of embolic material used, angiographic recanalization of renal arteries depended on the extent of necrosis. REM of 700–900 µm demonstrated the lowest infarction rate and the best recanalization rate.     

Double Coaxial Microcatheter Technique for Transarterial Aneurysm Sac Embolization of Type II Endoleaks after Endovascular Abdominal Aortic Repair

PurposeTo evaluate the feasibility and efficacy of transarterial sac embolization with a mixture of N-butyl cyanoacrylate and ethiodized oil (Lipiodol; Guerbet Japan, Tokyo, Japan) (NBCA-LPD) for type II endoleaks after endovascular aortic repair (EVAR) using a double coaxial microcatheter technique.Materials and MethodsA retrospective review was performed of 20 consecutive cases of type II endoleaks treated by transarterial embolization using the technique from August 2010 to June 2013. The treatment indication was persistent type II endoleak over 6 months after EVAR associated with aneurysm expansion ≥ 5 mm in maximum diameter. A 1.9-F nontapered microcatheter was advanced to the aneurysmal sac through a 2.7-F microcatheter, which was coaxially introduced through a catheter. The endpoint of the procedure was intrasaccular filling with NBCA-LPD and occlusion of the feeder of the type II endoleak. The technical success rate was defined as success in transarterial intrasaccular approach followed by embolization of the intrasaccular channel and inflow arteries. Clinical success was defined as aneurysmal sac shrinkage or stabilization (freedom from sac expansion > 5 mm in maximum diameter).ResultsTechnical success was achieved in 18 of 20 cases. During a mean follow-up period of 18.5 months, complete sac occlusion was observed in 13 cases (65%). Clinical success was achieved in 16 cases (80%). No serious complications were observed.ConclusionsThe transarterial intrasaccular approach with a double coaxial microcatheter technique can be successfully performed in most cases, and transarterial aneurysm sac embolization using NBCA-LPD has been proven to be feasible.     

Embolic Effects of Transcatheter Mesenteric Arterial Embolization with Microspheres on the Small Bowel in a Dog Model

PurposeTo determine the arterial distribution and ischemic effects of various particle sizes after transcatheter embolization of the small bowel in a dog model.Materials and MethodsIn 10 dogs, selective microsphere embolization was performed in six branches of the superior mesenteric artery. Microspheres were allocated into three size ranges (100–300 μm, 300–500 μm, and 500–700 μm) and four volume concentrations (0.625%, 1.25%, 2.5%, and 5%). For each size and volume concentration, embolization was performed of five branches at the origin of the last arcade. The distribution of microspheres and the range of ischemic changes of mucosa were evaluated histologically. Angiograms were categorized into two groups: group A, only the vasa recta nonopacified; group B, the last arcade or more proximal branches nonopacified.ResultsMicrospheres sized 100–300 μm penetrated into intramural arteries and 500–700 μm microspheres mainly blocked arteries in the mesentery. There was a significant difference among three sizes in terms of the locations within the vasculature (P < .0001). The larger volume and the smaller size resulted in more ischemia. The range of ischemic changes among three sizes and among four volume concentrations was significantly different (P = .004 and P < .0001, respectively). The range of ischemic changes with 500–700 μm microspheres in group B was significantly greater than in group A (0% in group A vs 83% in group B, P = .001).ConclusionsIn a dog model, embolization of the small bowel limited to the vasa recta with the use if 500–700 μm microspheres reduced the range of ischemic changes.     

The Use of Technetium-99m–Labeled Human Serum Albumin Diethylenetriamine Pentaacetic Acid Single-Photon Emission CT Scan in the Follow-up of Type II Endoleak Treatment

An 84-year-old woman presented with persistent type II endoleak with sac expansion from 57 mm to 75 mm during 4-year follow-up after endovascular abdominal aortic aneurysm repair. The patient underwent transabdominal embolization with coils and N-butyl cyanoacrylate/ethiodized oil (Lipiodol; Guerbet, Villepinte, France) mixture (2.5 mL). Because of the anticipated embolization artifacts on follow-up computed tomography (CT), technetium-99m-labeled human serum albumin diethylenetriamine pentaacetic acid single-photon emission computed tomography (^99mTc-HSAD SPECT) was performed before and after the intervention. Perigraft accumulation on ^99mTc-HSAD SPECT corresponding to the endoleak disappeared after embolization. CT scan performed 12 months after embolization showed no signs of sac expansion. ^99mTc-HSAD SPECT may be useful for evaluating therapeutic effect after embolization for endoleak.     

In Vivo Evaluation of Irinotecan-Loaded QuadraSphere Microspheres for Use in Chemoembolization of VX2 Liver Tumors

PurposeTo investigate the pharmacokinetics and chemoembolization efficacy of irinotecan-loaded QuadraSphere microspheres (QSMs) in a rabbit VX2 liver tumor model.Materials and MethodsFourteen rabbits with VX2 liver tumors were divided into two groups. In the irinotecan-loaded QSM group (n = 7), 3 mg of QSMs (30–60 μm) containing 12 mg of irinotecan (0.6 mL; 20 mg/mL) were injected into the left hepatic artery. In the control group (hepatic arterial infusion [HAI] and QSMs; n = 7), 3 mg of QSMs suspended in ioxaglic acid were injected following a bolus injection of 0.6 mL of irinotecan solution (20 mg/mL). Sequential irinotecan, SN-38, and SN-38G concentration changes were measured in plasma within 24 hours and at 1 week and in tissues at 1 week. The VX2 tumor growth rates at 1 and 2 weeks were calculated from computed tomographic images.ResultsAll rabbits underwent successful embolization. Plasma irinotecan, SN-38, and SN-38G concentrations in the irinotecan-loaded QSM group showed significantly sustained release compared with the control group (P = .01). Compared with the control group, the irinotecan-loaded QSM group had significantly higher irinotecan concentration in liver tumors (P = .03) and a tendency toward higher SN-38 concentration in liver tumors (P = .29). The SN-38G tissue concentrations were below the limits of quantification. The tumor growth rate was significantly lower and the tumor necrosis rate significantly higher in the irinotecan-loaded QSM group (P = .02 and P = .01, respectively).ConclusionChemoembolization via irinotecan-loaded QSMs more effectively suppresses tumor growth than chemoembolization with unloaded QSMs after HAI. A clinical feasibility study is warranted.     

Pediatric Abdominal and Pelvic Trauma: Safety and Efficacy of Arterial Embolization

PurposeAlthough transcatheter embolization is a well established technique to treat adults in the trauma setting, evidence is lacking in the pediatric population. This study assesses the safety and efficacy of arterial embolization for blunt abdominal and pelvic trauma in the pediatric population.Materials and MethodsA retrospective review of abdominal and pelvic angiograms in 97 pediatric patients with blunt trauma was conducted over an 11-year period. Abdominal angiography and embolization was performed for ongoing hepatic, renal, splenic, or nonvisceral retroperitoneal injury. Pelvic angiography was performed in the setting of pelvic fracture with ongoing pelvic hemorrhage. Complications and clinical success rates of these procedures were assessed.ResultsOf the 97 pediatric patients who underwent angiography for acute abdominal or pelvic trauma, 54 (56%) required embolization involving 62 separate sites. Injury severity score greater than 15 was present in 94% of patients. Targets of embolization included the pelvis (n = 39), liver (n = 8), kidney (n = 7), spleen (n = 6), and retroperitoneum (n = 2). Effective hemorrhage control was achieved in 47 patients (87%). Overall mortality rate was 22% (12 of 54), with most deaths related to traumatic brain injury. Five complications occurred in four patients (7%), including three major complications (hepatic abscess, bile leak, and urinary incontinence).ConclusionsAngiography and embolization is relatively safe and potentially effective in the setting of abdominal and pelvic trauma in the pediatric population. Angiography with embolization should be considered in the treatment algorithm for this patient population.     

Calibrated Bioresorbable Microspheres: A Preliminary Study on the Level of Occlusion and Arterial Distribution in a Rabbit Kidney Model

PurposeTo assess the level of occlusion and arterial distribution of calibrated bioresorbable microspheres (BRMS-I and BRMS-II) compared with tris-acryl gelatin microspheres (TGMS) after renal embolization.Materials and MethodsSix rabbits underwent renal embolization with 100–300 µm BRMS-I and TGMS; three rabbits received partial occlusion (group 1, n = 3), and three rabbits received total occlusion (group 2, n = 3). Four other rabbits received 100–300 µm BRMS-II (with higher cross-linking density than BRMS-I) in the left kidneys reaching total occlusion (group 3, n = 4). Coronal sections of the kidneys were histologically analyzed. Ease of injection, microsphere deformation, vessel sizes, and arterial distribution were assessed.ResultsThe injection of BRMS-I, BRMS-II, and TGMS through microcatheters went smoothly without any clogging. In group 1, BRMS identification was easier than TGMS. In group 2, both BRMS-I and TGMS were observed in all three arterial levels (interlobar, arcuate, and interlobular arteries) without a significant difference (P = .84). BRMS-I were not significantly different from TGMS in the mean diameter of vessels occluded (197 µm ± 23 vs 158 µm ± 21, P = .25) or the microsphere deformation (8.85% ± 0.53% vs 11.80% ± 0.64%, P = .071). In group 3, the arterial distribution of BRMS-II was significantly different from BRMS-I and TGMS (P < .0001).ConclusionsIn occluding arteries, 100–300 µm BRMS-I were not significantly different from 100–300 µm TGMS. Arterial distribution of BRMS can be influenced by their cross-linking density.     

Coils versus Gelatin Particles with or without Intraarterial Antibiotics for Partial Splenic Embolization: A Comparative Evaluation

PurposeTo compare the efficacy, complications, and inflammatory levels in partial splenic embolization (PSE) with coils or gelatin sponge (GS) particles with or without intraarterial antibiotic agents.Materials and MethodsForty-four patients with hypersplenism treated by PSE were assessed. GS particles were used in 31 patients, and coils were used in 13 patients. In 17 of the 31 patients who received GS, GS suspended in antibiotic solution was injected via the splenic artery. In the other 14 patients, antibiotic agents were not used. In all 13 coil group patients, an antibiotic solution was intraarterially injected before embolization. Platelet counts were compared between the GS and coil groups. Complications and serum C-reactive protein (CRP) levels were compared among the three groups.ResultsThere were no significant differences in platelet counts and platelet increased ratios at 6 months (10.0 × 10⁴/µL and 193% in the GS group vs 9.0 × 10⁴/µL and 221% in the coil group), and no significant differences in frequencies of complications. However, one splenic abscess occurred in a patient treated with GS without antibiotics, resulting in death. The mean serum CRP level in the GS with antibiotic group at 2 weeks was significantly lower than in the other two groups.ConclusionsThe efficacy of PSE is similar with the use of coils versus GS particles. Prophylactic intraarterial antibiotic treatment could be useful in preventing inflammatory reactions after PSE.     

A Novel Resorbable Embolization Microsphere for Transient Uterine Artery Occlusion: A Comparative Study with Trisacryl-Gelatin Microspheres in the Sheep Model

PurposeTo evaluate angiographic recanalization, inflammatory reaction, and uterine damage after sheep uterine artery embolization (UAE) with a novel calibrated resorbable embolization microsphere (REM) and compare the results with control nonresorbable microspheres.Materials and MethodsSix hormonally artificially cycled sheep underwent bilateral UAE until stasis with either REM or trisacryl-gelatin microspheres (TGMS). At 7 days, control angiograms were obtained to assess the residual vascularization at arterial and parenchymal phases. The animals were then sacrificed for analysis of the presence of microspheres, inflammatory foreign body reaction, and surface areas of uterine damage.ResultsMean volume of microspheres injected per uterine artery (UA) or per animal did not differ between groups. At day 7, the flow was normal for six of six UAs that received embolization with REM versus only three of six UAs with TGMS (P = .0455, χ² test). Uterine parenchymography showed no defects in six UAs in the REM group versus five defects in six UAs in the TGMS group (P = .0060, χ² test). No REM or residual fragments of microspheres were observed on histologic analysis. TGMS were observed in tissues and accompanied by a mild inflammatory response. Necrosis rates were not significantly different between the two products, either in endometrium (REM 23.5% ± 28.8% [median 8.1%] vs TGMS 21.8% ± 23.7% [median 14.6%]) or in myometrium (REM 8.2% ± 22.7% [median 0.0%] vs TGMS 8.8% ± 20.8% [median 0.9%]). Endometrium alteration rate was lower with REM than with TGMS (39.7% ± 25.7% [median 34%] vs 60.6% ± 27.1% [median 71%]; P = .0060, Mann-Whitney test). Myometrium alteration rates were not significantly different between REM (45.7% ± 37.1% [median 63.0%]) and TGMS (37.8% ± 34.0% [median 19.1%]).ConclusionsAt 1 week after sheep UAE with REM, the recanalization was complete, the microspheres were completely degraded, and there was no remnant inflammatory response.     

Safety and Efficacy of Transcatheter Arterial Embolization for Lower Gastrointestinal Bleeding: A Single-center Experience with 112 Patients

PurposeTo assess the safety and efficacy of transcatheter arterial embolization for lower gastrointestinal bleeding (LGIB) and to determine the prognostic factors that affect clinical outcome.Materials and MethodsAll patients diagnosed with LGIB by angiography at a single institution from April 2006 to January 2013 were included in a retrospective study. The rates of technical success, early recurrent bleeding, major complications, clinical success, and in-hospital mortality for transcatheter arterial embolization were determined. The influence of possible prognostic factors on the outcome was analyzed.ResultsA total of 112 patients were included (36 with small-bowel LGIB, 36 with colon LGIB, and 40 with rectal LGIB). N-butyl cyanoacrylate (NBCA) was the embolic agent for 84 patients (75.0%), whereas gelatin sponge pledgets (n = 20), microcoils (n = 2), polyvinyl alcohol particles with adjunctive gelatin sponge pledgets (n = 1), and blood clots (n = 1) were used in the other patients. The technical success rate was 96.4%. For the entire group, the rates of early recurrent bleeding, major complications, clinical success, and in-hospital mortality were 17.4%, 4.6%, 74.5%, and 25.0%, respectively. These were 15.2%, 4.8%, 75.3%, and 26.2%, respectively, in the NBCA group. Hematologic malignancy, immobilization status, and coagulopathy were significant prognostic factors for clinical outcomes.ConclusionsTranscatheter arterial embolization is a safe and effective treatment for LGIB. NBCA could be used as a primary embolic agent for this procedure.     

Drug-Eluting Beads Loaded with Antiangiogenic Agents for Chemoembolization: In Vitro Sunitinib Loading and Release and In Vivo Pharmacokinetics in an Animal Model

PurposeThe combination of embolic beads with a multitargeted tyrosine kinase inhibitor that inhibits tumor vessel growth is suggested as an alternative and improvement to the current standard doxorubicin-eluting beads for use in transarterial chemoembolization. This study demonstrates the in vitro loading and release kinetics of sunitinib using commercially available embolization microspheres and evaluates the in vitro biologic efficacy on cell cultures and the resulting in vivo pharmacokinetics profiles in an animal model.Materials and MethodsDC Bead microspheres, 70–150 µm and 100–300 µm (Biocompatibles Ltd., Farnham, United Kingdom), were loaded by immersion in sunitinib solution. Drug release was measured in saline in a USP-approved flow-through apparatus and quantified by spectrophotometry. Activity after release was confirmed in cell culture. For pharmacokinetics and in vivo toxicity evaluation, New Zealand white rabbits received sunitinib either by intraarterial injection of 100–300 µm sized beads or per os. Plasma and liver tissue drug concentrations were assessed by liquid chromatography–tandem mass spectroscopy.ResultsSunitinib loading on beads was close to complete and homogeneous. A total release of 80% in saline was measured, with similar fast-release profiles for both sphere sizes. After embolization, drug plasma levels remained below the therapeutic threshold (< 50 ng/mL), but high concentrations at 6 hours (14.9 µg/g) and 24 hours (3.4 µg/g) were found in the liver tissue.ConclusionsDC Bead microspheres of two sizes were efficiently loaded with sunitinib and displayed a fast and almost complete release in saline. High liver drug concentrations and low systemic levels indicated the potential of sunitinib-eluting beads for use in embolization.     

Pharmacokinetics and Antitumor Efficacy of Chemoembolization Using 40 µm Irinotecan-Loaded Microspheres in a Rabbit Liver Tumor Model

PurposeTo evaluate the pharmacokinetics and antitumor efficacy of 40 μm irinotecan-loaded drug-eluting microspheres (Embozene TANDEM Microspheres; CeloNova BioSciences, Inc, San Antonio, Texas) (TANDEM-IRI).Materials and MethodsThe following three groups included eight VX2 rabbits each: group 1, full-loaded (50 mg irinotecan/1 mL TANDEM)/high-dose injection (1 mg irinotecan/kg); group 2, full-loaded (50 mg irinotecan/1 mL TANDEM)/low-dose injection (0.5 mg irinotecan/kg); and group 3, half-loaded (25 mg irinotecan/1 mL TANDEM)/low-dose injection (0.5 mg irinotecan/kg). Irinotecan and SN-38 in the plasma and tumors were measured within 72 hours. Histologic examinations were conducted on days 1, 3, and 7.ResultsSerum irinotecan levels remained near the maximum concentration for 180 minutes after transarterial chemoembolization; in group 1, levels were 351.4 ng/mL at 30 minutes, 329.0 ng/mL at 60 minutes, and 333.5 ng/mL at 180 minutes. The area under the curve for 0–24 hours of irinotecan in group 1 was approximately two times higher than the same value in groups 2 and 3. High irinotecan and SN-38 concentrations in the tumors were measured at 24 hours and 72 hours. After transarterial chemoembolization, levels of liver enzymes aspartate aminotransferase and alkaline phosphatase were significantly higher in group 1 compared with groups 2 and 3. Histologic findings showed microspheres had deeply penetrated into tumors. Significantly higher tumor necrosis ratios were observed in groups 1 (86.6%–90.0%) and 3 (90.0%–100%) compared with group 2 (63.3%–70%) (P = .031 and P = .016).ConclusionsSlow drug release with high drug concentration in tumors can be provided with 40 μm TANDEM-IRI. When complete arterial embolization is performed, the dose of irinotecan loaded on 40 μm TANDEM microspheres can be reduced while maintaining efficacy.     

Transcatheter CT Arterial Portography and CT Hepatic Arteriography for Liver Tumor Visualization during Percutaneous Ablation

PurposeTo evaluate the feasibility of combining transcatheter computed tomography (CT) arterial portography or transcatheter CT hepatic arteriography with percutaneous liver ablation for optimized and repeated tumor exposure.Materials and MethodsStudy participants were 20 patients (13 men and 7 women; mean age, 59.4 y; range, 40–76 y) with unresectable liver-only malignancies—14 with colorectal liver metastases (29 lesions), 5 with hepatocellular carcinoma (7 lesions), and 1 with intrahepatic cholangiocarcinoma (2 lesions)—that were obscure on nonenhanced CT. A catheter was placed within the superior mesenteric artery (CT arterial portography) or in the hepatic artery (CT hepatic arteriography). CT arterial portography or CT hepatic arteriography was repeatedly performed after injecting 30–60 mL 1:2 diluted contrast material to plan, guide, and evaluate ablation. The operator confidence levels and the liver-to-lesion attenuation differences were assessed as well as needle-to-target mismatch distance, technical success, and technique effectiveness after 3 months.ResultsTechnical success rate was 100%; there were no major complications. Compared with conventional unenhanced CT, operator confidence increased significantly for CT arterial portography or CT hepatic arteriography cases (P < .001). The liver-to-lesion attenuation differences between unenhanced CT, contrast-enhanced CT, and CT arterial portography or CT hepatic arteriography were statistically significant (mean attenuation difference, 5 HU vs 28 HU vs 70 HU; P < .001). Mean needle-to-target mismatch distance was 2.4 mm ± 1.2 (range, 0–12.0 mm). Primary technique effectiveness at 3 months was 87% (33 of 38 lesions).ConclusionsIn patients with technically unresectable liver-only malignancies, single-session CT arterial portography–guided or CT hepatic arteriography–guided percutaneous tumor ablation enables repeated contrast-enhanced imaging and real-time contrast-enhanced CT fluoroscopy and improves lesion conspicuity.     

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

PurposeTo 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 MethodsA 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.ResultsOver 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.ConclusionsThe use of an ARM during planning angiography can significantly reduce fluoroscopy time, procedure time, and radiation dose.     

Preoperative Transcatheter Arterial Chemoembolization of Hepatoblastoma in Infants

PurposeTo evaluate the effect of preoperative transcatheter arterial chemoembolization of hepatoblastoma in infants.Materials and MethodsClinical data of 21 infants with hepatoblastoma treated between July 2008 and July 2012 in a single hospital were retrospectively analyzed. After preliminary diagnosis, surgical resection was performed in 9 infants (group I), and transcatheter arterial chemoembolization was performed in 12 infants (group II) before conventional resection. Surgical resection was performed when the tumor bulk appeared sufficiently reduced after transcatheter arterial chemoembolization alone or transcatheter arterial chemoembolization following chemotherapy in cases of pulmonary metastases.ResultsTumor shrinkage ranged from 25%–91% with a mean reduction of 69% (t = 3.816, P = .003) in group II. α-Fetoprotein levels were markedly decreased from 49%–99% with a mean level of 95% (t = 4.871, P = .000) in group II. Specimens in group II showed massive necrosis with a mean percentage of 72% with no significant treatment-related toxicity. In group II, the surgical time was significantly shorter (t = 3.438, P = .003), intraoperative blood loss was considerably less (t = 3.459, P = .003), and the weight of the resected liver was significantly less (t = 3.785, P = .001). Of 21 patients, 16 survived for 50 months without recurrence.ConclusionsTranscatheter arterial chemoembolization effectively reduced tumor volume, decreased α-fetoprotein, and reduced intraoperative hemorrhage. It represents a safe and effective adjuvant bridge to successful surgery for hepatoblastoma in infants.     

Comparison of Polyvinyl Alcohol Microspheres and Tris-Acryl Gelatin Microspheres for Uterine Fibroid Embolization: Results of a Single-Center Randomized Study

PurposeTo assess the efficacy of two embolic agents in the treatment of symptomatic uterine leiomyomas.Materials and MethodsA randomized, prospective, single-center study enrolled 60 women with symptomatic uterine leiomyomas. Uterine artery embolization (UAE) with spherical polyvinyl alcohol (SPVA) microspheres (n = 30; 700–900 μm and 900–1,200 μm; near-stasis or stasis endpoint) and tris-acryl gelatin (TAG) microspheres (n = 30; 500–700 μm; “pruned-tree” endpoint) was performed. Infarction rates were calculated for the dominant tumor and for small (< 2 cm) and large (> 2 cm) nondominant tumors. The primary endpoint was tumor infarction at 24 hours measured by contrast-enhanced magnetic resonance imaging assessed by a blinded reviewer.ResultsBaseline characteristics were similar between groups. The primary endpoint was similar in both treatments (≥ 91% dominant tumor infarction; SPVA. 86.2%; TAG, 93.3%, P = .35). Complete infarction (100%) was also similar between arms at 24 hours and 3 months. Symptom severity was reduced and quality of life improved equally at 3 and 12 months in each treatment group. Complications were minor in both groups.ConclusionsUterine leiomyoma infarction at 24 hours and 3 months after treatment with SPVA or TAG microspheres was comparable when using near-stasis as a procedural endpoint with SPVA microspheres. Symptom relief was maintained for as long as 12 months for both embolic agents.     

Feasibility of Time-Resolved MR Angiography for Detecting Recanalization of Pulmonary Arteriovenous Malformations Treated with Embolization with Platinum Coils

PurposeTo assess the feasibility of time-resolved magnetic resonance (MR) angiography as a follow-up method after embolization for pulmonary arteriovenous malformations (PAVMs).Materials and MethodsEvaluation of 28 PAVMs in 10 patients previously treated with embolization with platinum coils was performed. The mean observation period after embolization was 49 months. All patients underwent unenhanced chest computed tomography (CT) and time-resolved MR angiography followed by transcatheter digital subtraction angiography within 5 weeks for a definite diagnosis. Two radiologists reviewed the CT and time-resolved MR angiography findings using a blinded method. On CT, the draining veins of the PAVMs were measured before and after embolization, and shrinkage rates were calculated. On time-resolved MR angiography, recanalization was diagnosed when the draining vein or aneurysmal sac or both were enhanced in the pulmonary arterial phase. Correlations between recanalization, the shrinkage rate of the draining vein, and the diagnostic accuracies of CT and time-resolved MR angiography were assessed and compared with digital subtraction angiography.ResultsFive lesions could not be measured on CT because of metallic artifacts. The mean shrinkage rates of the draining vein for recanalized and occluded PAVMs were 23% ± 19 (SD) for recanalized PAVMs and 47% ± 21 for occluded PAVMs (P = .001). The sensitivity and specificity were 93% and 53%, respectively, when the shrinkage rate threshold was set to 50%. On time-resolved MR angiography, the sensitivity and specificity were 93% and 100%, respectively, for Reader 1 and 100% and 93%, respectively, for Reader 2. The κ coefficient was 0.86.ConclusionsTime-resolved MR angiography appears to be a feasible method for PAVM follow-up examinations and to provide a more accurate diagnosis of recanalization compared with unenhanced CT.     

Transcatheter Arterial Embolization with N-Butyl Cyanoacrylate for Nonvariceal Upper Gastrointestinal Bleeding in Hemodynamically Unstable Patients: Results and Predictors of Clinical Outcomes

PurposeTo assess the safety, efficacy, clinical outcomes, and prognostic factors associated with transcatheter arterial embolization (TAE) with N-butyl cyanoacrylate (NBCA) for nonvariceal upper gastrointestinal (GI) hemorrhage in hemodynamically unstable patients.Materials and MethodsBetween January 2008 and December 2012, 49 hemodynamically unstable patients (systolic blood pressure < 90 mm Hg and ongoing transfusion requirement) underwent emergency TAE with NBCA for nonvariceal upper GI bleeding and were included in the study. The technical (cessation of extravasation) and clinical (no residual bleeding within 7 d) success rates, incidence of ischemic complications, and clinical and technical predictors of recurrent bleeding within 30 days were analyzed.ResultsThe technical and clinical success rates were 98% and 71%, respectively. There were no ischemic bowel complications; one patient experienced hepatic infarction with elevated liver enzymes. The incidence of major complications was 2%. The incidence of rebleeding within 30 days was 39%. Hematologic malignancies (P = .017), coagulopathy (P = .003), steroid pulse therapy (P = .025), and the absence of NBCA in the target lesions (P = .003) were associated with recurrent bleeding.ConclusionsNBCA embolization can be safely performed in hemodynamically unstable patients with active nonvariceal upper GI bleeding. The clinical factors associated with rebleeding might influence the clinical outcome.     

Embolization of Angiographically Visible Type I and II Utero-ovarian Anastomoses during Uterine Artery Embolization for Fibroid Tumors: Impact on Symptom Recurrence and Permanent Amenorrhea

PurposeTo compare the incidences of symptom recurrence and permanent amenorrhea following uterine artery embolization (UAE) for symptomatic fibroid tumors in patients with type I and II utero-ovarian anastomoses (UOAs) with versus without ovarian artery embolization (OAE).Materials and MethodsA retrospective, institutional review board–approved study of 99 women who underwent UAE for symptomatic fibroid tumors from April 2005 to October 2010 was conducted to identify patients who had type I or II UOAs at the time of UAE. Based on the embolization technique, patients were categorized into standard (ie, UAE only), combined (ie, UAE and OAE), and control (patients without UOAs who underwent UAE) groups. Data collected included patient characteristics, procedural technique and findings, symptom recurrence, secondary interventions, and permanent amenorrhea. Statistical analysis was performed with the Fisher exact test, with significance reached at P < .05.ResultsTwenty patients (20.2%; mean age, 46.9 y ± 6.3) had type I (n = 3) or II (n = 17) UOAs. Thirteen (65%) underwent UAE only (standard group) and seven (35%) underwent UAE and OAE (combined group). There were no significant differences between groups in demographics or in the incidence of permanent amenorrhea after procedures (follow-up, 561 d ± 490). There was a significantly higher incidence of symptom recurrence in the standard group compared with the control group (P = .01), with no differences between combined and control groups (P = 1).ConclusionsThere were no statistical differences in permanent amenorrhea rates in the groups studied, with significantly higher symptom recurrence rates observed when OAE was not performed in the setting of UOA.