Clinical Impact of Sacroplasty on Patient Mobility

PurposeTo evaluate the effect of sacroplasty on patient mobility and pain when performed as a treatment for sacral insufficiency fractures.Materials and MethodsImaging with computed tomography (CT), magnetic resonance imaging, or bone scan confirmed the diagnosis of sacral insufficiency fractures. Baseline clinical mobility scale (CMS) score and visual analog scale (VAS) pain score were recorded. Sacroplasty was performed under CT guidance. Follow-up CMS and VAS scores were assessed at 4, 24, and 48 weeks.ResultsEighteen elderly patients (age 80 y ± 8.5; 17 women) were treated. Repeated-measures analysis of variance was conducted to assess changes in CMS and VAS scores over time. Pairwise comparisons revealed a significant increase in average CMS score between baseline and all three follow-up points—4 weeks (P < .001), 24 weeks (P < .001), and 48 weeks (P < .001)—indicating improvement in mobility over time. Pairwise comparisons revealed significant differences in mean VAS scores between baseline and all three follow-up time points—4 weeks (P < .001), 24 weeks (P < .001), and 48 weeks (P < .001)—indicating improvement in overall pain level over time.ConclusionsTreatment with CT-guided sacroplasty for sacral insufficiency fractures in this elderly population resulted in significant improvement in patient mobility.     

High-Frequency Jet Ventilation under General Anesthesia Facilitates CT-Guided Lung Tumor Thermal Ablation Compared with Normal Respiration under Conscious Analgesic Sedation

PurposeTo determine whether technical difficulty of computed tomography (CT)–guided percutaneous lung tumor thermal ablations is altered with the use of high-frequency jet ventilation (HFJV) under general anesthesia (GA) compared with procedures performed with normal respiration (NR) under conscious sedation (CS).Materials and MethodsThermal ablation treatment sessions performed with NR under CS or HFJV under GA with available anesthesia records and CT fluoroscopic images were retrospectively reviewed; 13 and 33 treatment sessions, respectively, were identified. One anesthesiologist determined the choice of anesthesiologic technique independently. Surrogate measures of procedure technical difficulty—time duration, number of CT fluoroscopic acquisitions, and radiation dose required for applicator placement for each tumor—were compared between anesthesiologic techniques. The anesthesiologist time and complications were also compared. Parametric and nonparametric data were compared by Student independent-samples t test and χ² test, respectively.ResultsPatients treated with HFJV under GA had higher American Society of Anesthesiologists classifications (mean, 2.66 vs 2.23; P = .009) and smaller lung tumors (16.09 mm vs 27.38 mm; P = .001). The time duration (220.30 s vs 393.94 s; P = .008), number of CT fluoroscopic acquisitions (10.31 vs 19.13; P = .023), and radiation dose (60.22 mGy·cm vs 127.68 mGy·cm; P = .012) required for applicator placement were significantly lower in treatment sessions performed with HFJV under GA. There was no significant differences in anesthesiologist time (P = .20), rate of pneumothorax (P = .62), or number of pneumothoraces requiring active treatment (P = .19).ConclusionsHFJV under GA appears to reduce technical difficulty of CT-guided percutaneous applicator placement for lung tumor thermal ablations, with similar complication rates compared with treatment sessions performed with NR under CS. The technique is safe and may facilitate treatment of technically challenging tumors.     

Serum MicroRNA-210 as a Predictive Biomarker for Treatment Response and Prognosis in Patients with Hepatocellular Carcinoma undergoing Transarterial Chemoembolization

PurposeTo investigate whether serum microRNA-210 (miR-210) level can serve as an indicator of prognosis and a predictor of efficacy of transarterial chemoembolization in patients with hepatocellular carcinoma (HCC).Materials and MethodsSerum miR-210 level was measured in 113 patients with HCC before transarterial chemoembolization (t1), 3 days after transarterial chemoembolization (t2), and 4 weeks after transarterial chemoembolization (t3) and compared with 39 healthy control subjects. The correlations between miR-210 levels and clinicopathologic factors, tumor responsiveness, and prognosis were analyzed. The modified Response Evaluation Criteria in Solid Tumors assessment was conducted at t3.ResultsA higher mean baseline miR-210 level was observed in patients with HCC compared with control subjects (3.69 ± 2.04 vs 1.08 ± 0.45, P < .001). A positive correlation between baseline miR-210 level and tumor size (P < .001), vascular invasion (P = .005), tumor differentiation (P = .037), and Barcelona Clinic Liver Cancer stage (P < .001) was observed. Elevated baseline miR-210 level also served as an independent prognostic factor predicting poor overall survival (risk ratio, 2.082; P = .003). Patients who did not respond to transarterial chemoembolization had higher baseline miR-210 levels than patients who did respond to treatment (4.34 ± 1.67 vs 3.28 ± 2.15, P < .001). In addition, miR-210 levels increased significantly 4 weeks after transarterial chemoembolization in nonresponders (5.79 ± 2.06 at t3 vs 4.34 ± 1.67 at t1, P < .001), whereas no significant change was observed in responders (3.53 ± 2.20 at t3 vs 3.28 ± 2.15 at t1, P = .116). Lastly, an inverse correlation was identified between miR-210 change t1–t3 with the time to radiologic progression (P < .001).ConclusionsSerum miR-210 may represent a novel biomarker for predicting efficacy of transarterial chemoembolization and overall survival for patients with HCC.     

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.     

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.     

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.     

Contemporary Systematic Review and Meta-Analysis of Early Outcomes with Percutaneous Treatment for Infrapopliteal Atherosclerotic Disease

PurposeThe need for specialty devices to improve the technical outcome of endovascular interventions is dependent on the rate of early failure in such procedures. This meta-analysis assessed procedural outcomes of such interventions to elucidate the rate of early procedural failures and the need for such specialty devices.Materials and MethodsMEDLINE and EMBASE were searched for contemporary studies (2000–2012) reporting procedural or short-term outcomes for revascularization of infrapopliteal atherosclerotic lesions. A random-effects metaanalysis was performed, which included post hoc comparisons among treatment groups.ResultsA total of 42 studies with 52 treatment arms representing 3,660 unique patients were included. Technical success rates were higher with bare metal stents (BMSs; 98.6%) than with atherectomy (92.2%; P < .05) or percutaneous transluminal angioplasty (PTA; 91.2%; P = .01), and higher with drug-eluting stents (DESs) than with PTA (P < .001). DES use had higher primary patency rates than atherectomy (P < .05), BMS use (P < .001), and PTA (P < .01). The 30-day rate of target lesion revascularization was significantly higher with PTA (8.1%) than with BMSs (2.2%; P < .05) and DESs (1.1%; P < .05). Thirty-day rates of major unplanned amputation (range, 1.5%–4.4%) and mortality (range, 0.9%–3.3%) were comparable among treatment groups. Significant heterogeneity among studies was noted for most PTA outcomes. Publication bias was evident for most PTA and DES outcomes.ConclusionsEarly failure of percutaneous therapies in patients with infrapopliteal atherosclerotic lesions is device- and technique-dependent. Specialty devices designed to reduce technical failure rates may therefore be of benefit in this selected group of patients. Study results are confounded by inconsistent data reporting, heterogeneity of treatment effects, and publication bias.     

SUPERA Interwoven Nitinol Stent Outcomes in Above-Knee IntErventions (SAKE) Study

PurposeTo report experience with the novel interwoven-wire self-expanding nitinol SUPERA stent (IDEV Technologies, Inc/Abbott Laboratories, Inc, Webster, Texas) for the treatment of severely diseased superficial femoral and popliteal arteries.Materials and MethodsConsecutive patients with severely diseased superficial femoral and popliteal arteries who received SUPERA stents (n = 80 patients [98 limbs]; mean age, 70.8 y; 80% male) were retrospectively identified. Patients were followed for an average of 14.3 months after intervention.ResultsTotal occlusions were present in 39% of the lesions, 21% had tissue loss, and 61% demonstrated calcification on fluoroscopy. Patients were prescribed dual antiplatelet therapy (aspirin and clopidogrel) for at least 30 days unless contraindicated, followed by aspirin alone indefinitely. The mean (± SD) lesion length was 143 mm (± 98). Based on need for clinical intervention, primary patency was 96.9% at 6 months and 85.8% at 12 months (Kaplan-Meier estimates). Assisted primary patency and secondary patency rates at 12 months were 96.8% and 100%, respectively. Ankle-brachial index increased from 0.60 at baseline to 0.83 at last follow-up (P < .001). No stent fractures were found by fluoroscopy inspection in 19 limbs (16 patients) that required reintervention.ConclusionsBased on experience with multiple operators at a single clinical center, the interwoven nitinol stent design provides a viable option for high-grade obstructive disease in the femoropopliteal artery.     

Percutaneous Metallic Stent Placement in Patients with Cancer Recurrence at Bilioenterostomy Site

PurposeTo investigate the outcomes of percutaneous metallic stent placement in patients with malignant bilioenterostomy obstruction and to assess the risk factors influencing stent patency.Materials and MethodsFrom August 2008 to January 2012, 53 patients with malignant bilioenterostomy obstructions were treated with percutaneous placement of biliary metallic stents; this included expanded polytetrafluoroethylene (ePTFE)–covered stent placement in 36 patients and uncovered stent placement in 17 patients.ResultsA total of 75 stents were successfully placed in 53 patients. No major complications occurred in any patients, and minor complications occurred in nine patients (17%). The mean serum bilirubin level, which was 3.6 mg/dL ± 0.7 before drainage, decreased significantly to 2.5 mg/dL ± 0.4 at 1 month after stent placement (P = .041). Successful internal drainage was achieved in 44 of the 53 patients (83%). Kaplan–Meier analysis showed a median overall survival time of 145 days (95% confidence interval, 100–190 d), a median stent patency time of 313 days (95% confidence interval, 46–580 d), and cumulative stent patency rates at 1, 3, 6, 9, and 12 months of 91%, 75%, 64%, 56%, and 45%, respectively. Multivariate Cox regression analysis showed that the use of uncovered stents (odds ratio, 2.924; P = .033) was the only significant independent factor associated with stent occlusion.ConclusionsPercutaneous metallic stent placement is a safe and effective method for the treatment of patients with malignant bilioenterostomy obstruction. Moreover, as uncovered stent placement is the only significant independent factor associated with stent occlusion, ePTFE-covered stent placement is preferable in these patients.     

Percutaneous Angioplasty Using a Paclitaxel-Coated Balloon Improves Target Lesion Restenosis on Inflow Lesions of Autogenous Radiocephalic Fistulas: A Pilot Study

PurposeTo determine whether the use of a paclitaxel-coated balloon (PCB) improves patency in patients undergoing percutaneous transluminal angioplasty (PTA) for recurrent juxtaanastomotic stenosis of radiocephalic arteriovenous fistulas (RCAVFs).Material and MethodsThis prospective study recruited hemodialysis patients with two short (< 2 cm) and separated inflow RCAVF lesions. After dilation of lesions using a 4-mm plain balloon (PB), half of the lesions were randomly selected for treatment with PTA using PCB (size, 4 mm; length, 2 cm) and PB (size, 5-mm or 6-mm) (group 1), and the other half were treated with PTA using PB alone (group 2). After the index PTA, dysfunction-driven angiography was performed to confirm target lesion restenosis (TLR). TLR and lesion patency were compared in the two groups by χ² test, t test, and Kaplan-Meier analysis.ResultsThe analysis of 20 lesions in 10 patients revealed that the TLR-free duration in group 1 was significantly longer than the TLR-free duration in group 2 (251.2 d vs 103.2 d; P < .01). The patency rate of the target lesion was significantly higher in group 1 than in group 2 at 6 months (70% vs 0%; P < .01) but not at 12 months (20% vs 0%; P > .05).ConclusionsThis early study suggests that, for improving short-term patency, PTA with PCB and PB is more effective than PTA with PB alone, warranting further study.     

Transcatheter Arterial Chemoembolization for Advanced Hepatocellular Carcinoma with Portal Vein Invasion: Safety,Efficacy, and Prognostic Factors

PurposeTo evaluate the safety and efficacy of transarterial chemoembolization and to identify the prognostic factors associated with survival in patients with hepatocellular carcinoma (HCC) and portal vein (PV) invasion.Materials and MethodsFrom January 2006 to March 2012, 50 patients with HCC invading into the PV (Barcelona Clinic Liver Cancer stage C) were treated with transarterial chemoembolization. The parenchymal tumor and PV tumor were confirmed by multidetector computed tomography (CT) and angiography. There were 14 patients with right PV tumor, 12 patients with left PV tumor, and 24 patients with main PV tumor. The response was evaluated by multidetector CT using Response Evaluation Criteria in Solid Tumors. Patients with residual tumors received repeated transarterial chemoembolization every 6–8 weeks unless the patients achieved complete remission or developed contraindications.ResultsThe median survival period of the entire group was 6.2 months (range, 1.7–50.9 mo), and the overall response rate was 42% (21 of 50 patients). The 6-month, 12-month, 24-month, and 36-month survival rates were 54%, 22%, 10%, and 8%. There were no instances of 30-day mortality or acute liver failure related to transarterial chemoembolization. The median survival of the 21 responders was 10.5 months, and the median survival of the 29 nonresponders was 5.5 months (P < .001). In both univariate and multivariate analyses, only the response to transarterial chemoembolization (hazard ratio = 0.25, P < .001) and the absence of ascites (hazard ratio = 0.24, P = .01) were significant prognostic factors.ConclusionsTransarterial chemoembolization is a safe and effective treatment for HCC with major PV invasion. The response to transarterial chemoembolization and the ascites status were the most significant predictive factors for prolonged survival.     

Comparison of Characteristics and Transarterial Chemoembolization Outcomes in Patients with Unresectable Hepatocellular Carcinoma and Different Viral Etiologies

PurposeTo determine any differences in patient characteristics and outcomes after transarterial chemoembolization between different viral etiologies of hepatocellular carcinoma (HCC).MethodsThis retrospective study consisted of 201 patients undergoing first-time transarterial chemoembolization for unresectable HCC from January to December 2009. The patients were divided into four groups: hepatitis B virus (HBV) only (n = 104), hepatitis C virus (HCV) only (n = 63), HBV and HCV (n = 10), and no viral hepatitis (n = 24). The clinical and laboratory data were obtained from electronic medical records, and imaging findings obtained before transarterial chemoembolization were analyzed. Kaplan-Meier analyses were used to assess the impact of HBV or HCV status, clinical characteristics, and imaging results on overall survival.ResultsAfter a median follow-up of 28.3 months ± 16.2, the 1-, 2-, and 3-year overall survival rates were 74.1%, 59.7%, and 53.2%. Patients with HBV had a significant association with younger age (P = .001), higher male-to-female ratio (P = .003), lower alanine aminotransferase levels (P = .018), higher albumin levels (P = .009), and multifocal tumors at diagnosis (P = .04) compared with patients with HCV. Patients with both HBV and HCV had significantly higher serum bilirubin levels compared with the other groups (P = .002). No significant difference was found in overall survival among the different hepatitis groups (P = .943). Multivariate analysis showed that statistically significant determinants for overall survival were Child-Pugh class (P = .002), Barcelona Clinic Liver Cancer stage (P < .001), tumor size (P < .001), and distribution (P < .001).ConclusionsViral etiology has no correlation with the outcome of patients with HCC undergoing transarterial chemoembolization.     

Microwave Thermal Ablation of Spinal Metastatic Bone Tumors

PurposeTo assess feasibility, safety, and efficacy of microwave ablation of spinal metastatic bone tumors.Materials and MethodsRetrospective study of 17 patients with 20 spinal metastatic tumors treated with microwave ablation under computed tomographic guidance between March 2011 and August 2013 was performed. Ablations were performed under local anesthesia and nitrous oxide ventilation. Lesions were lumbar (n = 10), sacral (n = 7), and thoracic (n = 3) in location. Primary neoplastic sites were lung (n = 9), prostate (n = 4), kidney (n = 6), and uterus (n = 1). Adjunct cementoplasty was performed in nine cases, and a temperature-monitoring device was used in four cases. Procedure effectiveness was evaluated by visual analog scale (VAS) during a 6-month follow-up. Patient medical records were reviewed, and demographic and clinical data, tumor characteristics, and information on pain were assessed.ResultsMean ablation time was 4.4 minutes ± 2.7 (range, 1–8 min), with an average of 3.8 cycles per ablation at 60 W (range, 30–70 W). The preprocedure mean VAS score was 7.4 ± 1.2 (range, 6–9). Pain relief was achieved in all but one patient. Follow-up VAS scores were as follows: day 0, 1.3 ± 1.8 (P < .001); day 7, 1.6 ± 1.7 (P < .001); month 1, 1.9 ± 1.6 (P < .001); month 3, 2.2 ± 1.5 (P < .001); and month 6, 2.3 ± 1.4 (P < .01). No complications were noted.ConclusionsMicrowave ablation appears to be feasible, safe, and an effective treatment of painful refractory spinal metastases and may be considered as a potential alternative percutaneous technique in the management of spinal metastases.     

Factors Affecting Periprocedural Morbidity and Mortality and Long-term Patient Survival after Arterial Embolization of Hepatic Neuroendocrine Metastases

PurposeTo identify factors affecting periprocedural morbidity and mortality and long-term survival following hepatic artery embolization (HAE) of hepatic neuroendocrine tumor (NET) metastases.Materials and MethodsThis single-center, institutional review board–approved retrospective review included 320 consecutive HAEs for NET metastases performed in 137 patients between September 1996 and September 2007. Forty-seven HAEs (15%) were performed urgently to manage refractory symptoms in inpatients (urgent group), and 273 HAEs (85%) were elective (elective group). Overall survival (OS) was estimated by Kaplan–Meier methodology. Complications were categorized per Common Terminology Criteria for Adverse Events, version 4.0. Univariate and multivariate analyses were performed to determine independent predictors for OS, complications, and 30-day mortality. The independent factors were combined to develop clinical risk score groups.ResultsUrgent HAE (P = .007), greater than 50% liver replacement by tumor (P < .0001), and extrahepatic metastasis (P = .007) were independent predictors for shorter OS. Patients with all three risk factors had decreased OS versus those with none (median, 8.5 vs 86 mo; P < .001). Thirty-day mortality was significantly lower in the elective (1%) versus the urgent group (8.5%; P = .0009). There were eight complications (3%) in the elective group and five (10.6%) in the urgent group (P = .03). Male sex and urgent group were independent factors for higher 30-day mortality rate (P = .023 and P =.016, respectively) and complications (P = .012 and P =.001, respectively).ConclusionsUrgent HAE, replacement of more than 50% of liver by tumor, and extrahepatic metastasis are strong independent predictors of shorter OS. Male sex and urgent HAE carry higher 30-day mortality and periprocedural morbidity risks.     

Inhibition of Growth in a Rabbit VX2 Thigh Tumor Model with Intraarterial Infusion of Carbon Dioxide–Saturated Solution

PurposeTo evaluate the efficacy of intraarterial infusion of CO₂-saturated solution in rabbit VX2 thigh tumors.Materials and MethodsFourteen Japanese white rabbits had VX2 tumors implanted in the right femoral muscle 3 weeks before intraarterial infusion. Rabbits were divided into control and CO₂ groups (n = 7 each). Fifty milliliters of solution (saline solution and CO₂-saturated solution for the control and CO₂ groups, respectively) was administered via a 24-gauge catheter in the ipsilateral iliac artery close to the feeding artery of the VX2 tumor. All rabbits were killed for tumor harvest on day 3 after the procedure. Tumor volume was evaluated with in vivo direct caliper measurement and contrast-enhanced computed tomography (CT). Tumor apoptotic changes were examined by DNA fragmentation assay and immunoblot analysis. The tumor growth ratio and apoptotic cell rate were analyzed.ResultsBody weight was equally increased in both groups, but the mean tumor growth ratio was significantly decreased in the CO₂ group compared with the control group (−9.5% ± 7.9 vs 27.2% ± 6.6 and 4.1% ± 4.4 vs 35.7% ± 4.5 measured by calipers and contrast-enhanced CT, respectively; P < .01). Apoptotic activity in the CO₂ group was higher than in the control group (number of apoptotic cells per area, 215.0 ± 58.7 vs 21.8 ± 5.4; adjusted relative density of cleaved caspase-3, 0.23 ± 0.07 vs 0.04 ± 0.01; P < .01).ConclusionsIntraarterial infusion of CO₂-saturated solution inhibits rabbit VX2 thigh tumor growth by activation of apoptotic cell death through cleaved caspase-3 upregulation.     

Radiofrequency Ablation–Induced Upregulation of Hypoxia-Inducible Factor-1α Can Be Suppressed with Adjuvant Bortezomib or Liposomal Chemotherapy

PurposeTo characterize upregulation of hypoxia-inducible factor (HIF)-1α after radiofrequency (RF) ablation and the influence of an adjuvant HIF-1α inhibitor (bortezomib) and nanodrugs on modulating RF ablation–upregulated hypoxic pathways.Materials and MethodsFisher 344 rats (n = 68) were used. First, RF ablation–induced periablational HIF-1α expression was evaluated in normal liver or subcutaneous R3230 tumors (14–16 mm). Next, the effect of varying RF ablation thermal dose (varying tip temperature 50°C–90°C for 2–20 minutes) on HIF-1α expression was studied in R3230 tumors. Third, RF ablation was performed in R3230 tumors without or with an adjuvant HIF-1α inhibitor, bortezomib (single intraperitoneal dose 0.1 mg/kg). Finally, the combination RF ablation and intravenous liposomal chemotherapeutics with known increases in periablational cellular cytotoxicity (doxorubicin, paclitaxel, and quercetin) was assessed for effect on periablational HIF-1α. Outcome measures included immunohistochemistry of HIF-1α and heat shock protein 70 (marker of nonlethal thermal injury).ResultsRF ablation increased periablational HIF-1α in both normal liver and R3230 tumor, peaking at 24–72 hours. Tumor RF ablation had similar HIF-1α rim thickness but significantly greater percent cell positivity compared with hepatic RF ablation (P < .001). HIF-1α after ablation was the same regardless of thermal dose. Bortezomib suppressed HIF-1α (rim thickness, 68.7 µm ± 21.5 vs 210.3 µm ± 85.1 for RF ablation alone; P < .02) and increased ablation size (11.0 mm ± 1.5 vs 7.7 mm ± 0.6 for RF ablation alone; P < .002). Finally, all three nanodrugs suppressed RF ablation–induced HIF-1α (ie, rim thickness and cell positivity; P < .02 for all comparisons), with liposomal doxorubicin suppressing HIF-1α the most (P < .03).ConclusionsRF ablation upregulates HIF-1α in normal liver and tumor in a temperature-independent manner. This progrowth, hypoxia pathway can be successfully suppressed with an adjuvant HIF-1α-specific inhibitor, bortezomib, or non–HIF-1α-specific liposomal chemotherapy.     

Prospective Evaluation of Optical Coherence Tomography in Lower Limb Arteries Compared with Intravascular Ultrasound

PurposeTo compare in a prospective noninferiority study optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in popliteal and infrapopliteal vessels.Materials and MethodsOCT and IVUS images of 112 popliteal and infrapopliteal arterial segments were prospectively obtained from 16 patients with peripheral arterial occlusive disease. Three observers evaluated the corresponding OCT and IVUS images for image quality, artifact frequency, discriminability of vessel wall layers, and plaque composition. Measurements of the lumen, vessel, and plaque areas were compared for both modalities.ResultsThe intrareader and interreader reproducibility of plaque tissue discrimination (0.88 vs 0.75), overall image quality, and vessel wall layer discriminability were significantly higher for OCT (all P < .001). Artifact frequency was higher in OCT, constraining the imaging of the tibioperoneal trunk. The results of measurements of the lumen and vessel area were comparable for both modalities (correlation > 0.9, P < .001). Plaque area measurements differed (correlation 0.8, P < .01) because OCT underestimated it. The OCT procedure caused vessel spasms in two patients.ConclusionsOCT imaging of infrapopliteal arteries is feasible and safe and provides high image quality. It enables an accurate assessment of vessel lumen, wall, and plaque. Compared with IVUS, OCT images provide excellent image quality and superior visualization of vessel wall layers and different plaque components. The penetration depth of OCT restricts its use to suitable vessel regions.     

Quantification of Tissue Shrinkage and Dehydration Caused by Microwave Ablation: Experimental Study in Kidneys for the Estimation of Effective Coagulation Volume

PurposeTo quantify the extent of tissue shrinkage and dehydration caused by microwave (MW) ablation in kidneys for estimation of effective coagulation volume.Materials and MethodsMW ablations were carried out in ex vivo porcine kidneys. Six study groups were defined: groups 1A, 2A, and 3A for MW ablation (90 W for 5 min, 7.5 min, or 10 min), and groups 1B, 2B, and 3B for control (without MW ablation). Pre- and postinterventional volume analyses were performed. Effective coagulation volumes (original tissue included in coagulation) were determined. Postinterventional dehydration analyses were performed with calculation of mean mass fractions of water.ResultsMean deployed energies were 21.6 kJ ± 1.1 for group 1A, 29.9 kJ ± 1.0 for group 2A, and 42.1 kJ ± 0.5 kJ for group 3A, and were significantly different (P < .0001). Differences between pre- and postinterventional volumes were ?3.8% ± 0.6 for group 1A, ?5.6% ± 0.9 for group 2A, and ?7.2% ± 0.4 for group 3A, and ?1.1% ± 0.3 for group 1B, ?1.8% ± 0.4 for group 2B, and ?1.1% ± 0.4 for group 3B. Postinterventional volumes were significantly smaller than preinterventional volumes for all groups (P < .01). Underestimations of effective coagulation volume from visualized coagulation volume were 26.1% ± 3.5 for group 1A, 35.2% ± 11.2 for group 2A, and 42.1% ± 4.9 for group 3A, which were significantly different (P < .01). Mean mass fractions of water were 64.2% ± 1.4 for group 1A, 63.2% ± 1.7 for group 2A, and 62.6% ± 1.8% for group 3A, with significant differences versus corresponding control groups (P < .01).ConclusionsFor MW ablation in kidneys, underestimation of effective coagulation volume based on visualized coagulation volume is significantly greater with greater deployed energy. Therefore, local dehydration with tissue shrinkage is a potential contributor.     

Technical Details and Clinical Outcomes of Transpopliteal Venous Stent Placement for Postthrombotic Chronic Total Occlusion of the Iliofemoral Vein

PurposeTo evaluate the technical aspects and early clinical results of stent placement for managing postthrombotic chronic total occlusion (CTO) of the iliofemoral vein through ipsilateral popliteal access.Materials and MethodsA retrospective analysis of 110 patients (44 men; mean age, 51 y; 118 limbs; 102 left limbs) with postthrombotic CTO of the iliofemoral vein treated with stent placement in a single institution from January 2007–December 2011 was conducted. All occlusions were initially accessed via ipsilateral popliteal veins under the guidance of venography or ultrasonography. Technical aspects, quality of life, stent patency, and Villalta scores were recorded at follow-up evaluation. Risk factors of in-stent restenosis and early in-stent thrombosis were evaluated using Cox proportional hazards regression model.ResultsPercutaneous recanalization was successful in 112 of 118 limbs (95%). The mean duration of the procedure was 43 minutes (range, 10–120 min). The quality of life and Villalta scores were significantly improved (P < .01). The 3-year primary, assisted primary, and secondary cumulative stent patency rates were 70%, 90%, and 94%. During a median follow-up period of 25 months (range, 1–52 mo), the relief rates of severe leg pain (visual analog scale > 5) and severe leg swelling (grade 3) were 72% (49 of 68) and 70% (64 of 91), respectively, and the healing of ulcers was successful in 78% (36 of 46) of the cases. After stent placement, the limbs with visible remaining collateral circulation had a higher rate of early in-stent thrombosis (22.5% vs 6.1%; P = .007). The patients with long stents extending below the inguinal ligament had a higher rate of in-stent restenosis (hazard ratio = 1.77–6.5; P = .0146).ConclusionsTranspopliteal venous stent placement is an effective, safe, and feasible method of managing postthrombotic CTO of the iliofemoral vein. The stent extending below the inguinal ligament is the major risk factor of in-stent restenosis. The visible remaining collateral circulation after stent placement may indicate persistent hemodynamically significant stenosis.     

Does Polyvinyl Alcohol Particle Size Change the Outcome of Prostatic Arterial Embolization for Benign Prostatic Hyperplasia? Results from a Single-Center Randomized Prospective Study

PurposeTo evaluate whether different polyvinyl alcohol (PVA) particle sizes change the outcome of prostatic arterial embolization (PAE) for benign prostatic hyperplasia (BPH).Materials and MethodsA randomized prospective study was undertaken in 80 patients (mean age, 63.9 y; range, 48–81 y) with symptomatic BPH undergoing PAE between May and December 2011. Forty patients underwent PAE with 100-µm (group A) and 200-µm PVA particles (group B). Visual analog scales were used to measure pain, and rates of adverse events were recorded. PAE outcomes were evaluated based on International Prostate Symptom Score (IPSS) and quality-of-life (QoL) questionnaires, prostate volume (PV), prostate-specific antigen (PSA) levels, and peak flow rate measurements at baseline and 6 months.ResultsNo differences between groups regarding baseline data, procedural details, or adverse events were noted. Mean pain scores were as follows: during embolization, 3.2 ± 2.97 (group A) versus 2.93 ± 3.28 (group B); after embolization, 0.10 ± 0.50 (group A) versus 0 (group B; P = .20); and the week after PAE, 0.85 ± 1.65 (group A) versus 0.87 ± 1.35 (group B; P = .96). Patients in group B had greater decreases in IPSS (3.64 points; P = .052) and QoL (0.57 points; P = .07). Patients in group A had a greater decrease in PV (8.75 cm³; P = .13) and PSA level (2.09 ng/mL; P < .001).ConclusionsNo significant differences were found in pain scores and adverse events between groups. Whereas PSA level and PV showed greater reductions after PAE with 100-µm PVA particles, clinical outcome was better with 200-µm particles.