Recanalization of Chronic Total Occlusions of the Superior Mesenteric Artery in Patients with Chronic Mesenteric Ischemia: Technical and Clinical Outcomes

PurposeTo evaluate the safety and outcomes of endovascular recanalization of chronic total occlusions (CTOs) of the superior mesenteric artery (SMA) in patients with chronic mesenteric ischemia (CMI).Materials and MethodsA single-institution retrospective review was performed of 47 consecutive patients (18 male, 29 female) who underwent endovascular stent placement for CTOs of the SMA between February 2006 and November 2012. All patients had symptoms of CMI. Procedural and follow-up data were collected for assessment of technical success, safety, and outcome.ResultsTechnical success was achieved in 41 of 47 patients (87%). Forty-two of the 47 procedures were performed from a femoral approach. Fifteen patients underwent concurrent revascularization of the celiac artery. All patients who underwent successful recanalization reported symptomatic improvement. Kaplan–Meier analysis revealed primary freedom from symptomatic recurrence of 95% at 12 months and 78% at 24 months. Symptomatic recurrence was observed in seven patients, all of whom underwent successful assisted or secondary endovascular procedures. Secondary freedom from symptomatic recurrence rates were 100% at 12 months and 88% 24 months. There were three (7%) minor access-related complications and no major complications.ConclusionsEndovascular stent-assisted recanalization of chronic SMA occlusions is safe and effective, with an acceptable rate of technical success and excellent midterm clinical outcomes.     

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.     

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.     

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.     

Long-term Outcomes of Coil Packing for Visceral Aneurysms: Correlation between Packing Density and Incidence of Coil Compaction or Recanalization

PurposeTo evaluate the correlation between packing density and the incidence of coil compaction or recanalization of visceral artery aneurysms (VAAs) after coil packing.Materials and MethodsBetween July 2004 and April 2012, coil packing was performed for 46 true visceral aneurysms (16 splenic, 11 pancreaticoduodenal, eight renal, six hepatic, three superior mesenteric, one right gastric, and one gastroepiploic) in 42 patients. The size and volume of the aneurysm, packing density, and the incidences of compaction and recanalization were evaluated retrospectively.ResultsThe mean follow-up period was 37 months ± 8 (range, 11–80 mo). The mean packing density was 19% ± 8 (range, 5%–42%), mean aneurysm size was 19 mm ± 8 (range, 5–40 mm), and mean volume was 4,108 mm³ ± 5,435 (range, 72–26,235 mm³). Compaction and recanalization occurred in two (4%) and 12 aneurysms (26%), respectively. The mean packing density was significantly lower in aneurysms with compaction or recanalization than in unaffected aneurysms (12% vs 22%; P = .00014). There was a significant difference in mean packing density between small (< 20 mm; 22%) and large (≥ 20 mm) aneurysms (15%; P = .0045). The mean size and volume were significantly larger for coil-compacted or recanalized aneurysms than for unaffected aneurysms (P < .05). In aneurysms with a packing density of at least 24%, no compaction or recanalization occurred.ConclusionsCoil compaction or recanalization after coil packing for VAAs more often occurs after insufficient embolization with low packing density and in patients with large aneurysms.     

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.     

Effect of Stent Implantation on the Deformations of the Superficial Femoral Artery and Popliteal Artery: In Vivo Three-Dimensional Deformational Analysis from Two-Dimensional Radiographs

The objective of this work was to develop a system for three-dimensional (3D) reconstruction of the femoropopliteal artery from two angiographic views and to quantify the in vivo 3D deformations in 18 patients before balloon angioplasty and after primary stent implantation. The procedure had an insignificant effect on the bending behavior of the artery, as the average mean curvature change within the lesion remained constant before (0.04 cm⁻¹ ± 0.03) and after stent implantation (0.03 cm⁻¹ ± 0.04). A significant effect of stent implantation was measured in terms of a decrease in arterial shortening during leg flexion.     

Endovascular Recanalization of Native Chronic Total Occlusions in Patients with Failed Lower-Extremity Bypass Grafts

PurposeTo investigate the feasibility, safety, and outcome of endovascular recanalization of native chronic total occlusions (CTOs) in patients with failed lower-extremity bypass grafts.Materials and MethodsRetrospective review of 19 limbs in 18 patients with failed lower-extremity bypass grafts that underwent recanalization of native arterial occlusions between February 2009 and April 2013 was performed. Nine of the limbs presented with acute ischemia and 10 presented with chronic ischemia, including eight with critical limb ischemia and two with disabling claudication.ResultsThe mean patency of the failed bypass grafts (63% venous) was 27 months. All limbs had Transatlantic Inter-Society Consensus class D lesions involving the native circulation. Technical success of the endovascular recanalization procedure was achieved in all but one limb (95%). The mean ankle brachial indices before and after treatment were 0.34 and 0.73, respectively. There were no major complications or emergency amputations. Mean patient follow-up was 64 weeks, and two patients were lost to follow-up. Primary patency rates at 3, 6, and 12 months were 87%, 48%, and 16%, respectively. Successful secondary procedures were performed in seven patients, with secondary patency rates at 3, 6, and 12 months of 88%, 73%, and 44%, respectively. Limb salvage rates at 12 and 24 months were 94% and 65%, and amputation-free survival rates at 12 and 24 months were 87% and 60%, respectively.ConclusionsEndovascular recanalization of native CTOs in patients with failed lower-extremity bypass grafts is technically feasible and safe and results in acceptable limb salvage.     

Acute Combined Revascularization in Acute Ischemic Stroke with Intracranial Arterial Occlusion: Self-expanding Solitaire Stent during Intravenous Thrombolysis

PurposeTo investigate the safety and efficacy of the self-expanding Solitaire stent used during intravenous thrombolysis (IVT) for intracranial arterial occlusion (IAO) in acute ischemic stroke (AIS).Materials and MethodsConsecutive nonselected patients with AIS with IAO documented on computed tomographic angiography or magnetic resonance angiography and treated with IVT were included in this prospective study. Stent intervention was initiated and performed during administration of IVT without waiting for any clinical or radiologic signs of potential recanalization. Stroke severity was assessed by National Institutes of Health Stroke Scale (NIHSS), and 90-day clinical outcome was assessed by modified Rankin scale (mRS), with a good outcome defined as an mRS score of 0–2. Recanalization was rated by thrombolysis in cerebral infarction (TICI) scale.ResultsFifty patients (mean age, 66.8 y ± 14.6) had a baseline median NIHSS score of 18.0. Overall recanalization was achieved in 94% of patients, and complete recanalization (ie, TICI 3 flow) was achieved in 72% of patients. The mean time from stroke onset to maximal recanalization was 244.2 minutes ± 87.9, with a median of 232.5 minutes. The average number of device passes was 1.5, with a mean procedure time to maximal recanalization of 49.5 minutes ± 13.0. Symptomatic intracerebral hemorrhage occurred in 6% of patients. The median mRS score at 90 days was 1, and 60% of patients had a good outcome (ie, mRS score 0–2). The overall 3-month mortality rate was 14%.ConclusionsCombined revascularization with the Solitaire stent during IVT appears to be safe and effective in the treatment of acute IAO.     

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.     

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.     

Apparent Diffusion Coefficient of Uterine Leiomyoma as a Predictor of the Potential Response to Uterine Artery Embolization

PurposeTo determine the utility of the apparent diffusion coefficient (ADC) of uterine leiomyoma for prediction of the potential response to uterine artery embolization (UAE).Materials and MethodsThis prospective study included 49 patients with uterine leiomyomas who underwent diffusion-weighted magnetic resonance (MR) imaging before UAE between May 2011 and January 2012. All patients also underwent 3-month follow-up MR imaging after UAE. Using conventional and diffusion-weighted MR imaging sequences, 72 uterine leiomyomas ≥ 3 cm were prospectively evaluated. The volume of each leiomyoma was calculated, and quantitative measurement of ADC was performed. Regression analysis was used to evaluate the relationship between ADC and volumetric response after UAE. Receiver operating characteristic curve analysis was performed to determine the sensitivity and specificity of ADC for prediction of the potential response to UAE. Interclass correlation coefficient analysis was used to assess interobserver variability between two radiologists.ResultsVolume reduction rates of leiomyomas after UAE ranged from 0.2%–89.1% (mean, 44.1%). ADC ranged from 0.559 × 10^?3 mm²/s to 1.814 × 10^?3 mm²/s (mean, 1.170 × 10^?3 mm²/s). ADC was statistically significantly related to volumetric response of leiomyomas (P = .014). Using a threshold of 1.092 × 10^?3 mm²/s, the sensitivity and specificity of ADC for prediction of > 50% volume reduction of the leiomyoma after UAE were 82.6% and 52.3%, respectively. Using a threshold of 1.023 × 10^?3 mm²/s, the sensitivity and specificity of ADC for prediction of < 30% volume reduction were 80.8% and 33.3%, respectively. The interclass correlation coefficient for measuring ADC of uterine leiomyomas between two radiologists was 0.98.ConclusionsADC of uterine leiomyomas was significantly related to the volume reduction after UAE. ADC may be useful in predicting the potential response to UAE. A high ADC of the uterine leiomyoma may be associated with a greater volume reduction after UAE.     

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.     

Chemoembolization via the Left Internal Mammary Artery Supplying Hepatocellular Carcinoma

PurposeTo present radiologic findings that show favorable tumor response after chemoembolization via the left internal mammary artery (LIMA).Materials and MethodsBetween October 2002 and April 2013, 57 patients with hepatocellular carcinoma (HCC) underwent 69 sessions of chemoembolization via the LIMA. Imaging findings including tumor size, location, and visibility of tumor-feeding artery on cross-sectional images were retrospectively reviewed in consensus by two radiologists. Tumor response after chemoembolization via the LIMA was assessed by the modified Response Evaluation Criteria in Solid Tumors on follow-up multidetector computed tomography in consensus.ResultsThe mean tumor size supplied by the LIMA was 6.8 cm (range, 1.0–21.0 cm). HCCs supplied by the LIMA tended to be located in the subcapsular area including exophytic features (57 of 57; 100%) and were more likely to be located in the left lobe of the liver (56 of 57; 98%). HCCs supplied by the LIMA were more likely to be multiple or infiltrative (52 of 57; 91%) and marginally recurred (43 of 57; 75%). Feeding arteries of the LIMA were identified in a high percentage of cases (49 of 66; 74%) on cross-sectional images obtained before embolization. Regarding tumor response, tumors that were newly developed or exclusively supplied by the LIMA showed better target tumor response (P = .011 and P < .0001, respectively). On multivariate analysis, tumors exclusively supplied by the LIMA showed significantly better target tumor response with odds ratio of 16.32.ConclusionsChemoembolization via the LIMA has a favorable target tumor response when HCCs are exclusively supplied by the LIMA.     

Feasibility of Percutaneous Cementoplasty Combined with Interventional Internal Fixation for Impending Pathologic Fracture of the Proximal Femur

PurposeTo evaluate the feasibility of percutaneous cementoplasty and interventional internal fixation for stabilization of impending pathologic fracture of the proximal femur.Materials and MethodsFrom May 2012 to August 2013, six consecutive patients (three men and three women; median age, 58.33 y ± 21.45; age range, 18–78 y) who underwent percutaneous cementoplasty plus interventional internal fixation for the treatment of metastases to the proximal femur were retrospectively analyzed. The Karnofsky performance status (KPS) and visual analog scale (VAS) score for pain were assessed before and 1 week after the procedure; moreover, the procedure duration, length of hospital stay, risk of fracture at the procedural site, and complications were assessed.ResultsThe KPS increased from 66.67 ± 12.11 (range, 60–90) before the procedure to 76.67 ± 13.66 (range, 60–100) 1 week after the procedure. For symptomatic patients (n = 5), the VAS score decreased from 6.80 ± 2.39 (range, 3–9) before the procedure to 1.80 ± 0.84 (range, 1–3) at 1 week after the procedure. The mean procedure duration was 90.00 minutes ± 10.56 (range, 72–102 min). The average length of hospital stay was 7 days ± 2 (range, 4–10 d). The only complication noted consisted of thrombophlebitis in one patient, on the operative side, at 15 days after the procedure. No cases of procedural site fracture during follow-up were noted (median, 192 d; range, 30–365 d).ConclusionsPercutaneous cementoplasty plus interventional internal fixation is a feasible technique for stabilization of impending pathologic fracture of the femur.     

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.     

Localized Hyperthermia with Iron Oxide–Doped Yttrium Microparticles: Steps toward Image-Guided Thermoradiotherapy in Liver Cancer

PurposeTo test whether iron oxide (IO)–containing yttrium aluminosilicate (YAS) microparticles (MPs) can generate localized therapeutic hyperthermia (≥ 43°C) when injected intratumorally in an animal model of liver cancer and whether MP distributions could be visualized with magnetic resonance (MR) imaging.Materials and MethodsTwenty-one Sprague–Dawley rats implanted with N1-S1 liver tumors were assigned to alternating magnetic field (AMF) exposure following intratumoral injection with IO-YAS MPs (n = 7), sham surgery (n = 7), or baseline iron quantification (n = 7). Three fiberoptic probes allowed spatial and temporal monitoring of temperatures during 24 minutes of AMF exposure. T2-weighted turbo spin-echo MR imaging was performed within 1 hour after the procedure to detect signal voids caused by IO-YAS deposition. Hematoxylin and eosin–stained pathologic slides were also obtained, and the presence of IO-YAS was evaluated with inductively coupled plasma optical emission spectroscopy.ResultsFollowing AMF exposure, intratumoral temperatures after IO-YAS MP injection achieved therapeutic hyperthermia whereas those after sham surgery did not (46.6°C ± 1.3 vs 36.8°C ± 0.4; P < .0001). Within the treated group, the normal hepatic parenchyma (NHP) and rectal temperatures were 37.4°C ± 0.9 and 36.5°C ± 1.0 (P = .0809) at the conclusion of AMF exposure, respectively. A T2-weighted signal void at the tumor site was observed in all seven treated animals, and intratumoral IO-YAS was visualized on subsequent histopathologic examination in each case. The mean ratio of tumor:NHP Fe concentrations attributable to IO-YAS MPs was 108:1.ConclusionsAMF exposure of intratumoral IO-YAS MPs generates localized therapeutic hyperthermia in an animal model of liver cancer. MR detectability and potential for combination brachytherapy warrants further investigation for thermoradiotherapy in liver cancer.     

Efficacy of Peripheral Interventional Radiologists Performing Endovascular Stroke Therapy Guided by CT Perfusion Triage of Patients

PurposeTo assess safety and efficacy of intraarterial mechanical thrombectomy for treatment of ischemic stroke in a community hospital by peripheral interventional radiologists employing computed tomography (CT) perfusion imaging for patient selection.Materials and MethodsForty patients, 11 men (27.5%) and 29 women (72.5%), were treated between February 2008 and October 2011. Eligible patients had a National Institutes of Health Stroke Scale (NIHSS) score greater than 8 and diagnosis of large-vessel ischemic stroke by head CT angiogram, and met previously reported CT perfusion imaging triage criteria.ResultsThe baseline NIHSS score was 18.0 ± 7.9 (range, 8–35). Sixteen patients (40%) had a baseline NIHSS score greater than 20. Symptom onset was unknown in five patients. Symptom onset to device time in the remaining 35 patients was 254.8 minutes ± 150.9 (range, 75–775 min). A total of 65% of patients showed thrombolysis in cerebral infarction (TICI) 2a, 2b, or 3 flow following the procedure. Symptomatic intracranial hemorrhage was seen in four patients (10.0%). At 90 days, 32 patients (80%) were alive and eight (20%) had died. The modified Rankin scale (mRS) score at 90 days was no more than 2 in 20 patients (50.0%). The mean mRS score at 90 days was 2.9 ± 2.0 (range, 0–6). NIHSS score at 90 days was 5.1 ± 6.1 (range, 0–24). In patients with successful recanalization (ie, TICI 2 or 3 flow), a good clinical outcome (ie, mRS score ≤ 2) was achieved in 65.3% of patients (mean, 2.4 ± 1.9; range, 0–6), and 90-day mortality rate was 15.4%, compared with 28.6% in patients with TICI 0/1 flow.ConclusionsPeripheral interventional radiologists who use CT perfusion imaging for patient triage can have good neurologic outcomes and provide sustainable, safe, and complete around-the-clock coverage for endovascular stroke treatment.     

Large Pulmonary Arteriovenous Malformations: Long-Term Results of Embolization with AMPLATZER Vascular Plugs

PurposeTo analyze the long-term results of endovascular treatment of large pulmonary arteriovenous malformations (PAVMs) using the AMPLATZER vascular plug (AVP; AGA Medical Corp, Golden Valley, Minnesota).Materials and MethodsBetween May 2007 and April 2011, 18 patients with 24 large PAVMs, defined as PAVMs that had a feeding artery with a diameter of ≥ 8 mm, were treated with AVP I or AVP II. A single AVP device was used for each PAVM. Aneurysmal sac diameters, sac perfusion, sac shrinkage, and complete resolution before and after the intervention were analyzed. Complete histories, laboratory values, physical examinations, and multidetector computed tomography images were reviewed. The mean occlusion time for AVP I and AVP II and the mean arterial oxygen saturation (SaO₂) before and after the intervention were compared.ResultsThe mean diameter of the feeding artery was 11.46 mm ± 2.18 (range, 8–13.3 mm). The mean occlusion time was 7.34 minutes ± 1.23 for AVP I and 6.25 minutes ± 1.12 for AVP II (P = .11). The mean SaO₂ before and after the intervention was 63.71% ± 8.10% (range, 51%–76%) and 96.28% ± 0.49% (range, 96%–97%), respectively (P = .045). No major periprocedural complications were observed. The mean follow-up duration was 36.33 months ± 10.63 (range, 28–56 mo). During the follow-up period, there were no persistent sac perfusions, migration of the AVPs, major complications, or recanalizations.ConclusionsTreatment of large PAVMs with AVPs is an effective method for obtaining excellent long-term results. Embolization of large feeding arteries can be accomplished with AVPs without major complications.