Endovascular Venous Thrombolysis in Children Younger than 24 Months

PurposeTo evaluate the technical feasibility and safety of percutaneous endovascular thrombolysis for extremity deep venous thrombosis (DVT) in children < 24 months old.Materials and MethodsA retrospective chart review of a clinical and imaging database was performed for pediatric patients who underwent endovascular therapy for DVT between January 2010 and July 2013. Indications, techniques, technical and clinical success, and complications were reviewed. Techniques for thrombolysis included catheter-directed therapy (CDT) using alteplase infusion via a multi–side hole catheter, mechanical thrombectomy, and angioplasty. Short-term outcomes were assessed using surgical and imaging follow-up examinations for patency of the targeted vessel. Patients included 11 children (mean age, 9 mo; range, 3 wk–23 mo) who consecutively underwent endovascular thrombolysis for upper extremity (n = 6) or lower extremity (n = 5) DVT. The most common indication was preservation of venous access for future cardiac surgery or medical therapy.ResultsThe most common risk factor was the presence of a central venous catheter (10 of 11 patients). All patients with upper extremity DVT had congenital heart disease. CDT and angioplasty were performed in all patients. Venous patency was established in all patients. A grade III (95%–100%) thrombolysis response was achieved in seven patients, and a grade II (50%–95%) thrombolysis response was achieved in four patients. A major complication of pulmonary embolism occurred in one patient with upper extremity thrombolysis and was managed by intravenous systemic alteplase and heparin. No recurrence of thrombosis was found on average follow-up of 11.8 months (range, 1–41 mo).ConclusionsPercutaneous endovascular thrombolysis for extremity DVT is safe and technically feasible in children < 24 months old.     

Relationship of Thrombus Length to Number of Stent Retrievals,Revascularization, and Outcomes in Acute Ischemic Stroke

PurposeTo study the relationship between intracranial thrombus length and number of stent retrievals, revascularization rates, and functional outcomes in stroke.Materials and MethodsRetrospective data were collected from consecutive cases of stroke treated with endovascular procedures at a single institution from April 2012–September 2013. Thrombus length was measured in the anterior cerebral circulation. Demographic and clinical details; involved vessels; and procedural details, including the number of devices used and number of retrievals used for each device, were recorded. Revascularization rates and 90-day functional outcomes were recorded.ResultsData regarding the length of thrombus in the anterior cerebral circulation were available for 28 patients. There was no significant association between thrombus length and number of stent retrievals (P = .3780), final thrombolysis in cerebral infarction (TICI) score (P = .4835), or 90-day modified Rankin Scale score (P = .4146). There was a significant difference (P = .0280) between number of retrievals and final TICI score, with lower number of retrieval passes corresponding to higher final TICI scores.ConclusionsThe data suggest no relationship between thrombus length and number of stent retrievals, final TICI score, or functional neurologic outcomes at 90 days in stent retrieval thrombectomy for acute ischemic stroke. These results do not support a predictive value for thrombus length quantification in the evaluation of stroke.     

Revascularization for Critical Limb Ischemia Using the SpiderFX Embolic Protection Device in the Below-the-Knee Circulation: Initial Results

PurposeTo examine the safety and efficacy of the SpiderFX embolic protection device (EPD) in the below-the-knee (BTK) circulation in patients with critical limb ischemia (CLI).Materials and MethodsA single-center retrospective review was performed to identify patients with CLI and single-vessel runoff in whom the SpiderFX EPD was used in the BTK circulation. Technical success and device-related complications were the primary endpoints. Retrieval of macroscopic debris in the EPD, 1-year freedom from major adverse limb events (MALEs), and 30-day perioperative death were also evaluated. A major amputation, surgical bypass, endovascular thrombectomy, or endovascular thrombolysis was considered a MALE. Thirty-six patients (21 men; mean age, 75.8 y) treated between 2008 and 2013 had endovascular revascularization with use of the SpiderFX EPD in the BTK circulation.ResultsThe SpiderFX EPD was successfully deployed in all cases; the technical success rate of revascularization was 100%. Two minor and zero major complications were observed related to the SpiderFX. Two MALEs, a major amputation and a subsequent surgical bypass, were observed in the cohort. All MALEs occurred within 1 year of treatment (1-y freedom from MALE rate, 90%). Debris was retrieved in the SpiderFX device in 47% of patients.ConclusionsThe use of the SpiderFX EPD in the BTK circulation in patients with CLI is safe and frequently retrieves debris.     

Ultrasound-Accelerated versus Standard Catheter-Directed Thrombolysis in 102 Patients with Acute and Subacute Limb Ischemia

PurposeTo compare the safety and efficacy of ultrasound-accelerated thrombolysis (UAT) and standard catheter-directed thrombolysis (CDT) in patients with acute and subacute limb ischemia.Materials and MethodsMedical records of all patients treated with thrombolysis for acute and subacute limb ischemia between August 2005 and January 2012 were reviewed. Coprimary (increase in ankle-brachial index, degree of lysis) and secondary endpoints (technical success, distal embolization, bleeding complications, need for additional interventions) were assessed. UAT was performed in 75 patients, and CDT was performed in 27 patients. Patients’ baseline demographic and clinical parameters and procedure details, including lytic drug infusion rate (P = .704 and P = .987), total infusion time (P = .787 and P = .377), and use of adjunctive procedures (P = .457), did not differ significantly between the two groups.ResultsComplete lysis was achieved in 72.0% (UAT) and 63.0% (CDT) of patients (P = .542); hemodynamic success was achieved in 91.8% (UAT) and 92.3% (CDT) (P = .956). Overall major and minor bleeding complications were observed in 6.9% (UAT) and 3.9% (CDT) of patients. Major (P = .075) and minor (P = .276) bleeding independently did not differ between UAT and CDT. Major and minor bleeding combined was lower: 6.7% (UAT) versus 22.2% (CDT) (P = .025). Overall target vessel patency after 8.0 months (range, 1.5–20.5 mo) was 73.5%; target vessel patency for UAT was 75.9% versus 64.3% for CDT (P = .379). Median long-term survival was not significantly different between UAT and CDT: 3.6 years (range, 2.42–5.33 y) versus 1.8 years (range, 1.33–4.92 y) (P = .061).ConclusionsBoth UAT and CDT are safe and efficient treatment modalities for patients with acute and subacute limb ischemia. The observed lower risk of total bleeding for UAT versus CDT may warrant prospective comparative trials.     

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.     

Portal Vein Thrombosis after Partial Splenic Embolization in Liver Cirrhosis: Efficacy of Anticoagulation and Long-term Follow-up

PurposeTo investigate the treatment and long-term outcome of portal vein thrombosis (PVT) after partial splenic embolization (PSE).Materials and MethodsFrom January 2006 to December 2011, 145 patients with hypersplenism caused by cirrhotic portal hypertension underwent PSE. In 11 cases, PVT was detected 13–42 days after PSE. Among the 11 patients, 5 underwent anticoagulant therapy because of clinical symptoms, and 6 did not receive anticoagulation because they were symptom-free (4 patients) or experienced variceal bleeding (2 patients). The long-term follow-up data from these 11 patients were analyzed retrospectively.ResultsThe 11 patients with PVT had a mean splenic infarction ratio of 71.5%. The mean duration of follow-up was 37.6 months. During the follow-up period, none of the 5 patients who underwent anticoagulation developed variceal hemorrhage despite presenting with large esophagogastric varices. Four of the five patients achieved complete resolution of thrombosis, and one did not develop thrombus progression. However, among the 6 patients who did not undergo anticoagulation, 2 developed esophagogastric variceal hemorrhage secondary to thrombus progression, 3 developed cavernous transformation of the portal vein and variceal progression, and 1 had partial calcification of the thrombus. Two patients who had variceal bleeding or rebleeding underwent a transjugular intrahepatic portosystemic shunt. Complete recanalization of the portal vein was achieved after the procedures.ConclusionsPVT is a severe, potentially fatal complication of PSE. Early detection of PVT and prompt anticoagulation are effective to avoid serious consequences of PVT.     

Impact on Pulmonary Arterial Pressures after Repeated Endovascular Thrombectomy of Dialysis Grafts: A Prospective Follow-up Study

PurposeVascular access thrombosis is a common complication of arteriovenous dialysis grafts that results in silent pulmonary embolism (PE) in a substantial proportion of patients. However, the impact of repeated PE on the pulmonary vasculature remains unclear.Materials and MethodsFrom January 2010 to April 2012, 110 patients undergoing maintenance hemodialysis via arteriovenous grafts were recruited. Hemodynamic assessments, including transthoracic echocardiography and right heart catheterization, were performed at baseline and after 1 year to evaluate the changes in pulmonary artery (PA) pressures and heart function.ResultsFifty-two patients completed the follow-up hemodynamic assessment at a median duration of 535 days and had at least one endovascular thrombectomy procedure (median of seven). There was no significant difference in mean PA pressures between baseline and the end of follow-up (23.1 mm Hg ± 6.8 vs 21.6 mm Hg ± 6.1; P = .16). The change in mean PA pressure did not correlate with the number of thrombectomy procedures in the overall cohort (r = −0.02, P = .89) or in the subgroup with cardiopulmonary disease (r = −0.30, P = .14). The changes of mean PA pressure were not associated with number of thrombectomy procedures (β = −0.03, P = .89).ConclusionsRepeated endovascular thrombectomy procedures are not related to changes in PA pressure in the short term. The present results support the safety of endovascular thrombectomy in the pulmonary vasculature.     

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.     

Endovascular Procedures versus Intravenous Thrombolysis in Stroke with Tandem Occlusion of the Anterior Circulation

PurposeStroke with tandem occlusion within the anterior circulation presents a lower probability of recanalization and good clinical outcome after intravenous (IV) thrombolysis than stroke with single occlusion. The present study describes the impact of endovascular procedures (EPs) compared with IV thrombolysis alone on recanalization and clinical outcome.Materials and MethodsThirty patients with symptom onset less than 4.5 hours and tandem occlusion within the anterior circulation were analyzed retrospectively. Recanalization was assessed per Thrombolysis In Cerebral Infarction (TICI) classification on computed tomography, magnetic resonance imaging, or digital subtraction angiography within 24 hours. Infarct size was detected on follow-up imaging as a dichotomized variable, ie, more than one third of the territory of the middle cerebral artery. Clinical outcomes were major neurologic improvement, independent outcome (90-d modified Rankin Scale [mRS] score), symptomatic intracerebral hemorrhage (sICH; per European Cooperative Acute Stroke Study criteria), and death within 7 days.ResultsPatients treated with EPs (n = 14) were significantly younger and had a history of arterial hypertension more frequently than patients treated with IV thrombolysis alone (n = 16). Recanalization (ie, TICI score 2b/3; EP, 64%; IV, 19%; P = .01), major neurologic improvement (EP, 64%; IV, 19%; P = .01), and independent outcome (mRS score ≤ 2; EP, 54% IV, 13%; P = .02) occurred more often in the EP group, whereas infarct sizes greater than one third of the MCA territory (EP, 43%; IV, 81%; P = .03) were observed less often. Rates of sICH (P = .12) and death within 7 days (P = .74) did not differ significantly.ConclusionsHigher recanalization rate, smaller infarct volume, and better clinical outcome in the EP group should encourage researchers to include this subgroup of patients in prospective randomized trials comparing IV thrombolysis versus EP in stroke.     

The DENALI Trial: An Interim Analysis of a Prospective,Multicenter Study of the Denali Retrievable Inferior Vena Cava Filter

PurposeTo assess safety and effectiveness of a nitinol retrievable inferior vena cava (IVC) filter in patients who require caval interruption to protect against pulmonary embolism (PE).Materials and MethodsTwo hundred patients with temporary indications for an IVC filter were enrolled in this prospective, multicenter clinical study. Patients undergoing filter implantation were to be followed for 2 years or for 30 days after filter retrieval. At the time of the present interim report, all 200 patients had been enrolled in the study, and 160 had undergone a retrieval attempt or been followed to 6 months with their filter in place. Primary study endpoints included technical and clinical success of filter placement and retrieval. Patients were also evaluated for recurrent PE, new or worsening deep vein thrombosis, and filter migration, fracture, penetration, and tilt.ResultsClinical success of placement was achieved in 94.5% of patients (172 of 182), with a one-sided lower limit of the 95% confidence interval of 90.1%. Technical success rate of filter placement was 99.5%. Technical success rate of retrieval was 97.3%; 108 filters were retrieved in 111 attempts. In two cases, the filter apex could not be engaged with a snare, and one device was engaged but could not be removed. Filter retrievals occurred at a mean indwell time of 165 days (range, 5–632 d). There were no instances of filter fracture, migration, or tilt greater than 15° at the time of retrieval or 6-month follow-up.ConclusionsIn this interim report, the nitinol retrievable IVC filter provided protection against pulmonary embolism, and the device could be retrieved with a low rate of complications.     

Peripherally Inserted Central Catheter Thrombosis—Reverse Tapered versus Nontapered Catheters: A Randomized Controlled Study

PurposeTo compare the thrombosis rate, ease of insertion, bleeding rate, and complications of a nontapered peripherally inserted central catheter (PICC) versus a reverse tapered PICC.MethodsThis was a prospective randomized, controlled trial conducted in single center. All patients 18–90 years old requiring PICC insertion were considered for the study. All patients were followed until PICC removal. Ultrasound examination of the arm was performed at PICC removal or at 28 days. There were 332 patients randomly assigned—164 to the nontapered PICC group and 168 to the reverse tapered PICC group.ResultsThe overall thrombosis rate was 71.9%. The thrombosis rate was 70.4% in the nontapered PICC group and 73.4% in the reverse tapered PICC group (P = .58). The symptomatic thrombosis rate was 4.3% in the nontapered PICC group and 3.6% in the reverse tapered PICC group (P = .75). The complete thrombosis rate was 15.6% in the nontapered PICC group compared with 20.8% in the reverse tapered PICC group (P = .44). There was a statistically significantly higher thrombosis rate in patients with cancer (71.9% vs 66.7%, P = .002).ConclusionsThis study showed a high incidence of thrombosis of peripheral veins used for PICC insertion. The implication of this thrombosis is significant in light of the morbidity and potential mortality associated with this condition. A difference in thrombosis rate between devices could not be detected in this study.     

Predictive Value of Pattern Classification 24 Hours after Radiofrequency Ablation of Liver Metastases on CT and Positron Emission Tomography/CT

PurposeTo assess a classification scheme for predicting local tumor progression (LTP) after radiofrequency (RF) ablation of liver metastases, using predefined patterns on contrast-enhanced computed tomography (CT) and positron emission tomography (PET) combined with CT (PET/CT) acquired 24 hours after RF ablation.Materials and MethodsThere were 45 metastases in 20 patients treated. After 24 hours, imaging of the ablation zones was performed with contrast-enhanced PET/CT. Three independent radiologists prospectively assessed contrast-enhanced CT and combined PET/CT images to identify three patterns: pattern I, no tissue enhancement or fluorodeoxyglucose uptake between the ablation zone and the liver parenchyma; pattern II, a rimlike pattern; and pattern III, a peripheral nodule. PET/CT images obtained after 8–10 weeks were evaluated for LTP. The patterns were analyzed for their sensitivity, specificity, positive predictive value, and negative predictive value for predicting LTP.ResultsPattern I was most frequently observed (81% for contrast-enhanced CT and 61% for PET/CT) as well as for ablation zones that showed LTP (52% and 37%, respectively). Conversely, pattern II was observed for tumors that were completely ablated (6% and 29%, respectively). Patterns II and III together had the highest sensitivity for predicting LTP (48% and 63%, respectively); pattern III had the highest specificity (94% and 95%, respectively). For nodular patterns, test characteristics were better for PET/CT compared with contrast-enhanced CT, but the difference was not significant. Nodular patterns > 1 cm achieved high positive predictive value (both 100%).ConclusionsInflammation and hyperemia can hinder interpretation on imaging 24 hours after RF ablation, especially on PET/CT. Nodular patterns around the ablation zone on early contrast-enhanced CT and PET/CT have a high predictive value for LTP and should be taken into account for disease management.     

Comparison of Intravascular Ultrasound with Conventional Venography for Detection of Extracranial Venous Abnormalities Indicative of Chronic Cerebrospinal Venous Insufficiency

PurposeTo investigate prevalence of extracranial abnormalities in azygos and internal jugular (IJ) veins using conventional venography and intravascular ultrasound (IVUS) in patients with multiple sclerosis (MS) being evaluated for chronic cerebrospinal venous insufficiency, a condition of vascular hemodynamic dysfunction.Materials and MethodsPREMiSe (Prospective Randomized Endovascular therapy in Multiple Sclerosis) is a venous angioplasty study that enrolled 30 patients with relapsing MS. The patients fulfilled two or more venous hemodynamic extracranial Doppler sonography screening criteria. Phase I of the study included 10 patients and was planned to assess safety and standardize venography, IVUS, and angioplasty and blinding procedures; phase II enrolled 20 patients and further validated diagnostic assessments using the two invasive techniques. Venography was considered abnormal when ≥ 50% lumen-diameter restriction was detected. IVUS was considered abnormal when ≥ 50% lumen-diameter restriction, intraluminal defects, or reduced pulsatility was detected.ResultsNo venography-related or IVUS-related complications, including vessel rupture, thrombosis, or side effects of contrast media were recorded among the 30 study patients. IVUS-detected venous abnormalities, including chronic, organized, thrombus-like inclusions were observed in 85% of azygos, 50% of right IJ, and 83.3% of left IJ veins, whereas venography demonstrated stenosis of ≥ 50% in 50% of azygos, 55% of right IJ, and 72% of left IJ veins. Sensitivity of venography for detecting IVUS abnormalities was 52.9%, 73.3%, and 80% for the azygos, left IJ, and right IJ veins, respectively.ConclusionsIVUS assessment of azygos and IJ veins showed a higher rate of venous abnormalities than venography. IVUS provides a diagnostic advantage over conventional venography in detecting extracranial venous abnormalities indicative of chronic cerebrospinal venous insufficiency.     

Imaging Follow-up of Endovascular Repair of Type B Aortic Dissection with Dual-Source,Dual-Energy CT and Late Delayed-Phase Scans

PurposeTo evaluate the diagnostic performance of dual-energy (DE) computed tomography (CT) after thoracic endovascular aortic repair (TEVAR) of type B dissection, and to investigate the value of late delayed (LD) acquisition in endoleak detection and false lumen patency assessment.Materials and MethodsTwenty-four patients with TEVAR for type B dissection underwent 53 tripe-phase CT examinations. Single-source unenhanced acquisition was followed by single-source arterial-phase and DE LD phase (300-s delay) imaging. Virtual noncontrast images were generated from DE acquisition. Two blinded radiologists retrospectively evaluated the cases in three reading sessions: session A (triphasic protocol), session B (virtual noncontrast and arterial phase), and session C (virtual noncontrast and arterial and LD phases). Endoleak detection accuracy during sessions B and C compared with session A (reference standard) was investigated. False lumen patency was assessed. Effective radiation dose was calculated.ResultsSession A revealed 37 endoleaks in 30 of 53 studies (56.6%). Session B revealed 31 of the 37 endoleaks, with one false-positive case, 83.8% sensitivity, 95.8% specificity, 79.3% negative predictive value, and 96.9% positive predictive value. Session C correctly depicted all 37 endoleaks, with one false-positive case, 100% sensitivity, 95.8% specificity, 100% negative predictive value, and 97.4% positive predictive value. Underestimation of false lumen patency was found in session B (P = .013). Virtual noncontrast imaging resulted in 17% radiation exposure reduction.ConclusionsVirtual noncontrast imaging can replace standard unenhanced images in follow-up after TEVAR of type B dissection, thus reducing radiation dose. Delayed-phase imaging is valuable in low-flow endoleaks detection and false lumen patency assessment.     

Outcomes of Endovascular Management for Complicated Chronic Type B Aortic Dissection: Effect of the Extent of Stent Graft Coverage and Anatomic Properties of Aortic Dissection

PurposeTo assess the effect of the extent of stent graft coverage and anatomic properties of aortic dissection on the outcomes of thoracic endovascular aortic repair (TEVAR) for complicated chronic type B aortic dissection (CCBAD) in terms of survival, reintervention, and false lumen thrombosis.Materials and MethodsA retrospective analysis was performed of 71 patients who underwent TEVAR for CCBAD. Mean patient age was 54.7 years. Distal extent of stent graft coverage was categorized as short (≤ T7) or long (≥ T8) coverage. Indications of reintervention were categorized into three groups: proximal, alongside, and distal according to the anatomic relationship of the culprit lesion and the stent graft. Overall survival, reintervention-free survival, and extent of false lumen thrombosis were compared.ResultsThe technical success rate was 97.2%. The 1-year, 3-year, and 5-year overall survival rates were 97.1%, 88.9%, and 88.9%, and 1-year, 3-year, and 5-year reintervention-free survival rates were 80.7%, 73.8%, and 60.6%. There were no differences in overall survival, reintervention-free survival rates, and extent of false lumen thrombosis between the groups. In the short coverage group, distal reintervention was more frequent in patients with an abdominal aortic diameter ≥ 37 mm compared with patients with an abdominal aortic diameter < 37 mm (P = .005).ConclusionsTEVAR was effective for CCBAD with a high technical success rate and low mortality. The extent of stent graft coverage did not make a difference in terms of survival and false lumen thrombosis. Reinterventions were more frequently performed in patients with a large baseline abdominal aortic diameter who were treated with short stent graft coverage, and so longer coverage is recommended in such patients.     

Evaluating Patency Rates of an Ultralow-Porosity Expanded Polytetrafluoroethylene Covered Stent in the Treatment of Venous Stenosis in Arteriovenous Dialysis Circuits

PurposeTo evaluate the efficacy of an ultralow-porosity expanded polytetrafluoroethylene (ePTFE) covered stent in the treatment of autogenous arteriovenous fistula (AVF) and prosthetic arteriovenous graft (AVG) venous outflow stenoses.Materials and MethodsClinical and angiographic outcomes of 20 consecutive patients with arteriovenous dialysis circuits treated with the endoprosthesis were reviewed following institutional review board approval. Patients were followed routinely at 2 months and 6 months after stent placement, or earlier if clinically warranted. The primary endpoint was 2- and 6-month primary treatment area patency. Secondary endpoints included primary circuit patency, primary assisted patency, and secondary patency.ResultsEleven patients with AVFs and nine patients with AVGs were treated successfully with the covered stent. Primary treatment area patency rates were 85% ± 16 at both 2 months and 6 months. Primary circuit patency rates were was 65% ± 21 and 45% ± 22, respectively; primary assisted patency rates were 90% ± 13 and 85% ± 16, respectively; and secondary patency rates were 100% and 90% ± 13, respectively. Of the three cases of lost primary treatment area patency, two developed thrombosis and one developed recurrent stenosis. No significant differences were found between patients with AVFs and AVGs.ConclusionsData from this preliminary study suggests that the ultralow-porosity ePTFE covered stent may be a clinically viable option for treatment of venous outflow stenoses in arteriovenous vascular access circuits.     

Comparison of Complication Rates Associated with Permanent and Retrievable Inferior Vena Cava Filters: A Review of the MAUDE Database

PurposeTo compare the safety of permanent and retrievable inferior vena cava (IVC) filters by reviewing the U.S. Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database.Materials and MethodsThe MAUDE database was reviewed from January 1, 2009, to December 31, 2012. Product class search criteria were “filter, intravascular, cardiovascular.” Type of device used and specific adverse events (AEs) were recorded.ResultsFor the period January 2009–December 2012, 1,606 reported AEs involving 1,057 IVC filters were identified in the MAUDE database . Of reported AEs, 1,394 (86.8%) involved retrievable inferior vena cava filters (rIVCFs), and 212 (13.2%) involved permanent inferior vena cava filters (pIVCFs) (P < .0001). Reported AEs included fracture, migration, limb embolization, tilt, IVC penetration, venous thromboembolism and pulmonary embolism, IVC thrombus, and malfunctions during placement. Each specific AE was reported with significantly higher frequency in rIVCFs compared with pIVCFs. The most common reported complication with rIVCFs was fracture, whereas the most commonly reported complications with pIVCFs were placement malfunctions. For rIVCFs, the most commonly reported AE varied depending on filter brand.ConclusionsThe MAUDE database reveals that complications occur with significantly higher frequency with rIVCFs compared with pIVCFs. This finding suggests that the self-reported complication rate with rIVCFs is significantly higher than the self-reported complication rate with pIVCFs.     

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.     

Irreversible Electroporation of the Pig Kidney with Involvement of the Renal Pelvis: Technical Aspects,Clinical Outcome,and Three-dimensional CT Rendering for Assessment of the Treatment Zone

PurposeTo analyze irreversible electroporation (IRE) of the pig kidney with involvement of the renal pelvis.Materials and MethodsIRE of renal tissue including the pelvis was performed in 10 kidneys in five pigs. Three study groups were defined: group I (two applicators with parallel configuration; n = 11), group II (three applicators with triangular configuration; n = 2), and group III (six applicators with complex configuration; n = 3). After IRE and before euthanasia, pigs underwent contrast-enhanced computed tomography (CT). Technical aspects (radial distance of applicators, resulting mean current), clinical outcome (complications, blood samples), and three-dimensional CT rendering for assessment of the treatment zone (short axis, circularity) were assessed.ResultsRadial distances of applicators were 14.3 mm ± 2.8 in group I, 12.3 mm ± 1.9 in group II, and 16.4 mm ± 3.5 in group III. Resulting mean currents were 25.7 A ± 6.5 in group I, 27.0 A ± 7.1 in group II, and 39.4 A ± 8.9 in group III. In group III, two perirenal hematomas were identified. There was no damage to the renal pelvis. During IRE, clinical blood parameters and cardiovascular markers did not change significantly. Short axis measurements were 20.6 mm ± 3.6 in group I, 31.9 mm ± 8.2 in group II, and 39.3 mm ± 2.4 in group III (P < .01 between groups). Circularity scores were 0.8 ± 0.2 in group I, 0.7 ± 0.1 in group II, and 0.7 ± 0.1 in group III, with a score of 1 indicating perfect roundness (P value not significant).ConclusionsIRE of the pig kidney with involvement of the renal pelvis is feasible and safe. Size but not shape of the treatment zone is significantly affected by applicator configuration.     

Morphologic Outcome after Endovascular Treatment of Complicated Type B Aortic Dissection

PurposeTo investigate the long-term morphologic changes of the aorta after thoracic endovascular aortic repair (TEVAR) for acute complicated type B aortic dissection and to analyze whether these changes differed between DeBakey class IIIa and IIIb dissections.Materials and MethodsDuring the period 1999–2009, 58 patients with acute complicated type B aortic dissection were treated with TEVAR. Seven patients lacked follow-up data, leaving 51 patients—17 patients with DeBakey IIIa aortic dissection and 34 patients with DeBakey IIIa aortic dissection IIIb—for inclusion in the study. Computed tomography scans performed before and after TEVAR were evaluated. Maximum thoracic and abdominal aortic diameters and diameters of the true lumen and false lumen at the level of the maximum aortic diameter in the thorax and abdomen were analyzed as well as degree of thrombosis of the false lumen.ResultsThere was an overall significant reduction of the thoracic aortic diameter, increased true lumen diameter, and reduced false lumen diameter (P < .05). Total thrombosis of the false lumen, with or without reintervention, was seen in 53% of all patients, in 41% primarily and in 12% after reintervention. The IIIa group had a higher degree of total false lumen thrombosis. All patients in the IIIb group had total thrombosis of the false lumen along the stent graft.ConclusionsLong-term follow-up showed favorable aortic remodeling after TEVAR for acute complicated type B aortic dissection. Total thrombosis of the false lumen occurred more often in patients with DeBakey IIIa aortic dissection compared with patients with DeBakey IIIb aortic dissection.