Showing papers in "CardioVascular and Interventional Radiology in 2006"

The road to bioabsorbable stents: reaching clinical reality?

Abstract: This article provides an overview of the evolution of revascularization devices since Gruntzig’s initial introduction of balloon angioplasty in 1977. In-stent restenosis (ISR) is the major shortcoming of conventional (permanent-implant) stent therapy; even with the innovation and promising benefits of drug-eluting stents, management of ISR is very difficult. ISR is mainly caused by the interaction between the blood and the stent surface and a permanent mechanical irritation of the vascular tissue. Thus stenting technology has moved toward the development of temporary implants composed of biocompatible materials which mechanically support the vessel during the period of high risk for recoil and then completely biodegrade in the long term. Preclinical and first clinical experiences with bioabsorbable magnesium stents are discussed.

Treatment of Unresectable Primary and Metastatic Liver Cancer with Yttrium-90 Microspheres (TheraSphere®): Assessment of Hepatic Arterial Embolization

Abstract: In Canada and Europe, yttrium-90 microspheres (TheraSphere®; MDS Nordion, Ottawa, Canada) are a primary treatment option for primary and secondary hepatic malignancies. We present data from 30 patients with hepatocellular carcinoma (HCC) and metastatic liver disease treated with TheraSphere from a single academic institution to evaluate the angiographically evident embolization that follows treatment. Seven interventional radiologists from one treatment center compared pretreatment and posttreatment angiograms. The reviewers were blinded to the timing of the studies. The incidence of postembolization syndrome (PES) was determined as well as objective tumor response rates by the World Health Organization (WHO), Response Evaluation Criteria in Solid Tumors (RECIST), and European Association for the Study of the Liver (EASL) criteria. There were 420 independent angiographic observations that were assessed using the chi-squared statistic. The pretreatment and posttreatment angiograms could not be correctly identified on average more than 43% of the time (p = 0.0004). The postprocedure arterial patency rate was 100%. The objective tumor response rates for all patients were 24%, 31%, and 72% for WHO, RECIST, and EASL criteria, respectively. All of the patients tolerated the procedure without complications and were treated on an outpatient basis, and four patients had evidence of PES. This treatment method does not result in macroscopic embolization of the hepatic arteries, thereby maintaining hepatic tissue perfusion. These data support the principle that the favorable response rates reported with TheraSphere are likely due to radiation and microscopic embolization rather than flow-related macroscopic embolization and ischemia.

Balloon-assisted occlusion of the internal iliac arteries in patients with placenta accreta/percreta.

Abstract: Background Placenta accreta/percreta is a leading cause of third trimester hemorrhage and postpartum maternal death. The current treatment for third trimester hemorrhage due to placenta accreta/percreta is cesarean hysterectomy, which may be complicated by large volume blood loss.

Percutaneous vertebroplasty for osteoporotic compression fracture: multivariate study of predictors of new vertebral body fracture.

Abstract: To investigate the risk factors and relative risk of new compression fractures following vertebroplasty Initially, we enrolled 104 consecutive patients with vertebral compression fractures caused by osteoporosis A total of 83 of the 104 patients visited our hospital for follow-up examinations for more than 4 weeks after vertebroplasty Logistic regression analysis of the data obtained from these 83 patients was used to determine relative risks of recurrent compression fractures, using 13 different factors We identified 59 new fractures in 30 of the 83 patients: 41 new fractures in vertebrae adjacent to treated vertebrae; and 18 new fractures in vertebrae not adjacent to treated vertebrae New fractures occurred in vertebrae adjacent to treated vertebrae significantly more frequently than in vertebrae not adjacent to treated vertebrae Only cement leakage into the disk was a significant predictor of new vertebral body fracture after vertebroplasty (odds ratio = 4633) None of the following covariates were associated with increased risk of new fracture: age, gender, bone mineral density, the number of vertebroplasty procedures, the number of vertebrae treated per procedure, the cumulative number of vertebrae treated, the presence of a single untreated vertebra between treated vertebrae, the presence of multiple untreated vertebrae between treated vertebrae, the amount of bone cement injected per procedure, the cumulative amount of bone cement injected, cement leakage into the soft tissue around the vertebra, and cement leakage into the vein

Covered Stent-Graft Treatment of Traumatic Internal Carotid Artery Pseudoaneurysms: A Review

Abstract: To review the literature concerning the management with placement of covered stent-grafts of traumatic pseudoaneurysms of the extracranial internal carotid artery (ICA) resulting from penetrating craniocervical injuries or skull base fractures. We have reviewed, from the Medline database, all the published cases in the English literature since 1990 and we have added a new case. We identified 20 patients with traumatic extracranial ICA pseudoaneurysms due to penetrating craniocervical injuries or skull base fractures who had been treated with covered stent-graft implantation. Many discrepancies have been ascertained regarding the anticoagulation therapy. In 3 patients the ICA was totally occluded in the follow-up period, giving an overall occlusion rate 15%. No serious complication was reported as a result of the endovascular procedure. Preliminary results suggest that placement of stent-grafts is a safe and effective method of treating ICA traumatic pseudoaneurysms resulting from penetrating craniocervical injuries or skull base fractures. The immediate results are satisfactory when the procedure takes place with appropriate anticoagulation therapy. The periprocedural morbidity and mortality and the early patency are also acceptable. A surveillance program with appropriate interventions to manage restenosis may improve the long-term patency.

Cone-beam CT with flat-panel-detector digital angiography system: early experience in abdominal interventional procedures.

Abstract: We developed a cone-beam computed tomography (CBCT) system equipped with a large flat-panel detector. Data obtained by 200° rotation imaging are reconstructed by means of CBCT to generate three-dimensional images. We report the use of CBCT angiography using CBCT in 10 patients with 8 liver malignancies and 2 hypersplenisms during abdominal interventional procedures. CBCT was very useful for interventional radiologists to confirm a perfusion area of the artery catheter wedged on CT by injection of contrast media through the catheter tip, although the image quality was slightly degraded, scoring as 2.60 on average by streak artifacts. CBCT is space-saving because it does not require a CT system with a gantry, and it is also time-saving because it does not require the transfer of patients.

Extrahepatic blood supply to hepatocellular carcinoma: angiographic demonstration and transcatheter arterial chemoembolization.

Abstract: Purpose To evaluate the incidence of each extrahepatic collateral pathway to hepatocellular carcinoma (HCC) and to assess technical success rates and complications of transcatheter arterial chemoembolization (TACE) through each collateral

PTA Versus Carbofilm-Coated Stents in Infrapopliteal Arteries: Pilot Study

Abstract: To determine the primary success and short-term patency of stent application as a primary treatment modality for high-grade lesions of the infrapopliteal arteries compared with treatment with percutaneous transluminal angioplasty (PTA) in critical limb ischemia in a randomized prospective study Endovascular therapy was performed on 95 lesions in 51 patients (mean age 720 years, range 47–80 years) who presented clinically with Fontaine stages III and IV One patient underwent treatment in both limbs After angiographic lesion identification, patients were randomized for treatment by PTA (53 lesions in 27 patients) or stent application (42 lesions in 24 patients) Follow-up by clinical investigation and conventional angiography or spiral CT angiography was performed in 37 patients (57 lesions) 6 to 12 months after the procedure, or when clinically indicated Evaluation was performed by two observers, double-blinded, with thresholds for lesion restenosis of 50% and 70% Statistical evaluation was performed on a lesion basis by Kaplan–Meier estimated probability rates, and log-rank and Wilcoxon tests The primary endpoint was the angiographic patency rate of treated lesions The inter-reader agreement was high (κ = 082) For the stent group the cumulative primary patency at 6 months was 837% at the 70% restenosis threshold, and 797% at the 50% restenosis threshold For PTA, the primary patency at 6 months was 611% at the 70% restenosis threshold and 456% at the 50% restenosis threshold Both results were statistically significant (p < 005) Infrapopliteal stent application is an effective treatment modality for high-grade lesions in chronic critical limb ischemia Compared with PTA, higher patency rates can be expected after 6 months

Quality Assurance Guidelines for Percutaneous Vertebroplasty

Abstract: Vertebral compression fracture is the reduction in individual vertebral body height by 20% or 4 mm [7]. PVP is a therapeutic, image-guided procedure that involves injection of radio-opaque cement into a partially collapsed vertebral body, in an effort to relieve pain and provide stability.

Usefulness of Transjugular Intrahepatic Portosystemic Shunt in the Management of Bleeding Ectopic Varices in Cirrhotic Patients

Abstract: Purpose To evaluate the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) in the control of bleeding from ectopic varices.

Quality assurance guidelines for superior vena cava stenting in malignant disease.

Abstract: Superior vena cava stenting for the treatment of malignant superior vena cava obstruction is now well established It offers simple, rapid, and safe palliation of a distressing and potentially fatal complication of mediastinal malignant disease and compares very favorably with standard therapies such as chemotherapy and radiotherapy The following are quality assurance guidelines for superior vena cava stenting

Outcomes of Endovascular Abdominal Aortic Aneurysm Repair in Patients with Hostile Neck Anatomy

Abstract: The principal anatomic contraindication to endovascular aneurysm repair (EVR) is an unfavorable proximal aortic neck. With increasing experience, a greater proportion of patients with unfavorable neck anatomy are being offered EVR. This study aimed to evaluate outcomes in patients with challenging proximal aortic neck anatomy. Prospectively collected data from 147 consecutive patients who underwent EVR between December 1997 and April 2005 were supplemented with a retrospective review of medical records and radiological images. Unfavorable anatomic features were defined as neck diameter >28 mm, angulation >60°, circumferential thrombus >50%, and length 30 days) (p = 0.57), distal type I endoleak (p = 0.40), type III endoleak (p = 0.51), secondary interventions (p = 1.0), aneurysm sac expansion (p = 0.44), or 30 day mortality (p = 0.70). The good neck group had a significantly increased incidence of type II endoleak (p = 0.023). By multivariate analysis, the incidence of intraoperative adjunctive procedures was significantly increased in the presence of severe angulation (p = 0.041, OR 3.08, 95% CI 1.05–9.04). Patients with severely hostile proximal aortic neck anatomy may be treated with EVR, although severely angulated necks require additional intraoperative procedures. Early outcomes are encouraging and suggest that indications for EVR may be expanded to include patients with hostile neck anatomy.

Computational fluid dynamics: hemodynamic changes in abdominal aortic aneurysm after stent-graft implantation.

Abstract: The aim of this study was to demonstrate quantitatively and qualitatively the hemodynamic changes in abdominal aortic aneurysms (AAA) after stent-graft placement based on multidetector CT angiography (MDCT-A) datasets using the possibilities of computational fluid dynamics (CFD). Eleven patients with AAA and one patient with left-side common iliac aneurysm undergoing MDCT-A before and after stent-graft implantation were included. Based on the CT datasets, three-dimensional grid-based models of AAA were built. The minimal size of tetrahedrons was determined for grid-independence simulation. The CFD program was validated by comparing the calculated flow with an experimentally generated flow in an identical, anatomically correct silicon model of an AAA. Based on the results, pulsatile flow was simulated. A laminar, incompressible flow-based inlet condition, zero traction-force outlet boundary, and a no-slip wall boundary condition was applied. The measured flow volume and visualized flow pattern, wall pressure, and wall shear stress before and after stent-graft implantation were compared. The experimentally and numerically generated streamlines are highly congruent. After stenting, the simulation shows a reduction of wall pressure and wall shear stress and a more equal flow through both external iliac arteries after stenting. The postimplantation flow pattern is characterized by a reduction of turbulences. New areas of high pressure and shear stress appear at the stent bifurcation and docking area. CFD is a versatile and noninvasive tool to demonstrate changes of flow rate and flow pattern caused by stent-graft implantation. The desired effect and possible complications of a stent-graft implantation can be visualized. CFD is a highly promising technique and improves our understanding of the local structural and fluid dynamic conditions for abdominal aortic stent placement.

Dual Antiplatelet Regime Versus Acetyl-acetic Acid for Carotid Artery Stenting

Abstract: Carotid artery stenting has been proposed as an option treatment of carotid artery stenosis. The aim of this single-institution study is to compare the dual-antiplatelet treatment and heparin combined with acetyl-acetic acid, in patients who underwent carotid artery stenting. We compared 2 groups of 50 patents each who underwent carotid artery stenting for primary atherosclerotic disease. Group A received heparin for 24 h combined with 325 mg acetyl-acetic acid and group B received 250 mg ticlopidine twice a day combined with 325 mg acetyl-acetic acid. Outcome measurements included 30-day bleeding and neurological complications and 30-day thrombosis/occlusion rates. The neurological complications were 16% in group A and 2% in group B (p 0.05). The 30-day thrombosis/occlusion rate was 2% in group A and 0% in group B (p > 0.05). Dual antiplatelet treatment is recommended in all patients undergoing carotid artery stenting.

Radiofrequency ablation combined with renal arterial embolization for the treatment of unresectable renal cell carcinoma larger than 3.5 cm: initial experience.

Abstract: The purpose of the study was to evaluate the feasibility, safety, and therapeutic effects of the combination of renal arterial embolization and radiofrequency (RF) ablation to reinforce the anticancer effect on renal cell carcinomas (RCCs) measuring 3.5 cm or larger. This study was undertaken to evaluate this combined therapy on large RCCs-based tumor geometry. Eleven patients with 12 RCCs 3.5 cm or larger in diameter (3.5–9.0 cm) underwent combined therapy. Two were exophytic tumors, and the remaining 10 tumors had components extending into the renal sinus fat. Tumor vessels were selectively embolized in nine patients and the renal artery was completely embolized in two patients with polyvinyl alcohol or ethanol mixed with iodized oil. RF ablation was percutaneously done under the computed tomographic (CT)–fluoroscopic guidance. Response to treatment was evaluated by dynamic contrast-enhanced CT and magnetic resonance (MR) imaging. Tumor enhancement was eliminated after a single RF session in nine tumors (75%), after two sessions in two tumors (17%), and after four sessions in one tumor (8%). Both exophytic tumors (100%) and 7 of 10 tumors having components in the renal sinus fat (70%) were completely ablated with a single RF session. All tumors remained controlled during a mean follow-up period of 13 months and showed significant reduction in tumor sizes (5.2 ± 1.7 cm to 3.6 ± 1.4 cm, p < 0.001). A delayed abscess developed in the ablated lesion in a patient, which was percutaneously drainaged. Combined therapy as described in this report is a feasible, relatively safe, and promising treatment method for large RCCs regardless of tumor geometry.

Transjugular intrahepatic portosystemic shunt placement in patients with cirrhosis and concomitant portal vein thrombosis.

Abstract: To determine the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) creation in patients with liver cirrhosis complicated by thrombosed portal vein This study reviewed 15 cases of TIPS creation in 15 cirrhotic patients with portal vein thrombosis at our institution over an 8-year period There were 2 women and 13 men with a mean age of 53 years Indications were refractory ascites, variceal hemorrhage, and refractory pleural effusion Clinical follow-up was performed in all patients The technical success rate was 75% (3/4) in patients with chronic portal vein thrombosis associated with cavernomatous transformation and 91% (10/11) in patients with acute thrombosis or partial thrombosis, giving an overall success rate of 87% Complications included postprocedural encephalopathy and localized hematoma at the access site In patients with successful shunt placement, the total follow-up time was 223 months The 30-day mortality rate was 13% Two patients underwent liver transplantation at 35 days and 7 months, respectively, after TIPS insertion One patient had an occluded shunt at 4 months with an unsuccessful revision The remaining patients had functioning shunts at follow-up TIPS creation in thrombosed portal vein is possible and might be a treatment option in certain patients

Pain and Return to Daily Activities after Uterine Artery Embolization and Hysterectomy in the Treatment of Symptomatic Uterine Fibroids: Results from the Randomized EMMY Trial

Abstract: Purpose To evaluate the safety and efficacy of uterine artery embolization (UAE) and hysterectomy for symptomatic uterine fibroids by means of a randomized controlled trial. The present paper analyses short-term outcomes, i.e., pain and return to daily activities.

Percutaneous Transhepatic Biliary Drainage in the Management of Postsurgical Biliary Leaks in Patients with Nondilated Intrahepatic Bile Ducts

Abstract: Purpose To assess the feasibility of percutaneous transhepatic biliary drainage (PTBD) for the treatment of postsurgical biliary leaks in patients with nondilated intrahepatic bile ducts, its efficacy in restoring the integrity of bile ducts, and technical procedures to reduce morbidity.

Microcoil Embolization for Acute Lower Gastrointestinal Bleeding

Abstract: To assess outcomes after microcoil embolization for active lower gastrointestinal (GI) bleeding. We retrospectively studied all consecutive patients in whom microcoil embolization was attempted to treat acute lower GI bleeding over 88 months. Baseline, procedural, and outcome parameters were recorded following current Society of Interventional Radiology guidelines. Outcomes included technical success, clinical success (rebleeding within 30 days), delayed rebleeding (>30 days), and major and minor complication rates. Follow-up consisted of clinical, endoscopic, and pathologic data. Nineteen patients (13 men, 6 women; mean age ± 95% confidence interval = 70 ± 6 years) requiring blood transfusion (10 ± 3 units) had angiography-proven bleeding distal to the marginal artery. Main comorbidities were malignancy (42%), coagulopathy (28%), and renal failure (26%). Bleeding was located in the small bowel (n = 5), colon (n = 13) or rectum (n = 1). Technical success was obtained in 17 patients (89%); 2 patients could not be embolized due to vessel tortuosity and stenoses. Clinical follow-up length was 145 ± 75 days. Clinical success was complete in 13 (68%), partial in 3 (16%), and failed in 2 patients (11%). Delayed rebleeding (3 patients, 27%) was always due to a different lesion in another bowel segment (0 late rebleeding in embolized area). Two patients experienced colonic ischemia (11%) and underwent uneventful colectomy. Two minor complications were noted. Microcoil embolization for active lower GI bleeding is safe and effective in most patients, with high technical and clinical success rates, no procedure-related mortality, and a low risk of bowel ischemia and late rebleeding.

Catheter-Directed Thrombolysis with Percutaneous Rheolytic Thrombectomy Versus Thrombolysis Alone in Upper and Lower Extremity Deep Vein Thrombosis

Abstract: To compare the efficacy of catheter-directed thrombolysis (CDT) alone versus CDT with rheolytic percutaneous mechanical thrombectomy (PMT) for upper and lower extremity deep vein thrombosis (DVT). A retrospective cohort of consecutive patients with acute iliofemoral or brachiosubclavian DVT treated with urokinase CDT was identified, and a chart review was conducted. Demographic characteristics, treatment duration, total lytic dose, clot lysis rates and complications were compared in patients treated with urokinase CDT alone or combined CDT and rheolytic PMT. Forty limbs in 36 patients were treated with urokinase CDT alone. Twenty-seven limbs in 21 patients were treated with urokinase CDT and rheolytic PMT. The mean treatment duration for urokinase CDT alone was 48.0 ± 27.1 hr compared with 26.3 ± 16.6 hr for urokinase CDT and rheolytic PMT (p = 0.0004). The mean urokinase dose required for CDT alone was 5.6 ± 5.3 million units compared with 2.7 ± 1.8 million units for urokinase CDT with rheolytic PMT (p = 0.008). Complete clot lysis was achieved in 73% (29/40) of DVT treated with urokinase CDT alone compared with 82% (22/27) treated with urokinase CDT with rheolytic PMT. Percutaneous CDT with rheolytic PMT is as effective as CDT alone for acute proximal extremity DVT but requires significantly shorter treatment duration and lower lytic doses. Randomized studies to confirm the benefits of pharmacomechanical thrombolysis in the treatment of acute proximal extremity DVT are warranted.

Percutaneous treatment of deep vein thrombosis in May-Thurner syndrome

Abstract: Background/Purpose May-Thurner syndrome is an uncommon disease entity in which the left common iliac vein is compressed by the right common iliac artery with subsequent development of deep vein thrombosis and chronic venous insufficiency. We report our experience on the treatment of extensive iliofemoral deep venous thrombosis due to May-Thurner syndrome using endovascular techniques.

Clinical assessment of percutaneous radiofrequency ablation for painful metastatic bone tumors.

Abstract: To investigate the pain-alleviating effects of radiofrequency ablation (RFA) on metastatic bone tumors in relation to tumor size, combined therapy, and percent tumor necrosis rate following RFA Subjects comprised 24 patients with 28 painful metastatic bone tumors A 17G internally cooled electrode was inserted into the tumor for CT guidance and ablation was performed Bone cement was injected following RFA for 4 tumors involving a weight-bearing bone, while 5 tumors were treated using combined RFA and external irradiation Percent necrosis rate of the tumor was measured using contrast-enhanced computed tomography 1 week after RFA Improvement in the visual analog scale (VAS) score was 46 ± 22 for large tumors (>5 cm, n = 12), 37 ± 18 for medium-sized tumors (31–50 cm, n = 11), and 35 ± 17 for small tumors (≤3 cm, n = 4), with no significant differences noted among tumor sizes Improvement in the VAS score was 35 ± 13 for the 4 tumors in the RFA + bone cement group, 32 ± 19 for the 5 tumors in the RFA + radiation therapy group, and 48 ± 22 for the 18 tumors in the RFA group No significant differences were identified between groups The improvement in the VAS score was 38 ± 23, 40 ± 19, and 47 ± 26 in patients with tumor necrosis rates of 0–49%, 50–74%, and 75–100%, respectively No significant association was observed among these three groups Percutaneous RFA therapy was effective in relieving pain due to metastatic bone tumors No relationships appear to exist between initial response and tumor size, combined therapy, and percent tumor necrosis

Radiological Follow-Up of New Compression Fractures Following Percutaneous Vertebroplasty

Abstract: The purpose of the present study was to ascertain chronological changes in the analgesic effects of percutaneous vertebroplasty (PVP) on osteoporotic vertebral compression factures and to radiologically follow new compression fractures after PVP. Seventy-six patients (206 vertebral bodies) were followed radiologically for a mean of 11.5 months. A visual analog scale (VAS; 0–10) was used to assess pain severity, and frontal and lateral plain radiographs of the thoracic and lumbar vertebrae were taken 1–3 days and 1, 4, 10, and 22 months after PVP. The average VAS score was 7.2 ± 2.0 (mean pain score ± standard deviation) before PVP, 2.5 ± 2.3 at 1–3 days after PVP, 2.2 ± 2.3 at 1 month, 1.9 ± 2.2 at 4 months, 1.8 ± 2.4 at 10 months, and 1.0 ± 0.2 at 22 months. A new compression fracture was confirmed in 56 vertebral bodies in 28 patients (36.8%), affecting 38 adjacent vertebral bodies (67.8%), 17 nonadjacent vertebral bodies (30.4%), and 1 treated vertebral body (1.8%). A new compression fracture occurred within 1 week of PVP in 2 vertebral bodies (3.6%), between 1 week and 1 month after PVP in 22 (39.3%), between 1 and 3 months in 12 (21.4%), between 3 and 6 months in 12 (21.4%), and after more than 6 months in 8 (14.3%). PVP was highly effective in relieving the pain associated with osteoporosis-induced vertebral compression fractures, and this analgesia was long lasting. Radiological follow-up observation revealed new compression fractures in about one-third of patients. More than half of these new compression fractures occurred in adjacent vertebral bodies within 3 months of PVP.

“Recovery™” Vena Cava Filter: Experience in 96 Patients

Abstract: The purpose of the study was to assess the clinical safety and efficacy of the “RecoveryTM” (Bard) inferior vena cava (IVC) filter. We retrospectively evaluated the clinical and imaging data of patients who had a “RecoveryTM” IVC filter placed between January 2003 and December 2004 in our institution. The clinical presentation, indications, and procedure-related complications during placement and retrieval were evaluated. Follow-up computed tomography (CT) examinations of the abdomen and chest were evaluated for filter-related complications and pulmonary embolism (PE), respectively. “Recovery” filters were placed in 96 patients (72 males and 24 females; age range: 16–87 years; mean: 46 years). Twenty-four patients presented with PE, 13 with deep vein thrombosis (DVT) and 2 with both PE and DVT. The remaining 57 patients had no symptoms of thromboembolism. Indications for filter placement included contraindication to anticoagulation (n = 27), complication of anticoagulation (n = 3), failure of anticoagulation (n = 5), and prophylaxis (n = 61). The device was successfully deployed in the infrarenal (n = 95) or suprarenal (n = 1) IVC through a femoral vein approach. Retrieval was attempted in 11 patients after a mean period of 117 days (range: 24–426). The filter was successfully removed in nine patients (82%). Failure of retrieval was due to technical difficulty (n = 1) and the presence of thrombus in the filter (n = 1). One of the nine patients who had the filter removed developed IVC thrombus after retrieval and another had an intimal tear of the IVC. Follow-up abdominal CT (n = 40) at a mean of 80 days (range: 1–513) showed penetration of the IVC by the filter arms in 11, of which 3 had fracture of filter components. In one patient, a broken arm migrated into the pancreas. Asymmetric deployment of the filter legs was seen in 12 patients and thrombus within the filter in 2 patients. No filter migration or caval occlusion was encountered. Follow-up chest CT (n = 27) at a mean of 63 days (range: 1–386) showed PE in one patient (3%). During clinical follow-up, 12 of 96 patients developed symptoms of PE and only 1 of the 12 had PE on CT. There was no fatal pulmonary embolism in our group of patients following “Recovery” filter placement. However, the current version of the filter is associated with structure weakness, a high incidence of IVC wall penetration, and asymmetric deployment of the filter legs.

Effective Dose of CT- and Fluoroscopy-Guided Perineural/Epidural Injections of the Lumbar Spine: A Comparative Study

Abstract: The objective of this study was to compare the effective radiation dose of perineural and epidural injections of the lumbar spine under computed tomography (CT) or fluoroscopic guidance with respect to dose-reduced protocols. We assessed the radiation dose with an Alderson Rando phantom at the lumbar segment L4/5 using 29 thermoluminescence dosimeters. Based on our clinical experience, 4–10 CT scans and 1-min fluoroscopy are appropriate. Effective doses were calculated for CT for a routine lumbar spine protocol and for maximum dose reduction; as well as for fluoroscopy in a continuous and a pulsed mode (3–15 pulses/s). Effective doses under CT guidance were 1.51 mSv for 4 scans and 3.53 mSv for 10 scans using a standard protocol and 0.22 mSv and 0.43 mSv for the low-dose protocol. In continuous mode, the effective doses ranged from 0.43 to 1.25 mSv for 1–3 min of fluoroscopy. Using 1 min of pulsed fluoroscopy, the effective dose was less than 0.1 mSv for 3 pulses/s. A consequent low-dose CT protocol reduces the effective dose compared to a standard lumbar spine protocol by more than 85%. The latter dose might be expected when applying about 1 min of continuous fluoroscopy for guidance. A pulsed mode further reduces the effective dose of fluoroscopy by 80–90%.

Endovascular Embolization of Visceral Artery Aneurysms with Ethylene-vinyl Alcohol (Onyx): A Case Series

Abstract: We report the application of the liquid embolic agent ethylene-vinyl alcohol (Onyx; MicroTherapeutics, Irvine, CA, USA) in the management of visceral artery aneurysms. The technique and indications for using Onyx are discussed with emphasis on the management of wide-necked aneurysms and maintenance of patency of the parent vessel. None of the cases was considered suitable for stent-grafting or embolization with conventional agents. Two aneurysms of the renal artery bifurcation and one aneurysm of the inferior pancreaticoduodenal artery were treated. Following treatment there was complete exclusion of all aneurysms. There was no evidence of end-organ infarction. Follow-up with intervals up to 6 months has shown sustained aneurysm exclusion. Onyx is known to be effective in the management of intracranial aneurysms. Our experience demonstrates the efficacy and applicability of the use of Onyx in the treatment of complex visceral artery aneurysms.

Lower Energy Endovenous Laser Ablation of the Great Saphenous Vein with 980 nm Diode Laser in Continuous Mode

Abstract: To assess clinical outcomes, complication rates, and unit energy applied using 980 nm diode endovenous laser treatment at 11 watts for symptomatic great saphenous vein (GSV) incompetence and reflux disease. Thirty-four consecutive ablation therapies with a 980 nm diode endovenous laser at 11 watts were studied. The diagnosis of GSV incompetence with reflux was made by clinical evaluation and duplex Doppler examinations. The treated GSVs had a mean diameter of 1.19 cm (range 0.5–2.2 cm). The patients were followed with clinical evaluation and color flow duplex studies up to 18.5 months (mean 12.19 months ± 4.18). Using 980 nm diode endovenous laser ablation in continuous mode, 100% technical success was noted. The mean length of GSVs treated was 33.82 cm (range 15–45 cm). The mean energy applied during the treatment was 1,155.81 joules (J) ± 239.50 (range 545.40–1620 J) for a mean treatment duration of 90.77 sec ± 21.77. The average laser fiber withdrawal speed was 0.35 cm/sec ± 0.054. The mean energy applied per length of GSV was 35.16 J/cm ± 8.43. Energy fluence, calculated separately for each patient, averaged 9.82 J/cm2 ± 4.97. At up to 18.5 months follow-up (mean 12.19 months), 0% recanalization was noted; 92% clinical improvement was achieved. There was no major complication. Minor complications included 1 patient with hematoma at the percutaneous venotomy site, 1 patient with thrombophlebitis on superficial tributary varices of the treated GSV, 24% ecchymoses, and 32% self-limiting hypersensitivity/tenderness/“pulling” sensation along the treatment area. One patient developed temporary paresthesia. Four endovenous laser ablation treatments (12%) were followed by adjunctive sclerotherapies for improved cosmetic results. Endovenous laser ablation treatment of GSV using a 980 nm diode laser at 11 watts in continuous mode appears safe and effective. Mean energy applied per treated GSV length of 35.16 J/cm or mean laser fluence of 9.82 J/cm2 appears adequate, resulting in 0% recanalization and low minor complication rates.

The size of gelatin sponge particles: differences with preparation method.

Abstract: Purpose To assess whether the size distribution of gelatin sponge particles differed according to the method used to make them and the type of original sheet.

Azygos tip placement for hemodialysis catheters in patients with superior vena cava occlusion.

Abstract: Chronic central venous access is necessary for numerous life-saving therapies. Repeated access is complicated by thrombosis and occlusion of the major veins, such as the superior vena cava (SVC), which then require novel vascular approaches if therapy is to be continued. We present two cases of catheterization of the azygos system in the presence of an SVC obstruction. We conclude that the azygos vein may be used for long-term vascular access when other conduits are unavailable and that imaging studies such as magnetic resonance venography, contrast-enhanced computed tomography or conventional venography can be employed prior to the procedure to aid with planning and prevent unforeseen complications.

Right Ventricular Migration of a Recovery IVC Filter’s Fractured Wire with Subsequent Pericardial Tamponade

Abstract: A Recovery filter (C.R. Bard, Tempe, AZ, USA) is a device for pulmonary embolism prophylaxis. There have been few case reports involving the migration of this particular filter or of a broken wire migrating to the heart. We report a case of right ventricular migration of a fractured wire from this filter in a patient who subsequently developed pericardial tamponade and required open heart surgery to extract the fractured wire. We discuss the current US Food and Drug Administration (FDA)-approved nonpermanent inferior vena cava filters and their reported complications. These complications can be life-threatening and may require immediate surgical intervention.