Radiofrequency Ablation of Hepatic Cysts: Evaluation of Therapeutic Efficacy

PurposeTo evaluate therapeutic efficacy of radiofrequency (RF) ablation for treatment of hepatic cysts with the use of a single cooled electrode after aspiration of the cyst contents.Materials and MethodsFourteen hepatic cysts (mean diameter, 7.8 cm; range, 3.7–12.7 cm) in 14 patients treated by RF ablation during a 3-year period were retrospectively reviewed. RF ablation was performed after aspiration of the cyst contents until a cyst measured no more 3 cm in diameter. The volumes of each cyst on computed tomography (CT) were measured before and after RF ablation, and volume reduction rates were calculated.ResultsFollow-up CT was performed a mean of 437 days after RF ablation (range, 32–1,326 d). One cyst was surgically removed because of regrowth. Nine had a volume reduction rate greater than 75%. Eight of nine cysts 8.5 cm in diameter or smaller markedly decreased in volume (mean reduction rate, 93.6%; range, 76.8%–100%). Cysts 8.5–12.0 cm in diameter (n = 4) showed a 61.7% reduction rate (range, 26.0%–98.8%). The mean volume reduction rate was 83.5% (range, 8.1%–100%) in the nine cysts with less than 10 mL of residual fluid after aspiration, compared with 43.2% in the five cysts with more than 10 mL of residual fluid. The volume reduction rate was 34.4% in septated cysts after aspiration, in contrast to 83.0% in nonseptated cysts. There were no major complications from RF ablation.ConclusionsRF ablation may be effective for the treatment of benign hepatic cysts and may be considered as an alternative to conventional sclerotherapy or surgery.     

Characterization of In Vivo Ablation Zones Following Percutaneous Microwave Ablation of the Liver with Two Commercially Available Devices: Are Manufacturer Published Reference Values Useful?

PurposeTo analyze in vivo ablation properties of microwave ablation antennae in tumor-bearing human livers by performing retrospective analysis of ablation zones following treatment with two microwave ablation systems.Materials and MethodsPercutaneous microwave ablations performed in the liver between February 2011 and February 2013 with use of the AMICA and Certus PR ablation antennae were included. Immediate postablation computed tomography images were evaluated retrospectively for ablation length, diameter, and volume. Ablation length, diameter, and volume indices were calculated and compared between in vivo results and references provided from each device manufacturer. The two microwave antenna models were then also compared versus each other.ResultsTwenty-five ablations were performed in 20 patients with the AMICA antenna, and 11 ablations were performed in eight patients with the Certus PR antenna. The AMICA and Certus PR antennae showed significant differences in ablation length (P = .013 and P = .009), diameter (P = .001 and P = .009), and volume (P = .003 and P = .009). The AMICA ablation indices were significantly higher than the Certus PR ablation indices in length (P = .026) and volume (P = .002), but there was no significant difference in ablation diameter indices (P = .110).ConclusionsIn vivo ablation indices of human tumors are significantly smaller than reference ex vivo ablation indices, and there are significant differences in ablation indices and sphericity between devices.     

Fracture and Migration of Celect Inferior Vena Cava Filters: A Retrospective Review of 741 Consecutive Implantations

PurposeTo determine the incidence of fracture and migration of the Celect inferior vena cava (IVC) filter at a single tertiary-care center.Materials and MethodsImages obtained after placement of Celect IVC filters between August 2007 and January 2013 were retrospectively reviewed for evidence of device fracture and migration. The probability of filter fracture at 6 and 12 months after filter placement was estimated, and a 95% upper confidence bound was constructed.ResultsA total of 741 consecutive Celect filters were placed, and the following studies were subsequently evaluated: 301 abdominal radiographs, 282 abdominal computed tomography (CT) scans, 154 cavagrams, 19 lumbar spine radiographs, 462 chest radiographs, 108 chest CT scans, and 31 pelvic radiographs. The mean imaging follow-up interval was 5.78 months ± 8.80 (range, 0.01–56.03 mo). There was no filter fracture or en-bloc migration outside the IVC. Upper 95% confidence bounds for the probability of fracture were 1.8% at 6 months and 4.3% at 12 months. Intracaval filter migration of more than 2 cm (mean, 2.43 ± 0.12 cm; range, –2.54 to 2.99 cm) was seen in 3.9% of patients (21 of 534; 12 cranial and nine caudal).ConclusionsNo fracture of a Celect filter was observed in this large cohort over a relatively short follow-up interval. The results also suggest that the Celect filter has an adequate securing mechanism to prevent distant en-bloc or significant intracaval migration.     

Calculation of Operating Expenses for Conventional Transarterial Chemoembolization in an Academic Medical Center: A Step toward Defining the Value of Transarterial Chemoembolization

PurposeTo determine the “real cost” of conventional transarterial chemoembolization in the treatment of patients with unresectable hepatocellular carcinoma (HCC).Materials and MethodsComprehensive cost data for performance of conventional transarterial chemoembolization were calculated from a retrospective review of records of 50 consecutive outpatient transarterial chemoembolization procedures in 36 patients with HCC. Costs included labor, equipment, facility acquisition and maintenance, overhead, and administrative costs in a single academic medical center. Hourly rate operational costs for the angiography suite and recovery area were calculated, to which the consumable supply costs were added. Conventional transarterial chemoembolization was defined as selective intrahepatic administration of chemotherapeutic agents (doxorubicin and mitomycin C) emulsified in ethiodized oil (Lipiodol).ResultsThe hourly rate to operate an angiography suite at the institution was calculated to be $539/h. Recovery time was calculated at $108/h. Median overall cost of conventional transarterial chemoembolization was $3,269 (range, $2,223–$5,654). This overall cost comprised median room and personnel costs of $763 (range, $404–$1,797), consumable costs of $1,886 (range, $1,134–$4,126), and recovery costs of $378 (range, $162–$864).ConclusionsThe largest contribution (62%) to the real cost of outpatient transarterial chemoembolization comes from the expendable equipment used in the procedure. The angiography suite and personnel costs constitute 25% of the total, and recovery costs constitute 13%. This finding is a change from previous reports in which angiography suite operation was the greatest contributor to cost. Understanding real cost is an essential step in determining the value of the procedure.     

Ablation Zones and Weight-Bearing Bones: Points of Caution for the Palliative Interventionalist

PurposeTo evaluate and classify underlying mechanisms of adverse outcomes after percutaneous computed tomography (CT)–guided cryoablation for palliation of painful musculoskeletal metastatic disease.Materials and MethodsData were collected for patients who underwent CT-guided percutaneous palliative cryoablation for painful musculoskeletal metastatic disease between January 2010 and December 2012. Cases with adverse outcomes or suboptimal response were identified and classified according to the Society of Interventional Radiology (SIR) classification system for complications by outcome and according to underlying mechanism of the outcome as delineated on follow-up examination.ResultsThere were 61 patients who received ablation for painful musculoskeletal metastatic disease. Six patients with adverse outcomes were identified. Two were minor complications (A, n = 1; B, n = 1), and four were major complications (C, n = 1; D, n = 3). Four patients incurred sequelae related to damage of ancillary structures included in the ablation zone, and two patients developed complete fractures after ablation of lesions in weight-bearing bones.ConclusionsComplete cryoablation of a painful musculoskeletal metastatic lesion may lead to ancillary damage of adjacent structures or fracture in weight-bearing bones.     

Ethanol Embolotherapy of Vascular Malformations: Clinical Outcomes at a Single Center

PurposeTo retrospectively evaluate the results of endovascular therapy of vascular malformations principally treated with ethanol embolization at a single center.Materials and MethodsFrom May 1999 to December 2012, 46 patients (28 female, 18 male) with vascular malformations (31 venous malformations, 15 arteriovenous malformations [AVMs]) throughout the body (nine upper extremity, 31 lower extremity, and six truncal) who underwent ethanol embolization were studied and followed up. Demographic factors, clinical findings, imaging data, and patient-reported changes in symptoms were collected and analyzed. Follow-up data were obtained by office visits, repeat imaging, and telephone contact.ResultsTwenty-four patients (52.2%) were considered cured, 12 (26.1%) showed improvement, and 10 (21.7%) had no change or showed worsening. Similar rates of cure or improvement were seen for AVMs and venous malformations (P = 0.67). Lesion location, depth, and size were not associated with differences in outcomes (P = .87, P = .37, and P = .61, respectively). Type 1 and type 2 AVMs were cured more often than other AVM types. The overall complication rate was 24% (11 of 46 patients). Minor complications were seen in six individuals (13%), and major complications developed in five patients (11%).ConclusionsEthanol embolization of vascular malformations produces good outcomes, with control or relief of symptoms in a majority of patients.     

Comparison of Primary Jejunostomy Tubes versus Gastrojejunostomy Tubes for Percutaneous Enteral Nutrition

PurposeTo evaluate technical success and long-term outcomes of percutaneous primary jejunostomy tubes for postpyloric enteral feeding compared with percutaneous gastrojejunostomy (GJ) tubes.Materials and MethodsOver a 25-month interval, 41 consecutive patients (26 male; mean age, 55.9 y) underwent attempted fluoroscopy-guided direct percutaneous jejunostomy tube insertion. Insertions at previous jejunostomy tube sites were excluded. The comparison group consisted of all primary GJ tube insertions performed over a 12-month interval concomitant with the jejunostomy tube interval (N = 169; 105 male; mean age, 59.4 y). Procedural, radiologic, and clinical data were retrospectively reviewed. Intervention rates were expressed as events per 100 catheter-days.ResultsThe technical success rate for percutaneous jejunostomy tube insertion was 96%, versus 93% for GJ tubes (P = .47). Mean fluoroscopy times were similar for jejunostomy and GJ tubes (9.8 vs 10.0 min, respectively; P value not significant). Jejunostomy tubes exhibited a lower rate of catheter dysfunction than GJ tubes, with catheter exchange rates of 0.24 versus 0.93, respectively, per 100 catheter-days (P = .045). GJ tube tip retraction into the stomach occurred in 9.5% of cases, at a rate of 0.21 per 100 catheter-days. Intervention rates related to leakage were 0.19 and 0.03 for jejunostomy and GJ tubes, respectively (P < .01). Jejunostomy and GJ tubes exhibited similar rates of catheter exchange for occlusion and replacement as a result of inadvertent removal. No major complications were encountered in either group.ConclusionsPercutaneous insertion of primary jejunostomy tubes demonstrated technical success and complication rates similar to those of GJ tubes. Jejunostomy tubes exhibited a lower dysfunction rate but a higher leakage rate compared with GJ tubes.     

Prevalence and Clinical Consequences of Fracture and Fragment Migration of the Bard G2 Filter: Imaging and Clinical Follow-up in 684 Implantations

PurposeTo investigate the prevalence and clinical sequelae of G2 filter (Bard Peripheral Vascular, Tempe, Arizona) fractures and fragment migration.Materials and MethodsPatients who underwent G2 filter placement between October 2005 and February 2010 were assessed for filter fractures and complications. Fracture prevalence was estimated at various time points based on data from patients with known fracture status.ResultsAmong 829 patients who underwent G2 filter placement, 684 had follow-up imaging and qualified for the study (381 men and 303 women; average age, 60.3 y; range, 15.8–95.2 y). For 541 (79%) patients, at least one image was available that contained the filter (imaging follow-up interval, 14.9 mo ± 20.0; range, 0–78.6 mo); images that did not include the filter but may have shown the migrated fracture fragment were available for 143 (21%) patients (follow-up interval, 11.2 mo ± 19.3; range, 0–83.4 mo). There were 16 fractured limbs identified in 13 patients (incidence, 1.9%; follow-up interval, 30.4 mo ± 18.7; range, 5.5–76.5 mo). Fracture fragments were identified in the pulmonary arteries (n = 4), right ventricle (n = 2), pericardium (n = 1), iliac vein (n = 1), and kidney (n = 1). Four fracture limbs remained near the filter; the remaining three could not be located. All patients with filter fracture were asymptomatic. The estimated 5-year fracture prevalence was 38% (95% confidence interval, 22.9%, 54.8%).ConclusionsThe early occurrence of G2 filter fractures was low, but the incidence increased over time. No life-threatening events occurred in patients with filter fracture during the study time frame.     

Percutaneous Transcervical Thoracic Duct Embolization for Treatment of a Cervical Lymphocele Following Anterior Spinal Fusion: A Case Report

Thoracic duct injury is an uncommon complication of neck dissection and cervical spinal surgery that is associated with significant morbidity. The authors describe an unusual case of thoracic duct injury during anterior spinal fusion resulting in a large prevertebral lymphocele presenting with dysphagia, respiratory distress, and chyloptysis. Surgical closure of the lymphocele was unsuccessful, and percutaneous drainage and sclerotherapy was performed. A large thoracic duct branch communicating with the lymphocele became evident during sclerotherapy, and embolization of the duct was performed via a percutaneous transcervical approach. Symptoms immediately resolved, and the patient remained asymptomatic at 6-month follow-up.     

Stent Graft Placement for Postsurgical Hemorrhage from the Hepatic Artery: Clinical Outcome and CT Findings

PurposeTo evaluate the clinical results and imaging follow-up findings of stent grafts placed for hemorrhage from hepatic arteries following surgery.Materials and MethodsThe investigation included 17 patients (14 men and 3 women) who underwent endovascular stent graft placement for hepatic arterial hemorrhage following surgery. Bleeding occurred from the common hepatic artery (n = 1; 6%), right hepatic artery (n = 1; 6%), proper hepatic artery (n = 6; 35%), and gastroduodenal artery stump (n = 9; 53%). Stent graft patency, thrombus at the graft, target hepatic artery diameter, and liver perfusion status were analyzed by comparing computed tomography (CT) scans performed before the procedure with follow-up CT scans. Laboratory data were also analyzed before the procedure and at follow-up intervals.ResultsThere were 17 stent grafts placed in 17 patients. The mean follow-up period was 356 days (range, 1–2,119 d). The stent graft primary patency rate was 79.5% at 1 month, 69.6% at 6 months, and 69.6% at 1 year. The clinical success rate was 82% (14 of 17 patients), and the technical success rate was 94% (16 of 17 patients). Mortality related to the stent graft was 12% (2 of 17 patients). Occlusion occurred in 4 of 16 stent grafts (25%). There was one technical failure. The mean stent graft diameter was 6.2 mm (range, 3.5–8.0 mm), and the degree of stent graft oversizing was 38% of the hepatic artery diameter on CT scans and 58% on angiography. Hepatic parenchymal perfusion was preserved in 80% of patients (12 of 15).ConclusionsHepatic artery hemorrhage following surgery can be treated effectively with stent graft placement.     

Comparison of the Efficacy of Covered versus Uncovered Metallic Stents in Treating Inoperable Malignant Common Bile Duct Obstruction: A Randomized Trial

PurposeTo compare patency and overall survival achieved with covered versus uncovered metallic stents among patients with inoperable malignant extrahepatic biliary obstruction.Materials and MethodsThere were 40 patients enrolled in this prospective randomized study between January 2012 and July 2013. Mean age of patients was 62.6 years (range, 43–86 y). The malignancies causing extrahepatic biliary obstruction were pancreatic cancer (n = 18), stomach cancer (n = 13), gallbladder cancer (n = 3), common bile duct cancer (n = 2), and other cancer types (n = 4). Uncovered (n = 20) and covered (n = 20) stents were used. Stent patency, overall survival, and complications were evaluated and statistically compared.ResultsMean patency of uncovered stents (413.3 d ± 63.0) was significantly longer than mean patency of covered ones (207.5 d ± 46.0; P = .041). Mean overall survival was 359.9 days ± 61.5 for uncovered stents, which was statistically similar to survival of 350.5 days ± 43.8 for covered stents (P = .271). Causes of recurrent obstruction included tumor ingrowth (n = 2), tumor overgrowth (n = 5), debris or food material (n = 5), and stent migration (n = 2). One case of acute cholecystitis occurred in covered stent group.ConclusionsUncovered metallic stents had superior patency duration than covered stents for patients with malignant extrahepatic biliary obstruction. However, the overall complication and survival rates achieved with covered and uncovered stents were similar.     

Chronic Total Occlusion of the Iliac Artery: Endoluminal Reentry Using a Metal Stiffening Cannula

When chronic total occlusion of the iliac artery cannot be crossed with traditional guide wires and catheters, the metal stiffener from a universal drainage catheter kit can be shaped and used to direct a guide wire from a subintimal tract into the true lumen. In the present report, reentry was achieved in 12 of 12 patients with the use of the cannula. This technique provides a useful alternative for treatment of chronic total iliac occlusions.     

Stent-Graft Repairs of Visceral and Renal Artery Aneurysms Are Effective and Result in Long-term Patency

PurposeTo report on the long-term outcomes of endovascular exclusion of visceral and renal artery aneurysms with the use of stent-grafts.Materials and MethodsNineteen consecutive patients (mean age, 59 y ± 16 [standard deviation]) with a total of 19 visceral artery aneurysms (VAAs; hepatic, n = 6; celiac, n = 4; renal, n = 4; splenic, n = 3; and superior mesenteric, n = 2) were electively (n = 9) or emergently (n = 10) treated with a variety of stent-grafts. The etiology of aneurysms was variable: postoperative (n = 9), infectious (n = 3), idiopathic (n = 4), Ehlers–Danlos syndrome (n = 2), and α1-antitrypsin deficiency (n = 1). The patients were followed up with clinical examinations and computed tomographic (CT) angiography.ResultsNo patient was lost to follow-up. The in-hospital mortality rate was 11% (n = 2). Three patients died of cancer after successful VAA treatment. At the last follow-up, the remaining 14 patients were alive and well. Three patients refused follow-up CT angiography. CT angiography demonstrated stent-graft patency at a mean follow-up of 28 months (range, 2–100 mo) in nine of 11 remaining patients (82%) and thrombosis in two patients (one with a splenic and one with a renal artery stent-graft). These events were asymptomatic. All aneurysms decreased in size. Late repeat intervention was performed to treat a celiac restenosis in a patient with a hepatic stent-graft.ConclusionsIrrespective of their etiology and acuteness, VAAs can be treated with stent-grafts, with an excellent clinical long-term outcome and a high patency rate.     

Percutaneous Vertebroplasty Performed with an 18-Gauge Needle for Treatment of Metastatic Severe Compression Fracture of the Cervical Vertebral Body

Percutaneous vertebroplasty (PVP) is considered technically difficult in patients with severe vertebral body compression, especially in the cervical spine. In this study, PVP was successfully performed with the use of an 18-gauge angiographic needle in four patients with severe cervical compression fractures from metastatic disease. There were no complications, and relief of pain was immediate in all patients. This technique may be an alternative treatment for intractable pain secondary to severe cervical compression fractures.     

Percutaneous Ablation of Peribiliary Tumors with Irreversible Electroporation

PurposeTo assess biliary complications after irreversible electroporation (IRE) ablation of hepatic tumors located < 1 cm from major bile ducts.Materials and MethodsA retrospective review was conducted of all percutaneous IRE ablations of hepatic tumors within 1 cm of the common, left, or right hepatic ducts at a single institution from January 2011 to September 2012. Computed tomography imaging performed before and after treatment was examined for evidence of bile duct dilatation, stricture, or leakage. Serum bilirubin and alkaline phosphatase levels were analyzed for evidence of biliary injury.ResultsThere were 22 hepatic metastases in 11 patients with at least one tumor within 1 cm of the common, left, or right hepatic duct that were treated with IRE ablations in 15 sessions. Median tumor size treated was 3.0 cm (mean, 2.8 cm ± 1.2, range, 1.0–4.7 cm). Laboratory values obtained after IRE were considered abnormal after four treatment sessions in three patients (bilirubin, 2.6–17.6 mg/dL; alkaline phosphatase, 130–1,035 U/L); these abnormal values were transient in two sessions. Two patients had prolonged elevation of values, and one required stent placement; both of these conditions appeared to be secondary to tumor progression rather than bile duct injury.ConclusionsThis clinical experience suggests that IRE may be a treatment option for centrally located liver tumors with margins adjacent to major bile ducts where thermal ablation techniques are contraindicated. Further studies with extended follow-up periods are necessary to establish the safety profile of IRE in this setting.     

Risk Factors of Pneumothorax after CT-Guided Coaxial Cutting Needle Lung Biopsy through Aerated versus Nonaerated Lung

PurposeTo compare the risk factors of developing a pneumothorax after computed tomography–guided lung biopsy in cases in which aerated lung is traversed and in cases in which aerated lung is not traversed.Materials and MethodsThe records of 381 patients from July 2005–December 2009 were retrospectively reviewed. Multivariable analysis of patient demographic characteristics, lung lesion characteristics, and biopsy procedure details was performed with respect to the development of pneumothorax.ResultsAmong 381 patients, 249 biopsies traversed aerated lung tissue, and 132 biopsies did not traverse aerated lung tissue. Patients in whom aerated lung tissue was traversed had a significantly higher rate of pneumothorax. When aerated lung was not traversed, lesion size (≤ 2 cm vs > 2 cm; P = .025) and pleural-lesion angle (odds ratio = 1.033/degree; P = .004) were associated with pneumothorax. When aerated lung was traversed, location (middle vs upper; P = .009) and a transfissure approach (yes vs no; P = .001) were associated with pneumothorax.ConclusionsWhen aerated lung was not traversed, lesion size and pleural-lesion angle were associated with pneumothorax, and when aerated lung was traversed, location and a transfissure approach were associated with pneumothorax.     

Coil Embolization with Side-Holed Catheter to Preserve Peripheral Flow for Visceral Artery Pseudoaneurysm: An Experimental Study in Swine

PurposeTo evaluate the safety and efficacy of coil embolization with an indwelling catheter with side holes to control visceral artery bleeding while simultaneously preserving peripheral artery flow.Materials and MethodsA 6-F anticoagulant-coated catheter with two symmetrically arranged side holes was used with coil embolization to induce hemostasis in the superior mesenteric artery (SMA) of 13 pigs. The SMA was punctured with a metal needle to induce bleeding. The catheter was advanced into the SMA immediately after the puncture, and the midpoint between its tip and side holes was adjusted to conform to the puncture site. The SMA was embolized by using microcoils placed around the catheter to achieve hemostasis. Hemostasis and gross ischemic changes of the intestine were visually observed during the abdominal surgery. Peripheral blood flow was assessed by using abdominal aortography for as long as 2 hours in 13 pigs and was assessed again at 7 days in three pigs.ResultsAntegrade peripheral artery flow through the indwelling catheter was preserved without stagnation for as long as 2 hours in all 13 pigs and at 7 days in two of three pigs. One catheter occlusion was seen at the 7-day time point. There were no observable instances of recurrent bleeding, ischemic changes in the intestine, or vascular adverse events during or after the procedure.ConclusionsThe hemostatic method described here is a technically feasible method of controlling acute visceral artery bleeding while preserving peripheral artery flow and may be particularly useful in cases of absence of collateral circulation. Further experiments are warranted for clinical application.     

Percutaneous Sclerotherapy for Treatment of Tumoral Calcinosis

Massive tumoral calcinosis developed in a 29-year-old woman with type 1 diabetes and failed pancreas and kidney transplant on peritoneal dialysis. The patient had a symptomatic calcified, fluid-filled posterior thigh mass. After percutaneous drainage of 260 mL of milky fluid, she had rapid recurrence of the collection. She underwent catheter-based sclerotherapy first with 110 mL of povidone-iodine followed 2 days later by 40 mL of 3% sodium tetradecyl sulfate foam. At 5.5 months after the procedure, the patient remained asymptomatic, and computed tomography imaging showed complete resolution of the collection.