Outcomes following Exchange and Upsizing of Malfunctioning Small-Caliber Double-J Ureteral Stents.

PURPOSE: To determine the effectiveness of exchange and upsizing of malfunctioning small-caliber double-J (JJ) ureteral stents. MATERIALS AND METHODS: Thirty-one patients with malfunctioning cystoscopically placed small-caliber (6 or 7 F) JJ stents underwent transurethral (n = 28) or transrenal (n = 3) exchange and upsizing to a large-caliber (10 F) JJ stent from 2013 to 2022. Ureteral obstruction was malignant in 20 patients (65%) and benign in 11 (35%). Fifteen patients (48%) presented with persistent hydroureteronephrosis and 16 patients (52%) with worsening hydronephrosis. Acute kidney injury (AKI) was present in 19 patients (61%) at the time of stent malfunction. Therapeutic success was defined as resolution of hydronephrosis and AKI, if present. RESULTS: JJ stent exchange and upsizing was technically successful in 31 patients (100%) with no immediate adverse events. Therapeutic success was achieved in 27 patients (87%). During follow-up (median, 97 days; IQR, 32-205 days), 2 patients who initially achieved therapeutic success had stent malfunction, requiring conversion to percutaneous nephrostomy drainage (2/27, 7%). CONCLUSIONS: Exchange and upsizing to large-caliber JJ stents can relieve urinary obstruction and resolve AKI in patients with malfunctioning small-caliber JJ stents. Large-caliber JJ stents should be considered as a salvage option for patients who wish to continue internal drainage and avoid percutaneous nephrostomy.

Infection Rates Following Hepatic Embolotherapy in Patients with Prior Biliary Interventions: Comparison of Single-Drug Moxifloxacin and Multidrug Antibiotic Prophylaxis.

PURPOSE: To investigate the incidence of infection in patients with prior biliary interventions undergoing hepatic embolotherapy following extended antibiotic prophylaxis using moxifloxacin monotherapy or a multidrug regimen. MATERIAL AND METHODS: Under an Institutional Review Board-approved protocol, retrospective review of a quality assurance database identified all liver-directed therapies (LDTs) at a tertiary care center between 2010 and 2019 with biliary intervention prior to LDT Records were reviewed for infectious complications within 3 months of chemo- or radioembolization. Patients were categorized based on extended antibiotic prophylaxis regimen: oral moxifloxacin monotherapy or multidrug regimen of levofloxacin and metroniodazole plus preprocedural neomycin and erythromycin. Procedures without at least 2 months of clinical follow-up, hepatic ablation, and procedures without extended antibiotic prophylaxis were excluded Regression analysis was used to analyze multivariate data to detect a difference in infection rate. RESULTS: Twenty-four chemoembolization and 58 radioembolization procedures were performed on 55 patients with prior biliary interventions. Forty-four used monotherapy and 38 used multidrug regimen. The incidence of infection was 16.7% (4/24) after chemoembolization and 13.8% (8/58) after radioembolization The incidence of infection in patients did not differ between antibiotic prophylaxis regimens (18.2% [8/44] with moxifloxacin monotherapy and 10.5% [4/38] multidrug regimen, P = .3) or between types of biliary interventions (24.1% [7/29] with bilioenteric anastomosis and 23.8% [5/21] biliary stenting, P = .3). CONCLUSIONS: The types of extended antibiotic prophylaxis (moxifloxacin monotherapy vs multitherapy), prior biliary intervention, and embolotherapy were not found to be associated with differences in the incidence of infectious complications in this population.

Chronic Hepatotoxicity in Patients with Metastatic Neuroendocrine Tumor: Transarterial Chemoembolization versus Transarterial Radioembolization.

PURPOSE: To compare the manifestations of chronic liver injury following transarterial chemoembolization with those of transarterial radioembolization (TARE) in patients with neuroendocrine tumor (NET). MATERIALS AND METHODS: This study consisted of an Institutional Review Board-approved single-institution retrospective analysis of NET patients who received transarterial chemoembolization from 2006 to 2016 and TARE from 2005 to 2014 and survived at least 1 year from the initial treatment. Patients receiving only transarterial chemoembolization (n = 63) or TARE (n = 28) were evaluated for the presence or absence of durable hepatic toxicities occurring at least 6 months after initial treatment. The definitions and grades of liver injury were adapted from Common Terminology Criteria for Adverse Events version 4.0 and were characterized by the presence of laboratory or clinical toxicities of Grade 3 or above. RESULTS: Chronic hepatic toxicity occurred in 14 of 63 transarterial chemoembolization patients (22%) with a total of 26 Grade 3-4 events, in whom elevation of bilirubin was the most common toxicity, compared to 8 of 28 TARE patients (29%) with a total of 16 Grade 3-4 and 2 Grade 5 events, in whom ascites were the most frequent toxicity. There were more laboratory toxicities in the transarterial chemoembolization group (65% vs 38%, P = .11) and fewer Grade 4-5 injuries (6% vs 27% of patients, P = .06). There was also a significantly higher number of patients who experienced intrahepatic progression of disease in the transarterial chemoembolization cohort than in the TARE patients (75% vs 43%, respectively; P = .005). CONCLUSIONS: Delayed hepatotoxicity from transarterial chemoembolization and TARE occurred in 22% and 29% of patients, respectively, from 6 months to several years following treatment. Transarterial chemoembolization-related toxicities on average were less severe and manifested primarily as laboratory derangements, compared to TARE toxicities which consisted of clinical hepatic decompensation.

Multicenter analysis of the use of transjugular intrahepatic portosystemic shunt for management of MPN-associated portal hypertension.

BCR-ABL1-negative myeloproliferative neoplasms (MPNs) are clonal stem cell disorders defined by proliferation of one or more myeloid lineages, and carry an increased risk of vascular events and progression to myelofibrosis and leukemia. Portal hypertension (pHTN) occurs in 7-18% of MPN patients via both thrombotic and nonthrombotic mechanisms and portends a poor prognosis. Transjugular intrahepatic portosystemic shunt (TIPS) has been used in the management of MPN-associated pHTN; however, data on long-term outcomes of TIPS in this setting is limited and the optimal management of medically refractory MPN-associated pHTN is not known. In order to assess the efficacy and long-term outcomes of TIPS in MPN-associated pHTN, we performed a retrospective analysis of 29 MPN patients who underwent TIPS at three academic medical centers between 1997 and 2016. The majority of patients experienced complete clinical resolution of pHTN and its clinical sequelae following TIPS. One, two, three, and four-year overall survival post-TIPS was 96.4%, 92.3%, 84.6%, and 71.4%, respectively. However, despite therapeutic anticoagulation, in-stent thrombosis occurred in 31.0% of patients after TIPS, necessitating additional interventions. In conclusion, TIPS can be an effective intervention for MPN-associated pHTN regardless of etiology. However, TIPS thrombosis is a frequent complication in the MPN population and indefinite anticoagulation post-TIPS should be considered.

A 16-F Sheath with Endobronchial Forceps Improves Reported Retrieval Success of Long-Dwelling "Closed Cell" Inferior Vena Cava Filter Designs.

PURPOSE: To report results of a 16-F sheath/endobronchial forceps combination in retrieval of "closed cell" inferior vena cava (IVC) filter designs with prolonged dwell times of ≥ 60 days. MATERIALS AND METHODS: Forceps retrieval of selected IVC filters using a 16-F 45-cm sheath was performed in 35 patients (25 women and 10 men). Patients presented with filters that were no longer needed without (n = 10) or with (n = 21) prior failed retrieval, caval thrombosis before lysis (n = 3), and back pain (n = 1). Filter designs included 19 Günther Tulip (54%), 10 Option (29%), and six OptEase (17%). Mean dwell time was 977 days. Imaging characteristics, technical success, fluoroscopy time, and complications were recorded. RESULTS: Filters included 20 tip-embedded, 6 tip-adherent, 4 fractured, and 6 containing thrombus. All were strut and wall-embedded. Initial snare failures occurred in 8 filters because of hook straightening (n = 4), adherent material (n = 2), snare breakage (n = 1), and filter tilt (n = 1). The 16-F sheath/forceps combination was 100% successful in removing filters. In 1 patient, 2 extravascular fragments could not be retrieved. Median fluoroscopy time, excluding 3 extended lysis procedures, was 8 minutes. Minor caval abnormalities, including caval spasm and caval defects, were noted in 17 patients, and filter fracture occurred in 2 patients. No major complications occurred. CONCLUSIONS: A high rate of retrieval for closed cell long-dwelling strut and wall-embedded filters may be achieved using a 16-F sheath/endobronchial forceps combination.

Retrieval of Tip-embedded Inferior Vena Cava Filters by Using the Endobronchial Forceps Technique: Experience at a Single Institution.

PURPOSE: To evaluate the use of endobronchial forceps to retrieve tip-embedded inferior vena cava (IVC) filters. MATERIALS AND METHODS: This institutional review board-approved, HIPAA-compliant retrospective study included 114 patients who presented with tip-embedded IVC filters for removal from January 2005 to April 2014. The included patients consisted of 77 women and 37 men with a mean age of 43 years (range, 18-79 years). Filters were identified as tip embedded by using rotational venography. Rigid bronchoscopy forceps were used to dissect the tip or hook of the filter from the wall of the IVC. The filter was then removed through the sheath by using the endobronchial forceps. Statistical analysis entailed calculating percentages, ranges, and means. RESULTS: The endobronchial forceps technique was used to successfully retrieve 109 of 114 (96%) tip-embedded IVC filters on an intention-to-treat basis. Five failures occurred in four patients in whom the technique was attempted but failed and one patient in whom retrieval was not attempted. Filters were in place for a mean of 465 days (range, 31-2976 days). The filters in this study included 10 Recovery, 33 G2, eight G2X, 11 Eclipse, one OptEase, six Option, 13 Günther Tulip, one ALN, and 31 Celect filters. Three minor complications and one major complication occurred, with no permanent sequelae. CONCLUSION: The endobronchial forceps technique can be safely used to remove tip-embedded IVC filters.

Recurrent Bleeding, Survival, and Longitudinal Pulmonary Function following Bronchial Artery Embolization for Hemoptysis in a U.S. Adult Population.

PURPOSE: To report outcomes of bronchial artery embolization (BAE) for hemoptysis, including recurrent bleeding, survival, and longitudinal pulmonary function. MATERIALS AND METHODS: A prospective database identified 69 patients who underwent 97 BAE procedures (n = 1-7 per patient) at a tertiary academic medical center over a period of 11 years. Technical and clinical success were determined. Recurrent bleeding and survival were compared by etiology of lung disease. Rates of change in pulmonary function (forced expiratory volume in 1 s [FEV1] and forced vital capacity [FVC]) were measured and compared before and after index BAE by linear regression in 17 patients. RESULTS: The technical success rate of BAE was 90%. Clinical success rates at 24 hours and 30 days were 82% and 68%, respectively. Thirty percent of patients had recurrent bleeding that required bronchoscopy (7%) or additional embolization (23%). Median time to recurrent bleeding was 29 days among the 13 patients with sarcoidosis, compared with 293 days among patients without sarcoidosis (P = .0013). The hazard ratio for death in patients with sarcoidosis compared with those without sarcoidosis was 4 (95% confidence interval, 2.6-14.6). Analyzing all instances of pulmonary function tests, slopes of decline in FEV1 and FVC were significantly different (FEV1, P = .0048; FVC, P < .0001) before and after index BAE, with an improvement after BAE (FEV1, 0.8%/y; FVC, 1%/y) and a decrease before BAE (FEV1, -1.6%/y; FVC, -1.4%/y). CONCLUSIONS: BAE is an effective therapy for hemoptysis, but patients with sarcoidosis are at significant risk of recurrent bleeding and death compared with patients with other lung diseases. BAE does not accelerate deterioration in lung function.

Long-term outcomes of a benign biliary stricture protocol.

PURPOSE: To evaluate long-term outcomes of a structured protocol for percutaneous treatment of benign biliary stricture. MATERIALS AND METHODS: Seventy-one patients (37 men, 34 women; mean age, 54 y; age range, 23-84 y) entered the protocol, which consisted of staged upsizing of internal/external biliary catheters, balloon dilation (nominally 8 mm), and prolonged stent treatment (6 mo) at maximal catheter size (nominally 18 F). It concluded with a capping trial and catheter removal if the stricture remained patent. Fifty-three patients completed the protocol and 18 did not (6 died, 6 underwent alternative treatment, 4 were lost to follow-up, and 2 underwent repeat transplantation). Stricture features, treatment parameters, complications, and outcomes were reviewed, and Kaplan-Meier analysis was conducted. RESULTS: Strictures were anastomotic in 45 patients (64%), intrahepatic in 14 (20%), extrahepatic in 7 (10%), and multiple (intra- and extrahepatic) in 5 (7%). A right-sided approach was used in 47 patients (66%) patients, a left-sided approach in 18 (25%), and a bilateral approach in 6 (9%). Forty-six patients who entered the protocol (65%) and 46 patients who completed the protocol (87%) showed stricture patency. Four of 7 patients in whom a capping trial failed underwent surgical revision, 2 required chronic biliary drainage, and 1 received a metal stent. Follow-up (range, 0-12 y; mean, 4.7 y) was obtained for 42 of 53 patients who completed the protocol (79%). Kaplan-Meier analysis showed stricture patency probabilities of 84% at 1 year after treatment, 78% at 2 years, 74% at 5 years, and 67% at 10 years. CONCLUSIONS: Use of a structured protocol for the percutaneous treatment of benign biliary strictures yields durable long-term results, suggesting that percutaneous treatment is an effective therapy.

Effect of central venous angioplasty on hemodialysis access circuit flow: prospective study of 25 symptomatic patients.

PURPOSE: To quantify the effect of central venous percutaneous transluminal angioplasty (PTA) on blood flow within hemodialysis access circuits in patients with symptomatic central venous stenosis (CVS). MATERIALS AND METHODS: This prospective study enrolled 30 adults with symptoms attributable to CVS ipsilateral to their access. Five subjects were deregistered because of a lack of CVS (n = 1), untreatable lesion (n = 1), or improper flow measurement timing (n = 3); 25 completed the study (15 men and 10 women; mean age, 62 y; age range, 33-87 y). There were 7 fistulae, 15 grafts, and 3 hybrid access circuits. Mean access age was 675 days (range, 16-3,039 d). Mean CVS symptom duration was 37 days (range, 3-120 d). Peripheral stenoses, if present, were treated first. Intraaccess flow was measured immediately before and immediately after CVS treatment (PTA, stent). RESULTS: Eleven patients had only CVS, whereas 14 had at least 1 peripheral lesion in addition to CVS. All stenoses underwent PTA. Mean flow rates were 1,424 mL/min (range, 565-2,765 mL/min) before PTA and 1,535 mL/min (range, 598-2,545 mL/min) afterward, yielding a mean increase of 111 mL/min ± 456 or 15% ± 34 (range, -70% to +100%; 95% confidence interval, 1%-29%). Flow was decreased in 9 patients (36%). CVS symptoms were reduced in 24 patients (96%) and recurred in 14 (58%) within a mean of 110 days (range, 7-459 d) after initial PTA. Mean follow-up was 371 days (range, 17-592 d). CONCLUSIONS: CVS symptoms were observed to occur over a wide range of blood flow rates. On average, central venous PTA only mildly increased flow yet reduced symptoms regardless of flow change.

Initial Clinical Experience: Symmetric-Tip Dialysis Catheter with Helical Flow Characteristics Improves Patient Outcomes.

PURPOSE: To report preliminary clinical experience with a new symmetric-tip dialysis catheter compared with a conventional split-tip catheter. MATERIALS AND METHODS: Over a 5-month period, patients requiring a tunneled catheter for hemodialysis or undergoing exchange of a dysfunctional dialysis catheter at a tertiary academic medical center were retrospectively analyzed. Patients underwent placement of a VectorFlow or Ash Split Cath catheter at the discretion of the inserting interventional radiologist. Patient demographics, catheter patency, mean blood flow rate, and arterial and venous pressures were compared according to catheter type. Catheter failure was analyzed based on clinical and anatomic variables by using a multivariate Cox proportional-hazards model. RESULTS: A total of 33 VectorFlow and 46 Ash Split Cath catheters were placed. Patients in the VectorFlow group had significantly higher body mass index (P = .013) and Charlson Comorbidity Index (P = .049), as well as more non-internal jugular vein placements. At 120 days, 89% of VectorFlow catheters remained functional, compared with 45% of Ash Split Cath catheters (P = .046). The VectorFlow catheter was associated with 16% lower arterial pressures during dialysis (P = .009); mean blood flow rate was equivalent. On multivariate analysis, the risk of catheter failure was 13.3 times higher in the Ash Split Cath group compared with the VectorFlow group (P = .004). Left-sided catheters were also predictive of catheter failure (relative risk = 5.5; P = .02). CONCLUSIONS: The VectorFlow catheter was associated with a significant increase in intervention-free catheter patency compared with the Ash Split Cath catheter, with equivalent flow at lower arterial pressures during dialysis.

Long-Term Patency and Clinical Analysis of Expanded Polytetrafluoroethylene-Covered Transjugular Intrahepatic Portosystemic Shunt Stent Grafts.

PURPOSE: To evaluate long-term patency and symptomatic recurrence rates following transjugular intrahepatic portosystemic shunt (TIPS) creation with expanded polytetrafluoroethylene (ePTFE)-covered stent grafts and to determine the necessity of extended clinical follow-up beyond 2 years after TIPS creation. MATERIALS AND METHODS: A retrospective review including 262 TIPSs created with ePTFE-covered stent grafts between July 2002 and October 2012 was performed. Primary, primary assisted, and secondary patency rates were calculated. Assessment of clinical data included technical, hemodynamic, and clinical success rates, as well as mortality after TIPS creation. RESULTS: Primary patency rates at 2, 4, and 6 years were 74%, 62%, and 50%, respectively. Primary assisted patency rates at 2, 4, and 6 years were 93%, 85%, and 78%, respectively. Secondary patency rates at 2, 4, and 6 years were 99%, 91%, and 84%, respectively. Technical and hemodynamic success rates were 99% and 93%, respectively. Clinical success rates for refractory ascites were 66% (complete response) and 90% (partial response); clinical success rate for bleeding/varices was 90%. Mortality rates at 2, 4, and 6 years after TIPS creation were 27%, 38%, and 46%, respectively. At the median wait time until transplantation, patients had an 84% chance of being alive. TIPS dysfunction developed in 21% of patients; 30% of revisions occurred later than 2 years during follow-up. CONCLUSIONS: Beyond 2 years after TIPS creation, patency rates gradually decrease, mortality rates continue to increase, and the chance of recurrent ascites or bleeding remains present. Together, these findings suggest that continued clinical follow-up beyond 2 years is necessary in patients with a TIPS created with an ePTFE-covered stent graft.

Should all inflow stenoses be treated in failing autogenous hemodialysis fistulae?

PURPOSE: To determine whether angioplasty of inflow stenosis in malfunctioning but patent autogenous hemodialysis fistulae has an impact on postintervention primary patency in patients without a clinical indicator of inflow-related access malfunction. MATERIALS AND METHODS: Medical records for 76 procedures in 62 patients with inflow stenoses undergoing fistulography in nonthrombosed mature autogenous fistulae without an inflow-related indication of access malfunction over a 5-year period were reviewed retrospectively. Control and treatment arms were defined as patients with untreated (26 procedures in 23 patients) and treated (50 procedures in 39 patients) inflow stenoses, respectively. All patients in both arms of the study had concurrent intrafistula and/or venous outflow stenosis, which were treated successfully with angioplasty. The clinical endpoint was defined as return for a failing or thrombosed access (ie, primary patency). A two-tailed unpaired Student t test was performed to compare primary patency and percent inflow stenosis in treatment (angioplasty) and control (untreated inflow stenoses) groups, with significance defined at P < .05. Kaplan-Meier analysis was performed. RESULTS: There was no significant difference in percent inflow stenosis between control and treatment arms (P = .95). There was no significant difference in access patency between the two groups (139 and 124 d for control and treated groups, respectively; P = .95). No procedural complications occurred in either arm of the study. CONCLUSIONS: Angioplasty of inflow stenosis in failing autogenous fistulae without an appropriate clinical indicator of an inflow pathologic process does not improve postintervention primary patency.

Comparison of polyvinyl alcohol microspheres and tris-acryl gelatin microspheres for uterine fibroid embolization: results of a single-center randomized study.

PURPOSE: To assess the efficacy of two embolic agents in the treatment of symptomatic uterine leiomyomas. MATERIALS AND METHODS: A randomized, prospective, single-center study enrolled 60 women with symptomatic uterine leiomyomas. Uterine artery embolization (UAE) with spherical polyvinyl alcohol (SPVA) microspheres (n = 30; 700-900 µm and 900-1,200 µm; near-stasis or stasis endpoint) and tris-acryl gelatin (TAG) microspheres (n = 30; 500-700 µm; "pruned-tree" endpoint) was performed. Infarction rates were calculated for the dominant tumor and for small (< 2 cm) and large (> 2 cm) nondominant tumors. The primary endpoint was tumor infarction at 24 hours measured by contrast-enhanced magnetic resonance imaging assessed by a blinded reviewer. RESULTS: Baseline characteristics were similar between groups. The primary endpoint was similar in both treatments (≥ 91% dominant tumor infarction; SPVA. 86.2%; TAG, 93.3%, P = .35). Complete infarction (100%) was also similar between arms at 24 hours and 3 months. Symptom severity was reduced and quality of life improved equally at 3 and 12 months in each treatment group. Complications were minor in both groups. CONCLUSIONS: Uterine leiomyoma infarction at 24 hours and 3 months after treatment with SPVA or TAG microspheres was comparable when using near-stasis as a procedural endpoint with SPVA microspheres. Symptom relief was maintained for as long as 12 months for both embolic agents.

Integrated Capecitabine-Temozolomide with Radioembolization for Liver-Dominant G2 NETs: Long-Term Outcomes of a Single-Institution Retrospective Study.

PURPOSE: Capecitabine-Temozolomide (CapTem) is an oral chemotherapy regimen for NETs. Both drugs are radiosensitizers. Integrating CapTem and Y90 transarterial radioembolization (TARE) in patients with grade 2 neuroendocrine tumor (NET) liver metastases achieved an encouraging objective response rate (ORR) and progression-free survival (PFS) in a feasibility study. This study expands that report to a larger cohort with longer follow-up. METHODS: Therapy consisted of monthly cycles of capecitabine 600 mg/m2 twice daily for 14 days and temozolomide 150-200 mg/m2 on day 10-14. Simulation angiography was performed during the initial cycle. The dominant lobe was treated with 90Y-resin microspheres using BSA dosimetry on day 7 of the second cycle of CapTem. Patients with bilobar disease had the other lobe treated on day 7 of the third or fourth cycle. CapTem was continued until progression or intolerance. Clinical and laboratory assessment was done monthly and imaging every 3 months. RESULTS: 35/37 patients completed the prescribed regimen. Primary sites of disease were pancreas (16), lung (10), gut (7) and unknown (4). Mean duration of CapTem was 12 months (range, 4-32 months). ORR in the liver was 72% with a disease control rate of 100%. Median PFS was 36 months (95% CI, 25-45 months). Median overall survival was 41 months (95% CI, 24-87 months) from initiation of CapTemY90 therapy and 130 months (95% CI, 56-172 months) from initial diagnosis. CONCLUSION: Chemoradiation with CapTem and TARE provided durable control of G2 NET liver metastases for substantially longer than expectations for embolotherapy or chemotherapy alone.

Objective and subjective assessment of physician labor and resource utilization in maintenance percutaneous transluminal angioplasty of nonthrombosed hemodialysis arteriovenous fistulas versus arteriovenous grafts.

PURPOSE: To complement prior studies that have shown that arteriovenous fistula (AVF) thrombectomies require more time and equipment than arteriovenous graft (AVG) thrombectomies by measuring work via established instruments to determine whether there is also a difference in maintenance percutaneous transluminal angioplasty (PTA) of nonthrombosed AVFs versus AVGs. MATERIALS AND METHODS: PTA procedures performed on a consecutive cohort of 42 patients with AVFs and 27 patients with AVGs were prospectively compared. To quantify resource utilization, procedure time and disposable equipment were measured. Established instruments developed by the American Medical Association for Current Procedural Terminology code valuation were used to measure subjective "physician work," including mental effort and judgment, technical skill, physical effort, and psychological stress. These items were scored by 1 of 12 attending interventional radiology physicians performing the procedure. RESULTS: Mean PTA procedure time was 74 minutes (range, 18-183 minutes) for AVFs and 71 minutes (range, 28-204 minutes) for AVGs; hemostasis time was 12 minutes for AVFs and 11 minutes for AVGs. There was no significant difference in equipment use between groups. "Physician work" for AVFs scored significantly higher in four categories (P≤ .05). CONCLUSIONS: Using established subjective instruments, maintenance PTA of AVFs was scored as more cognitively, physically, and psychologically demanding than maintenance PTA of AVGs. However, there was no significant difference in resource utilization between maintenance PTA of AVFs versus AVGs, as has been previously shown with thrombectomy of thrombosed AVFs and AVGs.

Percutaneous computed tomography-guided renal mass radiofrequency ablation versus cryoablation: doses of sedation medication used.

PURPOSE: To compare the amount of sedation medication administered during radiofrequency (RF) ablation versus cryoablation of small renal masses. MATERIALS AND METHODS: Records were retrospectively reviewed in patients who underwent percutaneous computed tomography-guided RF ablation and cryoablation of small renal masses from January 2002 to June 2011 for patient and tumor characteristics, amount of medications used for moderate sedation, and complications. Sedation was performed by giving patients titrated doses of midazolam and fentanyl. Additional medications were given if the desired level of sedation was not achieved. RESULTS: There were 116 patients who underwent 136 ablation procedures; 71 patients underwent RF ablation, and 65 patients underwent cryoablation. RF ablation was associated with a significantly higher mean dose of fentanyl (mean dose for RF ablation, 236.43 µg; mean dose for cryoablation, 172.27 µg; P<.001). RF ablation was also associated with a higher mean dose of midazolam (mean dose for RF ablation, 4.5 mg; mean dose for cryoablation, 3.27 mg; P<.001). In the RF ablation group, two patients required additional sedation with droperidol. As a result of oversedation, two patients in the RF ablation cohort required sedation reversal with naloxone and flumazenil. None of the patients who underwent cryoablation required sedation reversal. No other sedation-related complications occurred. CONCLUSIONS: Cryoablation of small renal masses was performed with less sedation medication than RF ablation. This finding suggests renal cryoablation is less painful than RF ablation; however, prospective studies with validated pain scales are needed to confirm these results.

Catheter-based intraaccess blood flow measurement as a problem-solving tool in hemodialysis access intervention.

PURPOSE: To investigate retrospectively the use of catheter-based intraaccess blood flow measurements as an adjunct to physical examination and fistulography in hemodialysis access interventions. MATERIALS AND METHODS: Among 1,540 dialysis interventions performed at a single institution in a 2.5-year period, 104 qualifying catheter-based flow measurements were made in 70 mature native fistula interventions in 55 patients and 34 graft interventions in 31 patients. The flow rate threshold prompting intervention was generally 600 mL/min, but some variation existed depending on the clinical setting. RESULTS: The most common indication for measurement of blood flow was to determine the hemodynamic significance of a fistula inflow stenosis (n = 25), of which only four had subsequent intervention. Other common indications included decision-making resulting in further angioplasty or stent implantation of noninflow lesions (fistulas, n = 10; grafts, n = 23) versus termination of the procedure (n = 23), problem-solving in cases in which there was no visible lesion to explain the clinical indicator of access failure (n = 17), evaluation for high-flow-related cardiac risk in aneurysmal fistulas (n = 13), suboptimal evaluation of the inflow (n = 8), and suboptimal physical examination (n = 6). Overall, flow measurements supported a decision to perform angioplasty (n = 11) or stent placement (n = 3) in 17% of fistula interventions and 35% of graft interventions. CONCLUSIONS: The major benefit of flow measurement was to support a decision to withhold further angioplasty or stent placement.

Outcomes of percutaneous interventions in transposed hemodialysis fistulas compared with nontransposed fistulas and grafts.

PURPOSE: To compare postpercutaneous intervention outcomes of autogenous venous-transposition arteriovenous fistulas (AVFs) versus those of autogenous nontransposed AVFs (nAVFs) and prosthetic arteriovenous grafts (AVGs). MATERIALS AND METHODS: A total of 591 hemodialysis accesses (195 transposed AVFs [tAVFs], 205 nAVFs, 191 AVGs) in 522 patients (278 male; mean age, 57 y; range, 15­91 y) underwent percutaneous transluminal angioplasty (PTA) and/or mechanical thrombectomy (ie, declotting). Access characteristics, surgical history, percutaneous interventions, postinterventional primary and secondary access patency, and follow-up data were collected. Cox proportional-hazards regression analyses, Fisher exact tests, and χ2 tests were performed. RESULTS: Mean follow-up period was 32 months. Mean access ages at initial percutaneous intervention were 260 days (tAVF), 206 days (nAVF), and 176 days (AVG; P < .01). One-year postinterventional primary patency (PIPP) rates were 25% (tAVF), 24% (nAVF), and 14% (AVG). One-year postinterventional secondary patency (PISP) rates were 77% (tAVF), 61% (nAVF), and 63% (AVG). Median PIPP durations were 138 days (tAVF), 121 days (nAVF), and 79 days (AVG; P = .0001). Median PISP durations were 1,076 days (tAVF), 783 days (nAVF), and 750 days (AVG; P = .019). Total interventions needed to maintain PISP were 2.4 (tAVF), 1.3 (nAVF), and 3.2 (AVG) per patient-year (P < .001), which included 1.9, 1.2, and 1.4 PTAs (P < .01) and 0.45, 0.15, and 1.8 declotting procedures, respectively (P < .001). CONCLUSIONS: Based on the number of percutaneous interventions needed to maintain PISP, these results confirm the current Dialysis Outcomes Quality Initiative access preference of nAVFs before tAVFs before AVGs. tAVFs offered superior postinterventional outcomes than AVGs. With additional interventions, tAVFs could even outperform nAVFs in terms of PISP.

Removal of fractured inferior vena cava filters: feasibility and outcomes.

PURPOSE: To examine the feasibility and outcomes of removing retrievable inferior vena cava (IVC) filters that have fractured. MATERIALS AND METHODS: Retrospective review of IVC filter retrievals over an 8-year period identified patients in whom there was an attempt to retrieve fractured filters and struts. Patient medical records were evaluated for filter type, recovery method for filter body and struts, removal attempt results, and complications. RESULTS: Between January 2002 and December 2010, 148 IVC filters were retrieved, 15 of which were fractured. All 15 fractured filter bodies were successfully retrieved. Nine of 15 fractured filters (60%) were removed in their entirety by using endobronchial forceps to retrieve the filter body and/or fractured struts. In three cases, forceps were used to retrieve the filter body and the fractured strut was removed with a snare. In six patients (40%), only the filter body could be removed, three with the Recovery Cone and three with endobronchial forceps. Failed attempts to remove fractured struts were made in three cases, with no attempt made in the remaining three. These struts were incorporated in the right ventricle, embedded in the IVC wall, or extraluminal. Minor caval defect was identified in five of 15 retrievals (33%); mild hemoptysis was noted in one case in which the strut was snared from a pulmonary artery. No major complications occurred. CONCLUSIONS: Fractured IVC filter bodies can be safely removed. Fractured filter struts can be removed when accessible, but are often in a position that makes retrieval not possible.

Impact on renal function of percutaneous thermal ablation of renal masses in patients with preexisting chronic kidney disease.

PURPOSE: To examine the effect of percutaneous thermal ablation of renal masses on renal function among patients with baseline chronic kidney disease (CKD). MATERIALS AND METHODS: Patients with baseline CKD (initial glomerular filtration rate [GFR] < 60 mL/min/1.73 m(2)) who underwent percutaneous cryoablation or radiofrequency (RF) ablation of renal masses were reviewed. RESULTS: A total of 48 patients with a GRF of 60 mL/min/1.73 m(2) or lower were treated with renal cryoablation or RF ablation and had follow-up GFR measurement 1 month afterward. Mean patient age was 73 years (range, 47-89 y). Cryoablation was performed in 22 patients and RF ablation was performed in 26. Mean tumor diameter was 3.4 cm (range, 0.9-10.2 cm). Mean overall GFRs were 39.8 mL/min/1.73 m(2) at baseline and 39.7 mL/min/1.73 m(2) at 1 month after ablation (P = .85). A total of 38 patients had 1-year follow-up GFR measurement (cryoablation, n = 18; RF ablation, n = 20), and their mean GFR was 40.9 mL/min/1.73 m(2) ± 11.4 (SD), compared with a preablation GFR of 41.2 mL/min/1.73 m(2)(P = .79). In the cryoablation group, mean GFRs at 1 month and 1 year were 41.4 mL/min/1.73 m(2) and 44.4 mL/min/1.73 m(2), compared with respective baseline GFRs of 41.1 mL/min/1.73 m(2) and 42.1 mL/min/1.73 m(2) (P = .75 and P = .19, respectively). In the RF ablation group, mean GFRs at 1 month and 1 year were 38.2 mL/min/1.73 m(2) and 37.8 mL/min/1.73 m(2), compared with respective baseline GFRs of 38.7 mL/min/1.73 m(2) and 40.4 mL/min/1.73 m(2) (P = .58 and P = .09, respectively). CONCLUSIONS: Independent of ablation modality, percutaneous renal mass ablation does not appear to affect renal function among patients with CKD.