Robert K. Ryu

Intravascular US–Guided Portal Vein Access: Improved Procedural Metrics during TIPS Creation

PURPOSE To evaluate transjugular intrahepatic portosystemic shunt (TIPS) outcomes and procedure metrics with the use of three different image guidance techniques for portal vein (PV) access during TIPS creation. MATERIALS AND METHODS A retrospective review of consecutive patients who underwent TIPS procedures for a range of indications during a 28-month study period identified a population of 68 patients. This was stratified by PV access techniques: fluoroscopic guidance with or without portography (n = 26), PV marker wire guidance (n = 18), or intravascular ultrasound (US) guidance (n = 24). Procedural outcomes and procedural metrics, including radiation exposure, contrast agent volume used, procedure duration, and PV access time, were analyzed. RESULTS No differences in demographic or procedural characteristics were found among the three groups. Technical success, technical success of the primary planned approach, hemodynamic success, portosystemic gradient, and procedure-related complications were not significantly different among groups. Fluoroscopy time (P = .003), air kerma (P = .01), contrast agent volume (P = .003), and total procedural time (P = .02) were reduced with intravascular US guidance compared with fluoroscopic guidance. Fluoroscopy time (P = .01) and contrast agent volume (P = .02) were reduced with intravascular US guidance compared with marker wire guidance. CONCLUSIONS Intravascular US guidance of PV access during TIPS creation not only facilitates successful TIPS creation in patients with challenging anatomy, as suggested by previous investigations, but also reduces important procedure metrics including radiation exposure, contrast agent volume, and overall procedure duration compared with fluoroscopically guided TIPS creation.

Percutaneous Management of Malignant Biliary Obstruction

Malignancy resulting in impaired biliary drainage includes a number of diagnoses familiar to the interventional radiologist. Adequate drainage of such a system can significantly improve patient quality of life, and can facilitate the further treatment options and care of such patients. In the setting of prior instrumentation, cholangitis can present as an urgent indication for drainage. Current initial interventional management of malignant biliary duct obstruction frequently includes endoscopic or percutaneous intervention, with local practices and preprocedural imaging guiding interventional approaches and subsequent management. This article addresses the indications for percutaneous drainage, technical considerations in performing such drainage, and specific techniques useful in attempting to achieve clinical end points in patients with malignant biliary duct obstruction.

A Comparison of Retrievability: Celect versus Option Filter

PURPOSE To compare the retrievability of 2 potentially retrievable inferior vena cava filter devices. MATERIALS AND METHODS A retrospective, institutional review board-approved study of Celect (Cook, Inc, Bloomington, Indiana) and Option (Rex Medical, Conshohocken, Pennsylvania) filters was conducted over a 33-month period at a single institution. Fluoroscopy time, significant filter tilt, use of adjunctive retrieval technique, and strut perforation in the inferior vena cava were recorded on retrieval. Fisher exact test and Mann-Whitney-Wilcoxon test were used for comparison. RESULTS There were 99 Celect and 86 Option filters deployed. After an average of 2.09 months (range, 0.3-7.6 mo) and 1.94 months (range, 0.47-9.13 mo), respectively, 59% (n = 58) of patients with Celect filters and 74.7% (n = 65) of patients with Option filters presented for filter retrieval. Retrieval failure rates were 3.4% for Celect filters versus 7.7% for Option filters (P = .45). Median fluoroscopy retrieval times were 4.25 minutes for Celect filters versus 6 minutes for Option filters (P = .006). Adjunctive retrieval techniques were used in 5.4% of Celect filter retrievals versus 18.3% of Option filter retrievals (P = .045). The incidence of significant tilting was 8.9% for Celect filters versus 16.7% for Option filters (P = .27). The incidence of strut perforation was 43% for Celect filters versus 0% for Option filters (P < .0001). CONCLUSIONS Retrieval rates for the Celect and Option filters were not significantly different. However, retrieval of the Option filter required a significantly increased amount of fluoroscopy time compared with the Celect filter, and there was a significantly greater usage of adjunctive retrieval techniques for the Option filter. The Celect filter had a significantly higher rate of strut perforation.

Defining Prolonged Dwell Time: When Are Advanced Inferior Vena Cava Filter Retrieval Techniques Necessary?: An Analysis in 762 Procedures

Background— Despite growth in placement of retrievable inferior vena cava filters, retrieval rates remain low. Filters with extended implantation times present a challenge to retrieval, where standard techniques often fail. The development of advanced retrieval techniques has positively impacted retrieval of retrievable inferior vena cava filters with prolonged dwell times; however, there is no precise definition of the time point when advanced techniques become necessary. We aim to define prolonged retrievable inferior vena cava filters dwell time by determining the inflection point when the risk of standard retrieval technique failure increases significantly, necessitating advanced retrieval techniques to maintain overall technical success of retrieval. Methods and Results— From January 2009 to April 2015, 762 retrieval procedures were identified from a prospectively acquired database. We assessed patient age/sex, filter dwell time, procedural technical success, the use of advanced techniques, and procedure-related adverse events. Overall retrieval success rate was 98% (n=745). When standard retrieval techniques failed, advanced techniques were used; this was necessary 18% of the time (n=138). Logistic regression identified that dwell time was the only risk factor for failure of standard retrieval technique (odds ratio, 1.08; 95% confidence interval, 1.05–1.10; P<0.001). Spline function regression analysis demonstrated that if dwell time exceeded 7 months, the risk of standard technique failure was 40.9%. Adverse events occurred at a rate of 2% (n=18; 15 minor and 3 major). Conclusions— The necessity of advanced techniques to maintain technical success of retrieval increases with dwell time. Patients with retrievable inferior vena cava filters in place beyond 7 months may benefit from referral to centers with expertise in advanced filter retrieval.

#TwittIR: Understanding and Establishing a Twitter Ecosystem for Interventional Radiologists and Their Practices

The use of social media among interventional radiologists is increasing, with Twitter receiving the most attention. Twitter is an ideal forum for open exchange of ideas from around the world. However, it is important for Twitter users to gain a rudimentary understanding of the many potential communication pathways to connect with other users. An intentional approach to Twitter is vital to efficient and successful use. This article describes several common communication pathways that can be utilized by physicians in their interventional radiology practice.

Anatomic and Technical Considerations: Inferior Vena Cava Filter Placement

Inferior vena cava (IVC) filters play an important role in preventing pulmonary embolism in patients with deep venous thrombosis. When preparing for IVC filter placement, there are several important anatomic and technical considerations. The IVC has complex embryologic origins, and normal variants are relatively common which may necessitate a change in technique or approach. When performing the procedure, the choice in imaging modality for deployment, location of deployment, and route of access must be considered. The pediatric and pregnant populations present unique situations that require special consideration and close examination of indications and contraindications.

National Trends and Outcomes of Transjugular Intrahepatic Portosystemic Shunt Creation Using the Nationwide Inpatient Sample

PURPOSE To elucidate trends in transjugular intrahepatic portosystemic shunt (TIPS) use and outcomes over the course of a decade, including predictors of inpatient mortality and extended length of hospital stay. MATERIALS AND METHODS The Nationwide Inpatient Sample was interrogated for the most recent 10 years available: 2003-2012. TIPS procedures and associated diagnoses were identified via International Classification of Diseases (version 9) codes, with the latter categorized into primary diagnoses in a hierarchy of disease severity. Linear regression analysis was used to determine trends of TIPS use and outcomes over time. Independent predictors of mortality and extended length of stay were determined by logistic regression. RESULTS A total of 55,145 TIPS procedures were captured during the study period. Annual procedural volume did not change significantly (5,979 in 2003, 5,880 in 2012). The majority of TIPSs were created for ascites and/or varices (84%). Inpatient mortality (12.5% in 2003, 10.6% in 2012; P < .05) decreased but varied considerably by diagnosis (from 3.7% to 59.3%), with a disparity between bleeding and nonbleeding varices (18.7% vs 3.8%; P < .01). Multivariate predictors of mortality (P < .001 for all) included primary diagnoses (bleeding varices, hepatorenal and abdominal compartment syndromes), patient characteristics (age > 80 y, black race), and sequelae of advanced cirrhosis (comorbid hepatocellular carcinoma, spontaneous bacterial peritonitis, encephalopathy, and coagulopathy). CONCLUSIONS National TIPS inpatient mortality has decreased since 2003 while procedural volume has not changed. Postprocedural outcome is a function of patient demographic and socioeconomic factors and associated diagnoses. Independent predictors of poor outcome identified in this large national population study may aid clinicians in better assessing preprocedural risk.

Vena Cava Filter Retrieval with Aorto-Iliac Arterial Strut Penetration

PurposeTo evaluate the safety and technical success of inferior vena cava (IVC) filter retrieval in the setting of aorto-iliac arterial strut penetration.Materials and MethodsIVC filter registries from six large United States IVC filter retrieval practices were retrospectively reviewed to identify patients who underwent IVC filter retrieval in the setting of filter strut penetration into the adjacent aorta or iliac artery. Patient demographics, implant duration, indication for placement, IVC filter type, retrieval technique and technical success, adverse events, and post procedural clinical outcomes were identified. Arterial penetration was determined based on pre-procedure CT imaging in all cases. The IVC filter retrieval technique used was at the discretion of the operating physician.ResultsSeventeen patients from six US centers who underwent retrieval of an IVC filter with at least one strut penetrating either the aorta or iliac artery were identified. Retrieval technical success rate was 100% (17/17), without any major adverse events. Post-retrieval follow-up ranging from 10 days to 2 years (mean 4.6 months) was available in 12/17 (71%) patients; no delayed adverse events were encountered.ConclusionsFindings from this series suggest that chronically indwelling IVC filters with aorto-iliac arterial strut penetration may be safely retrieved.

Response by Desai et al to Letter Regarding Article, “Defining Prolonged Dwell Time: When Are Advanced Inferior Vena Cava Filter Retrieval Techniques Necessary? An Analysis in 762 Procedures”

We appreciate the commentary by Drs Jia and Jiang on our study1 and offer a response. The intent of this study was to identify a retrievable inferior vena cava filter (rIVCF) dwell time when the risk of standard retrieval technique failure increases significantly, thereby requiring advanced techniques to maintain overall technical success. At 7 …