Faculty Bibliography

Purpose: TIPS creation fails to control ascites in 40% or more of patients, but the variables predicting outcome are unclear, with prior studies highlighting pre-TIPS portosystemic gradient (PSG) (Nair et al 2004; JVIR 15:1431). We studied which variables predict outcome of TIPS for refractory ascites. Materials and Methods: We retrospectively identified patients who underwent TIPS for refractory ascites between 1/12 and 5/14, yielding 40 patients. We excluded 17 patients due to insufficient peri-procedural documentation or technical failures, leaving 23 patients (16 men, 7 women, mean age 60 +/-2 yrs) for assessment of variables influencing osmotic (albumin and sodium levels) and hydrostatic (pre- and post- TIPS PSG and large varices) pressure. Responders were defined as those requiring fewer or no paracenteses; nonresponders had persistent ascites, with similar pre-TIPS frequency of therapeutic paracentesis. Complications within 1 month requiring hospitalization were noted. Multiple logistic regression, Mann-Whitney U tests, and one-tailed chi² tests assessed group differences. Results: Ten patients (43%: responders) had documented improvement in ascites. Multiple logistic regression including pre- and post-TIPS PSG significantly impacted outcome (p=0.04). Post- but not pre-TIPS PSG predicted outcome (p=0.04 vs. p=0.84). Responders had significantly lower post- TIPS gradient (5.8) compared with non-responders (7.6) (p=0.02). In contrast, responders and non-responders did not differ in albumin (2.7 vs. 2.7) or sodium (136 vs. 134) levels, or pre-TIPS gradient (13.9 vs. 14.7 mmHg) (p>0.05). Similar numbers of responders (50%) had large varices compared to non-responders (61%) (p=0.3). Responders (50%) had significantly more complications compared to non-responders (15%) (p=0.04), mostly encephalopathy (85%) requiring hospitalization. Conclusion: Only post-TIPS PSG predicted which patients had significantly reduced ascites, in contrast to prior studies suggesting importance of pre-TIPS gradient. Findings suggest aggressively lowering the gradient below 6 mmHg may be the most reliable technique to improve outcomes, although with expected higher risk of complications

Purpose: To evaluate if there is a significant difference in retrieval difficulty as determined by fluoroscopy time and equipment use when comparing three different filters: Denali, ALN, and Option/Option Elite. Materials and Methods: Retrospective analysis was performed of 33 filter retrievals performed over a 24 month period (12 men, 21 women; mean age 60). There were 8 Denali (Bard Peripheral Vascular), 9 ALN (ALN Implants), and 16 Option/ Option Elite (Argon Medical Devices) filter retrievals. Demographics, filter dwell time, fluoroscopy time during retrieval, and equipment used for retrieval were collected for each case. One Option case was excluded due to unsuccessful retrieval. Kruskal-Wallis H, two sample t-test and Chi-square analysis were used to determine significant differences in fluoroscopy time and equipment use between the three filter groups. Results: There were no significant differences between groups based on demographics or filter dwell time. Mean retrieval times were 4.9 min (SD: 3.6, range 1.2-10.3) for Denali, 9.9 min (SD: 5.5, range 2.9-18.6) for ALN, and 23.9 min (SD: 20.0, range 2.5 - 58) for Option/Option Elite. A Kruskal-Wallis H test showed a significant difference in these times (chi²=7.17, p=0.028), subsequent post-hoc analysis showed a significant difference only between Denali and Option but not between Denali and ALN or ALN and Option. Given normal distribution of fluoroscopy times for Denali and ALN, a separate t-test comparing these two filters did demonstrate a significant difference in fluoroscopy time (p=0.023). None of the Denali retrievals required additional equipment beyond a snare and sheath, 1/9 (11%) of ALN and 10/15 (67%) of Option retrievals required at least a tip deflecting wire or angled catheter (chi²=11.07, p=0.004). Sub-analysis separating Option and Option Elite filters did not change any results significantly. Conclusion: Denali filter retrieval involves significantly less fluoroscopy time than ALN or Option/Option Elite filter retrieval. In this series, Option/Option Elite retrieval also required significantly more equipment to achieve technical success compared to Denali and ALN retrieval. A larger sample size is required to corroborate these early results. (Table Presented)

Learning Objectives: Learn to utilize artificial ascites to safely perform radiofrequency ablation of subdiaphragmatic hepatocellular carcinoma. Background: RFA is an effective treatment of HCC. A relative contraindication is subdiaphragmatic tumor location because the diaphragm is at increased risk of thermal injury. Artificial ascites of 5-10 mm thickness creates a protective space between the tumor and diaphragm. 5% dextrose in water (D5W) is used because it provides greater electric isolation than normal saline. The ascites decreases post-procedural pain and recovery time without sacrificing efficacy because there is no significant associated heat sink effect. Clinical Findings/Procedure Details: Ultrasound guidance is used to advance a 20-gauge needle into the peritoneal cavity. If the tumor is in the right hepatic lobe, a subcostal approach along the anterior axillary line is used. If the tumor is in the left hepatic lobe, a subcostal epigastric approach is used. A small amount of D5W (20-50 mL) is injected to create a space for placement of an 8 French pigtail catheter. Placement of the catheter close to the tumor, between the liver and diaphragm is desirable. The catheter is infused with D5W and creation of artificial ascites is monitored under ultrasound or CT. Artificial ascites improves the sonic window for ultrasound guided placement of the RFA probe. If the tumor remains difficult to visualize, CT guidance is used for probe placement. Following completion of ablation, the catheter is drained to gravity. Blood tinged fluid is common following the procedure. The catheter is left in place 12-24 hours to drain residual ascites and prevent hemoperitoneum. Other potential complications include peritonitis, pleuritic chest pain, and pleural effusion. Conclusion and/or Teaching Points: Artificial ascites can effectively decrease risk of thermal injury to the diaphragm, post-procedural pain, and recovery time without sacrificing efficacy of subdiaphragmatic HCC radiofrequency ablation. The infusion catheter should be placed close to the tumor, between the liver and diaphragm, to create 5-10 mm thickness of D5W artificial ascites. The catheter should be drained for 12-24 hours post-procedurally to remove residual ascites and decrease risk of hemoperitoneum