Value of delayed duplex ultrasound assessment after endothermal ablation of the great saphenous vein.

OBJECTIVE: Endothermal ablation (ETA) of the great saphenous vein (GSV) is associated with a small but definite risk of endothermal heat-induced thrombosis (EHIT) extending into the common femoral vein. Follow-up duplex ultrasound imaging to detect EHIT after ETA is considered standard of care, although the exact timing of duplex ultrasound imaging to detect EHIT after ETA remains unclear. We hypothesized that an additional duplex ultrasound assessment 1 week after ETA would not identify a significant number of patients with EHIT and would significantly increase health care costs. METHODS: This was a retrospective review of consecutive ETA GSV procedures from 2007 to 2014. All patients were evaluated with duplex ultrasound imaging on postprocedure day 1, and 79% of patients underwent a second ultrasound assessment 1 week postprocedure. EHIT was considered present when proximal GSV closure progressed to level ≥4, based on a six-tier classification system. RESULTS: From January 1, 2007, until December 31, 2014, 842 patients underwent GSV ETA. Patients with EHIT were more likely to have had a prior deep venous thrombosis (DVT; P = .002) and a larger GSV (P = .006). Forty-three procedures (5.1%) were classified as having EHIT requiring anticoagulation, based on a level ≥4 proximal closure level. Of the 43 patients with EHIT, 20 (47%) were found on the initial ultrasound assessment performed 24 hours postprocedure, but 19 patients (44%) with EHIT would not have been identified with a single postoperative ultrasound scan performed 24 hours after intervention. These 19 patients had a level ≤3 closure level at the duplex ultrasound scan performed 24 hours postprocedure and progressed to EHIT on the delayed duplex ultrasound scan. Lastly, thrombotic complications in four patients (9%), representing three late DVT and one DVT/pulmonary embolism presenting to another hospital, would not have been identified regardless of the postoperative surveillance strategy. Maximum GSV diameter was the only significant predictor of progression to EHIT on multivariate analysis (P = .007). Based on 2014 United States dollars, the two-ultrasound surveillance paradigm is associated with health care charges of $31,109 per identified delayed venous thromboembolism event. CONCLUSIONS: Delayed duplex ultrasound assessment after ETA of the GSV comes with associated health care costs but does yield a significant number of patients with progression to EHIT. Better understanding of the timing, risk factors, and significance of EHIT is needed to cost-effectively care for patients after ETA for varicose veins.

Perforation of the IVC: rule rather than exception after longer indwelling times for the Günther Tulip and Celect retrievable filters.

PURPOSE: This study was designed to assess the incidence, magnitude, and impact upon retrievability of vena caval perforation by Günther Tulip and Celect conical inferior vena cava (IVC) filters on computed tomographic (CT) imaging. METHODS: Günther Tulip and Celect IVC filters placed between July 2007 and May 2009 were identified from medical records. Of 272 IVC filters placed, 50 (23 Günther Tulip, 46%; 27 Celect, 54%) were retrospectively assessed on follow-up abdominal CT scans performed for reasons unrelated to the filter. Computed tomography scans were examined for evidence of filter perforation through the vena caval wall, tilt, or pericaval tissue injury. Procedure records were reviewed to determine whether IVC filter retrieval was attempted and successful. RESULTS: Perforation of at least one filter component through the IVC was observed in 43 of 50 (86%) filters on CT scans obtained between 1 and 880 days after filter placement. All filters imaged after 71 days showed some degree of vena caval perforation, often as a progressive process. Filter tilt was seen in 20 of 50 (40%) filters, and all tilted filters also demonstrated vena caval perforation. Transjugular removal was attempted in 12 of 50 (24%) filters and was successful in 11 of 12 (92%). CONCLUSIONS: Longer indwelling times usually result in vena caval perforation by retrievable Günther Tulip and Celect IVC filters. Although infrequently reported in the literature, clinical sequelae from IVC filter components breaching the vena cava can be significant. We advocate filter retrieval as early as clinically indicated and increased attention to the appearance of IVC filters on all follow-up imaging studies.

Removal of the G2 filter: differences between implantation times greater and less than 180 days.

PURPOSE: To investigate whether filters implanted for longer periods are more difficult or hazardous to remove. MATERIALS AND METHODS: A retrospective review of G2 inferior vena cava filter removals was performed. Objective measures reflecting the difficulty of the removal procedure were evaluated for differences required to remove a filter with an implantation period greater or less than 180 days. RESULTS: One hundred seventy of 174 G2 filters were successfully removed (97.7% success rate). There was no significant difference in the success rate (P = .86), total procedure time (P = .87), fluoroscopy time (P = .13), or contrast medium use (P = .22) required to remove filters implanted for more than 180 days compared to those implanted for a shorter period of time. There was no significant difference in the frequency of filter movement (P = .90), tilt (P = .87), and caval penetration (P = .41) between the two groups. Six filter fractures were observed, all with implantation times greater than 180 days. CONCLUSIONS: The removal of a G2 filter that has been in place for more than 180 days can be performed as easily, as safely, and with a similar degree of success as one that has been in place for less time. Movement, tilt, and penetration are early events after implantation that may have an effect on successful filter removal.