Complicated inferior vena cava filter retrievals: associated factors identified at preretrieval CT.

PURPOSE: To examine filter characteristics at preretrieval computed tomography (CT) that are associated with complicated inferior vena cava (IVC) filter retrieval procedures. MATERIALS AND METHODS: This study was HIPAA compliant, and informed consent was waived. Institutional review board-approved retrospective review of IVC filter retrievals between January 2002 and July 2011 was performed to identify patients with preretrieval CT in whom a complicated retrieval was performed, as defined by use of nonstandard techniques, filter fracture, filter tip incorporation into the IVC wall, and retrieval failure. Age- and sex-matched control subjects with standard IVC filter retrieval were used for comparison. Preretrieval CT images were evaluated for tilt angle in mediolateral and anteroposterior directions, CT appearance of tip embedding, degree of filter strut perforation, and distance of filter tip from the nearest renal vein. Dwell time was also recorded. Statistical analysis was performed by using the Fisher exact test, Student t test, and Wilcoxon signed-rank test, depending on the variables being evaluated, as well as multivariate logistic regression. RESULTS: Forty-eight patients with complicated retrievals and 48 control subjects with uncomplicated retrievals were evaluable for preretrieval CT characteristics. Mediolateral and anteroposterior tilt angle, degree of perforation, and dwell time were higher for the complicated versus non-complicated retrieval group (P < .01). Odds of complicated retrieval were increased 129-fold with CT appearance of tip embedding (P < .0001), with an odds ratio of 33 with a tilt angle of more than 15° in any direction (P < .0001), while perforation and dwell time increased risk of a complicated retrieval by 10.7 (P < .0001) and 2.3 (P < .05) times, respectively. Distance from renal veins was noncontributory. CONCLUSION: CT appearance of tip embedding, increased tilt angle, higher-grade perforation, and longer dwell times are associated with complicated IVC filter retrieval. Therefore, preretrieval CT may be warranted in select patients for identification of these characteristics to tailor retrieval approach or to arrange a referral to a tertiary center if necessary.

Removal of retrievable inferior vena cava filters with computed tomography findings indicating tenting or penetration of the inferior vena cava wall.

PURPOSE: To examine the feasibility and safety of removing retrievable inferior vena cava (IVC) filters with struts external to the IVC wall on computed tomography (CT) imaging. MATERIALS AND METHODS: This retrospective study included 64 IVC filter retrievals from 62 patients over a 5-year period. CT images obtained before retrieval were used to describe the various imaging characteristics of filter interactions with the IVC wall. Patient medical records were reviewed for filter type, results of filter removal with standard or nonstandard techniques, and complications. RESULTS: Filter struts outside the IVC wall were a common finding on CT with 55 (85.9%) filters showing some degree of perforation. Of 64 filters, 57 (89.1%) were removed successfully; 7 (10.9%) filters could not be removed because of incorporation of filter struts or tip into the IVC wall. Before retrieval, filter fracture was detected in eight (12.5%) cases, and IVC stenosis was present in three (4.7%) cases. No major complications occurred during any retrieval. Two (3.1%) cases were complicated by postprocedure abdominal pain. Both cases clinically resolved, and no abnormalities were detected on postprocedure CT. CONCLUSIONS: The appearance of filter struts tenting or penetrating the IVC wall is a common finding on CT performed before filter retrieval. IVC filters with these findings can be removed safely and should not be a contraindication for IVC filter retrieval.

Ruptured pseudoaneurysm of the internal maxillary artery complicating CT-guided fine-needle aspiration in an irradiated, surgical bed.

BACKGROUND: CT-guided fine-needle aspiration (FNA) is a safe procedure, but major complications can occur rarely. Pseudoaneurysm rupture in the head and neck region following CT-guided FNA is an emergency that can result in life-threatening hemorrhage. This case emphasizes the salient risk factors for pseudoaneurysm formation and rupture in the head and neck region following CT-guided FNA. METHODS: A patient was seen with oral and facial hemorrhage as a result of a ruptured pseudoaneurysm 11 weeks following CT-guided FNA in a previously irradiated surgical bed. RESULTS: The patient was treated with coil embolization in and around the pseudoaneurysm and discharged without any further complications. CONCLUSIONS: Although CT-guided FNA is a safe and effective procedure, some patients may be at increased risk for rare but major complications. Caution should be used in proceeding with CT-guided FNA in an irradiated surgical bed of the head and neck.