Indications for insertion of IVC filters were separated into 7 categories and are listed in Table 1. Of the 536 filters, 31 filters were permanent, nonretrievable, while 505 were classified as retrievable. Ten complications occurred during the removal of permanent filters, while 22 occurred during the removal of retrievable filters, yielding complication rates of 32.3% and 4.4%, respectively. The complication rates associated with the removal of specific types of permanent filters and retrievable filters are summarized in Tables 2 and 3, respectively. Overall, 97.9% (525/536) of the filters were successfully removed, of which a 6.0% complication rate (32/536) was observed. The isolated snare technique was attempted in 347 retrievals, isolated forceps were utilized in 105 cases, and a combination of both loop snare and forceps was used in 68 cases. Removal was not attempted in seven cases due to chronic thrombus where risks of removal outweighed benefits and/or recurrent pulmonary embolism. Success rates and graded complication rates for these different retrieval techniques are summarized in Tables 4 and 5.
Table 1
Indications for IVC filter placement.
Indication for IVC filter placement | Number of filters |
Contraindication to anticoagulation in the setting of VTE | 187/536 (34.9%) |
Placement in the pre/post operative period in setting of major surgery | 134/536 (25.0%) |
Pharmaco-mechanical thrombectomy for iliofemoral DVT | 22/536 (4.1%) |
Venous thromboembolism on therapeutic anticoagulation | 20/536 (3.7%) |
Extensive VTE | 39/536 (7.3%) |
Prophylactic placement (for example in trauma) | 20/536 (3.7%) |
Placement at outside hospital or with an unknown indication | 114/536 (21.3%) |
Table 2
Complications associated with attempted retrieval of permanent filters.
Permanent Filter Complications |
Filter Type | Grade 1–2 Complications (Minor) | Grade 3–5 Complications (Major) | Complication Rate |
Trapease | 2 | 1 | 17.6% (3/17) |
Venatech | 1 | 0 | 50% (1/2) |
Simon Nitinol | 3 | 0 | 60% (3/5) |
Greenfield | 1 | 1 | 33.3% (2/6) |
Birdsnest | 1 | 0 | 100% (1/1) |
Total | 8 | 2 | 32.3% (10/31) |
Table 3
Complications associated with attempted retrieval of retrievable filters.
Retrievable Filter Complications |
Filter Type | Grade 1–2 Complications (Minor) | Grade 3–5 Complications (Major) | Complication Rate |
Denali | 2 | 0 | 1.3% (2/157) |
Gunther Tulip | 4 | 1 | 3.4% (5/147) |
Optease | 0 | 0 | 0% (0.8) |
Bard G2 | 1 | 0 | 3.8% (1/26) |
Bard Recovery | 2 | 0 | 9.5% (2/21) |
Eclipse | 0 | 0 | 0% (0/5) |
Celect | 5 | 1 | 10.7% (6/56) |
Option | 3 | 0 | 4.1% (3/74) |
Bard | 3 | 0 | 42.9% (3/7) |
Total | 20 | 2 | 4.4% (22/505) |
Table 4
IVC filter retrieval data stratified by retrieval technique. Success rate, complication rate, and dwell time are recorded.
TECHNIQUE | # PATIENTS | DWELL TIME AVG (DAYS) | % SUCCESS | % COMPLICATIONS |
Solo SNARE | 347 | 658 | (345/347)99.4% | 1.7% (6/347) |
Solo FORCEPS | 105 | 2778 | (104/105) 98.8% | 13.3% (14/105) |
Loop Snare + Forceps | 68 | 1364 | (67/68) 98.0% | 16.2% (11/68) |
OVERALL | 536 | 1203 | (525/536) 97.9% | 6.0% (32/536) |
Table 5
Graded complications for each retrieval technique. If multiple complications occurred during a single procedure, then the complication with the highest grade was recorded.
Complications of IVC Filter Retrieval Based on Techniques of Removal |
| Grade 1 | Grade 2 | Grade 3 | Grade 4 | Grade 5 | Total |
Loop Snare | 0.58% (2/347) | 0.86% (3/347) | 0.29% (1/347) | 0% (0/347) | 0% (0/347) | 1.7% (6/347) |
Forceps | 7.6% (8/105) | 2.9% (3/105) | 1.9% (2/105) | 0.95% (1/105) | 0% (0/105) | 13.3% (14/105) |
Forceps + Loop Snare | 7.4% (5/68) | 8.8% (6/68) | 0% (0/68) | 0% (0/68) | 0% (0/68) | 16.2% (11/68) |
Other Methods and Failed Filter Access | 6.3% (1/16) | 0% (0/16) | 0% (0/16) | 0% (0/16) | 0% (0/16) | 6.3% (1/16) |
Total | 3.0% (16/536) | 2.2% (12/536) | 0.56% (3/536) | 0.19% (1/536) | 0% (0/537) | 6.0% (32/536) |
The isolated loop snare technique exhibited a success rate of 99.4% (345/347), with 1.7% (6/347) of patients experiencing complications. Among these filters, 9 were permanent, and 338 were retrievable. The majority of the complications in this cohort demonstrated low grade complications (Two Grade 1; 2/347, 0.58% and three Grade 2; 3/347, 0.86%). One patient experienced retroperitoneal bleeding after standard IVCF removal (Grade 3; 1/347, 0.29%). A higher complication profile was seen in removal of permenant filters (2/5 complications, 40%). Filters removed with the snare technique had a mean dwell time of 658 days, ranging from 1 day to 5713 days. The median dwell time was 221 days.
Among all cases in which forceps retrieval was attempted, there was an overall 98.8% success rate (171/173). Solo forceps filter retrieval had a 99.05% (104/105) success rate, though it also reported a higher complication profile compared to isolated loop snare: 13.3% (14/105). Furthermore, higher grade complications were also more prevalent with forceps retrieval (one Grade 4 ; 1/105, 0.95%; IVC rupture requiring intra-procedural placement of thoracic aortic stent graft, and two Grade 3; 2/105, 1.9%; retroperitoneal bleeding delaying discharge or requiring later hospitalization). Higher grade complications (grade 3 and 4) soley occurred during the removal of permanent filters. Eight low grade complications were observed (one Grade 1: 8/105, 7.6%; and three Grade 2 complications 3/105, 2.9%). The majority of low grade complications occurred with the removal of retrievabale filters (7/11, 63.6%). The mean dwell time was 2778 days, with a minimum dwell time of one day and a maximum of 10,075 days. The median dwell time was 2917 days.
Combined snare and forceps retrieval (failed snare removal converted to forceps or planned concurrent use of forceps and snare) was successful in 98.5% (67/68) of attempted removals, and complications occurred in 16.2% (11/68) of these procedures. Primarily, only low grade complications were observed with combined technique (five Grade 1 5/68, 7.4% and six Grade 2 6/68, 8.8%). Two of these minor complications (2/11, 18.2%) occurred during the attempted retrieval of a permanent filter. The mean dwell time was 1364 days (range: 4–7470 days). The median dwell time was 568 days.
Any attempted filter removal that utilized forceps, regardless of concurrent technique, was classified as a forceps-directed retrieval. Filters retrieved with forceps had a statistically significant longer dwell time (median: 1734 days; range(1-10075 days) compared to filters removed with the solo snare technique (median: 221 days; range(1-5713 days), (p < 0.001). Despite this difference in dwell time, there was no statistically significant difference in retrieval rate between these two techniques (p = 0.60). However, complications were less likely in the solo snare group compared to the forceps retrieval group (OR:0.10; 95%CI:0.04–0.25), (p < 0.001).