Things Surgeons Should Know Before Placing IVC Filters
Johnson, S., McKenney, K., Boneva, D., Deeter, M, Ang, D., Barquist, E., McKenney, M.
Department of Trauma Surgery, Kendall Regional Medical Center, University of South Florida School of Medicine
Objective:
Understanding the inferior vena cava (IVC) anatomy can affect the surgical outcomes of IVC filter placement. Our
goal was to evaluate admission CTs on trauma patients to define the IVC anatomy for safe landing zones (LZ) and
identify anatomic variations that could impact placement.
Methods:
Admission CT’s were reviewed on 500 trauma patients. The landing zone was defined as the point equidistant from
the lowest renal vein to the bifurcation into the iliac veins. The thoracic and lumbar vertebral bodies were used to
anatomically identify the location of the renal veins and the bifurcation into the iliac veins. The IVC diameter was
determined from CT cross sectional imaging. Filters are normally intended for IVCs up to 28 mm. Additional
anatomic anomalies were identified using the admission CT that would affect the planning and placement of IVC
filters.
Results:
We reviewed 518 patients that had an admission abdominal/pelvic CT. The admission CT for 500 of 518 (96.5%)
trauma alert patients was of sufficient quality to accurately evaluate the IVC. The third lumbar vertebra was
identified as a safe landing zone in 476 of 500 (95.2%) (Graph 1).
The CT cross sectional diameter ranged from 14.9 cm to 36.8 cm. There were 41 (8.2%) patients who had a giant
IVC that was over 28 mm. Additional anatomic anomalies that included duplicate IVC and extra renal veins that
would affect IVC filter placement were present in 6 of 500 (1.2%) (Graph 2).
Conclusion:
The admission CT on trauma patients can be used to define the IVC for filter placement. The third lumbar region of
the IVC was a safe landing zone for IVC filters in over 95% of patients. Anatomical anomalies affecting IVC filter
placement were revealed in 9.4% of patients. The most common anatomic abnormality was a giant IVC. Other
anatomic variants that would affect IVC filter placement included duplicate IVC and extra renal veins.
Kendall Regional Medical Center ▪ 11750 Bird Road, Miami, FL 33175
Phone: 786-315-5935 ▪ Fax: 305-227-5556 ▪ Email: Sean.Johnson2@HCAHealthcare.com
Graph 1: depicts the location of the lowest
renal vein and IVC bifurcation as it relates to
the vertebral bodies, T12=12th thoracic
vertebral body, L1-5 = lumbar vertebral
bodies, S1 = sacrum
Graph 2: reveals the IVC anatomic anomalies
Graph 2
45
40
35
30
25
20
15
10
5
0
41
(8.2%)
3
(0.6%)
Giant IVC
(>28.0mm)
3
(0.6%)
Duplicate IVC Double/Triple
Renal Veins