Temporary IVC Filter Reduces Neurosurgery Complications in Thrombophilic Patients

Thrombophilic patients undergoing elective neurosurgery who receive a temporary inferior vena cava (IVC) filter show dramatically fewer thrombotic or hemorrhagic complications compared with thrombophilia patients who do not have the filter placed, results from a randomized trial show.

"The use of a temporary IVC filter in thrombophilic patients that need elective cranial or spinal surgery is safe and statistically significantly lessens pulmonary embolisms, sudden death from saddle pulmonary embolism, and hemorrhagic complications due to early re-anticoagulation," said Scott Shapiro, MD, Robert J. Campbell professor of neurosurgery at the Indiana University School of Medicine, in Indianapolis.

He presented the findings as part of the virtual American Association of Neurological Surgeons (AANS) 2020 Annual Meeting.

"This is a very easy strategy to implement in this high risk group and I strongly recommend (the) adoption of this approach," he said.

Studies have underscored an increased risk of the development of venous thromboembolism (VTE) in thrombophilic patients undergoing surgeries such as hip or knee surgery, and a 2004 study showed the use of a permanent IVC filter in high-risk spine surgery patients eliminated the risk of pulmonary embolism, although the filter was linked to a 5% risk of symptomatic deep vein thrombosis (DVT).

To determine the effect of temporary IVC filter placement in patients undergoing neurosurgery, Shapiro and colleagues conducted a trial in which thrombophilic patients with multiple DVTs or pulmonary embolisms identified between 2003 and 2018 were randomized to placement or no placement of a temporary IVC filter.

In the temporary IVC filter group of 93 patients, the filter was placed 1 week prior to the elective surgery, when anticoagulation was stopped, and their anticoagulation was resumed and IVC filter removed 2 weeks after surgery. Among those patients, 17 received craniotomies and 76 had spine surgeries.

Of 94 patients who received no IVC filter, anticoagulation was stopped before surgery and then resumed 3-7 days post-surgery. Of those patients, there were 16 craniotomies and 78 spine surgeries.

The patients in each group were nearly identically matched in terms of age, gender, thrombophilias, obesity, and other measures.

Of patients receiving the temporary IVC placement, there were no pulmonary embolisms, hemorrhagic complications, or deaths.

The filters that were removed in those patients revealed that 20 (22%) had a clot in the filter that would have resulted in a pulmonary embolism. One patient had a nonoperative leg hematoma at the filter removal.

Among patients who did not receive a temporary IVC filter, there were 14 (15%) pulmonary embolisms, eight (9%) hemorrhagic complications requiring reoperation, and seven (7%) sudden deaths due to pulmonary embolism.

The use of the temporary IVC filter significantly reduced the risk of pulmonary embolism (P < .001), sudden death due to pulmonary embolism (P < .01), and hemorrhages requiring reoperation (P < .01).

A multivariate analysis adjusting for factors including sex, length of surgery, type of surgery, or type of thrombophilia showed that only the placement of a temporary IVC filter significantly reduced complications (P < .01).

Despite lacking key aspects of a full published clinical trial, such as being blinded, the study shows impressive results, suggested Frederick Barker, MD, a professor of neurosurgery, Harvard Medical School, in Boston, Massachusetts, commenting on the study as a statistical discussant.

"The treatment benefit appears clear – 7% fewer patients died with temporary IVC filters. This result is both statistically and clinically significant," he said.

"One fewer patient died for every 14 patients treated with filters – these results justify [Shapiro's] recommendation to adopt the treatment."

A caveat could include that the benefits apply to those meeting the strict criteria for the study, which included having a personal history of more than one DVT or pulmonary embolism and a known molecular or clinical risk factor for thrombophilia.

"For patients who match these limited criteria, the trial establishes better results with temporary filters," Barker said.

"For more common clinical scenarios, such as one prior pulmonary embolism or DVT, with or without additional known thrombotic risk factors, additional trials may be needed before we can make a confident recommendation for filters."

Additional strengths of the study include that "the two randomized groups were remarkably similar with respect to control and treatment arms," Allan D. Levi, MD, PhD, of the Miami Project to Cure Paralysis, Department of Neurological Surgery, Miller School of Medicine, University of Miami, Florida, said when also commenting on the study as a discussant.

"It is an excellent study with...findings showing very significant differences regarding pulmonary embolism, hemorrhagic complications, and sudden death," he added.

Levi noted that important unanswered questions include what the lower extremity DVT rates were in each group, in addition to the explanation for the "remarkably low" complication rate in the IVC filter group.

"The [complication rate] is not in keeping with published literature," he noted. "Other groups have reported IVC thrombosis, filter migration, infection, IVC perforation, pulmonary embolism, and groin hematoma."

"The group should be congratulated on this remarkably low incidence," Levi said.

He added that a cost assessment of the intervention would be of benefit.

"It would be interesting to compare the additional cost of doing the temporary IVC filter versus the additional cost burden of the noted complications and deaths in the nontreatment group," Levi said.

In comments to Medscape Medical News, Shapiro responded that the complications reported in the literature pertain to permanent IVC filters.

"The temporary IVC filter does not migrate, get infected, or cause thrombosis as it is only in for 2 weeks," he said.

"I use the filter in every anticoagulated thrombophilic case that needs neurosurgery [and] all of my partners are now doing the same."

"The temporary filter is easy and safe to place and prevents pulmonary embolism."

Shapiro, Barker, and Levi have reported no relevant financial relationships.

AANS 2020 Annual Meeting. Abstract 414.

For more Medscape Neurology news, join us on Facebook and Twitter.