Prophylactic inferior vena cava filter placement prior to lumbar surgery in morbidly obese patients: Two-case study and literature review

Utility and Clinical Outcomes of Perioperative Inferior Vena Cava Filter Prophylaxis in Spine Surgery Patients

STUDY DESIGN

Single-center retrospective chart review study.

OBJECTIVE

This study aimed to assess the clinical outcomes of prophylactic inferior vena cava (IVC) filter use for pulmonary embolism (PE) prevention in spine surgery patients.

SUMMARY OF BACKGROUND DATA

IVC filters can serve an important prophylactic role in preventing PE, though research involving spine surgery patients is sparse.

MATERIALS AND METHODS

This Institutional Review Board-approved single-center retrospective study assessed the characteristics and outcomes of patients who underwent spine surgery and received perioperative IVC filters for PE prophylaxis from January 2007 until December 2021. Clinical outcomes centered primarily on the occurrence of venous thromboembolism (VTE) as well as complications related to filter placement and retrieval. Thrombi that may have been entrapped by the filters were recorded incidentally on computed tomography or during the filter retrieval procedure.

RESULTS

This cohort included 380 spine surgery patients (female 51%/male 49%; median age, 61) who had received perioperative prophylactic IVC filters. The mean dwell time was 6.7 months (1-39 mo), with an overall 62% retrieval rate. Retrievals were further categorized by retrieval complexity, with 92% classified as routine and 8% as involving advanced removal techniques, while complications involved 1% (four retrievals) and were all minor. Regarding VTE event occurrence, deep vein thrombi (DVT) were experienced by 11% of patients in the postplacement period, with 1% (n=4) experiencing a PE. There were 11 incidences of thrombi that were found within or near the filters (2.9%). A multivariate analysis further assessed patient characteristics that correlated with the occurrence of PE, DVT, entrapped filter thrombi, advanced technique filter removal, and removal complications.

CONCLUSIONS

IVC filters in this high-risk spine surgery cohort achieved a relatively low rate of DVT and PE as well as a low complication rate, whereas several patient characteristics were identified that correlated with VTE events and filter retrieval outcomes.

Risk Factors for Perioperative Complications in Morbidly Obese Patients Undergoing Elective Posterior Lumbar Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The prevalence of obesity-related low back pain and degenerative disc disease is on the rise. Past studies have demonstrated that obesity is associated with higher perioperative complication rates, but there remains a gap in the literature regarding additional risk factors that further predispose this already high-risk patient population to poor surgical outcomes following elective posterior lumbar fusion (PLF). The aim of the study is to identify independent risk factors for poor 30-day perioperative outcomes in morbidly obese patients undergoing elective PLF.

METHODS

We identified 22 909 patients in the American College of Surgeons National Surgical Quality Improvement Program database who underwent elective PLF. There were 1861 morbidly obese patients. Baseline patient demographics and medical comorbidities were collected. Univariate analysis was performed to compare perioperative complication rates between non-morbidly obese and morbidly obese patients. The 5 most common complications in the morbidly obese group were then selected for multivariate regression analysis to identify independent risk factors for poor 30-day outcomes.

RESULTS

Morbidly obese patients had a higher perioperative complication rate. The 5 most common complications were prolonged hospitalization, blood transfusion, readmission, wound complications, and reoperation. Independent risk factors for these complications were age ≥65 years, super obesity (ie, BMI > 48.6), chronic steroid use, American Society of Anesthesiology classification ≥3, poor functional status, long length of fusion ≥4 levels, and extended operative time (ie, operative time ≥318 minutes).

CONCLUSIONS

Morbidly obese patients are at higher risk of perioperative complications following elective PLF. Modifiable risk factors for the most common complications are obesity and preoperative steroid use.

More risks and complications for elective spine surgery in morbidly obese patients

Background:

The vast majority of studies emphasize the greater morbidity/mortality for elective spine surgery in morbidly obese patients.

Methods:

This review focuses on the increased morbidity/mortality of performing elective spinal operations in morbidly obese patients. There are two definitions of morbid obesity; a body mass index (BMI) of equal to or greater than 35 plus two major comorbid factors (e.g., hypertension, diabetes, etc.) or a BMI (morbidly obese III) of =≥40 kg/m².

Results:

For patients undergoing spinal surgery, morbid obesity increases perioperative morbidity/mortality for various reasons. The quality of preoperative and intraoperative imaging is often compromised potentially leading to mistaken preoperative diagnoses, and wrong level surgery. Resultant major technical surgical limitations include poor/inadequate operative exposure, and the risk of suboptimal placement of instrumentation There is also increased exposure to major perioperative complications such as deep venous thrombosis, pulmonary embolism, infection, pneumonia, cardiac complications, blindness in the prone position, brachial and lumbar plexus injuries, increased anesthetic risks (e.g., even using awake intubation/awake positioning), and postoperative wound seromas/hematomas.

Conclusions:

Most of the spinal literature documents the marked increased perioperative morbidity/mortality for morbidly obese patients undergoing elective spine surgery. If elective surgery is warranted in these patients, the risks and timing of surgical intervention should include consideration of major preoperative weight loss strategies including bariatric procedures to optimize outcomes.

24-48 hour preoperative "surveillance" lower extremity venous Doppler's: Aren't they worthwhile prior to spine surgery?

BACKGROUND

Most previous studies focused on the utility of Doppler surveillance to determine the incidence of deep venous thrombosis (DVT) following spine surgery. Here, we utilized Doppler surveillance to assess the frequency of DVT prior to spine surgery.

METHODS

We asked, how often do patients exhibit preoperative DVT? To answer this, for over a 7-month period, bilateral lower extremity venous Doppler's were prospectively obtained 24-48 hours prior to a variety of spinal operations among 45 patients. This did not include an analysis of postoperative venous Doppler's/incidence of pulmonary embolism for these patients.

RESULTS

Of the 45 patients, 3 (6.7%) exhibited preoperative positive/abnormal venous duplex studies (unilaterally) that led to cancellation of spinal surgery. One patient, a 56-year-old female, with a C6-C7 cervical disc, demonstrated a proximal right lower extremity DVT; she required full-dose anticoagulation and her surgery was cancelled. In two cases, a 42-year-old female and a 55-year-old male, exhibited DVT in the right posterior tibial and left peroneal veins respectively; both operations were cancelled, and they were placed on anticoagulants by their internists.

CONCLUSIONS

Over a 7-month period, prospective "surveillance Dopplers" of both lower extremities obtained 24-48 hours prior to spinal surgery documented 3 (6.7%) positive studies out of a series of 45 patients. One instance of DVT was proximal (e.g. femoral in local) whereas 2 were distal. These data showed that preoperative surveillance Doppler of both lower extremities was "worthwhile." However, performing these studies earlier than 24-48 hrs prior to surgery would help avoid last minute cancellations.