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Deep Vein Thrombosis and Pulmonary Embolism After Spine Surgery: Incidence and Patient Risk Factors.

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Anticoagulation after spine surgery confers the unique risk of epidural hematoma. We sought to determine the incidence of and patient risk factors for deep vein thrombosis (DVT) and pulmonary embolism (PE) after spine surgery. We retrospectively reviewed the charts of 1485 patients who had spine surgery at a single tertiary-care center between 2002 and 2009. DVT and PE incidence were recorded along with pertinent patient history information. Univariate and multivariate analyses were performed on the data. VTE incidence was 1.1% (DVTs, 0.7%; PEs, 0.4%). Univariate analysis demonstrated that VTEs had 9 positive risk factors: active malignancy, prior DVT or PE, estrogen replacement therapy, discharge to a rehabilitation facility, hypertension, major depressive disorder, renal disease, congestive heart failure, and benign prostatic hyperplasia (P<.05). Multivariate analysis demonstrated 4 independent risk factors: prior DVT or PE, estrogen replacement therapy, discharge to a rehabilitation facility, and major depressive disorder (P>.05). Surgeons with an improved understanding of VTE after spine surgery can balance the risks and benefits of postoperative anticoagulation.
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®
267
An Original Study
Deep Vein Thrombosis and
Pulmonary Embolism After Spine Surgery:
Incidence and Patient Risk Factors
Leah M. Schulte, MD, Joseph R. O’Brien, MD, MPH, Matthew C. Bean, BS, Todd P. Pierce, BS,
Warren D. Yu, MD, and Clifton Meals, MD
V
enous thromboembolic events (VTEs), including deep
vein thrombosis (DVT) and pulmonary embolism
(PE), are serious and potentially life-threatening com-
plications of surgical procedures. DVTs and PEs are uncommon
after spine surgery. A recent meta-analysis found a DVT rate of
1.09% and a PE rate of 0.06%.
1
Management of postoperative
DVTs and PEs is difcult in spine surgery patients because of
the risk for spinal epidural hematoma (SEH).
SEH is a severe but rare complication. Its incidence after
spine surgery is 0.1% to 3%.
2
High-dose anticoagulation in
the postoperative spine surgery patient with a PE may increase
the risk for SEH. Thus, any treatment plan for a spine surgery
patient with a postoperative VTE must balance the risk for SEH
with the benet of anticoagulation. Most treatment algorithms
for DVT and PE call for high-dose boluses and therapeutic doses
of high-molecular-weight heparinoids. Bleeding complications
of anticoagulant use have a predictable dose-response curve.
3
Thus, management of a postoperative DVT or PE may pose an
SEH risk signicantly higher than that posed by routine low-
dose chemoprophylaxis. It is important to note that routine
use of high-molecular-weight heparinoids has been shown to
be safe in postoperative spine surgery patients.
4
Despite the regulatory
5
and specialty society
6
focus thrombo-
embolic events, there are no clear guidelines for identifying good
spine surgery candidates for chemoprophylaxis—because of
increased risk, whether from surgical factors or patient factors—
or for managing postoperative DVTs and PEs in spine surgery
patients. The American College of Chest Physicians guidelines
7
(Table I) are unclear on several points. In particular, patient
risk factors (ie, factors that put patients at high risk for VTE)
have not been studied in detail. Although VTE is rare in spine
surgery patients, signicant research is warranted to more clearly
delineate these issues.
We conducted a retrospective study to determine the spine
surgery patient risk factors for VTEs at an elective spine surgery
practice. Here we report on the incidence of and patient risk
factors for DVT and PE in a general, mostly nontraumatic spine
practice. All types of surgeries were included, and relative risk
(RR) factors were calculated. Our overall goal was to expand
the knowledge base regarding the type of patients at increased
risk for postoperative DVT and PE.
Materials and Methods
After obtaining institutional review board approval, we re-
viewed all 1485 cases of spine surgery performed at our ter-
tiary-care center between 2002 and 2009. The surgeries were
performed by 2 spine fellowship-trained surgeons (JRB and
WDY). These surgeries addressed the cervical, lumbar, and
Abstract
Anticoagulation after spine surgery confers the
unique risk of epidural hematoma.
We sought to determine the incidence of and
patient risk factors for deep vein thrombosis
(DVT) and pulmonary embolism (PE) after spine
surgery. We retrospectively reviewed the charts
of 1485 patients who had spine surgery at a
single tertiary-care center between 2002 and
2009. DVT and PE incidence were recorded
along with pertinent patient history informa-
tion. Univariate and multivariate analyses were
performed on the data.
VTE incidence was 1.1% (DVTs, 0.7%; PEs,
0.4%). Univariate analysis demonstrated that
VTEs had 9 positive risk factors: active malig-
nancy, prior DVT or PE, estrogen replacement
therapy, discharge to a rehabilitation facility,
hypertension, major depressive disorder, renal
disease, congestive heart failure, and benign
prostatic hyperplasia (P<.05). Multivariate analy-
sis demonstrated 4 independent risk factors:
prior DVT or PE, estrogen replacement therapy,
discharge to a rehabilitation facility, and major
depressive disorder (P>.05).
Surgeons with an improved understanding of
VTE after spine surgery can balance the risks
and benets of postoperative anticoagulation.
Authors’ Disclosure Statement: The authors report no actual or potential conict of interest in relation to this article.
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268 TheAmericanJournalofOrthopedics
®
June 2013 www.amjorthopedics.com
DVT and PE After Spine Surgery
L. M. Schulte et al
thoracic regions and used anterior and posterior approaches
(Table II). Charts were reviewed for pertinent data, includ-
ing age, body mass index (BMI), past medical history, medi-
cations, smoking history, specic spine procedure, type of
DVT prophylaxis, length of hospital stay, DVT or PE diagnosis,
and admission to a rehabilitation facility. At our institution,
routine prophylaxis involves having patients wear thigh-high
compression stockings with sequential compression devices
(SCDs) during and after surgery. We investigated all VTEs that
had been the subject of clinical suspicion during the hospital
stay or at routine follow-ups; there was no routine screening.
All VTEs were diagnosed with ultrasonography, ventilation-
perfusion quotient scan, or chest computed tomography (CT)
with contrast. DVT incidence and PE incidence were calculated
for this population group. Possible risk factors—including age,
sex, obesity, history of thromboembolism, active malignancy,
other comorbidities, prolonged hospital stay or rehabilitation,
and smoking—were evaluated for their association to VTEs.
Obesity was dened as BMI higher than 30 and active malig-
nancy was dened as a cancer undergoing treatment.
Descriptive characteristics for the cohort were compiled.
Means and standard deviations were calculated. Logistic
regression analyses were performed to determine the as-
sociation of comorbidities and other factors with DVT and
PE occurrence. Binomial univariate logistic regression was
used to analyze age, sex, BMI, prior VTE, comorbidities, and
smoking status for an association with VTE occurrence. Vari-
ables found to be potentially predictive of the outcome vari-
able from the univariate model (P<.2) were included in the
multivariate logistic regression models. Multivariate models
were used to assess the statistical signicance of each individual
variable while adjusting for other covariates. Variables found to
be nonsignicant (P>.05) were removed from the multivariate
model in sequential fashion starting with the variable with the
highest P. For each variable, RRs and 95% condence intervals
were calculated. SPSS Version 18.0 (SPSS, IBM, Chicago, Il-
linois) was used for all statistics.
Results
Of the 1485 patients who had spine surgery between 2002 and
2009 (Table II), 817 were women (55%) and 668 men (45%).
Table I. American College of Chest Physicians Recommendations for Spine Surgery,
7
February 2012
Patient Category Details Recommendations
Spine surgery patients Mechanical prophylaxis, LDUH, or LMWH
High-risk patients undergoing
spine surgery
Malignant disease
Combined anterior-posterior approaches
Pharmacologic prophylaxis after adequate hemostasis
is achieved
Major trauma patients Spinal cord injury
Spine fracture requiring surgery
Pharmacologic plus mechanical prophylaxis
Contraindication to pharmacologic prophylaxis Mechanical prophylaxis
Add LDUH or LMWH when risk for bleeding normalizes
Do not use inferior vena cava filter for VTE prevention
Abbreviations: LDUH, low-dose unfractionated heparin; LMWH, low-molecular-weight heparin; VTE, venous thromboembolism.
Table II. Spine Procedures Performed
Type of Procedure n
Cervical 352
Posterior cervical decompression 3
Anterior cervical fusion/arthroplasty, 1 or 2 levels 216
Anterior cervical fusion, >2 levels 65
Posterior cervical fusion 53
Combined anterior/posterior cervical fusion 15
Thoracic 24
Thoracic fusion by thoracotomy 15
Posterior thoracic fusion 9
Lumbar 970
Diskectomy/1-level lumbar decompression 329
Multilevel lumbar decompression 25
Anterior lumbar fusion 35
Posterior lumbar fusion, 1 or 2 levels 388
Posterior lumbar fusion, 3-5 levels 146
Posterior thoracolumbar fusion, >5 levels 41
Lateral lumbar fusion 3
Combined anterior/posterior lumbar fusion 3
Other 139
Interspinous process insertion 67
Kyphoplasty 31
Miscellaneous 41
Total 1485
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DVT and PE After Spine Surgery
www.amjorthopedics.com June 2013 The American Journal of Orthopedics
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269
L. M. Schulte et al
Mean (SD) age was 53 (14) years (range, 16-103 years). Sixteen
patients (1.1%) had at least 1 VTE. Eleven (0.7%) had a DVT
and 6 (0.4%) had a PE; 1 patient (0.1%) was formally diagnosed
with both. No patient died from a VTE.
Univariate RR calculations demonstrated that prior DVT or
PE, active malignancy, estrogen replacement therapy (ERT),
discharge to a rehabilitation facility, major depressive disorder
(MDD), hypertension, renal disease, congestive heart failure,
and benign prostatic hyperplasia were risk factors for postop-
erative VTEs (P≤.05) (Table III). Smoking, multiple procedures
within 30 days, obesity, sex, gastroesophageal reux disease,
hyperlipidemia, and sleep apnea were not signicant risk fac-
tors (P>.05). Multivariate analysis demonstrated that prior DVT
or PE, discharge to a rehabilitation facility, ERT, and MDD were
independent risk factors (P>.05) (Table IV).
Discussion
Venous stasis, endothelial injury, and hypercoagulable states
all contribute to the postoperative development of DVT. It is
thought that in total knee and hip arthroplasty, direct injury to
the large vessels in the leg contributes to the high rates of DVT
and PE in the absence of postoperative chemoprophylaxis.
8
In major spine surgery, prolonged immobilization and bone
work may contribute to increased risk for postoperative DVT,
but direct endothelial injury generally does not. Anterior spine
surgery may be an exception. Other investigators have analyzed
surgical risk factors that may play a role in DVT and PE after
spine surgery. A recent review of 14,932 cases found routine
use of chemoprophylaxis was not necessary in posterior-only
spine surgery.
8
It may be considered in anterior spine surgery,
which involves manipulation of the great vessels. Aside from
surgical risk factors, patient risk factors may also contribute to
risk for postoperative VTE.
Use of chemoprophylaxis in spine surgery is controversial.
In elective spine surgery, DVT prophylaxis must be balanced
against the risks for postoperative bleeding and epidural hema-
toma.
9
Epidural hematoma is a unique complication of spine
surgery.
8
The incidence of symptomatic epidural hematoma
causing neurologic compromise requiring surgery is between
0.1% and 3%.
8
The result can be a permanent neurologic decit,
such as paralysis.
2,8,10
Despite the apprehension toward chemi-
cal anticoagulation, Awad and colleagues
4
found no increased
risk for developing an epidural hematoma with use of chemical
prophylaxis in a retrospective review of 14,932 spine surgery
patients.
9
However, symptomatic epidural hematoma has been
reported with therapeutic-dose chemical anticoagulation.
10
Blood loss and wound complications are also associated with
chemical prophylaxis.
11
Mechanical prophylaxis methods, spe-
cically use of SCDs alone, have effectively reduced DVT and
PE incidence.
12
Experience with VTEs has led some adult spine
deformity surgeons to routinely use chemoprophylaxis after
surgery. However, most spine surgeons use only mechanical
prophylaxis methods in elective spine surgery.
13,14
It is clear
that more work is needed to delineate which surgical and
patient factors increase the risk for VTE in the postoperative
spine surgery patient.
In this study, we identied some patient risk factors for
VTE after spine surgery. The statistically signicant risk factors
for DVT were prior DVT or PE, ERT, and MDD. Discharge to
a rehabilitation facility was a statistically signicant variable.
Other studies have implicated hypercoagulable states as a risk
factor for DVT,
4
so it is not surprising that prior DVT or PE was
a risk factor in this study. It is important to note that our center
does not treat patients with metastatic cancer on a regular basis.
Thus, this signicant risk factor may be excluded from our
results largely because of institutional selection bias. ERT has
also been implicated as a risk factor for DVT and PE in other
studies.
15
Discharge to a rehabilitation facility as a risk factor
is notable but may be more of a reection on the size of the
surgical procedure than on patient characteristics. For instance,
larger spinal fusion procedures with slow patient mobilization
may have led to prolonged recumbency and the need for more
rehabilitation. Thus, this risk factor may be a reection of
venous stasis. MDD as a risk factor may also reect prolonged
recumbency. It may also reect the use of various antidepres-
sants. Further investigation along those lines is warranted.
This study had a few limitations. It was retrospective and
did not use routine screening to identify patients with VTE.
Thus, the 1% incidence likely underestimates the actual in-
Table III. Univariate Analysis of Patient Risk Factors
Risk Factor RR CI P<
Active malignancy 8.9 2.1-37.0 .001
Prior DVT or PE 8.3 1.3-46.3 .018
Estrogen replacement therapy 6.2 1.4-26.1 .01
Discharge to rehabilitation facility 20.8 1.3-5.2 .018
Hypertension 7.7 1.2-48.2 .023
Major depressive disorder 9.5 2.5-35.9 .001
Renal disease 10.2 1.7-55.5 .007
Congestive heart failure 10.2 1.7-55.5 .007
Benign prostatic hypertrophy 6.6 1.1-37.7 .041
Abbreviations: CI, confidence interval; DVT, deep vein thrombosis; PE, pulmo-
nary embolism RR; relative risk.
Table IV. Multivariate Analysis of Patient Risk Factors
Risk Factor RR CI P<
Prior DVT or PE 2.4 1.8-60.7 .026
Estrogen replacement therapy 3.1 3.5-128.8 .007
Discharge to rehabilitation facility 2.9 2.4-40.3 .002
Major depressive disorder 1.7 1.1-24.7 .040
Abbreviations: CI, confidence interval; DVT, deep vein thrombosis; PE, pulmo-
nary embolism; RR, relative risk.
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DVT and PE After Spine Surgery
cidence that might be found with prospective screening of
postoperative spine surgery patients. Furthermore, the hospital
patient population used in this study did not include many
patients with spinal trauma or metastatic spine tumors. Thus,
our conclusions are limited by institutional selection bias.
More work at major spinal trauma centers and cancer centers
is needed to delineate patient risk factors for VTE.
We have described patient risk factors for postoperative
VTEs. Further work is needed to more clearly delineate patient
risk factors for VTEs after spine surgery.
Dr. Schulte and Dr. O’Brien are Assistant Professors, Mr. Bean and
Mr. Pierce are Medical Students, Dr. Yu is Associate Professor, and
Dr. Meals is Resident Surgeon, Department of Orthopaedic Surgery,
George Washington University, Washington, District of Columbia.
Address correspondence to: Leah M. Schulte, MD, Department of
Orthopaedic Surgery, George Washington University, 2150 Pennsyl-
vania Ave NW, 7th Floor, Washington, DC 20037 (tel, 216-287-114;
fax, 202-741-3313; e-mail, leahmschulte@gmail.com).
Am J Orthop. 2013;42(6):267-270. Copyright Frontline Medical Com-
munications Inc. 2013. All rights reserved.
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... Spinal epidural hematoma requiring surgical evacuation is a rare but severe complication of spine tumor surgery with an incidence of 0.30% (1). Previous studies have shown that patients undergoing major elective orthopaedic surgery have a significant risk of developing deep vein thrombosis (DVT), which may require intervention to prevent a fatal pulmonary embolism (PE) (2)(3)(4). In addition, the cardiac stress produced by the general anesthesia required for major spine surgery can cause myocardial ischemia and/or infarction, thus necessitating perioperative anticoagulation (5). ...
... The management of thromboembolic complications is difficult in spine surgery patients because of the bleeding risks associated with initiating anticoagulation (4,13). Several questions remain unanswered regarding the guidelines of postoperative anticoagulation in spine surgery patients. ...
Article
Full-text available
While the incidence and risk factors of pulmonary embolism (PE) and deep vein thrombosis (DVT) following spinal surgery have been well studied, the treatment of such thromboembolic disease in patients after spine surgery remains controversial. When initiating therapeutic anticoagulation after spine surgery, clinicians must weigh the catastrophic risk of a PE against the risk of bleeding complications associated with anticoagulation therapy. Here we report the case of a 56-year-old male who presented with symptoms of spinal cord compression secondary to metastatic renal cell carcinoma (RCC). An inferior vena cava (IVC) filter was inserted preoperatively and urgent decompression at the thoraco-lumbar region was performed. Therapeutic clexane was started on postoperative day (POD) 7 and he was discharged. On POD 8, he was readmitted following acute bilateral lower limb paralysis. Magnetic resonance imaging (MRI) revealed a large posterior spinal epidural hematoma with severe compression of the conus at L1 level. Urgent posterior decompression was performed but subsequent recovery was slow and incomplete. His power improved gradually over the right lower limb with attainment of grade 4/5 motor power but still had hemiparesis on his left lower limb upon discharge out of hospital. This case highlights the risk of starting therapeutic anticoagulation following spinal surgery. Prior to starting treatment, the clinician must consider the appropriate dose, timing and alternatives available to avoid unnecessary complications.
... 25 Multiple patient factors are known to increase VTE risk including personal history of VTE, trauma, active malignancy, and spinal cord injury and were assigned high-risk classification in our algorithm. 1,5,[26][27][28][29] A first-degree relative with VTE, poor mobilization postoperatively, use of prothrombotic medications, and conditions that limit pulmonary reserve including primary lung diseases, American Society of Anesthesiologists Physical Status Classification Scores greater than or equal to 3, obesity, congestive heart failure, and smoking were assigned moderate risk. [27][28][29] Hypertension, hyperlipidemia, and diabetes mellitus have not been consistently associated with a significant increase in the risk of VTE and were assigned low risk. ...
... 1,5,[26][27][28][29] A first-degree relative with VTE, poor mobilization postoperatively, use of prothrombotic medications, and conditions that limit pulmonary reserve including primary lung diseases, American Society of Anesthesiologists Physical Status Classification Scores greater than or equal to 3, obesity, congestive heart failure, and smoking were assigned moderate risk. [27][28][29] Hypertension, hyperlipidemia, and diabetes mellitus have not been consistently associated with a significant increase in the risk of VTE and were assigned low risk. 28,29 The type of surgery also affects the risk for VTE. ...
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Background: Although venous thromboembolism (VTE) is a potentially serious and life-threatening complication, there is no widely accepted protocol to guide VTE prophylaxis in adult degenerative spinal surgery, and pharmacologic overtreatment may result in hemorrhagic complications. Previously, we published the VTE Prophylaxis Risk/Benefit Score, an evidence-based algorithm that balances the risk and consequences of thrombotic versus hemorrhagic complications by taking consideration of patient-related risks, procedure-related risks, and the risk of neurological compromise to guide VTE prophylaxis. To objective of this study was to validate the VTE Prophylaxis Risk/Benefit Score. Methods: From January 1, 2016, to December 31, 2017, VTE Prophylaxis Risk/Benefit Scores and corresponding prophylaxes were prospectively assigned. When indicated, chemoprophylaxis was dosed 24 to 36 hours postoperatively to allow for adequate surgical hemostasis. Patients were retrospectively evaluated for immediate and short-term complications. The Fisher exact test compared incidence of complications by VTE prophylaxis. Multinomial logistic regression modeled the probability of complication by prophylaxis type, demographics, and comorbidities. Significance was set at P < .05. Results: Of the 266 patients who met inclusion criteria, 79.3% were given mechanical prophylaxis alone and 20.7% were given combined mechanical and chemical prophylaxis. Complications including VTE (0.38%), delayed wound healing or infection (2.26%), and hematoma (0.75%) were observed at rates similar to or lower than previously published studies with increased utilization of chemoprophylaxis. Use of chemoprophylaxis and continuation of perioperative aspirin were significantly associated with the development of a hemorrhagic complication. No patient developed persistent neurologic deficit from hematoma or pulmonary embolism. Conclusions: The VTE Prophylaxis Risk/Benefit Score comprehensively considers the risk of thrombotic, wound, and bleeding complications and is an effective tool for determining appropriate thromboprophylaxis in adult degenerative spinal surgery. Level of evidence: 3.
... 14,18,19 These results, however, put into question the role of depression in postoperative PE/DVT, which Parvizi et al found to be an independent risk factor for symptomatic PE after total joint arthroplasty (TJA), 14 while Schulte et al. found depression to be an independent risk factor of PE after spinal surgery. 20 Further examination of this association is warranted as the current literature correlating depression to rates of PE, DVT, or mortality remains inconclusive. ...
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We evaluate the patient demographics, perioperative outcomes, in-hospital complications, and assess recent national trends in clinically depressed and non-depressed patients undergoing primary total knee arthroplasty (TKA). Using the National Hospital Discharge Survey from 2001 and 2010, patients undergoing primary TKA in the United States were identified based upon the diagnosis of depression. Differences in gender, patient-demographics, comorbidities, complications, length of stay, and discharge disposition were analyzed. A total of 32,761 TKA patients were identified, consisting of 1,880 patients with a diagnosis of depression and 30,881 patients without. The depression group had an average age significantly younger than the non-depression cohort (p < 0.01). The depression group contained a significantly greater percentage of females when compared to the non-depression group. The non-depression group had a significantly greater percentage of African-Americans (p < 0.01), and a significantly smaller percentage of Caucasians (p < 0.01). Our findings contribute to the literature on the role of depression on perioperative outcomes of TKA. (Journal of Surgical Orthopaedic Advances 30(1):006-008, 2021)
... To our knowledge, this is the first retrospective study to examine screening for and prevalence of DVT in inpatients with osteoporotic vertebral fracture. Previous studies have focused on the incidence of DVT after high-energy injuries or spinal surgery (11,13,16 (15). In our study, the total incidence of DVT was six (12.0%) of 50 patients. ...
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Aim: This study aimed to determine the prevalence of a deep vein thrombosis (DVT) in osteoporotic vertebral fractures. Material and methods: Data were retrospectively collected from the medical records of 50 patients who were admitted to the Kameda Medical Center for osteoporotic vertebral fracture from 2019 to 2020. Inpatients were screened for DVT using D-dimer, and those who were screened positive underwent lower extremity venous ultrasonography to confirm DVT. Associations between various clinical factors and DVT were analyzed. Results: Six (12.0%) inpatients with osteoporotic vertebral fractures were found to have DVT. Two (33.3%) of the six had proximal DVT, although no pulmonary embolism was detected by chest computed tomography angiography. Univariate analysis showed that D-dimer values and duration from onset to hospitalization were predictive of DVT (P 0.05). Conclusion: The prevalence of DVT among inpatients with osteoporotic vertebral fractures was 12.0%. This finding emphasizes the importance of DVT screening using D-dimer in those with osteoporotic vertebral fractures.
... Of note, over 50% used oral estrogen in this study. Retrospective studies evaluating VTE risk with spinal surgery have not found an association with estrogen use, though overall event numbers and patients treated with estradiol in these studies were low [54,55]. ...
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Venous thromboembolism is a documented risk of some estradiol formulations, but evidence evaluating the perioperative risk of continuation of estradiol therapy is limited. This narrative review summarizes literature related to the perioperative venous thromboembolic risk of estradiol, with a focus on feminizing genitoplasty for trans people undergoing feminizing hormone therapy. Given the dearth of evidence underlying gender-affirming hormone therapy regimens, much of the risk is based on the menopausal hormone therapy literature. However, the doses used for trans people undergoing feminizing hormone therapy can be significantly higher than those used for menopausal hormone therapy and escalating estradiol dose is associated with an increased thrombotic risk. Transdermal formulations are not associated with an increased risk in postmenopausal people. Feminizing genitoplasty is associated with a low thromboembolic risk. However, many patients are instructed to cease estradiol therapy several weeks preoperatively based on reports of increased thrombotic risk in trans people undergoing feminizing hormone therapy and hemostatic changes with the oral contraceptive pill. This can result in psychological distress and vasomotor symptoms. There is insufficient evidence to support routine discontinuation of estradiol therapy in the perioperative period. There is a need for high-quality prospective trials evaluating the perioperative risk of estradiol therapy in trans people undergoing feminizing hormone therapy to formulate evidence-based recommendations.
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Study design: This was a retrospective database study. Objective: The objective of this study was to investigate preoperative risk factors and incidence of venous thromboembolic events (VTEs) after cervical spine surgery. Summary of background data: VTEs are preventable complications that may occur after spinal procedures. Globally, VTEs account for a major cause of morbidity and mortality. Preoperative risks factors associated with increased VTE incidence after cervical spine surgery have not been well-characterized. Materials and methods: Patients undergoing anterior cervical discectomy and fusion (ACDF); posterior cervical fusion (PCF); discectomy; and decompression from 2007 to 2017 were identified using the PearlDiver Database. International Classification of Diseases (ICD) Ninth and 10th Revision codes were used to identify VTEs at 1 week, 1 month, and 3 months postoperative as well as preoperative risk factors. Results: Risk factors with the highest incidence of VTE at 3 months were primary coagulation disorder [ACDF=7.82%, odds ratio (OR)=3.96; decompression=11.24%, OR=3.03], central venous line (ACDF=5.68%, OR=2.11; PCF=12.58%, OR=2.27; decompression=10.17%, OR=2.80) and extremity paralysis (ACDF=6.59%, OR=2.73; PCF=18.80%, OR=2.99; decompression=11.86, OR=3.74). VTE incidence at 3 months for populations with these risks was significant for all surgery types (P<0.001) with the exception of patients with primary coagulation disorder who underwent PCF. Tobacco use had the lowest VTE incidence for all surgery types. Conclusions: The total cumulative incidence of VTEs at 3-month follow-up was 3.10%, with the highest incidence of VTEs occurring within the first postoperative week (0.65% at 1 wk, 0.61% at 1 mo, 0.53% at 3 mo for ACDF; 2.56% at 1 wk, 1.93% at 1 mo, 1.45% at 3 mo for PCF; 1.37% at 1 wk, 0.93% at 1 mo, 0.91% at 3 mo for decompression). Several preoperative risk factors were found to be significant predictors for postoperative VTEs and can be used to suggest those at increased risk as well as decrease the incidence of preventable VTEs after cervical spine surgery. Level of evidence: Level III.
Article
Study design: A retrospective analysis (2015-2019) of data collected from patients who underwent posterior lumbar spinal surgery. Objective: This study aims to identify the incidence, perioperative hematological characteristics, potential prognostic indicators, and risk factors of deep venous thrombosis (DVT) in the lower limbs after posterior lumbar spinal surgery. Eliminating risk factors or taking measures against patients at risk may reduce the incidence of DVT. Summary of background data: Deep venous thromboses have been extensively studied in other reconstructive surgeries. Present literatures provide limited evidence for determining the prognostic and risk factors for this complication after spinal surgery. Methods: Patients who underwent posterior lumbar spinal surgery with internal fixation in the Spine Surgery Center of Peking Union Medical College Hospital (PUMCH) were evaluated. The patient demographics, the number of operative segments, the hematological and biochemical parameters on baseline and postoperative day one, and the presence of DVTs were obtained from all patients. The diagnosis of DVT was established by venous ultrasound when symptomatic. A multivariate logistic regression test was subsequently performed to determine the prognostic indicators and risk factors for DVT. Results: A total of 2,053 patients who received lumbar spine procedures were qualified and included. Patients were followed up for 12 weeks. Early symptomatic DVT occurred in 58 individuals (2.39%; 95% confidence interval [CI], 0.4-0.7%). Advanced age, higher preoperative serum D-dimer level, and lower serum potassium level were recognised as independent risk factors for symptomatic DVT. Conclusion: Multiple independent risk factors were identified for early symptomatic DVT after posterior lumbar spine surgery. Postoperative prophylactic anti-coagulation treatment might be warranted for patients with high D-dimer or low potassium levels before the procedure.Level of Evidence: 4.
Article
Objective The Elixhauser Comorbidity Index (ECI) and Charlson Comorbidity Index (CCI) are commonly utilized measures that use administrative data to characterize a patient’s comorbidity burden. The purpose of this study was to compare the ability of these measures to predict outcomes following anterior lumbar interbody fusions (ALIF). Methods he National Inpatient Sample (NIS) was queried for all ALIF procedures between 2013-2014. The area under the receiver operating curve (AUC) was used to compare the ECI and CCI in their ability to predict postoperative complications when incorporated into a base model containing age, sex, race, and primary payer. Percent superiority was computed using AUC values for ECI, CCI, and base models. Results A total of 43,930 hospitalizations were included in this study. The ECI was superior to the CCI and baseline models in predicting minor (AUC 71 vs. 0.66, p<0.0001) and major (AUC 0.74 vs. 0.67, p<0.0001) complications. When evaluating individual complications, the ECI was superior to the CCI in predicting airway complications (65% superior, AUC 0.85 vs. 0.72, p=0.0001), hemorrhagic anemia (83% superior, AUC 0.71 vs. 0.66, p<0.0001), myocardial infarction (76% superior, AUC 0.86 vs. 0.67, p<0.0001), cardiac arrest (75% superior, AUC 0.85 vs. 0.67, p<0.0001), pulmonary embolism (105% superior, AUC 0.91 vs. 0.71, p<0.0001), and urinary tract infection (43% superior, AUC 0.76 vs. 0.73, p=0.046). Conclusions The ECI was superior to the CCI in predicting 6 of the 15 complications analyzed in this study. Combined with previous results, the ECI may be a better predictive model in spine surgery.
Article
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The eighth iteration of the American College of Chest Physicians Antithrombotic Guidelines presented, in a paper version, a narrative evidence summary and rationale for the recommendations, a small number of evidence profiles summarizing bodies of evidence, and some articles with quite extensive summary tables of primary studies. In total, this represented 600 recommendations summarized in 968 pages of text. Many readers responded that the result was too voluminous for their liking or practical use.
Article
The optimal degree of heparin anticoagulation for peripheral vascular interventions (PVIs) has not been defined. We sought to correlate total heparin dose and peak procedural activated clotting time (ACT) with postprocedural outcomes in patients undergoing PVI. We studied 4743 patients who received heparin during PVIs in a regional, multicenter registry. From those, 1246 had recorded peak procedural ACT with the same point-of-care device. Periprocedural and in-hospital outcomes were compared between patients who received a total heparin dose <60 U/kg (n=2161) and ≥60 U/kg (n=2582). Similarly, outcomes were evaluated between groups with a peak procedural ACT <250 seconds (n=855) and ≥250 seconds (n=391). Technical and procedural success as well as intraprocedural thrombotic events did not differ between groups. Patients with heparin dose ≥60 U/kg had a higher rate of postprocedural hemoglobin drop ≥3 g/dL (7.09% versus 5.09%, respectively, P=0.004) and a higher transfusion rate compared with those with heparin dose <60 U/kg (4.92% versus 3.15%, respectively, P=0.002). In multivariate analysis, independent predictors of bleeding requiring transfusion were total heparin dose ≥60 U/kg, ACT ≥250 seconds, female sex, age ≥70 years, prior anemia, prior heart failure, low creatinine clearance, hybrid vascular surgery, rest pain, and below-knee intervention. In propensity-matched, risk-adjusted models and after hierarchical modeling, total heparin dose ≥60 U/kg and ACT ≥250 seconds remained strong predictors of post-PVI drop in hemoglobin ≥3 g/dL or transfusion. During PVI, higher total heparin dose (≥60 U/kg) and peak ACT ≥250 seconds were predictors of postprocedural transfusion. The high technical and procedural success in all groups suggests that use of weight-based heparin dosing with a target ACT <250 seconds in PVI may minimize the bleeding risk without compromising procedural success or increasing thromboembolic complications.
Article
Venous thromboembolic disease, including deep venous thrombosis and pulmonary embolism, is a serious and potentially life-threatening complication following orthopaedic surgical procedures. We sought to investigate the prevalence of thromboembolism as well as the efficacy and complications of various prophylactic measures in a population of patients who had undergone elective spine surgery. A meta-analysis and univariate logistic regression were performed on selected studies to determine the prevalence of and risk factors for deep venous thrombosis and pulmonary embolism following elective spine surgery. Studies were included on the basis of the selection criteria (specifically, the inclusion of only patients undergoing spine surgery, or the treatment of patients undergoing spine surgery as an independent cohort; the use of an objective diagnostic modality for the diagnosis of deep venous thrombosis, including Doppler ultrasonography or venography; the use of an objective diagnostic modality for the diagnosis of pulmonary embolism, including computed tomography of the chest or a ventilation-perfusion scan; and a study population of more than thirty patients). Patients with a known spinal cord injury were excluded. Fourteen studies (including a total of 4383 patients) met our selection criteria. On the basis of the meta-analysis, the prevalence of deep venous thrombosis was 1.09% (95% confidence interval, 0.54% to 1.64%) and the prevalence of pulmonary embolism was 0.06% (95% confidence interval, 0.01% to 0.12%) following elective spine surgery. The use of pharmacologic prophylaxis significantly reduced the prevalence of deep venous thrombosis relative to either mechanical prophylaxis (p = 0.047) or no prophylaxis (p < 0.01). One fatal pulmonary embolism was reported. An epidural hematoma requiring surgical evacuation was reported in eight of 2071 patients receiving pharmacologic prophylaxis; three of these patients had a permanent neurologic deficit. The risk of deep venous thrombosis and pulmonary embolism is relatively low following elective spine surgery, particularly for patients who receive pharmacologic prophylaxis. Unfortunately, pharmacologic prophylaxis exposes patients to a greater risk of epidural hematoma. More evidence is needed prior to establishing a protocol for prophylaxis against venous thromboembolic disease in patients undergoing elective spine surgery. Future prospective studies should seek to define the safety of various prophylactic modalities and to identify specific subpopulations of patients who are at greater risk for venous thromboembolism.
Article
A survey on thromboprophylaxis in spinal surgery and trauma was conducted among spine trauma surgeons. Neurosurgeons and orthopedic surgeons from the Spinal Trauma Study Group were surveyed in an attempt to understand current practices in the perioperative administration of thromboprophylaxis in spinal surgery. Although much research has been invested in the prevention of thromboembolic events following surgical procedures, there have been few investigations specific to spinal surgery, especially in the context of trauma. A total of 47 spine surgeons were provided with a 24-question survey pertaining to deep vein thrombosis prophylaxis in spine surgical patients. There was 100% response to the survey, and 46 of the 47 physicians (98%) responded to the case scenarios. Institutional protocols for deep vein thrombosis prophylaxis existed for 42 (89%) of the respondents; however, only 27 (57%) indicated that these protocols included spinal cord injury (SCI) patients. Before surgery, no prophylaxis or mechanical prophylactic measures for SCI and non-SCI spinal fracture patients were routinely used by 36 (77%) and 40 (85%) respondents, respectively. After surgery, pharmacologic prophylaxis was prescribed by 42 (91%) and 28 (62%) surgeons for SCI and non-SCI spinal fracture patients, respectively. There was a statistically significant tendency to use more intensive prophylactic measures for patients with SCI (x2, 10.86; P < 0.01) as well as a statistically significant longer duration of proposed thromboprophylaxis (x2, 24.62; P < 0.001). Postoperative pharmacologic thromboprophylaxis for elective anterior thoracolumbar spine surgery was reported by 23 (51%) of the respondents, whereas only 18 (40%) used pharmacological prophylaxis in elective posterior thoracolumbar spine cases. Spine complications from low-molecular weight heparin were reported by 22 (47%) surgeons, including fatal pulmonary embolism by 19 (40%) surgeons. A basis for a consensus protocol on thromboprophylaxis in spinal trauma was attempted. No more than mechanical prophylaxis was recommended before surgery for non-SCI patients or after surgery for elective cervical spine cases. Chemical prophylaxis was commonly used after surgery in patients with SCI and in patients with elective anterior thoracolumbar surgery.
Article
In order to prevent fatal pulmonary embolism, TED stockings, foot pumps and early mobilisation on the second post-operative day are used at our centre. Only patients deemed to be high risk (previous DVT/PE or obese) are given clexane as inpatients and warfarin for six weeks post-op. From the hospital database 1137 primary total hip replacements and 1017 primary total knee re-placements were identified and the figures were confirmed with the theatre implant order books. The cause of death for those patients on the database, now deceased, was obtained from the coroner. Where a postmortem had not been performed the patient was assumed to have died of a PE. Within three months of surgery, a fatal PE rate of 0.09% (95% CI 0.00-0.26%) following hip replacement and 0.20% (95% CI 0.00-0.46%) after knee replacement was found. Thirty-four patients had been discharged on warfarin according to the pharmacy records. We would therefore not recommend the routine use of chemical thromboprophylaxis following joint replacement.
Article
Systematic review of the literature and analysis of pooled data. To better understand the incidence of thromboembolic disease in postoperative spinal patients, and to establish a starting point for defining appropriate postoperative prophylaxis protocols. The risk of thromboembolic disease is well studied for some orthopedic procedures. However, the incidence of postoperative thromboembolic disease is less well-defined in patients who have had spinal surgery. The MEDLINE database was queried using the search terms deep venous thrombosis or DVT, pulmonary embolus, thromboembolic disease, and spinal or spine surgery. Abstracts of all identified articles were reviewed. Detailed information from eligible articles was extracted. Data were compiled and analyzed by simple summation methods when possible to stratify rates of DVT and/or pulmonary embolus for a given prophylaxis protocol, screening method, and type of spinal surgery. Twenty-five articles were eligible for full review. DVT risk ranged from 0.3% to 31%, varying between patient populations and methods of surveillance. Pooling data from the 25 studies, the overall rate of DVT was 2.1%. DVT rate was influenced by prophylaxis method: no prophylaxis, 2.7%; compression stockings (CS), 2.7%; pneumatic sequential compression device (PSCD), 4.6%; PSCD and CS, 1.3%; chemical anticoagulants, 0.6%; and inferior vena cava filters with/without another method of prophylaxis, 22%. DVT rate was also influenced by the method of diagnosis, ranging from 1% to 12.3%. As risk of DVT after routine elective spinal surgery is fairly low, it seems reasonable to use CS with PSCD as a primary method of prophylaxis. There is insufficient evidence to support or refute the use of chemical anticoagulants in routine elective spinal surgery. In addition, there is insufficient evidence to suggest that screening patients undergoing elective spinal surgery with ultrasound or venogram is routinely warranted.
Article
Survey study. To assess a sample of spine surgeons' current practices of thromboembolic prophylaxis after high-risk surgery for tumors and trauma. Although chemoprophylaxis for thromboembolic events is not routinely used after elective spinal surgery, it is more widely recommended in high-risk patients after spine surgery for trauma or tumors. In these high-risk cases, surgeons must decide what method(s) of prophylaxis to use and when it can be safely initiated. Unfortunately, there are limited data evaluating the efficacy or safety of different prophylaxis protocols after high-risk spinal surgery; as a result there are no accepted treatment guidelines concerning this issue. To the authors' knowledge, no previous study examining practices of thromboembolic prophylaxis after high-risk spinal surgery has been published. One hundred ninety-three orthopaedic and neurosurgical spine surgeons with established clinical interest and volume in spine trauma and/or spine tumor surgery were invited by email to complete an on-line questionnaire. Ten questions focused on varying issues that included the perceived risk of deep venous thrombosis (DVT), pulmonary embolism (PE), postoperative epidural hematoma, preferred chemoprophylactic agents, the safe time point for initiation of chemoprophylaxis, and use of inferior vena cava (IVC) filters. Ninety-four surgeons completed the questionnaire, which represented a 49% response rate. Regarding a safe time point to start chemoprophylaxis, the most common response was 48 hours after surgery (21 of 94, 22%). However, individual responses varied widely: 15% chose 24 hours, 13% chose 72 hours, 12% chose less than 24 hours, and 10% chose 96 hours. Some indicated they would start chemoprophylaxis before surgery, whereas others responded they would never use it. Sixty-three percent (59 of 94) stated that they based this decision on personal experience over evidence-based review of the literature. A majority of surgeons selected low-molecular-weight heparin as their agent of choice (54 of 94, 58%). Respondents most commonly (44 of 93, 47%) felt that the risk of clinically relevant postoperative epidural hematoma was between 1% and 5%; 29% (27 of 93) felt the risk was less than 1%; and 17% (16 of 93) felt it was as high as 5% to 10%. Those who felt the risk of epidural hematoma to be lower than 5% tended to initiate chemoprophylaxis earlier than those who estimated the risk to be higher than 5%. Thirty-seven percent (34 of 93) felt the perceived risk for a DVT was 1% to 5%; 25% (23 of 94) felt it was 5% to 10%; and 16% (15 of 93) felt it was less than 1%. Those who estimated the risk of DVT to be higher tended to initiate therapy earlier than groups that estimated the risk to be lower. Although the decision to use an IVC filter varied considerably, there was a clear trend towards having the filter placed before surgery (60 of 78, 77%). These data are the first to demonstrate the wide variability of surgeons' practices regarding thromboembolic prophylaxis in high-risk spine surgery patients. This variability is likely a symptom of the glaring paucity of scientific evidence concerning the risk for symptomatic epidural hematoma, DVT, and PE and the efficacy and safety of specific chemoprophylactic protocols after spine surgery. This study highlights the need for more rigorous prospective evaluation of thromboembolic risk after spinal surgery and, subsequently, the efficacy and safety of currently available thromboembolic prophylaxis protocols.
Article
Deep vein thrombosis (DVT) is a common condition. Most cases arise as complications during the perioperative period. This can largely be prevented by adequate prophylaxis, principally using low-dose subcutaneous heparin. Only a minority of DVTs produce serious complications, but it is not currently possible to predict the clinical behaviour of any DVT, once formed. For this reason, any identified DVT should be vigorously treated. The mainstay of treatment remains systemic anticoagulation with heparin and then warfarin. Warfarin should be continued for 1 month in postoperative cases and 3 months in spontaneous cases, provided there is no ongoing predisposing factor. Recurrent spontaneous DVT formation is an indication for lifelong anticoagulation. Recent evidence suggests that the subcutaneous route of administration of heparin has advantage over traditional intravenous infusion. Some large DVTs require thrombolysis, and it is now possible to treat the underlying anatomical defects with angioplasty and endovascular stenting, although the long-term outcome of these procedures has not yet been established. For patients with contraindications to the use of anticoagulants, a variety of (temporary and permanent) percutaneously inserted vena caval filters are now available. The principal complications of DVT are pulmonary embolism, which may be fatal, and the development of a postphlebitic leg. The avoidance of these depends on adequate prophylaxis and vigorous treatment of the primary DVT.
Article
The authors present a case of spinal epidural hematoma during anticoagulant therapy. Clinical presentation is characterized by classic paravertebral back pain, followed by progressive neurological deficit due to spinal cord and radicular compression, with sensory deficits and bladder disturbance. From the literature, 37 cases are collected of spinal epidural hematoma during anticoagulant therapy, treated surgically. Pathogenesis, diagnosis, and differential diagnosis are discussed. Early surgical decompression of the spinal cord minimizes the degree of permanent neurological damage, because of the long-time compression of the spinal cord resulting in irreversible disturbance of circulation; therefore an early diagnosis is a better prognosis. The thoracic and cervical spine canal is smaller than the lumbar, therefore there is less space to reward the formation of hematomas, consequently the postoperative recovery is lower in patient with high spinal epidural hematomas with respect to lumbo-sacral spinal epidural hematomas; at this level the epidural hematoma may be insidious in its onset and tends to become chronic before definite treatment is undertaken.
Article
Hormone replacement therapy (HRT) has been shown to increase the relative risk of idiopathic venous thromboembolism (VTE) about threefold in several observational studies and one randomised controlled trial. Whether or not this relative risk is higher in women with underlying thrombophilia phenotypes, such as activated protein C (APC) resistance, is unknown. We therefore restudied the participants in a case-control study of the relationship between the use of HRT and the occurrence of idiopathic VTE in women aged 45-64 years. After protocol exclusions, 66 of the cases in the original study and 163 of the controls were studied. Twenty haematological variables relevant to risk of VTE were analysed, including thrombotic states defined from the literature. The relative risk of VTE showed significant associations with APC resistance (OR 4.06; 95% CI 1.62, 10.21); low antithrombin (3.33; 1.15, 9.65) or protein C (2.93; 1.06, 8.14); and high coagulation factor IX (2.34; 1.26, 4.35), or fibrin D-dimer (3.84; 1.99, 7.42). HRT use increased the risk of VTE in women without any of these thrombotic states (OR 4.09; 95% CI 1.26, 13.30). A similar effect of HRT use on the relative risk of VTE was also found in women with prothrombotic states. Thus for example, the combination of HRT use and APC resistance increased the risk of VTE about 13-fold compared with women of similar age without either APC resistance or HRT use (OR 13.27; 95% CI 4.30, 40.97). We conclude that the combination of HRT use and thrombophilias (especially if multiple) increases the relative risk of VTE substantially; hence women known to have thrombophilias (especially if multiple) should be counselled about this increased risk prior to prescription of HRT. However, HRT increases the risk of VTE about fourfold even in women without any thrombotic abnormalities: possible causes are discussed.