1 Predicting Venous Thromboembolic Complications following Neurosurgical Procedures David Dornbos III, Varun Shah, Blake Priddy, Victoria Schunemann, Ciarán Powers
Venous Thromboembolic (VTE) Complications Approximately 900,000 cases of DVT and PE occur annually in the United States 33% mortality within 30 days of diagnosis Accounts for 10% of mortality in hospitalized patients Virchow s Triad Venous stasis Vascular injury Hypercoagulability Intraoperative venous distension Microvascular endothelial damage 2 Caprini et al. Am J Surg 199:S3-S10, 2010.
Thromboembolic Complications in Neurosurgery Numerous risk factors are common in neurosurgical cases Malignant diagnoses Prolonged immobility Long duration of surgery Elderly patients Stroke, polytrauma, spinal cord injury Rates of VTE in a neurosurgical population DVT: 0-34% PE: 0-3.8% Brain tumors present highest risk 24% risk of DVT within 6 weeks of surgery 30% risk of DVT within 12 months 3 Raslan et al. Neurocrit Care 12:297-309, 2010. Marras et al. Cancer 89:640-646, 2000.
Thromboembolic Complications in Neurosurgery Risk factors known to increase DVT risk in neurosurgery Intracranial (v spine) surgery Malignant (v benign) tumors Duration of surgery Presence of leg weakness Increased age 4 Geerts et al. Chest 119:132S-175S, 2001.
Prophylactic Strategies in Neurosurgery Mechanical (MP) Intermittent pneumatic compression decreases DVT incidence from 21% to 7% Elastic stockings little difference in DVT risk compared to IPC Chemical (CP) Significant risk reduction with combined strategies Physical alone: 26-33% DVT risk; 12-13% proximal DVT risk Physical + LMWH: 17-19% DVT risk; 5-7% proximal DVT risk 38% relative risk reduction Heparin use in isolated craniotomy patients Reduction in DVT rate from 34% (control) to 6% MP+UFH may be safer and more cost-effective at balancing VTE and ICH risk 5 Geerts et al. Chest 119:132S-175S, 2001. Algattas et al. Neurosurgery Epub, 2017.
Prophylactic Strategies in Neurosurgery 6 Collen et al. Chest 134:237-249, 2008.
Prophylactic Strategies in Neurosurgery Safety Numerous prospective studies have not demonstrated an increase in ICH rates following prophylactic heparin use Among patients presenting with spontaneous ICH Heparin 5000U TID, started on day 2, did not increase hemorrhagic complications Heparin on day 2 significantly decreased DVT rate compared to day 4 or day 10 7 Geerts et al. Chest 119:132S-175S, 2001.
Prophylactic Strategies in Neurosurgery 8 Collen et al. Chest 134:237-249, 2008.
Anti-Thrombotic Guidelines IPC +/- elastic stockings recommended in all patients Combination therapy with physical prophylaxis + UH/LMWH is strongly recommended More efficacious than IPC alone No significant increased risk of ICH 9 Geerts et al. Chest 119:132S-175S, 2001.
Compliance with Anti-Thrombotic Guidelines ACCP Antithrombotic Therapy Guidelines Neurosurgery: LMWH/LDUH 10 Yu et al. Am J Health Syst Pharm 64:69-76, 2007.
Compliance with Anti-Thrombotic Guidelines Reasons for non-compliance 11 Collen et al. Chest 134:237-249, 2008.
Caprini Risk Assessment Model 12 Caprini et al. Am J Surg 199:S3-S10, 2010. Bahl et al. Ann Surg 251:244-250, 2010.
Caprini Risk Assessment Model 13 Caprini et al. Am J Surg 199:S3-S10, 2010. Bahl et al. Ann Surg 251:244-250, 2010.
Caprini Risk Assessment Model 14 Caprini et al. Am J Surg 199:S3-S10, 2010. Bahl et al. Ann Surg 251:244-250, 2010.
Caprini Risk Assessment Model 15 Caprini et al. Am J Surg 199:S3-S10, 2010. Bahl et al. Ann Surg 251:244-250, 2010.
Caprini Risk Assessment Model 16 Caprini et al. Am J Surg 199:S3-S10, 2010. Bahl et al. Ann Surg 251:244-250, 2010.
Validation of the Caprini score in other surgical specialties Obi et al., 2015 critically ill patients (SICU admission) Overall incidence of VTE: 7.5% Caprini RAM effectively stratifies risk Score >8 had significantly greater risk than 7 or less (OR 1.37) Score 7-8 had significantly greater risk than 6 or less (OR 1.33) Pannucci et al., 2011 plastics/reconstructive surgery Overall incidence of VTE: 1.69% Caprini RAM effectively stratifies risk Score >8: 11.3% VTE risk High risk patients more than 50% develop VTE >14 days (within 60 days) 17 Obi et al. JAMA Surg 150:941-948, 2015. Pannucci et al. J Am Coll Surg 212:105-112, 2011.
Validation of the Caprini score in a neurosurgery population Retrospective Chart Review July 2014 Dec 2014 1395 patients undergoing neurosurgical procedures Collected baseline demographics, components of Caprini RAM Primary outcome: DVT/PE within 30 days of surgical procedure 18
Patient Demographics DVT/PE-Positive DVT/PE-Negative P value N 106 1289 Caprini score 8.11 ± 3.66 5.07 ± 3.42 <0.0001 Age 51.39 ± 14.71 51.04 ± 14.61 0.8153 BMI 34.38 ± 8.81 29.99 ± 8.32 <0.0001 Acute MI 3.77% 1.24% <0.05 Swollen legs 11.32% 1.55% <0.0001 CHF 2.83% 1.71% 0.4020 Bed rest 80.19% 31.42% <0.0001 Sepsis 7.55% 1.32% <0.0001 COPD 10.38% 7.68% 0.3220 Pneumonia 34.91% 7.14% <0.0001 Malignancy 35.85% 24.52% <0.01 Family thrombosis 4.72% 2.87% 0.2849 DVT/PE history 18.87% 6.36% <0.0001 Thrombophilia history 1.89% 0.57% 0.0625 Recent stroke 21.70% 8.77% <0.0001 Long bone fracture 0.00% 0.54% 0.4469 19
Predictors of DVT/PE Development (Univariate) OR 95% CI P value Caprini score 1.20 1.15-1.26 <0.001 BMI 1.05 1.03-1.08 <0.001 Acute MI 0.32 0.10-0.97 <0.05 Swollen legs 0.12 0.06-0.26 <0.001 Bed rest 0.11 0.07-0.19 <0.001 Sepsis 0.16 0.07-0.39 <0.001 Pneumonia 0.14 0.09-0.22 <0.001 Malignancy 0.61 0.40-0.92 <0.05 DVT/PE history 0.29 0.17-0.49 <0.001 Recent stroke 0.36 0.22-0.59 <0.001 20
Independent Predictors of DVT/PE Development OR 95% CI P value BMI 1.06 1.03-1.08 <0.001 Swollen legs 0.27 0.10-0.70 <0.01 Bed rest 0.17 0.09-0.32 <0.001 Pneumonia 0.27 0.15-0.49 <0.001 Malignancy 0.55 0.31-0.99 <0.05 DVT/PE history 0.49 0.23-1.07 0.073 Adjusting for any predictor of DVT/PE development with p<0.05 on univariate logistic regression analysis 21
Validation of the Caprini score in a neurosurgery population Initial Caprini score: 5 = very high risk Using 5 as cutoff Sensitivity 75.2% Specificity 68.4% AUROC = 0.75 22
Future Directions Developing a model that accurately stratifies risk in a neurosurgical population Cranial v spine procedures Evaluating benefit of personalizing VTE prophylactic strategies based on stratified risk 23
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