There is good evidence that the incidence of VTE in elective spine surgery with mechanical and/or chemoprophylaxis is 0-10% in the absence of significant risk factors.

Grade of Recommendation: A

Gruber et al1 conducted a randomized controlled trial assessing bleeding complications of miniheparin (2 x 2500 IU daily)-dihydroergotamine against a placebo in 50 patients having a lumbar disc operation. Patients were randomized using a closed envelope technique and computer-produced randomization list. There was one (4%) deep venous thrombosis (DVT) in the experimental group at postoperative day (POD) 5 and none in the placebo group. There were no pulmonary embolus (PE) noted. Patients averaged almost 11 days in the hospital postoperatively, and were assessed for VTE if symptomatic. This study provides Level I evidence that the incidence of symptomatic DVT in the 10 days after lumbar disc surgery is 4%.

Voth et al2 published a prospective randomized double blind investigation of two different regimens for VTE chemoprophylaxis. No mechanoprophylaxis was used. A total of 179 patients were randomized. Group I with low molecular weight heparin, dihydroergotamine (LMWH/DHE) contained 87 patients. Each received 1500U of low molecular weight heparin with 0.5mg of dihydroergotamine once per day plus a placebo injection once per day. Group II with heparin + dihydroergotamine (HDHE) contained 92 patients. Each received 5,000U sodium heparin plus 0.5mg dihydroergotamine twice per day. Both groups started treatment 2 hours before the procedure and all patients were treated for 7 days. All patients had posterior lumbar surgery for disc prolapse. All patients were hospitalized at least 7 days and received q12 hour injections. Immediately after surgery every patient received 100 microCurie of Iodine125 labelled fibrinogen. A radiofibrinogen uptake test was done daily to screen for DVT. Phlebography was done for positive screening results. There were 4/87 (4.6%) patients in LMWH/DHE group that had positive screening tests. There were 3/92 (3.3%) patients in the HDHE group that had positive screening tests. Phlebography was confirmatory in 1/4 in the LMWH/DHE group and 2/3 of the HDHE group. Extent of DVT not specified. No patients had signs of PE. No patients had increased intraoperative bleeding in the LMWH/DHE but 4/92 did have increased intraoperative bleeding in HDHE group. There were 9/179 patients that received post operative transfusions with no difference between groups. There were no wound hematomas or neurologic complications related to epidural hematomas. Risk factors for DVT could not be determined for individual patients in this study given the lack of demographic and historical data on the patients. The work group downgraded this potential Level I study due to unspecified randomization method. This study provides Level II evidence that VTE incidence after lumbar disc prolapse surgery is less than 5% when chemoprophylaxis is used without mechanoprophylaxis. The paper also provides evidence that the two regimens that were used were safe and caused no wound hematomas or clinically significant epidural hematomas. The paper also provides evidence that there is a low incidence of intraoperative bleeding in the LMWH/DHE group.

In a multicenter prospective cohort study, Piasecki et al3 studied the rate of VTE after anterior/posterior spinal reconstruction for adult spinal deformity. In this population with mechanoprophylaxis the incidence of all VTE events was 13.9% due to DVT (9.1%) or PE (7.6%), or a combination of both. A right-sided thoracoabdominal approach was an independent risk factor for developing a VTE; 1/3 developed a DVT and/or PE. The authors cautioned that the extensive nature of the fusion (average of 8 levels) may not allow application of these findings to all anterior/posterior combined procedures. This study provides Level II evidence that the incidence of VTE is high in adult spinal deformity fusion (average 8 segments), particularly with right-sided anterior approaches, treated with mechanoprophylaxis.

In a retrospective comparative study, Altshuler et al4 reviewed complications in traditional open and minimally invasive decompression with and without fusion, from a prospectively collected series of patients having surgery for lumbar degenerative conditions. The prophylaxis protocol was subcutaneous heparin on POD 1 and sequential compression device (SCD). Of the 1,435 total patients identified, the rate of DVT following decompression surgery in the minimally invasive surgery (MIS) group was 0.5% (3/555) with 1 PE, and the rate of DVT was 2.8% (8/284) in the open group, with zero PE. The rate of DVT when a fusion was also performed was 0.7% (3/406) in the MIS group, with no PE, and 2.1% (4/190) in the open group, with 3 PE. This study provides Level III evidence that the rate of venous thromboembolism in the minimally invasive spine surgery is lower than in open surgery. The overall incidence of DVT was 1.25% (18/1435) and PE was 0.28% (4/1435) in lumbar degenerative surgery patients.

Edwards et al5 retrospectively compared posterior-only spine surgery lasting more than 5 hours from prospectively collected data. The goal of the study was to identify the DVT risk in patients with lengthy, one-stage surgery compared to lengthy, multi-stage surgery. All patients received thigh high compression stockings, SCD, and ambulation encouraged on POD 1, and no chemoprophylaxis was used. All patients had a venous duplex ultrasound 2-4 days after surgery to screen for DVT. Data was analyzed for 107 patients, 81 with single-stage surgery and 26 had multiple operative encounters. The incidence of DVT was 7% (6/81) in the single-stage group and 19% (5/26) in the multi-stage group. The risk of PE was 1% (1/81) in the single-stage group and 0% in the multi-stage group. This study provides Level III evidence that the incidence of ultrosonographically diagnosed DVT following long (>5 hour) surgery is higher in staged surgery than in single stage surgery and the overall rate of DVT is 10% in this patient population.

Epstein et al6 reported on a case series of 139 patients undergoing lumbar decompression and fusion with routine duplex ultrasound screening for VTE on postoperative day 2, and later scanning if symptomatic. All patients had pneumatic compression stockings only, and no chemoprophylaxis. Four of the 139 (2.9%) developed a DVT and 1 of the 139 (0.7%) developed a PE. These 4 events of VTE were diagnosed between POD 2 and POD 6 and treated with vena cava filter. This study provides Level IV evidence of an incidence of VTE within 6 days of lumbar decompression and fusion for degenerative conditions of 0.7% for PE and 2.9% for DVT in a series of patients treated with mechanical prophylaxis only.

In a prospective comparative study, Epstein et al7 evaluated the efficacy of pneumatic compression stockings to prevent VTE in anterior cervical fusion with or without posterior cervical fusion. One hundred patients had a single level corpectomy only and another one hundred had anterior corpectomy and posterior fusion, and all had mechanical prophylaxis only and were screened for DVT with a duplex ultrasound of the lower extremities on POD 2. A computed tomography (CT) angiogram of the chest was done if DVT was detected. In the single level anterior group, none had a DVT on POD 2 screen; however, one patient developed a DVT/PE on POD 6 (1%). In the anterior and posterior group, seven of the 100 (7%) developed a DVT at a range of 2-14 days after surgery, and 2 had PE, one at 10 days and the other at 14 days post operatively. The work group downgraded this potential Level II study due to non-consecutive patients. This study provides Level III evidence that the incidence of DVT in anterior cervical surgery for degenerative indications ranges from 2-7%, and the incidence of PE is 1-2%, with the use of intermittent mechanical prophylaxis only.

Fawi et al8 published a retrospective comparative study of 2,181 patients undergoing elective thoracolumbar surgery and compared the use of anti-embolic stockings only versus subcutaneous enoxaparin given 6 hours postoperatively, using the rate of VTE, mortality, surgical site infection (SSI) and epidural hematoma. Only symptomatic patients had either duplex ultrasound of the extremities or CT angiogram/VQ scan. In the 689 patients that received enoxaparin, there were no VTE recorded. Seven patients had a negative doppler ultrasound and 10 had a negative CT angiogram. In the 1,677 patients with antiembolic stockings only, 25 required CT angiogram, with 9 (0.5%) positives for PE, and 10 required doppler ultrasound, of which 1 was positive for DVT (0.06%). There was not an epidural hematoma identified in either group. This study provides Level III evidence that the incidence of DVT is <1% in elective thoracolumbar surgery using early mobilization, hydration, and antiembolic stockings. There were no cases of VTE in patients using early mobilization, hydration and enoxaparin at 6 hours postoperatively.

Fourman et al9 conducted a retrospective comparative study assessing the use of chemoprophylaxis starting on POD 2 following elective thoracolumbar surgery, in patients deemed to be high risk for VTE. All patients received pneumatic compression devices (PCD) and either aspirin (ASA) for 30 days or fondaparinux during hospitalization and then ASA for a total of 30 days. During the study period, there were 377 identified as high risk-102 had ASA+PCD and 275 had fondaparinux+ASA+PCD. In the control group, there were 3 (2.9%) DVT and 2 (2%) PE. In the fondaparinux group, there were no DVT and 1 (0.4%) PE. There were no epidural hematoma in either group. This study provides Level III evidence that the incidence of DVT in elective lumbar surgery with mechanical prophylaxis and ASA is 2.9% and incidence of PE is 2%. The incidence with additional fondaparinux along with mechanical prophylaxis is 0% for DVT and 2% for PE.

Hamidi et al10 looked at the incidence of VTE in patients undergoing elective instrumented spine surgery and randomly receiving either LMWH or no treatment pre-operatively. All patients had postoperative compression stockings. All patients also had postoperative Doppler ultrasound. There was no significant difference in the 2 groups (n=89 patients) with respect to VTE incidence. The work group downgraded this potential Level I study due to small sample size. This study provides Level II evidence that the incidence of VTE is similar in patients with compression stockings and SCDs with, and without, chemoprophylaxis.

Moayer et al11 looked at incidence of DVT in 120 patients who underwent elective spine surgery at any spinal level. All patients received 5000u of Dalteparin on POD 1. No other preventive measures were used. One patient, on oral contraceptives, had a DVT. The work group downgraded this potential Level III study due to no control group and no randomization. This study provides Level IV evidence that Dalteparin prevents DVT in patients undergoing elective spine surgery.

Pateder et al12 retrospectively reviewed 407 patients undergoing surgery for adult deformity over 8 years ending in 2000. The authors only looked for PE and found 10 patients. All patients had compression stockings and SCDs pre- and postoperatively, and Coumadin for the first 7 years of the study and LMWH for the last year. They noted that these measures may have reduced PE in ventral surgeries by 50% compared to historical controls. The work group downgraded this potential Level III study due to no control group, retrospective nature, differing protocol, and no assessment of DVT. This study provides Level IV evidence that anticoagulation prevents PE in patients undergoing surgery for adult deformity.

Sethi et al13 presented results of an algorithm developed by their spine team in an attempt to decrease postoperative complications in patients undergoing elective surgery for adult deformity. This process involved the use of 2 surgeons, a live multidisciplinary conference, and an intraoperative pharmacologic protocol. This was an attempt to decrease all surgical complications, not just DVT/PE. All patients received 5000u heparin subcutaneous 3 times a day on POD 1. The work group downgraded this potential Level III study due to lack of control group and wide difference in case mix. This study provides Level IV evidence of an evidence-based algorithm that considered wound, thrombotic, and bleeding complications in recommending treatment for DVT prophylaxis.

In a retrospective case-cohort study, Sun et al14 compared two patient groups undergoing posterior lumbar interbody fusion (PLIF). One group received tranexamic acid (TXA) (26 patients) and the control group (37 patients) did not receive TXA. Only the 37 control group patients are relevant. No PE occurred in the control group and 1/37 (2.7%) patient had a DVT. All patients had mechanoprophylaxis. No patients received chemoprophylaxis. There was no demographic information for the one patient with DVT and no information on the number of levels fused, and all patients had PLIF so no comments regarding risk factors are included. This study provides Level III evidence that the incidence of VTE following posterior lumbar surgery is less than 5% when at least mechanoprophylaxis is used.

Tsahtsarlis et al15 conducted a prospective observational study of 100 consecutive minimally invasive 1 or 2 level PLIF. There were 89 transforaminal lumbar interbody fusion (TLIF) and 11 PLIF procedures. Two patients had PE within one month of the procedure. Both patients received subcutaneous heparin post operatively (dose not specified). All patients received compression stockings and SCDs. No additional demographic information on these 2 patients was provided. No comments regarding risk factors for VTE. This study provides Level IV evidence that the incidence of VTE following posterior lumbar surgery is less than 5% when at least mechanoprophylaxis is used.

Tsahtsarlis et al16 studied a prospective consecutive series of 23 patients with Grade I or Grade II lumbar spondylolisthesis. All patients had minimally invasive transforaminal interbody fusions. One patient had 2 level surgery, all others were single level. One patient was diagnosed with a PE (4.3%). All patients had compression stockings and SCDs. No additional demographic information was provided on the patient with PE so no comment on risk factors. This study provides Level IV evidence that the incidence of VTE following posterior lumbar surgery is less than 5% when mechanoprophylaxis is used.

Weber et al17 studied a single-institution case series of 107 instrumented lumbar fusions to determine the VTE incidence and associated risk factors. About 2/3 of all patients underwent lower extremity duplex ultrasonography on POD 4 or 5. The criteria for ultrasonography was not provided. The remaining 1/3 were monitored for VTE using clinical observation. When there was clinical suspicion of PE a computed tomography pulmonary angiogram was obtained. The Caprini model for thrombosis risk factors was retrospectively applied. All patients had compression stockings and SCDs applied intraoperatively. There were 40/107 (37%) patients who also received at least a single dose of LMWH on the day of surgery. There was no detected difference in the patient population that received LMWH and those that did not. Risk scores for 96.2% of patients were high or highest categories. A VTE occurred in 4/107 (3.7%) patients, none of whom received chemoprophylaxis. There were 2 patients with DVT and 2 patients with PE. There were no patients with epidural hematoma. A number of demographic and operative details and known VTE risk factors were collected. While various demographic data was collected there was no analysis given on the patients with VTE to determine risk factors. This paper provides Level IV evidence that the incidence of VTE in posterior instrumented lumbar surgery is less than 5% when mechanoprophylaxis is used. While some patients received LMWH, no comment can be made because there was no clear criteria or regimen. There were no epidural hematomas in the 40/107 that received at least one dose of LMWH.

Wei et al18 retrospectively reviewed patients undergoing posterior lumbar interbody fusions, to assess the incidence of VTE based on risk factors including preoperative plasma D Dimer levels. There were 2861 patients in the study. All patients received SCDs from induction of anesthesia to postoperative ambulation. Walking exercises began on POD 5. All patients received enoxaparin 40 mg/day beginning on POD 1 and continued to POD 7. Patients with elevated D Dimer preoperatively received the first dose of enoxaparin 12 hours preoperatively. Patients were monitored clinically for signs of VTE, wound hematoma or spinal epidural hematoma. All patients had Doppler ultrasonography within 24 hours of hospital admission, and a second Doppler ultrasonography study on POD 5. If there was clinical suspicion for DVT an additional ultrasound study was done. In the patients with ultrasonography-confirmed DVT, 252/269 (93.7%) had distal DVT and 17/269 (6.3%) were proximal DVT. There were no patients with clinical suspicion of PE. The patients with elevated D Dimer levels had a higher incidence of DVT than those with normal D Dimer levels (p<0.05). Patients with DVT also were significantly older with an average age of 61.3 in the positive group and 52.6 in the negative group. Age was a risk factor (p<0.013). The presence of rheumatoid arthritis was found to be a risk factor (p=0.028). Hypertension, diabetes mellitus, gender and coronary heart disease were not found to be independent risk factors. Both groups had similar body mass index (BMI) under 25. There were 6/2861 (0.21%) with spinal epidural hematoma. This study provides Level IV evidence that preoperative elevated D-Dimer plasma levels, age over 60, and rheumatoid arthritis are independent risk factors for DVT. This paper also provides evidence that enoxaparin 40mg/day does not significantly increase risk of epidural hematoma.

Yamada et al19 conducted a prospective observational study to determine the incidence of DVT in patients with degenerative cervical disease. All patients had preoperative D Dimer tests and lower extremity ultrasonography. Both tests were repeated at median POD 4. All patients received compression stockings and SCDs from anesthesia induction to ambulation. None received routine chemoprophylaxis, although all 9 DVT positive patients received heparin and/or warfarin. There were 289 patients, with 86 patients being female. There were 9/289 (3.1%) patients with distal DVT. The incidence of preoperative DVT was 1.1% and post operative incidence of DVT 2.1%. All patients with DVT were female. Univariate analysis found the statistically significant risk factors for perioperative DVT were female gender (p<0.01), advanced age (=0.04), low Japanese Orthopedic Association (JOA) score (p=0.03), rapidly progressive myelopathy (p<0.01), inability to walk (p=0.01). Multivariate analysis found rapidly progressive myelopathy (p=0.04) was the most significant risk factor. Posterior surgery was done in 8/9 DVT positive patients, but surgical factors including approach were determined to be not significant. Preoperative D Dimer level was found to be not significant as a risk factor for DVT. This paper found evidence that in degenerative cervical disease patient risk factors for DVT include female gender, advanced age, low JOA score, inability to walk, and most importantly rapidly progressive myelopathy. Factors not found to be associated with increased risk of DVT include increased D Dimer, surgical approach, blood loss, operative time, and +/- fusion. This study provides Level IV evidence regarding the timing of DVT occurrence with 1.1% of patients having preoperative DVT.

Yoshioka et al20 retrospectively studied 340 patients at a single institution. Patients were divided into 4 groups. Group 1, 79 patients treated with posterior decompression without fusion, the VTE incidence was 15.2%. Group 2, 90 patients with lumbar and thoracolumbar degenerative changes treated with posterior instrumented fusion, the incidence of VTE was 13.3%. Group 3, 89 patients with cervical degenerative disease treated with posterior decompression or instrumented fusion, the incidence of VTE was 4.5%. Group 4, 82 patients with spinal tumors treated with total spondylectomy or piecemeal excision with stabilization, the incidence of VTE was 22.0%. A total of 10 patients had PE with only 2/10 being symptomatic, and 6/10 did not have a concurrent DVT. Anterior surgery was an exclusionary criterion for groups 1, 2, and 3. All patients had screening for DVT and PE 7 to 10 days post operatively using bilateral duplex ultrasonography, and lung perfusion scintigraphy with CT venography for definitive PE diagnosis. Multivariate analysis found risk factors for VTE to be spinal tumors (p=0.11), neurologic deficits (p=0.01), and advanced age (p=0.004). Univariate analysis found duration of bedrest (p=0.026) and intraoperative blood loss (p=0.019). Posterior cervical surgery was lower risk. All patients received compression stockings and SCDs from anesthesia induction to ambulation. No chemoprophylaxis was used. This study provides Level IV evidence that risk factors for VTE include advanced age (mean 64.4 vs 57.9), tumor surgery, neurologic deficits, prolonged bedrest, and increased blood loss. Gender was evaluated but not significant. BMI was below 25 for both VTE positive and negative groups. No statement can be made about the risk of anterior surgery as anterior approaches occurred in only 4/340 patients.

In a prospective study, Yoshioka et al21 aimed to determine the incidence and risk factors for VTE at various spinal levels and different spinal pathologies. Study included 459 patients divided into 5 groups. Group 1, patients with degenerative cervical disease treated with posterior decompression with VTE 2.8%. Group 2, patients with degenerative cervical disease treated with spinal fusion with instrumentation, VTE 3.4%. Group 3, patients with thoracolumbar degenerative disease treated with instrumented fusion, VTE 10.8%. Group 4, patients with lumbar spinal stenosis treated with posterior decompression, VTE 12.5%. Group 5, patients with lumbar spondylolisthesis treated with single level posterior lumbar interbody fusion, VTE 10.1%. Factors identified with increased VTE risk included female gender (p<0.001), advanced age (mean 68.8 vs 60.7, p<0.001), spinal level, and paralysis (p<0.001). Cervical surgery was associated with a low risk (p=0.002). All patients had compression stockings and SCDs from anesthesia induction to ambulation. No chemoprophylaxis was used. All patients had bilateral venous ultrasonography and lung perfusion scintigraphy between day 7 and 10. CT venography was done if PE was suspected. This study provides Level III evidence that female gender, increased age, and paralysis increase risk of VTE. This study also provides evidence that cervical surgery has a lower risk of VTE.

References:

1. Gruber UF, Rem J, Meisner C, Gratzl O. Prevention of thromboembolic complications with miniheparin-dihydroergotamine in patients undergoing lumbar disc operations. Eur Arch Psychiatry Neurol Sci. 1984;234(3):157-161. doi:10.1007/BF00461554
2. Voth D, Schwarz M, Hahn K, Dei-Anang K, al Butmeh S, Wolf H. Prevention of deep vein thrombosis in neurosurgical patients: a prospective double-blind comparison of two prophylactic regimen. Neurosurg Rev. 1992;15(4):289-294. doi:10.1007/BF00257808
3. Piasecki DP, Poynton AR, Mintz DN, Roh JS, Peterson MGE, Rawlins BA, Charles G, Boachie-Adjei O (2008) Thromboembolic disease after combined anterior/posterior reconstruction for adult spinal deformity: a prospective cohort study using magnetic resonance venography. Spine. 33(6):668–672
4. Altshuler M, Mueller K, MacConnell A, Wirth P, Sandhu F, Voyadzis JM. Does minimally invasive spine surgery reduce the rate of perioperative medical complications? A retrospective single-center experience of 1435 degenerative lumbar spine surgeries. Eur Spine J. 2021;30(1):122-127. doi:10.1007/s00586-020-06536-y
5. Edwards CC 2nd, Lessing NL, Ford L, Edwards CC. Deep Vein Thrombosis After Complex Posterior Spine Surgery: Does Staged Surgery Make a Difference? Spine Deform. 2018;6(2):141-147. doi:10.1016/j.jspd.2017.08.012
6. Epstein NE. Efficacy of pneumatic compression stocking prophylaxis in the prevention of deep venous thrombosis and pulmonary embolism following 139 lumbar laminectomies with instrumented fusions. J Spinal Disord Tech. 2006;19(1):28-31. doi:10.1097/01.bsd.0000173454.71657.02
7. Epstein NE. Intermittent pneumatic compression stocking prophylaxis against deep venous thrombosis in anterior cervical spinal surgery: a prospective efficacy study in 200 patients and literature review. Spine (Phila Pa 1976). 2005;30(22):2538-2543. doi:10.1097/01.brs.0000186318.80139.40
8. Fawi HMT, Saba K, Cunningham A, et al. Venous thromboembolism in adult elective spinal surgery: a tertiary centre review of 2181 patients. Bone Joint J. 2017;99-B(9):1204-1209. doi:10.1302/0301-620X.99B9.BJJ-2016-1193.R2
9. Fourman MS, Shaw JD, Nwasike CO, et al. Use of Fondaparinux Following Elective Lumbar Spine Surgery Is Associated With a Reduction in Symptomatic Venous Thromboembolism. Global Spine J. 2020;10(7):844-850. doi:10.1177/2192568219878418
10. Hamidi S, Riazi M. Incidence of venous thromboembolic complications in instrumental spinal surgeries with preoperative chemoprophylaxis. J Korean Neurosurg Soc. 2015;57(2):114-118. doi:10.3340/jkns.2015.57.2.114
11. Moayer A, Mohebali N, Razmkon A. Incidence of Deep Vein Thrombosis in Patients Undergoing Degenerative Spine Surgery on Prophylactic Dalteparin; A Single Center Report. Bull Emerg Trauma. 2016;4(1):38-42.
12. Pateder DB, Gonzales RA, Kebaish KM, et al. Pulmonary embolism after adult spinal deformity surgery. Spine (Phila Pa 1976). 2008;33(3):301-305. doi:10.1097/BRS.0b013e31816245e1
13. Sethi RK, Pong RP, Leveque JC, Dean TC, Olivar SJ, Rupp SM. The Seattle Spine Team Approach to Adult Deformity Surgery: A Systems-Based Approach to Perioperative Care and Subsequent Reduction in Perioperative Complication Rates. Spine Deform. 2014;2(2):95-103. doi:10.1016/j.jspd.2013.12.002
14. Sun H, Deng L, Deng J, et al. The Efficacy and Safety of Prophylactic Intravenous Tranexamic Acid on Perioperative Blood Loss in Patients Treated with Posterior Lumbar Interbody Fusion. World Neurosurg. 2019;125:e198-e204. doi:10.1016/j.wneu.2019.01.040
15. Tsahtsarlis A, Efendy JL, Mannion RJ, Wood MJ. Complications from minimally invasive lumbar interbody fusion: experience from 100 patients. J Clin Neurosci. 2013;20(6):813-817. doi:10.1016/j.jocn.2012.05.055
16. Tsahtsarlis A, Wood M. Minimally invasive transforaminal lumber interbody fusion and spondylolisthesis. J Clin Neurosci. 2012; 19(6): 858-61.
17. Weber B, Seal A, McGirr J, Fielding K. Case series of elective instrumented posterior lumbar spinal fusions demonstrating a low incidence of venous thromboembolism. ANZ J Surg. 2016;86(10):796-800. doi:10.1111/ans.12702
18. Wei J, Li W, Pei Y, Shen Y, Li J. Clinical analysis of preoperative risk factors for the incidence of deep venous thromboembolism in patients undergoing posterior lumbar interbody fusion. J Orthop Surg Res. 2016;11(1):68. Published 2016 Jun 13. doi:10.1186/s13018-016-0403-0
19. Yamada K, Suda K, Matsumoto Harmon S, et al. Rapidly progressive cervical myelopathy had a high risk of developing deep venous thrombosis: a prospective observational study in 289 cases with degenerative cervical spine disease. Spinal Cord. 2019;57(1):58-64. doi:10.1038/s41393-018-0213-9
20. Yoshioka K, Murakami H, Demura S, et al. Comparative study of the prevalence of venous thromboembolism after elective spinal surgery. Orthopedics. 2013;36(2):e223-e228. doi:10.3928/01477447-20130122-26
21. Yoshioka K, Murakami H, Demura S, Kato S, Tsuchiya H. Prevalence and risk factors for development of venous thromboembolism after degenerative spinal surgery. Spine (Phila Pa 1976). 2015;40(5):E301-E306. doi:10.1097/BRS.0000000000000727

There is insufficient evidence to make a recommendation for or against a specific treatment protocol (mechanoprophylaxis, chemoprophylaxis) for elective spine surgery; however, the rate of VTE may be higher in anterior versus posterior lumbar surgery, lumbar versus cervical surgery, and surgery of more than four levels.

Grade of Recommendation: I

Piasecki et al1 conducted a multicenter prospective cohort study to determine the rate of VTE after anterior/posterior spinal reconstruction for adult spinal deformity. In this population with mechanoprophylaxis the incidence of all VTE events was 13.9% due to DVT (9.1%) or PE(7.6%), or a combination of both. A right-sided thoracoabdominal approach was an independent risk factor with an increased risk for developing a VTE; 1/3 developed a DVT and/or PE. The authors cautioned that the extensive nature of the fusion (average of 8 levels) may not allow application of these findings to all anterior/posterior combined procedures. This study provides Level II evidence that the incidence of VTE is high in adult spinal deformity fusion (average 8 segments), particularly with right-sided anterior approaches, treated with mechanoprophylaxis.

In a prospective study, Yoshioka et al2 aimed to determine the incidence and risk factors for VTE at various spinal levels and different spinal pathologies. Study included 459 patients divided into 5 groups. Group 1, patients with degenerative cervical disease treated with posterior decompression with VTE 2.8%. Group 2, patients with degenerative cervical disease treated with spinal fusion with instrumentation, VTE 3.4%. Group 3, patients with thoracolumbar degenerative disease treated with instrumented fusion, VTE 10.8%. Group 4, patients with lumbar spinal stenosis treated with posterior decompression, VTE 12.5%. Group 5, patients with lumbar spondylolisthesis treated with single level posterior lumbar interbody fusion, VTE 10.1%. Factors identified with increased VTE risk included female gender (p<0.001), advanced age (mean 68.8 vs 60.7, p<0.001), spinal level, and paralysis (p<0.001). Cervical surgery was associated with a low risk (p=0.002). All patients had compression stockings and SCDs from anesthesia induction to ambulation. No chemoprophylaxis was used. All patients had bilateral venous ultrasonography and lung perfusion scintigraphy between day 7 and 10. CT venography was done if PE was suspected. This study provides Level III evidence that female gender, increased age, and paralysis increase risk of VTE. This study also provides evidence that cervical surgery has a lower risk of VTE.

Yoshioka et al3 retrospectively studied 340 patients at a single institution. Patients were divided into 4 groups. Group 1, 79 patients treated with posterior decompression without fusion, the VTE incidence was 15.2%. Group 2, 90 patients with lumbar and thoracolumbar degenerative changes treated with posterior instrumented fusion, the incidence of VTE was 13.3%. Group 3, 89 patients with cervical degenerative disease treated with posterior decompression or instrumented fusion, the incidence of VTE was 4.5%. Group 4, 82 patients with spinal tumors treated with total spondylectomy or piecemeal excision with stabilization, the incidence of VTE was 22.0%. A total of 10 patients had PE with only 2/10 being symptomatic, and 6/10 did not have a concurrent DVT. Anterior surgery was an exclusionary criterion for groups 1, 2, and 3. All patients had screening for DVT and PE 7 to 10 days post operatively using bilateral duplex ultrasonography, and lung perfusion scintigraphy with CT venography for definitive PE diagnosis. Multivariate analysis found risk factors for VTE to be spinal tumors (p=0.11), neurologic deficits (p=0.01), and advanced age (p=0.004). Univariate analysis found duration of bedrest (p=0.026) and intraoperative blood loss (p=0.019). Posterior cervical surgery was lower risk. All patients received compression stockings and SCDs from anesthesia induction to ambulation. No chemoprophylaxis was used. This study provides Level IV evidence that risk factors for VTE include advanced age (mean 64.4 vs 57.9), tumor surgery, neurologic deficits, prolonged bedrest, and increased blood loss. Gender was evaluated but not significant. BMI was below 25 for both VTE positive and negative groups. No statement can be made about the risk of anterior surgery as anterior approaches occurred in only 4/340 patients.

Pateder et al4 retrospectively reviewed 407 patients undergoing surgery for adult deformity over eight years ending in 2000. The authors only looked for PE and found ten patients. All patients had compression stockings and SCDs pre- and post-op, and Coumadin for the first seven years of the study and LMWH for the last year. They noted that these measures may have reduced PE in ventral surgeries by 50% compared to historical controls. The work group downgraded this potential Level III study due to no control group, retrospective nature, differing protocol, and no assessment of DVT. This study provides Level IV evidence that anticoagulation prevents PE in patients undergoing surgery for adult deformity.

References:

1. Piasecki DP, Poynton AR, Mintz DN, Roh JS, Peterson MGE, Rawlins BA, Charles G, Boachie-Adjei O (2008) Thromboembolic disease after combined anterior/posterior reconstruction for adult spinal deformity: a prospective cohort study using magnetic resonance venography. Spine. 33(6):668–672
2. Yoshioka K, Murakami H, Demura S, Kato S, Tsuchiya H. Prevalence and risk factors for development of venous thromboembolism after degenerative spinal surgery. Spine (Phila Pa 1976). 2015;40(5):E301-E306. doi:10.1097/BRS.0000000000000727
3. Yoshioka K, Murakami H, Demura S, et al. Comparative study of the prevalence of venous thromboembolism after elective spinal surgery. Orthopedics. 2013;36(2):e223-e228. doi:10.3928/01477447-20130122-26
4. Pateder DB, Gonzales RA, Kebaish KM, et al. Pulmonary embolism after adult spinal deformity surgery. Spine (Phila Pa 1976). 2008;33(3):301-305. doi:10.1097/BRS.0b013e31816245e1

There is insufficient evidence to determine the timing of the occurrence of venous thromboembolism in the perioperative period; the range appears to vary from prior to surgery up to 30 days post-op depending on the protocol used for screening.

Grade of Recommendation: I

Fourman et al1 conducted a retrospective comparative study assessing the use of chemoprophylaxis starting on POD 2 following elective thoracolumbar surgery, in patients deemed to be high risk for VTE. All patients received pneumatic compression devices (PCD) and either aspirin (ASA) for 30 days or fondaparinux during hospitalization and then ASA for a total of 30 days. During the study period, there were 377 identified as high risk-102 had ASA+PCD and 275 had fondaparinux+ASA+PCD. Patients were deemed positive for VTE if an event was identified in the first 30 days after surgery. In the control group, there were 3(2.9%) DVT and 2(2%) PE. In the fondaparinux group, there were no DVT and 1(0.4%) PE. There were no epidural hematoma in either group. This study provides Level III evidence of that the incidence of DVT in elective lumbar surgery with mechanical prophylaxis and ASA is 2.9% and incidence of PE is 2%. The incidence with additional fondaparinux along with mechanical prophylaxis is 0% for DVT and 2% for PE.

Yamada et al2 conducted a prospective observational study to determine the incidence of DVT in patients with degenerative cervical disease. All patients had preoperative D Dimer tests and lower extremity ultrasonography. Both tests were repeated at median POD 4. All patients received compression stockings and SCDs from anesthesia induction to ambulation. None received routine chemoprophylaxis, although all 9 DVT positive patients received heparin and/or warfarin. There were 289 patients, with 86 patients being female. There were 9/289 (3.1%) patients with distal DVT. The incidence of preoperative DVT was 1.1% and post operative incidence of DVT 2.1%. All patients with DVT were female. Univariate analysis found the statistically significant risk factors for perioperative DVT were female gender (p<0.01), advanced age (=0.04), low JOA score (p=0.03), rapidly progressive myelopathy (p<0.01), inability to walk (p=0.01). Multivariate analysis found rapidly progressive myelopathy (p=0.04) was the most significant risk factor. Posterior surgery was done in 8/9 DVT positive patients, but surgical factors including approach were determined to be not significant. Preoperative D Dimer level was found to be not significant as a risk factor for DVT. This paper found evidence that in degenerative cervical disease patient risk factors for DVT include female gender, advanced age, low JOA score, inability to walk, and most importantly rapidly progressive myelopathy. Factors not found to be associated with increased risk of DVT include increased D Dimer, surgical approach, blood loss, operative time, and +/- fusion. This study provides Level IV evidence regarding the timing of DVT occurrence with 1.1% of patients having preoperative DVT.

References:

1. Fourman MS, Shaw JD, Nwasike CO, et al. Use of Fondaparinux Following Elective Lumbar Spine Surgery Is Associated With a Reduction in Symptomatic Venous Thromboembolism. Global Spine J. 2020;10(7):844-850. doi:10.1177/2192568219878418
2. Yamada K, Suda K, Matsumoto Harmon S, et al. Rapidly progressive cervical myelopathy had a high risk of developing deep venous thrombosis: a prospective observational study in 289 cases with degenerative cervical spine disease. Spinal Cord. 2019;57(1):58-64. doi:10.1038/s41393-018-0213-9

There is insufficient and conflicting evidence to make a recommendation for or against the superior effectiveness of combined chemoprophylaxis and mechanical prophylaxis vs either alone.

Grade of Recommendation: I

Gruber et al1 conducted a randomized controlled trial assessing bleeding complications of miniheparin (2 x 2500 IU daily)-dihydroergotamine against a placebo in 50 patients having a lumbar disc operation. Patients were randomized using a closed envelope technique and computer-produced randomization list. There was 1 (4%) deep venous thrombosis (DVT) in the experimental group at POD 5 and none in the placebo group. There were no pulmonary embolus (PE) noted. Patients averaged almost 11 days in the hospital postoperatively, and were assessed for VTE if symptomatic. This study provides Level I evidence that the incidence of symptomatic DVT in the 10 days after lumbar disc surgery is 4%.

Voth et al2 published a prospective randomized double blind investigation of 2 different regimens for VTE chemoprophylaxis. No mechanoprophylaxis was used. A total of 179 patients were randomized. Group I (LMWH/DHE) contained 87 patients. Each received 1500U of low molecular weight heparin with 0.5mg of dihydroergotamine once per day plus a placebo injection once per day. Group II (HDHE) contained 92 patients. Each received 5,000U sodium heparin plus 0.5mg dihydroergotamine twice per day. Both groups started treatment 2 hours before the procedure and all patients were treated for 7 days. All patients had posterior lumbar surgery for disc prolapse. All patients were hospitalized at least 7 days and received q12 hour injections. Immediately after surgery every patient received 100 microCurie of Iodine125 labelled fibrinogen. A radiofibrinogen uptake test was done daily to screen for DVT. Phlebography was done for positive screening results. There were 4/87 (4.6%) patients in LMWH/DHE group that had positive screening tests. There were 3/92 (3.3%) patients in the HDHE group that had positive screening tests. Plebography was confirmatory in 1/4 in the LMWH/DHE group and 2/3 of the HDHE group. Extent of DVT not specified. No patients had signs of PE. No patients had increased intraoperative bleeding in the LMWH/DHE but 4/92 did have increased intraoperative bleeding in HDHE group. There were 9/179 patients that received post operative transfusions with no difference between groups. There were no wound hematomas or neurologic complications related to epidural hematomas. Risk factors for DVT could not be determined for individual patients in this study given the lack of demographic and historical data on the patients. The work group downgraded this potential Level I study due to unspecified randomization method. This paper provides Level II evidence that VTE incidence after lumbar disc prolapse surgery is less than 5% when chemoprophylaxis is used without mechanoprophylaxis. The paper also provides evidence that the two regimens that were used were safe, and caused no wound hematomas or clinically significant epidural hematomas. The paper also provides evidence that there is a low incidence of intraoperative bleeding increase in the LMWH/DHE group.

Sethi et al3 presented results of an algorithm developed by their spine team in an attempt to decrease postoperative complications in patients undergoing elective surgery for adult deformity. This process involved the use of two surgeons, a live multidisciplinary conference, and an intraoperative pharmacologic protocol. This was an attempt to decrease all surgical complications, not just DVT/PE. All patients received 5000u heparin subcutaneous three times a day on postoperative day one. The work group downgraded this potential Level III study due to lack of control group and wide difference in case mix. This study provides Level IV evidence of an evidence-based algorithm that considered wound, thrombotic, and bleeding complications in recommending treatment for DVT prophylaxis.

Fourman et al4 conducted a retrospective comparative study assessing the use of chemoprophylaxis starting on POD2 following elective thoracolumbar surgery, in patients deemed to be high risk for VTE. All patients received pneumatic compression devices (PCD) and either aspirin (ASA) for 30 days or fondaparinux during hospitalization and then ASA for a total of 30 days. During the study period, there were 377 identified as high risk-102 had ASA+PCD and 275 had fondaparinux+ASA+PCD. In the control group, there were 3 (2.9%) DVT and 2 (2%) PE. In the fondaparinux group, there were no DVT and 1(0.4%) PE. There were no epidural hematoma in either group. This study provides Level III evidence that the incidence of DVT in elective lumbar surgery with mechanical prophylaxis and ASA is 2.9% and incidence of PE is 2%. The incidence with additional fondaparinux along with mechanical prophylaxis is 0% for DVT and 2% for PE.

Moayer et al5 looked at incidence of DVT in 120 patients who underwent elective spine surgery at all spinal levels. All patients received 5000u of dalteparin on POD 1. No other preventive measures were used. One patient, on oral contraceptives, had a DVT. The work group downgraded this potential Level III study due to no control group and no randomization. This study provides Level IV evidence that dalteparin prevents DVT in patients undergoing elective spine surgery.

Weber et al6 studied a single-institution case series of 107 instrumented lumbar fusions to determine the VTE incidence and associated risk factors. About 2/3 of all patients underwent lower extremity duplex ultrasonography on POD 4 or 5. The criteria for ultrasonography was not provided. The remaining 1/3 were monitored for VTE using clinical observation. When there was clinical suspicion of PE, a computed tomography pulmonary angiogram was obtained. The Caprini model for thrombosis risk factors was retrospectively applied. All patients had compression stockings and SCDs applied intraoperatively. There were 40/107 (37%) patients who also received at least a single dose of LMWH on the day of surgery. There was no detected difference in the patient population that received LMWH and those that did not. Risk scores for 96.2% of patients were high or highest categories. A VTE occurred in 4/107 (3.7%) patients, none of whom received chemoprophylaxis. There were 2 patients with DVT and 2 patients with PE. There were no patients with epidural hematoma. A number of demographic and operative details and known VTE risk factors were collected. While various demographic data was collected there was no analysis given on the patients with VTE to determine risk factors. This paper provides Level IV evidence that the incidence of VTE in posterior instrumented lumbar surgery is less than 5% when mechanoprophylaxis is used. While some patients received LMWH no comment can be made because there was no clear criteria or regimen. There were no epidural hematomas in the 40/107 that received at least one dose of LMWH.

References:

1. Gruber UF, Rem J, Meisner C, Gratzl O. Prevention of thromboembolic complications with miniheparin-dihydroergotamine in patients undergoing lumbar disc operations. Eur Arch Psychiatry Neurol Sci. 1984;234(3):157-161. doi:10.1007/BF00461554
2. Voth D, Schwarz M, Hahn K, Dei-Anang K, al Butmeh S, Wolf H. Prevention of deep vein thrombosis in neurosurgical patients: a prospective double-blind comparison of two prophylactic regimen. Neurosurg Rev. 1992;15(4):289-294. doi:10.1007/BF00257808
3. Sethi RK, Pong RP, Leveque JC, Dean TC, Olivar SJ, Rupp SM. The Seattle Spine Team Approach to Adult Deformity Surgery: A Systems-Based Approach to Perioperative Care and Subsequent Reduction in Perioperative Complication Rates. Spine Deform. 2014;2(2):95-103. doi:10.1016/j.jspd.2013.12.002
4. Fourman MS, Shaw JD, Nwasike CO, et al. Use of Fondaparinux Following Elective Lumbar Spine Surgery Is Associated With a Reduction in Symptomatic Venous Thromboembolism. Global Spine J. 2020;10(7):844-850. doi:10.1177/2192568219878418
5. Moayer A, Mohebali N, Razmkon A. Incidence of Deep Vein Thrombosis in Patients Undergoing Degenerative Spine Surgery on Prophylactic Dalteparin; A Single Center Report. Bull Emerg Trauma. 2016;4(1):38-42.
6. Weber B, Seal A, McGirr J, Fielding K. Case series of elective instrumented posterior lumbar spinal fusions demonstrating a low incidence of venous thromboembolism. ANZ J Surg. 2016;86(10):796-800. doi:10.1111/ans.12702

De la Garza et al1 performed a retrospective chart analysis of a single institution cohort of 65 patients who underwent surgery for spinal malignancy between 2012 and 2018. They found that the overall rate of VTE within 30 days was 16.9%. All patients with VTE had DVT and 2 (3.1%) had nonfatal PE. Thirty-six of the 65 patients received chemoprophylaxis in addition to mechanical prophylaxis. The rate of VTE in patients started on chemoprophylaxis within 3 days was 9.1% and the rate of VTE in patients started on chemoprophylaxis on POD 4 or later was 35.7%. There was one epidural hematoma noted in a patient who started chemoprophylaxis on POD 2. The work group downgraded this potential Level III study due to small sample size and lack of subgroup analysis (multiple different types of tumor and a wide range of neurological presentations). This study provides Level IV evidence supporting early institution of chemoprophylaxis. Groot et al2 presented a retrospective case series of 637 patients operated upon for spinal metastatic disease. They did a chart review to identify clinical evidence of symptomatic DVT through 90 days postoperative. Overall rate of VTE was 11%. Patients were treated for a variety of pathologies and were treated with a variety of chemoprophylactic agents in addition to standard mechanical prophylaxis. No statistical difference in VTE rates were seen between the different treatment regimens likely due to the variety of regimens used including aspirin, warfarin, heparin, low molecular weight heparin, and no chemoprophylaxis. This study provides Level III evidence that there is no significant association between patients’ chemoprophylaxis and symptomatic VTE. Kaewborisutsakul et al3 provide a retrospective analysis of 103 patients with spinal tumors. Sixty-eight of these patients were screened with doppler ultrasound. Patients were treated with either mechanical prophylaxis or low molecular weight heparin without any particular protocol. The overall rate of VTE was 2.9% although only 60% of patients were screened. There was no difference in incidence between prophylaxis groups but there was no subgroup analysis and the numbers were very small. This study provides Level III evidence that chemoprophylaxis did not lower VTE incidence in operative spinal tumor patients. Shen et al4 conducted a prospective observational case series of 21 patients with vertebral body tumors who underwent a single-stage corpectomy, expandable cage, anterior and posterior column reconstruction through a single posterior approach. Patients received mechanoprophylaxis without chemoprophylaxis. There were no DVTs and no PEs in these 21 patients. This study provides Level III evidence that the rate of VTE was 0%. Yoshioka et al5 retrospectively studied 340 patients at a single institution. Patients were divided into 4 groups. Group 1, 79 patients treated with posterior decompression without fusion, the VTE incidence was 15.2%. Group 2, 90 patients with lumbar and thoracolumbar degenerative changes treated with posterior instrumented fusion, the incidence of VTE was 13.3%. Group 3, 89 patients with cervical degenerative disease treated with posterior decompression or instrumented fusion, the incidence of VTE was 4.5%. Group 4, 82 patients with spinal tumors treated with total spondylectomy or piecemeal excision with stabilization, the incidence of VTE was 22.0%. A total of 10 patients had PE with only 2/10 being symptomatic, and 6/10 did not have a concurrent DVT. Anterior surgery was an exclusionary criterion for groups 1, 2, and 3. All patients had screening for DVT and PE 7 to 10 days postoperatively using bilateral duplex ultrasonography, and lung perfusion scintigraphy with CT venography for definitive PE diagnosis. Multivariate analysis found risk factors for VTE to be spinal tumors (p=0.11), neurologic deficits (p=0.01), and advanced age (p=0.004). Univariate analysis found duration of bedrest (p=0.026) and intraoperative blood loss (p=0.019). Posterior cervical surgery was lower risk. All patients received compression stockings and SCDs from anesthesia induction to ambulation. No chemoprophylaxis was used. This study provides Level IV evidence that risk factors for VTE include advanced age (mean 64.4 vs 57.9), tumor surgery, neurologic deficits, prolonged bedrest, and increased blood loss. Gender was evaluated but not significant. BMI was below 25 for both VTE positive and negative groups. No statement can be made about the risk of anterior surgery as anterior approaches occurred in only 4/340 patients.