EBS presentation:Pharmacological VTE prophylaxis in neurosurgical patients and risk of    intracranial haemorrhage        ...
VTE and neurosurgery•   Study by Hamilton et al. (1994):          •       Contributing factors for increased              ...
pharmacological VTE prophylaxis   intracranial surgery  benefit of VTE prevention        risk of intracranial hemorrhage
EBS question•   Does the use of perioperative pharmacological VTE    prophylaxis (ie heparin) provide an overall benefit fo...
Search Strategy•   Medline, combined search terms:    •   Brain surgery (MeSH)    •   Perioperative anticoagulation (MeSH)...
Search results    Search strategy yielded 64 articles in Medline•   2 x systematic reviews :                        (Hamil...
Non-RCT studiesAuthor and year   Study type     Study population               VTE prophylaxis protocol                   ...
Systematic review
Methodology (Hamilton et al, 2011)                                       Data extraction:Inclusion criteria: •    original...
Results (Hamilton et al, 2011)Heparin 5000 units BD starting 2 hrs pre-operative vs untreated controlsEnoxaparin 20 mg dai...
Incidence of VTE (Hamilton et al, 2011)                       •   Pooled RR = 0.58                       •   Absolute risk...
Incidence of VTE (Hamilton et al, 2011)                       •   Pooled RR = 0.58                       •   Absolute risk...
Incidence of ICH (Hamilton et al, 2011)                         •   ICH was more common in                             hep...
Discussion (Hamilton et al, 2011)•   Consistent finding across studies that heparin significantly reduces    rate of VTE by ...
Conclusion•   Does the use of perioperative pharmacological VTE    prophylaxis use provide a favourable outcome for patien...
References:Hamilton, M. G., R. D. Hull, et al. (1994). "Venous thromboembolism in neurosurgery and neurologypatients: a re...
Heparin dvt prophylaxis and intracranial surgery dec 2011
Heparin dvt prophylaxis and intracranial surgery dec 2011
Heparin dvt prophylaxis and intracranial surgery dec 2011
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Heparin dvt prophylaxis and intracranial surgery dec 2011

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Heparin dvt prophylaxis and intracranial surgery dec 2011

  1. 1. EBS presentation:Pharmacological VTE prophylaxis in neurosurgical patients and risk of intracranial haemorrhage 15 December 2011 Scholar: Jonathan Li Senior scholar: Behzad Eftekhar
  2. 2. VTE and neurosurgery• Study by Hamilton et al. (1994): • Contributing factors for increased risk of VTE in neurosurgery patients: - showed rate of VTE in patients undergoing cranitomy was 25% - intracranial surgery - risk of PE in general neurosurgical - malignancy population was ~5% with a mortality rate of 9 to 50%. - duration of surgery - decreased mobility postoperatively - postoperative paralysis
  3. 3. pharmacological VTE prophylaxis intracranial surgery benefit of VTE prevention risk of intracranial hemorrhage
  4. 4. EBS question• Does the use of perioperative pharmacological VTE prophylaxis (ie heparin) provide an overall benefit for patients undergoing elective intracranial surgery ? P elective intracranial surgery I pharmacological VTE prophylaxis C placebo or non-pharmacological VTE prophylaxis O favourable outcome ie. reduction of VTE risk with minimal risk of intracranial hemorrhage
  5. 5. Search Strategy• Medline, combined search terms: • Brain surgery (MeSH) • Perioperative anticoagulation (MeSH) • Perioperative hemorrhage (MeSH)• Cochrane database• Scopus
  6. 6. Search results Search strategy yielded 64 articles in Medline• 2 x systematic reviews : (Hamilton et al, 2011) - meta-analysis of 6 RCTs (Lorio and Agnelli, 2000)• 2 x Randomised control trials : (Agnelli et al, 1998) (Nurmohamed et al, 1996)• 3 x prospective studies : (Chibbaro et al, 2008) (Gerlach et al, 2003) (Barnett et al, 1977)• 2 x retrospective studies : (Bauman et al, 2009) - DBS patients only (Cage et al, 2009)
  7. 7. Non-RCT studiesAuthor and year Study type Study population VTE prophylaxis protocol OutcomeCage et al 2009 Retrospective 86 patients who had 86 patient treated between 2003 and 2005 3 patients in treatment group (12.5%) and case control craniotomy for meningioma were given clexane within 48 hrs after surgery 8 patients (12.9%) suffered postoperative between 2000 and 2005 for 1 to 7 days. intracranial hemorrhage. 62 control patients from 2000 to 2003 did not Incidence of VTE was 0% in clexane receive clexane group and 4.8% in non-clexane groupChibbaro et al Prospective 746 consecutive patients Stockings and compressors. 8 (1.07%) had significant postoperative2008 cohort undergoing intracranial Daily Tinzaparin started on 1st postoperative hemorrhage, 1 (0.13%) had fatal PE and 3 surgery day patients (0.4%) had clinically evident VTE.Gerlach et al 2003 Prospective 2823 intracranial procedures All patients had early postoperative imaging to 43 (1.5%) had major postoperative cohort from 1999 to 2002. rule out postoperative haemorrhage. hemorrhage, All patients received early (within 24hrs 42 (3.2%) in the major intracranial group 46.7% were major intracranial postoperative 0.3ml Nadroparin SC daily. All and 1 (0.07%) in non-major intracranial procedures patients received intra and postoperative group compression stockingsBarnett et al 1977 Prospective 150 neurosurgical patient 5000 SC heparin given preoperatively and Post op complications in 7 patients (4.6%) cohort procedures. 12hourly postoperatively for minimum of 3 4 patients developed wound seroma, 40 specific for intracranial days 2 patients developed wound hematoma procedure and 1 patient had non-fatal PE
  8. 8. Systematic review
  9. 9. Methodology (Hamilton et al, 2011) Data extraction:Inclusion criteria: • original data • type of DVT prophylaxis • RCTs • occurrence of VTE • DVT prophylaxis involved • occurrence of ICH unfractionated or LMW heparin • Extra-cranial bleeding (major and minor)Exclusion criteria: • Assessed each RCT’s methodology • studies that reported only on elective spinal neurosurgical procedures • Stratified analysis on whether mechanical methods of DVT or reported on patients prophylaxis was also used with stroke or trauma
  10. 10. Results (Hamilton et al, 2011)Heparin 5000 units BD starting 2 hrs pre-operative vs untreated controlsEnoxaparin 20 mg daily starting 18 to 24 hrs post-operatively vs placeboNadroparin 7500 units daily starting 18 to 24 hrs post-operatively with stockings vs placebo and stocking sEnoxaparin 40 mg daily starting within 24 hrs post-operatively with stockings vs placebo with stockingsPreoperative enoxaparin 30 mg at induction and then twice daily vs SCD treatment vs SCD and enoxoparinHeparin 5000 units starting 2 hrs pre-operative and continued twice daily until patient was ambulatory vs saline placebo
  11. 11. Incidence of VTE (Hamilton et al, 2011) • Pooled RR = 0.58 • Absolute risk reduction = 9.1% i.e. for every 1000 patients treated, 91 VTE events will be prevented NNT = 11 • heparin was protective regardless of whether mechanical prophylaxis was used ‣ RR=0.64 with dual prophylaxis ‣ RR=0.42 for heparin alone • Only 2 of the studies distinguished between proximal symptomatic VTE and distal screen-detected DVT
  12. 12. Incidence of VTE (Hamilton et al, 2011) • Pooled RR = 0.58 • Absolute risk reduction = 9.1% i.e. for every 1000 patients treated, 91 VTE events will be prevented • estimated 10 to 20% of VTE are symptomatic VTE events ➡ for every 1000 patients, 9 to 18 symptomatic VTE events will be prevented ➡ NNT 111 to 222
  13. 13. Incidence of ICH (Hamilton et al, 2011) • ICH was more common in heparin group (15) vs control group (8) • Pooled RR = 1.48 but no statistically significant • Absolute risk increase = 0.7% i.e. for every 1000 patients treated, 7 patients could experience ICH • Number need to harm = 143
  14. 14. Discussion (Hamilton et al, 2011)• Consistent finding across studies that heparin significantly reduces rate of VTE by 42% in patient undergoing intracranial surgery• There is an associated statistically insignificant 48% increase in risk of ICH, a risk of that remains therapeutically plausible.• Consideration need to be given to the clinical impact of events caused (bleeding) and prevented (VTE).• Study authors acknowledges the need to balance of statistical significance with clinical significance• Authors commented that the bleeding risk were not optimally evaluated or reported in the studied RCTs and the studies analysed were not well powered to study bleeding risk• Estimate for symptomatic VTE reduction by heparin is comparable to risk of ICH
  15. 15. Conclusion• Does the use of perioperative pharmacological VTE prophylaxis use provide a favourable outcome for patients undergoing intracranial surgery? From the available Level I evidence, the decision to use heparin prophylaxis is not clear cut, therefore the decision should be tailored to the individual patient and individual surgeons experience• The ratio of likelihood of help with symptomatic VTE to the likelihood of harm from ICH, is estimated to be between 1 to 2 suggesting symptomatic VTE reduction is almost matched by an equal risk of ICH• The use of heparin does significantly increase the efficacy of DVT prophylaxis over mechanical methods• Mechanical methods are less effective than anticoagulant prophylaxis but should continue to play an important role in DVT prophylaxis• The general reports in the literature is that bleeding risk is not ‘significantly’ increased in patient receiving anticoagulant prophylaxis
  16. 16. References:Hamilton, M. G., R. D. Hull, et al. (1994). "Venous thromboembolism in neurosurgery and neurologypatients: a review." Neurosurgery 34(2): 280-296; discussion 296.Hamilton, M. G., W. H.Yee, et al. (2011). "Venous thromboembolism prophylaxis in patients undergoingcranial neurosurgery: a systematic review and meta-analysis." Neurosurgery 68(3): 571-581.

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