Evidence Based Neurosurgery A David Mendelow Newcastle-upon-Tyne England January 2010.

Evidence Based Neurosurgery

A David MendelowNewcastle-upon-Tyne

EnglandJanuary 2010

Evidence Based Medicine

David Sackett (Oxford)Evidence Based DiagnosisEvidence Based TreatmentEvidence Based Prognosis



How reliable or accurate is a diagnostic

test?• For example – loss of venous

pulsation as a sign of raised ICP: Yes/No on a Chi squared test (2 x 2 table)

• For example – Height of JVP as a sign of cardiac failure: Continuous variable from 0 to 10 cm (sensitivity and specificity: ROC Curve analysis)

Figure 1: ROC curve for % change in SJVO2 as a predictor of clinical ischaemia during awake carotid endarterectomy




David Sackett (Oxford)Evidence Based DiagnosisEvidence Based Treatment (FIRST

TRIAL?)Evidence Based Prognosis

British Medical Journal 13th Oct. 2001

Review of EvidenceA.D.Mendelow 2001

Further review March 2007

Table 1: Class I Evidence from Prospective Randomised Controlled Trials (PRCT) in Neurosurgical Practice Conclusion Source Reference NEUROTRAUMA Head Injury Hypothermia not recommended PRCT [7] Anticonvulsants not recommended AANS/BTF book [6] Steroids not recommended for high ICP “ / “ “ [6] Mannitol bolus recommended in Acute Subdural Haematoma PRCT [8] CRASH and Dexanabinol trials in progress Spinal injury Cervical spine: No difference between surgery & medical Review [9, 10] and degen. No advantage with fusion vs discectomy PRCT [11]

Lumbar Spine: Surgery better at 1 year but not at 4 & 10 yearsReview [10, 12] Use high dose Methylprednisolone within 8 hours of injury PRCT [13] Rehabilitation Early rehab (7 – 10 days) reduces morbidity PRCT [14] SUBARACHNOID HAEMORRHAGE (SAH) Timing No significant benefit from early planned surgery PRCT [15, 16] Significant benefit from early surgery in USA centers PRCT (subgroup)[17] No significant benefit from HHH therapy PRCT [18] Nimodipine Use for 21 days in all aneurysmal SAH PRCT [19] ISAT trial of coiling or clipping in progress Hypothermia trial in progress INTRACEREBRAL HAEMORRHAGE (ICH) Supratent. ICH No benefit from surgery (7 PRCT) Meta-analysis [20] ISTICH trial in progress BRAIN TUMOURS Glioblastomas Radiotherapy doubles median survival PRCT [21] “ & extent of excision increases survival in young PRCT Partit. x 3 [22] Gliadel increases survival in primary and recurrent GBM PRCT x 2 [23, 24] Temozolamide improves survival with recurrent GBM Systematic Rev. [25] Interstitial chemo- and radiotherapy trials in progress TEMPORAL LOBE EPILEPSY (TLE) TLE Surgery superior to prolonged medical therapy PRCT & editorial [26, 27] STROKE Carotid stenosis Endarterectomy superior with symptomatic tight stenosis PRCT x 2 [28, 29] Endarterectomy superior with asymptomatic tight stenosis PRCT [30] Angioplasty no better than endarterectomy PRCT [31] Endarterectomy most effective in the elderly meta-analysis [32, 33] ACST ongoing for asymptomatic tight stenosis ACSS ongoing (stenting vs endarterectomy) HYDROCEPHALUS Type of Shunt No evidence of superiority of any shunt type PRCT x 2 [34, 35]

Table 1: Class I Evidence from Prospective Randomised Controlled Trials (PRCT) in Neurosurgical Practice

Conclusion Source Reference NEUROTRAUMA Head Injury Hypothermia not recommended PRCT [7] Anticonvulsants not recommended AANS/BTF book [6] Steroids not recommended for high ICP “ / “ “ [6] Mannitol bolus recommended in Acute Subdural Haematoma PRCT [8] CRASH and Dexanabinol trials in progress. Decompressive craniectomy trials planned Spinal injury Cervical spine: No difference between surgery & medical Review [9, 10] and degen. No advantage with fusion vs discectomy PRCT [11]

Lumbar Spine: Surgery better at 1 year but not at 4 & 10 years Review [10,12]

Use high dose Methylprednisolone within 8 hours of injury PRCT [13]

Rehabilitation Early rehab (7 – 10 days) reduces morbidity PRCT [14]

Table 1: Class I Evidence from Prospective Randomised Controlled Trials (PRCT)in Neurosurgical Practice

Conclusion Source Reference NEUROTRAUMA Head Injury Hypothermia not recommended PRCT [7] Anticonvulsants not recommended AANS/BTF book [6] Steroids not recommended for high ICP “ / “ “ [6] Mannitol bolus recommended in Acute Subdural Haematoma PRCT (????) [8]

CRASH (Steroids) HARM Dexanabinol No effect Decompressive craniectomy trials (RescueICP and SUDEN) In progress

Spinal injury Cervical spine: No difference between surgery & medical Review [9, 10] and degen. No advantage with fusion vs discectomy PRCT [11]




2007

Clinical Trials in Neurotrauma

• HEAD INJURY• Lack of Class I Evidence

– Dickinson K et al. BMJ 320:1308, 2000

• Cochrane Library - Systematic Reviews– Few systematic Reviews specific to HI

• SPINAL INJURY– Nachemson AL and Jonsson E, 2000

• REHABILITATION– Wade DT et al. 1998

Dickinson et al. BMJ 320: 1308-1311, 2000.

Head Injury Trials

• All head injury trials assessed to 1998– 208 trials; average number / trial = 82– NO trials large enough to detect a 5%

ABSOLUTE difference in outcome!!!!!!– ONLY 21 % reported that outcome

assessors were blinded to the treatment!!!!

Dickinson et al. BMJ 320: 1308-1311, 2000.

Head Injury Trials

• All head injury trials assessed to 1998– 208 trials; average number / trial = 82– NO trials large enough to detect a 5%

ABSOLUTE difference in outcome!!!!!!– ONLY 21 % reported that outcome

assessors were blinded to the treatment!!!!

• Then came CRASH: Steroids do harm– 200 of 10,000 randomised patients died

(Roberts et al. Lancet)

Cochrane reviews in head injury

• Only 9 systematic reviews specific to head injury

– Anticonvulsants– Barbiturates– Calcium Channel blockers– Hyperventilation– hypothermia– Cycle helmets– Mannitol– Nutrition– Steroids

• Insufficient evidence for Standards

BTF &AANS

1st Ed

1993

Evidence based medicine – classes of evidence

• Class I– Systematic reviews of PRCT (Cochrane collaboration)– Prospective randomised controlled trials (PRCT)

• The gold standard – methodology very important

• Class II– Observational and case control studies– Cohort and prevalence studies

• Class III– Retrospectively collected data– Clinical series, databases or registers– Case reviews, reports and expert opinion

• Technology assessment– Device accuracy and reliability– Therapeutic potential and cost effectiveness

BTFAndAANS

2nd Ed

2000

BTF &AANS2000

Page 9

BTF &AANS2000

Page 9

Pharmacological Treatments in head injury

(PRCT only)evidence for benefit?• Dexamethasone none

• Other steroids none (CRASH)• Tirilazad none• Anticonvulsants none• Nimodipine none• Barbiturates none• Tromethamine (THAM) none• PEG SOD none• NMDA receptor antagonists none• Hypothermia none• Mannitol pre-operatively yes (????)• Canabinoids none



Table 1: Class I Evidence from Prospective Randomised Controlled Trials (PRCT)in Neurosurgical Practice

Conclusion Source Reference NEUROTRAUMA Head Injury Hypothermia not recommended PRCT [7] Anticonvulsants not recommended AANS/BTF book [6] Steroids not recommended for high ICP “ / “ “ [6] Mannitol bolus recommended in Acute Subdural Haematoma PRCT (????) [8]

CRASH (Steroids) HARM Dexanabinol No effect Decompressive craniectomy trials (RescueICP and SUDEN) In progress

Spinal injury Cervical spine: No difference between surgery & medical Review [9, 10] and degen. No advantage with fusion vs discectomy PRCT [11]


Use high dose Methylprednisolone within 8 hours of injury (????) PRCT [13]

SPORT PRCT No benefit shown Rehabilitation Early rehab (7 – 10 days) reduces morbidity PRCT [14]

2007

Prospective Randomised Controlled Trials of surgery in Spinal injury (Information from Nachemson and Jonsson 2000)• Cervical Spine – ONLY 1 trial of

surgery vs. conservative treatment: NO difference at 1 year (Persson LC et al. Spine 22: 751, 1997)

• Lumbar Spine – Trial of surgery vs. conservative treatment: Surgery better at 1 year but not at 4 and 10 years (Weber H. Spine 8: 131, 1983)

• Lumbar Spine – SPORT Trial (2006) – 50% CROSSOVERS! No benefit shown

Table 1: Class I Evidence from Prospective Randomised Controlled Trials (PRCT) in Neurosurgical Practice

Conclusion Source Reference NEUROTRAUMA Head Injury Hypothermia not recommended PRCT [7] Anticonvulsants not recommended AANS/BTF book [6] Steroids not recommended for high ICP “ / “ “ [6] Mannitol bolus recommended in Acute Subdural Haematoma PRCT [8] CRASH and Dexanabinol trials in progress Spinal injury Cervical spine: No difference between surgery & medical Review [9, 10] and degen. No advantage with fusion vs discectomy PRCT [11]




Rehabilitation (Wade DT et al. JNNP 65: 177, 1998)

• 316 patients randomised• Early onset (7-10 day)

specialist services reduced social morbidity and severity of the post-concussion syndrome in the treatment group at 6 months after head injury

SUBARACHNOID HAEMORRHAGE (SAH)

Timing No significant benefit from early planned surgery PRCT [15, 16] Significant benefit from early surgery in USA centers PRCT (subgroup)[17] No significant benefit from HHH therapy PRCT [18] Nimodipine Use for 21 days in all aneurysmal SAH PRCT [19] All other pharmacological trials negative so far negative

ISAT trial of coiling or clipping PRCT Coiling better Hypothermia trial PRCT No benefit

ISAT One Year Outcome

EVT SURGERY

RANKIN 0-2

76.5% 68.9%

RANKIN 3-6

23.5% 31.1%

POOR OUTCOME

COIL

INTRACEREBRAL HAEMORRHAGE (ICH) Supratent. ICH 2 Trials of NOVO 7: Large phase III NEGATIVE

12 SURGICAL trials to date: Meta-analysis [20] STICH II trial in progress CLEAR IVH trial in progress MISTIE trial in progress

BRAIN TUMOURS

Glioblastomas Radiotherapy doubles median survival PRCT [21] “ & extent of excision increases survival in young PRCT Partit. x 3 [22] Gliadel increases survival in primary and recurrent GBM PRCT x 2 [23, 24] Temozolamide improves survival with recurrent GBM Systematic Rev. [25] Interstitial chemo- and radiotherapy trials in progress

J Nat Cancer Instit.85: 704 – 710, 1993

TEMPORAL LOBE EPILEPSY (TLE)

TLE Surgery superior to prolonged medical therapy PRCT & editorial [26, 27]

STROKE

Carotid stenosis - Endarterectomy

Endarterectomy superior with symptomatic tight stenosis PRCT x 2 [28, 29] Endarterectomy superior with asymptomatic tight stenosis PRCT [30] Endarterectomy most effective in the elderly meta-analysis [32, 33]

ACST for asymptomatic tight stenosis PRCT GALA trial in carotid endarterectomy ongoing ACST II ongoing Carotid stenosis – Stenting Angioplasty no better than endarterectomy (CAVATAS I) PRCT [31]

2 Stenting trials stopped – endarterectomy better CREST and ICSS ongoing

Acute Stroke NINDS - tPA within 3 hours

Decompressive craniectomy Meta-analysis of 3 trials shows benefit from decompression (HAMLET, DECIMAL and D………..)

NASCET 70 – 99%

ECST 70 – 99%

ACSTLancet May 2004

>75 NS

Lancet April 2001

Lancet April 2001

Endarterectomy vs. Stenting (FRENCH Trial)

Endarterectomy vs. Stenting (FRENCH Trial)

HYDROCEPHALUS

Type of Shunt No evidence of superiority of any shunt type PRCT x 2 [34, 35]

Neurosurgery Dec. 1999

Are Observational studies OK?


• about What Smallpox? (Class III)


• What about Smallpox? (Class III)• Why are we not smoking in here? (Class

III)


• What about Smallpox? (Class III)• Why are we not smoking in here? (Class

III)• No need for Class I evidence with EDH or

acute SDHDecompressive craniectomy for GMB?Parachute for sky falling?

Exophyticbrain tumor

Krause 1911

BMJ 2003;327:1459-1461 (20 December), doi:10.1136/bmj.327.7429.1459 Hazardous journeyParachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials Gordon C S Smith, professor1, Jill P Pell, consultant2 1 Department of Obstetrics and Gynaecology, Cambridge University, Cambridge CB2 2QQ, 2 Department of Public Health, Greater Glasgow NHS Board, Glasgow G3 8YU Correspondence to: G C S Smith [email protected] AbstractObjectives To determine whether parachutes are effective in preventing major trauma related to gravitational challenge.

Design Systematic review of randomised controlled trials.

Data sources: Medline, Web of Science, Embase, and the Cochrane Library databases; appropriate internet sites and citation lists.

Study selection: Studies showing the effects of using a parachute during free fall.

Main outcome measure Death or major trauma, defined as an injury severity score > 15.

Results We were unable to identify any randomised controlled trials of parachute intervention.

Conclusions As with many interventions intended to prevent ill health, the effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials. Advocates of evidence based medicine have criticised the adoption of interventions evaluated by using only observational data. We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute.



Thank you

Guidelines for head injury• Royal College of Surgeons of England

– All head injuries• Canadian Emergency Medicine Group

– Minor head injuries• American Association of Neurosurgeons

– Severe head injuries• American Brain Injury Consortium

– All head injuries• European Brain Injury Consortium

– All head injuries• American College of Surgeons

– Advanced Trauma Life Support• Society of British Neurosurgeons (SBNS/SIGN)

– Triage guidelines• Australian Guidelines (Rural and remote)• UK NHS: National Institute for Clinical Excellence (NICE)

NICEGuidelines

for head injury

are beingdeveloped

Canadian CT Head Rule for minor head injuries (GCS= 13

– 15)(Stiell IG. Lancet 357: 1391-6, 2001)

• High risk (5) – 100% sensitive for neurosurgical intervention (32% need scanning)– Failure to reach GCS 15 in 2 hours– Suspected open or depressed fracture– Basal fracture– Vomiting >1– Age >64

• Medium risk (7) – 98.4% sensitive for clinically important injury (54% need scan)– Amnesia pre impact > 30 minutes– Dangerous mechanism of injury (pedestrian, ejected

occupant, fall from > 3 feet or 5 stairs)

NICE (UK NHS) Guidelines for CT Imaging of the head following

Head Injury– Failure to reach GCS 15 in 2 hours– Suspected open or depressed fracture– Basal fracture– Vomiting >1– Age >64– Amnesia pre impact > 30 minutes– Dangerous mechanism of injury (pedestrian,

ejected occupant, fall from > 3 feet or 5 stairs)– Post traumatic seizure– Coagulopathy– Focal Neurological deficit

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Evidence Based Neurosurgery A David Mendelow Newcastle-upon-Tyne England January 2010.

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