funding: health foundation, esvs the gala trial general versus local anaesthesia for carotid...

Funding: Health Foundation, ESVS

The GALA Trial

General versus Local Anaesthesia for Carotid Endarterectomy

Michael J Gough

on behalf of the GALA Trial Collaborators

Discussants: Michael Gough, Michael Horrocks


Local Versus General Anaesthesia in Carotid Endarterectomy:a Systematic Review of the EvidenceC. Tangkanakul, C. E. Counsell, C. P. Warlow

Eur J Vasc Endovasc Surg 1997, 13: 491-499

The Differing Effects of Regional and General Anaesthesia onCerebral Metabolism During Carotid EndarterectomyA.J. McCleary, N. M. Dearden, D. H. Dickson, A. Watson, M. J. Gough

Eur J Vasc Endovasc Surg 1996, 12: 173-181

Introduction


Methods

• Eligibility

15 CEAs/surgeon/year + 10 LA

symptomatic or asymptomatic

uncertainty re: best method

co-operate with awake testing

no other surgery

randomise only once

• Randomisation

Stratified by centre

Telephone, Fax, Web

• Surgery

GA: follow normal practice

LA: shunt only on basis awake test testing

Monitoring, GA shunts, patch endarterectomy, as per normal

• Follow-up

Post-discharge/death form: 7 days

1 month: examination by “blind” independent neurologist

12 month FU: telephone, questionnaire, face-face


• Primary end points:

Stroke (retinal infarct)MI (fatal or non-

fatal)

Death

Analysis intention-to-treat


3526 randomised(95 centres, 24 countries)

GA1753 allocated: 1628 GA

31 no anaesthesia - 92 cross-over2 unknown

LA1773 allocated: 1655 LA

41 no anaesthesia - 75 cross-over2 unknown

1752 for primary outcome

21 incomplete FU 19 no 1m physician form

1771 for primary outcome

21 incomplete FU19 no 1m physician form

99.9% FU


Baseline Data

General Local

Age 70 (sd 9) 69 (sd 9)

Male 1232 (70%) 1256 (71%)

Asymptomatic stenosis 685 (39%) 677 (38%)

Mean % stenosis 81 (sd 11) 81 (sd 11)

Contralateral ICA occlusion 150 (9%) 160 (9%)

Smoking, PAD, CAD, AF, DM all equal


Compliance – No anaesthesia

Reasons:General (n=31)

Local (n=41)

Stroke/Death before operation 2 2

Carotid artery occlusion 8 8

Too ill (unrelated) 7 6

Stenosis/symptoms too mild 4 11

Patient refused 9 13

Carotid stent instead 1 1

Consent early – Randomise late


Compliance – Cross-overs

Reasons:General (n=92)

Local (n=75)

Medical decision 41 20

Administrative issues 15 9

Patient’s decision 29 44

Reason unknown 7 2


Conversions

Reasons: Local (n=69)

After start of anaesthesia, pre-surgery

Patient’s decision 6

Problem with position on table etc 3

Patient deteriorated after local block 8

After start of surgery

Pain at operative site 9

Discomfort, anxiety, claustrophobia 25

Physiological instability 5

Protracted or difficult surgery 6

Neurological deterioration on cross-clamping 7


Primary outcome events

70 66

4 9510

0%

1%

2%

3%

4%

5%

General

84/1752 (4.8%)

Local

80/1771 (4.5%)

Other deaths

MI (fatal ornon-fatal)

Stroke (fatalor non-fatal)


Primary outcome events

Stroke 3 (-10 to +16)

MI -4(-8 to +2)

Death (any cause) 4 (-3 to +12)

Stroke or death 4 (-9 to +18)

Stroke, MI or death 3 (-11 to +17)

Favours General Favours Local

Events prevented/1000 (95% CI)

-20 -10 0 10 20


Other Complications

General Local

Cranial nerve injuries 184 (11%) 213 (12%)

Wound haematoma 146 (8%) 150 (8%)

Wound haematoma requiring reoperation

45 (3%) 40 (2%)


Survival analysis

0%

2%

4%

6%

8%

10%

12%

14%

0 6 12Months since randomisation

% o

f pat

ient

s w

ith e

vent

.

General

Local

Number at risk: General Local

1752 1241 736 1771 1269 751

P=0.094


Subgroups (primary outcome)

Subgroup General Local P(% ) (% )

Contralateral carotid Yes 10.0% 5.0% 0.098occlusion No 4.3% 4.5%

Age (years) >75 5.3% 4.6% 0.741<=75 4.6% 4.5%

Baseline surgical High 4.1% 4.6% 0.933risk Medium 5.1% 4.9%

Low 4.7% 4.2%

Favours LA Favours GA

Odds ratio and 95% Confidence interval

0.1 1 10


Implications of GALA Stroke & Death

0.1 1 10

Favours Local Favours General

Meta-analysis of 7 earlier trials

GALA

Meta-analysis including GALA

OR (95% CI)

0.62 (0.24 to 1.59)

0.88 (0.64 to 1.23)

0.85 (0.63 to 1.16)


Implications of GALA Death

0.01 0.1 1 10 100

Favours Local Favours General

Meta-analysis of 7 earlier trials

GALA

Meta-analysis including GALA

OR (95% CI)

0.23 (0.05 - 1.01)

0.72 (0.40 - 1.30)

0.62 (0.36 – 1.07)


Primary outcome events(according to anaesthetic received)

0

1

2

3

4

5

GA LA

79/16214.9% 64/1575

4.1%

8 events prevented/1000 (95% CI: -6 to +23)


Confounding Factors

0

10

20

30

40

50

GA LA

P<0.001

BP manipulated up

25

30

35

40

45

50

GA LA

P<0.001

Patch angioplasty


Conclusions

• Primary outcomes: no reason to prefer LA or GA

• Secondary outcomes: no influence on length of stay or QOL

• Sub-groups: trend favouring LA for contralateral occlusion

• Trends favouring LA: Peri-operative deathEvent free survival to 1 year

• Implications: Offer both LA & GA for patient preference or medical reasons

funding: health foundation, esvs the gala trial general versus local anaesthesia for carotid...

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