Article Figures & Data
Tables
Randomized Treatment Hydrogel Bare Platinum No. % No. % No. of patients randomized 249 250 Received coil as allocated 236 94.8 246 98.4 Crossed over* 7 3.2 2 0.8 Procedure started but no coil inserted 2 0.8 1 0.4 Procedure not started 3 1.2 1 0.4 Consent revoked 1 0.4 0 * “Crossed over” in HydroCoil arm means that the patient was allocated HydroCoil but only bare platinum coils were deployed. In the control arm, it means that the patient was allocated bare platinum but some HydroCoil was deployed.
Randomized Treatment Hydrogel Bare Platinum No. % No. % Total No. patients randomized 249 250 Sex Female 176 70.7 174 69.6 Male 73 29.3 76 30.4 Age (years) <45 80 32.1 78 31.2 46–55 68 27.3 75 30.0 >55 101 40.6 97 38.8 Target aneurysm size (maximal dimension) 2–4.9 mm 42 16.9 41 16.4 5–9.9 mm 144 57.8 144 57.6 10–24.9 mm 63 25.3 65 26.0 Dome-to-neck ratio <1.5 83 33.3 81 32.4 >1.5 166 66.7 169 67.6 Baseline rupture status Yes, in previous 30 days 132 53.0 133 53.2 Yes, >30 days ago 5 2.0 4 1.6 Yes, but date unknown 2 0.8 1 0.4 No 110 44.2 112 44.8 Aneurysm shape Irregular (multilobulated) 76 30.5 77 30.8 Not multilobulated 173 69.5 173 69.2 Planned use of assist device Yes 112 45.0 115 46.0 No 122 49.0 121 48.4 Missing (see “Results”) 15 6.0 14 5.6 Assist device actually used * 116 46.6 115 46.0 Balloon 65 26.1 60 24.0 Stent 46 18.5 52 20.8 Other (TriSpan† double microcatheter techniques) 3 1.2 3 1.2 Assist device attempted but failed 2 0.8 0 0 Not known (consent withdrawn) 1 0.4 0 0 None 131 137 Randomized Americas‡ Yes 89 35.7 89 35.6 No 160 64.3 161 64.4 * More than 1 assist device may have been used in any individual case.
† Boston Scientific, Natick, Mass.
‡ This is North and South America combined.
Randomized Treatment Hydrogel Bare Platinum No. % No. % Procedural aneurysm rupture 9 3.6 8 3.2 Coil migration 15 6.0 10 4.0 Parent artery occlusion 4 1.6 8 3.2 Thromboembolic complication 14 5.6 25 10.0 Other procedure-related adverse events 8 3.2 9 3.6 Intra-arterial thrombolysis used 20 8.0 26 10.4 Neurologic deterioration immediately after coiling 18 7.2 17 6.8 Rebleed before discharge 0 0 2 0.8 Delayed ischemic neurologic deficit 34 13.7 38 15.2 Cerebral hematoma 9 3.6 11 4.4 Cardiorespiratory 11 4.4 13 5.2 Other disease-related† 13 5.2 9 3.6 * Events, especially procedural ones, may not have resulted in clinical sequelae.
† See “Results” for explanatory notes.
Randomized Treatment Hydrogel Bare Platinum Absolute Difference No. % No. % (95% CI) Total no. patients randomized 249 250 Died within 3 months of procedure*† 9 3.6 5 2.0 1.6% (−1.5% to +4.9%) Procedure-related/exacerbated (eg, rupture, rebleed) 5 2.0 2 0.8 1.2% (−1.2% to +3.9%) Disease-related 4 1.6 3 1.2 0.4% (−2.1% to +3.0%) Deaths by target aneurysm rupture status† Aneurysm ruptured <30 days before randomization 8/132 6.1 4/133 3.0 3.1% (−2.3% to +8.8%) Did not rupture <30 days before randomization‡ 1/117 0.9 1/117 0.9 0.0% (−3.9% to +3.9%) Note:—CI indicates confidence interval.
* All these 14 patients were coiled on the day of randomization.
† Test for interaction (to find whether the effect of treatment differs between subgroups); P = .6 from logistic regression.
‡ The patient in the hydrogel coil arm “not recently ruptured” who died was baseline WFNS 1 but died before discharge. The patient in control arm “not recently ruptured” who died was WFNS 0 and was discharged the day after the procedure but bled 9 days later and died. The intracerebral bleed was not thought to be from the target aneurysm.
Randomized Treatment Hydrogel Bare Platinum Absolute Difference No. % No. % 95% CI Total no. patients randomized 249 250 Ruptured aneurysm; no hydrocephalus 112 80.6 117 84.8 Ruptured aneurysm; hydrocephalus present 26 18.7 21 15.2 +3.5% (−5.4% to +12.4%) Consent withdrawn 1 0.7 0 Not recently ruptured; no hydrocephalus 108 98.2 109 97.3 Not recently ruptured; hydrocephalus present 2 1.8 3 2.7 −0.9% (−5.9% to +4.1%) Note:—CI indicates confidence interval; TA, target aneurysm (the one on which randomization was based).
* Test for interaction (to find out whether the effect of treatment differs between subgroups), P = 0.5, from logistic regression (ie, there is no evidence that the effect of treatment on hydrocephalus is different in ruptured and unruptured aneurysms).
- Table 6:
Procedure-related adverse events and mortality: comparison of assist device versus unassisted coiling cases
Randomized Treatment Hydrogel Bare Platinum Absolute Difference No. % No. % (95% CI) Procedure-related adverse event Stent used in acutely ruptured aneurysm 2/3 66.7 2/3 66.7 0% (−53% to +53%) Stent used in unruptured aneurysm 7/43 16.3 9/49 18.4 −2.1% (−17% to +14%) Balloon/other assist used in acutely ruptured aneurysm 9/32 28.1 8/30 26.7 +1.5% (−20% to +23%) Balloon/other assist used in unruptured aneurysm 9/38 23.7 6/31 19.4 +4.3% (−16% to +23%) No assist device, acutely ruptured aneurysm 18/104 17.3 22/101 21.8 −4.5% (−15% to +6.4%) No assist device, unruptured aneurysm 2/28 7.1 6/34 17.6 −10.5% (−27% to +7.6%) Mortality rate (0–3 months) Stent used in acutely ruptured aneurysm 2/3 66.7 2/3 66.7 0% (−53% to +53%) Stent used in unruptured aneurysm 0/43 0 1/49 2.0 −2% (−11% to +6.3%) Balloon/other assist used in acutely ruptured aneurysm 4/32 12.5 1/30 3.3 +9.2% (−6.1% to +25%) Balloon/other assist used in unruptured aneurysm 1/38 2.6 0/31 0 +2.6% (−8.6% to +14%) No assist device, acutely ruptured aneurysm 2/104 1.9 1/101 1.0 +0.9% (−3.7% to +5.8%) No assist device, unruptured aneurysm 0/28 0 0/34 0 0% (−10% to +12%) Note:—CI indicates confidence interval.
Randomization WFNS Discharge WFNS 0 1–2 3 4–5 Dead Missing Total 0 90 15 3 0 0 1 109 1 4 106 3 1 7 0 121 2 0 15 1 0 1 0 17 3 0 1 1 0 0 0 2 6 0 0 0 0 0 0 0 Total 94 137 8 1 8 1 249 Randomization WFNS Discharge WFNS 0 1–2 3 4–5 Dead Missing Total 0 94 14 1 0 0 0 109 1 2 107 2 1 1 0 113 2 1 18 2 2 1 0 24 3 0 0 2 0 1 0 3 6 1 0 0 0 0 0 1 Total 98 139 7 3 3 0 250 Randomized Treatment Absolute Difference Hydrogel Bare Platinum No. % No. % (95% CI) Total no. patients randomized 249 250 No coiling done 5 2.0 2 0.8 Consent withdrawn 1 0.4 0 0 Degree of occlusion (operator opinion)* Complete 115/243 47.3 118/248 47.6 −0.3% (−9.0% to +8.5%) Nearly complete 76/243 31.3 94/248 37.9 −6.6% (−14.9% to +1.8%) Incomplete 52/243 21.4 36/248 14.5 +6.9% (+0.1% to 13.7%) Note:—CI indicates confidence interval.
* χ2 test for trend, P = .3.
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