Chronic subdural hematoma (cSDH) drainage is one of the most common neurosurgical procedures. Previous studies show that subdural drain (SDD) use reduces the risk of repeat drainage, but others propose that an extracranial subperiosteal drain (SPD) is safer and equally effective.
Results of a prospective randomized controlled, non-inferiority trial at 2 hospitals (NCT01869855) for cSDH patients was reported. Symptomatic adults with cSDH on CT or MRI were eligible. Patients who required craniotomy for subacute subdural hematomas or membranes and those associated with an underlying condition (i.e. over-draining VP shunt) were excluded. Enrolled patients were randomized for SDD or SPD placement in the OR after completion of two burr-hole (frontal and parietal) cSDH drainage and irrigation. SDD patients had drains placed intracranially under the dura. In SPD patients, the burr holes were not sealed with hemostatic agents or other materials, and SPD drain was threaded under the scalp periosteum. Most were small Jackson-Pratt drains, and ventricular catheters were used in two cases. Bilateral burr holes cSDH drainage patients were treated as one case, and both sides were treated with the same drain (i.e. two SDDs or two SPDs). Primary outcome was recurrence of an ipsilateral cSDH requiring re-drainage within a year of the surgery. Secondary outcomes included complications, re-operation rates (other than recurrent cSDH surgery), mortality, clinical outcomes measured by various scales, length of stay, and postoperative CT characteristics (i.e. midline shift, hemorrhage, drain placement/misplacement).
Data were analyzed on a per-protocol basis, with cSDH recurrence rate estimated at 7%, and predefined non-inferiority margin of less than 3.5%. 220 patients were recruited: 107 patients randomized to SDD, 113 to SPD, and after accounting for crossovers at the surgeon’s discretion, the remaining 100 SDD patients and 120 SPD patients were analyzed on a per-protocol basis. cSDH recurrence at one year was 8.3% (n=10) in the SPD group (95% confidence interval, CI, 4.28-14.27) and 12% (n=12) in the SDD group (95% CI 6.7-19.7). Despite the 95% CI of the percentage difference in cSDH recurrence between drain groups exceeded the non-inferiority margin of 3.5%. The difference in the 95% CI of cSDH recurrence rate between the groups was 12.6% in favor of the SPD, and 5.3% in favor of the SDD. This indicates that SPD use causes a maximum of 5.3% more recurrent cSDH than SDD use.
Neurological improvement after surgery, postoperative seizure frequency, postoperative bleeds (acute subdural or epidural hematoma, subarachnoid hemorrhage), medical complications, and new postop neurological deficits was similar between both groups. Surgical infection rate was significantly lower in SPD group (2.5% versus 9%, p = 0.04). 17 SDD were misplaced (17%), and none in the SPD group. 5 of these 17 SDD patients had a related hemorrhage, and 3 had new neurological deficit.
In summary, the authors conclude that use of SPD after cSDH evacuation is similarly effective as SDD use (although not meeting the threshold for non-inferiority), with a lower risk of postoperative infection and little/no risk of drain misplacement.
Katherine E. Wagner, MD
Jamie S. Ullman, MD