Integrated Approach to Evacuation of Chronic Subdural Hematoma: Slotted Burr Hole Access and a Novel Bioactive Scaffold for Cranial Defect Closure

Burr hole craniotomy is the most common approach to chronic subdural hematoma (cSDH) evacuation, yet it leaves a cranial defect that can cause cosmetically significant scalp depression. Drain placement remains highly variable and is associated with migration, obstruction, and potential iatrogenic injury. Modified burr hole geometry and purpose-built closure devices may improve operative access, postoperative outcomes, and patient satisfaction. A systematic review of closure techniques for burr hole defects was performed. In silico and in vitro skull models compared standard burr holes, slotted burr holes, and 30-mm craniotomies in frontal, temporoparietal, and occipital locations. Actv-graft® was subjected to deflection testing, drainage simulation using a saline–carrageenan mixture, and drain dislodgement testing using a load sensor. The literature suggests that burr hole closure reduces visible skin depression without increased complications. Slotted burr holes provided greater surface visualization compared with conventional burr holes, with statistically significant improvement in in vitro simulations. Actv-graft® tolerated 21.9 N of load without dislodgement, demonstrated complete shape recovery, increased drainage volume before occlusion (17.5 versus 1.9 mL; P <0.01), and allowed safe drain removal with a low mean pulling force of 2.12 N. A slotted burr hole technique paired with the use of an Actv-graft® bioscaffold may enhance surgical exposure, reduce cosmetic deformity, improve drainage reliability, and permit safer drain stabilization. These findings support further in vivo evaluation of this integrated approach to burr hole management.