Frontal Approach

Positioning

Mayfield skull pin sites are placed behind hairline
For convexity lesions, flex or extend neck and turn head so that craniotomy flap is as parallel to floor as possible, with the operative site as the highest point on the field
For anterior interhemispheric approach, head may be neutral or lateral with lesion side down
Head position should allow gravity to facilitate brain retraction
Neck should be positioned to avoid excessive compression of jugular veins and the endotracheal tube
- Head of bed elevation and ipsilateral shoulder elevation with a roll (if the head is turned) are used to ensure adequate jugular venous return

Incision and Scalp Flap

Unilateral approach

Linear or curvilinear incisions are suitable for small lesions requiring unilateral craniotomies located behind the hairline

Bicoronal incision extending from 1 cm anterior to the ipsilateral tragus to the contralateral side (may terminate at 1 cm anterior to contralateral tragus for a true bicoronal incision, or at the contralateral superior temporal line for a modified bicoronal incision; Fig. 4.1A) is used for craniotomies anterior to the hairline
Bilateral approach
- True bicoronal incision permits access to floor of frontal fossa
- Avoid damage to superficial temporal artery to preserve vascular supply to scalp
Temporalis fascia and muscle are preserved unless lateral edge of bone flap is planned to extend inferior to superior temporal line and requires subperiosteal dissection of temporalis muscle
Self retaining retractors or fishhooks are used for anterior retraction of scalp flap, which is protected with wet sponge to preserve pericranium for possible graft and to prevent pressure necrosis on forehead

Burr Holes