Effectiveness of Temporal Augmentation Using a Calvarial Onlay Graft during Pterional Craniotomy

Abstract

Temporal hollowing occurs to varying degrees after pterional craniotomy. The most common cause of temporal hollowing is a bony defect of the pterional and temporal regions due to the resection of the sphenoid ridge and temporal squama for adequate exposure without overhang. The augmentation of such bony defects is important in preventing craniofacial deformities and postoperative hollowness. Temporal cranioplasty has been performed using a range of materials, such as acrylics, porous polyethylene, bone cement, titanium, muscle flaps, and prosthetic dermis. These methods are limited by the risk of damage to adjacent tissue and infection, a prolonged preparation phase, the possibility of reabsorption, and cost inefficiency. We have developed a method of temporal augmentation using a calvarial onlay graft as a single-stage neurosurgical reconstructive operation in patients requiring craniotomy. In this report, we describe the surgical details and review our institutional outcomes. The patients were divided into pterional craniotomy and onlay graft groups. Clinical temporal hollowing was assessed using a visual analog scale (VAS). Temporal soft tissue thickness was measured on preoperative and postoperative computed tomography (CT) studies. Both the VAS and CT-based assessments were compared between the groups. Our review indicated that the use of an onlay graft was associated with a lower VAS score and left-right discrepancy in the temporal contour than were observed in patients undergoing pterional craniotomy without an onlay graft.

Temporal augmentation with calvarial onlay graft during pterional craniotomy for prevention of temporal hollowing

“…Unlike the previous method using one big bone flap, we used two separate bone segments (which was divided from the large bone flap) to cover bony defect and to augment the temporal area. In addition, the current study included 100 patients to improve the reliability of the study [ 6 ].…”

“…The senior author had previously presented a primary temporal reconstruction technique using one autologous bone graft for coverage of temporal defect and temporal area [ 6 ]. This technique successfully prevented temporal hollowing, but the bony plate positioning was limited due to its large size.…”

Cosmetic Reconstruction of Frontotemporal Depression Using Polyethylene Implant after Pterional Craniotomy

“…Various therapeutic methods have been developed for reconstruction of temporal hollowing using both autograft and alloplast materials. Autologous bone has the advantages of being genetically identical to the patient, possessing the potential for growth and replacement of host cells, and a low incidence of infection [ 16 , 28 – 32 ]. However, it causes donor site morbidity, graft resorption, and difficulties with contouring, and additional time is required for harvesting of the graft [ 31 , 33 ].…”

Analysis of Factors Associated with Temporal Hollowing after Pterional Craniotomy

“…Some reports have argued that the most common cause of temporal hollowing is bony defect of the pterional and temporal regions due to the resection of the sphenoid ridge and temporal squama for adequate exposure. 17 However, no data have yet been produced to support this hypothesis. Our study showed that the average bony volume reduction was 9.10 cm 3 (3.99%).…”

“…Both immediate and late reconstructions of the temporal area have been reported, with many materials, including autogenous and nonbiologic materials, used. 14,[17][18][19][20][21][22][23][24] No definitive implants have demonstrably yielded the best results.…”