Postoperative Temporalis Muscle Atrophy and the Use of Electrocautery: A Volumetric MRI Comparison

ABSTRACT

Postoperative temporalis muscle atrophy from injury to the neurovascular supply can cause significant cosmetic disfigurement, and avoidance of electrocautery use has become a common practice in minimizing this outcome. We attempted to quantify the effects of electrocautery on temporalis atrophy by retrospectively reviewing postoperative magnetic resonance images in patients having undergone an orbital frontal craniotomy. We reviewed medical records and compared volumetric measurements of the temporalis muscle in 25 patients using the contralateral temporalis muscle as an internal control. The mean size of the nonsurgical temporalis muscle was 24.6 cm³ as compared with 23.6 cm³ on the operated side. The difference of 1.0 cm³ was not statistically significant (p = 0.32). The only postoperative atrophy noted visually on the magnetic resonance images developed in the posterior superior aspect of the temporalis muscle, behind the vertical incision of the temporalis muscle. In the small control group, with known injury to V3, the mean nonsurgical size was 27.7 cm³, whereas it was 16.5 cm³ on the contralateral surgical side. The difference of 11.2 cm³ was statistically significant (p = 0.04). These findings suggest that the use of electrocautery to dissect the temporalis muscle does not significantly contribute to atrophy provided careful surgical technique is practiced.

KEYWORDS

Temporalis muscle - magnetic resonance imaging (MRI) - atrophy - electrocoagulation - craniotomy

REFERENCES

• 1 de Andrade Júnior F C, de Andrade F C, de Araujo Filho C M, Carcagnolo Filho J. Dysfunction of the temporalis muscle after pterional craniotomy for intracranial aneurysms. Comparative, prospective and randomized study of one flap versus two flaps dieresis.  Arq Neuropsiquiatr. 1998;  56 200-205
• 2 Oikawa S, Mizuno M, Muraoka S, Kobayashi S. Retrograde dissection of the temporalis muscle preventing muscle atrophy for pterional craniotomy. Technical note.  J Neurosurg. 1996;  84 297-299
• 3 Kadri P AS, Al-Mefty O. The anatomical basis for surgical preservation of temporal muscle.  J Neurosurg. 2004;  100 517-522
• 4 Spetzler R F, Lee K S. Reconstruction of the temporalis muscle for the pterional craniotomy. Technical note.  J Neurosurg. 1990;  73 636-637
• 5 Bowles Jr A P. Reconstruction of the temporalis muscle for pterional and cranio-orbital craniotomies.  Surg Neurol. 1999;  52 524-529
• 6 Brunori A, DiBenedetto A, Chiappetta F. Transosseous reconstruction of temporalis muscle for pterional craniotomy: technical note.  Minim Invasive Neurosurg. 1997;  40 22-23
• 7 Cusimano M D, Suhardja A S. Craniotomy revisited: techniques for improved access and reconstruction.  Can J Neurol Sci. 2000;  27 44-48
• 8 Hayashi N, Hirashima Y, Kurimoto M, Asahi T, Tomita T, Endo S. One-piece pedunculated frontotemporal orbitozygomatic craniotomy by creation of a subperiosteal tunnel beneath the temporal muscle: technical note.  Neurosurgery. 2002;  51 1520-1523, discussion 1523–1524
• 9 Park J, Hamm I S. Cortical osteotomy technique for mobilizing the temporal muscle in pterional craniotomies. Technical note.  J Neurosurg. 2005;  102 174-178
• 10 Shigeno T, Tanaka J, Atsuchi M. Orbitozygomatic approach by transposition of temporalis muscle and one-piece osteotomy.  Surg Neurol. 1999;  52 81-83
• 11 Zabramski J M, Kiriş T, Sankhla S K, Cabiol J, Spetzler R F. Orbitozygomatic craniotomy. Technical note.  J Neurosurg. 1998;  89 336-341
• 12 Zager E L, DelVecchio D A, Bartlett S P. Temporal muscle microfixation in pterional craniotomies. Technical note.  J Neurosurg. 1993;  79 946-947