Elsevier

World Neurosurgery

Volume 108, December 2017, Pages 157-162
World Neurosurgery

Technical Note
Endoscopic Middle Cranial Fossa Reconstruction with a Subtemporal Keyhole

https://doi.org/10.1016/j.wneu.2017.08.153Get rights and content

Background

Skull base reconstruction is an essential technique for repairing cerebrospinal fluid (CSF) leakage. A reliable method for middle cranial fossa (MCF) reconstruction with minimal invasiveness has not been reported. An initial case of endoscopic MCF reconstruction with a subtemporal keyhole is described.

Case Description

A 57-year-old man developed severe meningitis and was diagnosed with spontaneous CSF leakage from bone defects on the tegmen tympani. Endoscopic MCF reconstruction with a subtemporal keyhole was carried out. Three skin incisions, including 1 subtemporal incision for a subtemporal keyhole and 2 temporal line incisions on the superior temporal line, were made, and a 0-degree endoscope was introduced into the subcutaneous space. The deep temporal fascia (DTF) was bluntly dissected and separated from the superficial temporal fascia and the temporal muscle, and the DTF was incised to shape a pedicled flap under endoscopic view. Blood supply to the pedicled DTF flap was confirmed with indocyanine green angiography. A subtemporal keyhole was then made, and a 30-degree endoscope was used to explore the extradural space of the MCF floor, visualizing the bone defects on the tegmen tympani. The vascularized DTF flap passed easily through the subtemporal keyhole and adequately overlaid the bone defects. The patient's postoperative course was uneventful, and the CSF leakage disappeared without mastication problems.

Conclusions

This purely endoscopic technique using a vascularized DTF flap provided reliable MCF reconstruction through a subtemporal keyhole. This technique is also expected to be applicable for MCF reconstruction after subtemporal keyhole surgery for skull base tumors.

Section snippets

Case Description

A 57-year-old man developed severe meningitis with otorrhea and aural fullness. He had no history of head injury or otolaryngologic diseases, and his body mass index was 23.0 kg/m2, indicating that he was not obese. Computed tomography (CT) and 3-dimensional CT revealed effusion in the left tympanic cavity and mastoid air cells (Figure 2A). A group of small temporal bone defects, each with a diameter of approximately 2 mm, and slight pneumocephalus around the bone defects were seen on the

Discussion

Vascularized pedicle tissue has been recommended for skull base reconstruction because it significantly decreases the incidence of CSF leakage,1, 2, 8, 9 and the vascularized temporal muscle flap has been commonly used for MCF reconstruction.10, 11 Although a temporal muscle flap is effective to repair CSF leakage from the MCF, postoperative pain, mastication problems, trismus, and poor cosmetic results continue.11, 12 In addition, the massive and bulky temporal muscle cannot be passed through

Conclusions

An initial case of endoscopic MCF reconstruction by subtemporal keyhole surgery was described. The vascularized DTF flap was flexible, long, and large enough to overlay bone defects on the MCF, overcoming the problems related to temporal muscle. This endoscopic technique could be a valid alternative for MCF reconstruction.

Acknowledgments

The authors greatly appreciate the assistance of Professor Manfred Tschabitscher of Brescia University, Italy, for teaching the endoscopic anatomy related to this surgical technique, and Dr. Mika Komatsu of Ohta Neurosurgical Clinic, Japan, for cooperation with previous anatomic studies and cordial advice regarding this study.

References (16)

There are more references available in the full text version of this article.

Cited by (0)

Supplementary digital content available online.

View full text