Facial nerve outcome in lateral skull base surgery for benign lesions

Comparative Anatomic Analysis of Neuronavigated Transmastoid-Infralabyrinthine Approaches for Jugular Fossa Pathologies: Short Anterior Rerouting Versus Nonrerouting and Tailored Nonrerouting Techniques

BACKGROUND AND OBJECTIVES

Access to the jugular fossa pathologies (JFPs) via the transmastoid infralabyrinthine approach (TI-A) using the nonrerouting technique (removing the bone anterior and posterior to the facial nerve while leaving the nerve protected within the fallopian canal) or with the short-rerouting technique (rerouting the mastoid segment of the facial nerve anteriorly) has been described in previous studies. The objective of this study is to compare the access to Fisch class C lesions (JFPs extending or destroying the infralabyrinthine and apical compartment of the temporal bone with or without involving the carotid canal) between the nonrerouting and the short-rerouting techniques. Also, some tailored steps to the nonrerouting technique (NR-T) were outlined to enhance access to the jugular fossa (JF) as an alternative to the short-rerouting technique.

METHODS

Neuronavigated TI-A was performed using the nonrerouting, tailored nonrerouting, and short-rerouting techniques on both sides of 10 human head specimens. Exposed area, horizontal distance, surgical freedom, and horizontal angle were calculated using vector coordinates for nonrerouting and short-rerouting techniques.

RESULTS

The short-rerouting technique had significantly higher values than the NR-T ( P < .01) for the exposed area (169.1 ± SD 11.5 mm 2 vs 151.0 ± SD 12.4 mm 2 ), horizontal distance (15.9 ± SD 0.6 mm vs 10.6 ± SD 0.5 mm 2 ), surgical freedom (19 650.2 ± SD 722.5 mm 2 vs 17 233.8 ± SD 631.7 mm 2 ), and horizontal angle (75.2 ± SD 5.1° vs 61.7 ± SD 4.6°). However, adding some tailored steps to the NR-T permitted comparable access to the JF.

CONCLUSION

Neuronavigated TI-A with the short-rerouting technique permits wider access to the JF compared with the NR-T. However, the tailored NR-T provides comparable access to the JF and may be a better option for class C1 and selected class C2 and C3 JFPs.

Facial nerve management in jugular paraganglioma surgery: a literature review

Objective:

This literature review analysed facial nerve management strategies in jugular paraganglioma surgery and discusses the tumour resection rate and the facial nerve outcome associated with each technique.

Methods:

A retrospective review of PubMed and Medline articles on the surgical treatments for jugular paraganglioma was performed. Tumour resection rates and post-operative facial nerve function after non-rerouting, short anterior rerouting and long anterior rerouting approaches were evaluated for each article.

Results:

A total of 15 studies involving a total of 688 patients were included. Post-operative facial nerve function was similar after non-rerouting and short anterior rerouting approaches (p= 0.169); however, both of these techniques had significantly better post-operative facial nerve outcomes compared with long anterior rerouting (p< 0.001 andp= 0.001, respectively). The total tumour removal rate was significantly higher for long anterior rerouting than with the non-rerouting approach (p= 0.016). There was no difference in total tumour removal rate between the long and short anterior rerouting approaches (p= 0.067) and between the short anterior rerouting and non-rerouting approaches (p= 0.867).

Conclusion:

No strict guidelines for facial nerve management in jugular paraganglioma resection are available. Although long anterior rerouting provides the best tumour exposure along with a low morbidity rate, case-by-case selection of the surgical approach is recommended.

Surgical management of glomus jugulare tumors: a proposal for approach selection based on tumor relationships with the facial nerve

Object

The goal of this paper is to analyze the extension and relationships of glomus jugulare tumor with the temporal bone and the results of its surgical treatment aiming at preservation of the facial nerve. Based on the tumor extension and its relationships with the facial nerve, new criteria to be used in the selection of different surgical approaches are proposed.

Methods

Between December 1997 and December 2007, 34 patients (22 female and 12 male) with glomus jugulare tumors were treated. Their mean age was 48 years. The mean follow-up was 52.5 months. Clinical findings included hearing loss in 88%, swallowing disturbance in 50%, and facial nerve palsy in 41%. Magnetic resonance imaging demonstrated a mass in the jugular foramen in all cases, a mass in the middle ear in 97%, a cervical mass in 85%, and an intradural mass in 41%. The tumor was supplied by the external carotid artery in all cases, the internal carotid artery in 44%, and the vertebral artery in 32%. Preoperative embolization was performed in 15 cases. The approach was tailored to each patient, and 4 types of approaches were designed. The infralabyrinthine retrofacial approach (Type A) was used in 32.5%; infralabyrinthine pre- and retrofacial approach without occlusion of the external acoustic meatus (Type B) in 20.5%; infralabyrinthine pre- and retrofacial approach with occlusion of the external acoustic meatus (Type C) in 41%; and the infralabyrinthine approach with transposition of the facial nerve and removal of the middle ear structures (Type D) in 6% of the patients.

Results

Radical removal was achieved in 91% of the cases and partial removal in 9%. Among 20 patients without preoperative facial nerve dysfunction, the nerve was kept in anatomical position in 19 (95%), and facial nerve function was normal during the immediate postoperative period in 17 (85%). Six patients (17.6%) had a new lower cranial nerve deficit, but recovery of swallowing function was adequate in all cases. Voice disturbance remained in all 6 cases. Cerebrospinal fluid leakage occurred in 6 patients (17.6%), with no need for reoperation in any of them. One patient died in the postoperative period due to pulmonary complications. The global recovery, based on the Karnofsky Performance Scale (KPS), was 100% in 15% of the patients, 90% in 45%, 80% in 33%, and 70% in 6%.

Conclusions

Radical removal of glomus jugulare tumor can be achieved without anterior transposition of the facial nerve. The extension of dissection, however, should be tailored to each case based on tumor blood supply, preoperative symptoms, and tumor extension. The operative field provided by the retrofacial infralabyrinthine approach, or the pre- and retrofacial approaches, with or without closure of the external acoustic meatus, allows a wide exposure of the jugular foramen area. Global functional recovery based on the KPS is acceptable in 94% of the patients.

Surgical outcomes of lateral approach for jugular foramen schwannoma: postoperative facial nerve and lower cranial nerve functions

The lateral surgical approach to jugular foramen schwannomas (JFS) may result in complications such as temporary facial nerve palsy (FNP) and hearing loss due to the complicated anatomical location. Ten patients with JFS surgically treated by variable methods of lateral approach were retrospectively reviewed with emphasis on surgical methods, postoperative FNP, and lower cranial nerve status. Gross total removal of the tumors was achieved in eight patients. Facial nerves were rerouted at the first genu (1G) in six patients and at the second genu in four patients. FNP of House-Brackmann (HB) grade III or worse developed immediately postoperatively in six patients regardless of the extent of rerouting. The FNP of HB grade III persisted for more than a year in one patient managed with rerouting at 1G. Among the lower cranial nerves, the vagus nerve was most frequently paralyzed preoperatively and lower cranial nerve palsies were newly developed in two patients. The methods of the surgical approach to JFS can be modified depending on the size and location of tumors to reduce injury of the facial nerve and loss of hearing. Careful manipulation and caution are also required for short facial nerve rerouting as well as for long rerouting to avoid immediately postoperative FNP.

Facial Nerve Rerouting in Skull Base Surgery

Facial nerve rerouting techniques were developed to facilitate re-section of extensive tumors occupying the skull base. Facial nerve rerouting has its own limitations and risks, requiring microsurgical expertise, additional surgical time, and often some degree of facial nerve paresis. This article presents different degrees of anterior and posterior facial nerve rerouting, techniques of facial nerve rerouting, and a comprehensive review of outcomes. It then reviews anatomic and functional preservation of the facial nerve in acoustic neuroma resection, technical aspects of facial nerve dissection, intracranial facial nerve repair options, and outcomes for successful acoustic neuroma surgery.

Modified infratemporal fossa approach via lateral transantral maxillotomy: a microsurgical model

BACKGROUND

Lateral approaches have traditionally been used to gain access to lesions of the infratemporal fossa (ITF). However, dysfunction of the facial nerve secondary to its translocation, conductive hearing loss, and dental malocclusion because of mandibular head resection or dislocation are significant limitations associated with some of these approaches. Although facial nerve translocation and extended maxillotomy approaches avoid some of these drawbacks, they are invasive and require extensive osteotomies and facial incisions. To avoid these potential complications and maintain an extranasal/extraoral exposure, we studied the use of a lateral and posterior extension of an anterior transmaxillary approach to the cavernous sinus.

METHODS

The study was performed on 12 cadaver specimens and two dry skulls. An initial nasolabial fold incision, followed by an en bloc osteotomy of the anterior and lateral maxilla provides a window into the medial ITF. After osteotomy of the pterygoid plate and the posterior maxillary wall, the floor of the middle fossa is exposed to reveal the mandibular and maxillary divisions of the trigeminal nerve exiting their respective foramina. The floor of the middle fossa is then drilled postero-medial to the foramen ovale to gain access to the course of the C3-C4 portion of the petrous carotid artery and the eustachian tube. The upper two-thirds of the clivus and the pituitary gland are accessed after drilling of the floor of the sella turcica and form the posterior limit of this exposure.

RESULTS

The technique offers a trajectory to the medial ITF and skull base that does not necessitate palatal splitting or opening of the nasopharynx. The anterior route avoids temporomandibular joint disruption, and spares the lacrimal apparatus and all branches of the facial nerve. In addition, the reflected pterygoid muscle can be used as a vascularized flap for closure of the skull base defect.

CONCLUSION

The approach may be an alternative less invasive approach to the ITF and may be suitable for ITF lesions that have minimal lateral or intracranial extension.