Usefulness of the bilateral anterolateral approach in operations on the cervical spine

Anterolateral Approach for Retrostyloid Superior Parapharyngeal Space Schwannomas Involving the Jugular Foramen Area: A 20-Year Experience

BACKGROUND

Schwannomas encompassing the superior parapharyngeal space are challenging lesions because of the anatomical complexity of this region and the frequent involvement of the neurovascular structures of the jugular foramen. The purpose of this study is to report the technical aspects and the advantages of the anterolateral approach, here proposed for schwannomas of this complex area.

METHODS

The main steps of the anterolateral approach are described in detail, along with the results of a consecutive series of 38 patients with a retrostyloid superior parapharyngeal schwannoma involving the jugular foramen operated on by means of this route between 1999 and 2019.

RESULTS

The supine position is generally preferred. The medial border of the sternocleidomastoid muscle, mastoid tip, and superior nuchal line are the landmarks for the hockey-stick skin incision. The accessory nerve is retrieved and mobilized cranially. Detachment of the sternocleidomastoid, digastric, and nuchal muscles allows for a 180° exposure of the extracranial side of the jugular foramen. Three working corridors, namely the pre-carotid, pre-jugular, and retro-jugular, allow access to the deeper part of the jugular foramen area and the superior parapharyngeal space. In the present series, a gross total resection was achieved in 89.4% of the patients. Three recurrences occurred after an average follow-up of 80.5 ± 51 months.

CONCLUSIONS

The anterolateral approach is highly effective in the treatment of retrostyloid superior parapharyngeal space schwannomas involving the jugular foramen. Its simplicity of execution, versatility, and very low morbidity are among its main strengths.

Lateral approach for recurrent unilateral cervical radiculopathy after anterior discectomy with fusion. Report of two cases

Recurrent radiculopathy after anterior cervical discectomy with fusion (ACDF) occurs in approximately 4% of cases. The main obstacles of revision surgery after ACDF via the same approach are scar tissue and arthrodesis. We present two patients with recurrent symptoms after ACDF who underwent revision surgery using an alternative, less invasive lateral approach (LA). These two patients both presented with recurrent unilateral cervical radiculopathy due to progression of intervertebral foraminal stenosis. The second patient also presented with paraparesis of the lower limbs and central stenosis. Anterior foraminotomy in the first case and oblique corpectomy in the second were performed via the LA. The previously implanted interbody cages were left intact and no new fusion procedures were needed. No spinal instability or symptom relapse was observed in follow-up. The lateral approach to the cervical spine enables direct and effective decompression of neural structures without violation of previously achieved interbody fusion.

Quantitative evaluation of the anatomical parameters for subaxial cervical spondylectomy: an anatomical study

OBJECT

The object of this investigation was to conduct a morphometric study in cadavers to determine anatomical structures, their relationships, and their morphometry for subaxial cervical spondylectomy.

METHODS

Forty sides of 20 cadavers were used for this study. Dissections were performed in 2 stages (anteriorly and posteriorly). Twenty-one morphometric measurements were performed for both sides of the C3-6 vertebrae. Data were analyzed statistically.

RESULTS

Morphometry of the laminas, tuberculum posterius, pedicle, corpus, foramen transversarium, and processus costalis were measured.

CONCLUSIONS

Detailed quantitative anatomical knowledge for operations requiring wide dissection and resection, such as cervical spondylectomy, lowers the morbidity rate.

Anterolateral approach to the cervical spine: major anatomical structures and landmarks. Technical note

OBJECT

The authors undertook a study to explore the topographic anatomical features seen during the anterolateral approach to cervical spine, anatomical variations, and certain landmarks related to the surgical procedure.

METHODS

The study was conducted in 30 fresh cadavers.

RESULTS

The common carotid artery bifurcation was mostly found at the level of C-4 (78%). The inferior belly of the omohyoid muscle was seen to cross the sternocleidomastoid muscle at the C5-6 disc level along the entire C-6 vertebral body. To reach the lower cervical region, the sacrifice of this muscle makes the procedure easier. The facial vein drained into the internal jugular vein mostly at the level of C3-4 (54%). The superior ganglion of the cervical sympathetic chain was located at the C-4 vertebra, but the location of the intermediate ganglion exhibited some variation. The vertebral artery entered the transverse foramen of C-6 in 27 cadavers (90%), the transverse foramen of C-7 in two cadavers (7%), and the transverse foramen of C-4 in one cadaver (3%). Because the inferior thyroid artery crossed the C6-7 interspace obliquely, the course of the inferior thyroid artery may complicate the procedure. The C-5 uncinate process was shortest and narrowest and had the greatest distance from the medial edge of the process to the anterior tubercle (p < 0.001).

CONCLUSIONS

Understanding the qualitative anatomy of this region not only improves the safety of anterior and anterolateral cervical spine surgery but also allows adequate decompression of neural elements and resolution of the other pathological processes of this region. In this fresh cadaveric study, our goal was to improve the approach and decrease the incidence of complications.