Muscular-stage Dissection during Far Lateral Approach and Its Transcondylar Extension

Abstract

The far lateral approach includes exposure of the C1 transverse process, vertebral artery, posterior arch of the atlas, and occipital condyle. We designed a method for systematic muscular-stage dissection and present our experience with this approach. We used a horseshoe scalp flap that was reflected downward and medially. The lateral muscle layers were separated layer to layer to expose the suboccipital triangle. The medial muscle layers were separated in the midline and reflected in a single layer. At this stage, the midline of the C1 process and the foramen magnum were identified. The rectus capitis posterior major muscle was reflected to expose the posterior arch of the atlas. The C1 transverse process and vertebral artery were identified by reflection of the superior oblique muscle. The occipital condyle was separated accordingly. We used this method of muscular dissection in 10 patients (foramen magnum meningioma, = 5; hypoglossal schwannoma, = 2; others, = 3). Systematic muscular-stage dissection facilitates identification of the anatomical landmarks with no vertebral artery injury. Gross total removal was obtained in all 9 patients with complex tumors. The patient with vertebral artery dissection successfully underwent proximal clipping. Our muscular-stage dissection could contribute to safe and effective surgery for the far lateral approach.

Jugular Foramen Tumors: Surgical Strategies and Representative Cases

“…The degree of drilling the occipital condyle will depend on the access area needed. The transcondylar approach is performed by drilling the posterior condyle, which gradually expands the working space to the anterior brainstem and petroclival area [19,20]. The percentage of condyle to be removed can vary from only the posterior one third with no instability of the craniovertebral junction to as far as the posterior half, which will require fixation of the craniovertebral junction due to instability of the atlanto-occipital joint [21,22].…”

Exposición de la oliva bulbar mediante los abordajes far lateral y retrosigmoideo bajo. Análisis comparativo de la superficie expuesta y ángulo de ataque

“…Sin embargo, en la presente tesis, en el estudio anatómico se realizó una disección plano por plano de toda la musculatura de la región occípito-cervical, para comprender la configuración tridimensional y relaciones anatómicas con implicaciones directas en el abordaje. 17,84 En la región de la nuca podemos diferenciar un total de cuatro planos musculares:…”

“…La tercera y última fase es intradural, donde se establecen las relaciones con las estructuras nerviosas y vasculares. 10,17,22,25,32,45,50,54,56,61,74,84,93,94,[96][97][98] El abordaje se puede hacer colocando al paciente en diferentes posiciones y la elección final de la posición operatoria depende de varios factores, entre ellos la preferencia del cirujano. La posición lateral es laboriosa y debe asegurar un buen almohadillado de la axila y brazo contralateral.…”

Exoscopic and Microscopic Combined Far Lateral Retrocondylar Approach for Resection of a Ventral Foramen Magnum Lesion: 2-Dimensional Operative Video

“…[1][2][3] Dissection of the superficial and intermediate muscle layers of the suboccipital region is critical for adequate exposure and to safely localize the vertebral artery. [4][5][6][7][8] Exoscopic assistance has hitherto been marginally explored yet may represent a useful tool for such proper dissection. 4 This illustrative operative video highlights the surgical anatomy and relevant steps to perform a combined exoscopic and microscopic far lateral retrocondylar approach for resection of a ventral foramen magnum meningioma in a 56-year-old woman who presented to the emergency department with severe myelopathy from brainstem and spinal cord compression.…”

“…[4][5][6][7][8] Exoscopic assistance has hitherto been marginally explored yet may represent a useful tool for such proper dissection. 4 This illustrative operative video highlights the surgical anatomy and relevant steps to perform a combined exoscopic and microscopic far lateral retrocondylar approach for resection of a ventral foramen magnum meningioma in a 56-year-old woman who presented to the emergency department with severe myelopathy from brainstem and spinal cord compression. Magnetic resonance imaging showed a 3 × 2.3 cm contrastenhancing foramen magnum lesion that was located ventrally and displaced the upper brainstem and lower cervical spinal cord dorsally causing severe compression.…”