Retractorless Surgery with Supine Retrosigmoid Approach

Introduction: The suboccipital retrosigmoid approach is a fast and tissue sparing skull base module that is suitable for a vast array of infratentorial pathology. For this approach a variety of patient positions have been described from sitting, half-sitting, over lateral decubital to half supine and supine. We use a dissection technique that circumvents the use of any brain retraction by combination of cisternal opening with well-known microneurosurgical principles in a simple supine patient position. In a case based manner, we report on principles and advantages of the applied technique, and present the series.

Method: In a single surgeon series all consecutive 87 cases that were operated via a retractorless retrosigmoid approach during a 7-year period were screened for practicability of retractorless surgery and for secondary insertion of a static retractor system.

Results: Thirty-five schwannomas, 13 meningiomas, 21 vascular pathologies, and 18 other pathologies were operated on (see table 1). The sagittal extension of pathology ranged from the supra/ infratentorial transition to foramen magnum level. In no case secondary placement of a retractor was necessary or found helpful for additional exposure. Use of a retractor blade was made initially as a shield for petrosal drilling, without exertion of actual retraction. The principles of retractorless surgery enabled for meticulous and tissue sparing dissection (CSF egress, bimanual arm-rested manipulation, mouthpiece and foot pedal, avoidance of excessive instruments and cotton patties). The advantages of the detailed approach are comfortable surgeon position with rested and slightly flexed arms and minimized shoulder-girdle fatigue enabling for steady, secure and long-lasting bimanual microsurgical downward dissection. The view is not obtunded by brain parenchyma. Positioning of the patient is eased substantially. The obtained field of view is excellent. There is no congestion of CSF nor blood in this position; an argument often times used for preferential sitting or semi-sitting positioning.

Conclusion: We are quite satisfied with this supine and retractor free approach, and since long have completely adopted it.

Table 1