Rethinking Dural Opening in the Posterior Fossa: The Vertical Paramedian Durotomy-Technical Considerations and Surgical Applicability.

BACKGROUND AND

OBJECTIVES

Posterior fossa lesions pose significant surgical challenges due to their proximity to critical neurovascular structures and the difficulty of obtaining adequate exposure with reliable dural closure. The traditional Y-shaped durotomy after a median suboccipital craniotomy remains the standard approach for midline infratentorial lesions but is often associated with cerebrospinal fluid leakage and complex dural repair. This study describes a vertical paramedian durotomy, performed parallel to the occipital sinus (OS) and combined with systematic C1 posterior arch removal, as a pragmatic alternative that preserves venous anatomy and facilitates linear primary closure.

METHODS

We conducted a retrospective, single-surgeon case series (January 2020-January 2025) including patients with midline infratentorial lesions whose operative corridor did not extend beyond the foramina of Luschka. All patients underwent median suboccipital craniotomy, routine C1 posterior arch removal, and a vertical paramedian durotomy parallel to the OS. Clinical records, operative notes/videos, and imaging, including preoperative magnetic resonance venography, were reviewed.

RESULTS

Nine patients (median age 44 years, range 9-69; 5 female) were treated. Lesion locations included the pons (5/9, 55.6%), cervicomedullary junction (2/9, 22.2%), fourth ventricle (1/9, 11.1%), and medulla (1/9, 11.1%). Diagnoses were cavernous malformation (5/9), ependymoma, hemangioblastoma, choroid plexus papilloma, and 1 unspecified tumor. The OS was identified in 2/9 cases; no marginal sinus was visualized. Gross total resection was achieved in 8/9 patients; 1 pontine lesion underwent biopsy only. No durotomy-related or wound-related complications occurred, and linear primary closure was achieved in all cases.

CONCLUSION

Vertical paramedian durotomy is a safe and effective alternative for selected midline posterior fossa lesions. By preserving the OS and simplifying dural reconstruction, it reduces the risk of cerebrospinal fluid-related complications and provides a straightforward method for achieving watertight closure. Larger prospective studies are warranted to further validate its long-term outcomes and broader applicability.