The chevron-shaped dural opening technique for the median suboccipital approach

The median suboccipital approach (MSOA) provides access to the posterior cranial fossa (PCF) and craniovertebral junction (CVJ). This study outlines a step-by-step description of the "chevron-shaped" dural opening technique for MSOA, emphasizing its anatomical rationale and presenting surgical outcomes. Between January 2020 and December 2024, 76 patients underwent MSOA at the Neurosurgical Department of the ASST Cremona, Italy. Exclusion criteria included a history of previous PCF/CVJ surgery or preoperative imaging evidence of oblique occipital sinus (OS). The chevron-shaped durotomy involved two oblique lateral incisions directed lateromedially and craniocaudally, converging at the midline over the foramen magnum, enabling the OS and marginal sinus to be severed safely. Intraoperative and postoperative complications were systematically recorded. The OS was identified intraoperatively in 93.4% of patients. Significant intraoperative venous bleeding occurred in three patients (3.9%) and was successfully controlled in all instances. No intraoperative blood transfusions were required, although five patients (6.6%) required postoperative transfusions. Intracranial hemorrhage occurred in two patients (2.6%). Asymptomatic pseudomeningocele was observed in 25 cases (32.9%) on CT scan at postoperative day 7, persisting in seven (9.2%) on CT at day 30. One patient (1.3%) developed bacterial meningitis associated with CSF leakage, which resolved with antibiotics and lumbar drainage. Hydrocephalus developed in three patients (3.9%), necessitating ventriculo-peritoneal shunt placement; no correlation with underlying pathology was noted. The dural opening for MSOA requires detailed anatomical knowledge, accurate preoperative imaging, and individualized surgical planning owing to significant inter-individual anatomical variability. The chevron-shaped dural opening technique represents a safe, effective and anatomically grounded alternative to traditional PCF durotomies, except in patients with an oblique OS.