Intraoperative anatomical variations during greater occipital nerve decompression.

Area of Science:

• Neurosurgery
• Anatomy
• Surgical anatomy

Background:

• The greater occipital nerve (GON) is a key structure in the occipital region.
• Variations in GON anatomy can complicate surgical procedures.
• Understanding these variations is vital for effective surgical outcomes.

Purpose of the Study:

• To elucidate anatomical variations of the greater occipital nerve (GON) and surrounding occipital tissues.
• To document intraoperative findings related to GON decompression surgery.
• To improve surgical planning and outcomes for patients undergoing GON decompression.

Main Methods:

• Prospective recording of anatomical and surgical variations in 272 patients undergoing GON decompression.
• Intraoperative data collection focusing on trapezius musculature extension, lymph nodes, GON branching, semispinalis capitis muscle, and occipital arterectomy.
• Analysis of variations in surgical procedures required during GON decompression.

Main Results:

• The GON pierced the semispinalis muscle bilaterally in all patients.
• Trapezius musculature extended to the midline in 67.3% of patients.
• GON branching occurred in 7.4% of patients, with intervening structures in 3.7%.
• Occipital arterectomy was needed in 64.0%, and semispinalis muscle resection in 10.7%.

Conclusions:

• The identified anatomical variations enhance understanding of intraoperative occipital anatomy.
• This knowledge aids in preventing surgical dissection errors and improving GON identification.
• Ensuring accurate surgical technique maximizes patient benefit from GON decompression, particularly for migraine (MH) patients.