Minimally Invasive Technique for Chiari I Decompression Without Durotomy: Surgical Technique and Preliminary Case Series

Background: Chiari I malformation, marked by severe headaches and potential brainstem/spinal cord issues, often requires surgical intervention when conservative methods fail. This study introduces a minimally invasive surgery (MIS) Chiari decompression technique utilizing a 3-blade retractor, aiming to reduce postoperative discomfort and optimize outcomes. Methods: Chiari type I malformation patients who underwent a MIS technique were included. Technique consisted of a minimal-soft tissue opening using a 3-blade retractor, suboccipital craniectomy, C1 laminectomy, and resection of the atlantooccipital band without a durotomy. Results: Ten patients were treated. Mean age was 43.3 years, with 7 female patients. All patients presented with occipital headaches; 50% retroorbital pain; 40% neck, upper back, or shoulder pain; and 30% limb paresthesias. Median pre-surgical modified Rankin Scale (mRS) was 3 (2–4) and pain visual analog score (VAS) was 7 (5–9). Mean operative time was 59 (59–71) minutes, with mean blood loss of 88.5 (50–140) mL. In our sample, 90% of patients were discharged the same surgical day (mean 7.2 [5.3–7.7] hours postoperative). No immediate or delayed postoperative complications were evidenced. At 6 months, 90% of patients had mRS 0–1. At last follow-up the mean VAS was 1.5 (range: 0–4, P < 0.001). Conclusions: The MIS 3-blade flexible retractor technique for Chiari decompression is feasible, provides wide visualization angles of the suboccipital region and C1 arch, allows 2-surgeon work, and minimizes skin and soft tissue disruption. This combination may diminish postoperative discomfort, reduce the risk of surgical site infections, and optimize outcomes.