Posterior paramedian approach combined with a novel inverted V-shaped surgical access for intraspinal schwannomas: a retrospective case series study

OBJECTIVE: To explore the efficacy and safety of the posterior paramedian approach combined with a novel inverted V-shaped surgical access for the treatment of intraspinal schwannomas. METHODS: This study retrospectively reviewed consecutive patients who underwent surgical resection of the intraspinal schwannomas via the inverted V-shaped approach at our center between January 2016 and May 2021. Changes between the preoperative and postoperative visual analog scale (VAS) scores and neurological function Japan Orthopaedic Association (JOA) scores were assessed. Secondary outcomes such as success rate of tumor resection, operation time, blood loss, spinal stability, and disruption degree of intervertebral joints. Postoperative complications were also investigated. RESULTS: Of these 36 consecutive patients, there were 6 cases in the cervical spine, 2 cases at the cervical-thoracic junction, 11 cases in the thoracic spine, 4 cases at the thoracic-lumbar junction and 13 cases in the lumbar spine. The average operation time was 99 min, and the average blood loss was 95.4 mL. The tumor removal rate was 100%. Postoperative CT re-examination showed that the spinous processes were intact in all cases, the facet joint surfaces were intact in 32 cases. At the time of last follow-up, the median JOA score was 25 (9–27), which was significantly improved compared to the preoperative median JOA score of 15 (10–22) (P < 0.01). The overall excellent and good rate were 88.9 %. The median VAS score at post-surgery was 0 (0–2), which was significantly improved compared to the preoperative median VAS score of 4 (2–8) (P < 0.01). As for complications, there were no cases of cerebrospinal fluid leakage or spinal instability. Three patients who had a postoperative fever finally recovered after lumbar cistern drainage. CONCLUSION: The inverted V-shaped surgical access via the posterior paramedian approach is an effective and safe method for the treatment of intraspinal schwannomas.