Functional Outcomes After Sacrectomy for Chordoma: The Critical Role of Bilateral S3 Nerve Root Preservation

Background Sacral chordomas are rare, locally aggressive malignancies where surgical resection is the primary treatment. In the previous reports, preservation of at least one S3 root is shown to be important for normal bowel and bladder function. This study aimed to evaluate the postoperative bowel and bladder function according to the level and laterality of sacral nerve root preservation. Methods We conducted a retrospective cohort study of 23 patients who underwent surgery for sacral chordoma at two tertiary referral centers in South Korea between March 2009 and February 2024. All patients underwent en bloc resection with wide margins. Functional outcomes (motor, bladder, and bowel function) based on the level of preserved sacral nerve roots were analyzed. Oncological outcomes included disease-specific survival [DSS], local recurrence-free survival [LRFS], and distant metastasis-free survival [DMFS]. Results The 23 patients were followed for a median of 7.0 years. 19 patients (82.6%) were alive at the last follow-up. Functional outcomes were dependent on the level of nerve preservation. For motor function, preserving more than one S2 root was sufficient to achieve normal function. For bowel and bladder function, preserving S3 root was critical. All patients with bilateral S3 root preservation (n = 4) maintained normal bladder and bowel function (100%). On the other hand, for patients with unilateral S3 preservation (n = 3), normal bladder and bowel function was observed in only 33.3%. Patients with bilateral S2 preservation (n = 9) had 22.2% normal bladder and 42.9% normal bowel function. DSS at 5 years and 10 years was 95.0% and 74.4%, respectively. LR occurred in 9 patients (39.1%), with 5-year and 10-year local recurrence-free survival (LRFS) rates of 65.7% and 52.5%, respectively. DM occurred in 7 patients (30.4%), with 5-year and 10-year distant metastasis-free survival (DMFS) rates of 72.4% and 60.4%, respectively. Conclusion Bilateral S3 preservation is critical for bowel and bladder function, achieving 100% normal continence compared to 33.3% with unilateral preservation. Favorable disease-specific survival (5-year 95.0%, 10-year 74.4%) was achieved despite a 39.1% local recurrence rate, emphasizing the importance of long-term surveillance beyond 5 years.