[Surgical Treatment of Sacral Chordoma]

PURPOSE OF THE STUDY The retrospective study of patients treated for sacral chordoma with respect of complications, clinical outcomes and longterm survival is presented. Three main hypotheses have been formulated. Hypothesis 1: survival of patients with respect to generalization of the disease, manifestation of local recurrence and metastases with a R0 resection margin achieved is longer than survival of patients with a R1 or R2 resection margin. Hypothesis 2: survival of patients with the tumor resected from low endplate of S2 distally is longer than in tumors with resection above this level. Hypothesis 3: resection of large tumors with tumor volume greater than 800 cm³ is associated with a significantly shorter survival than resection of tumors with tumor volume less than 800 cm³. MATERIAL AND METHODS A total of 12 patients (7 women, 5 men), with the mean age of 54.3 years, underwent surgical treatment at our department in 1998-2018. Sacral chordoma proximally achieved S1 level in three cases, S2 level in four cases and S3 level in five cases with volume less than 800 cm³ in eight and greater in four patients. In nine patients sacrectomy using isolated posterior approach was performed and in three patients antero-posterior approach was applied. The Kaplan-Meier survival curve was calculated to estimate the survival of patients. The patients were divided into groups and subsequently compared with respect of achieved radicality of surgical resection, i.e. R0 vs. R1 or R2 resection, secondly of the proximal margin of the tumor/resection, i.e. S1 or S2 vs. S3 distally, and thirdly of the volume of the tumor, i.e. less than 800 cm³ vs. more than 800 cm³. RESULTS At the time of evaluation, a total of seven patients were alive (58.3%), with the mean survival of 9.5 years. One patient died from complications associated with the treatment of obstructive ileus manifested 10 months after primary surgery. The remaining four patients died in relation to the generalization of the disease 14.8 years after primary surgery on average. All the patients, in whom R0 resection was achieved, at the average time of evaluation of 7.3 years (range 2.8-15.8 years) showed no signs of local recurrence or generalization of the disease, whereas in group with R1, R2 resection at the time of evaluation only two patients were still alive, both 16.8 years on average (range 15.2-18.4 years) after surgery with repeatedly treated recurrencies. Frequent postoperative complications were observed in a total of five patients (41.7%). DISCUSSION The study did not confirm any difference in patient's survival with respect of the proximal margin affection of sacrum or tumor size. The decisive factor for survival of patients with sacral chordoma is achieving the R0 resection. The size of the chordoma and proximal achievement increase the complexity of surgery, manifestation of early perioperative and subsequently postoperative complications. CONCLUSIONS In primary surgical treatment of sacral chordoma, we always try to achieve R0 resection. In the case of low-volume tumors from S3 distally, we resect the tumor using the isolated posterior approach. The anterior-posterior approach is preferred in the case of large tumors presenting in the S1/2 region. Key words: sacral chordoma, sacral cancer, wide resection, sacrectomy, vertical rectus abdominus myocutaneous (VRAM) flap.