Iatrogenic Seeding of Clival Chordoma after Endoscopic Endonasal Surgery

Background: Iatrogenic tumor seeding after open surgery for chordoma has been well described in the literature. The incidence after endoscopic endonasal approaches (EEA’s) has not been well defined.

Methods: We retrospectively reviewed our experience with EEA for clival chordoma, focusing on cases with iatrogenic seeding. The clinical, radiographic, as well as the pathological and molecular characterization data were reviewed.

Results: 173 EEAs for clival chordomas were performed at our institution between April 2003 and May 2016) with 2 cases in which iatrogenic seeding occurred (1.15% of cases). One case was in a 10 year-old and the other a 79 year-old male, both of whom underwent an EEA for resection of an extensive clival chordoma followed by adjuvant radiotherapy (with chemotherapy for the child). Seeding occurred 21 and 19 months postoperatively, in the inferior turbinate and floor of the nasal cavity, respectively. Both were treated with repeat endonasal resection and adjuvant radiation. Both patients’ original pathology reflected a fairly aggressive tumor with homozygous 1p deletions, and a K_i-67 of 10–15% and >20% (no 9p/p16 deletions were detected). Both surgeries were performed by a team of right-handed surgeons (ENT and neuro), with a four-handed technique (in which the endoscope and suction are typically passed through the right nostril, and other instruments, such as pituitary forceps, are unvisualized passing through the left).

Conclusion: Although uncommon, iatrogenic seeding occurs during endoscopic endonasal resections of clival chordomas. There seems to be a preponderance of left nasal cavity seeding, possibly due to unvisualized tumor removal through this corridor. In addition, tumors with more aggressive biology are likely at a higher risk for iatrogenic seeding and require increased vigilance on surveillance imaging and endoscopy. Nasal cavity protective sleeves may obviate this complication and tumor removal should be followed by close inspection and irrigation at the end of the procedure. Furthermore, although controversial, the inclusion of the nasal passage in the adjuvant radiation field in aggressive tumors may be considered.