Endoscope-assisted microsurgical transoral approach to the anterior craniovertebral junction compressive pathologies

Abstract

At the present time, an update to the classical microsurgical transoral decompression is strongly provided by the most recent literature dealing with the introduction of the endoscopy in spine surgery. In this paper, we present our experience on the endoscope-assisted microsurgical transoral approach to anterior craniovertebral junction (CVJ) compressive pathology. We analysed seven patients (3 paediatrics and 4 adults ranging from 6 to 78 years) operated on for CVJ decompressive procedures using an open access, microsurgical technique, neuronavigation and endoscopy. All techniques mentioned were simultaneously employed. Among the endoscopic routes described in the literature, we have preferred the transoral using 30° endoscopes. In all the cases endoscopy allowed a radical decompression compared to the microsurgical technique alone, as confirmed intraoperatively with contrast medium fluoroscopy. In conclusion, endoscopy represents a useful complement to the standard microsurgical approach to the anterior CVJ; it provides information for a better decompression with no need for soft palate splitting, hard palate resection, or extended maxillotomy. Moreover, intraoperative fluoroscopy helps to recognize residual compression. Virtually, in normal anatomic conditions, no surgical limitations exist for endoscopically assisted transoral approach, compared with the pure endonasal and transcervical endoscopic approaches. In our opinion, the endoscope deserves a role as "support" to the standard transoral microsurgical approach since 30° angulated endoscopy significantly increases the surgical area exposed at the level of the anterior CVJ.

Fig. 1

a Endoscopic view of the transoral surgical field: 1 the Crockard distractor valves (lingual, pharingeal and soft palate), 2 on the left the bone ultrasonic surgical aspirator (Sonopet), 3 on the right the diamond burr drill. b Higher magnification showing: 1 the dura after removal of the tectorial membrane, 2 the bone ultrasonic surgical aspirator (Sonopet) while removing the inferior border of the clivus

Fig. 2

Patient # 3. a Intraoperative fluoroscopy with Metrizamide before endoscopy showing a contrast defect at the level of right upper corner of the radiograph. b Intraoperative fluoroscopy after endoscopy showing the decompression of the right upper corner

Fig. 3

Patient #5. a, b Preoperative T2-weighted (a) and T1-weighted after contrast administration MR (b) showing a cystic and solid lesion with enhancement of the tectorial membrane impinging the bulbo-cervical junction. c Postoperative T2W image showing the complete removal of the lesion

Fig. 4

Patient # 3. a Preoperative T2-weighted MR showing a “balloon like” rheumatoid inflammatory pannus impinging the bulbo-cervical junction. b Postoperative T2-weighted MR showing the complete neural decompression

Fig. 5

Patient #2. a Preoperative T1-weighted MR documenting a chordoma extending from the oropharinx to the posterior cranial fossa and from the clivus to C2. b Postoperative T1-weighted MR showing removal of the lesion and decompression of the brainstem