Table 2.

Comparative study of the reported cases that underwent endoscopic transnasal odontoidectomy in the previous literatures

Authors	Case number	Etiology	Surgical methods	Techniques	Neurological outcome	Results			Complications
						Extubation	NG feeding	LOS (days)	Artery injurya	Cord injury	CSF leak
Kassam et al. [12]	1	RA	TNEA +PF	(1) Two nostrils approach (2) Middle turbinectomy (3) Ethmoidectomy (4) Sphenoidotomy (5) Posterior septectomy	Improved	2nd days	No	7	No	No	No
Kassam et al. [13]	1	RA			Improved	2nd days	No	7	No	No	No
Nayak et al. [14]	9	RA	TNEA +PF	(1) Two nostrils approach (2) Sphenoidotomy (3) Posterior septectomy	Improved	4 patients need tracheostomyb	n = 3c	Not mentioned	No	No	No
Wu et al. [11]	3	RA (n = 2); Trauma (n = 1)	TNEA +PF	Single-nostril using nasal speculum	Improved	2nd days	No	Not mentioned	No	No	n = 1d
Laufer et al. [15]	1	Juvenile RA	PF + TNEA	(1) Two nostrils (2) Open sphenoid sinus (3) Posterior septectomy	Improved	Within 12 h	No	Not mentioned	No	No	No
Leng et al. [16]	1	Os Odontoideum	PF + TNEA	(1) Two nostrils (2) Open sphenoid sinus (3) Posterior septectomy	Improved	1st day	No	Not mentioned	No	No	No
Gempt et al. [17]	1	RA	PF (20 years ago) + TNEA	(1) Two nostrils (2) Sphenoidotomy (3) Posterior septectomy	Improved	1st day	Removed 3 weekse	10	No	No	No
Hankinson et al. [18]	2	ACM-I	TNEA +PF (2nd day)	(1) Two nostrils (2) Posterior septectomy	Improved	Reintubationf	Not mentioned	7	No	No	No
Scholtes et al. [19]	1	ACM-I	TNEA	Not detailed mentioned	Improved	Within a few hours	Not mentioned	3	No	No	No
Cornelius et al. [20]	1	Infection	PF + TNEA	(1) Two nostrils (2) Sphenoidotomy (3) Posterior septectomy	Improved	2nd days	No	7	No	No	No
Grammatica et al. [21]	1	ACM-I	TNEA +PF (1 month later)	(1) Two nostrils (2) Posterior septectomy	Improved	Not mentioned	Not mentioned	7	No	No	No

NG feeding need for postoperative nasogastric tube feeding to bypass the pharyngeal wound, CSF cerebrospinal fluid, LOS length of stay in hospital (days), RA rheumatoid arthritis, TNEA transnasal endoscopic approach, PF posterior fusion, ACM-I Arnold-Chiari malformation

^aIncluding the vertebral artery and internal carotid artery injury

^bTwo of four patients had significant preoperative pharyngeal dysfunction

^cThe three patients had preoperative pharyngeal morbidity

^dIntraoperative minor cerebrospinal fluid leakage was encountered. The leakage was repaired with fat graft and tissue glue without intra- or postoperative lumbar drainage. No postoperative cerebrospinal fluid leak was observed

^eThe patient had depended on a nasogastric tube for more than 3 months preoperative

^fReintubation due to preexisting lower cranial nerve dysfunction