The present study described the endoscopic transnasal approach for orbital lesions medial and inferior to the optic nerve. This approach had been shown to provide excellent visualization of the surgical field without having to resort to globe retraction [1, 4, 8]. The downside of this approach is that the width of the surgical corridor might be insufficient for the multi-handed techniques required for surgery in the orbit.
In the mononostril approach, there is typically sufficient space for the 2- and 3-handed techniques routinely employed for extraconal lesions. For intraconal lesions that require a 4-handed approach, instrument maneuverability may be limited. Therefore, further expansion of the surgical corridor may be required [5, 9]. Sufficient space can be gained by resecting the middle turbinate or by creating a corridor through the nasal septum (binostril approach), either with a posterior septectomy, for lesions in the orbital apex, or by creating a septal window, for intraorbital lesions [5]. The trans-septal approach provides the surgeon with a good angle for dissection, but can increase nasal morbidity and may adversely influence nasal function.
An alternative approach is to create an auxiliary sublabial transantral corridor. Then, an endoscope and one other instrument can be introduced through the anterior wall of the maxillary sinus. This approach provides the shortest direct route to caudal orbital lesions. Few studies have investigated the combination transnasal-sublabial approach to the orbit [6, 7]. Alimomahadi et al. described their treatment experience with the combined endonasal and sublabial transantral approach for 4 patients with orbital and pterygopalatine fossa pathologies [6]. Har-El et al. described this combined approach for 2 patients with orbital apex lesions. They highlighted the advantages of this approach: it provided excellent visualization and avoided the struggle between surgical instruments and the endoscope, which is often encountered with the transnasal approach alone [7].
In our study, the combined mononostril transnasal and sublabial transantral endoscopic approach was employed in two patients with tumors in a mediocaudal location (Fig. 3). In these cases, the single nostril approach alone did not permit sufficient maneuverability for the instruments, even after performing a middle turbinate resection. However, the sublabial approach allowed the introduction of an endoscope and other instruments as necessary, and it provided excellent visualization of the anterior and lateral borders of the tumor (Fig. 4). The endoscope did not hinder the manipulation of the surgical instruments, and the field of view was sufficiently wide without resorting to an orbital bone resection.
Introducing an endoscope requires a fenestration greater than 4 mm wide, and at least 7–8 mm, when irrigation is required. A more extensive resection (2×2 cm) of the anterior maxillary bone allows other instruments (typically, suction) to be introduced alongside the endoscope. We considered this approach beneficial for several reasons: it provided excellent visualization of the surgical field without interference from the instruments introduced transnasally; the procedure was relatively simple and brief; and the technique is generally familiar among otolaryngologists. Moreover, this approach reduced the risk of interfering with nasal function, compared to the trans-septal approach, which requires a resection or incision of the nasal septum.
The sublabial transantral approach might lead to postoperative complications, including dysesthesia in regions innervated by the trigeminal nerve, emphysema, and facial edema. These complications occur mainly with the classic wide approach (the Caldwell-Luc procedure), which involves a large resection of the anterior wall of the maxillary sinus. However, the minimally invasive approach is typically associated with only temporary complications, such as facial hypoesthesia [7]. No complications were observed in our study.
The dreaded complications of enophthalmos and diplopia, which may arise with infraorbital resections, can also occur with the transantral approach. Having said that, the extent of resection is no greater with the combined approach than with the transnasal approach. We observed no recurrent diplopia postoperatively.
The combination mononostril transnasal and sublabial transantral approach ensured sufficient space for multi-handed techniques, allowed the shortest direct route to mediocaudal lesions, and provided a suitably wide field of view. This approach could be considered an appropriate alternative to the binostril approach.