DISCUSSION
Our study revealed that the transseptal approach had better patient-reported outcomes and objective endoscopic scores with intact olfactory function. Meanwhile, the neurosurgical outcomes and rate of complications were comparable. That is, endoscopic transseptal TSA facilitates nasal recovery without compromising neurosurgical outcomes.
In recent years, neurosurgeons and otolaryngologists have been making a joint effort to reduce nasal morbidities.13-17 There is increasing evidence indicating that endoscopic transnasal TSA has better neurosurgical outcomes and fewer complications than microscopic transsetpal TSA,18-20 while the sinonasal outcomes have been inconsistent.7, 21, 22 Interestingly, Hong et al. found better sinonasal quality of life in the early postoperative period in the microscopic transseptal group than in the endoscopic transnasal group.7 They proposed that their finding was because they avoided injury to the nasal mucosa in the microscopic transseptal approach. That is, the transseptal approach has a great potential with excellent nasal outcomes when manipulating nasal tissue carefully.
Therefore, the endoscopic endonasal transseptal approach can be deemed as a favorable technique with the advantages of both approaches: comparable neurosurgical outcomes from the endoscopic transnasal approach and minimal nasal morbidities from the microscopic transseptal approach. Previous studies reported solely on either neurosurgical or rhinological outcomes. Favier et al. reported similar gross total resection, endocrine outcomes and rates of neurosurgical complication in endoscopic transseptal approach comparing to results of endoscopic transnasal approach from other experienced teams. 4, 5Hong et al. reported fewer subjective nasal symptoms in the early postoperative period after the endoscopic transseptal approach.6 This study demonstrated lower SNOT-22 scores, lower postoperative Lund-Kennedy scores and intact olfactory function in the transseptal group. Meanwhile the neurosurgical outcome and rates of complications were not inferior. That is, the endoscopic transseptal approach enhances nasal recovery without compromising resection, making it a worthy tradeoff for better rhinological outcomes.
We observed that olfactory function was well preserved in both groups. The possible explanation is that olfactory neural fibers was not disrupted in either approaches.23 In the transseptal approach, the incisions are made anteriorly and the olfactory nerves can be retained within the elevated mucosal flaps. The binostril method also allows for less tension in the mucosal flap, preventing an unbalanced force from disrupting the olfactory neuroepithelium, as in microscopic TSA.24 For the transnasal approach, the main route includes the posterior septum and spared the main olfactory neuroepithelium from permanent dysfunction.25
Some may concern that managing unexpected high-flow intraoperative CSF leakage could be problematic for the endoscopic transseptal TSA. On the contrary, a nasoseptal flap can be harvested by dividing the septal mucosal flap superiorly and inferiorly. For patients with a high risk of CSF leakage, the septal incision can be made anteriorly to develop a larger nasoseptal flap.
Even though the endoscopic transseptal approach seems attractive, surgeons should remember that every procedure has its limitations. Dissection of the septal mucosal flap could be difficult in patients with previous nasal surgery including TSA, septoplasty and rhinoplasty. In addition, tumors with lateral extension to the cavernous sinus cannot be removed thoroughly. Finally, although septal infection presented only in one patient in our series, severe septal infection may result in perforation or nasal deformity. We should carefully examined patients with unusual postoperative nasal pain.
There were several limitations in this study. First, the study was retrospective in nature. Although we have controlled as many confounding factors as possible, the results still require validation by a prospective randomised controlled studies. Second, we included only pituitary adenoma and whether the conclusions can be generalised to other sellar pathologies remains unexplored. Finally, we only analysed data until 1 year after surgery. Long-term complications, especially for septal complications, require a longer follow-up.