Sniffin' Sticks to Measure Olfactory Function and Recovery Following Bilateral Superior Turbinate Resection as Part of Endoscopic Transsphenoidal Approach

Effects of Endoscopic Sinus Surgery on Olfactory Function

PURPOSE OF REVIEW

To review the effects of endoscopic sinus surgery and endonasal approaches to the skull base on olfaction.

RECENT FINDINGS

Advancements in endonasal endoscopic approaches to the sinuses and skull base allow for direct treatment of a variety of sinonasal and skull base diseases. However, these extended approaches will often require manipulation of normal anatomical structures and the olfactory neuroepithelium. Depending on the planned procedure and extent of disease, the prognosis of olfactory perception can vary significantly among patients. Endoscopic sinonasal surgical procedures may impact olfaction. Optimizing olfactory function requires proper surgical techniques, gentle handling of tissue, and perioperative care. Surgeons must discuss objectives and manage patient expectations. Routine olfactory assessment is crucial in surgical work-up and follow-up. Preserving anatomical structures while addressing the obstruction of the olfactory cleft helps to prevent decreased olfactory threshold. However, smell identification and discrimination do not always correlate with sinonasal anatomy.

Endoscopic 1½-transseptal approach for pituitary surgery

Background

We previously introduced the one-and-a-half (1½) nostril endoscopic transsphenoidal approach (OETA) to reduce the damage to the nasal structures. Here, we reported the modified approach which is called the endoscopic 1½-transseptal approach (EOTA) for pituitary surgery by combining the OETA and the microscopic transseptal approach to simplify intranasal procedures and protect nasal mucosa. In EOTA, we removed the sellar lesions in a corridor that is composed of the right submucosal space and the anterior left ½ nasal cavity.

Methods

We introduced EOTA with a detailed technical description and preliminary clinical outcomes. A total of 128 patients who underwent EOTA for pituitary surgery from July 2018 to September 2020 were reviewed for evaluation of the safety and efficacy of this approach.

Results

EOTA had a high gross total resection (GTR) rate and a 1ow complication rate. GTR was achieved in 106 (82.8%) patients, with 81.4% for pituitary adenomas and 93.3% for other non-adenomatous lesions. Post-operative complications included 3 patients (2.3%) with postoperative cerebrospinal fluid leak, 3 patients (2.3%) with diabetes insipidus, 5 patients (3.9%) with anterior pituitary insufficiency and 2 patients (1.6%) with meningitis. In addition, EOTA simplified the intranasal procedures, which led to shortened operation time (67.8 minutes). The results of ASK nasal-12, the Lund-Kennedy score, and the odor identification test showed that patients who underwent EOTA recovered quickly after surgery and the nasal cavity returned to the preoperative condition both apparently and physiologically one month after surgery.

Conclusions

EOTA is a simple, safe and effective approach for pituitary lesions, which provides not only a sufficient surgical corridor for 2-surgeon/4- or 3-hands technique but also minimally invasive access to the sellar region.

Optimizing Quality of Life and Minimizing Morbidity through Nasal Preservation in Endoscopic Skull Base Surgery: A Contemporary Review

Introduction  Endoscopic endonasal approaches (EEAs) are increasingly utilized for intracranial pathology. As opposed to sinonasal tumors, the nasal cavity is being used as a corridor to access these intracranial tumors but is not the site of primary surgical intent. Accordingly, there has been recent interest in preserving intranasal structures not directly involved by tumor and improving postoperative sinonasal quality of life (QOL). Objectives  The aim of the study is to highlight recent advances in EEA techniques focused on improving sinonasal QOL including turbinate preservation, reducing the morbidity of reconstructive techniques, and the development of alternative minimally invasive EEA corridors. Methods  The method of the study involves contemporary literature review and summary of implications for clinical practice. Results  Nasoseptal flap (NSF) harvest is associated with significant morbidity including septal perforation, prolonged nasal crusting, and external nasal deformities. Various grafting and local rotational flaps have demonstrated the ability to significantly limit donor site morbidity. Free mucosal grafts have re-emerged as a reliable reconstructive option for sellar defects with an excellent sinonasal morbidity profile. Middle turbinate preservation is achievable in most EEA cases and has not been shown to cause postoperative obstructive sinusitis. Recently developed minimally invasive EEA techniques such as the superior ethmoidal approach have been described to better preserve intranasal structures while allowing intracranial access to resect skull base tumors and have shown promising sinonasal QOL results. Conclusion  This contemporary review discusses balancing effective skull base reconstructive techniques with associated morbidity, the role of turbinate preservation in EEA, and the development of unique EEA techniques that allow for increased nasal structure preservation.

One-and-a-half nostril versus binostril endoscopic transsphenoidal approach to the pituitary adenomas: A prospective randomized controlled trial

Background

Binostril endoscopic transsphenoidal approach (BETA) is the most used approach for sellar lesions nowadays, while its damage to the nasal structures may cause nasal discomfort and affect nasal functions including respiration and olfaction. With the purpose to improve the post-operative sinonasal quality of life (QoL), we introduced the one-and-a-half nostril endoscopic transsphenoidal approach (OETA) in 2016 which preserved more natural structures and registered a prospective randomized controlled trial (ChiCTR-IOR-16008222) to compare the two approaches regarding the surgical outcomes and complications.

Methods

Sixty patients with pituitary adenomas were recruited and randomly assigned to the OETA group and the BETA group between April 2016 and May 2017 in Jinling Hospital. The tumor resection rate, endocrinal and visual outcomes, and surgical complications between the OETA and BETA groups were analyzed. Besides, the questionnaire Anterior Skull Base Nasal Inventory-12 (ASK Nasal-12) was used to evaluate patients’ sinonasal QoL at seven time points (pre-operative; 2-weeks, 1-month, 3-months, 6-months, 12-months, and long-term post-operatively). The Sniffin’ Sticks were used to assess patients’ olfactory function objectively in a long term. Each patient was followed for at least 12 months post-operatively.

Results

There was no significant difference in tumor resection rate, hormonal and visual outcomes, and surgical complications between the two groups. Regarding the ASK Nasal-12, patients in the OETA group complained less about dried nasal material at 2 weeks after surgery (P = 0.017). One month after surgery, the OETA group had better olfaction function (P = 0.019) compared with the BETA group. However, there was no significant difference in early and long-term postoperative sinonasal QoL between the two approaches according to the entire ASK Nasal-12 metric. The results of the Sniffin’ Sticks showed that the two groups had a similar olfactory performance at long-time follow-up.

Conclusion

In this single tertiary center trial, the results showed that the OETA achieved the same surgical outcomes and post-operative sinonasal QoL as the BETA.

Clinical Trial Registration

http://www.chictr.org.cn/showproj.aspx?proj=13852, identifier: ChiCTR-IOR-16008222

Olfaction after endoscopic surgery for sellar and parasellar disease: an updated systematic review and meta-analysis

Background: Whether endoscopic surgery for sellar/parasellar disease causes significant deficits in olfactory function remains unclear. We aimed to systematically review the olfactory outcomes in such settings based on the evidence up to date. Methods: PubMed, EMBASE, and CENTRAL were searched through February 1, 2021. Included studies were limited to endoscopic surgery for sellar/parasellar disease with follow-up olfactory function measured by standardized olfactory testing methods or subjective assessment. The primary outcome was the change in olfactory function after surgery assessed by standardized olfactory testing methods. The secondary outcome was the change in subjective olfactory function. Random-effects model was used in obtaining combine effects. Study quality was assessed using the Newcastle–Ottawa scale. Sensitivity analysis was carried out using the leave-one-out approach, and publication bias was assessed using Egger’s test. Results: The results show no significant difference in olfaction assessed by standardized olfactory testing methods at 1–3 months post-surgery (880 patients in 16 studies) or at 6–12 months post-surgery (1320 patients in 16 studies) compared to pre-surgery, whereas a significantly lower subjective olfaction at 3 months was observed. In addition, the lack of significant change in olfaction as assessed by standardized olfactory testing methods was observed regardless of whether patients were treated with or without the nasoseptal flap (NSF) harvesting. Heterogeneity and publication bias were observed, whereas sensitivity analysis showed the meta-analysis results are robust. Conclusion: The findings of this updated systematic review and meta-analysis support the conclusion that endoscopic surgery for sellar and parasellar pathology may pose no greater risk of olfactory dysfunction. In addition, the current evidence does not support there is an increased risk of diminished olfaction among patients treated with NSF during surgery.