Olfactory outcomes after endoscopic skull base surgery: A systematic review and meta‐analysis

Effect of preservation versus resection of turbinate on olfactory function in endoscopic trans-nasal trans-sphenoidal pituitary surgery: a systematic review and meta-analysis

BACKGROUND

Utilizing endoscopes in surgery offers advantages and concerns, including potential nasal function impacts. Hyposmia following Transseptal Transsphenoidal hypophysectomy ranges from 0% to 2.2%. Debates persist about managing the M.T. in endoscopic sinus surgery due to its impact on nasal function. While preservation is recommended for sinonasal health, debates continue, as certain cases require resection. Our meta-analysis aims to compare turbinate resection and preservation effects on olfactory function.

METHODS

We searched five electronic databases to collect all relevant studies. Records were screened for eligibility. Data were extracted from the included studies independently. Our continuous outcomes were pooled as standardized mean difference with 95% CI. Statistical analyses was done by RevMan.

RESULTS

Our meta-analysis included four studies involving 235 patients (81 males). Evaluating changes in olfaction scores, two one-month studies (82 patients) revealed no significant difference between preservation and resection groups (Std.MD = 0.05[-0.39, 0.50], p = 0.81). For three-month assessments (146 patients), SNOT tests indicated no significant difference (Std.MD = 0.21, 95% CI[-0.11, 0.54], p = 0.20). Two studies used other tests on 70 patients at three months, yielding no significant difference (Std.MD = 0.13, 95% CI [-0.35, 0.62], p = 0.59). Two six-month studies (72 patients) similarly found no significant difference (Std.MD = 0.09, 95% CI [-0.39, 0.56], p = 0.72).

CONCLUSION

Our meta-analysis involving 235 patients examined olfaction score changes over various time frames in trans-nasal trans-sphenoidal pituitary surgeries. No significant differences were observed between turbinate preservation and resection groups at one month, three months, or six months post-surgery.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Neurosurgery for the rhinologist

PURPOSE OF REVIEW

The purpose of this review is to provide a comprehensive anatomical appraisal of the neurosurgical anatomy exposed through the endonasal and paranasal sinuses routes, focusing on the most common expanded endonasal approaches (EEAs) as well as recent advances in this surgical field.

RECENT FINDINGS

The EEAs are redefining the management of skull base pathology. Neurovascular structures previously considered a limitation, can be now approached through these surgical corridors. Advances in this field include the development of new surgical techniques and routes that allow better visualization and access to pathologies located in the ventral skull base. Understanding the surgical anatomy related to EEAs is essential not only for neurosurgeons but also for rhinologists.

SUMMARY

Knowledge of the surgical anatomy of the most common EEAs that utilize paranasal sinuses as a surgical corridor enables more effective management of complex skull base pathologies. Comprehensive anatomical knowledge of these corridors and the surrounding neurovascular structures is crucial to maximize benefits of EEAs and improve outcomes.

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.

Will nasal airway surgery improve my sense of smell? A prospective observational study

BACKGROUND

The effect of nasal airway surgery on olfaction has not been well established. The goal of this study is to assess changes in olfaction after septoplasty with inferior turbinate reduction through both objective and patient-reported measures.

METHODS

Prospective, observational study was conducted of patients with nasal airway obstruction presenting between July 2017 and October 2019 who underwent septoplasty with inferior turbinate reduction. Nasal airflow was characterized with the Nasal Obstruction Symptom Evaluation (NOSE) scale and an 11-point ease-of-breathing (EOB) Likert scale, and olfaction with an 11-point olfactory Likert scale and the 40-item University of Pennsylvania Smell Identification Test (UPSIT), pre- and postoperatively. Pearson correlations were used to assess the relationship between measures of nasal obstruction and olfaction.

RESULTS

Among 80 patients, mean NOSE scores improved from 67.4 preoperatively to 19.6 postoperatively (p < 0.001). EOB Likert scores improved from a mean of 3.9/10 to 8.1/10 after surgery (p < 0.001). Olfactory Likert scores improved from a baseline of 6.1/10 preoperatively to 7.9/10 after surgery (p < 0.001). No statistically significant difference was noted in UPSIT testing pre- versus postoperatively. A moderate correlation was noted between the degree of change in NOSE scores and improved olfactory Likert scores (r = 0.51, p < 0.001), and similarly between the degree of change in EOB Likert scores and improved olfactory Likert scores (r = 0.55, p < 0.0001).

CONCLUSIONS

Based on our data, subjective tests of olfaction may improve with nasal airway surgery in some patients. Changes in olfaction best correlate with the extent to which surgery can improve subjective nasal obstructive symptoms.

Otolaryngology Considerations of Pituitary Surgery: What an Endocrinologist Should Know

Endoscopic endonasal skull base surgery is the preferred surgical approach for the management of pituitary adenomas. Perioperative management of pituitary lesions requires multidisciplinary care and typically includes a dual surgeon team consisting of a neurosurgeon and an otolaryngologist. The involvement of the otolaryngologist allows for a safe surgical approach with excellent intraoperative visualization of the tumor to enable an effective resection of the tumor by the neurosurgeon. Detection and treatment of sinonasal pathology is essential prior to surgery. Patients may experience sinonasal complaints following endoscopic transsphenoidal surgery, although this is typically temporary. Sinonasal care in the postoperative period can expedite recovery to baseline. Here we discuss the perioperative factors of endoscopic pituitary surgery that endocrinologists should be aware of, ranging from preoperative patient selection and optimization to postoperative care, with a particular emphasis on anatomic and surgical factors.

Olfactory changes after endonasal endoscopic cerebrospinal fluid fistula repair: long-term outcomes

OBJECTIVE

This study aimed to evaluate odour measurements after endoscopic repair of cerebrospinal fluid fistulas.

METHOD

Demographic characteristics, cerebrospinal fluid leak location, surgical procedure, aetiology and smell test results were retrospectively reviewed.

RESULTS

A total of 27 patients were included. The mean age was 43.52 years. The aetiology was spontaneous in 13 patients (48.1 per cent) and traumatic in 14 patients (51.9 per cent). The skull base defect was at the cribriform plate in 15 patients (55.6 per cent), the frontal sinus posterior wall in 4 patients (14.8 per cent), the sphenoid sinus posterior wall in 4 patients (14.8 per cent), around the anterior ethmoid artery in 2 patients (7.4 per cent), at the ethmoid roof in 1 patient (3.7 per cent) and at the sphenoid sinus posterolateral wall in 1 patient (3.7 per cent). After the comparison of pre-operative and post-operative values in identification, discrimination and threshold categories, a statistically significant difference was seen only in the threshold category (p = 0.014).

CONCLUSION

The results demonstrated that endoscopic repair of cerebrospinal fluid leak is safe in terms of olfactory functions.

Quality of Life Considerations in Endoscopic Endonasal Management of Anterior Cranial Base Tumors

Considering quality of life (QOL) is critical when discussing treatment options for patients undergoing endoscopic endonasal skull base surgery (EESBS) for cancers at the base of the skull. Several questionnaires have been developed and validated in the last 20 years to explore QOL in this patient population, including the Anterior Skull Base Questionnaire, Skull Base Inventory, EESBS Questionnaire, and the Sino-Nasal Outcome Test for Neurosurgery. The Sino-Nasal Outcomes Test-22 and Anterior Skull Base Nasal Inventory-12 are other tools that have been used to measure sinonasal QOL in anterior cranial base surgery. In addition to pathology-related perturbations in QOL endoscopic surgical options (transsellar approaches, anterior cranial base surgery, and various reconstructive techniques) all have unique morbidities and QOL implications that should be considered. Finally, we look ahead to new and emerging techniques and tools aimed to help preserve and improve QOL for patients with anterior cranial base malignancies.

Endoscopic Endonasal Skull Base Surgery Complication Avoidance: A Contemporary Review

The endoscopic endonasal approach (EEA) provides a direct trajectory to ventral skull base lesions, avoidance of brain retraction, and clear visualization of cranial nerves as they exit skull base foramina. Despite these benefits, the EEA is not without complications. Here, we review published literature highlighting complications associated with the EEA including cerebrospinal fluid (CSF) leak, cranial nerve (CN) dysfunction, pituitary gland dysfunction, internal carotid artery (ICA) injury, infection, and others; we place special emphasis on discussing the prevention of these complications. As widespread adoption of the EEA continues, it becomes critical to educate surgeons regarding potential complications and their prevention while identifying gaps in the current literature to guide future research and advances in clinical care.

Olfactory Outcomes After Middle Turbinate Resection in Endoscopic Transsphenoidal Surgery: A Prospective Randomized Study

OBJECTIVE

Endoscopic endonasal transsphenoidal surgery is safe and effective for sellar and parasellar tumor removal. Partial middle turbinate (MT) resection is sometimes performed to optimize the surgical field and facilitate postoperative care. Disturbances in olfaction are concerning because of the lack of randomized studies in this field.

STUDY DESIGN

Prospective randomized trial.

SETTING

Single academic medical center.

METHODS

We resected the lower halves of bilateral MTs in the resected group and laterally fractured bilateral MTs in the preserved group. Olfactory outcomes and sinonasal conditions were assessed by using the validated Taiwan Smell Identification Test and Lund-Kennedy Endoscopy Score, respectively. Forty-nine patients were enrolled in the final analysis, of whom 23 underwent partial MT resection.

RESULTS

The average Taiwan Smell Identification Test result was 36.9 one month after surgery, with a significant change of -4.4 ± 3.1 (mean ± SD; P < .01) from baseline. The impact was not significant at 3 months (-2.1 ± 2.6, P = .13) or 6 months (0.3 ± 2.0, P = .79). Between the MT resection and preservation groups, there were no significant differences at postoperative 1 month (P = .60), 3 months (P = .86), and 6 months (P > .99). Lund-Kennedy Endoscopy Score was still higher at 3 months (P = .006) after surgery but returned to the preoperative level at 6 months (P = .63).

CONCLUSIONS

Endoscopic endonasal transsphenoidal surgery may affect olfaction at 1 month after surgery, and olfactory function is expected to return after 3 months. Partial MT resection did not result in additional olfactory loss. It is safe to perform partial MT resection during surgery without compromising the olfactory outcomes.

Skull Base Registries: A Roadmap

Hospitals, payors, and patients increasingly expect us to report our outcomes in more detail and to justify our treatment decisions and costs. Although there are many stakeholders in surgical outcomes, physicians must take the lead role in defining how outcomes are assessed. Skull base lesions interact with surrounding anatomy to produce a complex spectrum of presentations and surgical challenges, requiring a wide variety of surgical approaches. Moreover, many skull base lesions are relatively rare. These factors and others often preclude the use of prospective randomized clinical trials, thus necessitating alternate methods of scientific inquiry. In this paper, we propose a roadmap for implementing a skull base registry, along with expected benefits and challenges.

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.

Mayo Clinic Clival Chordoma Case Series: Impact of Endoscopic Training on Clinical Care

The management of clival chordoma in our group shifted around 2013 to mostly endoscopic, and proton beam was introduced for our multidisciplinary team. Consecutive patients who had surgical resection from 1987 to 2021 were reviewed. A total of 58 patients (39 patients after 2013) were analyzed. The mean tumor size was 3.7 cm, and the most common location was the upper clivus (43%). Compared to before 2013, after 2013, the endoscopic endonasal approach was more common (90%, p < 0.001), and more gross or near total resections (64%, p = 0.002) were attained. Ten cases (17%) were revision surgeries referred from elsewhere, and three cases (5%) underwent additional surgery elsewhere before adjuvant radiation. The postoperative cerebrospinal fluid leak occurred in 7%. Post-operative new cranial nerve deficits occurred in 32% before 2013, compared to 2.6% after 2013 (p = 0.004). For cases before 2013, 10 patients (53%) recurred during the median follow-up of 144 months (mean, 142 months), whereas for cases after 2013, seven patients (18%) recurred with a median follow-up of 35 months (mean, 42 months). 5-year progression-free survival was 58%, and 5-year overall survival was 87%. A specialized multidisciplinary team improved the resection rate compared to a historical cohort with an excellent morbidity profile.

Improved nasal recovery and intact olfactory function after a transseptal approach for endoscopic endonasal transsphenoidal adenomectomy: A retrospective analysis

Objectives

Endoscopic endonasal transsphenoidal adenomectomy (TSA) is the most frequently performed skull base surgery, and researchers have recently focused on preserving nasal function. The endoscopic transseptal approach is a promising procedure due to its reduced injury to the nasal mucosa; however, there are no studies comparing rhinological and neurosurgical outcomes concurrently with the standard endoscopic transnasal approach. Therefore, we conducted this study to investigate whether the transseptal approach could reduce nasal morbidities with comparable neurosurgical outcomes.

Methods

We retrospectively reviewed 25 patients who underwent endoscopic endonasal transseptal TSA for pituitary adenoma without encasement of internal carotid artery from January 2019 to December 2020. Another 25 patients who received transnasal approach from January 2017 to December 2018 were selected as controls. Patients with diseases affecting the nasal cavity/olfaction or usage of a nasoseptal flap were excluded for a better comparison of the two procedures. We collected data from radiological studies, endocrine studies, endoscopic evaluations, 22-item sinonasal outcome tests (SNOT-22) and Top International Biotech Smell Identification Test (TIBSIT) for comparison.

Results

Lower postoperative SNOT-22 and Lund-Kennedy endoscopic scores were observed in the transseptal group. The effect size of differences were classified as large effect (The absolute value of Cohen's d > 0.8). Nevertheless, the TIBSIT scores were not significantly different. The rates of gross total resection, recovery of hormonal abnormalities, and complications were not significantly different. After controlling possible confounding factors using multivariate analysis, the endoscopic transseptal approach remained an independent factor for lower SNOT-22 scores and Lund-Kennedy endoscopic scores.

Conclusions

The endoscopic transseptal approach provides improved recovery of nasal mucosa and intact olfaction without compromising neurosurgical outcomes.

Level of Evidence

2b.

Olfactory Outcomes after Resection of Tuberculum Sella and Planum Sphenoidale Meningiomas via a Transcranial Approach

Objectives Controversy exists surrounding the optimal approaches to tuberculum sella meningioma (TSM) and planum meningioma (PM). Olfaction is infrequently considered within this context but is nonetheless an important quality of life measure. The evolution of olfactory outcomes following contemporary transcranial surgery remains unclear. This study reviews olfactory outcomes after supraorbital craniotomy for TSM or PM and defines temporal trends in its recovery.

Study Design A prospective study of a patients who underwent a minimally invasive supraorbital craniotomy for TSM or PM was conducted at a single neurosurgical center.

Participants & Main Outcome Measures All patients were questioned about olfaction at presentation 3 months postoperatively, 12 months postoperatively, and annually thereafter (median follow-up = 37 months). The olfactory status of patients was categorized as normosmia, anosmia, hyposmia, parosmia, (altered perception of odours), or phantosmia, (olfactory hallucinations).

Results Twenty-two patients were included in the study analysis, (range = 27–76). Precisely, 3 months after surgery, seven patients had normal olfaction (32%). Six patients were anosmic, (27%) four hyposmic, (18%), three parosmic, (14%), and two were phantosmic (9%). At 1-year follow-up, almost half of patients (10; 48%) were normosmic, while two patients (9.5%) were anosmic. There were no further improvements in olfaction between 1 year and long-term follow-up.

Conclusion Subfrontal transcranial approaches for TSM or PM appear to be associated with changes in olfaction that can improve with time; these improvements occur within the first year after surgery. Impacts upon olfaction should be considered when selecting a surgical approach and patients counseled appropriately.

The Posterior Septal Nasal Floor Mucosal Flap for Cranial Base Reconstruction

OBJECTIVE

While pedicled intranasal flaps, such as the nasoseptal flap (NSF), successfully reduce postoperative CSF leaks following endoscopic endonasal approaches (EEA) to the skull base, morbidity remains prevalent. This study describes the first cadaveric description and radiographic analysis of the posterior septal nasal floor mucosal flap (PSNF) designed to reduce pedicled nasal flap morbidity. A case series is also detailed.

STUDY DESIGN

Cadaveric dissection, radiographic analysis, and case series.

METHODS

Seven cadaver specimens underwent harvest of the PSNF. PSNF flap dimensions were measured on the thirty deidentified sinus computed tomography (CT) scans. A retrospective case series was performed on the first set of patients who received the PSNF for reconstruction of a sellar base defect. Information concerning complications, symptoms, and the appearance of the flap was recorded from records of the patient's postoperative inpatient stay, 1-week postop visit, and 1-month postop visit.

RESULTS

Cadaver dissection of the PSNF flap demonstrated good arc rotation along its pedicle with ability to cover both sellar and planum defects. Cadaveric flap measurements and CT-derived measurements estimated a mean surface area of 16.7 and 18.3 cm² , respectively. 15 patients underwent reconstruction of a sellar or planum defect using the PSNF technique. Only one CSF leak was encountered postoperatively. Minimal crusting of the flap and donor site was seen 1 month postoperatively.

CONCLUSION

The PSNF flap provides a sizeable pedicled region for reconstruction comparable to other pedicled nasal flaps. Our case series demonstrated good postoperative outcomes without reduced donor site morbidity.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

A Modified Microscopic-Endoscopic Bilateral Transseptal Approach for Pituitary Adenomas: Comparisons of Nasal Outcome and Quality of Life Using the Microscopic Transnasal Approach

OBJECTIVES

In this study, we introduced a novel modified microscopic-endoscopic bilateral transseptal approach for pituitary adenoma resection to minimize surgery-related nasal injury. We also retrospectively compared comprehensive nasal outcomes and quality of life between the microscopic transnasal approaches.

METHODS

Patients with pituitary adenomas who underwent modified microscopic-endoscopic bilateral transseptal or microscopic transnasal approaches were assessed for olfactory function and quality of life using the Sniffin' Sticks test, the Sino-Nasal Outcome Test-22 (SNOT-22), the SF-36, the anterior skull base (ASK) nasal inventory, and the subjective visual analog scale (VAS) before and 1 and 3 months after surgery. A nasal endoscopy procedure was also performed to evaluate structure abnormalities at 1 and 3 months after surgery.

RESULTS

Fifty-eight patients who underwent either modified microscopic-endoscopic bilateral transseptal (35 patients) or microscopic transnasal (23 patients) surgery were consecutively enrolled. Patients who underwent either transnasal approach experienced similar surgical complications, except for intraoperative cerebrospinal fluid leakage (43.5% vs 14.3% for modified microscopic-endoscopic bilateral transseptal or microscopic transnasal approach, respectively; p = 0.013). Patients who underwent the two approaches fully recovered according to the SF-36, SNOT-22, VAS, and Sniffin' Sticks surveys, but not ASK scores, 3 months post-operatively. There was no significant difference in nasal endoscopy outcome at 3 months follow-up between the two approaches.

CONCLUSIONS

The modified microscopic-endoscopic bilateral transseptal approach showed largely similar nasal mucosa protective outcomes to those of the microscopic transnasal approach for pituitary adenoma surgery. After pituitary adenoma resection using the modified approach, patients' postoperative olfactory function, nasal structure, and quality of life can be restored to preoperative status within 3 months.

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.

Aging-related olfactory loss is associated with olfactory stem cell transcriptional alterations in humans

BACKGROUNDPresbyosmia, or aging-related olfactory loss, occurs in a majority of humans over age 65 years, yet remains poorly understood, with no specific treatment options. The olfactory epithelium (OE) is the peripheral organ for olfaction and is subject to acquired damage, suggesting a likely site of pathology in aging. Adult stem cells reconstitute the neuroepithelium in response to cell loss under normal conditions. In aged OE, patches of respiratory-like metaplasia have been observed histologically, consistent with a failure in normal neuroepithelial homeostasis.MethodsAccordingly, we have focused on identifying cellular and molecular changes in presbyosmic OE. The study combined psychophysical testing with olfactory mucosa biopsy analysis, single-cell RNA-Sequencing (scRNA-Seq), and culture studies.ResultsWe identified evidence for inflammation-associated changes in the OE stem cells of presbyosmic patients. The presbyosmic basal stem cells exhibited increased expression of genes involved in response to cytokines or stress or the regulation of proliferation and differentiation. Using a culture model, we found that cytokine exposure drove increased TP63, a transcription factor acting to prevent OE stem cell differentiation.ConclusionsOur data suggest aging-related inflammatory changes in OE stem cells may contribute to presbyosmia via the disruption of normal epithelial homeostasis. OE stem cells may represent a therapeutic target for restoration of olfaction.FundingNIH grants DC018371, NS121067, DC016224; Office of Physician-Scientist Development, Burroughs-Wellcome Fund Research Fellowship for Medical Students Award, Duke University School of Medicine.

Surgical complications of endoscopic approach to skull base: analysis of 584 consecutive patients

PURPOSE

Endoscopic techniques have been widely applied for challenging cranial base surgeries in recent years. In this study, we evaluated the safety and efficacy of using the endoscopic endo-nasal route for various skull base pathologies in terms of postoperative complications.

METHODS

A total of 584 consecutive patients who underwent endoscopic skull base surgery were studied. Peri- and post-operative complications and risk factors affecting the occurrence of these complications were evaluated.

RESULTS

648 endoscopic skull base surgical procedures were performed on 584 patients (47.8% females and 52.2% males) with the mean age of 41.2 years. Pituitary adenoma (69.3%) was the most common pathology. Post-operative mortality was 2.0%. The rates of post-operative permanent neurological deficit (one case of 6th nerve injury, two 12th nerve injuries and one hemiparesis) and visual deterioration were 0.6% and 1.5%, respectively. Ten patients (1.7%) were complicated with meningitis and it was the cause of death in 3. Systemic complications not directly attributable to skull base surgical access occurred in 2% (11 patients) with 5 mortalities. The rate of intra-operative vascular injury was 1% and among them one patient died due to PCA injury. The most common post-operative complications were diabetes insipidus (12.5%), anterior pituitary dysfunction (10.6%) and CSF leak (3.6%), respectively. In general, reoperation, malignant lesions, and level IV of surgical complexity were associated with a higher incidence of complications.

CONCLUSION

Endoscopic endo-nasal approach can be a safe and less-morbid first-line treatment of patients with various skull base lesions.

Systematic Review of Olfactory Outcomes After Nasoseptal Flap Harvest for Endoscopic Skull Base Surgery: Does Using Cold Steel or Olfactory Strip Preservation Matter?

BACKGROUND

Several studies have described techniques aimed at mitigating olfactory dysfunction after nasoseptal flap (NSF) harvest for endoscopic skull base surgery (ESBS). No consensus exists as to whether popular methods including using cold-steel (CS) versus electrocautery (EC) or septal olfactory strip (SOS) preservation offer an advantage. This systematic review was performed to examine the impact of these two technical variations of NSF harvest on postoperative olfactory outcomes.

METHODS

Following PRISMA guidelines, Pubmed, Scopus, and Web of Science were searched for articles reporting olfactory outcomes in ESBS cases employing a NSF. Original articles focusing on technique variations of the NSF and reporting at least 1 objective olfactory measure were included.

RESULTS

Nine studies comprising 610 patients were included. Various, olfactory testing outcomes were reported, and post-op follow-up ranged from 6 weeks to 12 months. Three studies, including a randomized-controlled trial, compared the use of CS and EC for the superior incision of the NSF. No significant difference was found in objective olfactory function (p>0.05) when comparing these techniques. Five studies comprising 504 patients reported results from SOS sparing. SOS sparing technique in NSF harvest demonstrated smell preservation in the post-op setting when compared to pre-op measures (p>0.05), however, no direct comparison to non-SOS sparing techniques was made.

CONCLUSION

Use of CS as opposed to EC for the superior NSF incision does not appear to confer an advantage in preserving post-op olfactory function (grade B evidence). SOS preservation may be associated with better olfactory outcomes in NSF harvest (grade C evidence). This article is protected by copyright. All rights reserved.

Olfactory-Specific Quality of Life Outcomes after Endoscopic Endonasal Surgery of the Sella

Objective

To assess olfactory outcomes as measured by an olfactory-specific quality of life (QOL) questionnaire in patients undergoing EESBS for sellar lesions.

Design

Retrospective case series.

Setting

Tertiary academic medical center.

Participants

In total, 36 patients undergoing EESBS for lesions limited to the sella were evaluated.

Main Outcome Measures

The following were performed before and three months after surgery: 22-Item Sinonasal Outcomes Test (SNOT-22), University of Pennsylvania Smell Identification Test (UPSIT), and the Assessment of Self-reported Olfactory Functioning (ASOF), which has three domains: subjective olfactory capability scale (SOC), smell-related problems (SRP), and olfactory-related quality of life (ORQ).

Results

Median age at surgery was 52.5 years, with a median tumor size of 1.8 cm (range: 0.2 to 3.9 cm). Pre- and postoperative median scores were 35 [34, 36.2] and 34.5 [32, 36] for UPSIT, 21 [7.5, 33.5] and 21.5 [6.8, 35.7] for SNOT-22, 10 [9, 10] and 9 [8, 10] for ASOF-SOC, 5 [4.8, 5] and 4.5 [4, 5] for ASOF-SRP, and 5 [5, 5] and 5 [4.5, 5] for ASOF-ORQ. There was no significant change in the two of the three domains of the ASOF. Correlation between ASOF and UPSIT scores were weak. Older age and larger tumor size were associated with worsened olfaction after surgery.

Conclusions

Patients did not experience significant changes in olfactory-specific QOL three months after EESBS, as measured by two domains of the ASOF. The ASOF may serve as a useful adjunctive tool for assessing olfaction after surgery. The lack of correlation between UPSIT and ASOF suggests the need for more research in subjective olfactory-related quality of life after surgery.

Impact of Routine Endoscopic Skull Base Surgery on Subjective Olfaction and Gustation Outcomes

BACKGROUND

As endoscopic endonasal skull base surgery (EESBS) for sellar pathology has become routine, there is increasing awareness of quality-of-life (QOL) outcomes related to this approach. Similarly, there is a growing interest in postoperative chemosensory function, with notable emphasis on olfaction and the corresponding psychosocial implications of olfactory dysfunction. Meanwhile, there has been minimal direct investigation into gustatory outcomes, and the association between these 2 chemosensory functions remains poorly understood.

OBJECTIVE

To investigate patient-reported chemosensory function and rhinologic-specific QOL following EESBS for routine sellar pathologies.

METHODS

Comprehensive clinical characteristics and sinonasal QOL assessments, measured using Anterior Skull Base Nasal Inventory-12 (ASK Nasal-12), were collected from 46 patients undergoing EESBS for sellar pathology.

RESULTS

Forty-six patients were included: 65.2% female, average age 52.8 yr (range: 27-89). The most common pathology was nonfunctioning pituitary adenoma (n = 28). Preoperative ASK Nasal-12 scores (mean = 0.81) demonstrated postoperative worsening at 2 wk (mean = 2.52, P < .0001) and 1 mo (mean = 1.33, P = .0031), with no difference at 3 mo postoperatively (mean = 0.89, P = .92). Meanwhile, there was significant worsening of preoperative subjective smell (mean = 0.62) and taste function (mean = 0.42) at 2 wk (mean = 3.48, P < .0001; mean = 2.69, P < .0001) and 1 mo (mean = 2.40, P < .0001; mean = 2.03, P < .0001) postoperatively, which persisted at approximately 3 mo postoperatively (mean = 1.26, P = .04; mean = 1.15, P = .0059).

CONCLUSION

Patients undergoing EESBS for sellar pathologies experience anticipated, temporary disruptions in sinonasal QOL but may have longer lasting perturbations in subjective olfaction and gustation. Given the increasing use of the endoscopic endonasal corridor, further investigation in postoperative chemosensory function is essential.

Superior turbinate management and olfactory outcome after endoscopic endonasal transsphenoidal surgery for pituitary adenoma: a propensity score-matched cohort study

Background

Surgical management of the superior turbinate (ST) is required to access the sella in endoscopic endonasal transsphenoidal surgery (EETS) for pituitary adenoma. Two common ST management techniques include partial resection of the ST (PRST) and intentional lateralization of the ST (ILST). Given the concentrated distribution of the olfactory nerve fibers on the medial surface of the ST, in this study we aimed to ascertain whether PRST worsens the objective olfactory outcome when compared with ILST.

Methods

A retrospective, propensity score‒matched cohort study was performed at a tertiary referral center. A total of 232 adult patients undergoing EETS for pituitary adenoma were analyzed. The threshold test (STT) and the 12‐item identification test (SIT‐12) from “Sniffin’ Sticks” were administered for separate nostrils preoperatively and 6 months postoperatively.

Results

Of 232 patients, 109 had right‐sided PRST and 123 received right‐sided ILST. Propensity score matching—controlling for olfactory‐related confounding factors, including gender, age, medical comorbidities, surgical technique, and preoperative olfaction—resulted in 74 matched pairs. When comparing the 6‐month postoperative olfactory performance of the right nostril, the STT score was significantly lower in the PRST group than the ILST group (p = 0.036, η² for effect size estimate = 0.030), but the SIT‐12 scores were similar in the 2 groups (p = 0.325). Overall, the olfactory outcomes for the right nostril did not qualitatively differ between the PRST and ILST groups (p = 0.401).

Conclusion

Despite its association with threshold impairment, PRST in EETS does not seem to carry an additional risk of postoperative olfactory dysfunction.

Relationship Between the Bilateral Removal of the Middle Nasal Turbinate and the Olfactory Function in Endoscopic Skull Base Surgery

OBJECTIVE

To determine the impact of endonasal endoscopic access to the skull base on the olfaction sense, involving the harvest of a nasoseptal flap, with the removal of the middle nasal turbinate.

METHODS

A study was performed on a prospective cohort of 50 patients who underwent transnasal endoscopic surgery of the anterior skull base, with the harvest of a nasoseptal and reverse flap. The patients were divided into 2 groups: partial unilateral removal of the middle nasal turbinate and bilateral removal. Connecticut Chemosensory Clinical Research Center tests were administered before surgery and in months 1, 3, and 6 after surgery.

RESULTS

There was no difference in the olfactory sense, when comparing the partial removal of the middle nasal turbinate and the bilateral removal, as well as when comparing the side without the middle nasal turbinate and the side with this structure preserved. There was a worsening in olfaction (P < 0.001) in months 1 and 3 after surgery, returning to baseline in month 6 (P > 0.05).

CONCLUSIONS

Bilateral removal of the middle nasal turbinate, compared with unilateral resection, showed no impact on the olfactory function 6 months after surgery. In both groups, there was a transitory decrease in the first month, but this normalized by the sixth postoperative month.

Risk Factors for Patient-Reported Olfactory Dysfunction After Endoscopic Transsphenoidal Hypophysectomy

Importance

Iatrogenic olfactory dysfunction after endoscopic transsphenoidal hypophysectomy (ETSH) is an overlooked complication without elucidated risk factors.

Objective

To assess the independent prognostic role of demographic, comorbidity, cephalometric, intraoperative, histological, and postoperative parameters in patient-reported postoperative olfactory dysfunction, and to explore the association between anatomical measurements of the skull base and sinonasal cavity and postoperative olfactory dysfunction.

Design, Setting, and Participants

This retrospective cohort study in a tertiary care medical center enrolled consecutive patients with primary sellar lesions who underwent ETSH between January 1, 2015, and January 31, 2019. Patients were excluded if they underwent multiple sinonasal surgical procedures, presented with a sellar malignant neoplasm, required an expanded transsphenoidal approach, had nasal polyposis or a neurodegenerative disease, or sustained traumatic brain injury. After undergoing medical record review and telephone screening, patients were asked to participate in a 3-item telephone survey.

Main Outcomes and Measures

The primary outcome was the Clinical Global Impressions change in smell rating, a validated transitional patient-reported outcome measure. Patients rated their change in smell before and after ETSH on a 7-point Likert scale, with the following response options: (1) much better, (2) somewhat better, (3) slightly better, (4) neither better nor worse, (5) slightly worse, (6) somewhat worse, or (7) much worse. Responses of slightly worse, somewhat worse, and much worse were surrogates for postoperative olfactory dysfunction status. Patient medical records, preoperative imaging scans, operative notes, and pathology reports were reviewed.

Results

Of the 147 patients (mean [SD] age, 54 [15] years; 79 women [54%]) who responded to the telephone survey, 42 (29%) reported olfactory dysfunction after ETSH. Median (interquartile range [IQR]) time between the ETSH completion and survey response was 31.1 (21-43) months. On multivariable analysis, abdominal fat grafting (adjusted relative risk [aRR], 2.95; 95% CI, 1.89-4.60) was associated with postoperative olfactory dysfunction, whereas smoking history (aRR, 1.54; 95% CI, 0.95-2.51) demonstrated a clinically meaningful but imprecise effect size. A more obtuse angle between the planum sphenoidale and face of the sella turcica on sagittal imaging was protective (aRR, 0.98; 95% CI, 0.96-0.99). Increased number of months after the ETSH was associated with patient-reported normosmia (aRR, 0.93; 95% CI, 0.91-0.95). In contrast, other comorbidities; intraoperative variables such as turbinate resection, nasoseptal flap, and mucosal or bone grafting; histological variables such as pathology and proliferative index; and postoperative variables such as adjuvant radiotherapy were not associated with postoperative olfactory dysfunction.

Conclusions and Relevance

This study found that abdominal fat grafting, acute skull base angle, and smoking history appeared to be clinically significant risk factors for patient-reported postoperative olfactory dysfunction. Increased time after ETSH may be associated with better olfactory outcomes.

Postoperative management of patients with pituitary tumors submitted to pituitary surgery. Experience of a Spanish Pituitary Tumor Center of Excellence

There is a lack of evidence on timing, frequency, and duration of postoperative endocrine, radiologic, and ophthalmologic assessments that should be performed after pituitary surgery (PS). However, it is known that careful optimization of treatment and follow-up strategies as well as a multidisciplinary approach may have a significant impact on long-term outcomes, improving surgical results, minimize complications and facilitate their correct treatment if occurring, and optimize the hormonal, ophthalmological, and radiological reassessment throughout the follow-up. Considering that there are no specific guidelines on the postoperative management of patients with pituitary tumors (PT), we present our protocol for the postoperative management of patients with PT. It has been elaborated by the multidisciplinary team of a Spanish Pituitary Tumor Center of Excellence (PTCE) that includes at least one neurosurgeon, ENT, neuroradiologist, neuro-ophthalmologist, endocrine pathologist and endocrinologist specialized in pituitary diseases. We elaborated this guideline with the aim of sharing our experience with other centers involved in the management of PT thereby facilitating the postoperative management of patients submitted to PS.

Effect of endoscopic endonasal skull base surgery on snoring

BACKGROUND

As the number of endoscopic skull base surgeries has increased, postoperative changes in quality of life require attention, including evaluation of whether snoring symptoms change.

OBJECTIVE

To investigate the effect of endoscopic endonasal skull base surgery on snoring and nasal symptom scores.

METHODS

Between February 2009 and September 2018, 510 patients underwent skull base tumor resection via an endoscopic endonasal approach and were included in this study. Nasal symptoms were scored using the Nasal Obstruction Symptoms Evaluation (NOSE) scale and snoring symptoms were subjectively scored from 0 to 10 by partners using a visual analog scale (VAS). Computational fluid dynamics (CFD) was employed for pilot patient analysis.

RESULTS

A pituitary adenoma was the most common surgical pathology encountered over the past 10 years (81.6% of all tumors). The NOSE scores increased significantly after surgery (pre-surgery, 3.28 ± 3.18; post-surgery, 4.09 ± 3.61; P < .001). The snoring VAS score decreased significantly postoperatively (pre-surgery, 2.91 ± 2.74; post-surgery, 2.43 ± 2.45; P < .001). A positive correlation was apparent between the NOSE and snoring score changes (r = 0.374; P < .001).

CONCLUSIONS

Snoring improved after endoscopic endonasal skull base surgery, associated with changes in nasal symptoms.

LEVEL OF EVIDENCE

4.

Evaluation of olfactory function in patients undergoing endoscopic skull base surgery with nasoseptal flap

Introduction

Endoscopic transnasal access to the skull base, both for treatment and reconstruction, can cause olfactory morbidity. Knowing the main consequences of this intervention is essential to have objective criteria for decision-making regarding the appropriate surgical technique.

Objectives

The aim of this study is to determine the impact on olfactory function of the endonasal endoscopic access to the skull base with the creation of the nasoseptal flap.

Methods

A prospective research was carried out in which 22 patients who underwent endoscopic transnasal surgery at the skull base, with the creation of a nasoseptal flap. The Connecticut Chemosensory Clinical Research Center test was applied before and at the 1^st, 3^rd and 6^th postoperative months.

Results

The results showed that only in the first month of follow-up the mean patient classification was statistically worse than at the other evaluation moments (p < 0.05), but there was no mean difference in the Connecticut score classification between the other moments (p > 0.05); that is, patients showed worsening in the 1^st month and returned to the preoperative mean after the 3^rd month of follow-up.

Conclusion

The present study showed that the postoperative decrease in olfaction is transient, since the patient's sense of smell returns to pre-surgical values in the 3^rd postoperative month.

A Comparison of Olfactory and Sinonasal Outcomes in Endoscopic Pituitary Surgery Performed by a Single Neurosurgeon or a Collaborative Team of Surgeons

OBJECTIVES

Endoscopic pituitary surgery usually requires a collaboration between neurosurgeons and ENT surgeons to achieve optimal outcomes. However, neurosurgeons occasionally perform these procedures alone without an ENT surgeon. In this study, postoperative sinonasal quality of life and olfactory function were compared in patients who underwent endoscopic pituitary surgery performed by a single neurosurgeon or by a collaborative team of a neurosurgeon and an ENT surgeon.

METHODS

A retrospective review of prospectively collected data was performed. Patients who underwent endoscopic pituitary surgery for pituitary adenoma from January 2015 to April 2018 were included. The study patients were divided into two groups; patients in group 1 underwent surgery performed by a single neurosurgeon, while patients in group 2 received surgery performed by a collaborative team of surgeons. Olfaction was assessed using a subjective Likert scale, the Cross-Cultural Smell Identification Test (CC-SIT), and the butanol threshold test (BTT). In addition, patients answered the Sino-nasal Outcome Test (SNOT-22) questionnaire regarding sinonasal quality of life before and 3 months after surgery.

RESULTS

This study included 152 patients (46 patients in group 1 and 106 patients in group 2). Significant differences were not observed between the two groups regarding age, sex, tumor size, or operation time. Although subjective olfaction was not significantly different before and after surgery, group 2 showed significantly better objective olfactory function based on the CC-SIT (8.44±3.00 vs. 9.84±1.40; P=0.012) and BTT (4.67±0.84 vs. 5.02±0.33; P=0.022) scores at 3 months after surgery. The SNOT-22 scores were not statistically significantly different between the two groups (P>0.05).

CONCLUSION

In the present study, better olfactory outcomes were observed in patients who underwent surgery performed by a collaborative team of a neurosurgeon and an ENT surgeon. This result shows the need for collaboration between neurosurgeons and ENT surgeons in endoscopic pituitary surgery.