Can Tumor Size Be a Predictive Factor of Olfactory Dysfunction After Endoscopic Endonasal Trans-Sphenoidal Approach?

Effect of endoscopic endonasal skull base approaches on olfactory function and facial development in children

INTRODUCTION

Endoscopic approaches for skull base pathologies are increasingly being performed, and the subsequent complications, especially in the long term, have also been partially clarified. However, there is no information on the effects of endoscopic endonasal skull base surgeries (EESBS) in children on odor and facial development in parallel with long-term development. We conducted this study to investigate postoperative olfactory function and facial development in pediatric patients who underwent skull base surgery using the endoscopic endonasal method.

METHODS

We evaluated the smell test, sinonasal symptoms, and facial development of pediatric patients who underwent endoscopic endonasal skull base surgery after long-term follow-up. Odor was evaluated using the "Sniffin' Sticks" test kit, which assessed the T (odor threshold), D (odor discrimination), and I (odor identification) parameters. Sinonasal symptoms were evaluated using the SNOT-22 (sinus-nose outcome test) questionnaire. SNA (sella-nasion-A point), SNB (sella-nasion-B point), and ANB (A point-nasion-B point) angles were calculated from maxillofacial tomography and magnetic resonance imaging) to evaluate facial development. Data were compared with those of the healthy control group.

RESULTS

We included 30 patients comprising 19 (63.3%) boys and 11 (36.7%) girls, with no age difference between case and control groups. The mean follow-up period was 7 years. Odor test data, cephalometric measurements, and SNOT-22 analysis results showed no statistically significant differences between the two groups.

CONCLUSION

To our knowledge, this is a comprehensive study with the longest follow-up period in terms of evaluation of facial development after EESBS in children to analyze odor using the Sniffin' Sticks test kit and the quality of life using SNOT-22. Olfactory function, facial development, and quality of life remained unaffected after long-term follow-up after EESBS  in children. Although this surgical approach is minimally invasive, we recommend considering the possibility of complications, and the procedure should be performed by an experienced surgical team with adequate equipment.

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.

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.

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.

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.

Olfactory outcomes after endonasal skull base surgery: a systematic review

For the last two decades, endonasal approach has been regularly applied to treat skull base lesions. However, postoperative olfactory dysfunction remains an unsolved problem. This systematic review aimed to identify factors that might affect postoperative olfactory prognosis of patients undergoing endonasal surgery for resection of sellar/parasellar lesions. The literature search was conducted comprehensively to exhaust studies which focused on patients' olfaction with objective olfactory assessments after endonasal skull base surgery. We sought to characterize the potential factors that might affect postoperative olfactory outcomes. Nineteen articles met inclusion criteria. We found that (1) endoscopic surgery was beneficial to patients' olfactory prognosis than microscopic surgery (incidence of postoperative decreased olfactory function: 18.48% (39/211) for the endoscopic group and 36.88% (52/141) for the microscopic group, P < 0.01); meta-analysis for single rate, 20% (95% CI 9-30%) for the endoscopic group and 35% (95% CI 0-72%) for the microscopic group); (2) harvesting septal flaps was an unfavorable factor for olfactory recovery and the rescue flap technique should be preferred compared with the HB flap; (3) no evidence showed that resection of the middle turbinate was detrimental to recovery of olfaction. Patients undergoing endoscopic endonasal surgery may have better olfactory outcomes than those undergoing microscopic endonasal surgery for resection of sellar/parasellar lesions. Special attention should be paid when using septal flaps is planned and the rescue flap technique should be the preferred choice. After resecting the middle turbinate, patients' olfaction still has a great chance of returning to the baseline. More homogeneous and high-quality studies are needed for further assessment.

Olfaction in Juvenile Nasopharyngeal Angiofibroma: The first study

BACKGROUND

To study the pattern of olfactory dysfunction/recovery in juvenile nasopharyngeal angiofibroma (JNA).

METHODS

Olfactory assessment was undertaken in 30 patients (category1) both pre- & post-operatively and in another 18 (category 2) only postoperative. All patients underwent transpalatal excision and variables of interest included age, radiological stage/parameters & tumor size.

RESULTS

Objective olfactory dysfunction was seen in 60% while involvement of olfactory strip was suggested in 50%. Despite some marginal trends only noted between size/age with change of olfaction, Pearson's correlation test did not reveal any significance amongst multiple variables. However a better recovery of olfaction following surgery was evident in Category-2 where Chi-Square test (p < 0.05) significantly revealed this to be a function of postoperative duration. This regenerative course in JNA suggests an optimum period of 4 years for full recovery after surgery.

CONCLUSION

In this first study of olfaction in JNA many new trends have been appreciated. In general, deteriorations of olfaction were seen due to 'vascular-concussion' effect in early postoperative phase where post-surgical clearance of airway showed minimal effect in terms of improvement. The hypervascularity of olfactory epithelium with possible hormonal effects may be responsible for the unique pattern of olfactory function and recovery in JNA.

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.