Endoscopic Endonasal Transsphenoidal Approach From the Surgeon Point of View

Olfactory Function and Surgery of the Lateral Nasal Wall - Systematic Review

This study aimed to comprehend the influence of surgery on the lateral nasal wall, primarily focusing on the inferior turbinates, and its impact on olfactory function. A systematic review was carried out utilizing electronic databases like PubMed, Cochrane (including various registers and databases), and Web of Science. No restrictions were imposed on publication year or language. The PRISMA criteria guided study selection, and predefined inclusion and exclusion criteria were employed. Risk of bias assessment for randomized controlled trials (RCTs) utilized the "Revised Cochrane risk-of-bias tool for randomized trials (RoB 2)," while Hawker et al. scale evaluated the quality of non-RCT studies. The review encompassed nine studies after rigorous selection and bias assessment. All studies unanimously demonstrated improved olfactory function following surgery on the inferior turbinate. Different surgical techniques and olfactory assessment methods were employed across studies. Evaluation encompassed pre- and post-surgery olfactory measurements. Most studies employed the Visual Analogue Scale (VAS) and commercial smell test kits (like Sniffin' Stick Test). The Nasal Obstruction Symptom Evaluation (NOSE) scale was used in two studies, and the butanol threshold test in one. Olfactory improvement was measured through enhanced patient numbers or nasal cavities, often expressed via VAS scores. One study utilized both patient count and VAS scores. A few studies also employed NOSE scale and olfactory threshold measurements. All studies consistently concluded that olfactory function post-surgery was superior to preoperative measures. The collective evidence strongly suggests that surgery on inferior turbinates has a positive impact on olfactory function, as indicated by the studies reviewed. Nonetheless, for a comprehensive understanding of surgical efficacy, future research should incorporate randomized controlled trials featuring control groups. This would facilitate the establishment of optimal surgical techniques for specific indications and the formulation of practical guidelines.

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.

Sinonasal Outcomes of the Combined Transseptal/Transnasal Approach with Unilateral Nasoseptal Rescue Flap in Endoscopic Endonasal Transsphenoidal Surgery: A Propensity Score Matching Analysis

Objectives  The authors applied surgical techniques acquired during the use of endoscopic combined transseptal/transnasal approach to reduce approach-related morbidity and improve sinonasal outcomes. Study Design  This is a retrospective cohort study of a prospectively collected database. Setting  The study setting involves a tertiary referral center. Participants  A total of 86 patients who underwent endoscopic endonasal transsphenoidal surgery for newly diagnosed pituitary adenomas from April 2018 to March 2021 were included. Patients treated via the combined transseptal/transnasal approach served as the study group ( n  = 18); those treated via the bilateral transnasal approach comprised the control group ( n  = 68). From the control group, propensity score matching (PSM) analysis was further performed to account for potential confounders and selection bias. Main Outcome Measures  Paired analysis was performed for pre- and 6-month-postoperative time points in study group, control group, and PSM control group. Olfactory function was evaluated by Connecticut Chemosensory Clinical Research Center (CCCRC) test, Cross-Cultural Smell Identification Test (CCSIT), and sinonasal outcomes were assessed by Sino-Nasal Outcome Test-22 (SNOT-22). Results  In the study group, CCCRC ( p  = 0.517) and CCSIT ( p  = 0.497) did not show any significant difference before and after surgery. There was some improvement in the symptom score of SNOT-22, but it was not statistically significant ( p  = 0.115). In the control group adjusted with PSM, a significant decrease in olfaction ( p  = 0.047) was observed using CCCRC. The CCSIT score was also decreased but not significant ( p  = 0.163). Also, there was no difference in the improvement of SNOT-22 ( p  = 0.781). Conclusion  Our new surgical method preserves olfactory function without compromising surgical outcomes.

Venous thromboembolism chemical prophylaxis after endoscopic trans-sphenoidal pituitary surgery

PURPOSE

There is no compelling outcome data or clear guidance surrounding postoperative venous thromboembolism (VTE) prophylaxis using low molecular weight heparin (chemoprophylaxis) in patients undergoing pituitary surgery. Here we describe our experience of early chemoprophylaxis (post-operative day 1) following trans-sphenoidal pituitary surgery.

METHODS

Single-centre review of a prospective surgical database and VTE records. Adults undergoing first time trans-sphenoidal pituitary surgery were included (2009-2018). VTE was defined as either deep vein thrombosis and/or pulmonary embolism within 3 months of surgery. Postoperative haematomas were those associated with a clinical deterioration together with radiological evidence.

RESULTS

651 Patients included with a median age of 55 years (range 16-86 years). Most (99%) patients underwent trans-sphenoidal surgery using a standard endoscopic single nostril or bi-nostril trans-sphenoidal technique. More than three quarters had pituitary adenomas (n = 520, 80%). Postoperative chemoprophylaxis to prevent VTE was administered in 478 patients (73%). Chemoprophylaxis was initiated at a median of 1 day post-procedure (range 1-5 days postoperatively; 92% on postoperative day 1). Tinzaparin was used in 465/478 patients (97%) and enoxaparin was used in 14/478 (3%). There were no cases of VTE, even in 78 ACTH-dependent Cushing's disease patients. Six patients (1%) developed postoperative haematomas. Chemoprophylaxis was not associated with a significantly higher rate of postoperative haematoma formation (Fisher's Exact, p = 0.99) or epistaxis (Fisher's Exact, p > 0.99).

CONCLUSIONS

Chemoprophylaxis after trans-sphenoidal pituitary surgery on post-operative day 1 is a safe strategy to reduce the risk of VTE without significantly increasing the risk of postoperative bleeding events.

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.

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

BACKGROUND

Extended endoscopic transsphenoidal (EET) approaches can include complete resection of both superior turbinate (ST) for wider exposure. Moreover, ST resection has been associated with postoperative olfactory impairment.

OBJECTIVE

We sought to determine the impact of bilateral ST resection on olfaction during a transsphenoidal approach.

METHOD

A prospective observational study was conducted on 29 patients undergoing endoscopic skull base surgery sparing the olfactory tracts at a tertiary academic center. Olfactory function was measured with Sniffin' Sticks at the preoperative visit, 2-weeks and 6 to 8 weeks postoperatively. All components: odor threshold (OT), odor discrimination (OD), odor identification (OI) and composite scores (TDI = OT+OD+OI) were evaluated.

RESULT

Study was completed in 15 patients with 14 excluded due to a variety of reasons. At 2 weeks, a significant decrease was noted in composite scores (32.3 ± 5.4 vs. 23.8 ± 5.8, P < .05) and OT (7.7 vs. 3.2, P < .05). There was a significant increase in olfactory scores between post-op weeks 2 and 6 to 8 weeks in TDI (23.8 vs. 31.4, P < .05) as well as in OT (3.2 vs. 7.6, P < .05), OD (9.4 vs. 11.1, P < .05), and OI (11.1 vs. 12.7, P < .05). No significant difference was found between TDI (32.3 ± 5.4 vs. 31.4 ± 5.1), OT (7.7 vs. 7.6), OD (11.4 vs. 11.1) and OI (13.2 vs. 12.7) from preoperative and 6-8 weeks postoperative visits.

CONCLUSION

Patients undergoing bilateral ST resection during EET procedures experience transient hyposmia postoperatively. However, the olfactory function normalizes to preoperative levels at 6 to 8 weeks. The resection of the bilateral superior turbinate does not appear to decrease olfactory function.

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.

Olfactory Results of Endoscopic Endonasal Surgery for Pituitary Adenoma: A Prospective Study of 143 Patients

BACKGROUND

Clinical examination, including pre- and postoperative assessment of olfaction function, should be included in evaluating surgical outcomes in patients with pituitary adenomas. Most of the studies are lacking assessment of olfactory function.

METHODS

A prospective study of 143 patients who underwent surgical resection of pituitary adenomas from January 2014 to December 2017 was performed. Data on clinical presentation, pre- and postoperative neurologic, endocrinologic, and ophthalmologic examinations, complications, and follow-up outpatient examinations were recorded. Olfactory function was assessed using the Sniffin' Sticks odor identification test preoperatively, postoperatively (3 months), and 1 year after surgery.

RESULTS

Normosmia was present preoperatively in 93.7% of patients, postoperatively in 95.8% of patients, and in 95.1% 1 year postsurgery. Hyposmia was present preoperatively in 4.2% of patients, postoperatively in 2.1% of patients, and in 1.4% 1 year after surgery. Anosmia was present preoperatively in 2.1% of patients, postoperatively in 2.1% of patients, and in 3.5% 1 year after surgery. In patients with preoperative normosmia, postoperative hyposmia and anosmia were present in 1.5% of patients. There were no differences according to age, sex, size, or type of pituitary adenoma.

CONCLUSIONS

Assessment of olfactory function should be included in the analysis of pituitary adenoma surgery results. This prospective study showed low risk of olfaction deterioration if an endoscopic endonasal approach is used without any mucosal flaps for skull base reconstruction. Further studies that include objective olfaction assessment are warranted.

Olfactory function in patients after transsphenoidal surgery for pituitary adenomas-a short review

Olfaction is an important sensory input that obviously affects many daily activities. However, olfactory dysfunction (hyposmia and anosmia) leads to a pronounced decrease in quality of life. Surprisingly, little attention has been paid to olfactory changes after transsphenoidal surgery for pituitary tumors. In this review, we summarize current knowledge of the effects of transsphenoidal pituitary surgery on olfaction and compare different surgical techniques. Based on selected studies, the endoscopic approach, in comparison with the microscopic approach, seems to be superior in terms of preservation of olfactory function, although the quality of data from these studies is generally poor. The best results were observed when the endoscopic approach was used without harvesting of the nasoseptal flap.

The experience with transsphenoidal surgery and its importance to outcomes

PURPOSE

Surgical experience is considered paramount for excellent outcome of transsphenoidal surgery (TSS). However, objective data demonstrating the surgical success in relation to the experience of pituitary surgery units or individual experience of pituitary surgeons is sparse.

METHODS

Based on literature data, we have investigated the influence of experience with TSS for pituitary adenomas on endocrinological remission rates and on operative complications. The surgical experience was assessed by calculating the number of transsphenoidal operations per year.

RESULTS

For TSS of microprolactinomas, mean remission rates were 77% in centers with < 2 operations per year for microprolactinomas, 82% with 2-4 operations, 84% with 4-6 operations, and 91% with > 6 operations. A yearly experience with more than 10 initial operations for Cushing's disease (CD) warrants a remission rate exceeding 70%. Remission rates in CD exceeding 86% have only been reported for single surgeon series. Extraordinarily high complication rates were found in some series with < 25 yearly total operations for pituitary adenomas. Major vascular complications were less than 2% and revision rates for rhinorrhea usually < 2.5% in centers performing > 25 transsphenoidal operations per year.

CONCLUSIONS

We conclude that a center with experience of > 25 transsphenoidal operations for pituitary adenomas per year provides a high likelihood of safe TSS. Surgery for CD requires a particularly high level of practice to guarantee excellent remission rates. The endocrinologist has the unique opportunity to audit the surgical success by hormone measurement and to refer patients to neurosurgeons with proven excellence.

Evaluation of Olfactory Outcome After Frontolateral Approach for Treatment of Suprasellar Tumors

OBJECTIVE

We present the findings of our prospective study assessing olfactory function outcome in patients undergoing a frontolateral approach for the resection of suprasellar lesions.

METHODS

Eighteen consecutive patients (7 females, 11 males) surgically treated at our institute for suprasellar tumors were included in this prospective study. Olfactory function was evaluated at the admission and 14 days after the surgery using the standard 12-item "Sniffin' Sticks" screening (SSS) test. The olfactory outcome was correlated to the following variables: tumor type, size, consistency, and extent of vertical and lateral growth.

RESULTS

Preoperative and postoperative SSS test mean values were, respectively, 9.11 and 8.72 (not significant: P = 0.274). In only 1 case (5%), with larger suprasellar extension, the difference between preoperative and postoperative SSS was ≥3 (reduction of 5 points). At the subjective evaluation, no patient stated a deficit in smelling.

CONCLUSION

The frontolateral craniotomy is a minimally invasive route to treat suprasellar tumors and has a low approach-related morbidity. It allows tumor resection with low risk for the olfactory function. A risk factor for postoperative olfactory deficit could be significant brain retraction.