Nasoseptal Rescue Flap Research Articles

Application of a Novel Versatile Mini Posterior Nasoseptal Graft in Endoscopic Transsphenoidal Pituitary Adenoma Surgery.

Skull base reconstruction is a key technique in patients undergoing endoscopic transnasal skull base surgery. Although a pedicled nasoseptal flap (PNSF) is often used to repair large skull base defects with high-flow cerebrospinal fluid leakage, bone exposure of the donor site of the PNSF can result in long-term crusting. To design a novel and versatile mini posterior nasoseptal graft for the reconstruction of defects in the sellar floor or PNSF or pedicled nasoseptal rescue flap (PNSRF) donor site in patients undergoing pituitary adenoma surgery. Patients who underwent pituitary adenoma removal through an endoscopic endonasal approach and repair of a sellar defect or PNSF/PNSRF donor site using the mini posterior nasoseptal graft technique from January 2019 to January 2020 were retrospectively evaluated. Pituitary adenomas were removed using a binostril 4-hand technique through a transnasal transsphenoidal transsellar approach or an expanded transsellar approach. Mini posterior nasoseptal grafts were successfully used in 70 patients who underwent pituitary adenoma removal through an endoscopic transsphenoidal sellar approach. Mini posterior nasoseptal grafts repaired sellar defects in 40 patients and donor site defects of the contralateral PNSF/PNSRF in 30 patients. None of these patients experienced cerebrospinal fluid leakage or major complications. A mini posterior nasoseptal graft is a safe and effective technique for repairing sellar defects after endoscopic transnasal pituitary adenoma surgery. This technique can also be used to repair defects in PNSF/PNSRF donor sites.

Utility of Rescue Flap in the Reconstruction of Skull Base Defects Following Transnasal Endoscopic Excision of Sellar/Supra-sellar Lesions

Background: Naso-septal Rescue Flap(NSRF) technique involves the preservation of unilateral posterior septal artery pedicle without harvesting full Naso-Septal Flap (NSF). This enables usage of NSF flap when needed while allowing enough exposure to resect tumor completely. This also provides with added advantage of tailoring flap according to preference to cover the defect post tumor removal. This technique involves partial harvestation of only the most superior and posterior aspect of the flap to protect its pedicle, providing better instrumentation for the sphenoid sinus. At the end of the procedure, if there is unexpected CSF rhinorrhea or resultant bony defect is large then Nasoseptal flap is harvested from the rescue flap.
 As very few studies have been conducted for rescue flap technique in anterior skull base defect reconstruction following excision of sellar/supra-sellar lesions, the technique requires further validation, hence the present study is being undertaken.
 Objectives: 
 
 To study the post-operative outcome of Nasal Septal Rescue Flap (NSRF) in terms of donor site morbidity and CSF leak.
 To study the post-operative outcome of posterior nasoseptal flap in terms of donor site morbidity and CSF leak.
 
 Methodology: A cross-sectional study will be conducted at Department of E.N.T, AVBRH, Sawangi Wardha, during a period of August 2020 to August 2021. A sample size of 20 within 18 -70 years of age with sellar/supra-sellar lesions will be included for the research.
 Results: The observations obtained will be analyzed statistically and will be discussed in light of literature available.
 Conclusion: This study will help in formulating the guidelines for the NSF harvest with the goal of preventing unnecessary harvest, thereby decreasing peri-operative and post-operative disadvantages as well as preserving the flap for reconstruction in patients requiring revision surgery.

Modified Nasoseptal Rescue Flap Technique for Pituitary Adenoma Resection via Endoscopic Endonasal Approach.

Nasoseptal rescue flap (NSRF), which preserves the pedicle of the flap and is harvested as a nasoseptal flap (NSF) when intraoperative leakage of cerebrospinal fluid (CSF) occurs, is an alternative strategy for skull base reconstruction in patients with pituitary adenoma resection via an endoscopic endonasal approach. However, in practice, the original NSRF technique cannot meet the needs during operation. Therefore, the authors aimed to describe a modified NSRF technique for the resection of pituitary adenoma via endoscopic endonasal approach and to examine its utility and outcomes. The authors retrospectively analyzed the medical records of 87 consecutive patients with pituitary adenoma who underwent endoscopic endonasal surgery performed using NSRF technique from September 2019 to August 2020. Data on intraoperative CSF leakage, NSF conversion rate, and reconstruction-related complications were analyzed. The average age of patients was 50.1 years (men, 50.5%). Twenty-five cases of intraoperative CSF leakage were observed: 23 cases of low-flow CSF leakage and two cases of high-flow CSF leakage. NSRF was converted to NSF in 11 cases. Two patients experienced postoperative CSF leakage after reconstruction without NSF and required unplanned reoperation to rebuild the skull base with NSF. In conclusion, this modified NSRF utilized a minimally invasive way to provide sufficient surgical corridor without the need for pedicle retraction, and it can be effectively converted to an NSF for skull base reconstruction in patients with pituitary adenoma.

Utility of the Nasoseptal "Rescue" Flap Approach: Analysis of 125 Consecutive Patients and Implications for Routine Transsphenoidal Surgery.

Introduction The nasoseptal flap (NSF) is the reconstructive workhorse for endoscopic skull base surgery (ESBS). However, there is morbidity associated with its use and it is not always required for reconstruction. The bilateral nasoseptal “rescue” flap (NSRF) technique offers a quicker alternative to upfront NSF harvest, yet permits the use of a tailored NSF if needed after the defect has been created. The utility and implications of this strategy have not been well studied. Methods We retrospectively analyzed 125 consecutive transsphenoidal cases where an NSRF approach was used from January 2015 to October 2017 at the Cleveland Clinic. Records were analyzed for conversion to NSF, outcomes, and reconstruction-related complications. Results The mean age of patients included in the study was 51 years, with 51% females. NSRF was converted to full NSF in only 16% of cases. Rationale for conversion included an unanticipated high-flow (7) or low-flow (12) cerebrospinal fluid (CSF) leak and an exposed internal carotid artery (1). NSRF was utilized and converted to formal NSF in 3 patients who had previous remote transsphenoidal surgery. One patient who had an NSRF without a full NSF raised had a postoperative CSF leak; however, no CSF leaks or flap ischemia was noted for those who had full NSFs raised, even in revision surgery. Conclusion NSRF approach provides the reliability and flexibility of vascularized reconstruction, without the perioperative disadvantages of an upfront NSF harvest. The low and successful conversion rate to NSF demonstrates the utility of this strategy which should be incorporated into the standard approach for routine transsphenoidal surgery.

Analysis of Olfaction after Bilateral Nasoseptal Rescue Flap Transsphenoidal Approach with Olfactory Mucosal Preservation

To ascertain the impact of septal olfactory strip preservation and bilateral rescue flap elevation on the incidence of olfactory dysfunction. Case series with chart review of patients undergoing endoscopic endonasal skull base surgery (2012-2014). Providence Saint John's Health Center and John Wayne Cancer Institute. The incidences of postoperative epistaxis, hyposmia, and anosmia were analyzed using the Brief Smell Identification Test (B-SIT), which was completed in 110 of the 165 patients. Seventy-eight patients required extended approaches. Bilateral nasoseptal rescue flaps were elevated in 144 patients (87.3%) and pedicled nasoseptal or middle turbinate flaps in 21 patients (12.7%). The neurovascular pedicles were preserved in all patients, and there were no episodes of postoperative arterial epistaxis. Normal olfaction was noted in 95 patients (86%), with new hyposmia noted in 5 patients (5.5%). Within the rescue flap cohort, new hyposmia occurred in 6.3% (P < .01) of patients, balanced by improvement of olfaction in 43% of patients with preoperative dysfunction (overall pre- and postoperative olfactory function: 85% vs 86%). Patients with pedicled nasoseptal flaps did not have new hyposmia, with a net improvement of olfaction (71% vs 86%, P = .07). No patients experienced new anosmia. There was no difference between flap type within either subgroup. Superior olfactory strip preservation during elevation of reconstructive flaps preserves olfactory function and maintains adequate surgical exposure. In addition, rescue flaps have significantly diminished the rate of arterial postoperative epistaxis while maintaining the ability to harvest nasoseptal flaps for future reconstruction.

The application of nasoseptal " rescue" flap technique in endoscopic transsphenoidal pituitary adenoma resection

Objective To explore the reliability and superiority of nasoseptal flap technique in neuroendoscopic transnasal resection of pituitary adenoma. Methods A retrospective clinical analysis was conducted about 113 cases of endoscopic transsphenoidal pituitary adenoma resection with the application of nasoseptal flap technology in Department of Neurosurgery , Qilu Hospital of Shandong University from January 2016 to March 2017. The reliability and superiority of the technique were evaluated based on the duration of nasal cavity and sphenoid sinus stage, the incidence of post-operative anosmia and cerebrospinal rhinorrhea. Results The duration of nasal and sphenoid sinus stage was 15-30 minutes, averaging 24.0±4.5 minutes. There were 27 (23.9%) cases of intraoperative cerebrospinal fluid leakage including 24 cases of low flow cerebrospinal fluid leak and 3 cases of high flow cerebrospinal fluid leak. Twenty-three cases were converted from nasoseptal flap to nasal septum flap. The patients were followed up for 3-15 months, averaging 8.0±4.3 months. There were 17 cases(15.0%) of postoperative olfactory decline or disappearance, 1 case(0.9%) of epistaxis and 1 case(0.9%) of cerebrospinal rhinorrhea. Conclusions The application of nasoseptal flap technique could facilitate sellar floor reconstruction in case of intraoperative rupture of diaphragma sellae. There seems to be no increase of the duration of sphenoid sinus and nasal stage. Key words: Pituitary neoplasms; Natural orifice endoscopic surgery; Transphenoidal; Nasoseptal rescue flap; Nasal septum flap

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

The aim of this study is to investigate the relationships between tumor size, nasal symptoms including olfactory function, and posoperative atrophic mucosal changes after the endoscopic endonasal transsphenoidal approach (EETSA). This was a retrospective review of the medical records of 112 patients who underwent the 2 nostrils/4 hands EETSA with bilateral modified nasoseptal rescue flaps between February 2009 and January 2016. Pre- and postoperative paranasal sinus computed tomography, nasal cavity endoscopic images, the Connecticut Chemosensory Clinical Research Center (CCCRC) test, Cross-Cultural Smell Identification Test (CCSIT), the Nasal Obstruction Symptoms Evaluation, and the Sino-Nasal Outcome Test-20 were conducted. Nasal mucosal changes as determined by endoscopy were divided into 4 groups: normal to normal, Group A; atrophy to atrophy, Group B; normal to atrophy, Group C; and atrophy to more atrophy, Group D. The Mimics program was used to calculate nasal cavity volume changes after surgery. There were significant differences between pre- and postoperative olfactory function as reflected by the CCCRC (P < 0.001) and CCSIT (P < 0.001) scores. There was also a correlation between tumor size and olfactory function scores such as the CCCRC (P = 0.012) or CCSIT (P = 0.015). Moreover, nasal mucosal atrophic changes were related to tumor size and olfactory function tests. The tumor size was related to olfactory function and atrophic mucosal changes. Therefore, patients with large tumors should be informed that, after the EETSA, their olfaction may be altered and that nasal symptoms related to mucosal atrophy could occur.

Is Septoplasty Necessary When Using the Endoscopic Endonasal Transsphenoidal Approach for a Deviated Nasal Septum?

Objective This article describes the role played by endoscopic endonasal transsphenoidal approach (EETSA) to the sphenoidal process of the septal cartilage of a deviated nasal septum. Design Case series with chart review. Setting Tertiary referral center. Participants Between 2009 and 2016, 177 patients with skull base tumors who underwent EETSA were included. Main Outcome Measures In 8 cases, the conventional two nostrils-four hands technique was employed (group A). In 16 cases, we placed a right-side conventional nasoseptal flap and a left-side modified nasoseptal rescue flap (group B), and in 153 cases, bilateral modified nasoseptal rescue flaps (group C). The number of septoplasty-required cases and the change of nasal cavity area differences reflecting septal deviation were measured. Results Septoplasty during EETSA was performed in two cases: one from group B and one from group C. There was no significant difference in the ratio of septoplasty-required cases among the three groups ( p = 0.127). Between pre- and postoperative nasal cavity, the cross-sectional area difference at the anterior end of the middle turbinate level significantly decreased ( p = 0.045). Also, the angle of deviation at the level of ostiomeatal unit significantly decreased after EETSA ( p < 0.001). Conclusion Separation of a deviated complex surrounding the sphenoidal process of the septal cartilage is the key to relieving a deviated nasal septum. EETSA combined with the two nostrils-four hands technique allows posterior septectomy (including removal of this deviated complex) to be performed. Thus, EETSA may commence without preceding septoplasty even in cases with severe nasal septum deviations.

Endoscopic Endonasal Transsphenoidal Approach From the Surgeon Point of View.

In February 2009, the authors' center formed a team of neurosurgeons, otolaryngologists, endocrinologists, and radiologists to perform pituitary surgery using the endoscopic endonasal transsphenoidal approach (EETSA). This paper reviews the authors' experience with the technique, pathological outcomes, hormone profiles, and postoperative complications. Between February 2009 and December 2015, 535 patients underwent the EETSA with 2-nostrils/4-hands surgery. All of the patients had preoperative neurophthalmological and endocrinological assessments and neuroimaging. Patients were followed for at least 6 months with otolaryngological evaluations. The most common pathology treated was pituitary adenomas, with 390 (72.9%) patients. Of these, 287 (73.6%) were nonfunctioning adenomas. As the surgical method, the conventional 2-nostrils/4-hands technique was performed in 77 patients (14.4%), a right conventional nasoseptal flap and left modified nasoseptal rescue flap technique was used in 135 patients (25.2%), and bilateral modified nasoseptal rescue flaps were used in 323 patients (60.4%). Postoperative complications occurred in 46 patients (8.6%). The most common complications were vascular injury or hematoma (10 patients, 1.9%), and the most common postoperative sinonasal complaints were hyposmia or anosmia. Olfactory function was significantly decreased according to the Connecticut Chemosensory Clinical Research Center test (P <0.001) and Cross-Cultural Smell Identification Test scores (P <0.001) evaluated 6 months postoperatively. Skull-base tumor surgery via an EETSA with a team approach was performed for various extended tumors. It is important to consider postoperative sinonasal dysfunction, such as hyposmia or anosmia, and to have this followed by an otolaryngologist.

Effects of changes in nasal volume on voice in patients after endoscopic endonasal transsphenoidal surgery.

To investigate a potential correlation between changes in voice and changes in nasal volume. The endoscopic endonasal transsphenoidal approach (EETSA) was performed on 120 patients between February 2009 and August 2016 by using the bilateral modified nasoseptal rescue flaps method. All the patients were subjected to pre- and postoperative paranasal computed tomography (CT) and voice evaluations by using acoustic analyses, a nasometer to measure the nasalance, and determination of the voice handicap index (VHI). Paranasal CT and the medical image processing software were used to calculate changes in nasal cavity volume in three nasal sections. Enlargement of the nasal cavity after surgery was evident in all three areas (anteronasal, p < 0.001; midnasal, p = 0.005; postnasal, p = 0.025). In addition, EETSA resulted in significantly higher mean nasalance scores for the oronasal passage (p < 0.001) and nasal passage (p < 0.001); more frequency perturbation (jitter) (p < 0.001) and amplitude perturbation (shimmer) (p < 0.001); and higher grade, roughness, breathiness, asthenia, and strain scores (p < 0.001), and VHI (p = 0.01). However, only changes in the nasal volume after EETSA correlated with postnasal hypernasality (r = 0.2; p = 0.029). Although changes in nasal volume, voice, and speech may develop after EETSA, we found that changes in nasal volume were not correlated with changes in any voice-quality measure. However, the postnasal cavity was the region most dramatically affected by EETSA, and postnasal volume changes after surgery may be associated with hypernasal speech.

Direct Endonasal Approach with Partial Upper Posterior Septectomy. A "Rescue Flap" Technique Modification.

Objective Report a modification of the "rescue flap" technique using a direct endonasal approach with a partial superior septectomy for approaching pituitary tumors developed in our institution. Design Prospective study. Setting Hospital Universitario "Dr. José Eleuterio González," Universidad Autónoma de Nuevo León. Main Outcome Measures Since April 2015, we have performed 19 cases employing a direct endonasal approach with partial superior septectomy. Results and a technical note are described below. Results Nineteen patients were included in this report. Six patients presented transoperatory cerebrospinal fluid (CSF) leak, so a nasoseptal rescue flap was harvested. No patients developed postoperative CSF leak in this group. Two patients were submitted to a second surgical procedure. Nasoseptal flap was harvested without complications. In both patients, the size of the flap was enough to cover the dural defect and avoid CSF leak. Conclusion Direct endonasal approach with a partial posterior septectomy allows enough exposition of the sphenoidal sinus while preserving the nasoseptal septum with the possibility of a successful rescue flap when needed.

Intranasal Volume Changes Caused by the Endoscopic Endonasal Transsphenoidal Approach and Their Effects on Nasal Functions.

ObjectiveWe evaluated postoperative changes in nasal cavity volume and their effects on nasal function and symptoms after endoscopic endonasal transsphenoidal approach for antero-central skull base surgery.Study DesignRetrospective chart review at a tertiary referral center.MethodsWe studied 92 patients who underwent binostril, four-hand, endoscopic endonasal transsphenoidal approach surgery using the bilateral modified nasoseptal rescue flap technique. Pre- and postoperative paranasal computed tomography and the Mimics® program were used to assess nasal cavity volume changes at three sections. We also performed several pre- and postoperative tests, including the Connecticut Chemosensory Clinical Research Center test, Cross-Cultural Smell Identification Test, Nasal Obstruction Symptoms Evaluation, and Sino-Nasal Outcome Test-20. In addition, a visual analog scale was used to record subjective symptoms. We compared these data with the pre- and postoperative nasal cavity volumes.ResultsThree-dimensional, objective increases in nasal passage volumes were evident between the inferior and middle turbinates (p<0.001) and between the superior turbinate and choana (p = 0.006) postoperatively. However, these did not correlate with subjectively assessed symptoms (NOSE, SNOT-20 and VAS; all nasal cavity areas; p≥0.05) or olfactory dysfunction (CCCRC and CCSIT test; all nasal cavity areas; p≥0.05).ConclusionSkull base tumor surgery via an endoscopic endonasal transsphenoidal approach altered the patients’ nasal anatomy, but the changes in nasal cavity volumes did not affect nasal function or symptoms. These results will help surgeons to appropriately expose the surgical field during an endoscopic endonasal transsphenoidal approach.

Olfactory Outcomes after Endoscopic Transsphenoidal Pituitary Surgery with Nasoseptal or Nasoseptal “Rescue” Flap: A Systematic Review

Background: Nasoseptal flap (NSF)/nasoseptal rescue flap (NSRF) are frequently used after endoscopic pituitary surgery to repair the sellar defect. However, they are associated with an increase in incidence of post-operative hyposmia. The goal of this study is to review the current literature and determine the effects of NSF or NSRF on post-operative olfactory outcomes.

Comparison of Postoperative Complication between Nasoseptal Flap and Rescue Flap

Comparison of Postoperative Complication between Nasoseptal Flap and Rescue Flap

Anatomic Changes Caused by Endoscopic Endonasal Transsphenoidal Surgery and Their Effects on Nasal Functions.

We evaluated postoperative changes in nasal cavity dimensions and their effects on nasal functions and symptoms. Case series with chart review. Tertiary referral center. We studied patients who underwent binostril, 4-hand endoscopic endonasal transsphenoidal approach surgery with the bilateral modified nasoseptal rescue flap technique. Pre- and postoperative paranasal computed tomography scans were used to assess nasal cavity dimensional changes at 4 levels. We also performed several pre- and postoperative tests, including the Connecticut Chemosensory Clinical Research Center test and the Cross-Cultural Smell Identification Test (n = 119) to evaluate olfactory functions. Also, the Nasal Obstruction Symptoms Evaluation, the Sino-Nasal Outcome Test-20, and a visual analog scale were used (n = 157) to record subjective symptoms. We compared these data with the pre- and postoperative nasal cavity dimensions. Two-dimensional objective increases in nasal passage dimensions were evident postoperatively (all cross-sectional areas, P < .001, except choana and left inferior turbinate). However, these did not correlate with subjectively assessed symptoms (Nasal Obstruction Symptoms Evaluation, all cross-sectional areas, P ≥ .05, except right middle turbinate; Sino-Nasal Outcome Test-20, all cross-sectional areas, P ≥ .05) or olfactory dysfunction evaluated with the Connecticut Chemosensory Clinical Research Center test (all cross-sectional areas, P ≥ .05) or the Cross-Cultural Smell Identification Test (all cross-sectional areas, P ≥ .05). Endoscopic endonasal transsphenoidal approach surgery altered the patients' nasal anatomy, but the changes in nasal cavity dimensions did not affect nasal functions and symptoms. These results will help surgeons to appropriately expose the surgical field during endoscopic endonasal transsphenoidal approach surgery.

Technical nuances of commonly used vascularised flaps for skull base reconstruction.

Reconstruction with a vascularised flap provides the most reliable outcome, with post-operative cerebrospinal fluid leak rates of less than 5 per cent. This article aims to review and summarise the critical technical aspects of the vascularised flaps most commonly used for skull base reconstruction. Vascularised flaps are classified as intranasal or extranasal. The intranasal group includes the Hadad-Bassagaisteguy nasoseptal flap, the Caicedo reverse nasoseptal flap, the nasoseptal rescue flap, the posteriorly or anteriorly based lateral wall flaps, and the middle turbinate flap. Extranasal flaps include the transfrontal pericranial and transpterygoid temporoparietal flaps. The Hadad-Bassagaisteguy nasoseptal flap is overwhelmingly favoured for reconstructing extensive defects of anterior, middle and posterior cranial base. Its pertinent technical features are described. However, it is essential to master the skills required for the various extranasal or regional vascularised flaps because each can offer a reconstructive alternative for specific patients, especially when open approaches are needed and/or intranasal vascularised flaps are not feasible.

Bilateral Nasoseptal Rescue Flap with Olfactory Epithelium Preservation: A Prospective Study Analyzing Postoperative Olfaction and Epistaxis

Background: Adequate exposure and preservation of normal sinonasal function remain key but often competing goals in endoscopic skull base surgery. We have previously published our approach and rationale for utilizing bilateral nasoseptal rescue flaps. Herein, we report a prospective study to determine if this approach impacts the incidence of postoperative epistaxis and olfactory dysfunction.

Risk Factors Predicting Nasoseptal Flap Failure in Endoscopic Endonasal Transsphenoidal Approach

Objective: Reconstruction of the skull base using pedicled nasoseptal flap (NSF) seems to be advantageous after endoscopic endonasal transsphenoidal approach (EETSA). There were few reports to evaluate the cause of flap failure in EETSA using NSF. The aim of this study was to evaluate the perioperative risk factors for NSF failure. Methods: The study population comprised of patients who underwent EETSA with NSF elevation between February 2009 and November 2013. We retrospectively reviewed patients' medical records including operative findings. Results: A total of 374 patients (183 men, 191 women) underwent the EETSA and 310 patients underwent the EETSA with NSF elevation including modified nasoseptal rescue flap. The mean patient age was 48.0 years. The total cases of NSF failure were five (overall rate: 1.61%, 5/310; flap elevation: 0.35%, 1/282; flap reconstruction: 14.2%, 4/28). Two patients had diabetes mellitus. One patient had cardiovascular problems. Five patients had old age (mean 70 years, >60). Four patients had postoperative nasal infection. One patient had a radiation therapy. Conclusion: NSF is usually safe and effective technique for skull base reconstruction. However, the condition of diabetes mellitus, cardiovascular problems, an old age, postoperative nasal infection, and radiation therapy must require more attention to improve patient management and NSF survival.

Olfactory changes after endoscopic endonasal transsphenoidal approach for skull base tumors

The increased number of endoscopic endonasal transsphenoidal approaches (EETSA) has been associated with sinonasal complications such as olfactory dysfunction. Current studies have compared preoperative and postoperative olfactory function according to surgical type and age. Retrospective review of medical records at a tertiary referral center. Patients were divided into two groups according to surgical type and into four groups according to age. The two surgical groups were defined based on the bilateral nasoseptal flap technique (group A: right conventional nasoseptal flap and left modified nasoseptal rescure flap; group B: bilateral modified nasoseptal rescue flap). The four age groups were ≤ 30, 31-45, 46-60, and ≥ 61 years. Patients underwent preoperative olfactory function evaluation using a visual analogue scale (VAS), the Connecticut Chemosensory Clinical Research Center Test (CCCRC), and the Cross-Cultural Smell Identification Test (CCSIT). Repeat testing was performed 6-months postoperatively. A total of 226 patients who underwent binostril four-hand EETSA were included in this study. In both groups A and B, the olfactory function was significantly decreased according to CCCRC and CCSIT scores (P < 0.05). The VAS scores were significantly decreased in both groups (P < 0.05). The symptom scores and olfactory test results were significantly changed in >30-year-old patients who had undergone EETSA. EETSA might contribute to olfactory dysfunction independent of surgery type. In addition, age may affect the restoration of olfaction after EETSA. Patients who plan to undergo EETSA must be informed that their olfaction may be impaired. 4.

Olfactory Function following Bilateral Mucosal Preservation Nasoseptal Rescue Flap Technique in Endoscopic Skull Base Surgery: Preliminary Data

Introduction: Bilateral mucosal preservation nasoseptal rescue flap technique in endoscopic skull base surgery has been previously presented by our group. One of the perceived benefits of this technique is olfactory function preservation due to preservation of the septal olfactory strip (SOS) and middle and superior turbinates. Herein we present preliminary preoperative and postoperative olfactory function data from an ongoing IRB-approved study at our institution.