First Olfactory Fiber as an Anatomical Landmark for Frontal Sinus Surgery (original) (raw)
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Nepalese Journal of Radiology
Introduction:Endoscopic sinus surgery is a widely utilized surgical method for addressing chronic sinonasal diseases. To prevent major postoperative problems, an anatomical understanding of its variants is necessary. Our study aims to determine the occurrence and classification of different Keros types by analyzing paranasal sinus CT scans and retrospectively evaluating the depth of the olfactory fossa in our population.Methods:This is a retrospective single-centre analytical study on 254 patients who had undergone a non-enhanced paranasal sinus CT scan for 1 year after ethical approval from the Institutional Review Committee of Nobel Medical College Teaching Hospital. The statistical program SPSS version 25 was used to conduct the statistical analysis.Results:The average depth of the right olfactory fossa (OF) was 4.4±1.44 mm on the right side and 4.5±1.5 mm on the left side. According to the Keros classification, out of a total of 254 patients, 38 patients (15%) were classified as...
Journal of Craniofacial Surgery, 2020
Introduction: Endoscopic sinus surgeries (ESS) are frequently used in the treatment of optic nerve decompression, other intracranial lesions and sinonasal pathologies. The olfactory fossa can be localized on different levels in relation to the anterior cranial fossa. The aim of the present study was to evaluate the depth and width of the olfactory fossa (OF) in relation to nasal septum deviation (NSD). Methods: A total of 225 patient (141 female and 84 male, age range between 15 to 56 years) of cone beam computed tomography (CBCT) data was used in this study. NSD, OF width, OF depth were measured. OF depth which was grouped according to the Keros classification as Type I, II, and III was calculated. All measurements were performed bilaterally except for NSD. Results: In the right and left OF depth were found Keros Type I 32 (14.2%) and 30 (13.3%), Keros Type II 171 (76%) and 167 (74.2%), and Keros Type III 22 (9.8%) and 28 (12.4%) respectively. There was no statistically significant found between OF depth and NSD (P > 0.05). The mean angle of the NSD in men and women were 4.36 AE 4.69 o in women 4.11 AE 4.36 o , respectively. The mean width of the right OF was 2.50 AE 0.64 mm and 2.58 AE 0.72 mm for the left side and there was no statistically significant association between OF width-NSD and OF width-OF depth (P > 0.05). Conclusion: The anatomy of the OF should be well established before surgical intervention increase of the length of the lateral lamella is also increases the risk of developing complications such as cerebral damage, hemorrhage, and cerebrospinal fluid fistula during endoscopic sinus surgery. Although there is no significant difference between OF measurement and NSD, with three-dimensional imaging detailed research is required before endoscopic sinus surgical operations.
Radiological Analysis of Olfactory Fossa Depth: A Tertiary Care Hospital Based Study
Birat Journal of Health Sciences
Introduction: Computed tomogram (CT) of nose and paranasal sinuses provides the detailed knowledge of depth of olfactory fossa as per Keros' classification, which is important in endoscopic sinus surgery. Objective: To analyze the types and frequency of depth of olfactory fossa in Nepalese population. Methodology: This was a longitudinal study conducted from 1 May to 30 August 2018. Coronal CT scans of nose and paranasal sinuses were taken for analysis of olfactory fossa depth. The landmarks like infraorbital foramen, point of articulation of medial ethmoidal roof with lateral lamella of cribriform plate (MERP) and lowest point on the cribriform plate (CP) were taken. The lateral lamella of cribriform plate (LLCP) was calculated by subtracting CP height from MERP height (MERP-CP = LLCP). Results: There were total 101 patients included. The distribution of age was 33.72 ± 15.15 years. The keros' type I was the most common (86.1%). Regarding the olfactory fossa depth, right si...
Neurosurgery, 2005
The pterional approach represents the standard approach for most lesions of the anterior and middle cranial fossa. It requires some degree of frontal lobe retraction, which may result in temporary or permanent damage of olfaction because of nerve avulsion or mechanical compression. The purpose of this study, based on microanatomic dissection of human cadaveric specimens, was to review the microsurgical anatomic features of the nerve and suggest operative nuances that may contribute to reducing the rate of postoperative olfactory dysfunction. METHODS: Twenty olfactory nerves and tracts were examined in 10 human cadaveric heads obtained from three fresh and seven formalin-fixed adult cadavers. A standard pterional craniotomy was performed. The olfactory nerve was dissected from its arachnoidal envelopes and then mobilized for an average length of 30 mm (range, 25-35 mm).
Microsurgical Anatomy for Intraoperative Preservation of the Olfactory Bulb and Tract
Journal of Craniofacial Surgery, 2011
Damage to the olfactory bulb and tract is a frequently described complication of brain surgery in the frontal region, and it seems to be influenced by the surgical approaches. Eighty cerebral hemispheres and 5 formalin-fixed cadavers filled with colored latex were used. Parameters were directly measured, and after olfactory bulb and tract were mobilized with careful dissections, retraction of the frontal lobe was noted. The anterior border of the olfactory bulb is 22.21 (SD, 5.45) mm posterior to the frontomarginal sulcus, and arachnoidal dissection should be performed parallel to olfactory structures using sharp instruments to allow early visualization. Overall mobilization of the olfactory bulb and tract as 29.3 (SD, 6.4) mm in length is possible without disrupting the structures and enables a greater degree of the frontal-lobe elevation window up to 13.1 (SD, 3.2) mm. Using the morphometric data and anatomic knowledge may prevent unwanted anosmia complication during surgical approaches.
Endonasal anatomy of the olfactory neural network: Surgical implications
The Laryngoscope, 2018
Define the anatomic distribution of the olfactory filaments within specific mucosal regions of the nasal cavity. Cadaveric study. Seventeen cadaveric specimens (34 sides) were dissected to study the anatomical distribution and density of olfactory fila within different regions of the nasal cavity. Olfactory fila were dissected retrogradely to their point of entry into the anterior cranial fossa through the cribriform plate. Anatomic relationships among various components of the olfactory system and their corresponding arterial supply were determined subjectively. The highest density of olfactory fila was found at the mucosa of the ethmoid roof and superior turbinates. Olfactory fila were found at regions not previously considered to be part of the olfactory system: lateral wall of the nose, ethmoidal bullae, and between the os sphenoidale and arc of the posterior choana. Furthermore, at the septum, 20% of the olfactory fila crossed contralaterally before exiting the nose. The anteri...
Anatomy & Cell Biology
The Functional endoscopic sinus surgery through transnasal approach is a common modality of treatment for disorders of the nasal cavity, paranasal air sinuses as well as cranial cavity. The olfactory fossa (OF) is located along the superior aspect of cribriform plate which varies in shape and depth. This variable measurement of the depth of OF is mostly responsible for greater risk of intracranial infiltration during endoscopic procedures in and around the nasal cavity. The morphology of frontal and ethmoid sinus (ES) vary from simple to complex. This cadaveric study is planned to improve the ability of the otolaryngologist, radiologist to understand the possible morphological variations and plan steps of less invasive "precision surgery" to have a safe and complication free procedures. A total of 37 human head regions were included in the study. For classification of OF, Modified Kero's classification was used. The size, shape and cells of frontal and ES were noted. We found, type II (60.8%) OF was more common followed by type I (29.7%) than type III (9.5%). The shape of frontal sinus was comma shaped (55.4%) followed by oval (18.9%) than irregular (16.2%). Most common two cells type of ES was seen in 50.0% of both anterior and posterior ES. Out of 74 ES, 8.1% of Onodi cells and 14.9% of agger nasi cells were seen.
Olfactory and sinonasal outcomes in endoscopic transsphenoidal skull-base surgery
International Forum of Allergy & Rhinology, 2012
Background: Endoscopic anterior skull-base surgery has been previously suggested to cause a significant deterioration in olfactory function. Given the impact on quality of life, the objective of this study was to determine the effect of a unilateral middle-turbinate-sacrificing approach on olfactory function and sinonasal outcome.
Rhinology, 2011
The Modified Endoscopic Lothrop procedure (MELP) or Draf 3 is a complex procedure, performed for chronic frontal sinusitis that is refractory to standard functional endoscopic sinus surgery. The procedure involves drilling of the frontal T (formed by the septum and middle turbinate`s attachment to the skull base) onto the olfactory fossa often with exposure of the first olfactory neuron and may affect olfactory function. This study was performed to assess patients` subjective sense of smell following this procedure. Prospective study of retrospective data. Sixty-eight patients, who underwent modified endoscopic Lothrop by the senior author (PJW) between 2003 and 2008, completed a post-operative questionnaire asking about their perception of olfactory function. All patients had their pre-operative subjective sense of smell documented prior to undergoing surgery. Patient records were reviewed for pertinent medical information such as the presence of asthma, aspirin sensitivity and nas...
European Archives of Oto-Rhino-Laryngology, 2010
The aim of this study was to investigate the relationship between the intranasal airway around the turbinates and olfactory function. In total, 32 nostrils of 16 patients who were awaiting septal surgery were involved in this study. For measurements of the volume of the nasal cavity, paranasal sinus computed tomography scans were performed and reconstructed into three-dimensional images. The Butanol Threshold Test and Cross-Cultural Smell IdentiWcation Test were used to evaluate olfactory function. The results were analyzed with Pearson's test. The volume around the turbinates was signiWcantly correlated with the olfactory threshold. However, olfactory iden-tiWcation had no signiWcant correlation with each volume. The airway around the turbinates is very important for nasal airXow and its volume inXuences olfactory function.