10.14639/0392-100X-N1132
Objective. Smell dysfunctions are common with almost 20% percent of the population affected. There are no interventional solutions for these patients. The aim of this study is to investigate the feasibility and security of the balloon dilatation technique. Methods. This paper describes interventional steps and determines the feasibility and safety of endoscopic olfactory cleft dilatation via balloon device. We included 10 nasal cavities in the study and dilated olfactory cleft areas via balloon device.Results. We could smoothly perform the procedure and did not observe any fractures on the skull base or olfactory cleft of the cadavers after dilatation.Conclusions. A combination of this intervention with medical treatments can be promising for smell dysfunctions.
application/xml
1827-675X
1132
en
Samuel C. Leong
https://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
olfactory disorder
Endoscopic balloon dilatation of the olfactory cleft – a feasibility study of a novel technique in cadavers
Text.Serial.Journal
https://www.actaitalica.it/
41
Rhinology
2021-05-14
2020-09-22
2021-05-17
2021-05-17
168-172
1
Samuel C. Leong
2021/05/14
10.14639/0392-100X-N1132
168
The Liverpool Head and Neck Centre, United Kingdom
1827-675X
olfactory disorder
172
Endoscopic balloon dilatation of the olfactory cleft – a feasibility study of a novel technique in cadavers
https://www.actaitalica.it/article/download/1132/580
41
ACTA OTORHINOLARYNGOLOGICA ITALICA 2021;41:168-172; doi: 10.14639/0392-100X-N1132




Rhinology


Endoscopic balloon dilatation of the olfactory cleft –
a feasibility study of a novel technique in cadavers
Dilatazione endoscopica con balloon della fessura olfattoria – studio di fattibilità
di una tecnica innovativa su cadavere
Osman H. Çam1,2, Dafna Gershnabel Milk1,3, Fernando Alfaro-Iraheta1,4, Grace C. Khong1, Claire Tierney5,
Samuel C. Leong1
1
 The Liverpool Head and Neck Centre, United Kingdom; 2 Faculty of Medicine, Baskent University, Turkey; 3 Meir Medical Centers,
Department of Otolaryngology-Head and Neck Surgery, Kfar Saba, Israel; 4 Hospital Central Militar Mexico; 5 The Human Anatomy
Resource Centre, University of Liverpool, United Kingdom


SUMMARY
Objective. Smell dysfunctions are common with almost 20% percent of the population af-
fected. There are no interventional solutions for these patients. The aim of this study is to
investigate the feasibility and security of the balloon dilatation technique.
Methods. This paper describes interventional steps and determines the feasibility and safe-
ty of endoscopic olfactory cleft dilatation via balloon device. We included 10 nasal cavities
in the study and dilated olfactory cleft areas via balloon device.
Results. We could smoothly perform the procedure and did not observe any fractures on the
skull base or olfactory cleft of the cadavers after dilatation.
Conclusions. A combination of this intervention with medical treatments can be promising
for smell dysfunctions.                                                                             Received: September 22, 2020
                                                                                                    Accepted: January 10, 2021
KEY WORDS: olfactory cleft, balloon dilation, olfactory stenosis, olfactory disorder
                                                                                                    Correspondence
RIASSUNTO                                                                                           Osman H. Çam
Obiettivo. Le disfunzioni dell’olfatto sono comuni; quasi il 20 per cento della popolazione         Unalan Mh. Sarnıc Sokak, New City Istanbul No: 3/
ne è colpita. Non ci sono soluzioni risolutive per questi pazienti. Lo scopo di questo studio       A2/19, Uskudar, Istanbul, Turkey
è indagare la fattibilità e la sicurezza della tecnica di dilatazione con palloncino della          Tel. +90 505 701 84 70. Fax +90 216 4674951
                                                                                                    E-mail: osman.cam@gmail.com
fessura olfattoria.
Metodi. Questo paper descrive le fasi della procedura chirurgica e valuta la fattibilità e la
                                                                                                    Funding
sicurezza della dilatazione della fessura olfattiva endoscopica tramite dispositivo a pallon-
                                                                                                    None.
cino. Abbiamo incluso dieci fosse nasali nello studio e dilatato le fessure olfattorie tramite
dispositivo a palloncino.
                                                                                                    Conflict of interest
Risultati. Abbiamo potuto eseguire la procedura senza problemi e non abbiamo osservato              The Authors declare no conflict of interest.
alcuna frattura della base del cranio o della fessura olfattiva dei cadaveri dopo la dilatazione.
Conclusioni. Una combinazione di questo intervento con trattamenti medici può essere
promettente per le disfunzioni dell’olfatto.                                                          How to cite this article: Çam OH, Milk DG,
                                                                                                      Alfaro-Iraheta F, et al. Endoscopic balloon dila-
PAROLE CHIAVE: fessura olfattoria, dilatazione con balloon, stenosi olfattoria, disordine             tation of the olfactory cleft – a feasibility study
dell’olfatto                                                                                          of a novel technique in cadavers. Acta Otorhi-
                                                                                                      nolaryngol Ital 2021;41:168-172. https://doi.
                                                                                                      org/10.14639/0392-100X-N1132
Introduction
                                                                                                    © Società Italiana di Otorinolaringoiatria
The incidence of olfactory dysfunction is high, affecting approximately 20%                         e Chirurgia Cervico-Facciale
of the adult population 1. The most common aetiologies are upper respira-
tory tract viral infection, chronic rhinosinusitis and head trauma 2. Pre-existing                                 OPEN ACCESS

narrowing or stenosis of the olfactory cleft can also result in hyposmia 3. The                     This is an open access article distributed in accordance with
                                                                                                    the CC-BY-NC-ND (Creative Commons Attribution-Non-
management of olfactory dysfunction is focused on treating any reversible ae-                       Commercial-NoDerivatives 4.0 International) license. The
tiology. Topical intranasal steroids remain the primary treatment modality 4.                       article can be used by giving appropriate credit and mentio-
                                                                                                    ning the license, but only for non-commercial purposes and
Olfactory training, first described by Hummel et al. in 2009, is a crucial ad-                      only in the original version. For further information: https://
junct, especially in patients with post-viral olfactory dysfunction 5.                              creativecommons.org/licenses/by-nc-nd/4.0/deed.en




168
                                                                                                              Endoscopic balloon dilatation of the olfactory cleft




Similarly, surgical interventions are reserved for identifi-                        cal™ MN, USA) were utilised in this study (Fig. 1A). The
able causes when medical treatment has not resulted in                              device’s malleable tip was configured for the sphenoid si-
clinical improvement, e.g., endoscopic sinus surgery for                            nus using the supplied bending tool (Fig. 1B).
chronic rhinosinusitis, septoplasty for nasal obstruction 6.                        After the nasal cavity was irrigated with sterile water, endo-
When surgery is undertaken on the olfactory cleft, it is usu-                       scopic inspection of the olfactory cleft was performed, and
ally in the context of skull base tumour resection, which                           debris was suctioned (Fig. 2A). The anatomical insertion of
ultimately results in resection of not only mucosa but also                         the middle turbinate to the skull base was then identified.
the olfactory apparatus. At present, surgical intervention is                       An imaginary horizontal line was drawn across the leading
not considered for patients with idiopathic olfactory dys-                          edge of the turbinate bisecting the half of the vertical height
function or post-viral hyposmia.                                                    between the skull base and the inferior edge of the middle
This paper aims to describe the technical steps for endo-                           turbinate (Fig. 2B). The dilatation device’s tip was inserted
scopic balloon dilatation of the olfactory cleft with the view                      under direct endoscopic vision into the area between the
of providing clinical applicability of this novel technique.                        nasal septum and middle turbinate, bisecting the middle
                                                                                    turbinate half-height (Fig. 3A). With the device held stable,
Materials and methods                                                               the LED light fiber was advanced to facilitate endoscopic
                                                                                    confirmation of the position of the instrument tip with the
                                                                                    skull base. The balloon was then inflated for 20 seconds
Ethical considerations                                                              using the supplied inflation syringe (Fig. 3B).
This study was approved by the Central University Re-
search Ethics Committee of the University of Liverpool                              Post-dilatation inspection of the olfactory cleft
(reference 4473). A total of ten nasal cavities were utilised                       After completing the olfactory cleft dilatation, the mu-
for this study, fresh-frozen adult cadaver heads without a                          cosa overlying the olfactory cleft and perpendicular plate
previous history of sinonasal surgery.                                              of ethmoid was inspected for tears or defects. The mucosa
                                                                                    was then elevated to expose the underlying bone (Fig. 4A).
Balloon dilatation of the olfactory cleft                                           To accentuate any potential bony defects or fracture lines,
Two fellowship-trained rhinologists undertook all endo-                             we irrigated the exposed bony area with diluted blue food
scopic, endonasal balloon dilatation and surgical dissec-                           dye before the endoscopic inspection was repeated (Fig.
tions at the Human Anatomy Resource Centre at the Uni-                              4B). The presence of any bony defect in the skull base and
versity of Liverpool. Surgical dissection was performed                             perpendicular plate of ethmoid was recorded. The process
with a 4mm 30° rigid endoscope connected to a high-defi-                            was then repeated for all nasal cavities, as described above.
nition monitor and camera system, utilising standard endo-
scopic sinus surgery instrumentation (Karl Storz, Tuttlin-
gen, Germany).
                                                                                    Results
Both 6 mm and 7 mm diameter balloons of the XprESS                                  Endoscopic balloon dilatation of the olfactory cleft was com-
LoProfile ENT dilatation system (Stryker Entellus Medi-                             pleted in 10 nasal cavities. Six were dilated with the 6 mm bal-


A                                                                                    B




Figure 1. (A) XprESS LoProfile Ent Dilatation System. (B) Bender configured to sphenoid sinus (yellow circle; special bender, down arrow; led light fibre advancer,
up arrow; tip of the dilatation system).



                                                                                                                                                             169
O.H. Çam et al.




A                                                                               B




Figure 2. (A) Left nasal cavity, 0° endoscopic view. (B) The imaginary line is drawn to bisect half-height of the middle turbinate.



A                                                                               B




Figure 3. Left nasal cavity, 0° endoscopic view. (A) Advancement of the tip of the probe to the imaginary line. (B) The inflation of the balloon for 20 sec in the
olfactory groove (red arrow; skull base, black star; nasal septum, white star; middle turbinate, green star; the guide probe of the balloon device, yellow arrow; the
led light fibre, blue star; the balloon of the device).


loon, and the remaining four with the 7 mm balloon. No tears                         have been described in detail, and in our experience, this
or defects of the overlying mucosa were observed following                           minimally invasive procedure is both straightforward and
balloon dilatation. After the mucosa was resected and the area                       repeatable with a short learning curve. Additional instru-
irrigated with blue dye, no fractures or defects of the skull base                   ments, such as those typically required for sinus surgery,
were identified. However, one fracture oriented longitudinally                       were not utilised to complete the procedure.
was noted on the perpendicular plate of the ethmoid following                        This study has also attempted to address the safety aspects
dilatation with the 6 mm balloon (Fig. 5).                                           of this novel technique. Neither the 6 mm and 7 mm diam-
                                                                                     eter balloons caused trauma to the mucosa or the skull base’s
Discussion                                                                           underlying bone. A single fracture was observed in one nasal
Synopsis of key/new findings                                                         cavity, which was localised to the ethmoid’s perpendicular
This study has described a novel technique of balloon dila-                          plate. This fracture line was horizontally oriented in the sag-
tation of the olfactory cleft utilising standard, commercial-                        ittal plane and was over 5 mm away from the bony skull
ly-available sinus dilatation devices. The technical steps                           base. Despite the relative risk of bony injury occurring with-



170
                                                                                                                Endoscopic balloon dilatation of the olfactory cleft




A                                                                                    B




Figure 4. 30° endoscopic view of left olfactory groove, mucosal flap elevated. (A) Skull base and cribriform plate exposure with dissection. (B) The blue dye in
introduced in order to see fracture lines (red arrow; skull base, green arrows; cribriform plate and olfactory nerve fibres, black star; elevated mucosal flap, green
star; perpendicular plate of the ethmoid bone).


                                                                                     all pressure is distributed evenly throughout the surface
                                                                                     of the balloon. This contrasts with a study measuring the
                                                                                     magnitude of the forces exerted during punch osteotomy
                                                                                     with a Blakesley forceps, where the authors reported that
                                                                                     it required 17.80 N to breach the bony cribriform plate 7. A
                                                                                     follow-on study by the same group highlighted that caution
                                                                                     might be required in extrapolating force estimates from ca-
                                                                                     daver tissue to those required in living patients, which were
                                                                                     typically higher 8.
                                                                                     In this study, the midpoint vertical height of the middle tur-
                                                                                     binate was used as a reference point to introduce the curved
                                                                                     tip of the device. The insertion was undertaken with full en-
                                                                                     doscopic visualisation of the skull base. The LED light fibre
                                                                                     was advanced to confirm the tip’s position in relation to the
                                                                                     skull base before the balloon was introduced by fully ad-
Figure 5. 30° Endoscopic view of the right olfactory groove (red arrow; skull        vancing the balloon slide mechanism forward to position the
base, green star; perpendicular plate, black star; elevated mucosa, orange dia-      balloon within the olfactory cleft. The requirement to fully
mond; fracture in the perpendicular plate).
                                                                                     visualise the anatomy and device may preclude the need for
                                                                                     image guidance or fluoroscopic confirmation. Thus, a devi-
in the olfactory cleft following balloon dilatation, we believe                      ated nasal septum that obstructs visualisation of the area me-
that the fracture occurred in a “controlled” manner.                                 dial to the middle turbinate would be a relative contraindica-
                                                                                     tion to balloon dilatation of the olfactory cleft.
Strengths of the study
The dilatation device utilised in this study exerted 12-gauge                        Comparisons with other studies
atmospheric pressure (atm) consistently around all surfaces                          Olfactory cleft dilatation is a relatively new concept, first
of the balloon when it is dilated with the accompanying                              described in 2018 3. The authors described their experi-
inflation syringe. Although the pressure exerted along the                           ence with three patients suffering from olfactory dysfunc-
surface of the balloon appears high, it should be remem-                             tion. The surgical technique undertaken consisted of lat-
bered that the expansion of the balloon is limited to the                            eral fracture-dislocation of the lateral wall of the olfactory
maximum diameter of either 6 mm or 7 mm, and the over-                               cleft (i.e., middle turbinate) using a Cottle elevator and a



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O.H. Çam et al.




curved olive-shaped blunt aspirator. The authors reported          Conclusions
improved access to the olfactory cleft, with minimal trauma
to the mucosa. However, it should be recognised that this          Endoscopic olfactory cleft dilatation appears to be a viable
technique is not repeatable and is surgeon specific. The           technique to improve access into this anatomical region.
pressure exerted by the elevator is uncontrolled and de-           Our study suggests that the technique is both safe and asso-
pendent on tactile feedback.                                       ciated with a short learning curve. Given that many patients
In contrast, our technique allows for controlled and uni-          suffering from olfactory dysfunction still do not derive sat-
form pressure to be exerted along the balloon’s entire             isfactory outcomes from contemporary treatment modali-
length. Given that the balloon was not in contact with the         ties, the clinical efficacy of olfactory cleft dilatation should
bony skull base superiorly, inadvertent trauma can safely          be evaluated.
be avoided when the balloon is dilated. The additional step
of advancing the LED light probe to check the position of          References
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