10.14639/0392-100X-N1834
The success of laryngotracheal surgery is mainly related to adequate exposure of the airway lumen. To render airway surgery more efficient, many efforts have been made in recent decades to obtain a safe ventilation system which uses an orotracheal tube that is as small as possible. The first attempt was made by introducing the high frequency jet ventilation (HFJV) technology in clinical practice. Nonetheless, HFJV has some risks related to the high pressure needed for ventilation in the catheter. First, during HFJV, the expiration of air from the lungs is a passive backflow on the trachea wall, potentially causing hypercapnia and air trapping. Second, HFJV creates an open ventilation system that leads to aerosolisation of airborne particles with an increased infectious risk for the surgeon. To overcome these issues, an innovative flow-controlled ventilation (FCV) system with a narrow-cuffed catheter (Evone®; Ventinova, Eindhoven, The Netherlands) was introduced in clinical practice. This paper describes our initial experience with the Evone® FCV system, reporting the first 5 cases ventilated with this technology. In this observational study, we evaluate the feasibility and safety of the Evone® system and deliver a critical appraisal of this novel method of ventilation.
text/xml
1827-675X
1834
en
Giorgio Peretti
http://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
jet ventilation
Evone® Flow controlled ventilation: a new device for laryngotracheal surgery
Text.Serial.Journal
https://www.actaitalica.it/
42
Clinical techniques and technologies
2022-05-16
2021-09-28
2022-05-23
2022-05-23
189-193
1
Giorgio Peretti
2022/05/16
10.14639/0392-100X-N1834
189
Unit of Otorhinolaryngology, IRCCS Ospedale Policlinico San Martino, Genoa, Italy; Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Italy
1827-675X
jet ventilation
en
193
Evone® Flow controlled ventilation: a new device for laryngotracheal surgery
https://www.actaitalica.it/article/download/1834/804
42
ACTA OTORHINOLARYNGOLOGICA ITALICA 2022;42:189-193; doi: 10.14639/0392-100X-N1834




Clinical techniques and technologies


Evone® Flow controlled ventilation: a new device
for laryngotracheal surgery
Evone® Ventilazione a flusso controllato: un nuovo dispositivo per la chirurgia
laringo-tracheale
Marta Filauro1,2,3, Francesco Mora1,2, Alberto Vallin1,2, Palmiro Della Casa4, Carlotta Arceri4, Angelo Gratarola4,
Giorgio Peretti1,2
1
  Unit of Otorhinolaryngology, IRCCS Ospedale Policlinico San Martino, Genoa, Italy; 2 Department of Surgical Sciences and
Integrated Diagnostics (DISC), University of Genoa, Italy; 3 Department of Experimental Medicine (DIMES), University of Genoa, Italy;
4
  Unit of Anesthesiology, IRCCS Ospedale Policlinico San Martino, Genoa, Italy


SUMMARY
The success of laryngotracheal surgery is mainly related to adequate exposure of the airway
lumen. To render airway surgery more efficient, many efforts have been made in recent
decades to obtain a safe ventilation system which uses an orotracheal tube that is as small
as possible. The first attempt was made by introducing the high frequency jet ventilation
(HFJV) technology in clinical practice. Nonetheless, HFJV has some risks related to the
high pressure needed for ventilation in the catheter. First, during HFJV, the expiration of air
from the lungs is a passive backflow on the trachea wall, potentially causing hypercapnia
and air trapping. Second, HFJV creates an open ventilation system that leads to aerosolisa-
tion of airborne particles with an increased infectious risk for the surgeon. To overcome
these issues, an innovative flow-controlled ventilation (FCV) system with a narrow-cuffed
catheter (Evone®; Ventinova, Eindhoven, The Netherlands) was introduced in clinical prac-
tice. This paper describes our initial experience with the Evone® FCV system, reporting
the first 5 cases ventilated with this technology. In this observational study, we evaluate
the feasibility and safety of the Evone® system and deliver a critical appraisal of this novel
method of ventilation.
KEY WORDS: laryngotracheal surgery, intubation, stenosis, recurrent respiratory                   Received: September 28, 2021
papillomatosis, jet ventilation                                                                   Accepted: December 23, 2021

RIASSUNTO                                                                                         Correspondence
Il successo della chirurgia laringotracheale è principalmente correlato a un’adeguata             Alberto Vallin
esposizione delle vie aeree, con l’utilizzo di un tubo oro-tracheale più piccolo possibile. Il    Unit of Otorhinolaryngology - Head and Neck Sur-
                                                                                                  gery, IRCCS Policlinico San Martino, University of
primo tentativo è stato fatto introducendo la tecnologia della ventilazione a getto ad alta
                                                                                                  Genoa, largo R. Benzi, 16132 Genoa, Italy
frequenza (VGAF) nella pratica clinica. Tuttavia, la VGAF presenta alcuni rischi legati           E-mail: a.vallin07@gmail.com
all’alta pressione necessaria per la ventilazione. Innanzitutto, durante la VGAF, l’espi-
razione dell’aria dai polmoni è un riflusso passivo sulla parete della trachea, che poten-
zialmente causa ipercapnia e intrappolamento d’aria. In secondo luogo, la VGAF crea un              How to cite this article: Filauro M, Mora F, Val-
sistema di ventilazione aperto che aumenta il rischio infettivo per il personale sanitario, a       lin A, et al. Evone® Flow controlled ventilation:
causa dei droplets immessi in circolo tramite aerosol. Per superare questi problemi, è stato        a new device for laryngotracheal surgery. Acta
                                                                                                    Otorhinolaryngol Ital 2022;42:189-193. https://
introdotto nella pratica clinica un innovativo sistema di ventilazione a flusso controllato
                                                                                                    doi.org/10.14639/0392-100X-N1834
con catetere a cuffia stretta (Evone®; Ventinova, Eindhoven, Paesi Bassi). Questo articolo
descrive la nostra esperienza iniziale con il sistema Evone®, riportando i primi 5 casi di
                                                                                                  © Società Italiana di Otorinolaringoiatria
pazienti ventilati con questa tecnologia. In questo studio osservazionale, valutiamo la fatti-    e Chirurgia Cervico-Facciale
bilità e la sicurezza del sistema Evone® e forniamo una valutazione critica di questo nuovo
metodo di ventilazione.                                                                                          OPEN ACCESS
PAROLE CHIAVI: chirurgia laringo-tracheale, intubazione, stenosi, papillomatosi                   This is an open access article distributed in accordance with
respiratoria ricorrente, jet ventilation                                                          the CC-BY-NC-ND (Creative Commons Attribution-Non-
                                                                                                  Commercial-NoDerivatives 4.0 International) license. The
                                                                                                  article can be used by giving appropriate credit and mentio-
                                                                                                  ning the license, but only for non-commercial purposes and
                                                                                                  only in the original version. For further information: https://
                                                                                                  creativecommons.org/licenses/by-nc-nd/4.0/deed.en




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Introduction                                                   the ventilation system shifts automatically to the HFJV,
                                                               thereby avoiding the need for a sudden new orotracheal
The success of laryngotracheal surgery is positively in-       tube insertion. This new device seems very encouraging
fluenced by adequate exposure of the airway lumen. To          since it could conceivably unite all benefits of different
render airway surgery more efficient, many efforts have        ventilation techniques, as it could offer similar secure,
been made in recent decades to obtain a safe ventilation       steady, and easy-to-follow ventilation as a normal bore
system that reduces, as much as possible, the diameter         tube 2. This paper describes our initial experience with
of the orotracheal tube. Several laryngotracheal diseases      the Evone® FCV system, reporting the first 5 cases ven-
cause, in fact, a critical reduction of the airway patency.    tilated using this technology. In this observational study,
In these conditions, it is necessary to use a highly narrow    we evaluate the feasibility and safety of the Evone® sys-
orotracheal tube (i.e. inner diameter 4.5 mm) that in most     tem and deliver a critical appraisal of this novel method
cases, however, does not allow safe ventilation of pa-         of ventilation.
tients. The first attempt to overcome this crucial issue was
made by introducing the high frequency jet ventilation
(HFJV) technology in selected patients. This anaesthesio-      Description of clinical techniques
logic technique is based on gas puffs delivered under high     and technology
pressure through a small catheter placed in the airway,        We prospectively collected data on the first 5 patients treat-
thus creating an open ventilation system 1. HFJV is use-       ed from May 2021 to July 2021 at the Unit of Otorhino-
ful in situations where access to the airway is potentially    laryngology, Head and Neck surgery of IRCCS Policlinico
hindered by the orotracheal tube, thanks to the small size     San Martino, Genoa, Italy. All patients were female. Two
of the catheter 1. However, HFJV has some drawbacks            were affected by idiopathic subglottic stenosis (ISS) and 3
due to the high pressure employed for ventilation through      by RRP with subglottic and tracheal extension. During the
a small catheter and the passive backflow of expired air       5 procedures, Evone® FCV was employed as an alternative
from the lungs, potentially causing hypercapnia and air        to standard endotracheal intubation or HFJV. The decision
trapping 1,2. This phenomenon of air trapping is more like-    to use Evone® was based on the pathology and planned sur-
ly to occur in case of severe narrowing of the airway and      gical procedure (endoscopic radial incisions and dilation
acts as a counterweight to the benefits of a smaller tube 2.   of severe subglottic stenosis, and endoscopic removal and
Moreover, creating an open ventilation system leads to         photocoagulation of subglottic and/or tracheal papilloma)
aerosolisation of airborne particles with increased infec-     (Fig. 1).
tious risk for the surgical team.
The leading causes of critical narrowing of the airway         Anaesthesia material and technical data on working
lumen are malignant and benign diseases, the most fre-         mechanism of Evone®
quent of which are selected glottic carcinomas, recurrent      Evone® is a flow-controlled ventilation system that uses
respiratory papillomatosis (RRP) and laryngototracheal         a tube with three lumens: one for the inflation and defla-
stenosis. In such situations, HFJV is not the ideal device     tion of the cuff, one for the measurement of the pressure in
for ventilation. In the case of patients affected by RRP,      the trachea, and one for the patient ventilation. As a flow-
the risk of aerosolisation of viral particles would expose     controlled ventilator, the machine does not rely on the pas-
health care workers to an extremely high risk of conta-        sive elasticity of the lung, but produces a negative pres-
gion. On the other hand, in the case of severe airway ste-     sure thanks to the Bernoulli principle, actively recalling air
nosis, the phenomenon of air trapping would not allow for      out of the lung during the expiratory phase (Figs. 2, 3). As
adequate ventilation of the patient.                           reported by other authors in the literature 3, the attending
To overcome these limitations, an innovative flow-con-         anaesthesiologist set the following ventilator parameters:
trolled ventilation (FCV) system with a narrow-cuffed          FiO2, inspiratory flow rate, Inspiratory:Expiratory (I:E)
catheter (Evone®; Ventinova, Eindhoven, The Nether-            ratio, PIP and EEP. Conventional capnography was used
lands) can actively expel air out of the lungs through         for evaluation of end-tidal carbon dioxide partial pressure
negative pressure. The negative pressure is generated us-      (PetCO2). Further measured values were minute volume,
ing jet-flow (Bernoulli’s principle) and was devised to        respiratory rate, inspiratory tidal volume (VT), peripheral
be automatised. It is normally used with a cuffed small        blood oxygen saturation (SpO2), noninvasively measured
lumen tube, which streamlines the ventilation while al-        blood pressure (NIBP) and heart rate (HR). The intratidal
lowing airway protection, with allegedly less hypercap-        tracheal pressure amplitude (Dp), defined as the difference
nia and hypoxia. In case of unintentional cuff breaking,       between PIP and EEP, was calculated offline.



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                                                                                                                               Evone® for laryngotracheal surgery




                                                                                     Figure 2. Evone® FVC system.




                                                                                     Figure 3. Evone® Tritube. The tritube is a cuffed tube with an external diam-
                                                                                     eter of 4.4 mm allowing a larger surgical field during elective surgery with a
                                                                                     lower risk of contamination.


                                                                                     olaryngoscopy, an ELS grade IIIa subglottic stenosis was
                                                                                     found. Evone® FCV ventilation was employed. Radial inci-
                                                                                     sions with CO2 laser Lumenis Encore Ultrapulse (Tel Aviv,
                                                                                     Israel) coupled with a digital Acublade micromanipulator
                                                                                     were performed. Endoscopic dilation with Savary bougies
Figure 1. (A-C) preoperative office flexible view of idiopathic subglottic ste-      was done at the end of the procedure.
nosis (Cotton-Myer grade III); (B-D) the tritube provides minimal traumatic in-
tubation and guarantees an ideal working space and exposure by maintaining           G.M.E., female, 74 years old
stable ventilation; (E) an advanced case of RRP (Derkay site score: 12; Derkay
clinical score: 7); (F) this difficult intubation can be achieved by small-lumen     G.M.E. was affected by recurrent ISS grade IIIb according to
ventilation, such as Evone®. This latter, compared to HFJV, protects against         ELS classification. She underwent several endoscopic dila-
aerosolisation of papillomavirus in the operating theatre; (G) the larynx of a pa-   tions between 2016 and 2017. From 2017 to early 2021, she
tient repeatedly treated for RRP with a posterior glottic stenosis (Bogdasarian
II); (H) the use of a narrow tube allows the treatment of the posterior compart-
                                                                                     did not complain of significant dyspnoea. She arrived at our
ment of the larynx, despite the presence of the posterior web.                       clinic in May 2021 complaining of worsening dyspnoea.
                                                                                     At preoperative videolaryngoscopy, an ELS grade IIIb sub-
                                                                                     glottic stenosis was diagnosed. Evone® FCV ventilation
Patient characteristics                                                              was employed. Radial incisions with CO2 laser Lumenis
C.B., female, 49 years old                                                           Encore Ultrapulse (Tel Aviv, Israel) coupled with a digital
C.B. was affected by idiopathic subglottic stenosis (ISS)                            Acublade micromanipulator were performed. Endoscopic
grade IIIa according to European Laryngological Society                              dilation with Savary bougies was done at the end of the
(ELS) classification system. She underwent previous endo-                            procedure.
scopic treatment in 2017. In March 2021, she complained                              P.R., female, 84 years old
of a new worsening of dyspnoea. At preoperative vide-                                P.R. was affected by RRP. She had undergone several mi-



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M. Filauro et al.




crolaryngoscopic procedures for papilloma excision by           conventional orotracheal tube in the presence of conditions
microdebrider and CO2 laser. At the last videolaryngos-         that cause critical airway narrowing can be difficult to im-
copy, multiple laryngotracheal papillomas were detected.        possible. Moreover, the use of small orotracheal tubes (i.e.
Derkay’s score was used to assess the severity of RRP 4.        internal diameter 4.5 mm) would not allow safe ventila-
The site Derkay score was 17, while the clinical Derkay         tion or optimal visualisation of the surgical field. HFJV
score was 8. Surgical intervention was carried out in emer-     was developed as the first anaesthesiologic technique that
gency due to the patient’s critical dyspnoea. Evon® FCV         allows surgeons to operate with a minute catheter inside
ventilation was employed due to the airway stricture and        the airways. This technique relies on a non-cuffed narrow
subglottic and tracheal extension of papillomas. The de-        endotracheal tube with an outside diameter of 4.3 mm and a
bulking of the lesion was carried out by microdebrider          specialised high frequency ventilator that insufflates small
with angled-tip 4-mm laryngeal (22.5-cm-long) Skimmer           volumes of air at a supraphysiological rate (typically 100-
blades (Medtronic-Xomed, Jacksonville, Florida). Suction        150/min). In the case of neoplastic lesions located at the
was applied without irrigation in oscillating mode at speeds    posterior third of the larynx, HFJV permits ventilating the
of 700 rpm. Laser photocoagulation of papillomas was per-       patient through a narrow catheter that allows complete ex-
formed with Wolf 445 nm TruBlue, by A.R.C. laser.               posure of the posterior compartment of the larynx, thus re-
                                                                ducing the need for orotracheal tube anterior dislodgement
G.L., female, 80 years old
                                                                or tracheotomy and reducing the rate of positive posterior
G.L. was affected by RRP. She underwent several micro-
                                                                margins 5. Nonetheless, the most common HFJV compli-
laryngoscopic procedures for papilloma excision by mi-
                                                                cations are hypoxia, hypercarbia, emphysema and blood
crodebrider and CO2 laser. At the last videolaryngoscopy,
                                                                aspiration for the absence of the cuff. The need to main-
multiple laryngotracheal papillomas were found, in particu-     tain a FiO2 of 30% during CO2 laser procedures, together
lar at the level of the posterior commissure and subglottic     with the risk of hypoxia related to HFJV, requires frequent
area. The location and extension of papillomas, associated      breaks during the surgery, to ensure proper oxygenation of
with the presence of iatrogenic posterior glottic stenosis      the patient. In addition, most patients with laryngeal ma-
(Bogdasarian grade II), caused mild dyspnoea. Site Derkay       lignancies are heavy smokers and, therefore, have critical
score was 7 and clinical Derkay score was 3, for a total        pulmonary comorbidities, which places them at greater
Derjay score of 10. Evone® FCV ventilation was employed         risk of barotrauma. Moreover, HFJV causes fluttering of
to ensure adequate exposure of the posterior commissure,        vocal cords that makes the procedures potentially less ac-
subglottic and tracheal areas, allowing complete removal        curate 2. In addition, any condition that may reduce expira-
of papillomas. The patient underwent the same surgical ap-      tory flow, such as severe laryngotracheal stenosis, is to be
proach as case 3.                                               considered an absolute contraindication to the use of HFJV,
R.A., female, 42 years old                                      since it would increase the risk of air trapping and baro-
R.A. was affected by RRP. She underwent several micro-          trauma. Lastly, the use of HFJV during treatment of ob-
laryngoscopic procedures for papilloma excision by mi-          structive laryngotracheal RRP is debated; HFJV creates an
crodebrider and CO2 laser. At the last videolaryngoscopy,       open ventilation system, causing airborne aerosolisation of
multiple laryngeal and tracheal papillomas were found.          HPV, leading to an increased infectious risk for healthcare
Site Derkay score was 4, with a bulky lesion at the subglot-    workers.
tic level. Clinical Derkay score was 7, for a total Derkay      To overcome these issues, the most recent step in small lu-
score of 11. Evone® FCV ventilation was employed due to         men ventilation is the development of a ventilator that is
critical reduction of the airway lumen and subglottic and       able to actively remove air from the lungs using negative
tracheal extension of papillomas. The patient underwent         pressure. Ventilators that use this novel method of active air
the same surgical approach of the case n. 3.                    removal and that do not rely on passive lung emptying are
No minor or major complications were reported during an-        called ‘flow-controlled’ ventilators (FCVs) such as Evone®
aesthesiologic and surgical procedures. The postoperative       (Ventinova, Meerenakkerplein 7, 5652 BJ Eindhoven Neth-
course of all patients was regular and all patients were dis-   erlands) 2. The negative pressure is generated using jet-flow
charged the day after the operation.                            (Bernoulli’s principle) that is performed automatically. It
                                                                is used with a cuffed small lumen tube (e.g., Tritube® by
                                                                Ventinova), which optimises the ventilation and eliminates
Discussion                                                      the risk of blood aspiration, aerosilisation, hypoxia and hy-
Ensuring good exposure of the airway is key of success-         percapnia 2. The Tritube has three lumens: one for the infla-
ful transoral surgery, although attempting to introduce a       tion and deflation of the cuff, one for measurement tracheal



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                                                                                                           Evone® for laryngotracheal surgery




pressure, and one lumen for patient ventilation. The most          Conflict of interest statement
significant risk is that during the active removal of air from     The authors declare no conflict of interest.
the airways any thick secretions may obstruct the lumen of
the Tritube, thus preventing proper ventilation of the pa-         Funding
tient. For this reason, about an hour before the surgical pro-     This research did not receive any specific grant from fund-
cedure, it is recommended to perform premedication of the          ing agencies in the public, commercial, or not-for-profit
patient with a long-lasting anticholinergic drug to reduce         sectors.
secretions 2. The Tritube is not certified as a laser-safe tube,
and in case of accidental perforation of the cuff by laser the     Authors’ contributions
Evone® switches automatically to HFJV mode. Moreover,              All named authors meet the International Committee of
it is important to note that the Tritube is not made with an       Medical Journal Editors (ICMJE) criteria for authorship for
inflammable material, so that there is no risk for the patient.    this article, take responsibility for the integrity of the work
However, to avoid any issues, it is mandatory to protect the       as a whole, and have given their approval for this version
tube and the cuff with wet gauze and a FIO2 ≤ 30% should           to be published.
be maintained during laser procedures.
The Evone® system seems very promising: it can potential-          Ethical consideration
ly overcome all the drawbacks of HFJV, providing stable            This study was approved by the Institutional Ethics Com-
and safe ventilation, with the benefit of increasing exposure      mittee (Comitato Etico Regionale della Liguria) (protocol
of the working space for the surgeon. For these reasons, in        number 63/2021 - DB id 11240).
case of high-grade subglottic stenosis and/or diffuse RRP,         The research was conducted ethically, with all study pro-
our choice is the Evone® system to reduce the risk of com-         cedures being performed in accordance with the require-
plications thanks to the presence of the cuff and the possi-       ments of the World Medical Association’s Declaration of
bility to actively manage the expiratory phase, without the        Helsinki.
risk of air trapping, and with creation of a stable and wide       Written informed consent was obtained from each partici-
transoral surgical field: the cuff preserves the airways from      pant/patient for study participation and data publication.
bleeding and protects the surgical team from viral aerosoli-
sation during RRP surgery.
Finally, an additional field of application of the Evone® is       References
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