Introduction
Office-based laser laryngeal surgery has been an evolving therapeutic modality since it was first introduced for the treatment of benign laryngeal conditions.Reference Zeitels, Franco, Dailey, Burns, Hillman and Anderson 1 The advantages of this approach over traditional operating theatre techniques are numerous, and include decreased cost, improved safety and a shortened recovery time.Reference Halum and Moberly 2
The carbon dioxide (CO2) laser is invisible and absorbed by water. It has a penetration depth of 0.03 mm in soft tissue, and there is minimal reflection or scattering.Reference Reinisch, Ossoff, Snow and Ballenger 3 Because of these properties, the CO2 laser is commonly used in the surgical treatment of upper aero-digestive tract lesions. However, it was not until 2004 that the flexible CO2 laser was introduced to the surgical field.Reference Anastassiou, Weisberg, Dellemann, Shurgalin, Jacobs and Farinelli 4 The first reported use of the flexible CO2 laser in an office-based setting on laryngeal pathologies was in 2007.Reference Koufman, Rees, Frazier, Kilpatrick, Wright and Halum 5
This article demonstrates the feasibility of utilising clinic-based fibre-optic CO2 laser delivered via a transnasal flexible laryngo-oesophagoscope. Our case series, the largest to date, highlights the potential range of applications and the start-up costs for this technology.
Materials and methods
This study received approval from the local clinical research and audit governance committee. All patients provided informed consent before commencing treatment. Patient information was stored in a secure location, with anonymous evaluation of results.
This prospective case series comprised patients treated in a tertiary head and neck cancer centre from January 2015 through to June 2016. Thirteen patients (14 procedures) who underwent fibre-optic CO2 laser surgery delivered via a transnasal flexible laryngo-oesophagoscope in an out-patient clinic were included. Only adult patients with benign laryngo-pharyngeal pathologies who could tolerate a transnasal flexible laryngo-oesophagoscope procedure were included. Other inclusion criteria for CO2 laser surgery delivered via a transnasal flexible laryngo-oesophagoscope included lack of fitness for general anaesthesia (GA), because of an anatomically inaccessible larynx or because of multiple previous GA procedures.
Patients were assessed with regard to response to treatment and overall satisfaction using a validated questionnaire.Reference McCarthy, Trigg, John, Gough and Horrocks 6 We also conducted a systematic review, searching for relevant English-language publications published from 1 January 1995 to 31 July 2015.
Risks of CO2 laser delivered via a transnasal flexible laryngo-oesophagoscope were explained to patients. These include risks of the procedure itself (epistaxis, vasovagal episodes) and risks of the laser (inadvertent burns, fire, respiratory complications secondary to airway oedema).
A transnasal flexible laryngo-oesophagoscope (Pentax 80 K Series Digital Video Endoscope; Pentax, Slough, UK) was utilised to deliver the CO2 laser. This 5.1 mm diameter scope is equipped with a digital chip at the distal tip, with the capacity to view, print and record high-resolution colour images. Suction, irrigation and insufflation of the mucosal surface facilitate clinical assessment. In addition, a 2.0 mm instrument channel allows passage of the CO2 laser fibre or biopsy forceps.
Procedures were performed in a room that was assessed by health and safety officers, and modified to comply with national laser safety standards. Patients were seated in the centre of the room in a dental chair, which could be adjusted quickly in cases of a vasovagal episode. The transnasal flexible laryngo-oesophagoscope stack was positioned to the right side of the patient; the nurse was positioned to the left. The laser machine was located to the left of the patient and slightly to the back. The laser operator was positioned behind the laser machine, and the surgeon and a trained assistant stood in front of the patient. There was a suction machine and oxygen port with facemask and nasal prongs within the room. A resuscitation trolley was kept close by in case of any adverse effect. A topographic view of the setup is shown in Figure 1.
Topographic view of the transnasal flexible laryngo-oesophagoscope laser clinic setup. O2 = oxygen
All procedures in this study were performed by the senior author (RGN), whose role was to operate the laser pedal and navigate the transnasal flexible laryngo-oesophagoscope. The surgeon was assisted by a trained ENT doctor, who helped to keep the laser fibre at the right distance (approximately 5 mm) from the lesion (near-contact mode). There was also a trained nurse, who operated the laser device, and a circulating nurse.
The risk of fire was minimised because the laser was used in a near-contact point. In addition, all staff had undergone mandatory laser safety training. Safety glasses were worn and the door was locked while the procedure was taking place.
Use of the transnasal flexible laryngo-oesophagoscope has a long record of safety in the literature.Reference Mohammed, Masterson, Gendy and Nassif 7 Additionally, no significant airway oedema associated with CO2 laser delivered via a transnasal flexible laryngo-oesophagoscope has been recorded in the literature.
Carbon dioxide laser surgery delivered via a transnasal flexible laryngo-oesophagoscope was conducted under local anaesthesia, without sedation or cardiac monitoring. Two sprays of lidocaine hydrochloride (5 per cent) with phenylephidrine (0.5 per cent) aerosol solution were applied to each nostril. A further two sprays of lidocaine (10 per cent) aerosol solution were applied to the oropharynx. Then, a total of 5 ml lidocaine 2 per cent gel was used in the nostrils (1.5 ml in each nostril) and to lubricate the scope (2 ml). The laryngeal region was further anaesthetised with 1–2 ml of 4 per cent lidocaine passed down a Portex (16 gauge) epidural catheter using the transnasal flexible laryngo-oesophagoscope instrument channel.
The AcuPulse DUO CO2 device (Lumenis, Yokneam, Israel) was utilised to generate the laser beam. This method of delivery incorporates a FiberLase® single-use device inserted into the working channel of the flexible endoscope. When necessary, biopsies are taken using flexible biopsy forceps. Of note, there are new techniques, such as virtual chromoendoscopy,Reference Kodashima and Fujishiro 8 which could potentially aid decision making regarding the need for biopsy and increase the likelihood of more representative biopsies. However, such techniques are not an option with our transnasal flexible laryngo-oesophagoscope machine.
Results
The literature search yielded 53 articles, of which only 3 involved CO2 laser delivered via a transnasal flexible laryngo-oesophagoscope.Reference Halum and Moberly 2 , Reference Koufman, Rees, Frazier, Kilpatrick, Wright and Halum 5 , Reference Verma and Dailey 9 A further study was excluded because it lacked sufficient clinical information.Reference Verma and Dailey 9 The included studies are summarised in Table I.
Literature review of CO2 laser delivered via transnasal flexible laryngo-oesophagoscope
CO2 = carbon dioxide; No. = number; RRP = recurrent respiratory papillomatosis; GA = general anaesthesia
Details of patients who underwent treatment with flexible CO2 laser
*Patient underwent a second procedure for the other vocal fold. †Patient had previously been treated with flexible carbon dioxide laser via transnasal flexible laryngo-oesophagoscope under general anaesthetic. CO2 = carbon dioxide; M = male; VF = vocal fold; FU = follow up; RRP = recurrent respiratory papillomatosis; GA = general anaesthesia; TNFLO = transnasal flexible laryngo-oesophagoscope; F = female; RT = radiotherapy
Our study included 13 patients (7 males and 6 females), aged 36–77 years. Two patients underwent CO2 laser surgery delivered via a transnasal flexible laryngo-oesophagoscope twice. Demographics, clinical indications and outcomes are summarised in Table II.
Patient satisfaction outcomes revealed that 12 of the 13 patients tolerated the procedure well, with minimal discomfort and no complications (Figure 2).
Patients’ reported feedback on carbon dioxide laser delivered via a transnasal flexible laryngo-oesophagoscope.
The duration of the procedure (not including local anaesthesia application) ranged between 30 and 45 minutes.
Discussion
Previous research supports an improvement in peri-procedural discomfort levels for unsedated out-patient based laryngeal laser surgery in the small cohort of patients who have experienced both awake and GA CO2 laser interventions.Reference Koufman, Rees, Frazier, Kilpatrick, Wright and Halum 5 Patients’ feedback from our study showed overall satisfaction with the intervention, with only a mild degree of anxiety experienced during the procedure (Figure 2). All patients in this study except one tolerated the intervention.
The evidence thus far (including the findings of this study) suggest that CO2 laser delivered via a transnasal flexible laryngo-oesophagoscope is a versatile technique, with potential application for a range of benign pathologies in the laryngopharyngeal region. In our experience, it serves patients for whom traditional alternatives are not possible, or patients with pathologies requiring multiple procedures (e.g. recurrent respiratory papillomatosis, which was also highlighted in the literature).Reference Halum and Moberly 2 , Reference Koufman, Rees, Frazier, Kilpatrick, Wright and Halum 5
Limitations, in our experience, include the restricted length of the procedure, and dynamic changes in the surgical field (swallowing, breathing, vocalising and moving) which can lead to minor (not uncommon) inaccuracies with the laser beam. However, importantly, the distance travelled by the CO2 laser from the distal end of the optical fibre to the laryngeal surface (near-contact mode) is far less than in conventional microlaryngoscopy (approximately 400 mm). This reduces scattering and reflection of the laser (even when adjusting for dynamic changes). Additionally, CO2 laser delivered via a transnasal flexible laryngo-oesophagoscope was used to evaporate rather than excise lesions, which means that it is still necessary to obtain a tissue diagnosis before attempting the procedure. Another limitation is submucosal lesions (e.g. lingual tonsils), which can be very painful, even with repeat application of local anaesthesia. Of note, the amount of tissue that can be evaporated in one procedure is small to moderate, primarily because of patient tolerability issues. Finally, CO2 laser delivered via a transnasal flexible laryngo-oesophagoscope is best suited to non-vascular (rather than vascular) lesions.
In this technique, ‘cost’ can be divided into two types: the initial setup fee and the price of consumables for each patient. The AcuPulse DUO (costing approximately £80 000) can be used in an out-patient clinic or operating theatre, with extra accessories such as a micromanipulator being required. Currently, the consumable cost of the fibre and endoscopic sheath is approximately £770 per patient. The ‘payment by result’ remuneration for this procedure provides an advantage compared to similar GA interventions. This may enable other hospital managers to hire the initial equipment under a ‘lend lease’ agreement.
Conclusion
This article demonstrates the feasibility of utilising clinic-based CO2 laser delivered via a transnasal flexible laryngo-oesophagoscope, which has potential applications for a wide range of pathologies in the head and neck. It appears to be well tolerated by patients, with high satisfaction rates. It also offers significant long-term savings when compared to similar procedures performed under GA. Further research is required to standardise clinical indications for this promising new technique.
