Introduction
Moderate glottic airway compromise secondary to bilateral abductor vocal fold paralysis or fixation has previously been treated with bilateral transverse cordotomy, in order to avoid the morbidity resulting from a tracheostomy.Reference Kashima1, Reference Bajaj, Sethi, Shayah, Harris, Henshaw and Coatesworth2 However, loss of tissue from the posterior glottic aperture can reduce the quality of phonation.
Airway improvement can also be achieved by unilateral transverse cordotomy, in which case only one vocal fold is divided from the vocal process to allow it to retract anteriorly. This conservative approach widens the posterior glottic airway, while anterior thickening or ‘bunching-up’ of the vocal fold maintains phonatory contact with the unoperated vocal fold. The result is an improved airway, with some evidence for little or no change in voice.Reference Kashima1
Here, we present a series of seven consecutive cases treated with unilateral transverse cordotomy.
Materials and methods
Cases were recorded on the electronic otolaryngology database at University Hospital of South Manchester, UK (Table I).
Table I Case series
Sx = surgery; y = years; FU = follow up; mth = months; R = right; L = left; Sep = September; Apr = April; Aug = August; Oct = October; Hx = history; – = not applicable
All surgery was carried out by the last author (PHJ). Under maximum microscope magnification and using Bouchayer needle monopolar diathermy, the vocal fold was completely released from the vocal process of the arytenoid cartilage on one side, without loss of mucosa or cartilage. The procedure is shown diagrammatically in Figure 1. Post-operatively, patients were treated prophylactically with intravenous steroids for six to 24 hours.
Fig. 1 Line drawing illustrating left unilateral transverse cordotomy: (a) vocal folds lying in a paramedian position pre-operatively; (b) the incision, anterior to the vocal process; and (c) passive anterior retraction of the vocal fold.
Patients were assessed in a multi-disciplinary voice clinic. Pre-operative and post-operative airway and voice data were collected retrospectively from the patients’ medical and speech and language therapy records. Post-operative voice data were not available for two cases due to cancer-related mortality. Follow-up data for the remaining five cases were obtained prospectively. Subjective airway assessment was conducted using the Medical Research Council dyspnoea scale 2007 (Table II).Reference Fletcher3 Other outcome measures included the presence of stridor, exercise tolerance, Voice Symptom Scale score, Grade-Roughness-Breathiness-Asthenia-Strain (‘GRBAS’) scale score, and out-patient laryngoscopic appearance.Reference Webb, Carding, Deary, MacKenzie, Steen and Wilson4, Reference Wilson, Webb, Carding, Steen, MacKenzie and Deary5
Table II Medical research council dyspnoea scale 2007
Results and analysis
Eight consecutive patients who presented subacutely with airway compromise secondary to bilateral abductor vocal fold paralysis or fixation were selected to undergo unilateral transverse cordotomy between August 2006 and April 2010 at University Hospital of South Manchester, UK.
Aetiology included congenital factors, rheumatoid cricoarytenoid ankylosis, thoracic surgery, bronchogenic carcinoma, metastatic adenoid cystic carcinoma and presumed damage from glottic radiotherapy; some cases were idiopathic. Patient data are shown in Table I.
Transverse cordotomy was aborted in one patient with bilateral rheumatoid cricoarytenoid ankylosis (case H) because of inadequate transoral access; a tracheostomy was required.
The remaining seven cases underwent unilateral transverse cordotomy (six left-sided and one right-sided). Left-sided cordotomy was preferred by the surgeon, who was right-handed. Figure 2 shows typical examples of later endoscopic appearances after cordotomy.
Fig. 2 Fibre-optic laryngoscopic appearance after unilateral transverse cordotomy in (a) case A at 9 months and (b) case C at 12 months.
All seven successfully operated patients derived subjective airway function improvement, and none required contralateral cordotomy or permanent tracheostomy. There was no aspiration or dysphagia. Patients’ improvement in breathing is shown in Table III. Two patients died of cancer five and six weeks post-operatively, variously. Case C required a temporary tracheostomy tube prior to unilateral transverse cordotomy, and the tube was removed three months post-operatively without recurrence of airway compromise.
Table III Airway assessment before and after unilateral transverse cordotomy
Dysp score = Medical Research Council dyspnoea score 2007; URTIs = upper respiratory tract infections; mth = months; – = not done; FU = follow up; Ca = cancer; wk = weeks; ITU = intensive therapy unit
In four cases, voice could be assessed both pre-operatively and 12 to 36 months (mean 22 months) post-operatively. In these patients, the post-operative Voice Symptom Scale and Grade-Roughness-Breathiness-Asthenia-Strain scale scores, measured by a senior speech and language therapist (SMJ), were either unchanged or slightly worse, compared with pre-operative scores. These results are summarised in Table IV.
Table IV GRBAS and VoiSS scores before and after unilateral transverse cordotomy
GRBAS = Grade-Roughness-Breathiness-Asthenia-Strain scale; VoiSS = Voice Symptom Scale; – = not done
Discussion
In bilateral abductor vocal fold immobility, the vocal folds lie in a paramedian position, which may result in airway obstruction. The development of airway compromise is often gradual, and stridor may be worsened by an upper respiratory tract infection. The voice quality is usually good because the vocal folds are in the paramedian position. Bilateral vocal fold palsy may occur synchronously or asynchronously, and may be due to congenital factors, iatrogenic factors (such as thoracic surgery) or cancer (such as carcinoma of the lung). Some cases are idiopathic. During forced inspiration, the vocal folds are drawn together, and some cases require emergency tracheostomy.
When there is significant but not life-threatening airway obstruction, elective surgical intervention improves dyspnoea. Tracheostomy is an effective means of managing bilateral abductor vocal fold paralysis or fixation, but there is significant associated morbidity. In the subacute setting and even acutely, endoscopic techniques have been advocated as an alternative to tracheostomy; these include arytenoidectomy, cordectomy and cordotomy. However, these procedures improve the airway at the cost of compromising the voice. To date, there have been no randomised, controlled trials of such treatment, probably because of the relative infrequency of presentation of bilateral vocal fold paralysis and fixation.
In 1922, Jackson described the first cordectomy, in which the true vocal fold and part of the false vocal fold were excised unilaterally to enlarge the glottic aperture.Reference Jackson6 In 1939, King described external latero-fixation of the arytenoids, and two years later Kelly published a case treated with external arytenoidopexy.Reference King7, Reference Kelly8 External arytenoidectomy was described in 1946 by Woodman, and endoscopic arytenoidectomy in 1948 by Thornell.Reference Woodman9, Reference Thornell10 In 1908, Citelli described cordectomy by laryngofissure.Reference Citelli11 However, such external approaches have now been superseded by endolaryngeal surgery.
Steiner and Ambrosch have advocated posterior laser cordectomy, a technique first reported by Burian and Hofler in 1979, in which the posterior third of each vocal fold, including the vocal process, is resected using a laser.Reference Burian and Hofler12 Steiner and Ambrosch reported no aspiration following this procedure, but did encounter unpredictable granuloma and scar formation.Reference Steiner and Ambrosch13 Dennis and Kashima described posterior laser cordectomy in 1989, advocating its use in the acute situation as an alternative to tracheostomy.Reference Dennis and Kashima14 In one 1994 study comparing 18 patients treated with laser cordectomy and 10 patients treated with laser arytenoidectomy, airway and voice outcomes were equivalent.Reference Eckel, Thumfart, Wassermann, Vossing and Thumfart15 However, arytenoidectomy may cause aspiration, and in 1996 Remacle et al. described subtotal arytenoidectomy performed in an attempt to reduce the risk of aspiration.Reference Remacle, Lawson, Mayne and Jamart16 A retrospective review of 52 children treated in Boston, Massachusetts, concluded that the tracheostomy decannulation rate was higher after vocal fold lateralisation with partial arytenoidectomy (71 per cent) than after cordotomy (29 per cent, p = 0.008), full arytenoidectomy (25 per cent, p = 0.000004) or posterior cricoid split with costal cartilage graft insertion (60 per cent, p = 0.0004).Reference Hartnick, Brigger, Willging, Cotton and Myer17
In the cordotomy procedure, vocal ligament and muscle are completely divided from the vocal process so that the vocal fold retracts passively and anteriorly to enlarge the glottic aperture. This is shown in Figures 1 and 2. Kashima was the first to introduce unilateral transverse cordotomy, in 1991, and Wang et al. described the procedure in four cases.Reference Kashima1, Reference Wang, Zhou and Xu18 Bosley et al. described bilateral transverse cordotomy in 11 patients and compared it with medial arytenoidectomy in six; blinded perceptual voice analysis detected no difference between the two groups.Reference Bosley, Rosen, Simpson, McMullin and Gartner-Schmidt19
• Bilateral abductor vocal fold immobility impairs glottic airway, voice and swallow, and may require tracheostomy
• Bilateral transverse cordotomy has previously been used
• Unilateral transverse cordotomy divides the vocal fold on one side only
• It is an effective alternative, with reasonable voice preservation and no aspiration
In 2009, Lagier et al. published a series of 11 infants treated with laser posterior cordotomy, with a mean follow-up of 27 months. Seven of these 11 did not undergo tracheostomy, and cordotomy was the primary procedure. One of these seven infants died due to microcephaly. Of the four already treated with tracheostomy, two were decannulated following surgery, and two more were decannulated after revision surgery (one of these having undergone failed external King arytenoidopexy before cordotomy).Reference Lagier, Nicollas, Sanjuan, Benoit and Triglia20
In four of our cases, we were able to assess voice both before and after unilateral transverse cordotomy, and we found little change. Breath support may be improved following this procedure, compared with bilateral transverse cordotomy, because of the more conservative approach. We did not measure respiratory function in our patients; however, in a study of 16 patients with bilateral vocal fold immobility, the results of flow-volume loop analysis of breathing did not correlate with the dyspnoea score or the glottic aperture measured by computed tomography.Reference Gokcan, Kurtulus, Ustuner, Ozyurek, Kesici and Erdem21
Conclusions
In patients with bilateral abductor vocal fold paralysis or fixation, unilateral transverse cordotomy is an effective alternative to bilateral transverse cordotomy or tracheostomy. In our one case requiring temporary tracheostomy for airway obstruction, the tube was removed three months after unilateral transverse cordotomy, without return of dyspnoea or exercise limitation. The procedure results in improved airway function and capacity for physical activity, and leaves the voice unchanged or only slightly worse. This is a more conservative procedure than bilateral transverse cordotomy, with potentially better voice preservation.
