Introduction
Medialisation thyroplasty is considered the ‘gold standard’ treatment for unilateral vocal fold paralysis, enabling improvement of voice and swallowing function, and preventing life-threatening aspiration events.Reference Siu, Tam and Fung1 Though other procedures, such as injection laryngoplasty, arytenoid adduction and laryngeal reinnervation, can be used to treat this condition, medialisation thyroplasty has the advantage of allowing intra-operative manipulation of the implant to achieve the desired vocal quality.Reference Harries2, Reference Benninger, Crumley, Ford, Gould, Hanson and Ossoff3
Some of the most commonly used laryngeal implant materials include Gore-Tex®, Silastic® and hydroxyapatite,Reference Young, Zullo and Rosen4 but all induce some degree of local tissue inflammatory response, and carry the risk of immediate or delayed implant extrusion.Reference Alonso, Kaimal, Look, Swift, Fricton and Myers5, Reference Sclafani and Romo6 This risk is greater in patients who have received chemoradiation to the neck.Reference Rosow and Al-Bar7 Laryngeal framework surgery is generally considered to be safe in irradiated patients, but some studies have suggested a higher post-operative minor complication rate.Reference Shoffel-Havakuk, Merati and Johns8
Here, we describe a novel approach for medialisation thyroplasty, utilising a ribbon of autologous tensor fascia lata harvested at the time of surgery. This is layered within the paraglottic space in a manner similar to Gore-Tex thyroplasty. Tensor fascia lata is widely used for many applications including implanted slings for facial paralysis, with proven safety and durability.Reference Langille and Singh9 By auto-transplanting the patient's native tissue, we hypothesise that the risks of implant extrusion, and other minor complications such as local infection or transient oedema, will be significantly reduced. Fascia lata has been employed in a similar manner in the larynx in animal models, demonstrating minimal inflammatory response on histological sections.Reference Pinna Bde, Stavale, Pontes and Camponês do Brasil Ode10, Reference Reijonen, Leivo, Nevalainen and Rihkanen11
Given the increased risk of post-operative wound breakdown and infection in irradiated patients, we believe that this new approach will lead to improved outcomes and decreased complication rates, particularly in this patient population.
Materials and methods
Patients with a history of radiotherapy to the neck, with unilateral vocal fold paralysis and a large glottic gap, were selected to undergo the procedure (Figure 1). The procedure is performed under local anaesthesia with intravenous sedation, to allow for patient vocalisation intra-operatively. In order to accomplish this technique, a strip of tensor fascia lata is harvested from the lateral thigh. This is left to desiccate during the approach in the neck (Figure 2).
Fig. 1 Pre-operative examination showing: full abduction with inspiration (a), and full adduction with phonation (b). There is a large glottic gap with phonation due to right vocal fold paralysis despite contralateral hyperfunction.
Fig. 2 The patient had significant scarring and fibrosis of the neck because of a prior pectoralis flap and radiation exposure (a). The lateral thigh is prepped to allow for fascia lata harvest (b). The fascia lata is allowed to desiccate before being trimmed to an appropriate size, with the approximate cuts made to achieve the full length of fascia lata, outlined in green (c).
The thyroid cartilage is exposed from an anterior neck incision in the typical fashion. A window is drilled into the lower aspect of the thyroid lamina using cutting and diamond burrs, and subsequently the inner perichondrium of the thyroid lamina is entered using a Penfield elevator to create a tight pocket in which the graft will be placed.
The fascia lata is then cut into a 3 mm wide ribbon with a length of approximately 15–20 cm, as demonstrated in Figure 2c. The ribbon is layered into the paraglottic space. Flexible fibre-optic laryngoscopy is performed while the patient is asked to phonate. The graft amount and position is adjusted to obtain optimal vocal quality and glottic gap closure. The ribbon is trimmed at the appropriate length and the window sealed with bone wax to prevent migration. Additional means of implant fixation are avoided to minimise foreign body reaction. The neck and thigh are then closed in the usual fashion.
Results
Thus far, this method has been accomplished in two patients with unilateral vocal fold paralysis, who had previously received intensity-modulated radiotherapy to the primary site and ipsilateral neck for stage III oropharyngeal squamous cell carcinoma. Both patients had symptoms of aspiration and breathiness, which were significantly impacting quality of life prior to laryngoplasty.
Post-operatively, both patients demonstrated complete closure of the glottic gap during phonation and excellent wound healing (Figure 3). Neither patient has shown signs of infection, inflammation, airway compromise or extrusion. Voice quality improved, as demonstrated by a significant improvement in grade, roughness, breathiness, asthenia and strain (‘GRBAS’) scores. Pre-operatively to six weeks post-operatively, the scores improved from 8 to 0 in patient one, and from 11 to 2 in patient two. No complications were observed in the fascia lata donor site in the leg. Both patients have continued to experience excellent voice outcomes without complications one year after surgery.
Fig. 3 Post-operative examination showing: full abduction with inspiration (a), and full adduction with phonation (b).
Discussion
Patients with a history of radiation to the neck have a significantly increased risk for post-operative complications and wound infections for subsequent surgery in the head and neck.Reference Girod, McCulloch, Tsue and Weymuller12 Though generally considered safe for the carefully selected patient,Reference White, Orbelo, Noel, Pittelko, Maragos and Ekbom13 traditional laryngeal framework surgery in this population may be associated with minor post-operative wound complications.Reference Shoffel-Havakuk, Merati and Johns8 Major complications have been reported in some case series as well, including fistula formation and implant extrusion.Reference Netterville, Stone, Luken, Civantos and Ossoff14, Reference Lam, Ho, Ng and Wei15
Therefore, we developed the fascia lata thyroplasty technique so that permanent vocal fold medialisation could be achieved using the patient's native tissue, thus decreasing the likelihood of implant rejection or wound breakdown. This is the first time this technique has been described in the literature. Both patients who have undergone this procedure have had durable improvement in voice quality, without peri-operative or long-term wound complications. For patients with an increased risk of wound healing impairment, we believe that use of tensor fascia lata as the implanted material in type I thyroplasty should be strongly considered.
Conclusion
Patients with unilateral vocal fold paralysis and a history of radiation exposure have an increased risk for complications after conventional thyroplasty techniques, including extrusion or wound infection. Medialisation thyroplasty using a tensor fascia lata graft is a novel technique that produces excellent post-operative voice outcomes and may reduce the risk of developing surgical complications.
