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Presented at the Meeting of the Western Section of the American Laryngological, Rhinological and Otological Society, Inc., San Francisco, California, January 9, 2000.
Objective To describe the technique of combined Gore-Tex medialization thyroplasty with arytenoid adduction and to determine the long-term vocal outcome of patients treated for unilateral vocal cord paralysis with this procedure.
Study Design A retrospective chart review and patient reevaluation for patients treated at The University of Iowa Hospitals and Clinics between May 1995 and June 1999.
Methods The review addressed patient demographics, perioperative and long-term complications, and voice outcomes. Details of the surgical technique are provided within the manuscript.
Results Seventy-two Gore-Tex medialization procedures were completed. Arytenoid adduction was included in 22 of these procedures. This subset of patients was compared with the patients treated with Gore-Tex alone. No major postoperative complications occurred in either group. Preoperative and postoperative voice and videostroboscopy data were available for 19 arytenoid adduction patients and 25 Gore-Tex alone patients. On a seven-point scale (6 [severely abnormal] → 0 [normal voice]), the average patient rating of voice dysfunction improved from 4.2 to 1.6 (arytenoid adduction) and 4.5 to 2.8 (Gore-Tex alone). Maximum phonation time improved from 6.9 seconds to 16.7 seconds in the arytenoid adduction group. Subjective voice assessment employing the four-point GRBAS scale (3 [severely abnormal] → 0 [normal]) identified average improvement from an overall grade of 2.1 to 0.8 arytenoid adduction and 2.2 to 1.5 in the Gore-Tex alone group. Improvement was identified in the vocal quality of breathiness from 1.9 to 0.2 (arytenoid adduction) and 1.9 to 0.9 (Gore-Tex alone).
Conclusions The combined technique of Gore-Tex medialization thyroplasty and arytenoid adduction provide functional results that appear to exceed the improvement attained with medialization alone.
The use of Gore-Tex (W.L. Gore & Associates, Inc. Flagstaff, AZ) in medialization thyroplasty was first published in 1996 1 and a detailed description and preliminary results followed in 1998. 2 Additional experience with Gore-Tex was published by Giovanni et al. 3 in 1997. A follow-up article appeared in 1999. 4 These initial descriptions of the technique did not include details on the combination of Gore-Tex medialization thyroplasty and arytenoid adduction. Isshiki et al., 5 in their original description of arytenoid adduction, acknowledged the limitations of type I thyroplasty. In one of the cases reported in Isshiki's initial review arytenoid adduction was used to close the posterior glottis after incomplete closure following type I thyroplasty. Mahieu et al., 6 Slavit et al., 7 Thompson et al., 8 and others 1,9,10 have further detailed the surgical methods and clinical outcomes of combined Silastic medialization thyroplasty and arytenoid adduction. In many cases the presence of an open posterior glottis has made complete glottic closure difficult without manipulation of the thyroarytenoid joint and arytenoid position. The primary limitations of type I thyroplasty are inability to close a wide posterior glottal chink and change a difference in the horizontal plane of the two vocal folds. This repositioning is difficult with implant materials alone primarily because the posterior glottis and arytenoid cartilages reside outside the paraglottic space manipulated by implant materials. Gore-Tex has many advantages over hard implants, but it remains difficult to completely close a posterior glottic gap with the implant alone. Combining arytenoid adduction with Gore-Tex medialization resolves this difficulty.
In this current report we outline the modified surgical methods of combined Gore-Tex thyroplasty and arytenoid adduction, as well as discuss patient outcomes and voice results. As the techniques of arytenoid adduction and medialization thyroplasty have evolved, they have each become simpler and easier to perform, producing predictable vocal improvement. This current 4-year review provides a detailed assessment of outcomes as well as a verbal and illustrative outline of the technique of combined arytenoid adduction and Gore-Tex vocal cord medialization.
This study was approved by the University of Iowa, Human Subjects Investigational review board. The information was obtained through a review of the patient medical records, as well as voice data collected and stored in the Department of Speech Language Pathology. The charts were reviewed for patient demographics, prior laryngeal procedures, surgical data, perioperative complications, and long-term postoperative complications. This review included identification of postoperative infections and airway problems, as well as long-term infections, and swallowing, airway, or implant complications. The speech pathology departmental videostroboscopy and voice database was searched for voice data as outlined below.
The surgical technique of Gore-Tex thyroplasty has been previously reported, 2 but some minor modifications have since been made. The inclusion of arytenoid adduction requires additional dissection and cartilage removal, as well as additional forethought regarding cartilage removal for a thyroplasty window.
Patient preparation is consistent with Gore-Tex thyroplasty alone. 2 However, the patient should be informed of the slight increased risk of postoperative dyspnea, which is more common with arytenoid adduction procedures. The neck incision is made slightly longer and extended further posteriorly to aid in the exposure of the posterolateral thyroid lamina (Fig. 1). Cutting as opposed to retracting the sternohyoid and thyrohyoid muscle may also improve exposure. The inferior pharyngeal constrictor muscle must be removed from its insertion along the oblique line of the thyroid cartilage to expose the posterior portion of the lamina. The thyrohyoid muscle is removed inferiorly to provided access to the paraglottic space for the Gore-Tex implant. Anterior retraction of the cartilage with a small hook retractor can simplify these procedures (Fig. 2). Once the posterior lamina is exposed, dissection is carried around the posterior edge in a subperichondrial plane. A cookie-bite cartilage resection is then completed to allow exposure of the piriform mucosa and the muscular process of the arytenoid (Fig. 3).
Before arytenoid adduction sutures are placed, the posterior and inferior dissections are connected within the paraglottic space. A thyroplasty window and a secondary anterior arytenoid adduction suture hole are outlined and created in the lower half of the thyroid lamina. Two 4-0 Prolene sutures are placed through the muscular process and tied. These are passed anteriorly using a slightly bent Keith needle, one through the small thyroid hole at the level of the anterior commissure and the second below the thyroid cartilage. Care should be taken to pass the suture deep in the paraglottic opening to allow placement of the Gore-Tex “superficial” to the sutures (Fig. 4). Miller et al. 11 reported on the side effects of inadvertent lateral suture placements. If the arytenoid adduction sutures are placed lateral to the implant material or inadvertently passed through a lateral structure such as the posterior thyroid cartilage, the anterior traction on the sutures becomes redirected to produce a lateralizing force on the arytenoid.
Although sterile, as an added precaution, the Gore-Tex material is soaked in an antibiotic solution prior to implantation. 2 A precut implant is currently available, as produced by the Gore company, which provides 1.8 cm3 of implantable Gore-Tex. However, in the majority of the patients discussed here the implant was configured from a Gore-Tex cardiovascular patch. 2
The true vocal fold and paraglottic space resides at the lower one half to one third of the thyroid cartilage, 1,12 The Gore-Tex is passed from below the thyroid cartilage in an incremental fashion until the anterior medialization is complete. The window and posterior exposure are used primarily to position the Gore-Tex correctly. This method of placing the implant from below the thyroid cartilage prevents the common error of placing the implant material too superior and also allows residual Gore-Tex to be wrapped around the inferior strut of cartilage to add to implant security. The extent of medialization and arytenoid adduction suture tension is quantified by intraoperative voice assessment and flexible nasopharyngeal endoscopy. A large “thyroplasty” window is unnecessary and can make it difficult to retain the material in position, as it is held in place principally by the remaining inferior cartilage strut. Once adequate anterior medialization has been completed, the arytenoid adduction sutures are tied with only slight tension to hold the arytenoid in its medially rotated position. Figure 4 shows the final position of arytenoid adduction sutures and implant just before cutting off the residual Gore-Tex or rotating it into the window. Two 4-0 Prolene sutures are then passed through the implant to ensure placement retention. The wound is closed over a small drain. All patients receive perioperative antibiotics and steroids and are observed overnight.
A speech language pathologist performed the patient vocal assessment using patient self-rating and the independent listener GRABS scale of Hirano. 13 This scale is a modified form of Isshiki's original semantic differential voice evaluation tool. 14 Voice dysfunction severity was rated by the patient on a seven-point scale, with 0 equal to normal voice and 6 equal to the worst voice you can imagine. Vocal quality of life impact was rated in a similar fashion, with 0 equal to current voice having no quality of life impact and 6 equal to current voice quality affecting everything in daily life. Vocal effort was evaluated, as a percent effort required to produce sound for speech. Voice produced with normal effort was rated at 100, twice a normal effort at 200 and so on without an upper limit. Maximum phonation time (MPT) was measured during the production of a sustained /a/.
All patients treated with Gore-Tex vocal cord augmentation between May 1995 and June 1999 were considered eligible for inclusion in this review. Sixty-nine patients were identified in whom 72 procedures were performed, three as revisions. Four procedures were completed for nonparalysis laryngeal problems. Of the remaining 65 patients etiologic and demographic data were available for 62 (Table I). Six patients had their procedures at the affiliated Veterans Administration, hospital leaving 59 potential patients for review. The postoperative data analyzed for this report were the most recent data available for each patient at the time of this review. Patients who had not been evaluated within 6 months of this analysis were contacted and asked to return for videostroboscopic examination and vocal outcome assessment. Preoperative voice data were available for 46 patients, preoperative and postoperative data for 45 (26 with Gore-Tex alone and 19 with Gore-Tex plus arytenoid adduction). One additional patient was excluded from evaluation in the Gore-Tex alone group as noted below.
Table Table 1.. Demographics and Etiology (With Subset Distribution).
The patient group demographic and etiologic data are detailed in Table I. The Gore-Tex plus arytenoid adduction group is younger in mean age and includes a larger percentage of patients with surgically induced nerve injury, of which more than 50% were at the level of the skull base. The preoperative voice evaluations of the two groups were nearly identical (Table II). Prior injection laryngoplasty had been completed in 15 of the Gore-Tex alone patients (7 Gelfoam, 6 fat, and 2 Gelfoam followed by fat injection). In the arytenoid adduction group six patients had prior injection procedures (4 fat and 2 Gelfoam). Some patients have had additional fat or collagen injections during the postoperative period to augment the medialization of the superficial layers of the vocal fold. One of these patients had a supplemental fat injection 2 months after thyroplasty and her follow-up data have been excluded. The other patients have had late supplemental procedures and their follow-up data prior to additional treatment are included.
Table Table 2.. Preoperative Voice Assessment Total Group.
MPT = maximum phonation time.
In the 65 patients no major operative, postoperative, or implant-related complications have occurred (wound infections, implant extrusions, significant airway events). One patient had an implant procedure delayed due to airway swelling at the initial procedure. One case was modified from a Gore-Tex implant to a strap muscle implant when a mucosal perforation occurred while displacing the piriform mucosa for arytenoid adduction (this patient is not include in this current data set). Two patients have had episodic dyspnea after Gore-Tex thyroplasty and arytenoid adduction. One of these two required a tracheotomy 7 months after the thyroplasty as reported in the initial review. 2 The second patient's episodic dyspnea resolved spontaneously.
Voice outcomes are summarized in Table III. The data are presented as mean and standard deviations. Also included is the average duration of follow-up reported as mean days since last surgery. Three patients had revision thyroplasty procedures; two of the three are included in the voice outcome evaluation, one patient lacks follow-up data. The mean follow-up time for nearly all the patient data sets approximates or exceeds 1 year.
Table Table 3.. Preoperative and Postoperative Voice Data Matched Pairs.
Arytenoid adduction was initially described as a standalone procedure to treat patients with vocal cord paralysis and a significant posterior glottic gap. However, at its inception in 1978 Isshiki utilized arytenoid adduction in combination with type I thyroplasty. 5 Two of his first six patients underwent arytenoid adduction after Silastic medialization alone had failed to adequately close a posterior glottic chink.
Voice outcomes appear to support the liberalized use of combined arytenoid adduction with vocal cord medialization. Certainly our current data indicate that additional voice benefit is gained with the arytenoid adduction. Voice outcomes from medialization alone show overall improvements, but not to the extent of the combined procedure. Lu et al., 15 in an evaluation of type I thyroplasty with Silastic, identified improvement in hoarseness from 2.02 to 1.20 and in breathiness from 2.51 to 0.75 (using a five-point grading scale). Using the standard GRBAS four-point voice assessment scale, Dulguerov et al. 16 identified a grade change from 2.7 to 1.2, a breathiness change from 2.8 to 1.5, and an asthenia change from 2.5 to 1.4 in a group of patients medialized with self-carved Proplast. Cummings et al. 17 and Montgomery et al. 18 identified subjective improvement in the voice of approximately 90% of cases treated with preformed implants without arytenoid adduction. However, detailed vocal outcome evaluations were not provided. This current review (Table III), as well as our preliminary study of voice outcome for Gore-Tex thyroplasty show similar improvement in vocal grade and breathiness (grade improvement from 2.3 to 1.1, breathiness from 2.0 to 0.4). 2
The addition of arytenoid adduction appeared to improve the voice outcome as assessed by the GRABS scale and also patient voice satisfaction as subjectively assessed by the patients' self-rating of severity, effort, and impact (Table III). Additional objective support for improved vocal function comes from the prolongation of MPT. The Gore-Tex alone group improved by a mean of 19%, whereas the combined-procedure group showed a 140% improvement in MPT. When Miller et al. 11 compared similar groups (Silastic medialization alone vs. combined Silastic and arytenoid adduction) they found a 122% improvement versus a 219% improvement. In noncomparative studies of medialization alone, Lu et al. 15 showed improvements in MPT from a mean of 6.21 second to 11.16 seconds. Cummings et al. 17 noted a mean improvement in MPT from 3 to 4 seconds to 9 to 10 seconds (as estimated from graphs provided). Kraus et al. 10 in a group of 12 patients undergoing combined Silastic medialization and arytenoid adduction showed that MPT improved from a mean of 6.7 to 13.2 seconds. Woodson and Murry 19 in a series of 11 isolated arytenoid adduction patients showed MPT improvement from 6.88 seconds to 17.28 seconds. In general longer MPTs are seen after arytenoid adduction.
Certainly arytenoid adduction has its advantages and works in an additive fashion when combined with medialization techniques. Isshiki et al. 5 considered arytenoid adduction to be superior to medialization in patients with a wide glottic chink. Woodson and Murry were able to demonstrate that the arytenoid adduction technique provided measurable medial rotation of the posterior glottis and lengthening of the vocal cord in the majority of patients. In some elegant work by Neuman et al. 20 utilizing fresh cadaver laryngis the arytenoid motion induced by arytenoid adduction was quantified. The movement was described as an average 13° rotation along a helical axis with its principle vector in the inferosuperior direction, as well as moving the vocal process to a more medial position via internal rotation of the arytenoid without significant medial displacement of the body.
It remains controversial as to which patients are best served by the combined procedures. In most cases consent was obtained for a combined thyroplasty with arytenoid adduction. However, the preoperative assessment with videostroboscopy has strongly influenced the procedure choice in the past. There are patients with apparent midline arytenoids manifesting a breathy voice solely because of anterior vocal cord bowing. This type of patient would appear to be easily treated with Gore-Tex implantation alone. However, a detailed evaluation of glottic configuration and long-term vocal outcome has not been performed. Young patients and patients with identified posterior gaps will in most cases undergo a combined procedure. The decision to include arytenoid adduction with the thyroplasty was left to the surgeon. No presurgical patient selection guidelines were followed in this current set of patients, although no preoperative voice assessment differences were identified. There is likely a bias toward younger patients who will better tolerate the extended length of the combined procedure. The surgeon is more likely to include arytenoid adduction in these patients with the hope to gain the best possible long-term voice result. It also appears that the combined procedure group includes a larger percentage of patients with high vagal injury, who frequently manifest an open posterior glottis and are thus better treated with a combined approach.
The addition of posterior thyroid cartilage resection to the arytenoid adduction procedure has become commonplace. This significantly simplifies the procedure and thus improves its tolerance by an awake patient. The cartilage resection also decreases the extent of soft tissue dissection, which has the potential to magnify intraoperative edema and thus diminish the ability of the surgeon to fine tune the vocal position and predict the voice outcome.
Several authors have detailed this modification. 10,11,21 Maragos 21 included biomechanical theory to support the use of a smoothly curved posterior window to distribute stress and avoid fracture. The risk of fracture exists only during manipulation of the cartilage to place sutures for arytenoid adduction or during the placement of the medialization implant. All implants except Gore-Tex require a window large enough to accommodate the entire implant. Large implant windows also weaken the cartilage and increase fracture risk. Window size and location are significantly less important with the Gore-Tex method. The window is made primarily to help manipulate the material as it is passed from the inferior edge of the thyroid cartilage. Any cartilage fracture incurred can be stabilized with Prolene suture at the time of closure. These posterior fractures are unlikely to affect laryngeal function.
The closure of the posterior commissure produces some airway narrowing that is beneficial in voice production primarily by increasing glottal resistance and phonatory efficiency, leading to prolonged MPT and increased vocal volume. The additional posterior airway closure may lead to an increased frequency of postoperative airway complaints, primarily during the acute phase of healing while some traumatic edema remains within the vocal tract.
Two patients in this current study had airway complaints during the postoperative period. In 28 patients with combined Silastic thyroplasty and arytenoid adduction, Kraus et al. 10 identified an 18% complication rate, all minor. Two of the complications consisted of airway swelling that required extended observation and steroid use. In Rosen's extensive review of thyroplasty complications he identified implant migration and poor voice results as the primary problems, but an increase in airway compli-cations was noted with arytenoid adduction–treated patients. 22
The voice outcome and patient satisfaction data support the addition of arytenoid adduction to the medialization technique whenever possible. Miller et al. 11 state that after a review of more than 200 phonosurgery patients they now believe that all patients should have a direct operative assessment of the potential benefit of arytenoid adduction irrespective of the preoperative arytenoid position. Our current data support this philosophy. In some patients maximizing voice outcome will not be the primary goal. Attempts to decrease aspiration and provide a serviceable voice as quickly as possible may be all that is required. Patients do not always tolerate the additional surgical time required for the arytenoid adduction. Patients with a significant component of aspiration frequently have difficulty with prolonged periods of supine positioning. Many patients with true vocal cord paralysis have recently undergone cardiac or pulmonary surgery or are weakened by cancer. These patients may be better treated with medialization alone or on occasion injection procedures with Gelfoam, fat, or Teflon.
Arytenoid adduction combined with Gore-Tex medialization thyroplasty appears to provide the best long-term voice results as judged objectively and subjectively. This benefit is gained with a slightly longer operative time and a slight increase risk of postoperative airway complications. New techniques in both procedures make the combined procedure easier, safer, and more predictable. We now consider any patient undergoing medialization thyroplasty a potential candidate for the combined procedure of Gore-Tex medialization with arytenoid adduction.