Thyrohyoid Approach to Cidofovir Injection: A Case Study

A proposal for needle projections in transcutaneous injection laryngoplasty using three-dimensionally reconstructed CT scans

PURPOSE

This study aims to determine laryngeal dimension in relation to all three transcutaneous injection laryngoplasty (TIL) approaches (thyrohyoid, transthyroid and cricothyroid) using three-dimensionally reconstructed Computed Tomography (CT) scan and compare the measurements between sex, age group and ethnicity.

METHODS

CT scans of the neck of two hundred patients were analysed by two groups of raters. For thyrohyoid approach, mean distance from the superior border of the thyroid cartilage to the laryngeal cavity (THd) and mean angle from the superior border of the thyroid cartilage to mid-true cords (THa) were measured. For transthyroid approach, mean distance from mid-thyroid cartilage to mid-true cords (TTd) and Hounsfield unit (HU) at mid-thyroid cartilage (TTc) were measured. For cricothyroid approach, mean distance from the inferior border of the thyroid cartilage to the laryngeal cavity (CTd) and mean angle from the inferior border of the thyroid cartilage to mid-true cords (CTa) were measured.

RESULTS

There were statistically significant differences between males and females for all measurements except for CTa (p < 0.0001). No significant difference across age groups and ethnicities were found for all three approaches (p > 0.05). There was a significant fair positive correlation between age and TTc (p = 0.0002). For all measurements obtained, there were moderate to excellent inter-group consistency and intra-rater reliability.

CONCLUSION

This study demonstrated a significant sex dimorphism that may influence the three TIL approaches except for needle angulation in the cricothyroid approach. The knowledge of laryngeal dimension is important to increase success in TIL procedure.

Voice outcome measures after flexible endoscopic injection laryngoplasty

Objective

To report voice outcome measures after injection laryngoplasty using the transnasal or transoral flexible endoscopic technique.

Methods

A retrospective review of all patients who underwent flexible endoscopic injection laryngoplasty between June 2010 and August 2016 was carried out. Only those patients who had pre- and post-injection voice outcome measures recorded were included. Voice outcome measures recorded included perceptual voice evaluation using GRBAS, Voice Handicap Index-10 (VHI-10), maximum phonation time (MPT) and closed quotient (CQ) before and after treatment.

Results

Forty-six patients were identified, of which 32 had pre- and post-injection voice outcome measures recorded. There were 19 males and 13 females. The mean age was 56.97 years (range 20-86 years) and the most common indication was unilateral vocal fold paralysis. Thirteen patients had a transnasal flexible endoscopic injection), while 19 patients were injected transorally. Following injection laryngoplasty, there was significant improvement in the mean grade of dysphonia (2.81 vs. 1.22, P < 0.01, roughness (2.44 vs. 1.34, P < 0.01), breathiness (2.72 vs. 1.13, P < 0.01), asthenia (2.78 vs. 1.06, P < 0.01), and strain (2.44 vs. 1.19, P < 0.01), MPT (3.85 s vs. 9.85 s, P < 0.01) and mean CQ (0.19 vs. 0.46, P < 0.01). There was also a decrease in the mean VHI-10 score (33.31 vs. 7.94, P < 0.01).

Conclusion

s: Patients achieved significant improvement in both subjective and objective voice measures after flexible endoscopic injection laryngoplasty via the nasal or transoral route. Voice outcomes were comparable to those reported for other approaches. This technique provides an alternative approach for the management of patients with vocal fold paralysis or glottal insufficiency.

Thyrohyoid Approach for Vocal Fold Augmentation

Objectives:

I performed a retrospective chart review to evaluate the patient tolerance and clinical results of a new technique for office-based vocal fold augmentation.

Methods:

Ten patients undergoing the thyrohyoid approach for vocal fold augmentation were asked to rate their tolerance of the procedure using a 10-point rating scale (1 = “no problem” and 10 = “very uncomfortable”). The patients also filled out a quality-of-life survey (Voice Handicap Index-10) immediately before and 1 month after the procedure. I reviewed the preprocedure and postprocedure stroboscopic findings. The findings analyzed included changes in wave symmetry and glottal closure, and evidence of implant migration.

Results:

All patients successfully underwent the procedure. The mean patient tolerance score was found to be 2.1. The average score on the Voice Handicap Index-10 improved from 21.3 before the procedure (SD, 9.23) to 7.5 after the procedure (SD, 5.77). These values were compared by use of a paired t-test, and the difference was found to be significant, with a p value of .01. The analysis of stroboscopic results revealed “improvement” or “no change” in the wave symmetry, “improvement” in glottal closure, and “no evidence of migration” after the procedure in all cases.

Conclusions:

The study findings demonstrate that the thyrohyoid approach can be used successfully in patients who need vocal fold augmentation, and that it is generally well tolerated.

Office-based vocal fold injection with the laryngeal introducer technique

OBJECTIVES/HYPOTHESIS

There are numerous techniques for awake laryngeal injection, each with its limitations and technical challenges. We demonstrate a modification to the thyrohyoid approach for injection that stabilizes needle introduction and allows for consistent placement in a wide variety of larynges.

STUDY DESIGN

Retrospective review at a tertiary care institution.

METHODS

A retrospective review was performed of the charts for patients consecutively undergoing awake vocal fold injection laryngoplasty in 2013 for glottic insufficiency due to unilateral vocal fold paralysis, vocal fold atrophy, or sulcus vocalis using the laryngeal introducer technique. The consistency of needle placement, ease of technique, and patient tolerance was assessed. The technique utilizes a curved 1.5-inch 18-gauge needle as a laryngeal introducer through the thyroid notch. Laryngeal injection augmentation is then performed using a curved 3.5-inch 25-gauge spinal needle through the introducer.

RESULTS

Twenty-one patients were identified who underwent awake vocal fold injection laryngoplasty for glottic insufficiency. All 21 injections were successfully placed. Five of seven injections attempted by resident physicians were able to be completed without attending assistance. Patient experience data demonstrated good tolerance, with a preference for the awake procedure as compared to that performed under general anesthesia.

CONCLUSIONS

The laryngeal introducer technique is a novel way of performing awake laryngeal injections. It provides a high rate of success, the ability to be consistently performed by inexperienced clinicians, and is well tolerated by patients.

Systematic review of intralesional cidofovir dosing regimens in the treatment of recurrent respiratory papillomatosis

OBJECTIVE

Surgical management of recurrent respiratory papillomatosis (RRP) usually involves resection via microlaryngoscopy. Intralesional injection of cidofovir has been shown to be an effective adjuvant treatment, but remains unlicensed. United Kingdom General Medical Council guidelines recommend the prescribing doctor should "be satisfied that there is a sufficient evidence base and/or experience of using the medicine to demonstrate its safety and efficacy". This study reviews the published dosing regimens of intralesional cidofovir in the treatment of RRP in order to provide a precedent for those that wish to prescribe it.

METHODS

A systematic review of the literature was undertaken using Medline, EMBASE and CINAHL. Articles describing the use of intralesional cidofovir for RRP were reviewed. Information regarding cidofovir concentration, volume, total dose, number of treatments, interval between treatments, overall treatment period and follow up was extracted.

RESULTS

Fifty-one articles were identified. Concentration of cidofovir injected ranged from 0.0001mg/ml to 37.5mg/ml, with 5 to 7.5mg/ml being the most common. The volume of cidofovir solution injection ranged from 0.1 to 20ml. The total dose per injection ranged from 0.15 to 105mg. There was wide variation in dosing regimens with different intervals between endoscopies, number of injections and total doses delivered.

CONCLUSIONS

Based on this published literature, the precedent for prescribing intralesional cidofovir supports a concentration of 5 to 7.5mg/ml. Volumes up to 5ml per injection are routinely used. Total dose and frequency of cidofovir administration is highly variable. The need for repeat doses of cidofovir should be judged on an individual basis.

Single-Operator Flexible Nasolaryngoscopy-Guided Transthyrohyoid Vocal Fold Injections

Objectives:

A number of laryngeal injection techniques have been described for performing vocal fold medialization or delivery of medications, including peroral and percutaneous approaches. Although flexible nasolaryngoscopy-guided injection (FNGI) improves visualization and patient tolerance over rigid endoscopy, the technique requires an assistant to manipulate the laryngoscope. The efficacy and patient tolerance of a novel, single-operator technique for FNGI are evaluated.

Methods:

Patients who required laryngeal injection for vocal fold medialization or for administration of cidofovir or steroids were included in this study. Indications included vocal fold paresis or paralysis, sulcus deformities, recurrent respiratory papillomatosis, vocal fold polyps, and laryngeal granulomas. All procedures were performed in the office setting with topical and local anesthesia with the patient awake. The surgeon performed flexible nasolaryngoscopy with the nondominant hand while using the dominant hand to perform transthyrohyoid injection with a 25-gauge needle with proximal and distal bends.

Results:

Twenty-six patients underwent a total of 42 single-operator FNGI procedures; 19 unilateral and 23 bilateral injections were performed. All but 1 of the procedures were completed with adequate visualization and placement of injectant and good patient tolerance.

Conclusions:

Single-operator FNGI via a transthyrohyoid approach is a viable and versatile laryngeal injection technique for a variety of indications. It provides access to the anterior, middle, and posterior parts of the larynx. It eliminates the need for an assistant experienced in nasolaryngoscopy and allows the surgeon to adjust and optimize visualization in a fashion analogous to endoscopic sinus surgery.

Double-bend needle modification for transthyrohyoid vocal fold injection

Our objective was to describe an injection needle modification for awake in-office vocal fold injections through a percutaneous transthyrohyoid approach. Two separate 45° angle bends are created at the hub and 1 cm from the needle tip of a 25-gauge, 1.5-inch needle. After adequate endolaryngeal anesthesia, the needle is passed via the thyrohyoid membrane into the airway. The needle tip is at a 90° angle to the syringe, providing access to the entire vocal fold surface, regardless of chin position or thyroid cartilage angulation. The bend at 1 cm also serves as a marker to measure the depth of the needle within the soft tissue. The double-bend needle modification allows for complete access to the entire length of the true vocal fold in one pass as well as a marker to measure depth of the needle in the tissue. Limitations may include bleeding from the injection site, insufficient needle length in patients with a long anterior-posterior dimension of the larynx, and potential difficulty passing a needle through a calcified thyrohyoid membrane.

The thyrohyoid approach to in-office injection augmentation of the vocal fold

PURPOSE OF REVIEW

The purpose of this article is to review the history of vocal fold injection augmentation and provide a thorough description of the percutaneous thyrohyoid approach to office-based vocal fold injection augmentation for the management of glottic incompetence.

RECENT FINDINGS

A number of techniques for vocal fold injection augmentation have been developed since the first procedure was performed. Since vocal fold injection augmentation is performed without an open surgical approach, morbidity is reduced and the technique can be done in the outpatient setting. Accordingly, over the past decade there has been an effort to perfect techniques and to develop new materials and methods to make the procedure more effective and comfortable for the patient.

SUMMARY

Recently, office-based vocal fold injection augmentation has gained significant popularity among laryngologists. While there are a variety of in-office injection techniques, the thyrohyoid approach, in the authors' opinion, is the simplest and best tolerated. This technique is effective and eliminates many of the shortcomings of the other approaches. This approach continues to be the 'workhorse' for in-office vocal fold injection augmentation in the senior author's practice. It is important, however, for any practitioner to be familiar with the other approaches, as this technique is not universally effective for all patients.