Cricothyroid approximation

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Cricothyroid approximation was one of the most common surgeries of the past 20 years used to change the relaxed pitch of the voice. The normal action of the cricothyroid muscle is to increase tension of the vocal cord margin by lengthening the vocal cord [13]. The vocal quality produced by this increase in tension of the vocal cord is called falsetto. Contraction of this muscle brings the thyroid cartilage and cricoid cartilage into approximation in the anterior midline, so CTA surgery effectively sutures the cricothyroid muscle into a permanent position of contraction, although the degree is variable.

Your original voice in falsetto will sound the same after surgery as before surgery, so you can test out what your voice will sound like by speaking in falsetto. The surgery tries to prevent or limit dropping back down into the chest voice but doesn’t alter the quality of the falsetto voice. The surgery then doesn’t change speech patterns, intensity, resonance or inflection characteristics of the male voice into a female pattern, rather when successful, it limits the voice to the upper range. This can be a desirable limitation by relieving the effort of always trying to keep the voice up in falsetto. It also generally prevents an inadvertent drop into a deeper voice at an inopportune moment. 

Some of the positive attributes of CTA surgery include:

  • It is relatively easy to perform the surgery with the anatomy located very close beneath the skin.
  • Surgeons inexperienced with the procedure can perform it relatively easily.
  • There is minimal discomfort with the procedure and it may be performed under local anesthesia.
  • The patient may speak during the procedure if the surgeon has a desire to attempt to “tune” the pitch during the procedure, although for many “CTA surgery is typically performed with intentional hyper-elevation of pitch in anticipation of gradual relaxation of the induced vocal fold tension over time” [14].
  • Surgical costs associated with the procedure are low because it is relatively easy to perform, relatively safe from acute surgical complications and can be performed in a relatively short time, .

I began performing CTA surgery in 2001 for male to female transgender patients wishing to speak comfortably at a higher pitch in day-to-day conversation. I reviewed results on 23 patients in 2003 for a presentation (Thomas,J.P. Cricothyroid approximation & other phonosurgical procedures to alter the transgender voice. Biennial meeting of the Harry Benjamin International Gender Dysphoria Association, Inc. (HBIGDA), September 12, 2003, Ghent, Belgium). I noted,

  • There was elevation of the comfortable speaking pitch by 7 semitones
    • although this ranged from a lowering of the speaking pitch by two semitones in one patient to
    • an elevation of pitch by 18 semitones in one patient.
  • The range was wide and seemingly unpredictable.
  • Individuals lost an average of 9 semitones from the bottom of their speaking range, providing a speaking pitch not at risk for a sudden drop in pitch.

Significant issues I noted with the CTA procedure.

  • Some patients experienced an initial pitch elevation that faded back to a baseline pitch over a few months, ultimately experiencing no permanent change in their voice at all. This occurred in about one third of patients despite vocal cords that remained visibly stretched on endoscopy. Neumann et al also noted about one third of patients had a neutral pitch and about one third failed to gain in pitch [15]. 
  • During attempted surgical revisions on my own patients and on others, where a variety of sutures and a variety of suture placement techniques were utilized, I noted no cricothyroid suture failure. The cricothyroid space remained ablated, typically with the cricoid and thyroid cartilage fused in the anterior midline. I noted various suturing techniques including metal sutures, bolstered sutures, single or multiple sutures and none of the sutures had pulled out. Internally, during quiet respiration, the vocal process and membranous vocal cord margins were in alignment, a position typically only seen when the cricothyroid muscle is contracted. Patients appeared to have lost pitch elevation by losing internal tension.
  • Another problematic issue with patients undergoing CTA surgery is that many patients with successful pitch elevation spoke with an unnatural, hyper-elevated pitch ranging from an extreme falsetto to a mild falsetto quality of their voice. For some surgeons, “CTA surgery is typically performed with intentional hyper-elevation of pitch in anticipation of gradual relaxation of the induced vocal fold tension over time” [14]. Some of my patients describe this as a “gay male” sound.
  • My experience during revision surgery is that the cricoid and thyroid cartilages frequently fuse in the anterior midline. Even when surgically separated, the patient does not typically regain control over their falsetto range. My suspicion is that the cricothyroid joints ankylose after sufficient a period of immobilization.
  • I have observed at times that the cricothyroid joint appears to become so fixed, perhaps subluxed, such that an individual may almost completely lose the ability to change pitch and volume at all, leaving them with a monotonal voice.
  • Even when successful for a change in comfortable speaking pitch, a post CTA patient forfeits the use of her cricothyroid muscles. Tensioning the thyroarytenoid muscle must now produce so all pitch changes.
  • Loss of the use of the cricothyroid muscles also limits the ability to get loud since the cricothryoid muscles support the vocal cords during loud sound production.

Because I felt these issues were significant vocal compromises for gender transition patients, I looked for an alternative approach that would raise the comfortable speaking pitch and, I have stopped performing this surgery because of it's unpredictability. It is one of the easiest surgeries to perform, but I cannot predict who will be too squeaky and who will drop back down to their original pitch after surgery. In general, it is a very standardized surgery and perfomed similarly by different surgeons.

You may listen to some pre- and post-surgical voices here. These are from surgeries are performed some years ago.