Objective measurement of real time subglottic pressure during medialization thyroplasty: a feasibility study

Abstract

It is hypothesized that real time objective measurement of the subglottic pressure could contribute to the choice of the implant's size (IS) in medialization thyroplasty (MT). A prospective study was conducted with patients with glottal insufficiency. Patients had a MT using a Montgomery implant(®) (Boston medical, Boston, USA). Peak direct subglottic pressure (PDSGP) was measured intraoperatively using a catheter inserted in the cricothyroid membrane. The implant's choice was based on the results of PDSGP measured prior and after placement of the implant and was compared to the surgeon's and patient's perception and fiber optic estimation of the glottis aperture. Six patients were included in the first part of the study. The PDSGP could be measured in all the patients without increasing the surgical time or patients' discomfort. The mean PDSGP before and after the placement of the implant was 15.2 (SD = 5) and 10.6 (SD = 4) cmH(2)O, respectively. In the second part of the study, five patients were included. The PDSGP varied with the size of the implant and the implant with the lowest pressure was chosen in 4/5 patients. Peroperative measurement of PDSGP is easy, feasible and might allow a more objective choice of the IS in MT. Level of evidence 2c.

Using peak direct subglottic pressure level as an objective measure during medialization thyroplasty: a prospective study

“…During MT, reduction of the glottic gap reduces the SGP until the optimum glottic closure is reached, but then a rise in SGP is observed with over correction [14]. Based on this, the correct implant size should be the one with lowest SGP, but this measure is not done during MT and the surgeon relies on the degree of glottic closure and his perceptual judgment of the patient's voice intraoperatively to choose the implant size.…”

“…When they reported their experience in measuring PDSGP, Matar et al [14] emphasized the ease and practicality of using the PAS connected to a laptop in the operating room to obtain the measurements of PDSGP and there were no issues with sterility of the operating field as the system was solely handled by the attending speech therapist. The system was mobile and there was no issue in transporting it to the operating room.…”

“…All our measurements were taken while the patients were in the supine position and under light sedation as those conditions were reported not to influence SGP [14]. All our patients in this series underwent MT with MTIS and the PDSGP was obtained with ease.…”

“…Concurrently, a large peripheral venous flexible catheter of 18 gauge (BD INSYTE-WTM, NJ, USA) was inserted through the cricothyroid membrane in a sterile manner connected to the oral pressure sensor of the phonatory aerodynamic system (PAS, Kay-Pentax, USA) with a perfusion cable as described by Matar et al [14]. This allowed for real-time subjective visual assessment of the glottic closure and obtaining PDSGP levels.…”

“…Aerodynamic measurements include MPT, phonatory quotient (PQ) and subglottic pressure (SGP) [13]. Matar et al [14] used the peak direct subglottic pressure (PDSGP) intraoperatively during MT to see its variability and impact on patients' voice with different implants sizes and they found the chosen implant size to be the one with the least PDSGP in four out of five patients.…”