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Quantification of injection force mechanics during injection laryngoplasty
Author(s) -
Pearson Joseph J.,
Ortiz Alexandra S.,
Montelongo Sergio,
Simpson C. Blake,
Guda Teja,
Dion Gregory R.
Publication year - 2019
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1002/lary.27486
Subject(s) - medicine , stiffness , biomedical engineering , compression (physics) , laryngoplasty , hyaluronic acid , vocal folds , biomechanics , surgery , orthodontics , materials science , composite material , larynx , anatomy
Objectives In‐office or operative injection laryngoplasty requires needle stability for accurate material placement. To date, no reports compare injection forces based on needle gauge, bends, length, or material type or temperature. We hypothesize these factors alter injection forces and could impact clinical use. Methods Swine larynges were placed in a compression testing machine. Syringes were affixed to a stabilizing crossbeam. Straight needles (25G 1.5‐inch; 27G 1.25‐inch; or 9.8‐inch malleable shaft 16G per oral with 24G tapered needle tip) were inserted into the swine vocal folds to simulate realistic tissue resistance pressure. Compressive loading was conducted at 40 mm/minute until steady‐state force was achieved. Tests were completed with calcium hydroxylapatite (CaHa), carboxymethylcellulose, and hyaluronic acid at various temperatures and CaHa with various bends in the needles (n = 3 per group, comparisons performed by two‐way analysis of variance (ANOVA), Tukey's post‐hoc). Results Needle size, shape, and temperature altered injection force. Steady‐state force was highest with the per‐oral needle at a mean of 44.55N compared to 26.44N and 29.77N in the 25G and 27G percutaneous needles, respectively ( P < 0.001). Stiffness rate (initial increasing force vs. distance to initiate injection) ranged from 19.75N/mm (per oral) to 22.06N/mm (25G) to 24.56N/mm (27G), ( P = 0.875). Adding multiple bends to the per‐oral needle increased stiffness rate to 24.99N/mm ( P = 0.035), whereas the 25G needle stiffness rate remained unchanged ( P = 0.941), with the stiffness rate decreasing in the 27G needle with increasing bends ( P = 0.033). Increased temperature decreased injection forces across all materials. Conclusion Needle caliber, length, and bends impact steady‐state forces and stiffness rates during vocal fold injection. Level of Evidence NA Laryngoscope , 129:1060–1066, 2019