Groin and anterolateral thigh flaps for hemiglossectomy reconstruction: A comparison based on Japanese speech intelligibility

The differences in speech function between groin flap reconstruction and anterolateral thigh (ALT) flap reconstruction after hemiglossectomy have not been clarified to date. This study aimed to compare Japanese speech intelligibility after hemiglossectomy reconstruction using groin and ALT flaps of similar thickness. Data of patients who underwent hemiglossectomy reconstruction with groin or ALT flaps between April 2010 and March 2020 were collected from the medical chart database. The ALT flap was the first choice for hemiglossectomy reconstruction, and a groin flap was used when the ALT flap was >10 mm. Cases in which speech intelligibility assessments based on Hirose's 10-point scoring system, the TKR speech test, and the Japanese speech intelligibility test for 100 monosyllables were performed after 6 months postoperatively were extracted. The per-patient scores for each assessment were initially compared between the two flap groups. Then, the results of the Japanese speech intelligibility test for 100 monosyllables were reanalyzed on a syllable-by-syllable basis. Among the 44 hemiglossectomy patients who underwent free-flap reconstruction during the study period, 14 (seven each in the groin flap and ALT flap groups) underwent all three conventional speech intelligibility assessments after 6 months postoperatively. The two groups showed no significant difference in postoperative speech intelligibility in any of the three patient assessment methods. However, in intergroup comparisons based on per-syllable accuracy for each of the 100 monosyllables, the groin flap group showed 19 syllables with a significantly higher accuracy, whereas the ALT flap group showed one such syllable. In particular, five out of the six alveolar consonants (/t/ and /d/) were more accurately articulated in the groin flap group. Per-syllable accuracy was significantly higher in the groin flap group (74.6% vs. 66.7%; 95% confidence interval: 4.6–11.1, p < 0.001). In patients undergoing hemiglossectomy reconstruction, our new analysis method, which compared intelligibility by syllables, showed that the groin flap yielded higher speech intelligibility than the ALT flap. This difference was evident at all four articulation points involving the tongue, whereas there was no significant difference at the two articulation points without tongue involvement.