Study of Physical Parameters Used for Preoperative Prediction of Difficult Laryngeal Exposure during Suspension Microlaryngoscopy

Abstract

Ab s t r Ac t Aim: The aim of this study is to analyze the various physical parameters used for the preoperative prediction of difficult laryngeal exposure (DLE) during suspension microlaryngoscopy. Materials and methods: This is a single-center, retrospective study carried out in a tertiary care teaching hospital, comprising 50 patients who underwent suspension microlaryngoscopy at our center from June 2014 to April 2016. We assessed 10 physical parameters that can help in predicting DLE preoperatively. Results: The patients’ ages ranged from 20 to 69 years. The laryngeal exposure was assessed in all the patients and correlated with the 10 physical parameters. Out of the parameters assessed using the student t test, the modified Mallampati’s index (MMI) (class II and above), body mass index (BMI) (>27.1 kg/m2 ), thyroid–mental distance (≤4.9 cm), thyroid–mandibular angle (>122°), and horizontal thyroid distance (HTD) (≤3.8 cm) showed a statistical significance with p < 0.001. The ROC curve analysis showed that the thyroid–mental distance and HTD had the highest sensitivity (100%) and specificity (100%) each among the parameters assessed. Conclusion: Based on our study results, we conclude that the age and the sex of the patient have no role in predicting the risk of DLE during suspension microlaryngoscopy. The MMI, BMI, thyroid–mental distance, thyroid–mandibular angle, and HTD measurements help in the prediction of DLE preoperatively. Clinical significance: These physical parameters can be measured just prior to the surgery using simple measuring aids. The advantage of preoperative prediction of DLE being that it enables the surgeon to be prepared beforehand with additional measures to deal with the same and provide adequate treatment.