بررسی وضوح تصویر دو نمای سونوگرافیک ترانس تیروئید و سوپراتیروئید در تشخیص حرکت تارهای صوتی

Abstract Background :  Iatrogenic recurrent laryngeal nerve (RLN) injury is an uncommon but serious complication of Head and neck surgery and also thoracic procedures. laryngoscopy can be an invasive and uncomfortable procedure, therefore the use of sonography as an noninvasive method of screening patients for impaired vocal-cord mobility is desirable. The aim of this study was to assess the efficiency of ultrasonography as a screening tool for the detection of impaired vocal-cord movement and compare two sonographic view , supra thyroid and trans thyroid, to find the preferred view to observe the movement of vocal cord in different ages and sexes. Methods : In this clinical trial 144 patients were evaluated. All patients underwent vocal cord sonography in two sonographic views; Trans thyroid and supra thyroid, before and after surgery. After high risk surgery for vocal cord damage like thyroidectomy, parathyroidectomy, Carotid endartrectomy, anterior approach of cervical spine fixation and thoracic procedures Patients underwent direct laryngoscopy. To assess accuracy of ultrasound, Trans cutaneous sonography findings were correlated with direct laryngoscopy findings after extubating. Vocal cord Paresis or palsy was defined as abnormal vocal cord movement during respiration. Results : The quality of sonographic images in trans thyroid view was better than the supra thyroid view. Comparing sexes the quality of sonographic images in women was better. Moreover aging diminished the quality of the image. Conclusion : Ultrasonography evaluation of vocal cord movement after high risk surgery seems to be an ideal and painless method for RLN injury screening. Application of this method particular in non elderly women, conveys to more favorable results.