Supplementary Material for: Indications for the Gasless Transaxillary Robotic Approach to Thyroid Surgery: Experience of Forty-Seven Procedures at the American Hospital of Paris

<b><i>Background:</i></b> Thyroid surgery is in a state of evolution from traditional open approaches to novel robotic techniques. The gasless transaxillary approach to thyroid surgery is effective in the management of thyroid cancer, and complications after robotic thyroidectomy are no higher than experienced after open or endoscopic techniques. The transaxillary robotic approach also avoids an anterior neck scar. This paper presents what the authors believe to be the largest cohort of patients reported in Europe undergoing gasless transaxillary robotic thyroid surgery, with the aim of defining the indications for this procedure. <b><i>Methods:</i></b> Forty-six patients underwent robotic thyroid surgery via the transaxillary approach and were enrolled in this study between March 2010 and September 2012. All patients were operated on by one surgeon at one clinical center. Reviewed data included patient characteristics, pathological characteristics, extent of surgery and postoperative complications. The mean follow-up time was 7.29 months. <b><i>Results:</i></b> Forty-six patients underwent 47 procedures, the average age of the patients was 43 years and the male to female ratio was 1:22. Undertaken were 30 lobectomies, 3 subtotal thyroidectomies, 13 total thyroidectomies and 1 totalization. One case was converted to an open procedure. The ratio of malignant to benign disease was 1:6.67 (6:40 cases) and analysis of the surgical specimens showed 6 follicular lesions, 24 follicular adenomas, 3 colloid lesions, 1 case of thyroiditis/lymphatic lesion, 3 adenomatoid lesions, 3 oncocytic adenomas, 3 papillary cancers and 3 microcapillary cancers. The overall average size of an individual specimen removed was 45.40 ± 28.95 cm<sup>3</sup> (range 5-160, n = 47) and the average largest diameter of the lesion removed was 3.72 ± 0.95 cm (range 1.4-6.0, n = 47). Postoperatively, there were 5 recurrent laryngeal nerve injuries (4 transient), 2 transient brachial plexopathies, 1 case of postoperative dysphagia and 1 of collection of blood at the site of surgery. There were no cases of disease recurrence at follow-up. <b><i>Conclusions:</i></b> The gasless robotic transaxillary approach to thyroid surgery has been predicted to become a standard technique. It has been shown to be efficacious in the management of thyroid cancer with lateral neck metastases; however, more data relating to oncological safety in long-term follow-up is required. This intervention is also appropriate for benign thyroid disease including Graves' disease. To achieve consistently successful results, careful patient selection is fundamental in terms of patient characteristics and the anatomical aspects of the lesion. This is especially important with a geographical expansion to include North America and Europe. The excellent cosmetic results of this procedure make it ideal for patients who have esthetic concerns regarding particular difficulties with healing; however, in common with all new surgical procedures, further evidence must be sought to confirm its indications over time.