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The objective of the study was to assess the mechanism of recurrent laryngeal nerve (RLN) injury during video-assisted thyroidectomy (VAT).The study examined 201 nerves at risk (NAR). VAT with laryngeal neuromonitoring (LNM) was outlined according to this scheme: (a) preparation of the operative space; (b) vagal nerve stimulation (V1); (c) ligature of the superior thyroid vessels; (d) visualization, stimulation (R1), and dissection of the RLN; (e) extraction of the lobe; (f) resection of the thyroid lobe; (g) final hemostasis; (h) verification of the electrical integrity of the RLN (V2, R2). The site, cause, and circumstance of nerve injury were elucidated with the application of LNM. Laryngeal nerve injuries were classified into type 1 injury (segmental) and 2 (diffuse).Fourteen nerves (6.9 %) experienced loss of R2 and V2 signals. 80 percent of lesions occurred in the distal 1 cm of the course of the RLN. The incidence of type 1 and 2 injuries was 71 and 29 % respectively. The mechanisms of injury were traction (70 %) and thermal (30 %). Traction lesions were created during the extraction of the lobe from the mini-incision [point (e)]. Thermal injury occurred during energy-based device use in (f) and (g) circumstances.RLN palsy still occurs with routine endoscopic identification of the nerve, even combined with LNM. LNM has the advantage of elucidating the mechanism of RLN injury. Traction and thermal RLN injuries are the most frequent lesions in VAT.

Prophylactic surgery for patients carrying a positive RET proto-oncogene proved to be highly effective in curing those likely to experience the development of a medullary carcinoma. Video-assisted procedures have been proved feasible for central compartment dissection. A total of 15 patients (7 men and 8 women) with a positive RET proto-oncogene underwent total thyroidectomy and central compartment lymphadenectomy via a video-assisted approach. The mean age of the patients was 32.5 years. The echographically estimated mean volume was 10.3 ml, and the mean diameter of the main nodule was 8.8 mm. Preoperative ultrasound showed an absence of lateral neck lymph node involvement in all cases. No drain was used. Direct laryngoscopy was performed in all cases 1 month after surgery. The mean operative time was 67.3 min. A transient hypoparathyroidism occurred in one patient, and a permanent hypoparathyroidism occurred in another patient. No laryngeal nerve palsy was present. All the patients were discharged on postoperative day 1. Histology showed a medullary carcinoma in 10 patients and diffuse C-cell hyperplasia in 5 patients. The mean number of lymph nodes removed was 5.1. None of these nodes proved to be metastatic. Calcitonin levels were undetectable in all six patients who had a follow-up period longer than 1 year. Video-assisted central compartment lymphadenectomy was proved to be effective and safe. The procedure demonstrated a complication rate comparable with that for the conventional procedure, a better cosmetic outcome, and less postoperative pain. Although the video-assisted access proved to be a valid option for the treatment of patients carrying a positive RET proto-oncogene, a greater number of cases with a longer follow-up period is necessary to estimate the impact of the video-assisted approach on central neck lymphadenectomy.

Quick intraoperative parathormone assay (qPTHa) during paratyroidectomy has become a standard procedure for patients with primary hyperparathyroidism (PHPT). This paper aims to compare endoscopic bilateral neck exploration (BE) versus focused parathyroidectomy plus qPTHa during minimally invasive video-assisted parathyroidectomy (QM). The endpoints of the study are the mean operative time and outcome of the surgical procedure (PTH and calcemia normalization at one and six months postoperatively).Forty patients with PHPT, positive to preoperative localization studies (ultrasonography evaluation and (99)Tc-MIBI scan) for a single parathyroid adenoma, were randomly allotted into two groups. In the first group (QM), 20 patients (17 women, three men, mean age 57.6 years) underwent focused endoscopic parathyroidectomy (MIVAP tecnicque) plus qPTHa . In the second group (BE) 20 patients (17 women, three men, mean age 59.6 years) underwent endoscopic parathyroidectomy plus bilateral exploration in order to check the integrity of the remaining glands.There were no significant differences between groups at baseline. No conversion to cervicotomy was required. No postoperative complications were reported. The mean operative time was 32.0 vs 33.1 min [BE and QM group respectively, p = not significant (ns)]. A second macroscopically enlarged gland was removed in four patients in the BE group. Only one out of four glands was reported to be hyperplastic in the final histology. All patients were discharged on the first postoperative day. Calcemia levels were normalized in all patient of both groups, despite persistently high level of serum PTH in one patient in the QM group.BE can be performed endoscopically, avoiding both the time necessary for qPTHa and its cost, with the same effectiveness, but might in few cases lead to the unjustified removal of parathyroid glands slightly enlarged but not necessarily pathologic.

Dear Editor: Minimally invasive video-assisted thyroidectomy (MIVAT) [1], the most widespread minimally invasive technique, has been called into question by Benhidjeb et al. [2] because it is somewhat limited by the small size of the specimen removable through its 15-mm cervical incision. We were animated to comment on this first report of natural orifice surgery (NOS) applied in thyroid surgery. The authors report the first two totally scarless subtotal thyroidectomies performed on cadavers. This was a feasibility study, and the operation consisted of a transoral access with insertion of one 5-mm trocar and two 3-mm trocars into the oral cavity. Operative space was maintained by carbon dioxide (CO2) insufflation, and hemostasis was achieved using bipolar scissors. The thyroid gland was resected from the cranial to the caudal area and removed through the 5-mm midline mucosa incision. Furthermore, in the words of the authors, the retrothyroidal area is prepared and the laryngeal nerve visualized only ‘‘if necessary,’’ and finally, ‘‘if the gland is too large, the midline incision may be extended.’’ We do not disclaim the feasibility and reproducibility of their new endoscopic approach to the thyroid gland. The transoral video-assisted thyroidectomy (TOVAT) approach seems to respect surgical planes and to achieve an excellent cosmetic result, certainly better than other recently proposed endoscopic techniques such as chest, breast, and axillary approaches [3–5]. However, we have major concerns about the widespread applicability of this approach for live patients, and finally about its safety, for the following reasons: 1. With the cadavers, did the authors study the postoperative effects of CO2 after the operation? It is well known that CO2 insufflation, due to the absence of a virtual cavity in the neck, may lead to a troublesome postoperative emphysema, in addition to metabolic problems due to hypercarbia [6]. With MIVAT, we early abandoned the CO2 insufflation, shifting to an external retraction method with the aim of avoiding any complication due to gas insufflation and therefore any discharge delay. 2. Did the authors consider that multiple painful sutures in the mouth mucosa, even if invisible to others, may represent an important obstacle to oral intake after the operation? How many days should the patients fast and therefore remain in the hospital? This would mean a prolonged hospital stay, with neglect also of risks for infection and possible trauma to sublingual salivary glands. 3. Furthermore, the authors declare that they have retrieved the specimen from the 5-mm incision in the oral cavity, but they failed to report the size of the removed glands. Probably, a very normal gland can pass through such a narrow space, but it is difficult to understand how a nodule 2–3 cm or even larger can be retrieved without enlarging the mucosa wound. Consequently, with incisions larger than 5 mm, trauma to the oral cavity will be increased, taking us back to point 2. 4. A major concern is about laryngeal nerve dissection. Proper identification of the nerve would be the first target to achieve by a safe technique with both traditional and minimally invasive procedures. With MIVAT and other endoscopic techniques [7, 8], visualization of the nerve and parathyroids is enhanced by optical magnification and represents a fundamental P. Miccoli G. Materazzi (&) P. Berti Department of Surgery, University of Pisa, Pisa, Italy e-mail: gmaterazzi@yahoo.com

We thank Dr. Muenscher and collegues for their review of our article on the underlying pros and cons of endoscopic and video-assisted surgical approaches for neck surgery. In our opinion, some points have not been stressed properly. Since its initiation in 1999, the minimally invasive videoassisted thyroidectomy (MIVAT) approach has been widely used for both benign and malignant thyroid lesions in both adult and pediatric patients [1–3]. Although listed as a disadvantage, the operative time for MIVAT resembles that for conventional thyroidectomy after an adequate learning curve period [3]. Both the operative time and the complications rate for MIVAT equal those for open surgery [1–3]. A major criticism is the author’s reported absence of clinical studies investigating the completeness of videoassisted techniques in thyroid cancer. In fact, at least two clinical trials involving patients with lowand intermediate-risk papillary thyroid carcinomas (PTCs) have been reported by our university [4, 5]. We demonstrated that PTC patients who underwent MIVAT had a good outcome during a 5-year follow-up period. The outcome was similar to that for patients treated with conventional thyroidectomy and the same degree of exposure to post-surgical radioactive iodine treatment (I) [5]. Disclosures G. Donatini, G. Materazzi, and P. Miccoli have no conflicts of interest or financial ties to disclose.