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Abstract

I thank Dr. Miccoli and his colleagues for the comment, and I admire their success in performing 34 endoscopic parathyroidectomies for primary hyperparathyroidism. As intraoperative parathyroid hormone (PTH) assay is not available in our hospital, we invest great faith in preoperative localization techniques so as to avoid a long operation.Concerning endoscopic thyroidectomy, we received comments similar to yours when we presented our preliminary results locally. Our result, technique, and problems encountered are accepted for international publication [1,3]. I firmly believe that no gold standards of any surgical operation should be compromised just to have it performed endoscopically. For all our 10 cases of endoscopic hemithyroidectomy since 28 February 1997 (with 4 conversions), we performed a standard hemithyroidectomy, including the isthmus with intact capsule. There were no surgical complications.In the early phase of our study, we used the technique of endoscopic neck dissection for thyroid nodules up to 38 mm and retrieved the specimen successfully with some wound extension. A good analog would be the removal of an intact acutely inflamed gall bladder via the 12-mm umbilical wound. Thus, any thyroid specimen smaller than that would not be problematic. As we gained further experience, we concluded that a large specimen and lack of tailored instruments would render the long operation (180-300 min.) less worthwhile. We insisted that the whole course of the recurrent laryngeal nerve should be positively identified and protected (Fig. 1). One of our conversions resulted from inability to identify the nerve, even though we had almost completely mobilized the hemithyroid. We now have a strict limitation requiring that the nodule be smaller than 15-20 mm, and that the thyroid gland itself not hypertrophied. Ultrasonography can provide the necessary information. Apart from the usual lateral dissection for parathyroidectomy, we performed additional central dissection for the final approach to the pretracheal attachment of the thyroid gland [2].We also are aware of hypercapnia's potential complication as mentioned. The end-tidal CO 2 of our patients was monitored closely. However, in only 1 of our 15 endoscopic neck surgery cases, did the ventilator setting of the patient need to be modified to lower the end-tidal CO 2 . We started the first few seconds of insufflation with 15 mmHg of pressure to induce the surgical emphysema, instantly lowering it to 5 mmHg during the whole operation. The actual recorded pressure was even lower due to the persistent leakage from the trocar sites because tissue purchase is much less than with laparoscopic surgery. Furthermore, we encountered no noticeable emphysema in the patients once they recovered from the anesthesia.After the first nine cases of endoscopic thyroidectomy, we followed up the patients for 8-14 months to assess their clinical recovery and satisfaction. In the coming months, we shall be comparing prospectively the result of endoscopic thyroidectomy and open thyroide...