Reply to Dr. Agarwal’s letter to the Editor “Recurrent laryngeal nerve, phonation and voice preservation—energy devices in thyroid surgery—A note of caution”

Abstract

Sir, Dr. Brij B. Agarwal’s comments to my letter provide many hints for meditation on the overwhelming aggression of new technologies in general surgery [1]. Moreover, it is a clear invitation for the new generation general surgeons to be judicious and prudent before accepting to use any new technological device so smartly offered by the industry. Otherwise, we all know how difficult it is to propose to a patient to enter a prospective randomized control trial which proposes a new surgical procedure, or any related innovation. Surgery is not medicine, and any procedure “is not like an aspirin”. Nevertheless, the new devices proliferate, and many of them have been recently favorably received by the surgical community. The purpose of my letter to the Editor has been to focus the attention to the fact that ultrasonic coagulating– dissectioning systems (HCDS) and electrothermal bipolar vessel sealing systems (EBVSS)—which are now so widely used in thyroid surgery, either traditional or videoscopic [1]— may be potentially more treacherous due to the restricted space in which possible and unrecognized electrical and thermal effects could damage delicate structures such as the recurrent laryngeal nerve (RLN) [2, 3]. I perfectly agree with Dr. Agarwal that in thyroid surgery a meticulous technique during the dissection is absolutely essential; however, if the well-trained surgeon feels confident in using HCDS or EBVSS, possible solutions to avoid lesions due to the involuntary spread of invisible energy from these devices at present are a standardized technique (distance between HCDS or EBVSS shears to the RLN more than 5mm) and to have an intraoperative neuromonitoring (NM) of the preserved function of RLN [1]. Invisible RLN insult from thermal spread by HCDS or EBVSS goes undetected by the surgeon eye and only intraoperative electromyography with NM can exclude such an insult [1, 4]. NM is a new functional dimension of RLN intraoperative management during modern thyroid surgery, superior to visual identification for intraoperative RLN injury [1, 4]. The intraoperative (and not postoperative) assessment of RLN function during thyroid surgery is important for different reasons: clarification of RLN anatomy; intraoperative prediction of postoperative function (prognosis); prevention of bilateral RLN injury (“stage thyroidectomy”); identification of where and how the RLN was injured; early differentiation between RLN related and unrelated voice changes [4, 5]. I do not mean to emphasize new technologies over sound common sense and I do recognize that at present standards for recurrent laryngeal nerve (RLN) management during thyroid surgery are yet extensive knowledge of RLN anatomy, routine visual identification of nerve, cervical exposure of RLN, experience, training, and preand postoperative laryngoscopy [5]. Specific training and caution with NM is essential for optimal use: this modern device requires a senior endocrine surgeon and anesthesiologist with a high level of experience and a standardized approach with routine preand postthyroid resection vagus stimulation [4, 5]. Langenbecks Arch Surg (2009) 394:913–914 DOI 10.1007/s00423-009-0512-x