Volume 7, Issue 3-4 - Special Issue: Thyroid surgery

The laryngeal adductor reflex (LAR) is a life-sustaining airway protective mechanism that serves to shield the lower airways from inhaled foreign bodies. Over the past half century, the LAR has been extensively investigated and its dysfunction has been linked to far-ranging pathologies, from dysphagia to sudden infant death syndrome. Over the past 6 years, specific electromyographic waves in the LAR response have been used to devise a methodology for monitoring the vagus and recurrently laryngeal nerves during surgical procedures. This methodology involves continuous intraoperative neuromonitoring of the laryngeal adductor reflex and isthus termed ‘LAR-CIONM’. In this review paper, the physiology of the LAR will be summarized as it relates to LAR-CIONM and the technique of LAR-CIONM will be described. Applications of this technique and published outcomes of LAR-CIONM will be highlighted.

Objectives In over 30% of all thyroid surgeries, complications arise from transient and definitive hypoparathyroidism, underscoring the need for real-time identification and preservation of parathyroid glands (PGs). Here, we evaluate the promising intraoperative optical technologies available for the identification, preservation, and functional assessment of PGs to enhance endocrine surgery. Methods We performed a review of the literature to identify published studies on fluorescence imaging in thyroid and parathyroid surgery. Results Fluorescence imaging is a well-demonstrated approach for both in vivo and in vitro localization of specific cells or tissues, and is gaining popularity as a technique to detect PGs during endocrine surgery. Autofluorescence (AF) imaging and indocyanine green (ICG) angiography are two emerging optical techniques to improve outcomes in thyroid and parathyroid surgeries. Near-infrared-guided technology has significantly contributed to the localization of PGs, through the detection of glandular AF. Perfusion through the PGs can be visualized with ICG, which can also reveal the blood supply after dissection. Conclusions Near infrared AF and ICG angiography, providing a valuable spatial and anatomical information, can decrease the incidence of complications in thyroid surgery.

Objectives Fine-needle aspiration cytology (FNAC) is recommended by international guidelines for the preoperative evaluation of suspicious thyroid nodules >1 cm. Despite robust evidence from endocrine centers demonstrating the key role of FNAC results for the indication of surgery, the method is not routinely used in European clinics. The database EUROCRINE ® , which was introduced in 2015 with the scope of registering operations of the endocrine system, allows for a large-scale analysis of the current service reality in Europe concerning FNAC use and associated accuracy. Methods Operations performed to “exclude malignancy”, registered from January 2015 to December 2018 in EUROCRINE ® , were analyzed. Parameters of accuracy were calculated for FNAC. FNAC results were considered “test positive” in the case of Bethesda category IV, V, and VI, since these categories usually prompt surgical interventions in European centers for thyroid surgery. Bethesda category II and III were considered “test negative”. Results Of 8,791 operations, 5,780 had preoperative FNAC (65.7%). The overall malignancy rate was 28.3% (2,488/8,791). Malignancy rates were 68.8% for Bethesda VI, 69.9% for Bethesda V, 32.6% for Bethesda IV, 28.2% for III, 20.2% for Bethesda II, and 24.5% for Bethesda I. After exclusion of papillary microcarcinomas (PTMCs), the sensitivity of FNAC was 71.7% and specificity 43.5%, the positive predictive value was 29.1% and the negative predictive value 82.7%. Conclusions Although the indication to “exclude malignancy” was the predominant reason that prompted thyroid resection in the present cohort, FNAC was only used in about 65.7% of cases. When performed, FNAC was associated with unexpectedly low accuracy. Interestingly, in Bethesda II, 20.2% of malignant entities were present (13.3% after the exclusion of PTMCs).

Objectives Transoral thyroid surgery vestibular approach (TOETVA) is a novel and feasible surgical technique that allows for cervical surgery without visible incisions. TOETVA represents a new frontier in endocrine surgery since aesthetic results play a more and more decisive role in elective surgery. However, acceptance is different around the world with widespread prevalence in Asian countries and some high-volume centres in the US. While inclusion criteria for TOETVA are limited regarding size and volume a combination with other extracervical techniques like the retroauricular endoscopic cephalic access thyroid surgery (EndoCATS) approach or transaxillary access is an option. Methods TOETVA is carried out through a three-port technique placed at the oral vestibule. Originally one 10-mm port for a 30° endoscope and two additional 5-mm ports for dissecting and coagulating instruments are used. Alternatively, one 5-mm and one or two 3 mm ports can be used. CO2 insufflation pressure is set at 6 mmHg. An additional device to optimize gas outflow for optimum view might be helpful. An anterior cervical subplatysmal space is created by hydrodissection from the oral vestibule to the sternal notch, laterally to the sternocleidomastoid muscle. Conventional endoscopic instruments are used. Combination of TOETVA with a modified retroauricular access includes insertion of a 10–12 mm trocar placed subcutaneously via a skin incision on the scalp, behind the ear by blunt dissection. Results Since Anuwong published the first case series of 60 patients who underwent scarless thyroidectomy via the lower vestibule of the mouth with excellent results in 2016 almost 1,000 cases are reported in literature to date with comparable results especially regarding traditional complications. In contrast to other extracervical approaches, areolar or axillary for example, the transoral access route is short and the dissection planes are rather like transcervical surgery. Surgical indications and contraindications have been modified since its first description and are partly institution specific to date. To amend indications combination with other extracervical techniques is an option. In addition, patients must carefully be selected for and surgeons` candidacy is of utmost importance in transoral surgery. Conclusions Transoral surgery will likely continue to gain attraction as surgeons become more experienced with the technique. With increased operative use and surgeon experience the gap in conventional outcomes between transoral surgery and the transcervical approach will narrow, with both operative time and the incidence of specific complications diminishing. Experience in thyroid and endoscopic surgery is required to achieve excellent results with low complication rates. However, the new transoral technique is related to novel complications that must be evaluated.

Objectives Surgery of the thyroid takes place in a body part with complicated anatomy and several vital physiologic functions. Thyroidectomy is rarely associated with mortality but can be followed by significant complications, (i.e. hypoparathyroidism, hemorrhage, upper airway obstruction, laryngeal nerve injuries and thyrotoxic storm). This review aims to indicate surgical tips and techniques to sustain a low level of complications. Content MEDLINE database (PubMed) platform was used as a search engine and the articles related to the topic were selected using the keywords combination “thyroid surgery and complications”. Summary and Outlook The most common complication of total thyroidectomy with an occurrence ranging between 0.5 and 65% is hypoparathyroidism. Damage to recurrent laryngeal nerves can be temporary or permanent, unilateral or bilateral; bilateral lesion is associated with severe episodes of breathlessness. Thus, intraoperative monitoring of nerve function is essential to prevent damage. Ιn addition, hematoma formation can lead to breathing difficulties due to airway obstruction; preventive hemostasis during surgery is essential. The surgeon must have a complete anatomical understanding of not only the normal anatomy of the central visceral compartment of the neck, but also the common variations of the laryngeal nerves and parathyroid glands in order to keep the complication rate at a very low level.

In December 2019, the new coronavirus infection (COVID-19) was declared a pandemic by the World Health Organization after rapidly spreading over the world in just a few months. All elective operations and nonemergency treatments have been postponed worldwide. However, some patients require surgical therapy as well, and the time spent waiting should not have a negative impact on the surgical outcome or disease course. Following the initial onset of the COVID-19 epidemic, instructions for proper and safe surgery for healthcare staff and patients should develop. Thyroid surgeries have decreased during the COVID-19 pandemic. Most of them can be postponed for a long time. Assessment of thyroid nodules recommends clinical examination, imaging studies, fine needle aspiration (FNA) and vocal cord examination. All these procedures are necessary, and sometimes they cannot be postponed. To determine the best timing, a thorough preoperative assessment should be undertaken, taking into account both oncological and anatomical features. Furthermore, COVID-19 status must be negative prior to any intervention, and hospital infrastructure must be ready to deal with the demanding situation.

Objectives Thyroid liposarcoma is a rare tumor. Its low prevalence accounts for the scarcity of data in the literature, which consists mostly of small studies and case reports. Case presentation We present the case of a 60 years old male with no past medical or past surgical history and presented with neck discomfort and a large left thyroid nodule. Thyroid ultrasound and CT scan were performed and confirmed the existence of a thyroid nodule most probably inside the left inferior thyroid lobe. In the posterior mediastinum, two fatty formations were found. To complete, an MRI was performed, showing a mixed lesion, of the lower neck and upper chest. The patient underwent an extended resection which consisted of an en bloc resection of the lesion (left thyroid lobectomy and isthmus resection) by an anterior transverse cervical incision and a sternotomy. Tracheal and laryngeal shaving and esophageal shaving with resection of the esophageal muscularis was performed as well. The pathological evaluation of the specimen showed a grade II dedifferentiated liposarcoma with an inflammatory component. Conclusions Thyroid liposarcoma is a rare lesion of the thyroid. Its management requires an exhaustive workup followed by an en bloc resection of the lesion. Depending on the histology, postoperative radiation therapy may or may not be necessary.