Minimally invasive video-assisted thyroidectomy and parathyroidectomy with intraoperative recurrent laryngeal nerve monitoring

The transcutaneous electromyography recording method for intraoperative neuromonitoring of recurrent laryngeal nerve during minimally invasive parathyroidectomy

Intraoperative neuromonitoring (IONM) facilitates recurrent laryngeal nerve (RLN) protection in thyroid and parathyroid surgeries. This study aimed to investigate a novel transcutaneous electromyography (EMG) recording method for IONM of the RLN during minimally invasive parathyroidectomy (MIP). Twenty patients with primary hyperparathyroidism undergoing MIP were enrolled. Two paired needle electrodes were percutaneously inserted into the bilateral laminas of thyroid cartilage for monitoring the vagus nerve and RLN. A standardized IONM procedure (V₁-R₁-R₂-V₂ signals) was strictly followed, and the RLN was routinely located and mapped. Pre- and postoperative laryngofiberoscopy was performed to confirm vocal cord function. The proposed technique was successfully used in all patients, and typical EMG signals were effectively detected. No significant change in EMG signals before and after tumor resection was noted, and a normal vocal cord movement was ensured in all patients with postoperative laryngofiberoscopy. IONM helped localize the position of the RLN and facilitated the safe resection of the parathyroid tumor during MIP. The novel transcutaneous EMG recording method proposed in this study was feasible, convenient, reliable, and inexpensive.

Role of Intraoperative Nerve Monitoring During Parathyroidectomy to Prevent Recurrent Laryngeal Nerve Injury

Injury to the recurrent laryngeal nerve (RLN) is a well known, though less frequent, complication of parathyroid surgery. In recent years, the use of intraoperative nerve monitoring (IONM) has gained popularity amongst surgeons when operating on thyroid gland; however, its utilization in parathyroid surgery is not established. This trend continues to rise, despite multiple studies documenting no statistically significant difference that IONM decreases the incidence of RLN injury. Most surgeons use this technology as an adjunct to visualization alone for identification of RLN. The purpose of this review is to discuss the possible role of IONM in parathyroid surgery with regards to the accuracy, efficacy, and recent trends in the utilization of this technology. There is insufficient evidence that IONM reduces the risk of RLN injury in parathyroidectomy. Although IONM may decrease the likelihood of nerve injury by helping to identify and map the RLN during thyroidectomy, we did not find studies exclusive to parathyroid surgery to see if its use can be supported for parathyroidectomy. Despite this lack of evidence, we believe that IONM is a promising adjunct to visualization alone in detecting nerve structures during neck dissection, but more clinical trials are warranted to establish its role in preventing nerve injury in parathyroid surgery.

Magnetic Control of the Glottic Opening in an Ex Vivo Sheep Larynx Model: A Preliminary Study

OBJECTIVE/HYPOTHESIS

So far, a number of techniques have been described for the treatment of bilateral vocal fold paralysis. These techniques were reported to be successful in maintaining an adequate airway but also found to be associated with an increased risk of aspiration, dysphonia, and granulation tissue formation at the operation site. We aimed to investigate the effectiveness of a novel mucosa-sparing technique based on the generation of a magnetic field within the larynx for the tailored lateralization of the ipsilateral vocal fold.

STUDY DESIGN

This is an ex vivo experimental study.

METHODS

Twenty sheep larynges that were procured from the local slaughterhouse were used as a model. For each specimen, two neodymium (Nd) disc magnets with marked poles were used to create a unilateral attractive magnetic force at the glottic level. Following insertion of the magnets, the level of vocal fold lateralization was assessed under an operating microscope. The results were analyzed for their statistical significance.

RESULTS

Before the procedure, the mean value of the glottic openings of all the specimens was 4.985 mm. The postprocedure mean value was 5.640 mm. The mean amount of increase in the glottic openings after the procedure was 0.655 mm. This change was found to be statistically significant (P < 0.05).

CONCLUSIONS

A statistically significant increase in the cross-sectional area of the glottic region could be achieved. The mucosal integrity of the laryngeal airway was also preserved. The idea of "magnetic control of the glottic airway" is a novel concept but seems to be a promising option.

Different surgical approaches in parathyroid adenoma resections

Three patients were referred to our clinic for the management of a persistent symptomatic primary hyperparathyroidism. Pre-operative imageological localization revealed evidence of an adenoma. Here we are presenting three videos demonstrating the different surgical approaches of parathyroid adenoma resection, with the use of an intraoperative gamma probe and nerve monitoring.

Neuromonitoring of the laryngeal nerves in thyroid surgery: a critical appraisal of the literature

One of the most significant complication of thyroid surgery is injury of the recurrent laryngeal nerve. Injury of the external branch of the superior laryngeal nerve is a less obvious but occasionally significant problem. Recently, neuromonitoring during thyroidectomy has received considerable attention because of literature encouraging its use, but there is no consensus about its advantages and utility. A critical assessment of the literature on neuromonitoring was conducted in order to define its effectiveness, safety, cost-effectiveness and medical-legal impact. Available data does not show results superior to those obtained by traditional anatomical methods of nerve identification during thyroid surgery. Data about cost-effectiveness is scarce. The literature shows inconsistencies in methodology, patient selection and randomization in various published studies which may confound the conclusions of individual investigations. The current recommendation for use in "high risk" patients should be assessed because definition heterogeneity makes identification of these patients difficult. As routine use of neuromonitoring varies according to geography, its use should not be considered to be the standard of care.

Mini-invasive video-assisted surgery of the thyroid and parathyroid glands: a 2011 update

Thyroid surgery during the last century was characterized by a development of Kocher's concepts: through a relentless work of surgeons from all over the world thyroidectomy reached a standard of quality in terms of overall results which was unimaginable in the first half of the XX century. The flattering data collected in the literature until the 90's were all concordant in assuming that there would be little space for a real improvement in the quality standard of thyroid surgery. The introduction of laparoscopic surgery, though, changed very quickly the attitude of surgeons towards their operative behavior and countless new mini-invasive techniques were soon proposed for almost any field of surgery. In 1994, Gagner published the first series of laparoscopic adrenalectomies. Soon after, parathyroid adenomas seemed to offer an ideal field of application of these new surgical concepts. The first report of an endoscopic parathyroidectomy was in 1996. One year later other videoscopic procedures were described whose results seemed quite encouraging so as to push surgeons to try the same access and the same technique also for operations on thyroid. During the following decade several endoscopic or video-assisted approaches were proposed for the removal of thyroid gland. This paper aims to evaluate the results of minimally invasive thyroid and parathyroid surgery through an extensive review of the literature, in particular as far as minimally invasive video-assisted thyroidectomy is concerned.