Size of recurrent laryngeal nerve as a new risk factor for postoperative vocal cord paralysis

Multicentre randomized clinical trial on robot-assisted versus video-assisted thoracoscopic oesophagectomy (REVATE trial)

BACKGROUND

Surgery for oesophageal squamous cell carcinoma involves dissecting lymph nodes along the recurrent laryngeal nerve. This is technically challenging and injury to the recurrent laryngeal nerve may lead to vocal cord palsy, which increases the risk of pulmonary complications. The aim of this study was to compare the efficacy and safety of robot-assisted oesophagectomy (RAO) versus video-assisted thoracoscopic oesophagectomy (VAO) for dissection of lymph nodes along the left RLN.

METHODS

Patients with oesophageal squamous cell carcinoma who were scheduled for minimally invasive McKeown oesophagectomy were allocated randomly to RAO or VAO, stratified by centre. The primary endpoint was the success rate of left recurrent laryngeal nerve lymph node dissection. Success was defined as the removal of at least one lymph node without causing nerve damage lasting longer than 6 months. Secondary endpoints were perioperative and oncological outcomes.

RESULTS

From June 2018 to March 2022, 212 patients from 3 centres in Asia were randomized, and 203 were included in the analysis (RAO group 103; VAO group 100). Successful left recurrent laryngeal nerve lymph node dissection was achieved in 88.3% of the RAO group and 69% of the VAO group (P < 0.001). The rate of removal of at least one lymph node according to pathology was 94.2% for the RAO and 86% for the VAO group (P = 0.051). At 1 week after surgery, the RAO group had a lower incidence of left recurrent laryngeal nerve palsy than the VAO group (20.4 versus 34%; P = 0.029); permanent recurrent laryngeal nerve palsy rates at 6 months were 5.8 and 20% respectively (P = 0.003). More mediastinal lymph nodes were dissected in the RAO group (median 16 (i.q.r. 12-22) versus 14 (10-20); P = 0.035). Postoperative complication rates were comparable between the two groups and there were no in-hospital deaths.

CONCLUSION

In patients with oesophageal squamous cell carcinoma, RAO leads to more successful left recurrent laryngeal nerve lymph node dissection than VAO, including a lower rate of short- and long-term recurrent laryngeal nerve injury. Registration number: NCT03713749 (http://www.clinicaltrials.gov).

Screening for Vocal Fold Movement Impairment in Children Undergoing Esophageal and Airway Surgery

INTRODUCTION

Children undergoing cervical and/or thoracic operations are at risk for recurrent laryngeal nerve injury, resulting in vocal fold movement impairment (VFMI). Screening for VFMI is often reserved for symptomatic patients.

OBJECTIVE

Identify the prevalence of VFMI in screened preoperative patients prior to an at-risk operation to evaluate the value of screening all patients at-risk for VFMI, regardless of symptoms.

METHODS

A single center, retrospective review of all patients undergoing a preoperative flexible nasolaryngoscopy between 2017 and 2021, examining the presence of VFMI and associated symptoms.

RESULTS

We evaluated 297 patients with a median (IQR) age of 18 (7.8, 56.3) months and a weight of 11.3 (7.8, 17.7) kilograms. Most had a history of esophageal atresia (EA, 60%), and a prior at-risk cervical or thoracic operation (73%). Overall, 72 (24%) patients presented with VFMI (51% left, 26% right, and 22% bilateral). Of patients with VFMI, 47% did not exhibit the classic symptoms (stridor, dysphonia, and aspiration) of VFMI. Dysphonia was the most prevalent classic VFMI symptom, yet only present in 18 (25%) patients. Patients presenting with a history of at-risk surgery (OR 2.3, 95%CI 1.1, 4.8, p = 0.03), presence of a tracheostomy (OR 3.1, 95%CI 1.0, 10.0, p = 0.04), or presence of a surgical feeding tube (OR 3.1, 95%CI 1.6, 6.2, p = 0.001) were more likely to present with VFMI.

CONCLUSION

Routine screening for VFMI should be considered in all at-risk patients, regardless of symptoms or prior operations, particularly in those with a history of an at-risk surgery, presence of tracheostomy, or a surgical feeding tube.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:3564-3570, 2023.

Combined thoracoscopic and axillary subcutaneous endoscopic thyroidectomy: a novel approach for cervicomediastinal goiters

PURPOSE

After our group described the first remote-access thyroidectomy series in 2000, the procedure has been further developed. Although a thoracoscopic approach with a conventional open cervical incision for thyroid goiters with mediastinal extension has been performed at many institutions, remote-access thyroidectomy for cervicomediastinal goiters has not been established. We have performed combined thoracoscopic and axillary subcutaneous endoscopic thyroidectomies (axillo-thoracic endoscopic thyroidectomies). Here, we describe a novel technique for performing a remote-access thyroidectomy for a cervicomediastinal goiter (CMG).

PATIENTS AND METHODS

The patients with CMGs who agreed to an axillo-thoracic endoscopic thyroidectomy at one of two hospitals in Japan underwent a remote-access thyroidectomy.

RESULTS

We performed the axillo-thoracic endoscopic right or left hemithyroidectomy successfully, but most of the patients did not require the thoracoscopic procedure. None of the patients had complications, and none was converted to an open thyroidectomy.

CONCLUSIONS

Most thyroid goiters with substernal extension can be removed by the axillary approach, but some cases require a thoracoscopic approach. The novel approach described herein (axillo-thoracic endoscopic thyroidectomy) enables the safe excision of a CMG with high patient satisfaction for selected patients.

Association Between Recurrent Laryngeal Nerve Calibre and Body Figure: A Preoperative Tool to Assess Thin-Diameter Nerves in Thyroidectomy

Inadvertent recurrent laryngeal nerve (RLN) injury is a major complication of thyroidectomy. This study aimed to investigate the association between preoperative clinical parameters and RLN size prediction. Total thyroidectomy and thyroid lobectomy data were collected between January 2014 and April 2017. Routine identification of the recurrent laryngeal nerves was performed, while intraoperative findings (nerve diameter, thyroid gland weight, intraoperative neuromonitoring (IONM) use, and signal recording) and demographic data were collected for analysis. A total of 848 patients with 1357 RLNs at risk were enrolled in this study. RLN diameter was thinner in females, those with body height <160 cm, and those with a BMI <25 (all p < 0.001). RLN diameter was directly proportional to age, body weight, height, and BMI. RLN diameter was thinner (1.71 mm vs. 1.55 mm, p = 0.039) and branched nerve incidence was higher (18.5% vs. 29.7%, p = 0.09) in the postoperative RLN injury group. Branched nerves were more frequently encountered in female patients (female vs. male: 28.8% vs. 18.7%, p = 0.004). The risk of RLN palsy in intraoperative IONM loss patients was 27 times higher compared to that in IONM normal patients (1.55% vs. 30%, p < 0.001). Thinner nerves did not yield a higher rate of IONM signal loss. Thinner nerves and higher palsy rates could be anticipated in females, younger age groups, those with shorter stature, and those with low BMI. RLN diameter was not associated with the rate of IONM signal loss.

Risk factors and therapeutic measures for postoperative complications associated with esophagectomy

Esophageal cancer is one of the most common cancers associated with the high mortality rate. Timely diagnosis and treatment are important to manage the disease and prevent comorbidities. Surgical resection of the tumor and lymph nodes is usually practiced either with or without chemo or chemoradiotherapy. Despite advancements in surgical methods and skills, complex nature of the esophagus and invasiveness of the surgery can lead to serious complications in these patients. In order to predict postoperative outcomes, preoperative examination of the patients, in addition to risk factors, should be conducted. Conclusion: Lastly, early detection of adverse postoperative events may help faster recovery, reduce hospital stay and prevent other morbidities.

Cadaveric Measurements of the Left Recurrent Laryngeal Nerve, Ligamentum Arteriosum, Aortic Arch, and Pulmonary Artery in the Thorax with Clinical Implications and Comparison Between Two Sexes in the American Population

The left recurrent laryngeal nerve (RLN) is prone to get compressed or damaged, leading to vocal cord palsy, due to pathologies or surgeries of the structures closely surrounding this nerve in the thorax, including the esophagus, aortic arch, pulmonary trunk, and ligamentum arteriosum. We wanted to provide a data set including nerve diameter, its distance from the esophagus, measurements of the pulmonary artery, aorta, and ligamentum arteriosum in close proximity of the nerve in a healthy population to avoid its damage during surgery and predict its chances of compression during the diseased condition. We measured the left RLN and the surrounding structures in 39 well-embalmed cadavers. We compared the values among the male and female cadavers. We found that the mean diameter of the left RLN was 1.75 mm, the mean distance of the nerve from esophagus was 9.88 mm, the mean diameters of the aortic arch and pulmonary artery just distal to the attachment of the ligamentum arteriosum were 26.14 and 19.93 mm, respectively, and the length and width of ligamentum arteriosum were 15.89 and 2.79 mm, respectively. No clinically significant differences were found between male and female parameters. This set of values might be useful while investigating the cause of vocal cord palsies or during surgeries in close proximity to left RLN to avoid its damage.

Mesenteric excision of upper esophagus: a concept for rational anatomical lymphadenectomy of the recurrent laryngeal nodes in thoracoscopic esophagectomy

BACKGROUND

The recurrent laryngeal nerve (RLN) lymph nodes are among the most frequently involved lymph nodes in esophageal cancer. Surgical removal of these lymph nodes is considered beneficial for postoperative prognosis, especially in patients with squamous cell carcinoma. Unfortunately, the precise surgical anatomy of the upper mediastinum is not well understood and no distinct high-resolution images are currently available.

METHODS

In this article, we provide a simple intuitive concept of upper mediastinal surgical anatomy that could facilitate rational anatomical lymphadenectomy of the RLN lymph nodes. The essential concept of this mesenteric excision is to mobilize mesoesophagus including RLN in an en bloc fashion and to save RLN laterally by incising visceral sheath. This is applicable identically to both right and left upper mediastinum.

RESULTS

Between January 2009 and December 2017, thoracoscopic esophagectomy with upper mediastinal lymphadenectomy for primary esophageal cancer was performed in 189 patients. Median thoracoscopic procedure time was 297 (range 205-568) min and median intraoperative blood loss was 70 ml (range unmeasurable up to 2545 ml). Median number of harvested upper mediastinal lymph nodes was 12. Postoperative complication of Clavien-Dindo classification grade III or higher events was observed in 14% of patients. RLN palsy of grade II or higher occurred in 20 patients (11%).

CONCLUSION

The mesoesophagus in the upper mediastinum is an anatomical unit surrounded by fibrous connective tissue containing the esophagus, trachea, tracheoesophageal vessels, lymphatic tissue, and RLNs. Thus, mesenteric excision of esophagus is defined to resect this area by sparing trachea and RLNs for rational anatomical lymphadenectomy. We believe that this concept makes upper mediastinal lymphadenectomy safer and more appropriate.