Critical Review and Consensus Statement for Neural Monitoring in Otolaryngologic Head, Neck, and Endocrine Surgery

Direct visualization of intraparotid facial nerve assisting in parotid tumor resection

Precise recognition of the intraparotid facial nerve (IFN) is crucial during parotid tumor resection. We aimed to explore the application effect of direct visualization of the IFN in parotid tumor resection. Fifteen patients with parotid tumors were enrolled in this study and underwent specific radiological scanning in which the IFNs were displayed as high-intensity images. After image segmentation, IFN could be preoperatively directly visualized. Mixed reality combined with surgical navigation were applied to intraoperatively directly visualize the segmentation results as real-time three-dimensional holograms, guiding the surgeons in IFN dissection and tumor resection. Radiological visibility of the IFN, accuracy of image segmentation and postoperative facial nerve function were analyzed. The trunks of IFN were directly visible in radiological images for all patients. Of 37 landmark points on the IFN, 36 were accurately segmented. Four patients were classified as House-Brackmann Grade I postoperatively. Two patients with malignancies had postoperative long-standing facial paralysis. Direct visualization of IFN was a feasible novel method with high accuracy that could assist in recognition of IFN and therefore potentially improve the treatment outcome of parotid tumor resection.

The Utility of Intraoperative Neuromonitoring in Pediatric Surgical Oncology

BACKGROUND

Intraoperative nerve monitoring (IONM) is a technique used to decrease the possibility of nerve-associated morbidity and damage to nearby neural structures during complex surgical procedures. The use and potential benefits of IONM in pediatric surgical oncology are not well-described.

METHODS

An overview of the current literature was performed to elucidate the various techniques that may be useful to pediatric surgeons for resection of solid tumors in children.

RESULTS

The physiology and common types of IONM relevant to the pediatric surgeon are described. Important anesthetic considerations are reviewed. Specific applications for IONM that may be useful in pediatric surgical oncology are then summarized, including its use for monitoring the recurrent laryngeal nerve, the facial nerve, the brachial plexus, spinal nerves, and lower extremity nerves. Troubleshooting techniques regarding common pitfalls are then proposed.

CONCLUSION

IONM is a technique that may be beneficial in pediatric surgical oncology to minimize nerve injury during extensive tumor resections. This review aimed to elucidate the various techniques available. IONM should be considered as an adjunct for the safe resection of solid tumors in children in the proper setting with the appropriate level of expertise. A multidisciplinary approach is advised. Additional studies are necessary to further clarify the optimal use and outcomes in this patient population.

LEVELS OF EVIDENCE

Level III.

Preoperative voice analysis and survival outcomes in papillary thyroid cancer with recurrent laryngeal nerve invasion

OBJECTIVE

To investigate the clinicopathological characteristics of papillary thyroid cancer (PTC) and identify risk factors for postoperative recurrence of PTC with recurrent laryngeal nerve (RLN) involvement.

METHODS

In total, 171 patients (112 women and 59 men, age: 18-80 years, and 65 patients aged ≥ 55) with T4a PTC with RLN involvement, treated at Beijing Tongren Hospital, Capital Medical University, from January 2006 to December 2020, were retrospectively examined. Clinicopathological characteristics, including voice analysis results, and survival outcomes were assessed. The Mann-Whitney U and Kruskal-Wallis H tests were used to analyze differences in acoustic parameters. The Kaplan-Meier method was used to calculate the overall survival (OS) and recurrence-free (RFS) rates. Univariate and multivariate Cox regression analyses were performed of the clinical data.

RESULTS

The postoperative follow-up period ranged from 12 to 196 months (mean: 66.18 months). Of the 171 patients, 16 had recurrence and 8 died of thyroid-related diseases. The 5-year OS rate was 95.22%. The 5-year RFS rate was 89.38%. Jitter and shimmer were higher and maximum phonation time was shorter in patients with preoperative vocal cord paralysis (VCP) than in those without RLN involvement, and in those with RLN involvement but without preoperative VCP. Acoustic parameters were similar in patients with no preoperative VCP and those without RLN involvement. Voice analysis results did not differ between cases with RLN adhesion and RLN invasion. Univariate analysis showed that age at onset ≥ 55 years, preoperative RLN palsy, and esophageal invasion were risk factors for postoperative recurrence of PTC with RLN involvement. Multivariate analysis showed that onset age ≥ 55 years (OR 4.52, 95% confidence interval: 1.44-14.19, P = 0.010) was an independent risk factor for recurrence.

CONCLUSIONS

PTC patients with RLN invasion can achieve good outcomes. Preoperative voice analysis may offer insights into RLN function. Age of onset ≥ 55 years is an independent risk factor for postoperative recurrence in T4a PTC patients.

Clarifying optimal outcome measures in intermittent and continuous laryngeal neuromonitoring

BACKGROUND

Intraoperative neuromonitoring (IONM) techniques have evolved over the past decade into intermittent IONM (I-IONM) and continuous IONM (C-IONM) modes of application. Despite many prior publications on both types of IONM, there remains uncertainty about what outcomes should be measured for each form of IONM. The primary objective of this paper is to define categories of benefit for I-IONM/C-IONM and to clarify and standardize their reporting outcomes.

METHODS

Expert review consensus statement utilizing modified Delphi methodology.

RESULTS

I-IONM provides diagnosis, classification, and prevention of nerve injury through accurate and early nerve identification. C-IONM provides real-time information on nerve functional integrity and thus may prevent some types of nerve injury but cannot assist in nerve localization. Sudden mechanisms of nerve injury cannot be predicted or prevented by either technique.

CONCLUSIONS

I-IONM and C-IONM are complementary techniques. Future studies evaluating the utility of IONM should focus on outcomes that are appropriate to the type of IONM being utilized.