Intraoperative Nerve Monitoring System Research Articles

EVALUATION OF THE MICROSURGERY RESULTS FOR ACOUSTIC NEUROMA USING AN INTRAOPERATIVE NERVE MONITORING SYSTEM

Objectives: To evaluate the results of microsurgery for acoustic neuroma using an intraoperative nerve monitoring system. Subjects and methods: Cross-sectional, retrospective, and prospective description of 74 patients with acoustic neuroma who were microsurgically treated in Viet Duc University Hospital from October 2016 to March 2018. Results: Women (58.11%) were more predominant than men (41.89%). The age mean was 50.41% ± 9.43 years. There was no significant difference between the tumor location on the right and left side (54.41 compared to 45.59%). There were 40 patients with large tumors (54.05%), giant tumors in 20 patients (27.02%), and 14 patients (18.92%) with small tumors < 2.5cm. Postoperative magnetic resonance examinations were indicated for 100% of patients, in which 78.37% full of tumors were taken out and 21.63% were taken almost tumors. The rate of intact facial nerve was 93.3%. The damage rate of the facial nerve was about 20.28%. The most complications were cerebral edema, bleeding, hydrocephalus, death and meningitis (5.4%; 4.05%; 4.05%; 2.7%, and 1.35%, respectively). The recovery of the function of the VII nerve, grade I, II according to House-Brackmann was 79.72%. Conclusion: Neurosurgical intervention remains the main step in the effective management of vestibular schwannomas. Using a continuous monitoring system for the facial nerve in surgery for vestibular schwannoma has reduced the rate of post-operative facial nerve paralysis.

Intraoperative Management of the Recurrent Laryngeal Nerve Transected or Invaded by Thyroid Cancer.

Thyroid cancer often invades the recurrent laryngeal nerve (RLN), causing vocal cord paralysis. In such patients, the invaded portion of the RLN usually needs to be resected through curative surgery. We attempt to preserve the nerve by performing sharp dissection in such cases. During nerve dissection, an intraoperative nerve monitoring system helps identify the course of the RLN in the fibrous tissue around the tumor or even within the tumor, and also helps evaluate the nerve integrity. Because of extensive dissection, the preserved RLN may become much thinner than its original thickness. We refer to this procedure as “partial layer resection” of the RLN. In our cases, although the dissected RLNs became thinner, we found that vocal cord function recovered in most patients. If the RLN is fully involved by thyroid cancer or response of the vocal cord against electric stimulation to the RLN is lost, we resect the portion of the RLN together with the tumor and repair it using one of the reconstruction techniques. When a unilateral RLN is resected, the vocal cord on that side is paralyzed. Symptoms include hoarseness, mis-swallowing, and short phonation. RLN reconstruction using one of the reconstruction techniques leads to the recovery of phonatory and swallowing function, although the normal motion of the vocal cord on the side of the anastomosis is not restored. We used direct anastomosis, free nerve grafting, ansa cervicalis-RLN anastomosis, and vagus-RLN anastomosis to reconstruct the RLN. Thyroid cancer often invades the RLN near the Berry’s ligament. In such patients, surgeons might assume that reconstruction of the RLN may not be possible because the peripheral stump of the RLN cannot be observed. However, if we divide the inferior pharyngeal constrictor muscles along the lateral edge of the thyroid cartilage, the peripheral RLN can be identified, and nerve reconstruction can be performed. We refer to this procedure as “laryngeal approach”.In summary, of the patients with thyroid cancer who required resection of the RLN, RLN reconstruction led to the recovery of phonatory function. We suggest that all thyroid surgeons familiarize themselves with these reconstruction techniques.

Feasibility of Continuous Intraoperative Nerve Monitoring System for Esophageal Cancer during Transmediastinal Esophagectomy

Feasibility of Continuous Intraoperative Nerve Monitoring System for Esophageal Cancer during Transmediastinal Esophagectomy

A novel Killian\u2013Jamieson diverticulectomy using a thyroid gland flap: a case report

BackgroundA Killian–Jamieson diverticulum is a rare pharyngoesophageal diverticulum that is radically treated by diverticulectomy. However, there is no consensus on whether cricopharyngeal myotomy is necessary, and the optimal surgical methods that prevent postoperative complications such as leakage are undetermined.Case presentationA 49-year-old man was referred to our hospital with oropharyngeal dysphagia while eating. The patient was preoperatively diagnosed with a Killian–Jamieson diverticulum based on radiographic and clinical findings and underwent a transcervical diverticulectomy. The recurrent laryngeal nerves were preserved using an intraoperative nerve monitoring system, and the diverticulum was identified without difficulty. A partial cricopharyngeal myotomy was performed to expose the base of the diverticulum. The diverticulum was transected transversally using a linear stapler under the guidance of intraoperative upper intestinal endoscopy. A thyroid gland flap supplied by the superior thyroid artery was harvested and placed overlapping the area of the partial cricopharyngeal myotomy. Due to the proximity of the recurrent laryngeal nerve course to the diverticulum stump, the staple line was not buried with sutures. The thyroid gland flap with its rich vascular supply was fixed to completely cover the staple line on the cut surface of the thyroid gland. The postoperative course was uneventful, without vocal cord paralysis. The patient was discharged on postoperative day 8. He developed no clinical signs suggesting leakage, recurrence, or adverse events.ConclusionKillian–Jamieson diverticulectomy using a thyroid gland flap and partial cricopharyngeal myotomy is a valid treatment option that may prevent complications and recurrence. Precise evaluation of the diverticulum using an intraoperative nerve monitoring system is crucial for the repair.

Gonioprobe, an Innovative Gamma-probe to Guide Parathyroid Radioguided Surgery: First Clinical Experiences with Navigator and Lock-ontarget Functions.

Radioguided surgery represents a validated technique for the detection and the excision of abnormal parathyroid glands responsible for primary hyperparathyroidism (PHPT). To date little attention has been paid as to how the characteristics of gamma-probes can influence surgical procedure and time, thus having an impact on postoperative morbidity, hospitalization and costs. We designed a new prototype of gamma-probe, the Gonioprobe, and tested its clinical utility in the operating room. Gonioprobe, thanks to its 5 scintillating independent crystals, performs the dual function of Navigator and Lock-on-target. These characteristics allow the immediate guidance of the surgeon's hand towards the source with very high precision, and with a much higher spatial resolution than commercial probes. Gonioprobe was used during intervention to detect abnormal parathyroid tissue, and to ensure no radioactivity in surgery bed after adenoma removal. We tested our gamma-probe on parathyroid adenomas particularly difficult to identify at a visual inspection due to anatomy modifications from previous neck surgery and/or characterized by uncommon localization. Moreover, parathyroid adenomas were hardly removable due to the proximity to the esophagus, neck vessels and/or recurrent laryngeal nerve (RLN). An intraoperative nerve monitoring system was used to protect the recurrent laryngeal nerve from injuries. Parathyroid hormone (PTH) assay and frozen biopsy confirmed the successful excision of the adenomas. The intraoperative use of the innovative Gonioprobe along with the nerve monitoring system allowed an accurate and safe removal of parathyroid adenomas and offered a significant advantage by reducing surgical time and postoperative complications, as well as hospitalization and costs.

Clinical Experience with the Continuous Intraoperative Nerve Monitoring System in Mediastinoscopic Esophagectomy

Clinical Experience with the Continuous Intraoperative Nerve Monitoring System in Mediastinoscopic Esophagectomy

Killian-Jamieson diverticulum safely resected using a manual intraoperative neural monitoring system: a case report

BackgroundKillian-Jamieson diverticulum is a rare pharyngoesophageal diverticulum. The risk of intraoperative injury of the recurrent laryngeal nerve (RLN) is high during surgical resection of Killian-Jamieson diverticulum because the RLN usually runs next to the base of the diverticulum. We present a case of Killian-Jamieson diverticulum that was safely resected with effective use of an intraoperative nerve monitoring (IONM) system with a handheld stimulating probe to prevent RLN injury.Case presentationA 69-year-old man complaining of dysphagia was diagnosed with Killian-Jamieson diverticulum and underwent open transcervical diverticulectomy. Because the anterior aspect of the diverticulum was expected to be close to the RLN, the accurate location of the RLN was checked during dissection by intermittent stimulation using a handheld probe of the IONM system to avoid mechanical and thermal injury. The diverticulum was transected longitudinally using a linear stapler, and the staple line was buried using absorbable sutures from the distal end. During its closure, RLN was identified very close to the diverticulum stump by IONM, and the upper side of the stump was left unburied to avoid RLN injury. The postoperative course was uneventful and the patient was discharged on postoperative day 7. Postoperative evaluation showed no vocal cord paralysis.ConclusionIONM may be beneficial during open surgery for Killian-Jamieson diverticulum, which usually protrudes just lateral to the RLN.

Recurrent Laryngeal Nerve Palsy (RLNP) in the Esophageal Cancer Operation: Surgical Procedure of Lymph Node Dissection Avoiding RLNP, and Usefulness of an Intraoperative Nerve Monitoring System

Recurrent Laryngeal Nerve Palsy (RLNP) in the Esophageal Cancer Operation: Surgical Procedure of Lymph Node Dissection Avoiding RLNP, and Usefulness of an Intraoperative Nerve Monitoring System

Successful intraoperative electrophysiologic monitoring of the recurrent laryngeal nerve, a multidisciplinary approach: The Massachusetts Eye and Ear Infirmary monitoring collaborative protocol with experience in over 3000 cases.

Although intraoperative nerve monitoring (IONM) is utilized increasingly, the information on the related anesthesia technique is limited. This study presents an up-to-date clinical algorithm, including setup and troubleshooting of an IONM system, endotracheal tube placement, and anesthetic parameters. To our knowledge, this is the first interdisciplinary collaborative protocol for monitored neck surgery based on the published evidence and clinical experience. The Departments of Otolaryngology Head and Neck Surgery, Anesthesiology, and Audiology collaboratively developed a protocol for IONM of the recurrent laryngeal nerve (RLN) based on published evidence and our experience with 3000 patients over a 16-year period. No complications related to monitoring or endotracheal tube placement were noted when the IONM protocol was implemented at Massachusetts Eye and Ear Infirmary (MEEI). The IONM protocol has proven to be vital in standardizing care and in avoiding intraoperative errors. An IONM system entails an anesthesiologist who understands the challenges posed by this technique; muscle relaxation must be minimized/eliminated to optimize IONM. © 2016 Wiley Periodicals, Inc. Head Neck 38: First-1494, 2016.

Superior laryngeal nerve monitoring using laryngeal surface electrodes and intraoperative neurophysiological monitoring during thyroidectomy.

The objective of this study is to establish normative waveform data for the external branch of the superior laryngeal nerve (SLN) utilizing laryngeal surface electrodes and intraoperative neurophysiological monitoring (IONM) in conjunction with a clinical neurophysiologist. A retrospective chart review of 91 consecutive at-risk SLN were identified in 51 patients in whom IONM using laryngeal surface electrodes was performed by a clinical neurophysiologist using Dragonfly (Neurovision Medical Products, Ventura, CA) recording electrodes and a Protektor (Natus Medical Inc., San Carlos, CA)16 channel- intraoperative nerve monitoring system. Inclusion criteria were met for 30 SLN. Data collected included preoperative diagnosis, surgical procedure, rates of nerve identification and stimulation, and waveform characteristics. Waveform analysis for 30 SLN yielded a peak latency of 4.0 ± 0.2 ms, onset latency 2.3 ± 0.1 ms, peak-to-peak amplitude of 220.4 ± 31.1 µV, onset-to-peak amplitude of 186.0 ± 25.0 µV, and stimulation current threshold of 0.55 ± 0.03 mA (data = mean ± SEM). Two patients had abnormal SLN function documented clinically on postoperative laryngoscopic examination. Laryngeal surface electrodes were successfully utilized to identify and monitor SLN function intraoperatively. IONM using laryngeal surface electrodes enables analysis of waveform morphology and latency in addition to threshold and amplitude data obtained with the traditional NIM system, potentially improving the performance of nerve monitoring during thyroid surgery.

Serial Electromyography of the Thyroarytenoid Muscles Using the NIM-Response System in a Canine Model of Vocal Fold Paralysis

We sought to determine whether serial intraoperative laryngeal electromyography (L-EMG) or evoked L-EMG predicts vocal fold (VF) recovery following iatrogenic injury. Six beagles were sedated, and bipolar needle electrodes were inserted into each thyroarytenoid (TA) muscle. Endotracheal tube surface electrodes were also placed. As the sedation lightened, L-EMG activity was recorded from all electrodes with an intraoperative nerve monitoring system. The neck was opened, and direct recurrent laryngeal nerve (RLN) stimulation was performed. Subsequently, 4 animals underwent crush injury of the left RLN,and 2 animals underwent nerve transection. The L-EMG procedures were repeated every 1 to 2 weeks until left VF motion was observed in the dogs that suffered RLN crush injury. At each time point, the neck was opened and both RLNs were stimulated. Fibrillation potentials were detected in all animals after RLN injury. A change to electrical silence was seen in the animals in the crush injury group that were evaluated during the week preceding VF recovery. Fibrillation potentials and VF immobility persisted in the transection group throughout the complete time course of these experiments. The first appearance of an evoked response coincided with or occurred after the return of left VF motion in the crush injury group. The threshold, latency, and amplitude differed from those of the controls and approached normal values over time. No response was detected in the transected nerves. The disappearance of fibrillations on intraoperative L-EMG was noted in the animals tested the week before the return of VF motion, and the return of motor unit action potentials was seen along with return of VF function. Evoked L-EMG was not helpful in predicting the return of VF mobility, but it may help quantify degrees of RLN injury and predict the speed of recovery.