Clinical outcome of continuous facial nerve monitoring during primary parotidectomy

The Outcomes and Surgical Nuances of Minimally Invasive Parotid Surgery for Pleomorphic Adenoma

Benign parotid tumors follow an indolent course and present as slow-growing painless swelling in the pre-and-infra-auricular areas. The treatment of choice is surgery. Though the gold standard technique is Superficial Parotidectomy, Extracapsular Dissection (ECD) is an alternative option with the same outcome and decreased complications. This study discusses our experience with extracapsular dissection and the surgical nuances for better results. A retrospective study of histologically confirmed cases of pleomorphic adenoma of the parotid gland, who underwent Extracapsular dissection between September 2019 and March 2023, was done. The demographic details, clinical characteristics, and outcomes were evaluated. There were 33 patients, including 16 females and 17 males, with a mean age of 32.75 years. All cases presented as slow-growing painless swelling for a mean duration of 5 years. Most of the tumors (94%) were of size between 2 and 4 cm, with few tumors more than 4 cm. All underwent extracapsular dissection with complete excision. There was only one complication (seroma) and no incidence of facial palsy in our experience with ECD. The goal of a benign parotid surgery is the complete removal of the tumor with minimum complications, which could be achieved with ECD, which has good tumor clearance and lesser rates of complications with good cosmesis. Thus, this minimally invasive parotid surgery could be a worthwhile option in properly selected cases.

Imaging of Facial Nerve With 3D-DESS-WE-MRI Before Parotidectomy: Impact on Surgical Outcomes

OBJECTIVE

The intra-parotid facial nerve (FN) can be visualized using three-dimensional double-echo steady-state water-excitation sequence magnetic resonance imaging (3D-DESS-WE-MRI). However, the clinical impact of FN imaging using 3D-DESS-WE-MRI before parotidectomy has not yet been explored. We compared the clinical outcomes of parotidectomy in patients with and without preoperative 3D-DESS-WE-MRI.

MATERIALS AND METHODS

This prospective, non-randomized, single-institution study included 296 adult patients who underwent parotidectomy for parotid tumors, excluding superficial and mobile tumors. Preoperative evaluation with 3D-DESS-WE-MRI was performed in 122 patients, and not performed in 174 patients. FN visibility and tumor location relative to FN on 3D-DESS-WE-MRI were evaluated in 120 patients. Rates of FN palsy (FNP) and operation times were compared between patients with and without 3D-DESS-WE-MRI; propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were used to adjust for surgical and tumor factors.

RESULTS

The main trunk, temporofacial branch, and cervicofacial branch of the intra-parotid FN were identified using 3D-DESS-WE-MRI in approximately 97.5% (117/120), 44.2% (53/120), and 25.0% (30/120) of cases, respectively. The tumor location relative to FN, as assessed on magnetic resonance imaging, concurred with surgical findings in 90.8% (109/120) of cases. Rates of temporary and permanent FNP did not vary between patients with and without 3D-DESS-WE-MRI according to PSM (odds ratio, 2.29 [95% confidence interval {CI} 0.64-8.25] and 2.02 [95% CI: 0.32-12.90], respectively) and IPTW (odds ratio, 1.76 [95% CI: 0.19-16.75] and 1.94 [95% CI: 0.20-18.49], respectively). Conversely, operation time for surgical identification of FN was significantly shorter with 3D-DESS-WE-MRI (median, 25 vs. 35 min for PSM and 25 vs. 30 min for IPTW, P < 0.001).

CONCLUSION

Preoperative FN imaging with 3D-DESS-WE-MRI facilitated anatomical identification of FN and its relationship to the tumor during parotidectomy. This modality reduced operation time for FN identification, but did not significantly affect postoperative FNP rates.

Results of 301 Parotidectomies: A Twenty-Year Experience of One Single Institution

To evaluate demographic, clinical, surgical and histopathological results and complications of 301 parotidectomies performed in southern part of Turkey. The results of 297 patients undergoing 301 parotidectomies between 2000 and 2019 were retrospectively reviewed. Four patients underwent bilateral parotidectomy. Age, gender, side and size of lesion, postoperative facial nerve function (FNF) for benign tumors and types of surgery were evaluated. There were 172 male and 125 female patients. The mean age was 52.53 ± 16.67 years (range 11-90 years). Patients with malignant tumor had higher mean age than the patients with benign diseases (p < 0.001) and the mean age of Warthin tumor (WT) patients was significantly higher than pleomorphic adenoma (PA) (p < 0.001). There was a significant male dominancy in WTs than the PAs (p < 0.001). The mean size of the malignant tumors was significantly higher than the benign tumors (p = 0.012). The mean of cigarette smoking value (pack/year) was higher in WTs than the PAs (p < 0.001). WT incidence was slightly higher than PA in between years 2010 and 2019 (p = 0.272) compared to between years 2000 and 2009. Fine needle aspiration biopsy had a sensitivity of 96% and specificity of 78% for the benign tumors. Tumor location (p < 0.001) and tumor size (p = 0.034) had negative effect on the postoperative FNF. The incidence of WT had a significant rise in the last decade. Deep lobe tumors and increased tumor size had effect postoperative FNF. Experience of surgeon is more important than nerve monitoring to prevent facial paralysis. Partial superficial parotidectomy was available methods for small benign tumors in tail of the parotid gland.

Facial nerve dysfunction following parotidectomy: role of intraoperative facial nerve monitoring

PURPOSE

Facial nerve dysfunction (FND) is a frequent and serious parotidectomy outcome. Intraoperative facial nerve monitoring (IFNM) is an increasingly used technique to identify the facial nerve (FN) and minimize its injury. This study aimed to evaluate the determinant factors in the presence and severity of FND after parotidectomy, including IFNM.

STUDY DESIGN, SETTING AND METHODS

A total of 48 patients consecutively submitted to parotidectomy between 2005 and 2020 in a tertiary hospital were retrospectively analyzed. The House-Brackmann Scale (HBS) was used to assess the severity of FND.

RESULTS

There was a mean age of 54.2 ± 17.8 years, 50% were male. Pleomorphic adenoma (41.7%) and Warthin's tumor (25.0%) were most common. From the 23 patients (47.9%) who developed some degree of FND (HBS score of 3.41 ± 1.53), 19 (82.6%) showed facial movement recovery, with a mean recovery time of 4.78 ± 2.53 months. IFNM was performed in 39.6% of the surgeries. The use of IFNM (p = 0.514), the type of surgery-partial or total parotidectomy-(p = 0.853) and the type of histology-benign or malignant lesion-(p = 0.852) did not significantly influence the presence of FND in the postoperative period. However, in the subgroup of patients who developed FND, the HBS value was significantly lower in cases of benign pathology (p = 0.002) and in patients who underwent IFNM (p = 0.017), denoting a significantly lower severity.

CONCLUSION

In the present study, IFNM and the existence of a benign lesion have been shown to be associated with lower severity of FND.

Pediatric parotidectomy outcomes: A 14-year multicenter study

Objectives

Parotidectomy increases childhood challenges. This study aimed to determine the clinical profiles, investigations, and outcomes of pediatric patients who had undergone parotidectomy.

Methods

A multicenter retrospective review of parotidectomy in pediatric patients between 2007 and 2020.

Results

In 108 parotidectomies, the final diagnoses were benign (47.22%), malignant (36.11%), and non-neoplastic (16.67%). The incidence of facial palsy was 37.03%, which was significantly lower in the superficial group than that in the total parotidectomy group (p = .021). The incidence of facial nerve palsy was significantly higher in the malignancy group than that in the benign group (p = .035). Magnetic resonance imaging (MRI) detected malignancy with 92.8% overall accuracy, 83.3% sensitivity, and 100% specificity. The sensitivity and specificity of fine-needle aspiration (FNA) were 54.2% and 92.7%, respectively.

Conclusions

Parotidectomy is commonly performed for benign and non-neoplastic diseases in pediatric patients. Facial nerve palsy is significantly associated with malignant tumors and total parotidectomy. MRI is the most accurate imaging modality for diagnosing malignant lesions. FNA exhibits moderate agreement with the final pathology.

Level of Evidence

Level IV.

Proposals for Standardization of Intraoperative Facial Nerve Monitoring during Parotid Surgery

Intraoperative facial nerve monitoring (FNM) has been widely accepted as an adjunct during parotid surgery to facilitate identification of the facial nerve (FN) main trunk, dissection of FN branches, confirmation of FN function integrity, detection of FN injury and prognostication of facial expression after tumor resection. Although the use of FNM in parotidectomy is increasing, little uniformity exists in its application from the literature. Thus, not only are the results of many studies difficult to compare but the value of FNM technology is also limited. The article reviews the current literature and proposes our standardized FNM procedures during parotid surgery, such as standards in FNM setup, standards in general anesthesia, standards in FNM procedures and application of stimulus currents, interpretation of electrophysiologic signals and prediction of the facial expression outcome and pre-/post-operative assessment of facial expressions. We hope that the FNM standardized procedures will provide greater uniformity, improve the quality of applications and contribute to future research.

An institutional review of recurrent pleomorphic adenoma of the parotid gland

OBJECTIVE

Surgical resection is standard treatment for pleomorphic adenoma (PA) of the parotid gland. A small number (2-5%) of these tumors recur. Recurrence usually necessitates reoperation, which is technically challenging and puts the facial nerve (FN) at risk. The aim of this study is to characterize the recurrent parotid PA population and compare outcomes after surgery for singly recurrent and multiply recurrent tumors.

METHODS

This study was a retrospective chart review of patients at a single tertiary care academic medical center who underwent operations for recurrent PA of the parotid gland between 2007 and 2020. Demographic data, details of surgical interventions, pre- and postoperative FN function, and recurrence rates were studied. These factors were compared between patients with singly and multiply recurrent tumors.

RESULTS

Thirty-eight patients met criteria: 4 patients presented for primary PA and subsequently recurred, 26 with a first recurrence, 7 with a second recurrence, and 1 with a fourth recurrence. Multiply recurrent PAs were more likely to require at least partial nerve sacrifice at the time of reoperation (P = 0.0092). Significantly worse long-term FN outcomes were seen following surgery for multiply recurrent PA (P = 0.008). There was no significant difference between the rate of re-recurrence following first revision surgery vs second-fourth revision surgery. Time to reoperation was significantly shorter between the first and second revision surgery than between the primary surgery and first revision (P = 0.0017).

CONCLUSION

Surgery for recurrent PA incurs high risk to the FN, and this risk appears to increase in the setting of multiple recurrences.

Endoscopic and Robotic Parotidectomy for the Treatment of Parotid Tumors: A Systematic Review and Meta-Analysis

Background

The goal of this review was to introduce endoscopic/robotic parotidectomy (EP/RP) and compare EP/RP against conventional parotidectomy (CP) regarding the intraoperative and postoperative parameters in the treatment of parotid tumors.

Methods

A systematic literature search of medical databases (PubMed, Embase, and Cochrane Central Register of Controlled Trials) was performed from inception to November 2020 to generate relevant studies.

Results

A total of 13 eligible studies (572 patients) were included for systematic review, and 7 out of 13 comparable studies for the quantitative synthesis of outcomes. Patients who underwent EP were characterized by less intraoperative bleeding volume, shorter incision length, and higher satisfaction postoperatively (WMD, 95% CI, -42.80; - 58.23 to -27.37; p < 0.01; WMD, 95% CI, -5.64; -7.88 to -3.39; p < 0.01; SMD, 95% CI, 1.88; 1.46 to 2.31; p < 0.01, respectively). However, operative time and risk of facial palsy exhibited no significant differences (WMD, 95% CI, -11.17; -26.71 to 4.34; p = 0.16; OR, 95% CI,0.71; 0.39 to 1.32; p = 0.28, respectively).

Conclusions

Our findings suggest that the current evidence does not adequately support EP is equally safe and effective as CP. In certain selected cases, endoscopic technology has its unique advantages. For patients with strong cosmetic needs, endoscopic or robotic techniques may be an alternative through adequate preoperative evaluations.

Systematic Review Registration

International Prospective Register of Systematic Reviews, identifier CRD42020210299.

Correlation between Electrophysiological Change and Facial Function in Parotid Surgery Patients

This observational study investigated intraoperative electrophysiological changes and their correlation with postoperative facial expressions in parotidectomy patients with visual confirmation of facial nerve (FN) continuity. Maximal electromyography(EMG) amplitudes of the facial muscles corresponding to temporal, zygomatic, buccal and mandibular branches were compared before/after FN dissection, and facial function at four facial regions were evaluated before/after parotidectomy in 112 patients. Comparisons of 448 pairs of EMG signals revealed at least one signal decrease after FN dissection in 75 (67%) patients. Regional facial weakness was only found in 13 of 16 signals with >50% amplitude decreases. All facial dysfunctions completely recovered within 6 months. EMG amplitude decreases often occur after FN dissection. An amplitude decrease >50% in an FN branch is associated with a high incidence of dysfunction in the corresponding facial region. This study tries to establish a standard facial nerve monitoring (FNM) procedure and a proper facial function grading system for parotid surgery that will be useful for the future study of FNM in parotid surgery.

Assessment of Intraoperative Nerve Monitoring Parameters Associated With Facial Nerve Outcome in Parotidectomy for Benign Disease

Importance

Prior studies suggest that the use of facial nerve monitoring decreases the rate of immediate postoperative facial nerve weakness in parotid surgery, but published data are lacking on normative values for these parameters or cutoff values to prognosticate facial nerve outcomes.

Objective

To identify intraoperative facial nerve monitoring parameters associated with postoperative weakness and to evaluate cutoff values for these parameters under which normal nerve function is more likely.

Design, Setting, and Participants

This retrospective case series of 222 adult patients undergoing parotid surgery for benign disease performed with intraoperative nerve monitoring was conducted at an academic medical institution from September 13, 2004, to October 30, 2014. The data analysis was conducted from May 2018 to January 2019.

Main Outcomes and Measures

The main outcome measure was facial nerve weakness. Receiver operating characteristic curves were generated to define optimal cut point to maximize the sensitivity and specificity of the stimulation threshold, mechanical events, and spasm events associated with facial nerve weakness.

Results

Of 222 participants, 121 were women and 101 were men, with a mean (SD) age of 51 (16) years. The rate of temporary facial nerve paresis of any nerve branch was 45%, and the rate of permanent paralysis was 1.3%. The mean predissection threshold was 0.22 milliamperes (mA) (range, 0.1-0.6 mA) and the mean postdissection threshold was 0.24 mA (range, 0.08-1.0 mA). The average number of mechanical events was 9 (range, 0-66), and mean number of spontaneous spasm events was 1 (range, 0-12). Both the postdissection threshold (area under the curve [AUC], 0.69; 95% CI, 0.62-0.77) and the number of mechanical events (AUC, 0.58; 95% CI, 0.50-0.66) were associated with early postoperative facial nerve outcome. The number of spasm events was not associated with facial nerve outcome. The optimal cutoff value for the threshold was 0.25 mA, and the optimal cutoff for number of mechanical events was 8. If a threshold of greater than 0.25 mA was paired with more than 8 mechanical events, there was a 77% chance of postoperative nerve weakness. Conversely, if a threshold was 0.25 mA or less and there were 8 mechanical events or less, there was 69% chance of normal postoperative nerve function. No parameters were associated with permanent facial nerve injury.

Conclusions and Relevance

Postdissection threshold and the number of mechanical events are associated with immediate postoperative facial nerve function. Accurate prediction of facial nerve function may provide anticipatory guidance to patients and may provide surgeons with intraoperative feedback allowing adjustment in operative techniques and perioperative management.

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

BACKGROUND

Enhancing patient outcomes in an array of surgical procedures in the head and neck requires the maintenance of complex regional functions through the protection of cranial nerve integrity. This review and consensus statement cover the scope of cranial nerve monitoring of all cranial nerves that are of practical importance in head, neck, and endocrine surgery except for cranial nerves VII and VIII within the temporal bone. Complete and applied understanding of neurophysiologic principles facilitates the surgeon's ability to monitor the at-risk nerve.

METHODS

The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) identified the need for a consensus statement on cranial nerve monitoring. An AAO-HNS task force was created through soliciting experts on the subject. Relevant domains were identified, including residency education, neurophysiology, application, and various techniques for monitoring pertinent cranial nerves. A document was generated to incorporate and consolidate these domains. The panel used a modified Delphi method for consensus generation.

RESULTS

Consensus was achieved in the domains of education needs and anesthesia considerations, as well as setup, troubleshooting, and documentation. Specific cranial nerve monitoring was evaluated and reached consensus for all cranial nerves in statement 4 with the exception of the spinal accessory nerve. Although the spinal accessory nerve's value can never be marginalized, the task force did not feel that the existing literature was as robust to support a recommendation of routine monitoring of this nerve. In contrast, there is robust supporting literature cited and consensus for routine monitoring in certain procedures, such as thyroid surgery, to optimize patient outcomes.

CONCLUSIONS

The AAO-HNS Cranial Nerve Monitoring Task Force has provided a state-of-the-art review in neural monitoring in otolaryngologic head, neck, and endocrine surgery. The evidence-based review was complemented by consensus statements utilizing a modified Delphi method to prioritize key statements to enhance patient outcomes in an array of surgical procedures in the head and neck. A precise definition of what actually constitutes intraoperative nerve monitoring and its benefits have been provided.

Single-surgeon parotidectomy outcomes in an academic center experience during a 15-year period

OBJECTIVE

As large single-surgeon series in the literature are lacking, we sought to review a single-surgeon's experience with parotidectomy in an academic center, with a focused analysis of pathology, technique, and facial nerve (FN) weakness. Benchmark values for complications and operative times with routine trainee involvement and without continuous FN monitoring are offered.

MATERIALS AND METHODS

All patients who underwent parotidectomy, performed by D. G. D., for benign and malignant disease between January 2004 and December 2018 at an academic center were reviewed.

RESULTS

A total of 924 parotidectomies, with adequate evaluatable data were identified. The majority of patients had benign tumors (70.9%). Partial/superficial parotidectomy was the most common approach (65.7%). Selective FN branch sacrifice was rare (12.3%), but significantly more common among patients with malignant pathology (33.8% vs 3.5% for benign, P < .0001). Among patients with intact FN, post-operative short- and long-term FN weaknesses were rare (6.5% and 1.7%, respectively). These rates were lower among patients with benign tumors (5.4% and 1.3%). Partial/superficial parotidectomy for benign tumors was associated with a low rate of short- and long-term FN weaknesses (2.7% and 0.9%). Mean OR time was 185 minutes.

CONCLUSION

This is the largest single-surgeon series on parotidectomy, spanning 15 years. We demonstrate excellent long- and short-term FN paresis rates with acceptable operative times without regular use of continuous FN monitoring and with routine trainee involvement. These findings may provide valuable insight into parotid tumor pathology, FN outcomes, and feasibility and expectations of performing parotidectomy in an academic setting.

LEVEL OF EVIDENCE

4.

Continuous intraoperative neuromonitoring (cIONM) in head and neck surgery-a review

Although the history of intraoperative neuromonitoring (IONM) dates back to the 19th century, the method did not evolve further than the mere differentiation of nerves until recently. Only the development of continuous IONM (cIONM) has allowed for non-stop analysis of excitation amplitude and latency during surgical procedures, which is nowadays integrated into the software of almost all commercially available neuromonitoring devices. The objective of cIONM is real-time monitoring of nerve status in order to recognize and prevent impending nerve injury and predict postoperative nerve function. Despite some drawbacks such as false-positive/negative alarms, technical artefacts, and rare adverse effects, cIONM remains a good instrument which is still under development. Active (acIONM) and passive (pcIONM) methods of cIONM are described in literature. The main fields of cIONM implementation are currently thyroid surgery (in which the vagal nerve is continuously stimulated) and surgery to the cerebellopontine angle (in which the facial nerve is either continuously stimulated or the discharge signal of the nerve is analyzed via pcIONM). In the latter surgery, continuous monitoring of the cochlear nerve is also established.

Facial nerve monitoring during parotid gland surgery: a systematic review and meta-analysis

INTRODUCTION

Facial nerve injury remains the most severe complication of parotid gland surgery. However, the use of intraoperative facial nerve monitoring (IFNM) during parotid gland surgery among Otolaryngologist-Head and Neck Surgeons continues to be a matter of debate.

MATERIALS AND METHODS

A systematic review and meta-analysis of the literature was conducted including articles from 1970 to 2019 to try to determine the effectiveness of intraoperative facial nerve monitoring in preventing immediate and permanent postoperative facial nerve weakness in patients undergoing primary parotidectomy. Acceptable studies included controlled series that evaluated facial nerve function following primary parotidectomy with or without intraoperative facial nerve monitoring.

RESULTS

Ten articles met inclusion criteria, with a total of 1069 patients included in the final meta-analysis. The incidence of immediate and permanent postoperative weakness following parotidectomy was significantly lower in the IFNM group compared to the unmonitored group (23.4% vs. 38.4%; p = 0.001) and (5.7% vs. 13.6%; p = 0.001) when all studies were included. However, when we analyze just prospective data, we are not able to find any significant difference.

CONCLUSION

Our study suggests that IFNM may decrease the risk of immediate post-operative and permanent facial nerve weakness in primary parotid gland surgery. However, due to the low evidence level, additional prospective-randomized trials are needed to determine if these results can be translated into improved surgical safety and improved patient satisfaction.

Application of an Intraoperative Neuromonitoring System Using a Surface Pressure Sensor in Parotid Surgery: A Rabbit Model Study

Objectives

Facial nerve monitoring (FNM) can be used to identify the facial nerve, to obtain information regarding its course, and to evaluate its status during parotidectomy. However, there has been disagreement regarding the efficacy of FNM in reducing the incidence of facial nerve palsy during parotid surgery. Therefore, instead of using electromyography (EMG) to identify the location and state of the facial nerve, we applied an intraoperative neuromonitoring (IONM) system using a surface pressure sensor to detect facial muscle twitching. The objective of this study was to investigate the feasibility of using the IONM system with a surface pressure sensor to detect facial muscle twitching during parotidectomy.

Methods

We evaluated the stimulus thresholds for the detection of muscle twitching in the orbicularis oris and orbicularis oculi, as well as the amplitude and latency of EMG and the surface pressure sensor in 13 facial nerves of seven rabbits, using the same stimulus intensity.

Results

The surface pressure sensor detected muscle twitching in the orbicularis oris and orbicularis oculi in response to a stimulation of 0.1 mA in all 13 facial nerves. The stimulus threshold did not differ between the surface pressure sensor and EMG.

Conclusion

The application of IONM using a surface pressure sensor during parotidectomy is noninvasive, reliable, and feasible. Therefore, the IONM system with a surface pressure sensor to measure facial muscle twitching may be an alternative to EMG for verifying the status of the facial nerve.

[Continuous intraoperative neuromonitoring (cIONM) in head and neck surgery-a review. German version]

Obwohl die Geschichte des intraoperativen Neuromonitorings (IONM) bereits in das 19. Jahrhundert zurückdatiert werden kann, hat sich diese Methode bis vor Kurzem nicht von der reinen Differenzierung des Nervs weiterentwickelt. Erst das kontinuierliche IONM (cIONM) ermöglichte die durchgehende Analyse der Reizamplituden und -latenzen, welche mittlerweile ebenfalls in die Software gängiger Monitoringsysteme integriert wurde. Zielsetzung des cIONM ist ein Real-Time-Monitoring des Nervenstatus während des Eingriffs, um so drohende Nervenverletzung erkennen und verhindern zu können und die postoperative Funktion des Nervs vorhersehbar zu erhalten. Trotz einiger Nachteile wie falsch-positiver oder -negativer Alarme, technischer Artefakte und seltener Nebenwirkungen bleibt das cIONM ein gutes Hilfsmittel, das noch weiterentwickelt wird. In der Literatur sind sowohl aktive (acIONM) als auch passive (pcIONM) Reiz- und Ableitmethoden des cIONM beschrieben. Derzeit gängige Anwendungsgebiete des cIONM umfassen die Schilddrüsenchirurgie mit der kontinuierlichen Stimulation des N. vagus sowie die Chirurgie des Kleinhirnbrückenwinkels (KHBW) mit dem Monitoring des N. facialis; hierbei werden neben kontinuierlicher Stimulation auch die Entladungsmuster des Nervs analysiert. Des Weiteren ist in die Chirurgie des KHBW das kontinuierliche Monitoring des Hörnervs etabliert.

Incidence of postoperative facial weakness in parotid tumor surgery: a tumor subsite analysis of 794 parotidectomies

Background

The reported incidence of facial weakness immediately after parotid tumor surgery ranges from 14 to 65%. The purpose of this study was to evaluate the incidence of postoperative facial weakness related to parotidectomy with use of preoperative computed tomography (CT), intraoperative facial nerve monitoring, and surgical magnification. Also, we sought to elucidate additional information about risk factors for postoperative facial weakness in parotid tumor surgery, particularly focusing on the tumor subsites.

Methods

We retrospectively reviewed 794 cases with parotidectomy for benign and malignant tumors arising from the parotid gland (2009–2016). Patients with pretreatment facial palsy were excluded from the analyses. Tumor subsites were stratified based on their anatomical relations to the facial nerve as superficial, deep, or both. Multivariable logistic regression analyses were conducted to identify risk factors for postoperative facial weakness.

Results

The overall incidences of temporary and permanent (more than 6 months) facial weakness were 9.2 and 5.2% in our series utilizing preoperative CT, intraoperative facial nerve monitoring, and surgical magnification. Multivariable analysis revealed that old age, malignancy, and recurrent tumors (revision surgery) were common independent risk factors for both temporary and permanent postoperative facial weakness. In addition, tumor subsite (tumors involving superficial and deep lobe) was associated with postoperative facial weakness, but not tumor size. Extent of surgery was strongly correlated with tumor pathology (malignant tumors) and tumor subsite (tumors involving deep lobe).

Conclusion

Aside from risk factors for facial weakness in parotid tumor surgery such as old age, malignant, or recurrent tumors, the location of tumors was found to be related to postoperative facial weakness. This study result may provide background data in a future prospective study and up-to-date information for patient counseling.

Variation of the Great Auricular Nerve and Prediction of the Facial Nerve Trunk Size

Supplemental Digital Content is available in the text.

Background:

This study aimed to reveal the anatomical variation in the great auricular nerve (GAN) and the correlation between the size of the GAN and the facial nerve trunk (FNT), so as to aid surgeons to perform safe facelift surgery and parotidectomy.

Methods:

Sixteen human cadavers were studied on 16 left and 15 right facial sides. The GAN’s branching patterns, location, and the mean width of the GAN and FNT were measured.

Results:

The average distance where the nerve emerged from under the sternocleidomastoid muscle was 87.61 ± 12.13 mm when measured perpendicular to the Frankfort horizontal plane. The branching pattern of the GAN could be classified into 5 types of which the most common was type 3 (30.77%), where the GAN divided into the anterior (superficial) and posterior branches, and then the deep branch originated from the posterior branch of the GAN. The mean width of the GAN and FNT from all the dissections was 3.26 ± 0.67 mm and 3.36 ± 0.71 mm, respectively. There was a significant correlation between the width of the nerves on both facial sides (right: r =0.740, P =0.002; left: r = 0.839, P < 0.001).

Conclusions:

This study revealed the anatomical variation and the width of the GAN, which can strongly predict the width of the FNT. This should be taken into consideration during facelift surgery and parotidectomy, especially in patients with a small GAN to prevent iatrogenic injury to the small FNT.

Parotid tumours: clinical and oncologic outcomes after microscope-assisted parotidectomy with intraoperative nerve monitoring

Temporary and permanent facial nerve dysfunctions can be observed after parotidectomy for benign and malignant lesions. Intraoperative nerve monitoring is a recognised tool for the preservation of the nerve, while the efficacy of the operative microscope has been rarely stated. The authors report their experience on 198 consecutive parotidectomies performed on 196 patients with the aid of the operative microscope and intraoperative nerve monitoring. 145 parotidectomies were performed for benign lesions and 53 for malignancies. Thirteen patients treated for benign tumours experienced temporary (11 cases) or permanent facial palsy (2 cases, both of House-Brackmann grade II). Ten patients with malignant tumour presented with preoperative facial nerve weakness that did not improve after treatment. Five and 6 patients with malignant lesion without preoperative facial nerve deficit experienced postoperative temporary and permanent weakness respectively (the sacrifice of a branch of the nerve was decided intraoperatively in 2 cases). Long-term facial nerve weakness after parotidectomy for lesions not directly involving or originating from the facial nerve (n = 185) was 2.7%. Patients treated for benign tumours of the extra facial portion of the gland without inflammatory behaviour (n = 91) had 4.4% facial nerve temporary weakness rate and no permanent palsy. The combined use of the operative microscope and intraoperative nerve monitoring seems to guarantee facial nerve preservation during parotidectomy.

Intraoperative monitoring of marginal mandibular nerve during neck dissection

BACKGROUND

The purpose of this study was to assess the efficacy of intraoperative nerve integrity monitoring (NIM) to prevent marginal mandibular nerve injuries during neck dissection.

METHODS

This prospective study compared 36 patients undergoing NIM-assisted neck dissection from July 2014 to March 2015 to a cohort of 35 patients subjected to neck dissection over an identical period of time before the technique was introduced. We also assessed possible correlations between marginal mandibular nerve injuries and other factors, such as anthropometric measurements, presence of clinical neck metastases, type of neck dissection, and site of primary tumor.

RESULTS

The incidence of marginal mandibular nerve paralyses was significantly lower among the group of patients undergoing NIM-assisted neck dissection (P = .021). There was no significant difference in the duration of the procedure, and the technique resulted in a limited increase of cost. No other factor seemed to influence the onset of marginal mandibular nerve palsy.

CONCLUSION

In our opinion, NIM is a valuable aid for preventing marginal mandibular nerve injuries during neck dissection.

The accuracy of fine-needle aspiration cytology for diagnosis of parotid gland masses: a clinicopathological study of 114 patients

Objective

Fine-needle aspiration cytology is a valuable method for preoperative assessment of head and neck tumors. However, its accuracy in detection of salivary gland masses is controversial compared with other methods. The aim of this work was to evaluate the effectiveness and accuracy of fine-needle aspiration cytology (FNAC) in the diagnosis of parotid gland masses.

Material and Methods

Over a 10-year period, 126 parotid gland masses were resected. Retrospective chart reviews of 114 patients were performed. The results of FNAC and final histological diagnosis were compared and the accuracy of FNAC was determined.

Results

Final histological evaluation revealed 11 malignant tumors and 103 benign lesions. Pleomorphic adenoma was the most common neoplasm (63%), followed by Warthin’s tumor (17.5%). The sensitivity of FNAC in detecting malignant tumors was 73% and the specificity was 97%. Positive predictive value (PPV) was 73% and negative predictive value (NPV) was 97%. The overall accuracy of FNAC in detecting parotid masses was 95%. False-negative diagnosis was found in mucoepidermoid carcinoma, acinic cell carcinoma, and epithelial-myoepithelial carcinoma whereas there was false-positive diagnosis in cases of pleomorphic adenoma and normal parotid gland tissue.

Conclusion

FNAC is a reliable minimally invasive diagnostic method with a high sensitivity in diagnosis of lesions in parotid glands. The sensitivity of detection of malignant tumors in parotid glands was low due to the biopsy technique used, and depended on tumor location. Postoperative complications decreased after superficial parotidectomy.

Improved facial nerve identification during parotidectomy with fluorescently labeled peptide

OBJECTIVES/HYPOTHESIS

Additional intraoperative guidance could reduce the risk of iatrogenic injury during parotid gland cancer surgery. We evaluated the intraoperative use of fluorescently labeled nerve binding peptide NP41 to aid facial nerve identification and preservation during parotidectomy in an orthotopic model of murine parotid gland cancer. We also quantified the accuracy of intraoperative nerve detection for surface and buried nerves in the head and neck with NP41 versus white light (WL) alone.

STUDY DESIGN

Twenty-eight mice underwent parotid gland cancer surgeries with additional fluorescence (FL) guidance versus WL reflectance (WLR) alone. Eight mice were used for additional nerve-imaging experiments.

METHODS

Twenty-eight parotid tumor-bearing mice underwent parotidectomy. Eight mice underwent imaging of both sides of the face after skin removal. Postoperative assessment of facial nerve function measured by automated whisker tracking were compared between FL guidance (n = 13) versus WL alone (n=15). In eight mice, nerve to surrounding tissue contrast was measured under FL versus WLR for all nerve branches detectable in the field of view.

RESULTS

Postoperative facial nerve function after parotid gland cancer surgery tended to be better with additional FL guidance. Fluorescent labeling significantly improved nerve to surrounding tissue contrast for both large and smaller buried nerve branches compared to WLR visualization and improved detection sensitivity and specificity.

CONCLUSIONS

NP41 FL imaging significantly aids the intraoperative identification of nerve braches otherwise nearly invisible to the naked eye. Its application in a murine model of parotid gland cancer surgery tended to improve functional preservation of the facial nerve.

LEVEL OF EVIDENCE

NA Laryngoscope, 126:2711-2717, 2016.

Effectiveness of facial exercise therapy for facial nerve dysfunction after superficial parotidectomy: a randomized controlled trial

OBJECTIVES

To compare the effectiveness of a daily home-based facial exercise therapy with a supervised rehabilitation technique for the treatment of postoperative facial dysfunction in patients undergoing conventional superficial parotidectomy.

DESIGN

Prospective, randomized trial, controlled.

SETTING

Surgery and Rehabilitation Units, university hospital.

SUBJECTS

Consecutive patients ( n=79, mean age 48 years) who underwent superficial parotidectomy with facial nerve dissection were randomly divided into two groups.

INTERVENTION

Control group (CG) were given a daily homework manual to perform ordinary postoperative facial mimic exercises autonomously in front of the mirror at home. Experimental group (EG) patients with moderate-severe paresis received supervised rehabilitation therapy that consisted in weekly sessions with facial exercises and massages and performed daily facial exercises at home. EG patients with slight paresis were instructed to undertake self-massage and mirror exercises.

MAIN OUTCOME MEASURES

Postoperative dysfunction of facial nerve and branches was quantified measuring the prevalence, magnitude and duration of paresis by the House-Brackmann Facial Nerve Grading System up to 12^th months.

RESULTS

Facial paresis incidence at 1^st week was 77.2%, being the marginal-mandibular nerve the most affected (64.5%). No statistically significant differences were found at any time of the study when comparing the frequency, magnitude and duration of paresis between EG and CG and among patients who had presented moderate-severe paresis. In the absence of intraoperative nerve injury, complete recovery of facial mobility was observed within 12 months, regardless of treatment group.

CONCLUSION

Rehabilitation therapy and mirror facial exercises performed autonomously at home were equally effective for postoperative functional recovery.

Use of sugammadex in parotid surgery: a case report

Background

Parotid surgery is a common ear, nose, and throat procedure. Facial nerve paralysis is the main feared complication following this surgery. To avoid this paralysis, intraoperative facial nerve monitoring is often used, but neuromuscular blocking agents interfere with this technique. Therefore, the neuromuscular blocking agent used should have a short duration of muscle relaxation. With the discovery of sugammadex, a steroidal neuromuscular blocking agent has acquired the potential to be used in place of succinylcholine.

Case presentation

A 41-year-old African woman was scheduled for a parotidectomy at our hospital. Rocuronium-induced neuromuscular block was reversed intraoperatively with sugammadex to facilitate identification of facial nerve function. The facial nerve was identified without incident, and surgical conditions were good for the removal of the tumor. During postoperative follow-up, no evidence of residual paralysis has been noted.

Conclusions

In parotid surgery, the use of sugammadex allows free use of a steroidal neuromuscular blocking agent for intubation and thus intraoperative facial nerve monitoring can be done safely.

Malignant Parotid Tumor and Facial Palsy

OBJECTIVE: To evaluate risk factors for postoperative facial palsy in patients with parotid carcinoma.

STUDY DESIGN AND SETTING: We conducted a retrospective chart review of patients with parotid carcinoma who underwent parotidectomy at National Taiwan University Hospital from 1980 to 2000.

RESULTS: Eighty-eight patients with a mean age of 53 ± 17 y were recruited. Sixty patients (68.2%) experienced postoperative facial palsy. Tumor size of larger than 4 cm was associated with an increased incidence of facial palsy ( P = 0.0422). Facial palsy was noted in 95.5 percent of patients with facial nerve involvement and 51.3 percent of patients without facial nerve involvement ( P = 0.0004). Of 42 patients with tumor over the deep lobe, 37 (88.1%) had facial palsy but only 50 percent (23 of 46) of those with tumor over the superficial lobe had facial palsy ( P = 0.0001).

CONCLUSION: There were no significant associations between histopathology and facial palsy. Increasing tumor size, deep lobe tumor location, and tumor invasion of facial nerve increased the incidence of postparotidectomy facial palsy.

SIGNIFICANCE: By paying attention to these risk factors a reduction of postoperative facial nerve palsy my be achieved.

Continuous Laryngeal Nerve Integrity Monitoring During Thyroidectomy: Does it Reduce Risk of Injury?

OBJECTIVE: To determine if continuous laryngeal nerve integrity monitoring (NIM) during thyroidectomy is associated with a decreased risk of postoperative recurrent laryngeal nerve (RLN) injury.

STUDY DESIGN AND SETTING: Retrospective cohort study of 165 patients who underwent thyroidectomy at a resident teaching institution between 1999 and 2002. The control group had 120 nerves at risk (NAR) whereas the NIM group consisted of 116 NAR. Primary outcome measures included postoperative RLN paralysis, paresis, and total injury rates.

RESULTS: RLN paralysis occurred in 2.54% NAR in the control group and 0.86% in the NIM group (relative risk (RR) = 0.34, 95% confidence interval (CI95) = 0.04-3.27, P = 0.62). Temporary RLN paresis occurred in 4.24% NAR in the control group and 3.45% in the NIM group (RR = 0.9, CI95 = 0.23-3.55, P = 0.89). Total RLN injury occurred in 6.78% NAR in the control group and 4.31% in the NIM group (RR = 0.66, CI95 = 0.21-2.09, P = 0.48). When compared to all other NAR, advanced T-stage malignancy was associated with a significantly increased risk of RLN paresis (T4 RR = 9.0, CI95 = 2.56-31.67, P = 0.0006; T3+T4 RR = 7.5, CI95 = 2.17-25.86, P = 0.0001) but not paralysis. NIM did not significantly reduce the risk of RLN paresis in the advanced T-stage subset (T3+T4 RR = 0.36, CI95 = 0.04-3.0, P = 0.59).

CONCLUSION: There were no statistically significant differences in RLN paralysis, paresis, or total injury rates between control and NIM groups, even in subsets with advanced T-stage and increased baseline risk. Advanced T-stage is a significant predictor of RLN paresis in this cohort.

Patterns of Use of Facial Nerve Monitoring During Parotid Gland Surgery

OBJECTIVE: To determine current patterns of use of facial nerve monitoring during parotid gland surgery by otolaryngologists in the United States.

STUDY DESIGN AND SETTING: A questionnaire encompassing surgeon training background, practice setting, patterns of facial nerve monitor usage during parotid gland surgery, and history of permanent facial nerve injury or legal action resulting from parotid surgery was mailed to 3139 otolaryngologists in the United States. Associations between facial nerve monitor usage and dependent variables were examined by using the χ 2 test. Magnitudes of the associations were determined from odds ratios calculated using logistic regression.

RESULTS: A 49.3% questionnaire response rate was achieved. Sixty percent of respondents who perform parotidectomy employed facial nerve monitoring some or all of the time. Respondents were 5.6 times more likely to use the monitor in practice if they used it in training and 79% more likely to use it if they performed more than 10 parotidectomies per year. Respondents were 35% less likely to have a history of inadvertent nerve injury if they performed more than 10 parotidectomies per year. Surgeons who employed monitoring in their practice were 20.8% less likely to have a history of a parotid surgery-associated lawsuit. Additional information regarding surgeon demographics, types of nerve monitors used, and reasons for and against monitor usage are discussed.

CONCLUSION: Permanent facial nerve paralysis after parotidectomy occurs in 0-7% of cases. Currently, a majority of otolaryngologists in the United States are employing facial nerve monitoring during parotid surgery some or all of the time, even though no studies to date have demonstrated improved outcomes with its use. Physician training background and surgery caseload were significant factors influencing usage of facial nerve monitoring in this study.

Preoperative percutaneous nerve mapping of the mandibular marginal branch of the facial nerve

OBJECTIVE

In this study, we introduce a reliable method for mapping the location of the mandibular marginal branch of the facial nerve. The utility of preoperative percutaneous mandibular marginal branch mapping and continuous intraoperative nerve monitoring during operation with a submandibular approach is reported.

MATERIALS AND METHODS

The mapping technique was performed in 40 patients. Electromyography surface electrodes were placed on the orbicularis oris muscles. A modified bipolar probe with an adjustable distance between the 2 tips was used to apply surface stimulation at a frequency of 1 Hz to 2 Hz. The stimulating current most frequently used was 5.0 mA to 5.5 mA. By moving the electrode at right angles across the suspected path of the nerve around the marginal border of the mandible, 4 to 5 points were marked and connected, where the orbicularis oris contracted and the action potential was evoked. After general anesthesia, the mapping path was verified using needle electrodes with different needle-to-nerve distances.

RESULTS

The nerve could be mapped preoperatively in all patients and were protected in 39 patients. The thresholds of the needle electrode on the mapping path were at or below 0.5 mA, verifying the accuracy of mapping.

CONCLUSIONS

Preoperative percutaneous nerve mapping was a precise method of identifying the location of the nerve and could protect the nerve from accidental injury.

Facial Nerve Monitoring during Parotidectomy

Objectives

To determine the effectiveness of intraoperative facial nerve monitoring (FNM) in preventing immediate and permanent postoperative facial nerve weakness in patients undergoing primary parotidectomy.

Data Sources

PubMed-NCBI database from 1970 to 2014.

Review Methods

A systematic review and meta-analysis of the literature was conducted. Acceptable studies included controlled series that evaluated facial nerve function following primary parotidectomy with or without FNM (intraoperative nerve monitor vs control). Primary and secondary end points were defined as immediate postoperative and permanent facial nerve weakness (House-Brackmann score, ≥2), respectively.

Results

After a review of 1414 potential publications, 7 articles met inclusion criteria, with a total of 546 patients included in the final meta-analysis. The incidence of immediate postoperative weakness following parotidectomy was significantly lower in the FNM group compared to the unmonitored group (22.5% vs 34.9%; P = .001). The incidence of permanent weakness was not statistically different in the long term (3.9% vs 7.1%; P = .18). The number of monitored cases needed to prevent 1 incidence of immediate postoperative facial nerve weakness was 9, given an absolute risk reduction of 11.7% This corresponded to a 47% decrease in the incidence of immediate facial nerve dysfunction (odds ratio, 0.53; 95% CI, 0.35 to 0.79; P = .002).

Conclusion

In primary cases of parotidectomy, intraoperative FNM decreases the risk of immediate postoperative facial nerve weakness but does not appear to influence the final outcome of permanent facial nerve weakness.

Transtracheal lidocaine: An alternative to intraoperative propofol infusion when muscle relaxants are not used

Background:

Facial nerve monitoring, often required during total parotidectomy, precludes use of long acting muscle relaxants and propofol infusion is used solely to ensure patient immobility. We aimed to compare intraoperative patient immobility, hemodynamic stability and propofol consumption during total parotidectomy following a transtracheal block.

Material and Methods:

Forty patients were allocated to 2 equal groups. Preoperatively, group A patients received transtracheal block with 4 ml of 4% lidocaine, while no block was given to patients in group B. If there was patient movement, tachycardia or hypertension, group A patients received a bolus of propofol 30 mg and propofol infusion was started (100mg/hr). In group B, propofol infusion was started (100mg/hr) soon after intubation.

Result:

Both group A and B were comparable with respect to patient immobility and hemodynamic stability. There was no intraoperative propofol requirement in group A.

Conclusion:

Transtracheal block is a safe and successful alternative to propofol infusion during surgeries where muscle relaxants are to be avoided.

Salivary Gland Surgery and Medical Malpractice

Objective

To better understand the causes and outcomes of lawsuits involving salivary gland surgery by analyzing malpractice litigation trends to prevent future litigation and improve physician education.

Study Design

Analysis of a national database.

Setting

All US civil trials.

Subjects and Methods

The WESTLAW database was reviewed from January 1987 to March 2011. Data were compiled on the demographics of the defendant, anatomic site of injury, initial pathology, nature of injury, legal allegations, verdicts, and indemnities.

Results

Twenty-six cases met inclusion criteria and were selected for review. Verdicts/settlements for the plaintiffs predominated (58%), and the average sum of the plaintiff’s monetary award was $933,235. Sixteen cases (62%) involved injury to the parotid gland/duct, with 10 cases involving injury to the facial nerve. No cases were filed on the grounds of failure to use facial nerve monitoring. Nine cases (35%) involved injury to the submandibular gland/duct. The most common legal allegations listed were improper performance followed by unnecessary procedures. If failure or inadequate consent was a component of the legal allegations, the verdict outcome significantly favored the defendants.

Conclusion

Our study reveals that the plaintiffs in litigations involving salivary gland surgery have a slight advantage in outcomes with a fairly substantial award. Our litigation review reiterates the importance of detailed anatomic knowledge of the lingual and facial nerve to avoid the pitfalls of surgical error and consequent litigation. In addition, thorough preoperative evaluation of salivary gland pathology, including radiographic studies and needle biopsy, may help avoid errors in diagnosis and subsequent litigations.

Safety of extracapsular dissection in benign superficial parotid lesions

INTRODUCTION

The current practice for removal of clinically benign superficial parotid lesions is an appropriate superficial parotidectomy with a cuff of normal parotid tissue for complete pathological clearance. This technique requires the identification of the facial nerve at the main trunk and dissection of the segment of the facial nerve deep to the lesion. The reported major complications of this procedure include temporary or permanent facial nerve weakness, Frey's syndrome and salivary leaks. In order to avoid these complications, a local extracapsular dissection technique can be utilised in the management of small inferiorly located benign lesions of the parotid gland.

METHODS

A retrospective case note review was performed for all parotidectomies between 2004 and 2009 in Addenbrooke's Hospital, Cambridge by the senior authors.

RESULTS

A total of 172 cases were identified out which 46 underwent an extracapsular dissection. The average size of these lesions was 1.9 cm (0.9-2.4 cm) with all universally located inferior or posterior to the angle of the mandible. The pathologies were 14 pleomorphic adenomas, 24 Warthin's tumours, 6 lymphangiomas and 2 simple cysts. There were no post-operative facial nerve weaknesses, Frey's syndrome or salivary leaks within the extracapsular dissection group. The median follow-up of these patients were 4.6 years (2-6 years) with 6 patients lost to follow-up. No recurrences have been noted in the cohort at follow-up.

Facial disability index (FDI): adaptation to Spanish, reliability and validity

Objectives: To adapt to Spanish the facial disability index (FDI) described by VanSwearingen and Brach in 1995 and to assess its reliability and validity in patients with facial nerve paresis after parotidectomy. Study Design: The present study was conducted in two different stages: a) cross-cultural adaptation of the questionnaire and b) cross-sectional study of a control group of 79 Spanish-speaking patients who suffered facial paresis after superficial parotidectomy with facial nerve preservation. The cross-cultural adaptation process comprised the following stages: (I) initial translation, (II) synthesis of the translated document, (III) retro-translation, (IV) review by a board of experts, (V) pilot study of the pre-final draft and (VI) analysis of the pilot study and final draft. Results: The reliability and internal consistency of every one of the rating scales included in the FDI (Cronbach’s alpha coefficient) was 0.83 for the complete scale and 0.77 and 0.82 for the physical and the social well-being subscales. The analysis of the factorial validity of the main components of the adapted FDI yielded similar results to the original questionnaire. Bivariate correlations between FDI and House-Brackmann scale were positive. The variance percentage was calculated for all FDI components. Conclusions: The FDI questionnaire is a specific instrument for assessing facial neuromuscular dysfunction which becomes a useful tool in order to determine quality of life in patients with facial nerve paralysis. Spanish adapted FDI is equivalent to the original questionnaire and shows similar reliability and validity. The proven reproducibi-lity, reliability and validity of this questionnaire make it a useful additional tool for evaluating the impact of facial nerve paralysis in Spanish-speaking patients.

Key words:Parotidectomy, facial nerve paralysis, facial disability.

An objective assessment of proximal and distal facial nerve exploration during superficial parotidectomy

AIM

This study was undertaken to compare the proximal and distal facial nerve exploration approach during superficial parotidectomy.

MATERIALS AND METHODS

A retrospective analysis of patients who underwent superficial parotidectomy at our center was conducted. Cases were divided into those who underwent superficial parotidectomy using distal facial nerve exploration and those who underwent standard proximal facial nerve exploration. Statistical comparisons of intraoperative blood loss and margin status (negative, focally, positive) were conducted between these two approaches.

RESULTS

A total of 39 patients underwent superficial parotidectomy at our center between 2008 and 2010. The technique used in most of the cases was conventional proximal nerve exploration technique (29 cases). Distal exploration of the buccal branch was undertaken only in 10 cases, on account of difficulty in locating the main trunk intraoperatively due to the presence of postinflammatory fibrosis. The average patient age was 48 years with a female preponderance (67%). Both the techniques consumed almost same average operative time (2.4 hours) and average intraoperative blood loss (68.0 cc vs 25.4 cc) was more in the cases where proximal nerve exploration was resorted (S.E (d) = 0.89). No significant difference in surgical margin status was noticed between the two techniques (P > 0.05).

CONCLUSION

Both the techniques are efficient without compromising the surgical margins, but the average intraoperative blood loss is less in distal facial nerve exploration technique.

Proximal and distal Facial nerve exploration during superficial parotidectomy

One of the most technique sensitive surgeries in the maxillofacial region is the parotid gland surgery owing to the close relation between the gland and the extra-cranial course of facial nerve. Facial nerve is generally located by means of a proximal surgical identification technique aimed at identifying the facial nerve at its point of exit from the stylomastoid foramen to its entry into the posteromedial surface of parotid gland. There are reports in the literature on distal nerve identification techniques, either as a choice or in cases where proximal nerve identification is difficult. The present report deals with personal clinical experience, describing both the techniques for detection of the facial nerve in 17 cases reported. The technique mainly chosen was conventional proximal nerve identification technique in 16 cases. Distal exploration of the buccal branch was undertaken only in one case, on account of difficulty in locating the main trunk intraoperatively, due to the presence of a post inflammatory fibrosis. The decision to resort to the identification of the buccal nerve is supported by the regular course and adequate size of this branch of facial nerve in its peripheral area co-located with stenson's duct, which enable it to be easily identified during surgery.

Cost-effectiveness of intraoperative facial nerve monitoring in middle ear or mastoid surgery

OBJECTIVES

Despite the utility of intraoperative facial nerve monitoring in reducing the risk of iatrogenic facial nerve injury during neurotologic surgery, its routine use during primary or revision surgery remains controversial. One of the major barriers to its acceptance is cost. This study evaluates the cost-effectiveness of intraoperative facial nerve monitoring during middle ear or mastoid surgery.

RESEARCH DESIGN/METHODS

A simple decision analytic cost-effectiveness model and a societal approach were used to evaluate three cohorts of individuals who received (1) intraoperative facial nerve monitoring for both primary and revision middle ear or mastoid surgeries, or (2) facial nerve monitoring for revision surgeries only, or (3) no monitoring for any middle ear or mastoid surgeries.

RESULTS

Our results strongly favored the use of intraoperative facial nerve monitoring in all patients undergoing middle ear or mastoid surgery, adding about $222.73 to $528.00 US dollars to the total cost. The strategy to monitor primary and revision surgeries had the greatest effectiveness and lowest cost, with an average quality-adjusted life-year (QALY) of 45.68 at an average cost of $238 US dollars. Facial nerve monitoring in revision patients only had similar QALYs (45.67) and higher costs ($292.1). Finally, the strategy not to monitor had the lowest QALY (45.65) and highest cost ($449.8). The analysis was robust across a wide range of changes in both costs and probabilities.

CONCLUSIONS

Facial nerve monitoring is cost-effective, and its routine use should be adopted to reduce the risk of iatrogenic facial nerve injury during otologic surgery.

Electrophysiologic facial nerve monitoring during parotidectomy

Facial nerve monitoring is an adjunctive method available to a surgeon during parotid surgery to assist with the functional preservation of the facial nerve. This review describes the goals, applications, technique, and benefits of electrophysiologic facial nerve monitoring during parotid surgery. A review and analysis of the relevant medical literature related to electrophysiologic facial nerve monitoring during parotid surgery are included.

The precision of four commonly used surgical landmarks for locating the facial nerve in anterograde parotidectomy in humans

In addition to using intra-operative facial nerve monitoring in helping to locate the position of the facial nerve in anterograde parotidectomy, numerous soft tissue and bony landmarks have been proposed to assist the surgeon in the early identification of this nerve. There is still dispute within the literature as to the most effective method, if any, of locating the nerve. The purpose of this study was to measure the distance (in twenty-six embalmed cadavers) from four of the most commonly used surgical landmarks to the main trunk of the facial nerve-the posterior belly of digastric muscle (PBDM), the tragal pointer (TP), the junction between the bony and cartilaginous ear canal (EAM) and the tympanomastoid suture (TMS). The main trunk of the facial nerve was found 5.5+/-2.1mm from the PBDM, 6.9+/-1.8 mm from the TP, 10.9+/-1.7 mm from the EAM and 2.5+/-0.4 mm from the TMS. From this, the TMS can be used as a reliable indicator for locating the main trunk of the facial nerve. In addition, this study also demonstrated a statistically significant difference between the sexes in relation to the two bony landmarks used here, the EAM and the TMS, with the facial nerve found further away from those landmarks in females compared to males. With the advent of 3D construction and reformatting of images, these values may come to the forefront in pre-operative planning for locating the facial nerve in anterograde parotidectomy.