Ultrasound-guided greater auricular nerve block for surgical anesthesia of the external ear.

The Greater Auricular Nerve (GAN), a branch of the cervical plexus, is used to provide anesthesia or pain relief in the ear and neck region. This case report details the use of a GAN block in a 71-year-old male patient with basal cell carcinoma on his right auricular helix. Due to multiple comorbidities (myocardial infarction resulting in a cardiac stent, hypertension), regional anesthesia was preferred. We aim to share our experience with the GAN block for ear surgery.

Development of the interscutularis model as an outcome measure for facial nerve surgery.

INTRODUCTION: Animal models for the study of facial paralysis have been well developed, but concern has arisen regarding the accuracy of eye closure and whisker movement as outcome measures due to new data regarding interconnectivity between facial nerve branches and autonomic innervation. The posterior auricular nerve (PAN) is an isolated branch of the facial nerve which has been confirmed as the sole motor innervat or of the interscutularis muscle. This study was designed to develop a model for facial nerve palsy utilizing the PAN and interscutularis muscle. METHODS: A custom-made automated video capture system was built into a poly methyl methacrylate cage using a high definition monochrome digital camera and image sensor to record the animal as it drank from a water feeder. A copper floor pad and copper collar around the water feeder were connected to an electrical circuit for automatic saving of the video recording 10 s prior to and 30 s following the drinking event. A pre-operative baseline recording of ear movement during drinking was captured. Female YFP-16 mice at 6 weeks were assigned to sham (Sh, n = 5), nerve excision (Ex, n = 10), or nerve crush (Cr, n = 10) groups with all interventions performed on the right PAN. Sh mice were irrigated with 10 ml normal saline as were the Ex and Cr mice following operative intervention. In Ex mice, a 3 mm section of the PAN was sharply excised and nerve gap was confirmed with fluorescent microscopy. In Cr mice, the PAN was crushed 3 mm from the origin of the facial nerve trunk with size 5 jeweler's forceps for two periods of 20 s. Post-operative video recordings were collected on post-operative days (POD) 1, 10, 20, and 30. To determine the change in ear movement, the right ear was graphically compared to the left control side. RESULTS: Sh animals exhibited a statistically significant reduction in ear movement at POD01 compared to other POD recordings (p < 0.05), but no significant change in right ear movement following POD05. Ex animals had a significant reduction in right ear movement at all PODs in comparison to the left ear (p < 0.05) with no significant change in right ear movement during the study period (p = 0.94). Cr animals showed a significant reduction in right ear movement compared to the left at POD01, POD10, and POD20 (p < 0.05). At POD30, there was no significant difference between ear movement on either side (p = 0.35). There was a significant change in right ear movement during the data collection period (p < 0.05). CONCLUSION: The results show that significant differences were demonstrated between the experimental groups and that significant changes within the crush group were identifiable making this an acceptable model to develop as an accurate outcome measure following rodent facial nerve surgery.

Sensation loss after superficial parotidectomy: A prospective controlled multicenter trial.

BACKGROUND: The purpose of this study was to evaluate the occurrence of hypoesthesia after superficial parotidectomy depending on preservation of posterior branch of the great auricular nerve (GAN). METHODS: This prospective, controlled, double blind, multicenter trial included 130 patients. The posterior branch was preserved in 93 patients (GAN group), and ligated in 33 patients (non-GAN group). In 4 patients, GAN status was unknown. Included patients underwent sensory testing (TouchTest) and subjective evaluation at 6, 12, and 24 months after surgery. RESULTS: Better improvement of sensation was present in the GAN group. After 12 months, 59% of the patients in the GAN-group showed positive test results in the lobule, versus 24% of the non-GAN group (p = .013). Additionally, after 24 months, 71% of the patients in the GAN-group showed a positive test in the antitragus, versus 31% in the non-GAN group (p = .045). Hypoesthesia equally limited quality of life in both groups (all p > .05). CONCLUSION: Preservation of the posterior branch of the GAN led to significantly better improvement of sensation in the lobule and antitragus, and should be recommended during parotidectomy. © 2017 Wiley Periodicals, Inc. Head Neck 39: 520-526, 2017.

[The study of preserving the great auricular nerve in the parotidectomy].

OBJECTIVE: To assess the effect for local sensory to preserve great auricular nerve in the parotidectomy. METHOD: It was a prospective study. Eighy-one patients who underwent parotidectomy were randomly divided into 2 groups, preserving the great auricular nerve group and no preserving the great auricular nerve group. They were tested with the subjective and objective sensory function testing in 3, 6, 9, 12 months after operation. We assessed the result. RESULT: In the subjective sensory function testing, the result of the preserving the great auricular nerve group was better than no preserving the great auricular nerve group. In the objective sensory function testing, the result of the preserving the great auricular nerve group was obviously better than no preserving the great auricular nerve group. There was significant difference between the 2 groups (P<0.05). CONCLUSION: It was effective for recovering the sensory function that we preserved the great auricular nerve in the parotidectomy.

Sensory dysfunction and quality of life after great auricular nerve sacrifice during parotidectomy: our experience.

OBJECTIVE: This study aimed to investigate the impact on patients' quality of life of great auricular nerve sacrifice during parotidectomy. METHODS: A retrospective review was conducted of 191 consecutive patients who underwent parotidectomy with great auricular nerve sacrifice between 2006 and 2011. Residual sensory dysfunction and its impact on quality of life was analysed using an eight-item quality of life survey. RESULTS: In all, 139 out of 191 patients (72.8 per cent) experienced one or more abnormal sensations in the ear or neck region after surgery. There was a moderate inverse correlation between the number of abnormal sensations and time elapsed since surgery. Moreover, the degree of discomfort correlated significantly with the frequency of symptom occurrence (p < 0.001), duration of the abnormal sensation (p < 0.001) and size of the affected area (p < 0.001). CONCLUSION: Sacrifice of the great auricular nerve has only a small impact on patient quality of life; their daily activities are not significantly affected.

Parotidectomy combined with identification and preservation procedures of the great auricular nerve.

CONCLUSIONS: We found that the great auricular nerve (GAN) passes at the median (m) point between the tips of the mandibular angle and mastoid process. We also established the GAN definitive line using this point for rapid identification of the trunk of the GAN and systematic parotidectomy combined with procedures for identification of the GAN, elevation of the skin flap, and exposure of the parotid capsule, which showed a high rate of preservation of the nerve and the lobular branch. OBJECTIVE: The aim of this study was to improve parotidectomy and the rate of preservation of the GAN. METHODS: This study comprised 74 consecutive patients who were scheduled to have parotidectomy for benign tumors at our department between November 2011 and April 2014. We examined whether our GAN definitive line including the m point was useful to identify the trunk of the GAN and whether anterograde dissection of the nerve could be performed simultaneously with skin flap elevation and exposure of the parotid capsule and contributed to preservation of the trunk to the lobular branch. RESULTS: The trunk was identified under the GAN definitive line drawn preoperatively in 97.3% of cases (72/74). Combined surgery was successfully performed with a 95.9% (71/74) preservation rate of the GAN including the lobular branch.

[Replantation of amputated ear with anastomosis of vessel].

OBJECTIVE: To investigate the application of microsurgical technique in the replantation of amputated ear. METHODS: 7 cases of amputated ears were analyzed from June 2009 to April 2015 in our department. We used microsurgical technique to anastomose about five vessels and nerves. The blood supply of auricle was restored within three to six hours. All subjects underwent treatments including anti-freezing, anti-spasm and anti-infection treatment after the emergency surgery. RESULTS: 7 amputated ears were all survived after replantation. The patients were followed up for one month to six months ( average for 28 months). The appearances of survived ears body were fully recovered without any significant atrophy or pigmentation. The sensory function of ears recovered to normal after 1 year. CONCLUSIONS: The application of microsurgical technique in the replantation of amputated ear can expect the high success rate of ear replantation. However, skilled and high-quality anastomosis technique of small vascular are required.

Anatomic and histological study of great auricular nerve and its clinical implication.

BACKGROUND: The great auricular nerve (GAN) is often sacrificed during parotidectomy, rhytidectomy, and platysma flap operation. Transection of the nerve results in a wooden numbness of preauricular region, pain, and neuroma. The aim of this study was to describe the branching patterns and distribution area of the GAN. METHODS: Twenty-five embalmed, adult hemifacial Korean cadavers (16 males, nine females; mean age 62.5 years) were used in this study. The branching of the GAN was determined through careful dissection. The histological structure of the GAN was also examined by harvesting and sectioning specimens, and then viewing them with the aid of a light microscope. RESULTS: The branching pattern of the anterior, posterior, deep, and superficial branches of the GAN could be classified into five types: type I (20%), where the deep branches arose from the anterior branch; type II (24%), where all branches originated at the same point; type III (28%), where the deep branch arose from the posterior branch; type IV (8%), where the superficial branches arose from the posterior branch; and type V (20%), where the anterior and posterior branches ran independently. A connection between the GAN and the facial nerve trunk was observed in all specimens, and a connection with the auriculotemporal nerve was observed in a few specimens. The total fascicular area of both regions decreased from proximal (1.42 mm2) to distal (0.60 mm2). There were 2.5 and 5 fascicles in the proximal and distal regions, respectively. CONCLUSION: The results reported herein will help toward preservation of the GAN during surgery in the region of the parotid gland. Furthermore, the histologic findings suggest that the GAN would be a good donor site for nerve grafting.

Electrical stimulation of the vagus nerve dermatome in the external ear is protective in rat cerebral ischemia.

BACKGROUND: Although cervical vagus nerve stimulation is effective for reducing infarct volume in rats, it is not feasible for acute human stroke as it requires surgical incision of the neck. We hypothesized that stimulation of the dermatome in the external ear innervated by the vagus nerve (auricular vagus nerve stimulation; aVNS) reduces infarct volume after transient focal ischemia in rats. METHODS: Animals were randomized to active aVNS or sham stimulation. For aVNS, electrical stimulation of the left cavum concha (1 h duration) using percutaneous needles was initiated 30 min after induction of ischemia. Behavioral and tissue outcome were measured 24 h after induction of ischemia. In a separate experimental dataset, c-Fos immunohistochemistry was performed to identify the brain regions activated after the stimulation. RESULTS: Stimulation of the left cavum concha resulted in bilateral c-Fos staining in the nuclei tractus solitarii and the loci coerulei in all animals. There was no c-Fos staining in any part of the brainstem in sham control animals. The mean infarct volume (SD) as calculated by indirect method was 44.20 ± 7.58% in controls and 31.65 ± 9.67% in treated animals (P < 0.0001). The effect of aVNS on tissue outcome was associated with better neurological scores at 24 h after ischemia (P < 0.0001). CONCLUSIONS: Electric stimulation of the vagus nerve dermatome in the external ear activates brainstem afferent vagal nuclei and reduces infarct volume in rats. This finding has potential to facilitate the development of treatments that leverage the brain's endogenous neuroprotective pathways at the setting of acute ischemic stroke.

[Aural Stimulation with Capsaicin Ointment Improved the Swallowing Function in Patients with Dysphagia: Evaluation by the SMRC Scale].

Cough and swallowing reflexes are important airway-protective mechanisms against aspiration. Angiotensin-converting enzyme (ACE) inhibitors, one of the side effects of which is cough, have been reported to reduce the incidence of aspiration pneumonia in hypertensive patients with stroke. ACE inhibitors have also been reported to improve the swallowing function in post-stroke patients. On the other hand, stimulation of the Arnold nerve, the auricular branch of the vagus, triggers the cough reflex (Arnold's ear-cough reflex). Capsaicin, an agonist of Transient Receptor Potential Vanilloid 1 (TRPV1), has been shown to activate the peripheral sensory C-fibers. Stimulation of the sensory branches of the vagus in the laryngotracheal mucosa with capsaicin induces the cough reflex and has been reported to improve the swallowing function in patients with dysphagia. In our previous study, we showed that aural stimulation of the Arnold nerve with 0.025% capsaicin ointment improved the swallowing function, as evaluated by the endoscopic swallowing score, in 26 patients with dysphagia. In the present study, the video images of swallowing recorded in the previous study were re-evaluated using the SMRC scale by an independent otolaryngologist who was blinded to the information about the patients and the endoscopic swallowing score. The SMRC scale is used to evaluate four aspects of the swallowing function: 1) Sensory: the initiation of the swallowing reflex as assessed by the white-out timing; 2) Motion: the ability to hold blue-dyed water in the oral cavity and induce laryngeal elevation; 3) Reflex: glottal closure and the cough reflex induced by touching the epiglottis or arytenoid with the endoscope; 4) Clearance: pharyngeal clearance of the blue-dyed water after swallowing. Accordingly, we demonstrated that a single application of capsaicin ointment to the external auditory canal of patients with dysphagia significantly improved the R, but not the S, M or C scores, and this effect lasted for 60 min. After repeated aural stimulation with the ointment for 7 days, the R score improved significantly in patients with severe dysphagia. The present findings suggest that stimulation of the Arnold's branch of the vagus in the external auditory canal with capsaicin improves the glottal closure and cough reflex in patients with dysphagia. Thus, aural stimulation with capsaicin represents a novel treatment for dysphagia. It is also suggested that repeated alternative aural stimulation with capsaicin for a week, rather than a single application, is needed to improve the swallowing function in patients with severe dysphagia. By the same mechanism as that underlying the effect of ACE inhibitors, aural stimulation with capsaicin may reduce the incidence of aspiration pneumonia in patients with dysphagia.

High-Resolution Ultrasound for Diagnostic Assessment of the Great Auricular Nerve--Normal and First Pathologic Findings.

PURPOSE: The great auricular nerve (GAN) is a sensory branch of the superficial cervical plexus. While its blockade is an established procedure, little is known about the ultrasound appearance of pathologic conditions of the GAN itself. We, therefore, aimed to evaluate the possibility of the visualization and diagnostic assessment of the GAN along its entire course by means of high-resolution ultrasound (HRUS). MATERIALS AND METHODS: To assess the feasibility of visualization, we performed HRUS with an 18 MHz probe, HRUS-guided, fine-needle ink markings and consecutive dissection in six anatomical specimens. Then, we measured the diameter of the GAN in healthy volunteers and finally performed a retrospective review of patients referred for HRUS examinations because of pain within GAN territory between August 1, 2012 and August 1, 2013. RESULTS: The GAN was clearly visible with HRUS from its formation to the final branches, and was marked successfully on both sides in all anatomical specimens (n = 12). The mean average in-vivo was 0.14 cm ± 0.03 (range 0.08-0.2). Seven cases of patients with GAN pathologies of various origins (idiopathic, traumatic, tumorous and iatrogenic) were identified, of which 6 were visible on HRUS and all of which could be confirmed by complete resolution of symptoms after selective HRUS-guided GAN block. CONCLUSION: This study confirms the reliable ability to visualize the GAN with HRUS throughout its course, both in anatomical specimens and in vivo. The provided cases show that pathologies of the GAN seem to have a variety of causes and may not be rare. We, therefore, encourage the use of HRUS in patients with unclear pain in the auricular, periauricular and posterior-lateral head.

Great auricular nerve preservation during parotidectomy for benign tumors.

The great auricular nerve, the largest sensory branch of the cervical plexus, arises from the third cervical nerve (C3) with irregular contribution from the C2. The first part of its course is deep to the sternocleidomastoid muscle. In few years, many experiences by different authors concerning the issue of great auricular nerve integrity during parotidectomy were published in the literature. The aims of our article were to report our experience with 78 consecutive patients who underwent standard superficial, subtotal, or total parotidectomy for benign tumors and to illustrate postsurgical findings regarding the sensibility of the pinna and mandibular angle as subjectively reported in the early postsurgical period and after 3, 6, and 12 months from surgery.

Preservation of greater auricular nerve during parotidectomy: sensation, quality of life, and morbidity issues. A systematic review.

BACKGROUND: Our objectives were to assess the evidence of preservation of the greater auricular nerve in parotidectomy with regard to morbidity and quality of life. METHODS: This was a systematic review. Inclusion criteria were: English literature, prospective and retrospective studies. Exclusion criteria were: single case reports, "teaching" reviews. Outcome measures were: tactile sensation, pain, thermal sensitivity, and quality of life. RESULTS: Although quality of life does not seem to be adversely affected when the greater auricular nerve is sacrificed, preservation of the posterior branch was recommended in 8 studies. When preserving the nerve, the incremental operative time increase is no more than 10 to 5 minutes after a rapid learning curve. CONCLUSIONS: There is level Ib evidence that preservation of the greater auricular nerve minimizes the postoperative sensory disturbance and should be considered whenever tumor clearance is not compromised. There is no evidence that overall quality of life is affected when the greater auricular nerve is sacrificed.

Surgical decompression of the great auricular nerve: a therapeutic option for neurapraxia following rhytidectomy.

BACKGROUND: Great auricular nerve injuries are the most frequent nerve injuries following rhytidectomy, occurring at a rate of 6 percent. Short-scar techniques may decrease visualization and increase the risk of injury/compression of the great auricular nerve. Recent reviews have identified that great auricular nerve injury can contribute to long-term paresthesias and allodynia in a majority of patients. Identification of this injury, with subsequent exploration, wide release, and decompression, should be performed. METHODS: Four patients with injury of the great auricular nerve were referred for persistent allodynia as a complication of short-scar rhytidectomy. Following confirmation of a Tinel sign over the great auricular nerve, each patient underwent subsequent exploration and neurolysis. RESULTS: Diagnosis of compression and suture impingement was confirmed at exploration, and extensive decompression was performed with care taken to protect the nerve from postoperative scar formation. All patients noted postoperative improvement in symptoms, with nearly complete resolution at 6 months. CONCLUSIONS: Minimally invasive techniques may impart increased risk of nerve injury in exchange for reduced scar length. In instances of great auricular nerve injury, progressive metabolic changes and increased vascular permeability allow for inflammatory cellular influx and fibrin deposition, compounding nerve dysfunction and symptomatic complaints. Noninvasive modalities may not alleviate complaints of pain and hyperesthesia, particularly in the event of suture compression. Persistent injuries can affect quality of life, with intrusive thoughts about symptoms, or an inability to perform grooming activities. Exploration and decompression of the great auricular nerve may offer a long-term solution for the patient with postrhytidectomy allodynia. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Does the great auricular nerve predict the size of the main trunk of the facial nerve? A clinical and cadaveric study.

There seems to be only individual clinical experience and some anecdotal evidence about a relation between the width of the great auricular nerve (GAN) and the size of the main trunk of the facial nerve during parotidectomy. To our knowledge no anatomical studies have been published. In this cadaveric and clinical study we measured the widest point of the GAN as it crosses the sternomastoid muscle before it divides, and the main trunk of the facial nerve before it bifurcates. Measurements were obtained from 16 patients who required formal superficial parotidectomies with identification of the facial nerve, and from 21 cadavers (16 formalin-fixed and 5 fresh frozen) where both sides were dissected. We recorded the results and the side of dissection. The mean (SD) width of the GAN and facial nerve from all the dissections was 2.75 (0.53)mm and 2.83 (0.54)mm, respectively. There was a strong correlation between the width of the nerves from both sides (left: r=0.934, p<0.001; right: r=0.940, p<0.001). The nerves did not differ significantly in size in patients or cadavers (GAN: right, p=0.873; left, p=0.486; facial nerve: right, p=0.931; left, p=0.691). We have found that the GAN accurately predicts the width of the main trunk of the facial nerve. This is particularly useful surgically as a narrow GAN can alert the surgeon to expect a small facial nerve.

Selective deep lobe parotidectomy for pleomorphic adenomas.

The authors' experience of the selective deep lobe parotidectomy for the treatment of pleomorphic adenomas of the deep parotid lobe is presented. A retrospective analysis of 11 patients treated between 1997 and 2010 was performed; seven were males and four were females, ranging in age from 35 to 51 years. Parameters evaluated included facial nerve weakness, the occurrence of Frey's syndrome, cosmetic outcome, and recurrence. Follow-up ranged from 18 months to 11 years. No major complications, permanent facial nerve weakness, or Frey's syndrome occurred. Four patients developed temporary facial nerve impairments that lasted between 2 and 6 weeks, and two developed a sialocele that healed in 9 days in one case and 12 days in the other. The overall cosmetic assessment was excellent in eight patients, good in two, and satisfactory in the remaining one. No recurrences occurred. The selective deep lobe parotidectomy can be considered an effective technique for the management of deep parotid lobe pleomorphic adenomas. The major advantages of this procedure include a reduction in complications such as facial nerve impairments and Frey's syndrome, and an improved cosmetic outcome.

Posterior auricular nerve found anterior to the cartilage of the external auditory meatus--a previously unreported variant.

We describe a previously unreported anatomical variant of the posterior auricular nerve found during parotidectomy, and discuss its clinical implications.

Masseteric-facial nerve anastomosis for early facial reanimation.

OBJECTIVE: Early repair of facial nerve paralysis when cortical neural input cannot be provided by the facial nerve nucleus, is generally accomplished anastomozing the extracranial stump of the facial nerve to a motor donor nerve. That is generally the hypoglossus, which carries a variable degree of morbidity. The present work aims to demonstrate the effectiveness of the masseteric nerve as donor for early facial reanimation, with the advantage that harvesting is associated with negligible morbidity. METHODS: Between October 2007 and August 2009, 7 patients (2 males, 5 women) with unilateral facial paralysis underwent a masseter-facial nerves anastomosis with an interpositional nerve graft of the great auricular nerve. The interval between the onset of paralysis and surgery ranged from 8 to 48 months (mean 19.2 months). All patients included in the study had signs of facial mimetic muscle fibrillations on electromyography. The degree of preoperative facial nerve dysfunction was grade VI following the House-Brackmann scale for all patients. RESULTS: At the time of the study, all the patients with a minimum follow-up time of 12 months after the onset of mimetic function had recovered facial animation. Facial muscles showed signs of recovery within 2-9 months, mean 4.8 months, with the restoration of facial symmetry at rest. Facial movements appeared while the patients activated their chewing musculature. Morbidity related to this intervention is only the loss of sensitivity of earlobe and preauricular region. CONCLUSION: The present technique seems to be a valid alternative to classical hypoglossal-facial nerve anastomosis because of similar facial nerve recovery and lower morbidity.

[Auriculotherapy, an anodyne technique in oncology]. / L'auriculothérapie, une technique antalgique en cancérologie.

Auriculotherapy is a complementary therapy recommended for the treatment of chronic pain. Effectively, the whole of the body's innervation territory is mapped out on the ear auricles, "connected" on the level of the brainstem, the relay station of all the body's sensory information. The therapy consists in inserting semi-permanent needles or localised stimulations in the auricles. The ear point is determined on the basis of neurophysiological reasoning.