The vestigial pinna-orienting system in humans briefly suppresses superior auricular muscle activity during reflexive orienting toward auditory stimuli.

The vestigial pinna-orienting system in humans is capable of increasing the activity of several auricular muscles in response to lateralized transient auditory stimuli. For example, transient increases in electromyographic activity in the posterior auricular muscle (PAM) to an attention-capturing stimulus have been documented. For the current study, surface electromyograms (EMGs) were recorded from the PAMs and superior auricular muscles (SAMs) of 10 normal-hearing participants. During the experiments, lateralized transient auditory stimuli, such as a crying baby, a shattering vase, or the participant's first names, were presented. These transient stimuli were either presented in silence or when participants actively listened to a podcast. Although ipsilateral PAM activity increased in response to transient stimuli, the SAM displayed the opposite behavior, i.e., a brief, ipsilateral suppression of activity. This suppression of ipsilateral SAM activity was more frequent on the right (75%) than left side (35%), whereas an ipsilateral PAM increase was roughly equal in prevalence on the two sides (left: 90%, right: 95%). During the active listening task, SAM suppression on the right ear was significantly larger in response to ipsilateral stimuli, compared with contralateral ones (P = 0.002), whereas PAM activity increased significantly (P = 0.002). Overall, this study provides evidence of a systematic transient suppression of the SAM during exogenous attention. This could suggest a more complex system than previously assumed, as the presence of synchronized excitatory and inhibitory components in different auricular muscles points toward a coordinated attempt at reflexively orienting the pinna toward a sound.NEW & NOTEWORTHY This study provides evidence that two auricular muscles in humans, the posterior and superior auricular muscles (PAM, SAM), react fundamentally different to lateralized transient auditory stimuli, especially during active listening. Although the PAM reacts with a transient increase in ipsilateral activity, ongoing ipsilateral SAM activity is briefly suppressed at the same time. This indicates the presence of a more complex and nuanced pinna-orienting system, with synchronized excitatory and inhibitory components in humans, than previously suspected.

The Use of Posterior Auricular Fascia Graft (PAFG) for Slight Dorsal Augmentation and Irregular Dorsum Coverage in Primary and Revision Rhinoplasty: A Prospective Study.

INTRODUCTION: Augmentation and coverage of irregularities of the nasal dorsum remain a challenge in rhinoplasty. Different techniques have been described in the current literature for this purpose. The aim of this study is to assess and illustrate the author experience and outcomes using the posterior auricular fascia graft (PAFG) for dorsal camouflage and augmentation in primary and revision rhinoplasty. MATERIAL AND METHODS: A prospective bicentric study was conducted, including patients with slight dorsal deficiencies and/or with dorsal irregularities following hump resection, trauma or previous rhinoplasty receiving PAFG to improve the rhinoplasty outcome. To objectively assess the graft resorption rate, MRI was performed 2 weeks and 18 months after surgery. To investigate patient satisfaction, the preoperative and 1-year postoperative scores obtained using the rhinoplasty outcomes evaluation (ROE) scale were compared. The scores following a normal distribution obtained for each patient were compared using a paired t-test. RESULTS: Forty-five patients were enroled in this study. Average follow-up duration was 35.4 months. Patients' age ranged from 17 to 57 years. No cases of infection or major graft resorption were observed. No postoperative scars were visible at the donor site. All patients were satisfied after surgery, and a statistically significant difference between pre- and postoperative scores (p<0.0001) was observed. CONCLUSION: This study showed that PAFG is a reliable technique for dorsal camouflage and slight augmentation in primary and revision rhinoplasty. The procedure is safe, easy and quick and only requires a small learning curve. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Use of the Posterior Auricular Artery for Indirect Bypass in Moyamoya: A Pediatric Case Series.

INTRODUCTION: Encephaloduroarteriosynangiosis (EDAS) for moyamoya is predominantly performed using a branch of the superficial temporal artery (STA) as the donor artery. At times, other branches of the external carotid artery are better suited for EDAS than is the STA. There is little information in the literature concerning using the posterior auricular artery (PAA) for EDAS in the pediatric age-group. In this case series, we review our experience using the PAA for EDAS in children and adolescents. CASE PRESENTATIONS: We describe the presentations, imaging, and outcomes of 3 patients in whom the PAA was used for EDAS, as well our surgical technique. There were no complications. All 3 patients were confirmed to have radiologic revascularization from their surgeries. All patients also had improvement of their preoperative symptoms, and no patient has had a stroke postoperatively. CONCLUSION: The PAA is a viable option for use as a donor artery in EDAS for the treatment of moyamoya in children and adolescents.

Salvage of Ear Framework Exposure Following Autologous Microtia Reconstruction: Repair Strategy for Each Location of Exposure.

One of the most common complications of total auricular reconstruction is exposure of the ear framework. Various reconstruction methods have been reported depending on the location and size of exposed cartilage. This report describes a safe reconstruction method for each exposed part of the grafted ear framework. From January 2019 to August 2021, 2 cases (4 areas) of framework exposure were observed following autologous microtia reconstruction. The first case developed 2 small areas of skin necrosis on the anterior helix and lower antihelix to concha. The former was reconstructed with a temporal fascia flap and the latter with a local transposition flap. The second case also developed 2 small areas of skin necrosis on the posterior helix and lower antihelix to concha. The former was sutured directly and the latter with a local transposition flap. However, both wounds recurred due to flap necrosis and the cartilage was exposed again. The 3rd operation was performed by covering both wounds with a posterior auricular turnover flap and skin graft. In both cases, the exposed framework was completely covered with the flaps, and the reconstructed ears showed well-defined convolutions. Covering exposed cartilage with a local flap with a random pattern of blood circulation is convenient because no additional skin grafts are required. However, the blood circulation of the flaps is inadequate when an elongated flap is required; consequently, flap necrosis may occur. On the other hand, a temporal fascia flap and posterior auricular flap, which have axillary pattern blood circulation, are considered to be safer. We believe that it is safe to use a temporal fascia flap for cartilage exposure in the upper half of the auricle, and a posterior auricular turnover flap for the lower half.

The posterior auricular muscle complex graft as a porous orbital implant wrap: long-term follow-up over a 31-year period.

PURPOSE: Orbital implant exposures, infections, and extrusions can occur many years following enucleation or evisceration. This study analyzes complication rates following porous orbital implant wrapped with a posterior auricular muscle complex graft (PAMCG). METHODS: This is a retrospective study of patients who underwent orbital implantation following enucleation using this technique between 1992 and 2013. Only cases with a minimum of 18 months of follow-up were included. No patients underwent peg implantation. Patient's demographics, follow-up time, type of implant, complications including wound dehiscence, exposure, postoperative infection, and extrusion were recorded. RESULTS: This study included 36 orbits of 36 patients with a mean age of 39.3 ± 23.2 years (range, 3-84 years). Thirty patients had hydroxyapatite implants and six had porous polyethylene. The average follow-up time was 12.6 ± 5.6 years (range, 1.5-31.0 years). There were no implant extrusions, and only one exposure resulting in orbital infection that necessitated implant removal (2.8%). CONCLUSION: Wrapping porous orbital implants with PAMCG had favorable long-term outcomes over a thirty-one-year period.

Occipital artery-anterior cerebral artery bypass with posterior auricular artery-middle cerebral artery bypass for stenosis of the internal carotid artery bifurcation.

Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass, and STA-anterior cerebral artery (ACA) bypass, are options for direct revascularisation of anterior circulation. However, some patients don't have a suitable STA to use as a donor, so an alternative procedure must be performed. A 59-year-old, right-handed man presented with dysphasia and right-sided hemiparesis due to a transient ischaemic attack. Imaging studies revealed severe stenosis of the left internal carotid artery bifurcation. Iodoamphetamine single photon emission computed tomography demonstrated reduced cerebrovascular reserve capacity in the left hemisphere. The patient was started on antiplatelet therapy, but the ischaemic attacks persisted after one month. Thus, revascularisation of the ACA and MCA territories was considered. Digital subtraction angiography revealed prominence in the left occipital artery (OA) and posterior auricular artery (PAA), while the left STA was hypoplastic, terminating at the squamous suture level. Therefore, anastomoses were performed between both the OA and ACA and the PAA and MCA. Revascularisation was successful, and the ischaemic attacks disappeared. OA-ACA bypass, together with PAA-MCA bypass, may be effective for wide cerebral revascularisation when the STA is not available.

A new method for tracing the facial nerve trunk using the posterior auricular nerve.

Tracing the facial nerve trunk is an essential action in parotid surgery, because of the implications of injury to the nerve or its branches. More than a few landmarks that may help the surgeon in this task have been proposed (e.g., the posterior belly of the digastric muscle, the tragal pointer, among others), under the assumption that additional access methods improve the surgical technique and reduce the possibility of harmful post-operative consequences. Here we present evidence that the posterior auricular nerve may be used to trace the facial nerve trunk. We dissected 75 cadaveric heminecks, exposed the auricularis posterior muscle and adnexa, and attempted to follow the posterior auricular nerve to the facial nerve trunk. The auricularis posterior muscle, nerve, and artery were identified in all heminecks, securing an anatomically reliable route to the facial nerve trunk. Average length of the nerve from the auricularis posterior muscle to the facial nerve trunk was 28 mm (±6.2 mm). The angle between the posterior auricular nerve and the vertical segment of the FN trunk was 39.5° (±7.7°). We conclude that the posterior auricular nerve may be used as a landmark to trace the facial nerve trunk. It is advantageous due to the relatively simple and consistent regional anatomy, and also because manipulation of this nerve does not present a risk given that the auricularis posterior muscle is vestigial. The proposed landmark is particularly important in revision surgery, where the pre-auricular anatomy may have been distorted and scarred by previous operations. Clin. Anat. 32:453-457, 2019. © 2019 Wiley Periodicals, Inc.

Fetal anatomy of the facial nerve trunk and its relationship with posterior auricular artery.

PURPOSE: The aims of the study are to define anatomy of the facial nerve (FN) and its main trunks as well as their relationship with the posterior auricular artery in fetal period to evaluate the data for regional surgery in newborns and young infants. METHODS: Formalin-fixed 34 fetuses from anatomy laboratory collection with a mean gestational age of 26.4 ± 4.6 (20-36) weeks were dissected. Parameters regarding the presence of major or minor trunks, width, length, branching pattern of FN were evaluated according to side, gender and trimester. The positional relationship of posterior auricular artery with the FN trunk was inspected. RESULTS: On all sides only the major trunk of the FN was detected. For length and width parameters, there was no statistically significant difference for side and gender except for trimester. Linear functions were found as 0.329 + 0.025 × weeks for width and 5.264 + 0.185 × weeks for length. There are statistically significant linear relationships between width and length of the FN trunk and week parameters as r = 0.507, p < 0.001 and r = 0.484, p < 0.001, respectively. Posterior auricular artery crossed FN trunk laterally in 42 of 53 sides, medially in 9 sides while it was puncturing it proximally in 2 sides. In all cases, it was in close contact to the FN trunk. FN trunk showed bifurcation in 82% and trifurcation in 18%. CONCLUSION: Dimensions of FN trunk, growth ratio and linear functions can be beneficial in understanding the fetal growth of FN trunk and its usage for grafts. Data about the relationship of the posterior auricular artery with FN trunk may be crucial in avoiding iatrogenic injuries during surgery in early ages.

Posterior auricular muscle patch graft for exposed orbital implant.

The purpose of this article is to describe a surgical technique to repair an exposed orbital implant by posterior auricular muscle autograft. A retrospective review was conducted of four patients with an exposed orbital implant that were treated with a posterior auricular muscle graft. Four patients received posterior auricular muscle patch graft to the exposed orbital implant. The donor site healed with minimal scarring and remained well hidden. The graft incorporated fully into surrounding orbital tissue with no recurrent exposure at average of 13 month follow-up. The posterior auricular muscle autograft is a viable technique for repairing an exposed orbital implant.

Reevaluation of the arterial blood supply of the auricle.

The anatomical basis for auricular flaps used in multiple aesthetic and reconstructive procedures is currently based on a random distribution of the underlying arterial network. However, recent findings reveal a systematic pattern as opposed to the present concepts. Therefore, we designed this study to assess the arterial vascular pattern of the auricle in order to provide reliable data about the vascular map required for surgical interventions. Sixteen human auricles from eight body donors (five females/three males, 84.33 ± 9.0 years) were investigated using the unique 'Spalteholz' method. After arterial injection of silicone, a complete transparency of the tissue was achieved and the auricular arteries and branches were visible. Qualitative and quantitative evaluation of the arterial vascular pattern was performed. The superior and the inferior anterior auricular artery provided the vascular supply to the helical rim, forming an arcade, i.e. helical rim arcade. On the superior third of the helical rim another arcade was confirmed between the superior anterior auricular artery and the posterior auricular artery (PAA), i.e. the helical arcade. The perforators of the PAA were identified lying in a vertical line 1 cm posterior to the tragus, supplying the concha, inferior crus, triangular fossa, antihelix and the earlobe. The results of this study confirmed the constant presence of the helical rim arcade (Zilinsky-Cotofana), consistent perforating branches of the PAA, and the helical arcade (Erdman), and will help and guide physicians performing auricular surgeries toward fast and simple procedures with optimal patient satisfaction.

An anatomical study of the transversus nuchae muscle: Application to better understanding occipital neuralgia.

The transversus nuchae muscle appears inconsistently in the occipital region. It has gained attention as one of the muscles composing the superficial musculoaponeurotic system (SMAS). The purpose of this study was to clarify its detailed anatomical features. We examined 124 sides of 62 cadavers. The transversus nuchae muscle was identified when present and examined after it had been completely exposed. We also examined its relationship to the occipital cutaneous nerves.The transversus nuchae muscle was detected in 40 sides (40/124, 32.2%) of 26 cadavers; it was present bilaterally in 14 and unilaterally in 12. It originated from the external occipital protuberance; 43% of the observed muscles inserted around the mastoid process, and 58% curved upward around the mastoid process and became the uppermost bundle of the platysma. In one case, an additional bundle originated from the lower posterior border of the sternocleidomastoid muscle and coursed obliquely upward along with platysma. Ninety percent of the muscles ran below the sling through which the greater occipital nerve passed; 65% of the lesser occipital nerves ran deep to the muscle, and 55% of the great auricular nerves ran superficial to it. Our observations clarify the unique anatomical features of the transversus nuchae muscle. We found that it occurs at a rate similar to that described in previous reports, but its arrangement is variable. Further investigations will be performed to clarify its innervation and other anatomical features. Clin. Anat. 30:32-38, 2017. © 2016 Wiley Periodicals, Inc.

The Versatile Posterior Auricular Fascia in Secondary Rhinoplasty Procedures.

BACKGROUND: Secondary rhinoplasty often involves the addition of autogenous graft material to add volume, structure, support and to camouflage cartilage and bone grafts. A variety of fascias have been used to camouflage, wrap and give "fill" in secondary rhinoplasty. The posterior auricular fascia is a source of material ideal for such purposes, and its quantity, anatomical structure and ease of harvest with minimal donor site morbidity make it a versatile and attractive autogenous graft. METHODS: The clinical records of patients receiving autogenous posterior auricular fascial grafts were reviewed. There were two main uses of this graft material, one was to cover the tip reconstruction in secondary rhinoplasties under thin tip skin. This is a camouflage graft. The second use is for fill and augmentation, especially for the nasal dorsum and as an interpostitional graft between the dorsum and the tip. CONCLUSION: The posterior auricular fascial graft has many potential uses in secondary rhinoplasties and is readily harvested as a generous graft concurrent to conchal cartilage harvest and with a concealed scar behind the ear. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Iatrogenic Through-and-Through Conchal Defect Secondary to Auricular Cartilage Graft.

BACKGROUND: Over the past few years, conchal cartilage has been most often used in rhinoplasty. The donor site complications following conchal cartilage graft harvesting are scar formation, hematoma formation, and delayed wound healing, although hematoma is one of the most important and common complications. A complete conchal defect as a complication of auricular cartilage graft harvesting has not been previously reported in the literature. The authors report an unusual case of an iatrogenic conchal defect resulting from conchal cartilage graft harvesting that was treated using a posterior auricular island flap. METHODS: A 24-year-old male with a left conchal inflammation and perforation visited our plastic surgery department after receiving augmentation rhinoplasty and tip plasty using a conchal cartilage graft. A tight dressing had been applied to the ear, and postoperative infection was uncontrolled, which resulted in iatrogenic conchal perforation. RESULTS: A tie-over bolster dressing has been widely used to prevent hematoma following conchal cartilage graft harvesting with an associated donor site complication. However, a tight tie-over dressing and inappropriate postoperative care can cause complete through-and-through conchal defects. The posterior auricular island flap provides an elegant means of reconstructing conchal defects. CONCLUSIONS: In the described case, aesthetic reconstruction of a conspicuous iatrogenic conchal defect was achieved with minimal scarring using the posterior auricular island flap. To the best of our knowledge, this report is the first to describe reconstruction of an iatrogenic defect in the concha as a complication of auricular cartilage graft harvesting. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Morphological study of the occipital belly of the occipitofrontalis muscle and its innervation.

PURPOSE: Occipital belly (OB) of occipitofrontalis muscle (epicranius) is a muscle which covers the occipital part of the skull. The posterior auricular nerve (PAN) is the first extracranial branch of the facial nerve, which supplies the OB. The PAN is one of the structures used to identify the facial nerve during surgeries such as parotidectomy and mastoidectomy. In the present report, we provide detailed anatomical knowledge of the OB and its innervation. METHODS: Twenty-six hemifaces from 14 Korean cadavers were dissected. The mastoid tip, external occipital protuberance (EOP), a horizontal line that is parallel to the Frankfurt horizontal plane (x-axis), and a vertical line through the EOP (y-axis) were used as reference points and lines. RESULTS: The OB demonstrated a variety of features and was mostly asymmetrical. The muscle bellies were observed to angle toward the temporoparietalis muscle laterally, with the aponeurosis angled at approximately 55°-65°. The mean width and height were 60.9 ± 8.7 and 31.7 ± 7.5 mm, respectively. Muscle bellies were located at a mean distance of 7.1 ± 2.5 mm superior to the x-axis and 29.6 ± 6.4 mm lateral to the y-axis. The mean vertical distance from the origin of the PAN at the anterior border of the mastoid process (MP) to the mastoid tip was 6.1 ± 2.1 mm. The mean nerve angle between the PAN and the x-axis was 55.7° ± 6.8°. The entry point of the PAN that innervates the OB was positioned at a mean distance of 9.0 ± 3.5 mm superior to the x-axis and 79.0 ± 8.1 mm lateral to the y-axis. CONCLUSIONS: Understanding the morphometrical characteristics of the OB and its innervation may potentially improve surgical outcomes to assist in locating the posterior auricular branch of the facial nerve.

The Posterior Auricularis Muscle as Superficial Landmark for the Sigmoid Sinus and Transverse-Sigmoid Sinus Junction: An Anatomical Study.

OBJECTIVE: Neuronavigation systems coupled with previously reported external anatomical landmarks assist neurosurgeons during intracranial procedures. We aimed to verify whether the posterior auricularis muscle (PAM) could be used as an external landmark for identifying the sigmoid sinus (SS) and the transverse-sigmoid sinus junction (TSSJ) during posterior cranial fossa surgery. METHODS: The PAM was dissected in 10 adult cadaveric heads and after drilling the underlying bone, the relationships with the underlying SS and TSSJ were noted. The width and length of the PAM, and the distance between the muscle and reference points (asterion, mastoid tip, and midline), were measured. RESULTS: The PAM was identified in 18 sides (9 left, 9 right). The first 20 mm of the muscle length (mean 28.28 mm) consistently overlay the mastoid process anteriorly and the proximal half of the SS slightly posteriorly on all sides. The superior border was a mean of 2.22 mm inferior to the TSSJ and, especially when the muscle length exceeded 20 mm, this border extended closer to the transverse sinus; it was usually found at a mean of 3.11 mm (range 0.0-13.80 mm) inferior to the distal third of the transverse sinus. CONCLUSIONS: Superficial landmarks give surgeons improved surgical access, avoiding overexposure of deep neurovascular structures and reducing brain retraction. On the basis of our cadaveric study, the PAM is a reliable and accurate direct landmark for identifying the SS and TSSJ. The PAM could potentially be used for guiding the retrosigmoid approach.

The topographical anatomy of the posterior auricular artery: a computed tomography angiography analysis with implications for reconstructive surgery.

BACKGROUND: The anatomy of the posterior auricular artery (PAA) is highly variable and relevant in various plastic and reconstructive procedures. MATERIALS AND METHODS: The results of 55 consecutive patients who underwent head and neck computed tomography angiography (CTA) were analyzed. A total of 78 hemifaces were evaluated. The analysis has been performed in 19 categories. RESULTS: Median PAA length was found to be 47.59 mm (LQ = 32.75; HQ = 56.16). The median PAA diameter (at its origin) was established at 2.55 mm (LQ = 2.29; HQ = 2.90). Moreover, the median PAA cross-sectional area (at its origin) was set to be 3.22 mm (LQ = 2.49; HQ = 4.13). Sexual dimorphism regarding all of the measured parameters was also evaluated. Statistically significant differences (p ≤ 0.05) were found in 13 of the measured categories. CONCLUSIONS: The present study demonstrated the complete anatomy of the PAA. The most frequent origin of the said artery was from the ECA, and its mean length was 45.07 mm; which did not differ between males and females significantly (p>0.05). Moreover, we have provided surgeons with tools to localize this artery pre- and intraoperatively using simple landmarks, namely the apex of the mastoid process and the center of the external acoustic meatus. The exact position of the origin of the PAA was also demonstrated by a heat map of the auricular region. Our findings have the potential to assist surgeons in developing a mental visualization of the arterial anatomy of the retroauricular region. This visualization can be instrumental in precisely identifying the location of the PAA during reconstructive surgeries, thereby minimizing complications and enhancing surgical outcomes.

Posterior auricular artery as a novel anatomic landmark for identification of the facial nerve: A clinical study.

Background: In our previous cadaveric study, we highlighted the posterior auricular artery (PAA) as a potential landmark for early identification of facial nerve (FN) when performing parotidectomy. However, further clinical study is critically needed before this landmark could be applied in clinical practice. Methods: For 31 patients enrolled, we tried to identify the FN by the guide of the PAA during parotidectomy. Additionally, the FN function was evaluated during follow-up. Results: PAA could be exposed in 28 out of 31 (90.3%) patients during parotidectomy. Moreover, the FN trunk could be identified by the guide of the PAA in all these 28 patients with identifiable PAA. Furthermore, no iatrogenic FN damage happened in this study and the transient FN dysfunction rate was 5.7%. Conclusion: The PAA is an ideal landmark for early identification of the FN trunk when performing parotidectomy.

[Surgical treatment of variant preauricular fistula complicated with posterior auricular abscess in children].

Objective:To summarize the clinical experience in treating children with variant preauricular fistula who present with posterior auricular abscess, and to improve the diagnostic accuracy and therapeutic outcome. Methods:The clinical data of 11 children with preauricular fistula with retroauricular abscess as the main clinical manifestation were analyzed retrospectively. Among them, 10 patients underwent surgical treatment after infection control, and 1 patient underwent preauricular fistula resection during infection period. During the operation, methylene blue was used to trace the fistula, and the fistula and the infected tissue behind the ear were removed as a whole. Follow up regularly after operation. Results:The fistulas of the 11 patients were all located at the helix crus. After the auricular fistula resection with double-incision, the patients were followed up for more than 1 year without recurrence. Conclusion:Children with variant anterior auricular fistula who manifested with postauricular abscess could be successfully managed by Preauricular fistula resection with Double-incision. Careful physical examination before operation and the complete removal of the fistula and the attached cartilage during the operation can avoid misdiagnosis and postoperative recurrence.

A supportive donor nerve for long-term facial paralysis: Anatomical analysis of the posterior auricular nerve and micro-anatomical comparison with zygomatic nerve.

BACKGROUND: The posterior auricular nerve (PAN) is an inspiring candidate for the additional axonal source in long-term facial paralysis to improve the functional results of the cross-facial nerve (FN) graft technique. However, no studies have analyzed the PAN's axonal load and its microscopic anatomy to assess its utilization in facial reanimation. The present study aims to examine the anatomical and microscopic features of the PAN to analyze its feasibility as a donor nerve. METHODS: The bilateral facial side of 14 fresh frozen adult human cadavers was examined for the study. The PAN's anatomical course was recorded, and nerve specimens from the PAN and zygomatic nerve (ZN) were obtained to compare their microscopic anatomy and axon counts using a light microscope and transmission electron microscope. RESULTS: The PAN's average branching distance and its course length were 5.8 ± 2.69 mm and 59.2 ± 5.85, respectively. The mean number of myelinated axons was 600.28 ± 69.97 in the PAN and 728.85 ± 166.31 in the ZN. This difference between the two nerves was statistically significant (p = 0.002). However, considering the gender variable, the mean axon counts of PAN and ZN were statistically similar for face sides and their average. Furthermore, the ultrastructural anatomy of both nerves was similar in electron microscopic evaluation. CONCLUSIONS: The present study confirms that the PAN is a proper candidate to be a supportive donor nerve due to its isolated site, consistent anatomical course, convenient ultrastructural anatomy as well as axonal load.

Ear ischemia induced by endovascular therapy for arteriovenous fistula of the sigmoid sinus: A case report.

BACKGROUND: Arteriovenous fistula of the sigmoid sinus is an abnormal connection of arteries with the sigmoid sinus. Endovascular treatments of such lesions are considered safe and with low rates of complications. CASE SUMMARY: A 62-year-old female patient underwent endovascular treatment of an arteriovenous fistula of the right sigmoid sinus on February 7, 2017, but her tinnitus was not cured. She was admitted to the Beijing Tiantan Hospital, Capital Medical University, on March 20, 2017, and her pre-operative diagnosis, by digital subtraction cerebral angiography, was arteriovenous fistula of the sigmoid sinus. She underwent endovascular embolization of the distal occipital artery and posterior auricular artery using Onyx-18. The arteriovenous fistula of the sigmoid sinus was cured, and her tinnitus disappeared, but ischemia of the upper 2/3 of the right auricle occurred without hearing loss. The patient received treatment to improve microcirculation, in addition to fluid supplementation, analgesia, and hyperbaric oxygen, and the swelling due to ischemia in the right auricle did not progress further. The patient reported no tinnitus , and the right auricle had returned to normal 3 years later. CONCLUSION: Ischemic complications of vital organs should be considered when performing embolization procedures for arteriovenous fistulas of cerebral sinuses. Compensation of the organs should be evaluated before the operation, and the related treatment regimens should be planned.