Great auricular nerve preservation in parotid gland surgery: Long-term outcomes

Great auricular nerve conservation and parotidectomy for tumor

OBJECTIVE

To describe the key technical points for preserving the great auricular nerve during parotidectomy for tumor, and to discuss the literature regarding the benefits, limitations and indications for nerve-sparing surgery. Data suggested that great auricular nerve preservation should be discussed in the preoperative consultation, attempted intraoperatively and mentioned in the operative report once parotidectomy completed.

Impact of great auricular nerve sacrifice on sensory disturbance after parotidectomy

PURPOSE

To investigate the association between great auricular nerve (GAN) sacrifice during parotidectomy and postoperative sensory disturbance.

MATERIALS AND METHODS

Patients who underwent parotidectomy between November 2016 and May 2020 at a single academic institution were included in this retrospective chart review. Operative notes were reviewed to determine incidence of GAN sacrifice. Prevalence of patient-reported sensory complaints in the GAN distribution and time to spontaneous resolution of symptoms were assessed.

RESULTS

Of 305 parotidectomy patients, 111 (36.4%) endorsed complaints of postoperative sensory disturbances in the GAN distribution typically characterized by numbness or shooting pains. GAN sacrifice was present in 9 (8.1%) of 111 patients who experienced sensory disturbances compared to 9 (4.6%) who reported no sensory disturbances (p > 0.05). Twenty-five patients (32.5%) experienced spontaneous resolution of symptoms at their most recent follow-up at a mean of 6.2 months after onset of symptoms. Of those that experienced a sensory disturbance, GAN preservation was not significantly associated with likelihood of spontaneous recovery (p > 0.05).

CONCLUSIONS

We report the largest series to date of post-operative sensory disturbance in parotidectomy patients as it relates to intraoperative GAN sacrifice. Although the relationship between GAN sacrifice and the incidence of postoperative sensory disturbance and its subsequent resolution were not significant, we continue to advocate for GAN preservation to reduce incidence of postoperative sensory disturbances.

The Great Auricular Nerve Trigger Site: Anatomy, Compression Point Topography, and Treatment Options for Headache Pain

BACKGROUND

Peripheral nerve decompression surgery can effectively address headache pain caused by compression of peripheral nerves of the head and neck. Despite decompression of known trigger sites, there are a subset of patients with trigger sites centered over the postauricular area coursing. The authors hypothesize that these patients experience primary or residual pain caused by compression of the great auricular nerve.

METHODS

Anatomical dissections were carried out on 16 formalin-fixed cadaveric heads. Possible points of compression along fascia, muscle, and parotid gland were identified. Ultrasound technology was used to confirm these anatomical findings in a living volunteer.

RESULTS

The authors' findings demonstrate that the possible points of compression for the great auricular nerve are at Erb's point (point 1), at the anterior border of the sternocleidomastoid muscle in the dense connective tissue before entry into the parotid gland (point 2), and within its intraparotid course (point 3). The mean topographic measurements were as follows: Erb's point to the mastoid process at 7.32 cm/7.35 (right/left), Erb's point to the angle of the mandible at 6.04 cm/5.89 cm (right/left), and the posterior aspect of the sternocleidomastoid muscle to the mastoid process at 3.88 cm/4.43 cm (right/left). All three possible points of compression could be identified using ultrasound.

CONCLUSIONS

This study identified three possible points of compression of the great auricular nerve that could be decompressed with peripheral nerve decompression surgery: Erb's point (point 1), at the anterior border of the sternocleidomastoid muscle (point 2), and within its intraparotid course (point 3).

A comprehensive review of the great auricular nerve graft

The great auricular nerve (GAN) is a superficial branch of the cervical plexus that innervates parts of the mandible, auricle, and earlobe. Over the past 30 years, the GAN has become the nerve graft donor of choice for many surgeons for reconstructing injured facial nerves. In this review, we discuss the anatomy and function of the GAN, while focusing on surgical landmarks and the characteristics that make it a suitable nerve graft donor. In addition, we present and summarize published case reports on use of the GAN for grafting. We hope that this review will provide surgeons with an up-to-date and concise reference.

Quantitative sensory testing of periauricular skin in healthy adults

The aim of this study was to investigate the test-retest reliability of quantitative sensory testing (QST) and mechanical sensitivity mapping of the periauricular skin. Twenty volunteers (10 men, 10 women) participated in two sessions at intervals of one week. Cold and warm detection threshold (CDT&WDT), cold and heat pain threshold (CPT&HPT), mechanical detection and pain threshold (MDT&MPT), pressure pain threshold (PPT) and two-point discrimination (2PD) were measured at five sites: bilateral subauricular and postauricular sites (LA, RA, LB, RB) and the dorsum of left hand (control). Pressure stimulation was applied at each of the four periauricular test sites. The test-retest reliability of the QST data implied fair to excellent agreement as evaluated by the intra-class correlation coefficients (ICC; all >0.4) for different days. There was no difference between each side in the QST parameters and mechanical sensitivity mapping (P ≥ 0.057). Significant differences between subauricular and postauricular sites were shown for WDT and PPT (P ≤ 0.028). NRS scores of mechanical sensitivity mapping showed significant effects of gender, site and point (P ≤ 0.040). QST and mechanical sensitivity mapping can be considered to be a reliable technique to assess somatosensory function of the periauricular skin.

Effects of an antiadhesive agent on functional recovery of the greater auricular nerve after parotidectomy: a double-blind randomized controlled trial

PURPOSE

Periauricular sensory deficit occurs frequently after parotidectomy even in cases with preservation of the greater auricular nerve (GAN). This study was performed to evaluate the effects of antiadhesive agent in functional recovery of the GAN after parotidectomy.

METHODS

Ninety-eight patients undergoing partial parotidectomy for benign parotid tumors were prospectively enrolled in this multicenter, double-blind randomized controlled study and randomly assigned to either the study or control group. Antiadhesive agent was applied in the study group. The results of sensory tests (tactile, heat, and cold sensitivity) and a questionnaire on quality of life (QoL) were acquired at postoperative 1, 8, and 24 weeks after surgery. Clinical parameters, and the results of the sensory tests and the questionnaire, were compared between the two groups.

RESULTS

A total of 80 patients were finally enrolled. On sensory evaluation, tactile sensation and warm sensation in the ear lobule, and warm sensation in the mastoid area, showed significant improvement at 24 weeks postoperatively in the study group. There were no significant differences between the two groups on any questions in the QoL questionnaire, at any follow-up time point.

CONCLUSIONS

Antiadhesive agents have some positive effects on functional recovery of the GAN after parotidectomy. Therefore, applying antiadhesive agents after parotidectomy can reduce discomfort in patients.

Complications after superficial parotidectomy for pleomorphic adenoma

Background

The significance of complications after superficial parotidectomy remains unclear, since prospective studies are lacking. The aim of this study was to evaluate facial nerve dysfunction and other postoperative complications after superficial parotidectomy for pleomorphic adenoma of the superficial lobe and to identify the associated risk factors.

Material and Methods

Prospective and descriptive clinical study on 79 patients undergoing formal superficial parotidectomy with the modified facelift incision, dissection of the facial nerve and reconstruction with the superficial musculoaponeurotic system flap. Function of the facial nerve using the House-Brackmann scale and the intra- and postoperative complications were recorded at 1 week and 1, 3, 6 and 12 months. A descriptive, inferential and binary logistic regression analysis were performed for the variables facial nerve dysfunction, tumor size and location, clinical presentation and duration of surgery.

Results

77.2% of the patients presented facial paresis at 1 week, with the marginal-mandibular branch being the most commonly affected (64.5%). 94.9% recovered the facial function at 6 months and 100% at 12 months. A statistically significant relationship was found between the appearance of facial paresis and tumor location in the superior lateral area of the superficial lobe, size >2 cm and prolonged operative time. None of the remaining variables showed significant differences at any study timepoint. At 12 months, 57% of patients had recovered tactile sensitivity in the earlobe. The clinical occurrence of Frey’s syndrome was 11.4%.

Conclusions

Despite the high incidence of postoperative facial paresis at 1 week, its magnitude was low and the recovery time was short. Tumor location in the parotid superficial lobe upper area, size and prolonged operative time are risk factors that can worsen facial paresis at different study timepoints. The knowledge of these complications is relevant for patient´s counseling and to achieve better long-term outcomes.

Key words:Superficial parotidectomy, pleomorphic adenoma, parotid gland, facial nerve paralysis, postoperative complications.

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.

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.