Two-Incision Approach for Hypoglossal Nerve Stimulator Placement: A Single Institution Assessment.

OBJECTIVE(S): Upper airway stimulator (UAS) placement is a treatment for obstructive sleep apnea (OSA) with few complications and low morbidity. UAS placement has traditionally been performed using a three-incision approach, however, it has been implanted using a two-incision approach. This approach could significantly decrease operation time without a difference in postoperative complications, demonstrating its safety and feasibility for UAS placement. The objective was to assess operative time and complication rate in the two-incision approach for UAS placement compared to the three-incision approach. STUDY DESIGN: Retrospectively reviewed. METHODS: Patients who underwent UAS placement using the two- or three-incision approach at a single academic institution from November 2014 to June 2021 were retrospectively reviewed. The two-incision approach did not include the incision at the mid-axillary line. Main outcome measures included operation time and complication rates. RESULTS: Three-hundred forty-eight patients underwent UAS placement. The three-incision approach demonstrated an average operation time of 143.3 minutes whereas the two-incision approach averaged 129.4 minutes (P < .001). There was no significant difference in rate of postoperative complications between the two- and three-incision cohorts including pneumothorax (0% vs. 0.4%, P > .99), patient-reported discomfort (5.6% vs. 6.5%, P > .99), activity restriction (0% vs. 1.4%, P > .50), and incisional pain (0.0% vs. 1.0%, P > .99). No patients experienced incision site bleeding or infection. The two-incision approach was associated with decreased rate of revision surgery (0.0% vs. 5.4%, P = .048). CONCLUSION: The UAS two-incision approach proved to have a significantly shorter operative time without an increase in complications as compared to the three-incision approach. This approach is a safe and feasible option. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:1687-1691, 2022.

Assessment of axonal sprouting and motor performance after hypoglossal-facial end-to-side nerve repair: experimental study in rats.

Hypoglossal-facial nerve anastomosis (HFA) aims to reanimate denervated mimic muscles with hypoglossal axons when the transected facial nerve is not accessible. The aim of this study was to evaluate the recovery of HFA using a "Y" tube in two variants: (1) the proximal stump of the hypoglossal nerve was entubulated to the "Y" tube (classic "Y" tube HFA) and (2) the "Y" tube was sutured to an epineurial window of a slightly damaged hypoglossal nerve (end-to-side "Y" tube HFA). A total of 48 adult female rats were divided into four groups: intact controls (group 1), sham operated (group 2), classic "Y" tube HFA (group 3) and end-to-side "Y" tube HFA (group 4). The abdominal aorta with both common iliac arteries of isogeneic male rats served as the Y-tube conduit. Animals from group 4 recovered better than those from group 3: the degree of collateral axonal branching (3 ± 1%) was significantly lower than that determined in group 3 (13 ± 1%). The mean deviation of the tongue from the midline was significantly smaller in group 4 (6 ± 4°) than that measured in animals from group 3 (41 ± 6°). In the determination of vibrissal motor function in group 3 and group 4, a decrease in amplitude was found to be - 66% and - 92%, respectively. No differences in the reinnervation pattern of the target muscles were detected. As a result, these surgical models were not determined to be able to improve vibrissal movements. It was concluded that performance of end-to-side "Y" tube HFA diminishes collateral axonal branching at the lesion site, which in turn, promotes better recovery of tongue- and vibrissal-motor performance.

Long-term electrophysiological assessment after hypoglossal-facial anastomosis.

PURPOSE: To investigate and provide objective documentation of the possible differences in the axonal reinnervation process of facial muscles after hypoglossal-facial nerve anastomosis. Then, to search for the presence of the trigemino-hypoglossal reflex and determine whether it indicates better peripheral recovery. METHODS: Electrophysiological examination performed on 20 patients who had undergone VII-XII anastomosis, with follow-up periods of more than 2 years. RESULTS: The mean follow-up time after surgery was 4.1 ± 1.3 years (range 2-8 years). The degrees of axonal reinnervation for the orbicularis oculi (OOc) and orbicularis oris (OOr) were 46.91 ± 19.77 and 32.65 ± 14.85, respectively. And the difference between these muscles was statistically significant (p = 0.018) in favor of the OOc. In addition, R1 blink reflexes that were not followed by R2 components were observed in 30% of the patients. However, these 6 patients with short-latency potential did not differ from the others in terms of latency, the amplitude of compound muscle action potential (CMAP), and degree of axonal reinnervation (p > 0.05) at both muscles (OOc and OOr). CONCLUSION: The recoveries of the lower face and upper face are different after VII-XII anastomosis, and in our patients the OOc healed better. In addition, R1 blink reflexes that were not followed by R2 components were observed in 30% of the patients. However, the patients with these blink reflexes did not have better peripheral healing in their neuromuscular units, which suggests that the blink reflex is not an indicator for peripheral recovery.

Dynamic Quantitative Assessment of Motor Axon Sprouting after Direct Facial-Hypoglossal End-To-Side Neurorrhaphy in Rats.

BACKGROUND: End-to-side (ETS) neurorrhaphy is a promising procedure for peripheral nerve repair, yet controversies regarding the efficacy of this repair in facial nerve anastomosis for facial paralysis still exist. MATERIALS AND METHODS: Thirty rats were divided into three groups: intact control group, direct facial-hypoglossal ETS neurorrhaphy, and end-to-end (ETE) neurorrhaphy. Nerve regeneration was assessed with vibrissae motor performance, electrophysiological tests, retrograde labeling, and histomorphological analysis at 4 and 8 months postoperatively. RESULTS: Both ETS and ETE neurorrhaphies resulted in axonal regeneration and functional recovery of the recipient nerve but did not reach the level of intact controls. Significantly higher numbers of myelinated axons and labeled neurons giving regenerating fibers were found in group ETE compared with group ETS at both time points, consistent with the functional and electrophysiological recovery. Group ETS showed significantly smaller fiber diameter and thinner myelin thickness than group ETE at 4 months, but the difference became nonsignificant at 8 months. ETS neurorrhaphy had a very slight effect on the donor nerve, as determined electrophysiologically and histomorphologically. Sparsely distributed double-labeled neurons and relatively large amounts of single-labeled neurons contributing to reinnervation were found through double retrograde neuronal labeling in group ETS. Further quantitative analysis of the percentage of double-labeled neurons showed a pronounced tendency to decline from 19.8% at 4 months to 6.0% at 8 months postoperatively. CONCLUSION: Successful reinnervation after ETS neurorrhaphy could be achieved through both collateral sprouting and terminal sprouting, with the latter seeming to be the principal origin of motor nerve sprouting.

Global assessment of outcomes after varying reinnervation techniques for patients with facial paralysis subsequent to acoustic neuroma excision.

OBJECTIVE: To determine whether there are objective and/or subjective differences in facial function, tongue function and quality of life in patients who have undergone 1) direct facial-to-facial (Primary, 4 patients), 2) direct facial-to-hypoglossal (End-to-End, 7 patients), 3) end-to-side facial-to-hypoglossal nerve anastomoses with sural nerve/greater auricular nerve interposition (End-to-Side with Interposition Graft, 7 patients), and 4) end-to-side facial-to-hypoglossal nerve anastomoses (End-to-Side, 7 patients) after acoustic neuroma excision. SETTING: Tertiary university referral center. STUDY DESIGN: Case series. METHODS: Twenty-five patients with complete facial paralysis after acoustic neuroma surgery who have also undergone 1 of 4 types of facial musculature reinnervation volunteered for the study. The mean duration of follow-up was 11.5 years (range, 1-25 yr). Each patient was globally assessed using the Sunnybrook Facial Grading scale (objective), Facial Disability Index (subjective), Oral-Pharyngeal Disability Index (subjective), Tongue Movement/Muscle symmetry (objective), and short-form SF-36 quality-of-life index (subjective). RESULTS: Patients who underwent direct facial-to-hypoglossal anastomosis had generally poorer outcomes some of which were statistically significant (p < 0.05) in some components of the Oral-Pharyngeal Disability Index. All of these patients had reduced lateral tongue movement as well as ipsilateral tongue atrophy. There was no significant difference in the Sunnybrook Facial Grading scale scores in those patients in whom end-to-side interposition reinnervation surgery was performed compared with those in whom direct end-to-side anastomosis surgery was performed. CONCLUSION: Complete sacrifice of the ipsilateral hypoglossal nerve does present with clinically and statistically significant morbidity in patients. Facial function is statistically similar in patients who underwent an end-to-side anastomosis with or without an interposition graft. These findings suggest thatin the setting of the posttranslabryinthine approach, the technicallyeasier interposition graft procedure is not acompromise.

Hypoglossal-facial nerve anastomosis: assessment of clinical results and patient benefit for facial nerve palsy following acoustic neuroma excision.

Despite advances in neuro-otological techniques permanent complete facial palsy may still occur in up to 10% of patients undergoing removal of cerebellopontine angle tumours. Hypoglossal-facial nerve anastomosis is the procedure of choice in our unit for facial reanimation in such patients and below we report the results of hypoglossal-facial nerve anastomosis performed on 29 patients. Assessment of patient benefit from hypoglossal-facial nerve anastomosis was obtained using a questionnaire based on the Glasgow Benefit Inventory. The results showed all patients to have an improvement in their House Brackmann grade following hypoglossal-facial anastomosis with 65% achieving grade III or better. Of the 20 patients who completed the questionnaire, 18 showed a positive benefit (median score 59.5, range 40-77). There was a significant correlation (P < 0.045) between the Glasgow benefit inventory score and House Brackmann grade. Outcome was not affected by the time interval between the acoustic neuroma surgery and performing the hypoglossal-facial nerve anastomosis, sex or length of follow-up. However the Glasgow benefit score was significantly influenced by age (P = 0.023) with younger patients showing more benefit independent of improvement in facial nerve function.

[Assessment of reinnervation of the muscles of facial expression following plastic repair of the facial nerve with the descending branch of the hypoglossal nerve (according to electromyographic findings)]. / Otsenka reinnervatsii mimicheskikh myshts posle plastiki litsevogo nerva niskhodiashchei vetv'iu pod''iazychnogo nerva (po dannym élektromiografii)

The data of electromyographic studies of the bioelectrical activity of the facial muscles following plastic repair of the facial nerve with the aid of the descending branch of the hypoglossal nerve permit to interpret the succession and quality of the reinnervation of the muscles. Myoelectrogenesis, as shown by the examinations of 13 patients, develops earlier and with greater completeness in the muscles around the mouth than in the orbicular eye muscle and the frontal muscle, which corresponds to the clinical observations. In the process of reinnervation the activity of the zygomaticus muscle favoured the formation of joint and voluntary movements of the orbicular muscle of the eye and of the frontal muscle.

[A comparative assessment of the results of plastic surgery on the facial nerve following total removal of neurinomas of the acoustic nerve]. / Sravnitel'naia otsenka rezul'tatov plasticheskikh operatsii na litsevom nerve posle total'nogo udaleniia nevrinom slukhovogo nerva

The study was conducted in 3 patients following the application of intracranial facial nerve anastomoses, in 25 patients with the facial nerve anastomosed with the accessory nerve, and in 17 patients with facial-hypoglossal nerve anastomoses. Apart from the clinical observations of the facial muscle contractions, the comparative evaluation of the plastic operations was conducted with the aid of electromyography, electrogustometry and salivary glands secretion studies. The authors concluded that the intracranial anastomosis results in better restoration of the motor function of the facial muscles, the gustation being also partially restored on the side on the intervention. Among the anastomoses of the VII nerve with the XII and XI that with the XII is preferred.