Facial Anastomosis Research Articles

Expression Profile of Stress Proteins, Intermediate Filaments, and Adhesion Molecules in Experimentally Denervated and Reinnervated Rat Facial Muscle

The immunohistochemical profiles of ubiquitin, heat shock protein 70, α-B-crystallin, desmin, vimentin, neural cell adhesion molecule (N-CAM), and tenascin in rat facial muscle were studied after permanent denervation by transection of the facial plexus on one side and compared with findings after immediate reinnervation by hypoglossal–facial nerve anastomosis subsequent to transection on the contralateral side. Levator labii muscle samples were collected sequentially at 2, 6, 7, 10, 20, and 24 weeks after surgery. Normal levator labii muscle fibers showed physiological expression of desmin and α-B-crystallin. Denervated rat facial muscle displayed distinct up-regulation of ubiquitin, α-B-crystallin, N-CAM, and tenascin. While α-B-crystallin and N-CAM decreased in long-standing denervation, tenascin had completely disappeared at 6 weeks. Likewise, reinnervated muscles displayed enhanced expression of ubiquitin, α-B-crystallin, N-CAM, tenascin, and, additionally, desmin. Strong expression of desmin and ubiquitin was found up to the 10th week as well as of α-B-crystallin, N-CAM, and tenascin up to the 7th week of reinnervation. Afterward, expression of stress proteins, intermediate filaments, and adhesion molecules returned to expression profiles of normal controls, indicating that enhancement of these proteins was restricted to the “atrophic and regenerative” states with a decline to physiological levels after successful reinnervation and restoration of muscle fibers. Furthermore, part of regeneration from damage seems to resemble reactivated developmental mechanisms by reappearance of developmentally expressed proteins like desmin, N-CAM, and tenascin.

The widened retrolabyrinthe approach: a new concept in acoustic neuroma surgery.

For many years, the retrolabyrinthine approach has been limited to functional surgery of the cerebellopontine angle (CPA). As a result of the increased surgical exposure, particularly the opening of the internal auditory meatus (IAM), the widened retrolabyrinthine technique permits tumor excision from both the CPA and the IAM, regardless of the histological nature of the tumor. The authors have treated 60 acoustic neuromas of varying sizes via this approach (6% intrameatal tumors; 30% > 25 mm in diameter). The postoperative mortality rate was 0%. The risk of fistula formation was 3.3%, and 3.3% of the patients suffered from postoperative meningitis. The results for facial nerve function were equivalent to those obtained previously via a widened translabyrinthine approach and those in a series treated via a suboccipital approach (80% with Grades I and II, 15% with Grade III, and 5% with Grades V and VI). One patient (1.7%) required a secondary hypoglossal-facial nerve anastomosis and had attained a Grade IV result 6 months later. Postoperatively 21.7% of these patients maintained socially useful hearing and 20% had mediocre hearing. Socially useful hearing was preserved in 50% of a subgroup of 20 patients who had both good preoperative hearing and a tumor that involved less than half of the IAM regardless of its volume. Additionally, 15% had mediocre hearing that could be improved with hearing aids. Because of its efficacy in preserving hearing, the authors favor the retrolabyrinthine over the occipital approach, with the latter being considered less subtle and more aggressive.

Hypoglossal-facial nerve side-to-end anastomosis for preservation of hypoglossal function: results of delayed treatment with a new technique.

This report describes a new surgical technique to improve the results of conventional hypoglossal-facial nerve anastomosis that does not necessitate the use of nerve grafts or hemihypoglossal nerve splitting. Using this technique, the mastoid process is partially resected to open the stylomastoid foramen and the descending portion of the facial nerve in the mastoid cavity is exposed by drilling to the level of the external genu and then sectioning its most proximal portion. The hypoglossal nerve beneath the internal jugular vein is exposed at the level of the axis and dissected as proximally as possible. One-half of the hypoglossal nerve is transected: use of less than one-half of the hypoglossal nerve is adequate for approximation to the distal stump of the atrophic facial nerve. The nerve endings, the proximally cut end of the hypoglossal nerve, and the distal stump of the facial nerve are approximated and anastomosed without tension. This technique was used in four patients with long-standing facial paralysis (greater than 24 months), and it provided satisfactory facial reanimation, with no evidence of hemitongue atrophy or dysfunction. Because it completely preserves glossal function, the hemihypoglossal-facial nerve anastomosis described here constitutes a successful approach in patients with long-standing facial paralysis who do not wish to have tongue function compromised.

Experimental study of hypoglossal facial anastomosis and accessory-facial anastomosis in guinea pigs

Hypoglossal facial nerve anastomosis (XII-VII anastomosis) or accessory-facial anastomosis (XI-VII anastomosis) have been chosen for facial rehabilitation when the facial nerve is widely sacrificed and end-to-end anastomosis or nerve grafting is unavailable. However, no detailed study has been conducted to determine which donor nerve is better for the anastomosis procedure in view of regeneration of the facial nerve. To compare and evaluate nerve regeneration after XII-VII anastomosis and XI-VII anastomosis, animal models of these anastomoses were made in guinea pigs by using a Y-shaped silicon tube. The proximal cut-ends of the hypoglossal nerve and accessory nerve were suspended in the paired inlet limbs of a Y-shaped silicone tube with a 9-0 nylon suture, and the distal cut-end of the facial nerve was suspended in the single outlet limb in a similar manner. After 4 and 8 weeks, histological studies were carried out. An electrophysiological study of conduction velocity and amplitude of evoked electromyography were measured at 8 weeks postoperation. The nerve fibers regenerated from the hypoglossal nerve were significantly more numerous than those from the accessory nerve at both 4 and 8 weeks after anastomosis. The amplitude of evoked electromyography elicited from the hypoglossal nerve was greater than that from the accessory nerve, even though there is no significant difference in conduction velocities between the two anastomoses. The nerve regeneration by the cross-over procedure was influenced by many factors such as the number of nerve fibers in the donor nerve and the affinity between donor and recipient nerves. The number of nerve fibers in the hypoglossal nerve was significantly greater than that in the accessory nerve. However, there was no significant difference in the ratios of regenerated nerve fibers to the preoperative nerve fibers. Accordingly, we concluded that the affinity of the hypoglossal or accessory nerve to the facial nerve is a minor factor if it exists, and the difference in the fiber count in these nerves is a major factor in the outcome of nerve regeneration.

Anastomotic Methods of Facial Nerve Repair‐How to Do It

Educational objectives: To know about nerve degeneration and regeneration and how to choose the best technique for facial nerve anastomosis.

Hemihypoglossal—facial nerve anastomosis in treating unilateral facial palsy after acoustic neurinoma resection

Eight patients underwent hemihypoglossal-facial nerve anastomosis (anastomosis of a split hypoglossal nerve to the facial nerve) for treatment of unilateral facial palsy. All patients previously had undergone resection of a large acoustic neurinoma and the facial nerve had been resected at that time. The interval between tumor resection and hemihypoglossal-facial nerve anastomosis ranged from 1 to 6 months, with an average of 2.1 months. Postoperative recovery of facial movement was good in all cases during an average follow-up period of 4.2 years. In all eight patients, the degree of hypoglossal nerve atrophy on the operated side was graded mild or moderate, but not severe. It was concluded that hemihypoglossal-facial nerve anastomosis results in good facial reanimation as long as the procedure is performed early after the onset of facial palsy and that this procedure may reduce the degree of hemiglossal atrophy in comparison with classic hypoglossal-facial nerve anastomosis.

Intracranial Facial Nerve Anastomosis

Intracranial Facial Nerve Anastomosis

Regeneration of facial nerve after hypoglossal facial anastomosis: An animal study

Hypoglossal-facial nerve anastomosis was carried out in 20 adult guinea pigs. Electromyographic responses of orbicularis oculi muscle evoked by blink reflex were recorded 2, 4, and 6 months after surgery. Then the anastomotic site was reopened, and a segment of buccal branch and the anastomotic trunk were resected for detailed histologic study. Regenerated axons were counted and the cross-sectional area of axons and fasciculi was measured. Data obtained from both blink reflex measurement and histologic study demonstrate a good quality of regeneration of the facial nerve from the hypoglossal nerve completed 6 months after the operation. In addition a new nerve bundle was regenerated from the proximal stump of the facial nerve connecting to the anastomotic site in 80% of the animals. Postoperative change in innervation pattern of the facial nerve was also illustrated.

Facial Nerve Neuroma

Facial nerve neuromas are uncommon, slow-growing neoplasms that may occur anywhere along the course of the facial nerve from the brainstem to the facial muscles. The signs and symptoms are characteristic and vary with the anatomic site of origin. Surgery should not be attempted until a complete and thorough diagnostic examination has been completed. The surgeon should be prepared to perform a middle-cranial fossa or translabyrinthine approach in all cases, and must expect to do a nerve graft. The results of 37 patients treated by the author reveal that, under optimal conditions, patients who have had a facial nerve graft, can be expected to regain an average of 80 % facial nerve strength in almost every case. All patients who have had a facial nerve graft will have some degree of synkinesis. No graft was required in 3 patients, and a hypoglossal facial anastomosis was used for one. Facial function was completely normal in 2 patients, 16 had 80 – 90 % return, 5 patients had 50 – 80 % return, 4 had 20 – 50% return, one had no recovery at all and 9 recent patients have not reached the time for their expected recovery. Early diagnosis, prompt surgical removal and VII - VII Nerve graft for facial paralysis of ten or fewer years duration offers patients the best opportunity to avoid a permanent facial palsy.

Partial Hypoglossal to Facial Nerve Anastomosis for Reinnervation of the Paralyzed Face in Patients with Lower Cranial Nerve Palsies

Partial Hypoglossal to Facial Nerve Anastomosis for Reinnervation of the Paralyzed Face in Patients with Lower Cranial Nerve Palsies

CO2 laser repair of the facial nerve: an experimental study in the rat

The facial nerve is often injured by trauma, infection or during the course of tumour resection. Many techniques of nerve anastomosis have been described with the current standard nerve repair using the microscope and monofilament suture. The purpose of this study was to evaluate the CO2 surgical laser as a tool for facial nerve anastomosis. Following preliminary electrical measurements 36 nerves were anastomosed using either laser or conventional monofilament suture. Laser anastomosis had neither beneficial nor detrimental effects on nerve regeneration. This method of anastomosis may be advantageous when surgical access is limited. In addition this study found that the use of CO2 laser as a dissecting or vapourizing tool in proximity to intact facial nerves results in degenerative changes.

Anastomosis of intratemporal facial nerve with fibrin tissue adhesive.

Traumatic facial paralysis can be iatrogenic or catastrophic. The iatrogenic lesion can be deliberate or inadvertent. The catastrophic can be form temporal bone fracture, firearm shooting, or cutting lesions of the face.

Recovery of original nerve supply after hypoglossal-facial anastomosis causes permanent motor hyperinnervation of the whisker-pad muscles in the rat.

Hypoglossal-facial anastomosis (HFA), used in humans for the treatment of facial palsy, was experimentally performed in adult female Wistar rats. The time course of facial reinnervation and the extent of the new motor nerve supply of the vibrissal muscles that develops after HFA were estimated by counting all motoneurons in the brainstem labeled by injection of horseradish peroxidase (HRP) into the whisker pad; muscle innervation by motor endplates was not studied. In untreated animals, HRP injection labels 1,254 +/- 54 (mean +/- S.D.; n = 6) motoneurons, localized exclusively in the lateral subdivision of the facial nucleus. Immediately following HFA, this number drops to zero. The first HRP-labeled motoneurons appear in the hypoglossal nucleus at 28 days postoperation (dpo) and at 56 dpo their number reaches 1,096 +/- 48. Unexpectedly, the facial nerve, whose proximal stump has been left as blind end during surgery, additionally sends axons to the facial periphery. This resprouting is first detected at 42 dpo with HRP-marked neurons throughout the facial nucleus lacking somatotopic organization. The number of these labeled neurons also rises with time, and at 56 dpo, a total of 1,797 +/- 142 facial and hypoglossal motoneurons, that is, 43% more motoneurons than in normal animals, supplies the whisker pad. This hyperinnervation, that is, the projection of more motoneurons into the target muscle than under normal conditions--further increases to 1,978 +/- 92 motoneurons at 224 dpo and may provide a new animal model for studying the competitive relationships between motoneurons in their search for peripheral targets.

Anastomosis of the Intratemporal Facial Nerve Using Fibrin Tissue Adhesive

This work aimed at studying the results obtained by the repair of complete lesions of the facial nerve in its intratemporal portions. Clinical, electrophysiological and surgical techniques were studied. Twenty-three patients with traumatic facial nerve lesions were operated. Nerve grafts were made in 10, and end-to-end anastomosis in thirteen. The surgical technique performed was the coaptation of the stumps and stabilization with fibrin tissue adhesive. Sixteen months after surgery, a clinical and electrophysiological evaluation was made. The use of fibrin tissue adhesive to stabilize intratemporal anastomosis of facial nerve showed clinical and electrophysiological evidence of axonal growth and reinnervation of mimical muscles of the face. These results were similar to that obtained by other authors that used other methods of microanastomosis. The use of fibrin tissue adhesive is an effective technique to utilize in intratemporal anastomosis of the facial nerve.

Facial Nerve Neuroma

Facial nerve neuromas are uncommon, slow-growing neoplasms that may occur anywhere along the course of the facial nerve from the brainstem to the facial muscles. The signs and symptoms are characteristic and vary with the anatomic site of origin. Surgery should not be attempted until a complete and thorough diagnostic examination has been completed. The surgeon should be prepared to perform a middle-cranial fossa or translabyrinthine approach in all cases, and must expect to do a nerve graft. The results of 37 patients treated by the author reveal that, under optimal conditions, patients who have had a facial nerve graft, can be expected to regain an average of 80% facial nerve strength in almost every case. All patients who have had a facial nerve graft will have some degree of synkinesis. No graft was required in 3 patients, and a hypoglossal facial anastomosis was used for one. Facial function was completely normal in 2 patients, 16 had 80-90% return, 5 patients had 50-80% return, 4 had 20-50% return, one had no recovery at all and 9 recent patients have not reached the time for their expected recovery. Early diagnosis, prompt surgical removal and VII-VII Nerve graft for facial paralysis of ten or fewer years duration offers patients the best opportunity to avoid a permanent facial palsy.

Temporalis muscle for facial reanimation. A 13-year experience with 224 procedures.

A procedure for temporalis muscle transposition was used to reanimate the paralyzed face in 219 patients. In most cases, facial paralysis had followed an operation to remove an acoustic tumor. Analysis of the results showed this procedure to be highly successful and the method of choice, alone in cases of long-standing facial paralysis or to augment the effects of facial nerve grafting or hypoglossal-facial nerve anastomosis, in reanimating the mouth. It was successful in restoring a smile to 80% of the 219 patients and provided overall improvement in mouth function in 96%. Complications occurred in 21% of patients, with the most common being infection (12% of patients). Since one of us began to use the procedure to reanimate the eye and mouth, results of temporalis muscle transposition have been improved by the following: (1) using the procedure to reanimate the mouth only; (2) performing revision surgery, most often tightening the corner of the mouth (25% of patients), as indicated; (3) transposing only the midsection of the muscle; (4) implanting a prefabricated Silastic prosthesis to fill the muscle defect; (5) when indicated, lengthening the muscle with polytef (Gore-Tex+); and (6) placing the muscle in a tunnel lateral to the superficial musculoaponeurotic system to avoid injuring the underlying facial nerve should some spontaneous recovery of facial nerve function be possible.

Long-term results of spinal accessory nerve-facial nerve anastomosis.

A number of methods have been developed to reduce the cosmetic and functional disability resulting from facial nerve loss. It has often been suggested that the major trunk of the spinal accessory nerve should not be sacrificed for providing dynamic facial function because of shoulder disability and pain. A review of Mayo Clinic records has revealed that, between the years of 1975 and 1983, 25 patients underwent spinal accessory nerve-facial nerve anastomosis using the major division (branch to the trapezius muscle) of the spinal accessory nerve. There were 11 males and 14 females, ranging in age from 16 to 60 years (mean 41 years). The interval between facial nerve loss and anastomosis was 1 week to 34 months (mean 4.62 months). The duration of follow-up study ranged from 7 to 15 years (mean 10.8 years). Twenty patients had no complaints or symptoms related to their shoulder or arm at the time of this review and no patient had significant shoulder morbidity. The facial function achieved was "minimal" in five cases, "moderate" in six, and good to excellent in 14. Most patients appeared to benefit significantly from the spinal accessory nerve-facial nerve anastomosis. The morbidity of the procedure seemed quite minimal even in the young and active. The authors continue to believe that the spinal accessory nerve-facial nerve anastomosis, even when using the major trunk of the spinal accessory nerve, is a very useful and beneficial procedure.

Current results of the retrosigmoid approach to acoustic neurinoma

Since 1984 when cranial nerve monitoring became routinely performed at the Mayo Clinic, 255 patients have undergone 256 procedures using the retrosigmoid approach for the removal of acoustic neurinomas. Of these, 221 patients had some hearing before surgery and 52 maintained hearing following surgery. The anatomical continuity of the facial nerve was preserved in 237 of these 256 procedures. It was possible to perform a primary end-to-end anastomosis in seven of the remaining 19 patients, and one patient had a cable graft inserted. Thus, 95.7% of these patients were believed to have potential for spontaneous facial nerve function. Of the 11 patients in whom this was not possible, seven underwent early spinal accessory facial anastomosis, in two hypoglossal-facial anastomosis was performed, and two had no facial nerve procedures and have paralysis of the facial nerve. There were two deaths from a pulmonary embolus in the early postoperative period, both 4 days following otherwise uneventful surgery. The most common postoperative complication was cerebrospinal fluid leakage, which has not resulted in significant permanent morbidity although early repair for this problem is now routinely recommended. Other complications were quite rare and have generally not resulted in any major change in patient lifestyle or activity level. This review reconfirms that the retrosigmoid surgical treatment of acoustic tumors continues to be an acceptable treatment option.

フィブリン糊を用いた顔面神経吻合の基礎的研究

We evaluated the utility of fibrin glue adhesive in experimental facial nerve anastomosis. The zygomaticopalpebral branch of the facial nerve in guinea pigs was transected and repaired with either fibrin glue or nylon suture. The course of recovery was evaluated electrophysiologically by measuring evoked electromyography and palpebral muscle contraction rate. No significant difference between the two groups was observed. Histopathologically, foreign body reaction to the fibrin glue was mild, and the glue had been almost completely absorbed by 4 weeks after the anastomosis. We conclude that the use of fibrin glue adhesive for facial nerve anastomosis is useful, simple, and less traumatic to the nerve than is nylon suture.

Intratemporal facial nerve anastomosis: A temporal bone study

The temporal bone findings in a patient who suffered a transverse temporal bone fracture and subsequently underwent intratemporal facial nerve anastomosis are presented. The patient returned a year after surgery with otorrhea and partial return of facial function that was documented clinically, and by electromyograph 12 days before death. The temporal bone shows breakdown of the posterior external canal wall and infection of the surgical cavity. At the facial nerve anastomosis, there is a fibrosis and lack of myelination in the few regenerating nerve fibers. These results demonstrate a seldom-mentioned complication of the translabyrinthine approach, and suggest changes in the technique of facial nerve anastomosis to improve the results.