Advanced Surgical treatment of facial paralysis progress

Facial paralysis is the result of a combination of facial nerve damage, a loss of facial expression and organization functions as the main obstacles to performance nutrition comprehensive syndrome   [1] . Over the course of more than 2002 facial paralysis for advanced facial paralysis   [2] , their treatment has always been a major problem so far has not very satisfactory way   [1 ~ 4] .  1 Advanced Surgical treatment of facial paralysis Review 
Advanced treatment of facial paralysis and can be divided into non-dynamic dynamic treatment of major categories. 
1.1 non-dynamic therapy 
Treatment of advanced facial paralysis is the traditional method, is more commonly used clinical, on the improvement of the static effect of certain malformations, including fascia suspension, leather suspension, suspension and other organizations substitutes method   [1,5] . One fascia lata suspended non-dynamic therapy the most representative of the way. This method was not suitable for the application of power from the various reasons for the treatment of advanced facial paralysis. 
1.2 Dynamic treatment 
There are mainly muscle flap transfer of nerve transfer anastomosis, the inter-facial nerve transplantation, muscle graft and undertaken in recent years neuromuscular free vascularized grafting, through facial expressions surgery was under the dynamic symmetry. 
1.2.1 muscle flap transfer of:  1908 Eden first Lexer and masseter and temporalis muscle flap separation were transferred to, the lower lip and upper and lower eyelid deformity to correct facial paralysis. Gillies was temporalis muscle and fascia application for the transfer of facial paralysis, the effect affirmed the 1960s to the 1970s is widely used   [5] , are still used. Anonson, etc.   [6]  launched in 1986 hypoglossal nerve loop neuromuscular pedicle shift to the clinical application of facial muscles. Xianghong, etc.   [7 ]  on the use of nerve and trapezius with vascular pedicle flap for the transposition to repair facial paralysis. The transfer of the muscle flap method is relatively simple, not to do any of the cases can be complicated surgery of this type   [2] . 
1.2.2 nerve transfer anastomosis:  Facial nerve injury to the central terminal near impossible anastomosis, a nerve distal end anastomosis conditions, but no obvious facial expressions muscle atrophy,   [1] . Drobnik 1896 application was first vice  anastomosis treatment of facial nerve paralysis   [1,2,5] , sublingual  facial nerve anastomosis by Korte 1903 first reported   [1,5] . There are other using phrenic nerve, the glossopharyngeal nerve, nerve movement of the mandibular nerve transfer of   [8] . After the transfer of nerve, facial muscle movement with the transfer of the original disclaimer accompanying muscle movement, but is only a kind of coarse, mixed, the bulk nature of sports   [8] , it now has fewer applications. 
1.2.3 inter-facial nerve transplantation:  By Scaramella 1970 was first reported that apply to facial expression of muscle atrophy or no serious expressions muscle atrophy choice secondary vascular anastomosis neural transplantation of the muscle-stage surgery   [1] . Alain such   [9]  advocate for the second phase of the operation, in order to prevent scar impede nerve regeneration. This method has the advantage of being accepted from side-expression side muscle nerve fiber regeneration, and even the dynamic muscle contralateral facial expression, facial expressions more natural, holistic. 
1.2.4 muscle graft:  Thompson   [10]  1971 First Free Application extensor digitorum brevis transplantation to treat facial paralysis, and surgery at two, more satisfied with the results. Thompson considered for the first stage of muscle Denervation is a prerequisite for successful operation. This method not vascular anastomosis, simple operation, applicable to advanced facial paralysis, facial muscles has been shrinking. Its inadequacies of the district must rely on the muscle for muscle can be nerve again dominated, it has limited application. 
2 microsurgical technique in the treatment of advanced facial paralysis Application 
2.1 points in the second phase with vascular surgery neuromuscular graft 
The first-stage surgery for facial nerve transplant, Part II period for the free vascular anastomosis nerve muscle graft. The method in 1976, such as by Harii   [11]  report first, then gradually be popularized, in the past more than ten years been a relatively rapid development. 1989 Terzis, and other   [12]  use small chest muscle repair facial paralysis. He believes that small chest muscle is the ideal form, adequate size and dual innervation (chest lateral thoracic nerve and the medial nerve), the permissible level, the lower part of the independence movement, is the most ideal for muscle, the most suitable for children with facial paralysis. CAO Yi-lin, and other   [13]  used similar methods on 10 patients with advanced treatment of facial paralysis, three months after the myoelectric activity measured, six of muscle movement visible to the naked eye, to the best effect in one year. O'Brien, and other   [14]  Harii also with the use of vascularized nerve gracilis muscle graft to facial paralysis treatment. He believes that gracilis muscle easy to cut, fewer sequels can be divided into several segments play different functions, the better for muscle, but after more bloated. Ueda and other   [15]  with neurovascular using the gracilis muscle or latissimus dorsi free transplantation in the treatment of 4 to 15-year-old children facial paralysis, the result of the initial transplant muscle contraction earlier time than adults, adult functional recovery than good. But children with growth process, not found any deformation and facial area for any dysfunction District, recommends muscle transplantation in the treatment of children and young patients. 
2.2 with neuromuscular a vascular graft 
The second phase of vascular surgery with neuromuscular graft satisfied with the results, but to stage operation, increased patient suffering. Wang Wei, and other   [16,17]  1989 raised for the first time long vascular pedicle flap nerve transplant a facial nerve paralysis treatment of the concept, so that an operation possible. As for surgery to latissimus dorsi muscle, choose their thin distal segments, this will ensure that there are 14 to 17 cm long nerve vascular pedicle, as long segment latissimus dorsi muscle pedicle flap transplantation. To make thinning muscle flap, flap resectable segments of the dirt layer, known as segmental fault muscle flap   [1, 2] . The technique is based on the anatomy   [18] : latissimus dorsi the blood supply comes mainly from thoracodorsal artery, the artery around the scapular angle under the plane into the top and lateral branch, the separation of muscle after segmental artery and the nerve thoracodorsal nerve and artery accompanied paragraph. As long pedicle graft, to 14 ~ 17 cm, from the subscapular arterial vascular pedicle the initial cut, but often need to be of the distal arterial anatomy within the muscle separation. The characteristics of the operation   [1] : (1) to replace a second surgery completed, shortened the treatment cycle. (2) Variable block muscle transplant for segmental muscle flap transplantation, may need to be cut. (3) the non-vascular cross-face nerve graft replaced with the vascular graft is conducive to the growth and transplantation of nerve repair. (4) full-thickness change fault muscle transplant for transplant muscle flap, flap become thinner. After the way the gradual application and the improvement   [3,19,20] . Jianghua   [21] , such as Sun top 100   [22]  use thumb Show muscle transplant for a free repair facial paralysis, has been successful. 
More than 2.3 neurovascular pedicle flap transplantation 
Free vascularized muscle nerve transplant muscle flap over a single nerve Beattie, only to face the next 2 / 3 expression repair, far from being able to restore the more muscular expression of sexual function. In recent years, more domestic and foreign scholars root nerve and muscle transplants carried out a full-scale restoration of the research   [4,23 ~ 27] . The rectus abdominis muscles are used, as well as intra-abdominal superior oblique latissimus dorsi muscle and joint sawing before transplantation. These use the same technique is different muscle innervation, will be divided into two muscle flap or a total of two neighboring vascularized muscle and innervation different, as different parts to restore facial expression. The advantage is more nerve vascular pedicle, viable full restoration, but more complex surgery, trauma larger. 
Application vascularized nerve muscle graft treatment of advanced facial paralysis, and after, there will be autonomous, more symmetrical and natural expression campaign by the majority scholars think is so far the treatment of advanced facial paralysis most effective approach, with no other operation by the superiority of late is the development of facial paralysis treatment direction. However, the scope and method of operation is very high, we must have skilled microsurgical technique and corresponding equipment, the hospital harder at the grassroots level to promote. The frail elderly who can not afford the operation is not appropriate. 
3 Problems and Prospects 
3.1 expressions resume incomplete: Because of expression muscle innervation of skeletal muscle than rich, the site looked different muscle fiber direction, its movement is rich and varied expressions, so to rely solely on one or two muscle is no substitute for all the expressions muscle   [25] . But when the nerve regeneration and to the possibility of a labyrinth dislocation that facial symmetry coordinated action to be affected. This will be the future of a facial paralysis research direction   [19] . 
There is no ideal for 3.2 muscle: Although currently used for a variety of muscle   [1,16] , but there is a lack of a greater or lesser extent, has not fully met the requirements of an ideal muscle   [1,22] , this is still many scholars and experts in the course of our efforts. 
3.3 transplant muscle atrophy: ischemic surgery is the main reason, the nerve trauma and vascular anastomosis not disposable and support for the transplant, such as muscle, so some people advocate using larger muscle   [11] , but that could easily lead after bloated. He believed that after the accumulation and research will certainly be able to find a suitable proportion of transplant volume. 
3.4 operation choice: one or two vascularized nerve muscle graft, two kinds of operation Which is more reasonable and the results better, how to choose clinical, still controversial. Terzis   [12]  that a nerve surgery vascular pedicle long, nerve growth slow in the muscle flap endplate shrinking, and so long to endplate nerve, muscle flap has been shrinking. But clinical results is not the case, a treatment efficacy also more satisfied with   [3,16 ~ 19,22,25,26,28] . The reason for this may include the following: (1) As long associated with the vascular pedicle nerve dependent, easy to transplant survival, and has accelerated the process of healing   [16,28] . (2) a method nerve axon regeneration only through a nerve suture, reduce scar effect on the quantity and quality of power source the adverse effects   [28] . (3) the segmental fault muscle flap transplantation is a nerve with the target organ transplantation, such transplantation can produce a class of nerve induced directional growth, and nutrition and promote nerve growth of active substances   [2] . So far, this has yet to see a comparison of two kinds of basic research reports. Animal model for the future can conduct a comprehensive, based on comparative studies, the choice of method for clinical provide a theoretical basis. 
Apart from the above mentioned, along with the development of tissue engineering and continuous improvement, I believe nerves and muscles can be cultured in vitro, can waive time for the surgery. The development of gene technology is one of the fastest growing technology, if adopted transgenic approach to the treatment of facial paralysis, will undoubtedly achieve perfect results.