Cross-face neurotized platysmal muscular graft for upper eyelid reanimation: an anatomic feasibility study

Dynamic Eye Closure Restoration in Facial Palsy with Neurotized Platysma Muscle Graft in Rats

BACKGROUND

 One of the most devastating deficits of facial paralysis is eyelid dysfunction, which is controlled by the orbicularis oculi muscle (OOM), as it leads to loss of the protective mechanism of the eye. This study used a rat model to assess the functional outcomes of neurotized platysma muscle grafts (PMGs) for OOM replacement.

METHODS

 Forty male Sprague-Dawley rats with iatrogenic right eyelid dysfunction were divided into five groups: one control group and four groups utilizing PMG with different sources of nerve innervation. Eyelid function recovery was assessed at 2, 4, 6, and 8 weeks. The PMGs were harvested for pathological examination at the end of the study.

RESULTS

 All rats except those in the control group and one from the group using ipsilateral frontal and upper zygomatic frontal nerve branches directly neurotized to the PMG (nerve-to-muscle) recovered eyelid closure function within 8 weeks of the study period. The mean recovery time was 3.87 ± 1.28 weeks. A total of 87.5% of rats that had the contralateral zygomatic branch as the donor nerve regained the consensual corneal reflex (p-value < 0.001).

CONCLUSION

 Replacement of neurotized PMG for OOM function is successful in a rat model. Using the upper zygomatic branch as the donor nerve, it was possible to restore the consensual corneal reflex. This method shows promise for further human studies.

Dynamic eyelid reconstruction in facial nerve palsy

The consequences of facial nerve palsy and the secondary inability of eyelid closure and blink may lead to devastating complications for the patient, including blindness. Reconstruction techniques to improve eyelid position and function can be broadly classified into 'static' and 'dynamic' techniques. Generally, ophthalmologists have been familiar with static procedures such as upper eyelid loading, tarsorrhaphy, canthoplasty, and lower eyelid suspension. Recently, dynamic techniques are being increasingly described for patients who require definitive strategies to improve eyelid function, once the initial critical goals of corneal protection and vision preservation have been achieved. The choice of technique(s) is dependent upon the status of the main protractor of the eyelid region, as well as the age of the patient, the patient's morbidities and expectations, and surgeon preference. This review shall first describe the clinical and surgical anatomy relevant to the ophthalmic consequences of facial paralysis and discuss methods of defining function and outcomes. A comprehensive review of dynamic eyelid reconstruction is then presented with a discussion of the literature. These various techniques may not be familiar to all clinicians. It is important that ophthalmic surgeons are aware of all options available for their patients. Furthermore, eye care providers must have an understanding of when referral may be appropriate to provide timely intervention and optimal chances of recovery.

Eyelid Reanimation with Free Platysma Graft: Final Stage of Reconstruction after Gunshot Wound to Face

Patients with gunshot wounds to the face have massive soft tissue and bony damage from projectile and blast injuries. They often require multiple, staged reconstructive surgeries with cross-facial nerve grafting and free muscle flap for re-establishment of facial expression. Injury to or total loss of the facial nerve and branches can result in loss of function of the orbicularis oculi muscle, which leads to the loss of protective mechanisms of eyelid function and blink reflex. The purpose of this article is to provide a literature review and discussion of eyelid reanimation after facial paralysis and to discuss our surgical technique with free platysma muscle grafts of the eyelid. The patient is a 45-year-old man with a history of a gunshot wound to the right face. He underwent multiple reconstructive surgeries in the past, and in preparation for eyelid reanimation, he underwent a cross-facial nerve graft from the left temporal branch to the right eyelid. At initial postoperative evaluation, the patient was able to close his right eye with minimal lagophthalmos, and at 3-month follow-up, he exhibited stronger blinking reflex. This case demonstrates that a free platysma graft with direct neurotization with cross-facial nerve graft fascicles can be utilized for restoration of spontaneous eyelid animation. However, there may be failure of neurotization and inability of the spontaneous blink reflex to be present. Despite these limitations, we still recommend the utilization of free platysma graft to provide upper eyelid reanimation through cross-facial nerve graft.

Anatomy of the Platysma Muscle

The aim of this paper was to review the anatomy the platysma systematically.The term "platysma AND anatomy" was used to search PubMed and Scopus, producing 394 and 214 papers, respectively. After excluding 95 duplicate titles, 513 abstracts and 98 full papers were reviewed. Among these 98 papers, 83 were excluded and 5 were added. Ultimately, 20 papers were analyzed.The most common aging-related change of the platysma was shortening (70.7%), followed by thinning (25.2%). The platysma most commonly originated from the upper portion of thorax anterior to clavicle (67.7%), followed by the subcutaneous tissue of the subclavicular and acromial regions (22.6%) and pectoralis (9.7%). The platysma ascended upward and medially (68.5%) or ascended from the clavicle to the face (31.5%). The platysma most commonly inserted on the cheek skin (57.5%), followed by the cutaneous muscles around the mouth (18.6%), the mandibulocutaneous ligament or zygoma (18.6%), and the parotid fascia or periosteum of the mandible (5.3%). The platysma was most commonly innervated by the cervical branch of the facial nerve (38.2%) or the cervical branch and mandibular branch of the facial nerve (60.5%), followed by the cervical plexus (0.6%), the cervical motor nucleus (0.6%), and the glossopharyngeal nerve (0.1%). The most common action of the platysma was drawing the lips inferiorly (83.3%) or posteriorly (12.9%). Four papers classified the platysma into subtypes; however, these classification strategies used arbitrary standards.Further studies will be necessary to establish the thickness of the platysma and to characterize age-related changes of the platysma.