Applied Anatomy Of Soft Tissue Structure Of Upper Eyelid

I Objectives:1. To conduct systematic and comprehensive anatomical studies of upper eyelid tissues and fill in the research gaps in this respect in China.2. To study the relations between the distribution characteristics of periorbital adipose tissues and the formation of sunken upper eyelid as well as corpulent and hypertrophic upper eyelid; to probe into the role that periorbital adipose tissues play in plastic surgery for the eye regions and explore proper methods for the treatment of periorbital adipose tissues during blepharoplasty.3. To study basic anatomy for muscle-fascia-fat flap at the supraorbital margin, and to explore the clinical application value of orbicularisoculi muscle and periorbital adipose tissues during clinical anatomical surgery, in an effort to find a simple and practicable surgical method for sunken upper eyelid.4. To probe into basic anatomy and clinical application value of upper eyelid vasculature, have a clear idea of the run and distribution range of ophthalmic artery branches; to make sure of the distribution characteristics and source of arterial arcades of upper eyelid, so as to serve as guidance to clinical treatment of injuries to upper eyelid; to explore the potential regions for periorbital artery anastomosis to avert complications caused by clinical injection of fillers.II Materials and methods1、Sixteen heads(32 facial halves) from fresh adult corpses were processed using the P45 plastination method. The sagittal median section of the eyeballs was dissected after using the polymer that resulted in transparent plastination.2、A total of 12 cases(24 sides) of head-neck samples were selected foranatomy of upper eyelid regions. The selected samples were aged between 40 and 70, with 10 male head-neck samples and 2 female ones. From the outside to inside, the uppereyelid was dissected layer by layer, and observation was made of the soft tissue distribution at the upper eyelid regions and the position, boundary and adjacent structure of various adipose tissues; and meanwhile, comparison was made of the results of cross-section sheet plastinations to make sure whether or not there is any correlation. Straightedge was used for measurement and photos were taken throughout the whole process. Altogether 56 cases of female patients aged 33 to 65, with an average age of 54, who had undergone eyebrow life surgery atthe Department of Plastic Surgery of the First Affiliated Hospital of Dalian Medical University between 2010 and 2015, were targeted for clinical anatomical observation. Of the 56 cases, patients with senile sunken upper eyelid were in the majority, with concurrent flabby upper eyelid skin as major symptoms. During the surgery, visual inspection and measurement were conducted, and meanwhile, observation was made of the distribution range of adipose tissues and the run of the muscles where frontalis muscle aponeurosis and orbicularis oculi muscleinterlace. Besides, the thickness and length of frontalis muscle aponeurosis and orbicularis oculi muscle as well as of the soft tissues at this region were measured, in an attempt to explore the feasibility for clinical treatment of senile sunken upper eyelid.3、Ten fresh adult head-neck samples were selected for arterial blood vessel perfusion with gelatin-lead oxide, 3-D reconstruction, and subsequent gross anatomy. And another 2 fresh adult head-neck samples were selected for producing cast form of blood vessel, so as to serve as basic anatomical guidance to periorbital plastic surgery, offer visualized and comprehensive morphological data, and to establish three-dimensional anatomical model of upper eyelid vasculature.III Results1、P45 cross-section sheet plastination samples:From 32 cases of P45 sheet plastinations of upper eyelid, we observed the hierarchical structure of upper eyelid, successively arranged from the outside to the inside,respectively,skin,orbicularis oculi muscle,preaponeurotic fat, orbital septum,preseptal fat,conjunctiva.As to the structure of levator muscle, Mueller’s muscle and levator aponeurosis, there were two kinds of variation, shown as follows: Type I: the sublayer of levator muscle was particularly thin, and played a part in the formation of 75% Mueller’s muscles. Type II: There was no sublayer at the end of levator muscle, and it just extended forward to form Mueller’s muscle. Levator aponeurosis, making up 25%, originated from the upper surface of the levator muscle, and was quite thin. Based on the amount of fat distribution, upper eyelid was divided into three groups: preseptal fat predominant type, preaponeurotic fat predominant type, and orbital septum equilibrium type with the distribution proportion as per P45 sheet plastination in 32 cadavers being 31.3%, 12.5%, and 56.3% and as per gross anatomy in 12 cadavers was 29.2%, 16.7%, and 54.2%, respectively.2、Gross anatomy and clinical anatomical surgery:The gross anatomy findings regarding the distribution of preseptal and preaponeurotic fat were consistent with those on the P45 sheet-plastinated sagittal sections. The preseptal fat predominant type was dominant in 29.2% of individuals.A prominent amount of fat and fascia fibers in preseptal fat obviously extruded. In these individuals, the fat tissue was mainly distributed in the superior and lateral superior segments of the upper eyelids. The preaponeurotic fat predominant type was dominant in 16.7% of individuals. The preseptal fat tissue was extremely thin and slender, nearly invisible, and the preaponeurotic fat was mainly located to the middle inferior and medial segments of the upper eyelids.The orbital septum equilibrium type was dominant in 54.2% of individuals. Preseptal fat was less abundant than that in individuals with the preseptal fat predominant type and more abundant than that in individuals with the preaponeurotic fat predominant type, and was evenly distributed around the medial, middle, and lateral segments of the upper eyelids, with predominant distribution in the superior middle segment. Preaponeurotic fat wasabundant as well.56 cases of patients with mild and moderatesenile sunken upper eyelid had received the treatment with muscle–fascia–fat flap of orbicularis oculi muscle, with complete success. The sunken upper eyelid was satisfactorily repaired, withouthematoma or other complications, noparesthesia at upper eyelid or orbita complained of, with frontalis muscleaponeurosis andorbicularis oculi musclefunctionally normal. Secondary sunken upper eyelid did not occur. The patients were satisfied during the 12-month post-operation follow-up survey. Clinicallyanatomical observation and measurement during the surgery showed that: the average thickness of muscular fascia oforbicularis oculi muscle was(2.24 ± 0.15) mm, and the acceptable length to strip the muscular fascia downward was(7.56 ± 0.12) mm.3、3-D reconstruction of the vascular system in the upper eyelidThe terminal branches of upper eyelid artery includesupraorbital artery, supratrochlear artery, medial palpebral arteries, dorsal nasal artery,lacrimal artery,angular arteryand the run ofophthalmic artery is divided into run outside orbital septum, run inside orbital septum, absence of dorsal nasal artery and absence of supraorbital artery. As regards the run outside orbital septum, we observed two subtypes. In the first subtype, the ophthalmic artery runs downward first to form dorsal nasal artery after running out of the orbital septum, then it runs upward to formsupratrochlear artery. In the second subtype, the ophthalmic arteryforms two branches simultaneously after running out of the orbital septum, namely the downward dorsal nasal artery and the upward supratrochlear artery.Arterial bloodvessels of the upper eyelid source from five transverse arterial arcades and one longitudinalarterial arcade, respectively,the marginal arcade,the supratarsal arcade,the preseptal arcade,the superficial orbital arcade,the surrounding arcade; the longitudinalarterial arcade forms arterial arcade of orbicularisoculi muscle. Most of the preseptal arcades source from the branches of supratrochlear artery, while a fewfrom supraorbital artery.There are mainly three anastomosis areas for periorbitalarterial vessels. One is the area at glabella and nasal dorsum, mainly the anastomosis(anastomosis point 4-6) of bilateral supratrochlear arteries. The second one is nasal area, mainly the anastomosis of nasal wing artery, dorsal nasal artery and the nasolabial groove artery. The third one is lateralorbit area, mainly the anastomosis ofpreseptal arcade, superficial arcade and temporal artery frontal branch. These three areas mentioned above feature potential risks for injected fillers to move reversely into the blood.IV Conclusions1、P45 plastination is a new technique being used to investigate circumocular soft tissue.2、The morphology and external appearance of the upper eyelids depend on the distribution relationship between preseptal and preaponeurotic fat. There are three fat distribution types in upper eyelid, which are front orbital septum dominate type based more on preseptal fat, back orbital septum dominate type based more onorbital fat, equilibrium orbital septum type with equal fat distribution.3、The preseptal fat containing large amount of fascia fibrous tissue acts as barrier and form an upper eyelid fat advantage area in front of supraorbital margin together with preaponeurotic fat pad4、During the upper eyelid surgery, damage to the advantageous areas of the upper eyelid fat should be avoided. Meanwhile the use of the advantageous areas of the upper eyelid fat could be used to guide some upper eyelid operations5、The method for the treatment of mild and moderate senile sunken upper eyelid with muscle-fascia-fat flap of upper eyelid orbicularisoculi muscle is easy to operate and effective, with fewer complications.6、The run of terminal branches of ophthalmic artery of the upper eyelid is divided into run outside the orbital septum, run inside the orbital septum, absence of dorsal nasal artery and absence of supraorbital artery. As for the run outside the orbital septum, it can be classified into three subtypes. What mainly distinguishes the three subtypes from each other lies in the spatial order in which the supratrochlear artery and dorsal nasal artery run out of the ophthalmic artery. A clear idea of the relations betweensupratrochlear artery and dorsal nasal artery will help avoid injuries to dorsal nasal artery during the repairing of dorsal nasal with supratrochlear artery used as vascular pedicles of flaps.7、Arterial bloodvessels of the upper eyelid source from five transverse arterial arcades and one longitudinalarterial arcade which runs inside the orbicularisoculi muscle. A clear idea of the run and distribution of upper eyelid arterial arcade means more reliable vascular pedicle sources for selected flaps during the surgical repairing of upper eyelid, laying reliable anatomical basis for the repairing of upper eyelid flaps.8、There are mainly three anastomosis areas for periorbitalarterialvessels, namely the area at glabella and nasion, nasal wing area, and lateral orbit. In these areas, thevascular anastomosis is linked with ophthalmic artery, with little resistance to antidromic motion.9、For the treatment of facial defect by injecting fillers, great care should be taken to avoid injuries to the arterial vessels at the glabellum area, nasal wing area and lateral orbit area, guard against the movement of the fillers into blood of these areas, and minimize complications caused by the fillers during the cosmetic surgery.