The Anatomy And Digitization Of Pedicled Island Skin Flap With Arterial Arch At The Superior Border Of Abductor Hallucis Muscle

Background:Skin soft tissue defects caused by front foot damage, often combined with the exposure of cartilage, arthrosis, tendons, nerves and blood vessels, seriously affect the function of foot and is difficult to repair clinically because the wound have poor blood circulation as the quality of weight-bearing of front foot. The principles to repair the skin tissue defects of front foot with flaps are as follows:①The flap must have the quality of good elasticity, high wear resistance and thin texture;②The flap should have sufficient blood supply so as to cure fast and not to be frozen and crushed;③The protective sense is necessary. The front foot damage caused by skin and soft tissue defects, which was difficult to be repaired and reconstructed. Because of too much complication, traditional podicle flap is used less and less in clinical experience. As a difficult and risky method, free flap are restrained in clinical applications. With the development of microsurgical anatomy, a variety of island flap to repair the front foot skin defects have emerged one after another, including dorsal skin area, ankle area on the skin, plantar skin area and foot medial area of skin. Therefore, the proper therapeutic scheme, and active prevention and treatment of complications are of importance to the front foot skin and soft tissue defect. From Shanahan and Reiffel reported the anatomic basis of the medialis pedis island flap. This flap was an ideal one with many advantages, such as:the distinct anatomic landmark, large area, the thick diameter, the covert donor site, the non weight area of medial plantar, easy to be incised; the vessel pedicle of flap is not main blood vessels and the excision of them affects blood supply to the foot insignificantly. With the development of microsurgical technology, this flap obtained widespread application. To cut more plantaris medialis flap and prolong its vascular pedicel. Chen MaoLing firstly named the "arterial arch at the superior border of abductor hallucis muscle" in1997, and indicated that plantaris medialis flap pedicle with this arterial arch could reconstruct the foot skin tissue defect. This technique was a new one and it was easy to be operated, and it’s worthy to be widely used. Subsequently, many researchers explore the surgery that base on the flap pedicle arterial arch at the superior border of the abductor hallucis muscle. But the anatomical basis were not been reported. So this flap was promoted limitedly in clinic because of its disadvantage of much vascellum mutation and poor cognition.Vascular patency is the key of survival of the flap. Previous anatomic studies on vascular system of the skin flap in the field of microsurgery have carried out widely, such as the microsurgical anatomy and cast specimens. Since the technology of was firstly applied to display the dermatic vascular structure by Miches in1936, this technology as a gold standard of vascular visualization had been acquired widespread application and reform. The structure of vascellum and other vessels were illustrated in high clarity, especially the feeding arteries of the small blood vessels and the adjacent relations between muscles and skin, which do much meaning to the clinical application, training and research.However, as one body specimen can only make one cast specimen, made the cast specimen can not be duplicated and not be shared. With the development of micro-diagnose and treat and Three-dimensional (3D) computerized reconstructions,3D reconstruction is widely used in the field of medicine.3D reconstruction technique, being an important research direction of computer image processing, had been applied extensively in anatomic study of skeleton, vascular, gastrointestinal tract and so on. In recent years, there were many reports about the3D reconstruction and human body visualization. It’s a well-rounded technique on the research of the vessels to study the regional vessels in the3D space after the perfusion of the vessels, the contrast radiography and3D reconstruction. In this technique, the vessels were perfused with the radio-opaque material and CT scanned, the3D reconstruction software was used to reconstruct the vessels and other structures. In the3D structure, the bones and vessels could be viewed in different layers and different aspect, the structures could be viewed separately or combined. To one region, the cause and the distribution of the vessels could be viewed directly, it could apply the well-defmed anatomical basis for the tissue flap. Re-establishment of skin flap3D dissect establishing a foundation for observation on the state of skin flap blood supply stereoscopically and making best operative route and treatment plan, implementing the development from plane anatomy to stereoseopic and digital anatomy.Re-establishment of skin flap3D faced with two important problems recently:①Segmentation and3D reconstruction of the small blood vessels;②Segmentation and3D reconstruction between muscles and skin.Therefore, in these studies, the micro-macro anatomic techniques, cast specimens and the3D reconstruction were used to study. Base on the advantages of those methods, homologized anatomic data was obtained from models through observation and measurement, to group arteries of arterial arch at the superior border of the abductor hallucis muscle according to their constitute, and explore the blood supply of the reverse pedicled island skin flap with arterial arch at the superior border of abductor hallucis muscle. These results will provide anatomical basis for reverse pedicled bifolicated flap with arterial arch at the superior border of abductor hallucis muscle, offer3D models of various types of anatomical variations for surgery planning and simulation, supply digitalization atlas for anatomic teaching and enrich anatomic teaching method. This topic was supported from the investigation and development plan of high-tech in contry.Our research includes the following three parts:Chapter.l The grouping and clinical significance of the arterial arch at the superior border of abductor hallucis muscleObjective:To group arteries of arterial arch at the superior border of the abductor hallucis muscle according to their constitute and provide anatomical basis for reverse island skin flap based on it.Methods:The constitute, track-way and distribution of the artery,which supply the medial pedis flap, the medial plantar and flap the medial tarsal flap, especial the pedicled island skin flap with arterial arch at the superior border of abductor hallucis muscle were observed and analyzed on81lower limbs cast specimens and2fresh feet specimens perfused with red latex.Results:According to their constitute, arterial arch at the superior border of the abductor hallucis muscle can be classified into3types:①type Ⅰ, It was constituted mainly by the branch of anterior medial malleolus artery and(or) the medial tarsal artery, with the occurrence rate of22.9%(19case, left7, right12);②type Ⅱ, It was constituted mainly by the superficial branch of the medial plantar artery, with the occurrence rate of3.6%(3case, left2, right1);③type Ⅲ, It was constituted mainly by the superficial branch of the medial plantar artery anastomose with the branch of anterior medial malleolus artery and the branch of medial tarsal artery, which was divided into2subtypes according to the different anastomosis of the artery:The anastomosed directly and the anastomosed indirectly, type Ⅲ1, The type of anastomosed directly was about48.2%(40case, left22, right18), with the constituted of the arterial arch from the anterior medial malleolus artery and(or) the medial tarsal artery anastomose directly with the superficial branch of the medial plantar artery. type Ⅲ2, The type of anastomosed indirectly was about24.1%(20case, left8, right12), with the constituted of the arterial arch from the arterial circle,which anastomosed by the branch of anterior medial malleolus artery, the branch of medial tarsal artery and the superficial branch of the medial plantar artery with each other.Conclusions:According to the constitute of arterial arch at the superior border of the abductor hallucis muscle can be classified into3types:The type of anterior medial malleolus artery and medial tarsal artery, the type of superficial branch of the medial plantar artery and the type of mixed. For the type of the type of mixed,2subtypes can be classified according to the different anastomosis of the artery.Chapter.2Applied anatomy of the reverse pedicled island skin flap with arterial arch at the superior border of abductor hallucis muscle for repairing fore foot skin defect.Objective:To explore the blood supply of the reverse pedicled island skin flap with arterial arch at the superior border of abductor hallucis muscle, to offer anatomy basis for repairing fore foot skin defect.Methods:The constitute, track-way, distribution, external diameter of arterial arch at the superior border of the abductor hallucis muscle, accompanied by one concomitant vein and nerves were observed and analyzed on12sides of adult cadaveric foot specimens perfused with red latex and12sides of fresh specimens perfused with red latex. And then, the operational approach of using arterial arch at the superior border of the abductor hallucis muscle repair fore foot skin defect were designed and executed.Results:The arterial arch at the superior border of the abductor hallucis muscle, constituted by the branch of medial tarsal artery or the branch of anterior medial malleolus artery anastomose with the superficial branch of medial basal hallucal artery or the branch of the superficial branch of medial plantar artery or the above four, become the axis of the medial tarsal and the medialis pedis and medial plantar. The external diameters of the anterior medial malleolus artery was (1.02±0.03)mm,91.67%of them accompanied by one concomitant vein with the external diameters of (1.01±0.03)mm, the other8.33%by two concomitant vein; the external diameters of the medial tarsal artery was (0.73±0.04)mm,91.67%of them accompanied by one concomitant vein with the external diameters of (0.81±0.04)mm, the other8.33%by two concomitant vein; the external diameters of the branch of the superficial branch of medial plantar artery was (0.56±0.02)mm,91.67%of them accompanied by one concomitant vein with the external diameters of (0.57±0.01)mm, the other8.33%by two concomitant vein; the external diameters of the distal arterial arch at the superior border of the abductor hallucis muscle was(0.53±0.14)mm,91.67%of them accompanied by one concomitant vein with the external diameters of (0.61±0.02)mm, the other8.33%by two concomitant vein.Conclusions:There are three methods to repair fore foot skin defect with the reverse pedicled island skin flap with arterial arch at the superior border of abductor hallucis muscle, vessel pedicle, the major arteries of the flap, formed by the branch of anterior medial malleolus artery and(or) the medial tarsal artery or the superficial branch of the medial plantar artery or the above three; the pivot point, formed by the neck of the first metatarsal or metatarsophalangeal joint, is rather long vessel pedicles and Larger flap areas for increasing the flexibility of clinical application.Chapter.3The-dimensional visualizational investigation for pedicled island skin flap with arterial arch at the superior border of abductor hallucis muscleObjective:To discuss the three dimensional reconstruction of pedicled island skin flap with arterial arch at the superior border of abductor hallucis muscle, and to establish their digitized visible models.Methods: One fresh adult cadaver specimen was perfused with the mixture of lead oxide-gelatine by anterior tibial artery and posterior tibial artery to be subject to spiral CT scanning, the branch of anterior medial malleolus artery, the medial tarsal artery and the superficial branch of medial plantar artery3D model respectively were reconstructed by Mimics10.0the constitute, track-way and distribution of arterial arch at the superior border of abductor hallucis were observed and analyzed on it. According to the feature of anatomical structures, reconstruction were conducted in skin and the vessel to obtain three-dimensional arterial skin flap structure.Results:The layers of the anatomical model were distinctively displayed, the small blood vessels between adjoining arteries were illustrated in high clarity. The3D images of the flap and its blood vessel structure by Mimics10.0were clearly displayed, and the surface and volume information could be obtained. The3D images could display perfectly the main structures of flap and other adjacent structures.Conclusion:Three dimensional reconstruction for pedicled island skin flap with arterial arch at the superior border of abductor hallucis muscle may provide great value for clinical experiments, basic research and surgical planning, and provided visual reference for the individual operation design and the oretically is able to enhance the effect of surgery.