Refers To The Application Of Anatomical And Clinical Study Of The Artery Dorsal Branch Of The Pedicle Refers To The Dorsal Fascia Flap

Traumatic soft tissue defect of finger is often combined with bone, joint, tendon, blood vessel or nerve exposure. Its coverage remains a challenge for surgeons, who must choose to use flap mostly. There are three common kinds of flaps to repair digital soft tissue defects: local flap, distant flap and free flap. The traditional flaps commonly used include local rotation flap, various kinds of digital advancement flaps, cross finger flap, cross brachial flap, pedicled abdominal flap, digital artery island flap and various kinds of free flaps, and so on[1-4]. These flaps have some disadvantages, such as limitation of repairing area of soft tissue defect, hindrance of hand functional rehabilitation because of long-time fixation, fat and clumsy appearance, sacrificing a digital artery, requirement of anastomosing vascellum, complicated operative procedure and larger risks. Skin of finger are characterized by thinness, soft texture, rich blood supply and sensitive sensation. As the donor site of flap, only hand and foot have these characteristics. Various kinds of tissue flaps in the foot can perfectly repair correspondingly regional digital tissue defects. But these flaps also have some disadvantages, such as requiring very proficient anastomosis skill of small vessel, complicated and time-consuming operative procedure, existence of the risk of tissue flap necrosis and possibility of pedal tendon exposure resulting from skin graft necrosis in the donor site. So their clinical applications are limited. The skin of dorsal digit and metacarpus neighbouring the digital raw surface is characterized by thinness, soft and loosening texture, rich blood supply, existence of cutaneous nerves and capability of repairing soft tissue defect of middle and distal phalanx because of long arch of rotation. So it is an ideal donor site of skin flap for coverage of soft tissue defect in the finger. Therefore, the dorsal digital and metacarpal island flap have become a hot spot of research to surgeons and dissectors[5-15]. Presently, there are only a few documents about applied anatomy and clinical application of the dorsal digital and metacarpal fasciocutaneous flap based on the dorsal cutaneous branch of the proper digital artery both at home and abroad. Especially, Chinese systematical and exact applied anatomical data about the dorsal digital and metacarpal fasciocutaneous flap based on the dorsal cutaneous branch of the proper digital artery in the proximal and middle phalanx are absent . In order to provide systematical and exact applied anatomic evidences for the application of the dorsal digital and metacarpal fasciocutaneous flap based on the dorsal cutaneous branch of the proper digital artery,we designed the microscopic study of fresh adult cadaveric hands which were injected with latex via arterial cannula. Meanwhile, on the basis of our anatomical findings, the flaps were applied to clinical cases to make sure their clinical effects.Chapter I Applied anatomic study of the dorsal digital and metacarpal fasciocutaneous flap based on the dorsal cutaneous branch of the proper digital arteryObjective To provide systematical and exact applied anatomic evidences for the application of the dorsal digital and metacarpal fasciocutaneous flap based on the dorsal cutaneous branch of the proper digital artery.Methods Fourteen fresh adult cadaveric hands were injected with red latex via arterial cannula. After the cadaveric hands were frozen for 48 h, the dorsal digital and metacarpal vessels of the cadaveric hands were dissected microscopically layer by layer, and their course, distribution, connection and external diameter were observed and measured with the aid of an operating microscope. The measured numerical data were treated with SPSS 11.0 statistical software.Results There are rich cutaneous arterial networks and four relatively large cutaneous arterial arches paralleling dorsal metacarpal arteries in the superficial fascia of dorsal metacarpus. The dorsal metacarpal artery or the distal dorsal perforator of deep palmar arch constantly gives off a relatively large recurrent branch at the distal margin of junctura tendineae. The teminal segment of dorsal metacarpal artery and distal dorsal perforator of deep palmar arch give off 3.82±0.89(range 2 to 7)cutaneous twigs travelling to each unilateral dorsal aspect of metacarpophalageal joint and proximal phalanx whose external diameters range from 0.1mm to 0.72mm. The second, third and fourth interdigital web arteries exist constantly,only one fourth interdigital web artery is absent among fourteen cadaveric hands. There are 1 to 7 indirect dorsal cutaneous branches and 2 to 8 direct dorsal cutaneous branches of the proper digital artery in each side of proximal and middle phalanx, respectively. There is a relatively large dorsal cutaneous branch of the digital artery in each side of the middle and distal third of the proximal phalanx, the proximal or middle third of the second phalanx, respectively. The dorsal digital branches of the teminal segment of dorsal metacarpal artery and distal dorsal perforator of deep palmar arch supply to the dorsum of proximal and middle segment of proximal phalanx, where they anastomose with the dorsal cutaneous branches of the digital artery. The dorsal cutaneous branches of the digital artery in different segments anastomose with each other in the dorsolateral aspect of phalanx,where a arterial link is formed.Conclusion The reverse dorsal digital and metacarpal fasciocutaneous flap based on the dorsal cutaneous branch of the proper digital artery is more suitable to repairing comparatively large-area soft tissue defects of middle and distal phalanx because of the advantages of easy and secure dissection, longer arch of rotation. The pivot point of the distally based dorsal digital and metacarpal fasciocutaneous flap can be more distally designed at middle or distal segment of proximal phalanx.Chapter II Clinical application of the dorsal digital and metacarpal fasciocutaneous flaps based on the dorsal cutaneous branches of the proper digital arteryObjective To probe the feasibility of repairing soft tissue defects in the middle and distal phalanx with the dorsal digital and metacarpal fasciocutaneous flap based on the dorsal cutaneous branches of the proper digital artery.Methods Fifteen fingers of the soft tissue defects in the middle and distal phalanx were repaired with the dorsal digital and metacarpal fasciocutaneous flaps based on the dorsal cutaneous branches of the proper digital artery, and their pivot points were located at the midpoint or distal segment of proximal phalanx.Results Among 15 flaps, 14 survived completely, cuticular layer in the distal part of one flap was partially necrotic. The flaps were characterized by rich blood supply, cold-resistance, suitable thickness, soft texture and good colour. There was no adhesion of extensor tendon and interdigital web contraction in the donor sites.Conclusion The dorsal digital and metacarpal fasciocutaneous flap based on the dorsal cutaneous branches of the proper digital artery is an ideal option for repairing soft tissue defects of middle and distal phalanx because of the advantages of easy and secure dissection, reliable blood supply, longer arch of rotation, closer to the raw surface of finger, less injury to the donor site, good appearance, avoidance of sacrificing major arteries and reconstruction of sensation by anastomosing cutaneous nerve.