Study On The Stratified Microanatomy Of Forearm Perforators

Background The forearm perforator flap has the advantages of soft skin texture,good color,rich blood supply,large donor area,and no damage to the main blood vessels.It can be used for pedicle transfer and free transplantation,and is widely used in clinical practice for wound repair in the head,neck,hand,and wrist.For the exploration of forearm perforator vessels,domestic and foreign scholars have conducted anatomical studies on ink or lead oxide gelatin perfusion specimens,studied the morphology and distribution of blood vessels in the whole body flap,including the forearm,through radiographic technology and computer image processing technology,and quantitatively analyzed the number,caliber,type,and supply area of perforator vessels.Later,scholars have conducted specialized research on forearm perforator vessels based on previous research.Further clarified the specific distribution of vascular bodies in the forearm skin,muscles,and bones.Other scholars conducted in-depth studies on the origin,course and distribution of perforating vessels from the forearm radial artery,anterior interosseous artery,ulnar artery and posterior interosseous artery,which promoted the clinical application of the forearm perforator flap.Some scholars also found three perforator vessel chains in the forearm through the observation of vascular cast specimens and specimen anatomy,namely,the ulnar artery perforator vessel chain,the radial artery perforator vessel chain,the posterior interosseous artery and the anterior interosseous artery vessel chain.They described the routing,distribution,feeding area of the skin and the corresponding flap cutting method of the perforator vessels in each vessel chain.The forearm perforating vessels are abundant,and previous literature has rarely described the overall and systematic anatomical observation of the forearm cutaneous perforating vessels on solid specimens.The distribution pattern of the forearm perforating vessels penetrating the deep fascia,as well as the positional relationship with the superficial muscles and muscle spaces of the forearm,are also relatively rare.We conducted a systematic and comprehensive dissection of the perforating blood vessels in the forearm using the method of microscale dissection,revealing the vascular chains and networks in the forearm perforating space intuitively.This allowed us to have a more comprehensive and three-dimensional understanding of the forearm perforating blood vessels,clarify the types and distribution patterns of the forearm perforating blood vessels,and provide anatomical basis for the clinical application of the forearm perforating flap.Objective Anatomy and observation of the forearm perforator vessels to explore their distribution patterns,providing anatomical basis for the precise design and harvesting of forearm perforator flaps in clinical practice.Method Fresh human forearm specimens on 10 sides,with arteries infused with red latex.Forearm specimens were measured using a ruler to measure the length of the radiocarpal plane to the elbow plane,and the lengths of the forearms were divided into 4 parts on average,sequentially named distal segment,mid distal segment,mid proximal segment and proximal segment from distal to proximal,and the circumference of the skin at the beginning of each segment was measured and averaged as the skin circumference of that segment using a precisionπ-ruler(precision 0.1 mm).Extent of dissection:distal to radiocarpal plane,proximal to elbow plane;Under the operating microscope,a longitudinal incision was made on the volar and dorsal sides of the dissected area of the forearm,with the depth of the incision down to the dermis;The skin was removed along the incision to both sides with microsurgical instruments,revealing the subdermal vascular network;The fat and other tissues in the superficial fascia were carefully removed with microsurgical instruments,and the perforator vessels in the superficial fascia of the free forearm and their anastomosed vascular network with each other were dissected,revealing the superficial forearm veins,cutaneous nerves,skin perforators,and vascular network;The superficial vein and cutaneous nerve were removed,and only 1-2 cm of cutaneous perforators remained;Dissect through the deep fascia and follow each perforating vessel with microsurgical instruments toward the deep dissection until its origin.Record its origin,course,and relationship with the position of the forearm muscles were observed.Under the surgical microscope,use an electronic vernier caliper(with an accuracy of 0.01mm)to measure the diameter of each perforating vessel at the point of penetrating the deep fascia.The diameter of each perforating vessel,in which the diameter was≥0.2 mm,was included in the statistics.Meanwhile electronic vernier calipers(precision 0.01 mm)were used to measure the vessel diameter at the origin of perforating vessels from the trunk,as well as the vessel pedicle length at the origin of perforating vessels from the trunk to perforate the deep fascia.Result Data measured from forearm specimens were summarized according to segment,intermuscular space1 Mean circumference of skin in each segment of the forearm:Distal segment 162.5 mm;Mid distal segment 188.4 mm;Mid proximal segment 218.7 mm;Proximal segment 238.0 mm.The mean number of perforating vessels in each segment of the forearm was:14.4 in the distal segment,8.2 in the middle distal segment,7.4 in the middle proximal segment,and 14.5 in the proximal segment.Forearm perforator pedicle mean length:Distal segment 12.85 mm;Mid distal segment 17.90 mm;Mid proximal segment 26.86 mm;Proximal segment 28.11mm.2 Forearm skin perforators were 45.20 ± 5.42 branches,of which the intermuscular space perforators predominate(85.0%).The intermuscular space perforators were more constant(93.8%)penetrating out from the following 5 vascular perforator spaces:2.1 Radial volar side space:between brachioradialis and flexor carpi radialis(24.2%);2.2 Ulnar volar side space:between flexor digitorum superficialis and flexor carpi ulnaris(16.4%);2.3 Ulnar side space:between flexor carpi ulnaris and extensor carpi ulnaris(20.8%);2.4 Ulnar dorsal side space:between extensor carpi ulnaris and extensor digitorum brevis(15.9%);2.5 Radial dorsal side space:between extensor digitorum and extensor carpi radialis long and short(16.7%).A vascular chain is formed longitudinally along this space by perforators within the same vascular perforator space and forms a vascular network with perforators in other vascular perforator spaces and musculocutaneous perforators.Conclusion The distribution of perforating vessels in the distal and proximal segments of the forearm is concentrated,which is an important area for selecting and harvesting forearm flaps;The circumference of the forearm skin and the length of the cutaneous perforator gradually increase from distal to proximal;The forearm has 5 important vascular perforator spaces,and the vascular chains formed by the perforators emitted from these spaces are the axis for safely design and harvesting of the forearm flap.Using these vascular perforator spaces as the axis,longer forearm flaps can be cut;Smaller forearm flaps can also be designed in these vascular perforator space areas to facilitate clinical search for vascular pedicle.