Anatomical Study And Clinical Application Of The Lateral Sural Artery Perforators And The Nutrient Vessels Of The Lateral Sural Cutaneous Nerve

Objective: The purpose of this study is to observe and measure theanatomic relationship between the lateral sural artery perforators and thenutrient vessels of the lateral sural cutaneous nerve, meanwhile,to design akind of muscle flap of which pedicle is combined the lateral sural arteryperforator with nutrient vessels of the lateral sural cutaneous nerve,based onthe anatomical study. Observe the effect of the compound pedicled muscleflap clinical application, and design a new flap repairing the skin and softtissue defects of the anterior patellar and proximal tibial.Many studies on themicro-anatomy and DSA (digital subtraction angiography) of the lateral suralartery perforators and nutrient vessels of the lateral sural cutaneous nerve havebeen reported.And many anatomical and clinical application studies on thesural neurocutaneous island flap and the gastrocnemius muscle flap also havebeen reported.But through the clinical practice,we find,for the complicatedwound such as the wound accompanied by bone defects or osteomyelitis onthe anterior of patellar and proximal tibia,that muscle flaps would damagemuch muscle of the donor site and it's too fat to meet the requirements of theknee in appearance and function.However, the fasciocutaneous flap is difficultto fill the wound that would leave space with many exudates.It may easilyform a focal infection leading the necrosis of the flap. Based on this, weconsider that we could combine muscle blood vessels and nerve nutritionblood vessels, then design a compound pedicled muscle flap to repair thecomplicated wound.Methods: Choose5(10sides) adult and fresh cadaver lower limbs, by theHebei Medical University anatomy lab. Two normal cases were accessed by digital subtraction angiography (DSA) from department of invasivetechnology, the Third Hospital of Hebei Medical University.We collect the clinical data of5patients (5males,21to47years old, mean32.8+9.6years) who accepted hospitalization from February2009toNovember2011in the Third Hospital of Hebei Medical University. Causes ofinjury: traffic accident injury with soft tissue defect in4cases, crush injury in1case. The clinical course:36~56d. Damage Locations: the skin, soft tissueand bone defects of the anterior patellar and proximal tibial. Wound area:6cm×9cm~9cm×12cm.1Anatomical method (Stratified dissection): The line from the middle of thepopliteal fossa to the midpoint of the lateral malleolus and the achilles tendonis the surface projection line of the axis of sural nerve nutritional vessels(Fig.1). Cut the skin and superficial fascia along this line and find the suralnerve and its nutrient vessels (Fig.2, Fig.3). Cut the deep fascia on theproximal lateral sural nerve and find the lateral gastrocnemius(Fig.4), thenpull out the lateral gastrocnemius to expose its arteries andnerves(Fig.5,Fig.6),and anatomise the distal lateral sural artery to reveal itsmain branches (Fig.7,Fig.8).Observe and record the number,origin and outerdiameter of lateral sural artery perforators,and the relation between theperforators and nutrient vessels of the lateral sural cutaneous nerve under thesurgical microscope.The diameter was measured by vernier caliper,the lengthand it's distribution were measured by the tape. Analyse the data using SPSS13.0, and the results are expressed as the mean±SE.2Surgical method: Detect the perforators of the lateral sural artery usingDoppler flow detector in the range of4~10cm beyond the popliteal fold and1~4cm beyond the behind midline line of the crus, and then mark the mostproximal perforator.The flap axis is the line from the middle of the poplitealfossa to the midpoint of the lateral malleolus and the achilles tendon.Designthe flap by the injuries and the location of marked perforator.The size ofdesigned flap should be larger than the area of wound. Find the lateral suralartery above the mark2cm and between the two heads of gastrocnemius.Separate the muscle along this artery, retain1~3musculocutaneous perforating branches and1~2muscle vessels.When thelength of pedicle achieves the requirement of repairing the defect, the skinaround the flap is cut.We should confirm the flap includes the lateral suralartery, the sural nerve and its nutrient vessels axis.Results:1The result of anatomy: The lateral sural nerve is the branch of the commonperoneal nerve, and its nutrient area is the2/3range of the posterolateral lowerleg.Its main nutrient artery is the lateral popliteal cutaneous artery.The lengthof the lateral sural artery from the starting point to the1mm outerdiameter:163.5±5.0mm.The distance from the starting point of the lateral suralartery to the location of its entering the muscle:50.9±2.1mm. The distancefrom the starting point of the lateral sural artery to the starting point of thelateral sural nerve:53.9±2.1mm.The horizontal distance from the starting pointof the lateral sural artery to the lateral sural nerve:9.4±1.6mm.Along themuscle fiber direction,the lateral sural artery with two veins distribute in themiddle of the lateral gastrocnemius,and3~5musculocutaneous perforatingbranches(outer diameter:0.20~1.80mm) arise from it.The outer diameter of thefirst lateral sural artery perforator:1.16±0.37mm.The distance from thelocation of its entering the muscle to its starting point:23.2±4.08mm.Thedistance from the location of its entering the muscle to the lateral sural nerve'sstarting point:81.8±3.05mm.The distance from the location of its entering themuscle to the midline of the lower leg(popliteal artery):9.7±1.77mm.The outerdiameter of the second lateral sural artery perforator:0.76±0.21mm.Thedistance from the location of its entering the muscle to its starting point:53.4±4.06mm.The distance from the location of its entering the muscle to the lateralsural nerve's starting point:108.9±3.81mm.The distance from the location ofits entering the muscle to the midline of the lower leg(popliteal artery):21.6±3.2mm.The outer diameter of the third lateral sural artery perforator:0.43±0.11mm.The distance from the location of its entering the muscle to itsstarting point:120.0±8.67mm.The distance from the location of its entering the muscle to the lateral sural nerve's starting point:173.6±4.03mm. Thedistance from the location of its entering the muscle to the midline of thelower leg(popliteal artery):12.9±3.0mm.The fourth and the fifth lateral suralartery perforators are not count in the statistics,because their variation aregreat, the experimental data is limited, and the flap often is designed by thefirst and the second perforators (Table1,Table2).2The DSA of lower limb showed that the lateral sural artery perforatorsinosculate with the nutrient vessels of the lateral sural cutaneous nerve inthe2/3range of the upside after lower leg. They constitute a vascular chainwhich participates in the formation of superficial and deep fascia vascularnetwork.This support the findings in the anatomical experiments and operation(Fig.10, Fig.11).3The result of clinical application:Flaps in4patients completely survived.1cases had partial superficial necrosis on the distal part of the flap,and afterdressing change it gradually healed.Postoperation follow-up between2monthsand6months, the flaps had good shape, texture and color with no abrasion.They were not bloated and did not require secondary operation. And the donaraera heeled well with no obvious dysfunction.The clinical results weresatisfied (Fig.16).Conclusion:1There are3~5perforators (outer diameter:0.20~1.80mm), which are thenutrient arteries of the lateral gastrocnemius and its surrounding soft tissue andskin, arise from the lateral gastrocnemius artery along the muscle issue. Theperforators contact with the the nutrient vessels of the lateral sural cutaneousnerve and they form the shallow and deep fascia retevasculosum together.2The compound pedicled muscle flap has two sets of blood supply that couldexpand the area of the flap, and there is a sensory nerve in the flap whichcould guarantee its feeling.This kind of flap could repair the complicated skinand soft tissue defects around the knee joint.3The flap of which pedicle is not bloated transfers easily and does notdamage the major vessels.The clinical application is easily.