in general , the great saphenous vein ( gsv ) starts with medial marginal vein at the ankle , passes through saphenous compartment , and ends at the saphenofemoral junction ( sfj ) .
the vein running out of the saphenous compartment is classified as accessory vein or tributary vein .
if the diameter of the gsv becomes smaller or diminished , it is called as gsv hypoplasia or aplasia [ 1 , 3 ] . most of them is a segmental condition localized to a part of the gsv and has vein that connect the start and end points of the hypoplastic or aplastic segment .
this connecting vein usually travels outside the saphenous compartment . however , there were reports of hypoplasia extended up to the groin rather than a segmental condition located around the knee . even in these cases ,
most of them has anterior accessory saphenous vein ( aasv ) as a connecting vein [ 3 , 4 ] .
the purpose of this study is to report a case of long - segment hypoplasia of gsv with posterior asv ( pasv ) as a connecting vein .
a 22-year - old male patient visited the clinic complaining dull pain and heaviness in the right calf that had lasted for about 5 months .
he had no medical history or family history of varicose vein . upon physical examination ,
dilated tributary veins were observed at the posterior aspect of right calf but edema of the leg was not observed ( fig .
2 ) . normal gsv without reflux was observed in the saphenous compartment of left lower limb . on right lower limb ,
the pasv connected the normal gsv 3 cm distal to the sfj and normal gsv below the knee .
significant reflux ( reverse flow lasting more than 0.5 s ) was observed throughout the whole length of pasv and gsv in the proximal part of the hypoplastic segment .
the tributary vein joined about 1.5 cm below the area where pasv and normal gsv below the knee were connected .
no reflux was observed in the normal gsv below the knee . under local anesthesia with tumescent solution ,
high ligation of gsv and stripping of pasv and gsv proximal to hypoplastic segment were performed . for dilated tributary vein at the posterior calf , ambulatory phlebectomy
he had follow - ups at 1 , 3 and 6 months after the surgery .
the symptoms before the surgery were improved after the surgery , and final revised vcss was 1 . 

figure 1:photograph of posterior accessory saphenous vein ( arrow ) and its tributary ( arrow head ) . 

dotted gray line represents the hypoplastic segment of the gsv and solid blue line represents the posterior accessory saphenous vein .
photograph of posterior accessory saphenous vein ( arrow ) and its tributary ( arrow head ) .
dotted gray line represents the hypoplastic segment of the gsv and solid blue line represents the posterior accessory saphenous vein .
aplasia or hypoplasia of gsv is known to be found in about 12~39.9% of general population and they are unilateral in general [ 2 , 3 , 7 ] . according to reports , aplasia or hypoplasia of gsv is more commonly observed in patient with varicose vein than without varicose vein [ 1 , 2 ] . while these are common conditions ,
the reason for more frequent reflux in these patients is thought to be because the connecting vein ( accessory saphenous vein ) has thin wall and poor muscle composition compared to gsv , and it 's surrounded solely by subcutaneous fat without supporting structures such as saphenous fascia of gsv which can prevent vasodilation . since normal gsv
endothermal ablation which is the standard treatment for varicose vein   has a risk of thermal injury to the skin and can not be easily performed for connecting vein . in our case , we used high ligation and inversion stripping instead of endothermal ablation to prevent thermal injury of the skin .
aplasia or hypoplasia of gsv is uncommon at proximal or distal gsv , and usually segmental around the knee [ 2 , 3 ] . in most cases , aplasia or
however , a few cases of hypoplasia continuing to inguinal region ( 2.4% ) with aasv as connecting vein are reported .
but the aasv is known to be located slightly lateral to the gsv and aligned with femoral vessel . in our case , long - segment hypoplasia of gsv was detoured from the lower part of popliteal crease to groin through pasv which is located medial to the gsv and femoral vessel , and this case is rarely reported .
therefore accurate preoperative ultrasound examination of the anatomy of the gsv and its tributaries is necessary . in this report
, the author discussed a rare case of long - segment hypoplasia of gsv with  pasv as a connecting vein .
the authors confirmed that written informed consent was obtained from the patient for publication of this case report and accompanying images .
 abstractaplasia or hypoplasia of great saphenous vein ( gsv ) is relatively common . 
 most of them are segmental and localized around the knee . 
 they rarely extend to the inguinal area , yet in case of this , the anterior accessory saphenous vein ( aasv ) is the most common connecting vein . 
 we report a case of a 22-year - old male who underwent surgery for pain and heaviness of the right calf . 
 he had the hypoplasia of right gsv extended from below the popliteal crease to near the saphenofemoral junction with posterior asv ( pasv ) as a connecting vein . 
 significant reflux was observed in pasv and gsv which are proximal to pasv . 
 high ligation and stripping was performed , and symptoms improved after surgery . in this report , the author discussed a rare case of long - segment hypoplasia of gsv with pasv as a connecting vein . 
INTRODUCTION
CASE REPORT
DISCUSSION
CONFLICT OF INTEREST STATEMENT
FUNDING
ETHICAL APPROVAL
INFORMED CONSENT