▶ Previous Artlcle : #2-2. Functions of the Venous System
Short Saphenous Vein (SSV)
The short saphenous vein (SSV) used to be also known as LSV (Lesser Saphenous Vein). The SSV originates between the ankle bone and achilles tendon, runs upward the posterior of the calf near the sural nerve. This superficial vein then joins the deep, intramuscular vein behind the knee. The superficial tributaries of the SSV travel up the leg and are integrated into the GSV on the medial side. Under the knee, in the posterior and medial calf, communicating veins connecting to the deep, intramuscular vein penetrate various fascia to join with the deep, intramuscular vein.
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The SSV is close to the tibial, sural nerve and varix forming in this vein may stimulate the nerve to cause pain. The SSV joins GSV in the mid-thigh. This joining area is adjacent to the sciatic nerve and varix forming in the GSV may cause pain very similar to sciatica. As the saphenous nerve runs very close to the GSV and SSV, great caution is needed during surgery performed in this area for the prevention of nerve injury.
I have encountered one patient in whom the nerve was sutured in subcutaneous suture following successful SSV stripping. He suffered severe pain when he emerged from anesthesia. Therefore, close attention should be paid not to suture the nerve.
The SSV is surrounded by fascia. If the incision made during the fascia surgery is too long, it is advisable to suture fascia during SSV surgery. If the fascia is not sutured, among intramuscular veins, muscle vein which is close to the SPJ (sapheno popliteal junction) take on the properties of a perforating vein in the skin area with lower pressure and cause recurrence of varicose veins. In my clinical experience, among all patients receiving surgical treatment of varicose veins, 17% operated for surgery due to SSV valve anomaly.
In addition, the average diameter of a normal SSV was 2-4mm at the location of SPJ. As in the GSV, if the SSV is thicker than this, regurgitation can be suspected. However, the diameter is actually measured 1cm below the SPJ.
Lateral Subdermic Venous System (LSVS)
Among superficial, subcutaneous veins, there is also the lateral subdermic venous system (LSVS) which does not belong to either the GSV or SSV systems. This vein is located in the lateral side of the leg and courses above or below the knee. In this unique venous system, blood does not flow from the leg toward the heart but in the opposite direction. The blood is then sent into the collecting vein, perforating vein in the lateral thigh or perforating vein in the knee. Although this venous system is not easily visible, it is very important. It is found more often in young women and can independently cause telangiectasia. If regurgitation occurs in this system, telangiectasia becomes widespread and venule dilation causes a burning sensation.
The cause of this less common LSVS disease is that embryologically, the deep, intramuscular venous system and superficial, subcutaneous venous system were not connected above the knee during the fetal stage. Abnormality in this venous system occurs at a young age but differs from other types of varicose veins in that it does not exacerbate with age.
The incidence of reflux in the perforating vein of the knee and lateral thigh is 85% among LSVS. If reflux is present in the superior gluteal vein, the vein runs zigzag along the posterior thigh and are dilated. The LSVS veins can be easily treated with vein sclerotherapy with good outcomes. Many cases present anomaly only in the LSVS but just as many also present concurrent problems in the GSV and SSV. LSVS anomaly can be easily diagnosed with Continuous Wave Doppler.
Muscle Vein
Among the deep, intramuscular veins in the thigh muscles, the gastrocnemius and soleus are important muscle veins. Blood stasis may frequently occur in these veins, which are important as a calf muscle pump. Especially, the soleus vein is very large and winding, which gave it the name soleal venous sinus. As various muscle veins gather around the SPJ and form a complicated mass, close attention should be paid at ultrasound examinations to check for regurgitation.
In some cases, varicose veins arose from muscle veins connecting to the perforating veins toward the skin while the GSV and SSV are normal.
Perforator
The perforating veins in the lower extremities are closely associated with the development of varicose veins. if the perforating vein suffers valvular insufficiency, pressure within the muscle is directly transferred to the superficial, subcutaneous veins, causing varicose veins.
The number of perforating veins in the lower limb is 64-55 which increases toward the lower area (ratio of numbers in thigh : leg : foot =1 : 2 : 8 ). In 60% of patients, it runs alongside the artery and has 1-3 valves. These perforating veins have been given the name of the discovering scholar, which shows their clinical importance. The most famous of these is Hunter’s perforator, a vein located 15cm superior to the medial knee. This vein sends blood from the superficial femoral vein to the deep, intramuscular vein. Boyd’s perforator sends blood from the posterior tibial vein to the deep, intramuscular vein and Cockett perforators, which consist of three veins, send blood from posterior tibial vein below the knee to the deep, intramuscular vein. The perforating vein found inferior to the ankle is called Kustler's perforator and is without a valve in most cases. This increases the likelihood of typical corona phlebectasia in the foot
Under normal circumstances perforating veins are not visible on the ultrasound, however, they become visible when there is valve anomaly. In diagnosis of perforating vein anomaly, their shape emerging from the fascia should be checked. They run in an S shape and due to this tortuosity, they can be missed during diagnosis.
Some of the most common causes of recurrence in varicose veins include failure to discover perforating vein anomaly before treatment initiation and inadequate treatment of perforating veins. It is crucial to treat them with an appropriate therapy based on location, size and severity of regurgitation.
In my clinical experience, among patients among all patients receiving surgical treatment of varicose veins, about 5% presented with perforating vein anomaly and normal GSV and SSV. Rest of the patients had valve anomaly in the GSV, SSV accompanied by perforating vein problems. In anatomical diagnosis of venous diseases it is crucial to find the origin of regurgitation. If regurgitation is present, the doctor should first determine if it has saphenous origin.
If found to have saphenous origin, it is necessary to check if it is GSV or SSV. With GSV origin, closely examine with ultrasound scans starting from the SFJ if these veins are GSV tributaries, if the cause of cystic dilation is GSV and their shapes. This will help to choose the optimal treatment. As many tributaries exist around SFJ, it is important to remember screening for dilation or regurgitation in these tributaries. It is of utmost importance to find the origin of regurgitation. In some cases, many venous tributaries are severely dilated around the SFJ accompanied with regurgitation, leading to the diagnosis of venous plexus. Here, crossectomy is necessary to prevent future recurrence. Operating in a patient with this condition requires a great deal of caution as venous walls are very thin and tear easily. Hemorrhage arising from torn vessels disturbs vision for the surgeon and caution is needed to prevent bleeding. For the SSV as well, confirm if the origin of regurgitation if the SPJ with ultrasound scans.
With a non-saphenous origin, the cause most likely is the perforating vein. Varicose veins often occur inferior to the origin of regurgitation, however, the blood current makes a U-turn above the origin and causes varicose veins in many patients. Therefore, accurately locating the origin of reflux with ultrasound CW Doppler, etc. followed by effective treatment of reflux point will minimize recurrence of varicose veins.
-To be continued-
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