One of the newest minimally invasive surgical approaches for lower extremity varicose veins is endovenous laser treatment (EVLT). It can be performed under local anesthesia, leaving no surgical scars, less patient pain and shorter recovery time.
1.The principle of EVLT
The intracavitary laser is delivered to the tissue via fiber optics, and the laser output power and emission pattern are adjusted to achieve the best and highly controllable tissue effect. For soft tissue excision, vaporization, and coagulation, a bare fiber can be used to contact the tissue. When the fiber touches the tissue, the laser emitted at its end produces a thermal effect within the tissue with minimal penetration and minimal damage for therapeutic purposes.EVLT applies the fiber to deliver infrared laser light at different wavelengths (810nm and 940nm) within the vein, resulting in endothelial cell and vein wall damage and eventually fibrosis and occlusion of the vein trunk and its geniculate branches. For veins larger than 0.5 mm in diameter and at least 0.5 mm in subcutaneous diameter, the absorption of hemoglobin in the long wavelength visible to near infrared range (800-1000 nm) is of great importance.
2. Advantages of EVLT
Compared with other minimally invasive procedures such as transcatheter sclerotherapy, electrocoagulation or radiofrequency therapy, EVLT is delivered via a small-diameter, bendable fiber with surgical puncture; the laser energy penetrates to a shallow depth and causes less damage to surrounding tissues than energy sources that rely entirely on heat; EVLT can also be applied to patients who have been fitted with pacemakers. Compared with ultrasound-guided sclerotherapy, side effects such as accidental injection of sclerosing agent into the artery and allergic reactions are avoided, and the damage to the vein wall can be precisely controlled to reduce the recanalization rate [4]. Laser combined with surgical treatment can expand the indications for surgical treatment and achieve good efficacy. Later, under certain conditions and selection of appropriate patients, the treatment can also be carried out in outpatient clinics.
3.Pre-surgery preparation
(1) Routine laboratory tests and biochemical and functional examinations of important organs on admission.
(2) Ultrasound examination of varicose veins of lower limbs.
(3) Parallel venography of lower limbs.
4.Surgical procedure of EVLT
(1) Prepare for power on and check whether the laser is working normally before surgery. Connect the optical fiber, set the parameters: power 12W, repeat pulse mode (or continuous pulse mode), 1 second pulse, 1 second interval (i.e. the laser fires for one second and intermittently for one second). Set the laser to ready mode (ready) and a red targeting beam will be seen at the end of the fiber.
(2) Treatment position: supine position.
(3) Anesthesia selection: Epidural or general anesthesia, or local anesthesia option.
(4) A small transverse incision is made medial to the femoral artery pulsation, below the inguinal ligament and at the transverse crease at the root of the thigh, following the skin line; an incision about 2 cm long, extended if necessary. The subcutaneous tissue is bluntly separated with two small pulling grooves, and the saphenous vein is found on the superficial surface of the deep fascia, at the site of the oval fossa; at this point, the saphenous vein must be carefully identified from the femoral artery. The saphenous vein is freed and ligated and sutured at the proximal end, and the distal end is blocked with a vascular clamp for backup.
(5) A tourniquet is tied above the medial ankle, the saphenous vein is found at the medial ankle, and the saphenous vein is punctured with an 18-gauge puncture needle with a plastic outer casing in the 5F sheath set, and the needle is withdrawn after successful puncture, leaving the plastic cannula in place. Then, the 0.035 guidewire in the sheath group was introduced into the saphenous vein through the plastic cannula, withdrawn from the plastic cannula, and then inserted into the sheath tube through the guidewire.
(6) Through the sheath, a 0.035, 150-cm-long guidewire and a 5F straight-tipped catheter are inserted successively up to the inguinal incision at the root of the saphenous vein, and the catheter is determined to be in the lumen of the saphenous vein under direct vision, sometimes noting the presence of a double-branch saphenous vein.
(7) Withdraw the long guidewire and insert the fiber along the catheter to the tip of the catheter, which can be seen under direct vision as indicated by the red light at the tip of the fiber. The catheter is withdrawn 3 mm to 5 mm so that the end of the fiber is kept at a certain distance from the catheter. Then, the saphenous vein stump is ligated.
(8) At this point, push up the affected limb about 15 degrees to 25 degrees to empty the superficial vein of blood as much as possible. Start the laser machine and step down the foot switch while retracting the catheter and fiber at the same time at a distance of about 0.5 cm to 1 cm. the authors believe that if the internal diameter of the vein is thick, the distance of fiber retraction should be as short as possible to facilitate the destruction of the intima of the venous lumen.
(9) Through the skin, the end of the fiber can be positioned by looking directly at the end of the fiber through the red indicator light, or by ultrasound if available; reduce the brightness of the room and check the position of the end of the fiber again based on the red aiming light; press the red indicator light with the hand to make the end of the fiber close to the inner wall of the vessel for contact treatment mode. When the laser is fired, the surgeon slowly draws back the fiber at a distance of 3mm~5mm per second, and stops drawing back the fiber in the second between the two pulses, and treats at this speed until the desired saphenous vein is treated and the procedure is finished.
(10) The varicose veins in the lower extremities or the branch veins of the lower legs are treated with multi-point puncture fiber introduction.
(11) After the procedure, a compression bandage with an elastic bandage is applied, and a self-adhesive bandage is best. The duration of bandage should be no less than 2 weeks. Or wear a sequential decompression elastic stocking.
5.Post-operative precautions for EVLT
(1) Encourage the patient to get out of bed on the first day after surgery.
(2)Prophylactic antibiotic injection intramuscularly or intravenously for a total of 3 to 5 days.
(3) Compression bandage with elastic bandage for at least 14 days.
(4) May also be changed to sequential decompression elastic stockings after 3 days, 14 days to 2 months.
(5) Normal sports may be performed, avoiding hot baths for the affected limb and strenuous sports.
(6)If you have postoperative discomfort, you can take painkillers.