Layman's information on the new laser procedure
Patient Education: Endovenous Laser Procedure (EVLP) -
INTRODUCTION
Venous insufficiency from superficial reflux through varicose veins is a serious problem that usually is inexorably progressive if left untreated. When the refluxing circuit involves failure of the primary valves at the saphenofemoral junction, treatment options for the patient are limited, and early recurrences are the rule rather than the exception.
In a traditional surgical approach, ligation and division of the saphenous trunk and all proximal tributaries is followed by stripping or by avulsion phlebectomy. Proximal ligation requires a small incision at the groin crease. Patients with reflux at the level of the groin require ligation. Stripping of the vein may require additional incisions at the knee or below the knee and may associated with a high incidence of haematomas.
Ablation of the vein by endovenous laser (EVLP) is a newer procedure that is less invasive than surgery and has a lower complication rate but may have a higher rate of recurrence. The procedure is well tolerated by patients and produces good cosmetic results. Good clinical results are observed at 1-2 years, but the long-term effectiveness of EVLP is not yet known. Patients who have varicose veins with a diameter of more than 1.5 cm are not adequate candidates for this treatment. Patients at an early stage of disease respond well.
TECHNOLOGY
Endovenous ablation works by means of thermal destruction of the venous tissues. Laser energy from an 940-nm diode laser is delivered to the desired location inside the vein by using a bare laser fiber. When the laser is fired, it deposits thermal energy in the blood and venous tissues, causing irreversible localized venous tissue damage. The laser is repeatedly fired as the laser fiber is gradually withdrawn along the course of the vein until the entire vessel is treated. Although a hole may be created in the vessel wall where the laser beam makes contact with it, permanent ablation of the vein is caused by thermal injury to the entire circumference of the vessel.
Many laser sources are available for medical applications, and many lasers may be effective for endovenous ablation.
TECHNIQUE
Endovenous prcedure is of value in the treatment of truncal varicose veins (eg, greater saphenous vein) in patients with saphenofemoral incompetence. This procedure is also effective in the treatment of large branch veins and other large tributaries. Laser introducer catheters can be passed along small and crooked veins, but they cannot be passed along an extremely tortuous vein with ease.
For treatment of the greater saphenous vein and the saphenofemoral junction, ultrasonography is used to confirm and map all areas of reflux and to trace the path of the refluxing greater saphenous trunk from the saphenofemoral junction down the leg to the upper calf. An appropriate entry point is selected just above or just below the knee at a point that permits cannulation of the vessel with a standard or micropuncture needle introducer. The course of the vein, the saphenofemoral junction, and the anticipated entry point are marked on the skin with a surgical marker.
The leg is prepared and draped, and a superficial local anesthetic agent is used to numb the site of cannulation.
We prefer 2 techniques: the first in cases of saphenofemoral reflux is combined with a high tie at the level of the groin. The faser is then introduced through the vein in a retrograde way. The second technique is performed if there is minimal reflux at the saphenofemoral junction. Ultrasonography is used to guide needle puncture of the vessel. The Seldinger technique is used to place a guidewire into the vessel, and the guidewire is passed proximally to the saphenofemoral junction and into the femoral vein. A long introducer sheath (25-45 cm) is passed over the guidewire, which is removed.
Under ultrasonographic guidance, a dilute local anaesthetic agent is injected into the tissues surrounding the greater saphenous vein within its fascial sheath. An anesthetic is injected along the entire course of the vein from the catheter insertion point to the saphenofemoral junction. In most patients, 60-120 mL of lidocaine 0.25% is sufficient to anaesthetise and compress the vessel. Delivering the anaesthetic in the correct interfascial location with a volume sufficient to compress the vein and dissect it away from other structures along its entire length is important. Some practitioners prefer a local anaesthetic with epinephrine, whereas others prefer not to use epinephrine. The procedure is quick and does not cause early postoperative pain; thus, no long-acting local anesthetic agents are needed.
Ultrasonography is used to reconfirm the position of the laser fiber and catheter. The laser fiber tip is placed at the level of the subterminal valve of the saphenofemoral junction, and it should protrude approximately 2 cm from the end of the catheter sheath. Neither the fiber tip nor the laser beam should extend into the femoral vein because injury to the femoral vein may cause deep venous thrombosis.
When the laser console is switched on, a red aiming beam is visible through the skin at the level of the saphenofemoral junction. Failure to observe this beam is a reliable indication of malpositioning.
The console is set to deliver 12 J per pulse in 1-second pulses. The laser can be fired manually, but most often, it is controlled by a foot pedal with automatic pulses at 1-second intervals.
Manual pressure is applied to achieve venous wall apposition around the laser fiber tip, and the laser is fired. The sheath and laser fiber are pulled back approximately 3 mm; manual pressure is again applied, and the laser is fired again. This procedure is repeated along the entire length of the vessel to be treated. With pulses delivered once per second at 3-mm intervals, an entire 30-cm greater saphenous vein can be treated in 90 seconds.
If the vein is small, the laser energy may be adjusted to a lower intensity after the laser fiber has been withdrawn 5 cm or more below the saphenofemoral junction. In veins smaller than 0.5 cm in diameter, the laser energy can be reduced to 8 J per pulse, with no apparent change in the outcome.
On rare occasions, the patient experiences momentary pain if the laser is fired in an area with an adherent nerve. Subsequent laser pulses immediately below this position usually do not cause the same sensation, and the patient may be reassured that no postoperative paresthesias due to the procedure have been reported.
When the red guiding light is 2 cm from the entry point, the procedure is complete. The sheath and fiber are withdrawn from the skin, and pressure is applied to the puncture site for a few minutes.
Immediately after the procedure, ultrasonography shows a patent vessel that is in spasm through most or all of its length. Follow-up ultrasonography at 1 week demonstrates nearly 100% early closure of vessels.
FOLLOW-UP CARE
Compression is vitally important after any venous procedure. Compression can reduce the (theoretic) risk of venous thromboembolism in the treated and untreated leg, and it is also highly effective in reducing postoperative bruising and tenderness.
Postoperative bruising can be significant after endovenous laser treatment, but it is much less prominent when lidocaine with epinephrine is used as the local anesthetic. Bruising may be completely absent in patients who wear compression hose continuously during the first 2 weeks after treatment. Postoperative tenderness after day 3 has also been reported, and it may be related to the amount of intravascular clot in the closing vessel. Tenderness is usually not observed in patients who wear compression hose continuously during the first week after endovenous laser treatment.
Except when used by experts, wrapped bandages do not provide a safe or effective means of compression. Bandages may slip spontaneously, or the patient may remove them and reapply them incorrectly. The loss of gradient compression with the development of a tourniquet syndrome can increase the patient's risk for distal venous stasis and venous thrombosis. In the UK, gradient compression is most often applied by using surgical compression stockings. At least 30-40 mm Hg of compression is necessary for effective compression of the superficial veins.
Immediately after the procedure, a class II compression stocking (ie, one with a gradient of 30-40 mm Hg) is applied to the treated leg. Panty hose-style stockings, with compression applied to both legs, are preferred because the risk that the stocking will slip or roll is less. The stockings are worn for at least 1 week; they are kept in place continuously for the first 72 hours, but they may be removed for showering thereafter. Bedrest and heavy lifting are forbidden, but normal activity is otherwise encouraged.
The patient is re-evaluated on postoperative days 3 and 7, at which time duplex ultrasonography should demonstrate a closed greater saphenous vein and no evidence of thrombus in the femoral, popliteal, or calf deep veins. If the vessel is not closed by day 7, the procedure may be repeated.
At 6 weeks, an examination should reveal clinical resolution of truncal varices, and an ultrasonographic evaluation should demonstrate a completely closed vessel and no remaining reflux. If any residual open segments or branch veins are noted, perform sclerotherapy under ultrasonographic guidance.
COMPLICATIONS
Worldwide experience with this procedure is growing rapidly and few complications of the procedure have been reported to date.
Despite the absence of reported complications thus far, no procedure is without risks. Risk is associated with procedural problems such as malpositioning of the laser fiber. Any venous ablation procedure can trigger venous thrombosis in a susceptible patient.
OUTCOMES
Although the procedure is new, published results show a high early success rate with a low subsequent recurrence rate for as long as 18 months after treatment. Early results are comparable to those obtained with more invasive surgical techniques, but no evidence regarding the long-term effectiveness of the procedure exists.
Patient satisfaction with the procedure is high.
References
1. Feied CF: Peripheral venous disease. In: Rosen P, Barkin RM, eds. Emergency Medicine: Principles and Practice. 4th ed. Mosby-Year Book; 1998:chap 107.
2. Holme JB, Skajaa K, Holme K: Incidence of lesions of the saphenous nerve after partial or complete stripping of the long saphenous vein. Acta Chir Scand 1990 Feb; 156(2): 145-8[Medline].
3. Melliere D, Almou M, Lellouche D, et al: [Arterial complications following surgery or sclerotherapy of varices]. J Mal Vasc 1986; 11(1): 19-22[Medline].
4. Navarro L, Min RJ, Bone C: Endovenous laser: a new minimally invasive method of treatment for varicose veins--preliminary observations using an 810 nm diode laser. Dermatol Surg 2001 Feb; 27(2): 117-22[Medline].
5. Staunton MD: Some complications from surgery in varicose veins. Phlebologie 1982 Jan-Mar; 35(1): 329-35[Medline].
6. Weiss RA, Feied CF, Weiss MA: Vein Diagnosis & Treatment: A Comprehensive Approach. McGraw-Hill; 2001:1-304.
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Note: This information is designed to complement and not replace the relationship that exists with your existing family doctor or travel health professional. Please discuss your travel health requirements with your regular family doctor or practice nurse. |
