|HOW DO I DO IT?
|Year : 2021 | Volume
| Issue : 6 | Page : 153-156
Radiofrequency ablation of varicose veins, How do I do it?
Robin Man Karmacharya, Satish Vaidya, Amit Kumar Singh, Prasesh Dhakal, Sushil Dahal, Niroj Bhandari, Sohail Bade, Sahil Bade, Prabha Shrestha
Department of Surgery, Vascular Surgical Unit, Dhulikhel Hospital, Dhulikhel, Nepal
|Date of Submission||19-Jan-2021|
|Date of Acceptance||25-Jun-2021|
|Date of Web Publication||20-Jan-2022|
Robin Man Karmacharya
Department of Surgery, Vascular Surgical Unit, Dhulikhel Hospital, Dhulikhel
Source of Support: None, Conflict of Interest: None
Radiofrequency ablation (RFA) is one of the recent yet adequately studied minimal invasive surgery for varicose veins. The aim of this manuscript is to share our technique of RFA for varicose veins. The technique has been revised over time and has been standardized over all the surgeons doing this procedure in our institute. We have been using few of the terms to define specific scenario in relation to the procedure.
Keywords: Radiofrequency ablation, varicose veins, veins
|How to cite this article:|
Karmacharya RM, Vaidya S, Singh AK, Dhakal P, Dahal S, Bhandari N, Bade S, Bade S, Shrestha P. Radiofrequency ablation of varicose veins, How do I do it?. Indian J Vasc Endovasc Surg 2021;8, Suppl S2:153-6
|How to cite this URL:|
Karmacharya RM, Vaidya S, Singh AK, Dhakal P, Dahal S, Bhandari N, Bade S, Bade S, Shrestha P. Radiofrequency ablation of varicose veins, How do I do it?. Indian J Vasc Endovasc Surg [serial online] 2021 [cited 2022 Jul 4];8, Suppl S2:153-6. Available from: https://www.indjvascsurg.org/text.asp?2021/8/6/153/336098
| Introduction|| |
Varicose veins are prominent, dilated superficial veins usually seen in lower limbs and are associated with pain, heaviness, itchiness, pigmentation, and sometimes even ulceration.,, Worldwide incidence of varicose vein varies from 10% to 25% of adult population.,, This is more common in people engaged in longer duration of standing in their work.
Varicose veins can involve one or both of great saphenous veins (GSVs) and short saphenous vein. However, it is more common in GSV. In our earlier published series of varicose veins, 88.2% of varicose veins were in the GSV. Most common pathophysiology of varicose vein is junction incompetence (saphenofemoral junction [SFJ] in case of GSV and saphenopopliteal junction in case of short saphenous vein) followed by perforator incompetence. Endovenous treatment modalities are getting popularity for the management of this problem owing to less pain, less scar, earlier return to work.
Although many surgeons are practicing this technique there is a lack of uniformity in the surgical techniques as many variations exist leading to the same or similar results. We perform radiofrequency ablation (RFA) for the treatment of varicose veins and have been refining certain steps of RFA for better outcomes. The aim of this manuscript is to make vascular surgeons aware of how we are doing RFA. The details on this procedure are based on the experience of 1100 RFA of GSV cases performed at our institution from August 1, 2013, to December 31, 2020.
| Patient Selection|| |
RFA was done in all cases of varicose veins involving GSV (characterized by diameter of GSV more than 5 mm, superficial dilated and tortuous veins commonly in the anteromedial aspect of thigh and calf, reflux in the SFJ and dilated SFJ) unless there were contraindications for RFA.
| Principle of Radiofrequency Ablation of Great Saphenous Vein|| |
RFA uses an RFA catheter that heats local tissue at the site of direct contact, with the heat conducted to deeper tissue planes, causing collagen shrinkage, denudation of endothelium, and obliteration of the venous lumen.
| General Setup in Operation Theater|| |
Besides standard equipment for any major vascular surgery, equipment specific for RFA with/without adjunct procedure necessary are:
Radiofrequency ablation generator device
We are using RFA generator by Covidien termed as VNUS Closure fast RF generator. The device generates RF energy with the aim of reaching 120° centigrade within 3 s and continuing for a total of 20 s after which the temperature drops. For this, it generally fires between 10 and 20 watts.
Radio frequency ablation catheter
RFA catheter of length 60 and 100 cm are available. The length of the catheter to select for each patient depends on the height of the patient and the length of the straight segment of GSV being planned for RFA. In general, 60 cm catheter is generally used for patients with height <5 feet and 8 inches and 100 cm for patients taller than that.
The catheter consists of heating segment, endoluminal part, switch on/off button, and cabling to connect to the RF generator.
Doppler ultrasonography machine
We are using Kalamed KUT 500 machine with 7–12 MHz linear probe with appropriate gian and color settings.
Standard vascular surgical instruments such as scalpel, Debaky forceps, lid hook retractor, and mosquito forceps are used depending upon need during the surgical procedure.
| Procedure|| |
We usually prefer to do RFA in spinal anesthesia. For patients who want the procedure to be done as daycare, it can be done under IGEL or under intravenous analgesia plus local anesthesia. In some selected cases, RFA needs to be done under general anesthesia.
The procedure is done in supine position. If the concomitant procedure for short saphenous vein or ligation of perforators in short saphenous system needs to be done, supine followed by prone position is required.
Cannulation of great saphenous vein
The cannulation point can be decided based on the “Rule of 5” devised by us which includes the area of GSV which is most distal and is >5 mm in diameter, <5 mm from skin, 5 cm long segment, and no branches in that 5 cm. If this area is not present, the area which fulfills most of the criteria is selected. For cannulation, we prefer the “Geometry based cannulation” technique. We can as well use in-plane or out-plane techniques. Details are available in our previously published article relating to GSV cannulation.
Radiofrequency ablation preparation
Once GSV is cannulated, a guidewire is inserted which is then exchanged with a dilator and sheath as in standard Seldinger's technique. If there is some problem in inserting the dilator, a small (2–3 mm) nick can be given beside the guidewire (noting the scalpel direction is opposite the guidewire). Then the dilator is taken out by doing a twisting movement and pulling back. The presence of the sheath inside the vein is noted by observing blood in the side tail of the sheath. After this, the sheath is closed by putting the knob in the side tail in off position. Then 60 cm or 100 cm length RFA catheter is measured over the skin simulating the tentative course of GSV. A marker is placed on the catheter which is expected to be at the level of end of sheath. Then the RFA catheter is moistened by normal saline and is inserted inside the sheath. While inserting the catheter, as per our experience, it is safest to insert a maximum of 2 cm of the catheter at one time. We call it a “Rule of 2 cm” as anything above this length has a risk of kinking the catheter and can damage the integrity of the catheter. If any resistance is noted, we first try pulling out the catheter by about 1 cm and pushing it in again. If this technique is not successful, we do the “Lateral Pulling Maneuver” in which the bulk of muscle over the area where RFA cannot be negotiated is pulled laterally by the left hand and the right hand is used to gently push the catheter. If this is also not possible, we proceed with “Ultrasound guided technique” of negotiating the catheter in which the troubling tributaries is selectively pressed (using finger or peanut) making passage of RFA in GSV easier. Despite all the maneuvers, if RFA cannot be negotiated, it needs to be done in “Double prepuncture technique.”
Finalizing radiofrequency ablation catheter tip position
RFA catheter is inserted to GSV up to 2 cm away from SFJ. An easy guide for this position is to remember that this position is usually just distal to a prominent lymph node near the junction. This is also distal to the inferior epigastric branch of GSV. In transverse position, distance between GSV and femoral vein is measured which is desired to be around 2–2.5 cm. Then “Perpendicular Movement Maneuver” is done to change the view from transverse to longitudinal view. In this maneuver, the probe is moved about 2 cm distally first. With GSV in the centerline of the screen, the probe is turned in clockwise direction such that the mark in the probe is being turned cephalad. Point to be noted is that during the maneuver, GSV should always be in the centerline of the screen. It is common that GSV can be swayed to the right or left side during which the probe should be gently adjusted to put GSV in the center. Once complete perpendicular movement is done, we can see GSV traversing from right to left part of the screen. Minor adjustment of the probe to the right or left side is needed to get a better view. The whole of the probe is shifted slightly cephalad (1–2 cm) to get a good view of femoral vein, SFJ, and GSV. Then the distance between SFJ and RFA catheter tip is measured which is also expected to be 2–2.5 cm as shown in [Figure 1]. In experienced hands, this whole process takes less than a minute.
|Figure 1: Distance of radio frequency ablation catheter tip to sapheno femoral junction|
Click here to view
Finalizing RFA catheter tip position is extremely vital; if the catheter tip is too near the junction, it can cause deep vein thrombosis (DVT) and if it is too far it can cause recurrence. So we devised a sign called “Vanishing sign” for reconfirming the final position of the catheter. Here, the probe is gently pulled by about 1 cm during which we should note the complete absence of catheter (no acoustic shadow, no hyperechoic picture (“tika” like phenomenon) which comes back once the catheter is gently pushed. Another technique is to gently move the probe in caudal direction during which vanishing of the probe should also be noted. We feel this is the most confirmatory sign for RFA tip localization.
After all these preparations, marking of GSV course is done using a sterile permanent marker. For this, ultrasonography probe is placed in a transverse position in the junction and a mark is made just below the probe. Here, if we place GSV in the center, the marking should be done at the center of the probe. An acoustic shadow thus formed should correspond to the GSV. This process is repeated by shifting the probe distally by about 5 cm distally until it reaches the cannulation site. In a thinly built patient, we can palpate the RFA catheter and mark (usually possible in region distal to knee). Then, all the marks are joined to note the complete course of GSV.
Injecting perivenous fluid
There are various options of making perivenous fluid. As most of the cases are done in spinal anesthesia followed by IGEL, local anesthesia is not mixed in the perivenous fluid. We use warmed normal saline (expected temperature around 40°C) in which injection ceftriaxone sodium is added. Some practice putting sodium bicarbonate. If the case needs to be done under local anesthesia, a cocktail of local anesthesia including 20 ml of 2% plain lidocaine and 10 ml of 0.5% bupivacaine need to be added for both short- and long-term effects.
The popular five reasons for injecting perivenous fluid are:
- It takes space between the vein and skin. So this prevents skin from burning
- Because of the physical weight of the fluid in confined space, it compresses the GSV so that better contact with the RFA catheter is present
- If the perivenous fluid is prepared with higher sodium content, due to osmosis, the fluid from lumen of GSV moves towards the perivenous region causing decrease in lumen size and helping in ablation
- The perivenous fluid is preheated to about 40°C. This will also slightly preheat GSV before ablation
- After ablation, there can be some bleeding especially in the areas where there are tributaries or where the GSV is too large. In such scenarios, perivenous fluid will cause hemostasis.
We prefer to inject perivenous fluid by using two 20cc syringe injecting from either side of GSV. However, to begin with, we have to see a triangle made by GSV, Femoral vein and lymph node (in transverse view at the level of tip of RFA catheter). We term this as “Dhulikhel Triangle.” Here 10–15cc of normal saline is injected such that the distance between GSV and femoral vein increases. This will help prevent DVT. In our series of 950 RFAs (till the time this manuscript is being written), we only have had one case of DVT detected after 8 days of surgery (in the first follow-up).
Following this, the needle in the syringe is bent, and fluid is injected on either side of the GSV making sure to insert the needle fully in the correct plane and slowly withdrawing the needle while injecting the fluid. We prefer to inject about 10cc fluid per cm of the vein.
Once all the preparation is done, final reconfirmation is done with the scrub nurse. Scrub nurse should check that the final position of RFA catheter was checked by ultrasound guidance and that the perivenous fluid was injected. Then using a tetra, gentle compression is given at the location of the RFA catheter heating segment and RFA is switched on. The RFA machine is set to heat the heating segment to 120°C within 3 s and maintain that for 17 s (total 20 s). The wattage changes so as to maintain the temperature to 120°C. Normally the wattage is between 10 and 20 W. If more wattage is required, we can either give more compression or inject more perivenous fluid. Two segment RFA is done in the first segment, last segment, and segments where there is perforator or distal insufficiency point or major tributaries. Also in areas where the diameter of GSV is more than 1 cm, double RFA is recommended.
After every segment RFA, the catheter is withdrawn 6.5 cm. So there is overlap of 5 mm as the heating segment is 7 cm. For ease, there are marks present in the RFA catheter. While pulling the catheter out, it should be noted that if “zebra cross” marks are seen. We need to pull the sheath as well before continuing RFA as the heating segment is close to the sheath. After the zebra cross mark, we can see a mark mentioning 11 followed by 7 and the last mark is 3. These indicate the distance in cm remaining for RFA to be done.
Things to note while doing RFA:
- Never push RFA catheter after distal segment is burnt
- Note the presence of zebra cross sign indicating that the sheath is nearby the burning segment and thus should be pulled
- Note the presence of mark “3” which indicates the last segment (3 cm away from the cannulation site). Here double segment RFA is usually done.
After RFA is done at all the segments, the catheter should be pulled. While pulling the catheter, the temperature of the heating segment (can be seen in the RFA generator device) should be <60°C otherwise there is risk for burn-in skin or in the gloves or surgeon or nurses. During completion of the RFA catheter pulling, gentle compression in GSV distal to cannulation site should be done so as to limit bleeding from the distal GSV. Usually, we do not expect bleeding from the proximal part of GSV (where RFA is done). In some cases, we put one suture over the cannulation scar using 3'O vicryl. Details on position of limb during cannulation, double pre-puncture technique for RFA and typical appearance of perforator vein are shown in [Figure 2],[Figure 3],[Figure 4] respectively.
|Figure 2: Standard position during cannulation. For ease in visualization, a second monitor can be used opposite the surgeon which is connected to the ultrasonography device|
Click here to view
|Figure 3: After successful cannulation followed by insertion of radio frequency ablation catheter and marking over the course of the vein. Presence of guidewire in second great saphenous veins (in case of duplicated great saphenous veins) can also be seen which is termed as “Double Prepuncture Technique”|
Click here to view
|Figure 4: A typical appearance of perforator vein. If great saphenous veins is cannulated distal to perforator, this segment of vein needs ablation for 2 times|
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| Conclusion|| |
The steps for RFA of GSV mentioned above are to be kept in mind during the procedure and some modification might be needed as per the disease condition. Standardization of the procedure helps in easier teaching of the procedure to vascular surgeons and will result in the desired outcome.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]