2:35 p.m. Percutaneous Techniques for Treatment of Saphenous Vein Reflux: Radiofrequency Melvin Rosenblatt, MD Connecticut Image-guided Surgery Milford, CT Introduction The development of superficial varicosities is a consequence of valvular dysfunction within the superficial venous system. When valves fail, high venous pressure leaks into the superficial venous system causing the thin waJled superficial veins to dilate and become varicose. The partern of varicosities follows well-defined anatomical pathways. These patterns provide important clues to the precise origin of high-pressure Jeaks into the superficial venous system. Appropriate treatment is directed towards eradicating these leaks. Traditionally, surgical ligation Ol' vein stripping has been performed to eliminate these leaks. These treatments can be very painful and often require a prolonged recovery. Recently, new percutaneous endovenous techniques have been introduced that permit noninvasive treatment of superficial venous insufficiency. These procedures are far less painful and recovery is quite rapid. The reduced invasiveness of these techniques is a consequence of image guidance. Ultrasound is used almost exclusively to guide these procedures. However, f1uoroscopy, which is rarely used, can be a very useful adjunct. This syllabus will initially and primarily review superficial venous anatomy of the lower extremity because its' understanding is essential for appropriate diagnosis and subsequent treatment of superficial venous insufficiency. Subsequently, noninvasive treatment modalities will be briefly reviewed. Venous Anatomy of the Lower Extremity CVowden,1998,449) The venous drainage from the lower extremity is split into the deep and superficial venous systems. The deep veins are located below the deep fascia. The deep fascial layer is a dense fibrous membrane that surrounds the entire lower limb like an elastic stocking. This fascial layer serves as a functional boundary between the deep and superficial veins. Ali veins above this fascial !ayer are considered part of the superficial venous system. Some of the larger superficial veins are contained within the superficial fascia. The superficial fascia is composed of a layer of loculated fatty tissue known as Campers fascia and a deeper layer of collagen and elastic tissue known as Scarpa's fascia. The superficial fascia surrounds the saphenous trunks, however, many of the tributaries arising from the saphenous vein are superficial to this fascial layer. Deep Venous System Deep venous drainage of the lower calf is accomplished through three groups of veins. The anterior tibia! vein
P6
Extemal iliac veln __- - Commonfemoral vein . - . _ - - Oeep temoral veln
_-+- Femoral veln
Popliteal segment ot temoral veln
---"r--- Anterior t1bial velns ...+ - - Peronealveins f-lr--
~-+--
Posterior tiblal veins Plantar metatarsal veln
Figure 1. Deep venous system.
drains the dorsum of the foot. The postetior tibial vein drains the sole of the foot, and the peritoneal vein drains the lateral aspect of the foat. These veins, which are often paired, ascend up the calf and coalesce to form the popliteal vein. The popliteal vein continues upward and becomes the femoral vein as it passes through the adductor cana!. The femoral vein, after traversing the !ength of the thigh, then joins with the deep femoral vein Ol' profunda vein to form the corrunon femoral vein (CFV). The CFV then traverses underneath the inguinal ligament to become the external iliac vein. These deep veins contain valves, all of which selve to prevent retrograde flow of blood in the deep system (Fig 1).
Superfi.cial Venous System The superficial venous system can be divided into three major divisions: the greater saphenous system, the lesser saphenous system and the lateral venous system. Each of these divisions gives rise to multiple branches. The branches that extend superficially are termed tributaries and often form the visually apparent varicosities. Branches that extend inward to perforate the deep fascia and communicate with the deep venous system are termed perforators.
Greater Saphenous Vein The greater saphenous vein (GSV) (Fig 2) originates as a continuation of the media! venous arch of the foot. This vessel courses upward, anterior to the medial malleolus, and continues along the anterior medial aspect of the cal( to the leve! of the knee, At this level, the saphenous nerve is in c10se proximity to this portion of the vein and, therefore, is susceptible to inadvertent injury during saphenous vein ablation, The saphenous nerve innervates the skin on the medial surface of the leg and with its infrapatellar branch innervates the skin just below the patella, At the knee, the vessel courses more medially, running along the medial aspect of the thigh, to join with the common femoral vein in the groin, From the upper calf tO the groin, the greater saphenous vein is usually contained within an envelope of superficial fascia!. This fascial envelope helps to limit dilatation of the greater saphenous vein even when it is exposed to high venous pressures, Typically, the greater saphenous vein normally measures only 3-4 mm at the level of the mid thigh, Unfortunately this fascial covering is often not effective and diseased saphenOLIs vejns can enlarge to diameters well above 10 mm, The GSV has several tributaries, which arise at variable points along its course, In the thigh, several large important tributaries are notable, Arising off of the upper portion of the greater saphenous vein in hunter's canal, are the anterior and posterior accessory saphenous veins, These vessels run paraliel to the greater saphenous vein, The epigastric vein, superficial circumflex vein and pudendal veins are all relatively constant tri butaries that arise off the upper portion of the greater saphenous vein, The anterolateral thigh vein often arises off the mid 01' upper portion of the great~r saphenous vein and courses anteriorly than laterally down the leg, The posterior medial tributalY often arises from the greater saphenous vein in the mid thigh, This vessel courses medially and posteriorly down the leg, In the calf, an anterior tributalY commonly arises off of the greater saphenous vein just bellow the level of the knee, Additionally, a posterior branch, termed the posterior arch branch, arises from the greater saphenous vein below the knee and runs paralleI to it to connect with the dorsal arch vein of the foot. Perforators occur along the entire course of the GSV and extend inward to connect with the deep venous system, These perforators are variable in number and position, Despite this variability, several characteristic groups of perforators are faidy constant. In Hunter's canal, commonly there are perforators arising from the proximal greater saphenous vein connecting to the femoral vein, This group of perforators is known as Hunterian perforators, Arising from the lower mid greater saphenous vein is a group of perforators called Dodd perforators, Below this level, in the medial mid-calf, arismg off the GSV or its tributaries, are a group of perforators termed Boyd's perforators, Lastly, perforators arisjng from the posterior arch vein, along the posterior
aphenofemoral junctlon -
Eplgastric veln
Superficlal clrcumflex -
Pudendal veln
Anterolateral thlgh trlbutary
Ant8rlor thigh veln Graaler saphenous Veln
Ant8rlor branch
Po.terlor branch
Graaler saphenous veln
Corsal arch
Figure 2. Saphenous venous system,
medial aspect of the anJde are termed Cockett's perforators, GSV is the sapheThe termination point for the GSv nofemoral junction where the GSv GSV drains into the common femoral vein, This junction contains valves, which prevent high-pressure reflux mto the GSV from the CFV, The terminal valve of the GSV is located within the junction itself. Below this level are additional valves termed subterminal valves, In most instances, onJy a single subtermjnal valve can be identified and is located approximately 1 cm distal to the terminal valve. Frequently an additional subterminal valve also occurs and is usually noted within 3 cm of tlle saphenofemoral junction. AJong the course of the GSV are several other valves, which hel p to maintain an upward f10w of blood.
Lesser Saphenous Vein The lesser saphenous vein (LSV) (Fig 3) arises along the lateral aspecl of the foot as a continuation of the dorsal venous arch. This vessel passes posterior to the lateral malleolus and extends up the posterior calf towards the knee. In this region the medial cutaneous sural nerve accompanies the LSV. This nerve later joins the peroneal communicating branch to form the sural nerve, which innervates the skin along the posterior leg and lateral foot. The LSV is surrounded by two superficial fascial layers and traverses between the two heads of the gastrocnemius into the popliteal fossa. The termination of the lesser saphenous vein is highly variable, Most commonly, the vessel terminates into the popliteal vein just above the popliteal fossa. In some instances, the lesser saphenous vein extends up along the posterior thigh and in the mid-thigh, divides into several branches, which pg
• - - - - f - Femoral veln
Veln
ot Glacomini
""'--4-
Short saphenous -..-+-- I veln
Short saphenopopliteal junction
1-1'---- Posterlor arch
branch
Figure 3. Lesser saphenous venous system.
then connect to the femoral vein. In some instances, the lesser saphenous vein terminates into the vein of Giacomini. This vein is a commonly occurring connection between the lesser saphenous vein and the upper portion of the greater saphenous vein. This vessel travels along the posterior aspect of the thigh and in the upper third of the thigh courses medially to connect with the greater saphenous vein. Lateral Su.bdermic VenotlS System The lateral venous system (Fig 4) also known as the 1ateral subdermic venous system is a system of smali caliber veins located along the lateral aspect of the leg. These veins extend both above and below the knee. In contradistinction to other superficial veins, normai venous flow in this system is downward from the collecting veins in the proximal thigh towards lateral thigh perforators and perforators at the knee. It has been postulated that varicosities of this lateral subdermic venous system are a result of a developmental defect where embryologically, these superncial veins and their connections to the deep venous system failed to involute normally. This persistent communication to the deep system results in high venous pressure in these thin walled vessels and as a consequence, prominent telangiectasias and venulectasias form along the lateral and posterior thigh. Often these prominent varicosities are associated with symptoms of buming and focal sensitivity.
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Figure 4. Lateral subdermic venous system.
Gastrocnemial Tributaries Varicosities along the posterior calf may be completely independent from the saphenOlIS veins. These varicosities may instead arise from incompetent perforators that connect directly to deep muscular veins within the calf. Commonly these connections are to the gastrocnemial veins. The gastrocnemial veins originate in the venous sinuses buried deep within the gastrocnemills muscle. The drainage of these vessels is variable. Normally, they join the peritoneal vein to drain ioto the popliteal vein. However, on many occasions, these veins terminate ioto the popliteal vein adjacent to the termination point of the lesser saphenous vein. Perforating Veins As mentioned previously, perforating veins are veins that connett the superncial veins to the deep venous system. These vessels pass obliquely through fascial defects between muscle bundles. These vessels, which normaII norma li y measure between 1-2 mm, contain valves that onJy permits flow from the superficial venous system into the deep. Occasionally, these vessels do not contain any valves. However, their oblique course through the muscle is uSllally sufficienl to prevent reflllx. The number of perforators fOllnd in the leg varies greatly. Some repolts suggest that more than 15,000 perforators can occur within a leg. In general, these perforators are more commonly found in the distal calf as opposed to the high by factor 8:1. The majority of perforating veins are located on either side of the sartorius and peritoneal musc!es and between the vastuslateralis and hamstring muscles. In
most instances an artery closely accompanies d1ese perforating veins. The vast number of perforators present in a lower extremity prevents naming individual perforating veins. In generał, d1ese veins are considered in loose regional groupings. Hunterian, Oodd's, Boyd's, and Cockett perforators are four distinct groups of perforators d1at commonly occur and are associated with the greater saphenous vein Ol' its tributaries (Fig 5). ReAux within any of these perforators can result in varicose veins even in the absence of ref/ux within the saphenous system. Besides these four groups of perforating vessels, d1ere are many other unnamed groups of perforators, which can cause varicosities if incompetent. Thus, it is important to search for incompetent perforators when evaluating patients for varicosities. Duplex ultrasound is the oniy defmitive modality where by these perforators can be identified. Diagnosis Duplex color Aow ultrasound evaluation of the venous system of the lower extremity must always be the first step in evaluating patients wid1 c1inical evidence of Sl1perficial venous insufficiency. This examination should be condl1cted wid1 d1e patient in the upright position. In this position upward venous f/ow can be appreciated in the GSV when d1e calf is manually compressed. Upon compression completion upward f/ow halts and retrograde f/ow is prevented by valve closure. If valvular dysfunction is present then retrograde f/ow is not prevented. This abnormaJ f/ow can be appreciated with color-Aow Ol' Doppler imaging. Normally, after compression, 0.5 seconds Ol' less of retrograde f1ow, can be appreciated. This f/ow represents the time required for normai valve ciosu re. However, retrograde f/ow lasting greater then 0.5 seconds is considered abnormal and is consistent with venous reAux. Treatment Modalities Endovenous RF Ablation
When significant venous ref/liX is found treatment is directed towards the obliteration of the abnormal vein from its' deep venous origin. The C1osUl'e device (VNUS Medical Technologies, Sunnyvale, CA), which is FDA approved, accomplishes this task by applying radio frequency (RP) thermal energy to d1e wall of vein via a endovenous approach (ChandleI', 2000, 733; Kabnick, 2001, 734; Manfrini, 2000, 725; Pichot, 2000, 85; Goldman, 2000, 78). A 6- or 8-F catheter containing retractable e1eetrodes delivers d1e RP energy. This catheter, which is placed percutaneously, is connected to a generator that controls the RF output. Electrode temperature is maintained at 85°C to denature the collagen in the vessel wall. The device is slowly retracted (l-2 cm/min) so that the d1ermal energy is distribl1ted along the course of the vessel causing the treated portion of d1e vessel to contract and occlude. Tumescent anesthesia, which involves infiltrating the perivenous space with a large volume of 0.25% Iidocane, is l1tilized to provide pain
Hun~n perforator(s) in. proximal thigh
Oodd perforator(s) in distal thigh Boyd's perforator(s) around the knee
Cockett's perforators of the posteńor arch vein
Figure 5. Venous perforators.
relief and skin protection. This device is most commonly used to obliterate an abnormal GSV. However, other ref/uxing veins can be treated provided their course is straight enough to allow d1e catheter to pass.
Endovenous Laser Tberapy Endovenous laser therapy (EVLT), currendy only available for investigational use, is similar to endovenous RP therapy in that it delivers thermal energy to the wall of the abnormal vein to obliterate it (Navarro, 2001, 23). The thermal energy with d1is techniql1e is prodl1ced by a laser and delivered to the vein wall by a thin optical fiber. 111e tip temperature generated by this techniql1e is very high causing rapid destmction of d1e vessel collagen. Consequendy, the fiber can be retracted quickly permitting rapid treatment of the entire length of abnormai vein. Retraction time for this technique is l1sually less then 5 minlltes as opposed to RP ablation, which requires significandy longer retraction times. The optical fiber lItilized with this technique is inexpensive but can only be delivered tłuough a previously placed cad1eter Ol' sheath. Typically, a long 5F sheath is placed into the GSV and advanced to the saphenofemoral junction. The laser fiber is then advanced through d1e sheath and beyond it opening. With me fiber in position d1e laser is activated and the sheath and fiber are retracted together. ]ust as with RP tumescent anesd1esia along d1e entire course of the vein that is to be treated is needed. Sclerotherapy Sclerosants are often used for the trearrnent of varicose veins. Detailing the various agents and their proper use is beyond the scope of this syllabus (Green, 1998, 560; Green, 1998, 565; Tessari, 2001, 59]. However, image-
P11
guided sc1erotherapy can be helpful in treating primary sources of ref]ux that are not amenabJe to treatment with other percutaneous modalities. Sc1erosants can be injected, under direct f]uoroscopic guidance, into these vessels and held in place with the use of occ1usion balloons. This technique prolongs the vessels exposure to the sc1erosant, thus increasing effectiveness, while reducing the likelihood of injury to deep venous structures. Typically, we utilize sotrodecol to accomplish this task. Sotrodecol is usually effective in concentrations of 1% to 2%. Higher concentrations in supemcial veins can result in permanent, disfiguring, skin piginentation. Additionally, the inf]ammatory response associated with the use of sc1erosants can be severe and prolonged often lasting several months. Because of this, it is our practice to only utiJize this technique for the treatment of deeper vessels that have been documented as the source of reflux. Sc1erotherapy, for the treatment of superficial, visibly apparent varicosities can be effective but should only be utilized after the primary ref]uxing sources have been treated. In this situation imaging guidance is rarely needed.
Ambulatory Phlebectomy Surgical removal of large visibly apparent varicosities is cOl1UnonJy performed. Often multiple smali (1-2 cm) incisions are made along the course of the vein removing it in segments. Unfortunately, this technique can leave scars that are cosmetically displeasing. Ambulatory phlebectomy accomplishes the same thing but is performed with specialized "hooks" through tiny skin punctures (De Roos, 1998, 542; OJivencia, 1997, 658; Olivencia, 1997, 702; Otley, 1999, 241; Ramelet, 1997, 646; Ricci, 1998, 543). This technique is easily preformed with local anesthesia and leaves little scaring in its' wake (Smith, 1998, 544). A detailed description of this technique is beyond the scope of this syllabus and I refer the reader to the cited references. Conclusion The formation of varicosities in the lower extremity results from a high-pressure leak out of the deep venous system into the superficial venous system. Often these leaks occur at well-established junction points between the two systems. Treatment focuses on eradicating these points of pathologicaJ communication. Thus, the physician faced with diagnosing and treating this disorder, must be thoroughly familiar with the anatomy of the superficial venous system and its variations. Additionally, the introduetion of new percutaneous techniques for the treatment of this disorder has been a godsend to aff]icted patients. In contradistinction to open surgical therapies, these new techniques can be performed under local anesthesia with minimai discomfort. Post procedure recovery is often insignificant with patients returning to normal activities within a day or two. The key to these new treatment techniques is image guidance. The intelventional radiologist, having access to sophisticated
P12
imaging tools and the expertise to use them, is ideally suited to treat this disorder.
3:05 p.m. Percutaneous Techniques for Treatment of Saphenous Vein Reflux: Endovenous Laser Robert]. Min, MD Comell Vascular New York, NY The greater saphenous vein (GSV) is the major vein of the superficial venous system. GSV reflux is often associated with large supemciaJ varices. When incompetence of the saphenofemoral junction (SP)) is detected, treatment should first be directed towards eliminating this source of reflux with ablation of the incompetent venous segments. The traditionaJ approach to treating SP] incompetence with GSV reflux has been surgical Iigation and stripping. The drawbacks of surgery inc!ude risks associated with general anesthesia, surgical complications (paresthesia, bleeding, infection, scars), increased in-hospital costs, and prolonged recovery periods. In addition to the potentiaJ risks of surgery and the more extensive anesthesia needed for ligation and stripping, surgical treatment of the GSV is not free from recurrence. Sarin et al (1) reported an 18% rate of recurrent GSV refJux following Iigation and stripping and a 45% rate of recurrence following high Iigation alone, appearing as early as 3 months foJlowing treatment. Similarly, Dwerryhouse et al (2) found a recurrence rate of 29% foJlowing Iigation and stripping of the GSV and 71% following high ligation alone. In recent years, less invasive alternatives to surgical treatment of the incompetent GSV have been explored. MinimaJly invasive treatment aJternatives seek to reduce risk, morbidity and cost while leading to acceptable short- and long-term results. Early attempts to selectively damage saphenous veins in order to occlude them, as an alternative to stripping, involved electrocoagulation. The search for less invasive treatment alternatives has more recently led to the development of uJtrasound-guided sclerotherapy. These techniques appear to be useful in expert hands with an estimated 50o/(}-BO% 1-year efficacy. Major risks of sclerotherapy of saphenous veins include anaphylaxis and intra-arterial injection, although the risk of the latter complication may be reduced with transeatheter techniques (3). Poam sclerotherapy may improve efficacy but probably does not decrease risk. The newest minimally invasive technique to be developed is endovenous laser. Endovenous laser treatment allows delivery of laser energy directly into the blood vessel lumen in order to produce endothelial and vein wall damage with subsequent fibrosis.
Technique Pollowing ultrasound mapping of the SP] and incompetent GSV, an entry point is chosen. The GSV is usuaJly entered at the knee level, below the Hunterian canal
P6
Extemal iliac veln __- - Commonfemoral vein . - . _ - - Oeep temoral veln
_-+- Femoral veln
Popliteal segment ot temoral veln
---"r--- Anterior t1bial velns ...+ - - Peronealveins f-lr--
~-+--
Posterior tiblal veins Plantar metatarsal veln
Figure 1. Deep venous system.
drains the dorsum of the foot. The postetior tibial vein drains the sole of the foot, and the peritoneal vein drains the lateral aspect of the foat. These veins, which are often paired, ascend up the calf and coalesce to form the popliteal vein. The popliteal vein continues upward and becomes the femoral vein as it passes through the adductor cana!. The femoral vein, after traversing the !ength of the thigh, then joins with the deep femoral vein Ol' profunda vein to form the corrunon femoral vein (CFV). The CFV then traverses underneath the inguinal ligament to become the external iliac vein. These deep veins contain valves, all of which selve to prevent retrograde flow of blood in the deep system (Fig 1).
Superfi.cial Venous System The superficial venous system can be divided into three major divisions: the greater saphenous system, the lesser saphenous system and the lateral venous system. Each of these divisions gives rise to multiple branches. The branches that extend superficially are termed tributaries and often form the visually apparent varicosities. Branches that extend inward to perforate the deep fascia and communicate with the deep venous system are termed perforators.
Greater Saphenous Vein The greater saphenous vein (GSV) (Fig 2) originates as a continuation of the media! venous arch of the foot. This vessel courses upward, anterior to the medial malleolus, and continues along the anterior medial aspect of the cal( to the leve! of the knee, At this level, the saphenous nerve is in c10se proximity to this portion of the vein and, therefore, is susceptible to inadvertent injury during saphenous vein ablation, The saphenous nerve innervates the skin on the medial surface of the leg and with its infrapatellar branch innervates the skin just below the patella, At the knee, the vessel courses more medially, running along the medial aspect of the thigh, to join with the common femoral vein in the groin, From the upper calf tO the groin, the greater saphenous vein is usually contained within an envelope of superficial fascia!. This fascial envelope helps to limit dilatation of the greater saphenous vein even when it is exposed to high venous pressures, Typically, the greater saphenous vein normally measures only 3-4 mm at the level of the mid thigh, Unfortunately this fascial covering is often not effective and diseased saphenOLIs vejns can enlarge to diameters well above 10 mm, The GSV has several tributaries, which arise at variable points along its course, In the thigh, several large important tributaries are notable, Arising off of the upper portion of the greater saphenous vein in hunter's canal, are the anterior and posterior accessory saphenous veins, These vessels run paraliel to the greater saphenous vein, The epigastric vein, superficial circumflex vein and pudendal veins are all relatively constant tri butaries that arise off the upper portion of the greater saphenous vein, The anterolateral thigh vein often arises off the mid 01' upper portion of the great~r saphenous vein and courses anteriorly than laterally down the leg, The posterior medial tributalY often arises from the greater saphenous vein in the mid thigh, This vessel courses medially and posteriorly down the leg, In the calf, an anterior tributalY commonly arises off of the greater saphenous vein just bellow the level of the knee, Additionally, a posterior branch, termed the posterior arch branch, arises from the greater saphenous vein below the knee and runs paralleI to it to connect with the dorsal arch vein of the foot. Perforators occur along the entire course of the GSV and extend inward to connect with the deep venous system, These perforators are variable in number and position, Despite this variability, several characteristic groups of perforators are faidy constant. In Hunter's canal, commonly there are perforators arising from the proximal greater saphenous vein connecting to the femoral vein, This group of perforators is known as Hunterian perforators, Arising from the lower mid greater saphenous vein is a group of perforators called Dodd perforators, Below this level, in the medial mid-calf, arismg off the GSV or its tributaries, are a group of perforators termed Boyd's perforators, Lastly, perforators arisjng from the posterior arch vein, along the posterior
aphenofemoral junctlon -
Eplgastric veln
Superficlal clrcumflex -
Pudendal veln
Anterolateral thlgh trlbutary
Ant8rlor thigh veln Graaler saphenous Veln
Ant8rlor branch
Po.terlor branch
Graaler saphenous veln
Corsal arch
Figure 2. Saphenous venous system,
medial aspect of the anJde are termed Cockett's perforators, GSV is the sapheThe termination point for the GSv nofemoral junction where the GSv GSV drains into the common femoral vein, This junction contains valves, which prevent high-pressure reflux mto the GSV from the CFV, The terminal valve of the GSV is located within the junction itself. Below this level are additional valves termed subterminal valves, In most instances, onJy a single subtermjnal valve can be identified and is located approximately 1 cm distal to the terminal valve. Frequently an additional subterminal valve also occurs and is usually noted within 3 cm of tlle saphenofemoral junction. AJong the course of the GSV are several other valves, which hel p to maintain an upward f10w of blood.
Lesser Saphenous Vein The lesser saphenous vein (LSV) (Fig 3) arises along the lateral aspecl of the foot as a continuation of the dorsal venous arch. This vessel passes posterior to the lateral malleolus and extends up the posterior calf towards the knee. In this region the medial cutaneous sural nerve accompanies the LSV. This nerve later joins the peroneal communicating branch to form the sural nerve, which innervates the skin along the posterior leg and lateral foot. The LSV is surrounded by two superficial fascial layers and traverses between the two heads of the gastrocnemius into the popliteal fossa. The termination of the lesser saphenous vein is highly variable, Most commonly, the vessel terminates into the popliteal vein just above the popliteal fossa. In some instances, the lesser saphenous vein extends up along the posterior thigh and in the mid-thigh, divides into several branches, which pg
• - - - - f - Femoral veln
Veln
ot Glacomini
""'--4-
Short saphenous -..-+-- I veln
Short saphenopopliteal junction
1-1'---- Posterlor arch
branch
Figure 3. Lesser saphenous venous system.
then connect to the femoral vein. In some instances, the lesser saphenous vein terminates into the vein of Giacomini. This vein is a commonly occurring connection between the lesser saphenous vein and the upper portion of the greater saphenous vein. This vessel travels along the posterior aspect of the thigh and in the upper third of the thigh courses medially to connect with the greater saphenous vein. Lateral Su.bdermic VenotlS System The lateral venous system (Fig 4) also known as the 1ateral subdermic venous system is a system of smali caliber veins located along the lateral aspect of the leg. These veins extend both above and below the knee. In contradistinction to other superficial veins, normai venous flow in this system is downward from the collecting veins in the proximal thigh towards lateral thigh perforators and perforators at the knee. It has been postulated that varicosities of this lateral subdermic venous system are a result of a developmental defect where embryologically, these superncial veins and their connections to the deep venous system failed to involute normally. This persistent communication to the deep system results in high venous pressure in these thin walled vessels and as a consequence, prominent telangiectasias and venulectasias form along the lateral and posterior thigh. Often these prominent varicosities are associated with symptoms of buming and focal sensitivity.
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Figure 4. Lateral subdermic venous system.
Gastrocnemial Tributaries Varicosities along the posterior calf may be completely independent from the saphenOlIS veins. These varicosities may instead arise from incompetent perforators that connect directly to deep muscular veins within the calf. Commonly these connections are to the gastrocnemial veins. The gastrocnemial veins originate in the venous sinuses buried deep within the gastrocnemills muscle. The drainage of these vessels is variable. Normally, they join the peritoneal vein to drain ioto the popliteal vein. However, on many occasions, these veins terminate ioto the popliteal vein adjacent to the termination point of the lesser saphenous vein. Perforating Veins As mentioned previously, perforating veins are veins that connett the superncial veins to the deep venous system. These vessels pass obliquely through fascial defects between muscle bundles. These vessels, which normaII norma li y measure between 1-2 mm, contain valves that onJy permits flow from the superficial venous system into the deep. Occasionally, these vessels do not contain any valves. However, their oblique course through the muscle is uSllally sufficienl to prevent reflllx. The number of perforators fOllnd in the leg varies greatly. Some repolts suggest that more than 15,000 perforators can occur within a leg. In general, these perforators are more commonly found in the distal calf as opposed to the high by factor 8:1. The majority of perforating veins are located on either side of the sartorius and peritoneal musc!es and between the vastuslateralis and hamstring muscles. In
most instances an artery closely accompanies d1ese perforating veins. The vast number of perforators present in a lower extremity prevents naming individual perforating veins. In generał, d1ese veins are considered in loose regional groupings. Hunterian, Oodd's, Boyd's, and Cockett perforators are four distinct groups of perforators d1at commonly occur and are associated with the greater saphenous vein Ol' its tributaries (Fig 5). ReAux within any of these perforators can result in varicose veins even in the absence of ref/ux within the saphenous system. Besides these four groups of perforating vessels, d1ere are many other unnamed groups of perforators, which can cause varicosities if incompetent. Thus, it is important to search for incompetent perforators when evaluating patients for varicosities. Duplex ultrasound is the oniy defmitive modality where by these perforators can be identified. Diagnosis Duplex color Aow ultrasound evaluation of the venous system of the lower extremity must always be the first step in evaluating patients wid1 c1inical evidence of Sl1perficial venous insufficiency. This examination should be condl1cted wid1 d1e patient in the upright position. In this position upward venous f/ow can be appreciated in the GSV when d1e calf is manually compressed. Upon compression completion upward f/ow halts and retrograde f/ow is prevented by valve closure. If valvular dysfunction is present then retrograde f/ow is not prevented. This abnormaJ f/ow can be appreciated with color-Aow Ol' Doppler imaging. Normally, after compression, 0.5 seconds Ol' less of retrograde f1ow, can be appreciated. This f/ow represents the time required for normai valve ciosu re. However, retrograde f/ow lasting greater then 0.5 seconds is considered abnormal and is consistent with venous reAux. Treatment Modalities Endovenous RF Ablation
When significant venous ref/liX is found treatment is directed towards the obliteration of the abnormal vein from its' deep venous origin. The C1osUl'e device (VNUS Medical Technologies, Sunnyvale, CA), which is FDA approved, accomplishes this task by applying radio frequency (RP) thermal energy to d1e wall of vein via a endovenous approach (ChandleI', 2000, 733; Kabnick, 2001, 734; Manfrini, 2000, 725; Pichot, 2000, 85; Goldman, 2000, 78). A 6- or 8-F catheter containing retractable e1eetrodes delivers d1e RP energy. This catheter, which is placed percutaneously, is connected to a generator that controls the RF output. Electrode temperature is maintained at 85°C to denature the collagen in the vessel wall. The device is slowly retracted (l-2 cm/min) so that the d1ermal energy is distribl1ted along the course of the vessel causing the treated portion of d1e vessel to contract and occlude. Tumescent anesthesia, which involves infiltrating the perivenous space with a large volume of 0.25% Iidocane, is l1tilized to provide pain
Hun~n perforator(s) in. proximal thigh
Oodd perforator(s) in distal thigh Boyd's perforator(s) around the knee
Cockett's perforators of the posteńor arch vein
Figure 5. Venous perforators.
relief and skin protection. This device is most commonly used to obliterate an abnormal GSV. However, other ref/uxing veins can be treated provided their course is straight enough to allow d1e catheter to pass.
Endovenous Laser Tberapy Endovenous laser therapy (EVLT), currendy only available for investigational use, is similar to endovenous RP therapy in that it delivers thermal energy to the wall of the abnormal vein to obliterate it (Navarro, 2001, 23). The thermal energy with d1is techniql1e is prodl1ced by a laser and delivered to the vein wall by a thin optical fiber. 111e tip temperature generated by this techniql1e is very high causing rapid destmction of d1e vessel collagen. Consequendy, the fiber can be retracted quickly permitting rapid treatment of the entire length of abnormai vein. Retraction time for this technique is l1sually less then 5 minlltes as opposed to RP ablation, which requires significandy longer retraction times. The optical fiber lItilized with this technique is inexpensive but can only be delivered tłuough a previously placed cad1eter Ol' sheath. Typically, a long 5F sheath is placed into the GSV and advanced to the saphenofemoral junction. The laser fiber is then advanced through d1e sheath and beyond it opening. With me fiber in position d1e laser is activated and the sheath and fiber are retracted together. ]ust as with RP tumescent anesd1esia along d1e entire course of the vein that is to be treated is needed. Sclerotherapy Sclerosants are often used for the trearrnent of varicose veins. Detailing the various agents and their proper use is beyond the scope of this syllabus (Green, 1998, 560; Green, 1998, 565; Tessari, 2001, 59]. However, image-
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guided sc1erotherapy can be helpful in treating primary sources of ref]ux that are not amenabJe to treatment with other percutaneous modalities. Sc1erosants can be injected, under direct f]uoroscopic guidance, into these vessels and held in place with the use of occ1usion balloons. This technique prolongs the vessels exposure to the sc1erosant, thus increasing effectiveness, while reducing the likelihood of injury to deep venous structures. Typically, we utilize sotrodecol to accomplish this task. Sotrodecol is usually effective in concentrations of 1% to 2%. Higher concentrations in supemcial veins can result in permanent, disfiguring, skin piginentation. Additionally, the inf]ammatory response associated with the use of sc1erosants can be severe and prolonged often lasting several months. Because of this, it is our practice to only utiJize this technique for the treatment of deeper vessels that have been documented as the source of reflux. Sc1erotherapy, for the treatment of superficial, visibly apparent varicosities can be effective but should only be utilized after the primary ref]uxing sources have been treated. In this situation imaging guidance is rarely needed.
Ambulatory Phlebectomy Surgical removal of large visibly apparent varicosities is cOl1UnonJy performed. Often multiple smali (1-2 cm) incisions are made along the course of the vein removing it in segments. Unfortunately, this technique can leave scars that are cosmetically displeasing. Ambulatory phlebectomy accomplishes the same thing but is performed with specialized "hooks" through tiny skin punctures (De Roos, 1998, 542; OJivencia, 1997, 658; Olivencia, 1997, 702; Otley, 1999, 241; Ramelet, 1997, 646; Ricci, 1998, 543). This technique is easily preformed with local anesthesia and leaves little scaring in its' wake (Smith, 1998, 544). A detailed description of this technique is beyond the scope of this syllabus and I refer the reader to the cited references. Conclusion The formation of varicosities in the lower extremity results from a high-pressure leak out of the deep venous system into the superficial venous system. Often these leaks occur at well-established junction points between the two systems. Treatment focuses on eradicating these points of pathologicaJ communication. Thus, the physician faced with diagnosing and treating this disorder, must be thoroughly familiar with the anatomy of the superficial venous system and its variations. Additionally, the introduetion of new percutaneous techniques for the treatment of this disorder has been a godsend to aff]icted patients. In contradistinction to open surgical therapies, these new techniques can be performed under local anesthesia with minimai discomfort. Post procedure recovery is often insignificant with patients returning to normal activities within a day or two. The key to these new treatment techniques is image guidance. The intelventional radiologist, having access to sophisticated
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imaging tools and the expertise to use them, is ideally suited to treat this disorder.
3:05 p.m. Percutaneous Techniques for Treatment of Saphenous Vein Reflux: Endovenous Laser Robert]. Min, MD Comell Vascular New York, NY The greater saphenous vein (GSV) is the major vein of the superficial venous system. GSV reflux is often associated with large supemciaJ varices. When incompetence of the saphenofemoral junction (SP)) is detected, treatment should first be directed towards eliminating this source of reflux with ablation of the incompetent venous segments. The traditionaJ approach to treating SP] incompetence with GSV reflux has been surgical Iigation and stripping. The drawbacks of surgery inc!ude risks associated with general anesthesia, surgical complications (paresthesia, bleeding, infection, scars), increased in-hospital costs, and prolonged recovery periods. In addition to the potentiaJ risks of surgery and the more extensive anesthesia needed for ligation and stripping, surgical treatment of the GSV is not free from recurrence. Sarin et al (1) reported an 18% rate of recurrent GSV refJux following Iigation and stripping and a 45% rate of recurrence following high Iigation alone, appearing as early as 3 months foJlowing treatment. Similarly, Dwerryhouse et al (2) found a recurrence rate of 29% foJlowing Iigation and stripping of the GSV and 71% following high ligation alone. In recent years, less invasive alternatives to surgical treatment of the incompetent GSV have been explored. MinimaJly invasive treatment aJternatives seek to reduce risk, morbidity and cost while leading to acceptable short- and long-term results. Early attempts to selectively damage saphenous veins in order to occlude them, as an alternative to stripping, involved electrocoagulation. The search for less invasive treatment alternatives has more recently led to the development of uJtrasound-guided sclerotherapy. These techniques appear to be useful in expert hands with an estimated 50o/(}-BO% 1-year efficacy. Major risks of sclerotherapy of saphenous veins include anaphylaxis and intra-arterial injection, although the risk of the latter complication may be reduced with transeatheter techniques (3). Poam sclerotherapy may improve efficacy but probably does not decrease risk. The newest minimally invasive technique to be developed is endovenous laser. Endovenous laser treatment allows delivery of laser energy directly into the blood vessel lumen in order to produce endothelial and vein wall damage with subsequent fibrosis.
Technique Pollowing ultrasound mapping of the SP] and incompetent GSV, an entry point is chosen. The GSV is usuaJly entered at the knee level, below the Hunterian canal
