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Acs0619 Endovascular Procedures For Lower Extremity Disease

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Acs0619 Endovascular Procedures For Lower Extremity Disease

  1. 1. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 1 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE Heather Y.Wolford, M.D., and Mark G. Davies, M.D., Ph.D., F.A.C.S. Endovascular procedures are increasingly being applied to the agent to decrease total nephrotoxic dye volumes (see below) may treatment of lower-extremity vascular disease: for many common be considered. Patients taking oral hypoglycemic agents are asked vascular conditions, minimally invasive approaches have become to stop doing so on the day of the procedure and not to resume important supplements to (or even supplanted) conventional open for 48 hours after the procedure. In general, to prevent bleeding surgical approaches.1 The evolution of these endovascular tech- complications, it is preferred that the international normalized niques is likely to result in a corresponding evolution in the thera- ratio (INR) be lower than 1.6 and the platelet count higher than peutic decision-making process for patients with lower-extremity 50,000/mm3 at the time of intervention. vascular disease. Research into the long-term outcomes of lower- If a therapeutic intervention is planned, the patient should be extremity endovascular procedures will be necessary for a better given aspirin, 81 mg/day, and clopidogrel, 75 mg/day, for at least 3 understanding of the indications for treatment and of the risks and days beforehand. If there is not enough time to do this, the patient benefits for patients. may be given clopidogrel, 150 to 300 mg, within the 2 hours pre- ceding the procedure. Arterial Procedures Investigative studies Imaging is required before any inter- Arterial conditions of the lower extremity that may be treated with vention. Noninvasive vascular ultrasonographic studies document endoluminal therapy include chronic ischemia, acute ischemia, and the initial status of the arterial blood supply and allow localization aneurysmal disease. The fundamental skill set and the basic tech- of the culprit lesions. The ankle-brachial index (ABI) (or, in dia- niques employed are the same for all of these conditions. Accor- betics and patients with incompressible ankle vessels, the toe-brachial dingly, the ensuing discussion first reviews the basics of endovas- index), pulse-volume recordings (PVRs), and segmental pressures cular therapy and then focuses on specific areas of chronic, acute, quantify arterial perfusion and define areas of stenosis or occlu- and aneurysmal arterial disease of the lower extremity that are sion within each leg. Duplex ultrasonography is an alternative to amenable to endoluminal intervention. PVRs and segmental pressures and provides further diagnostic information that allows the interventionalist to identify involved BASIC ENDOVASCULAR PROCEDURES vessel segments and lesions amenable to percutaneous therapy. These objective measurements serve as a baseline against which Preprocedural Evaluation postinterventional results may be assessed. Clinical evaluation The first step in the intervention con- Generally, noninvasive studies provide sufficient information to sists of a thorough history and a careful physical examination. allow one to proceed with diagnostic angiography and possible Patients should be specifically asked about chronic renal insuffi- endoluminal intervention. In many cases, however, additional ciency, current or past anticoagulant therapy, and previous vascu- studies are required to refine the interventional plan and to reduce lar and endovascular interventions. Lower-extremity pulses should the time and resources required. Computed tomographic angiog- be assessed, and the degree of ischemia present should be deter- raphy (CTA) provides two-dimensional images of the arterial sys- mined [see Table 1]. Basic serum biochemical and hematologic tem, which are then postprocessed to generate three-dimensional data should be obtained and reviewed.The results of any previous reconstructions. It is particularly effective for imaging tibial ves- imaging studies should also be obtained and reviewed. Patients sels.The main drawbacks of CTA are the time necessary to recon- with serum creatinine concentrations higher than 1.5 mg/dl struct the images, the possibility of interference from metal im- should be considered for a renal protection protocol [see Table 2], plants, and the contrast load involved. Magnetic resonance angiog- and at the time of the procedure, the use of an alternative contrast raphy (MRA) also provides potentially helpful preprocedural Table 1—Classification of Critical Ischemia Arterial Venous Grade Limb Status Prognosis for Limb Capillary Refill Motor Changes Sensory Loss Doppler US Doppler US I Viable Not threatened Intact None None + + IIa Threatened Salvageable Slow None Partial – + IIb Threatened Salvageable with emergency intervention Slow or absent Diminished function Partial – + III Irreversible Nonsalvageable Absent No function Complete – – US—ultrasonography
  2. 2. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 2 Table 2 Renal Protection Strategies 5 French multi–side-hole diagnostic catheter (in a straight, curv- ed, or pigtail configuration) is then placed over a wire into the jux- Oral Therapy Other Strategies tarenal aorta. After the initial aortic films are obtained in the an- teroposterior (AP) projection, the diagnostic catheter is moved N-acetylcysteine, 600 mg p.o., b.i.d., Hydration with normal saline, starting down to a point 2 to 3 cm above the aortic bifurcation, and a for total of four doses; first dose 1 hr before procedure and continued series of pelvic images are taken in the AP and lateral projections. given 12 hr before procedure for 3 hr after procedure Theophylline, 200 mg I.V., given 30 Sodium bicarbonate drip, 154 mEq/L, The aortic bifurcation is generally traversed with a curved min before procedure, or 200 mg starting 1 hr before procedure and catheter; the curve of the tip should be similar to the angle of the p.o., b.i.d., starting 24 hr before continued for 6 hr after procedure bifurcation. A wire is maneuvered into the iliac system and posi- procedure and continued for 48 hr Use of alternative contrast agent after procedure tioned in the external iliac artery or the CFA, and the curved diag- nostic catheter is advanced to the point where its tip lies within the distal external iliac artery and its holes are beyond the ostium of information and has the advantage of using gadolinium, which is the internal iliac artery. a relatively low risk contrast agent for patients with renal insuffi- Once the catheter has been correctly positioned, further con- ciency. The main drawbacks of MRA are relatively poor patient trast injections are performed. Complete lower-extremity images, tolerance of the machine, the tendency to overestimate lesion which should include tibial and pedal vessels (in AP and magni- severity, the long image acquisition time, and the variability in fied lateral foot views), are taken before the intervention so that image quality as one proceeds distally in the leg. Patients with lim- preprocedural status can be compared with postprocedural status ited arterial access will benefit from a cross-sectional imaging and any distal complications can be recognized. Contrast doses com- algorithm: such an approach allows one to perform a focused monly employed for digital subtraction arteriography (DSA) depend angiogram and to make more efficient use of resources during a on the specific arterial segment being addressed [see Table 3]. therapeutic intervention. Alternative contrast agents. Standard angiography is performed Preprocedural Planning with an iodinated nonionic contrast agent. In patients with creati- Choice of arterial access site The common femoral artery nine concentrations higher than 1.5 mg/dl, an alternative contrast (CFA) contralateral to the affected side is the arterial access site agent may be preferable. Carbon dioxide may be used to image most commonly employed. If the patient has an occluded CFA or the abdominal aorta, the iliac arteries, and, occasionally, the prox- a “hostile groin,” a radial, high brachial, or axillary artery imal leg arteries. As the vessels become smaller, however, CO2 approach may be chosen instead; however, access at these sites is images become less clear. Elevating the legs may help in obtain- associated with a relatively higher incidence of complications. ing adequate imaging to the level of the knees. For CO2 imaging, Ideally, to facilitate manual compression, the access site should lie a 60 ml syringe is connected to a three-way stopcock, and CO2 over a flat bony prominence. An antegrade ipsilateral CFA ap- from a tank is loaded into the syringe through the stopcock assem- proach is a useful alternative to contralateral access if there is a bly while the stopcock is submerged in normal saline and manu- contraindication to working from the contralateral side (e.g., sig- ally kept under pressure. The submerged system is flushed with nificant contralateral iliac disease, a heavily scarred groin, recent CO2 several times to purge any residual air. The CO2-containing application of a vascular closure device, or a bifurcated aortic syringe is connected to an indwelling catheter, and the CO2 is graft) and if preoperative imaging has demonstrated that there is then injected forcefully by hand while the fluoroscopy unit is acti- an adequate working distance (generally, at least 15 to 20 cm) vated. The resulting images must undergo postprocessing to be between the CFA access point and the target lesion. If an ante- viewed correctly. CO2 imaging should not be used above the grade approach fails, a retrograde approach may be employed to diaphragm or in the visceral artery segment of the aorta. target ipsilateral iliac arterial disease from the CFA or superficial Gadolinium may also be used to image the pelvic vessels and femoral artery (SFA) disease from the popliteal artery. the proximal leg arteries. Like CO2 images, gadolinium images become less clear as the lower-extremity arteries become smaller Selective Lower-Extremity Angiography and more distal. Gadolinium is loaded into the power injector or Technique Standard methods of obtaining vascular access injected by hand, like standard contrast agents. Doses higher than for angiography are described in more detail elsewhere [see 6:8 0.3 mmol/kg may be nephrotoxic.2 Fundamentals of Endovascular Surgery]. For selective angiography of the lower extremity, a 4 or 5 French diagnostic sheath is initially Troubleshooting If crossing the aortic bifurcation proves placed in the CFA contralateral to the affected extremity. A 4 or difficult, changing to a hydrophilic wire (e.g., a 0.035-in. soft or Table 3 DSA Imaging Techniques with Power Injector Arterial Segment Imaged View Contrast Dosage Delay Infrarenal aorta AP 10–20 ml/sec for 2 sec No Iliac arteries AP/oblique 3–10 ml/sec for 2–3 sec No CFA and SFA AP 3–10 ml/sec for 2–3 sec Flow dependent Tibial arteries AP 3–5 ml/sec for 3–4 sec Yes Pedal artery AP/lateral foot 3–6 ml/sec for 3–4 sec Yes AP—anteroposterior CFA—common femoral artery SFA—superficial femoral artery
  3. 3. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 3 stiff glide wire) may help. Occasionally, if one has trouble advanc- wire may be preferred, in that hydrophilic wires tend to create dis- ing the 5 French catheter, using a 4 French hydrophilic catheter section planes. Often, the occlusion cannot be crossed, and a may mitigate the problem. Attempts at passing the bifurcation subintimal plane must be developed. A glide wire is used to gain should not be abandoned until several different angled catheters access near the proximal portion of the lesion at a branch point have been tried. If all such attempts fail and contralateral access is and allowed to deform in such a way as to form a loop; the wire is imperative, ipsilateral puncture with introduction of a snare to then pushed forward, supported by a 4 or 5 French catheter. grasp the contralateral wire in the abdominal aorta should be con- Often, the true lumen is accessed without any difficulty, and the sidered. Alternatively, DSA may be performed from the aortic location of the wire within the lumen is confirmed by contrast bifurcation; however, the contrast loads will be significantly high- injections. Occasionally, however, reentry into the true lumen er in this situation. proves difficult. Various manipulations and techniques may be employed to help with this technical issue. In addition, two sys- Crossing of Lesion tems have been developed with this potential problem in mind. The diagnostic imaging studies and the preliminary angiogram The CrossPoint IVUS catheter (Medtronic, Minneapolis, Minnesota) should suffice to identify a lesion that is amenable to endovascular combines an intravascular ultrasound probe with a puncture nee- therapy. Once such a lesion is identified, wire access across the dle and allows one to visualize the true lumen, enter it with a hollow target lesion is required to establish a platform for subsequent needle, and pass a wire to maintain access. The Outback catheter intervention. (LuMend, Redwood City, California) has a special tip that micro- dissects the plaque to facilitate reentry into the true lumen. If these Technique Iliac lesions may be approached either in a retro- options fail, retrograde puncture and retrograde passage of a wire, grade fashion from the ipsilateral CFA or in an antegrade fashion with interval snaring to “floss” the occlusion, may be considered. from the contralateral CFA if there is adequate working distance between the bifurcation and the iliac lesion. For more distal Troubleshooting In crossing occlusions, the following three lesions, when a contralateral CFA approach is used, a guide sheath points must be emphasized. is required to stabilize catheters and wires. A wire is placed in the 1. Care must be taken to ensure that the operator is in the true external iliac artery on the affected side (see above), and the diag- lumen. nostic catheter placed across the bifurcation is replaced with a stiff 2. To preserve subsequent bypass targets, the next segment of sheath, such as a 6 French Balkin sheath (Cook Incorporated, the vessel must not be compromised by an overly aggressive Bloomington, Indiana), which has a curve that naturally rests over attempt to regain access from a subintimal dissection plane. the bifurcation. Occasionally, it is difficult to get the sheath to cross 3. Wire access across the lesion must be maintained at all times. the bifurcation. In such a situation, the initial wire may be exchanged for a stiffer wire, such as a 0.035-in. Amplatz wire A low-dose intravenous bolus of heparin (2,000 to 5,000 IU) (Cook Urological, Spencer, Indiana), and the sheath may be must be given before any intervention to help prevent the throm- placed over this wire. The use of a reinforced or stiff guide sheath bosis that may result from manipulation and transient occlusion of eliminates the mechanical disadvantage of a wire that moves away the lesion. from the limb with all manipulations, and it solidifies unilateral limb access for subsequent angiography during the therapeutic Angioplasty and Stenting portion of the procedure. Technique Angioplasty. Angioplasty is the initial treatment Once the sheath is in place, a long, angled end-hole catheter and for most lower-extremity lesions. It may be the only therapeutic a glide wire are directed toward the specific vessel segment being intervention required, or it may be employed as a prelude to stent treated and carefully manipulated so as to cross the target lesion. deployment as a means of ensuring that the arterial lumen is wide Road mapping, fluoroscopy fade, or intermittent puffing of con- enough to allow free passage of a platform. Angioplasty balloons trast material through the guide catheter can delineate the con- exist in several varieties, which are reviewed in more detail else- tours of the vessel, identify the correct path to take, and help keep where [see 6:8 Fundamentals of Endovascular Surgery]. In general, a the wire within the true lumen. In general, a stenosis can be noncompliant balloon is chosen that is 1 to 2 mm smaller than the crossed by a curved or J-tip wire, a 0.035-in. hydrophilic glide normal or anticipated final vessel diameter for the area of the vas- wire, or a Wholey wire (a 0.035-in. wire with a floppy tip; culature being addressed.The normal vessel diameter may be esti- Mallinckrodt, St. Louis, Missouri).The hydrophilic coating on the mated on the basis of operator experience, measured with a glide wire makes it more prone to dissection than the other wires radiopaque ruler placed alongside the vessel, or quantitated with are. With angled catheters, it is essential to use torque devices to the calibration software available on most imaging systems. direct the tip of the wire in the appropriate direction. In some Once the balloon has been successfully maneuvered into posi- cases, using a TAD II wire with a 0.018-in. distal tip and a 0.035- tion across the lesion, it is inflated with a manual inflation device in. main body (Mallinckrodt, St. Louis, Missouri) makes access to allow controlled delivery of a defined pressure load. Inflation is through a tight lesion easier to obtain; in addition, it provides a continued until the waist of the balloon disappears or maximal transition to a larger, more robust wire, which can be a very effec- balloon inflation pressure (8 to 15 atm on most standard balloons) tive platform. For tibial stenoses, a 0.014-in. or 0.018-in. system is is reached. If an optimally sized balloon or stent will not cross a generally employed to cross tighter lesions. To stabilize the 0.014- highly stenotic lesion, preangioplasty dilatation with a lower-pro- in. wire, a 3 or 4 French catheter may be used as a guide catheter, file, smaller-diameter balloon is required. placed just proximal to the lesion. If the lesion is in close proximity to or involves a bifurcation Occlusions can be difficult to cross, particularly when signifi- (e.g., the aortic bifurcation, the femoral bifurcation, or the cant calcification is apparent on the plain films obtained before tibioperoneal trunk), care must be taken to prevent occlusion of angiography.The techniques employed are the same as those used the other branching vessel during dilatation of the target lesion.To to cross a stenosis. The goal is to traverse the occlusion and gain this end, most interventionalists advocate use of the so-called kiss- access to the true lumen distally; accordingly, a J-tip or Wholey ing balloon technique, which involves simultaneous dilatation or
  4. 4. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 4 a b Figure 1 Basic endovascular techniques: angioplasty and stenting. Shown is the so-called kissing balloon technique. The patient presented with bilateral claudication, a decreased ABI on exercise treadmill testing, and a duplex ultrasonogram that suggested iliac occlusive disease. (a) Illustration shows two balloons “kiss- ing” in the common iliac arteries. (b) Radiograph shows two stents “kissing” in the iliac arteries. stenting of both branching vessels of the bifurcation to preserve and concomitantly promotes apoptosis and reduces the restenosis both lumina. This technique is most commonly employed for response. To date, the PolarCath has been employed mainly in the proximal common iliac artery lesions [see Figure 1]. Alternatively, SFA; it is currently being tested for use in the tibial vessels. In initial one may place a guard wire in the unaffected vessel and use this reports, anatomic patency rates in the femoropopliteal arteries have wire as a safety measure if there is a danger of luminal compro- exceeded 80% at 1 year for TransAtlantic Inter-Society Consensus mise, or one may deploy a balloon in the unaffected ostium while (TASC) grade A, B, and C lesions.3 the affected ostium is treated. Another such device is the Peripheral Cutting Balloon (Boston Scientific, Natick, Massachusetts) [see Figure 2b], which is increas- Stenting. Basic stent choices are discussed more fully else- ingly being used on lower-extremity vascular lesions, particularly where [see 6:8 Fundamentals of Endovascular Surgery]. Stents may those that proved resistant to balloon angioplasty.This device con- be placed either primarily or as a secondary procedure when ini- sists of a noncompliant balloon that has four thin blades placed tial angioplasty yields inadequate results (generally defined as longitudinally around it; it is available in sizes ranging from 2 mm either greater than 30% residual stenosis or the occurrence of an to 8 mm, and it operates over a 0.018-in. platform. The theoreti- angioplasty-related complication, such as arterial wall perfora- cal rationale for its use is that fracturing or cutting the lesion in a tion or flow-limiting dissection). Stents are generally sized controlled pattern may reduce the severity of the vessel injury according to the normal diameter of the adjacent vessel; 10% to while achieving a satisfactory luminal response and mitigating the 15% oversizing is acceptable. If the stent will be crossing two restenosis response. Initial results in stenotic vein grafts have been vessel segments with mismatched diameters (e.g., the common encouraging, with 95% patency reported at 11 months’ follow-up iliac artery and the external iliac artery), it is preferable to use a in one small study.4 self-expanding stent, which is better able to adjust to such mis- Directional atherectomy devices are being used to treat chronic matching. Treatment of specific arteries is discussed more fully atherosclerotic leg ischemia in the belief that debulking the lesion in connection with management of chronic lower-extremity will allow greater increases in luminal diameter than the conven- ischemia [see Procedures for Chronic Lower-Extremity Ische- tional methods of angioplasty and stenting, which merely displace mia, below]. plaque. Multiple different systems are available, all of which appear to be yielding roughly equivalent results. One of the more Adjuncts to angioplasty and stenting. Over the past few years, sev- widely used directional atherectomy devices is the SilverHawk eral innovative devices have been developed that expand on the Plaque Excision System (FoxHollow Technologies, Redwood basic concepts of angioplasty and stenting in the lower extremities. City, California), which consists of a catheter that is compatible One such device is the PolarCath cryoplasty balloon (Boston with a 0.014-in. wire and that has a rotating blade at the tip. As the Scientific, Natick, Massachusetts) [see Figure 2a].This device deliv- blade shaves plaque off the vessel wall, the shavings are stored in ers cold thermal energy to the vessel wall in the form of nitrous oxide the tip of the catheter. When the storage unit in the tip becomes (−10° C) and is inflated to a pressure of 8 atm. It is presumed that full, the catheter is removed and cleaned, then reinserted. Initial the freezing of the vessel allows a more controlled vessel wall injury intermediate-term results have been satisfactory; however, wider
  5. 5. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 5 a b Figure 2 Basic endovascular techniques: angioplasty and stenting. (a) Shown is the PolarCath peripheral dilatation system, comprising an inflation unit, a cryoplasty bal- loon, a cord attached to a separate power module, and a nitrous oxide cartridge. (b) Shown is the Peripheral Cutting Balloon, with an enlarged view of an atherotome. (Images provided courtesy of Boston Scientific, Natick, Massachusetts). use of this device will depend on the results of the multicenter a possible nonthrombotic embolic event, aspiration or open TALON registry.5 embolectomy may be required to achieve satisfactory reconstitu- Drug-eluting stents have become popular for use within the tion of flow. coronary circulation, but at present, they are only in the initial When a vessel is heavily calcified, a self-expanding stent may be stages of investigation for treatment of lower-extremity arterial dis- unable to deploy and may be effectively “jailed” in the lesion. In ease. Initial trials with the sirolimus-coated S.M.A.R.T. stent this situation, wire access must be maintained, and a low-profile (Cordis, Miami Lakes, Florida) showed a nonsignificant trend balloon should be used to enlarge the operating lumen so that a toward decreased restenosis rates.6 high-pressure balloon can then be introduced.The introduction of a series of balloons with successively larger diameters will eventu- Troubleshooting Angioplasty can result in either non–flow- ally allow the stent to be deployed. Balloon perforation often limiting or flow-limiting dissections. If dissection occurs, reinfla- occurs in these cases, and care should be taken to extract the per- tion of the balloon over the dissection for 5 to 10 minutes may forated balloon intact. anneal the flap to the wall. If balloon reinflation fails and flow is Unplanned stent dislodgment is rare but not unknown. If it still disrupted, a stent should be placed. occurs, the errant stent may be fixed in place by placing an addi- In situ thrombosis of the vessel occasionally occurs after angio- tional overlapping stent. Alternatively, a balloon may be inflated plasty or stent placement. If it develops in a patient who under- distal to the tip of the dislodged stent and used to move the stent went angioplasty alone, the thrombosed vessel may be stented to another vessel, where it may be safely deployed. open. If this measure fails or if the in situ thrombosis develops after stent placement, a thrombolysis catheter is placed across the Complications The most common complications of angio- lesion and a single bolus of a thrombolytic agent administered. If plasty and stenting in the lower extremities are access-related this approach yields suboptimal results, an indwelling catheter is issues, including hematoma, arteriovenous fistula formation, and placed for a 12- to 24-hour infusion [see Procedures for Acute pseudoaneurysm. The incidence of hematoma can be minimized Lower-Extremity Ischemia, below]. Alternatively, mechanical by using the smallest sheath possible, waiting for normalization of thrombectomy with a rheolytic catheter may be considered. the activated clotting time before pulling the sheath, and holding Finally, restenting with an open or covered stent is an option, but manual pressure for 30 minutes after the procedure. Devices it may result in distal embolization. designed for vessel closure after percutaneous intervention are Perforation of the vessel can occur during angioplasty or recan- available but have not been proved to reduce the incidence of nulization. Perforations that are small or that occurred during a access-related complications.7 With several of these closure de- failed recannulization need not be treated. Perforations associated vices, it is recommended that access of the groin not be attempt- with persistent extravasation of contrast may be managed primar- ed for up to 90 days after insertion. ily with balloon tamponade (20 minutes of inflation, with inter- PROCEDURES FOR CHRONIC LOWER-EXTREMITY ISCHEMIA mittent deflations to allow distal circulation and reversal of anti- coagulation) and secondarily with placement of a covered stent. Endoluminal intervention to treat plaque can result in distal Preprocedural Evaluation embolization of cholesterol or plaque or distal dislodgment of Patients presenting with chronic lower-limb ischemia are eval- thrombi. Mechanical or pharmacologic thrombolysis remains the uated as previously outlined [see Basic Endovascular Procedures, mainstay option in such cases. If, however, one is concerned about Preprocedural Evaluation, above]. Patients with claudication are
  6. 6. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 6 should also be subjected to a chemical challenge. Local intra-arte- Patient has chronic arterial ischemia rial delivery of a vasodilator (e.g., papaverine, 30 mg; priscoline, 25 mg; or nitroglycerin, 200 µg) will create distal vasodilatation, ac- Assess severity of ischemia. centuate the translesional gradient, and, in many cases, unmask a significant lesion that might otherwise be missed. Iliac lesions may be treated either by means of primary angio- plasty, with stenting reserved for cases in which angioplasty yields unsatisfactory results, or by means of primary stenting. Either bal- Patient has limb Patient has critical claudication limb ischemia loon-expandable or self-expanding stents may be used in the iliac vessels. Highly calcified lesions and lesions in smaller iliac vessels Treat medically: Determine whether (< 7 mm) generally are best treated with self-expanding stents. • Risk-factor modification patient is a candidate Lesions in the external iliac artery or the femoral artery (including • Exercise therapy for intervention. • Smoking cessation the CFA, the profunda femoris [PF], and the SFA) are best treat- ed with angioplasty alone. In these vessels, stents usually are placed only when angioplasty has been unsuccessful or dissection or vessel rupture has occurred. As a rule, stenting for SFA lesions is best done with self-expanding stents, though very focal lesions Claudication is Claudication continues may be treated with balloon-expandable stents. Stenting is rela- managed and is disabling tively contraindicated in the popliteal artery; the extended range of motion across the nearby joint often leads to stent fracture. At pres- Determine whether patient is a candidate for intervention. ent, stents are not used as primary therapy in infrapopliteal vessels. If stenting is required at infrapopliteal sites, coronary balloon- mounted platforms are the only available choices. Postprocedural Care After the procedure, patients require at least 2 to 12 hours of bed rest. Hydration with I.V. infusion of normal saline should be initi- Patient is not a candidate Patient is a candidate ated, and appropriate dosages of renal-protective agents should be for intervention for intervention given. Aspirin, 81 mg/day, should be given on a long-term basis, Perform diagnostic angiography. and clopidogrel, 75 mg/day, should be administered for 30 days. Amputate limb. Determine whether lesion is Outcome Evaluation amenable to endovascular therapy. In most series, rates of technical success (defined as less than 30% residual stenosis) have exceeded 90%. Secondary patency rates for iliac interventions at 10 years have exceeded 50%.9 Angioplasty and stenting in the SFA have been studied, for the most part, in a retrospective fashion. Intermediate-term data have Lesion is amenable to Lesion is not amenable endovascular therapy suggested patency rates of 70%, 60% and 50% at 1, 3, and 5 years, to endovascular surgery respectively. The reported clinical benefit has generally exceeded Treat with angioplasty, stenting, Treat surgically. the anatomic patency rates.10-12 None of the randomized studies or both as appropriate. published to date have found primary stenting to have any advan- tage over primary angioplasty in the femoral vessels.13-16 Factors Figure 3 Algorithm illustrates workup of patients with chronic indicative of a poor prognosis include intervention for more lower-extremity ischemia. advanced limb ischemia, diabetes, complete occlusion (as opposed to stenosis), lesions longer than 10 cm, and poor distal runoff.8 The use of TASC criteria to stratify lesions anatomically helps managed medically by controlling risk factors, instituting exercise predict which patients are likely to benefit most from endovascu- therapy, and providing advice on smoking cessation.8 In patients lar therapy in the SFA.17 In one study that included almost 400 with disabling claudication, rest pain, or tissue loss, diagnostic SFA interventions, patients who had TASC A and B lesions expe- imaging studies are performed with the intent of identifying and rienced significantly better outcomes than those who had TASC C subsequently treating any lesion that is amenable to endovascular and D lesions, with an overall 6-year patency rate of 52%.10 therapy [see Figure 3]. If an intervention is indicated, patients are Currently, angioplasty is being evaluated for use in infrapopliteal pretreated with antiplatelet agents as appropriate. disease. Some initial success has been reported, though it still appears that this approach is best reserved for patients in whom Technique open surgical management is relatively contraindicated.18 Techniques and protocols for diagnostic angiography and accessing the target lesion have been outlined [see Basic Endo- PROCEDURES FOR ACUTE LOWER-EXTREMITY ISCHEMIA vascular Procedures, above]. If it is unclear whether a vessel has a hemodynamically significant stenosis, arterial pressures can be Preprocedural Evaluation measured across the lesion by connecting an end-hole catheter to The initial decision in managing acute lower-extremity a pressure transducer. A drop of more than 10 mm Hg in systolic ischemia limb should be whether to proceed directly to surgery or blood pressure or more than 5 mm Hg in mean arterial pressure to obtain a diagnostic angiogram and consider endovascular ther- across the lesion is considered significant. The area in question apy. The Working Party on Thrombolysis developed a consensus
  7. 7. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 7 Table 4 Contraindications to Thrombolysis fibrin.21,22 To prevent buildup of clot around the sheath, all patients undergoing pharmacologic thrombolysis also receive Relative Contraindications Absolute Contraindications heparin in a continuously administered low dosage (200 to 500 U/hr); higher dosages are associated with a substantially increased Recent surgery (within 2 wk) Active internal bleeding risk of hemorrhagic complications. Recent trauma (within 1 mo) Recent stroke (within 2 mo) History of coagulopathy Intracranial pathology Mechanical adjuncts to thrombolysis. Several mechanical ad- Pregnancy or recent delivery juncts are available to reduce thrombolytic time or enhance the completeness of clot dissolution. These adjuncts can also be ben- eficial when thrombolytic therapy is contraindicated. on how to approach patients with acute arterial ischemia. The Various mechanical thrombectomy systems are commercially main message of this consensus was that classifying patients available. One such system is the AngioJet system (Possis Medical, according to their grade of ischemia is essential to forming treat- Minneapolis, Minnesota). The Angiojet consists of a pump drive ment plans [see 6:5 Pulseless Extremity and Atheroembolism].19 unit and a 4 to 6 French catheter, which is passed over a 0.035-in. Grade IIa and early grade IIb ischemia may be amenable to endo- wire to the target area.The catheter has two lumens: one is used to luminal therapy, including thrombolysis. Established grade IIb pulse heparinized normal saline at a pressure of 10,000 psi, and the ischemia is best treated by means of surgical embolectomy or other contains the wire and serves as the route by which clot debris thrombectomy, with intraoperative angiography, intraoperative thrombolysis, and over-the-wire embolectomy as options. Grade III ischemia is nonsalvageable and generally necessitates amputa- tion [see 6:20 Lower-Extremity Amputation for Ischemia]. Arterial Thrombolysis Thrombolysis, either pharmacologic or mechanical, is the main- stay of endovascular therapy for acute arterial ischemia.20 Relative and absolute contraindications to thrombolytic therapy have been established [see Table 4]. Technique An initial diagnostic angiogram of the affected limb is obtained, with care taken to gain arterial access in such a way that thrombolytic therapy is not prevented. The standard approach is from the contralateral groin (see above).To reduce the chances of access site hematoma during administration of a thrombolytic agent, access should be gained at a substantial dis- tance from the occlusion. Crossing the lesion involves identifying the origin of the occlusion. In cases of native vessel occlusion, this is generally a straightforward process. If a bypass graft is occlud- ed, one may be able to visualize a stump of the graft, which will aid in direct management [see Figure 4].The standard methods of crossing a stenosis or an occlusion [see Basic Endovascular Proce- dures, Crossing of Lesion, above] should be employed. Once the lesion has been crossed securely with a wire, an infu- sion catheter (e.g., a 3 French multi–side-hole catheter) is advanced over the wire and situated in the occlusion. An infusion wire may also be inserted through the infusion catheter in a coaxial fashion and placed distally to increase the area of direct lysis, to protect the outflow vessel, or to address two separate lesions [see Figure 5]. The position of the catheter and the wire are then documented by means of fluoroscopy. With the infusion catheter left securely in place, the thrombolytic infusion is begun. Often, it helps to insert a guide sheath into the contralateral iliac system to prevent dis- lodgment and facilitate subsequent access. Pharmacologic agents. The use of thrombolytic drugs has been refined over the past decade. In the United States, urokinase and tissue plasminogen activator (t-PA) have been the most widely used agents. Urokinase was popular in the 1980s and 1990s, but Figure 4 Arterial thrombolysis. Patient presented with grade IIa its temporary withdrawal from the market in 1998 because of ischemia, and duplex ultrasonography showed evidence of an manufacturing problems allowed physicians to become more occluded femoropopliteal reverse saphenous vein bypass graft. comfortable working with t-PA. At present, recombinant t-PA (rt- Angiogram taken from the ipsilateral external iliac artery demon- PA) (e.g., alteplase) is the lytic agent most commonly used in the strating a patent but diseased CFA and a patent PF. The SFA is United States. Reteplase is a newer recombinant agent that is sim- occluded. The stump of the occluded arterial bypass graft is visi- ilar to rt-PA but has a longer half-life and a less specific affinity for ble (arrow).
  8. 8. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 8 a b c Figure 5 Arterial thrombolysis. Follow-up imaging of the patient in Figure 4 illustrates the use of a thrombolytic infusion catheter. (a) Shown is the proximal end of the occluded CFA–popliteal artery bypass graft. (b) The infusion catheter (black arrow) is placed. (c) The infusion wire rests in the distal bypass graft (hollow arrow), increasing the infusion length for the thrombolytic agent. is removed.The power pulse spray technique, with rt-PA added to Over-the-wire embolectomy is another mechanical means of the saline (10 mg in 100 ml) and delivered by the rheolytic catheter removing clot. Newer designs of the standard Fogarty embolecto- directly into the clot, may also be employed to help dissolve clot. In my catheter have been developed that include an inner lumen, so this technique, the system is modified so that the outflow circuit is that the catheter can be passed over a 0.035-in. wire. Use of these closed and the unit pulses the saline–rt-PA mixture into the clot, devices facilitates fluoroscopically guided embolectomy and en- allowing simultaneous lysis and maceration. Once the thrombus sures that the catheter can be passed to all target vessels. Over-the- has been treated and an additional 15-minute interval has elapsed, wire embolectomy provides an efficient percutaneous method of conventional catheter therapy is employed to remove the clot and removing clot without any need for the constant monitoring that the residual rt-PA.The advantage of this approach is that it permits pharmacologic thrombolysis requires. high-dose lysis while imposing only a low systemic load.23 If more This embolectomy technique may be supplemented by intra- than 750 ml of saline is used with the AngioJet catheter during a operative catheter-directed thrombolytic therapy when postopera- single session, there is a significant risk of acute renal impairment tive imaging reveals residual clot or inadequate perfusion. Under secondary to hemolytic debris. fluoroscopic guidance, an end-hole catheter or a multi–side-hole Also used for mechanical thrombectomy are wall-contact instru- infusion catheter is guided over a wire into the target vessel or ves- ments such as the Arrow-Trerotola device (Arrow International, sels, and a thrombolytic agent (e.g., rt-PA, 0.5 mg/kg over 30 min- Reading, Pennsylvania). Such devices result in significant endo- utes) is directly infused with inflow occlusion. Imaging is recom- thelial damage and distal clot embolization and thus are better mended both before and after thrombolysis. Adjunctive use of an suited for hemodialysis grafts. Another option is the Helix Clot embolectomy catheter may also be beneficial. If, however, there is Buster (ev3, Plymouth, Minnesota), which creates a vortex at the still no perfusion after adequate thrombolytic therapy and embo- catheter tip that macerates the clot into microscopic fragments; it lectomy, the situation generally is not retrievable, and alternative differs from the AngioJet in that it lacks an aspirating port.The Oasis therapies should be explored. In the clinical trials of perioperative thrombectomy catheter (Boston Scientific, Natick, Massachusetts) thrombolytic therapy published to date, success rates ranged from also fragments thrombus into small particles. The use of these 64% to 100%. Bleeding was the most common complication. devices in the setting of acute arterial occlusion was addressed in a comprehensive review published in 2001.24 All of these devices Postprocedural care After the intervention, the patient is may be used either in place of or in addition to pharmacologic observed in a monitored unit by personnel trained in the manage- thrombolysis. ment of thrombolytic therapy. Lower-extremity neurovascular At present, the evidence supporting the use of mechanical examinations are carried out frequently (every 1 to 2 hours). The thrombectomy devices in the setting of acute limb ischemia is mod- patient’s clinical status is also monitored for evidence of bleeding, est. One retrospective study demonstrated successful recanalization including access-site hematoma, neurologic changes, and hypo- in approximately 60% of patients.25 At our own institution, we have tension. Repeat angiograms are performed at 12-hour intervals (or found these devices to be useful in decreasing the clot burden on sooner if clinical examination reveals significant deterioration) to the second or third t-PA check (24 to 36 hours after commence- assess the progress of lytic therapy and to allow changes in catheter ment of the infusion), after the clot has been softened by the initial positioning. Some physicians recommend following fibrinogen pharmacologic lysis. It remains to be seen whether this approach levels and discontinuing the lytic agent if levels fall below 150 reduces the overall time needed for thrombolytic therapy. mg/dl. Other end points for the thrombolytic therapy are failure to
  9. 9. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 9 progress, complete lysis of the target thrombus, or significant crossed, the thrombolytic agent may be delivered just proximal to bleeding complications necessitating discontinuance of lysis. the lesion for 2 to 4 hours after initiation of therapy, but the Once lysis is discontinued, the heparin dosage should be in- chances of a good outcome with this approach are diminished. creased to achieve therapeutic levels of anticoagulation. Any lesions Whereas it is common for clinical findings to worsen slightly (as unmasked by thrombolytic therapy should be treated, either by a result of distal microembolization) before improving—the so- endovascular means or with an open procedure. Whether long- called storm before the calm phenomenon—dramatic worsening term anticoagulation is indicated depends on the patient’s cir- of the physical findings calls for urgent angiography. Possible rea- cumstances and the specific cause of the thrombosis. sons for ischemic progression include propagation of clot (treat- able by performing open embolectomy or thrombectomy), dis- Troubleshooting Many of the issues raised in connection placement of the lysis catheter (treatable by repositioning the with basic arterial access techniques arise during attempts at catheter), or distal embolization of clot resulting in obstruction of thrombolysis. Occasionally, the interventionalist experiences signif- the principal runoff vessels (treatable by advancing the infusion icant difficulty in accessing an occluded bypass graft.Thrombolysis catheter or wire more distally, employing a rheolytic catheter, or of these occluded grafts can often be facilitated by employing a performing open embolectomy or thrombectomy). double-puncture technique, in which both a retrograde and an antegrade puncture of a bypass graft are performed under ultra- Complications General access-site complications—includ- sonographic guidance, allowing the infusion catheters to be placed ing hematoma, pseudoaneurysm formation, ischemia to the con- so as to cover the entire length of the graft [see Figure 6].26 With this tralateral leg from an occlusive sheath, nerve damage (which is approach, there is no need for CFA puncture, which is often made more common with axillary or brachial puncture secondary to an difficult by the presence of scar tissue, and the problem of finding axillary sheath hematoma), arterial dissection of the access vessel, access to the graft takeoff is eliminated. If a lesion cannot be and distal embolization of the clot—are also seen with thrombolyt- a c e Diagnostic Infusion Catheter Catheters Infusion Wire b d Guidewire Antegrade Wire Diagnostic Catheter Figure 6 Arterial thrombolysis. Illustrated is ultrasound-guided double puncture of an arterial bypass graft for thrombolysis.26
  10. 10. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 10 Table 5 Prospective, Randomized, Controlled Trials of Arterial Thrombolytic Therapy Limb Salvage Rate at Trial (Date) N Lytic Agent 1 Yr (Surgery vs. Lytic 30-Day Mortality (Surgery Bleeding Complication Therapy) vs. Lytic Therapy) Rate with Lytic Therapy Rochester (1994)41 114 Urokinase 82% vs. 82% (NS) 18% vs.12% (NS) 11% STILE (1994)27 393 Urokinase/rt-PA 100% vs. 90% No difference 5.6% TOPAS (1996)42 213 Urokinase 65% vs. 75% (NS) 5% vs. 3% (NS) 10% NS—not significant STILE—Surgery versus Thrombolysis for Ischemia of the Lower Extremity TOPAS—Thrombolysis Or Peripheral Arterial Surgery ic therapy. Bleeding complications have presented a significant hur- Overall success rates may exceed 95%. Complications include dis- dle for thrombolytic therapy. Early studies that used therapeutic tal native artery thrombosis and distal embolization, which gener- doses of heparin and higher doses of thrombolytics reported unac- ally can be treated with I.V. heparin.28 ceptable rates of intracranial hemorrhage and other bleeding com- plications. Currently, most physicians employ rt-PA doses in the Placement of Covered Stent range of 0.25 to 0.50 mg/hr without compromising results. Overall, Treatment of lower-extremity aneurysms with covered stents is rates of bleeding complications with urokinase and rt-PA range currently being studied. Isolated iliac artery and SFA lesions, from 5% to 10%, and the incidence of intracranial hemorrhage is though rare, lend themselves to endovascular repair [see Figure 7]. less than 2%.22 As with open surgical therapy, compartment syn- Initial data suggest that repair of popliteal aneurysms with covered drome can complicate reperfusion of the ischemic limb; this com- stents is also feasible in high-risk patients.29 Newer stents are being plication should be checked for on serial clinical examinations. developed that are better able to withstand the stresses imposed by the repetitive motion of the knee joint. Outcome evaluation The use of thrombolysis to treat acute lower-extremity arterial occlusion has been extensively studied. The results of the major prospective, randomized trials [see Table 5] Venous Procedures showed thrombolytic therapy to be equivalent to surgery with As endovascular therapy for arterial disease continues to evolve, respect to limb salvage and mortality and superior with respect to techniques learned in the arterial tree are increasingly being the need for complex surgical intervention. Most of these major applied to the venous system. At present, the main venous disease trials were performed with urokinase and t-PA. The information processes being treated with endovascular techniques are gained from them has helped surgeons determine which patients iliofemoral deep vein thrombosis (DVT) and superficial reflux of are good candidates for thrombolytic therapy. Factors predictive of the greater saphenous system causing symptomatic varicose veins. successful thrombolysis include symptoms of less than 14 days’ VENOUS THROMBOLYSIS duration, prosthetic graft occlusion, and high medical risk for open operation. Factors predictive of a poor outcome include chronic Lower-extremity DVT can have a significant impact on occlusion, native artery occlusion, and a lesion that cannot be patients’ quality of life. Multiple studies indicate that approxi- crossed with a wire.27 mately 50% of patients experience postthrombophlebitic syn- drome (PTS) and that the majority of patients with PTS report PROCEDURES FOR LOWER-EXTREMITY ARTERIAL ANEURYSMS that physical and emotional well-being are negatively affected.30 The goals of venous lysis are to relieve obstruction and to preserve Ultrasound-Guided Thrombin Injection valve function. Pseudoaneurysms of the CFA are a complication of femoral access for therapeutic procedures and are often amenable to per- Preprocedural Evaluation cutaneous therapy. The pseudoaneurysm is visualized with a 7.5- If DVT is less than 1 month old, a trial of lytic therapy is appro- MHz duplex ultrasound probe. Contraindications to injection of priate. The ideal candidate for such therapy has a symptomatic the sac are the presence of a wide mouth and no discernible neck, clot with lower-extremity swelling, is young and mobile, is not in a the development of an arteriovenous fistula, compression of adja- hypercoagulable state, and has no contraindications to lysis. cent structures by the pseudoaneurysm, and skin changes overly- Currently, lytic therapy is more commonly employed in active ing the pseudoaneurysm. If infection is a possibility, the procedure patients, whose quality of life is more likely to be negatively affect- should not be attempted. The ABI should be determined and ed by PTS. In cases of unprovoked DVT or recurrent DVT, a duplex ultrasonography of the groin performed before injection. hypercoagulability workup is indicated.31 Venous thrombosis is Once it is certain that the pseudoaneurysm meets the criteria discussed more fully elsewhere [see 6:6 Venous Thromboembolism]. for thrombin injection, the sac is injected in the fundus area, away from the native artery, under direct ultrasonographic visualization Technique and after infiltration of a local anesthetic. Usually, 1,000 units of The initial diagnostic venogram can be obtained via almost any thrombin is injected, and injection may be repeated one or more venous access site. Our preference is to perform an ipsilateral times. With multilobar aneurysms, serial injections into each fun- popliteal vein stick with the patient in the prone position; the pos- dus may be required to achieve complete resolution. terior tibial vein or the contralateral femoral vein can also be used. Factors associated with successful treatment are a long, narrow The popliteal vein is accessed with a micropuncture needle under pseudoaneurysm neck and a sac diameter smaller than 8 cm. ultrasonographic guidance by means of a Seldinger technique.
  11. 11. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 11 The micropuncture sheath is then replaced with a 5 French than 50% lysis was achieved in 83% of the patients; 11% experi- sheath over a 0.035-in. wire. The diagnostic venogram is per- enced complications, and 1% had pulmonary emboli.33 Small formed through the sheath or with a straight multi–side-hole diag- prospective, randomized trials found that thrombolysis yielded nostic catheter. increased patency and decreased venous reflux in comparison As in arterial thrombolysis [see Arterial Procedures, Procedures with standard anticoagulation therapy.35 Retrospective studies for Acute Lower-Extremity Ischemia, Arterial Thrombolysis, indicated that this improved venous patency and valve function above], a 3 French infusion catheter is advanced over the wire and might translate into better quality of life than would be achieved positioned within the clot. Longer lesions can be managed with a with anticoagulation alone.36 coaxial infusion catheter–wire system.The lytic infusion is started, TREATMENT OF SAPHENOFEMORAL VENOUS REFLUX and a low-dose intravenous heparin infusion is initiated through the sheath. Mechanical thrombectomy and power pulse spray The application of endovascular techniques to saphenofemoral thrombectomy can efficiently debulk thrombus and may be ben- venous reflux has significantly changed the treatment of this con- eficial in patients with phlegmasia caerulea dolens.32 The patient dition.37 Over the past decade, two minimally invasive approach- is kept in a monitored floor bed, and repeat venograms are per- es have been developed to replace standard high ligation and strip- formed every 12 to 24 hours. ping of the greater saphenous vein (GSV): radiofrequency abla- In some patients, May-Thurner syndrome (compression of the tion (RFA) and endolaser obliteration. iliac vein by the overlying iliac artery) develops; it is treated by placing a venous stent in the iliac vein to help reduce the effect of Preprocedural Evaluation external compression and presumably treat the initiating factor. Initially, symptomatic varicose veins are treated conservatively, Venous stents are larger than corresponding arterial stents in a with compression stockings. If conservative methods fail to pro- given vascular bed. Because of the increased compliance of the vide relief, a varicose vein–related complication develops, and venous wall, self-expanding stents are preferred for use in veins. there is evidence of significant superficial reflux on duplex ultra- Once lysis either is complete or has been continued for 72 sonography, the patient may be considered for endovenous treat- hours, the lytic infusion is stopped, and the heparin infusion is ment of GSV reflux. increased to therapeutic levels. The patient is placed on warfarin therapy and should be treated in accordance with current algo- Preprocedural Planning rithms for DVT [see 6:6 Venous Thromboembolism]. GSV ablation procedures may be performed either in an office or in an operating or procedure room. If an office setting is cho- Complications sen, the patient must be able to tolerate a small amount of dis- Reported rates of bleeding complications after venous lysis are comfort with light sedation. The interventionalist must be certi- higher than those after arterial lysis, typically ranging from 10% to fied to deliver conscious sedation and must be laser qualified if 15%.33 Pulmonary embolism, though rare in this setting, is known providing laser therapy.The procedure room, whether in an office to occur, presumably as a result of partially lysed clot breaking off. or a medical facility, should be equipped with a procedure table To prevent this complication, some authors advocate prophylactic capable of a steep Trendelenburg position, a high-resolution placement of an inferior vena cava (IVC) filter.34 Ongoing devel- duplex ultrasonography device, and the appropriate ablation opment and wider use of retrievable IVC filters may accelerate the equipment. For more symptomatic side-branch varicosities, stab application of this adjunctive technique. avulsions may be needed; as a rule, these are best done in the OR. Outcome Evaluation Technique In a large retrospective study of 312 cases of iliofemoral and RFA of GSV The development of the Closure system femoropopliteal DVT treated with urokinase infusion, greater (VNUS Medical Technologies, Sunnyvale, California) has allowed a b c Figure 7 Placement of covered stent. Shown is endovascular repair of an external iliac artery aneurysm. The patient presented with left groin pain several months after undergoing urologic surgery. (a) CT scan demonstrates a left external iliac artery pseudoaneurysm. (b) Angiogram demonstrates the same pseudoaneurysm. (c) Shown is the left external iliac artery after covered stent placement successfully excluded the pseudoaneurysm.
  12. 12. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 6 VASCULAR SYSTEM 19 ENDOVASCULAR PROCEDURES FOR LOWER-EXTREMITY DISEASE — 12 the application of RFA to GSV reflux therapy. Before the proce- RFA is that the laser wire can be pulled back relatively quickly (up dure, the GSV is mapped by means of ultrasonography. The to 18 mm/min). patient is placed in the Trendelenburg position with a tourniquet around the upper thigh. Access to the GSV is obtained at the knee Complications with an introducer needle and a wire threaded into the vein, and The most serious complication associated with any of these the needle is then replaced with a proprietary sheath.The Closure endovenous techniques is DVT.There have been several reports of catheter is threaded through the sheath, and the tip is placed under DVT resulting from RFA of the GSV, with incidences as high as ultrasonographic guidance just proximal to the takeoff of the 16%.38 As of September 2005, four instances of pulmonary superficial epigastric vein at the saphenofemoral junction (SFJ). A embolism from these clots had been reported in the United States mixture of normal saline (500 ml), 1% lidocaine with epinephrine Food and Drug Administration’s Manufacturer and User Facility (50 ml), and sodium bicarbonate (5 mg) is injected under ultra- Device Experience (MAUDE) database (http://www.fda.gov/ sonographic guidance through the sheath and into the area sur- cdrh/maude.html), with at least one patient dying of a pulmonary rounding the GSV to provide anesthesia, improve impedance, and embolism after the procedure. protect the overlying tissues from exposure to the heat (so-called Lower-extremity DVT has also been reported after endovenous tumescent anesthesia). laser therapy. Other problems include saphenous nerve paresthe- The Closure device is then connected to the RFA delivery sys- sias along the course of the GSV, bruising, skin burns, and super- tem, deployed, and pulled back at a controlled rate (initially, 1 cm ficial phlebitis. If endovenous laser therapy fails to obliterate the every 30 seconds), with both impedance and temperature GSV, the problem can be remedied by prompt high ligation at the checked periodically. Manual compression, particularly in the time of ablation. Clot in the common femoral vein can be treated upper thigh, may help in obtaining optimal numeric values on the with standard anticoagulation. Clot abutting the common femoral RFA unit, as well as increase the efficiency of ablation. After the vein can be treated with clopidogrel, 75 mg/day orally for 1 month; catheter has been withdrawn into the sheath, it is removed, and serial ultrasonograms should be obtained to confirm that the clot ultrasonography is performed to confirm that the GSV has been is not propagating. obliterated. Outcome Evaluation Endovenous laser treatment of GSV Access to the GSV is Overall, good results are obtained with endovenous treatment obtained as in RFA (see above), and a wire is advanced under of GSV reflux. In one study of patients who underwent RFA of the ultrasonographic guidance to a point above the SFJ. A 600 µm GSV, 85% of patients had complete occlusion of the GSV at 2 laser fiber is placed over the wire and positioned just distal to the years, and 90% of all patients were free of GSV reflux at that SFJ in the GSV. A tumescent anesthetic solution is injected. Laser time.39 In a study of patients who underwent endolaser oblitera- energy is delivered (e.g., with an 810 nm diode laser) as the laser tion, similar results were obtained: ultrasonographic surveillance fiber is pulled back. One advantage endolaser obliteration has over documented a 93% rate of complete GSV closure at 2 years.40 References 1. Pell JP: Impact of intermittent claudication on placement. Radiology 224:731, 2002 and clinical results. J Vasc Interv Radiol 11:1021, quality of life. Eur J Vasc Endovasc 9:469, 1995 10. Surowiec SM, Davies MG, Lee D, et al: Percu- 2000 2. Spinosa D, Kaufmann JA, Hartwell GD: taneous angioplasty and stenting of the superficial 19. Working Party on Thrombolysis in the Management Gadolinium chelates in angiography and interven- femoral artery. J Vasc Surg 41:269, 2005 of Limb Ischemia:Thrombolysis in the management tional radiology: a useful alternative to iodinated 11. Murphy TP, Khwaja AA, Webb MS: Aortoiliac of lower limb peripheral arterial occlusion—a con- contrast media for angiography. Radiology stent placement in patients treated for intermit- sensus document. Am J Cardiol 81:207, 1998 223:319, 2002 tent claudication. J Vasc Interv Radiol 9:421, 1998 20. Davies MG, Lee DE, Green RM: Current Spec- 3. Fava M, Loyola S, Polydorou A, et al: Cryoplasty 12. Karch LA, Mattos MA, Henretta JP, et al: Clinical trum of Thrombolysis, 3rd ed. WB Saunders Co, for femoropopliteal arterial disease: late angio- failure after percutaneous transluminal angioplas- Philadelphia, 2001 graphic results of inital human experience. J Vasc ty of the SFA and popliteal arteries. J Vasc Surg 21. Ouriel K: A history of thrombolytic therapy. J Interv Radiol 15:1239, 2004 31:880, 2000 Endovasc Ther 11:128, 2004 4. Kasirajan K, Schneider PA: Early outcome of 13. Becquemin JP, Allaire E, Qvarfordt P, et al: Surg- 22. Ouriel K, Kandarpa K: Safety of thrombolytic “cutting” balloon angioplasty for infrainguinal ical transluminal iliac angioplasty with selective therapy with urokinase or recombinant tissue plas- vein graft stenosis. J Vasc Surg 39:702, 2004 stenting: long term results assessed by means of minogen activator for peripheral arterial occlu- 5. Zeller T, Rastan A, Schwarzwalder U, et al: Percuta- duplex scanning. J Vasc Surg 29:422, 1999 sion: a comprehensive compilation of published neous peripheral atherectomy of femoropopliteal 14. Cejna M, Schoder M, Lammer J: PTA versus stent work. J Endovasc Ther 11:436, 2004 stenosis using a new-generation device: six-month in femoropopliteal obstruction. Radiologie 39:144, 23. Allie DE, Herbert CJ, Lirtzman MD, et al: Novel results from a single-center experience. J Endovasc 1999 simultaneous combination chemical thromboly- Ther 11:676, 2004 sis/rheolytic thrombectomy therapy for acute crit- 15. Vroegindeweij D, Vos LD, Buth J, et al: Balloon 6. Duda SH, Bosiers M, Lammer J, et al: The angioplasty combined with primary stenting versus ical limb ischemia: the power-pulse spray tech- SIROCCO II trial: sirolimus-eluting versus bare balloon angioplasty alone in femoropopliteal ob- nique. Catheter Cardiovasc Interv 63:512, 2004 nitinol stent for obstructive superficial femoral structions: a comparative randomized study. Car- 24. Kasirajan K, Gray B, Beavers FP, et al: Rheolytic artery disease. J Vasc Interv Radiol 16:331, 2005 diovasc Interv Radiol 20:420, 1997 thrombectomy in the management of acute and 7. Nikolsky E, Mehran R, Halkin A, et al: Vascular 16. Zdanowski Z, Albrechtsson U, Lundin A, et al: subacute limb-threatening ischemia. 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