Managing complications of renovascular interventions

Managing Complications of Renovascular Interventions Gastone A. Crea, MD, John H. Rundback, MD, and Shekher Maddineni, MD

Complications of renal angioplasty and stent placement occur in approximately 15% of patients. Many of these complications can be avoided by appropriate patient Selection, preprocedure planning, and meticulous attention to procedural detail. However, when complications occur, they can often be treated by percutaneous techniques. This article outlines an approach for the catheter-directed management of common complications occurring with renal angioplasty and renal stent placement. Copyright 9 1999 by W.B. Saunders Company

s noted by other investigators throughout this issue, the

A techniques ~of renal angioplasty (PTRA) and stent place,

ment have become widely used for the treatment of renal arterY stenosis (RAS).! However, a description of the types and management of complications occurring with these procedures has received less attention. Reported complications for stenting have ranged from 4% to 29%, 1-n with major complications in 0% to 22% of patients (Table 1). Similar ranges have been reported for PTRA alone, with an emphasis on a "learning curve" for the procedure. 12Although this great variation in the described frequency of complications is no doubt due to real differences between centers, nonstandardized reporting also appears to be a contributing factor. Uniform reporting criteria are needed to allow an accurate assessment of the true morbidity and mortality of these techniques.

Classification of Complications Beek et a112 divided complications of renal stenting into three categories: (1) catheterization-related, (2) stent placementrelated, and (3) those related to either catheterization or stent placement (Table 2). Using these definitions, Beek further classified complications based on their clinical relevance: severe clinical significance-complications resulting in prolonged hospitalization for more than 2 days or increased number of outpatient visits; minor clinical significancecomplications causing prolonged hospitalization for 2 days or less, and; radiological-technical complications-events occurring during catheterization or stent deployment with no

From the Division of Vascular and Interventional Radiology, New York Medical College, Westchester Medical Center, Valhalla, NY. Address reprint requests to John H. Rundback, MD, Assistant Professor of Radiology, Division of Vascular and Interventional Radiology, New York Medical College, Westchester Medical Center, Valhalla, NY 10595. Copyright 9 1999 by W.B. Saunders Company 1089-2516/99/0202-0007S10.00/0

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clinical consequences but causing an increase in procedure time and/or cost.

Management

of Complications

General Precautions Complications can often be avoided by appropriate preprocedure preparation, the use of pharmacological adjuncts during catheterization and angioplasty, and meticulous detail to catheter-and guidewire techniques. An evaluation of the indicadons, contraindications and appropriateness of performing the i0rocedure should occur on a case-to-case basis. Laboratory results are checked including blood urea nitrogen, creatinine, platelet count, and coagulation times. Patients in whom impaired renal function is identified can be studied using limited or diluted iodine-containing contrast or alternative contrast agents such as CO2 gas or gadolinium. 13 Limiting oral intake to clear liquids only allows continuation of oral medications and aides in preventing dehydration. In addition, intravenous fluid administration with monitoring of fluid status should be routinely performed to reduce the risk of contrastinduced nephrotoxicity. Preprocedure preparation specific to renovascular interventions includes the administration of aspirin starting the day before the planned intervention to protect against thrombotic and embolic events. The risk of thrombus formation is further reduced by using pre- and intraprocedural heparin sulfate and spasmolytics. Patients should be fully anticoagu|ated before crossing the renal artery stenosis, and if possible, the coagulation status should be carefully monitored throughout the procedure. Intra-arterial nitroglycerin (100 to 200 l~g boluses) should be used liberally to reduce catheter- and wire-related spasm in the renal artery. In refractory cases, intra-arterial verapamil (1 to 2.5 mg aliquots) will often relieve spasm. Antiplatelet drugs routinely used by invasive cardiologists include the glycoprotein IIb-IIIa receptor inhibitor ReoPro (abciximab; Centocor, Inc, Malvern, PA), Ticfid (ticlopidine hydrochloride; Roche Laboratories, Nutley, NJ), and C|opidogrel (Sanofi Pharmaceuticals, NY, NY). Although these have been shown to reduce coronary restenosis rates, there is little e~perience in the interventional radiology communit): Further investigation is necessary to determine whether pharmacological manipulation with these and other agents will prove useful in improving outcomes. 2 Despite these measures, complications do and will occur, even in the most experienced hands. Fortunately, many of the complications that occur can be treated using catheter-related techniques.

Techniques in Vascular and Interventional Radiology, Vol 2, No 2 (June), 1999: pp 98-106

TABLE 1. Complications of Palmaz Stent Placement in Contemporary Series First Author, Year

N

Total Complications (%)

Major Complications (%)

Type (No. of Each Occurrence)

Van de yen, 19951

24

29

8

Henry, 19962

59

3

3

Lannone, 19963

63*

44

22

Boisclair, 19974

33

21

21

Taylor, 19975

29

24

3

Cholesterol embolization resulting in ARF (2) Acute thrombosis RX w/UK (1), rupture (1) Transfusion (10), peripheral embolism (1), PSA (1), HD (2) RA thrombosis (1), RA emboli (1), cholesterol embolization (1), femoral hematoma (1) Death (1)

White, 19976

100

10

1

Acute thrombosis (1)

Blum, 19977 Fiala, 1998a

68 21

4 24

14

Rundback, 19989

45

9

9

163

15

2

21

29

19

623

16

7

Dorros, 19981~ Shannon, 199811 Totals

Minor Complications (%)

Femoral PSA/HD (1), brachial PSA (1), peripheral emboli (1) Thrombosis (1), HD (1), death (2) Death (1), retrop~ritoneal hematoma (2) . Hematom& (1), death (2), retroperitoneal he r_natome (1).

21

Type (No. of Each Occurrence)

Distal Malpositioning

Malpositioning (4), guidewire perforation (1)

4 of 28

Groin hematoma (6), transient ARF (6), guidewire perforation (2)

-

22 -

21 9

4 10

0 of 35

Transient anuria (1), compressed PSA (2), heinetome (3) Transient ARF (2), GR hematoma (5), compressed PSA (1), brach artery occlusion RX w/PTA (1) Hematoma (3) Dissection requiring additional stent (2)

-~

3 of 32 -

2 of 74 1 of 54

13

Transient ARF (21)

-

10

Hematoma (2)

2 of 21

13

5%

Abbreviations: ARF, acute renal failure; PSA, puncture site pseudoaneurysm; HD, hemodialysis: *Primary stent placement.

Artelial Throntbosis Thrombosis can occur from thrombus formation on the catheter and guidewire and low-flow states resulting from spasm, balloon inflation, catheter occlusion of the stenosis, and dissection. Elsewhere in this issue, Trost et al have provided an excellent review of thrombolytic techniques for patients with acute iatrogenic thrombosis.

Dissection Dissections are usually due to deep intimal-medial dehiscences occurring as a result of balloon dilatation. Dissection may also TABLE 2. Types of Complications Occurring With Renal Stenting Catheterization-related Flow-limiting dissection Guidewire vessel perforation Femoral pseudoaneurysm requiring surgery or transfusion Groin hematoma requiring surgery, transfusion, or prolonged hospitalization Stenting-related Distal malpositioning of the stent with >50% residual stenosis Protrusion of the stent into the aorta by >2 mm Stent dislodgment with nontarget vessel deployment or requiring surgical removal Related to either catheterization or stenting Atheroembolization-livedo reticularis, eosinophilia, and/or decreased renal function Spasm Thrombosis Data from Beek FJA, Kaatee R, Beutler J, et al. 12

MANAGING COMPLICATIONS OF PTRA

be secondary to subintimal passage during catheter and wire manipulations. 14 Most operators will use a guiding sheath to cross the stenosis when delivering a balloon mounted stent. Care must be taken when advancing the blunt sheath over its dilator into the renal artery as this may result in intimal injury (Fig 1). Predilating a severe stenosis should allow for less traumatic guiding catheter placement. Focal dissections may not require further action if no blood flow impairment is seen. For flow-limiting dissections, prolonged (1 to 2 minutes) balloon redilatation may successfully reduce the flap and restore flow. This technique is valuable in small or accessory arteries in which stent placement is not desirable, or in the event that stenting is not available. However, although still under regulatory scrutin); most cases of flow-limiting dissection or dissection resulting in >30% luminal compromise should be stented (Fig 1). In fact, PTRA should probably not be performed unless the operator has the skills and materials necessary for endovascular stenting.

Perforation Vessel'p~erforation due to guidewire advancement is usually self-limited and seals without" intervention. Nevertheless, this is avoidable with nontraumatic cannulation of the stenosis using digital subtraction road map techniques, appropriately shaped diagnostic catheters and guides that match the renal anatom); floppy-tip 0.035" or smaller wires, and a brachial or axillary artery approach when necessary due to severe caudal angulation of the renal artery. Frank vessel rupture during

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Fig 1. Guiding sheath injury resulting in dissection. An abdominal aortogram shows severe bilateral renal artery stenosis (A). Early image after right renal angioplasty and stenting. The artery seems widely patent. The left renal artery was previously stented (B). Late image shows focal dissection conforming to the blunt end of guiding sheath (arrow) (C). A 10-minute delayed angiogram shows progressive dissection and luminal narrowing (D). After placement of a second stent distally, patency was restored (E).

100

CREA, RUNDBACK, AND MADDINENI

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Fig 2. Postangioplasty pseudoaneurysm. Angiography after 6-mm ostial PTRA shows a focal pseudoaneurysm (arrowhead) (A). A balloon-mounted, polytetrafluoroethylene-covered 15-mmlong Palmaz stent (P154, Cordis Corp, Warren, NJ) was positioned at the site of the pseudoaneurysm. The covered stent was delivered through a 14F femoral sheath, but advanced unsheathed into the renal artery (B). Angiography after stentgraft deployment shows exclusion of the pseudoaneurysm and no residual rupture. (Courtesy of Dr Bart Dolmatch) (C).

C balloon dilatation has been reported to occur in 1% to 2% of cases. Careful balloon sizing to avoid overdilating more than 10% to 20% is accepted as safe. If in doubt, an undersized balloon should be used initially with redilatation using a larger balloon as needed. The amount of pain the patient experiences during the inflation is a good indicator of balloon sizing. Mild-to-moderate back or flank pain, which resolves quickly on deflation, is desirable. If pain persists, angiography should be performed while maintaining guidewire access across the arter), to evaluate for vessel rupture. Successful conservative management of focal, limited PTRA-related rupture has been reported, 15 although the patients should be monitored closely and a computed tomography scan obtained to assess the extent

MANAGING COMPLICATIONSOF PTRA

of retroperitoneal hemorrhage. If a large arterial rupture with frank extravasation of contrast is identified, urgent treatment is necessary to avoid exsanguinating hemorrhage and possible renal loss. Initially, the angioplasty balloon or a latex occlusion balloon should be repositioned and inflated across the site of stenosis to tamponade the bleeding. Heparinized whole blood, drawn from the femoral sheath, can be infused through the inflated balloon catheter to maintain renal viabilit): Treatment is urgent surgical repair or autotransplantation. Nonsurgical alternatives, such as deployment of a covered stent, are limited by operator experience and stent availability (Fig 2). Catheterdirected embolotherapy is also useful in selected cases to permanently occlude the injured vessel (Fig 3), although this

101

results in complete or segmental renal infarction. Embolization is valuable for perforations occurring in branch vessels, when surgical backup is not readily available, and in patients with normally functioning contralateral kidneys who are not good surgical candidates.

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Puncture Site Complications

i

Most renal angioplasty and stenting can be performed from the femoral approach. Despite careful technique, access site complications including hematoma, thrombosis, dissection, pseudoaneurysm, arteriovenous fistula formation, neurologic injur); and limb loss are possible after any angiographic procedure. The use of a sheath reduces the chance of damaging the common femoral artery during catheter exchanges. A sheath that extends to the distal abdominal aorta can be used to protect the aorta if it is severely diseased and decreases the risk of embolization of thrombus or atheromatous material. A sheath will also facilitate the transmission of torque to the catheter tip, providing better catheter control and safety for crossing and treating the renal artery lesion. 9Stent Misplacement :The most common radiological-technical complication encountered during renal ~rtery stenting is misplacement, occurring in up to 25% of cases. 16 Misplacement may be either distal, resulting in an initial failure to cover the lesion, or proximal, with an undesirably large portion extending into the aorta. Distal misplacement may be due to several factors. The proper imaging obliquity must be selected to adequately view the renal artery origin in profile, thereby avoiding stent placement distal to an orificial lesion. Angiography should be performed through the guiding catheter or sheath as often as necessary before final stent deployment to assure accurate positioning. When performing this angiogram, it is important that the back end (aortic side) of the stent remain partially covered by the guide. If this trailing edge of the stent is bare, it may difficult to reposition the stent proximally as the stent can "catch" at the site of the stenosis or at the aortorenal angle and slide off of the balloon. Distal embolization may also occur if balloon rupture occurs before the stent is fully deployed. Use of puncture-resistant balloons made from coextruded materials, nylon, or nylon covering is recommended. Balloons coated with hydrophilic or silicone coatings do not allow for secure anchoring of the stent and increase the likelihood of migration during deployment. If it is necessary to use a balloon of this type, the coating must first be removed by wiping with an alcohol swab. Fluoroscopic confirmation of stent positioning in relation to the balloon markers is done before unsheathing; if the stent appears to have moved on the balloon during advancement through the sheath then the entire stent-balloon

Fig 3. Frank rupture. Selective right renal angiogram reveals stenosis due to fibromuscular dysplasia (A). Arterial rupture and extravasation of contrast is noted after angioplasty (B). Coil embolization of the renal artery was performed to stop bleeding. Because the contralateral renal artery was patent, no further treatment was undertaken (C).

102

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Fig 4. Distal stent malpositioning. Selective renal arteriogram after, stent placement shows a residual uncovered ostial stenosis (curved arrow) (A). After placement of a second stent no residual Stenosis is noted (B).

assembly should be removed and the stent remounted. If the stent slides on the balloon after unsheathing but before final positioning, it can be gripped and repositioned by slightly inflating the balloon. It is important that the stent is deployed by gradual balloon inflation over several seconds, as rapid balloon inflation increases the risk of stent slippage. Stent misplacement should be recognized immediatel); and any residual stenosis left uncovered should be treated, usually by placement of a second stent (Fig 4). Although theoretical, it is probably desirable to use the shortest possible second stent to avoid excessive overlap that may result in restenosis. Stents that have embolized into the intrarenal branches should be crossed with a guidewire, if possible, and balloon dilated to match the size of the affected branch. Low-profile 0.018" or 0.014" guidewires and microcatheter or coronary balloons are often necessary (Fig 5). Proximal misplacement may result in excessive stent extruding into the aorta, or to complete dislodgement of the constrained stent into the aorta. Careful crimping of the stent onto the balloon and centered between the balloon markers as well as careful introduction across the hemostatic valve of the sheath will avoid predelivery stent slippage. After deployment, the stent can catch on the balloon and be pulled proximally as the balloon is withdrawn. Reinflation of the balloon may help fix the stent in place. As the balloon is deflated, gentle counterclockwise rotation and forward advancement will usually disengage the balloon from the stent. In addition, the guide catheter can be used to hold the stent in place as the balloon is withdrawn. Balloon rupture may also cause stent nondeployment. In these cases, it is sometimes possible to pull the stent-mounted balloon back into the mid- or lower aorta, align it with the sheath, and retract the entire assembly into the guide or femoral sheath. If this is not possible, or if the stem has been misplaced off of the balloon, snare retrieval can be performed (Fig 6). First, the balloon is removed while keeping

MANAGING COMPLICATIONS OF PTRA

the stent constrained on the wire. In fact, the wire should be maintained with its tip still within the renal artery; both to prevent stent loss and to allow subsequent treatment of the renal lesion after stem retrieval. An Amplatz gooseneck snare (Microvena, Vadnais Heights, MN) is then placed alongside the guidewire in the sheath, with the snare itself looped around the wire (Fig 7). The proximal end of the stent is then grabbed and pulled down into the sheath. If the distal end of the stent is snared it may be crushed against the edge of the sheath and form a jagged, deformed mass that cannot be pulled into the sheath. The risk of injury to the femoral artery is increased if this jagged stent/sheath combination is pulled out at the puncture site. Stents that extend too far into the aorta but still adequately cover the renal artery lesion do not need any specific treatment.

Stent Infection An infrequent but documented complication of endovascular stent placement is stent infection. Although rare in both the iliac and renal artery experience, it is potentially devastating and life threateningY Reported instances in the literature include four cases of iliac artery, one case of coronary artery, and two cases of renal artery stent infections. ~s-2~Most occur soon after stent placement; however, a chronic infected pseudoaneurysm has been reported which occurred 22 months after iliad-artery stenting. 2~ Based on the potentially devastating nature, the administration of prophylactic antibiotics effective against skin flora should be considered before any procedure in which placement of an arterial stent is considered. 7 If stent infection is suspected, a prompt evaluation including blood cultures and computed tomography scan should be performed, and broad-spectrum antibiotics should be administered. Depending on the response to treatment, surgical resection of the

103

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Fig 5. Stent embolization. Predeployment positioning of balloon mounted stent (A). Distal embolization resulted during balloon inflation. Note that the stent is not fully expanded in the distal renal artery (arrow) (B). A low-profile balloon was advanced over a 0.018" guidewire through the stent. The ostium has already been treated by a second stent (C). After balloon dilatation, the stent is fully expanded within a segmental branch (D).

104

CREA, RUNDBACK, AND MADD1NENI

A

B

C

Fig 6. Technique of stent retrieval. The Amplatz snare (shown with its catheter) is advanced,through the femoral sheath over the wire and parallel to the stent, The snare is first positioned above the stent and then fully opened (A). The stent is snare by retracting on the snare (B). The snare is closed around the proximal ~nd of the stent by advancing its catheter, although a renal guide catheter or long femoral sheath may also be used (C). An attempt should be made to pull the proximal stent barbs into the sheath to avoid access site trauma during removal. The entire system (including the femoral sheath) is then removed while maintaining wire position and tension on the snare.

Fig 7. Radiograph showing snare capture of a misplaced stent for subsequent retrieval. The tip of the femoral sheath is indicated with an arrowhead.

MANAGING COMPLICATIONS OF PTRA

105

stent and affected artery with extra-anatomic (eg, splenorenal or hepatorenal) bypass grafting should be considered.

References 1. Van de yen PJG, Beutler JJ, Kaatee R, et al: Transluminal vascular stent for ostial atherosclerotic renal artery stenosis. Lancet 346:672674, 1995 2. Henry M, Amor M, Henry I, et al: Stent placement in the renal artery: Three-year experience with the Palmaz Stent. J Vasc Interv Radiol 7:343-350, 1996 3. lannone LA, Underwood PL, Nath A, et al: Effect of primary balloon expandable renal artery stents on long-term patency, renal function, and blood pressure in hypertensive and renal insufficient patients with renal artery stenosis. Catheteriz Cardiovasc Diag 37:243-250, 1996 4. Boisclair C, Therasse E, Oliva VL, et al: Treatment of renal angioplasty failure by percutaneous renal artery stenting with Palmaz stents: midterm technical and clinical results. Am J Roentgenol 168:245-251, 1997 5. TaylorA, Sheppard D, Macleod MJ, et al: Renal artery stent placement in renal artery stenosis: Technical and early clinical results. Clin Radiol 52:451-457, 1997 6. White CUJ, Ramee SR, Collins TJ, et al: Renal artery stent placement: Utility in lesions difficult to treat with balloon angioplasty. J Am Coil Cardio130:1445-1450, 1997 7. Blum U, Krumme B, Flugel P, Gabelmann A, et al: Treatment of ostial renal artery stenoses with vascular endoprostheses after unsuccessful balloon angioplasty. N Engl J Med 336:459-465, 1997 8. Fiala LA, Jackson MR, Gillespie DL, et al: Primary stenting of atherosclerotic renal artery stenosis. Ann Vasc Surg 12:128:133, 1998

1 06

9. Rundback JH, Gray R, Rozenblit G, et al: Renal artery stent placement for the management of ischemic nephropathy. J Vasc Interv Radiol 9:413-420, 1998 10. Dorros G, Jaff M, Mathiak L, et al: Four-year follow-up of PalmazSchatz stent revascularization as treatment for atherosclerotir renal artery stenosis. Circulation 98:642-647, 1998 11. Shannon HM, Gillespie IN, Moss JG: Salvage of the solitary kidney by insertion of a renal artery stent. Am J Roentgeno1171:217-222, 1998 12. Beek FJA, Kaatee R, Beutler J, et al: Complications during renal artery stent placement for atherosclerotic ostial stenosis. Cardiovasc Intervent Radio120:184-190, 1997 13. Matsumoto AH: Renal stents: When and how to use them. University of Pennsylvania Medical Center, 6th Annual Course Interventional Radiology and Vascular Imaging Handbook. Puerto Rico. November 4-7, 1998 14. Gardiner GA, Meyerovitz MF, Stokes KR, et al: Complications of transluminal angioplasty. Radiology 159:201-208, 1986 15. Ashenburg RJ, Blair RJ, Rivera FJ, Weigele JB: Renal artery rupture complicating transluminal angioplasty: Successful conservative management. Radiology 174:983-985, 1990 16. Kuhn FP, Kutkuhn B, Torsello G, Modder U: Renal artery stenosis: Preliminary results of treatment with the Strecker stent. Radiology 180:367-372, 1991 17. DeMaioribus CA, Anderson CA, Popham SSG: Mycotic renal artery degeneration and systemic sepsis caused by infected renal artery stent. J Vasc Surg 28:547-550, 1998 18. Deparaine MK, Ballard JL, Taylor FC, Chase DR: Endovascular stent infection. J Vasc Surg 23:529-533, 1996 19, Leroy O, Martin E, Prat A, et al: Fatal infection of coronary stent implantation. Cathet Cardiovasc Design 39:168-170, 1996 20. Bunt TJ, Gill HK, Smith DC, Taylor FC: Infection of a chronically implanted iliac artery stent. Ann Vasc Surg 11:529-532, 1997

CREA, RUNDBACK, AND MADDINENI