Endovascular Stents Covered with Pre-expanded Polytetrafluoroethylene for Treatment of Iliac Artery Aneurysms and Fistulas

Endovascular Stents Covered with Pre-expanded Polytetrafluoroethylene for Treatment of Iliac Artery Aneurysms and ~istulasl Stephen F. Quinn, MD Robert C. Sheley, MD Kevin G. Semonsen, MD Robert B. Sanchez, MD Roger W. Hallin, MD

Index terms: Aneurysm, iliac Arteries, grafts and prostheses. Arteries, iliac Fistula, iliac. Stents and prostheses

.

JVIR 1997; 8:1057-1063 Abbreviations: FTFE = polytetrafluoroethylene, TPEG = trans~umina~ly placed endovascular graft

PURPOSE: This report describes the early clinical experience with use of a transluminally placed endovascular graft (TPEG) covered with pre-expanded polytetrafluoroethylene (PTFE) to treat iliac artery aneurysms and fistulas. MATERIALS AND METHODS: Eight patients with iliac artery aneurysms (n = 7) and common iliac artery to common iliac vein fistula (n = 1)were treated with TPEGs. The iliac artery aneurysms were either common iliac (n = 6) or hypogastric (n = 1).All of the patients had significant comorbid diseases. The TPEG devices were made with pre-expanded PTFE sutured to Palmaz stents and delivered through 10- or 12-Fsheaths. RESULTS: The aneurysms were successfully excluded in six of seven patients and the one iliac artery-to-vein fistula was successfully occluded. There were no immediate procedural complications related to the TPEG devices. Follow-up was limited (mean, 12 months), but no stenoses or occlusions of the TPEG devices were detected. The one failure was probably due to the marked tortuousity of the iliac artery, which prevented an adequate seal. CONCLUSION: In the authors' early clinical experience, the use of TPEG devices with pre-expanded PTFE successfully treated iliac artery aneurysms and an iliac artery-to-vein fistula. Although the results are encouraging, longer follow-up is necessary to better evaluate this type of treatment.

From the Departments of Radiology (S.F.Q., R.C.S., K.G.S.) and Surgery (R.w.H.), GOO^ Samaritan Hospital, 1015 NW 22nd, Portland, OR 97210; and the Department of Radiology (R.B.S.), Presbyterian Hospital, Albuquerque, New Mexice. ~ ~~ ~ ~ ~i l1997; 1 0 ~,revisioni requested May 27; revision received June 13; accepted June 14. Address correspondence to S.F.Q.

o SCVIR, 1997

TRANSLUMINALLY placed endovascular grafts (TPEGs) are being used for treatment of thoracic aneuwsms (I), abdominal aortic anellv s m s (2-71, and traumatic arterial injuries (8,9) in selected patients. Iliac aneurysms (6,10,11) and iliac artery-to-vein fistulas (12) also have been treated with TPEGs. In this report we summarize our early experience with use of a TPEG syswith pre-expanded polytetra(PTFE) that can be ~ fluoroethylene ~ d placed without a surgical cutdown and can be modified to accommodate different lengths and diameters.

MATERIALS

METHODS

~ i patients ~ hwith~iliac artery aneurysm (n = 6), pseudoaneurysm and common iliac artery to (n = common iliac vein fistula (n = 1) were treated with TPEGs (Table). The procedures were performed at three institutions during a period of 2 years. The Investigational Review Boards at each institution approved these ~roceduresyand on sent forms were signed. The iliac artery aneurysms were either common iliac (n = 5), common and external iliac (n = I), or

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Summary of Aneurysms and Fistuala and the Techniques Used Proximal and Distal Iliac Arterial Segment Diameters

Aneurysm Diameter (mm)

Aneurysm Length (mm)

Hypogastric artery aneurysm Common iliac and external iliac arteries

40

60

Proximal: 10 mm Distal: 9 mm

40

70

Proximal: 12 mm Distal: 8 mm

Common and external iliac arteries

50

50

Proximal: 14 mm Distal: 8 mm

Anastomotic aneurysm involving proximal external iliac artery

35

50

Proximal: 8 mm Distal: 8 mm

Common iliac artery aneurysm filling retrograde after aortoiliac graft Common iliac artery aneurysm

55

55

Proximal: 9 mm Distal: 8 mm

25

30

Common iliac artery aneurysm

30

Common iliac artery to common iliac vein fistula

NA

Lesion Type

Note.-NA

=

not applicable.

Covered Stent Device

Ancillary Procedures

Sheath Size

P394 covered with pre-expanded PTFE P308 with windsock segment of preexpanded PTFE supported by a 10-mm Wallstent P308 with windsock segment of preexpanded PTFE supported with a 12-mm Wallstent P394 with windsock segment of preexpanded PTFE supported with a 10-mm Wallstent P394 stent covered with pre-expanded PTFE

Embolized hypogastric branches Embolized hypogastric artery

10 F

Exclusion

12 F

Failed; converted to surgical bypass

Embolized hypogastric artery

12 F

Exclusion

Embolized hypogastric

12 F

Exclusion

Embolized aneurysm and hypogastric artery

10 F

Exclusion

Proximal: 8 mm Distal: 8 mm

P394 stent covered with pre-expanded PTFE

10 F

Exclusion

35

Proximal: 9 mm Distal: 9 mm

P394 stents (n = 2) covered with pre-expanded PTFE

10 F

Exclusion

NA

Proximal: 9 mm Distal: 9 mm

P394 stent covered with pre-expanded PTFE

Associated iliac artery stenosis distal to aneurysm also stented Associated iliac artery stenosis also stented. Recanalized and stented contralateral iliac artery occlusion. Dilated and stented other bilateral iliac artery stenoses

10 F

Exclusion

Outcome

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by predilating 3-mm-diameter, thinhypogastric ( n = 1). Four of the six common and external iliac arterv wall PTFE (Impra, Tempe, AZ) to a aneurysms involved the origins of 12-mm diameter. The PTFE matethe hypogastric arteries. Two of the rial was sewn to the proximal end five common iliac aneurysms inof a balloon-expandable stent (P394 volved the proximal external iliac or P308 Palmaz stent; Johnson & arteries. One of the common iliac Johnson, Warren, NJ) with two 5-0 artery aneurysms filled retrogradely sutures (Prolene; Ethicon, Summerfrom the native external iliac artery ville, NJ) 180" apart. A 450-mmafter an aorto-iliac bypass procelong, 6- or 7-F sheath (Cook, Bloomdure. The other four ~ a t i e n t swith ington, IN) was placed over an 8common iliac artery aneurysms had 14-mm-diameter balloon catheter not undergone iliac bypass surgery. (8-10 mm, Ultra-thin or MS ClasThe external iliac artery pseudoansique; Medi-techBoston Scientific, eurysm involved the distal common Watertown, MA; > 10 mm, XXL; iliac artery. Medi-tech/Boston Scientific). The 6The study group comprised six or 7-F sheath was used to stabilize men and two women who ranged in the covered endovascular stent on age from 67 to 78 years (mean, 74 the balloon catheter. The distal end years). All eight patients were conof the 6- or 7-F sheath was posisidered to be poor surgical canditioned so that roughly one half of dates because of comorbid diseases. the struts of the Palmaz stent were The referring surgeons believed inside the sheath lumen and the that the comorbid diseases ~ u t others were outside the lumen. This these patients a t a relativefy high positioning prevented the covered risk of complications, with possible Palmaz stent from being pushed off extended hospitalization times and the balloon in a proximal direction. long recovery periods. Seven of the The windsock segment of the TPEG eight patients had documented corodevice was outside the 6- or 7-F nary artery disease. Two patients sheath. The stent device was delivhad insulin-de~endentdiabetes melered through a 10-F (P394 devices) litus. Four had chronic obor 12-F (P308 devices), 400-mmstructive airway disease. Two palong sheath (Cook). tients had undergone previous-pelThe TPEGs were configured in vic irradiation. Five patients had two manners, depending on the undergone pelvic surgery. Four palength of area needed to be covered. tients presented with claudication In five patients in whom the target and had additional stenotic and oclength was less than 40 mm, the clusive arterial disease. Three papre-expanded PTFE material was tients had ipsilateral common iliac cut to the approximate length of the stenoses, and one of these patients P394 or P308 stents. In four of had a contralateral iliac occlusion. these five patients, one covered The fourth patient had distal occlustent was used to cover the target sive disease. Two of the patients region. In one of the five patients, a presented with pain thought to be second covered stent was overrelated to aneurysm size. One palapped with the first to completely tient presented with a palpable cover the target area. In three of common femoral artery pseudoaneurysm, and the iliac artery pseudo- the seven patients with target lengths greater than 40 mm, the aneurysm was discovered incidenPTFE material was cut longer than tally. One patient presented with the stent and allowed to "windsock claudication and had an ankle bradistally. The windsock segment was chial index of 0.5. The patient with then dilated with an angioplasty the iliac artery-to-iliac vein fistula balloon from the proximal to the was one of the patients who predistal end to better distend the masented with claudication. The fistula was secondary to a discectomy terial. This windsock segment was at the L5-S1 level 1 year prior to then supported with a self-expandpresentation. ing flexible stent (Wallstent) to preThe graft material was prepared vent kinking and twisting and to

ensure that the graft material was closely applied to the vessel wall. In four of the patients with common iliac artery aneurysms, the ipsilateral hypogastric artery was embolized with embolization coils (Cook). In one of these patients (in whom the aneurysm filled retrogradely from the external iliac artery), the hypogastric artery could not be catheterized. The coils were released in the common iliac artery aneurysm and some of these embolized hypogastric branches. Because of incomplete occlusion of the hypogastric branches, the common iliac artery aneurysm was packed with a 0.035-inch guide wire mandrel (Cook). In the patient with the hypogastric artery aneurysm, the proximal outflow branches were embolized with coils. The retroa-ade " flow into the native external iliac artery helped prevent inadvertent embolization of the external iliac and infrainguinal arteries. The external iliac artery origin was covered with a TPEG device after the aneurvsm was embolized. All kight patients underwent completion angiography. The injections for the completion angiography were done in the distal abdominal aorta so that both iliac svstems were opacified. Seven of the eight patients underwent preoperative computed tomographic (CT) examinations. Five of the eight CT examinations were done wituh use of the CT angiographic technique. All eight patients underwent postoperative CT examinations. All patients underwent a follow-up CT examination within 2 weeks of the TPEG procedure and a t 6-month intervals for 3 years. All eight of the procedures were performed percutaneously and, in two of the patients, the site was closed surgically. One of the these patients had a second pseudoaneurysm involving the common femoral artery that was treated surgically immediatelv after the TPEG was used to treat the common iliac artery pseudoaneurysm. All patients were followed up with physical examinations and noninvasive vascular studies. The noninvasive vascular studies included segmental pres-

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sures, brachial indexes before and after exercise, Doppler wave form patterns, and volume pulse recordings.

I RESULTS In all eight patients, the TPEG devices were deployed (Figs 1-3). In six of the eight patients, completion angiography showed complete exclusion of the aneurysm or fistula. In one of the two patients without immediate closure of a common iliac artery aneurysm, a follow-up CT angiogram a t 4 weeks showed complete exclusion of the aneurysm and a widely patent TPEG. In the second patient without immediate aneurysm exclusion, follow-up angiography showed persistent filling of the common iliac artery aneurysm. The persistent leak was probably related to a n inadequate proximal seal related to extreme vascular tortuousity. This patient went on to undergo a surgical bypass procedure. Seven of the eight patients showed complete aneurysm or fistula exclusion on follow-up CT examinations. One of the eight patients was converted to a surgical bypass and, therefore, was not followed up with CT examinations. The CT examinations were performed 1-210 days after the procedure. CT angiographic technique and demonstrated TPEG patency in all patients. Follow-up periods varied from 5 to 32 months (mean, 14 months). The one patient with the common iliac and-common femoral artery aneurysms developed a stenosis 10 months after surgery a t the site of the common femoral artery pseudoaneurysm repair. This was treated with percutaneous transluminal angioplasty. Evaluations of noninvasive vascular studies and clinical symptoms showed no evidence of TPEG stenoses or occlusions. There were no procedural deaths. In one of the patients with a tortuous common iliac artery aneurysm, the first TPEG device failed to exclude the aneurysm and a second device was placed inside the first, which then

Figure 1. Iliac and common femoral pseudoaneurysms in a 67-year-old man who was treated with combined TPEG and surgery. (a)The angiogram shows a fusiform pseudoaneurysm of the common femoral and external iliac arteries and a saccular pseudoaneurysm of the common femoral artery. (b) After placement of a TPEG device, there is complete exclusion of the iliac pseudoaneurysm. There is a ring-like stenosis involving the central portion of the stent that did not have a gradient across it. This may be due to scar tissue from a previous endarterectomy. The hypogastric artery was embolized with coils. The common femoral artery pseudoaneurysm was treated surgically.

and 1% external iliac (15). In this same series, seven of 50 (14%) aneurysms ruptured. The common iliac artery aneurysms measured 47 mm, and the internal iliac aneurysms were larger, averaging 77 mm (14). Recently, several published reports have described experiences with use of TPEG devices to treat iliac artery aneurysms. Cardon et a1 DISCUSSION (16) described their use of a commercially available device in Europe Isolated iliac artery aneurysms have an incidence of 0.03% (13) and to treat 27 patients with iliac artery aneurysms. The authors report a n tend to occur in male patients (5:l) immediate failure rate of 18.5%, and in older individuals (mean age, 74.6 years) (14). The natural history including two failed deployments, one patient death, and two persisof iliac artery aneurysm is similar tent leaks. Additionally, with a to that of abdominal aortic aneumean follow-up of 12 months, one rysms (15). In one series of 55 paTPEG thrombosed and another detients, the operative mortality for veloped a stenosis, requiring PTA. elective procedures was 11% and Marin and others (17) reported was 33% for emergency repairs (14). their experience with use of a In another series of 50 patients TPEG device composed of PTFE suwith iliac aneurysms, 89% were tured to Palmaz stents. With this common iliac, 10% internal iliac

excluded the aneurysm. There were no infections, episodes of distal embolization, vessel ruptures, renal failure, or ischemic problems related to hypogastric artery embolizations. There were no puncture site complications in five of the seven patients who were treated only percutaneously.

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Figure 2. Common iliac artery aneurysm filling retrogradely from external iliac artery in a 78-year-old man with an aortic bi-iliac graft. (a)The preprocedural CT examination shows the left common iliac artery aneurysm. (b) The angiogram shows a left common iliac artery aneurysm filling retrogradely. There also is a pseudoaneurysm involving the left iliac anastomosis. (c) The completion angiogram shows exclusion of the common iliac artery aneurysm. Embolization coils fill the iliac aneurysm. (d) The curved reformation from the follow-up CT angiogram 2 weeks after the TPEG placement shows complete exclusion of the iliac artery aneurysm.

device, they treated 11 patients successfully without complications. The mean follow-up time was 11 months. The authors used unexpanded 6-mm PTFE through 14-F sheaths and surgical cutdowns. Murphy and others (18) also used PTFE sutured to Palmaz stents to successfully treat five iliac artery aneurysms and pseudoaneurysms. One of the iliac arteries ruptured during TPEG deployment. The au-

thors used unexpanded 4-mm PTFE through 14-F sheaths and surgical cutdowns. Razavi and others (11)used TPEGs to treat nine iliac artery aneurysms in eight patients. They used Gianturco stents in seven cases and Palmaz stents in two cases. The authors covered the stents with woven Dacron. All of the procedures were successful without reported complications. The delivery sheath sizes var-

ied from 12 to 16 F. Three of the patients had surgical cutdowns and the others were managed completely percutaneously. Iliac artery-to-vein fistulas are uncommon. The reported causes include aortoiliac bypass surgery (191, lumbar disk surgery (20,211, renal transplant biopsies (22), and atherosclerotic aneurysms (23,241. The clinical triad is high-output cardiac failure, a pulsatile abdominal mass

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accompanied by a thrill and bruit, and unilateral lower extremity ischemia or venous engorgement (23). There have been reports regarding the repair of arterial injuries with TPEG devices. Marin and others (8) described their use of TPEG devices to treat one arteriovenous fistula and six pseudoaneurysms. The TPEG devices were made of PTFE and Palmaz stents. The authors reported no complications with a mean follow-up of 6.5 months. McCarter (25) and Zajko (12) both published case reports describing their use of TPEG devices to successfully treat iliac arteriovenous fistulas in patients after lumbar disk surgery. Becker and others (9) published a case report describing a TPEG device used to treat life-threatening hemorrhage in a subclavian artery. Our approach to using pre-expanded PTFE has several advantages. In most cases, we can now use a 10-F sheath, which allows this procedure to be percutaneous. Because of our own experiences, we prefer pre-expanding the PTFE to expanding the PTFE and stent while in the blood vessel. PTFE can sometimes expand unpredictably, leaving a ring of graft that cannot be expanded even with a high-pressure balloon. The graft material can sometimes unpredictably rupture when dilated on a stent, particularly at the site of suturing. The technique we use allows the treatment of different types of iliac artery aneurysms. Shorter lesions can be treated with a single covered stent. Longer lesions can be treated by anchoring the proximal segment of PTFE with a Palmaz stent and windsocking the distal segment. The windsock segment can then be supported with uncovered stents. We prefer to use the Wallstent rather than the Palmaz stent to support the windsock segment, although either will work. The Wallstent is available in longer lengths than the Palmaz stent and that is our primary reason for using it. Additionally, the Wallstent may be better suited for some tortuous iliac segments. Alternatively, for longer lesions, two or more covered stents

Figure 3. Hypogastric artery aneurysm in a 70-year-old man. (a)The preprocedural angiogram shows filling of hypogastric aneurysm. (b)The completion angiogram demonstrates exclusion of the hypogastric aneurysm. The outflow vessels coming off the aneurysm were embolized with coils and the TPEG device was placed across the origin of the hypogastric artery.

can be overlapped to exclude a lesion. This system will work for any target diameter up to 18 mm. The delivery sheaths are 10 or 12 F, which means they can be used percutaneously in many patients. To date, we have not had complications related to the TPEG devices, but our series of patients is small. The most important concern is that stenoses will develop because of the TPEG devices. Longer follow-up will help define this type of complication. We did have one unsuccessful procedure in which the iliac artery aneurysm was not successfully excluded. That was our first patient and the iliac system was markedly tortuous. We believe the failure was due to an incomplete seal a t the proximal portion of the TPEG device. In this patient, the leak appeared to be small based on the slow filling of the aneurysm and the patient was fully anticoagulated. It was hoped that the small leak would seal after the anticoagulation was stopped, but it did not. In the second patient with a persistent

leak a t completion angiography, the same situation existed, that is, a small leak in a patient given anticoagulants. All attempts to seal the leak, including adding another TPEG, failed to completely stop a small, slow leak. On follow-up CT examinations, the aneurysm was completely excluded. Our early clinical experience with TPEG devices in the treatment of iliac artery aneurysms and fistulas with pre-expanded PTFE is encouraging and is similar to the results of others. Long-term follow-up is necessary so that the role of these devices can be defined. References 1. Dake MD, Miller DC, Semba CP, Mitchell RS, Walker PJ, Liddell RP. Transluminal placement of endovascular stent-grafts for the treatment of descending thoracic aortic aneurysms. N Engl J Med 1994; 331:1729-1734. 2. Chuter TAM, Risberg B, Hopkinson BR, et al. Clinical experience with a bifurcated endovascular graft for

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3.

4.

5.

6.

7.

8.

9.

10.

abdominal aortic aneurysm repair. J Vasc Surg 1996; 24555-666. May J , White G, Waugh R, Yu W, Harris J . Treatment of complex abdominal aortic aneurysms by a combination of endoluminal and extraluminal aortofemoral grafts. J Vasc Surg 1994; 19:924-933. Parodi JC, Criado FJ, Barone HD, Schonholz C, Queral LA. Endoluminal aortic aneurysm repair using a balloon-expandable stent-graft device: a progress report. Ann Vasc Surg 1994; 8:523-529. Richter GM, Palmaz JC, Allenberg JR, Kauffmann GW. Transluminal stent prosthesis in aneurysm of the abdominal aorta. Initial experiences with a new procedure. [German] Radiologe 1994; 34:511-518. White RA, Donayre CE, Walot I, et al. Preliminary clinical outcome and imaging criterion for endovascular prosthesis development in highrisk patients who have aortoiliac and traumatic arterial lesions. J Vasc Surg 1996; 24:556-571. Moore WS, Rutherford RB. Transfemoral endovascular repair of abdominal aortic aneurysm: results of the North American EVT phase 1 trial. J Vasc Surg 1996; 23:543-545. Marin ML, Veith FJ, Panetta TF, et al. Transluminally placed endovascular stented graft repair for arterial trauma. J Vasc Surg 1994; 20: 466-472; discussion 472-473. Becker GJ, Benenati JF, Zemel G, et al. Percutaneous placement of a balloon-expandable intraluminal graft for life-threatening subclavian arterial hemorrhage. JVIR 1991; 2:225-229. Cynamon J , Marin ML, Veith FJ, et al. Endovascular repair of a n in-

ternal iliac artery aneurysm with use of a stented graft and embolization coils. JVIR 1995; 6:509-512. 11. Razavi MK, Dake MD, Semba CP, Nyman URO, Liddell RP. Percutaneous endoluminal placement of stent-grafts for the treatment of isolated iliac artery aneurysms. Radiology 1995; 197:801-804. 12. Zajko AB, Little AF, Steed DL, Curtis~ EI. Endovascular stent-graft repair of common iliac artery-to-inferior vena cava fistula. JVIR 1995; 6:803-806. 13. Brunkwall J , Hauksson H, Bengtsson H, Bergqvist D, Takolander R, Bergentz SE. Solitary aneurysms of the iliac arterial system: an estimate of their frequency of occurrence. J Vasc Surg 1989; 10:381384. 14. Richardson JW, Greenfield LJ. Natural history and management of iliac aneurysms (review). J Vasc Surg 1988; 8:165-171. 15. McCready RA, Pairolero PC, Gilmore JC, Kazmier FJ, Cherry KJ J r , Hollier LH. Isolated iliac artery aneurysms. Surgery 1983; 93:688693. 16. Cardon JM, Cardon A, Joyeux A, Vidal V, Noblet D. Endovascular repair of iliac artery aneurysm with Endoprosystem I: a multicentric French study. J Cardiovasc Surg 1996; 37(suppl):45-50. 17. Marin ML, Veith FJ, Lyon RT, Cynamon J , Sanchez LA. Transfemoral endovascular repair of iliac artery aneurysms. Am J Surg 1995; 170:179-182. 18. Murphy KD, Richter GM, Henry M, Encarnacion CE, Le VA, Palmaz JC. Aortoiliac aneurysms: management with endovascular stent-graft placement. Radiology 1996; 198:473-480.

19. Levy PJ, Holt JB, Close TP, Rush DS, Haynes JL. Rare presentation of anastomotic iliac artery false aneurysm: rupture with formation of ilio-iliac arteriovenous fistula. Am Surg 1993; 59:713-715. 20. Machado-Atias I, Fornes 0 , Gonzalez-Bello R, Machado-Hernandez I. Iliac arteriovenous fistula due to spinal disk surgery causes severe hemodynamic repercussion with pulmonary hypertension. Texas Heart Inst J 1993; 20:60-64. 21. Serrano Hernando FJ, Paredero VM, Solis JV, et al. Iliac arteriovenous fistula as a complication of lumbar disc surgery: report of two cases and review of literature. J Cardiovasc Surg 1986; 27:180184. 22. Salahudeen AK, Sellars L, Murthy LN, et al. Extrarenal arteriovenous fistula: a n unusual complication of percutaneous renal transplant biopsy. Nephron 1984; 37:6465. 23. McAuley CE, Peitzman AB, deVries EJ, Silver MR, Steed DL, Webster MW. The syndrome of spontaneous iliac arteriovenous fistula: a distinct clinical and pathophysiologic entity. Surgery 1986; 99:373-377. 24. Morrow C, Lewinstein C, Ben-Menachem Y. Spontaneous iliac arteriovenous fistula (review). J Vasc Surg 1987; 6:524-527. 25. McCarter DH, Johnstone RD, McInnes GC, Reid DB, Pollock JG, Reid AW. Iliac arteriovenous fistula following lumbar disc surgery treated by percutaneous endoluminal stent grafting. Br J Surg 1996; 83:796-797.