Secondary interventions after endovascular abdominal aortic aneurysm repair

The American Journal of Surgery 190 (2005) 787–794

Paper

Secondary interventions after endovascular abdominal aortic aneurysm repair Stephen Lalka, M.D.*, Michael Dalsing, M.D., Dolores Cikrit, M.D., Alan Sawchuk, M.D., Shoaib Shafique, M.D., Ryan Nachreiner, M.D., Keshav Pandurangi, M.D. Peripheral Vascular Surgery Section, Richard L. Roudebush Veteran’s Affairs Medical Center, 1481 West 10th St., Indianapolis, IN 46202, USA Manuscript received June 23, 2005; revised manuscript July 22, 2005 Presented at the 29th Annual Surgical Symposium of the Association of VA Surgeons, Salt Lake City, Utah, March 11–13, 2005

Abstract Background: One adverse outcome of endovascular abdominal aortic aneurysm (AAA) repair (EVAR) is a significantly increased incidence of secondary interventions (SIs) required compared with traditional open aortic repair. We present a consecutive series of EVARs using a single endograft to identify the incidence and types of SIs performed. Methods: From February 1, 2000, to January 31, 2005, we repaired 136 AAAs with the Zenith (Cook, Bloomington, Indiana) endograft. All patients met the same strict anatomic inclusion and exclusion criteria. Follow-up lasted from 1.5 to 61 months (median 36). The indications for SI group A were procedural and technical errors, for group B were aortic morphology, and for group C were device failures. Results: Twenty-one SIs were required in 17 of 136 patients (12.5%). Three patients required multiple interventions. Nine patients were in group A, four were in group B, and six were in group C. All but 4 patients required SIs for late (⬎30 days) complications. Conclusions: Although it is a viable alternative to open aortic repair, EVAR is associated with a significantly higher rate of SIs. To maintain the efficacy of EVAR, patients must be followed-up in a vigilant graft surveillance protocol for life. © 2005 Excerpta Medica Inc. All rights reserved. Keywords: Endovascular aneurysm repair; Secondary interventions

Open repair of an abdominal aortic aneurysm (AAA) has been performed for ⬎50 years and has proven to be a durable procedure that infrequently requires reoperation [1–3]. Endovascular aneurysm repair (EVAR), in its 15 years of clinical application, has proven to be a safe and effective alternative to open aneurysm repair (OAR) [4,5] However, the durability of EVAR has not yet been established given the paucity of long-term data [6,7]. One apparent consequence of EVAR is a significantly increased incidence of secondary interventions (SIs) relative to those required after OAR [8,9]. We reviewed our consecutive series of EVAR using a single endograft with strict inclusion and exclusion criteria to better identify the incidence and types of SIs.

* Corresponding author. Tel.: ⫹1-317-554-0000, ext. 2353; fax: ⫹1317-554-0618. E-mail address: [email protected]

Materials and Methods Between February 1, 2000, and January 31, 2005, 136 aortoiliac aneurysms were repaired by the investigators at the Indiana University Medical Center, Indianapolis, Indiana (Roudebush Veterans Administration Medical Center, Methodist Hospital, and Wishard Memorial Hospital) using the Zenith (Cook, Bloomington, Indiana) endograft. The 104 patients entered into the study between February 1, 2000, and May 21, 2003, were enrolled in the Food and Drug Administration (FDA) phase II trial of the Zenith device, which received FDA approval on May 23, 2003. Since then, the same anatomic inclusion and exclusion criteria of the Zenith trial have been applied to all prospective candidates for EVAR during evaluation by a single surgeon (S. L.). Details concerning the Zenith device and the inclusion and exclusion criteria are described in Greenberg et al [4]. Adverse events requiring SI after EVAR were identified

0002-9610/05/$ – see front matter © 2005 Excerpta Medica Inc. All rights reserved. doi:10.1016/j.amjsurg.2005.07.021

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Table 1 Group A indication for SI: procedure or technical error related Patient no.

Indication for SI

1

Twisted (L) iliac limb with new-onset claudication and decrease in ABI Top covered stent partial overlap of (L) renal orifice with decreased perfusion to (L) kidney Top covered stent overlap (R) renal orifice with decreased perfusion Occluded (R) iliac limb from kink because of vessel tortuosity Top covered stent partial overlap (L) renal orifice with decreased perfusion (R) lower extremity embolization

2 3 4 5 6 7 8 9

Interval (days)*

(L) renal artery orifice partially covered by composite cuff deployed at SI to repair top-stent detachment Occluded (R) iliac limb from kink because of vessel tortuosity Type B thoracic aortic dissection from guidewire or tip of delivery device

Open (O)/ Perc (P)

SI procedure

Success (Y/N)

34

P

Deployment of balloon-expandable stent

Y

215

P

Y

245

P

10 29

O P

Y Y

1

O

886

P

Deployment of balloon-expandable renal stent Angiogram with attempted renal stent deployment (L)-to-(R) femoral-femoral bypass graft Deployment of balloon-expandable renal stent Thrombectomy, (R) femoral-popliteal bypass, and fasciotomy Deployment of balloon expandable stent

114 6

O P

(L)-to-(R) femoral-femoral bypass graft Deployment of thoracic aortic endograft

Y Y

N

Y Y

* Interval from original EVAR to SI. ABI ⫽ Ankle-to-brachial ratio by Doppler; EVAR ⫽ endovascular obdominal aortic aneurysm repair; (L) ⫽ left; O ⫽ open femoral; P ⫽ percutaneous femoral access; (R) ⫽ right; SI ⫽ secondary intervention.

by the postprocedure surveillance protocol employed for all 136 patients, which included history and physical examination, lower-extremity arterial segmental Doppler examination, 4-view plain abdominal radiograph (supine, lateral, 30° right posterior oblique and 30° left posterior oblique to assess the wire-frame of the endograft itself as well as its relationship to the bony landmarks), and computed tomographic angiography (CTA) with 3-dimensional reconstructions. These evaluations occurred at the following intervals: postprocedure and predischarge, 30 days, 6 months, 12 months, and yearly thereafter. Follow-up in our group (minimum for consideration in this study was 31 days) ranged from 1.5 to 61 months (median 36). The indications for SI were divided into 3 groups: (1) procedure and technical error related (ie, related to the physical characteristics and deployment techniques of the Zenith device or errors in deployment by the surgeons); (2) aortic morphology related (eg, branch endoleaks); and (3) device related (ie, failure of the device after successful deployment).

Results During a 60-month period, we deployed 136 Zenith endografts to repair aortoiliac aneurysms with 100% technical success and 0% mortality at 30 days; no conversions to OAR were required either early (ⱕ30 days) or late. Twentyone SIs were required in 17 of 136 patients (12.5%). Details of the SIs are listed in Tables 1 to 3. Three patients required multiple interventions: one patient (no. 7) required 2 interventions (1 each for group A and C indications); a second patient (no. 10) required 3 interventions (2 for group B and 1 for group C indications); a third patient (no. 13) required 2 interventions for group B indication (nos. 10 and 13 each required 2 separate coil embolization procedures because of failure to eradicate the lumbar endoleaks at their initial SIs). In addition to the 2 failed initial embolization attempts, one other unsuccessful intervention involved patient no. 3, who was found on surveillance CTA to have impaired perfusion to 1 kidney with evidence of renal artery occlusion. At angiography, the main body was noted to be almost

Table 2 Group B indication for secondary intervention (SI): aortic morphology related Patient no.

Indication for SI

10 11 10 12 13 13

Type Type Type Type Type Type

II II II II II II

lumbar lumbar lumbar lumbar lumbar lumbar

endoleak endoleak endoleak endoleak endoleak endoleak

with with with with with with

AAA AAA AAA AAA AAA AAA

sac sac sac sac sac sac

expansion expansion expansion expansion expansion expansion

Interval (days)*

Open (O)/ Perc (P)

SI procedure

926 431 954 976 889 946

P P P P P P

Coil Coil Coil Coil Coil Coil

embolization embolization embolization embolization embolization embolization

Success (Y/N) of of of of of of

(R) lumbar branch bilateral lumbar branches (L) lumbar branch bilateral lumbar branches bilateral lumbar branches bilateral lumbar branches

N Y Y Y N Y

* Interval from original EVAR to SI. AAA ⫽ Abdominal aortic aneurysm; EVAR ⫽ endovascular AAA repair; (L) ⫽ left; O ⫽ open femoral; P ⫽ percutaneous access; (R) ⫽ right; SI ⫽ secondary intervention.

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Table 3 Group C indication for SI: device failure related Patient Indication for SI no.

Interval Open (O)/ SI procedure (days)* Perc (P)

14

Distal type I endoleak

78

O

15

Type III endoleak from main body of Zenith device 315 (fabric tear) Detachment of top covered stent from suprarenal 961 stent Detachment of top covered stent from suprarenal 853 stent Distal type I endoleak from (R) iliac limb retracting 1360 cephalad into AAA sac Migration and detachment of iliac limbs from main 1485 body with type II endoleak

O

16 7 17 10

completely overlapping the orifice of the renal artery, which had gone unappreciated at the time of EVAR. Multiple attempts to cross the occlusion were not successful. Given the patient’s normal contralateral kidney with a widely patent renal artery and only stable mild increase in creatinine, an open renal revascularization was believed to be contraindicated. Seven patients’ SIs are depicted in Figs. 1 through 7: Patient no. 1 had inadvertent rotation of the main body delivery device during deployment, resulting in an inaccessible contralateral “gate.” To allow cannulation, the device was “derotated,” resulting in a twist in the ipsilateral iliac portion of the main body that was not apparent on completion angiogram or predischarge CTA. At 2-week follow-up, whole-leg claudication and decreased ankle-to-brachial Doppler pressure index led to successful intervention with balloon-expandable iliac stent deployment. Patient no. 2 had no defects noted on completion angiogram or on predischarge or 30-day CTA. At 6-month follow-up, an increase in creatinine (0.8 to 1.2 mg/dL) and decreased renal perfusion on CTA led to percutaneous renal stent deployment to correct origin stenosis from partial overlap of the lowermost renal by the first covered stent of the endograft. Patient no. 10 had persistent type II endoleak from EVAR despite continued sac shrinkage. The sac underwent significant morphologic change to a saccular distal aneurysm with anterior displacement of the endograft within the sac. Focal posterior sac enlargement led to coil embolization of lumbar branches (requiring two interventions). However, at 4-year surveillance imaging, there was complete detachment of the left iliac endograft limb and migration of the right iliac endograft limb. SI for this type III endoleak was performed with deployment of Zenith iliac limbs spanning the original junction zones with the main body. Patient no. 11 had a type II endoleak at EVAR associated with stable aneurysm sac size until an increase from 56 to 60 mm maximum diameter at 12-month follow-up. This was treated with lumbar branch coil embolization by way of hypogastric-to-iliolumbar access.

O O O O

Deployment of Zenith extension limb to land in more distal less-calcified common iliac Deployment of Zenith aortic cuff and balloon-expandable stent Deployment of Zenith composite cuff (uncovered suprarenal and 2 covered infrarenal stents) Deployment of Zenith composite cuff (uncovered suprarenal and 2 covered infrarenal stents) Deployment of Zenith iliac limb extension into (R) external iliac with coil embolization of (R) hypogastric Deployment of bilateral Zenith iliac limbs across original junction zone of main body and iliac limbs

Success (Y/N) Y Y Y Y Y Y

Patient no. 15 had a midaortic endoleak first noted at 6 months. Dynamic CTA [10] showed type III leak from a fabric tear where the main graft body draped over a large posterior calcified plaque. This was treated with deployment of Zenith aortic cuff segments and deployment of an uncovered balloon-expandable stent to compress the plaque and seal the leak. Patient no. 16 had a narrow distal aorta that did not allow the contralateral limb of the main body to open. The device was pushed cephalad to open the contralateral limb and then pulled caudad; the remainder of the procedure was uneventful. At 24-month follow-up, there was partial detachment of the top stent and 5-mm distal migration of the first covered stent (this was a Zenith device with only 1 set of sutures attaching each suprarenal stent strut to the first covered stent; the number of sutures was doubled in a design change in August 2002 [4]). This was repaired with a composite uncovered suprarenal with covered infrarenal Zenith aortic cuff. Patient no. 17 had marked remodeling of the aneurysm sac thrombus after EVAR, resulting in loss of anterior mural thrombus and anterior displacement of the endograft. Despite adequate (⬎20-mm) purchase of the right iliac limb at EVAR, an asymptomatic type I distal endoleak was demonstrated on the 3 year follow-up CTA. This was repaired with a Zenith iliac limb deployed across the junction zone.

Comments One measure of the durability and reliability of EVAR and OAR is the need for SI after the initial AAA repair. However, the true incidence is difficult to ascertain because the methods of data acquisition are so varied between literature reports. Based on a collected review of published series of patients who underwent successful OAR from 1981 to 1991, Hollier et al [1] found that late graft-related complications (at 6 to 12 years after surgery) occurred with an overall incidence of 2.8% and consisted of aorta– enteric fistula (0.9%), pseudoaneu-

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Fig. 1. Patient no. 1. Twisted, stenotic left iliac limb at junction with main body.

rysm (1.3%), graft infection (0.4%), and bowel ischemia (0.3%). In a retrospective review of a single center with a large nonlocal referral base (where late complications might well be treated elsewhere), Hertzer et al [3] from the Cleveland Clinic reported on their 1047 OARs from 1989 to 1998 and identified only 4 late graft complications (0.4%): 2 graft infections, 1 graft limb occlusion, and 1 femoral pseudoaneurysm; the investigators did state that their patients were not subjected to surveillance with any imaging technique. In contrast, Hallet et al [2] studied all patients who underwent OAR between 1957 and 1990 in a geographically defined community where all AAA repairs were performed and followed-up by a single surgical practice, thus minimizing referral bias and loss to follow-up. In addition, 46% of patients eligible for long-term follow-up underwent late graft imaging studies. At a mean follow-up of 5.8 years (range ⬍30 days to 36 years), a total of 33 major graft-related complications occurred in 29 of the 304 patients who survived OAR (9.5%), including anastomotic pseudoaneurysms (3.0%), graft limb thrombosis (2.0%), graft-enteric erosion or fistula (1.6%), graft infection (1.3%), anastomotic hem-

Fig. 2. Patient no. 2. (A) Surveillance CTA demonstrating stenotic left renal artery origin and decreased nephrogram. (B) Partial coverage of left renal artery orifice by top edge of first covered stent. (C) Left renal artery balloon-expandable stent deployed by way of cannulation through suprarenal uncovered stent of Zenith device. CTA ⫽ computed tomographic angiography.

S. Lalka et al. / The American Journal of Surgery 190 (2005) 787–794

Fig. 3. Patient no. 10. (A) Detachment of left iliac limb of endograft and distal migration of right limb seen on plain abdominal radiograph with type III endoleak demonstrated on CTA reconstruction (B). CTA ⫽ computed tomographic angiography.

orrhage (1.3%), colon ischemia (0.7%), and atheroembolism (0.3%). Of note, 24% of all late (⬎30 days) complications appeared between 5 and 10 years after the procedure, and 16% were discovered after 10 years. An additional late finding important to the durability of any technique of AAA repair was that 13% of the 61 patients followed-up with imaging had an aortic size ⱖ30 mm

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Fig. 4. Patient no. 11. (A) Cannulation of iliolumbar branch of right hypogastric to demonstrate type II lumbar endoleak just proximal to bifurcation of endograft. (B) Coil embolization of inflow and outflow lumbar branches by way of microcatheter placement successfully eradicated the endoleak.

(range 30 to 45) above the proximal anastomosis, indicating true aneurysmal degeneration. Given that the first EVAR was reported only 14 years ago [11], long-term follow-up data, as in the OAR studies sited previously, does not exist to any significant degree. Graft-related complications of EVAR include continued pressurization or repressurization of the aneurysm sac caused by perigraft flow (endoleaks), increase in aneurysm sac size without endoleak (endotension), failure of device integrity (eg, hook, barb, or wire-frame fracture, disassoci-

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Fig. 5. Patient no. 15. CTA demonstrating posterior calcified aortic plaque (A) causing late type III endoleak (B). Endoleak behind midbody of graft (C) successfully repaired with deployment of aortic cuffs and balloon-expandable stent (D). CTA ⫽ computed tomographic angiography; EL ⫽ endoleak.

ation of graft limbs at junction zones in modular systems, and fabric tears), device migration, and graft limb thrombosis. As with OAR, endografts are still subject to infection (usually by hematogenous source), and pelvic, colonic, and lower-extremity ischemia can result from disruption of unstable mural thrombus and atherosclerotic plaque despite the most careful technique. Compared with OAR, and despite the still-limited length of follow-up, there is a high rate of graft-related complications requiring SIs after EVAR. Both the Eurostar registry [8] and Sampram et al [9] reported high (33% and 35%, respectively) rates of SI within 3 years of EVAR. Specific graft-related complications requiring SI were multifactorial, and the incidence varied with the device used. For example,

graft limb occlusion after EVAR has been reported to occur with an incidence of 0% to 15% [12–14] Thrombosis occurred because of excessive oversizing of the endograft leading to infolding of the graft material within the lumen; twisting of the limb during deployment; landing an iliac limb at a point of angulation of the native vessel; and use of an unsupported endograft, which is 15 times more likely to require SI because of kinking than with a fully-supported device [15]. Another example of the variability in reporting of graft-related complications of EVAR is endoleaks. This complication is unique to EVAR, which is reported to occur at a widely varied rate: from 5% to 47% [16]. There are 5 different types of endoleaks [17], and depending on the type and quality of surveillance imaging, it may be difficult to

S. Lalka et al. / The American Journal of Surgery 190 (2005) 787–794

Fig. 6. Patient no. 16. (A and B) Detachment of suprarenal, uncovered top stent with distal migration of first covered stent.

identity the specific type of endoleak, thus impeding SI. In addition, approximately 50% of endoleaks resolve spontaneously, whereas other persistent endoleaks may be associated with stable or shrinking aneurysm sacs, further limiting the need for SI [18]. Our experience with the Zenith endograft is best evaluated in comparison with the results of the Zenith phase II FDA trial (January 2000 to July 2001), which included 200 endovascular patients and 80 nonrandomized surgical control patients, both having standard surgical comor-

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Fig. 7. Patient no. 17. (A and B) Sagittal multiplanar reformatted CTA images of right iliac limb with late withdrawal into aneurysm sac causing type I distal endoleak. CTA ⫽ computed tomographic angiography.

bidities, with the latter group meeting a least 1 of the anatomic exclusion criteria. SIs were required significantly more frequently after EVAR: 13.1% of patients who survived a technically successful deployment of the Zenith endograft underwent SIs in the first 24 months, including 5 late conversions to OAR (1 contained rupture caused by proximal migration of an iliac limb into the aneurysm sac at 222 days; 1 persistent type I proximal endoleak at 248 days; development of 1 remote visceral

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aortic segment aneurysm at 112 days; and 2 grafts [at different centers] infected with Staphylococcus aureus from hematogenous spread at 543 days); 6 endovascular interventions for type I endoleaks, 5 for type II endoleaks, and 1 for a type III (modular junction disassociation) endoleak; 5 interventions for renal artery stenosis; 3 interventions for iliac occlusive complications; and 1 revascularization for infrainguinal occlusion [4]. Given the wide variation in SIs rates reported for EVAR, we presented our experience from a prospectively evaluated series of patients treated with 1 type of endograft with uniform inclusion and exclusion criteria applied. Our SI rate of 12.5%, with median follow-up of 36 months, is consistent with the 24-month data (13.1%) from the Zenith multicenter trial. The critical importance of vigilant long-term surveillance required for EVAR is emphasized in our study by those patients having late appearance of type II endoleak (patient no. 13), aneurysm sac remodeling causing type I endoleak from withdrawal of an iliac limb into the sac (patient no. 17), migration and detachment of an iliac limb at the modular junction zone with type III endoleak (patient no. 10), and technical errors during deployment causing device failure (top stent detachment in patients no. 7 and 16) during the 2 years after surgery. One can conclude that the durability of EVAR has yet to be determined. What is certain is that life-long graft surveillance is required after EVAR.

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