J CARDIOVASC SURG 2003;44:549-52
Repair of abdominal aortic aneurysms with the ExcludefBJ bifurcated stent-graft T. PFAMMATIER1, D. MAYER2, R. PFIFFNER1, C. KOEHLER2, L. HECHELHAMMER1, M. L. LACHAT2
The design of the Excluder®, which is considered a . 3 ed generation device for endovascular repair of abdominal aortic aneurysms, is described. Based on a literature search, clinical short- to mid-term results are reviewed. So far, efficacy and safety of the Exc1uder® for elective and emergent aneurysm repair have been demonstrated. In none of the studies perioperative conversion to open surgery or late aneurysm rupture has been reported. The cumulative 30day-mortality rate was below 1%. Compared to the other commercial devices, aneurysm shrinkage is less marked after repair with the Excluder®. Whether this is inconvenient remains to be proven on long-term follow-up. KEy WORDS: Aortic anet.l1ysm, abdominal, urgery - Vascular surgical procedures - Blood vessel prosthesis implantation.
Device description
T
h e fir t clinical eries of elective repair of abdominal aortic aneurysms (AAA) with 1st and 2nd generation c mmercial stent-grafts were reported between 1996 and 1997.1-3 The Excluder® (W. 1. Gore & Assoc. , Flag taff, Arizona, USA) was ilnplanted first in 1997 and is considered a 3rd generation device. Th Excluder® system for infrarenal AAA's is a bifurcated, hort body, 2-component device (Figure 1). The larger cOlnponent is the tnlnk-ipsilateral iliac leg prosthesis, the smaller the contralateral aorto-iliac limb. Proximal aortic as well as iliac extension prostheses are available. The graft material is expanded polytetrafluoroethylene (ePTFE). The entire length of the device is supported by a .. ~ddre~~ l:e print requests to: T. Pfammatter, MD, Universitatspital Zunch, Ramlstras e 100, 8091 Zurich, Switzerland. E-mail: thomas.pfamma tte
[email protected]
Vol. 44 - No.4
. . ~/nstitute of Diagnostic Radiology University Hospital of Zurich, Zurich, Switzerland ., ~Clinic of Cardiovascular Surgery University Hospital of Zurich, Zurich, Switzerland
self-expanding external nitinol stent. In addition to the radial self-expanding force aortic fixation is implen1ented by small nitinol anchors and an ePTFE cuff. The stent-graft i compacted onto a delivery catheter and restrained within a PTFE sleeve. Once the device i in the int nded position, the prostheses components are released by pulling the string of the sleeve utur. Currently available stent-graft dian1eters range from 23 InlTI to 32 mm for the aortic trunk and either 12 nun to 20 mm for the iliac limbs. Entirely covered, straight aortic extender stent-grafts are 3.3 (diameters of 23 mm to 28.5 mm) or 4.5 em (32 mm diameter) long. The iliac extender endoprosthe es are 7 C111 long and tapered to either 10, 12 or 14.5 mm. Both extender devices have the same releasing mechanism as the bifurcated prosthesis. In comparison to other commercial devices, the Excluder is rather flexible and requires smaller introducer heaths (18F for trunks smaller than 28.5 ffiffi, 20F for the 32 mm trunk 12F for the contralateral leg with a distal diamete;' up to 14.5 mm, 18F for the larger contralaleral pieces). The Excluder® stent-graft has aCE-mark and has recently been FDA-approved. Clinical Excluder® studies
A Medline literature research revealed 4 clinical studies focussing entirely on the Exc1uder®.
THE JOURNAL OF CARDIOVASCUlAR URGERY
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PFAMMATIER
REPAIR OF ABDOMINAL AORTIC ANEURYSM ~ WlTH TI-IE EXCLUDER® BIFURCATED TENT-GRAFT
Figure l.-Exc1 uder® ste nt graft for AAA's. Trunk-ipsilateral Jeg endoprosthesis m01..mted on the application cathete r, note f1exibility (A) . Reiea. eel modu lar endograft (E) . Hub of the introducing cathete r; after retrieval of [be sheath [he prostheses is unzipped by pulling the knob (arrow) (C). CIa -up vi w of the aortic nd of the pro th sis; th arrows indicate the paired anchor (8 sets). Til PTFE graft is welded to the nitinol exoskeleto n with polyethylene tap e no sutures) CD . .
Three of theiTI are ingle-center feaSibility studies, 4-6 the 3 rcl one is a US-lTIulticenter phase II trial. 7 These studies are SUlTIlnarized in Table 1. In these studies a total of 392 patients underwent endovascu lar aortic repair ( EVAR) with the Excluder®. The longest follow-ups extend to 46 months. In all reports there was a 0% intraoperative conversion rate, which is astoni hingly low compared to earlier EVAR studies. In addition, there were no p erioperative death in the phase II lTIulticenter trial conducted at 19 US ce nter and 1 death in each of the single-institutional series. This might b e attributed to experienced clinicians at those investigation centers, but certainly also reflects the ease of use of this particular device as the learning curves are included. Patient selection bias seems unlikely as the Inulti-
550
center trial was a controlled non-rando111iz e d study comparing open versus EVAR with the Excluder® and greater severity of important risk factors was found in the EVAR group . A quite consistent lack of endoleaks at 6 month followup CT in 880/0 to 97% of the treated patient is re porte d in the 3 singh~-center stu die ,whil 2 years a fter EVAR 80% of th e patients had no endoleaks in the Inulticenter trial. The reintervention rate in the ll1ulticenter study was 7% per y ar with a total of 3 late conversions out of 235 patients , who underwent EVAR. The rea on for the conversions were enlarging aneurysms. In 2 of the patients endotension was assumed as no endoleak was noted on imaging and intraoperatively; in the 3rd one a type II endoleak was known , but the patient preferred open repair
THE JOURNAL OF CARDIOVASCULAR SURGERY
Augu:;t 2003
PFAl\IIMA'li 'ER
REPAIR OF ABDOMINAL AORTI C ANEURYSMS WITH THE EXCLUDER@ BIFURCATED ST ENT-GRAFT
TABLE
I.-Summary of clinical studies conceTning the Excluder-® for elective AM EVAR. Variable
No . cases Mean AAA-diamet r (mm) Follow-up (months) range Intraoperative conversion Major morbidity rate (%) 30-day mortality rate (%) Minor morbidity rate (%) Mean length of hospital stay (days) 30-day technical success (%) Aneurysm exclusion rate at 6 months (%) Aneurysm exclusion rate at 24 months (%) AAA diameter changes Late conversions (%) Late reintelventions (%) SecondalY ruptures (%)
Atla nra 6
19 58 9.8 2-12 0 5.3 5.3 17 2.9
79 97 No change 0 0 0
Vienna
