University of Groningen. Covered stents in aortoiliac occlusive disease Grimme, Frederike. DOI: /j.ejvs /j.jvir

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1 University of Groningen Covered stents in aortoiliac occlusive disease Grimme, Frederike DOI: 0.06/j.ejvs /j.jvir IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the document version below. Document Version Publisher's PDF, also known as Version of record Publication date: 205 Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Grimme, F. (205). Covered stents in aortoiliac occlusive disease [Groningen]: University of Groningen DOI: 0.06/j.ejvs , 0.06/j.jvir Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons). Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Downloaded from the University of Groningen/UMCG research database (Pure): For technical reasons the number of authors shown on this cover page is limited to 0 maximum. Download date:

2 Chapter. Covered Endovascular Reconstruction of Aortic Bifurcation (CERAB) technique: A new approach in treating extensive aortoiliac occlusive disease Authors Frederike AB Grimme, Peter CJM Goverde, Paul JEM Verbruggen, Clark JAM Zeebregts, Michel MPJ Reijnen Submitted

3 Chapter Abstract Background: In this study we present the first results of a new endovascular technique using covered stents to reconstruct the aortic bifurcation in patients with aortoiliac occlusive disease. With the Covered Endovascular Reconstruction of the Aortic Bifurcation (CERAB) technique, the anatomy and physiology of the aortic bifurcation is mimicked. Material and Methods: Between 200 and March 204, the first 03 patients (5 male, 52 female) were treated with CERAB for complex aortoiliac lesions, in two clinics. The median age was 6 years (range years). Indications for treatment were chronic ischemia, including Rutherford category (N=), 3 (N=64), 4 (N=20), 5 (N=7) and 6 (N=). Lesion morphology was evaluated with the use of CT angiography. There were 6 TASC-2 B lesions, TASC-2 C lesions and 88 TASC-2 D lesions treated. Follow-up consisted of clinical examination, ankle-brachial indices and duplex ultrasound examination. Median follow-up was 2 months (range 0-4 months). Results: Technical success was obtained in 8 procedures (5.%). In five procedures lesions could not be recanalized. Primary patency was 87.3% at one year and 82.3% at two years, while secondary patency was 7.8% at one year and 5.0% at two years. Mean ankle-brachial indices improved significantly from 0.64±0.2 before to 0.±04 after the procedure (P<.00). Overall 30-day complication-rate was 23.3%, including 22 minor complications and two major complications (.%). There was no 30-day mortality. Median hospital stay was two days (range -6 days). Conclusion: The CERAB technique appears to be a safe and feasible alternative for open surgical reconstruction of the aortic bifurcation in complex occlusive disease. Comparative studies with the current gold standards are indicated. 26

4 Results of CERAB Introduction According to the Trans Atlantic Intersociety Consensus group (TASC-II) surgical reconstruction, typically by means of aorto-bi-iliac bypass grafting, is the treatment of choice for extensive lesions, classified as TASC-II D, and should also be considered in case of bilateral occlusion of the common iliac arteries (TASC-II C). This is the consequence of the good long-term patency rates of surgical reconstruction. Surgery, however, is related to both early and late morbidity and perioperative mortality. Therefore, co-morbidity should be taken into consideration when planning a reconstruction for aortoiliac occlusive disease (AIOD). In the kissing stent technique was introduced as an endovascular treatment alternative for bilateral aortoiliac occlusive disease. In this technique, two stents are placed simultaneously in the common iliac arteries, with an overlap in the distal aorta. 2,3 Reported technical success rates, varied between 8% and 00% with a one-year primary patency rate between 76% and 8% with the use of bare metal stents (BMS) in TASC-II C and D lesions. 4 A variation in patient and lesion characteristics and used techniques may have caused this variation in outcome. Covered stents may increase patency rates in extensive disease as was shown by the COBEST trial and confirmed in various case series. 5- The COBEST trial showed covered balloon expandable stents (CBES) have a superior primary patency rate and clinical improvement outcome at 24 months when compared to bare metal stents. Also, CBES may immediately treat or reduce the risk on procedural complications as dissection, perforation and embolization thus possibly reducing morbidity and mortality. The Covered Endovascular Reconstruction of the Aortic Bifurcation (CERAB) technique was developed in an attempt to overcome the anatomical and physiological disadvantages of kissing stents. 0 Patency rates of kissing stents may be influenced by geometrical factors like radial mismatch, protrusion mismatch and stent conformation. All of these factors may cause flow disturbances leading to recirculation, turbulation and stasis of blood, that, in turn, may cause thrombus formation and intimal neohyperplasia. -4 A recent in vitro geometrical study of our group showed a superior stent conformation and a lower radial mismatch in the CERAB configuration when compared to the kissing stent configuration. 5 In the present study the first clinical results of the CERAB technique are presented. 27

5 Chapter Methods Patients All consecutive treated patients, using the CERAB technique, between February 200 and March 204 were prospectively gathered in a database and retrospectively analyzed. Permission by the Institutional Review Board was obtained. Patients were treated in two hospitals including Rijnstate Hospital Arnhem, The Netherlands and ZNA Clinics, Antwerp, Belgium. Patients that were treated with an acute limb ischemia were excluded from this analysis, as were patients treated with chimney configurations. Anatomical suitability for the CERAB procedure was assessed using computed tomography (CT) angiography. In all patients cardiovascular risk reduction was performed, including the prescription of anti-platelet therapy (in absence of anticoagulant therapy) and statins when indicated. All patients treated for intermittent claudication were initially treated with (supervised) walking exercise and considered for treatment only if symptoms persisted and were disabling. Demographics, clinical status, medical history and procedural aspects were noted. The clinical status was assessed using the Rutherford Classification for chronic ischemia. 6 Co-morbidity was scored according to the Society for Vascular Surgery and American Association for Vascular Surgery medical co-morbidity scoring system. 7 CT images were reviewed and scored according to the TASC-II criteria. Clinical assessment, ankle-brachial index (ABI) measurements and duplex ultrasound scans at, 3, 6 and 2 months and yearly thereafter were aspects of routine follow-up. Complications and additional treatments were registered in the hospital files. Table : Characteristics of patients treated with CERAB 28 Rutherford Category for chronic Ischemia: mild intermittent claudication, walking distance unlimited 2 moderate claudication, walking distance >200m 3 severe claudication, walking distance <200m 4 ischemic rest pain 5 focal tissue loss 6 diffuse gangrene ASA score * N % % 0% 62.%.4% 6.5%.0% 0% 67.0% 26.2% 6.8%

6 Results of CERAB Tobacco use Never, >0 years ago No, but <0 years ago Yes < 20/day Yes > 20/day Unknown Diabetes Mellitus No Adult, dietary or oral medication controlled Adult, insulin dependent Juvenile diabetes Unknown Hypertension No Treated by single drug Treated by two drugs Treated by three drugs Unknown Hyperlipidemia Normal lipids Mildly elevated, dietary control Treated with drugs Unknown Cardiac disease Asymptomatic Non recent myocardial infarction (MI) (>6m)/ asymptomatic MI on EKG** Stable angina pectoris, arrhythmias, treatable heart failure Instable angina pectoris, recent MI(<6m) Unknown Pulmonary disease Asymptomatic Mild dyspnea Moderate dyspnea O2-dependent, pulmonary hypertension Carotid disease No disease Asymptomatic, but sign of disease TIA /stroke without temporary deficit TIA/stroke with permanent deficit Unknown Renal disease No GFRǂ 30-50mL/min GFR 5-30mL/min GFR < 5mL/min or renal transplant Unknown N % %.7% 43.7% 3.% 2.% 68.% 4.6% 3.6% 0% 2.% 2.4% 35.% 2.% 0.7% 2.% 2.%.7% 76.7% 8.7% 56.3% 25.2%.7% 6.8%.% 55.3% 24.3% 20.4% 0% 8.6% 2.6% 2.%.%.0% 8.6% 4.6%.0%.%.0% *ASA = American Society of Anesthesiologists physical status classification system ǂ GFR = Glomerular filtration rate 2 TIA = transient ischemic attack **EKG = electrocardiogram

7 Chapter Technique Details of the CERAB technique have been previously described. 0 Briefly, patients were either treated in a hybrid operating theater or in a catheterization laboratory. Two introducer sheaths were introduced (Fr and 7Fr, respectively) in the common femoral arteries, either percutaneous or by surgical cut down units of heparin were administered to all patients. The occlusive lesion was then passed, either subintimal or endoluminal, using regular catheters (Super Torque, Cordis Corporation, Miami Lakes, FL, USA) and a Terumo wire (Terumo Medical Corporation, Elkton, MD, USA). After getting a re-entry into the lumen of the aorta, in case of subintimal passing, angiography was made to confirm proper position (fig. A). A 2mm V2 LD balloon expandable eptfe covered stent (Atrium Medical, Maquet Getinge Group, Hudson, NH, USA) was expanded in the distal aorta approximately 20 mm above the bifurcation through the Fr sheath. The expanded stent was proximally flaired to adapt the aortic diameter with a larger balloon, usually 6 mm, thereby creating a funnel-shaped covered stent. Subsequently, two covered CBES were placed in the distal 20 mm of the cuff, consequently the part of the covered stent that is still 2 mm in diameter, into the common iliac arteries and were simultaneously deployed (fig. B). That way these two stents create a tight connection with the first aortic stent, thereby creating the new aortic bifurcation (fig. C). When required distal extensions were used. The sheaths were removed from the common femoral artery and the puncture sites were closed usually using a closure device (Angio-Seal, St. Jude Medical, St. Paul, MN or Perclose /Starclose, Abbott Vascular,Abbott Park, IL,USA) or sutured in case of open introduction. A concomitant endarterectomy of the femoral artery or external iliac artery was performed in case of multilevel disease. Patients received standard statin treatment and dual anti-platelets for six months followed by mono therapy, unless oral anticoagulation was indicated for other reasons. 30 Definitions The primary outcome measure was one-year primary patency. Secondary outcomes were technical success, length of hospital stay, morbidity, mortality, clinical improvement, secondary patency and limb salvage.

8 Results of CERAB A B C Figure A Angiography of a 52-year old female patient with disabling intermittent claudication showing a total occlusion of the distal aorta and both iliac arteries Figure B Both iliac stents are simultaneously deployed, with 2cm overlap into the funnel shaped aortic stent, thereby creating a tight connection Figure C Control angiography showing the CERAB configuration in place, thereby creating a new aortic bifurcation Classifications were used according to the reporting standards. 6,8 Technical success was defined as stent placement restoring blood flow with <30% residual stenosis. Primary patency was defined as an uninterrupted patency in absence of re-stenosis or occlusion, without any procedures performed on the vessel or stent. Secondary patency was defined as patency achieved by all procedures aimed at recanalizing an occluded CBES, thereby preserving the endograft. Freedom from target lesion revascularization (TLR) was defined as an open endograft without procedures performed for re-stenosis or occlusion leading to symptoms requiring an intervention. Clinical improvement was defined as a hemodynamic improvement with at least 0.0 in ABI, combined with a symptomatic improvement of at least one Rutherford category. Re-stenosis was defined as a lesion with a peak systolic value (PSV) ratio 2.5 as measured in the endograft and proximal or distal from the endograft or an angiographic diameter reduction of >50%. 8, Limb salvage rate was defined as all patients without above ankle amputations. Minor complications were defined as complications only temporary leading to impairment, major complications were defined by permanent damage or death. 3

9 Chapter Statistical Analysis Variables were expressed as mean ± one standard deviation (SD) in case of normal distribution, or median plus range in other distributions. In all patients the mean ABI of both legs was calculated to compare pre- and post procedural ABI with paired t-tests. Patency rates and limb salvage rate were estimated using the Kaplan-Meier survival analysis. To test for statistically survival differences, analyses with the log-rank (Mantel- Cox), or the generalized Wilcoxon (Breslow) tests were used. Probability values given are based on two-sided analyses of test results. A significance level of 5% was used. Statistical analysis was performed with SPSS version.0 (Statistical Package for the Social Sciences, Inc., Chicago, IL, USA). Results 03 patients (5 male, 52 female) underwent a CERAB procedure for chronic ischemia during the study period and were included in this study. Five other patients were treated with a CERAB configuration for acute ischemia in this period and were excluded from this analysis, as were five patient who were treated with chimney grafts in the inferior mesenteric artery or renal artery in combination with a CERAB. The median age was 6 years (range years). Patient characteristics and co-morbidity are listed in Table. The indication for treatment was disabling claudication in 64 patients (62.%) and critical limb ischemia in 38 patients (36.%) (Table ). One patient was classified as Rutherford Category. He was treated for an aorto-bi-femoral bypass at risk for occlusion due to subtotal stenosis at the proximal anastomosis of this bypass. The median follow-up was 2 months (range 0-4 months). There was no 30-day mortality, but eight patients died during follow-up. Six patients died to non-procedure related causes (Table 2) and in the other two patients the cause of death was unknown. Table 2: Cause of death during follow-up of patients treated with CERAB 32 Pulmonary N= 36 days after procedure Cardiac N=2 48 and 62 days, respectively, after procedure Malignancy N=2 235 and 286 days, respectively, after procedure Bowel ischemia N= 25 days after procedure Unknown N=2 35 and 3 days, respectively, after procedure

10 Results of CERAB Duplex follow-up at six months was available for 74 patients, at one year for 52 patients and at two years for 2 patients. In 6 patients (67.0%) it was the first procedure performed in the aortoiliac segment, 26 patients (25.2%) previously underwent endovascular procedures in this segment, including stent placements in 7 patients. Eight patients (7.8%) had earlier surgical reconstructions, including four aorto-bi-iliac bypasses and two aorto-bi-femoral bypasses. The lesion characteristics are depicted in Table 3. The vast majority of patients were treated for TASC-2 D lesions. Procedural outcome Technical success was achieved in 8 patients (5.%). In three procedures the guidewire could not be passed due to heavily calcified lesions. In one procedure the guidewire could be advanced, but the sheath could not pass the lesion. In one case no re-entry could be made into the vascular lumen. In two of these patients a surgical bypass was constructed by means of an aorto-bi-iliac bypass and an iliac-femoral crossover bypass. In another patient, a second attempt was successfully performed (with growing experience), two years after the first procedure. The fourth patient, suffering from focal tissue loss, died 48 days after the attempt and before a secondary treatment could be performed. Seventy-seven procedures (74.0%) were performed percutaneously, whereas 27 procedures (26.0%) were performed by surgical cut down (8 one site, both sites). In 2 of them the procedure was combined with an endarterectomy of the common femoral artery and/or distal external iliac artery. In five patients an additional PTA was performed in the external iliac arteries, in one patient followed by stent placement. In one case a thrombectomy of an occluded leg of a bifemoral bypass was performed. In one patient the femoral artery occluded during the procedure, this resolved after a thrombectomy. In 60.6% the CERAB configuration consisted of a 2mm aortic stent, of either 6mm (N=28) or 4mm (N=63) length and two 8x5mm iliac stents. In 65.7% of the successful procedures the CERAB was completed with the use of three covered stents, as the technique was initially described. The remainder required distal extensions in order to cover the entire diseased segment. Stent specifications are listed in Table 3. 33

11 Chapter Table 3: Lesion characteristics of patients treated with CERAB TASC-2* B C D Outflow vessels External iliac artery Internal iliac artery Superficial femoral artery Deep femoral artery Aorta stent length (mm) Unknown Aorta stent diameter (mm) Stent iliac artery length (mm) Stent iliac artery diameter (mm) Number of stents used open; with stenosis; occluded open; with stenosis; occluded open; with stenosis; occluded open; with stenosis; occluded 6 (5.8%) (8.7%) 88 (85.4%) Right 66;27;8 6;26;4 67;3;3 0;;0 5 (5.%) (.0%) 64 (64.6%) 28 (28.2%) (.0%) (.0%) 5 (6.0%) 2 (2.0%) (.0%) Right 7 (7.%) (.0%) 80 (80.%) (.0%) 4 (4.0%) 2 (2.0%) 88 (88.%) (.0%) 3 (3.0%) (.0%) 65 (65.7%) (.2%) 5 (5.2%) Left 73;23;5 5;26;6 70;28;3 2;;0 Left 4 (4.%) 2 (2.0%) 83 (83.8%) 0 5 (5.%) 3 (3.0%) 85 (85.%) 2 (2.0%) 3 (3.0%) (.0%) *TASC-2 = Classification of Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) 34 Procedural complications included 0 dissections, of which six were treated with balloon angioplasty alone and three with an additional stent. One dissection was left untreated since it was not flow limiting (Table 4). There were two ruptures of the iliac artery. One was covered by CERAB itself and in the other one a self expanding covered stent was

12 Results of CERAB placed. In one case, already mentioned above, thrombus formation occurred for which a thrombectomy was performed. In two early cases a stent dislodged from the balloon. Once the dislodged stent was placed in the external iliac artery and one time it was used as a proximal, additional stent in the aorta. The overall procedural complication rate was 4.6%. All complications, except the surgical thrombectomy, were resolved endovascularly and did not lead to any permanent deficit. Table 4: Complications Procedural Dissection Rupture/bleeding Dislocation stent Thrombus formation Post-procedural Minor complications Groin hematoma Re-bleed False aneurysm Fever unknown cause Atrial fibrillation Major complications Kidney failure Pneumonia N Severity Treated in same procedure, no influence on health Treated in same procedure, no influence on health Treated in same procedure, no influence on health Treated in same procedure, no influence on health No influence on health, one temporary impairment Temporary impairment, no intervention One recovered after intervention, other temporary impairment Temporary impairment Temporary impairment Permanent damage Leading to death Clinical outcome Thirty-day post procedural complications are listed in Table 4. There were 22 minor complications and two major complications. Minor complications included 6 groin hematomas, which were left untreated. There were two pseudoaneurysms treated with thrombine injection and compression bandage, respectively. There was one re-bleeding which was conservatively treated with a compression bandage. One patient developed atrial fibrillation treated with medication. In the postoperative course two patients developed fever with unknown origin and both were treated with antibiotics. Major complications consisted of one patient with deterioration of chronic renal insufficiency after the procedure. The calculated glomular filtration rate decreased from 53 to 36 ml/ min/,73m2 after the procedure. Eventually, this patient required permanent dialysis one year after the procedure. One patient developed a bilateral pneumonia and died five weeks after the procedure. The 30 day overall-complication rate was 23.3%, the major 35

13 Chapter complication rate was.% and the 30-day mortality was 0%. Median duration of admission was two days (range -6 days). In total 2 patients (20.3%) were admitted to an Intensive Care Unit for the median duration of day (range -3 days). The mean ABI, measured bilaterally, significantly improved from 0.64±0.2 before the procedure to 0.±0.4 after the procedure (P<.00). The highest measured ABI before the procedure did improve from 0.7±0.25 to 0.3±0.4 after the procedure measured at the same leg. Clinical improvement with at least one Rutherford category occurred in 8 of 6 patients (2.7%) within six months (83 within first six weeks). In the remaining three patients with technical successful CERAB no post-procedural Rutherford was documented in the files. The patients that did not improve included the patient with Rutherford, who was treated for a bypass at risk. One patient had no improvement due to a persistent dissection distal from the additional stent which was placed during the procedure. She was treated with a new stent placement, three months after the CERAB procedure. Two patients had a stent collapse/severe kinking of one of the iliac stents at day 2 and day 30, respectively. One patient underwent kissing balloon PTA and the other patient was converted into an aortic-bi-iliac surgical bypass as the patient refused further endovascular treatment. One patient did not improve due to a short occlusion of the common femoral artery for which an endarterectomy was performed five months after the CERAB procedure. Another patient did not improve due to multiple stenotic lesions in the superficial femoral artery for which balloon angioplasty was performed. In one patient, treated for severe claudication, the CERAB was extended to the external iliac artery for a stenosis distal from the stent after a month, without clinical improvement. The patient deceased before another reintervention could be performed. 36 Patency rates The primary patency rate at six months was.5%, at one year 87.3% and at two years 82.3% (fig. 2). At six months the secondary patency rate was 7.8%, 5.0% at one year and 5.0% at two years (fig. 2). Freedom from TLR was 3.7% at six months, 88.2% after one year and 85.6% at two years (fig. 2). Univariate analysis showed no significant influence of smoking, diabetes mellitus, hypertension, dyslipidemia, renal disease, coronary artery disease or carotid disease on the primary patency rates. Neither was there a difference in the primary patency between patients treated for critical limb ischemia or intermittent claudication. There

14 Results of CERAB were no differences in primary patency rate between the first twenty treated patients in each clinic, compared to the patients treated thereafter (P=.33). Figure 2 Kaplan Meier Survival analysis showing patency curves of patients treated with CERAB In fifteen patients (5.%) there was loss of primary patency during follow-up. Ten patients had re-stenosis, of which three were caused by kinking of one of the iliac stents or stent collapse. These patients were treated with PTA and in one case with an additional stent placement. The other seven patients developed a stenosis above the aortic stent (N=) or distal from the iliac stents (N=6), referred to as edge stenosis. Two cases were not treated as the patients were symptom-free, in three cases the iliac leg was extended with an additional CBES and in the other two cases a PTA was performed. Five CERAB s 37

15 Chapter occluded of which one occurred after the patient stopped the anti-platelets. In two patients, treated with surgical thrombectomy and fibrinolysis, respectively, an outflow stenosis was found in the external iliac artery and treated by PTA in one case and an extra CBES in the other. In one patient there was a stent collapse of one of the iliac CBES. There was no known cause of occlusion in the last patient. The latter two were treated with a surgical bypass. Limb salvage rate was 00%. 38 Discussion In this study we present the first results of the CERAB technique, which confirm the safety and efficacy of this new endovascular approach for extensive and complex occlusive lesions of the aortic bifurcation. Up to day, surgical reconstruction has been the gold standard for the treatment of TASC-II C and D lesions according to the TASC-II guidelines. By mimicking the aortic bifurcation anatomically and physiologically, CERAB might improve patency rates of endovascular techniques and also reduce the risk of severe complications when compared to surgical reconstruction. The technique therefore possibly provides a valid alternative for current treatment modalities. Calculated primary patency rates of the CERAB procedure in this study cohort are 87.3% at one year and 82.3% at two years. These primary patency rates appear to be at the same level as have been described for kissing stents. However, many patients in our study, in contrast to the kissing stent series, were treated for the more complex TASC-II D lesions. The published kissing stent series usually consist of mixed populations treated for all TASC lesions and treated for different indications. In a recent review, we have shown that the indications for treatment with kissing stents varied greatly, from 33 to 00% of patients treated for claudication (Groot Jebbink E, Holewijn S, Lardenoije JWHP, Reijnen MM. Systematic review of results of kissing stents in the treatment of aortoiliac occlusive disease. Submitted). In our study 36.% of the patients were treated for critical limb ischemia. In addition, the incidence of TASC A and B lesions treated with kissing stents varied from 0% to 2%, rendering comparisons with our group of patients, that were mostly treated for TASC-II D lesions, unfair. Another point of interest is the used definition of loss of primary patency. We used the definition that includes re-stenosis, as was also used by Sabri et al. in their historical cohort study on kissing covered stents. 8 This is in contrast to the outcomes presented by Humphries et al., where primary patency was only affected by stent occlusion or reinterventions. 20 To our opinion, re-stenosis is

16 Results of CERAB an important outcome of endovascular procedures and should be taken into account, as Diehm et al. have suggested. 8 Moreover, re-interventions performed to improve or preserve outflow will decrease primary patency rates. As we learned that two patients developed occlusions based on outflow impairment, we now advocate to treat stenosis in the iliac tract aggressively in order to prevent occlusions. This may lead to an increased incidence of re-interventions, even in the absence of symptoms. Secondary patency rates were excellent, 5.0% at two years. This implicates longer durability of CERAB when preventive reinterventions are performed. When we look at reinterventions performed for clinical symptoms (e.g. freedom from TLR) patency rates are 88.2% at one year and 85.6% at two years. Loss of primary patency was affected by three major causes. The first and most important reason for loss of patency was stenosis resulting in outflow obstruction. This emphasizes that it is essential to cover the entire stenotic area, with special care for the distal end before deployment. Otherwise the atherosclerotic lesion may advance distally, resulting in an edge stenosis. We therefore advocate to cover the disease from healthy-to-healthy areas, although obviously intimal disease will always be present in atherosclerosis. Second, we did see four cases of stent collapse or kinking in the iliac tract. In three cases the collapse was situated at the point of crossing of the iliac stents, at the level of the cuff of the aortic stent, thereby pointing at a weakness of our technique. Another collapse occurred in a 6mm stent distally from the aortic cuff, at the origin of the native iliac artery. Possibly, highly calcified lesions may overcome the radial force of the CBES, especially in small diameters, and hopefully improvement in stent design will overcome this problem. One patient had an occlusion possibly related to poor therapy compliance. It underlines the importance of the use of antiplatelet or anticoagulation therapy. In our study protocol, all patients were treated with anti-platelet therapy including lifelong acetyl salicylic acid and clopidogrel during the first six months (with exception for patients treated with anti-coagulants such as acenocoumarol or warfarin for other indications). In a high flow reconstruction however, single antiplatelet therapy might also be adequate, but of course we cannot provide any scientific argument for an advise in this first case series. In the present study all patients were included from the first in man in February 200. Since patency curves did not differ significantly after the treatment of 20 patients, a learning curve was not found to be a factor that affected the results. One would expect that with growing experience results will improve. However, with growing experience the indication for CERAB was expanded in both hospitals to patients with more and 3

17 Chapter 40 more complex lesions, that possibly could have affected results negatively, thereby hiding a learning curve effect. One of the advantages of the use of CBES is that it might prevent or immediately treat procedural complications such as rupture and distal embolization. There were no clinical signs of distal embolization in our series. The two ruptures that occurred during procedure were both treated endovascularly, one with the CERAB itself. Other complications during the procedure could all be treated endovascularly, without clinical consequences for the patient making the procedure extremely safe. Two major complications occurred, rendering a major complication rate of.%. In one patient, pre-operative renal function loss worsened after treatment, ultimately leading to hemodialysis after one year. This underlines the importance of peri-operative measures to reduce risk of contrast induced nephropathy. The other major complication consisted of a bilateral pneumonia. This patient was admitted from the department of cardiology and was deemed unfit for a surgical bypass procedure due to cardiac and pulmonary comorbidity. After three days of post-procedural observation at the ICU he was readmitted to the department of cardiology where he developed a bilateral pneumonia. Eventually the patient deceased five weeks after the procedure. This demonstrates the vulnerability of this group of patients. CBES are more expensive than bare metal stents and therefore the cost-effectiveness of the CERAB procedure is unclear and needs to be addressed. The need for re-interventions may even expand costs on the long term. However, the low morbidity and mortality compared to surgical repair suppresses costs, also with regard to in-hospital and ICU stay, may cut the costs. Moreover, the long-term morbidity of surgical repair, including incisional hernia and adhesion formation with the risk of short bowel obstruction, is accompanied by high costs as well, but are often neglected. With CERAB the in-hospital stay is short with a median hospital stay of two days. The first patients treated were post-operatively observed at the Intensive Care Unit (ICU) according to the protocol of aortic bifurcation reconstructions. Meanwhile we have changed protocol for endovascular reconstructions. Therefore we think that the 20.3% ICU admission is a large overestimation of the need for close hemodynamic observation. Observation at a so called Medium Care facility could provide an alternative, however one of the hospitals included in this study does not have such a unit. From the last 60 patients treated, only nine were observed at ICU, for cardiac or pulmonary reasons. The majority of our patients were treated for TASC-II D lesions, for which current

18 Results of CERAB guidelines advocate surgical reconstruction. We think that CERAB expands the possibilities of treatment, since patients deemed unfit for surgery because of co-morbidity or a hostile abdomen can now be treated. In addition, after CERAB, the option of surgical reconstruction remains. Long term results of CERAB have to be awaited before considering the technique as a new standard for extensive AIOD. A randomized controlled trial to compare surgical bypass procedures and CERAB for TASC-II D lesions is indicated to compare morbidity, outcome and cost-effectiveness. The feasibility of such a study however is low because of the relative low incidence of these lesions and since the comorbidity in many patients could drive the physicians towards an endovascular preference, to reduce morbidity and mortality. Conclusion The CERAB technique is a safe and feasible alternative for open surgical reconstruction of the aortic bifurcation in complex AIOD. Comparative studies with the current gold standards are indicated to define the role of this technique in the treatment algorithm of TASC-II C and D lesions. Critical issues include cost effectiveness, patient selection, finetuning of the technique and defining the optimal medical support. Conflicts of Interest and Source of Funding: PG receives speakers fees from Maquet. MR receives speakers fees from Maquet and received research grants from Maquet. For the remaining authors, none were declared. 4

19 Chapter 42 References. Norgren L, Hiatt WR, Dormandy JA et al. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II). J Vasc Surg 2007;:S Kuffer G, Spengel F, Steckmeier B. Percutaneous reconstruction of the aortic bifurcation with Palmaz stents: case report. Cardiovasc Intervent Radiol ;4: Palmaz JC, Encarnacion CE, Garcia OJ et al. Aortic bifurcation stenosis: treatment with intravascular stents. J Vasc Interv Radiol ;2: Grimme FA, Goverde PA, Van Oostayen JA et al. Covered stents for aortoiliac reconstruction of chronic occlusive lesions. J Cardiovasc Surg (Torino) 202;53: Bosiers M, Iyer V, Deloose K et al. Flemish experience using the Advanta V2 stent-graft for the treatment of iliac artery occlusive disease. J Cardiovasc Surg (Torino) 2007;48: Grimme FA, Spithoven JH, Zeebregts CJ et al. Mid-term outcome of balloon expandable polytetrafluoroethylene covered stents in the treatment of iliac artery chronic occlusive disease. J Endovasc Ther 202;: Grimme FA, Reijnen MM, Pfister K et al. Polytetrafluoroethylene covered stent placement for focal occlusive disease of the infrarenal aorta. Eur J Vasc Endovasc Surg 204;48: Sabri SS, Choudhri A, Orgera G et al. Outcomes of covered kissing stent placement compared with bare metal stent placement in the treatment of atherosclerotic occlusive disease at the aortic bifurcation. J Vasc Interv Radiol 200;2: Mwipatayi BP, Thomas S, Wong J et al. A comparison of covered vs bare expandable stents for the treatment of aortoiliac occlusive disease. J Vasc Surg 20; 54: Goverde PC, Grimme FA, Verbruggen PJ et al. Covered endovascular reconstruction of aortic bifurcation (CERAB) technique: a new approach in treating extensive aortoiliac occlusive disease. J Cardiovasc Surg (Torino) 203;54: Brittenden J, Beattie G, Bradbury AW. Outcome of iliac kissing stents. Eur J Vasc Endovasc Surg 200;22: Sharafuddin MJ, Hoballah JJ, Kresowik TF et al. Long-term outcome following stent reconstruction of the aortic bifurcation and the role of geometric determinants. Ann Vasc Surg 2008;22: Hughes M, Forauer AR, Lindh M et al. Conformation of adjacent self-expanding stents: a cross-sectional in vitro study. Cardiovasc Intervent Radiol 2006;2: Saker MB, Oppat WF, Kent SA et al. Early failure of aortoiliac kissing stents: histopathologic correlation. J Vasc Interv Radiol 2000;: Groot Jebbink E, Grimme FA, Goverde PC et al. Geometrical consequences of kissing stents and the Covered Endovascular Reconstruction of the Aortic Bifurcation configuration in an in vitro model for endovascular reconstruction of aortic bifurcation. J Vasc Surg 204; [E-pub ahead of print]; Available at org/0.06/j.jvs Rutherford RB, Baker JD, Ernst C et al. Recommended standards for reports dealing with lower extremity ischemia: revised version. J Vasc Surg 7;26: Chaikof EL, Fillinger MF, Matsumura JS et al. Identifying and grading factors that modify the outcome of endovascular aortic aneurysm repair. J Vasc Surg 2002;35: Diehm N, Pattynama PM, Jaff MR et al. Clinical endpoints in peripheral endovascular revascula rization trials: a case for standardized definitions. Eur J Vasc Endovasc Surg 2008;36: de Smet AA, Ermers EJM, Kitslaar PJ. Duplex velocity characteristics of aortoiliac stenoses. J Vasc Surg 6;23: Humphries MD, Armstrong E, Laird J et al. Outcomes of covered versus bare-metal balloon-expandable stents for aortoiliac occlusive disease. J Vasc Surg 204;60:

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