Endovascular abdominal aortic aneurysm repair by interventional cardiologistsa communitybased experience

Endovascular Abdominal Aortic Aneurysm Repair by Interventional
Cardiologists—A Community-Based Experience
ABHIJEET BASOOR, M.D.,1,2 KIRITKUMAR C. PATEL, M.D., F.A.C.C.,2,3,4 JOHN F. COTANT, M.D., F.A.C.C.,2 ABDUL R. HALABI, M.D., F.A.C.C.,2,3,4 MINA TODOROV, M.D.,5 HAROON CHUGHTAI, M.D.,2 NISHIT CHOKSI, M.D., F.A.C.C.2,3,4 BENJAMIN DIACZOK, M.D., F.A.C.P.,1 SUSAN ZONIA, PH.D.,6 and MICHELE DEGREGORIO, M.D., F.A.C.C.2,3,4 From the 1Department of Medicine, St. Joseph Mercy Oakland Hospital, Pontiac, Michigan; 2Division of Cardiology, St. Joseph MercyOakland Hospital, Pontiac, Michigan; 3Interventional Cardiology Unit, Department of Cardiovascular Medicine, William Beaumont Hospital,Royal Oak, Michigan; 4Division of Cardiology, Detroit Medical Center, Detroit, Michigan; 5Department of Surgery, St. Joseph Mercy OaklandHospital, Pontiac, Michigan; and 6Chair of I.R.B., St. Joseph Mercy Oakland Hospital, Pontiac, Michigan Introduction: Endovascular repair of abdominal aortic aneurysm (AAA) is a relatively recent technology. In
comparison to the conventional open surgical treatment for AAA, endovascular AAA repair (EVAR) combines a
less-invasive approach with lower morbidity and mortality. There have been few studies regarding the performance
of this procedure in a community-based setting. We report our experience of EVAR performed primarily by
interventional cardiologists in a community hospital.
Methods: In our community hospital setting, between September 2005 and November 2007, we included all
patients who underwent EVAR by interventional cardiologists, with available on-site vascular surgical support.
Clinical and serial computed angiographic imaging outcomes were followed by a retrospective chart review. Data
collection tools included demographic and clinical characteristics, anatomical aneurysm features, length of stay,
peri- and postprocedural complications, and mortality.
Results: A total of 71 consecutive patients had EVAR attempted. The endovascular stent placement was successful
in 67 (93%) patients. Thirty-day mortality in this study was 1 of 71 (1.4%). All four procedural failures and
the single periprocedural mortality occurred in women. Mean follow-up was 12 months. There were a total of
six mortalities and among these four were women (P ≤ 0.001); however, multivariate analysis revealed loss of
significant difference in mortality (P = 0.16). Major complications following EVAR were noted in 10 of 71 (14%)
patients.
Conclusion: EVAR can be successfully performed by experienced interventional cardiologists with vascular
surgical support in a community-based setting. In our experience, there is acceptable rate of complications and
mortality in a carefully selected patient population. (J Interven Cardiol 2010;23:485–490)
Introduction
Michele DeGregorio, M.D., is a physician proctor for Endologix Abdominal aortic aneurysm (AAA) is a condition powerlink device since September 2008. This role of the author associated with high mortality and morbidity. Histori- began after the completion of the study.
cally, open surgical repair for AAA has been the only The other authors report no financial relationships or conflicts of available therapy. Recently, endovascular AAA repair interest regarding the content herein.
(EVAR) has become an increasingly attractive andminimally invasive treatment modality for AAA. The Address for reprints: Abhijeet Basoor, M.D., Medical Education- first endovascular treatment of AAA was performed Department of Cardiology, St. Joseph Mercy Oakland Hospital,44405 Woodward Avenue, Pontiac, MI 48341. Fax: 248-858-3244; in 1990 and reported by Parodi et al. in 1991.1 Since Parodi’s initial report, numerous studies have shown that endovascular treatment of AAAs can be performed Table 1. Inclusion and Exclusion Criteria
General Inclusion Criteria:
According to the 2005 American College of Car- diology (ACC)/American Heart Association (AHA) guidelines for AAA, EVAR is a reasonable alternative 3. Patient to comply with posttreatment follow-up requirements.
procedure to open surgery in patients that are at high Anatomic Inclusion Criteria:
1. Only one of the following four conditions needs to be met:
risk (Class IIa) and at low or average risk for compli- cations (Class IIb). As the results of EVAR-1 trial have b. Saccular aneurysm ≥ 3.0 cm in outer diameter, shown, endovascular repair, compared to open repair c. Aneurysm twice the normal aortic outer diameter, and of AAA, offers a clear benefit in terms of reduction d. Rapidly growing aneurysm (≥5 mm over 6 months).
in postoperative adverse events and 30-day mortality.2 2. Proximal aortic neck fixation length that is nonaneurismal aorta between the lowest renal artery and the aneurysm ∼15 mm.
Subsequently, other studies have repeatedly demon- 3. Nonaneurismal proximal aortic neck diameter 18–26 mm.
strated that endovascular treatment is associated with 4. Minimum internal diameter of the external iliac artery ≥ 7 mm lower morbidity rates and potentially decreased mor- tality rates, when compared to open surgical repair.3–7 5. Common iliac artery inner diameter vessel size 10–14 mm for Based on a meta-analysis of randomized controlled tri- use with 16-mm outer-diameter graft or 14–18 mm with 20-mmouter-diameter graft.
als, the operative mortality rate of open repair was 4.7% General Exclusion Criteria:
and that of EVAR was 1.6%.8 Non-randomized case studies and comparative observational reports showed the incidence of major complications following EVAR to be 19.5% versus 37.5% for open repair.9 4. Contraindications for nonionic contrast medium or In most institutions, EVAR is performed by vascular 5. Coagulopathy or bleeding disorder present, and surgeons. Recent developments in transcatheter deliv- 6. Active systemic or localized groin infection.
ery of vascular prosthetic devices have allowed non- Anatomic Exclusion Criteria:
surgical endovascular specialists to use these devices 1. Proximal aortic attachment site ≥60◦ angle to the body of the for treatment of a variety of vascular defects. There are few published studies regarding EVAR performed 3. ≤15 mm of nonaneurysm common iliac artery above the by interventional cardiologists in a community-based internal/external iliac bifurcation on both sides, and setting. We report the outcomes of EVAR on subjects 4. Thrombus ≥30% at implantation site.
undergoing the procedure in our community hospi-tal, performed by interventional cardiologists with anavailable on-site vascular surgery support.
of aneurysm, type of graft used, primary conversionto open repair, procedural success, and periprocedu-ral complications/mortality), and follow-ups (length of Material and Methods
hospital stay, endoleaks, secondary conversions, andpostprocedural complications/mortality). All patients Approval was obtained by the Institutional Board were followed with serial clinical and computed tomo- Review of our hospital for the study. Consecutive pa- graphic angiograms at 1 month, 3–6 months, 1 year, tients who underwent EVAR in our community hos- and every year thereafter (as per the follow-up proto- pital between September 2005 and November 2007 col). All the data collection including the follow-up were included in the study. All procedures were per- was performed through the retrospective chart review formed by cardiologists experienced in percutaneous of the hospital and outpatient clinic records.
interventions with vascular surgery support. As per the Definitions.
protocol of our hospital interventional lab, all patients cessful deployment of the endograft without any AAA- underwent strict screening using the inclusion and ex- related rupture or death. Primary conversion was clusion criteria as shown in Table 1.
defined as EVAR requiring conversion to open sur- Data Collection Tools.
gical repair due to vessel rupture or any other serious demographic variables (age, gender, body surface area complications during or immediately following the en- [BSA], body mass index [BMI], comorbidities, and dovascular repair. Secondary conversion was open re- risk factors), procedural details (type of procedure, size pair of aneurysm after the completion of EVAR. The ENDOVASCULAR AAA REPAIR BY INTERVENTIONAL CARDIOLOGISTS periprocedural mortality rate was defined as death Table 2. Baseline Characteristics of the Study Population
related to EVAR within 30 days of the procedure.
Aneurysm-related death was defined as death due to aneurysm rupture or aneurysm repair. Complicationswere defined as periprocedural if they occurred within 30 days and postprocedural if after 30 days of the pro- cedure. Major complications included all of the follow- ing: limb or life threatening, ischemic, cardiac, respi- ratory, renal, neurological, hemorrhagic (requiring the transfusion of ≥3 units of blood products), systemic in- fection, major endoleaks, graft failure, migration, and fistulae formation. In accordance with other published reports, endoleaks were classified as a minor compli- cation if the contrast agent was localized to a local por- tion of the sac and major if it opacified the whole sac.10 Data were categorized as primary outcomes (peripro- cedural mortality and primary conversion) and sec- ondary outcomes (delayed mortality, major and minor Statistical Analysis.
continuous or categorical. Independent Student’s t-testand chi-square test were used to find the significant Note: BSA = body surface area; BMI = body mass index.
differences between the groups. Multiple regressionswere used to adjust the association between gender and prevalent (P = 0.001 and P < 0.0001, respectively) in unsuccessful procedure/mortality for confounding fac- tors (age, gender, hypertension, peripheral vascular dis- Success Rate, Type of Stent Used, and Procedure
ease, dyslipidemia, and BSA). We also calculated the Abandonment Rate.
odds ratio for unsuccessful procedure in the presence EVARs is shown in Figure 1. The endovascular stent of each of the above-mentioned variables. Data were placement was successful in 66 patients (success rate of analyzed using SPSS version 11 (IBM, Chicago, IL, 93%). Sixty-four patients received an Endologix Pow- USA). Unless stated otherwise, data were presented as erlink stent (Endologix Inc., Irvine, CA, USA), and two mean ± standard deviation; a two-sided P value ≤0.05 patients received Medtronic AneuRx stent (Medtronic Inc., Santa Rosa, CA, USA). The endovascular stentcould not be deployed in 4 patients due to unfavorablevessel anatomy resulting in approximately 6% (4 out Patient Characteristics.
had EVAR attempted. Baseline and clinical charac-teristics of the study participants are shown in Table2. The mean age of the patient population was 73 ± 8years, (range 54–89 years) with 33% women. The meanAAA diameter was 4.85 cm (range 4.0–7.4 cm). Threepatients had bilateral iliac artery aneurysms, three pa-tients had unilateral iliac artery aneurysms, and threepatients had a saccular aneurysm. An aortic proximalcuff was used in 10 patients. Risk factors and comor-bidities were more prevalent in women. Specifically,hypertension and dyslipidemia were significantly more Figure 1. Success and failure rates of EVAR procedure.
Table 3. Characteristics of Patients with Unsuccessful EVAR
Tortuosity of the infrarenal aorta (unable to deploy graft) Stenosed and severely calcified right iliac artery (unable to deploy graft) Stenosed bilateral iliac arteries (unable to deploy graft) Right iliac and common femoral artery rupture (converted to open procedure) of 71) abandonment rate. The characteristics of these tients). This patient went into hemorrhagic shock dur- patients who could not undergo EVAR successfully are ing the procedure due to rupture of the right iliac and common femoral arteries leading to a retroperitoneal Outcomes after EVAR.
hematoma. The endovascular stent was immediately pital stay for all patients who successfully under- removed, and the procedure was converted to open went EVAR was 2.8 days (range 1–17 days). The repair. The periprocedural mortality was 1 of 71 pa- mean follow-up was 12 months (range 3–29 months).
tients (1.4%) due to acute renal failure in a patient The periprocedural and follow-up outcomes are shown who refused hemodialysis. There was no AAA rup- in Table 4. Major periprocedural complications after ture in the study. During the follow-up, 5 additional EVAR were noted in 14% of patients. The compli- patients died and the causes of death are shown in cations included limb ischemia requiring surgical in- Table 5. Aneurysm-related death was seen in 2 pa- tervention in 5 patients, compartment syndrome in 1, tients, a rate of 2.8% per year (one periprocedural ischemic colitis in 1, renal ischemia in 1, and foot drop and another one during further follow-up). The over- in 1 patient. Among the endoleaks, localized type II all mortality rate was 8% in 1-year average follow- was seen in 6 patients at 1-month follow-up, but it was up. Of the 6 deceased patients, 4 were women and persistent in only 2 patients during further follow-up.
2 men giving a statistically significant difference in This corresponds to a 66% spontaneous closure rate for mortality (P ≤ 0.001). However, we performed a mul- type II endoleaks. The other complications included tivariate analysis using age, gender, peripheral vascu- 16 local complications at the percutaneous entry site lar disease, hypertension, BSA, and dyslipidemia as including pseudoaneurysms, groin hematomas, sero- covariates. We noticed a loss of significant difference mas, and abscess formation. The primary conver- in mortality after adjusting for these variables (P = sion rate in this study was 1.4% (1 out of 71 pa- 0.16). Similarly, we also performed a multivariate anal-ysis for association of gender with unsuccessful proce-dures. We noticed a loss of significant difference after Table 4. Periprocedural (30 days) and Further Follow-up
adjusting for above-mentioned variables (P = 0.99) Discussion
The overall patient mortality rate for ruptured AAA is between 75% and 85%, making it the 13th lead- ing cause of death in the United States. Since its initial description in 1991, EVAR has gained signif- icant popularity and acceptance in the cardiovascu- lar community. Via insertion of a vascular endograft into the lumen of the aneurysm, EVAR excludes the aneurysm from flowing through the aorta thereby min- imizing its risk of rupture. Some of the common com- plications that are specific to the endovascular repair are endoleaks and limb ischemia.8,9 Endoleak is the presence of persistent flow of blood into the aneurysm ENDOVASCULAR AAA REPAIR BY INTERVENTIONAL CARDIOLOGISTS Table 5. Deceased Patients and Their Characteristics
CAD, CKD, dyslipidemia, DM, HTN, PVD, smoking CAD, CHF, dyslipidemia, HTN, PVD, smoking Note: ARF = acute renal failure; CAD = coronary artery disease; CKD = chronic kidney disease; DM = diabetes mellitus; HTN = hypertension;PVD = peripheral vascular disease; CHF = congestive heart failure; PE = pulmonary embolism.
sac after the device placement. Endoleaks have been smaller vessel size compared to men.16–18 In our sam- classified as Types I–V.11,12 Type II endoleak oc- ple, all EVAR failures and the one periprocedure death curs when there is perigraft flow from collateral ves- were among women. Women also had a higher proce- sels. These are the most common endoleaks, affecting dure abandonment rate. However, after adjustment for up to 56% of patients.13 They are associated with a confounding factors, we noticed a loss of significant as- low risk of rupture (0.52% in 15 months) and have sociation between women and unsuccessful procedure.
a high rate (75% in 5 years) of spontaneous clo- After successful deployment of the endograft, none of sure.14,15 In this study, the spontaneous closure rate the patients studied required an open surgical repair.
was 66% in 1 year. Limb ischemia occurs as a re- The primary conversion rate was 1.4%, and there was sult of graft limb occlusion, embolization, or com- no delayed or secondary conversion to open repair. We mon femoral artery thrombosis. In the presented co- feel the most likely reasons for this are careful selection hort of patients, there were 5 counts of this major of patients whose aneurysms are amenable to endovas- complication due to thromboembolism in the limb.
cular repair and vigilant iliac angioplasty to facilitate In this study, there were no secondary reinterventions delivery of the stent. This result is encouraging, as most required for any of the major complications. Major reports cite a surgical conversion rate of 2–20%.7,19–22 complications such as other endoleaks (types I, III, A total of 6 patients died in this study. All these patients and IV), graft migration, structural failure, graft dis- were older than 70 years. As shown in Table 5, only tortion, aortoenteric fistula, or aneurysm rupture were 2 patients had aneurysm-related death. Survival at an not encountered during the follow-up. This may be at- average of 1-year follow-up was 92%, which is com- tributed to the advancements in graft design as well as parable to other studies.5 In this particular review, the operator-dependent insertion technique. Other authors complication rate was lower than in comparable stud- have shown higher complication rates in women due to ies. One of the factors responsible for this could be theuse of newer generation bifurcating grafts, which areunibodied and usually require unilateral vascular ex- Table 6. Multivariate Analysis by Using Unsuccessful Procedure
posure. Further device developments are still needed, as decreasing the size of the delivery system will allowaccess to the aorta percutaneously.
Among patients diagnosed with AAA, screening and evaluation is vital in deciding whether or not an en- dovascular repair is appropriate. In this study, unsuc- cessful procedures (Table 3) were more likely in older, shorter, and obese women. However, after multivari- ate analysis, the significance was lost, showing thatthe difference was due to the higher prevalence of thecomorbidities and older age. Small sample size also Note: PVD = peripheral vascular disease; HTN = hypertension;BSA = body surface area.
might be responsible for this finding. It appears that younger nonobese patients with fewer risk factors are abdominal aortic aneurysm repair: Six-year results. J Vasc Surg ideal candidates. These may be important considera- White GH, Yu W, May J, et al. Three-year experience with the tions in patient selection for EVAR. Future prospective White-Yu Endovascular GAD Graft for transluminal repair of trials are needed in order to get better understanding aortic and iliac aneurysms. J Endovasc Surg 1997;4:124–136.
of the selection criteria. If EVAR is not feasible or if Becquemin JP, Allaire E, Desgranges P, et al. Delayed compli-cations following EVAR. Tech Vasc Interv Radiol 2005;8:30– the patient does not meet the current selection criteria, the candidate should be meticulously followed up and Drury D, Michaels JA, Jones L, et al. Systemic review of re- monitored for aneurysm growth, as delineated in the cent evidence for the safety and efficacy of elective endovas-cular repair in the management of infrarenal abdominal aortic aneurysm. Br J Surg 2005;92:937–946.
10. Howell MH, Zaqqa M, Villareal RP, et al. Endovascular exclusion of abdominal aortic aneurysms: Initial experience Conclusion
with stent-grafts in cardiology practice. Tex Heart Inst J2000;27:136–145.
11. White GH, May J, Waugh RC, et al. Type III and type IV EVAR is an effective minimally invasive procedure, endoleak: Toward a complete definition of blood flow in the sac which may be done by interventional cardiologists sup- after endoluminal AAA repair. J Endovasc Surg 1998;5:305– ported by vascular surgery. It has a high success rate 12. White GH, May J, Petrasek P, et al. Endotension: An explana- with acceptable risk of complications especially when tion for continued AAA growth after successful endoluminal there is appropriate patient selection, and it is per- repair. J Endovasc Surg 1999;6:308–315.
formed by a highly skilled interventional team.
13. Chernyak V, Rozenblit AM, Patlas M, et al. Type II endoleak after endoaortic graft implantation: Diagnosis with helical CTarteriography. Radiology 2006;240:885–893.
14. van Marrewijk C, Buth J, Harris PL, et al. Significance of endoleaks after endovascular repair of abdominal aor- Acknowledgments: The authors thank Thanh Phan, M.D., for his tic aneurysms: The EUROSTAR experience. J Vasc Surg support in performing endovascular repair of AAA and to Dhaval Kapadia, M.D., in helping with data collection.
15. Silverberg D, Baril DT, Ellozy SH, et al. An 8-year experi- ence with type II endoleaks: Natural history suggests selec-tive intervention is a safe approach. J Vasc Surg 2006;44:453–459.
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