- Email: [email protected]
Midterm results of the fenestrated Anaconda endograft for short-neck infrarenal and juxtarenal abdominal aortic aneurysm repair
Midterm results of the fenestrated Anaconda endograft for short-neck infrarenal and juxtarenal abdominal aortic aneurysm repair Louise L. Blankensteijn, BS,a Martijn L. Dijkstra, MD,a Ignace F. J. Tielliu, MD, PhD,a Michel M. P. J. Reijnen, MD, PhD,b and Clark J. Zeebregts, MD, PhD,a on behalf of the Dutch Fenestrated Anaconda Research Group,* Groningen and Arnhem, The Netherlands
ABSTRACT Objective: The fenestrated Anaconda endograft (Vascutek, Renfrewshire, Scotland) was introduced in 2010 and showed promising short-term results with high technical success and low morbidity rates. The aim of this study was to present the midterm results, with a minimum of 12 months follow-up, for all patients treated with the fenestrated Anaconda endograft in The Netherlands. Methods: Patients treated with the fenestrated Anaconda endograft between May 2011 and February 2015 were included. Follow-up consisted of computed tomography angiography at 1 month and 1 year, and duplex ultrasound yearly thereafter with additional computed tomography angiography if indicated using a standard protocol. Results: A total of 60 patients were included; 48 patients (80.0%) were treated for juxtarenal aneurysms, and 12 (20.0%) were short-neck infrarenal aneurysms. Mean aneurysm size was 64 6 9 mm. A total of 140 fenestrations were incorporated. Median follow-up was 16.4 months (interquartile range, 11.9-27.4). The 30-day mortality was 3.4% (n ¼ 2). Kaplan-Meier estimates for 1-year, 2-year, and 3-year survival were 91.4%, 89.5%, and 86.3%, respectively, without aneurysm-related mortality during follow-up. Main body primary and secondary endograft patencies were 98.3% and 100%, respectively. Target vessel primary and secondary patencies were 95.0% and 98.6%, respectively. Early type IA endoleaks occurred in seven patients (11.7%) and spontaneously resolved in all patients. At 1-year follow-up 4 (6.7%) type II endoleaks persisted. One patient experienced aneurysm rupture because of a late type III endoleak attributable to a dislodged renal stent and subsequently underwent successful conversion to open surgery. Conclusions: The fenestrated Anaconda is a viable treatment option for complex abdominal aortic aneurysms. Acceptable mortality and morbidity and low reintervention rates contribute to good midterm results. Occurrence of early type I endoleak was relatively common, but these resolved spontaneously in all patients. (J Vasc Surg 2016;-:1-7.)
Endovascular aneurysm repair (EVAR) has evolved rapidly since its introduction in 1991, and the majority of patients with an abdominal aortic aneurysm (AAA) are now treated by endovascular means.1 However, up to 30% of all patients with AAAs are not suitable for treatment using standard infrarenal endografts because of complex anatomy, including short infrarenal neck length
From the Division of Vascular Surgery, Department of Surgery, University Medical Center Groningen, University of Groningen, Groningena; and the Department of Surgery, Rijnstate Hospital, Arnhem.b
*A list of members of the Dutch Fenestrated Anaconda Research Group is listed in the Appendix. Author conflict of interest: M.M.P.J.R. and C.J.Z. are consultants for Vascutek, Renfrewshire, Scotland. Correspondence: Clark J. Zeebregts, MD, PhD, Division of Vascular Surgery, Department of Surgery, University Medical Center Groningen, PO Box 30 001, Groningen 9700 RB, The Netherlands (e-mail: [email protected]). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a conflict of interest. 0741-5214 Copyright Ó 2016 by the Society for Vascular Surgery. Published by Elsevier Inc. http://dx.doi.org/10.1016/j.jvs.2016.08.092
(<15 mm), severe angulation (>60 ), or aneurysms that involve important (visceral) side branches.2 To overcome these technical difficulties, the concept of fenestrated EVAR (FEVAR) was developed and successfully introduced in 1999.3 Subsequent advances in FEVAR treatment and techniques have resulted in successful treatment of not only short-neck infrarenal and juxtarenal aneurysms, but also thoracoabdominal aneurysms with increasing anatomic complexity.4-7 Most of the current knowledge is based on the Zenith custom-made fenestrated endograft (Cook Medical Australia, Brisbane, Queensland, Australia). The fenestrated Anaconda endograft (Vascutek, Renfrewshire, Scotland) was introduced in 2010, and initial reports on use of the fenestrated Anaconda were published in 2011 and 2012 by Bungay et al.8,9 The Dutch Fenestrated Anaconda Research Group subsequently published the short-term results of the first 25 patients treated in The Netherlands.10 The possible advantages of the fenestrated Anaconda were explored, and the data showed promising short-term results with high technical success rates and low morbidity. However, durability has yet to be proven because there are no mid- and 1
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longer-term data available regarding this new fenestrated device. A larger number of patients have now been treated using the fenestrated Anaconda in The Netherlands. The aim of this study was to present an update of the previous cohort and subsequent patients treated, and to present the midterm results of this larger cohort.
METHODS Design of the study. Patients who underwent exclusion of an aneurysm with a fenestrated Anaconda endograft in The Netherlands between May 2011 and February 2015 were included. The current population in The Netherlands is approximately 17 million people; 49.6% is male, and 15.6% is aged 65 and over. Data were collected in the respective hospitals and retrospectively analyzed. All patients were assessed preoperatively using multislice detector computed tomography angiography (CTA). Patients were treated in accordance with current international treatment guidelines.11,12 Indications for FEVAR included unsuitable anatomy for conventional EVAR (short-neck length [<15 mm], hostile proximal sealing zone, or important aortic side branches involved in the aneurysm) and was ultimately decided by the treating physician. The procedures were performed in either a hybrid suite equipped for both interventional radiology and open surgical procedures or a surgical theater using a recent generation mobile C-arm. Followup consisted of CTA at 1 month and 1 year, and duplex ultrasound yearly thereafter with additional CTA if indicated using a standard protocol. The standard CTA protocol included noncontrast, early (arterial), and delayed contrast series. In case of a suspected endoleak on duplex ultrasound during follow-up, a subsequent CTA was performed. All patients who were included had at least 12 months of follow-up except for those who died before reaching the 1-year follow-up. The fenestrated Anaconda endograft. A detailed description of the fenestrated Anaconda and possible advantages compared to other fenestrated devices have been published previously.8,10 The fenestrated Anaconda is a repositionable customized device for individual patient use based on the Anaconda AAA endograft system.13 There are a number of theoretical advantages compared with other devices, including the following. (1) It is repositionable after full deployment, allowing for accurate deployment and repositioning of the endograft body and its fenestrations. (2) Fenestrations are placed in the unsupported region maximizing the area available and potentially allowing for easier alignment and subsequent cannulation of target vessels. (3) The lack of columnar strength combined with a ringed distal design might also allow for treatment of more angulated and stenotic anatomy. A range of configurations is currently available allowing for the device
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from one fenestration up to five fenestrations, although a maximum of four fenestrations were used in this study. Also, the addition of an augmented valley (comparable to a scallop), and either a bifurcated or a tube design add further possibilities to enable treatment of AAAs with a varying range of complex anatomy. Stent implantation. The procedural details have been published previously.10 In short, bilateral femoral access was obtained either percutaneously or by cutdown. All patients were heparinized perioperatively. After introduction and deployment of the fenestrated main body, the fenestrations and target vessels were cannulated and angiography performed to confirm the position. If not satisfactory, the main body would be collapsed and repositioned to achieve a more satisfactory position. Once in place, the target vessels were cannulated with balloon expandable covered stents using standard endovascular techniques. Finally, the endograft was completed by placing the limb extensions, and a completion angiogram was performed. In case of a type IA or III endoleak on the completion angiogram, repeat angioplasty was performed at the respective site of the endoleak if possible. Residual type IA endoleaks after repeat angioplasty were accepted. Definitions. Juxtarenal was defined as an aneurysm that abuts the renal arteries, but does not involve the renal arteries (no normal sized aorta between upper extent of aneurysm and renal arteries).14 Short neck was defined as an aneurysm with a normal portion of the aorta between the upper extent of the aneurysm and lowest renal artery, and with a neck length <15 mm. Clinical success (midterm) was defined as successful deployment of the endovascular device at the intended location without type I or III endoleak, graft infection or thrombosis, aneurysm expansion (diameter >5 mm), aneurysm rupture or conversion to open repair, graft migration, a failure of device integrity, or death as a result of aneurysm-related treatment.14 Technical success was defined as successful introduction and deployment of the device in the absence of surgical conversion or mortality, type I or III endoleaks, or graft limb obstruction. Statistics. Continuous variables are described as mean and standard deviation or median and interquartile range in case of skewed data. To test for normality a Kolmogorov-Smirnov test was performed. Differences between continuous variables were tested using a paired Student t-test or Mann-Whitney U test in case of skewed data. Survival and intervention free survival analysis were conducted using Kaplan-Meier estimates. Two-sided P values of <.05 were considered significant. Statistical analysis was performed using SPSS statistics v 20.0 (IBM Corporation, Armonk, NY).
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Table I. Demographics
Table II. Procedural details Mean 6 SD
Age, years
No. (%)
Male Female
Mean (6SD) or median (IQR)
72 (67) 52 (86.7)
Juxtarenal
8 (13.3)
Short neck Neck length, mm
ASA class 22 (36.7)
Maximum AAA diameter, mm
ASA 3
36 (60.0)
Endograft type
ASA 4
2 (3.3)
Bifurcated
ASA 2
8 (13.3)
Hypertension Yes
39 (65.0) 34 (56.7)
Smoking 22 (36.7)
Cardiac disease Yes
33 (55.0) 16 (26.7)
Renal disease Yes
64 (9) 58 (96.7) 2 (3.3)
Type of top stent Standard
21 (35.0)
Augmented valley
39 (65.0)
25
17 (28.3)
ASA, American Society of Anesthesiologists; SD, standard deviation.
2 (3.3)
28
13 (21.7)
30
13 (21.7)
32
16 (26.7)
34
16 (26.7)
Oversize, %
Pulmonary disease Yes
12 (20.0) 6 (4)
Main device diameter, mm
Hypercholesterolemia
Yes
48 (80.0)
Aortouniiliac
Diabetes mellitus Yes
No. (%)
Type of aneurysm
Sex
Yes
3
-
19.7 (3.4)
Number of fenestrations 1
5 (8.3)
2
34 (56.7)
3
17 (28.3)
4
4 (6.7)
Main device repositioned
RESULTS A total of 60 patients were treated in 13 sites located in The Netherlands. The mean age was 72 6 7 years, and 52 of these patients were male (86.7%). Patients treated were mainly classified as American Society of Anesthesiologists III (60.0%) because of significant comorbidities. Full demographics are shown in Table I. The median number of procedures per hospital was 4.5 (1-7). The majority of patients (n ¼ 48; 80.0%) were treated for juxtarenal aneurysms, while the remaining 12 (20.0%) were short-neck aneurysms. Mean proximal neck length was 6 6 4 mm. Mean aneurysm diameter was 64 6 9 mm. Two (3.3%) aortouniiliac devices were used; the remaining 58 (96.7%) were bifurcated devices. Data on the specific device configurations are summarized in Table II. About one-half of the endografts had a twofenestration design (56.7%) incorporating the renal arteries. Mean operative time was 262 6 96 minutes with a median contrast dose of 178 mL (range, 70-380 mL). The option to reposition the main device was used in 41 cases (68.3%). Upper access was used in 18 (30.0%) patients. Patients had a median total length of stay of 6 days (4-9). Perioperative complications occurred in 14 patients and included pneumonia (n ¼ 3), surgical site infection (n ¼ 1), delirium (n ¼ 1), cerebral vascular accident (n ¼ 1), decline in renal function (n ¼ 4), anemia (n ¼ 3), gastroenteritis
No
19 (31.7)
Yes
41 (68.3)
Upper access No
42 (60.0)
Yes Fluoroscopy time, minutes
18 (30.0) 78 (40)
Procedure time, minutes
262 (96)
Contrast dosage, mL
178 (68)
AAA, Abdominal aortic aneurysm; IQR, interquartile range; SD, standard deviation.
(n ¼ 1), and lower leg compartment syndrome (n ¼ 1), with a total 30-day morbidity rate of 25.0% (n ¼ 15). 30day mortality rate was 3.3% (n ¼ 2). Cause of death was postoperative bowel ischemia in one patient, which is described in detail previously10 and unknown in the second patient. Median follow-up was 16.4 months (interquartile range, 11.9-27.4). There was no loss to follow-up. Postoperative (temporary) decrease in renal function was observed in 18 patients (30.0%). Long-term renal dysfunction was found in four patients (6.7%), of which two patients had preexisting renal dysfunction. One patient (1.7%) required dialysis treatment. In the longer term, there was a minor but significant decline in estimated glomerular filtration rate (eGFR in mL/min) from
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Table III. Follow-up Median (IQR) Follow-up, months
16.4 (11.9-27.4)
eGFR, mL/min
57.5 (41.8-75.8)
No. (%)
Midterm clinical success Yes
53 (88.3)
No
7 (11.7)
Kinking No
60 (100.0)
Yes
0 (0.0)
Migration No
59 (98.3)
Yes
1 (1.7)
Graft infection No
60 (100.0)
Yes
0 (0.0)
Fig 1. Kaplan-Meier survival analysis, showing survival of patients after fenestrated endovascular aneurysm repair (FEVAR) using the fenestrated Anaconda.
Endoleak Type I
0 (0.0)
Type II
4 (6.7)
Type III
0 (0.0)
Aneurysm size Increase
5 (8.3)
Decrease
35 (58.3)
Stable
14 (23.3)
Unknown
6 (10.0)
Reintervention Yes
4 (6.7)
No
50 (83.3)
eGFR, Estimated glomerular filtration rate; IQR, interquartile range.
60.0 (57.0-77.5) to 57.5 (41.8-75.8; P < .05) at the last follow-up visit. Follow-up details are shown in Table III. Five patients died during follow-up. Cause of death was pneumosepsis (n ¼ 1), congestive heart failure (n ¼ 1), cardiac arrhythmia (n ¼ 1), hemorrhagic cerebral vascular accident (n ¼ 1), and unknown (n ¼ 1). Kaplan-Meier survival estimates for 1-year, 2-year, and 3-year survival were 91.4%, 89.5%, and 86.3%, respectively. Kaplan-Meier patient survival analysis is shown in Fig 1. There were no aneurysm-related deaths after 30-days follow-up. One patient suffered bowel ischemia perioperatively as previously described. The other patient died 1 month postoperatively after being discharged on the fifth postoperative day and before having the 1-month follow-up CTA. Cause of death remains unknown. The patient did have signs of a type IA endoleak at completion angiogram, and, therefore, we cannot exclude the possibility of aneurysm-related death. One patient experienced a rupture 1 year postoperatively because of a type III endoleak. The patient experienced the rupture while traveling abroad and was admitted to a local hospital. CTA was performed that
showed dislodgement of a renal fenestration stent, and the patient underwent successful emergent open surgery and reconstruction with a tube graft. There were two graft migrations reported. In the first patient, this occurred 1 month postoperatively and resulted in bilateral occlusion of the renal arteries, after which the patient required dialysis treatment. In the second patient, graft migration occurred 3 months postoperatively with subsequent dislocation of the stents to the right renal artery (RRA), left renal artery (LRA), superior mesenteric artery, and celiac trunk. The patient underwent open revascularization of both renal arteries and the celiac trunk. There was one left iliac limb occlusion at 17 months, which was successfully treated by surgical thrombectomy and subsequent endarterectomy of an atherosclerotic left common femoral artery. Therefore, primary and secondary endograft patency rates were 98.3% and 100%, respectively. There were no graft infections. No kinking of the main body or limbs occurred. A total of 140 fenestrations were incorporated to accommodate the target vessels; 136 fenestrations were successfully cannulated and stented (97.1%). During follow-up four target vessels occluded in three patients (RRA, n ¼ 2; LRA, n ¼ 2). For the target vessels, primary patency was, therefore, 95.0%. Two of the occluded target vessels were successfully treated by endovascular means. Therefore, secondary target vessel patency was 98.6%. In total, 27 (45.0%) patients had an endoleak on either the perioperative completion angiogram or on the discharge CTA, including type IA (n ¼ 7, 11.7%), type II (n ¼ 18, 30.0%), and type III endoleaks (n ¼ 2, 3.3%). Technical success was, therefore, 85.0%. The majority of the endoleaks resolved spontaneously. At 1-year followup, only four (6.7%) type II endoleaks persisted. As mentioned above, one late type III endoleak led to subsequent aneurysm rupture and conversion to
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Fig 2. Kaplan-Meier intervention free survival analysis, showing intervention free survival of patients after fenestrated endovascular aneurysm repair (FEVAR) using the fenestrated Anaconda.
open surgery. Intervention free survival analysis using Kaplan-Meier estimates is shown in Fig 2. There were no significant differences in demographics, endograft configuration, or periprocedural variables between patients with an endoleak compared with those without signs of endoleaks. Aneurysm size decreased in 36 (60.0%) patients, remained stable in 15 (25.0%), and increased in five (8.3%) patients. In the subgroup of patients that showed an increase in aneurysm size, one early type IA endoleak and two type II endoleaks were observed. This resulted in an overall midterm clinical success rate of 88.3%.
DISCUSSION The presented midterm data on the fenestrated Anaconda endograft indicate the device to be a viable alternative for the treatment of patients with complex AAAs. The midterm clinical success and patency rates are high with a low reintervention rate and no proven aneurysm-related mortality during follow-up. A 30-day mortality rate of 3.4% (n ¼ 2) was achieved in this cohort, which is comparable to midterm results with the Zenith custom-made fenestrated endograft (Cook Medical Australia).5,15,16 The option to reposition the graft after initial deployment was frequently used (68.3%). This feature can be helpful in complex anatomy where precise positioning is paramount. On the other hand, caution was advised in using this feature because of the possible induction of thromboembolic events, as was the case in the patient who developed bowel ischemia (n ¼ 1). In this larger cohort, fortunately, no additional perioperative thromboembolic complications were observed. Procedure time and contrast dosage compare with other devices currently used.4,17,18
Compared with earlier reports, there is a high incidence of endoleaks, including type IA and type II endoleaks.8,10 This also explains the “low” technical success rate of 85.0%. As described in our previous report, it was hypothesized that early type IA endoleaks seem to disappear spontaneously, possibly because of the specific endograft top stent design. This is believed to be due to increased embedding of the proximal stents with the vessel wall in time, providing improved apposition and sealing after initial device deployment. The increased embedding occurs as the stent material temperature increases to body temperature following deployment, causing the stent’s radial force to increase, while the vessel conforms locally to the shape of the stent. In the longer term, it is known that the stents continue to embed over the months following implantation. This hypothesis holds true in the current series, where 10 early type I endoleaks were observed. Obviously, in case of a type IA endoleak attempts were made to correct this intraoperatively either by repositioning the endograft or by re-ballooning the proximal seal. The latter is only possible in a four-fenestration design where there is enough room above the fenestrations. Obviously, it is not advocated to readily accept type IA endoleaks. However, a type IA endoleak that persisted despite attempts to correct this was accepted, and patients underwent standard follow-up including 1-month CTA and subsequent reintervention if appropriate. In this cohort, no type IA endoleak persisted and no reinterventions were necessary. In this cohort one rupture did occur because of a type III endoleak, for which the patient was successfully converted to open surgery. The patient was traveling abroad at the time of the event and was, therefore, treated in a local hospital. The correspondence notes dislodgement of a renal fenestration and subsequent type III endoleak and rupture. This patient had a shortneck infrarenal aneurysm (proximal neck length of 6 mm) and was treated with a two-fenestration endograft (RRA and LRA). The procedure was uneventful, and the follow-up imaging showed a type II endoleak but no other signs of complications up to the event. Noteworthy, there was no indication of migration. The proximal oversize in this case was 16.7%. In this specific case, there was, however, an increase of the aneurysm sac diameter of 2 mm at the 6-month follow-up CTA, which should prompt caution but not necessarily immediate reintervention for the known type II endoleak. The treating physician made numerous efforts to obtain the imaging performed at the time of the event, ultimately without success and unfortunately the exact cause for stent dislodgement remains unclear. Analysis of the data did not show any significant differences in demographics, endograft configuration, or perioperative variables between the “endoleak” and “no endoleak” groups, which is in part due to the still
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relatively small numbers. The consensus that type II endoleaks can be safely managed conservatively seems to hold true in the current series, especially if there is a stable or decreasing aneurysm diameter. Type III endoleaks also spontaneously resolved. Re-evaluation of these type III endoleaks showed they were actually type II endoleaks that had been misinterpreted at the time of original analysis. All of these had been diagnosed on the perioperative completion angiography, and the 1-month follow-up CTA, however, did not show any type III endoleaks. In total, five (8.3%) patients underwent either an endovascular or an open reintervention during follow-up as discussed in the Results section, which is relatively low compared with other reports of FEVAR.5,15,16 Four patients showed a decline in renal function postoperatively with patent side branches, and during follow-up, there was a minor, but significant decrease in renal function (eGFR in mL/min) preoperatively 60.0 (57.0-77.5) to 57.5 (41.8-75.8; P < .05) at final follow-up visit. In a subanalysis excluding those patients with known renal disease, there was also a significant decline in renal function (eGFR in mL/min) during follow-up of 70.0 (60.0-83.0) to 60.0 (50.8-84.5; P < .05). In one patient, the main device migrated causing dislocation and subsequent occlusion of both renal arteries. In this case, a short-neck infrarenal aneurysm was treated (proximal neck length 5 mm) using a three-fenestration device (RRA, LRA, and an ancillary LRA). No cause for the migration was identified; the procedure was uneventful without signs of endoleak on completion angiography, and the device was adequately oversized by 21.4%. In spite of a reintervention aimed to restore renal artery perfusion, only the ancillary LRA was successfully recanalized, and the patient became dialysis dependent. This in part explains the drop in eGFR. Second, contrast induced nephropathy might also have contributed. Previous studies have shown a decline in renal function to be a significant risk after FEVAR, as is the case in this cohort.19 Given patients with renal complications after FEVAR are at risk for dialysis or even death, maximal efforts should be undertaken to reduce contrast dosage. Also, advances in techniques, including advanced imaging and perioperative guidance,20 experience, and perioperative care are important to minimize these effects. The current results are comparable to results with the most commonly used fenestrated endograft (Cook Zenith custom-made). Midterm results using the Cook device showed similar all-cause mortality (13.0%) and 30-day mortality (2.6%) rates, as well as similar contrast dosages and procedure times. The reported visceral primary branch patency was 92.0% at 46 months.15 All postoperative occlusions in this study by Muhs et al15 occurred in unstented fenestrations or scallops. It has now become common practice to stent all fenestrations and most scallops as well.21 This may explain the higher primary and secondary fenestration patency in the
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present study (95.0% and 98.6, respectively). Another study by Oderich et al22 reported a slightly lower 30-day mortality of 1.5% in 67 patients using the Zenith fenestrated AAA endovascular graft. In this cohort, there were no early type IA endoleaks and one late type IA endoleak, which was successfully treated by coil embolization, and 16 patients had a type II endoleak (29%). In the current cohort, there was a higher incidence of endoleaks regardless of the type. However, the difference is largely explained by the early type IA endoleaks (11.7%) with a comparable incidence of type II endoleak (30.0%). The present study has several limitations. The data were prospectively collected in the respective hospitals, but retrospectively analyzed. As with any new device, a learning curve is to be expected, although all treating centers and physicians had extensive experience with complex endovascular procedures. With a total of 13 centers in The Netherlands participating, the median number of procedures for each center is limited. However, a subanalysis of the centers with the lowest number of procedures did not show a significant increase in serious adverse events or mortality. The cause of death remained unknown in three patients. These deaths are likely not aneurysm related, however, no definitive statements can be made to this regard. Specifically, in the patient who died before having the 1-month follow-up CTA, assuming the worst possible outcome, he would have had a rupture because of the small type IA endoleak on completion angiogram. This, however, is considered unlikely, given the experiences with other type IA endoleaks as presented. Unfortunately no postmortem examination was performed. Given the still relatively small sample size, no predisposing factors for adverse outcomes (eg, which type IA endoleaks require intervention) could be identified. Further studies are needed to identify those patients at risk and clarify indications for reintervention.
CONCLUSIONS The fenestrated Anaconda is a viable treatment option for complex AAAs. Acceptable mortality and morbidity and low reintervention rates contributed to good midterm results. Occurrence of early type I endoleak was relatively common, but these resolved spontaneously in all patients.
AUTHOR CONTRIBUTIONS Conception and design: LB, MD, IT, MR, CZ Analysis and interpretation: LB, MD, CZ Data collection: LB, MD Writing the article: LB, MD, CZ Critical revision of the article: LB, MD, IT, MR, CZ Final approval of the article: LB, MD, IT, MR, CZ Statistical analysis: LB, MD, CZ Obtained funding: Not applicable
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Overall responsibility: CZ LB and MD contributed equally to this article and share co-first authorship.
REFERENCES 1. Dua A, Kuy S, Lee CJ, Upchurch GR Jr, Desai SS. Epidemiology of aortic aneurysm repair in the United States from 2000 to 2010. J Vasc Surg 2014;59:1512-7. 2. Buck DB, van Herwaarden JA, Schermerhorn ML, Moll FL. Endovascular treatment of abdominal aortic aneurysms. Nat Rev Cardiol 2014;11:112-23. 3. Faruqi RM, Chuter TA, Reilly LM, Sawhney R, Wall S, Canto C, et al. Endovascular repair of abdominal aortic aneurysm using a pararenal fenestrated stent graft. J Endovasc Surg 1999;6:354-8. 4. Verhoeven EL, Prins TR, Tielliu IF, van den Dungen JJ, Zeebregts CJ, Hulsebos RG, et al. Treatment of short-necked infrarenal aortic aneurysms with fenestrated stent grafts: short-term results. Eur J Vasc Endovasc Surg 2004;27:477-83. 5. Greenberg RK, Sternbergh WC III, Makaroun M, Ohki T, Chuter T, Bharadwaj P, et al. Intermediate results of a United States multicenter trial of fenestrated endograft repair for juxtarenal abdominal aortic aneurysms. J Vasc Surg 2009;50: 730-7.e1. 6. Verhoeven EL, Vourliotakis G, Bos WT, Tielliu IF, Zeebregts CJ, Prins TR, et al. Fenestrated stent grafting for short-necked and juxtarenal abdominal aortic aneurysm: an 8-year singlecentre experience. Eur J Vasc Endovasc Surg 2010;39:529-36. 7. Mastracci TM, Greenberg RK, Eagleton MJ, Hernandez AV. Durability of branches in branched and fenestrated endografts. J Vasc Surg 2013;57:926-33. 8. Bungay PM, Burfitt N, Sritharan K, Muir L, Khan SL, De Nunzio MC, et al. Initial experience with a new fenestrated stent graft. J Vasc Surg 2011;54:1832-8. 9. Bungay P. The use of the Anaconda stent graft for abdominal aortic aneurysms. J Cardiovasc Surg (Torino) 2012;53:571-7. 10. Dijkstra ML, Tielliu IF, Meerwaldt R, Pierie M, van Brussel J, Schurink GW, et al. Dutch experience with the fenestrated Anaconda endograft for short-neck infrarenal and juxtarenal abdominal aortic aneurysm repair. J Vasc Surg 2014;60: 301-7. 11. Chaikof EL, Brewster DC, Dalman RL, Makaroun MS, Illig KA, Sicard GA, et al. SVS practice guidelines for the care of patients with an abdominal aortic aneurysm: executive summary. J Vasc Surg 2009;50:880-96. 12. Moll FL, Powell JT, Fraedrich G, Verzini F, Haulon S, Waltham M, et al. Management of abdominal aortic aneurysms clinical practice guidelines of the European society for vascular surgery. Eur J Vasc Endovasc Surg 2011;41(Suppl 1):S1-58. 13. Rodel SG, Geelkerken RH, Prescott RJ, Florek HJ, Kasprzak P, Brunkwall J. The Anaconda AAA stent graft system: 2-year clinical and technical results of a multicentre clinical evaluation. Eur J Vasc Endovasc Surg 2009;38:732-40. 14. Chaikof EL, Blankensteijn JD, Harris PL, White GH, Zarins CK, Bernhard VM, et al. Reporting standards for endovascular aortic aneurysm repair. J Vasc Surg 2002;35:1048-60. 15. Muhs BE, Verhoeven EL, Zeebregts CJ, Tielliu IF, Prins TR, Verhagen HJ, et al. Mid-term results of endovascular aneurysm repair with branched and fenestrated endografts. J Vasc Surg 2006;44:9-15. 16. O’Neill S, Greenberg RK, Haddad F, Resch T, Sereika J, Katz E. A prospective analysis of fenestrated endovascular grafting: intermediate-term outcomes. Eur J Vasc Endovasc Surg 2006;32:115-23. 17. Greenberg RK, Haulon S, Lyden SP, Srivastava SD, Turc A, Eagleton MJ, et al. Endovascular management of juxtarenal
aneurysms with fenestrated endovascular grafting. J Vasc Surg 2004;39:279-87. 18. Holden A, Mertens R, Hill A, Marine L, Clair DG. Initial experience with the Ventana fenestrated system for endovascular repair of juxtarenal and pararenal aortic aneurysms. J Vasc Surg 2013;57:1235-45. 19. Haddad F, Greenberg RK, Walker E, Nally J, O’Neill S, Kolin G, et al. Fenestrated endovascular grafting: the renal side of the story. J Vasc Surg 2005;41:181-90. 20. Dijkstra ML, Eagleton MJ, Greenberg RK, Mastracci T, Hernandez A. Intraoperative C-arm cone-beam computed tomography in fenestrated/branched aortic endografting. J Vasc Surg 2011;53:583-90. 21. Grimme FA, Zeebregts CJ, Verhoeven EL, Bekkema F, Reijnen MM, Tielliu IF. Visceral stent patency in fenestrated stent grafting for abdominal aortic aneurysm repair. J Vasc Surg 2014;59:298-306. 22. Oderich GS, Greenberg RK, Farber M, Lyden S, Sanchez L, Fairman R, et al. Results of the United States multicenter prospective study evaluating the Zenith fenestrated endovascular graft for treatment of juxtarenal abdominal aortic aneurysms. J Vasc Surg 2014;60:1420-8. e1-5.
Submitted Jul 3, 2016; accepted Aug 26, 2016.
APPENDIX Dutch Fenestrated Anaconda Research Group. Clark J. Zeebregts, MD, PhD,* Ignace F. J. Tielliu, MD, PhD, Department of Surgery, Division of Vascular Surgery, University Medical Center Groningen, Groningen, The Netherlands Robert H. Geelkerken, MD, PhD,* Robert Meerwaldt, MD, PhD,* Department of Surgery, Division of Vascular Surgery, Medical Spectrum Twente, Enschede, The Netherlands Maurice E. N. Pierie, MD, PhD, Department of Surgery, Division of Vascular Surgery, Isala Clinics, Zwolle, The Netherlands Jerome P. van Brussel, MD, PhD, Department of Surgery, Division of Vascular Surgery, Sint Franciscus Gasthuis, Rotterdam, The Netherlands Ronald F. van den Haak, MD, Department of Surgery, Division of Vascular Surgery, Jeroen Bosch Ziekenhuis, ’s-Hertogenbosch, The Netherlands Geert-Willem H. Schurink, MD, PhD, Department of Surgery, Maastricht University Medical Center, Maastricht, The Netherlands Joost A. van Herwaarden, MD, PhD, Department of Surgery, Division of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands Jan-Willem Lardenoije, MD, PhD,* Michel M. P. J. Reijnen, MD, PhD, Department of Surgery, Division of Vascular Surgery, Rijnstate Hospital, Arnhem, The Netherlands Abdelkarime K. Jahrome, MD, PhD, Department of Surgery, Division of Vascular Surgery, Medical Centre Leeuwarden, Leeuwarden, The Netherlands Ron Balm, MD, PhD, Department of Surgery, Division of Vascular Surgery, Academic Medical Centre, Amsterdam, The Netherlands
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Peter L. Klemm, MD, PhD, Marianne E. Witte, MD, Department of Surgery, Division of Vascular Surgery, Gelre Hospital, Apeldoorn, The Netherlands Evert J. Waasdorp, MD, PhD, Peter M. Schlejen, MD, Department of Surgery, Division of Vascular Surgery, ’t Groene Hart Hospital, Gouda, The Netherlands Marie Josee van Rijn, MD, PhD, Hence J. M. Verhagen, MD, PhD, Department of Surgery, Division of Vascular Surgery, University Medical Center Erasmus, Rotterdam, The Netherlands *Consultants for Vascutek, Renfrewshire, Scotland
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ABSTRACT Objective: The fenestrated Anaconda endograft (Vascutek, Renfrewshire, Scotland) was introduced in 2010 and showed promising short-term results with high technical success and low morbidity rates. The aim of this study was to present the midterm results, with a minimum of 12 months follow-up, for all patients treated with the fenestrated Anaconda endograft in The Netherlands. Methods: Patients treated with the fenestrated Anaconda endograft between May 2011 and February 2015 were included. Follow-up consisted of computed tomography angiography at 1 month and 1 year, and duplex ultrasound yearly thereafter with additional computed tomography angiography if indicated using a standard protocol. Results: A total of 60 patients were included; 48 patients (80.0%) were treated for juxtarenal aneurysms, and 12 (20.0%) were short-neck infrarenal aneurysms. Mean aneurysm size was 64 6 9 mm. A total of 140 fenestrations were incorporated. Median follow-up was 16.4 months (interquartile range, 11.9-27.4). The 30-day mortality was 3.4% (n ¼ 2). Kaplan-Meier estimates for 1-year, 2-year, and 3-year survival were 91.4%, 89.5%, and 86.3%, respectively, without aneurysm-related mortality during follow-up. Main body primary and secondary endograft patencies were 98.3% and 100%, respectively. Target vessel primary and secondary patencies were 95.0% and 98.6%, respectively. Early type IA endoleaks occurred in seven patients (11.7%) and spontaneously resolved in all patients. At 1-year follow-up 4 (6.7%) type II endoleaks persisted. One patient experienced aneurysm rupture because of a late type III endoleak attributable to a dislodged renal stent and subsequently underwent successful conversion to open surgery. Conclusions: The fenestrated Anaconda is a viable treatment option for complex abdominal aortic aneurysms. Acceptable mortality and morbidity and low reintervention rates contribute to good midterm results. Occurrence of early type I endoleak was relatively common, but these resolved spontaneously in all patients. (J Vasc Surg 2016;-:1-7.)
Endovascular aneurysm repair (EVAR) has evolved rapidly since its introduction in 1991, and the majority of patients with an abdominal aortic aneurysm (AAA) are now treated by endovascular means.1 However, up to 30% of all patients with AAAs are not suitable for treatment using standard infrarenal endografts because of complex anatomy, including short infrarenal neck length
From the Division of Vascular Surgery, Department of Surgery, University Medical Center Groningen, University of Groningen, Groningena; and the Department of Surgery, Rijnstate Hospital, Arnhem.b
*A list of members of the Dutch Fenestrated Anaconda Research Group is listed in the Appendix. Author conflict of interest: M.M.P.J.R. and C.J.Z. are consultants for Vascutek, Renfrewshire, Scotland. Correspondence: Clark J. Zeebregts, MD, PhD, Division of Vascular Surgery, Department of Surgery, University Medical Center Groningen, PO Box 30 001, Groningen 9700 RB, The Netherlands (e-mail: [email protected]). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a conflict of interest. 0741-5214 Copyright Ó 2016 by the Society for Vascular Surgery. Published by Elsevier Inc. http://dx.doi.org/10.1016/j.jvs.2016.08.092
(<15 mm), severe angulation (>60 ), or aneurysms that involve important (visceral) side branches.2 To overcome these technical difficulties, the concept of fenestrated EVAR (FEVAR) was developed and successfully introduced in 1999.3 Subsequent advances in FEVAR treatment and techniques have resulted in successful treatment of not only short-neck infrarenal and juxtarenal aneurysms, but also thoracoabdominal aneurysms with increasing anatomic complexity.4-7 Most of the current knowledge is based on the Zenith custom-made fenestrated endograft (Cook Medical Australia, Brisbane, Queensland, Australia). The fenestrated Anaconda endograft (Vascutek, Renfrewshire, Scotland) was introduced in 2010, and initial reports on use of the fenestrated Anaconda were published in 2011 and 2012 by Bungay et al.8,9 The Dutch Fenestrated Anaconda Research Group subsequently published the short-term results of the first 25 patients treated in The Netherlands.10 The possible advantages of the fenestrated Anaconda were explored, and the data showed promising short-term results with high technical success rates and low morbidity. However, durability has yet to be proven because there are no mid- and 1
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longer-term data available regarding this new fenestrated device. A larger number of patients have now been treated using the fenestrated Anaconda in The Netherlands. The aim of this study was to present an update of the previous cohort and subsequent patients treated, and to present the midterm results of this larger cohort.
METHODS Design of the study. Patients who underwent exclusion of an aneurysm with a fenestrated Anaconda endograft in The Netherlands between May 2011 and February 2015 were included. The current population in The Netherlands is approximately 17 million people; 49.6% is male, and 15.6% is aged 65 and over. Data were collected in the respective hospitals and retrospectively analyzed. All patients were assessed preoperatively using multislice detector computed tomography angiography (CTA). Patients were treated in accordance with current international treatment guidelines.11,12 Indications for FEVAR included unsuitable anatomy for conventional EVAR (short-neck length [<15 mm], hostile proximal sealing zone, or important aortic side branches involved in the aneurysm) and was ultimately decided by the treating physician. The procedures were performed in either a hybrid suite equipped for both interventional radiology and open surgical procedures or a surgical theater using a recent generation mobile C-arm. Followup consisted of CTA at 1 month and 1 year, and duplex ultrasound yearly thereafter with additional CTA if indicated using a standard protocol. The standard CTA protocol included noncontrast, early (arterial), and delayed contrast series. In case of a suspected endoleak on duplex ultrasound during follow-up, a subsequent CTA was performed. All patients who were included had at least 12 months of follow-up except for those who died before reaching the 1-year follow-up. The fenestrated Anaconda endograft. A detailed description of the fenestrated Anaconda and possible advantages compared to other fenestrated devices have been published previously.8,10 The fenestrated Anaconda is a repositionable customized device for individual patient use based on the Anaconda AAA endograft system.13 There are a number of theoretical advantages compared with other devices, including the following. (1) It is repositionable after full deployment, allowing for accurate deployment and repositioning of the endograft body and its fenestrations. (2) Fenestrations are placed in the unsupported region maximizing the area available and potentially allowing for easier alignment and subsequent cannulation of target vessels. (3) The lack of columnar strength combined with a ringed distal design might also allow for treatment of more angulated and stenotic anatomy. A range of configurations is currently available allowing for the device
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from one fenestration up to five fenestrations, although a maximum of four fenestrations were used in this study. Also, the addition of an augmented valley (comparable to a scallop), and either a bifurcated or a tube design add further possibilities to enable treatment of AAAs with a varying range of complex anatomy. Stent implantation. The procedural details have been published previously.10 In short, bilateral femoral access was obtained either percutaneously or by cutdown. All patients were heparinized perioperatively. After introduction and deployment of the fenestrated main body, the fenestrations and target vessels were cannulated and angiography performed to confirm the position. If not satisfactory, the main body would be collapsed and repositioned to achieve a more satisfactory position. Once in place, the target vessels were cannulated with balloon expandable covered stents using standard endovascular techniques. Finally, the endograft was completed by placing the limb extensions, and a completion angiogram was performed. In case of a type IA or III endoleak on the completion angiogram, repeat angioplasty was performed at the respective site of the endoleak if possible. Residual type IA endoleaks after repeat angioplasty were accepted. Definitions. Juxtarenal was defined as an aneurysm that abuts the renal arteries, but does not involve the renal arteries (no normal sized aorta between upper extent of aneurysm and renal arteries).14 Short neck was defined as an aneurysm with a normal portion of the aorta between the upper extent of the aneurysm and lowest renal artery, and with a neck length <15 mm. Clinical success (midterm) was defined as successful deployment of the endovascular device at the intended location without type I or III endoleak, graft infection or thrombosis, aneurysm expansion (diameter >5 mm), aneurysm rupture or conversion to open repair, graft migration, a failure of device integrity, or death as a result of aneurysm-related treatment.14 Technical success was defined as successful introduction and deployment of the device in the absence of surgical conversion or mortality, type I or III endoleaks, or graft limb obstruction. Statistics. Continuous variables are described as mean and standard deviation or median and interquartile range in case of skewed data. To test for normality a Kolmogorov-Smirnov test was performed. Differences between continuous variables were tested using a paired Student t-test or Mann-Whitney U test in case of skewed data. Survival and intervention free survival analysis were conducted using Kaplan-Meier estimates. Two-sided P values of <.05 were considered significant. Statistical analysis was performed using SPSS statistics v 20.0 (IBM Corporation, Armonk, NY).
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Table I. Demographics
Table II. Procedural details Mean 6 SD
Age, years
No. (%)
Male Female
Mean (6SD) or median (IQR)
72 (67) 52 (86.7)
Juxtarenal
8 (13.3)
Short neck Neck length, mm
ASA class 22 (36.7)
Maximum AAA diameter, mm
ASA 3
36 (60.0)
Endograft type
ASA 4
2 (3.3)
Bifurcated
ASA 2
8 (13.3)
Hypertension Yes
39 (65.0) 34 (56.7)
Smoking 22 (36.7)
Cardiac disease Yes
33 (55.0) 16 (26.7)
Renal disease Yes
64 (9) 58 (96.7) 2 (3.3)
Type of top stent Standard
21 (35.0)
Augmented valley
39 (65.0)
25
17 (28.3)
ASA, American Society of Anesthesiologists; SD, standard deviation.
2 (3.3)
28
13 (21.7)
30
13 (21.7)
32
16 (26.7)
34
16 (26.7)
Oversize, %
Pulmonary disease Yes
12 (20.0) 6 (4)
Main device diameter, mm
Hypercholesterolemia
Yes
48 (80.0)
Aortouniiliac
Diabetes mellitus Yes
No. (%)
Type of aneurysm
Sex
Yes
3
-
19.7 (3.4)
Number of fenestrations 1
5 (8.3)
2
34 (56.7)
3
17 (28.3)
4
4 (6.7)
Main device repositioned
RESULTS A total of 60 patients were treated in 13 sites located in The Netherlands. The mean age was 72 6 7 years, and 52 of these patients were male (86.7%). Patients treated were mainly classified as American Society of Anesthesiologists III (60.0%) because of significant comorbidities. Full demographics are shown in Table I. The median number of procedures per hospital was 4.5 (1-7). The majority of patients (n ¼ 48; 80.0%) were treated for juxtarenal aneurysms, while the remaining 12 (20.0%) were short-neck aneurysms. Mean proximal neck length was 6 6 4 mm. Mean aneurysm diameter was 64 6 9 mm. Two (3.3%) aortouniiliac devices were used; the remaining 58 (96.7%) were bifurcated devices. Data on the specific device configurations are summarized in Table II. About one-half of the endografts had a twofenestration design (56.7%) incorporating the renal arteries. Mean operative time was 262 6 96 minutes with a median contrast dose of 178 mL (range, 70-380 mL). The option to reposition the main device was used in 41 cases (68.3%). Upper access was used in 18 (30.0%) patients. Patients had a median total length of stay of 6 days (4-9). Perioperative complications occurred in 14 patients and included pneumonia (n ¼ 3), surgical site infection (n ¼ 1), delirium (n ¼ 1), cerebral vascular accident (n ¼ 1), decline in renal function (n ¼ 4), anemia (n ¼ 3), gastroenteritis
No
19 (31.7)
Yes
41 (68.3)
Upper access No
42 (60.0)
Yes Fluoroscopy time, minutes
18 (30.0) 78 (40)
Procedure time, minutes
262 (96)
Contrast dosage, mL
178 (68)
AAA, Abdominal aortic aneurysm; IQR, interquartile range; SD, standard deviation.
(n ¼ 1), and lower leg compartment syndrome (n ¼ 1), with a total 30-day morbidity rate of 25.0% (n ¼ 15). 30day mortality rate was 3.3% (n ¼ 2). Cause of death was postoperative bowel ischemia in one patient, which is described in detail previously10 and unknown in the second patient. Median follow-up was 16.4 months (interquartile range, 11.9-27.4). There was no loss to follow-up. Postoperative (temporary) decrease in renal function was observed in 18 patients (30.0%). Long-term renal dysfunction was found in four patients (6.7%), of which two patients had preexisting renal dysfunction. One patient (1.7%) required dialysis treatment. In the longer term, there was a minor but significant decline in estimated glomerular filtration rate (eGFR in mL/min) from
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Table III. Follow-up Median (IQR) Follow-up, months
16.4 (11.9-27.4)
eGFR, mL/min
57.5 (41.8-75.8)
No. (%)
Midterm clinical success Yes
53 (88.3)
No
7 (11.7)
Kinking No
60 (100.0)
Yes
0 (0.0)
Migration No
59 (98.3)
Yes
1 (1.7)
Graft infection No
60 (100.0)
Yes
0 (0.0)
Fig 1. Kaplan-Meier survival analysis, showing survival of patients after fenestrated endovascular aneurysm repair (FEVAR) using the fenestrated Anaconda.
Endoleak Type I
0 (0.0)
Type II
4 (6.7)
Type III
0 (0.0)
Aneurysm size Increase
5 (8.3)
Decrease
35 (58.3)
Stable
14 (23.3)
Unknown
6 (10.0)
Reintervention Yes
4 (6.7)
No
50 (83.3)
eGFR, Estimated glomerular filtration rate; IQR, interquartile range.
60.0 (57.0-77.5) to 57.5 (41.8-75.8; P < .05) at the last follow-up visit. Follow-up details are shown in Table III. Five patients died during follow-up. Cause of death was pneumosepsis (n ¼ 1), congestive heart failure (n ¼ 1), cardiac arrhythmia (n ¼ 1), hemorrhagic cerebral vascular accident (n ¼ 1), and unknown (n ¼ 1). Kaplan-Meier survival estimates for 1-year, 2-year, and 3-year survival were 91.4%, 89.5%, and 86.3%, respectively. Kaplan-Meier patient survival analysis is shown in Fig 1. There were no aneurysm-related deaths after 30-days follow-up. One patient suffered bowel ischemia perioperatively as previously described. The other patient died 1 month postoperatively after being discharged on the fifth postoperative day and before having the 1-month follow-up CTA. Cause of death remains unknown. The patient did have signs of a type IA endoleak at completion angiogram, and, therefore, we cannot exclude the possibility of aneurysm-related death. One patient experienced a rupture 1 year postoperatively because of a type III endoleak. The patient experienced the rupture while traveling abroad and was admitted to a local hospital. CTA was performed that
showed dislodgement of a renal fenestration stent, and the patient underwent successful emergent open surgery and reconstruction with a tube graft. There were two graft migrations reported. In the first patient, this occurred 1 month postoperatively and resulted in bilateral occlusion of the renal arteries, after which the patient required dialysis treatment. In the second patient, graft migration occurred 3 months postoperatively with subsequent dislocation of the stents to the right renal artery (RRA), left renal artery (LRA), superior mesenteric artery, and celiac trunk. The patient underwent open revascularization of both renal arteries and the celiac trunk. There was one left iliac limb occlusion at 17 months, which was successfully treated by surgical thrombectomy and subsequent endarterectomy of an atherosclerotic left common femoral artery. Therefore, primary and secondary endograft patency rates were 98.3% and 100%, respectively. There were no graft infections. No kinking of the main body or limbs occurred. A total of 140 fenestrations were incorporated to accommodate the target vessels; 136 fenestrations were successfully cannulated and stented (97.1%). During follow-up four target vessels occluded in three patients (RRA, n ¼ 2; LRA, n ¼ 2). For the target vessels, primary patency was, therefore, 95.0%. Two of the occluded target vessels were successfully treated by endovascular means. Therefore, secondary target vessel patency was 98.6%. In total, 27 (45.0%) patients had an endoleak on either the perioperative completion angiogram or on the discharge CTA, including type IA (n ¼ 7, 11.7%), type II (n ¼ 18, 30.0%), and type III endoleaks (n ¼ 2, 3.3%). Technical success was, therefore, 85.0%. The majority of the endoleaks resolved spontaneously. At 1-year followup, only four (6.7%) type II endoleaks persisted. As mentioned above, one late type III endoleak led to subsequent aneurysm rupture and conversion to
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Fig 2. Kaplan-Meier intervention free survival analysis, showing intervention free survival of patients after fenestrated endovascular aneurysm repair (FEVAR) using the fenestrated Anaconda.
open surgery. Intervention free survival analysis using Kaplan-Meier estimates is shown in Fig 2. There were no significant differences in demographics, endograft configuration, or periprocedural variables between patients with an endoleak compared with those without signs of endoleaks. Aneurysm size decreased in 36 (60.0%) patients, remained stable in 15 (25.0%), and increased in five (8.3%) patients. In the subgroup of patients that showed an increase in aneurysm size, one early type IA endoleak and two type II endoleaks were observed. This resulted in an overall midterm clinical success rate of 88.3%.
DISCUSSION The presented midterm data on the fenestrated Anaconda endograft indicate the device to be a viable alternative for the treatment of patients with complex AAAs. The midterm clinical success and patency rates are high with a low reintervention rate and no proven aneurysm-related mortality during follow-up. A 30-day mortality rate of 3.4% (n ¼ 2) was achieved in this cohort, which is comparable to midterm results with the Zenith custom-made fenestrated endograft (Cook Medical Australia).5,15,16 The option to reposition the graft after initial deployment was frequently used (68.3%). This feature can be helpful in complex anatomy where precise positioning is paramount. On the other hand, caution was advised in using this feature because of the possible induction of thromboembolic events, as was the case in the patient who developed bowel ischemia (n ¼ 1). In this larger cohort, fortunately, no additional perioperative thromboembolic complications were observed. Procedure time and contrast dosage compare with other devices currently used.4,17,18
Compared with earlier reports, there is a high incidence of endoleaks, including type IA and type II endoleaks.8,10 This also explains the “low” technical success rate of 85.0%. As described in our previous report, it was hypothesized that early type IA endoleaks seem to disappear spontaneously, possibly because of the specific endograft top stent design. This is believed to be due to increased embedding of the proximal stents with the vessel wall in time, providing improved apposition and sealing after initial device deployment. The increased embedding occurs as the stent material temperature increases to body temperature following deployment, causing the stent’s radial force to increase, while the vessel conforms locally to the shape of the stent. In the longer term, it is known that the stents continue to embed over the months following implantation. This hypothesis holds true in the current series, where 10 early type I endoleaks were observed. Obviously, in case of a type IA endoleak attempts were made to correct this intraoperatively either by repositioning the endograft or by re-ballooning the proximal seal. The latter is only possible in a four-fenestration design where there is enough room above the fenestrations. Obviously, it is not advocated to readily accept type IA endoleaks. However, a type IA endoleak that persisted despite attempts to correct this was accepted, and patients underwent standard follow-up including 1-month CTA and subsequent reintervention if appropriate. In this cohort, no type IA endoleak persisted and no reinterventions were necessary. In this cohort one rupture did occur because of a type III endoleak, for which the patient was successfully converted to open surgery. The patient was traveling abroad at the time of the event and was, therefore, treated in a local hospital. The correspondence notes dislodgement of a renal fenestration and subsequent type III endoleak and rupture. This patient had a shortneck infrarenal aneurysm (proximal neck length of 6 mm) and was treated with a two-fenestration endograft (RRA and LRA). The procedure was uneventful, and the follow-up imaging showed a type II endoleak but no other signs of complications up to the event. Noteworthy, there was no indication of migration. The proximal oversize in this case was 16.7%. In this specific case, there was, however, an increase of the aneurysm sac diameter of 2 mm at the 6-month follow-up CTA, which should prompt caution but not necessarily immediate reintervention for the known type II endoleak. The treating physician made numerous efforts to obtain the imaging performed at the time of the event, ultimately without success and unfortunately the exact cause for stent dislodgement remains unclear. Analysis of the data did not show any significant differences in demographics, endograft configuration, or perioperative variables between the “endoleak” and “no endoleak” groups, which is in part due to the still
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relatively small numbers. The consensus that type II endoleaks can be safely managed conservatively seems to hold true in the current series, especially if there is a stable or decreasing aneurysm diameter. Type III endoleaks also spontaneously resolved. Re-evaluation of these type III endoleaks showed they were actually type II endoleaks that had been misinterpreted at the time of original analysis. All of these had been diagnosed on the perioperative completion angiography, and the 1-month follow-up CTA, however, did not show any type III endoleaks. In total, five (8.3%) patients underwent either an endovascular or an open reintervention during follow-up as discussed in the Results section, which is relatively low compared with other reports of FEVAR.5,15,16 Four patients showed a decline in renal function postoperatively with patent side branches, and during follow-up, there was a minor, but significant decrease in renal function (eGFR in mL/min) preoperatively 60.0 (57.0-77.5) to 57.5 (41.8-75.8; P < .05) at final follow-up visit. In a subanalysis excluding those patients with known renal disease, there was also a significant decline in renal function (eGFR in mL/min) during follow-up of 70.0 (60.0-83.0) to 60.0 (50.8-84.5; P < .05). In one patient, the main device migrated causing dislocation and subsequent occlusion of both renal arteries. In this case, a short-neck infrarenal aneurysm was treated (proximal neck length 5 mm) using a three-fenestration device (RRA, LRA, and an ancillary LRA). No cause for the migration was identified; the procedure was uneventful without signs of endoleak on completion angiography, and the device was adequately oversized by 21.4%. In spite of a reintervention aimed to restore renal artery perfusion, only the ancillary LRA was successfully recanalized, and the patient became dialysis dependent. This in part explains the drop in eGFR. Second, contrast induced nephropathy might also have contributed. Previous studies have shown a decline in renal function to be a significant risk after FEVAR, as is the case in this cohort.19 Given patients with renal complications after FEVAR are at risk for dialysis or even death, maximal efforts should be undertaken to reduce contrast dosage. Also, advances in techniques, including advanced imaging and perioperative guidance,20 experience, and perioperative care are important to minimize these effects. The current results are comparable to results with the most commonly used fenestrated endograft (Cook Zenith custom-made). Midterm results using the Cook device showed similar all-cause mortality (13.0%) and 30-day mortality (2.6%) rates, as well as similar contrast dosages and procedure times. The reported visceral primary branch patency was 92.0% at 46 months.15 All postoperative occlusions in this study by Muhs et al15 occurred in unstented fenestrations or scallops. It has now become common practice to stent all fenestrations and most scallops as well.21 This may explain the higher primary and secondary fenestration patency in the
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present study (95.0% and 98.6, respectively). Another study by Oderich et al22 reported a slightly lower 30-day mortality of 1.5% in 67 patients using the Zenith fenestrated AAA endovascular graft. In this cohort, there were no early type IA endoleaks and one late type IA endoleak, which was successfully treated by coil embolization, and 16 patients had a type II endoleak (29%). In the current cohort, there was a higher incidence of endoleaks regardless of the type. However, the difference is largely explained by the early type IA endoleaks (11.7%) with a comparable incidence of type II endoleak (30.0%). The present study has several limitations. The data were prospectively collected in the respective hospitals, but retrospectively analyzed. As with any new device, a learning curve is to be expected, although all treating centers and physicians had extensive experience with complex endovascular procedures. With a total of 13 centers in The Netherlands participating, the median number of procedures for each center is limited. However, a subanalysis of the centers with the lowest number of procedures did not show a significant increase in serious adverse events or mortality. The cause of death remained unknown in three patients. These deaths are likely not aneurysm related, however, no definitive statements can be made to this regard. Specifically, in the patient who died before having the 1-month follow-up CTA, assuming the worst possible outcome, he would have had a rupture because of the small type IA endoleak on completion angiogram. This, however, is considered unlikely, given the experiences with other type IA endoleaks as presented. Unfortunately no postmortem examination was performed. Given the still relatively small sample size, no predisposing factors for adverse outcomes (eg, which type IA endoleaks require intervention) could be identified. Further studies are needed to identify those patients at risk and clarify indications for reintervention.
CONCLUSIONS The fenestrated Anaconda is a viable treatment option for complex AAAs. Acceptable mortality and morbidity and low reintervention rates contributed to good midterm results. Occurrence of early type I endoleak was relatively common, but these resolved spontaneously in all patients.
AUTHOR CONTRIBUTIONS Conception and design: LB, MD, IT, MR, CZ Analysis and interpretation: LB, MD, CZ Data collection: LB, MD Writing the article: LB, MD, CZ Critical revision of the article: LB, MD, IT, MR, CZ Final approval of the article: LB, MD, IT, MR, CZ Statistical analysis: LB, MD, CZ Obtained funding: Not applicable
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Overall responsibility: CZ LB and MD contributed equally to this article and share co-first authorship.
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aneurysms with fenestrated endovascular grafting. J Vasc Surg 2004;39:279-87. 18. Holden A, Mertens R, Hill A, Marine L, Clair DG. Initial experience with the Ventana fenestrated system for endovascular repair of juxtarenal and pararenal aortic aneurysms. J Vasc Surg 2013;57:1235-45. 19. Haddad F, Greenberg RK, Walker E, Nally J, O’Neill S, Kolin G, et al. Fenestrated endovascular grafting: the renal side of the story. J Vasc Surg 2005;41:181-90. 20. Dijkstra ML, Eagleton MJ, Greenberg RK, Mastracci T, Hernandez A. Intraoperative C-arm cone-beam computed tomography in fenestrated/branched aortic endografting. J Vasc Surg 2011;53:583-90. 21. Grimme FA, Zeebregts CJ, Verhoeven EL, Bekkema F, Reijnen MM, Tielliu IF. Visceral stent patency in fenestrated stent grafting for abdominal aortic aneurysm repair. J Vasc Surg 2014;59:298-306. 22. Oderich GS, Greenberg RK, Farber M, Lyden S, Sanchez L, Fairman R, et al. Results of the United States multicenter prospective study evaluating the Zenith fenestrated endovascular graft for treatment of juxtarenal abdominal aortic aneurysms. J Vasc Surg 2014;60:1420-8. e1-5.
Submitted Jul 3, 2016; accepted Aug 26, 2016.
APPENDIX Dutch Fenestrated Anaconda Research Group. Clark J. Zeebregts, MD, PhD,* Ignace F. J. Tielliu, MD, PhD, Department of Surgery, Division of Vascular Surgery, University Medical Center Groningen, Groningen, The Netherlands Robert H. Geelkerken, MD, PhD,* Robert Meerwaldt, MD, PhD,* Department of Surgery, Division of Vascular Surgery, Medical Spectrum Twente, Enschede, The Netherlands Maurice E. N. Pierie, MD, PhD, Department of Surgery, Division of Vascular Surgery, Isala Clinics, Zwolle, The Netherlands Jerome P. van Brussel, MD, PhD, Department of Surgery, Division of Vascular Surgery, Sint Franciscus Gasthuis, Rotterdam, The Netherlands Ronald F. van den Haak, MD, Department of Surgery, Division of Vascular Surgery, Jeroen Bosch Ziekenhuis, ’s-Hertogenbosch, The Netherlands Geert-Willem H. Schurink, MD, PhD, Department of Surgery, Maastricht University Medical Center, Maastricht, The Netherlands Joost A. van Herwaarden, MD, PhD, Department of Surgery, Division of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands Jan-Willem Lardenoije, MD, PhD,* Michel M. P. J. Reijnen, MD, PhD, Department of Surgery, Division of Vascular Surgery, Rijnstate Hospital, Arnhem, The Netherlands Abdelkarime K. Jahrome, MD, PhD, Department of Surgery, Division of Vascular Surgery, Medical Centre Leeuwarden, Leeuwarden, The Netherlands Ron Balm, MD, PhD, Department of Surgery, Division of Vascular Surgery, Academic Medical Centre, Amsterdam, The Netherlands
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Peter L. Klemm, MD, PhD, Marianne E. Witte, MD, Department of Surgery, Division of Vascular Surgery, Gelre Hospital, Apeldoorn, The Netherlands Evert J. Waasdorp, MD, PhD, Peter M. Schlejen, MD, Department of Surgery, Division of Vascular Surgery, ’t Groene Hart Hospital, Gouda, The Netherlands Marie Josee van Rijn, MD, PhD, Hence J. M. Verhagen, MD, PhD, Department of Surgery, Division of Vascular Surgery, University Medical Center Erasmus, Rotterdam, The Netherlands *Consultants for Vascutek, Renfrewshire, Scotland
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