FEVAR is generally the best option
The advent of endovascular aortic aneurysm repair (EVAR) has steadily become the standard of care in the management of infrarenal abdominal aortic aneurysms (AAAs). In fact, it has now surpassed open surgical repair and is the predominant therapeutic modality in managing this disease entity. Clearly, there are specific anatomic and technical factors that may preclude the use of traditional EVAR – most notably, challenging proximal neck anatomy, be it insufficient length or severe angulation.
It is estimated that up to 30%-40% of patients are unsuitable candidates because of these concerns.1 Such patients are thus relegated to traditional open repair with the associated concerns for supravisceral clamping, including dramatic changes in hemodynamics and prolonged ICU and hospital stays.
However, with increasing surgeon experience and volume, complex endovascular strategies are being championed and performed, including use of traditional infrarenal devices outside the instructions-for-use indications, “back-table” physician modified devices, chimney/snorkel barreled parallel covered grafts (Ch-EVAR), custom built fenestrated endografts (FEVAR), and use of adjunctive techniques such as endoanchors.
Open surgical repair of pararenal, juxtarenal, and suprarenal AAAs is tried, tested, and durable. Knott and the group from Mayo Clinic reviewed their repair of 126 consecutive elective juxtarenal AAAs requiring suprarenal aortic clamping noting a 30-day mortality of .8%.2 More recent data from Kabbani and the Henry Ford group involved their 27-year clinical experience suggesting that open repair of complex proximal aortic aneurysms can be performed with clinical outcomes that are similar to those of open infrarenal repair.3 I respectfully accept this traditional – and historic – treatment modality.
However, we vascular surgeons are progressive and resilient in our quest to innovate and modernize – some of us even modified the traditional endografts on the back table. We charged forward despite the initial paucity of data on infrarenal EVAR compared to traditional open repair of aneurysms in the past. Now, a large percentage of infrarenal AAA repairs are performed via EVAR. In fact, our steadfast progression to advanced endovascular techniques has raised the concern that our graduating trainees are no longer proficient, competent, or even capable, in open complex aneurysm repair!
Tsilimparis and colleagues reported the first outcomes comparing open repair and FEVAR.4 They queried the NSQIP database comparing 1,091 patients undergoing open repair with 264 in the FEVAR group. There was an increased risk of morbidity in all combined endpoints including pulmonary and cardiovascular complications as well as length of stay in patients undergoing the open repair group. A larger comprehensive review pooled the results from 8 FEVAR and 12 open repair series. Analysis of the data found the groups to be identical. Open repair, however, was found to have an increased 30-day mortality when compared to FEVAR (relative risk 1.03, 2% increased absolute mortality).5
Gupta and colleagues reported the latest multi-institutional data noting that open repair was associated with higher risk than FEVAR for 30-day mortality, cardiac and pulmonary complications, renal failure requiring dialysis, return to the operating room, and in this age of cost-containment, length of stay (2 days vs. 7 days; P less than .0001).6
A further study by Donas and colleagues evaluated 90 consecutive patients with primary degenerative juxtarenal AAAs to different operative strategies based on morphologic and clinical characteristics – 29 FEVAR, 30 chEVAR, and 31 open repair.7 Early procedure-related and all-cause 30-day mortality was 0% in the endovascular group and 6.4% in the open group.
Although open repair for juxtarenal AAAs is the gold standard, short- and mid-term data on the outcomes for complex endovascular repair are excellent. Data on long-term durability, graft fixation/migration as well as the integrity of the graft and concerns for endoleaks and branch vessel patency, however, are limited. We do not have long-term data because we have not been doing these newer procedures for that long – but the data thus far show great promise.
We need to continue to challenge the status quo, particularly when the current data are satisfactory and the procedure feasible. With our continued appraisal of the data we publish as vascular surgeons, we can then identify if these innovations and techniques will withstand the test of time. After all, we are vascular surgeons (particularly those of us who have trained extensively in open repair) – and if open repair is necessary, then we will be ready.
But, if I can avoid a thoracoabdominal incision for a few percutaneous access sites, then sign me up!
Dr. Mouawad is chief of vascular and endovascular surgery, medical director of the vascular laboratory, and vice-chair of the department of surgery at McLaren Bay Region, Bay City, Mich. He is assistant professor of surgery at Michigan State University and Central Michigan University.
FEVAR may not be the best choice
Over the past 3 decades, EVAR, with its very low periprocedural morbidity and mortality, and satisfactory long-term results, has become the primary treatment modality for the majority of infrarenal AAAs. The success of stent grafts for the repair of AAA relies heavily on satisfactory proximal and distal seal zones. Each commercially available standard EVAR graft has a manufacturer’s instructions for use requiring a proximal landing zone length of between 10 and 15 mm. Patients with less than this required length are considered to have “short necks.” Evaluation of this group of patients has demonstrated that this is not an uncommon finding and that EVAR performed outside the instructions for use has been associated with an increased risk of intraoperative failure, aneurysm expansion, and later complications.1-3
Current treatment options for patients with short necks include open surgical repair (OSR), FEVAR, and EVAR with the chimney graft technique (Ch-EVAR).
The Ch-EVAR technique currently lacks any significant long term follow-up, and with the availability of more proven commercially available devices is presently a lower tier endovascular treatment option. There are no head-to-head trials available between FEVAR and OSR of short neck aneurysms to guide our treatment choice.
Thus, current knowledge acquired from case series, registries, and clinical experience must be used in deciding which therapeutic option to offer patients. Relevant factors influencing this decision include the availability and adaptability of the technique, early outcomes including technical success, morbidity and mortality, and late outcomes including survival, need for reintervention, and other late morbidity. Finally, in an era of value-based medical care, cost also must be considered.
Currently there is only one Food and Drug Administration–approved fenestrated graft. When used in properly selected patients, excellent periprocedural results have been reported approaching those of standard EVAR. However, there are limitations in both the availability and adaptability of FEVAR. These grafts are custom made for each patient, often requiring several weeks of lead time. Adaptability also has its limitations, including access vessels, severe neck angulation, calcification, mural thrombus, and branch vessel size, number, location, and associated arterial disease. Any of these factors may preclude the use of this technology. Open repair, on the other hand, is not limited by graft availability and allows for custom modification for each patient’s specific disease morphology. The essential limitation for open repair is the patient’s physiological ability to withstand the operation.
Several studies attempting to compare the early outcomes of FEVAR versus comparable patients undergoing OSR of similar aneurysms have reported significantly lower 30-day mortality and major morbidity rates for FEVAR.4,5 However, Rao et al., in a recent systematic review and meta-analysis that included data on 2,326 patients from 35 case series reporting on elective repair of juxtarenal aneurysms by either OSR or FEVAR, found perioperative mortality to not be significantly different (4.1% for both). Also, no significant difference was found between the two groups when evaluating postoperative renal insufficiency and need for permanent dialysis. However, OSR did have significantly higher major complication rates (25% vs. 15.7%).6 These findings suggest that both modalities can be performed successfully, but that long term outcomes need to be considered to determine if the increased initial morbidity of OSR is justified by differences in long term results between the two modalities.
Open surgical repair of juxtarenal AAA has been shown to be a durable repair.7 While early and even intermediate results of FEVAR appear to be satisfactory, long-term durability has yet to be determined.4,8 Along with continuing to exclude the aneurysm sac, as with standard EVAR, there is the additional concern regarding the outcome of the organs supplied by the fenestrated/stent-grafted branches with FEVAR. Longer-term follow-up in the same review by Rao et al. showed that significantly more FEVAR patients developed renal failure compared with OSR patients (19.7% vs. 7.7%). FEVAR patients also had a higher rate of reintervention.
And finally, long-term survival was significantly greater in OSR patients compared to FEVAR at 3 and 5 years (80% vs. 74% vs. 73% vs. 55%). These authors concluded that open repair remains the gold standard while FEVAR is a favorable option for high risk patients.6
These new and innovative stent graft devices come at considerable expense. While this aspect of FEVAR has not been extensively studied, Michel et al., in their report from the multicenter prospective, attempted to evaluate the economic aspect of FEVAR. They compared a group of patients who underwent FEVAR to patients from a large national hospital discharge database who underwent OSR. No difference in 30-day mortality was noted between these two groups; however, there was a significantly greater cost with FEVAR. The authors concluded that FEVAR did not appear to be justified for patients fit for open surgery with juxtarenal AAA.9
For now, the roles of OSR and FEVAR would appear to be complementary. Current evidence suggests that OSR is the most appropriate intervention for good risk patients with an anticipated longer life expectancy. Patients with appropriate anatomy for FEVAR and who are at higher risk for open repair would benefit from FEVAR. As further experience and outcomes are accumulated, our ability to select the appropriate therapy for individual patients should improve.
Dr. Weaver is an assistant clinical professor for surgery at Wayne State School of Medicine, Detroit, and an attending in the division of vascular surgery, Henry Ford Hospital.