Endovascular Grafts for Abdominal Aortic Aneurysms
Endovascular grafts are minimally invasive alternatives to open surgical repair for treatment of abdominal aortic aneurysms (AAAs). Open surgical repair of AAAs has high morbidity and mortality, and endovascular grafts have the potential to reduce the operative risk associated with AAA repair.
The conventional management of a clinically significant abdominal aortic aneurysm consists of surgical excision with placement of a sutured woven graft. Surgical excision is associated with a perioperative mortality rate of 4%, which may rise to 10% in symptomatic patients. Due to this high mortality rate, endovascular prostheses have been investigated as a minimally invasive, catheter-based alternative to open surgical excision of abdominal aortic aneurysms. These devices are deployed across the aneurysm such that the aneurysm is effectively “excluded” from the circulation, with subsequent restoration of normal blood flow.
There are several types of grafts currently under investigation—straight grafts, in which both ends are anchored to the infrarenal aorta, and bifurcated grafts, in which the proximal end is anchored to the infrarenal aorta and the distal ends are anchored to the iliac arteries. Recently, fenestrated grafts have also been investigated. These grafts are designed with openings in the wall that can be placed across the renal or celiac arteries while still protecting vessel patency through these critical arteries. In addition, extensions can be placed from inside the main endograft body into the visceral arteries to create a hemostatic seal.
In 1999, the U.S. Food and Drug Administration (FDA) approved 2 endovascular grafts for use in the abdominal aorta: the EVT Abdominal Aortic Endovascular Grafting System (Guidant Endovascular Technologies) and the AneuRx® Prosthesis System (now called AneuRX® AAAdvantage Stent Graft - Medtronic Vascular, Inc.). In the Guidant system, the endograft is placed in the aorta and expanded using balloon dilation. The graft is anchored to the vessel wall using sutureless hooks at its superior and inferior ends. The AneuRx® system consists of a woven polyester interior surface with a self-expanding nitinol exoskeleton. The radial force of the expanding stent embeds the exoskeleton into the aneurysm wall, and thus constitutes the attachment mechanism. In April 2002, the FDA approved an additional Guidant device, the Ancure® Aortoiliac System. The Ancure device consists of a woven polyester graft that is housed within a long flexible delivery tube (catheter) for use in patients whose anatomy is not suited for the use of the single tube or bifurcated endograft device. This version is identical to the earlier Guidant Endovascular Grafting System except that the aortoiliac Ancure grafts have suture loops on the superior and inferior attachment systems. Several other grafts have been subsequently approved, including the Gore® Excluder® (2002), the Zenith® AAA Endovascular Graft (2003- now called Zenith Flex® AAA Endovascular Graft), and the Endologix Powerlink® (2004), the Medtronic Talent® Abdominal Stent Graft System (2008), the Medtronic Vascular Endurant® II AAA Stent Graft System (2010), and the Aorfix™ AAA Flexible Stent Graft System (2013, Lombard Medical, PLC). In 2012, the Ovation™ Abdominal Stent Graft System (TriVascular Inc.), a lower-profile stent graft that uses a postimplantation polymer deployment system to seal the device to the aorta, was approved for endovascular repair of abdominal aortic aneurysms with suitable anatomy.
The Zenith® Fenestrated AAA Endovascular Graft, a graft that extends across the visceral arteries, was approved by FDA with the adjunctive Zenith Alignment Stent in April 2012. The device is approved for endovascular treatment of aortic or aortoiliac aneurysms that are suitable for endovascular repair with the following:
Note: This policy addresses abdominal aortic aneurysms only. For discussion of endoprostheses for the treatment of thoracic aortic aneurysms, please see Endovascular Stent Grafts for Thoracic Aortic Aneurysms policy.
POLICYThe use of FDA-approved endoprostheses as a treatment of abdominal aortic aneurysms may be considered medically necessary as a treatment of abdominal aortic aneurysms in any of the following clinical situations:
The use of endoprostheses approved by the FDA as a treatment of abdominal aortic aneurysms is considered investigational when the above criteria are not met, including but not limited to the following clinical situations:
POLICY GUIDELINESFor treatment of ruptured abdominal aortic aneurysm with endoprostheses, several factors must be considered including the following:
To monitor for leaking of the graft after implantation, patients will typically undergo routine imaging with either computed tomography or ultrasonography every 6 to 12 months, or more frequently if perivascular leaks or aneurysm enlargement is detected.
The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member’s specific benefit plan language.
POLICY HISTORY1/20/2009: Policy added.
6/04/2010: Description section revised to add more common name for abdominal graft systems such as AneuRX® AAAdvantage; Zenith Flex® AAA Endovascular and Medtronic TalentTM System. Policy statement revised to include a ruptured abdominal aortic aneurysm as a clinical situation that the use of FDA-approved endoprostheses may be considered medically necessary. Policy statement regarding the use of endoprostheses as a treatment of ruptured abdominal aortic aneurysm is investigational was removed. Policy Guidelines section was revised to include factors to be considered when treating ruptured abdominal aortic aneurysms with endoprostheses and the use of monitoring for leaking of the graft after implantation. ICD-9 Diagnosis codes 441.3 and 441.4 were added to Covered Codes Table.
06/21/2011: Policy reviewed; no changes.
05/09/2012: Added the following policy statement: The use of endoprostheses approved by the FDA as a treatment of abdominal aortic aneurysms is considered investigational for the following clinical situations: treatment of smaller aneurysms that do not meet the current recommended threshold for surgery or treatment of aneurysms that do meet the recommended threshold for surgery in patients who are ineligible for open repair due to physical limitations or other factors.
08/07/2013: Policy reviewed; no changes.
07/16/2014: Policy reviewed; description updated regarding available devices. Second policy statement revised to add "when the above criteria are not met, including but not limited to" for clarity purposes.
SOURCESBlue Cross Blue Shield Association Policy # 7.01.67
CODE REFERENCEThis may not be a comprehensive list of procedure codes applicable to this policy.
The code(s) listed below are ONLY medically necessary if the procedure is performed according to the "Policy" section of this document.