When Not to Implant the Multilayer Flow Modulator: Lessons Learned From Application Outside the Indications for Use in Patients With Thoracoabdominal Pathologies

Abstract

There are clinical scenarios in which the MFM does not perform well. The MFM is not a solution for patients living on borrowed time and should not be used indiscriminately in patients in whom other modalities of aortic repair are not feasible. Its use must adhere to the IFU, and robust clinical data are required before constructing a randomized controlled trial.

Total Endovascular Repair of Thoracoabdominal Aortic Aneurysms With Non-Customized Stent Grafts

“…One-year outcomes within our clinical series were also satisfactory; technical success was achieved in all cases, decrease in maximum diameter by over 5 mm was documented in 4 out of 6 patients (range, 5.2 to 18.6 mm), aneurysm stabilization was seen in the remaining 2 patients, and no aneurysm expansion was noticed. This result is in contrast with previously published less-favorable data regarding the flow-diverting stents in treating aortic pathologies [11,27], and offers a preliminary experience in improving this technique by using the stent grafts as adjuncts.…”

“…Persistent sac perfusion and subsequent aneurysm rupture have been reported by Lazaris and colleagues in 2012 [25]; stent rigidity leading to aortic rupture has been noticed by Ferrero and colleagues in 2013 [26]. Sultan and colleagues [27] recently released a result of 38 patients with TAAAs treated by off-label use of multilayer stents, in which an aneurysm-related mortality rate of 71.1% was documented. These drawbacks indicate that further refinements of this technique are required before its large-scale clinical application.…”

Endovascular repair of a juxtarenal saccular aneurysm using the Multilayer Flow Modulator: report of the first case performed in a Public Hospital in Brazil

“…Multilayer stents are contraindicated for cases of arteriovenous fistulas; vascular outflow insufficiencies; history of coagulation problems; suspected infections; aortic arch aneurysms; pseudoaneurysms and ruptured aneurysms. 25 In the case described here, indications for treatment with a Multilayer stent were respected and the results exceeded expectations, as was shown by early follow-up imaging exams.…”

“…[23][24][25] Successful use of the technique is dependent on respecting strict criteria for indications and conditions, including: previous treatment of stenosis of visceral branches; the extremities of the Multilayer stent must lie in normal arteries; where stents overlap, the larger diameter prosthesis must be within the smaller diameter device with oversizing of 15% to 25% and at least 60 mm extension of overlap; mobilization must be minimized, the delivery device must not be rotated inside the artery, extreme angles should be avoided to prevent risk of kinking and the device should not be forced if there is resistance from stenosis or calcifications; the correct size must be chosen according to the manufacturer's recommendations; care must be taken in maneuvering catheters and guide wires inside the aneurysm sac to avoid displacing emboli; care must be taken when withdrawing the delivery device to avoid displacing the Multilayer stent; and double antiplatelet treatment should be maintained for at least 3 months. Multilayer stents are contraindicated for cases of arteriovenous fistulas; vascular outflow insufficiencies; history of coagulation problems; suspected infections; aortic arch aneurysms; pseudoaneurysms and ruptured aneurysms.…”

Commentary: Multilayer Stent for the Treatment of Complex Aortic Pathologies: A Long or Short Road Ahead?

“…Wrong oversizing, hazardous landing zones, and misuse of the endoprosthesis are typically the causes of ineffective or failed MFM procedures. 1,2 The aorta is a dynamic element, changing its mechanical structure with every heart beat. The forces inside the aortic arch are completely different from those acting on the aortoiliac bifurcation.…”