Descending Thoracic Aorta Remodeling after Multilayer Stent Release Antonio Bozzani, Vittorio Arici, Giovanni Bonalumi, and Angelo Argenteri, Pavia, Italy
The multilayer flow modulator (MFM) is a device whose real effectiveness in the treatment of thoracoabdominal aortic aneurysms is not clear yet. A 68-year-old man with a 18-mm blisterlike aneurysm of the descending thoracic aorta underwent endovascular exclusion, complicated by the thrombosis of a previous aortobi-iliac prosthesis, treated with embolectomy and femorofemoral bypass. Therefore, an MFM placement was planned. The postoperative course was uneventful and the 6-month computed tomography scan showed a complete thrombosis and remodeling of the aneurysm. The MFM stent could be an alternative treatment for saccular thoracic aortic aneurysm in high-risk patients but should not be used indiscriminately when other modalities of aortic repair are not feasible. Longer follow-up is mandatory to prove the efficacy of this technology.
The operative risk of open surgical repair of thoracic and thoracoabdominal aortic aneurysms remains high. Thoracic endovascular aortic repair (TEVAR) offers a less-invasive approach, but it is not always feasible. Moreover, technical success of more complex procedures (branched or fenestrated stent graft) has been high only if performed in selected high-volume centers. The Multilayer Flow Modulator (MFM) is a new therapeutic option for the treatment of aortic pathologies, but its effectiveness is not yet clear. We present a case of a descending thoracic aorta (DTA) blister-like aneurysm secondary to a type B penetrating aortic ulcer (PAU-B) successfully treated with MFM.
CASE REPORT An asymptomatic 68-year-old man presented with an 18-mm blister-like aneurysm secondary to a PAU-B. The
Division of Vascular and Endovascular Surgery, Foundation IRCCS Policlinico San Matteo, Pavia, Italy. Correspondence to: Antonio Bozzani, MD, Division of Vascular Surgery, Foundation IRCCS Policlinico San Matteo, P.le Golgi 19, Pavia 27100, Italy; E-mail: [email protected] Ann Vasc Surg 2015; 29: 1018.e9e1018.e11 http://dx.doi.org/10.1016/j.avsg.2015.01.016 Ó 2015 Elsevier Inc. All rights reserved. Manuscript received: October 9, 2014; manuscript accepted: January 5, 2015; published online: March 9, 2015.
clinical history was consistent with atrial fibrillation, hypertension, ascending aorta aneurysm, and previous aortobi-iliac (ABIL) Dacron graft (16 8 mm diameter). Preoperative medical treatment was enalapril 20 mg/ day, bisoprolol 2.5 mg/day, and acetylsalicylic acid 100 mg/day. An endovascular graft exclusion was planned because of high operative risk. A first treatment attempt was made using a thoracic endograft (38 38 100 mm, Captivia 24F introducer sheath; Medtronic Vascular, Santa Rosa, CA), but the procedure was complicated by the blockade of the graft deployer device in the left limb of the previous surgical graft and its complete thrombosis, resolved with left iliofemoral and crossover femorofemoral bypasses. Therefore, considering the small accesses diameter, MFM positioning was planned. Through a left femoral surgical access an 18F delivery system was introduced in the graft left limb over a 0.035-in stiff guidewire; subsequently, a 30 150-mm MFM (Cardiatis Crossmed, Isnes, Belgium) was deployed in the DTA. The completion angiography showed a decreased blood flow within the saccular aneurysm. The postoperative course was uneventful, and the patient was discharged home in the fifth postoperative day with dual antiplatelet therapy for 1 month followed by aspirin lifelong. A 6-month CT scan confirmed satisfactory placement of the MFM, complete aneurysm thrombosis, and DTA remodeling with patency of intercostal arteries (Figs. 1 and 2). The aneurysm diameter at 6 months was 14 mm, showing a shrinkage of nearly 25%.
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Fig. 1. Blister-like aneurysm of the descending thoracic aorta with multiple thrombotic appositions and penetrating ulcers (A). The 6-month CT scan showed the complete aneurysm thrombosis and descending thoracic aorta remodeling (B).
Fig. 2. Major patent intercostal artery arising from the tract of the aorta covered by MFM.
DISCUSSION Currently, TEVAR represents the less-invasive treatment of DTA aneurysms (DTAA).1 This approach also apply to the thoracoabdominal aorta aneurysms (TAAA) using more complex techniques such as branched or fenestrated stent graft, or chimney, sandwich and periscope procedures. In the patients with TAAA unfit for surgery and unsuitable for endovascular exclusion, MFM was proposed as alternative. The MFM represents a new concept of 3-dimensional stent,
formed by several interconnected layers giving a porosity which will laminate the blood flow in the aneurysmal sac preserving the branches and collaterals. The blood flow dynamics is modified within the aneurysmal sac by relieving local peak wall shear stress and achieving stabilization of sac pressure.2 MFM appears to be safe and effective, and early results suggest that it can help prevent aortic ruptureerelated mortalities.3 In our case, we reached a very good healing of the aortic lesion, avoiding open surgery and in the presence of challenging access.
Vol. 29, No. 5, July 2015
In the STRATO trial, Vaislic et al. reported 23 cases of type II and III TAAAs treated with MFM with no aneurysm rupture; no migrations or fractures; and no incidences of spinal cord ischemia, respiratory, renal, or peripheral complications. They report 5 cases of endoleaks (3 type I and 2 type III). At 1 year, the rate of aneurysm sac complete exclusion was 75% and aneurysm sac diameter was stable for 90% of cases.4 DTA (in relation to its straight and uniform size) and saccular aneurysms (conversion of turbulent to laminar flow with complete aneurysm thrombosis after the stent deployment) represent an ideal condition for MFM that causes a process of aortic remodeling involving initial thrombus deposition which slows between 6 and 12 months.5 In our case, a 6-month CT scan control confirmed DTA remodeling and patency of intercostal arteries. MFM represents a new device that can be safely used in patient with thoracic aneurysm. MFM is a new concept of an active barrier that has several unique features in comparison with traditional grafted stent; our case shows that endovascular
Case reports 1018.e11
treatment of saccular DTAA with MFM is feasible. Additional studies for treatment of this pathology are needed to better assess outcomes compared existing therapies.
REFERENCES 1. Pirrelli S, Bozzani A, Arici V, et al. Complete aortic arch remodeling after stent graft of acute type B dissection and Kommerell’s diverticulum. Ann Thorac Surg 2012;93:673. 2. Henry M, Benjelloun A, Henry I, et al. The multilayer flow modulator stent for the treatment of arterial aneurysms. J Cardiovasc Surg 2013;54:763e83. 3. Eggebrecht H, Plicht B, Kahlert P, et al. Intramural hematoma and penetrating ulcers: indications to endovascular treatment. Eur J Vasc Endovasc Surg 2009;38:659e65. 4. Vaislic CD, Fabiani JN, Chocron S. One-year-outcomes following repair of thoracoabdominal aneurysms with the multilayer flow modulator: report from the STRATO Trial. J Endovasc Ther 2014;21:85e95. 5. Sultan S, Sultan M, Hynes N. Early mid-term results of the first 103 cases of multilayer flow modulator stent done under indication for use in the management of thoracoabdominal aortic pathology from the independent global MFM registry. J Cardiovasc Surg 2014;55:21e32.
The multilayer flow modulator (MFM) is a device whose real effectiveness in the treatment of thoracoabdominal aortic aneurysms is not clear yet. A 68-year-old man with a 18-mm blisterlike aneurysm of the descending thoracic aorta underwent endovascular exclusion, complicated by the thrombosis of a previous aortobi-iliac prosthesis, treated with embolectomy and femorofemoral bypass. Therefore, an MFM placement was planned. The postoperative course was uneventful and the 6-month computed tomography scan showed a complete thrombosis and remodeling of the aneurysm. The MFM stent could be an alternative treatment for saccular thoracic aortic aneurysm in high-risk patients but should not be used indiscriminately when other modalities of aortic repair are not feasible. Longer follow-up is mandatory to prove the efficacy of this technology.
The operative risk of open surgical repair of thoracic and thoracoabdominal aortic aneurysms remains high. Thoracic endovascular aortic repair (TEVAR) offers a less-invasive approach, but it is not always feasible. Moreover, technical success of more complex procedures (branched or fenestrated stent graft) has been high only if performed in selected high-volume centers. The Multilayer Flow Modulator (MFM) is a new therapeutic option for the treatment of aortic pathologies, but its effectiveness is not yet clear. We present a case of a descending thoracic aorta (DTA) blister-like aneurysm secondary to a type B penetrating aortic ulcer (PAU-B) successfully treated with MFM.
CASE REPORT An asymptomatic 68-year-old man presented with an 18-mm blister-like aneurysm secondary to a PAU-B. The
Division of Vascular and Endovascular Surgery, Foundation IRCCS Policlinico San Matteo, Pavia, Italy. Correspondence to: Antonio Bozzani, MD, Division of Vascular Surgery, Foundation IRCCS Policlinico San Matteo, P.le Golgi 19, Pavia 27100, Italy; E-mail: [email protected] Ann Vasc Surg 2015; 29: 1018.e9e1018.e11 http://dx.doi.org/10.1016/j.avsg.2015.01.016 Ó 2015 Elsevier Inc. All rights reserved. Manuscript received: October 9, 2014; manuscript accepted: January 5, 2015; published online: March 9, 2015.
clinical history was consistent with atrial fibrillation, hypertension, ascending aorta aneurysm, and previous aortobi-iliac (ABIL) Dacron graft (16 8 mm diameter). Preoperative medical treatment was enalapril 20 mg/ day, bisoprolol 2.5 mg/day, and acetylsalicylic acid 100 mg/day. An endovascular graft exclusion was planned because of high operative risk. A first treatment attempt was made using a thoracic endograft (38 38 100 mm, Captivia 24F introducer sheath; Medtronic Vascular, Santa Rosa, CA), but the procedure was complicated by the blockade of the graft deployer device in the left limb of the previous surgical graft and its complete thrombosis, resolved with left iliofemoral and crossover femorofemoral bypasses. Therefore, considering the small accesses diameter, MFM positioning was planned. Through a left femoral surgical access an 18F delivery system was introduced in the graft left limb over a 0.035-in stiff guidewire; subsequently, a 30 150-mm MFM (Cardiatis Crossmed, Isnes, Belgium) was deployed in the DTA. The completion angiography showed a decreased blood flow within the saccular aneurysm. The postoperative course was uneventful, and the patient was discharged home in the fifth postoperative day with dual antiplatelet therapy for 1 month followed by aspirin lifelong. A 6-month CT scan confirmed satisfactory placement of the MFM, complete aneurysm thrombosis, and DTA remodeling with patency of intercostal arteries (Figs. 1 and 2). The aneurysm diameter at 6 months was 14 mm, showing a shrinkage of nearly 25%.
1018.e9
1018.e10 Case reports
Annals of Vascular Surgery
Fig. 1. Blister-like aneurysm of the descending thoracic aorta with multiple thrombotic appositions and penetrating ulcers (A). The 6-month CT scan showed the complete aneurysm thrombosis and descending thoracic aorta remodeling (B).
Fig. 2. Major patent intercostal artery arising from the tract of the aorta covered by MFM.
DISCUSSION Currently, TEVAR represents the less-invasive treatment of DTA aneurysms (DTAA).1 This approach also apply to the thoracoabdominal aorta aneurysms (TAAA) using more complex techniques such as branched or fenestrated stent graft, or chimney, sandwich and periscope procedures. In the patients with TAAA unfit for surgery and unsuitable for endovascular exclusion, MFM was proposed as alternative. The MFM represents a new concept of 3-dimensional stent,
formed by several interconnected layers giving a porosity which will laminate the blood flow in the aneurysmal sac preserving the branches and collaterals. The blood flow dynamics is modified within the aneurysmal sac by relieving local peak wall shear stress and achieving stabilization of sac pressure.2 MFM appears to be safe and effective, and early results suggest that it can help prevent aortic ruptureerelated mortalities.3 In our case, we reached a very good healing of the aortic lesion, avoiding open surgery and in the presence of challenging access.
Vol. 29, No. 5, July 2015
In the STRATO trial, Vaislic et al. reported 23 cases of type II and III TAAAs treated with MFM with no aneurysm rupture; no migrations or fractures; and no incidences of spinal cord ischemia, respiratory, renal, or peripheral complications. They report 5 cases of endoleaks (3 type I and 2 type III). At 1 year, the rate of aneurysm sac complete exclusion was 75% and aneurysm sac diameter was stable for 90% of cases.4 DTA (in relation to its straight and uniform size) and saccular aneurysms (conversion of turbulent to laminar flow with complete aneurysm thrombosis after the stent deployment) represent an ideal condition for MFM that causes a process of aortic remodeling involving initial thrombus deposition which slows between 6 and 12 months.5 In our case, a 6-month CT scan control confirmed DTA remodeling and patency of intercostal arteries. MFM represents a new device that can be safely used in patient with thoracic aneurysm. MFM is a new concept of an active barrier that has several unique features in comparison with traditional grafted stent; our case shows that endovascular
Case reports 1018.e11
treatment of saccular DTAA with MFM is feasible. Additional studies for treatment of this pathology are needed to better assess outcomes compared existing therapies.
REFERENCES 1. Pirrelli S, Bozzani A, Arici V, et al. Complete aortic arch remodeling after stent graft of acute type B dissection and Kommerell’s diverticulum. Ann Thorac Surg 2012;93:673. 2. Henry M, Benjelloun A, Henry I, et al. The multilayer flow modulator stent for the treatment of arterial aneurysms. J Cardiovasc Surg 2013;54:763e83. 3. Eggebrecht H, Plicht B, Kahlert P, et al. Intramural hematoma and penetrating ulcers: indications to endovascular treatment. Eur J Vasc Endovasc Surg 2009;38:659e65. 4. Vaislic CD, Fabiani JN, Chocron S. One-year-outcomes following repair of thoracoabdominal aneurysms with the multilayer flow modulator: report from the STRATO Trial. J Endovasc Ther 2014;21:85e95. 5. Sultan S, Sultan M, Hynes N. Early mid-term results of the first 103 cases of multilayer flow modulator stent done under indication for use in the management of thoracoabdominal aortic pathology from the independent global MFM registry. J Cardiovasc Surg 2014;55:21e32.
