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Abdominal Endograft Collapse with Acute Bilateral Lower Limb Ischemia
570 䡲 Letters to the Editor
Sfyroeras et al 䡲 JVIR
Figure 2. (a) Three-dimensional CT reconstruction after surgery demonstrates the extraanatomic bypass between the ascending thoracic aorta and the supraceliac thoracoabdominal aorta (asterisk). Note the migrated plug (arrow) in the abdominal aorta at the level of the origin of the superior mesenteric artery (arrowhead). (b) Lateral flush aortography confirms the position of the migrated plug (arrow) in front of the origin of the superior mesenteric artery (arrowhead). (Available in color online at www.jvir.org.)
This particular case shows that migration of an initially correctly placed AMPLATZER device can occur especially if open surgery and mechanical manipulation around the occluded vessel are performed. Additionally, when a firstgeneration AMPLATZER plug is fully expanded, the spaces between the wire meshes can remain widely open and flow through the device without any symptoms might persist, especially in the pulsatile, high-pressure arterial system. In such a clinical condition, a conservative management is a valuable option analogous to the asymptomatic outcome of migrated bare stents into the pulmonary circulation (5); however, in potential similar cases with a migrated last-generation AMPLATZER plug, conservative management may be unadvisable because of the higher risk of early or late severe thromboembolic complications, as last-generation AMPLATZER plugs (6) have more and denser layers of wire meshes, making persistent flow over time less likely.
REFERENCES 1. Ratnam LA, Walkden RM, Munneke GJ, Morgan RA, Belli AM. The Amplatzer vascular plug for large vessel occlusion in the endovascular management of aneurysms. Eur Radiol 2008; 18:2006 –2012.
2. Achen SE, Miller MW, Gordon SG, Saunders AB, Roland RM, Drourr LT. Transarterial ductal occlusion with the Amplatzer vascular plug in 31 dogs. J Vet Intern Med 2008; 22:1348 –1352. 3. Dorenberg EJ, Hafsahl G, Andersen R, Krohg-Sorensen K. Recurrent rupture of a hypogastric aneurysm caused by spontaneous recanalization of an Amplatzer vascular plug. J Vasc Interv Radiol 2006; 17:1037– 1041. 4. Fidelman N, Gordon RL, Bloom AI, LaBerge JM, Kerlan RK Jr. Reperfusion of pulmonary arteriovenous malformations after successful embolotherapy with vascular plugs. J Vasc Interv Radiol 2008; 19:1246 – 1250. 5. Marcy PY, Magné N, Bruneton JN. Strecker stent migration to the pulmonary artery: long-term result of a “wait-and-see attitude.” Eur Radiol 2001; 11:767– 670. 6. Mordasini P, Szucs-Farkas Z, Do DD, Gralla J, Kettenbach J, Hoppe H. Use of a latest-generation vascular plug for peripheral vascular embolization with use of a diagnostic catheter: preliminary clinical experience. J Vasc Interv Radiol 2010; 21:1185–1190.
Abdominal Endograft Collapse with Acute Bilateral Lower Limb Ischemia From: Giorgos S. Sfyroeras, MD, Dimitris Maras, MD, Vassileios Andrikopoulos, MD Department of Vascular Surgery Red Cross Hospital of Athens 15, Athinaidos str Voula, 16673, Athens, Greece
Volume 22 䡲 Number 4 䡲 April 䡲 2011
571
Figure. (a) A 68-year-old man was treated for a 5.0-cm infrarenal abdominal aortic aneurysm (AAA). The proximal neck had a reverse taper, 20 mm long, measuring 25 mm proximally and 29 mm distally. The anatomic configuration of the infrarenal aorta was characterized by an angulation of 45 degrees. (b,c) Abdominal computed tomography (CT) scan with intravenous contrast enhancement 15 days postoperatively when the patient was admitted with acute bilateral lower limb ischemia. There is an endoleak, collapse of the main body and the limbs of the endograft, and thrombosis. (d) Abdominal CT scan 3 days after the second operation shows restoration of the shape of the endograft and blood flow through the limbs with remnant thrombus. There is still a small endoleak.
Editor: Endovascular repair (EVAR) is a minimally invasive method for the treatment of abdominal aortic aneurysm (AAA). The technique has been associated with several endograft-related complications, however. Endograft proximal infolding, characterized as collapse, is a rare complication described predominately in thoracic aortic endografts. The institutional review board at the participating institution did not require approval for the conduct and preparation of this research report. An informed consent was obtained from the patient. None of the authors have identified a conflict of interest. DOI: 10.1016/j.jvir.2010.12.026
An active 68-year-old man with a medical history of coronary artery disease and hypertension was treated with EVAR for a 5.0-cm infrarenal asymptomatic AAA. The infrarenal neck had a reverse taper, 20 mm long, measuring 25 mm proximally and 29 mm distally, and an angulation of 45 degrees (Fig, a). Using a standard procedure, an endovascular bifurcated graft of 31 mm in main body diameter, 14 mm in limb diameter, and 17 cm in length was implanted (Excluder; W. L. Gore and Associates Inc, Flagstaff, Arizona). Balloon remodeling of the proximal and distal portions of the endograft and all overlapping sites was performed. Completion angiography revealed adequate graft apposition, with exclusion of the aneurysm sac and no signs of endoleak. Postoperatively, the patient had palpable pedal pulses. He had an uneventful recovery and was discharged on the 3rd postoperative day.
572 䡲 Letters to the Editor
He presented to the emergency department 15 days after surgery with bilateral lower extremity ischemia. All infrainguinal pulses were nonpalpable, and Doppler signals were absent in both feet. He had sensory loss in both feet, with impaired mobility. Abdominal computed tomography (CT) with intravenous administration of contrast agent revealed complete endograft collapse and an endoleak (Fig, b and c). The patient underwent bilateral femoral artery cutdowns under general anesthesia. After bilateral open femoral catheterization, two guide wires were passed to the thoracic aorta. Balloon remodeling was performed first, and then we decided to deploy at the collapsed site a 32-mm diameter, 40-mm long proximal cuff (Excluder) through the endoprosthesis. The cuff was ballooned after deployment. Bilateral limb thrombectomy with a Fogarty catheter was performed, restoring blood flow to the femoral arteries. Movement of the iliac limbs during the passage of the Fogarty catheter was not noted. Postoperatively, the patient’s sensory and motor examination and pulses were normal. An abdominal CT scan at postoperative day 3 showed restoration of the shape of the endograft and blood flow through the limbs with remnant thrombus. There was still a small endoleak (Fig, d). CT angiography performed 6 months and 12 months after the secondary procedure showed a normal endograft lumen, without any signs of endoleak or migration and no residual thrombus. During follow-up, the patient had palpable peripheral pulses. Endograft collapse is a rare complication reported to occur mainly in thoracic aortic grafts. Factors predisposing to graft collapse in the thoracic aorta include excessive oversizing, tight aortic arch diameter, and poor wall apposition of the graft (1). Most cases of thoracic endograft collapse involved the Gore TAG endoprosthesis. Possibly the mechanical properties of the particular endograft and its packaging and release mechanism predispose to material infolding under specific conditions. This complication is extremely rare in cases of EVAR of AAA, with only three reports in the literature (2– 4). In the first case, an Excluder endograft collapsed proximally 1 month after implantation. It was discovered incidentally on the 1-month follow-up CT scan. No endoleak was shown because the examination was performed without intravenous contrast enhancement. The patient was asymptomatic (2). Stent graft collapse was treated endovascularly with cuff implantation and balloon dilation (2). In the second report, an AneuRx endograft (Medtronic, Inc, Minneapolis, Minnesota) collapsed 9.5 years after implantation because of distal migration. It was discovered incidentally and treated with open conversion (3). In the third case, an Endologix Powerlink endograft (Endologix, Inc, Irvine, California) collapsed 1– 6 months after implantation because of “bird’s beak” effect. The patient was asymptomatic and was treated endovascularly with thoracic endograft and bare stent deployment (4). Regarding our patient, possible causes that might have led to this complication include the angulation of the proximal neck and stent graft oversizing. Because of the reverse
Orlacchio et al 䡲 JVIR
taper configuration of the infrarenal neck with a proximal diameter of 25 mm and distal diameter of 29 mm, a 31-mm endograft was used; this resulted in 24% oversizing in the proximal part of the neck, greater than the maximum suggested by the graft manufacturer. Oversizing might have led to perimeter folding and insufficient apposition of the endograft to the aortic wall. Endograft collapse is a rare complication of EVAR of AAA. It is a result of proximal neck angulation, excessive oversizing, and mechanical properties of the endograft. EVAR of stent graft collapse seems to be a feasible solution.
REFERENCES 1. Muhs BE, Balm R, White GH, Verhagen HJ. Anatomic factors associated with acute endograft collapse after Gore TAG treatment of thoracic aortic dissection or traumatic rupture. J Vasc Surg 2007;45:655– 661. 2. Matsagas MI, Papakostas JC, Arnaoutoglou HM, Michalis LK. Abdominal aortic endograft proximal collapse: successful repair by endovascular means. J Vasc Surg 2009;49:1316 –1318. 3. McCready RA, Bryant MA, Divelbiss JL, Phillips JL. Complete endograft collapse 9½ years following endograft repair of an abdominal aortic aneurysm. Vasc Endovasc Surg 2009;43:627– 630. 4. Loh SA, Jacobowiz GR, Rockman CB, Veith FJ, Cayne NS. Endovascular repair of a collapsed abdominal aortic endograft due to bird-beaking. J Vasc Surg 2010;52:813– 814.
Heat Sink during Radiofrequency Ablation of a Hepatocellular Carcinoma Abutting a Large Hepatic Cystic Lesion From: Antonio Orlacchio, MD Francesca Bolacchi, MD Claudia Salimbeni, MD Giovanni Simonetti, MD Department of Diagnostic Imaging and Interventional Radiology University Hospital “Tor Vergata” Viale Oxford, 81 00133 Rome, Italy
Editor: Hepatocellular carcinoma (HCC) is the most common primary hepatic tumor and one of the most common cancers worldwide. Surgical resection of hepatocellular carcinomas and liver transplant are considered to be the gold standard treatments. Radiofrequency ablation is a standard therapeutic option for patients who are not candidates for surgical resection (1). Technical end points vary among commercially available RF ablation systems. The LeVeen RF ablation system (Boston Scientific, Natick, Massachusetts) detects the electrical impedance (Ohm) of the hepatic tissue during the delivery of RF energy. Complete ablation of target tissue with this RF ablation system is achieved when tissue desiccation causes the increase of the impedance in the
None of the authors have identified a conflict of interest. DOI: 10.1016/j.jvir.2010.12.036
Sfyroeras et al 䡲 JVIR
Figure 2. (a) Three-dimensional CT reconstruction after surgery demonstrates the extraanatomic bypass between the ascending thoracic aorta and the supraceliac thoracoabdominal aorta (asterisk). Note the migrated plug (arrow) in the abdominal aorta at the level of the origin of the superior mesenteric artery (arrowhead). (b) Lateral flush aortography confirms the position of the migrated plug (arrow) in front of the origin of the superior mesenteric artery (arrowhead). (Available in color online at www.jvir.org.)
This particular case shows that migration of an initially correctly placed AMPLATZER device can occur especially if open surgery and mechanical manipulation around the occluded vessel are performed. Additionally, when a firstgeneration AMPLATZER plug is fully expanded, the spaces between the wire meshes can remain widely open and flow through the device without any symptoms might persist, especially in the pulsatile, high-pressure arterial system. In such a clinical condition, a conservative management is a valuable option analogous to the asymptomatic outcome of migrated bare stents into the pulmonary circulation (5); however, in potential similar cases with a migrated last-generation AMPLATZER plug, conservative management may be unadvisable because of the higher risk of early or late severe thromboembolic complications, as last-generation AMPLATZER plugs (6) have more and denser layers of wire meshes, making persistent flow over time less likely.
REFERENCES 1. Ratnam LA, Walkden RM, Munneke GJ, Morgan RA, Belli AM. The Amplatzer vascular plug for large vessel occlusion in the endovascular management of aneurysms. Eur Radiol 2008; 18:2006 –2012.
2. Achen SE, Miller MW, Gordon SG, Saunders AB, Roland RM, Drourr LT. Transarterial ductal occlusion with the Amplatzer vascular plug in 31 dogs. J Vet Intern Med 2008; 22:1348 –1352. 3. Dorenberg EJ, Hafsahl G, Andersen R, Krohg-Sorensen K. Recurrent rupture of a hypogastric aneurysm caused by spontaneous recanalization of an Amplatzer vascular plug. J Vasc Interv Radiol 2006; 17:1037– 1041. 4. Fidelman N, Gordon RL, Bloom AI, LaBerge JM, Kerlan RK Jr. Reperfusion of pulmonary arteriovenous malformations after successful embolotherapy with vascular plugs. J Vasc Interv Radiol 2008; 19:1246 – 1250. 5. Marcy PY, Magné N, Bruneton JN. Strecker stent migration to the pulmonary artery: long-term result of a “wait-and-see attitude.” Eur Radiol 2001; 11:767– 670. 6. Mordasini P, Szucs-Farkas Z, Do DD, Gralla J, Kettenbach J, Hoppe H. Use of a latest-generation vascular plug for peripheral vascular embolization with use of a diagnostic catheter: preliminary clinical experience. J Vasc Interv Radiol 2010; 21:1185–1190.
Abdominal Endograft Collapse with Acute Bilateral Lower Limb Ischemia From: Giorgos S. Sfyroeras, MD, Dimitris Maras, MD, Vassileios Andrikopoulos, MD Department of Vascular Surgery Red Cross Hospital of Athens 15, Athinaidos str Voula, 16673, Athens, Greece
Volume 22 䡲 Number 4 䡲 April 䡲 2011
571
Figure. (a) A 68-year-old man was treated for a 5.0-cm infrarenal abdominal aortic aneurysm (AAA). The proximal neck had a reverse taper, 20 mm long, measuring 25 mm proximally and 29 mm distally. The anatomic configuration of the infrarenal aorta was characterized by an angulation of 45 degrees. (b,c) Abdominal computed tomography (CT) scan with intravenous contrast enhancement 15 days postoperatively when the patient was admitted with acute bilateral lower limb ischemia. There is an endoleak, collapse of the main body and the limbs of the endograft, and thrombosis. (d) Abdominal CT scan 3 days after the second operation shows restoration of the shape of the endograft and blood flow through the limbs with remnant thrombus. There is still a small endoleak.
Editor: Endovascular repair (EVAR) is a minimally invasive method for the treatment of abdominal aortic aneurysm (AAA). The technique has been associated with several endograft-related complications, however. Endograft proximal infolding, characterized as collapse, is a rare complication described predominately in thoracic aortic endografts. The institutional review board at the participating institution did not require approval for the conduct and preparation of this research report. An informed consent was obtained from the patient. None of the authors have identified a conflict of interest. DOI: 10.1016/j.jvir.2010.12.026
An active 68-year-old man with a medical history of coronary artery disease and hypertension was treated with EVAR for a 5.0-cm infrarenal asymptomatic AAA. The infrarenal neck had a reverse taper, 20 mm long, measuring 25 mm proximally and 29 mm distally, and an angulation of 45 degrees (Fig, a). Using a standard procedure, an endovascular bifurcated graft of 31 mm in main body diameter, 14 mm in limb diameter, and 17 cm in length was implanted (Excluder; W. L. Gore and Associates Inc, Flagstaff, Arizona). Balloon remodeling of the proximal and distal portions of the endograft and all overlapping sites was performed. Completion angiography revealed adequate graft apposition, with exclusion of the aneurysm sac and no signs of endoleak. Postoperatively, the patient had palpable pedal pulses. He had an uneventful recovery and was discharged on the 3rd postoperative day.
572 䡲 Letters to the Editor
He presented to the emergency department 15 days after surgery with bilateral lower extremity ischemia. All infrainguinal pulses were nonpalpable, and Doppler signals were absent in both feet. He had sensory loss in both feet, with impaired mobility. Abdominal computed tomography (CT) with intravenous administration of contrast agent revealed complete endograft collapse and an endoleak (Fig, b and c). The patient underwent bilateral femoral artery cutdowns under general anesthesia. After bilateral open femoral catheterization, two guide wires were passed to the thoracic aorta. Balloon remodeling was performed first, and then we decided to deploy at the collapsed site a 32-mm diameter, 40-mm long proximal cuff (Excluder) through the endoprosthesis. The cuff was ballooned after deployment. Bilateral limb thrombectomy with a Fogarty catheter was performed, restoring blood flow to the femoral arteries. Movement of the iliac limbs during the passage of the Fogarty catheter was not noted. Postoperatively, the patient’s sensory and motor examination and pulses were normal. An abdominal CT scan at postoperative day 3 showed restoration of the shape of the endograft and blood flow through the limbs with remnant thrombus. There was still a small endoleak (Fig, d). CT angiography performed 6 months and 12 months after the secondary procedure showed a normal endograft lumen, without any signs of endoleak or migration and no residual thrombus. During follow-up, the patient had palpable peripheral pulses. Endograft collapse is a rare complication reported to occur mainly in thoracic aortic grafts. Factors predisposing to graft collapse in the thoracic aorta include excessive oversizing, tight aortic arch diameter, and poor wall apposition of the graft (1). Most cases of thoracic endograft collapse involved the Gore TAG endoprosthesis. Possibly the mechanical properties of the particular endograft and its packaging and release mechanism predispose to material infolding under specific conditions. This complication is extremely rare in cases of EVAR of AAA, with only three reports in the literature (2– 4). In the first case, an Excluder endograft collapsed proximally 1 month after implantation. It was discovered incidentally on the 1-month follow-up CT scan. No endoleak was shown because the examination was performed without intravenous contrast enhancement. The patient was asymptomatic (2). Stent graft collapse was treated endovascularly with cuff implantation and balloon dilation (2). In the second report, an AneuRx endograft (Medtronic, Inc, Minneapolis, Minnesota) collapsed 9.5 years after implantation because of distal migration. It was discovered incidentally and treated with open conversion (3). In the third case, an Endologix Powerlink endograft (Endologix, Inc, Irvine, California) collapsed 1– 6 months after implantation because of “bird’s beak” effect. The patient was asymptomatic and was treated endovascularly with thoracic endograft and bare stent deployment (4). Regarding our patient, possible causes that might have led to this complication include the angulation of the proximal neck and stent graft oversizing. Because of the reverse
Orlacchio et al 䡲 JVIR
taper configuration of the infrarenal neck with a proximal diameter of 25 mm and distal diameter of 29 mm, a 31-mm endograft was used; this resulted in 24% oversizing in the proximal part of the neck, greater than the maximum suggested by the graft manufacturer. Oversizing might have led to perimeter folding and insufficient apposition of the endograft to the aortic wall. Endograft collapse is a rare complication of EVAR of AAA. It is a result of proximal neck angulation, excessive oversizing, and mechanical properties of the endograft. EVAR of stent graft collapse seems to be a feasible solution.
REFERENCES 1. Muhs BE, Balm R, White GH, Verhagen HJ. Anatomic factors associated with acute endograft collapse after Gore TAG treatment of thoracic aortic dissection or traumatic rupture. J Vasc Surg 2007;45:655– 661. 2. Matsagas MI, Papakostas JC, Arnaoutoglou HM, Michalis LK. Abdominal aortic endograft proximal collapse: successful repair by endovascular means. J Vasc Surg 2009;49:1316 –1318. 3. McCready RA, Bryant MA, Divelbiss JL, Phillips JL. Complete endograft collapse 9½ years following endograft repair of an abdominal aortic aneurysm. Vasc Endovasc Surg 2009;43:627– 630. 4. Loh SA, Jacobowiz GR, Rockman CB, Veith FJ, Cayne NS. Endovascular repair of a collapsed abdominal aortic endograft due to bird-beaking. J Vasc Surg 2010;52:813– 814.
Heat Sink during Radiofrequency Ablation of a Hepatocellular Carcinoma Abutting a Large Hepatic Cystic Lesion From: Antonio Orlacchio, MD Francesca Bolacchi, MD Claudia Salimbeni, MD Giovanni Simonetti, MD Department of Diagnostic Imaging and Interventional Radiology University Hospital “Tor Vergata” Viale Oxford, 81 00133 Rome, Italy
Editor: Hepatocellular carcinoma (HCC) is the most common primary hepatic tumor and one of the most common cancers worldwide. Surgical resection of hepatocellular carcinomas and liver transplant are considered to be the gold standard treatments. Radiofrequency ablation is a standard therapeutic option for patients who are not candidates for surgical resection (1). Technical end points vary among commercially available RF ablation systems. The LeVeen RF ablation system (Boston Scientific, Natick, Massachusetts) detects the electrical impedance (Ohm) of the hepatic tissue during the delivery of RF energy. Complete ablation of target tissue with this RF ablation system is achieved when tissue desiccation causes the increase of the impedance in the
None of the authors have identified a conflict of interest. DOI: 10.1016/j.jvir.2010.12.036