While many of the pitfalls encountered when imaging the vascular system are common to other body ... more While many of the pitfalls encountered when imaging the vascular system are common to other body systems, specific challenges are posed by pulsatility and flow within the venous and arterial tree. A good knowledge of variant anatomy and artifacts is essential to the interpretation of all vascular studies and is of particular importance in the emergency setting where, for example, a confident exclusion of aortic dissection may save the patient from major and potentially life-threatening surgery. The need for appreciation of these variables, in particular the vascular territories, is essential, and important examples include the use of ultrasound imaging and magnetic resonance angiography in the delineation and quantification of carotid disease. Catheter angiography is now less frequently undertaken as a diagnostic modality and, as a result, may be more susceptible to errors related to angiographic technique and technical factors. Evaluation of the venous system presents particular ch...
Endovascular management of massive bilateral superior intercostal artery aneurysms following late... more Endovascular management of massive bilateral superior intercostal artery aneurysms following late surgical repair of juxtaductal coarctation of the aorta is described in a 40-year-old male patient. Both aneurysms were successfully treated by coil embolisation without the need for further surgical intervention.
A 70-year-old patient, who had previously undergone open surgical repair of an aneurysmal aberran... more A 70-year-old patient, who had previously undergone open surgical repair of an aneurysmal aberrant right subclavian artery (ARSA), presented with recurrent symptoms and reperfusion of the aneurysm at the site of proximal ligation. This was successfully treated by a staged endovascular procedure.
Journal of Vascular and Interventional Radiology, 2010
To determine immediate and long-term outcomes following catheter-directed intraarterial thromboly... more To determine immediate and long-term outcomes following catheter-directed intraarterial thrombolysis of occluded native arteries and infrainguinal vein grafts by using low-dose tissue-type plasminogen activator (tPA) in patients with lower limb ischemia. One hundred eleven intraarterial thrombolysis procedures were performed in 96 patients during the 2-year study period. Patient records were available for retrospective review in 85 thrombolytic procedures performed in 74 (77%) of the 96 patients. Forty-one native vessels (four iliac, 24 superficial/common femoral, and 13 popliteal/below-knee vessels), six iliac stents, and 38 infrainguinal vein grafts were treated by using a low-dose (0.5 mg/h recombinant tPA) catheter-directed thrombolytic regimen. Procedural success was based on angiographic and clinical outcomes, and the need for further reconstructive surgery or amputation was documented. Intraarterial thrombolysis was successful in 76%, was partially successful in 11%, and failed in 13%. Adjunctive angioplasty was performed in 33 of 55 patients (60%) with successful lysis, and immediate reconstructive surgery was required in five patients. There was one episode of puncture site bleeding and one gastrointestinal hemorrhage but no procedure-related deaths at 30 days. After a median follow-up of 6.5 years, 30 of the 55 patients (55%) who underwent successful thrombolysis required no further surgical intervention; however, further surgery was required in 45% of patients after a mean interval of 301 days (range, 2-1,344 days), including 10 (18%) amputations (six major and four minor). Low-dose intraarterial thrombolysis is safe and effective, delaying and dramatically reducing the need for surgical intervention in lower limb ischemia due to native vessel or infrainguinal graft occlusion.
Journal of Vascular and Interventional Radiology, 2011
This case report describes repair of a type I endoleak at the distal landing zone of a thoracic a... more This case report describes repair of a type I endoleak at the distal landing zone of a thoracic aortic stent graft by endovascular placement of a thoracoabdominal fenestrated stent graft (Cook, Brisbane, Australia). The fenestrated stent graft was interposed between a previous abdominal aortic aneurysm (AAA) Gelsoft tube graft (Sulzer Vascutek Ltd, Inchinnan, United Kingdom) and two overlapping Zenith thoracic endografts (Cook Inc, Bloomington, Indiana). Placement was made more complex because the distal thoracic endograft had rotated into a horizontal position. At 3-year clinical and computed tomography (CT) follow-up, continued clinical and radiologic success was shown with no further intervention required.
Journal of Vascular and Interventional Radiology, 2011
To assess the feasibility, complications, and long-term success of embolization of pulmonary arte... more To assess the feasibility, complications, and long-term success of embolization of pulmonary arteriovenous malformations (PAVMs) with the AMPLATZER Vascular Plug and AMPLATZER Vascular Plug II. The study included 15 consecutive patients (19 embolization episodes) who had embolization of PAVMs between April 2004 and April 2009 with an AMPLATZER Vascular Plug or AMPLATZER Vascular Plug II. There were 4 men and 11 women, with a mean age of 56 years (range 24-74 years). A prospective database of all cases of PAVM embolization is kept in the department. Patient history, detailed procedural records, and clinical and radiological follow-up were reviewed. Among the 19 PAVMs, an AMPLATZER Vascular Plug was deployed in 11, and an AMPLATZER Vascular Plug II was deployed in 8. The technical success of the procedure was 100% for PAVM occlusion; 30-day mortality in the group was zero. Successful radiologic follow-up with the AMPLATZER Vascular Plug was a mean of 28 months (range 0-60 months) and with the AMPLATZER Vascular Plug II was a mean of 18 months (range 12-36 months). There was one recanalization of an AMPLATZER Vascular Plug 36 months after embolization giving an annual event rate of 0.03 recanalizations per AMPLATZER Vascular Plug or AMPLATZER Vascular Plug II per year. There were no major complications. Clinically, there was one (1 of 18 cases [5%]) immediate complication of chest pain that resolved in 24 hours with simple analgesia. There were no early or late clinical complications. The treatment of PAVM with either an AMPLATZER Vascular Plug or an AMPLATZER Vascular Plug II is safe and effective and associated with a low reintervention rate. Further follow-up is ongoing to ensure continued occlusion of treated PAVMs.
Journal of Vascular and Interventional Radiology, 1997
The results of treating malignant superior vena cava obstruction by means of percutaneous self-ex... more The results of treating malignant superior vena cava obstruction by means of percutaneous self-expanding stent insertion or by means of radiation therapy were compared. Seventy-six patients with malignant superior vena cava obstruction who were treated by stent insertion were studied prospectively and 25 patients who were treated by radiation therapy were studied retrospectively. A superior vena cava obstruction score was devised to measure treatment effectiveness. Speed of symptom relief and complications were recorded. End points in the study were recurrent obstruction or death. Asymptomatic survival times were compared by log rank and Mann Whitney tests of significance, as well as Kaplan-Meier analysis. A subgroup of 26 patients who were treated by stent placement only were compared with the radiation therapy group and analyzed separately. There were seven complications in the overall stent group, one in the stent-only group, and 25 in the radiation therapy group. Stent insertion provided faster relief of symptoms and significantly greater improvement in the superior vena cava obstruction score than radiation therapy (P < .001, Mann-Whitney U test). A Kaplan-Meier analysis of asymptomatic survival demonstrated that significantly fewer patients in the overall and stent-only groups developed recurrent symptoms (P = .0005 and .001, respectively, log rank test). This study suggests that percutaneous stent insertion in malignant superior vena cava obstruction fulfills the requirements of a palliative procedure significantly better than radiation therapy and that it should be the procedure of first choice.
Journal of Medical Imaging and Radiation Oncology, 2010
There is limited long-term prospective data on the use of endovascular techniques and the use of ... more There is limited long-term prospective data on the use of endovascular techniques and the use of thrombolysis in malfunctioning autologous haemodialysis fistulas. Prospective assessment of clinical outcomes following angioplasty with or without low-dose thrombolysis was undertaken in patients who presented with malfunctioning autologous haemodialysis fistulas. Consecutive patients referred to our department over a 6-month period were included. Twenty-five patients underwent percutaneous intervention by angioplasty alone (n = 14), angioplasty and stent (n = 2), thrombolysis alone (n = 2), angioplasty, thrombolysis and stent (n = 2) and angioplasty and thrombolysis (n = 5). Patients underwent clinical follow-up and were reviewed at 6, 12, 18 and 24 months to determine fistula status. Thirty-day mortality in the group was two patients. Statistical analysis was performed with Mann-Whitney, chi-squared and Kruskal-Wallis tests. Kaplan-Meier curves were constructed to compare primary and secondary patency rates. Technical success and initial clinical success rates were 88% and 76%, respectively. Primary and secondary clinical success rates at 6 months were 68% and 72%, at 12 months were 68% and 72%, at 18 months were 60% and 68% and at 24 months were 52% and 68%, respectively. There were no major complications following interventional procedures. There were four minor complications. After an initially successful procedure, five patients required subsequent intervention during the follow-up period. The overall fistula event rate was very low (five per 600 patient months or 0.0996 per access year) with a fistula loss rate of 0.14 per access year. Our results confirm that excellent clinical results can be achieved by percutaneous endovascular treatment in malfunctioning autologous fistulas, justifying their continued use as first-line management.
The rapid imaging evaluation and diagnosis of rupture and impending rupture of an abdominal aorti... more The rapid imaging evaluation and diagnosis of rupture and impending rupture of an abdominal aortic aneurysm (AAA) is imperative. This article describes the imaging findings of rupture, impending rupture, and other abdominal aortic abnormalities. It is important not to overlook AAA as the consequences can be life threatening. All patients who had open or endovascular repair of AAA rupture over 6 years (2008-2012) were identified from our departmental database. The computed tomography (CT) images of 99 patients were reviewed for relevant findings. The mean age of the patients was 65 years and 85% were male.
Aortic penetrating atherosclerotic ulcer (PAU) is a relatively common incidental finding on thora... more Aortic penetrating atherosclerotic ulcer (PAU) is a relatively common incidental finding on thoracic computed tomography (CT) examinations. This is likely to relate to the steady increase in the number of CT examinations performed and also due, in part, to the increasing age of the general population. There is as yet no consensus on the management of incidental PAUs in asymptomatic patients. This article aims to review the literature and discuss the natural history, prognosis, and management of incidental PAU.
Acute aortic syndrome (AAS) is a constellation of potentially life-threatening acute aortic disea... more Acute aortic syndrome (AAS) is a constellation of potentially life-threatening acute aortic diseases. The spectrum includes penetrating atherosclerotic ulcer, intramural haematoma, dissection, and unstable thoracic aneurysm. AAS cannot be reliably diagnosed clinically and multidetector computed tomography (MDCT) has revolutionized the diagnosis and management of this group of conditions in the acute setting due to its availability, speed, and accuracy. The purpose of this review is to illustrate key MDCT findings of AAS. Imaging techniques, radiological findings, and common pitfalls are also discussed.
We describe the unusual case of a 71-year-old male with a history of deep vein thrombosis and rec... more We describe the unusual case of a 71-year-old male with a history of deep vein thrombosis and recurrent multiple pulmonary embolism (PE) despite adequate anticoagulation. Computed tomography (CT) and brachiocephalic venography revealed a left-sided superior vena cava. We describe successful placement of an inferior vena cava filter via a left-sided superior vena cava.
Magnetic resonance angiography (MRA) has become an established imaging modality in the management... more Magnetic resonance angiography (MRA) has become an established imaging modality in the management of lower-limb arterial disease, with emerging roles in treatment planning and follow-up. Contrast-enhanced MRA is now the most widely used technique with clinically acceptable results in the majority of patients. Difficulties in imaging and image interpretation are recognised in certain subgroups, including patients with critical limb ischaemia as well as patients with stents. Although newer contrast agents and refined imaging protocols may offer some solutions to these problems, this optimism is balanced by concerns about the toxicity of certain gadolinium chelates. Further development of interventional MRA remains one of the most significant challenges in the development of magnetic resonance imaging-guided peripheral vascular intervention. The status of MRA in managing patients with lower-limb arterial disease in current clinical practice is reviewed.
Carotid stump syndrome is one of the recognised causes of recurrent ipsilateral cerebrovascular e... more Carotid stump syndrome is one of the recognised causes of recurrent ipsilateral cerebrovascular events after occlusion of the internal carotid artery. It is believed that microemboli arising from the stump of the occluded internal carotid artery or the ipsilateral external carotid artery can pass into the middle cerebral artery circulation as a result of patent external carotid-internal carotid anastomotic channels. Different pathophysiologic causes of this syndrome and endovascular options for treatment are discussed.
While many of the pitfalls encountered when imaging the vascular system are common to other body ... more While many of the pitfalls encountered when imaging the vascular system are common to other body systems, specific challenges are posed by pulsatility and flow within the venous and arterial tree. A good knowledge of variant anatomy and artifacts is essential to the interpretation of all vascular studies and is of particular importance in the emergency setting where, for example, a confident exclusion of aortic dissection may save the patient from major and potentially life-threatening surgery. The need for appreciation of these variables, in particular the vascular territories, is essential, and important examples include the use of ultrasound imaging and magnetic resonance angiography in the delineation and quantification of carotid disease. Catheter angiography is now less frequently undertaken as a diagnostic modality and, as a result, may be more susceptible to errors related to angiographic technique and technical factors. Evaluation of the venous system presents particular ch...
Endovascular management of massive bilateral superior intercostal artery aneurysms following late... more Endovascular management of massive bilateral superior intercostal artery aneurysms following late surgical repair of juxtaductal coarctation of the aorta is described in a 40-year-old male patient. Both aneurysms were successfully treated by coil embolisation without the need for further surgical intervention.
A 70-year-old patient, who had previously undergone open surgical repair of an aneurysmal aberran... more A 70-year-old patient, who had previously undergone open surgical repair of an aneurysmal aberrant right subclavian artery (ARSA), presented with recurrent symptoms and reperfusion of the aneurysm at the site of proximal ligation. This was successfully treated by a staged endovascular procedure.
Journal of Vascular and Interventional Radiology, 2010
To determine immediate and long-term outcomes following catheter-directed intraarterial thromboly... more To determine immediate and long-term outcomes following catheter-directed intraarterial thrombolysis of occluded native arteries and infrainguinal vein grafts by using low-dose tissue-type plasminogen activator (tPA) in patients with lower limb ischemia. One hundred eleven intraarterial thrombolysis procedures were performed in 96 patients during the 2-year study period. Patient records were available for retrospective review in 85 thrombolytic procedures performed in 74 (77%) of the 96 patients. Forty-one native vessels (four iliac, 24 superficial/common femoral, and 13 popliteal/below-knee vessels), six iliac stents, and 38 infrainguinal vein grafts were treated by using a low-dose (0.5 mg/h recombinant tPA) catheter-directed thrombolytic regimen. Procedural success was based on angiographic and clinical outcomes, and the need for further reconstructive surgery or amputation was documented. Intraarterial thrombolysis was successful in 76%, was partially successful in 11%, and failed in 13%. Adjunctive angioplasty was performed in 33 of 55 patients (60%) with successful lysis, and immediate reconstructive surgery was required in five patients. There was one episode of puncture site bleeding and one gastrointestinal hemorrhage but no procedure-related deaths at 30 days. After a median follow-up of 6.5 years, 30 of the 55 patients (55%) who underwent successful thrombolysis required no further surgical intervention; however, further surgery was required in 45% of patients after a mean interval of 301 days (range, 2-1,344 days), including 10 (18%) amputations (six major and four minor). Low-dose intraarterial thrombolysis is safe and effective, delaying and dramatically reducing the need for surgical intervention in lower limb ischemia due to native vessel or infrainguinal graft occlusion.
Journal of Vascular and Interventional Radiology, 2011
This case report describes repair of a type I endoleak at the distal landing zone of a thoracic a... more This case report describes repair of a type I endoleak at the distal landing zone of a thoracic aortic stent graft by endovascular placement of a thoracoabdominal fenestrated stent graft (Cook, Brisbane, Australia). The fenestrated stent graft was interposed between a previous abdominal aortic aneurysm (AAA) Gelsoft tube graft (Sulzer Vascutek Ltd, Inchinnan, United Kingdom) and two overlapping Zenith thoracic endografts (Cook Inc, Bloomington, Indiana). Placement was made more complex because the distal thoracic endograft had rotated into a horizontal position. At 3-year clinical and computed tomography (CT) follow-up, continued clinical and radiologic success was shown with no further intervention required.
Journal of Vascular and Interventional Radiology, 2011
To assess the feasibility, complications, and long-term success of embolization of pulmonary arte... more To assess the feasibility, complications, and long-term success of embolization of pulmonary arteriovenous malformations (PAVMs) with the AMPLATZER Vascular Plug and AMPLATZER Vascular Plug II. The study included 15 consecutive patients (19 embolization episodes) who had embolization of PAVMs between April 2004 and April 2009 with an AMPLATZER Vascular Plug or AMPLATZER Vascular Plug II. There were 4 men and 11 women, with a mean age of 56 years (range 24-74 years). A prospective database of all cases of PAVM embolization is kept in the department. Patient history, detailed procedural records, and clinical and radiological follow-up were reviewed. Among the 19 PAVMs, an AMPLATZER Vascular Plug was deployed in 11, and an AMPLATZER Vascular Plug II was deployed in 8. The technical success of the procedure was 100% for PAVM occlusion; 30-day mortality in the group was zero. Successful radiologic follow-up with the AMPLATZER Vascular Plug was a mean of 28 months (range 0-60 months) and with the AMPLATZER Vascular Plug II was a mean of 18 months (range 12-36 months). There was one recanalization of an AMPLATZER Vascular Plug 36 months after embolization giving an annual event rate of 0.03 recanalizations per AMPLATZER Vascular Plug or AMPLATZER Vascular Plug II per year. There were no major complications. Clinically, there was one (1 of 18 cases [5%]) immediate complication of chest pain that resolved in 24 hours with simple analgesia. There were no early or late clinical complications. The treatment of PAVM with either an AMPLATZER Vascular Plug or an AMPLATZER Vascular Plug II is safe and effective and associated with a low reintervention rate. Further follow-up is ongoing to ensure continued occlusion of treated PAVMs.
Journal of Vascular and Interventional Radiology, 1997
The results of treating malignant superior vena cava obstruction by means of percutaneous self-ex... more The results of treating malignant superior vena cava obstruction by means of percutaneous self-expanding stent insertion or by means of radiation therapy were compared. Seventy-six patients with malignant superior vena cava obstruction who were treated by stent insertion were studied prospectively and 25 patients who were treated by radiation therapy were studied retrospectively. A superior vena cava obstruction score was devised to measure treatment effectiveness. Speed of symptom relief and complications were recorded. End points in the study were recurrent obstruction or death. Asymptomatic survival times were compared by log rank and Mann Whitney tests of significance, as well as Kaplan-Meier analysis. A subgroup of 26 patients who were treated by stent placement only were compared with the radiation therapy group and analyzed separately. There were seven complications in the overall stent group, one in the stent-only group, and 25 in the radiation therapy group. Stent insertion provided faster relief of symptoms and significantly greater improvement in the superior vena cava obstruction score than radiation therapy (P < .001, Mann-Whitney U test). A Kaplan-Meier analysis of asymptomatic survival demonstrated that significantly fewer patients in the overall and stent-only groups developed recurrent symptoms (P = .0005 and .001, respectively, log rank test). This study suggests that percutaneous stent insertion in malignant superior vena cava obstruction fulfills the requirements of a palliative procedure significantly better than radiation therapy and that it should be the procedure of first choice.
Journal of Medical Imaging and Radiation Oncology, 2010
There is limited long-term prospective data on the use of endovascular techniques and the use of ... more There is limited long-term prospective data on the use of endovascular techniques and the use of thrombolysis in malfunctioning autologous haemodialysis fistulas. Prospective assessment of clinical outcomes following angioplasty with or without low-dose thrombolysis was undertaken in patients who presented with malfunctioning autologous haemodialysis fistulas. Consecutive patients referred to our department over a 6-month period were included. Twenty-five patients underwent percutaneous intervention by angioplasty alone (n = 14), angioplasty and stent (n = 2), thrombolysis alone (n = 2), angioplasty, thrombolysis and stent (n = 2) and angioplasty and thrombolysis (n = 5). Patients underwent clinical follow-up and were reviewed at 6, 12, 18 and 24 months to determine fistula status. Thirty-day mortality in the group was two patients. Statistical analysis was performed with Mann-Whitney, chi-squared and Kruskal-Wallis tests. Kaplan-Meier curves were constructed to compare primary and secondary patency rates. Technical success and initial clinical success rates were 88% and 76%, respectively. Primary and secondary clinical success rates at 6 months were 68% and 72%, at 12 months were 68% and 72%, at 18 months were 60% and 68% and at 24 months were 52% and 68%, respectively. There were no major complications following interventional procedures. There were four minor complications. After an initially successful procedure, five patients required subsequent intervention during the follow-up period. The overall fistula event rate was very low (five per 600 patient months or 0.0996 per access year) with a fistula loss rate of 0.14 per access year. Our results confirm that excellent clinical results can be achieved by percutaneous endovascular treatment in malfunctioning autologous fistulas, justifying their continued use as first-line management.
The rapid imaging evaluation and diagnosis of rupture and impending rupture of an abdominal aorti... more The rapid imaging evaluation and diagnosis of rupture and impending rupture of an abdominal aortic aneurysm (AAA) is imperative. This article describes the imaging findings of rupture, impending rupture, and other abdominal aortic abnormalities. It is important not to overlook AAA as the consequences can be life threatening. All patients who had open or endovascular repair of AAA rupture over 6 years (2008-2012) were identified from our departmental database. The computed tomography (CT) images of 99 patients were reviewed for relevant findings. The mean age of the patients was 65 years and 85% were male.
Aortic penetrating atherosclerotic ulcer (PAU) is a relatively common incidental finding on thora... more Aortic penetrating atherosclerotic ulcer (PAU) is a relatively common incidental finding on thoracic computed tomography (CT) examinations. This is likely to relate to the steady increase in the number of CT examinations performed and also due, in part, to the increasing age of the general population. There is as yet no consensus on the management of incidental PAUs in asymptomatic patients. This article aims to review the literature and discuss the natural history, prognosis, and management of incidental PAU.
Acute aortic syndrome (AAS) is a constellation of potentially life-threatening acute aortic disea... more Acute aortic syndrome (AAS) is a constellation of potentially life-threatening acute aortic diseases. The spectrum includes penetrating atherosclerotic ulcer, intramural haematoma, dissection, and unstable thoracic aneurysm. AAS cannot be reliably diagnosed clinically and multidetector computed tomography (MDCT) has revolutionized the diagnosis and management of this group of conditions in the acute setting due to its availability, speed, and accuracy. The purpose of this review is to illustrate key MDCT findings of AAS. Imaging techniques, radiological findings, and common pitfalls are also discussed.
We describe the unusual case of a 71-year-old male with a history of deep vein thrombosis and rec... more We describe the unusual case of a 71-year-old male with a history of deep vein thrombosis and recurrent multiple pulmonary embolism (PE) despite adequate anticoagulation. Computed tomography (CT) and brachiocephalic venography revealed a left-sided superior vena cava. We describe successful placement of an inferior vena cava filter via a left-sided superior vena cava.
Magnetic resonance angiography (MRA) has become an established imaging modality in the management... more Magnetic resonance angiography (MRA) has become an established imaging modality in the management of lower-limb arterial disease, with emerging roles in treatment planning and follow-up. Contrast-enhanced MRA is now the most widely used technique with clinically acceptable results in the majority of patients. Difficulties in imaging and image interpretation are recognised in certain subgroups, including patients with critical limb ischaemia as well as patients with stents. Although newer contrast agents and refined imaging protocols may offer some solutions to these problems, this optimism is balanced by concerns about the toxicity of certain gadolinium chelates. Further development of interventional MRA remains one of the most significant challenges in the development of magnetic resonance imaging-guided peripheral vascular intervention. The status of MRA in managing patients with lower-limb arterial disease in current clinical practice is reviewed.
Carotid stump syndrome is one of the recognised causes of recurrent ipsilateral cerebrovascular e... more Carotid stump syndrome is one of the recognised causes of recurrent ipsilateral cerebrovascular events after occlusion of the internal carotid artery. It is believed that microemboli arising from the stump of the occluded internal carotid artery or the ipsilateral external carotid artery can pass into the middle cerebral artery circulation as a result of patent external carotid-internal carotid anastomotic channels. Different pathophysiologic causes of this syndrome and endovascular options for treatment are discussed.
Uploads
Papers by Duncan Ettles