K.E.M. Radiology
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Interventional Case Record
Interventional Case Record
Endovascular management in a case of infrarenal abdominal aortic aneurysm
Endovascular management in a case of infrarenal abdominal aortic aneurysm
Contributed by : Shubhankar Deshpande
Contributed by : Shubhankar Deshpande
Introduction:
Introduction:
Abdominal aortic aneurysm (AAA) can be defined as an abnormal, progressive dilatation of the abdominal aorta, carrying a substantial risk for fatal aneurysmal rupture(1). While aneurysms can occur along the entire length of the aorta, the infrarenal location is the most common. The indication for repair includes either symptomatic aneurysms or aneurysms with a diameter greater than 5.5 cm(2,3). Treatment options for the repair of infrarenal aortic aneurysms are open surgical repair (OSR) and endovascular aneurysm repair (EVAR). Currently, EVAR is the primary treatment method for the repair of infrarenal aortic aneurysms due to improved short-term morbidity and mortality outcomes (4).
Abdominal aortic aneurysm (AAA) can be defined as an abnormal, progressive dilatation of the abdominal aorta, carrying a substantial risk for fatal aneurysmal rupture(1). While aneurysms can occur along the entire length of the aorta, the infrarenal location is the most common. The indication for repair includes either symptomatic aneurysms or aneurysms with a diameter greater than 5.5 cm(2,3). Treatment options for the repair of infrarenal aortic aneurysms are open surgical repair (OSR) and endovascular aneurysm repair (EVAR). Currently, EVAR is the primary treatment method for the repair of infrarenal aortic aneurysms due to improved short-term morbidity and mortality outcomes (4).
Case presentation:
Case presentation:
A 57-year-old female presented with dull aching abdominal pain in the umbilical region since 15 days. She was a known hypertensive with chronic kidney disease, on antihypertensive medications. There was no history of any past medical admission. Clinical examination of her respiratory and cardiovascular system was normal. On abdominal examination, a pulsatile mass was palpable in umbilical region.
A 57-year-old female presented with dull aching abdominal pain in the umbilical region since 15 days. She was a known hypertensive with chronic kidney disease, on antihypertensive medications. There was no history of any past medical admission. Clinical examination of her respiratory and cardiovascular system was normal. On abdominal examination, a pulsatile mass was palpable in umbilical region.
USG abdomen showed a tortuous fusiform dilatation of the infrarenal abdominal aorta with aliasing colour flow on doppler. Computed tomographic (CT) aortogram demonstrated a fusiform aneurysm of the infrarenal abdominal aorta measuring 5.7 x5.2 x6.7 cm in anteroposterior, transverse and craniocaudal dimensions respectively(Figure 1).
USG abdomen showed a tortuous fusiform dilatation of the infrarenal abdominal aorta with aliasing colour flow on doppler. Computed tomographic (CT) aortogram demonstrated a fusiform aneurysm of the infrarenal abdominal aorta measuring 5.7 x5.2 x6.7 cm in anteroposterior, transverse and craniocaudal dimensions respectively(Figure 1).
Figure 1: CT aortogram shows the maximum diameter of the infrarenal abdominal aortic aneurysm(AAA), measuring 5.7 cm, with peripheral thrombosis.
The distance from the lowermost(right) renal artery was 3.1 cm and the infrarenal angle was 130 degrees. The aneurysm extended caudally to the aortic bifurcation, with normal sized iliac arteries(Video 1). Endovascular repair was planned for the patient(EVAR)
The distance from the lowermost(right) renal artery was 3.1 cm and the infrarenal angle was 130 degrees. The aneurysm extended caudally to the aortic bifurcation, with normal sized iliac arteries(Video 1). Endovascular repair was planned for the patient(EVAR)
Video1 edited.mp4Video 1: CT aortogram in axial sections demonstrates the entire extent of the infrarenal AAA.
Stent Graft Deployment:
Stent Graft Deployment:
Bilateral common femoral artery arteriotomies were performed. A 5F sheath was placed in the right CFA, through which a Lunderquist wire was positioned in the descending thoracic aorta using 5F headhunter catheter. A 5F pigtail catheter was placed through the left CFA access, for angiographic shoots during deployment of the stent graft(Video 2).
Bilateral common femoral artery arteriotomies were performed. A 5F sheath was placed in the right CFA, through which a Lunderquist wire was positioned in the descending thoracic aorta using 5F headhunter catheter. A 5F pigtail catheter was placed through the left CFA access, for angiographic shoots during deployment of the stent graft(Video 2).
VIDEO2edited.mp4Video 2: Pigtail angiogram placed in the upper abdominal aorta showing the infrarenal AAA.
Based on preoperative measurements and aortic morphology, the main body stent graft of length 16 cm, proximal diameter 22 mm, distal diameter 10 mm (Ankura TAA, Lifetech) was selected and advanced over the Lunderquist wire. The covered segment of stent graft was deployed in the infrarenal aorta after precise confirmation of the location of bilateral renal orifices; the cranial end of the covered portion of the main body stent-graft was placed 1 cm below the lower-most(right) renal artery orifice.
Based on preoperative measurements and aortic morphology, the main body stent graft of length 16 cm, proximal diameter 22 mm, distal diameter 10 mm (Ankura TAA, Lifetech) was selected and advanced over the Lunderquist wire. The covered segment of stent graft was deployed in the infrarenal aorta after precise confirmation of the location of bilateral renal orifices; the cranial end of the covered portion of the main body stent-graft was placed 1 cm below the lower-most(right) renal artery orifice.
Cannulation of the gate of the main body stent-graft, which was located at the origin of the left common iliac artery, was performed through the access taken from left CFA. Over a Lunderquist wire, stent graft of diameter 14 mm and length 120 mm was deployed up to the origin of left internal iliac artery(Video 3).
Cannulation of the gate of the main body stent-graft, which was located at the origin of the left common iliac artery, was performed through the access taken from left CFA. Over a Lunderquist wire, stent graft of diameter 14 mm and length 120 mm was deployed up to the origin of left internal iliac artery(Video 3).
Vid3.mp4Video 3: After cannulation of contralateral gate, deployment of left common iliac artery stent-graft was performed over a Lunderquist wire.
Another stent graft of diameter 14 mm and length 100 mm was deployed in the right common iliac artery(Video 4)
Another stent graft of diameter 14 mm and length 100 mm was deployed in the right common iliac artery(Video 4)
Vid4.mp4Video 4: Deployment of right common iliac artery stent-graft was performed over a Lunderquist wire.
Completion Angiography: Post-stent graft deployment, completion angiography was performed to confirm proper graft position, assess endoleaks, and verify exclusion of the aneurysm. It showed adequate placement of the stent graft(Video 5)
Completion Angiography: Post-stent graft deployment, completion angiography was performed to confirm proper graft position, assess endoleaks, and verify exclusion of the aneurysm. It showed adequate placement of the stent graft(Video 5)
vidEO5.mp4Video 5: Angiogram performed via pigtail catheter after deployment of main body stent graft and bilateral iliac arterial stent-grafts, showing exclusion of aneurysm from circulation without any endoleak.
Discussion:
Discussion:
Abdominal aortic aneurysms remain one of the leading causes of morbidity and mortality in patients over the age of 65(5). Despite increased evidence supporting the utility of screening for AAAs in high risk patient populations, the most common way that these are detected is incidentally while undergoing an ultrasound, radiography of the back or abdomen, CT scan, or MRI for the evaluation of another problem. Endovascular repair has become the preferred therapy for the management of infrarenal AAAs and accounts for up to 80% of repairs in some institutions due to decreased perioperative morbidity and mortality as well as faster initial recovery times(6).
Abdominal aortic aneurysms remain one of the leading causes of morbidity and mortality in patients over the age of 65(5). Despite increased evidence supporting the utility of screening for AAAs in high risk patient populations, the most common way that these are detected is incidentally while undergoing an ultrasound, radiography of the back or abdomen, CT scan, or MRI for the evaluation of another problem. Endovascular repair has become the preferred therapy for the management of infrarenal AAAs and accounts for up to 80% of repairs in some institutions due to decreased perioperative morbidity and mortality as well as faster initial recovery times(6).
The decision to treat AAA is based on patient's clinical presentation and aneurysm status. According to the society for vascular surgery practice guidelines, anatomical treatment such as open surgical repair or EVAR is indicated with strong recommendation level in case of ruptured AAA, symptomatic unruptured AAA, increasing size of the aneurysm on serial documentation and large AAA > 5.5 cm in diameter.
The decision to treat AAA is based on patient's clinical presentation and aneurysm status. According to the society for vascular surgery practice guidelines, anatomical treatment such as open surgical repair or EVAR is indicated with strong recommendation level in case of ruptured AAA, symptomatic unruptured AAA, increasing size of the aneurysm on serial documentation and large AAA > 5.5 cm in diameter.
Anatomical suitability is an essential factor for successful EVAR. Some of the anatomical considerations include:
Anatomical suitability is an essential factor for successful EVAR. Some of the anatomical considerations include:
1)Aortic Neck Anatomy: The length, angle, presence of calcification or thrombus, and the diameter and shape of aortic neck should be carefully considered. The aortic neck length is defined as the distance from the lowest renal artery to the top of the aneurysm.
1)Aortic Neck Anatomy: The length, angle, presence of calcification or thrombus, and the diameter and shape of aortic neck should be carefully considered. The aortic neck length is defined as the distance from the lowest renal artery to the top of the aneurysm.
2)Anatomy of Aneurysm: The aneurysmal angle, presence of intraluminal mural thrombus, and branching vessels from the aneurysm have to be taken into consideration
2)Anatomy of Aneurysm: The aneurysmal angle, presence of intraluminal mural thrombus, and branching vessels from the aneurysm have to be taken into consideration
3)Access Vessels: The tortuosity and diameter of the iliac artery, presence of atherosclerotic lesion along the iliac artery, and length of the common iliac artery should be considered for adequate EVAR(7)
3)Access Vessels: The tortuosity and diameter of the iliac artery, presence of atherosclerotic lesion along the iliac artery, and length of the common iliac artery should be considered for adequate EVAR(7)
The stent-graft is made up of a self-expanding Nitinol stent that uses radial force for fixation, and a polytetrafluoroethylene(PTFE) fabric that creates a new conduit for blood flow and prohibits the blood from entering the aneurysm sac. Stent grafts used for infrarenal AAA are bifurcated, giving them the ability for a limb extension to extent the graft inferiorly.(aortic stent graft image)
The stent-graft is made up of a self-expanding Nitinol stent that uses radial force for fixation, and a polytetrafluoroethylene(PTFE) fabric that creates a new conduit for blood flow and prohibits the blood from entering the aneurysm sac. Stent grafts used for infrarenal AAA are bifurcated, giving them the ability for a limb extension to extent the graft inferiorly.(aortic stent graft image)
Complications such as stent-graft infection, pelvic ischemia, pseudoaneurysm and graft occlusion can occur with both EVAR and open repair. Complications more commonly seen in EVAR include post-implantation syndrome, limb thrombosis, migration of stent-graft, enlargement of sac and rupture, and endoleaks(8).
Complications such as stent-graft infection, pelvic ischemia, pseudoaneurysm and graft occlusion can occur with both EVAR and open repair. Complications more commonly seen in EVAR include post-implantation syndrome, limb thrombosis, migration of stent-graft, enlargement of sac and rupture, and endoleaks(8).
Endoleak is defined as the persistent perigraft blood flow within the aneurysm sac(9).
Endoleak is defined as the persistent perigraft blood flow within the aneurysm sac(9).
Type I- due to poor apposition at proximal or distal landing zones.
Type I- due to poor apposition at proximal or distal landing zones.
Type II- Due to retrograde flow into the aneurysm sac via branch vessels eg. intercostal arteries, IMA, lumbar arteries etc.
Type II- Due to retrograde flow into the aneurysm sac via branch vessels eg. intercostal arteries, IMA, lumbar arteries etc.
Type III- due to poor overlap between two grafts
Type III- due to poor overlap between two grafts
Type IV- due to porosity within the graft material
Type IV- due to porosity within the graft material
Type V- Endotension- expansion of the aneurysm sac when no leak is identified.
Type V- Endotension- expansion of the aneurysm sac when no leak is identified.
Type I and III require urgent management during the procedure itself.
Type I and III require urgent management during the procedure itself.
Patients require life-long imaging surveillance to monitor for endoleak, aneurysm expansion and for graft integrity. This is most commonly performed via CTA.
Patients require life-long imaging surveillance to monitor for endoleak, aneurysm expansion and for graft integrity. This is most commonly performed via CTA.
In conclusion, a safe and technically precise implantation requires management of anticoagulation, blood pressure regulation in general anesthesia. Modern endograft implantation involves highly technical resources, including guide wires or catheters(10). Beside patient selection, an optimal procedure planning, graft model choice and endovascular skills are mandatory aspects to prevent complications
In conclusion, a safe and technically precise implantation requires management of anticoagulation, blood pressure regulation in general anesthesia. Modern endograft implantation involves highly technical resources, including guide wires or catheters(10). Beside patient selection, an optimal procedure planning, graft model choice and endovascular skills are mandatory aspects to prevent complications
References:
References:
1. Holt P, Thompson MM. Abdominal aortic aneurysm, evaluation and decision making. In: Cronenwett JL, Johnston KW. editors. Rutherford’s vascular surgery. 8th ed. Philadelphia (PA): Elsevier Saunders, 2014:1999-2023.
1. Holt P, Thompson MM. Abdominal aortic aneurysm, evaluation and decision making. In: Cronenwett JL, Johnston KW. editors. Rutherford’s vascular surgery. 8th ed. Philadelphia (PA): Elsevier Saunders, 2014:1999-2023.
2. Kuivaniemi H, Elmore JR. Opportunities in abdominal aortic aneurysm research: epidemiology, genetics, and pathophysiology. Ann Vasc Surg 2012;26:862-70. 10.1016/j.avsg.2012.02.005
2. Kuivaniemi H, Elmore JR. Opportunities in abdominal aortic aneurysm research: epidemiology, genetics, and pathophysiology. Ann Vasc Surg 2012;26:862-70. 10.1016/j.avsg.2012.02.005
3. Holt P, Thompson MM. Abdominal aortic aneurysm, evaluation and decision making. In: Cronenwett JL, Johnston KW. editors. Rutherford’s vascular surgery. 8th ed. Philadelphia (PA): Elsevier Saunders, 2014:1999-2023.
3. Holt P, Thompson MM. Abdominal aortic aneurysm, evaluation and decision making. In: Cronenwett JL, Johnston KW. editors. Rutherford’s vascular surgery. 8th ed. Philadelphia (PA): Elsevier Saunders, 2014:1999-2023.
4. Kuivaniemi H, Elmore JR. Opportunities in abdominal aortic aneurysm research: epidemiology, genetics, and pathophysiology. Ann Vasc Surg 2012;26:862-70. 10.1016/j.avsg.2012.02.005
4. Kuivaniemi H, Elmore JR. Opportunities in abdominal aortic aneurysm research: epidemiology, genetics, and pathophysiology. Ann Vasc Surg 2012;26:862-70. 10.1016/j.avsg.2012.02.005
5. Lederle FA, Johnson GR, Wilson SE, et al. Relationship of age, gender, race, and body size to infrarenal aortic diameter. The Aneurysm Detection and Management (ADAM) Veterans Affairs Cooperative Study Investigators. J Vasc Surg 1997;26:595-601. 10.1016/S0741-5214(97)70057-0
5. Lederle FA, Johnson GR, Wilson SE, et al. Relationship of age, gender, race, and body size to infrarenal aortic diameter. The Aneurysm Detection and Management (ADAM) Veterans Affairs Cooperative Study Investigators. J Vasc Surg 1997;26:595-601. 10.1016/S0741-5214(97)70057-0
6. Lederle FA, Johnson GR, Wilson SE. Abdominal aortic aneurysm in women. J Vasc Surg 2001;34:122-6. 10.1067/mva.2001.115275
6. Lederle FA, Johnson GR, Wilson SE. Abdominal aortic aneurysm in women. J Vasc Surg 2001;34:122-6. 10.1067/mva.2001.115275
7. Scott RA, Ashton HA, Kay DN. Abdominal aortic aneurysm in 4237 screened patients: prevalence, development and management over 6 years. Br J Surg 1991;78:1122-5. 10.1002/bjs.1800780929
7. Scott RA, Ashton HA, Kay DN. Abdominal aortic aneurysm in 4237 screened patients: prevalence, development and management over 6 years. Br J Surg 1991;78:1122-5. 10.1002/bjs.1800780929
8. Thompson SG, Asthon HA, Gao L, et al. Final follow-up of the Multicentre Aneurysm Screening Study (MASS) randomized trial of abdominal aortic aneurysm screening. Br J Surg 2012;99:1649-56. 10.1002/bjs.8897
8. Thompson SG, Asthon HA, Gao L, et al. Final follow-up of the Multicentre Aneurysm Screening Study (MASS) randomized trial of abdominal aortic aneurysm screening. Br J Surg 2012;99:1649-56. 10.1002/bjs.8897
9. LeFevre ML. Screening for abdominal aortic aneurysm: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2014;161:281-90. 10.7326/M14-1204
9. LeFevre ML. Screening for abdominal aortic aneurysm: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2014;161:281-90. 10.7326/M14-1204
10. Chaikof EL, Brewster DC, Dalman RL, et al. The care of patients with an abdominal aortic aneurysm: the Society for Vascular Surgery practice guidelines. J Vasc Surg 2009;50:S2-49. 10.1016/j.jvs.2009.07.002
10. Chaikof EL, Brewster DC, Dalman RL, et al. The care of patients with an abdominal aortic aneurysm: the Society for Vascular Surgery practice guidelines. J Vasc Surg 2009;50:S2-49. 10.1016/j.jvs.2009.07.002