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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3869_Библиотеки_им_академика_М_И_Перельмана.pdf
370 H. Aryafar and T. Kinney
◦ Non-target embolization to other pulmonary segments. Systemic embolization of
coils, thrombus, or air if communication to the pulmonary vein is present.
◦ Dysrhythmias.
◦ Hemoptysis.
◦ Contrast allergies.
◦ Contrast-induced renal failure.
Keypoints
1. Pre-procedure imaging and/or bronchoscopy may be helpful in determining the site of bleeding.
2. The majority of massive hemoptysis arises from the bronchial artery
(discussed in another chapter of this book).
3. Care must be taken in the setting of a right-to-left shunt, in order to prevent
paradoxical embolization.
4. Large permanent agents, such as coils and Amplatzer plugs, are typically
used for pulmonary artery hemorrhage.
5. If bleeding persists after pulmonary embolization, consider systemic
arterial sources.
Suggested Reading
1. Andersen PE Imaging and Interventional Radiological Treatment of Hemoptysis, Acta
Radiologica 2006; 47(8): 780–792
2. Yoon W, Kim JK, Kim YH, Chung TW, Kang HK. Bronchial and nonbronchial systemic artery
embolization for life-threatening hemoptysis: a comprehensive review. Radiographics 2002;
22: 1395–1409.
3. Pulmonary and Bronchial arteries. In Valji K (ed). Vascular and Interventional Radiology.
Philadelphia, Saunders Elsevier, 2006; 347: 259–282.
Chapter 37
Endoleaks Following EVAR
Stephen Johnson, Jennifer Fraser, and Rajan Gupta
Clinical Features
• Continued perfusion of an abdominal aortic aneurysm (AAA) after endovascular
stent-graft deployment has been termed an “endoleak.”
• There are five types of endoleaks:
• Type I: inadequate seal at the proximal or distal attachment sites.
• Type II: continued blood flow through a patent inferior mesenteric artery
(IMA), lumbar artery or hypogastric artery. Requires an inflow and outflow
artery. (Most common type of endoleak.)
• Type III: midgraft leak from fabric holes or an inadequate seal between graft
components.
• Type IV: transgraft flow from porosity of the graft (usually takes place
immediately after placement).
• Type V: also known as endotension; aneurysm enlargement without an identi-
fiable leak.
• Endoleaks contributing to continued perfusion of the aneurysmal sac can lead to
enlargement and possibly rupture of the sac.
• Treatment involves interrupting vessel flow and includes the use of coils, onyx
(ethylene–vinyl alcohol) and thrombin ± gelfoam.
• Embolization can be performed either at the time of EVAR or during a subsequent
procedure.
Diagnostic Evaluation
Laboratory
Prior to the procedure, patients should have labs drawn for CBC, BUN/Cr, and
PT/INR.
Transcatheter Embolization and Therapy,
Techniques in Interventional Radiology, DOI 10.1007/978-1-84800-897-7_37,
C
Springer-Verlag London Limited 2010
371
372 S. Johnson et al.
Imaging
Patients undergoing EVAR should have CT imaging prior to EVAR to evaluate
vascular anatomy.
Direct fluoroscopic imaging is used at the time of EVAR to identify endoleaks
and proper graft placement.
Patients should undergo subsequent CT evaluation at 1 month, 6 months, and
yearly for evidence of aneurysmal growth (i.e., endoleak).
Indications
Presence of an endoleak, aneurysmal growth.
Alternative Therapies
Open surgical repair, ligation of feeding arteries.
Watchful waiting—follow endoleak with CT for continued aneurysmal growth.
Contraindications
Inability to access aneurysm sac, patient unable to tolerate second procedure.
Specific Complications
Common: failure of embolization with continued perfusion of aneurysmal sac,
enlargement of aneurysm.
Uncommon: bowel or spinal ischemia.
Anatomy
Since EVAR is performed to repair an abdominal aneurysm, the related vasculature
anatomy can be very diseased and difficult to access. Therefore, imaging prior to
the procedure is essential. Additionally, the anatomy of contributing arteries varies
greatly and must be visualized with either angiography or direct fluoroscopy with
contrast.
Normal Anatomy
Patent bilateral femoral arteries, iliac arteries, and abdominal aorta.
Aberrant Anatomy
Tortuous vasculature, stenotic, or atherosclerotic arteries.
37 Endoleaks Following EVAR 373
Equipment
Catheters
• Non-selective catheters: 4 Fr kumpke
• Selective catheters: microcatheters
• Guide catheter
Embolic Agents
• Multiple approaches to embolization have been used and they vary depending on
the type and severity of the endoleak. Embolization should continue until there is
no further pulsatile blood return. Confirmation is obtained with contrast injection
during direct fluoroscopy.
• Coils
◦ Embolic coils can be used for selective embolization of vessels feeding the
endoleak, as well as to embolize the aneurysmal sac itself.
◦ Stainless steel coils vs. platinum coils
• Stainless steel coils are more difficult to see under fluoroscopy than platinum
coils.
• However, stainless steel coils are preferred because they cause fewer artifacts
on follow-up imaging.
◦ Coils can also be particularly effective for the treatment of retrograde
endoleaks.
• Onyx
◦ Onyx embolizes by filling the aneurysm sac with an elastic polymer which
conforms closely to the wall of the sac, occluding flow.
• Thrombin
◦ Can be used with or without Gelfoam.
◦ As a liquid mixture, thrombin ± Gelfoam can be injected directly into the
aneurysmal sac to induce embolization.
◦ Must be used cautiously to avoid non-selective embolization.
Medication
• Pain control: conscious sedation using PRN Fentanyl and Versed if not using
general anesthesia.
• Infection control: prophylactic antibiotics (e.g., Cephazolin).
• Sickness control: PRN antiemetics.
• Hydration: IV fluids.
374 S. Johnson et al.
Angiography
Access
• Femoral artery access via one or both femoral arteries at the time of EVAR.
• Translumbar access into aneurysm sac.
Angiography
Direct fluoroscopic angiography is obtained either at the time of EVAR or during a
subsequent procedure to identify the source(s) of the endoleak.
• Selective catheterization with contrast injection of feeding arteries, such as the
IMA or lumbar arteries, can be done to identify source of endoleak.
Assessing the Lesion
• Assessment of the lesion can be done at the time of EVAR or during follow-up
evaluation.
• At the time of EVAR, a catheter placed in the excluded sac can signify the
presence of an endoleak with the return of pulsatile blood flow (type II endoleak).
• Types I and III can be detected at the time of graft deployment with fluoroscopic
imaging.
• Endoleaks can also be assessed using follow-up CT. The aneurysmal sac can be
measured and analyzed for interval growth.
Angiographic Appearance
• The endoleak is identified angiographically by the extravasation of contrast from
within the graft lumen into the aneurysm sac (type I and III endoleaks).
• Type II endoleaks can be identified during angiography by the presence of
contrast traveling from a peripherally catheterized vessel into the excluded
aneurysm sac.
Treatment Plan and Technique
There are several different approaches to endoleak treatment, and treatment varies
with the type of endoleak present.
• Type I: identified at the time of graft placement and can be corrected by securing the graft attachment sites with angioplasty balloons, stents, or stent-graft
extensions.
37 Endoleaks Following EVAR 375
• Type II: currently, type II endoleaks are treated either at the time of EVAR
through a transarterial approach or during a secondary procedure via direct
translumbar endoleak puncture. Different types of embolization materials are
outlined above.
• Type III: Type III endoleaks can be corrected by covering the defect with a stentgraft extension.
• Type IV: This type of endoleak is not associated with aneurysmal growth and
rupture; therefore, treatment generally involves monitoring of the aneurysmal sac
with subsequent CT scans.
• Type V: the etiology of graft-related endotension is unknown, and therefore
treatment has not yet been established.
Aftercare
Arterial puncture site: monitor for hematoma, extravasation.
Post-embolization
Patients should be monitored for signs of embolization-related bowel or spinal
ischemia and continued endoleak with aneurysm sac growth.
Follow-Up
Follow-up CT angiogram at 1 month, 6 months, and yearly for aneurysmal growth
(Fig. 37.1)
Keypoints
• Endoleaks are a common complication of endovascular AAA repair
(EVAR) and can lead to aneurysm growth and rupture.
• There are five different types of endoleaks.
• Endoleaks may be identified at the time of EVAR or upon follow-up
imaging.
• Treatment of endoleaks depends on the type of endoleak present.
• Treatment of type I and III endoleaks may involve graft extensions,
ballooning or stents.
• Treatment of type II endoleaks involves the use of embolic coils, onyx,
or thrombin, and can be done at the time of EVAR or during a secondary
procedure through a translumbar sac puncture.
376 S. Johnson et al.
a
b
c
Fig. 37.1 (a) Contrast-enhanced CT scan, venous phase, in a patient undergoing routine imaging
follow-up after bifurcated endograft placement. Notice the contrast accumulation in the aneurysm
sac (arrow). On review of the non-contrast-enhanced CT (not shown), the finding was not visualized. (b) Contrast injection following direct puncture of the aneurysm sac under fluoroscopic
guidance demonstrating retrograde filling of a lumbar arterial branch. (c) Fluoroscopic image
following injection of onyx
Suggested Readings
Golzarian J, Maes ED, Sun S. Endoleak: treatment options. Tach Vasc Interv Radiol 2005;8(1):
41–49
Stavropoulos SW, Baum RA. Catheter-based treatments of endoleaks. Semin Vasc Surg
2004;17(4):279–283
Chapter 38
Internal Iliac Artery—Isolated
Aneurysm and Pre-EVAR Embolization
David O. Kessel
Clinical Features
This is a relatively uncommon indication for internal iliac artery territory embolization compared with embolization for uterine fibroids, pelvic trauma, and hemorrhage. Prophylactic embolization to prevent type II endoleak pre-endovascular
aneurysm repair (EVAR) is much more common than embolization for isolated
internal iliac artery aneurysm (IIAA).
• Most internal IIAAs are asymptomatic and occur in the context of aortoiliac
aneurysm. Isolated IIAA are rare.
• Symptomatic aneurysms may present with rupture or compression of adjacent
structures.
• IIAAs are challenging to repair surgically, and endovascular treatment is the
preferred option.
• In male patients, pre-procedure history must document erectile function and
presence or absence of buttock claudication.
Diagnostic Evaluation
Most IIAA will be detected as incidental findings on ultrasound, CT, or MRI.
Evaluation is similar to that for endovascular aneurysm repair. If aneurysms
are symptomatic or greater than 4 cm in diameter, then CT angiography with
reconstruction is the investigation of choice.
Laboratory
Beware of renal impairment and ensure adequate hydration. Consult renal physicians if necessary.
Transcatheter Embolization and Therapy,
Techniques in Interventional Radiology, DOI 10.1007/978-1-84800-897-7_38,
C
Springer-Verlag London Limited 2010
377
378 D.O. Kessel
Imaging
Use contrast-enhanced CT/MRI (Fig. 38.1)to
ac
Fig. 38.1 (a) 5 cm IIAA (arrowheads) presenting with deep vein thrombosis, (b) associated left
hydronephrosis (arrowheads), and (c) external iliac vein compression (arrowheads)
• Demonstrate patency of the contralateral internal iliac artery
• The length and size of the internal iliac artery
• Verify the size of the aneurysm
• Demonstrate the extent of involvement of the aortoiliac segments
• Demonstrate whether other structures are affected
• Assess factors that will influence the approach (e.g., iliac artery tortuosity and
configuration of the aortic bifurcation)
b
Indications
• Symptomatic, large, or ruptured IIAA
• Need to occlude internal iliac artery (± IIAA) in association with aortoiliac
aneurysm pre-EVAR
Alternative Therapies
• Branched stent grafts for some aortoiliac aneurysms
• Aorto-uniiliac stent graft with femorofemoral crossover, and contralateral exter-
nal iliac to IIA stent graft
• Aneurysm resection or primary repair
Contraindications
• Contraindications are relative and relate to the indication and severity of the
underlying disease, and thus there is little that will prevent emergency embolization for hemorrhage.
38 Internal Iliac Artery—Isolated Aneurysm and Pre-EVAR Embolization 379
Specific Complications
• Buttock claudication
• Erectile dysfunction
• Descending colon/sigmoid colon/rectal ischemia
• Bladder ischemia
Complications are most common if the entire internal iliac circulation is
embolized (i.e., bilateral embolization or embolization of the only IIA) or if
embolization involves the branches of the IIA.
Anatomy
Normal Anatomy
• The vast majority of patients have conventional aortoiliac arterial anatomy.
• The common iliac artery bifurcates to form internal and external iliac arteries.
• The internal iliac artery bifurcates into anterior and posterior divisions, which
supply pelvic organs as well as the gluteal muscles.
• Occlusion of the internal iliac artery proximal to its bifurcation is less likely to
result in ischemia.
• Principal consideration will be anatomical factors influencing the approach for
emoblization.
Aberrant anatomy: very uncommon, but there are also iatrogenic (post-operative)
variations in pelvic vasculature.
• Persistent sciatic artery supplying the leg. Embolization might be needed in this
context as the persistent sciatic artery is prone to aneurysm developing. In this
case, embolization needs to be combined with revascularization of the leg.
• Renal transplant anastomosed to internal iliac artery.
• Iliofemoral crossover graft.
Equipment
Catheters
• Non-selective catheters: Pigtail or straight catheter if flush aortogram necessary.
• Selective catheters: cobra, renal double curve, sidewinder to catheterize the IIA
or cross the aortic bifurcation. Microcatheter occasionally needed for selective
embolization.
• Guide catheter with detachable hemostatic valve if using Amplatzer vascular
plugs (AVP) or working over the aortic bifurcation.