2. Endovascular surgery
Endovascular surgery is a form of minimally invasive
surgery/procedures for imaging the circulation or for
treating vascular disorders from within the circulation,
through catheters/miniature instruments inserted
percutaneously into the blood vessels
10. ACCESS
Common femoral artery, popliteal, tibial, axillary,
brachial, radial, carotid, subclavian
Bone/bony prominence beneath the artery
Avoid diseased areas
Away from side brances, bifurcations, or crossing veins
External skin markings, ultrasound guided, fluoroscopy
11. Puncture site: common femoral artery on the medial
3rd of femoral head 1-2 cm below the inguinal ligament
A puncture site below the ligament cannot be
compressed and could result in a large pelvic
hemorrhage
Puncture of the SFA must be avoided to prevent
pseudo-aneurysm and hematoma correlate to the
inefficacy of the compression
12. ACCESS
1. Retrograde-relatively large diameter, ease of
compression, options for image guided puncture
2. Antegrade- commonly used for infrageniculate
interventions, aortic bifurcations that are prohibitive
to a contralateral retrograde CFA access and for
chronic total occlusions
straight line approach- easy maneuvering
15. • Core
• Stainless Steel
– Used for support
– Stiffness varies based on taper / diameter of core
• Nitinol
– Used for it’s flexibility, memory and kink resistance
• Tip
• Platinum / Gold
– Provides radiopacity
– Atraumatic
– Ribbon formed for shaping tip
18. Sheaths
Sheaths are hemostatic conduits inserted into the
vessel. They allow passage of guidewires, catheters and
interventional devices.
Hemostatic valve at the tip and a side port for
aspiration/administration of drugs
Helps minimize local trauma to the vessel from
repeated exchanges as well as decrease blood loss and
hematoma formation
19.
20. Sheaths
Peripheral and coronary sheaths have a universal color code
Universal color coding
4 Fr = red
5 Fr = gray
6 Fr = green
7 Fr = orange
8 Fr = blue
9 Fr = black
10 Fr = violet
11 Fr = yellow
Sheaths are measured inner diameter in french size (1fr =
.33mm)
22. Endovascular surgery
Typically performed under LA
Less invasive
Quicker return to function
Durability compared to open surgical options
Highly skilled operator
Endovascular suite with fluoroscopy
Costly
24. Seldinger technique
Sven Ivar Seldinger- Swedish radiologist (1953)
The Seldinger technique is a medical procedure to obtain safe access
to blood vessels
The desired vessel is punctured with a sharp hollow needle called a
trocar, with ultrasound guidance .
Guidewire is then advanced through the lumen of the trocar, and the
trocar is withdrawn. A "sheath" or blunt cannula is passed over the
guidewire into the cavity or vessel. After passing a sheath or tube, the
guidewire is withdrawn.
A sheath can be used to introduce catheters or other devices to perform
endoluminal procedures.
Fluoroscopy is used to confirm the position of the catheter and to
manoeuvre it to the desired location. Injection of radiocontrast may be
used to visualize organs.
Upon completion of the desired procedure, the sheath is withdrawn. a
sealing device may be used to close the hole made by the procedure.
25.
26. Balloon angioplasty
Fogarthy (1963)- used endovascular catheter for extraction of arterial
emboli and thrombi
Dotter and Judkins (1964)-transluminal treatment of arterial stenosis
Types
Percutaneous transluminal angioplasty (PTA)
Subintimal angioplasty
PTA with stenting
27. Technique
Shortest distance from the access vessel to the target vessel
Retrograde right common femoral artery access
Tibial occlusive disease-I/L anterior common femoral access
Heparinization-5000 IU as standard bolus dose after arterial
access. 1000 IU/L heparinized saline for flushing
Arteriography to identify the lesion and severity
Lesion crossed and contrast injected
Balloon diameter and length carefully chosen
IVUS/CTA- for sizing the lesion
Balloon inflated for 1 min, withrawn after deflating
Contrast injection to assess the PTA result
28. Iliac and femoro popliteal segments. Less successful
for below knee narrowing
Coronary arteries
Complications- failure, hematoma formation,
bleeding, thrombosis, distal embolisation
29.
30. Subintimal angioplasty
Bolia et al (1989)-for chronic total occlusions
Creating an intentional subintimal plane across the occlusion
with a guidewire and wire redirected back into the true lumen
Iliac and femoropopliteal occlusions- successful in highly
calcified lesions, long occlusions(>15 cm)
Higher patency rates were observed in limbs treated for
claudication than limbs treated for chronic total occlusions
and criticallimb ischaemia
12 month patency <70%
Mean increase in ABI is 0.3
Technical failure rate ~26%- mostly due to inability to reenter
the true lumen distal to the occlusion(70%)
31.
32. Types of balloon
Complaint balloon
Non complaint balloon
Complaint balloon
–expand in the direction of least resistance
- more potential for arterial injury
-potentially treat vessels of varying diameter
Non complaint balloon
-polyolefin copolymer/polyethylene/nylon reinforcement
-provide higher uniform dilating force –highly calcific
lesions
33. Cutting balloon angioplasty-
Ballon loaded with metal atherotome or microsurgical blades
Designed to create controlled incisions into the thrombus
and dilate the vessel with less force than conventional balloon
angioplasty
CBA- reasonable option for infrainguinal vein graft stenosis
-superior results to PTA
-more chance of perforation
34. Endovascular cryotherapy
Balloon catheter inflated with nitrous oxide delivering cold
thermal energy(-10 C) to the arterial wall.
Alters healing response after angioplasty, principally inducing
smooth muscle cell apoptosis rather than necrosis, thus
reducing myointimal hyperplasia
CLIMB study
-initial success rate 95%
-stents required in 17%
-primary patency at 12 months @56% and comparible with
those achieved with conventional PTA
-recommended for lesions >55mm
35. Drug coated balloons(DCBs)
Substantial amounts of antiproliferative agents were delivered
to the arterial wall during short periods of balloon inflation.
For prevention of re stenosis and myointimal hyperplasia
Paclitaxel coated balloons deliver drug during balloon
inflation( superficial femoral artery)
Drug eluting stents (DES)
-coronary circulation/infrainguinal arterial occlusive disease
-Sirolimus/paclitaxel-inhibits smooth muscle cell proliferation
36. Stenting
Stent-comes from 19th century London dentist-
Charles Stent
Charles Dotter (1983)-nitinol stents were first used
Palmaz et al (1985)-balloon expandable stent
Two types
Bare metal stent
Stent graft
Two types based on deployment method
Balloon expandable
Self expanding
37.
38. Balloon expandable Self expandable
High radial/longitudinal
force
Precise placement
Further expansion with larger
balloons
Radiopaque
Short length
Prone to crushing
Flexibility
Long stent lengths
Continued radial force if
oversized
Crush resistant
Ability to clamp the stent
Low radial force
Inaccurate/less precise
placement
Limited radiopacity
39. Angioscopy
Used for visualizing the interior of blood vessels
Arterial embolism, adjunctive procedure during
vascular bypass to visualize valves within venous
conduit
Visualize stents in catheterization lab
40. Intravascular ultrasound
Uses miniature ultrasound probe attached to distal
end of an intravascular catheter(uses 20-40MHz)
Useful with unreliable angiographic images-lumen of
ostial lesions, or in regions with multiple overlapping
arterial segments
Advantages over angiography-measures atheroma
hidden within the vessel wall, identifies vulnerable
plaque. Measures the effect of different treatment
strategies for changing the evolution of the
atherosclerosis disease process
41.
42. Atherectomy
Endovascular atherectomy allows the physical removal of
atherosclerotic plaque material from the blood vessel, with a
theoretical benefit of removing the obstructing plaque rather
than mere displacing it, as with angioplasty and stenting
Open atherectomy remains the gold standard. Endovascular
atherectomy is useful in vessels with difficult access
Excisional atherectomy catheters remove and collect the
atheroma, whereas ablative device fragment the atheroma into
small particles
3 types of atherectomy devices
Directional
Rotational
Laser
43. Directional atherectomy
Best suited for discrete calcified atherosclerotic lesions
of infrainguinal arteries. Not used for chronic total
occlusion
Silverhawk plaque excision system-the device is
advanced under fluoroscopic guidance to the proximal
portion of the target lesion, where a carbide cutter excise
the atheroma and traps it within the nose come of the
device; once filled with plaque the device is removed,
the nose cone is emptied, and the device is reintroduced
over a guidewire
44.
45. Rotational atherectomy utilizes a rotating burr or
blade to excise plaque, whose microparticles are either
aspirated or allowed to embolize distally
Jetstream – device success rate 99%.TLR -15% and 26%
at 6 and 12 months respectively; restonosis 38% at 1yr
May cause vasospasm-calcium channel blockers/
nitroglycerine
46. Laser atherectomy
Utilized in CTOs, both de novo or in in stent thrombosis
Cold tip laser that delivers burst of ultraviolet xenon
energy in short pulse duration.
Key features is the ability to debulk tissue without
damaging surrounding tissue, minimizing restenosis
COMPLICATIONS
-embolism 1.3%
47. Thromboembolectomy
Management of acute thrombotic or embolic arterial
occlusions
Fogarty catheter
Purely percutaneous thrombolectomy
Aspiration
Rheolytic devices
Mechanical fragmentation with or without
pharmacologic lysis
48.
49. Simple aspiration either via a large sheath or guide
catheter work well in small vessels< 6mm
Rheolytic devices utilize jets of saline, directed from
the tip of the catheter back toward its more proximal
portion, to create a venturi effect, resulting in clot lysis
and aspiration.
Arterial access is ideally made antegrade to the area of
thrombotic occlusion. Lower extremity lesions are
approached through contralateral femoral artery
53. Intraarterial thrombolysis
In IA thrombolysis, the cervicocephalic arterial tree is
traversed with an endovascular microcatheter delivery
system, the catheter port is positioned immediately within
and adjacent to the offending thrombus, and fibrinolytic
agents are infused directly into the clot. This delivery
technique permits high concentrations of lytic agent to be
applied to the clot while minimizing systemic exposure.
In acute ischaemic stroke within 6 hours of symptom onset
It is usually infused over 1 to 2 hours while serial
angiographic studies are obtained
reduced hemorrhagic complications (due to the use of
lower doses of pharmacologic thrombolytics
54. Myocardial infarction, ischaemic stroke, massive PE,
acute limb ischaemia
Recanalization rates for IAT have been shown to be
superior to those for IVT for major cerebrovascular
occlusions, averaging 70% versus 34%
Agents used
Streptokinase
Urokinase
Recombinant tpa
Alteplase
Reteplase
55. Contraindications to thrombolysis
Intolerable ischaemia(for arterial thrombosis)
Active bleeding(not including menses)
Recent stroke or neurosurgical procedure < 2 months
Intracranial neoplasms
Recent major surgery(<2 weeks), major trauma,parturition,
organ biopsy
Active peptic ulcer or recent GI bleed(<2 weeks)
Uncontrolled HTN
Bacterial endocarditis, left heart thrombus, hemorrhagic
diabetic retinopathy
Coagulopathy or current use of warfarin
pregnancy
56. Endovascular aneurysm
repair(EVAR)
Indications-
Symptomatic aneurysm of any size
Aneurysm >5.5cm in size(5 cm in females)
Increase in diameter > 0.5 cm/yr
Saccular aneurysms
Poorly controlled HTN(DBP>100mmHg)
Significant COPD(FEV1 <50% of predicted value)
Contraindications-recent MI, intractable CHF,
unreconstructible CAD, life expectancy <2 yrs,
incapacitating neurologic disease after a stroke
57. EVAR-suitable in 50% of infrarenal aneurysms
Reduced mortality and morbidity, shorter hospital stay
Similar rates of survival to open surgery
Close follow up with CT necessary
Unsuitable- short, flared or angulated neck, presence
of intraluminal thrombus and significant calcification,
renal artery/large accessory renal artery arising from
proximal neck, horseshoe kidney, iliac artery
tortuosity, calcification and luminal narrowing
58.
59. Complications
Early-branch occlusion, distal embolization, graft
thrombosis and arterial injury
Arterial dissection
Bowel ischaemia, renal dysfunction
Graft migration(1-6%)
Endoleak- is defined as failure to exclude the
aneurysmal sac fully from arterial blood flow, potentially
predisposing to rupture of the aneurysm sac
60.
61. Endovenous ablation of various
veins
Endovenous laser ablation(EVLA)- 2001
Radiofrequency ablation(RFA)
Indicated in primary and recurrent varicose
veins(recurrent surgery-40% complication rate)
Procedure includes the insertion of a probe into the greater
saphenous vein under usg guidance. Emits either laser or
radiofrequency energy, which coagulates the vein walls,
causing lumen obliteration.
RFA-85-120 celsius
Effectively treats junctional and truncal incompetence.
Varicosities are better treated with concomitant
phlebectomy
64. Embolisation
Therapeutic embolization is a nonsurgical, minimally invasive
procedure performed by interventional radiologists and
interventional neuroradiologists . It involves the selective
occlusion of blood vessels by purposely introducing emboli.
Recurrent hemoptysis
Arteriovenous malformations(AVMs)
Cerebral aneurysm
Gastrointestinal bleeding
Epistaxis
Varicocele
Primary post-partum hemorrhage
Surgical hemorrhage
Uterine fibroids
65. Kidney lesions
Liver lesions, typically hepatocellular carcinoma
(HCC). Treated either by particle infarction or
transcatheter arterial chemoembolization (TACE).
Uterine fibroids
Access to the organ by guidewire and catheter
Location of the pathology by DSA
66. Embolic agents
Liquid embolic agents
-used in AVMs. Flows through complex vascular
structures, so need not target each vessel
N-butyl-2 cyanoacrylate
Ethiodole
onyx
Sclerosing agents
-slow setting, cannot be used for large/high flow vessels
Ethanol
Ethanolamine oleate
sotradecol
68. Mechanical occlusive device
Coils
-used for AVM, aneurysm and trauma
-good for fast flowing vessels- immediately clot the
vessel. Platinum or steel
-induce clot due to dacron wool tails around the
wire
Detachable baloon
- balloon implanted into a vessel, fill with saline
69.
70.
71. Advantages
Minimally invasive
No scarring
Minimal risk of infection
No or rare use of general anesthetic
Faster recovery time
High success rate compared to other procedures
Preserves fertility and anatomical integrity
72. Disadvantages
User dependent success rate
Risk of emboli reaching healthy tissue potentially
causing gastric, stomach or duodenal ulcers. There are
methods, techniques and devices that decrease the
occurrence of this type of adverse side effect.
Not suitable for everyone
Recurrence more likely
73. Transcatheter arterial
chemoemolization
Transcatheter arterial chemoembolization (also called
transarterial chemoembolization or TACE) is a minimally
invasive procedure performed in interventional radiology to
restrict a tumor's blood supply. Small embolic particles coated
with chemotherapeutic agents are injected selectively into an
artery directly supplying a tumor.
two primary mechanisms.
- arterial embolization preferentially interrupts the tumor's blood
supply and stalls growth until neovascularization.
- focused administration of chemotherapy allows for delivery of a
higher dose to the tissue while simultaneously reducing systemic
exposure, which is typically the dose limiting factor. Effectively,
this results in a higher concentration of drug to be in contact
with the tumor for a longer period of time.
74. Embolization induces ischemic necrosis of tumor
causing a failure of the transmembrane pump,
resulting in a greater absorption of agents by the
tumor cells. Tissue concentration of agents within the
tumor is greater than 40 times that of the surrounding
normal liver.
Clinical applications- hepatocellular carcinoma,
neuroendocrine tumours, ocular melanoma,
cholangiocarcinoma, sarcoma, metastatic colon cancer
75.
76. Lipiodol- mixed with chemotherapeutic agents
Drug eluting particles
-PVA microspheres-loaded with doxorubicin
COMPLICATIONS
-necrosis of tumours release cytokines causing pain,
fever and malaise
-intrahepatic abscess, irreversible hepatic necrosis
- Restrict TACE to single lobe or major branch of hepatic
artery