11- Angiography and intervention - basic endovascular techniques. Basic vascular surgery techniques, vascular grafts

What are endovascular treatments

• percutaneous, catheter based intervention using X ray fluoroscopic control

what are the characteristics of endovascular surgeries

• doesn’t require

  • surgical cutdown

  • general anesthesia

• can be performed as an outpatient procedure

what is the seldinger technique

• used to get access to vessels and heart

• needle → guidewire → remove needle → sheath → insert

what is angiography

• used to diagnose and treat CAD- narrowing or blockage of arteries

What is a balloon angioplasty

• A catheter with a tiny, folded balloon on its tip is inserted into the artery → inflated once the catheter reaches the narrowed/blocked artery → opens artery

what are the advantages of balloon angioplasty

• low profile devices can be used to treat high caliber arteries

• its size and flexibility allows to reach small vessels 1.5mm

what are the disadvantages of balloon angioplasty

• elastic recoil

  • especially in stenosis of arterial orifices

  • flow limiting dissection is relatively common

  • can be ineffictive against calcified plaques!

when are stents used

• after unsuccessful or non effective PTA

• flow limiting or unstable dissection

• stenosis in venous system

what are the types of stents

• balloon expandable stent system

• self expanding stent system

describe balloon expandable stents

• Stainless steel

• Easy positioning; stent shortening is minimal

• High radial force

• Limited stent length

• Rigidity (external forces can deform)

describe self expanding stents

• delivered in a stent

• continuous expansion force

• adapts to changes in diameter- bifurcation

• stent length can vary- bigger than diameter, shorter the stent

what is the cause of restenosis after endovascular treatment

• intimal proliferation due to vessel wall damage during intervention

• can be inhibited using drug eluting devices

what is the first choice metho for aorto-iliac segment

• endovascular!

  • favourable in occlusion sin patients with severe comorbidities

• open is recommended only for extensive lesions

what technique is used in the aortoiliac segment

• “kissing stent”

• reconstruction of aortic bifurcation by placing 2 stents simultaneously

• prohibits contralateral displacement of plaque material

what are the characteristics of femoropopliteal disease

• long segment lesions, complex plaque-morphology and prominent calcification

what is the occurrence of restenosis in femoropopliteal diseases

• high occurrence in cases with long and/or complex lesions (40-60%)

  • only recommend when the total length of lesion is shorter than 25cm

• stents give better results- occurrence of in-stent restenosis and stent fracture limits its usability

what are the goals of treating infrapopliteal arteries

• ensure adequate circulation to limb in critical limb ischemia

• eliminate ischemic pain

• wound leaning and limb salvage

what is the treatment of infrapopliteal arterial disease

• surgical bypass- GOLD STANDARD

• endovascular therapy can be first treatment

in what patients is surgical bypass not suitable

• severe comorbidity

• lack of veins for bypass

• lack of adequate receiving artery

what are the types of invasive treatments of arterial diseases

• percutaneous interventions

• open surgical techniques

• hybrid techniques

• graft materials

what are the types of open surgical techniques

• arteriotomy

• embolectomy, thrombectomy, endarterectomy

• vascular reconstruction

  • vessel closure

  • bypass, interposition

define arteriotomy

• opening of artery

• done when there is an occlusion in the arteries

• most common in femoral!

what is the difference in the reason for doing an arteriotomy in different locations

• in lower extremities- treat ongoing problem- decrease LL ischemia

• carotid- prevent stroke

what are the types of arteriotomies

• transverse arteriotomy and direct suture

• longitudinal arteriotomy and patch plasty

why would you do a transverse vs longitudinal

• when its a longer segment→ longitudinal

• shorter segment → transverse

  • for emboli- arterial from heart!

what is desobliteration

• removal of obliterated part

what are the types of desobliterations

• thrombectomy

• embolectomy

• endarterectomy

what is done in a thrombectomy

• removal thrombus + plaque

  • will have another thrombus otherwise

• usually with endarterectomy- thrombendarterectomy

define endarterectomy

• removal of the intimal + media

  • external media + adventitia stays

what are the types of anastomosis

• end to end

• end to side

what are the types of vessel reconstructions

• interposition

• bypass

what is interposition

• vascular pathology is resected

  • flap remains- open + replace vessel

• end to end anastomosis

• eg aneurysm

what is a bypass

• vascular pathology remains

• end to side anastomosis

• eg occlusive diseases

what is the difference between bypass and interposition

• bypass- leaves vessel intact

• interposition- prosthetics in line of blood flow

what are the types of graft materials used

• prosthetic

  • dacron

  • PTFE

• auto-, allo-, and xenogenic grafts

describe dacron graft material

• most frequently used prosthetic
• aorto-ilio-femoral reconstructions
  • bigger vessels
• patchplasty
• can have silver coated
• knitted or woven graft

describe PTFE

• polytetrafluoroethylene
• aka goretex, teflon
• aorto-femoral-popliteal- crural reconstruction, artificial AV fistula
  • better on smaller vessels
• stretch on non stretch
• can have enforced with external rings
• monolayer graft

what are the other auto,-allo-, xenogenic grafts

• great saphenous vein
  • most common
  • have to make multiple incisions, more time consuming, infection
• femoral vein
  • septic surgery
• homograft- allograft
  • septic surgery
  • from donors
  • don’t need immunosuppression for this
• bovine pericardium patch
• porcine pericardium patch

describe the hybrid surgeries

• “multilevel disease” that requires complicated one stage surgery
• alternative solution if percutaneous or open surgery is impossible or dangerou