Chapter%20review:%20anastomotic%20aneurysms

1
Chapter review anastomotic aneurysms
2
Incidence

• 30 year experience 6090 aorto-iliofemoral
  anastomoses
• 2.4 femoral arteries, 0.4 aorta, 0.8 iliac
  arteries
• 20 year follow-up of 518 with ultrasonography or
  angiography
• 13.6 femoral arteries, 4.8 aorta, 6.3 iliac
  arteries

3
Etiology

• Suture line disruption
• Anastomic strength depends of suture coaptation
  of the graft to vessel wall
• Silk, very high rate of anastomotic aneurysms
  within 5 to 10 years when used with prosthetic
  grafts
• Dacron, good strength but poor incorporation,
  persistent inflammatory reaction, and suture
  drag

4
Etiology

• Nylon, lose significant amount of tensile
  strength, but readily formable to thin sutures
  9-0 and 10-0, lack of brittle qualities
• PTFE, little inflammatory reaction, does not have
  same cross-sectional strength as polypropylene
• Polypropylene, minimally reactive, incorporates
  into tissue well, maintains strength over time,
  low coefficient of friction, resistant to
  bacterial films

5
etiology

• Nonsuture methods of anastomosis
• Adhesives, stents, rings, vascular clips, and
  laser welding
• Vascular clips promising for autogenous tissue
  anastomoses not involving an endarterectomy

6
etiology graft failure

• Earlier generations of PTFE and dacron found to
  fail over time
• Possibility of edge fraying of woven velour
  dacron grafts
• Take big bites or thermally seal edges

7
Etiology arterial wall failure

• Can deteriorate and lead to pseudoaneurysm
• Difficult to determine if false or true aneurysm
  by imaging
• Assume lesion is a pseudoaneurysm for surgical
  planning

8
Etiology - inflammation

• 45 pseudoaneurysms
• Bacterial cultures positive for 60 of cases
• 89 of cases were coagulase neg staph

9
Etiology technical errors

• Adequate number of suture loops, adequate bites
  of tissue, following curve of needle important
  aspects
• Endarterectomy can lead to aneurysmal
  degeneration because intima and media are removed

10
Etiology physical stress

• Include hypertension, direct trauma, and
  compression and distraction forces with
  anastomosis across a joint
• Size mismatch can also be a factor, prosthetic
  grafts generally less compliant than native
  tissue
• Lateral forces generate stress preferentially on
  the native tissue
• Physical stresses increase as aneurysm size
  increases

11
Clinical presentation

• Generally asymptomatic, but are usually found on
  physical exam
• Can cause symptoms fullness, pain, pulsatility,
  and symptoms associated with local compression
  (weakness from compression of an adjacent
  nerve.)
• Clinical problems include rupture and bleeding
  into adjacent tissues, embolization from mural
  thrombus, thrombosis with distal ischemia, and
  venous congestion or thrombosis from compression
  of an adjacent vein
• Emergency operative intervention carries a higher
  morbidity and mortality
• Median time to indentification is 6 years,
  earlier manifestations should prompt an
  investigation into an infectious etiology
  including high resolution ct angio and esr rate

12
Femoral artery anastomosis

• Most prevalent site of anastomotic
  pseudoaneurysms
• Most cases are diagnosed as an asymptomatic
  pulsatile mass in up to 44 of cases less than
  10 require surgical intervention
• These should be monitored until they have a
  significant growth rate or the size is 2 to 2.5cm
• These should never be catheterized
• Can be monitored by ultrasound study, both sides
  should be investigated
• Endoluminal repair not an option as this is over
  a hip joint

13
Abdominal aorta anastomosis

• More common with aneurysmal pathology vs.
  occlusive disease, occur in 2 to 5 of patients
  with aortic grafts
• Imaging study should be performed every 5 to 10
  years
• Patients may present with back or abdominal pain,
  also rupture with hemorrhage, thrombosis or
  embolism, and less commonly erosion into an
  adjacent structure such as bowel or vena cava
• Indications for intervention
• Symptomatic aneurysm
• Patient presenting with complications of
  anastomotic aneurysm
• Diameter greater than twice the diameter of the
  graft or more than 4 cm
• Also presence of a saccular rather than a
  fusiform aneurysm
• Retroperitoneal approach in preferrable providing
  better exposure for suprarenal/supraceliac
  control
• In noninfected cases endoluminal repair should be
  considered

14
Iliac artery anastomosis

• Can erode into small bowel or colon, not duodenum
  like the aorta
• Compression of iliac vein can lead to lower
  extremity swelling or DVT, also desmoplastic
  reaction around the anastomosis can lead ureteral
  obstruction and hyrdronephrosis
• Indication for repair include presence of
  symptoms, presence of complication, aneurysmal
  size 2.5 to 3 cm
• Iliac artery anastomotic aneurysms most suitable
  to endoluminal repair
• Need low probability of infectious cause
• Aneurysm does not need to be debulked
• No contraindication to internal iliac artery coil
  embolization
• Can be used for acute rupture depending on
  surgeon experience

15
Carotid artery pseudoaneurysms

• Incidence is rare 0.6
• Due to technical problems, use of poor quality
  vein for patch, very bulbous reconstruction of
  the arteriotomy or infective process for
  prosthetic patch
• Can present as painful pulsatile cervical mass,
  also TIAs
• Workup by ultrasound and CT angio, regular
  angiography not helpful
• Even small asymptomatic pseudoaneurysms should be
  fixed as they may degenerate and produce small
  thrombus and embolic material
• Author recommends bypass around aneurysm and
  endoluminal repair is contraindicated due to
  significant debris in lumen