Chapter 46 - Graft thrombosis

Question 1

1 year natural course after below knee graft failure

Answer 1

50% major amputation 25% rest pain 15% dead

Question 2

Technical error rate that contributes to early graft thrombosis

Answer 2

4-25%

Question 3

Patency definitions

Answer 3

Primary patency: patent without any intervention Primary assisted: pre-emptive intervention to maintain but never thrombosed Secondary: thrombosed but brought back

Question 4

Ways to assess adequacy of bypass post-op

Answer 4

1) arteriography (con: 2D, misses proximal, contrast) 2) ultrasound (cannot see new PTFE and dacron) 3) angioscope (potential to injury vessel) 4) IVUS (most accurate but costly) 5) pressure measurement 6) plethysmography 7) transcutaneous oxygen tension

Question 5

Factors associated with early graft failure

Answer 5

NSQIP 1) younger age < 60 yo 2) african american 3) crural target 4) HD 5) smk 6) small vein diameter <3 mm 7) non compliance with graft surveillance 8) higher BMI 0) diabetes

Question 6

Percentage of vascular reconstructions that will have some restenosis or eventual occlusion

Answer 6

50% need surveillance

Question 7

5 elements critical for sustained function of arterial recon

Answer 7

1) inflow 2) outflow 3) conduit 4) operative technique 5) coag profile

Question 8

Classification of graft failure by time interval, etiology and associated treatment

Answer 8

TABLE 46.2

Question 9

Early graft thrombosis < 30 days rate of technical error

Answer 9

used to be 25% now 10% due to improve completion imaging

Question 10

Rate of thrombolysed vein graft extended patency at 1 year

Answer 10

15-20%

Question 11

Rate of surgical vein graft thrombectomy restenosis rate 1 month; patency 1 year

Answer 11

39% stenosis at 1 month 47% secondary patency 1 year

Question 12

Graft patency in > 1 year before thrombosis and in patient without diabetes, 2 year patency after thrombolysis

Answer 12

44%