Chapter 63 - Autogenous grafts Flashcards
First use of autogenous vein for occlusive arterial disease
1944 Dos Santos
Difference between vein and arterial wall
Endothelium - cuboidal with poor interendothelial tight junctions Internal elastic lamina - not well developed, large fenestrations Medial - type I collagen dominate; sparse elastin fragments only External elastic lamina - not well developped Adventitia - loose connection matrix with sparse vasa vasorum
New name for the saphenofemoral junction
Confluence of superficial inguinal veins
Proper names for the saphenous veins
Great saphenous Small saphenous
Where does the small saphenous join popliteal in relation to knee crease
5 cm proximal
Where does the femoral vein join the deep femoral in relation to inguinal ligament
9 cm below
Median cubital vein course
start at apex of antecubital fossa branch of cephalic ascends medially to join basilic vein
Origin of the axillary vein
brachial vein + basilic vein
Which never runs with basilic vein
Medial cutaneous nerve of the forearm paresthesia along medial portion of forearm
Probe frequency to use for vein mapping
> 8 MHz
Reference zones of the lower extremity
Zone 2-4 = proximal, middle distal thigh Zone 5-7 = proximal middle distal calf same with upper extremity
Minimal usable vein diameter
2-3 mm
Improved patency of the pedicle harvest technique
90% vs 76% after 8.5 years due to less touch or actually due to more NO from the surrounding adipose tissue
Irrigation for the harvested vein solution type
crystalloid. buffered chrystalloid or blood no clear difference but buffered solution suggested
Concentration of papaverine to be used
120 mg/L
Other vasodilators to use intraop for vein dilatation
Trinitrate 8.3 mg/L Verapamil 16.7 mg/L
Vein dilation maximum pressure
100-150 mmHg
Wound complication with skip incisions vs open filet
9.6 vs 28%
Factors that dictate saving the contralateral GSV for future revasc
1) Age < 70 2) DM 3) CAD 4) ABI < 0.7 if 3/4 then risk of needing it is 25-43% in 5 years
Project of ex-vivo vein graft engineering via transfection PREVENT III database on vein type and size
>3.5 GSV as reference 3.0-3.5 = 1.5x primary failure < 3.0 mm = 2.4x primary failure (63% secondary patency 1 year) composite vein = 1.5x failure arm vein = 1.6x failure
Valves in the reversed vein graft
1) lysis decreases 15% hydrodynamic resistance 2) lysis increases flow rate 15-30%
Reversed vein valves in long term how often stenosis and critical stenosis
10% > 50% stenosis 2.5% critical stenosis some demodynamic significant valves also regress with time
Nonreversed graft after lysis vs reversed grafts in flow rate
nonreversed with lysis 20% better flow rate more pronounced in smaller veins 2-2.5mm where leaflets can take up 45% of lumen
Valvulotome types
1) Mills 2) Lemaitre expandable 3) fixed uresil
Mills valvulotome steps
1) introduce via side branch or distal end 2) advance through valve leaflet 3) distend graft 4) slowly withdraw
Lemaitre valvulotome vein diameteres
1.8 - 6 mm
Fixed valvulotome head sizes
2, 3, 4 mm
Ability of angiography or duplex to detect retaining valves
20% only
Intraoperative venography or duplex on identifying side branches of GSV angioscope
50% only Angioscope 67%
GSV fistula natural course
1/3 close spontaneously 1/3 decrease graft velocity 1/3 stable persistent no need to intervene
Cephalic vein conduit key points
Upper arm cephalic 4-6 mm reverse implant, too thin to lyse Forearm cephalic has webs and phlebitis due to previous access thick enough for lysis
Basilic vein conduit key points
upper arm large diameter hard for valve lysis forearm - too small, posterior position; rarely used
Patency of SSV in composite graft 1 and 3 year primary
50% and 35%
Patency of SSV primary 1 and 3 year
75% and 60%
Patency of FV for conduit
same as GSV
Patency of SFA as conduit
75% blow out in infection 1 year patency 60% primary Acute thrombosis in the absent of stenotic lesion
Causes of graft failure within 30 days
1) inadequate inflow 2) inadequate outflow 3) extrinsic lesions 4) intrinsic lesions
Pathogenesis of intimal hyperplasia
1) injury 2) chemokine and GF release 3) neutrophil and mononuclear cells recruited 4) amplified inflammation 5) SMC differentiate from contractile to synthetic phenotype 6) SMC migrate into intima 7) thickening of intima
Rate of restenosis at prox + dis anastomosis
53%
Rate that restenosis at retained valves
20%
Rate of annual graft patency loss due to atherosclerosis
4%/year during the 2-10 year mark
Edifoligide what is it
Double stranded oligodeoxynucleotide Inactivation of E2F transcription factor pathway inhibit bursts of SMC proliferation no difference
Papaverine concentration to treat vein graft spasm
30-60 mg in 1-2ml saline
Intraoperative duplex monitoring criteria and management
TABLE 63.2
Surveillance duplex diagnostic criteria and management
TABLE 63.3
Duplex scanning for follow up surveillance evidence
Cohort study suggest cost effective RCT disagree Recommendation for now is clinical follow-up +/- duplex but not strong recommendation
