Editing Infra-inguinal bypass (section)

== '''Procedure:''' ==

* Assessing inflow site:
** Compare with radial artery pressure - drop of 10mm Hg is significant, as is >15% drop in pressure after administration of intra-arterial papaverine.
** If no good, need to move more proximally or address the inflow problem (endarterectomy vs angioplasty).
* Harvesting the vein
** GSV
*** Groin incision over SFJ (plan ahead if also accessing CFA/SFA to use the same incision). Incise along GSV, directly over it.
*** Identify SFJ (easiest in fossa ovalis) then follow GSV down. Skip incisions are preferable.
*** Grasp adventitia, not the vein itself
*** Side branches ligated with 3/0 or 4/0 silk, leaving a short stump so as not to impinge on the conduit
*** Vein spasm can turn a blue vein white and should be treated with local papaverine or lidocaine irrigation
*** Cannulate vein with a 3mm olive tip needle and gently distend with hep saline - it should flow readily, distend smoothly, and be free of fibrotic and non-distensible segments
*** Missed or small avulsed branches should be repaired with longitudinally-oriented 6/0 or 7/0 prolene on a BV-1 or BV-175 needle
*** Small bulldog on proximal end and flush hep saline from the distal end, avoiding overdistension. 
*** Place in hep saline bath
** SSV
*** Harvested prone
*** Longitudinal incision on posterior calf
*** Dissect down to vein
*** Careful of sural nerve, which follows SSV
* Tunnel conduit
** Tunneller passed from groin incision, beneath sartorius, to the popliteal fossa
** Mark vein to check orientation
** Pull vein through
** Re-check orientation
* Proximal anastomosis
** IV heparin 5000 units 5 minutes prior to clamping
** Clamp inflow vessels
** Arteriotomy with an 11 blade, and extend proximally and distally with Potts scissors
** Running 5/0 prolene suture
*** Start with heel and sew halfway along the anastomosis
*** Start with toe and sew back towards the first suture
*** Sew continuously towards each other
** Flush with hep saline
** Release clamps
** Fix obvious problems
** Apply haemostatic agent (FloSeel powder)
** Further repairs
* Distal anastomosis 
** Check flow through graft
** Check orientation
** Same as above
* Closure
** Reapproximate fascia with 3/0 vicryl
** Subcutaneous tissue closed in layers
** Consider drains, especially if concern for lymphatic leak
* Completion assessment
** Distal pulse palpation
** Doppler flow assessment
** Arteriography
*** Gold standard, especially in circumstances where run-off is in question
*** Use a 4 or 5 Fr sheath to deliver contrast, preferably for DSA rather than fluoroscopy
** Angioscopy