title: Strategies to reduce intraluminal clot formation in endoscopically harvested saphenous veins.
abstract: OBJECTIVE
  Residual clot strands within the excised saphenous vein are an increasingly recognized sequela of endoscopic vein harvest. We hypothesized that endoscopic visualization facilitated by sealed carbon dioxide insufflation causes stagnation of blood within the saphenous vein. In the absence of prior heparin administration, this stasis provokes clot formation.
  
  
  METHODS
  Forty consecutive patients having coronary artery bypass grafting underwent endoscopic vein harvest using sealed (Guidant VasoView, n = 30; Guidant Corp, Minneapolis, Minn) or open (Datascope ClearGlide, n = 10; Datascope Corp, Montvale, NJ) carbon dioxide insufflation followed by ex vivo assessment of intraluminal saphenous vein clot via optical coherence tomography. In the sealed carbon dioxide insufflation groups, clot formation was compared with (preheparinized, n = 20) and without (control, n = 10) heparin administration before endoscopic vein harvest, either at a fixed dose or titrated to an activated clotting time greater than 300 seconds. Risk factors for clot formation were assessed.
  
  
  RESULTS
  Residual saphenous vein clot was a universal finding in control veins (sealed carbon dioxide insufflation endoscopic vein harvest without preheparinization). At either dose used, heparin given before endoscopic vein harvest significantly decreased saphenous vein clot burden. A similar reduction in clot was observed when using open carbon dioxide insufflation endoscopic vein harvest without preheparinization. Intraoperative blood loss and blood product requirements were similar in all groups. Patient age and preoperative maximum amplitude of the thrombelastography tracing showed a linear correlation with saphenous vein clot volume.
  
  
  CONCLUSIONS
  By enabling the quantification of this issue as never before possible, optical coherence tomography screening revealed that intraluminal saphenous vein clot is frequently found after endoscopic vein harvest. Systemic heparinization before harvest or an open carbon dioxide endoscopic vein harvest system are benign changes in practice that can significantly lessen this complication.
authors.affiliation: Department of Surgery, Division of Cardiac Surgery, University of Maryland School of Medicine, Baltimore, Md 21201, USA.
authors.forename: Emile N
authors.initials: EN
authors.lastname: Brown
authors.forename: Zachary N
authors.initials: ZN
authors.lastname: Kon
authors.forename: Richard
authors.initials: R
authors.lastname: Tran
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Burris
authors.forename: Junyen
authors.initials: J
authors.lastname: Gu
authors.forename: Patrick
authors.initials: P
authors.lastname: Laird
authors.forename: Philip S
authors.initials: PS
authors.lastname: Brazio
authors.forename: Seeta
authors.initials: S
authors.lastname: Kallam
authors.forename: Kimberly
authors.initials: K
authors.lastname: Schwartz
authors.forename: Lisa
authors.initials: L
authors.lastname: Bechtel
authors.forename: Ashish
authors.initials: A
authors.lastname: Joshi
authors.forename: Shaosong
authors.initials: S
authors.lastname: Zhang
authors.forename: Robert S
authors.initials: RS
authors.lastname: Poston
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use*; D001026:Coronary Artery Bypass; D004724:Endoscopy / Q000009:adverse effects; D005260:Female; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012501:Saphenous Vein / Q000637:transplantation*; D020858:Tissue and Organ Harvesting / Q000009:adverse effects* / Q000295:instrumentation; D041623:Tomography, Optical Coherence; D020246:Venous Thrombosis / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D006493:Heparin