title: The value of pre-discharge Duplex scanning in infrainguinal graft surveillance.
abstract: OBJECTIVE
  Protocols and criteria for Duplex-based graft surveillance programmes (GS) vary widely as to the optimum regimens for maximising detection of "at risk" grafts. Few centres recommend starting GS before discharge. The aim of this study was to audit our experience with respect to early scanning.
  
  
  METHODS
  Vascular Studies Unit, Bristol Royal Infirmary.
  
  
  METHODS
  The records of 123 patients entering GS from January 1992 were reviewed. Patients were scanned at 1 week, 6 weeks and 3, 6, 9 and 12 months post-bypass. Haemodynamic criteria used were a peak mean velocity (PMV) less than 45 cm/s and a focal velocity disturbance with a V2/V1 ratio of 1.5 or more.
  
  
  RESULTS
  Forty-six abnormalities (37% detection rate) were identified on scans within one week. In all cases, on-table completion studies with either arteriography and/or flow measurements had failed to identify the anomalies subsequently detected by Duplex. At 1 week, six grafts had occluded, 27 had a focal PMV increase (mean V2/V1 ratio: 2.6; range 1.5-4.3), four had low flow velocities, four had arteriovenous fistulae, one contained mobile thrombus, two had retained cusps and two had hamstring entrapment. Of 40 patent, but compromised grafts, 18 warranted immediate investigation. Of the 27 patients with velocity disturbances on Duplex, 25 were simply observed but, eight have since required intervention for definitive stenoses at these sites which, in retrospect, were evident within the first postoperative week.
  
  
  CONCLUSIONS
  Pre-discharge scanning is a useful modality for detecting technical problems. Intrinsic graft abnormalities, possibly the sites of future definitive stenoses, have been visualised even at 1 week and once identified, can be more closely scrutinised thereafter. Pre-discharge colour Duplex is recommended as standard practice for quality control after infrainguinal bypass.
authors.affiliation: Vascular Studies Unit, Bristol Royal Infirmary, U.K.
authors.forename: Y G
authors.initials: YG
authors.lastname: Wilson
authors.forename: A H
authors.initials: AH
authors.lastname: Davies
authors.forename: I C
authors.initials: IC
authors.lastname: Currie
authors.forename: C
authors.initials: C
authors.lastname: McGrath
authors.forename: M
authors.initials: M
authors.lastname: Morgan
authors.forename: R N
authors.initials: RN
authors.lastname: Baird
authors.forename: P M
authors.initials: PM
authors.lastname: Lamont
mesh_terms: D001157:Arterial Occlusive Diseases / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging*; D006801:Humans; D007866:Leg / Q000098:blood supply*; D010351:Patient Discharge; D011138:Polytetrafluoroethylene; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D018616:Ultrasonography, Doppler, Duplex; D014680:Veins / Q000637:transplantation
chemical_list: D011138:Polytetrafluoroethylene