title: Infrapopliteal bypasses to severely calcified, unclampable outflow arteries: two-year results.
abstract: OBJECTIVE
  Although severe, circumferential calcification of distal outflow vessels is frequently encountered, its effect on bypass graft patency rates has not been well established.
  
  
  METHODS
  Using a computerized vascular registry database, we conducted a retrospective review of 1957 bypass grafts with distal anastomoses to infrapopliteal vessels performed at a single institution between 1990 and 1995. Of these cases, 101 procedures involved outflow arteries classified by the operating surgeon as severely calcified and unclampable (requiring intraluminal occluders for vascular control), whereas in 105 cases the outflow arteries had no calcification present at the distal anastomotic site. The remaining cases had varying intermediate degrees of calcification and were not analyzed. Indication for bypass procedure was limb-threatening ischemia in 90% of severe calcification cases and in 84% of cases without calcification. Atherosclerotic risk factors were similar except for the presence of diabetes (92% vs 74%, p < 0.001), creatinine level > 2.0 mg/dl (21% vs 8%, p < 0.01), and dialysis dependency (17% vs 3%, p < 0.001), all of which were more prevalent in the severe calcification group. Infrapopliteal distal anastomotic location and type of conduit ( > 90% autogenous vein) were comparable between groups.
  
  
  RESULTS
  Primary patency, secondary patency, and foot salvage rates at 24 months were 60%, 65%, and 77% for the severe calcification group and 74%, 82%, and 93% for the no calcification group, respectively. With secondary procedures comprising 26% of cases in each group, data from the 150 primary procedures were reanalyzed separately. In this primary procedure group, 24-month primary patency, secondary patency, and foot salvage rates were 66%, 69%, and 77% for the severe calcification group and 84%, 90%, and 96% for the no calcification group, respectively. Although patency and salvage rates were consistently lower for the severe calcification group in all analyses, these differences did not achieve significance by log-rank life-table analysis at 2-year follow-up. Perioperative 30-day mortality (0.99% severe calcification vs 0.95% no calcification) and 24-month survival rates (84% severe calcification vs 83% no calcification) were also similar between groups.
  
  
  CONCLUSIONS
  These data suggest that effective techniques exist to perform infrapopliteal bypasses to severely calcified, unclampable outflow arteries with results comparable with those obtained with clampable, uncalcified vessels. The finding of severe, circumferential calcification of outflow target arteries should not dissuade vascular surgeons from distal bypass for limb salvage indications.
authors.affiliation: Division of Vascular Surgery, Deaconess Hospital, Boston, MA 02215, USA.
authors.forename: B D
authors.initials: BD
authors.lastname: Misare
authors.forename: F B
authors.initials: FB
authors.lastname: Pomposelli
authors.forename: G W
authors.initials: GW
authors.lastname: Gibbons
authors.forename: D R
authors.initials: DR
authors.lastname: Campbell
authors.forename: D V
authors.initials: DV
authors.lastname: Freeman
authors.forename: F W
authors.initials: FW
authors.lastname: LoGerfo
mesh_terms: D000368:Aged; D001161:Arteriosclerosis / Q000453:epidemiology; D001807:Blood Vessel Prosthesis; D002114:Calcinosis / Q000453:epidemiology / Q000601:surgery*; D016022:Case-Control Studies; D003925:Diabetic Angiopathies / Q000453:epidemiology; D005260:Female; D006488:Hemostasis, Surgical; D006801:Humans; D007511:Ischemia / Q000453:epidemiology / Q000601:surgery; D007866:Leg / Q000098:blood supply; D015993:Life Tables; D008297:Male; D016491:Peripheral Vascular Diseases / Q000453:epidemiology / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology; D051437:Renal Insufficiency / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D012501:Saphenous Vein / Q000637:transplantation; D013997:Time Factors; D014654:Vascular Patency