Predictors of surgical outcome in patients undergoing aortobifemoral bypass reconstruction.
ABSTRACT We report a prospective study with 2 years of follow-up including 105 consecutive symptomatic patients (58.1% claudication and 41.9% severe ischemia) undergoing aortobifemoral bypass surgery (ABF/BP). Proportional-hazards, stepwise regression, and life-table analyses were used to determine predictors of the following outcome criteria: graft patency, amputation, mortality, symptomatic recurrence, and palliation. The operative mortality was 5.7% and the 2-year cumulative mortality was 15.5%. Most deaths (61.5%) were cardiac-related. There were 3 predictors of mortality: the presence of more than 1 surgical risk factor (relative risk [RR] 6.2; p less than 0.001), advanced age (RR 2.9; p = 0.03) and the presence of ischemic heart disease (RR 1.5; p = 0.045). No patient required amputation. Early graft patency rate was 94.3% and the 2-year cumulative patency was 92.8%. The only predictor of graft failure was preoperative ankle/brachial index (ABI) of less than 0.4 (RR 6.1; p = 0.003). Early symptomatic relief was 98.1% and at 2 years it was 77.3%. There were 2 predictors of symptomatic recurrence: postoperative smoking (RR 2.4; p less than 0.001) and impaired runoff (RR 2.5; p = 0.017). Cumulative palliation was 87.6% at 1 month and 66.5% at 2 years postoperatively. There were 2 predictors of palliation: the presence of more than 1 surgical risk-factor (RR 1.8; p = 0.001) and postoperative transcutaneous oximetry (PtcO2) of less than 35 mmHg (RR 3.1; p = 0.04). We conclude that the best predictors of outcome in patients undergoing ABF/BP surgery were the number of preoperative risk factors, age, ischemic heart disease, ABI, PtcO2, postoperative smoking, and angiographic runoff.(ABSTRACT TRUNCATED AT 250 WORDS)
Article: Transcutaneous oximetry in clinical practice: consensus statements from an expert panel based on evidence.[show abstract] [hide abstract]
ABSTRACT: Transcutaneous oximetry (PtcO2) is finding increasing application as a diagnostic tool to assess the peri-wound oxygen tension of wounds, ulcers, and skin flaps. It must be remembered that PtcO2 measures the oxygen partial pressure in adjacent areas of a wound and does not represent the actual partial pressure of oxygen within the wound, which is extremely difficult to perform. To provide clinical practice guidelines, an expert panel was convened with participants drawn from the transcutaneous oximetry workshop held on June 13, 2007, in Maui, Hawaii. Important consensus statements were (a) tissue hypoxia is defined as a PtcO2 <40 mm Hg; (b) in patients without vascular disease, PtcO2 values on the extremity increase to a value >100 mm Hg when breathing 100% oxygen under normobaric pressures; (c) patients with critical limb ischemia (ankle systolic pressure of < or =50 mm Hg or toe systolic pressure of < or =30 mm Hg) breathing air will usually have a PtcO2 <30 mm Hg; (d) low PtcO2 values obtained while breathing normobaric air can be caused by a diffusion barrier; (e) a PtcO2 <40 mm Hg obtained while breathing normobaric air is associated with a reduced likelihood of amputation healing; (f) if the baseline PtcO2 increases <10 mm Hg while breathing 100% normobaric oxygen, this is at least 68% accurate in predicting failure of healing post-amputation; (g) an increase in PtcO2 to >40 mm Hg during normobaric air breathing after revascularization is usually associated with subsequent healing, although the increase in PtcO2 may be delayed; (h) PtcO2 obtained while breathing normobaric air can assist in identifying which patients will not heal spontaneously.Undersea & hyperbaric medicine: journal of the Undersea and Hyperbaric Medical Society, Inc 36(1):43-53. · 0.80 Impact Factor