Micro-lightguide spectrophotometry (O2C®) as a predictor of intermediate outcome in patients with critical limb ischemia after percutaneous transluminal angioplasty (PTA).
OBJECTIVE
Micro-lightguide spectrophotometry (O2C®) provides easily and rapidly measurable parameters of tissue microcirculation. The aim of this study was to assess whether micro-lightguide spectrophotometer (O2C®) based parameters of the tissue microcirculation can serve as predictors of ulcer healing. Furthermore, we tried to identify cut off values to forecast patient outcome and check other diagnostic meanings of individual O2C-parameters.


METHODS
Forty individuals, all suffering from critical limb ischemia and arterial or arteriovenous ulcers were retrospectively investigated concerning O2C®- and ankle/toe brachial index-measurements before and up to two times after percutaneous transluminal angioplasty (PTA). At a median follow-up of 7 (range 3 to 14) months after PTA the current peripheral arterial disease (PAD) status, ulcer healing, adverse cardiovascular events including death and endovascular or surgical treatments were noted.


RESULTS
We found in patients with healing wounds a significant increase in oxygen saturation (SO2, median 26.35±26.94%) compared to non-healers (-4.27±25.24%, P=0.006) as well as regarding blood flow (median 41.12±51.23AU vs. -9.46±24.01 AU, P=0.005). Additionally, the parameter rHb separated reliably between arterial and arteriovenous ulcers (P=0.024). In Cox regression models, increases after revascularisation of more than 6 % in SO2 (HRR=6.08, 95%CI 1.56-23.65, P=0.009) and flow decreases of less than 12 AU (HRR 4.95, 95%CI 1.42-17.31, P=0.012) were significantly associated with amputation-free survival.


CONCLUSIONS
The O2C®-parameters SO2 and flow provide prognostic information for ulcer healing as well as for amputation-free survival, and rHB adds information about a possible arterial or arteriovenous genesis of an ulcer.
Division of Vascular Medicine, Department of Cardiovascular Medicine, University Hospital of Muenster, Muenster, Germany - Holger.Reinecke@ukmuenster.de.
K
K
Weber
K
K
Gebauer
F
F
Lüders
M
M
Meyborg
N
N
Malyar
T
T
Goerge
H
H
Reinecke
D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty / Q000009:adverse effects / Q000379:methods; D055109:Ankle Brachial Index / Q000379:methods; D005260:Female; D006801:Humans; D007511:Ischemia / Q000209:etiology / Q000503:physiopathology; D007871:Leg Ulcer / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D035002:Lower Extremity / Q000098:blood supply; D008297:Male; D008833:Microcirculation; D015591:Microspectrophotometry / Q000379:methods*; D008875:Middle Aged; D010101:Oxygen Consumption; D058729:Peripheral Arterial Disease / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D011182:Postoperative Care / Q000379:methods; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D014945:Wound Healing