Matthieu Zingg1, Alain Lacraz1, Helia Robert-Ebadi2, Benjamin Kressmann1, Frédéric Glauser2, Felix Waibel3, Martin Berli1,3 and Ilker Uçkay1,3*
1Department of Orthopaedic Surgery Service, Geneva University Hospitals & Faculty of Medicine, Switzerland
2Division of Angiology and Hemostasis, Geneva University Hospitals & Faculty of Medicine, Switzerland
3Balgrist University Hospital, Switzerland
Objective: Surgeons often recur to Transcutaneous Oxygen Pressure (TCOP) measurements to select the amputation level in patients with critical limb ischemia. Thirty-five mmHg are considered as acceptable threshold for uneventful stump healing.
Methods: Single-centre cohort over 11 years.
Results: We included 303 amputations in 211 adult patients. Forty-two amputations (14%) concerned the mid-foot, 7 (2%) the ankle, 154 (51%) the leg, 28 (9%) the knee joint and 72 (24%) the thigh region. We witnessed 78 stump failures (78/303; 26%) defined as the need for surgical revision or new-level amputation. Our TCOP threshold of 35 mmHg did not discriminate between success and stump failure. Specifically, considering foot and ankle amputations, a 20 mmHg value yielded the same prediction for stump failure as 40 mmHg. The sensitivity, specificity, positive and negative predictive values of a threshold of 35 mmHg for stump failure in foot amputations were 58%, 48%, 56%, and 50%, respectively. The Receiver-Operating-Curve/Area-Under-The-Curve ratio was 0.55. Regarding limb amputations, the threshold of 35 mmHg yielded sensitivity, specificity, positive and negative predictive values of 64%, 51%, 83%, and 28%, respectively. In multivariate analysis adjusting for case-mix, TCOP values were unrelated to stump failure, except for thigh amputations.
Conclusion: For foot and limb amputations, TCOP may confirm clinical impression but does not replace it. Surgeons should avoid using them solely to select the level of amputation.
Transcutaneous oxygen; Amputation; Chronic ischemia; Epidemiology; Stump
Zingg M, Lacraz A, Robert-Ebadi H, Kressmann B, Glauser F, Waibel F, et al. Transcutaneous Oxygen Pressure Values Often Fail to Predict Stump Failures after Foot or Limb Amputation in Chronically Ischemic Patients. Clin Surg. 2019; 4: 2366.