Aims: Despite the clinical usefulness of transcutaneous oxygen tension (TcPO
2) to assess the severity of limb ischemia, the factors determining TcPO
2 in patients with peripheral arterial disease (PAD) have not been fully clarified. We therefore examined the regions of arterial stenosis and clinical factors affecting lower-extremity TcPO
2.
Methods: Resting TcPO
2 (REST-TcPO
2) and postexercise TcPO
2 (Ex-TcPO
2) in the calf region and the dorsalis pedis were measured simultaneously in 66 patients (132 limbs) with clinically suspected PAD, in whom angiography was also performed.
Results: The peripheral arteries of the lower extremities were divided into five segments, and the impact of significant stenosis in each segment on ipsilateral TcPO
2 was evaluated by multiple regression analysis. In the calf region, significant stenosis of the proximal arteries (common-external iliac artery) revealed stronger involvement determining Ex-TcPO
2 than the peripheral segment (posterior tibial artery). In the dorsalis pedis, the peripheral segment (anterior tibial artery) more strongly determined Ex-TcPO
2 and REST-TcPO
2 than proximal segments. Age, creatinine, and diabetes were associated with REST-TcPO
2 of the calf region independent of arterial stenoses, while those of the dorsalis pedis were independently associated with age, and creatinine. In contrast, Ex-TcPO
2 in both regions was not independently associated with clinical factors, except for stenosis of the perfusing arteries.
Conclusion: The vascular lesions affecting TcPO
2 differ between the calf region (proximal > peripheral) and the dorsalis pedis (proximal < peripheral). In addition postexercise TcPO
2 is solely determined by stenosis of the perfusing arteries, while TcPO
2 at rest is affected by multiple clinical factors.
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