Feasibility of Photo-Optical Transcutaneous Oxygen Tension Measurement During Revascularization of the Lower Extremity

Abstract

Objectives: A novel approach in the evaluation of peripheral arterial disease is the photo-optical oxygen tension measurement (pTCpO2). This modality is suggested to be more practical in use in comparison to standard electro-chemical oxygen tension measurement. Hence, pTCpO2 might be of added value to evaluate revascularization of the lower extremities periprocedural. We conducted a preliminary feasibility study to analyze the potential of pTCpO2 dur ing revascular ization. Methods: Ten patients scheduled for revascularization of the lower extremities were enrolled. pTCpO2 values of the affected lower extremity were measured pre-operatively, during revascularization and after revascularization. Results were compared to the pre-and postoperative ankle-brachial index (ABI) and to perioperative angiography. Primary endpoint was the feasibility of perioperative pTCpO2 measurement. Secondary endpoints were concordance between pTCpO2, ABI, angiography and clinical outcome. Results: Two out of twelve measurements were unsuccessful. Eight out of ten patients experienced significant clinical improvement and pTCpO2 increase. Two patients that did not experience clinical improvement corresponded with no changes in intraoperative angiography and without increase in ABI or pTCpO2. A significant and strong correlation was found between prior and after revascularization ABI and pTCpO2 measurements ( r = 0.82 P = 0.04). Conclusions: Photo-optical transcutaneous oxygen tension measurement may serve as an intraoperative tool to evaluate the success of revascularization. pTCpO2 could be an alternative for the ABI to determine the success of lower extremity revascularization.

Guide for the non-invasive study of chronic ischemia of the lower limbs

“…La determinación de la TcPO2 puede obtenerse utilizando un método electroquímico o fotoóptico (11)(12)(13)(19)(20)(21). El método electroquímico (eTcPO 2 ) (Fig.…”

“…La duración media de la prueba es de 25-30 minutos. Una de sus limitaciones es que consume tiempo, ya que el electrodo requiere un periodo de calentamiento para alcanzar una temperatura cutánea, que oscila entre 42 y 45 °C, según los estudios (se desconoce cuál es el valor óptimo) (11,12,15,21,22). El método fotoóptico (pTcPO 2 ) (Fig.…”

“…Además, tampoco precisa limpieza adicional de los electrodos ni cambio de membrana. Por lo tanto, este método de medición consume menos tiempo, y además es más sencillo y económico, por lo que resulta más accesible (20,21).…”

“…Aunque la pTcPO 2 tiene tendencia a registrar valores mayores en comparación con la eTcPO 2 (probablemente porque el electrodo Clark consume oxígeno), existe una alta correlación de los valores de TcPO 2 obtenidos con ambos métodos. Se ha observado un potencial beneficio de la pTcPO 2 frente a la eTcPO 2 (20,21).…”

“…Aunque en relación con esto, algunos autores han establecido un índice de perfusión regional, que es el cociente entre la TcPO 2 medida en la extremidad afectada y la TcPO 2 obtenida en la otra localización. Hoy en día no existe unanimidad en su valor de referencia (11,12,15,21,22).…”