Optimal waiting period for foot salvage surgery following limb revascularization

It is not clear how soon after bypass surgery tissue perfusion in the ischemic foot is adequate for healing. The purpose of this study was to determine the time interval for tissue to receive adequate oxygenation for healing following limb revascularization. Eleven patients with severe foot ischemia as defined by a transcutaneous oxygen tension (TcPO2) of 30 mm Hg or less were included in the study. TcPO2 measurements were performed prior to the lower extremity bypass and at postoperative day 1, 2, and 3. The mean preoperative value (9.27 mm Hg) was compared with the mean value at postoperative day 1 (17.73 mm Hg), postoperative day 2 (20.36 mm Hg), and postoperative day 3 (36.82 mm Hg) using paired samples t-tests. Statistically significant differences were observed between the mean preoperative TcPO2 measurement and the mean TcPO2 measurement taken on the 3rd postoperative day. The mean TcPO2 level increased from 9.27 mm Hg preoperatively to 36.82 mm Hg by the 3rd postoperative day (p = .001). There was also a statistically significant difference between the mean values on the 2nd (20.36 mm Hg) and 3rd postoperative day (36.82 mm Hg) (p = .002). Despite this finding, 5 of the 11 patients still had individual TcPO2 readings of less than 30 mm Hg on the 3rd postoperative day. Therefore, it can be concluded that in most instances tissue oxygenation reaches an adequate level after waiting at least 3 days following a bypass. Waiting 3 or more days could give adequate time for tissue reperfusion to promote healing of the surgical site.