Transcutaneous Oximetry May Predict Wound Healing Complications In Preoperatively Radiated Soft Tissue Sarcoma

Abstract

Background: Preoperative radiation is frequently used in management of soft tissue sarcoma. We hypothesize that anoxic tissue from preoperative radiation contributes to surgical wound complications and that transcutaneous oximetry (TcO2) measurements made preoperatively can predict wounds at risk.

Methods: Ten consecutive patients were prospectively enrolled. TcO2 was recorded at five time points. Wound complications (defined as major or minor) and healing outcomes were recorded out to 120 days postoperatively. Means between groups with and without wound complications were compared by use of a Student's t-test (p < 0.05).

Results: There were three major and one minor wound complication. During the time from radiation to surgery, patients with wound complications had a 13.1 mmHg decrease in mean TcO2 while those who healed uneventfully had an increase of 2.3 mm Hg (p=0.09). Patients with complications had a low preoperative TcO2 of 18.7 mmHg compared to those without complications (18.7 vs. 33.4 mmHg; p=0.09). No patient with a TcO2 greater than 25 mmHg immediately preoperatively developed a wound complication.

Conclusions: This data suggests an earlier recovery of tissue oxygenation in patients that healed without complication. The TcO2 measurement immediately preceding surgery seems to be the most important in predicting wound complications. Larger scale investigation may determine if TcO2 measurement is a viable clinical tool to aid in risk assessment for potential wound complications.

Figures

Figure 1.

A clinical photograph demonstrating the placement of leads around a planned incision for resection of a medial thigh soft tissue sarcoma. The red line demonstrates the planned incision.

Figure 2.

This chart demonstrates the change in the mean TcO2 measurement for each time interval for the whole patient series (black), as well as divided between cohorts with (diagonal lines) and without (gray) complications. Interval 1 represents the time from start of radiation to the middle of radiation. Interval 2 represents the time from middle of radiation to completion of radiation. Interval 3 (the “rest period”) represents the time from completion of radiation to immediately prior to surgical resection. Lastly, interval 4 represents the time from immediately preoperative to two weeks postoperative.

Figure 3.

This chart demonstrates the change in the lowest TcO2 measurement for each time interval for the whole patient series (black), as well as divided between cohorts with (diagonal lines) and without (gray) complications. The intervals are as described in Figure 2.

Figure 4.

This graph represents the mean TcO2 measurement for each time point for the whole patient series as well as those patients with and without wound healing complications.

Figure 5.

This graph represents the lowest TcO2 measurement for each time point for the whole patient series as well as those patients with and without wound healing complications.