Evaluation of a non‐invasive monitoring method for free flap breast reconstruction using laser doppler flowmetrie and tissue spectrophotometry

Abstract

Background: Despite advances in the monitoring of free flaps, there is still a demand for new technology to detect ischemic complications at an early stage. The aim of the present study was to evaluate the reliability of the O2C-device in terms of detecting flap failure in commonly used perforator flaps for breast reconstruction. Methods: A total of 34 patients undergoing breast reconstruction were involved in this study. The perfusion dynamics of 23 deep inferior epigastric perforator flaps and 11 superior gluteal arterial perforator flaps were assessed using the O2C-device, which combines a laser light, to determine blood flow (flow), velocity, and white light to determine hemoglobin oxygenation (SO 2 ) and relative amount of hemoglobin (rHB). Measurements were carried out intra-operatively after clamping and declamping the perforator vessels. In the post-operative period measurements were carried out every hour for the first 48 hours and from 3rd to 7th for every 2 hours. These dates were compared to findings of clinical assessment. Results: Several intra-operative measurements, during the clamping and declamping the different perforator vessels, revealed a high correlation for all parameters: Flow (r 5 0.89, P < 0. 05), Velo (r 5 0.92, P < 0. 05), SO 2 (r 50.84, P <0. 05), and rHB (r 50.83 P < 0.05). Vessel occlusion was detected in five cases, of which three were due to arterial thrombosis and two further cases were due to venous occlusion. Of the five cases, one flap loss caused by venous occlusion was noted. Conclusion: The O2C-device seems to be a reliable, objective, and non-invasive device for the monitoring of free flaps. Thus, it may improve flap survival rates by detecting vascular compromise at an early stage. V V C 2013 Wiley Periodicals, Inc. Microsurgery 33: 350-357, 2013.

Identification of perioperative risk factor by laser-doppler spectroscopy after free flap perfusion in the head and neck: A prospective clinical study

“…As shown by this study, the role of the superficial and deep flow as well as the deep velocity values are very important at the first postoperative day, demonstrating that the ischemic period is more important than absolute values of oxygen saturation or hemoglobin levels within the flap as supported in the established literature . At the second postoperative day, all superficial values as well as the deep flow are important in creating a cluster of values which by revealing a trend in perfusion can influence the need or otherwise for a microsurgical revision of the transferred free flap …”

Current Evidence for Postoperative Monitoring of Microvascular Free Flaps

“…108,131 In a prospective study of 34 patients and 5 reexploration attempts, O2C produced 80% salvage rate, which is favorable to the standard clinical monitoring. 132 Recently, a prospective study by Mucke et al 133 demonstrated that using O2C that during early stages of the free flap integration, different parameters contribute at different times. In the immediate postoperative period, both superficial and deep blood flow and velocity decrease below the baseline.…”

Skin Perfusion Changes within 12 h after Axillary Plexus Block

“…The measurements represent only the nutritive, microvascular vessels because the light is completely absorbed if the vessel diameter is greater than 100 mm [14]. This device has been proven to be a reliable and valid tool in various conditions, such as microvascular flap monitoring [15], flap microperfusion [16], skin perfusion in sore-prone pressure areas [14], determining the need for medical leeches in congested tissues [17], and microcirculatory changes of cold contact injuries [18]. …”