Ulf Dornseifer1, Andreas Max Fichter2, Sarah Von Isenburg1, Sofia Stergioula1, Ina-Christine Rondak3, Milomir Ninkovic1. 1. Department of Plastic, Reconstructive, Hand and Burn Surgery, Bogenhausen Academic Hospital, Technische Universität München, Munich, 81925, Germany. 2. Department of Oral and Maxillofacial Surgery, Technische Universität München, Klinikum rechts der Isar, Munich, 81675, Germany. 3. Institute of Medical Statistics and Epidemiology, Technische Universität München, Munich, 81675, Germany.
Abstract
BACKGROUND: While it is a known fact that warming increases blood flow in healthy tissue, little is known about the impact of active thermoregulation on the altered microcirculation of free flaps. The objective of the study was to identify the impact of postoperative active thermoregulation on free flap microcirculation. METHODS: Tissue temperature was assessed in 25 free perforator flaps using an implanted probe. Active thermoregulation was achieved using a water circulation based system. Changes in microcirculation were evaluated at the day of surgery and throughout the first three postoperative days after passive cooling (room temperature), passive warming (wound dressing), active warming (38 °C) and active cooling (15 °C) using laser Doppler flowmetry and remission spectroscopy. RESULTS: Active warming increased flap temperature by 7.7% to 36.4 °C ± 0.5 °C in comparison to the initial values of flaps without dressing (P < 0.001). As a result, the blood flow increased by 77.7% of the base value (P < 0.001). A significant correlation between all microcirculation parameters and tissue temperature was observed with a 5.52 AU blood flow increase per degree temperature increase (r = 0.7; P < 0.001). All microcirculation parameters showed a statistically significant increase after both passive and active warming, whereby active warming showed significantly higher values than passive warming. CONCLUSIONS: Active thermoregulation using water-based circulation is an effective and safe procedure to improve microcirculation in free flaps and is superior to conventional passive warming strategies.
BACKGROUND: While it is a known fact that warming increases blood flow in healthy tissue, little is known about the impact of active thermoregulation on the altered microcirculation of free flaps. The objective of the study was to identify the impact of postoperative active thermoregulation on free flap microcirculation. METHODS: Tissue temperature was assessed in 25 free perforator flaps using an implanted probe. Active thermoregulation was achieved using a water circulation based system. Changes in microcirculation were evaluated at the day of surgery and throughout the first three postoperative days after passive cooling (room temperature), passive warming (wound dressing), active warming (38 °C) and active cooling (15 °C) using laser Doppler flowmetry and remission spectroscopy. RESULTS: Active warming increased flap temperature by 7.7% to 36.4 °C ± 0.5 °C in comparison to the initial values of flaps without dressing (P < 0.001). As a result, the blood flow increased by 77.7% of the base value (P < 0.001). A significant correlation between all microcirculation parameters and tissue temperature was observed with a 5.52 AU blood flow increase per degree temperature increase (r = 0.7; P < 0.001). All microcirculation parameters showed a statistically significant increase after both passive and active warming, whereby active warming showed significantly higher values than passive warming. CONCLUSIONS: Active thermoregulation using water-based circulation is an effective and safe procedure to improve microcirculation in free flaps and is superior to conventional passive warming strategies.
Authors: Andreas M Fichter; Lucas M Ritschl; Luisa K Robitzky; Stefan Wagenpfeil; David A Mitchell; Klaus-Dietrich Wolff; Thomas Mücke Journal: Sci Rep Date: 2016-10-21 Impact factor: 4.379