Prediction of Border Necrosis in Skin Flaps of Pigs with Microdialysis

Abstract

Metabolic changes were studied in newly-raised pedicled skin flaps of pigs. These flaps were constructed so that their distal parts were predestined to necrotize. The objective was to find new ways of making early postoperative prognostications about future flap viability. For that purpose, the fluorescein penetration technique was compared with microdialysis monitoring of interstitial tissue concentrations of glucose, lactate, and glycerol. These parameters were measured 6 to 24 hr postoperatively, and collected at five different sites, ranging from base to end of the flap. The fluorescein penetration border appeared closer to the flap base than a subsequent necrotic border, thereby confirming that this technique--when applied early in the postoperative period--underestimates flap viability. The authors also observed that glucose concentration in the flap declined at an early stage close to the border of fluorescein penetration. No further change was seen in more distal parts of the flap. Consequently, glucose concentration underestimates the viable flap area just as fluorescein does. In contrast, both glycerol and lactate concentrations began to increase closer to the necrotic border. Both increased significantly on passing the border between viable tissue and tissue which later on would become necrotic, and reached levels in the necrotic portion which were never seen in the viable parts. These results were obtained within the first postoperative hours. They suggest that microdialysis monitoring of lactate and glycerol concentrations in skin flaps of pigs can be used to estimate at an early stage where the necrotic border will appear later on. If these results hold true in humans, they may have important clinical applications.

Deep Sedation with Dexmedetomidine in a Porcine Model Does Not Compromise the Viability of Free Microvascular Flap as Depicted by Microdialysis and Tissue Oxygen Tension

“…In addition, flap tissue oxygenation was stable in both groups. Earlier studies with microdialysis have shown that glucose and lactate concentrations change in a characteristic way when ischemia is present (21)(22)(23). Moreover, Setälä et al (24) have shown in a similar animal model that microdialysis is a sensitive method in the early diagnosis of ischemia in musculocutaneous flaps.…”

Microdialysis of the rectus abdominis muscle for early detection of impending abdominal compartment syndrome

“…Microdialysis has been used in experimental and clinical settings for monitoring of energy metabolism in severe brain injury [10], liver transplantation [11], plastic surgery [12], and cardiovascular surgery [13]. An increased lactate-to-pyruvate ratio (L/P ratio) has evolved as a reliable marker for ischemia, and increased glycerol levels as an indicator for cell membrane damage [14][15][16][17].…”

Hepatic cell membrane damage during cold preservation sensitizes liver grafts to rewarming injury

“…Differences between the concentration of the metabolite in the ingoing perfusion solution and that in the outgoing perfusate are determined. The procedure has already reached widespread application in neurosurgery,4,5 neurointensive care, cardiovascular9 and plastic surgery,10 and in the monitoring of skeletal muscle,11,12 adipose tissue, and some metabolic diseases 17. It has also been used in the monitoring of liver grafts in rats …”