Acellular fish skin matrix on thin-skin graft donor sites: a preliminary study.

OBJECTIVE: Surgery for head and neck cancer often requires free flap reconstructions, whose harvesting site often requires a thin-skin graft. Wounds from the thin-skin donor site are comparable to an intermediate or deep second-degree burn. This is uncomfortable and can lead to complications such as a long healing time, local infections and pain. Since they are reproducible, these wounds may serve as a model for an objective assessment of new healing medical devices. The acellular fish skin matrix is a new medical device designed to improve healing quality and time. METHODS: We compared the outcomes between standard procedure and the use of this matrix placed on the split-thickness skin graft (STSG) donor site, in patients operated on in our centre for radial forearm free flap reconstruction for head and neck wounds. RESULTS: There were 21 patients included. The healing time was halved when using the acellular fish skin matrix, from 68 to 32 days on average. Acellular fish skin matrix reduced pain levels and local infection. The visual analogue pain scale (VAS) was ≥3 at five days (p=0.0034) and infection rate reduced from 60% to 0% (p=0.0039). CONCLUSION: These results are extremely encouraging. However, it is important to take into account the relatively high cost of this matrix for its future indications. A larger study including an overall cost estimation and an assessment on different wound types would be interesting, to better target the indications of the acellular fish skin matrix.

Dense red blood cell and oxygen desaturation in sickle-cell disease.

Production of abnormal hemoglobin (HbS) in sickle-cell disease (SCD) results in its polymerization in deoxygenated conditions and in sickled-RBC formation. Dense RBCs (DRBCs), defined as density >1.11 and characterized by increased rigidity are absent in normal AA subjects, but present at percentages that vary of a patient to another remaining stable throughout adulthood for each patient. Polymerized HbS has reduced affinity for oxygen, demonstrated by the rightward shift of the oxygen-dissociation curve, leading to disturbances in oxygen transport. Ninety-two SCD patients' total RBCs were separated into LightDRBC (LRBC) (d < 1.11 g/mL) and DRBC fractions. Venous blood partial oxygen pressure and RBC-fraction-deoxygenation and -reoxygenation Hb-oxygen-equilibrium curves were determined. All patients took a 6-minute walking test (6MWT); 10 had results before and after >6 months on hydroxyurea. 6MWT time with SpO2 < 88% (TSpO2 < 88) assessed the physiological impact of exertion. Elevated mean corpuscular hemoglobin (Hb) concentrations, decreased %HbF, and 2,3-bisphosphoglycerates in DRBCs modulated Hb-oxygen affinity. Deoxygenation and reoxygenation Hb-oxygen equilibrium curves differed between normal Hb AA and SS RBCs and between LRBCs and DRBCs, with rightward shifts confirming HbS-polymerization's role in affinity loss. In bivariate analyses, 50% Hb saturation correlated positively with %DRBCs (P < 0.0001, r(2) = 0.34) and negatively with %HbF (P < 0.0001, r(2) = 0.25). The higher the %DRBCs, the longer the TSpO2 88 (P = 0.04). Hydroxyurea was associated with significantly shorter TSpO2 < 88 (P = 0.01). We report that the %DRBCs directly affects SCD patients' SpO2 during exertion; hydroxyurea improves oxygen affinity and lowers the %DRBCs. Am. J. Hematol. 91:1008-1013, 2016. © 2016 Wiley Periodicals, Inc.