A Novel Small-Animal Model of Irradiated, Implant-Based Breast Reconstruction.

BACKGROUND: There is currently a need for a clinically relevant small-animal model for irradiated, implant-based breast reconstruction. Present models are inadequate in terms of suboptimal location of expander placement and mode of radiation delivery, correlating poorly with the human clinical scenario. The authors hypothesized that by delivering fractionated radiation and placing an expander under the scalp of the animal, they would achieve soft-tissue changes histologically analogous to those seen in human irradiated, implant-based breast reconstruction. METHODS: This study consisted of 11 immunocompetent, hairless rats divided into three groups as follows: untreated control (n = 3), tissue-expanded scalps (n = 4), and fractionated irradiation plus tissue expansion of the scalp (n = 4). At the completion of the experiment for each group, skin tissue samples were analyzed histologically for vascularity, epidermal and dermal thickness, and collagen fiber alignment or scar formation. RESULTS: Expanded rat epidermis was significantly thicker and dermis was more vascular than nonexpanded skin. The authors observed a greater degree of collagen fiber alignment in the expanded group compared with nonexpanded skin. The combination of irradiation and expansion resulted in significant dermal thinning, vascular depletion, and increased scar formation compared with expanded skin alone. CONCLUSIONS: The authors describe a novel small-animal model for irradiated, implant-based breast reconstruction where histologic analysis shows structural changes in the skin consistent with known effects of radiation therapy and expansion in human skin. This model represents a significant improvement from previous ones and, as such, holds the potential to be used to test new therapeutic agents to improve clinical outcomes.

Use of tranexamic acid in craniosynostosis surgery.

BACKGROUND: Intraoperative tranexamic acid (TXA) administration has been used to abate blood loss in a variety of surgical procedures. Several recent studies have supported its efficacy in reducing transfusion requirements in pediatric cranial vault reconstruction (CVR). OBJECTIVE: To conduct a retrospective chart review to determine whether a significant reduction in packed red blood cell (PRBC) and fresh frozen plasma (FFP) transfusions exists when TXA is used. METHODS: A retrospective cohort study of 28 patients who underwent CVR for sagittal craniosynostosis was performed. Transfusion requirements for 14 patients who did not receive TXA were compared with 14 patients who did. Predictors of increased blood product transfusion were also studied. RESULTS: Total volume of PRBC transfusion was reduced by 50% with the use of TXA (P=0.004) with a 34% reduction in intraoperative PRBC transfusion (P=0.017) and a 67% reduction in postoperative PRBC transfusion (P<0.001). Total volume of FFP transfusion was reduced by 46% (P=0.002) and postoperative FFP transfusion was reduced by 100% (P=0.001). The use of TXA was associated with a lower total volume of PRBC (P=0.003) and FFP (P=0.003) transfusions. Older patient age was associated with lower total volume of PRBC transfused (P=0.046 and P=0.002), but not with FFP (P=0.183 and P=0.099) transfusion volumes. Increasing patient weight was associated with lower PRBC (P=0.010 and P=0.020) and FFP (P=0.045 and P=0.016) transfusion volumes. CONCLUSION: TXA decreased blood product transfusion requirements in patients undergoing CVR for sagittal craniosynostosis, and should be a routine part of the strategy to reduce blood loss in these procedures.

HISTORIQUE: L'administration d'acide tranexamique (ATX) intraopératoire vise à limiter la perte de sang dans le cadre de diverses interventions chirurgicales. Plusieurs études récentes en appuient l'efficacité pour réduire les transfusions lors des reconstructions de la voûte crânienne (RVC) en pédiatrie. OBJECTIF: Effectuer une analyse rétrospective des dossiers pour déterminer si l'utilisation d'ATX s'associe à une diminution importante des transfusions de culots globulaires (CG) et de plasma frais congelé (PFC). MÉTHODOLOGIE: Les chercheurs ont réalisé une étude rétrospective de cohorte auprès de 28 patients qui ont subi une RVC pour corriger une craniosystose sagittale. Ils ont comparé les transfusions chez 14 patients qui n'avaient pas reçu d'ATX à celles des 14 patients qui en avaient reçu. Ils ont également étudié les prédicteurs d'une transfusion accrue de produits sanguins. RÉSULTATS: Le volume total de transfusion de CG diminuait de 50 % grâce à l'utilisation d'ATX (P=0,004), y compris une réduction de 34 % des transfusions de CG intraopératoire (P=0,017) et de 67 % des transfusions de CG postopératoire (P<0,001). Le volume total de transfusion de PFC intraopératoire diminuait de 46 % (P=0,002) et celui de transfusion postopératoire, de 100 % (P=0,001). L'utilisation d'ATX s'associait à une diminution du volume total de transfusions de CG (P=0,003) et de PFC (P=0,003). Un âge plus avancé était lié à un volume total de CG transfusé plus faible (P=0,046 et P=0,002), mais pas à celui de PFC (P=0,183 et P=0,099). Un poids plus élevé s'associait à un volume CG (P=0,010 et P=0,020) et de PFC (P=0,045 et P=0,016) plus faible. CONCLUSION: L'ATX réduisait le volume de transfusion de produits sanguins chez les patients subissant une RVC pour corriger une craniosynostose sagittale. Son utilisation devrait être systématique pour réduire la perte de sang lors de ces interventions.