The influence of haematogenous bone marrow on the early osseointegration of a titanium implant which penetrates the endosteum / La influencia de la médula ósea hematógena en la osteointegración temprana de un implante de titanio que penetra en el endostio

SUMMARY: The utility of metallic bio-medical implants in osseous or dental affections is irrefutable. The paper aims to test the tolerance of the bone marrow to titanium implants. Titanium implants were inserted in the femur of 11-months old rabbits. The implants penetrated the endosteum, half of their length getting into the haematogenous bone marrow. Seven days after the insertion we collected bone fragments containing the implant. The CT exam revealed a significant decrease in the density of the bone at the interface with the implant and a more discrete one aloof from the insertion area. The histologic exam after 7 days revealed osseous reparatory processes only in the endosteal area from where it expanded on the surface of the implant which was inside the marrow. The presence and intensity of the osseous reparatory processes after only seven days post-implant demonstrates that the marrow actively participates in bone regeneration and implants osseointegration.

RESUMEN: La utilidad de los implantes biomédicos metálicos en afecciones óseas o dentales es irrefutable. El documento tiene como objetivo probar la tolerancia de la médula ósea a los implantes de titanio. Se insertaron implantes de titanio en el fémur de conejos de 11 meses. Los implantes penetraron en el endostio y la mitad de su longitud penetró en la médula ósea hematógena. Siete días después de la inserción, recolectamos fragmentos de hueso que contenían el implante. El examen de TC reveló una disminución significativa en la densidad del hueso en la interfaz con el implante y una más discreta alejada del área de inserción. El examen histológico a los 7 días reveló procesos de reparación ósea solo en el área endóstica desde donde se expandió en la superficie del implante que estaba dentro de la médula. La presencia e intensidad de los procesos de reparación ósea después de solo siete días del implante demuestra que la médula ósea participa activamente en la regeneración ósea y en la osteointegración de los implantes.

Free-flap breast reconstruction on experimental porcine model.

INTRODUCTION: Free flaps require mastering microsurgical technique. In addition, breast reconstruction implies accuracy not only in flap survival, but also satisfying aesthetic outcome. Thus, such complex abilities can be acquired by creating experimental models for surgical training. MATERIALS AND METHODS: In accordance with relevant anatomy data found in literature, we chose a porcine model and performed a flap similar to the human deep inferior epigastric perforator (DIEP). Furthermore we developed a surgical protocol for a free flap transfer similar to a double-pedicle DIEP flap. The adipo-cutaneous flap was harvested as a free flap based on the superior abdominal vascularization and microsurgical anastomoses were performed to both the internal thoracic and thoracodorsal vessels. RESULTS: We were able to harvest a superior epigastric double-perforator free flap with increased similarity to the human DIEP flap. Microsurgical anastomoses were possible to both to the internal thoracic vessels and thoracodorsal vessels, which both proved to have optimal caliber for termino-terminal anastomosis. CONCLUSION: Although there are several differences when comparing a swine experimental model with human anatomy, our protocol enhances the possibilities for training in breast reconstruction.

Using dynamic infrared thermography to optimize color Doppler ultrasound mapping of cutaneous perforators.

AIMS: The high technical demands associated with perforator flaps demand a precise preoperative identification and evaluation of perforator vessels. Color Doppler Ultrasonography (CDU) and Dynamic Infrared Thermography (DIRT) are currently used for preoperative perforator mapping. Each individual technique has advantages and disadvantages. The purpose of this paper is to analyze the value of combining the two methods in order to optimize the process of preoperative perforator mapping. MATERIAL AND METHODS: CDU and DIRT were used for preoperative perforator mapping in 10 pigs. The results were compared to intraoperative findings. Total number of perforators, localization, and identification of the dominant perforator was analyzed for each method. The examination time was recorded for each procedure. RESULTS: Both methods had a high sensitivity in determining the number and localization of perforators when compared to those identified during surgery. DIRT produced a higher number of false positive results. CDU accurately identified the emergence of the perforators in the fascia in all cases. Both methods correctly identified the dominant perforator. The sensitivity, positive predictive value, and accuracy of CDU were 93.56%, 97%, and 91.30% respectively and for DIRT 95.05%, 80.67%, and 77.41% respectively. The average examination was 39.76 minutes for CDU and 10.24 minutes for DIRT. The average time taken into account for the analysis of a single perforator in order to confirm DIRT findings was 1.83 minutes. CONCLUSIONS: Preoperative perforator mapping has become a compulsory step in nearly all reconstructive procedures. In our study, both CDU and DIRT correctly identified the dominant perforator in all cases. By combining the two examinations overall mapping time can be reduced significantly. A reduced examination time translates into increased patient compliance and a lower procedure cost. The combined mapping technique facilitates the selection of the ideal perforator in all cases. Correctly identifying the dominant perforator preoperatively reduces operative time, lowers complication rates and ensures an overall better result.