[en] Background and objectives: The Deep Inferior Epigastric Perforator (DIEP) flap is the first option for autologous microsurgical reconstruction for oncological mastectomy, with great results. However, one of its most frequent complications is fat necrosis (up to 62.5%), as a consequence of a deficient regional perfusion of the flap, which could have important clinical and psychological repercussions, deteriorating the results and increasing reconstruction costs. The indocyanine green angiography (ICGA) has been successfully used for years in the assessment of perfusion in free flaps surgeries, and the aim of this study was to demonstrate the intraoperative use of ICGA to reduce fat necrosis in DIEP flap. Besides, it has not yet been established when the ICGA should be performed during the surgery, so the second main aim of this study is to evaluate whether it is better to perform the test on the donor or recipient sites of the DIEP flap. Methods: Two studies have been conducted. In the first one, 61 patients who underwent unilateral DIEP flap procedures for breast reconstruction after oncological mastectomy were included (24 cases with intraoperative use of ICGA during surgery, 37 cases in the control group). The follow-up period was 1 year after surgery. The association between the use of ICGA and the incidence of fat necrosis in the first postoperative year, differences in fat necrosis grade (I-V), differences in fat necrosis requiring reoperation, quality of life, and patient satisfaction were analyzed. In the second study, the intraoperative perfusion of 46 DIEP flaps was assessed twice, on the donor and recipient sites. Differences between both ischemic areas of each flap were statistically analyzed. In addition, perforator location and risk factors were evaluated in order to assess whether they are associated with changes in the perfusion of the flap between both sites. Results: In the first article, the incidence of fat necrosis was reduced from 59.5% (control group) to 29% (ICG-group) (P = 0.021) (relative risk = 0.49 [95% CI, 0.25- 0.97]). The major difference was in grade II (27% vs 2.7%, P = 0.038). The number of second surgeries for fat necrosis treatment was also reduced (45.9% vs 20.8%, P = 0.046). The ICG group had higher scores on the BREAST-Q. In the second study, differences between ischemic areas on the donor and recipient sites were statistically significant (p = 0.012). In all cases in which there was a change of area between both zones, it was always less in the donor site. That means that in all cases the flap was the same or better perfused in the recipient site. The final flap design only changed in two cases (4.3%) because of the ICGA findings on the recipient site. Besides, performing the ICGA on the donor site facilitated the identification of the best perfused areas, allowed a better planning of its placement into the recipient site, and also can be useful to choose the best perforator. Bilateral DIEP flap, lateral location of the perforator and tobacco use had a statistically significant association with lower probability to increase the perfusion area between both sites Conclusions: Intraoperative ICGA is a useful technique for reconstructive microsurgery that might improve patient satisfaction and reduce the incidence of fat necrosis by half as well as reduce its grade and the number of secondary surgeries. In addition, several advantages have been found in performing the ICGA on the donor site to assess the perfusion of the DIEP flap. In addition, performing the ICGA in the donor site (before the flap pedicle section) allowed to achieve a flap design based on the best perfused areas with greater precision.

[es] El verde de indocianina (ICG) es un contraste que permite la valoración de la perfusión de los tejidos de manera intraoperatoria y dinámica, aportando información de interés en el campo de la reconstrucción mamaria. Este trabajo se focaliza en el estudio de su uso en reconstrucción microquirúrgica de mastectomía con colgajo DIEP (Deep Inferior Epigastric Perforator). El objetivo principal es optimizar el rendimiento de esta prueba a la hora de diseñar el colgajo, estableciendo en qué momento durante la intervención quirúrgica es más efectivo valorar su perfusión, y demostrar que con su uso es posible reducir la tasa de esteatonecrosis postoperatoria, una de las complicaciones más frecuentes en este tipo de reconstrucciones. Para ello se plantearon 2 estudios: - En el primer estudio se valoró si existían diferencias en la tasa de esteatonecrosis postoperatoria en los colgajos DIEP para mastectomía oncológica en función de si se empleó (grupo de estudio) o no (grupo control) el ICG durante la intervención quirúrgica. - En el segundo estudio se comparó la perfusión del colgajo DIEP con ICG en dos momentos de la cirugía, cuando la vascularización dependía del pedículo original (zona donante) y tras la anastomosis microquirúrgica a los vasos receptores mamarios internos (zona receptora). Además, se valoraron las ventajas e inconvenientes asociados a la realización de la prueba en cada momento. Los resultados de ambos estudios mostraron que con la angiografía con ICG intraoperatoria es posible disminuir la esteatonecrosis postoperatoria, tanto su incidencia como su grado y la necesidad de tratamientos quirúrgicos secundarios, siendo mayor su efectividad a la hora de diseñar el colgajo DIEP cuando se realiza en la zona donante (antes de la sección del pedículo en el que se basa).