PURPOSE: Within the past 5 years, laser-assisted intraoperative indocyanine green fluorescent-dye angiography (LA-ICGA) has been successfully adopted by cardiac surgeons for its ability to provide unparalleled, real time vascular images. Recently, we described our experience with the application of this new technology for the purpose of evaluating arterial and venous flow as well as flap perfusion in microsurgical breast reconstruction. The purpose of this study is to update in the literature our experience with this outstanding imaging technique which serves to confirm anastomotic patency and tissue perfusion during microsurgical breast reconstruction procedures.
METHODS: Following IRB approval, LA-ICGA technology was introduced into our perforator flap protocol. To capture images, the SPY™ intra-operative imaging system (Novadaq, Toronto) was employed. In our practice, autologous breast reconstruction is performed with deep or superficial inferior epigastric perforator flaps or free TRAM using standard technique. In a prospective fashion, LA-ICGA was performed prior to harvest and following microsurgical anastomosis. Examined and imaged prior to harvest were the arterial and venous pedicles as well as the subdermal plexus of the flap. Examined and imaged following inset were the arterial and venous anastomoses, the vascular pedicles and the perfusion of the flaps through both adipose tissue and skin.
EXPERIENCE: Fifteen (15) female patients undergoing autologous breast reconstruction as outlined above were included in the study. Reconstructive techniques included eleven (11) DIEP flaps, three (3) SIEP flaps, and two (2) free TRAMs. Average age 46.3 years. (range 38 – 62 years of age). In 4 patients the anastomoses were performed using a mechanical coupler and in the remaining cases the anastomoses were performed by hand. In each case, intraoperative angiography was performed at several strategic points during the case. Following dissection of the flaps and the pedicles, but prior to actual flap harvest, ICG angiography was performed on the donor pedicles and on the skin and subcutaneous tissue comprising the flap. Following free tissue transfer and microsurgical anastomosis of both the artery and vein(s) LA-ICG angiography was again performed visualizing the post-anastomotic circulation through the artery and vein(s) as well as the skin and subcutaneous tissue of the flap. Finally, ICG imaging of the flaps, from the skin side, following inset was performed for each flap. Additional visualization of the mastectomy flaps was also obtained.
SUMMARY OF RESULTS: Flap survival was 100% and one flap (6.7%) required return to operating room for venous congestion. In 6 cases, imaging demonstrated flow or perfusion deemed “marginal or “poor” by the operating surgeons. In 2 of these cases, one involving poor arterial inflow, one of poor venous outflow, the intra-operative plan was adjusted accordingly by further dissection and follow up imaging demonstrated improvement. In the 3rd case, imaging demonstrated poor perfusion of a mastectomy flap and this was débrided guided by the pattern of subdermal perfusion on LA-ICGA imaging. In the 4th case, flow through a coupler used on an artery appeared “poor” by clinical assessment per the operating surgeon. However, LA-ICGA imaging confirmed excellent flow, and dissuaded us from performing re-anastomosis unnecessarily. In the 5th case clinically apparent “poor” flow, initially attributed to vasospasm, appeared adequate on imaging and allowed us to preserve a SIEP rather that dissecting a deep perforator. In the 6th case, clinically apparent “poor” flow was seen but no adjustment was made at operation. However this patient required return to the operating room for venous congestion of the flap which was corrected without sequela. Additionally it was found that flap perfusion was well visualized on African American skin where clinical exam is often confounded.
CONCLUSIONS: LA-ICGA appears to be a valuable adjunct in surgery involving microsurgical anastomoses. It can be used to evaluate arterial, venous and subdermal plexus perfusion prior to harvest of flaps and following anastomosis. As additional data is collected and analyzed, the ability to interpret findings will develop. A multicenter trial is recommended to evaluate the effect of this new technology on clinical outcome.