Firefly™ technology enhances precision of complex reconstructive robotic surgery

Robot-assisted surgery is rapidly advancing the field of urologic surgery. Many procedures previously performed as open surgery, such as ureteral reconstruction, can now be accomplished as minimally invasive robotic procedures.¹ At Penn State Health, surgeons are using Firefly™ Fluorescence Imaging for da Vinci® XI, which is integrated with the robotic surgical system to further optimize minimally invasive procedures.

“Firefly technology gives the surgeon the ability to work in a magnified 3D field and evaluate the microperfusion and vascular supply of anatomical structures,” said Dr. Alireza Aminsharifi, urologic surgeon at Penn State Health Milton S. Hershey Medical Center and an associate professor of urology, urologic oncology and minimally invasive surgery at Penn State College of Medicine. “It makes the robotic platform well-equipped for technically demanding surgeries, especially for reconstruction of vulnerable urinary tract tissues.”

Heightened capabilities

Firefly technology uses near-infrared fluorescence imaging, allowing precise, real-time visualization of anatomic structures and their vascular perfusion during surgery. The surgeon administers indocyanine green dye, which acts as a microvascular contrast agent and appears bright green under the near-infrared fluorescent camera. The dye can be given either intravenously or by injection into the surgical area, enabling the surgeon to delineate both the vascular supply and contours of anatomic structures.

“For example, ureteral reconstruction can be challenging in patients with previous ipsilateral surgery, as normal tissue planes are often disrupted or obliterated, and the ureter is encased in fibrotic tissue,” Aminsharifi said. “With Firefly technology, the surgeon can identify the ureter in its surrounding fibrotic tissues, track the course of the ureter precisely and dissect it safely, without injury to the ureter or surrounding vital structures.”

Less chance of recurrence of stricture

Traditional ureteral reconstruction poses additional challenges, as identifying the precise margins of a ureteral stricture can be difficult.

“Accurate localization and excision of the site of ureteral stricture cannot be overemphasized. The diseased segment of the ureter should be completely excised or bypassed to prevent stricture recurrence,” Aminsharifi said. “Using intravenous indocyanine green, the surgeon can accurately identify the proximal and distal stricture margins under the camera, because well-perfused tissue appears bright green and poorly perfused tissue appears dark. After excising all nonviable tissue, the surgeon can proceed with reconstruction on viable margins.”

Therefore, in addition to greater visualization and precision when used during robotic surgery, Firefly technology offers other benefits.

The da Vinci surgical system’s interface allows the surgeon to toggle between normal illumination and fluorescence imaging modes, as necessary. The illuminator also uses LED technology, which leads to cost savings in operating expenses, with fewer lamp replacements.

Additionally, imaging with Firefly technology appears in 3DHD quality, allowing surgeons to get clear, detailed views of vessels, blood flow and related tissue perfusion.

Multiple uses

While the use of Firefly technology in reconstructive urologic procedures is relatively new, it is also useful in other surgical settings, including oncologic robotic procedures. For example, the technology can help surgeons differentiate between cancerous and normal kidney tissue during a robotic partial nephrectomy.

“As a real-time vascular contrast agent, the use of near-infrared fluorescence imaging can be very helpful for selective or super-selective clamping of arterial branches to the kidney tumor,” Aminsharifi said. “This results in minimum ischemia to the normal renal parenchyma.”

Recent studies have shown that using a standardized dose of indocyanine green during partial nephrectomies can greatly reduce the rate of positive margins. One study in 2020 found this technique yielded a positive margin rate of 0.3 percent.²

These advantages, along with the benefits of all minimally invasive robotic surgery – smaller incisions and reduced recovery time – have led to improved patient outcomes. However, Firefly technology is a new technique, and more studies are needed to establish its place in urological and other robotic surgeries.

“The applications of Firefly technology in urology are promising,” Aminsharifi said. “But further investigations are needed to improve the understanding of the clinical value of this innovative technology and provide evidence of its many benefits.”

References

1. Babbar P, Yerram N, Sun A, et al. Robot-assisted ureteral reconstruction – current status and future directions. Urology Annals. 2018 Jan-Mar; 10(1): 7–14. doi: 10.4103/UA.UA_94_17.
2. Sentell KT, Ferroni MC, Abaza R. BJU International. Near-infrared fluorescence imaging for intraoperative margin assessment during robot-assisted partial nephrectomy. 2020 Aug;126(2):259-264. doi: 10.1111/bju.15089.