Using fluorescence lymphangiography to define the ileocolic mesentery: proof of concept for the watershed area using real-time imaging

Abstract

Recent advances in mesenteric science have demonstrated that the mesentery is a continuous structure with a 'watershed' area at the mesenteric apex between the right colon and terminal ileum, where lymphatic flow can proceed either proximally or distally. With this new understanding of the anatomy, functional features are emerging, which can have an impact on surgical management. Fluorescence lymphangiography or lymphoscintigraphy with indocyanine green allows real-time visualization of lymphatic channels, which highlights sentinel lymph nodes and may facilitate identification of the ideal margins for mesenteric lymphadenectomy during bowel resection for colon cancer. By using this novel technology, it is possible to demonstrate a watershed area in the ileocolic region and may facilitate more precise mesenteric dissection. In the present study, we provide proof of concept for the ileocolic watershed area using fluorescence lymphangiography.

The significance of intraoperative fluorescence angiography in miniinvasive low rectal resections.

“…Technical execution slightly increased the duration of the surgical procedure. The administration of the indocyanine green, including repeating the dose, was completely safe, in agreement with other works [12,17,19,[21][22][23][24][25]. Based on our experience we consider intraoperative fluorescence angiography to be a feasible and safe method.…”

The current state of the transanal approach to the ileal pouch-anal anastomosis

“…Another important application of technology is fluorescence angiography. Intraoperative assessment with fluorescence angiography has shown significant benefit for confirming adequate blood flow to the anastomosis and guiding resections for benign and malignant disease [43][44][45]. There are specific benefits for fluorescence angiography in pouch construction, where it can be invaluable to demonstrate the vascular map to the visualize accurately which arteries are supplying the ileocolic region of the future pouch and ensuring the appropriate branches are resected and saved for optimal vascularization of the pouch during lengthening procedures [20].…”

What is the added value of intraoperative indocyanine-green in right colectomy for cancer?

“…Recently, a new concept of the mesentery as a separate "organ" with its own lymphatic and a vascular watershed area has been introduced by Keller et al (7). This anatomical concept has its surgical contra part with the complete mesocolic excision (CME) as treatment for right colon cancer proposed by Hohenberger et al (8).…”

“…Nevertheless, the routine used of CME is controversial as well as technically demanding. Recently Keller et al (7) proposed the use of fluorescence to enhance the identification of the mesenteric plane by injecting 1 mL of ICG (concentration 5 mg/10 mL) into the subserosa layer of the colon waiting for ICG to spread into the mesentery to help surgeons to define the embryological planes. This concept has been also investigated in gastric cancer where endoscopic injection of ICG the day before surgery can help during the lymphadenectomy to define the mesogastric area.…”