MARS System for Fluorescent Diagnostics in the Near-Infrared Range

The MARS system is designed for monitoring blood flow in arterial and venous vessels, lymph flow, perfusion of organs and tissues during surgery as well.

Indocyanine green (ICG) is used as a fluorescent dye to perform diagnostics by means of this system.

Indocyanine green is excited in the near-infrared range at wavelengths of 780–810 nm and emits fluorescent light in the range of 805–880 nm. For examining blood flow and tissue perfusion, an ICG solution is administered intravenously, whereas for assessing lymph flow it is injected subcutaneously.

Unlike X-ray angiography, the MARS equipment uses a laser signal source operating at 785 nm – at the peak absorption of indocyanine green.

The ICG-based MARS system improves diagnostic quality, enhances the effectiveness of operations, and reduces the incidence of postoperative complications and fatalities, including those related to intraoperative issues

The system stands out from its counterparts by its ability to determine blood flow parameters using special software. The following indicators can be calculated:

• Dynamics of the average blood flow intensity.
• Blood flow supply rate.
• Map of the time to reach maximum fluorescence intensity.

The ICG-fluorescent navigation and diagnostics method offers various ways to introduce the fluorescent contrast – intravenously, intratissue, directly into a duct or shunt.

The MARS system has already demonstrated positive results and proven itself in numerous areas of open surgery. Surgeons particularly note the following advantages:

• Thanks to the diode laser, the penetration depth is 1.1 cm, which provides improved visualization of deeper areas of interest.
• The articulated arm (pantograph) stand frees the surgeon’s hands and does not require an assistant during the procedure.
• The laser’s power enables operation under ambient light, eliminating the need to darken the operating room and reducing the risk of unforeseen errors.
• The mobile stand is easy to control, and its large casters allow effortless movement of the device between operating rooms.
• The software calculates quantitative values, thereby enhancing quality through standardization and the establishment of norms.
• Made in Russia with its own service center ensures the manufacturer’s warranty, ready availability of consumables and components, and a personalized approach.

This method has no age restrictions and does not involve radiation exposure, while its wide range of applications, mobility, and simplicity make it an important component of safety systems in surgery.

• Registration of fluorescent images in black and white mode.
• Registration of visible images in color mode.
• Control of image registration modes.
• Real-time overlay of fluorescent images on color images.
• Coloring of the fluorescent image in any, most contrasting color.
• Recording of the fluorescent video stream from 1 second to 3 hours.
• Recording of the combined video stream from 1 second to 3 hours.
• Saving frames in real time during video file processing.
• Control of camera zoom and focus.
• Obtaining brightness profiles of the image in real time and during processing/viewing of recorded files.
• Calculation of the average brightness within regions of interest in real time and during processing/viewing of recorded files.
• Calculation of the dynamics of average brightness within regions of interest in recorded video files.
• Determination of critical points in the dynamics of average brightness within regions of interest: the onset of fluorescence, the maximum value, and the rate of fluorescence onset.

Cardiology

Indocyanine green (ICG) is administered intravenously.
The MARS registration block is positioned at a distance of approximately 30 cm, directed towards the shunt installed by the surgeon. Within a minute after administration, areas of the heart receiving blood begin to light up on the monitor. Thus, depending on the brightness level of the areas of interest (indicated by rectangles on the photo below), the surgeon can assess the quality of the shunting procedure. In addition to qualitative visual assessment, the doctor can quantitatively examine the necessary areas.

This method is used for the detection of the sentinel lymph node when assessing the stage of breast cancer.

When performing a biopsy of the sentinel lymph node (SLN), ICG is administered subcutaneously. The MARS registration block is positioned approximately 30 cm from the area of interest and is first directed towards the lymphatic duct emerging from the areola, then, after locating the lymph node, directly onto the SLN (in the axillary region). The time between ICG administration and the incision in the axillary region is approximately 5–10 minutes. In addition, a massage is recommended near the injection area for 2 minutes. During surgery, more than one SLN may be removed.

Using the ICG-navigation technique to search for sentinel lymph nodes in many cases reduces the extent of lymphadenectomy and ultimately improves the quality of life for patients after surgery by reducing the risk of postoperative complications (lymphoedema, swelling, etc.).

Screenshot from the MARS system monitor during lymphatic system mapping and sentinel lymph node detection MKNC named after A.S. Loginov

Fluorescent video diagnostics allows for precise staging of skin melanoma (CM) to determine prognosis and choose treatment strategy.

Surgical removal of the primary melanoma and metastatically altered regional lymph nodes (LNs) is the primary treatment for tumors from stage 0 to III.

Removed fluorescent lymph node
GBUZ GKB named after S.P. Botkin, DZM

Moreover, some studies have shown that the application of ICG-navigation enables surgeons to detect transient metastases of melanoma in the skin and subcutaneous adipose tissue, which spread through lymphatic ducts and are located between the primary focus (>2 cm in diameter) and regional lymph nodes.

The ICG-navigation technology is applied for the detection of the sentinel lymph node in patients diagnosed with stage I endometrial cancer and cervical cancer. The injection of indocyanine is made into the cervix.

The advantage of the method lies in the increased detection rate (including bilateral detection) of sentinel lymph nodes and, consequently, in reducing the number of surgeries that require lymphadenectomy.

1. Color camera mode, 2. Fluorescent mode, 3. Overlay mode NII of Urology and Interventional Radiology named after N.A. Lopatkin – branch of FGUB “NMIC Radiology” of the Ministry of Health of Russia

The aim of the method is to control the preservation of the parathyroid glands and reduce postoperative complications such as hypoparathyroidism.

ICG solution is injected as a bolus. Within 30–60 seconds after injection, the dye appears in the tissues. The registration block is positioned at the manufacturer’s recommended distance, approximately 30 cm from the area of interest. In real time, the spread of ICG along the vessels is assessed in black and white, tracking the flow of the dye towards the parathyroid and thyroid glands, and locating the parathyroid glands.

If necessary, the MARS system software allows for graph construction and evaluation of the fluorescence index of the areas of interest (see the figure below).

Fluorescent visualization of the retrothyroid area on the right. 1 – soft tissues; 2 – normal thyroid tissue; 3 – papillary thyroid carcinoma; 4 – upper right parathyroid gland (189 relative units); 5 – lower right parathyroid gland (125 relative units).
FGUB “NMIC Endocrinology” of the Ministry of Health of Russia

The purpose of using ICG technology is to assess the blood supply to the soft tissues of the foot in cases of ischemic damage to the lower extremities.

Existing diagnostic methods do not always provide an objective understanding of the peculiarities of the arteries supplying the limb in patients. Therefore, it is challenging for doctors to determine the need for surgical intervention to restore blood flow in the legs – so-called endovascular or bypass procedures.

The MARS device software registers the time of appearance and distribution of the intravenously administered fluorescent substance in the foot tissues, which allows both visual and quantitative assessment of tissue perfusion. This has been confirmed by studies conducted in the “Diabetic Foot” department.

Visual and quantitative assessment of foot tissue perfusion FGUB “NMIC Endocrinology” of the Ministry of Health of Russia

The purpose of applying fluorescent diagnostic technology is to accurately determine the resection margins of an anastomosis and to control its integrity.

Indocyanine green is administered into the bloodstream, after which its fluorescence in the near-infrared range is observed on the screen. The level of fluorescence intensity helps in choosing the correct resection line and later assessing the blood supply to the formed anastomosis.

A screenshot from the MARS system monitor during an operation for removal of a diseased intestinal segment / photograph from the operating room
FGUB "SZONKC named after L.G. Sokolov FMBA of Russia"

Fluorescent diagnostics during the resection of focal liver lesions improves the delineation of the resection plane, which, together with other navigation methods, potentially increases the effectiveness and safety of the operation.

The “Indocyanine Green” preparation is administered to the patient 24 hours before the operation, infused intravenously via a central venous catheter at a dose of 0.25 mg/kg. Intraoperative administration of the contrast is performed directly into the tumor formation (5 mg of indocyanine green solution).

Detection of liver lesions using the ICG methodology MONIKI named after M.F. Vladimirskiy

ICG technology helps surgeons achieve radical resection of lesions while preserving the maximum possible volume of liver parenchyma.

ICG visualization allows for a qualitative assessment of tissue perfusion.

Current methods used to evaluate tissue perfusion are subjective and do not include quantitative clinical indicators. These methods rely on clinical assessments based on the color and edema of the skin, the presence of skin wrinkles, and the color and turgor of the deep tissues. The subjective or imprecise nature of these evaluations leads to significant variations in treatment and a lack of progress in developing objective treatment protocols.

Through video-fluorescent diagnostics in the near-infrared range, the viability of soft tissues and their perfusion are evaluated during plastic surgeries, such as the perfusion assessment of a free skin flap or breast reconstruction. Thus, the method is also well suited for assessing the microcirculation of organs and limbs.

Evaluation of blood supply during free skin flap transplantation helps minimize the risk of marginal necrosis.

First MGMU named after I.M. Sechenov

*Note: The “Indocyanine Green” medicine is not supplied by “Kriptomed, ltd.”

Dosage and other recommendations for its use should be confirmed with the supplying company.*