Javier La Fontaine, DPM, MS, associate professor of plastic surgery at the University of Texas Southwestern Medical Center, demonstrated how he used hyperspectral imaging to save a patient’s toe from amputation at the MOEMS-MEMS symposium, part of the recent Photonics West event in San Francisco.
Developed in 1996 by Texas Instruments, the technology incorporates a digital micromirror device (DMD), which is a set of millions of microscopic mirrors, measuring about 10 µm each. These mirrors generate instant high-resolution images that show the presence of specific molecules, and in this case were used to monitor oxygen levels in blood and tissues.
“Oxygen is delivered by blood hemoglobin…it is required to be able to heal,” La Fontaine told O&P Business News.
Oxygen levels
Javier La Fontaine
During the operation, early feedback showed details of the foot, indicating high and low blood oxygen in red and blue, respectively. The HSI analysis allowed La Fontaine to know exactly what to remove, what not to remove and make a fast decision regarding his patient’s condition.
“My first impression of the patient’s toes was that they needed to be amputated,” La Fontaine initially thought; both the fourth and fifth toes specifically. However, after performing the HSI scan, his assessment changed.
The fifth toe was determined to be beyond saving. “Once I saw the images demonstrating level of blood oxygenation, I thought that we should give the fourth toe a chance to survive, if the infection was well controlled,” he said.
“We noticed that right after the amputation of the fifth toe, the image of HSI demonstrated increased oxygenation. Then, we knew that this patient had a good chance to save the rest of the foot.”
After feedback and careful analysis of the scan, the patient’s fourth toe was saved.
In these types of procedures, surgeons often need to re-amputate due to infection or ischemia. However, the images from the HSI scan helped La Fontaine decide precisely how much dead tissue to remove, which prevented a return to the operating room for his patient.
“The patient progressed very well…and continues aggressive local wound care,” La Fontaine said. “He healed approximately 2 months after the surgery.”
Clinical benefits
Although early in the application stage, HSI shows increasing potential and will offer many clinical benefits the more it is studied, according to La Fontaine.
“Cancerous tumors often exhibit increased blood flow, so HSI may be able to demonstrate the extent of the lesion based on the oxygenation level in the picture,” La Fontaine said.
“There are multiple areas that could be researched,” he said. “In a nutshell, in any type medical illness that is related to blood flow, HSI may deserve to be studied. I think identifying areas of poor blood flow in the lower extremity early in the disease process, visualizing oxygenation level in chronic wounds where the eyes of the practitioner can detect and demarcating the extent of a tumor, may be the area of most use.” — by Shawn M. Carter
Disclosure: La Fontaine has no relevant financial disclosures.
