Did you know that breakthroughs in breast reconstruction surgery are happening right here in Rockford? Meet a team of doctors and engineers who are changing the lives of women with cancer.
Breast cancer is one of the most devastating diagnoses a woman can hear.
Not only does she face bouts of chemotherapy or radiation, but often surgery to remove the cancerous tumor. It isn’t just a life-threatening health concern, serious as that is; it’s also a blow to her feelings about her body and her self-esteem.
One of the ways in which specialists such as Dr. Sarah Hagarty, a board-certified plastic surgeon with OSF Saint Anthony Medical Center, help women to recover their sense of wholeness is through breast reconstruction. Hagarty and her colleagues are constantly striving to improve every single aspect of this delicate, sensitive process.
“I came to OSF in 2006, right about the same time a new technique was rapidly catching on nationwide and internationally for simpler implant-based breast reconstruction that not only supported but helped preserve a more natural breast shape,” Hagarty explains. “A human-derived material called ADM (autogenous dermal matrices), specifically AlloDerm, was already being used in surgeries in many other places in the body to help reinforce strength, such as for hernias or other areas of deep tissue loss. It was now being applied to the bottom and inside part of the breast reconstruction, in a sling fashion, sutured to the pectoral muscle to make a neat inner pocket, or ‘internal bra’ for the breast implant. This also helped preserve the natural ‘tear drop’ shape of the woman’s breast.”
Hagarty explains that AlloDerm is derived from harvested cadaver skin. Because it’s natural human skin, the patient’s body accepts it with fewer issues of rejection. It eventually heals and bonds with the patient’s own tissue, increasing the protective layer over the implant and adding strength and stability.
However, one of the downsides to AlloDerm in breast reconstruction was that it required longer periods for post-surgical drains to be present, often several weeks. For some reason, more fluid was produced. Studies showed no increase in infection, but patients would often complain, finding the drains to be painful and uncomfortable. Hagarty listened to her patients and kept track of patient outcomes. She tried various thicknesses of the ADM, working with the company that provides the material to be sure it was optimal.
Several groups around the world were manipulating the ADM to try to improve the drainage problem. The company came out with a perforated version of the ADM, and some groups simply put little cuts into it, to try to get it to heal into the local tissues faster, thus decreasing the drain time. All of these techniques made sense. The holes would allow fluid to move more freely and increase the contact area for healing. Hagarty’s partner, Dr. Pedro Rodriguez, attended a meeting where surgeons discussed a technique of running the ADM through a commonly used device in the plastic surgeon’s toolkit – a skin graft mesher, which cuts evenly spaced holes. Hagarty and Rodriguez incorporated this into their practice, and were happy to see that patients were getting their drains out much quicker with this adjustment.
Hagarty is an Associate Professor of Surgery at University of Illinois College of Medicine in Rockford. As well as teaching in the clinic and operating room, she has supervised several medical students’ research projects. Many of these focused on the collection and analysis of data on the outcomes of breast reconstruction surgery in her practice. She says it’s important to not only subjectively observe something, but also to test the numbers statistically to be sure assumptions are correct, so that the level of care and outcomes for patients continually improves.
Recently, Hagarty reached a stage where actually testing the strength of the material became essential to completing the whole picture for the study.
“I received a phone call from Dr. Hagarty asking if I was interested in doing some work within the program,” says Dr. Ramaswamy Kalyanasundaram, DVM, Ph.D., who heads up the medical biotechnology department at the University of Illinois College of Medicine in Rockford. “She was interested in testing some materials in connection with breast reconstruction. Because we did not have the equipment needed for this testing, I told her I would try to find a community connection that could help.” Kalyanasundaram first called EIGERlab in Rockford, but was told they didn’t have the appropriate equipment to conduct the necessary testing.
“They suggested that we contact ATRONA Test Labs, which not only had the tools we needed but also was very willing to help,” says Kalysansundaram. “It was a nice project on that count, and because it seemed the tests would lead to faster healing for women who were undergoing breast reconstruction.”
At the school of medicine, ATRONA came on board. Atif (Ott) Odeh, owner and principal metallurgical engineer for ATRONA Test Labs in Loves Park, Ill., says Hagarty brought pieces of the ADM to be tested for tensile strength and elongation potential. She wanted to know what impact the little holes had on the strength of the material. Odeh exlains that ATRONA routinely conducts tension and compression testing on various materials using tensile testers with load cells. Other analysis conducted at ATRONA Test Labs includes fracture analysis testing, failure analysis, microscopic analysis, chemical analysis, polymer testing, and mechanical testing using highly specialized technology not commonly available.
“This is really not the sort of material we typically test,” Odeh says. “We normally test metals and plastics, so this was very unusual for us.”
Hagarty applied for a research grant to fund the lab work, which was graciously supported by The OSF Foundation. She also petitioned the company Acellity, which makes the AlloDerm, to donate nearly $40,000 of material to be tested.
Odeh explains that, with non-organic material testing, tension testing of materials typically yields about zero to 50 percent elongation prior to fracture.
“When we tested the specimens brought in by Dr. Hagarty, we were amazed to discover that they elongated as much as 1,000 percent before tearing,” says Odeh. “While we were not specifically told that the samples were human skin, we presumed they were.”
Even more astounding, says Odeh, was that, when the grippers holding the samples were removed, the material had impressions from the grippers that completely disappeared within 1 to 5 minutes, leaving the specimens looking as if they had never been gripped.
“Visually, they were totally back to normal,” Odeh says.
After findings on the first control batch of specimens were submitted to Hagarty, ATRONA received a second round of materials to be tested.
“These samples consisted of various materials with a pattern of tiny holes cut into them,” Odeh says. “We tested each to learn which ones provided more tensile strength and elongation capabilities. After testing was conducted, certain fractures were analyzed using scanning electron microscopy.”
Odeh says the materials were prepared prior to placement in the scanning electron microscope (SEM) with a special procedure, which included drying out the samples and gold plating the skin specimens to make them more conductive for better view in the SEM chamber. ATRONA has two scanning electron microscopes, each capable of magnifying to half-a-million times, which is sensitive enough to expose the smallest fracture, tear or flaw in the tested material. In this investigation, ATRONA was also assessing to see if the fracture mechanism progressed through the grains or through the grain boundaries.
“It’s a rigorous process to see even the tiniest tears and evaluate if those tears occur in any sort of pattern,” Odeh says. “In summary, we provided Dr. Hagarty with a test protocol consisting of a procedure to provide important insight to the strength, elongation and behavior of the skin samples that were submitted to us. This was a fascinating project, and we hope the test results provided to Dr. Hagarty by ATRONA Test Labs provided additional insight to this very important research and development project that Dr. Hagarty was conducting.”
They did, indeed. Hagarty says the process to manipulate the AlloDerm has shown some very impressive improvements in patient outcomes.
“We roll the AlloDerm through what we call a mesher,” she explains. “It’s a lot like rolling pasta, but it punctures the material with a pattern of tiny holes.”
This step lets the patient’s body fluids flow more freely through the ADM, and appears to facilitate healing. The end result is nothing short of astounding. The results were analyzed with the help of James Scholar third-year medical student Lawrence Yen and Dr. Manorama Khare, a Ph.D. statistician and researcher at the school of medicine.
“After using this manipulated ADM, we discovered that the length of time the patient required drainage tubes after surgery was reduced by nearly two weeks, across the board,” Hagarty says.
Another surprising and unexpected finding was that the patients were requiring significantly less intravenous morphine. The dose dropped from an average 30 mg over their hospital stay to 6 mg, Hagarty says. The hypothesis is that, since the holes make the ADM more flexible, it exerts less pull on the muscles and is therefore more comfortable for the patient.
“Further, the average patient stay in the hospital was shortened from two days to one,” Hagarty adds. “There also appears to be a subtle but significant lower incidence of minor infection.”
In an abstract published by Hagarty in the Annals of Plastic Surgery, the conclusion of the preliminary two-year study found: “This is the first study to examine the relationship between post-operative drain time and complication rates of patients receiving meshed verses unmeshed AlloDerm in breast reconstruction. Our study results provide surgical implications on improving patient outcomes.”
“This research project brought together several entities within this great community of Rockford – from academia and industry – in a mutual quest to help make life better for women recovering from breast cancer,” Hagarty says. “This is one of the most satisfying aspects of the project.”
Hagarty’s research into more improvements for breast cancer survivors is ongoing. She will be presenting further data from this study at The American Society of Plastic Surgery’s annual meeting in Boston this fall. But Hagarty says the most gratifying result of her years of work is the benefit to women who face breast cancer and can have some of their confidence and quality of life restored through breast reconstruction.