From this year’s annual Clinical Congress, the American College of Surgeons is profiling two new technologies that are showing great promise in animal and clinical trials. One is an experimental technique to make sutureless arterial anastomoses, and the other the device you might have seen on our pages before:
Dr. Gurtner [Geoffrey C. Gurtner, MD, FACS, plastic surgeon at Stanford –ed.] described his new technique by first explaining that when he is trying to sew tiny blood vessels together, they tend to collapse because there is no blood in them, as clamps have been applied to hold blood back. As these floppy, hollow vessels become smaller and smaller, he has increasing difficulty putting sutures into them. One thing that is easy to do, however, is to fill them with fluid.
Instead of attempting to stitch hollow, floppy vessels together, Dr. Gurtner explained, he fills the blood vessels with a liquid poloxamer already approved by the US Food and Drug Administration (FDA) for other human-delivery purposes. He describes this material as a clear, colorless, hair-gel-like synthetic polymer. When the blood vessels are filled, he heats the liquid polymer using a convection blower, like a hair dryer. The liquid phases into a solid at 38 degrees Celsius (100.4 degrees Fahrenheit) and is solid at 40 degrees Celsius (104 degrees Fahrenheit).
The floppy vessels stiffen like straws, and he lines the vessels up end to end. He seals the vessels together with Dermabond®, a liquid skin adhesive used by doctors to close wounds, then releases the clamps. The normal body temperature blood rushes into the vessels and hits the thermoreversible polymer. The polymer dissolves within one to two seconds and is excreted by the kidneys.
Dr. Gurtner has been performing sutureless anastomosis since early 2006 in animals and has seen no evidence of embolization, toxicity or end organ damage. Particularly because this solid melts into a liquid within seconds after returning to normal body temperature, he believes there is a large margin of safety with its use. Follow-up angiograms and other tests demonstrated equivalent open and unblocked vessels and vessel diameters, burst strength, and volumetric flow between the sutureless group and the control. Inflammation and scarring were dramatically decreased in the sutureless group, however.
Dr. Gurtner and his colleagues who are pioneering this technology with him are now working with Synvascular, Inc., Palo Alto, CA, to complete the final regulatory groundwork to assure the FDA that this technology is safe. [Company does not have a website yet –ed.] They anticipate beginning human trials in 2009.
Farther along in development is a clever FDA-approved device called the INSORB® absorbable dermal stapler that Jeffrey A. Ascherman, MD, FACS, Columbia University Medical Center, New York, NY, has been using for about a year. He reports that the stapler works well, and he has provided significant data showing that this device gets just as good cosmetic results; saves time and operating room expense; and is safer for patients than the usual practice of suturing the dermis.
Dr. Ascherman, who is chief of plastic surgery at the Columbia University campus of New York-Presbyterian Hospital, explained that plastic surgeons normally close incisions in layers, which takes tension off the outer surface of the skin, known as the epidermis, allowinga less noticeable scar. Traditionally, the epidermis as well as the deep layer underneath called the dermis are closed with sutures. This new dermal stapler, however, allows a novel way to close that deep dermal layer of skin.
“We found that the cosmetic results were comparable with staples,” Dr. Ascherman said. “We didn’t have any wound infections or separations in any of our groups, so we really couldn’t compare that, so there were no overall complication rates. The scar results were roughly the same. The stapler was more than three times faster than sutures, so there was a very statistically significant savings in time and, therefore, in cost.”
Dr. Ascherman and his colleagues designed a prospective, randomized, blinded study to follow 18 patients with abdominal incisions. Of these patients, 10 were randomized to dermal closure with the INSORB® stapler and eight received sutures. At follow-up, no difference was found for scar vascularity, pigmentation, pliability, or height. The dermal stapler closed wounds approximately 33.6 seconds per centimeter faster than sutures (21.7 minutes of time saved per abdominal closure). With an operating room cost of $2,000 per hour, overall savings for abdominoplasty on these particular patients with staples was about $658 per patient.
Full story: SURGEONS USE EXCITING NEW TOOLS TO PROVIDE SAFER, COST-EFFECTIVE CARE
Product page: INSORB
Flashbacks: Insorb Resorbable Subcuticular Skin Stapler ; The Wall Street Journal’s 2006 Technology Innovation Awards
Image credit: Wellcome images: Surgery by robot…