Student inventors design award-winning device for suturing

Credit: Will Kirk / Johns Hopkins University

After a surgeon stitches up a patient's abdomen, costly complications—some life-threatening—can occur. To cut down on these postoperative problems, Johns Hopkins undergraduates have invented a disposable suturing tool to guide the placement of stitches and guard against the accidental puncture of internal organs.

Image caption: Back row from left: Daniel Peng, Leslie Myint, Ang Tu, and Sohail Zahid. Front row from left: Luis Herrera, Stephen Van Kooten, Anvesh Annadanam, and Haley Huang.

Image credit: Will Kirk / Johns Hopkins University

The eight student inventors describe their device, called FastStitch, as a cross between a pliers and a hole-puncher. Although the device is still in the prototype stage, the FastStitch team has already received recognition and raised more than $90,000 this year in grant and prize money to move its project forward. Among its wins were first-place finishes in University of California, Irvine, and University of Maryland business plan competitions; the ASME International Innovation Showcase; and the National Institute of Biomedical Imaging and Bioengineering's Design by Biomedical Undergraduate Teams Challenge. This month, the device is a finalist in the Collegiate Inventors Competition.

FastStitch is needed, the students say, to improve the way up to 5 million open abdominal surgeries are conducted annually in the United States alone for treatment of cancer, liver problems, and other ailments. If incisions are not closed properly, a patient can develop complications such as infection, herniation, and evisceration, all of which require additional treatment and, in some cases, more surgery. Just one of these complications—herniation, in which intestinal tissue can protrude through the abdominal wall after the muscle layer splits apart—leads to $2.5 billion in additional costs annually in follow-up treatment and medical malpractice expenses, the students say.

Addressing this problem became a biomedical engineering course assignment over the past school year. The students were asked to design and test a tool that would improve the way surgeons stitch together the strongest part of the abdomen, the muscle layer called the fascia, which is located just below the skin. "Doctors who have to suture the fascial layer say it can be like pushing a needle through the leather of your shoe," says Luis Herrera, a sophomore biomedical engineering major. "If the needle accidentally cuts into the bowel, it can lead to a sepsis infection that can be very dangerous."

To help prevent this, the students designed the FastStitch needle to remain housed within the jaws of the stitching tool. "You place the fascial layer between the top and bottom arms of the device," says Sohail Zahid, leader of the team. "Then, as you close the arms, the spring-loaded clamp is strong enough to punch the needle through the fascial layer. When this happens, the needle moves from one arm of the tool to the other."

The device also features a visual guide to help ensure that the stitches are placed evenly, located the proper distance from the incision and apart from one another. This should also reduce postoperative complications, the students say. The hand-size plierslike shape was chosen because it would feel familiar to surgeons and require less training. The prototype was constructed mostly of ABS plastic, so that the instrument can be inexpensive and discarded after one use.

"We're developing the future of suture," says Zahid, who earned his undergraduate degree in May and is hoping to enter Johns Hopkins' MD/PhD program in biomedical engineering. "We believe that if the FastStitch tool is used to close abdominal incisions, it will help surgeons by making the closure process simpler and safer. It will help hospitals by reducing costs. And, most importantly, it will help patients by reducing postoperative complications."

Hien Nguyen, an assistant professor of surgery in the Johns Hopkins School of Medicine, served as the students' clinical adviser during the development of FastStitch. "Just about every major operation in the chest and abdomen requires a large cut to be made through the muscle layers," he says. "If these layers are not brought back together evenly, complications can occur. This device allows the surgeon to bring the layers back together evenly, safely, and quickly, and this can lead to better outcomes and fewer complications."

Nguyen had discussed the need for a better suture tool with the undergraduate design team in a program offered by the Department of Biomedical Engineering, which is shared by the university's schools of Medicine and Engineering. The program is conducted within the Center for Bioengineering Innovation and Design.

In addition to Zahid and Herrera, the students who have participated in the project are Andy Tu, Daniel Peng, Stephen Van Kootyen, Leslie Myint, Anvesh Annadanam, and Haley Huang. Through the Johns Hopkins Technology Transfer Office, the team has obtained preliminary patent protection for its invention. All eight students are listed as co-inventors, along with Nguyen and graduate student Adam Clark.

The students have formed a Baltimore-based company, Archon Medical Technologies, to conduct further research and development of FastStitch. The company is being supported by grant funding and by most of the prize money won in the student invention and business plan contests earlier this year. Animal testing of the device is under way, and further testing with human cadavers is expected to begin later this year.