Magnetic needle and thread help surgeons do sutures in small spaces

A magnetic needle and thread lets surgeons maneuver in tight spots.

The current method of suturing used in surgery—stitching with a needle and thread—has been around for thousands of years. Kaifeng Liu, MD, a research fellow at Boston Children’s Hospital, hopes to reimagine this fundamental operating room practice. His workbench is filled with various prototypes of a magnetic needle, a device he hopes will make suturing simpler, faster and more efficient for researchers and clinicians alike.

“Sometimes it is the simplest things in medicine that stay the same over time,” says Liu, whose invention will be featured later this week at Boston Children’s Hospital’s Global Pediatric Innovation Summit + Awards 2014 (October 30-31).

Liu attended Tongji Medical College and practiced as a thoracic surgeon in China before coming to Boston Children’s Division of Pulmonary and Respiratory Diseases. He now focuses on experimental surgery in the lab of Gary Visner, DO. His work in animal surgery inspired him to create a new method of suturing for small, confined or otherwise challenging surgical fields.

In traditional suturing, Liu explains, the surgeon grasps a curved needle with needle holders and drives it into the tissues with a twisting motion. The thread, attached to the back of the needle, is pulled through the tissue, while the surgeon’s non-dominant hand uses tweezers to guide the needle and re-grasp it. This method of suturing not only requires extra space to accommodate the curved needle, but also requires surgeons to constantly transfer the needle between needle holder and tweezers.

“Each additional action takes time and energy of the surgeon,” says Liu.

Liu demonstrates how the needle is used, in a chicken breast.

Liu’s new method of suturing employs a short needle with a magnetic element. The needle is fixed to the needle holder and is used with suturing threads that themselves have a small magnet at their tip.

Using Liu’s method, the needle first pierces the tissue to be stitched and then engages the end of the suture thread through magnetic attraction. The needle and thread are then pulled back through the tissue and the process is repeated for each stitch, without the surgeon needing to switch the needle from instrument to instrument. “With our design, the stitching method changes,” says Liu. “The magnetic attraction makes the elements come together on their own without requiring a time-consuming transfer.”

Kiafeng Liu, MD magnetic suturing needle

Liu

The main advantage of this method is that the needle can be used in very small spaces. Liu says he can create reusable needles as small as 1mm in diameter and 5mm in length. He envisions their use in especially tiny, deep or confined surgical fields, such as in endoscopic surgery on the esophagus or the bronchi, gynecologic or colorectal surgery in the pelvis, or ophthalmologic procedures on the eye. He also believes the needles will be valuable in procedures that require creating anastomoses—bringing two tubular structures together—as is done in biliary, bowel and vascular surgery.

Liu hopes to introduce his design, currently in the prototype stage, in animal surgery before testing it in patients. “Experimental surgery,” he says, “can be even more challenging than in a human being.” In many animal surgeries, he says, the traditional method of suturing is almost impossible, and better strategies are needed to navigate these miniscule surgical fields. He believes the new technique will be affordable and hopes that surgeons and researchers will embrace it.

“The old needle was invented from the traditional knitting needle, so the current paradigm has been around for thousands of years,” says Liu. “But we have changed the concept, changed the way it’s done to make it simpler. And the simpler the better for the surgeon.”

For more on the magnetic needle, which is available for licensing, visit Boston Children’s Technology and Innovation Development Office.

Joshua Feblowitz is a science writer and 4th year student at Harvard Medical School.

The needle and other innovations will be on display this week at Boston Children’s Global Pediatric Innovation Summit + Awards 2014 (Oct. 30-31). The summit is sold out, but keep checking www.takingontomorrow.org or follow the hashtag #pedinno14 on Twitter to stay on top of the action.