STAPLE FIRING Besides ease of use, the stapler features that matter most to surgeons are secure staple lines and uniform staple formation.

Does it fire consistently? And does it give you a uniform staple line formation? "No malfunctions and no leakage — that's all surgeons care about when it comes to surgical staplers," says David Renton, MD, MPH, an assistant professor of surgery at Ohio State University's Center for Minimally Invasive Surgery in Columbus.

Marlene Brunswick, RN, MSN, CNOR, RNFA, director of perioperative services at Mercy St. Vincent's Medical Center in Toledo, Ohio, takes it a step further. She says a surgeon she once worked with was so concerned about whether his laparoscopic staples would hold that it often meant the difference between a restful or a sleepless night. She says his mind would race with what-ifs from the day's cases:

• Is the blood going to leak past the staple?
• Is the bile going to leak?
• Is the anastomosis going to hold?
• Will the lung re-expand without breaking through the staple line with the next breath?

Dr. Renton still remembers when his stapler malfunctioned during a case. Not misfired. Malfunctioned.

The stapler fired all the way through, but its jaws, as though locked in cement, wouldn't let go. Thankfully, the stapler rep was in the room. He got his manager on the phone and they were able to dismantle the stapler inside the patient. "Let's just say there's a lot of moving parts, and we didn't have a sterile screwdriver," says Dr. Renton. "You don't want to dismantle a stapler on the field."

Kidding aside, staplers that misfire or jam will surely draw your surgeons' ire. "The more uniform the staple formation, the better seal you have" says Dr. Renton. "You want every staple to look like it's supposed to look after you fire it." Across tissue or a vessel, staples should fire like "the dotted center line on a highway," says Tina Frank, RN, BSN, nurse manager of the operating room, endoscopy and anesthesia technicians at Pinnacle Health in Harrisburg, Pa. The key to perfectly aligned staples is choosing the proper staple height and width.

"One key physician need is accurate deployment of the staple," says Nancy Burden, RN, manager of ASC quality and education at the BayCare Health System in South Florida. "When a staple becomes lodged in the gun with a misfire, the physician wastes time and can become frustrated when his attention must be directed to the instrument."

As a general rule, to prevent blood leakage in vascular tissue, you want to use "real small, real tight" staples, says Dr. Renton. For abdominal and bowel stapling, you'll want to use larger staplers so that they form and meet on the other side of the tissue. "It all depends on how thick the tissue is that you want to staple," says Ms. Frank. Dr. Renton prefers to use staplers with different tiers of staple sizes: larger on the outer edge and smaller on the insider edge. "With tiered staple height," he says, "you'll reach the cut end and seal it so it doesn't leak."

EASE OF USE A study shows that powered stapling devices can reduce surgeon fatigue often experienced when using mechanical staplers.

Advances in technology
Today's staplers offer greater access to the surgical cavity and let surgeons perform more abdominal cases laparoscopically. Ergonomically designed staplers not only let surgeons reach deeper, but also get better margins and better anastamosis. "Con-sidering the larger size of the population, a stapler of this sort will allow more patients a chance at minimally invasive surgery," says a nurse manager at a government facility.

Applying mesh to an abdominal defect during an open hernia repair has been compared to trying to wallpaper your ceiling. Dr. Renton recently trialed a new stapler that he says improves open hernia repairs. He says the ergonomically designed stapler lets surgeons reach deeper into the abdominal cavity to apply tacks uniquely designed to take a bite of mesh when fired at any angle.

Laparoscopic staplers need to be able to reach and approximate the tissue intended to be stapled, says Ms. Brunswick. "To get there, the device needs to be the right length — from pediatric length to bariatric length," she says. The angle at which the tissue needs to be approached is not always the most direct, of course. Manufacturers have responded so that you can rotate, turn and articulate the stapler shaft in many directions to make the use more comfortable for the surgeon and more appropriate for the patient's best outcomes, says Ms. Brunswick. Ergonomics matter, too (see "Can Staplers Cause Surgeon Fatigue?"). Manufacturers have improved stapler handles and grips, and accounted for right- and left-handed use.

All of these advances are not without their challenges. Purchasing and materials management staff must keep track of the many new products and SKUs on the shelf. The scrub and circulator have to learn how to operate the multiple devices. "In-service staff to make sure how they know how to take the stapler apart and put it back together," says Ms. Frank.

OR ERGONIMICS
Can Staplers Cause Surgeon Fatigue?

STRONG SEAL A surgeon prepares to staple the vessels by the gallbladder.

Laparoscopic procedures often require surgeons to position their bodies in awkward angles and perform repetitive maneuvers for several hours, causing enormous strain on their hands and bodies. That painful fact is powering the push to design ergonomic surgical tools that address surgeon fatigue.

Take staplers, for example. A poster, "Comparing the Biomechanical Characteristics of Manual and Powered Laparoscopic Stapler Designs," presented at the 2012 Society of American Gastrointestinal and Endoscopic Surgeons, shows that powered stapling devices can reduce surgeon fatigue often experienced when using mechanical staplers and protect surgeons' hands from long-term damage. The researchers also found that powered devices help surgeons with smaller hands, particularly females, perform surgery with much greater ease. This is because, they say, powered stapling instruments demonstrate negligible staple firing and blade retraction forces when compared to manual staplers. These factors may increase instrument stability and decrease surgeon fatigue.

The study, conducted by researchers at the University of Connecticut Health Center and Yale University, found that powered instruments, if properly designed, may help to control, and possibly eliminate, some of the musculoskeletal issues inherent to minimally invasive surgeries.

"We have now established a method to assess the biomechanical risks that surgeons face when performing minimally invasive surgery," says Donald R. Peterson, PhD, MS, of the University of Connecticut Health Center Biodynamics Laboratory in the Division of Occupational and Environmental Medicine. "This should provide invaluable information to guide the development and design of new ergonomic surgical tools."

To compare the biomechanical risks associated with the use of manual and powered surgical staplers, researchers measured the physical characteristics and forces required to activate the various functions of a stapler, including staple firing and blade retraction, for 2 manual designs and 1 powered design. Measurements included handle shape and contour, handle angle, hand and finger reach, and grip spans. Researchers used 4 stacked layers of 4-mm thick foam as a tissue surrogate for all clamping and firing operations.

Both manual staplers subjected users to repeated grip forces in excess of 20 pounds during staple firing and blade retraction functions, the researchers found. Published literature indicates that maximum grip force levels should not exceed 25 pounds when designing a hand tool for use by 95% of the female population. They also found that the dimensions of the manual staplers are not adequately suited for use by male or female surgeons having a glove size less than 6.5.

— Dan O'Connor