Virtual reality brings surgery into a new dimension

Men and women in front of a large screen, each wearing a pair of thick, dark glasses.

Five doctors stand in front of a large screen, staring in silence. Each wear a pair a thick, dark glasses, almost “goggle-like” in appearance.

The silence is broken: “I feel like I’m in the future right now.”

Through those glasses, they are taking a three dimensional virtual ‘tour’ through the hearts of conjoined twin infants Paisleigh and Paislyn Martinez.

In the small group is Pediatric Surgeon Daniel Saltzman, M.D., Ph.D., a professor in the University of Minnesota Medical School's Department of Surgery. He’s tasked with separating the twin girls, whose hearts appear on the screen before him, color coded in red and blue, and enhanced more than five times in size. 

From the ground up

Paisleigh and Paislyn were thoraco-omphalopagus conjoined twins- joined from the lower two-thirds of the breast bone to the belly button, although they lacked a breast bone. Their livers were fused in the middle, and their hearts appeared to be touching.

The girls’ doctors knew the only way to successfully care for the babies and their mother from prenatal care, to birth, to separation and after, was to have a team-oriented approach. Physicians from specialty areas all across the hospital met weekly with advanced practice nurse leaders. The surgical team also met several times in the operating room for ‘simulations,’ or practice runs, of the operation.

“There’s a lot of planning. There’s been a lot of sleepless nights I’ll be honest with you,” said Saltzman, who is also a Masonic Cancer Center member. “There’s a lot of thinking about how we are going to do this. Nobody has a huge amount of experience here.”

Calling on the depth of University for in-depth answers

Experts used virtual reality imaging and 3D models to plan for separating conjoined twins.

A key component of that preparation was the expertise and collaboration of faculty and researchers at the Earl E. Bakken Medical Devices Center – home to the 3D virtual reality imaging capabilities Saltzman and the team utilized to visualize the Martinez twins’ hearts. That device is one of just 5 to exist world-wide. 

“Just like a 3D movie, these virtual environments are able to show in-depth information about anatomy that is not available on a standard computer screen,” said Bethany Tourek, Ph.D. student with the Earl E. Bakken Medical Devices Center. 

Tourek worked with the medical team to create a computed tomography angiography (CTA) of each twin's anatomy. She reached out to the University of Minnesota Visible Heart Laboratory to ensure the anatomy anomalies were segmented correctly. A handful of separate models were created detailing the twins’ skeletal structures, lungs and heart cavities.

The Medical Devices Center created a 3-D model of the hearts of conjoined twins who were separated at the University of Minnesota Masonic Children's HospitalThe model is an identical replica of Paisleigh (red and blue) and Paislyn's (purple) hearts. 

“The surgeons were able to explore the twins’ anatomy and make the appropriate plan before the procedure began. I like to think that we offered a service that improved the outcome of the twins,” said Tourek.

The surgeons agree. For starters, that technology coupled with 3-D models of the babies’ hearts revealed what they couldn’t see before: an actual physical connection bridging the two girls’ hearts. 

“It was scary,” said Pediatric Cardiologist Matthew Ambrose, M.D., assistant professor in the Medical School's Department of Pediatrics. He vividly remembers the moment he saw the connection. “There were multiple reports of other babies with that connection who died during surgery. But I suspect it’s because it wasn’t recognized before surgery.”

Thinking on their feet

Fortunately, it was recognized, and that allowed the team to better prepare for the surgery – adapting their approach to accommodate the complexities unique to Paisleigh and Paislyn

“What we had to do was separate the moderate to large communication,” explained Pediatric Cardiothoracic Surgeon Tony Azakie, M.D. Azakie is professor and chief of the Division of Pediatric Cardiac Surgery. “My thinking was if we approach it as originally planned, then we would have to push the hearts away to access that bridge which would be located in the back and that may have caused them to become unstable. It may have compromised their circulation. So our strategy then changed.”

We anticipated every little problem we were going to have. - Dr. Saltzman

The surgical team decided to flip the orientation of the twins 180 degrees. Their original plan had Paisleigh staying in the OR while her sister was taken to a different operating room. Now, Paislyn would stay. Since Paislyn was born with a complex congenital heart defect, called tricuspid atresia with transposition of the great vessels and a ventricular septal defect, surgeons were planning to perform an additional surgery on Paislyn after separation. But with the new information about the heart bridge and a new surgical approach, the team had to bring additional cardiac resources and team members into the room to address Paislyn’s other heart problems.

“We anticipated every little problem we were going to have,” said Saltzman, “We had everything down to where we were going to put monitors, how were are going to transport them, to how we were going to close the skin, and put the dressings on.”

It takes a village

Daniel Saltzman, M.D., assists in the twins' separation surgery Daniel Saltzman, M.D., assists on the twins' separation surgery.

On May 25th, at 6:30 am, all the preparation and planning was put to the test. Nine hours later, Paislyn and Paisleigh were successfully separated and on the road to recovery. 

“I think there was an element of not knowing what we were going to encounter, but at the same time that was balanced with the fact that we had spent a lot of time planning and imaging so we did have a certain understanding of what we were going to find, and how we were going to find it,” Azakie said. “The 3D modeling and some of the other imaging really helped us prepare for that.”

And it will continue to prepare others.  Preforming a conjoined twins separation surgery is rare. The innovative thinking, collaboration and cooperation it required could be applied to many future medical cases, and that wisdom will be passed on to health sciences students, Minnesota’s future health care leaders. 

“When you have the right team almost anything is possible,” said Ambrose, looking back. “I’m still kind of in awe of the trust their parents placed in us, knowing this is something we’re inventing from the ground up. To know they trusted us to do this was very humbling.”