Conjoined twins surgeon, of Sacramento, built prestigious career out of healing kids

A polished metal sculpture on Dr. Peter Lorenz’s otherwise stark desk depicts a faceless male figure raising up a small child - a symbol of the reconstructive surgeon’s commitment to helping and healing his tiniest patients.

The Stanford University doctor and Sacramento native has dedicated his career to reshaping childrens’ skin and bones to repair cleft palates, elongated skulls and other defects that hinder their quality of life, always watching closely to make sure their wounds heal just right. His attention to detail has put him at the top of his field in pediatric reconstruction, and has made him the go-to person for sewing up sets of separated conjoined twins including, most recently, Eva and Erika Sandoval of Antelope.

The 2-year-old girls, successfully separated on Dec. 6, were fused from the chest down and survived surgery with gaping wounds where their abdomens and lower bodies were once joined. The exposed area was larger than what Lorenz had seen on the two sets of conjoined twins he had previously operated on, and closing it presented a unique challenge.

But Lorenz, 55 and a parent to three daughters including two toddlers, said finding ways to mend children in dire situations is just part of his job.

“Sometimes you see kids that remind you of your own and you’re like ‘Wow, this could be my daughter, too,’ and it really kind of shakes you a little bit,” he said. “But on the other hand you think, ‘Maybe there’s a problem I can make better, that I can fix,’ and that gives you a good feeling at the same time.”

Lorenz became interested in medicine early on, inspired by his grandfather Dr. Hermann Lorenz, who served as chief of staff at Mercy General Hospital in the 1950s. Growing up in Sacramento’s Greenhaven neighborhood, he said, the young Lorenz looked up to his grandfather and took notice of the way the elder doctor was respected in the community.

The medical interest paired well with Lorenz’s knack for building things from scratch, his siblings said. At home he carefully assembled model cars and rocket ships and in shop class designed a solid mahogany table that lasted 30 years past its creation. Family members still wonder if his way with wood and nails was a precursor to his surgical skills.

At John F. Kennedy High School, Lorenz excelled at math and science, although he received straight As across the board. After begrudgingly joining a community swim team at his mother’s request, he became a star swimmer and later a high school captain.

“He’s this guy who has always been, since he was a little kid, very focused,” said his younger sister Margaret Lorenz, who works as a voice coach in Sacramento. “Whatever he was doing, he would be extremely focused on it. He didn’t procrastinate. … That’s just how he always was.”

Fueled by his still developing dream of becoming an orthopedist, or a sports physician, Lorenz began his studies in 1979 at UCLA, where he majored in biology. With a few pre-medical classes, his interest in human anatomy grew. When he returned to Sacramento after his freshman year, he sought out a job as an orderly at Sutter General Hospital.

That summer, while cleaning operating rooms and pushing gurneys through the long, sterile halls, he snuck peeks at surgeries and imagined one day wielding the scalpel himself.

“I liked surgery,” Lorenz said. “I was in the OR and I thought, ‘This is amazing - I can’t believe people can do this.’... But I knew it was something that interested me and I could see myself doing it. And so that started me on the surgical track.”

He never moved back to Sacramento full-time, instead journeying to the University of Michigan for medical school and then to the Bay Area for a five-year general surgery residency and a three-year research residency at the University of California, San Francisco.

During medical school Lorenz was drawn to cardiac surgery, but the doctor he was supposed to study with left UC San Francisco during his second year of residency. Instead Lorenz ended up elbow deep in wound research with Dr. Michael Harrison, a pediatric surgeon who was studying how fetuses could use their own stem cells to heal without scarring after in utero operations.

Harrison, now an emeritus professor at UC San Francisco, said that while Lorenz worked in his laboratory, he “contributed tremendously” to the work. Even now, at Stanford, Lorenz spends much of his non-surgical time in the lab studying the human wound-healing potential of regenerative stem cells.

“He’s very calm and deliberate,” Harrison said. “He’s just very level headed in terms of his surgical judgment and his approach to life.”

During those early research years, Lorenz became interested in fetuses with cleft lip and palate defects because they showed potential for regenerative healing. Later, during a plastic surgery residency at UCLA, Lorenz practiced fixing the defect in the operating room. He also traveled to Bangladesh and Ecuador to help children who would otherwise live out their lives with the condition, which can affect speech and the ability to eat.

Now at the Lucile Packard Children’s Hospital Stanford, he works with children who are brought to the U.S. from countries that don’t have the resources to carry out the complex operations.

“That really opened my eyes to the cleft problem globally,” he said. “Here I see patients who are adopted form China, they’re usually 2 or 3 years old. They learn to speak English. Some come with malnutrition and they quickly catch up and thrive here. It’s amazing to see them do so well.”

For someone with a portfolio of successful surgeries and an office lined with framed certificates, Lorenz doesn’t brag or even talk much unless prompted. Sandy-haired with a slight build and thick-rimmed glasses, he has a casual air that puts strangers at ease. When complimented he offers a sheepish smile and tries to gently change the subject.

Lorenz relied on his calm demeanor when preparing for the Sandoval surgery this fall. Having successfully separated a set of conjoined twins from Costa Rica in 2007 and another set from the Philippines in 2011, he felt prepared for his latest assignment, especially given the planning that he, lead surgeon Dr. Gary Hartman and about 50 other hospital staff put into the complex procedure, he said. In the week leading up to the surgery, Lorenz tried to sleep well and lower his stress by swimming laps.

While twin separations can seem daunting at first, they’re actually a combination of many different skills that surgeons already have, Lorenz said. That’s why it was crucial to approach the Sandovals, who shared a pelvis, liver and some digestive tract, with a team that included orthopedists, urologists and general surgeons.

“The amount of specialization to do it is too diverse for one person,” he said. “That’s the part I like the most. It allows you to participate in something that’s bigger than yourself in each individual team.”

Lorenz didn’t take his post in the operating room until about 6 p.m. on surgery day, about 10 hours in, after Dr. Hartman and other physicians involved in the actual separation had made their final cuts. Then Lorenz took over, moving quickly back and forth between Eva and Erika’s rooms to see that the girls’ large wounds were properly managed.

Prior to surgery, Lorenz had implanted the twins with tissue expanders in their torsos and backs so he could harvest extra skin for grafting. He had just enough from the expanders and from the girls’ formerly shared third leg to pull the skin together. For the last two weeks, Lorenz and his team have been watching the twins closely for any signs of stretching or infection. The girls remain stable and in recovery.

“We’re like the clean-up batter, because of the wound issue,” Lorenz said. “We’re watching the flaps heal and if those have any healing delay or any wound issue, that means more surgeries. We’re never quite off the hook.”

Lorenz said he’s looking forward to seeing the two girls grow up just a short drive away from where he did.

“It’s the most exciting thing we essentially do,” he said. After you spend all this time planning and separating you finally make that little cut. … That’s the point where I think ‘Wow, this is really different,’ and it makes you feel good as a surgeon.”

Sammy Caiola: 916-321-1636, @SammyCaiola

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