Kickball used to mimic womb.
Kickball used to mimic womb.
Source: Johns Hopkins Medicine

Kickballs, chicken and 3D models help prepare for fetal surgeries

By combining high-tech 3D printing technology with everyday items such as a kickball and pieces of chicken breast, surgeons at Johns Hopkins report they have devised an innovative way to “rehearse” a complex minimally invasive surgical repair of open lesions on fetal spinal cords inside the womb.

The procedure, called fetoscopic myelomeningocele repair, is performed by a maternal fetal medicine specialist and pediatric neurosurgeon working together to correct a particular form of spina bifida, a birth defect marked by failure of the spinal column to close normally during early fetal development. It occurs in about three to four of every 10,000 pregnancies and can result in permanent nerve damage if left untreated.

The standard of care for the condition is surgery to close the spine as soon after birth as possible, says Jena L. Miller, M.D., an assistant professor of gynecology and obstetrics at the Johns Hopkins University School of Medicine and member of the Johns Hopkins Center for Fetal Therapy. For select patients, prenatal—or fetal—surgery is performed by making an incision on the mother’s abdomen and womb to expose the baby’s back, close the spinal opening, sew up the womb and maternal abdomen, and let the pregnancy continue. Although that approach can successfully reduce the risk of spinal cord damage and disability, it carries risks for the mother’s health and her ability to sustain future pregnancies.

A handful of hospitals, including The Johns Hopkins Hospital, are performing the surgery minimally invasively through two small ports rather than through open, large incisions on the maternal womb.

But, the Johns Hopkins surgeons say, training to do it has been challenging. To address the difficulty, a Johns Hopkins team prepared for its first such procedure last year on the fetus of a 31-year-old woman 25 weeks pregnant by creating models on which to practice.

Photo
Faux fetus with spina bifida
Source: Johns Hopkins Medicine

First, the surgeons report, they used ultrasound technology to obtain an accurate image of the fetal spine and lesion. Then, they created mesh models of the region to be operated on and generated a 3D print model of the area using flexible materials such as Tango (a material with rubberlike properties) and NinjaFlex (a filament with elasticity), adding a combination of silicones to produce a skinlike cover.

The surgeons also used a 10-inch diameter kickball secured to a Plexiglas base to mimic a uterus. “A kickball is about the size of a uterus at that time in pregnancy,” Miller says. “It holds its shape pretty well when sealed and unlike other trainers for laparoscopic surgery, it’s not see-through so it’s a more realistic model.”

For their practice sessions, the team cut two slits in the top of the kickball to serve as ports for surgical instruments. Then, inside the kickball, they placed the 3D printed model with its silicone cover secured to a plastic fetus over a layer of marbles to mimic the intraoperative motion and instability of the fetus. Then they practiced the surgical steps in that environment.

Besides practicing on the 3D printed model, they also practiced on a section of a skin-on chicken breast secured to a model of a fetus—placed inside the kickball—to get a better sense of touch for operating on multiple layers of tissue. This was helpful, Miller says, because chicken has more realistic properties than the 3D printed model.

During their planning, the team members also used a variety of instruments, suture materials and techniques until they achieved consistent times and outcomes for the individual steps of the operation. Their first live surgery went well, consistent with their practice on the 3D model, and they were able to make a complete watertight closure without complications. The woman had a vaginal delivery at term and the newborn has not required any additional procedures. The team has since used the technique to prepare for six additional cases.

“Repetitive practice by a dedicated surgical team in a patient-matched model lets us know exactly what to anticipate specific to each case,” Miller says. The goal of such rehearsals, Miller adds, is to pre-identify potential obstacles, and decrease operating time and risks. While the new procedure is promising, the surgeons caution that more study is needed to improve training, continue advancing the surgical technique, and reduce surgical time and potential risks of needing to convert to open fetal surgery.

Subscribe to our newsletter

Related articles

Advanced tech enables simulated sinus surgery

Advanced tech enables simulated sinus surgery

The world’s first international online training session utilizing advanced 3D sinus models and a telemedicine system has taken place.

Endoscopic prostate surgery performed on human-like phantom

Endoscopic prostate surgery performed on human-like phantom

Scientists have made a decisive contribution to improving complex surgical training by developing a very realistic prostate phantom.

Cyber-physical organ twins to train surgeons

Cyber-physical organ twins to train surgeons

Researchers have developed a range of artificial organ phantoms to serve as training platforms for surgeons.

Hip implant simulator for virtual surgery training

Hip implant simulator for virtual surgery training

The team of the Dynamic HIPS are working on a hip replacement simulator that will help future surgeons to practice the intervention.

3D printing helps surgeons correct birth defect

3D printing helps surgeons correct birth defect

Lifelike fetal 3D models show anatomical details that help surgeons prepare and predict challenges for delicate and complicated surgery.

Fortnite and Zelda can up your surgical game

Fortnite and Zelda can up your surgical game

Video games offer students obvious respite from the stresses of studies and, now, a study has found they could benefit surgical skills training.

4D-simulator breakthrough in brain surgery

4D-simulator breakthrough in brain surgery

A new training technology will improve patient safety during future procedures: a new 4D simulator enables the planning, testing and optimization of the procedure.

Creating an accessible surgery simulator

Creating an accessible surgery simulator

Researchers are developing a simulator that could be used to train both surgeons who are in the early stages of their career and those who are more experienced.

Medical customers adopt Stratasys 3D Printer

Medical customers adopt Stratasys 3D Printer

Stratasys Ltd. announced it has successfully sold and installed the J750 Digital Anatomy 3D printer at healthcare institutions and medical service providers in major markets across the globe.

Popular articles

Subscribe to Newsletter