University of Michigan (UM) Congenital Heart Center paediatric heart surgeons presented their results on January 28 at the annual meeting of the Society of Thoracic Surgeons, as part of a workshop for other surgeons on robot-assisted options for young heart patients.
Surgeon Richard Ohye, M.D., stated: "Robot-assisted surgery has already shown quite a bit of promise in the adult population, including adults who have congenital heart anomalies. But we feel from our experience that it can be used on many paediatric patients weighing more than 10 kilograms, and can reduce hospital stays, operative trauma, cosmetic impact and overall recovery time. And we found it does so with an acceptable impact on a patient's time in the operating room."
Despite the added expense of operating room time and the robot itself, Dr. Ohye feels that the machine will more than offset its costs over time by reducing the time a child spends in the hospital after surgery, the complications he or she will face during recovery, and his or her parents' time away from work.
Dr. Ohye and UM paediatric cardiac surgery colleagues Edward Bove, M.D. and Eric Devaney, M.D. performed the robot-assisted and open surgeries compared in the report. Drs. Ohye and Devaney began using the robot at the UM's C.S. Mott Children's Hospital in November 2002, one year after the UM Health System (UMHS) acquired the $1 million da Vinci robot system. The surgeons use the robot for a small minority of the more than 900 surgical procedures they perform each year on UM Congenital Heart Center patients, but they expect the number will grow in the future.
The system has two main components: a seven-foot-high robot with three cable-driven arms that hold tiny instruments and a small camera while they are inserted into the patient's chest through small incisions, and a visualization and guidance station where the surgeon can manipulate the robot arms using three-dimensional images from the camera inside the patient.
The Congenital Heart Center surgeons share the robot with numerous other adult and paediatric surgeons at UMHS, from urologists who use it to remove prostate glands without damaging nearby nerves, to gynaecologists who extract fibroids while sparing a woman's uterus.
At the Society of Thoracic Surgeons' meeting, Dr. Ohye showed video footage of operations to divide a vascular ring, a rare birth defect in which blood vessels surround the esophagus and trachea, reducing a child's ability to breathe. He also presented data on five vascular ring division patients who had a robot-assisted minimally invasive operation, and ten who had conventional open-chest surgery for the same problem. The data also include two other children who had robot-assisted surgery for other congenital heart defects: a persistent left superior vena cava, and the placement of electrical leads for an implanted pacemaker to correct a heart rhythm irregularity.
The robot-assisted children ranged in age from 1 to 10 years, and the smallest weighed 10 kilograms, since the camera is too large to fit between the ribs of a smaller child. The seven robot-assisted children had a median hospital stay of two days, compared with four days for children who had open-chest surgery. One patient in each group experienced a complication called a chylothorax, in which a lymphatic duct was punctured and leaked fluid into the chest cavity.
The children who had robot-assisted surgery were in the operating room for a median of 116 minutes, compared with a median of 83 minutes for the open-chest procedures. This difference was statistically significant. But Dr. Ohye feels it is not unreasonable, especially given the other positive effects of using the robot. The UM team is now offering robot-assisted surgery as an option to the parents of patients with vascular rings and certain other conditions, even as they plan to expand the range of procedures they perform with it.
Someday, they hope that real-time, three-dimensional images of the inside of the heart made by sound wave echos or electromagnetic devices rather than cameras will allow them to perform minimally invasive versions of procedures that involve entering the heart itself. Right now, the imaging techniques are used to aid open-chest procedures.
"In five or so years, perhaps we'll perform most of the basic procedures with the robot's help", Dr. Ohye predicted. "But for now, we're starting with building the case for its safety and its cost-effectiveness, in certain types of cases. And we're finding that parents of our patients are embracing it, and in some cases even asking for it."
The Michigan Congenital Heart Center (MCHC) is one of the world's top centres for the diagnosis and treatment of heart and vascular disorders that arise during foetal development or childhood. Patients are often followed from before birth through adulthood. The MCHC takes a multi-disciplinary team approach to patient care, and offers support services to help families cope. More than 900 surgical procedures, 600 heart catheterizations, and thousands of clinic visits take place at the MCHC each year. About half of the MCHC's patients are from within Michigan, but families travel to Ann Arbor from around the country and throughout the world for treatment and surgery.