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Laser surgery helps odds for unborn twins with rare transfusion syndrome
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Dr. Stephen Emery, fetal surgeon, left, prepares to have the laser activated by the operating room team for surgery done to the placenta of Rachel Lendyak-Peters, right, which is being shared by her identical twins. -
Dr. David C. Streitman, center, a fetal surgeon and an associate of Dr. Stephen Emery, fetal surgeon, right, checks the insertion of operating instruments for laser surgery done to the placenta of Rachel Lendyak-Peters, which is being shared by her identical twins. -
Ryan Peters and Rachel Lendyak-Peters chose fetal surgery to try to help their unborn twins, who have twin-twin transfusion syndrome.
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A small monitor attached to an ultrasound machine showed Rachel Lendyak-Peters' twin boy fetuses moving in the uterus they share.
"Welcome to the intrauterine world."
The words were spoken by maternal-fetal medicine specialist Stephen Emery, director of the Fetal Diagnosis and Treatment Center at Magee-Womens Hospital of UPMC, who was about to do laser surgery on the twins.
Ms. Lendyak-Peters of Verona was in the operating room for the second time in her 22-week pregnancy because her fetuses were suffering from twin-twin transfusion syndrome. It is a rare disease, occurring in just 10 percent of the pregnancies in which identical twins are in separate amniotic sacs but share a placenta.
PG GRAPHICNormally blood vessels fan out from each twin's umbilical cord and connect to the placenta. But sometimes vessels of one twin find vessels of the other and form connections, causing blood to pass freely from the "donor twin" to the "recipient twin." Twin-twin transfusion syndrome occurs, and the lives of both twins are threatened. The donor twin stops making urine, and amniotic fluid decreases, usually leading to death. The recipient gets increasingly high blood pressure, develops heart failure, and also usually dies. The death of one twin usually results in the death of or injury to the other.
Dr. Emery's goal on this Friday in mid-June was to find the connections that were making Baby A donate his blood to Baby B, and then block the transfusion by using the light of a laser to burn and seal off the wayward blood vessels.
Laser surgery, done by highly trained sub-specialists in only 15 medical centers in the nation, is statistically the most successful way of treating twin-twin transfusion syndrome. According to Dr. Emery, the twins have a survival rate of 70 to 75 percent, with an 8 percent chance of neurological impairment.
Next most successful is a method called serial amnioreduction, in which a general obstetrician repeatedly withdraws excess amniotic fluid from the sac of the recipient twin. Survival rate is about 50 percent, Dr. Emery said, with approximately 33 percent chance of neurological impairment.
Other options include doing nothing, in which the "loss rate is essentially 100 percent" and the mother faces such risks as hemorrhage; termination of the pregnancy; delivery after 24 weeks gestation; and selective termination of one twin. Survival of twins delivered at 24 weeks is 50-50, Dr. Emery said, with a 50 percent chance of major disability in survivors. In selective termination, which is "technically complicated," he said, the outcome of the surviving twin is based on such factors as the stage of the syndrome at intervention and whether it is the donor or recipient.
For Ms. Lendyak-Peters, 26, and her husband, Ryan Peters, 25, the decision on which option to choose was easy.
"I know that laser is the best chance for both babies," she said. "There was no way I could say get rid of one. No way."
Six weeks earlier, when Ms. Lendyak-Peters was just 16 weeks pregnant -- a time when most cases of the transfusion syndrome require only ultrasound monitoring -- her twins were already at Stage II of a five-stage progression of the syndrome. "That tells you that she had early disease that was aggressive," Dr. Emery said.
The nature of the syndrome at 16 weeks was the opposite of what it later became: Baby B was the donor twin and Baby A the recipient. That day at 16 weeks Dr. Emery lasered 16 vessels, nearly triple the usual six or seven that need to be taken care of.
"It was successful," he said. "Within a week, the disease was arrested. It was gone. All of the ultrasound findings returned to normal, and that was true at 17, 18, 19, 20, 21 weeks. At 22 weeks, she had reverse twin-twin ... which implied that there were vessels in there that were too small for us to appreciate at 16 weeks or had developed into anastomoses [connections], or that were deep in the placenta."
Dr. Emery said sometimes the donor twin is smaller than the recipient, but that was not the case with these two.
For the second procedure, he hoped, a scope inserted through Ms. Lendyak-Peters' abdomen and into her uterus would allow him and David Streitman, a maternal-fetal medicine specialist being trained in the procedure, to track and laser those dangerous vessels.
Guided by ultrasound, the device known as a fetoscope, containing a thin fiber to carry the laser light energy, is inserted into the amniotic sac of the recipient twin. The surgeon looks through the fetoscope to see the blood vessels on the surface of the placenta and detect which vessels are shared by the twins, and these are sealed off. An ultrasound probe measures heart rate and amniotic fluid volume in the recipient twin.
Identifying, or mapping, the shared blood vessels and then backtracking over the same placental ground, the two doctors eventually picked out and lasered six unpaired donor vessels draining into the recipient twin.
Then Dr. Streitman removed some of the amniotic fluid that had built up and closed up Ms. Lendyak-Peters' tiny incision, which was about the length of a grain of rice.
Afterward Dr. Emery acknowledged he was still concerned about the twins, the 10th case he has treated since his first at Magee in July last year. (He trained by observing surgery by Timothy Crombleholme once a month for two years at Cincinnati Children's Hospital Medical Center.)
"My concern is that there are deep vascular [connections] that we are not going to be able to treat," Dr. Emery said. "We are going to have to do our best and hope that the disease arrests; that she gets to a respectable gestational age; and that we can get two healthy kids out of it."
Dr. Emery has lost donor twins in three Stage III cases. Twins also died in a patient with Stage II disease several weeks after surgery. "The autopsy showed acute reversal of the disease," he said, and suggested there were hidden connections in the placenta. "These cases serve as a reminder of how serious the diagnosis of TTTS is. ...
"There's never a time when twin-to-twin can't happen. It can happen all the way up to the due date."
Laser surgery, he added later, "improves on an otherwise grim situation, but is not magic."
Still, he said he was optimistic after the second surgery on Ms. Lendyak-Peters' twins, which was done after diagnosis at Stage I of the twin-twin transfusion syndrome, that the six vessels he lasered were the "culprits."
As she did after week 16, she will undergo ultrasound on the twins weekly, but Dr. Emery said he doubted he'd do another laser surgery if the disease recurred again. "Each time there is a 7 percent chance of membrane rupture," he said. "We can't perform laser after 26 weeks. We will have to do something else."
For Ms. Lendyak-Peters, the pregnancy and her weekly trips to Magee have been a roller-coaster ride since she found out she and her husband were having twins.
Because she had started bleeding at six weeks, she was sent for an ultrasound at Magee and "during the ultrasound I started crying." The technician asked her what was wrong, and, she remembered, "I said, 'I want to know if I'm still pregnant.' She said, 'They're still there.' That's how we found out we were having twins."
She also learned that though they were in separate sacs, the fetuses shared a placenta, putting them at higher risk. Ms. Lendyak-Peters, who had hoped to deliver by midwife, was sent to the department of maternal-fetal medicine, where she was told of the chance her twins would develop the transfusion syndrome.
"So they start screening for this around 16 weeks," she said, "and the doctor I talked to said they don't usually find it until 18 weeks." But when she had her 16-week ultrasound, it took so long for the test she sensed something was wrong. Eventually Dr. Emery came in and explained her options. That was on a Tuesday; that Friday she had surgery.
Since then, she said, she has been up and down emotionally. "The twins' lives are at risk, and that's the hard thing to deal with."
But she likes and trusts Dr. Emery and his staff.
"I feel everybody [is] invested in me and my babies, and that puts me at ease," she said.
And "invested" is exactly what Dr. Emery is, not only in Ms. Lendyak-Peters' case but in laser surgery and twin-twin transfusion syndrome, period.
He talks of his gratitude that the Twenty-Five Club, a group of philanthropic businesswomen that supports Magee, purchased the equipment that makes the laser surgery possible.
He speaks passionately about a study he headed that showed early diagnosis and surveillance of transfusion syndrome cases would save lives. "We should diagnose them at Stage I," when parents have time to think and make an informed decision, he said. "The days of diagnosing at Stage III or Stage IV have got to go. It's just not right."
He also wants to spread the word that Magee is providing the surgery. Until last July, the closest sites of availability were Cincinnati Children's or The Children's Hospital of Philadelphia. "People need to know that," he said.
"The advantages of performing fetal surgery at a maternity hospital are obvious: Health of the mother is always paramount."
First Published July 4, 2011 12:00 am
