A Fetal Surgery Checklist
Aside from myelomeningocele repair, placental laser ablation in cases of severe twin-twin transfusion syndrome is the fetal surgery with the best evidence base and, for now, it’s also the most frequently performed fetal surgery, although experts say it’s also underused.
"The success story of fetal surgery is laser ablation for TTTS," said Dr. Francois I. Luks, director of the Fetal Treatment Program at Hasbro Children’s Hospital in Providence, R.I. "Left untreated, severe TTTS leads to greater than 80% dual mortality. With laser surgery, survival of at least one twin is in excess of 80%."
First established as a good alternative to standard amnioreduction therapy in a 2004 randomized trial (N. Engl. J. Med. 2004;351:136-44), placental laser ablation has since become standard-of-care for TTTS.
"More and more groups are taking [laser ablation for TTTS] on because they believe they should provide it to patients," and it currently is available at about 30 U.S. centers, said Dr. Lim. "The maternal risk [from placental laser ablation] is acceptable and the outcomes are quite good. But some cases [of TTTS] are still being misdiagnosed," he said.
"Awareness is more widespread, but not at the rate it should be. We still have patients who are not referred until something bad happens," Dr. Lim said in an interview.
In Cincinnati alone, the program does more than 100 placental laser ablations each year, he added.
About 80 per year are performed at CHOP, and roughly 300-400 per year total at the 24 U.S. and Canadian centers that form the North American Fetal Therapy Network (NAFTNet), said Dr. Luks. (CHOP and Cincinnati Children’s are members of NAFTNet.) At least two other U.S. centers not in NAFTNet do more than 100 laser ablations each annually, and several other hospitals outside of NAFTNet do smaller numbers yearly, which means that while the current annual U.S. volume of these cases is uncertain it easily exceeds 500, Dr. Luks said.
All the other fetal surgeries each occur in fewer than about 50 U.S. cases a year, are available at fewer U.S. centers and, in some cases, have a checkered history of success and failure although today several are considered effective, relatively safe, and standard therapy.
The third most-common fetal surgery, based on NAFTNet records, are various types of selective umbilical cord occlusions in twin pregnancies, for reasons such as intrauterine growth retardation, placental insufficiency, and other situations in which problems with one twin puts a healthy twin at risk, said Dr. Johnson.
Dr. Johnson, Dr. Hirose, Dr. Adzick, Dr. Moldenhauer, Dr. Lee, Dr. Tulipan, Dr. Lim, and Dr. Evans all said that they had no relevant financial disclosures.
* This story was updated on 10/3/1012.