Endoscopic Laser Surgery for Twin-to-Twin Transfusion Syndrome (TTTS)

Jump To Section

• TTTS Treatment Overview
• Laser Surgery Technique
• Finding a Specialist
• TTTS Surgery Outcomes
• Prematurity Risks
• Optimal Delivery Timing
• Full Transcript

TTTS Treatment Overview

Endoscopic laser surgery is the standard treatment for twin-to-twin transfusion syndrome. Dr. Yves Ville, MD, a pioneer in the field, explains that this procedure directly addresses the root cause of TTTS. The condition occurs when identical twins share a placenta but have unequal blood flow. One twin receives too much blood, while the other receives too little. The surgery involves using a fetoscope to visualize and treat the problematic blood vessels on the placental surface.

Laser Surgery Technique

The surgical technique for TTTS is highly reproducible. Dr. Yves Ville, MD, emphasizes that the most critical step is correctly entering the uterus to expose the operating field. The surgery itself involves coagulating the abnormal connecting blood vessels on the placenta. Dr. Yves Ville, MD, notes that this does not require extraordinary surgical skill but rather meticulousness and thoroughness. The goal is to identify and laser all the vessels responsible for the unbalanced blood flow between the twins.

Finding a Specialist

Access to expert care for TTTS has improved significantly. Dr. Yves Ville, MD, states that endoscopic fetal surgery is now performed in many reputable centers across developed countries. This is crucial because women affected by this syndrome often cannot travel long distances comfortably. The procedure, first performed in 1991, has a 30-year track record of success. Dr. Anton Titov, MD, highlights the importance of patients being aware of this treatment option to find an appropriate specialist near them.

TTTS Surgery Outcomes

The outcomes for TTTS surgery are well-established and highly positive. Dr. Yves Ville, MD, provides clear survival statistics from the procedure. There is a 75% chance that both twins will survive. The survival rate for at least one twin is 90%. This means the risk of losing one twin is about 15%, and the risk of losing both is approximately 5%. Critically, Dr. Ville confirms that if both twins survive, their neurological development is typically completely normal.

Prematurity Risks

The primary risk following TTTS surgery is preterm premature rupture of membranes (PPROM). Dr. Yves Ville, MD, explains that this occurs because the surgical instruments must pass through the amniotic membranes, which are fragile. This complication happens in about 20% of cases. While not all cases of PPROM lead to immediate delivery, it is a significant concern. The average gestation at delivery after this fetal surgery is 33 weeks. This prematurity becomes the main challenge after the TTTS has been successfully treated.

Optimal Delivery Timing

Planning delivery timing is a key part of post-surgical care. Dr. Ville advises that delivery typically occurs around 34 to 35 weeks gestation. This is a deliberate strategy to prevent late accidents, such as intrauterine death or placental abruption, which can occur after operating on the placenta. Dr. Anton Titov, MD, discusses this timing in the context of standard twin pregnancies, which are now recommended for delivery by 37 weeks. Delivery at 35 weeks is considered a safe and planned outcome for babies who have undergone this life-saving procedure.

Full Transcript

Dr. Anton Titov, MD: You have already mentioned something like that, but let me ask this more specific question. You are specialized in treating unborn children and complicated pregnancies, as you mentioned. One particular complication is a pregnancy with two fetuses, and these two fetuses share a blood supply, but the blood flows are not even for each fetus. Therefore, this leads to overnutrition and oversupply of blood in one fetus and undernutrition in another.

As you mentioned, you are using endoscopic laser surgery to treat twin-to-twin blood transfusion syndrome. You are operating not on a fetus or a developing child but actually on the placenta. Could you please more specifically outline how you approach twin-to-twin blood transfusion syndrome? How do patients perhaps find you in these situations? Not everybody who has those conditions probably has the opportunity to come to an expert like you.

Nevertheless, I think it is important so people are aware of how that is done and so they can find an appropriate expert.

Dr. Yves Ville, MD: The surgery for twin-to-twin transfusion now is reproducible in several centers. I think that is what we could be proud of: to have designed a technique that is being used by different people with the same success. That is not something you start from the night before, but once you have done about 50 cases, if you apply the proper rationale to your strategy, entering the uterus is the most important.

You expose correctly the operating field; then the surgery is not difficult because it is just a matter of coagulating vessels. There is no surgeon skill; it is just to enter the right place. So if you can do that, you are meticulous enough and exhaustive in searching for the abnormal vessels, then this surgery can be done in many places.

Also, these women are affected by this syndrome; they cannot travel very easily. So if there is a reputable center nearby—and there are now, in all developed countries, people who do endoscopic fetal surgery—it is better than traveling long distances because that is not comfortable for them to travel.

This fetal endoscopic surgery, the first one, was done in 1991. So it has been 30 years to have been able to assess its success and reproducibility. I think it is a standard of care now.

Dr. Anton Titov, MD: How are the outcomes? Usually, what is the expected clinical outcome for twin-to-twin blood transfusion syndrome?

Dr. Yves Ville, MD: What people could expect is 75% survival of both twins and 90% survival of at least one twin. So the risk is to lose one in about 15% and lose both in about 5%, something like that. If both twins survive, then the development is otherwise normal; it is completely normal.

Dr. Anton Titov, MD: Yeah, depending on at what gestation age they are delivered, but then the problem is prematurity. It is not twin-to-twin blood transfusion syndrome anymore. Is it common that prematurity affects the fetus after the surgery?

Dr. Yves Ville, MD: Yeah, one of the Achilles' heels of fetal surgery—endoscopic fetal surgery and open fetal surgery, but again, we do not do it—is rupture of membranes because you have to go through those membranes with your instruments. So the membranes are fragile; rupture of the membranes during the weeks following the surgery is very common. It is about 20%. Some of them end up with preterm delivery; some do not because it is only mechanical.

After that, not all women deliver very prematurely, but on average, women deliver at 33 weeks. In any case, we do not go further than 34 weeks because once you operated on the placenta, you have probably switched off part of the placenta in its function as well.

Initially, years back, we observed some late accidents like intrauterine death or placenta abruption, and we thought that we could be more careful and deliver those babies a bit before. So on average, 34 to 35 weeks, we think it is the right time to deliver a baby after fetal surgery.

But since then, things even for normal twin pregnancies have moved on. It is well established now that twins should not be delivered later than 37 weeks. So if you deliver them at 35, after what they have been through with the syndrome, I do not think that is your problem.