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The Art of Fetoscopy: A Step Toward Minimally Invasive Fetal Therapy

  • Posted on- Jun 18, 2016
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Introduction

Prenatal ultrasound and wide implementation of antenatal screening programs allow for the timely diagnosis of many fetal congenital anomalies, which, if left untreated, could be fatal or cause severe disabilities despite optimal postnatal care. Some of them are amenable to intrauterine fetal surgical interventions. In most parts of the world, open fetal surgery is poorly accepted because of its invasiveness and the high incidence of premature labor and rupture of the fetal membranes. In the 1990s, the merger of fetoscopy and advanced video-endoscopic surgery formed the basis for endoscopic fetal surgery. Minimally invasive techniques, ‘‘Fetendo (fetal endoscopy)/ Fetoscopy’’ are now real possibilities. This procedure offers access to the placental surface, umbilical cord, and fetus using small endoscopes placed percutaneously through the mother’s abdominal wall, under ultrasound guidance. Fetoscopy requires special endoscopes with their respective sheaths, cannulas, and additional instruments, designed for the procedure of interest, and most gynecologists are therefore not familiar with them. The technique was first used on women undergoing Medical Termination of Pregnancy (MTP), or to exclude external malformations in ongoing pregnancies for an ‘‘adequate learning curve’’ approved by the ethical committees. As with intrauterine prenatal diagnostic procedures like amniocentesis, chorion villus sampling, cord blood sampling, intrauterine fetal blood transfusion and shunts, the procedure of fetoscopy ethically should be ‘‘learnt’’ expertise and confidence gained—first by observation and then by performing the procedure in MTP cases and not training directly on ongoing pregnancies, thereby putting the pregnancy and fetus in jeopardy. Studies are going on with regard to the appropriate operating timing, standardization of selection criteria, and multicenter randomized trials are also ongoing to define whether fetal surgery is associated with better outcomes as compared with postnatal treatment.The aim of the study was to establish the feasibility, learning curve of fetoscopy for clear visualization of fetal, placental external features, and congenital malformations in utero, so as to become skilled and confident in the manipulations before embarking on fetal surgery in highrisk ongoing pregnancies.

Methods

Institute ethical clearance was obtained for starting the procedure in the Department. Informed written consent was taken from the couple. Women with pregnancies more than 20 weeks of gestation, with previous uterine scar, medical disorder, Rh negative, or with any complication like leaking or bleeding per vaginum, and oligohydramnios were excluded from the study. Fetoscopy was attempted in 12 pregnancies with fetal congenital malformations, and/or for MTP) between 12 and 20 weeks of gestation. Fine fetal endoscopes (fetoscopes) of varying and increasing sizes 1 mm/1.2 mm/2 mm were used in different patients. The women were first sedated with pethidine or calmpose injection in the operation theater, with an Anesthetist as standby. Ultrasound was performed to identify the placental site, and fetal position to mark out the fetoscope entry point for the best visualization of fetus and placenta. Local anesthesia was given over the maternal abdomen and a small 3-mm incision made with fine tip knife. The trocar and cannula were introduced under ultrasound guidance, preferably avoiding the placenta, through the maternal abdomen and uterine wall into the amniotic cavity. The cannula was removed and the fetoscope introduced through the trocar to visualize and examine the fetal face (eyes, lips, nose, and mouth) the limbs (and fingers/toes), the abdominal wall, and umbilical cord insertion, the back, etc. The placenta was examined for placental vessels, or any abnormalities. The clarity of vision, intra-amniotic bleeding, or any procedural problems were noted. Visibility was maintained with continuous saline amnioinfusion system, monitoring the volume infused. In two, cases, laser coagulation of placental vessels were tried. The placental vessels were identified etoscopically, and the ones distant from the uterine wall were chosen. Diode laser fiber was introduced through the operating channel of the fetoscope and power switched on. The laser beam was focused on the vessel for few seconds till the vessel was seen to become white and blanched. All cases had MTP after 48 h with use of vaginal misoprostol (9 cases), oral mifepristone and vaginal misoprostol (2 cases) and intrauterine PGF2 alpha (1 case). Procedural problems and complications were noted during and after fetoscopy.

Results

Fetoscopy required great skill, patience, and extensive use of ultrasound for correct orientation. Visualization was better with endoscope of 2-mm diameter. Laser coagulation of placental vessels using diode laser system was possible in the last two cases. There were no major complications.

Conclusion

Fetal endoscopy—‘‘Fetoscopy’’ is a feasible, safe procedure in the hands of experts in fetal diagnostic and therapeutic techniques. Fetoscopy has been established at our center, and the process was an intense ‘‘learning curve,’’ posing unique requirements, extreme care, precision, and technical expertise, with innovation and refinement. Practice with the new equipment and finer instruments, and proper orientation to the intrauterine environment with ultrasound—fetoscopy—laser coordination was absolutely essential, to become skilled in the procedure before embarking on fetoscopic fetal surgery in high-risk ongoingpregnancies, which we are now ready for.

Comments

user profile image
19-01-2018 05:38 AM

Didn’t understand the whole article. Please write it in a simpler way.

user profile image
28-01-2017 12:49 PM

Not upto the mark.

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