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Transabdominal fetoscopy was developed as a method of prenatal diagnosis12. We now report on the use of in utero operative endoscopic techniques to ligate the umbilical cord of an acardiac twin at 19 weeks' gestation. The procedure was followed by the uncomplicated birth of a normal twin at 36 weeks' gestation.
Case Report
A twin pregnancy with twin reversed-arterial-perfusion sequence was diagnosed at 18 weeks' gestation in a 24-year-old woman (gravida 3, para 1) at our institution. The affected fetus was an acardius acephalus, had characteristic cystic structures in the thoracoabdominal areas, and had no upper limbs. Analysis of color Doppler wave forms (Acuson 128-VP/10 OB, Mountain View, Calif.) confirmed arterial flow from the placenta toward the acardiac twin (Figure 1). The abdominal circumference of the acardiac twin was much larger than that of the normal twin (195 mm vs. 125 mm, a recipient twin:pump twin ratio of 156 percent). The pump twin appeared structurally normal with no hydramnios. Chromosomal studies indicated a normal 46,XY karyotype in both fetuses.
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The procedure was performed with the use of general anesthesia to decrease fetal activity and minimize discomfort to the mother. Ultrasonography revealed that the placenta covered most of the anterior uterine wall. Areas free of placenta were identified for the insertion of the operating instruments. The placental and fetal sites of insertion of the umbilical cord were identified sonographically in both fetuses. The umbilical cord of the acardiac twin lay beneath the fetus, beside the posterior uterine wall. A 12-gauge trocar with a check-flow valve (Cook Ob/Gyn, Spencer, Ind.) was introduced percutaneously under ultrasound guidance into the amniotic cavity at the level of the uterine fundus through a 2-mm skin incision (the viewing port). A 5-degree multilens endoscope that was 1.9 mm in diameter and 11 cm long (Richard Wolf, Vernon Hills, Ill.) was inserted through this sleeve into the amniotic cavity of the normal twin. A video camera (Karl Storz, Culver City, Calif.) was attached to the eyepiece of the endoscope, and the fetoscopic images were recorded. Severe oligohydramnios of the acardiac twin precluded fetoscopic access to its umbilical cord. Therefore, an 18-gauge needle (Cook Ob/Gyn) was used to infuse the sac of the acardiac twin with Ringer's lactated solution. A second 12-gauge trocar (Cook Ob/Gyn) (the working port) was placed approximately 10 cm below the first port, to avoid the placenta. The amniotic membrane of the sac of the acardiac twin was cut with 5-French semirigid scissors (Richard Wolf) to expose the umbilical cord. A 3-0 Vicryl suture (Ethicon, Sommerville, N.J.) was passed beneath the umbilical cord with a 5-French semirigid automatic rat-tooth grasper (Cook Ob/ Gyn). The grasper was then passed over the cord so that the suture could be grasped on the other side. The suture was pulled through the trocar sleeve back outside the amniotic cavity to the level of the patient's skin. The other end of the suture had previously been fed through a 19.5-gauge knot pusher (Cook Ob/Gyn). A tight extracorporeal knot was tied with four throws with the knot pusher through the working port (Figure 2). Wave-form analysis of the umbilical artery of the normal fetus demonstrated an increase in the systolic:diastolic ratio from 3.9 before the procedure to 5.0 after ligation, but no signs of heart failure were apparent. The ends of the sutures were cut with the scissors within the amniotic cavity, approximately 1 cm away from the knot. A second knot was tied around the cord approximately 3 cm away from the first knot.
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At 22 weeks' gestation, the patient reported the leakage of fluid from the vagina. Examination with a sterile speculum confirmed premature rupture of membranes (positive Nitrazine [Bristol-Myers, Princeton, N.J.], fern, and pool tests). Amniotic fluid obtained by amniocentesis was negative on Gram's staining and culture for microorganisms, and the leukocyte count and glucose concentration were within normal limits. Ultrasonography revealed decreased amniotic-fluid volume, with an amniotic-fluid index of 5 cm; the index decreased further to 2 cm during the next three days. After seven days of hospitalization, the patient noted no further leakage of fluid. Ultrasound assessment confirmed a progressively increasing amniotic-fluid volume (amniotic-fluid index of 8 cm on the 14th day of hospitalization). The patient was sent home. The cystic areas in the anomalous twin disappeared, but this fetus was still visible on ultrasonography throughout the pregnancy. The patient was hospitalized at 36 weeks' gestation with spontaneous rupture of the membranes. She went into spontaneous labor and delivered a healthy 2640-g boy with Apgar scores of 8 and 9 at one and five minutes, respectively. The neonate had a benign course, went home with his mother on the third day, and had a normal pediatric evaluation at three months of age. The acardiac acephalic twin weighed 31 g. Pathological analysis showed two distinct constrictions on the umbilical cord and fibrosis of the umbilical vessels distal to the ligation sites.
Discussion
The successful in utero management of twin reversed-arterial-perfusion sequence described in this report represents a new approach, that of operative fetoscopy, to the management of fetal disease. Previously used methods included selective delivery of the abnormal fetus through a hysterotomy5,6,7 and intraarterial injection of either thrombogenic coils8,9,10 or fibrin in the umbilical cord of the recipient twin11. Although these methods have been used with some success, the first approach requires a hysterotomy and a subsequent cesarean section and has been associated with abruptio placentae, preterm labor, preterm birth, and prolonged maternal hospitalization6. The insertion of thrombogenic coils or fibrin has been associated with the death of both twins9,11 and recanalization of the umbilical cord. Fetoscopic ligation of the umbilical cord is inherently less morbid than hysterotomy and does not have the recanalization problems associated with percutaneous, ultrasound-guided thrombosis of the umbilical cord.
The execution of this procedure required the development of a set of instruments and skills suitable for the performance of intrauterine surgery under endoscopic control. These instruments and techniques were tested first on animals (unpublished data). Special 2-mm trocars (to minimize trauma to the fetal membranes) with check-flow valves were adapted to allow the introduction of the operative and optical instruments without interrupting amniotic-fluid exchange and the monitoring of intraamniotic pressure. Skills were developed to allow the precise orientation of operative instruments inside the uterine cavity under simultaneous endoscopic and sonographic control. Purple Vicryl 3-0 suture was used because of its color, strength, ease of handling, degree of friction, and pliability. The extracorporeal knot-pushing technique used was similar to that described by Clarke14.
The patient's postoperative course was complicated by premature rupture of the membranes three weeks after the procedure. Given that the membranes resealed, we wonder whether rupture of the membranes after operative fetoscopy may not follow the same natural history as spontaneous premature rupture of the membranes.
We anticipate that in utero operative endoscopic techniques will have a role in the care of monochorionic twins discordant for anomalies, pedunculated sacrococcygeal teratomas, and other fetal and placental diseases amenable to surgical treatment. However, one must exercise appropriate prudence and caution when applying recent advances in endoscopic surgery from other fields and from experiments in animals to human fetal surgery. Operative fetoscopy is a new frontier in fetal medicine.
We are indebted to our sonographer, Ms. Mary King, for her support in the evaluation of the patient, to Dr. Faisal Qureshi for the pathological analysis of the acardiac twin and placenta, and to Mr. Rodney Bosley of Cook Ob/Gyn and Mr. Bart Bracy of Richard Wolf, Inc., for their invaluable and pivotal technical assistance.
Source Information
From the Center for Fetal Diagnosis and Therapy, Fetal Endoscopy Program, Department of Obstetrics and Gynecology, Hutzel Hospital, Wayne State University, Detroit (R.A.Q., K.S.P., M.B., M.I.E., D.B.C., R.R.); Wyoming Valley Gyn Associates, Kingston, Pa. (H.R.); and the Perinatology Research Branch, National Institutes of Child Health and Human Development, Bethesda, Md. (R.R.).
Address reprint requests to Dr. Quintero at Hutzel Hospital, 4707 St. Antoine Blvd., Detroit, MI 48201.
References
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Related Letters:
A Simpler Technique for Umbilical-Cord Blockade of an Acardiac Twin
Holzgreve W., Tercanli S., Krings W., Schuierer G., Quintero R. A.
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Full Text
N Engl J Med 1994;
331:56-57, Jul 7, 1994.
Correspondence
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