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Endoscopic Nd:YAG laser coagulation of superficial chorionic plate vessels has been suggested as a 'causal' therapy for severe twin-to-twin transfusion syndrome (TTS), as it is believed to arrest flow over vascular anastomoses. The therapy remains debated, partly because it is questioned whether coagulation of superficial chorionic vessels can arrest blood flow over deeply located anastomoses. The latter are believed to be responsible for the majority of cases of severe TTs. In this study, the coagulation performance, and the immediate and delayed tissue effects of laser coagulation were evaluated in an in vivo ovine model. Eight pregnant ewes of about 100 days' gestational age (term= 145 days) were studied. In utero coagulation was done through a 1.2 mm fetoscope loaded with a 600 microm laser fibre, connected to an Nd:YAG laser in continuous mode. Superficial cotyledonary vessels were coagulated under visual control at a distance of 1 cm with a mean power of 60 watts. 31 lasered cotyledons were harvested, either immediately (n= 15), 14 days (n = 8) or 42 days (n = 8) after the surgery and evaluated by inspection and histology. Control cotyledons were either neighbouring cotyledons from the same amniotic sac (internal control) or cotyledons from another gestational-age-matched sac (external control). Immediate effects consisted of localized coagulation necrosis at the zone of laser impact with no significant histological effect at more than 2 mm distance, except tissue congestion. Long-term effects consisted of fibrosis without any vascular recanalization or tissue regeneration extending from the impact site over the whole cotyledon. All treated cotyledons underwent complete infarction over time. This study provides experimental evidence supporting that laser coagulation of superficial chorionic vessels entering a cotyledon achieves complete functional elimination of the involved cotyledon.

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OBJECTIVE: We studied closure techniques for amniotic access in midgestational rabbits. STUDY DESIGN: Twenty-eight rabbits with a total of 313 amniotic sacs were used for this study. In each animal a 1 cm hysteroamniotomy was made in two amniotic sacs at 22 days' gestation (term = 32). For 12 amniotic sacs (group 1) only the myometrium was closed by microsurgical suturing. In group 2 (n = 12), sutures included myometrium and membranes. In group 3 (n = 8), a collagen plug was placed, and in group 4 (n = 12) fibrin glue was used. Twelve sacs were left unclosed (positive controls) and the unmanipulated 257 sacs were negative controls. Eight days later (gestational age 30 days) amniotic sacs were evaluated for the presence of amniotic fluid, membrane integrity, and fetal weight and survival. Statistics were done with two-tailed Fisher's exact test and one-way analysis of variance. RESULTS: Membrane integrity (p = 0.0036) and amniotic fluid (p = 0.047) were best restored after myometrial closure. Fetal weight and survival rate were not affected by different closure techniques. CONCLUSION: In this model primary closure of the myometrium only yielded best results.

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Nd: YAG laser coagulation is used to treat severe twin-to-twin transfusion syndrome (TTS). Success of the technique depends on visualization of the placenta, the fetal membranes and the targeted vessels, as well as obtaining an optimal inclination angle for laser coagulation. In the rare case of an extensive anterior placenta, it may be difficult to achieve these conditions using the percutaneous approach. Here, we propose an alternative to the percutaneous procedure. Modifications involve an open access and the use of a flexible cannula and bent scope. An extraplacental area, usually at the fundus, is identified by B-mode and color Doppler imaging. A mini-laparotomy is made under general anesthesia. The viscera are retracted and the cannula is inserted under direct view and ultrasound control by the Seldinger technique. The curved fiberscope is passed through the flexible cannula, allowing adequate inspection of the placenta, and target vessels can be coagulated at an angle close to 90 degrees. After the procedure, the uterus is closed primarily to prevent postoperative leakage of amniotic fluid or hemorrhage. This technique has been successfully used in six patients with TTS and a completely anterior placenta, with a gestational age between 18.5 and 22.0 weeks. In all patients, the amniotic cavity was accessed without hemorrhage. The outcomes are similar to those published previously for laser coagulation. The mean interval from intervention until delivery was 10.5 weeks. All 12 fetuses were live born but four died from complications of extreme prematurity. No maternal complications occurred.

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OBJECTIVE: In the case of a monochorionic multiple pregnancy with one non-viable fetus who compromises its co-twin, fetoscopic cord ligation may be performed. We describe our fetoscopic cord ligation technique and discuss the efficacy of cord ligation for salvaging the co-twin, based on available data. STUDY DESIGN: Descriptive case series of four cases and review of the cases published up to 1996. RESULTS: We performed four successful ligations. Of the 23 reported cases, which include the present series, two ligations failed. Four fetuses died in utero, and 17 were born alive at a mean of 8 weeks following the procedure. Two babies died in the perinatal period, a third after 60 days. Preterm uterine contractions do not seem to be a clinical problem. Preterm prelabour rupture of the membranes (PPROM) complicates about 40% of cases, the majority occurring prior to 32 weeks. CONCLUSION: Fetoscopic cord ligation is a feasible procedure with a 71% survival rate and a high risk for PPROM.

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OBJECTIVE: Intra-uterine tracheal occlusion has been proposed to reverse pulmonary hypoplasia, an important prognostic factor in congenital diaphragmatic hernia. We aimed to evaluate the feasibility and pulmonary effects of tracheoscopic tracheal obstruction with a detachable balloon. STUDY DESIGN: Fourteen mid-trimester fetuses out of 24 in 13 ewes underwent tracheoscopic balloon obstruction. Ten non-operated fetuses served as controls. Plugging was performed under fiber-tracheoscopy using a detachable balloon. Outcome measures consisted of: total operating time, tracheoscopy time, fetal survival, efficiency of plugging, and pulmonary effects. The Mann-Whitney test and linear regression were used for statistical analysis. RESULTS: Mean operating time and tracheoscopy time were 65+/-12 and 6.6+/-3.9 min, respectively. One intra-operative death occurred in each group. The post-operative mortality was 2/13 for cases and 2/9 for controls. In all 14 fetuses, the trachea was successfully obstructed. In the 11 treated animals born alive, the lung-to-body-weight ratio was 0.060+/-0.01, while in controls it was 0.031+/-0.01 (P = 0.0001). In a subset of six fetuses obstructed for 14-18 days, mean-terminal-bronchial density was 0.95+/-0.59, compared to 2.06+/-0.80 for controls (P = 0.046). CONCLUSIONS: Using fetal tracheoscopy, the trachea can successfully be obstructed with an inflatable balloon. Pulmonary hyperplasia is achieved when the obstruction lasts 2 weeks.

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Training in endoscopic, intracorporeal knot tying, was evaluated in 29 obstetrics and gynaecology trainees who performed 100 consecutive intracorporeal, two turn, flat, square knots. An obvious learning curve was observed. With training the quality of the knots increased, whereas the mean duration to tie a knot decreased from 277 +/- 114 to 67 +/- 27 s for the first 10 and the last 10 knots respectively. The initial and final duration of knot tying were lower in more experienced trainees, as estimated by the year of training or the Royal College of Obstetrics and Gynaecology (RCOG) level of experience. More specifically, duration of knot tying was shorter when more diagnostic laparoscopies, laparoscopic sterilizations or adnexectomies had been performed. This effect of previous experience was however limited compared with the overall effect of training. Previous passive experience, however, as determined by the number of assisted or observed surgical interventions, did not affect the learning curves. Speed of knot tying was slightly higher in trainees who spent more of their leisure time performing handicrafts than in trainees who were more interested in reading, but although significant, these differences were only marginal. In conclusion, the data show an important effect of training on the speed and quality of intracorporeal knot tying and confirm that learning curves improve with previous training.

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Endoscopic coagulation of placental and umbilical cord vessels has been suggested as a treatment for selected cases of twin-twin transfusion syndrome and of acardiac twin. The feasibility, safety and hemostatic effect of neodymium:yttrium-aluminium-garnet (Nd:YAG) laser in an underwater environment were experimentally studied in an in vivo model, mimicking the in utero situation and fetoplacental vessels. In 10 male Wistar rats, immersed in normal saline at 38 degrees C, femoral vessels, carotid artery, abdominal aorta and vena cava were coagulated under endoscopic control. A 100-Watt Nd:YAG laser was used in continuous mode with a 600-micron fiber. Outcome measurements were vascular diameter, total energy (joules) used to obtain visual coagulation and subsequent vascular obliteration. Overall failure rate was 32% and perforation of the vessel occurred in 7.7% of cases.

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OBJECTIVE: To describe and evaluate the surgical treatment of large ovarian endometriomas by an extraovarian endosurgical technique. DESIGN: Prospective case series study. SETTING: University center and tertiary referral center for endoscopic surgery. PATIENTS: Patients with large ovarian endometriomas. INTERVENTION: A two-step endosurgical procedure: the first step is a combined diagnostic and operative procedure confirming the diagnosis and preparing the involution of the pseudocyst and the second step includes adhesiolysis and superficial coagulation of the inverted cortex. MAIN OUTCOME MEASURES: Operative findings and recurrence of endometriomas in the operated ovaries. RESULTS: Sixteen patients presenting with 20 large typical ovarian endometriomas were operated using the two-step endosurgical technique. Both steps were performed on 18 endometriomas. One patient with bilateral endometriomas refused the second endoscopic procedure. The long-term follow-up showed no recurrence in the 18 ovaries that were treated by the two-step endoscopic technique. CONCLUSIONS: The two-step extraovarian endosurgical technique can be applied in large typical endometriomas to reconstruct the ovary without excision and is followed by a low recurrence rate.

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Laser coagulation of anastomosing placental chorionic plate vessels was suggested as a treatment of severe twin-twin transfusion syndrome in midtrimester. An anteriorly located placenta may hamper access and visualization of the vessels involved. We treated six women with completely anterior placenta at 18 to 22 weeks' gestation. Through a 2- to 3-cm minilaparotomy the uterus was accessed after retraction of the viscera. A flexible cannula was inserted through the uterine fundus, and a 35-degree, 0.20-mm minifibroscope and 400-mm fiber were introduced. All vessels crossing the intertwining membrane were coagulated in a continuous mode and a maximum output of 45 W. All fetuses survived the operation. One fetus died in utero 6 weeks postoperatively from cardiac failure, and its receptor twin was born alive. All other pregnancies are either continuing, or the women delivered two healthy babies. Thus far, total fetal survival is 91.6%, compared with results with posterior-sided placentas. Neodymium:yttrium-aluminum-garnet laser coagulation is also possible in case of anterior placenta, but requires a minimal maternal incision and general anesthesia to allow safe cannula placement. A bent scope allows for a larger placental surface to be treated.

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