Laser for the treatment of twin to twin transfusion syndrome

Maternal and perinatal outcomes of minimally invasive fetal surgeries: experience from two reference centers in Rio de Janeiro, Brazil

BACKGROUND

Concerns regarding high open surgery-related maternal morbidity have led to improvements in minimally invasive fetal surgeries.

OBJECTIVE

To analyze the perinatal and maternal outcomes of minimally invasive fetal surgery performed in Rio de Janeiro, Brazil.

DESIGN AND SETTING

Retrospective cohort study conducted in two tertiary reference centers.

METHODS

This retrospective descriptive study was conducted using medical records from 2011 to 2019. The outcomes included maternal and pregnancy complications, neonatal morbidity, and mortality from the intrauterine period to hospital discharge.

RESULTS

Fifty mothers and 70 fetuses were included in this study. The pathologies included twin-twin transfusion syndrome, congenital diaphragmatic hernia, myelomeningocele, lower urinary tract obstruction, pleural effusion, congenital upper airway obstruction syndrome, and amniotic band syndrome. Regarding maternal complications, 8% had anesthetic complications, 12% had infectious complications, and 6% required blood transfusions. The mean gestational age at surgery was 25 weeks, the mean gestational age at delivery was 33 weeks, 83% of fetuses undergoing surgery were born alive, and 69% were discharged from the neonatal intensive care unit.

CONCLUSION

Despite the small sample size, we demonstrated that minimally invasive fetal surgeries are safe for pregnant women. Perinatal mortality and prematurity rates in this study were comparable to those previously. Prematurity remains the most significant problem associated with fetal surgery.

Use of the Learning Curve-Cumulative Summation test for quantitative and individualized assessment of competency of a surgical procedure in obstetrics and gynecology: fetoscopic laser ablation as a model

OBJECTIVE

We sought to determine the learning curve (LC) for fetoscopic laser photocoagulation (FLP) as a model for the evaluation of training in surgical procedures.

STUDY DESIGN

A retrospective review of consecutive case series of FLP from 2 centers with 3 operators (operator I [O-I], observer trained; operator II [O-II], hands-on trained; and operator III [O-III], clinical fellow) was performed and the LC-cumulative summation (CUSUM) test was plotted.

RESULTS

The acceptable and unacceptable success rates for at least 1 fetus survival after FLP were set at 82% and 70%, respectively, from a systematic review. A total of 171 consecutive cases were performed by the 3 operators (O-I, 91; O-II, 49; and O-III, 31). From LC-CUSUM test O-I needed 60 procedures, O-II needed 20 procedures, and O-III needed 20 procedures to reach an acceptable performance rate for at least 1 survivor.

CONCLUSION

The LC-CUSUM test can be used to accurately assess the LC in a surgical procedure in obstetrics and gynecology. Hands-on trained operators exhibit a shorter LC.

A novel ultrasmall composite optical fiberscope

BACKGROUND

Accurately aiming laser energy at a target from a two-dimensional endoscopic view is difficult during endoscopic laser surgery, particularly when the endoscope and the laser fiber are misaligned. We developed a composite optical fiberscope (COF) that can simultaneously visualize a target area and perform laser irradiation. The identical orientation of the endoscope and the laser fiber allows intuitive aiming at a target, even from a two-dimensional endoscopic view.

METHODS

We developed an ultrasmall COF (1.1-mm diameter) with a central cauterizing laser fiber surrounded by imaging and illumination fibers as a tool for various surgical applications. Porcine mesenteric blood vessels were laser irradiated in vivo and the procedure was filmed using ultrahigh-speed (max 1,000,000 frames per second) and thermographic cameras. Blood flow and vessel diameters were measured before and after laser irradiation.

RESULTS

The target vessels were highly visible and laser energy was delivered to the center of the view. Images from the ultrahigh-speed camera showed the blocking of the target vessel by the laser irradiation. The irradiated point initially became constricted, then discolored, and then decreased in size. Blood flow was decreased by 81.7% after laser irradiation and the diameter of the vessels at the irradiated point was approximately 46-48% smaller than that of the unirradiated vessels. Medical doctors also confirmed that the blood vessel was blocked after the experiments.

CONCLUSIONS

Our new laser surgery device may be useful for many surgical applications because it allows simultaneous diagnosis and treatment as well as intuitive aiming at a target despite its ultrasmall 1.1-mm diameter.

Maternal complications of fetoscopic laser photocoagulation (FLP) for treatment of twin-twin transfusion syndrome (TTTS)

AIMS

Fetoscopic laser photocoagulation (FLP) has become standard therapy for severe twin-twin transfusion syndrome. Data on adverse maternal events are rare. We performed a literature review to obtain data on maternal complications of FLP.

METHODS

Extensive literature review, searching MEDLINE and other databases from 1990 to 2009, using MESH-terms and further keywords. Data extraction was performed using the following criteria: (i) maternal complications reported as primary or secondary outcome parameters; (ii) any comment on adverse maternal events.

RESULTS

Of 321 publications found 40 were included, comprising 1785 patients. The overall rate of adverse maternal events was 5.4%. In studies with systematic assessment (n=3, 379 patients) the complication rate was significantly higher (17.4% vs. 2.2%, P<0.0001). Adverse events were classified and the rate was 1.0% (1.8% vs. 0.8%, P=0.12) for severe complications; 2.9% (11.9% vs. 0.5%, P<0.0001) for intermediate/minor adverse events; and 1.5% (3.7% vs. 0.9%, P<0.0001) for complications with undetermined relevance.

CONCLUSIONS

High-quality data on maternal complications of FLP are rare. With systematic assessment, the rate of adverse events is significantly higher. Underreporting has to be assumed. Further studies are required to confirm these data.

Modification of the gasless fetoscopy technique for the treatment of large myelomeningocele: a study in sheep

OBJECTIVE

To change the gasless fetoscopy technique in order to reduce the diameter of entry orifices in the myometrium.

METHODS

Seven pregnant ewes were submitted to fetoscopy for repairing a large skin defect measuring 4.0 × 3.0 cm, created in the fetal lumbar region at the gestational age of 100 days. The defect was repaired through continuous suture of the skin with approximation of borders. Gasless fetoscopy was used for performing the suture with three orifices to allow entry of the trocar into the myometrium. A 5.0-mm optical trocar, and 3.5-mm grasping, dissecting and suturing forceps were used. After surgery, pregnancy was maintained until the animals were euthanized on the 133rd day of gestation, and the fetuses were evaluated.

RESULTS

Seven pregnant ewes underwent surgery; the first two cases were characterized as the Pilot Group, in which the endoscopic technique was modified and caliber reduction was possible in two out of three entry orifices in the myometrium. In the five remaining cases (Study Group), the repair was successfully carried out in all the fetuses, and the mean duration of fetoscopy was 98 minutes. There was a case of maternal death attributed to intrauterine infection. Mean intrauterine permanence after surgery was 12 days.

CONCLUSIONS

The technique was successfully modified, allowing reduction of the uterine orifices necessary to perform the repair of a skin defect in the fetal lumbar region through a new fetoscopy technique. The impact of this modification in repair of myelomeningocele in human fetuses should be studied.