Real-time computerized video enhancement for minimally invasive fetoscopic surgery

Background:The only definitive treatment for twin-to-twin transfusion syndrome is minimally invasive fetoscopic surgery for the selective coagulation of placental blood vessels.Fetoscopic surgery is a technically challenging operation,mainly due to the poor visibility conditions in the uterine environment.We present the design of an algorithm for the computerized enhancement of fetoscopic video and show that the enhanced video increases the ability of human users to identify blood vessels within fetoscopic video rapidly and accurately.Methods:A computer algorithm for the enhancement of fetoscopic video frames was created.First,optical fiber artifacts were removed via a modification of unsharp masking.Second,image contrast was increased via Contrast Limited Adaptive Histogram Equalization(CLAHE).Third,the effect of contrast enhancements on stationary features was removed by normalizing to a windowed mean of the video frames.Fourth,color information was reincorporated by combining the mean-normalized result with the unnormalized contrast enhanced image using the soft light blending algorithm.Medical trainees(n?16)were recruited into a study to validate the algorithm.Subjects were shown enhanced or unenhanced fetoscopic video frames on a screen and were asked to identify whether a randomly placed marker fell on a blood vessel or on background.The accuracy of their responses was recorded.Results:On the subset of images where subjects had the lowest mean accuracy in identifying the placement of the marker,subjects performed better when viewing video frames enhanced by the computer(accuracy 74.27%;SE 0.97)than when viewing unenhanced video frames(accuracy 63.78%;SE 2.79).This result was statistically significant(p<0.01).Conclusion:Real-time computerized enhancement of fetoscopic video has the potential to ease the readability of video in poor lighting conditions,thus providing a benefit to the surgeon intraoperatively.

Neurodevelopmental Outcome After Fetoscopic Laser Surgery for Twin-twin Transfusion Syndrome:A Systematic Review of Follow-up Studies from the Last Decade

Objective:To review the literature on long-term neurodevelopmental outcome after fetoscopic laser surgery for twin-twin transfusion syndrome(TTTS).Methods:A literature search in PubMed,Embase,Emcare,Web of Science,Cochrane library,and Academic Search Premier was performed.Inclusion criteria were studies between 2009 and 2019 in TTTS-survivors treated with fetoscopic laser surgery and followed-up after the neonatal period with cognitive developmental tests and neurologic exams.Exclusion criteria were non-English articles and reviews,case reports,letters,and guidelines.Results:Nineteen articles were included.Long-term severe neurodevelopmental impairment(NDI)was reported by seven and ranged from 4.0%to 18.0%with a mean of 9.7%(95%confidence interval(CI):7.8-11.5).The prevalence of cerebral palsy ranged from 1.6%to 18.2%,with a mean of 5.1%(95%CI:4.1-6.2).The mean prevalence of minor impairment was 13.7%(95%CI:11.4-16.0).However,only 78.9%(15/19)studies used a validated neurodevelopmental test.As studies lack uniform definitions of primary outcome,timing of follow-up,inclusion criteria,and methods,adequate comparison is hampered.Conclusion:The prevalence of severe NDI and cerebral palsy after fetoscopic laser surgery for TTTS in the last decade remains stable around 9.7%and 5.1%,respectively.International agreements on primary outcomes,methods,and follow-up are necessary to improve the knowledge of NDI in TTTS-survivors.