OBJECTIVE: To characterise arterio-venous anastomoses (AVA) in monochorionic (MC) placentae and determine (i) whether shared cotyledons lie beneath the co-termination of an artery from one twin and a vein to the contralateral twin and (ii) whether all AVA can be detected by visual inspection of the chorionic plate. METHODS: Vascular casts were made of 15 MC placentae. The number of typical AVAs suspected visually before digestion was compared with the number of AVAs identified after acid digestion. RESULTS: Thirty-three of 67 (49%) suspected typical AVAs were confirmed as typical after casting. There were five false positives and no false negatives. The remainder were classified as atypical AVAs, found in > or =90% of MC placentae. Type I (small vascular connections between two apparently normal cotyledons not seen before casting) and Type II (shared cotyledons arising within larger apparently normal cotyledons) atypical AVAs were found in 53% and 73% of placentae, respectively. CONCLUSIONS: Only half the shared cotyledons in MC placentae are characterised by co-termination of an artery and vein on the chorionic plate. We report the existence of deep anastomoses beneath the chorionic plate that cannot be visualised by chorionic plate inspection. These findings have implications for laser treatment of twin-twin transfusion syndrome.
OBJECTIVE: To characterise arterio-venous anastomoses (AVA) in monochorionic (MC) placentae and determine (i) whether shared cotyledons lie beneath the co-termination of an artery from one twin and a vein to the contralateral twin and (ii) whether all AVA can be detected by visual inspection of the chorionic plate. METHODS: Vascular casts were made of 15 MC placentae. The number of typical AVAs suspected visually before digestion was compared with the number of AVAs identified after acid digestion. RESULTS: Thirty-three of 67 (49%) suspected typical AVAs were confirmed as typical after casting. There were five false positives and no false negatives. The remainder were classified as atypical AVAs, found in > or =90% of MC placentae. Type I (small vascular connections between two apparently normal cotyledons not seen before casting) and Type II (shared cotyledons arising within larger apparently normal cotyledons) atypical AVAs were found in 53% and 73% of placentae, respectively. CONCLUSIONS: Only half the shared cotyledons in MC placentae are characterised by co-termination of an artery and vein on the chorionic plate. We report the existence of deep anastomoses beneath the chorionic plate that cannot be visualised by chorionic plate inspection. These findings have implications for laser treatment of twin-twin transfusion syndrome.
Authors: Eric B Jelin; Samuel C Schecter; Kelly D Gonzales; Shinjiro Hirose; Hanmin Lee; Geoffrey A Machin; Larry Rand; Vickie A Feldstein Journal: J Vis Exp Date: 2011-09-05 Impact factor: 1.355
Authors: Andrew Melbourne; Rosalind Aughwane; Magdalena Sokolska; David Owen; Giles Kendall; Dimitra Flouri; Alan Bainbridge; David Atkinson; Jan Deprest; Tom Vercauteren; Anna David; Sebastien Ourselin Journal: Magn Reson Med Date: 2018-09-21 Impact factor: 4.668
Authors: Efthymios Maneas; Rosalind Aughwane; Nam Huynh; Wenfeng Xia; Rehman Ansari; Mithun Kuniyil Ajith Singh; J Ciaran Hutchinson; Neil J Sebire; Owen J Arthurs; Jan Deprest; Sebastien Ourselin; Paul C Beard; Andrew Melbourne; Tom Vercauteren; Anna L David; Adrien E Desjardins Journal: J Biophotonics Date: 2019-11-25 Impact factor: 3.207