Therefore, composite grafting should be reserved for the case of severely stenotic coronary target, especially if multiple arterial sequential anastomoses have to be performed on the lateral-inferior wall of the heart. Finally, an accurate tool such as the fractional flow reserve to evaluate the stenosis severity should be the milestone of coronary surgery in order to decrease the rate of flow competition and improve arterial grafting functionality.

Conclusion

Competition flow plays a crucial role in arterial grafting functionality. Grafting strategy should address this by appropriate graft choice and configuration in order to avoid graft attrition.”
“OBJECTIVE: To establish the level of birth weight discordance

at which perinatal morbidity increases in monochorionic and dichorionic twin pregnancy.

METHODS: This prospective multicenter cohort study included Wnt inhibitor 1,028 unselected twin pairs recruited over a 2-year period. Participants underwent two weekly ultra-sonographic surveillance from 24 weeks of gestation with surveillance of monochorionic twins two-weekly JQ-EZ-05 in vivo from 16 weeks. Analysis using Cox proportional hazards compared a composite measure of perinatal morbidity (including any of the following: mortality, respiratory distress syndrome, hypoxic-ischemic encephalopathy, periventricular leukomalacia, necrotizing enterocolitis, or sepsis) at different degrees of birth weight discordance with adjustment for chorionicity, ARN-509 in vivo gestational age, twin-twin transfusion syndrome, birth order, gender, and growth restriction.

RESULTS: Perinatal outcome data were recorded for 977 patients (100%) who continued the study with both fetuses alive beyond 24 weeks, including 14 cases of twin-twin transfusion syndrome. Adjusting for gestation at delivery, twin order,

gender, and growth restriction, perinatal mortality, individual morbidity, and composite perinatal morbidity were all seen to increase with birth weight discordance exceeding 18% for dichorionic pairs (hazard ratio 2.2, 95% confidence interval [CI] 1.6-2.9, P<.001) and 18% for monochorionic twins without twin-twin transfusion syndrome (hazard ratio 2.6, 95% CI 1.6-4.3, P<.001). A minimum twofold increase in risk of perinatal morbidity persisted even when both twin birth weights were appropriate for gestational age.

CONCLUSION: The threshold for birth weight discordance established by this prospective study is 18% both for dichorionic twin pairs and for monochorionic twins without twin-twin transfusion syndrome. This threshold is considerably lower than that defined by many retrospective series as pathologic. We suggest that an anticipated difference of 18% in birth weight should prompt more intensive fetal monitoring. (Obstet Gynecol 2011;118:94-103) DOI: 10.1097/AOG.