Clinical Application Of Pulmonary Vascular Volume Index In The Evaluation Of Pulmonary Vessel Development In Congenital Heart Disease

ObjectiveThe development status of pulmonary artery is one of the most important criteria for decision-making strategy and predicting postoperative outcome in congenital heart disease with diminutive pulmonary blood flow.Currently,McGoon index,Nakata index have been used as morphologic index in evaluating the development status of pulmonary artery.But there are some disagreements on clinical application of these indexes.Pulmonary vascular volume index(PVVI) was introduced as a novel evaluating index to evaluate the development status of pulmonary artery before surgery.Moreover,this new index was adopted to compare the early effect on the different hemodynamic mode to the development status of pulmonary vessel.Methods(1)Pulmonary arteries which were quantified as McGoon index,Nakata index and pulmonary vascular volume index were measured by 64-slice spiral CT in 25 The correlative analysis was done between different indexes and postoperative outcome.(2)O₂ saturation,haemoglobin and hematocrit were measured in 21 out of the above 25 children with TOF and 4 children with complex congenital heart disease who accepted bi-directional Glenn shunt before and 10 days after surgery.We adopted 64-slice spiral CT to measure McGoon index,Nakata index,left and right pulmonary vascular volume before and 10 days after surgery and calculate the pulmonary vascular volume index.We compared these indexes by statistics.Results(1)The length of stay in ICU,mechanical ventilation time,dose of inotropic drugs correlated well with PVVI better than Nakata index, with Nakata index better than McGoon index.When left PVVI＜50 cm³/m²,right PVVI＜70 cm³/m²,total PVVI＜120 cm³/m²,the sensitivity of predicting low cardiac output were 100.0%and positive predictive value were 87.5%,63.6%å’Œ87.5%respectively.The values of different pulmonary vascular predicting index of the children with low cardiac output were smaller than those of children without low cardiac output after surgery.In children with total PVVI＜120 cm³/m²,postoperative hemodynamics was unstable,the frequency of low cardiac output syndrome and mortality significantly increased.(2)Postoperative O₂ saturation,right PVVI and total PVVI of the children with TOF total correction were significantly increased and haemoglobin and hematocrit were significantly decreased,so were the children with bi-directional Glenn shunt.Postoperative left PVVI significantly increased and the ratio of left PVVI to right PVVI did not change significantly in the children with TOF total correction. Postoperative left PVVI and the ratio of left PVVI to right PVVI significantly decreased in the children with bi-directional Glenn shunt.Conclusions(1)Compared with McGoon index and Nakata index,PVVI is a much valuable index in evaluating development status of pulmonary vessel.In children with total PVVI＜120 cm³/m²,postoperative hemodynamics was unstable,the frequency of low cardiac output syndrome and mortality significantly increased.(2)Both antegrade pulmonary blood flow and hi-directional Glenn shunt with additional pulmonary blood flow can ameliorate severe hypoxia status and increase the total pulmonary vascular volume. Antegrade pulmonary blood flow made both left and right pulmonary vessel acquire balanced development by antegrade blood flow,but bi-directional Glenn shunt resulted in a significant increase in the right pulmonary vascular volume and a significant decrease in the left pulmonary vascular volume.