The Value Of Real-Time Three-Dimensional Transesophageal Echocardiography In Percutaneous Closure Of The Left Atrial Appendage

Objective: The aims of this study were to investigate the value of real-time three-dimensional transesophageal echocardiography(RT3DTEE)in measuring the size of the left atrial appendage(LAA),identifying the shape of the LAA and guiding the operation process in percutaneous closure of the LAA(LAAC).In addition,this study also explored the change in the size of the LAA from 24 hours before the operation to just before implantation during the operation.Methods: We retrospectively analyzed 32 patients who underwent LAAC in our hospital from september 2014 to july 2018.All patients underwent two-dimensional transesophageal echocardiography(2DTEE)and RT3 DTEE examination 24 hours before operation,during the operation and 45 days after the operation.1.The parameters of measurement and observation at 24 hours before operation : We measured the LAA orifice diameter(LAAOD),occluder landing zone diameter(LZD)and left atrial appendage depth(LAAD)at 0°,45°,90°,135° by 2DTEE,and the maximum value of LAAOD(LAAODmax),the minimum value of LAAOD(LAAODmin),the maximum value of LZD(LZDmax),the minimum value of LZD(LZDmin),the maximum value of LAAD(LAADmax)were obtained;We started 3D-ZOOM imaging procedure to acquire 3D image of the LAA,and to analyze 3D image of LAA by QLab software.LAAODmax,LAAODmin,LZDmax,LZDmin,LAADmax were measured.In addition,we were to discriminate the LAA orifice shape,differentiate the LAA morphology and to identify the number of LAA lobes.2.Parameters of measurement and observation during operation:We measured the LAAOD,LZD and LAAD at 0°,45°,90°,135° by 2DTEE,and the LAAODmax,the LAAODmin,the LZDmax,the LZDmin and the LAADmax were obtained.We measured the LAAODmax,LAAODmin,LZDmax,LZDmin,LAADmax by RT3 DTEE.We were to guide the operation process and to monitor the left atrium(LA)and/or LAA for signs of thrombosis by 2DTEE and RT3 DTEE during the whole operation;After the occluder was successfully released,we measured the diameter of the compressed occluder(COD)by two-plane procedure of RT3 DTEE.And then we used the color doppler flow imaging to detect peri-device leaks and to measure its width.3.Observed parameters 45 days after operation: We used the 2DTEE and RT3 DTEE to observe whether there was peri-device leaks and to measure its width,whether the occluder affected the adjacent structure of LAA,and to evaluate the stability of the occluder.Results:1.Comparative analysis of LAA diameters measured 24 hours before operation and during operation: Compared with 24 hours before operation,the LAAODmax,LAAODmin,LZDmax,LZDmin and LAADmax during operation were higher,and the difference was statistically significant(all p<0.01).2.Comparison of LZDmax and COD measured by 2DTEE and RT3 DTEE 24 hours before operation and during operation: LZDmax(19.0±2.8mm,20.4±2.7mm)measured by 2DTEE and RT3 DTEE 24 hours before operation,LZDmax(20.4±2.8mm,22.6±3.0mm)measured by intraoperative 2DTEE and RT3 DTEE respectively correlation analysis with COD(23.0±3.4mm)showed that the correlation between LZDmax measured by intraoperative RT3 DTEE and COD was better(R=0.90,p<0.01).Consistent analysis of each of the above parameters with COD,the Bland-Altman plot showed that the consistency of LZDmax measured by intraoperative RT3 DTEE and COD was better.3.Preoperative LAA morphological analysis,intraoperative procedure monitoring and evaluation of 45 days postoperative closure: 24 hours before operation,RT3 DTEE showed that chicken wing type of LAA accounted for a large proportion,and most of the LAA had a multi-lobe structure.During operation,the atrial wall was worn through by the sheath in one case and all patients had no sign of thrombosis in LAA and LA.After the occluder was successfully released,10 patients existed peri-device leaks(all had no clinical significance),and all compressed occluder did not affect adjacent structure of LAA.Follow-up results after 45 days of operation,10 patients(4 cases disappeared,4 cases newly issued)existed peri-device leaks(all had no clinical significance),no device displacement and no thrombosis in LA and/or LAA atrial surface were found.Conclusions:1.The size of LAA during operation was greater than that 24 hours before operation,so the LZDmax measured during operation were closer to the actual occluder landing zone diameter.2.LZDmax measured by intraoperative RT3 DTEE was more accurately than it measured by intraoperative 2DTEE,thus RT3 DTEE could be used to guide the selection of the appropriate size of the occluder.3.RT3 DTEE had unique advantages in guiding the process of the LAAC.Therefore,it had a good application prospect in LAAC.