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Objective To compare the biomechanical stabilities among different combinations of anterior and medial cortical supports after intramedullary nailing for unstable intertrochanteric fractures.Methods Twenty-seven synthesized femur specimens were used to create models of unstable intertrochanteric fracture of type 31A2.1 according to AO/ASIF classification.They were divided into 9 groups (n =3) according to 9 combinations of anterior and medial cortical supports on the anteroposterior and lateral X-ray films:positive-positive,positive-neutral,positive-negative,neutral-positive,neutral-neutral,neutral-negative,negative-positive,negative-neutral,negative-negative groups.After all the fractures were fixated with the newly adapted femoral intertrochanteric nails (FITN),static loadings were applied for tests of fatigue and destruction to investigate the relative displacements and yield loads of the head-neck fragments.Results For the positive-positive,positive-neutral,positive-negative,neutral-positive,neutral-neutral,neutral-negative,negative-positive,negative-neutral,negative-negative groups,the vertical displacements of the head-neck fragments under fatigue loading were respectively 5.33 ±0.58 mm,7.83 ±0.29mm,7.73 ±0.15 mm,8.17 ± 0.29 mm,8.33±1.15 mm,8.83±0.29 mm,9.33±0.58 mm,9.67±1.15 mm and 12.0±1.0 mm,showing significant differences (P ＜ 0.05).The smallest displacement was observed in the positive-positive group,significantly smaller than that in any other groups (P ＜ 0.05).For the above 9 groups,the yield loads were respectively 4,967 ± 153 N,4,467 ± 58 N,3,717 ± 76 N,2,767 ± 58 N,2,533 ± 58 N,2,267 ± 58 N,1,833 ± 58 N,1,667 ± 58 N and 1,333 ± 58 N,showing significant differences between any 2 groups (P ＜ 0.05).In the destruction test,bone interface loosening in the femoral head happened in 2 cases,bone interface loosening in the intertrochanteric zone in 15 cases,split fracture at the zone of distal locking nail in 2 cases,and loosening and breakage of the internal fixator in the distal femur in 8 cases.Conclusions The medial cortical support plays a major role and the anterior cortical support plays a secondary role in the stability of unstable intertrochanteric fracture.In the surgical procedure,surgeons should avoid the medial cortical negative support as much as possible.
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Objective To investigate the value of three-dimensional speckle tracking imaging (3D-STI) in quantitative evaluation of left ventricular global strain in patients with atrial septal defect (ASD) before and after transcatheter closure.Methods Totally 35 patients with secondary ASD who received successful transcatheter occlusion were selected.Routine echocardiography and 3D-STI examination were performed before the operation,2 days,1 month,3 months and 6 months after the operation.Routine echocardiography was used to obtain the parameters of left ventricular end diastolic diameter (LVEDD),left ventricular end systolic diameter (LVEDS),left ventricular end diastolic volume (LVEDV),left ventricular end systolic volume (LVESV),stroke volume (SV) and other parameters.The left ventricular global peak longitudinal strain (GPLS),left ventricular global peak circumferential strain (GPCS),left ventricular global peak radial strain (GPRS) and left ventricular global peak area strain (GPAS) were examined with 3D-STI.The preoperative and postoperative parameters at each time point were analyzed statistically.Results Routine echocardiography showed that LVEDD,LVEDS,LVEDV,LVESV and SV increased significantly after operation,but no significant difference was found to compare each other 2 days,1 month,3 months and 6 months after operation (all P＞0.05).3D-STI examination showed that left ventricular GPLS,GPCS,GPRS and GPAS increased after operation,and the most increase was noticed at the second day after transcatheter occlusion.GPLS,GPCS and GPAS 6 months after operation were larger than those 3 months after operation (all P＞0.05).Conclusion 3D-STI technique can evaluate the left ventricular global strain in patients with ASD before and after occlusion.Compared with conventional echocardiography,3D-STI technique can objectively and effectively evaluate the changes of left ventricular systolic function.
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Objective@#To explore the application of real-time three-dimensional ultrasound in locating the course, the brand and the blind end of internal opening of congenital preauricular fistula.@*Methods@#Congenital preauricular fistula patients from Changhai Hospital were studied. All the cases were evaluated using two-dimensional and three-dimensional ultrasound before surgeries. The surgery findings were utilized as the gold standard. The imaging features of 3D ultrasound were described to determine the accuracy of the blind end location, the course of the main fistula tract and the branch tracts. The diagnosis was compared with the surgery findings.@*Results@#In 89 cases, among which there were 21 branch fistulae. There were 68 bend fistulae without branch. The diagnostic accuracy of both two-dimensional ultrasound and three-dimensional ultrasound was 100%. The accuracy in locating the blind end of internal opening, the course of the branch tracts with 3D ultrasound was 92.1%(82/89), 85.7%(18/21) , compared to 80.9%(72/89), 57.1%(12/21) with 2D ultrasound. It was obvious that 3D ultrasound had more advantages. These differences were statistically significant (χ2=4.8, P<0.05; χ2=4.2, P<0.05).@*Conclusions@#Compared with 2D ultrasound, 3D ultrasound can accurately locate the blind end of internal opening, the course, and the branch of preauricular fistula, clearly display the morphology and the spatial structure of preauricular fistulaand its surroundings. It has high clinical application value in preoperative imaging examination.
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Objective To evaluate the feasibility and safety of a delivery pathway for the performance of percutaneous left atrial appendage (LAA) occlusion in experimental canine models. Methods Transseptal puncture was performed via femoral vein approach under fluoroscopic and angiographic guidance in 12 experimental dogs. A pigtail catheter was advanced into the left atrium (LA), which was followed by LA angiography. The diameters of the neck of LAA were measured on LAA angiogram obtained in appropriate projection. After the delivery sheath was advanced along the wire into LA, a pigtail catheter was inserted into the ostium of the LAA and the sheath was then advanced over the pigtail into the LAA. LAA angiography was then performed through the delivery sheath to confirm the position of the delivery sheath. One hour after the procedure both electrocardiography (ECG) and transthoracic echocardiography (TTE) were carried out in five dogs to check the results, immediately after which the five dogs were sacrificed to macroscopically observe the damages of the puncture site of inter-atrial septum as well as inside the LA and LAA. One hour and 2 weeks after the procedure TTE was conducted in the remaining 7 dogs and these dogs were followed up for one month. Results One dog died of pericardial tamponade during the operation. In 8 dogs the LAA was clearly displayed in the projection position of right anterior oblique (RAO) 30°/cranial (CRA) 20°,while in 3 dogs the LAA was well visualized in the projection position of RAO 30° , and in one dog in the projection position of RAO 30°/caudal (CAU) 20°. The diameter of LAA neck was (13.6 ± 5.2) mm. The delivery sheath was safely advanced into the LAA along the pigtail catheter in all dogs, and no air embolism, thrombus or pericardial tamponade occurred. Hematoma at puncture point of groin occurred in 2 dogs, which was absorbed through pressure dressing. Macroscopic examination of the heart performed immediately after the operation showed that no bloody pericardial effusion was found, and mild hematoma at posterior wall of LA was seen in one dog and mild damage of the upper-margin intima of LAA was noted in 2 dogs. The mean fluoroscopy time was (10.1 ± 2.5) minutes and the mean operation time was (58 ± 12) minutes. TEE showed no pericardial effusion 2 weeks after the procedure. During the follow-up period of one month no sudden death, stroke or infection occurred. Conclusion This method of placing the delivery sheath into the LAA is clinically safe and effective, and it can reliably establish a pathway to advance the LAA occluder into LAA.
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Objective To analyze the motion, elastic and derived parameters of normal common carotid artery (CCA) wall in short-axis orientation with velocity vector imaging (VVI) technique. Methods Two-dimensional dynamic images of CCA in 40 healthy volunteers people were obtained in short-axis view with Siemens Acuson Sequoia 512 color Doppler ultrasound. The motion, elastic and derived parameters were analyzed in right CCA including 6 segments: Anterior wall, posterior wall, anterolateral wall, anterior internal wall, posterolateral wall and posterointernal wall. Relationship between these parameters and the influencing factors were analyzed as well. Results There was no statistical difference of the elastic parameters among 6 walls (P>0.05). Some of the motion parameters of the lateral wall and anterior wall were higher than those of the posterior wall and internal wall (P<0.05). Age and intima-media thickness were negatively correlated with some elastic parameters and some motion parameters (P<0.05). Heart rate were positively correlated with some elastic parameters and some motion parameters (P<0.05). Elastic parameters were positively correlated with motion parameters (P<0.05) and positive correlation was found between time to peak of elastic and motion parameters (P<0.05). Conclusion VVI is an effective technique for observing CCA mechanical characteristics of the movement in normal human, and has potential for studying some of related factors of the characteristics.
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Objective: To understand the effect of dobutamine on the integrated backscatter of myocardium. Methods: Nineteen open-chest dogs were detected by HP Sonos 5500 with S8 transducer, and the WT, AIBS and CVIB were measured before and after the dobutamine stress. Results: During the dobutamine stress, following the increase of WT, the transmural, subepicardial and subendocardial CVIB all increased. And the increase of subepicardial CVIB was greater than that of subendocardial CVIB, leading to the decrease of TGI. But the AIBS didn't change significantly in the whole process. Conclusion: Dobutamine can enhance myocardium CVIB but has no obvious infleunce on AIBS.
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Objective To evaluate the possibility, methods and efficiency of simultaneous transcatheter therapy for perimembranous ventricular septal defect(PMVSD) combined with atrial septal defect(ASD).Methods Four patients with PMVSD combined with ASD, including 3 males and 1 female, age ranging from 12 to 26 years; underwent simultaneous attempted transcatheter therapy. The diameters of PMVSD were 3-6 mm and the distances from the defect rim to aortic valve were 2-6 mm by the echocardiography before the precedure. The stretched diameter of ASD was 6-10 mm. PMVSD were occluded using homemade two-disc PMVSD occluder first and the ASD were occluded later on. Results All patients were treated successfully at one time. The diameter of PMVSD were 3.5-10.0 mm, the diameters of occluder was 4-12 mm. The stretched diameter of ASD was 6-10 mm and the occluder diameter was 6-12 mm. No residual shunt was found by the transthoracic echocardiography and left ventriculography after the occluders deployed. No complication occurred. Conclusion Simultaneous transcatheter therapy for PMVSD combined with ASD is feasible, safe and effective.
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Objective: To understand the effect of dobutamine on the integrated backscatter of myocardium. Methods: Nineteen open chest dogs were detected by HP Sonos 5500 with S8 transducer, and the WT, AIBS and CVIB were measured before and after the dobutamine stress. Results: During the dobutamine stress, following the increase of WT, the transmural, subepicardial and subendocardial CVIB all increased. And the increase of subepicardial CVIB was greater than that of subendocardial CVIB, leading to the decrease of TGI. But the AIBS didn't change significantly in the whole process. Conclusion: Dobutamine can enhance myocardium CVIB but has no obvious infleunce on AIBS. [
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Objective: To study left ventricular diastolic function (LVDF) in patients with coronary artery disease(CAD) by tissue Doppler imaging (TDI) and color Doppler echocardiography. Methods: The maximum velocity ( V max ) and time velocity integration(TVI) in early and late diastolic stage of mitral valve orifice of 80 patients with CAD and 79 normal subjects were measured by color Doppler echocardiography at apical 4 chamber view. Meanwhile, the V max and/or TVI of the myocardial motion spectrum of left ventricular lateral wall near the mitral valve annulet were measured by TDI. These data were compared and analysed by statistical method. Results: In the normal subjects, the older the subject, the lower the V max and TVI of early diastolic stage, the higher the V max and TVI of late diastolic stage. In CAD group, changes were not associated with ages and were affected by the degree of the myocardial pathology. The LVDF couldn't be exactly judged by color Doppler echocardiography when pseudonormalization blood flow spectrum appeared, but TDI technique was relatively sensitive. Any regional myocardial motion could be measured by TDI according to the examiner's design. Conclusion: LVDF by color Doppler echocardiography is simple and convenient. TDI technique can be used for determining overall LVDF and left ventricular systolic function. [