Mechanism of balloon burst during transcatheter aortic valve replacement pre-dilatation: Image observation and validation by finite element analysis.

BACKGROUND: Balloon burst during transcatheter aortic valve replacement (TAVR) is serious complication. This study pioneers a novel approach by combining image observation and computer simulation validation to unravel the mechanism of balloon burst in a patient with bicuspid aortic valve (BAV) stenosis. METHOD: A new computational model for balloon pre-dilatation was developed by incorporating the element failure criteria according to the Law of Laplace. The effects of calcification and aortic tissue material parameters, friction coefficients, balloon types and aortic anatomy classification were performed to validate and compare the expansion behavior and rupture mode of actual balloon. RESULTS: Balloon burst was dissected into three distinct stages based on observable morphological changes. The mechanism leading to the complete transverse burst of the non-compliant balloon initiated at the folding edges, where contacted with heavily calcified masses at the right coronary sinus, resulting in high maximum principal stress. Local sharp spiked calcifications facilitated rapid crack propagation. The elastic moduli of calcification significantly influenced balloon expansion behavior and crack morphology. The simulation case of the calcific elastic modulus was set at 12.6 MPa could closely mirror clinical appearance of expansion behavior and crack pattern. Furthermore, the case of semi-compliant balloons introduced an alternative rupture mechanism as pinhole rupture, driven by local sharp spiked calcifications. CONCLUSIONS: The computational model of virtual balloons could effectively simulate balloon dilation behavior and burst mode during TAVR pre-dilation. Further research with a larger cohort is needed to investigate the balloon morphology during pre-dilation by using this method to guide prosthesis sizing for potential favorable outcomes.

Feasibility of Left Bundle Branch Area Pacing Combined with Atrioventricular Node Ablation in Atrial Fibrillation Patients with Heart Failure.

BACKGROUND: Pacemaker implantation combined with atrioventricular node ablation (AVNA) could be a practical choice for atrial fibrillation (AF) patients with heart failure (HF). Left bundle branch area pacing (LBBaP) has been widely reported. OBJECTIVES: To explore the safety and efficacy of LBBaP combined with AVNA in AF patients with HF. METHODS AND RESULTS: Fifty-six AF patients with HF attempted LBBaP and AVNA from January 2019 to December 2020. Standard LBBaP was achieved in forty-six patients, and another ten received left ventricular septal pacing (LVSP). The cardiac function indexes and pacemaker parameters were evaluated at baseline, and we conducted a 1-month and 1-year follow-up. RESULT: At the time of implantation and 1-month and 1-year follow-up, QRS duration of LVSP group was longer than that of LBBaP group. The pacemaker parameters remained stable in both the LBBaP and LVSP groups. At 1-month and 1-year follow-up after LBBaP and AVNA, left ventricular ejection fraction, left ventricular end-diastolic diameter, and NYHA classification continued to improve. Baseline left ventricular ejection fraction and QRS duration change at implantation can predict the magnitude of improvement of left ventricular ejection fraction at 1-year after LBBaP. Baseline right atrial left-right diameter, the degree of tricuspid regurgitation, and interventricular septum thickness may be the factors affecting the success of LBBaP. CONCLUSION: LBBaP combined with AVNA is safe and effective for patients with AF and HF. Baseline right atrial left-right diameter, the degree of tricuspid regurgitation, and interventricular septum thickness may be the factors affecting the success of LBBaP.

A dissecting aneurysm of interventricular septum resulting from congenital coronary artery fistula.

RATIONALE: Ventricular septal dissecting aneurysms are rarely caused by congenital coronary artery fistulas. PATIENT CONCERNS: We present a rare case of ventricular septal dissecting aneurysm that resulted from a congenital coronary artery fistula in a 41-year-old female patient with the complaint of chest pain. DIAGNOSIS: Ventricular septal dissecting aneurysm resulting from a right coronary artery fistula. INTERVENTIONS: The patient was advised to receive transcatheter interventional therapy in the department of cardiology. OUTCOMES: It was difficult for the cardiac catheter to reach the orifice of fistula due to the long and circuitous nature of the right coronary artery, which ultimately resulted in abandoning interventional fistula occlusion therapy. The patient finally decided to undergo surgical treatment in Shanghai and the symptoms have been markedly improved after hemodynamic correction. LESSONS: The right coronary artery was the dominant vessel and the fistula was located in the distal part of the posterior descending branch of right coronary artery. Hence, transcatheter closure was appropriate; however, due to the fact that right coronary artery was too long and circuitous, the length of cardiac catheter was relatively insufficient. For this reason, a comprehensive and careful assessment before the operation is necessary.

Features of lymph node metastasis of papillary thyroid carcinoma in ultrasonography and CT and the significance of their combination in the diagnosis and prognosis of lymph node metastasis.

PURPOSE: To investigate the characteristics of lymph node (LN) metastasis of papillary thyroid carcinoma (PTC) with ultrasonography (US) and spiral computed tomography (CT) and the significance of their combination in the diagnosis and prognosis of LN metastasis. METHODS: A total of 93 PTC patients admitted to and treated in the oncology department of our hospital were randomly enrolled in this study. LN imaging signs were explored by US, CT and their combination. Through the comparison with pathological findings, the diagnostic efficiency of three methods in LN metastasis in patients with PTC was analyzed. Postoperatively, all patients were followed up for 1-3 years to analyze the relationship between LN metastasis and the prognosis of PTC. RESULTS: Among 93 PTC patients, 69 (74.19%) had LN metastasis, and 24 (25.81%) had not. US examination revealed that metastatic LN were hypoechoic and obviously calcified, and had aspect ratio >1 and strong blood flow signals. Among them, there were significant differences in calcification and blood flow between LN metastasis group and non-metastasis group (p<0.05). CT images indicated that metastatic LN were swollen, had low-density and were calcified with abundant blood flow signals. In addition, the edge, calcification and CT reinforced examination showed obvious differences between the LN metastasis group and the non-metastasis group (p<0.05). The sensitivity, specificity and accuracy of US alone in the diagnosis of LN metastasis were clearly better than those of CT alone (p<0.05), while their combination was better than both US and CT alone in the sensitivity, specificity and accuracy in the diagnosis of LN metastasis (p<0.05). Follow-up data suggested that the 3-year recurrence or metastasis rates of patients in the metastasis and non-metastasis groups were 4.54 and 11.27%, respectively, showing a statistically significant difference (p<0.05). CONCLUSIONS: US combined with CT can make up for the deficiencies of each examination alone, and improve the sensitivity and specificity of PTC LN metastasis detection. It is worthy of clinical promotion.

Clinical value of serial ultrasonography in the dynamic observation of foetal cystic adrenal lesions.

OBJECTIVES: The objective of the study is to evaluate the diagnostic value of ultrasonography in cystic lesions of the adrenal gland. METHODS: Twenty-two cases of adrenal cystic lesions found in the foetal period were retrospectively analysed. All foetuses were followed up by ultrasound after birth, and all lesions were confirmed by operation or ultrasound-guided biopsy. RESULTS: Sixteen foetuses displayed anechoic findings, and 6 had patchy mixed echoic findings. Nevertheless, the characteristics of these lesions changed in the neonatal period: 7 cases presented as anechoic and 15 cases presented as mixed echoic. The final pathology revealed simple cysts in 7 cases, intracystic haemorrhage in 9 cases, and 6 cases of spontaneous haemorrhage of the adrenal glands. CONCLUSIONS: The ultrasonographic findings of foetal cystic lesions in the adrenal gland and the change they undergo after birth may provide valuable information for clinical diagnosis.

Improvement of continuous subcutaneous insulin infusion on patients with type 2 diabetes mellitus by 3-dimensional speckle tracking echocardiography.

Three-dimensional speckle tracking echocardiography (3D-STE) was used to evaluate the improvement of continuous subcutaneous insulin infusion on the left ventricular (LV) systolic function of patients with type 2 diabetes mellitu (T2DM). We recruited T2DM patients (38 cases, diabetic group) and healthy volunteers (35 cases, control group) to collect LV full volume imaging. TomTec software was used for calculating LV global longitudinal strain (LVGLS), global circumferential strain (LVGCS), peak twist (LVTW), peak apical rotation (LVPAR), ejection fraction (LVEF), and torsion (LVT). All indices were re-tested 2 weeks later after intensive treatment of insulin pump. LVGLS, LVGCS, LVTW and LVPAR in diabetic group were significantly decreased than control group. LVGLS and LVGCS in pre-treatment diabetic group were significantly increased than post-treatment. LVGLS, LVGCS, LVTW and LVPAR had correlations among control, pre-treatment and post-treatment diabetic groups. There were no significant differences in LVEDV, LVESV, LVEF, LVT and R-R. LV systolic function of patients with T2DM complicated with microangiopathy was improved after treatment of continuous subcutaneous insulin infusion. In addition, therapeutic effect could be accurately evaluated by 3D-STE which had vital clinical application.

Dose-response studies of Ropivacaine in blood flow of upper extremity after supraclavicular block: a double-blind randomized controlled study.

BACKGROUND: The sympathetic block of upper limb leading to increased blood flow has important clinical implication in microvascular surgery. However, little is known regarding the relationship between concentration of local anesthetic and blood flow of upper limb. The aim of this dose-response study was to determine the ED50 and ED95 of ropivacaine in blood flow after supraclavicular block (SB). METHODS: Patients undergoing upper limb surgery and supraclavicular block were randomly assigned to receive 30ml ropivacaine in concentrations of 0.125%(A Group), 0.2%(B Group), 0.25%(C Group), 0.375%(D Group), 0.5%(E Group), or 0.75%(F Group) (n=13 per group). All patients received supraclavicular block (SB). Time average maximum velocity (TAMAX), cross-sectional area (CSA) of brachial artery and skin temperatures (Ts) were measured repeatedly at the same marked points, they were taken at baseline (before block, t0) and at 30min after SB (t1). Blood flow(BF) = TAMAX× CSA×60 sec.. Relative blood flow (ΔBF) = BFt1/ BFt0. Success of SB was assessed simultaneously. Supplementary anesthesia and other adverse events (AE) were recorded. RESULTS: Significant increase in TAMAX, CSA, BF and Ts were seen in all concentration groups at t1 comparing with t0 (P<0.001). There was an upward trend of TAMAX, CSA, BF with the increasing concentration of ropivacaine except Ts. There was no significant different of Ts at t1 among different concentration group. The dose-response formula of ropivacaine on ΔBF was Y=1+3.188/(1+10^((-2.451-X) × 1.730)) and ED50/ED95 (95%CI) were 0.35/1.94%(0.25-0.45/0.83-4.52), and R2 (coefficient of determination) =0.85. ED50/ED95 (95%CI) values of sensory block were 0.18/0.33% (0.15-0.21/0.27-0.51), R2=0.904. CONCLUSIONS: The dose-response curve between SB ropivacaine and the changes of BF was determined. The ED50/ED95 of ropivacaine of ΔBF are 0.35/1.94% (0.25-0.45/0.83-4.52). TAMAX, CSA and BF consistently increased with ropivacaine concentration. The maximal sympathetic block needs higher concentration than that complete sensation block needs which may benefit for microvascular surgery. TRIAL REGISTRATION: Clinicaltrials.gov NCT02139982 . Retrospectively registered (Date of registration: May, 2014).

The value of ultrasound in the preoperative diagnosis of muscle herniation: A comparison with magnetic resonance imaging.

OBJECTIVES: To evaluate the clinic value of ultrasound (US) in the diagnosis of muscle herniation. METHODS: This retrospective study was performed on 26 patients with muscle herniation confirmed by surgery. All patients were examined by US and magnetic resonance imaging (MRI) preoperatively. The final histopathologic findings were retrospectively compared with the results of US and MRI. RESULTS: The accuracy of ultrasonography and MRI were 92.3%(24/26) and 84.6%(22/26) respectively. There was no significant difference between two methods (χ2=0.25, P>0.05). CONCLUSIONS: US can be used to observe the shape, size, location, internal echo and fascial defect of the mass of muscle herniation in a dynamical way. Ultrasound is a convenient method with high accuracy, it can be used as the first choice of imaging modality for the diagnosis of muscle herniation.

[Transabdominal ultrasound measurement of intravesical prostatic protrusion helps diagnosis of benign prostatic obstruction].

OBJECTIVE: To evaluate the measurement of intravesical prostatic protrusion (IPP) by transabdominal ultrasonography (TAUS) in the diagnosis of benign prostatic obstruction (BPO). METHODS: We studied the clinical data of 109 BPH patients referred for lower urinary tract symptoms (LUTS) from April 2005 to December 2006. IPP was measured by TAUS, urodynamic parameters such as Qmax and PdetQmax obtained by urodynamic studies and AG values calculated. The patients were divided into an obstruction and a non-obstruction group according to their AG values. RESULTS: IPP was found statistically different between the obstruction and non-obstruction groups (P<0.001) and positively correlated with the AG value (r=0.729, P=0.001). With the cutoff at IPP > or = 10 mm for the diagnosis of BPO, the sensitivity, specificity and accuracy of the diagnosis were 89.9%, 97.5% and 92.7%, respectively. CONCLUSION: The measurement of IPP by TAUS offers a valuable help for the diagnosis of BPO.

[Efficacy of axillary approach brachial plexus blocking by ultrasound-guided four points via one-puncture technique].

OBJECTIVE: To investigate the clinical effects and safety of the technique of axillary approach brachial plexus blocking by ultrasound-guided four points via one-puncture. METHODS: Eighty patients scheduled for elective operation were randomly divided into 2 equal groups to undergo axillary approach brachial plexus blocking by ultrasound-guided four points via one-puncture technique (Group U) or nerve stimulator-guided brachial plexus blocking (Group N). The main branches of brachial plexus (radial, median, ulnar, and musculocutaneous nerves) were localized by ultrasound-guided or nerve stimulator-guided techniques. In Group U 8 ml of mixed anesthetic solution containing isovolumetric 0.75% ropivacaine and 2% lidocaine was injected into the 4 main branches of brachial plexus, with a total volume of 32 ml. The ultrasonic manifestations of the brachial plexus and its surrounding tissues were observed. The values of diameter and depth of the 4 nerves and the distance of the musculocutaneous nerve to the midpoint of axillary artery were measured. The manipulation time, onset time, maintaining time, efficacy of blocking, and incidence of complication were recorded. RESULTS: The manipulation time of Group U was 5.2 +/- 2.1 min, significantly shorter than that of Group N (14.6 +/- 3.2 min, P = 0.000), The onset times of the median, radial, and ulnar nerves of Group U were 3.3 +/- 1.9 min, 3.0 +/- 1.7 min, and 3.4 +/- 1.9 min respectively, all significantly shorter than those of Group N (4.6 +/- 2.0 min, 7.3 +/- 7.4 min, and 6.4 +/- 6.1 min respectively, P < 0.01 or P < 0.05). The anesthetic success rate of Group U was 100%, significantly higher than that of Group N (77.5%, P = 0.005). The rate of accidental puncture to blood vessel of Group U was 0, significantly lower than that of Group N (40%, P = 0.000). CONCLUSION: With significantly higher anesthetic success rate, shorter manipulation time and onset time, and lower complication rate, the technique of axillary approach brachial plexus blocking by ultrasound-guided four points via one-puncture is a safe and reliable blocking method in comparison with the nerve stimulator-guided method.