Lower extremity artery thromboembolism during removal of Impella after repair for ventricular septal rupture: A case report.

Although the anticoagulant complications of Impella are well known, the timing of heparin administration when using Impella immediately after open heart surgery has not been established. We report a case of a 59-year-old man with Impella-assisted repair of a ventricular septal perforation after acute myocardial infarction who developed thromboembolism of the lower extremity arteries after removal of Impella.

Thermoelastic wave generation and its longitudinal wave propagation measurement by a microscopic optical interferometer.

Laser ultrasonics is a noncontact measurement method that uses a laser-induced elastic wave source in combination with an optical surface displacement-tracking system. This study compared the performances of two optical interferometers with different characteristics when applied to measurement of pulsed thermoelastic waves. The surface displacement-tracking system was designed to measure the center of the microscopic view. A pulsed laser beam irradiated a black ink layer to generate the thermoelastic waves. The out-of-plane displacement on the axially opposite side was then measured using either a Michelson interferometer or a Sagnac interferometer. The objective lens of the system was of a type commonly used in biological observations. The Michelson interferometer estimated a maximum displacement of 0.43 nm and a maximum sound pressure of 24.7 kPa. The signal-to-noise ratios from 16 averages were 14.9 dB (Michelson interferometer) and 19.2 dB (Sagnac interferometer). Furthermore, this paper compares the performance of the numerically estimated Sagnac interferometer outputs calculated from the measured Michelson interferometer outputs with the experimentally obtained Sagnac interferometer outputs. The numerically estimated Sagnac interferometer's output was shown to be identical to the experimentally acquired output. The Michelson interferometer requires a higher average operating frequency (i.e., it needs a longer data acquisition time), although this interferometer does offer superior displacement output linearity. This property enables calculation of the sound pressure from the displacement amplitude. These findings indicated that combination of the measurement points of the Sagnac interferometer with those of the sparsely distributed Michelson interferometer reduced the measurement time when compared with a single use of the Michelson interferometer while also maintaining the data acquisition quality.

[Surgical Treatment for Ruptured Thoracoabdominal Aneurysm Following Descending Aortic Replacement with Double Barrel Anastomosis].

A 75-year-old woman was diagnosed with type B acute aortic dissection 14 years ago and 3-channeled aortic dissection 7 years ago. She received total arch replacement 6 years ago and descending aortic replacement with double barrel anastomosis technique for distal anastomosis 5 years ago. Computed tomography( CT) revealed giant thyroid tumor and thoracoabdominal aortic aneurysm( 58 mm in diameter). She suffered from back pain during her follow-up period. CT revealed ruptured thoracoabdominal aortic aneurysm. First, the false lumen of descending aorta was closed by thoracic endovascular aortic repair, and then thoracoabdominal aortic replacement was performed uneventfully.

Detection of Individual Microbubbles by Burst-Wave-Aided Contrast-Enhanced Active Doppler Ultrasonography.

We propose burst-wave-aided, contrast-enhanced, active Doppler ultrasonography for visualizing lymph vessels. This technique forces ultrasound contrast agents (UCAs) to move using the acoustic radiation force induced by burst waves with low amplitude while suppressing their destruction. Using a flow phantom, we measured the average, decrease rate of echo intensity [i.e., pulse intensity integral (PII)], and the velocity of individual contrast agents, which directly affects the performance of imaging and tracking contrast agents under stationary flow conditions. Comparison with pulse-inversion Doppler without exposure to the burst wave demonstrated that the velocity of the contrast agents could be enhanced up to several tens of millimeters per second by the effect of the burst wave, maximizing the echo intensity extracted by a clutter filter. The contrast ratio (CR), defined as the ratio of the contrast echo to the phantom echo outside the channel, did not change appreciably, even when the lower cut-off velocity of the clutter filter was increased up to 10 mm/s. This implies a better robustness against the motion of the tissue. In addition, the performance for detecting contrast agents (i.e., echo intensity) was superior or similar to that of pulse-inversion Doppler, even in undesirable conditions where the flow had a velocity component in the opposite direction to that of the acoustic radiation force. The echo intensity was lower or the same as that in pulse-inversion Doppler, demonstrating the potential for suppressing the destruction of contrast agents and enabling long-term observations. From these results, we expect that the proposed method will be beneficial for visualizing lymph vessels.

The Effect of Steatosis on Shear-Wave Velocity and Viscoelastic Properties Related to Liver Fibrosis Progression in Rat Models.

OBJECTIVE: Hepatic fibrosis has recently been evaluated using ultrasonography or magnetic resonance elastography. Although the shear wave velocity (SWV) obtained using point shear wave elastography (pSWE) provides a valuable measure of fibrosis, underlying steatosis may affect its measurement. METHODS: Using hepatic fibrosis samples, this study evaluated the effect of steatosis on the shear wave velocity of pSWE (Vs) and viscoelastic properties (assessed by dynamic mechanical analysis) of rat liver. Fifty rats with various grades of steatosis and fibrosis underwent open abdominal in vivo Vs measurements using a commercial ultrasound scanner. The mechanical properties of hepatic tissue were also characterized under ex vivo conditions using dynamic mechanical analysis and the Zener model of viscoelasticity. RESULTS: Fibrosis and steatosis progression influenced Vs and elasticity. The SWV computed using the Zener model and Vs showed a substantial correlation (r > 0.8). Fibrosis progression increased SWV. Steatosis was also related to SWV. Steatosis progression obscured the SWV change associated with fibrosis progression. CONCLUSION: We conclude that steatosis progression affects the evaluation of fibrosis progression. This finding could aid discrimination of non-alcoholic steatohepatitis from non-alcoholic fatty liver disease using SWV.

Impact of Accessory Renal Artery Embolization on Renal Deterioration Under Endovascular Aortic Repair.

OBJECTIVE: The optimal management strategy for patients with accessory renal arteries undergoing endovascular aortic repair is unclear. This study aimed to investigate the impact of accessory renal artery (aRA) embolization on postoperative renal deterioration and to identify the predictors of postoperative renal deterioration in patients who underwent endovascular aortic repair (EVAR). METHODS: A retrospective single-centre observational study was conducted at our hospital. Of 331 consecutive patients who underwent endovascular aortic repair between April 2011 and February 2021, 29 patients with an aRA were included in this study. Spearman's rank correlation coefficients of decrease in estimated glomerular filtration rate (eGFR), renal volume reduction rate, infarcted renal volume, and quantity of contrast use for postoperative renal deterioration were analyzed. The correlation coefficients of the correlations between infarcted renal volume, renal volume reduction rate, and decrease in eGFR and the rate of aRA diameter were also analyzed. Multivariable nominal logistic regression analyses were conducted to evaluate the odds of postoperative renal deterioration. RESULTS: The renal volume reduction rate and infarcted renal volume had a significant positive correlation with the decrease in eGFR. Body surface area and preoperative renal volume were significantly but negatively correlated with the decrease in eGFR. The infarcted renal volume, renal volume reduction rate, and decrease in eGFR were significantly and positively correlated with the aRA diameter. The odds ratio for decreased eGFR rate in preoperative renal volume was .96 (95% CI 0.930‒.996, P = .009). CONCLUSIONS: EVAR with aRA embolization impacts postoperative renal deterioration in patients with preoperative low renal volume, and the diameter of the embolized aRA might be a predictor of postoperative renal deterioration.

Modified multi-Rayleigh model-based statistical analysis of ultrasound envelope for quantification of liver steatosis and fibrosis.

PURPOSE: Quantitative diagnosis of the degree of fibrosis progression is currently a focus of attention for fatty liver in nonalcoholic steatohepatitis (NASH). However, previous studies have focused on either lipid droplets or fibrotic tissue, and few have reported the evaluation of both in patients whose livers contain adipose and fibrous features. Our aim was to evaluate fibrosis tissue and lipid droplets in the liver. METHODS: We used an analytical method combining the multi-Rayleigh (MRA) model and a healthy liver structure filter (HLSF) as a technique for statistical analysis of the amplitude envelope to estimate fat and fibrotic volumes in clinical datasets with different degrees of fat and fibrosis progression. RESULTS: Fat mass was estimated based on the non-MRA fraction corresponding to the signal characteristics of aggregated lipid droplets. Non-MRA fraction has a positive correlation with fat mass and is effective for detecting moderate and severe fatty livers. Progression of fibrosis was estimated using MRA parameters in combination with the HLSF. The proposed method was used to extract non-healthy areas with characteristics of fibrotic tissue. Fibrosis in early fatty liver suggested the possibility of evaluation. On the other hand, fat was identified as a factor that reduced the accuracy of estimating fibrosis progression in moderate and severe fatty livers. CONCLUSION: The proposed method was used to simultaneously evaluate fat mass and fibrosis progression in early fatty liver, suggesting the possibility of quantitative evaluation for discriminating between lipid droplets and fibrous tissue in the early fatty liver.

[Delayed Type â ¢b Endoleak After Thoracic Endovascular Aortic Repair for Thoracic Aortic Aneurysm: Report of a Case].

An 85-year-old woman underwent aortic arch replacement and thoracic endovascular aortic repair (TEVAR) 5 years ago. She suffered from chest and back pain. Computed tomography (CT) demonstrated enlargement of the aortic aneurysm by a type Ⅲb endoleak. TEVAR was performed to close a type Ⅲb endoleak with a relining technique uneventfully. Intraoperative completion aortography and postoperative CT confirmed the disappearance of a type Ⅲb endoleak. She was discharged 27 days after the treatment.

[Acute Type A Aortic Dissection Complicated by Cerebral Malperfusion and Leg Ischemia:Report of a Case].

An 82-year-old woman suddenly developed chest pain and apoplexy. Computed tomography (CT) showed acute type A aortic dissection, the true lumen in the brachicephalic artery was severely compressed by the faulse lumen. Pulsation in the either leg was not detected during induction of anesthesia. We evaluated the cerebral blood flow and lower extremity blood flow using near infrared spectroscopy (NIRS) during the operation, tissue oxygenation index (TOI) was continuously monitored during the operation. Cardiopulmonary bypass( CPB) was established by puncturing the true lumen in the ascending aorta and bicaval venous drainage. TOI was returned to normal range by CPB. Although the central repair (ascending aorta replacement) was performed, leg ischemia persisted. We performed ascending aorta-bifemoral bypass. After the operation, leg ischemia disappeared and CT revealed patency of the bypass graft. Postoperative course was uneventful without deterioration of neurological function. She was discharged 49 days after the operation.