A novel double-balloon catheter for percutaneous balloon pulmonary valvuloplasty under echocardiographic guidance only.

BACKGROUND: Percutaneous balloon pulmonary valvuloplasty (PBPV) is the procedure of choice for uncomplicated severe or symptomatic pulmonary stenosis. Echocardiography (echo)-guided PBPV can completely avoid the use of radiation and contrast agents compared to fluoroscopy-guided PBPV. Although we have confirmed that echo-guided PBPV is feasible in humans, the poor visibility of the traditional catheter under echo greatly limits the promotion of this new technology. METHODS: We produced a novel double-balloon catheter to make the catheter easy to be detected by echo through adding a guiding balloon at the distal end of the catheter. Echo-guided PBPV was performed on thirty healthy swine using either a novel catheter or a traditional catheter to evaluate the feasibility and safety of the novel double-balloon catheter. The feasibility was evaluated by the success rate of balloon inflation at the pulmonary valve annulus and the operating time. The safety was evaluated by the frequency of balloon slippage and the incidence of complications. RESULTS: There were no significant between-group differences in terms of weight and the ratio of balloon diameter to pulmonary annulus diameter. The success rate was 93.3% and 60% in the novel and traditional groups, respectively. The novel group had significantly (p<0.05) lower mean procedure time (6.33±6.86min vs 24.8±9.79min) and lower frequency of balloon slippage (0.07±0.26 vs 0.53±0.52), arrhythmia (0.07±0.26 vs 0.47±0.52), and tricuspid regurgitation (6.7% vs 40%) than the traditional group. No myocardial hematoma or pericardial tamponade occurred in the novel catheter group. CONCLUSION: Although further studies and improvements are required, the study results indicate that the novel double-balloon catheter for echo-guided PBPV is feasible and safe.

Percutaneous closure of patent foramen ovale under transthoracic echocardiography guidance-midterm results.

BACKGROUND: Conventional percutaneous closure of patent foramen ovale (PFO) is usually performed under the guidance of fluoroscopy. Whether closure of PFO under transthoracic echocardiography (TTE) guidance only is safe and effective is unknown. The present study therefore aimed to assess the safety and efficacy of percutaneous closure of PFO under TTE guidance only. METHODS: This study retrospectively enrolled a total of 52 consecutive patients (55.8% male, mean age 34.0±13.0 years, range, 10-59 years) with PFO treated at our institution from June 2015 to September 2017 by percutaneous closure under echocardiographic guidance only. The patients mean body weight was 58.7±10.8 kg. Patients underwent follow-up by TTE immediately post procedure by electrocardiogram and TTE at 1, 3, 6 and 12 months after discharge and annually thereafter, and by clinical evaluation at all time points. RESULTS: Of the 52 patients, 47 (90.4%) were successfully treated by percutaneous closure under TTE guidance. The mean procedure duration (from puncture to sheath removal) was 21.0±6.2 (range, 11-33) minutes. A trivial residual shunt which disappeared 24 hours later was observed in only 1 (1.9%) patient immediately post procedure. Median hospital stay was 3.0 days without severe complications such as peripheral vascular injury or cardiac perforation at discharge. At median 15.5 (11.3, 18.0) months follow-up, there were no complications such as death, stroke, transient ischemic attack (TIA) and residual shunt. CONCLUSIONS: In this single center study of mostly lean patients, percutaneous closure of PFO under TTE guidance as the only imaging tool appeared effective at midterm follow-up, while avoiding radiation exposure, endotracheal intubation and contrast agent use.

Validation of the Pretreatment Neutrophil-to-Lymphocyte Ratio as a Prognostic Factor in a Large Cohort of Chinese Patients with Upper Tract Urothelial Carcinoma.

BACKGROUND: The pretreatment neutrophil-to-lymphocyte ratio (NLR) has been reported to be a prognostic factor in various types of carcinomas. The aim of this study was to investigate the prognostic value of pretreatment NLR in a large cohort of Chinese patients with upper tract urothelial carcinoma (UTUC). METHODS: We retrospectively analyzed the medical data of 656 UTUC patients who underwent radical nephroureterectomy (RNU) from 2001 to 2011 at Peking University First Hospital. Receiver operating characteristic (ROC) curve analysis was performed to calculate the optimal cutoff point of pretreatment NLR. Uni- and multi-variate analyses were used to identify the prognostic factors for cancer-specific survival (CSS) and intravesical recurrence-free survival (IVRFS). RESULTS: The optimal cutoff point of pretreatment NLR was 2.40 by ROC curves, by which patients with high NLR (NLR ≥2.40) and low NLR (NLR <2.40) accounted for 314 (47.9%) and 342 (52.1%) patients, respectively. Patients with a high pretreatment NLR tended to have high tumor grades (χ2 = 15.725, P< 0.001), high tumor stages (χ2 = 25.416, P< 0.001), tumor sizes >5 cm (χ2 = 8.213, P= 0.005), ipsilateral hydronephrosis (χ2 = 4.624, P= 0.033), and concomitant carcinoma in situ(CIS) (χ2 = 9.517, P= 0.003). A high pretreatment NLR (hazard ratio [HR] = 1.820, P= 0.001), main tumor diameter >5 cm (HR = 1.789, P= 0.009), lymph node metastasis (HR = 1.863, P= 0.024), and high tumor stage (HR = 1.745, P< 0.001) independently predicted poor CSS after surgery, while only concomitant carcinoma in situ(CIS) (HR = 2.164, P= 0.034), ureteroscopy before surgery (HR = 1.701, P= 0.015), and high tumor grade (HR = 1.645, P= 0.018) were independent predictors of IVRFS after RNU. CONCLUSIONS: The pretreatment NLR was related to some adverse clinicopathological features and was an independent predictor of CSS, although not IVRFS, in Chinese UTUC patients.

An NMR approach applicable to biomolecular structure characterization.

A generalized 2D correlation NMR (GEN2D-NMR) scheme capable of substantially reducing the experimental time for two-dimensional correlation NMR experiments is described. The experimental time used in GEN2D-NMR is shortened to less than one-tenth of that required in traditional double Fourier transform 2D-NMR (FT2D-NMR) for a 13C-13C spin diffusion experiment for Nephila edulis spider threads. Experimentally, one needs to acquire many fewer points in GEN2D-NMR than that in FT2D-NMR in the evolution time domain. By keeping other acquisition pulse sequence and parameters the same in both methods, the GEN2D-NMR technique can produce a 2D-NMR spectrum using fewer points along the evolution time domain equivalent to that produced by the FT2D-NMR technique using more points. GEN2D-NMR would provide a significant advantage for those molecules that are difficult to highly isotropically label, such as proteins, polypeptides, and polymers, or those which become unstable in a prolonged measurement time.