Retracted: A review of the clinical applications and performance of laser speckle contrast imaging

Laser speckle contrast imaging (LSCI) is a useful tool for visualizing full-field blood flow images. Speckle pattern is formed when a coherent light illuminates a rough object, and the backscattered radiation is transformed into images and be shown on a screen. Movement within the object results in the fluctuation of patterns over time. The same data can be obtained by employing the Doppler effect, yet producing a two-dimensional Doppler map needs scanning;speckle imaging renders the same information without the requirement to scan. Nowadays, LSCI has gained expanded consideration, in part because of its accelerated adoption for blood flow studies in the different surgical departments. Here we represent and review the application of laser speckle contrast methods to the field of perfusion visualization as clinical studies from various medical fields and discuss the limitations hindering clinical acceptance

Percutaneous balloon valvuloplasty of pulmonary valve stenosis: state of the art and future prospects

This study is aimed to delineate readers with an overview of percutaneous balloon pulmonary valvuloplasty (PBPV) of pulmonary valve stenosis (PVS) and highlighting outcome based on influential and recent studies. It has been four decades since Kan et al first introduce PBPV. Since then, PBPV has recognized as a gold standard therapy for PVS of all ages. Nowadays, PBPV is practiced for a broad range of indication such as PVS, PV dysplasia and pulmonary atresia. Typically, PBPV is recommended when gradient across the PV is >50 mmHg. The procedure involves the placement of one or more balloon catheters across the stenotic PV with the guidance of a guidewire; thereafter, inflation of the balloons is done by pressure, thus producing valvotomy. Nowadays, PBPV is done by echocardiographic guidance, but previously, it was done by fluoroscopic guidance. The main disadvantage of fluoroscopy was the radiation injury of patients. The recently recommended balloon/annulus ratio is 1.2 to 1.25. Following the procedure, the dramatic reduction of pressure gradient, free motion of the PV leaflets with less doming, the rise of cardiac output have been noted, whereas complications may occur but are unusual and minimal. Significant predictors of restenosis include balloon/annulus ratio <1.2 and immediate post-PBPV gradient ≥30 mmHg. Only a few percentages of patients needed repeat PBPV. Long-term follow-up results are surprisingly excellent. In conclusion, it is our opinion that PBPV is equally successful in patients of all ages, while worldwide recognized studies prove the safety, feasibility, and effectiveness. However, for early detection of any complication, life-long clinical follow-up is mandatory.