Preliminary experience of oblique occlusion technique in robot-assisted infrahepatic inferior vena cava thrombectomy: step-by-step procedures and short term outcomes.

BACKGROUND: We aimed to compare the oncological outcomes between the oblique occlusion technique and the traditional technique for robot-assisted radical nephrectomy (RARN) with inferior vena cava (IVC) thrombectomy, and to explore the safety and effectiveness of the oblique occlusion technique. METHODS: Overall, 21 patients with renal cell carcinoma (RCC) and IVC tumor thrombus (TT) were admitted to our hospital from August 2019 to June 2020. All the patients underwent RARN with IVC thrombectomy, of which the IVC oblique occlusion technique was used in 11 patients and traditional occlusion technique was used in 10 patients. The oblique occlusion technique refers to oblique blocking from the upper corner of the right renal vein to the lower corner of the left renal vein using a vessel tourniquet or a vessel clamp (left RCC with IVCTT as an example). RESULTS: Compared with patients in the traditional group, those in the oblique group had lower serum creatinine at follow-up (3 month) (95 ± 21.1 vs. 131 ± 30.7 µmol/L, P = 0.03). There was no significant difference in operation time [149 (IQR 143-245) min vs. 148 (IQR 108-261) min, p = 0.86], IVC clamping time [18 (IQR 12-20) min vs. 20 (IQR 14-23) min, p = 0.41], and estimated intraoperative blood loss [300 (IQR 100-800) mL vs. 500 (IQR 175-738) mL, p = 0.51] between both groups. During a 16-month (range, 15-23 months) follow-up period, two cases progressed in the oblique group and three cases progressed in the traditional group. CONCLUSIONS: The modified IVC oblique occlusion technique procedure is relatively safe and effective in RARN with IVC thrombectomy. The IVC oblique occlusion technique may play a role in the protection of renal function.

Correlation between properties of HfO2 films and preparing parameters by ion beam sputtering deposition.

Ion beam sputtering is one of the most important technologies for preparing hafnium dioxide thin films. In this paper, the correlation between properties of hafnium dioxide thin films and preparing parameters was systematically researched by using the orthogonal experiment design method. The properties of hafnium oxide films (refractive index, extinction coefficient, deposition rate, stress, and inhomogeneity of refractive index) were studied. The refractive index, extinction coefficient, physical thickness, and inhomogeneity of refractive index were obtained by the multiple wavelength curve-fitting method from the reflectance and transmittance of single layers. The stress of thin film was measured by elastic deformation of the thin film-substrate system. An orthogonal experimental strategy was designed using substrate temperature, ion beam voltage, ion beam current, and oxygen flow rate as the variables. The experimental results indicated that the temperature of the substrate is the key influencing parameter on the properties of hafnium oxide films, while other preparing parameters are also correlated with specific properties. The experimental results are significant for selecting proper parameters for preparing hafnium oxide films with different applications.

Topologically crafted spatiotemporal vortices in acoustics.

Vortices in fluids and gases have piqued the human interest for centuries. Development of classical-wave physics and quantum mechanics highlighted wave vortices characterized by phase singularities and topological charges. In particular, vortex beams have found numerous applications in modern optics and other areas. Recently, optical spatiotemporal vortex states exhibiting the phase singularity both in space and time have been described. Here, we report the topologically robust generation of acoustic spatiotemporal vortex pulses. We utilize an acoustic meta-grating with broken mirror symmetry which exhibits a topological phase transition with a pair of phase singularities with opposite topological charges emerging in the momentum-frequency domain. We show that these vortices are topologically robust against structural perturbations of the meta-grating and can be employed for the generation of spatiotemporal vortex pulses. Our work paves the way for studies and applications of spatiotemporal structured waves in acoustics and other wave systems.

Completely laparoscopic versus open radical nephrectomy and infrahepatic tumor thrombectomy: Comparison of surgical complexity and prognosis.

OBJECTIVE: To compare the operation complexity and prognosis of completely laparoscopic versus open radical nephrectomy and infrahepatic tumor thrombectomy. METHODS: We reviewed and analyzed the clinical data of 87 patients with infrahepatic tumor thrombus from January 2015 to April 2019 retrospectively. Completely laparoscopic infrahepatic tumor thrombectomy was completed in 41 cases, and open surgery was completed in 46 cases. RESULTS: All 41 patients successfully completed laparoscopic operation, and there were no cases of death during the operation. The completely laparoscopic group were older, had smaller renal tumor diameter, shorter median operation time, lower median intraoperative hemorrhage volume, and lower median transfusion volume of suspended red blood cells compared with open surgeries. The proportion of low-level tumor thrombus (Mayo I) in the completely laparoscopic group was higher (63.4%), while the proportion of low-level tumor thrombus in the open surgery group was lower (30.4%) (P = 0.002). The postoperative complications incidence of laparoscopic surgery was 19.5%, which was lower than that of open surgery (47.8%) (P = 0.004). The mean cancer-specific survival time of the laparoscopic surgery group was 36.6 ± 2.5 months, while that of the open surgery group was 32.3 ± 2.7 months (P = 0.277). There was no statistical difference between the two groups. CONCLUSION: Although completely laparoscopic radical nephrectomy and infrahepatic tumor thrombectomy is a challenging operation, it could be feasible and safely performed, especially in the hands of highly-experienced laparoscopic urologists for well selected cases.