Laparoscopic laser soldering for repair of ureteropelvic junction obstruction in the porcine model.

BACKGROUND AND PURPOSE: Laparoscopic pyeloplasty is used for the repair of ureteropelvic junction (UPJ) obstruction. Our objective was to introduce laser soldering to this procedure. MATERIALS AND METHODS: We developed a system based on a CO2 laser, an infrared detector, and two infrared transmitting optical fibers to obtain temperature-controlled laser soldering of cuts in tissues. The system was used for laparoscopic soldering of incisions in the kidneys of pigs. RESULTS: We carried out laparoscopic pyeloplasty successfully in a porcine model using fiberoptic laser soldering. Laparoscopic laser soldering was found to be faster than suturing. It was easier to use and provided watertight bonding. CONCLUSIONS: This technique will be useful in pyeloplasty as well as other laparoscopic surgical procedures.

Study of urological devices coated with fullerene-like nanoparticles.

Insertion of endoscopes and other medical devices into the human body are ubiquitous, especially among aged males. The applied force for the insertion/extraction of the device from the urethra must overcome endoscope-surface-human-tissue interactions. In daily practice a gel is applied on the endoscope surface, in order to facilitate its entry into the urethra, providing also for local anesthesia. In the present work, a new solid-state lubricant has been added to the gel, in order to reduce the metal-urethra interaction and alleviate the potential damage to the epithelial tissue. For that purpose, a urethra model was designed and fabricated, which allowed a quantitative assessment of the applied force for extraction of the endoscope from a soft polymer-based ring. It is shown that the addition of MoS2 nanoparticles with fullerene-like structure (IF-MoS2) and in particular rhenium-doped nanoparticles (Re:IF-MoS2) to Esracain gel applied on the metal-lead reduced the friction substantially. The Re:IF-MoS2 showed better results than the undoped fullerene-like nanoparticles and both performed better than the gel alone. The mechanism of friction reduction is attributed to fullerenes' ability to roll and act as a separator between the active parts of the model.

Filling cystoureterography facilitates stone visualization in patients with previously inserted double-J ureteral stents.

In our study, we assessed the ability of a filling cystogram to induce vesicoureteral reflux (VUR) and to evaluate its role in stone targeting during ESWL in the presence of a double-J ureteral stent (JJ-S). Filling cystoureterography was performed during ESWL in 17 patients with previously inserted 4.7 F JJ-S. The examination ended with stone localization. In every procedure, 3,500 shock waves were delivered with an energy range of 18-23 kV. Patients were evaluated 4 weeks after ESWL. A stone-free result was defined as no evidence of calculi in the first or second visits. Because contrast material was employed in this study, we also evaluated its possible interference with the results of lithotripsy. All radiolucent or poorly calcified stones were successfully localized. In four patients, rhythmic suprapubic manual pressure was performed to initiate VUR. Reflux was low grade in 35% and high grade in 65% of renal units. The efficiency quotient reached 59%. In vitro artificial stones were successfully disintegrated both in water and solutions of Ultravist. In the presence of a JJ-S, filling cystography can easily localize radiolucent stones during SWL. No special catheters or stents are required for this technique. Ultravist in particular does not affect the results of ESWL unfavorably.