Biomedical subjects

Oscar E Fugita

Publications and source records attributed to Oscar E Fugita.

3 recordsLinked to original sources

PubMed2003

Telementoring between Brazil and the United States: initial experience.

BACKGROUND AND PURPOSE: To assess the safety and feasibility of transcontinental telementored and telepresence surgery, we report on two procedures carried out with participation by surgeons in Baltimore in the United States and São Paulo and Recife in Brazil. PATIENTS AND METHODS: Over a period of 3 months, a laparoscopic bilateral varicocelectomy and a percutaneous renal access for a percutaneous nephrolithotomy were performed. The mentoring surgeon (LRK) was the same for both procedures. He used a 650-MHz personal computer fitted with a Z360 video COder/ DECoder (CODEC) and a Z208 communication board (Zydacron Corp, Manchester, NH) that comprise the core of the telesurgical station. In the first case, a surgical robot, AESOP 3000 (Computer Motion Inc.), was attached to a laparoscope, and the remote surgeon drove the robot via a controller on the remote computer. In the second case, another robot (Percutaneous Access to the Kidney; PAKY) was used for percutaneous needle placement into the renal collecting system. RESULTS: The two procedures were completed successfully. In the first case, the operative time was 25 minutes, with minimal estimated blood loss. The patient was discharged home the next day. At 3-month follow-up, there was no scrotal pain or varicocele. In the second case, access to the urinary tract was achieved with the first needle pass, and percutaneous nephrolithotomy was uneventful. Blood loss was minimal, and the patient was discharged home on the second postoperative day. At 3-month follow-up, the patient was free of urinary stones and of symptoms. CONCLUSIONS: The first transcontinental telementored and telepresence urologic surgical procedures have been reported previously. The success observed with the novel surgical techniques has motivated great interest. The cases reported here demonstrate that several types of procedures can be mentored safely and effectively with telemedicine technology.

Adolescent↗

PubMed2002

Local hemostasis during laparoscopic partial nephrectomy using biodegradable hydrogels: initial porcine results.

BACKGROUND AND PURPOSE: Despite the advance of laparoscopic partial nephrectomy, significant technical limitations remain with regard to control of bleeding and closure of the collecting system. An attractive approach on the horizon for local hemostatic and wound control is the use of local tissue sealants. To date, sealants remain largely derived from natural biologic products and are difficult to apply laparoscopically with precise local control. In this study, we examined the novel strategy of forming occlusive tissue-adherent hydrogels utilizing a synthetic biodegradable polyethylene glycol-lactide copolymer (PEG-lactide) as an in situ occlusive barrier for hemostasis and wound control. Specifically, the objects of this study were to determine if PEG-lactide hydrogels could be formed intraperitoneally on renal tissue, to test the adhesiveness of the hydrogels to injured renal parenchyma, and to evaluate the ability of adherent hydrogel barriers to limit renal parenchymal bleeding and collecting system leakage following renal pole amputation or wedge excision. MATERIALS AND METHODS: Five kidneys from three female pigs were used in a nonsurvival study. A standardized model for laparoscopic partial nephrectomy was created by performing wedge excision or polar amputation under vascular control using a laparoscopic Satinsky clamp. Bleeding briskness following injury was assessed utilizing a scoring system and free blood quantitated comparing a conventional "clamp and wait" strategy with an adherent hydrogel strategy. For the hydrogel group, PEG-lactide hydrogel primer and macromer were applied through laparoscopic ports. The hydrogel was polymerized using a xenon light source, and the pedicle clamp was released to observe for bleeding. A subsequent opposite polar injury was created to confirm renal perfusion and the sites were compared. The kidneys were removed, and the adhesion of the hydrogel to the renal parenchyma was examined. RESULTS: The PEG-lactide macromer was effectively applied to five kidneys following partial nephrectomy. In all cases, successful intraperitoneal in situ polymerization was achieved, with resultant hydrogel formation. Polymeric hydrogel adhesion to the cut renal parenchyma was assessed semiquantitatively following vigorous cyclic washing. In all cases, polymer gels remained adherent without any evidence of peeling, delamination, or separation from the underlying tissue surface. In the control group, the mean bleeding score was 2.63 +/- 0.48 v 0.00 +/- 0.00 in the gel-treated group (P < 0.001). Blood loss in the control group was 56 +/- 5 ml v 0.00 +/- 0.00 in the gel-treated group (P < 0.001). In an ex vivo retrograde ureteral perfusion, no leakage was observed at pressure as high as 100 mm Hg. CONCLUSIONS: In this feasibility study, a biodegradable PEG-lactide polymer system photopolymerized rapidly in situ on exposed renal parenchymal surfaces, forming adherent hydrogel barriers. When applied during vascular clamping, an adequate physical bond and patch-like cap was created to prevent bleeding at physiologic renal perfusion pressures. Use of locally applied occlusive hydrogels holds promise for hemostasis and local wound control during laparoscopic urologic procedures.

Absorbable Implants↗

PubMed2002

Measurement of needle-tip bioimpedance to facilitate percutaneous access of the urinary and biliary systems: first assessment of an experimental system.

RATIONALE AND OBJECTIVES: Percutaneous access to the renal collecting system or biliary system is most frequently performed under image guidance. However, current techniques lack a feedback mechanism to help confirm successful access. A percutaneous needle system has been developed consisting of a modified 18-gauge percutaneous access needle that measures tissue impedance at its needle tip. Initial results in utilizing this novel system to determine successful access into dilated kidney and gall bladder specimens are reported. METHODS: Impedance measurements were recorded as the needle was precisely advanced through ex vivo kidney and liver/gall bladder specimens. In an anesthetized porcine model, impedance values were recorded with laparoscopic visualization as the needle was advanced percutaneously through abdominal wall, liver, and into gall bladder. RESULTS: A characteristic, reproducible drop in impedance was noted with successful entry into ex vivo distended kidney and gall bladder specimens. This feature was also noted during in vivo percutaneous cholecystostomy. CONCLUSIONS: A measurable, characteristic drop in tissue impedance signifies successful entry into the urinary and biliary systems. This impedance needle system may facilitate current percutaneous access techniques.

Animals↗