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Biomedical subjects

Dan Stoianovici

Publications and source records attributed to Dan Stoianovici.

8 recordsLinked to original sources

Is telesurgery a new reality? Our experience with laparoscopic and percutaneous procedures.

BACKGROUND: Minimally invasive surgery offers many advantages, but its correct practice is associated with a steep learning curve. Telesurgery allows a surgeon at a remote site to guide and teach surgeons at a primary site by utilizing robotic devices, telecommunications, and video technology, thereby reducing complications. PATIENTS AND METHODS: From September 1998 to July 2000, 17 procedures were telementored between two sites 9230 km apart: a primary operating room at the Policlinico Casilino "Tor Vergata" University of Rome and a remote site at the Johns Hopkins Medical Institutions in Baltimore. Of these procedures, 14 were laparoscopic cases: 8 spermatic vein ligations, 2 retroperitoneal renal biopsies, 3 simple nephrectomies, and 1 pyeloplasty. Three procedures were carried out to obtain percutaneous renal access. All procedures were performed with the help of two robots: the first robot, AESOP, for the orientation of the laparoscope, and the second one, PAKY, to perform the percutaneous renal access. In addition to the robotic device, the system provided four ISDN lines, a PC with dedicated software to manage the connection, audio and video connections, an external video camera with a panoramic view of the operating room, and remote control of the electrocautery and the Telestrator. RESULTS: All the procedures were accomplished with an uneventful postoperative course. Ten operative cases were telementored successfully. In five cases, it was not possible to establish a connection to the remote site, and two procedures were converted to open surgery because of intraoperative complications. The time delay of the image transmission was <1 second. CONCLUSION: This preliminary experience has demonstrated the feasibility of international telementoring. It could provide education to surgeons and decrease the likelihood of complications attributable to inexperience with new techniques.

Humans↗

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↗

System for robotically assisted prostate biopsy and therapy with intraoperative CT guidance.

RATIONALE AND OBJECTIVES: The purpose of this study was to assess the work-in-progress prototype of an image-guided, robotic system for accurate and consistent placement of transperineal needles into the prostate with intraoperative image guidance inside the gantry of a computed tomographic (CT) scanner. MATERIALS AND METHODS: The coach-mounted system consists of a seven-degrees-of-freedom, passive mounting arm: a remote-center-of-motion robot; and a motorized, radiolucent needle-insertion device to deliver 17-18-gauge implant and biopsy needles into the prostate with the transperineal route. The robot is registered to the image space with a stereotactic adapter. The surgeon plans and controls the intervention in the CT scanner room with a desktop computer that receives DICOM images from the CT scanner. The complete system fits in a carry-on suitcase, does not need calibration, and does not utilize vendor-specific features of the CT scanner. RESULTS: In open air, the average accuracy was better than 1 mm at a 5-8-cm depth. In various phantoms, the average orientation error was 1.3 degrees, and the average distance between the needle tip and the target was 2 mm. CONCLUSION: Results of preliminary experiments indicate that this robotic system may be suitable for transperineal needle placement into the prostate and shows potential in a variety of other percutaneous clinical applications.

Biopsy, Needle↗

Robotically assisted nerve and facet blocks: a cadaveric study.

RATIONALE AND OBJECTIVES: This study was performed to evaluate the feasibility of using a joystick-controlled robotic needle driver to place a 22-gauge needle for nerve and facet blocks. MATERIALS AND METHODS: Biplane fluoroscopy and a robotic needle driver were used to place 12 needles into the lumbar paraspinal region of an embalmed female cadaver (age at death, 98 years). Small metal BB nipple markers (1 mm in diameter) were inserted percutaneously to serve as targets. Six needles were then placed near the nerve root, and six were placed near the facet root. Anteroposterior and lateral radiographs were obtained after each needle placement to assess its accuracy. RESULTS: All needles were placed within 3 mm of the target BB. The average distance was 1.44 mm +/- 0.66 (standard deviation). DISCUSSION: A robotic needle driver can be used to place needles accurately in the nerve and facet regions. Clinical studies are required to investigate the advantages and disadvantages of this system for interventional procedures involving needles.

Aged↗

Robot-assisted stapedotomy: micropick fenestration of the stapes footplate.

OBJECTIVE: Micropick fenestration of the stapes footplate, a difficult step in stapedotomy, was selected for trials evaluating the potential for robotic assistance (RA) to improve clinical measures of surgical performance. STUDY DESIGN: In a surgical model of stapedotomy, we measured accuracy of fenestration to a desired point location and force applied to the stapes footplate. Performance variables were measured for 3 experienced and 3 less-experienced surgeons. RESULTS: RA significantly reduced the maximum force applied to the stapes footplate. For fenestration targeting, RA significantly improved accuracy for less-experienced surgeons and significantly worsened targeting for more-experienced surgeons. CONCLUSIONS: RA significantly improves performance for micropick fenestration in a surgical model of stapedotomy. For certain tasks, RA differentially affects performance for users of different experience levels. CLINICAL SIGNIFICANCE: These are the first results showing quantitative improvements in performance during simulated ear surgery using RA and differential effects of RA on performance for users of different experience levels.

Clinical Competence↗

Robotic percutaneous access to the kidney: comparison with standard manual access.

PURPOSE: To evaluate the efficiency, accuracy, and safety of robotic percutaneous access to the kidney (PAKY) for percutaneous nephrolithotomy in comparison with conventional manual techniques. MATERIALS AND METHODS: We compared the intraoperative access variables (number of access attempts, time to successful access, estimated blood loss, complications) of 23 patients who underwent robotic PAKY with the remote center of motion device (PAKY-RCM) with the same data from a contemporaneous series of 23 patients who underwent conventional manual percutaneous access to the kidney. The PAKY-RCM incorporates a robotic arm and a friction transmission with axial loading system to accurately position and insert a standard 18-gauge needle percutaneously into the kidney. The blood loss during percutaneous access was estimated on a four-point scale (1 = minimal to 4 = large). The color of effluent urine was graded on a four-point scale (1 = clear to 4 = red). RESULTS: The mean target calix width was 13.5 +/- 9.2 mm in the robotic group and 12.2 +/- 4.5 mm in the manual group (P = 0.57). When comparing PAKY-RCM with standard manual techniques, the mean number of attempts was 2.2 +/- 1.6 v 3.2 +/- 2.5 (P = 0.14), time to access was 10.4 +/- 6.5 minutes v 15.1 +/- 8.8 minutes (P = 0.06), estimated blood loss score was 1.3 +/- 0.49 v 1.7 +/- 0.66 (P = 0.14), and color of effluent urine following access was 2.0 +/- 0.90 v 2.1 +/- 0.7 (P = 0.82). The PAKY-RCM was successful in obtaining access in 87% (20 of 23) of cases. The other three patients (13%) required conversion to manual techniques. There were no major intraoperative complications in either group. CONCLUSIONS: Robotic PAKY is a feasible, safe, and efficacious method of obtaining renal access for nephrolithotomy. The number of attempts and time to access were comparable to those of standard manual percutaneous access techniques. These findings provide the groundwork for the development of a completely automated robot-assisted percutaneous renal access device.

Blood Loss, Surgical↗

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↗

Robotically driven interventions: a method of using CT fluoroscopy without radiation exposure to the physician.

Radiation exposure to physicians' hands during interventional procedures with computed tomography (CT) fluoroscopic guidance may be high. A robot was developed that could hold, orient, and advance a needle, with CT fluoroscopic guidance. This robot could be either computer or joystick controlled. Twenty-three robotically guided percutaneous interventions were performed without complication. Physician radiation exposure was negligible during the CT fluoroscopy-guided procedures.

Aged↗