ABSTRACTS -Fifteen Annual Meeting

EXPANSION OF THE RENAL PELVIS FOR RECONSTRUCTION OF UPPER URETERAL DEFECTS

Evangelos N. Liotsikos, Norberto 0. Bernardo, Caner Z . Dinlenc, Mihai Alexinu, Rakesh Kapoor, David Pikhasov Ann E. Anderson, Arthur D. Smith. Albert Einstein College of Medicine, Long Island Jewish Medical Center, Departments of Urology and Pathology New Hyde park, New York.

Seven female pigs were enrolled in our study. The expansion of the renal pelvis was performed by a percutoneously placed Council balloon catheter (Bard. Covington,USA). Daily and progressive injection of saline during the following 4 weeks allowed for an expansion of the renal pelvis with 70-75cc. Open surgery was performed 4 to 6 weeks after the initial intervention resecting the proximal ureter and replacing it with the tubularized spiral flap of the expanded renal pelvis. Two weeks after the latter procedure the animals were euthanazed, and the area of manipulation was resected and sent for pathology evaluation.

All animals reached the desired expansion of the pelvis, and in all cases the created spiral flap was successfully fashioned and anastomosed to the distal ureteral segment bridging the initial defect (mean lenght: 7 cm). Two animals died from sepsis 4 and 6 days after the spiral flap reconstruction. A viable lumen with a patent anastomosis and a functioning pelvocalyceal unit was observed on intravenous urography.

The use of a balloon expander in the renal pelvis is a novel safeand effective technique of producing native tissue for the reconstrucion of ureteral defects and or strictures of the upper ureteral segment.



A MINIATURE TRANSMISSION FOR SURGICAL ROBOTS


Dan Stoianovici Ph.D., Louis Kavoussi M. D.
Johns Hopkins University The James Buchanan Brady Urological Institute,
Whiting School of Engineering


The development of robotic systems for surgical procedures is highy demanding as compared to classic industrial robotic design due to particular features such as safety, sterility, compatibility with imaging devices, size, ergonomics, etc. Among these, the reduced size and precision of the robotic system are critical. Presently there are no commercially available transmissions for actuating revolute joints that satisfy these requirements.

We present the 'ball-worm' transmission, a transmission of rotational motion between two shafts with non intersecting axes using rolling elements. It represents a combination of two mechanical principles: the worm transmission and the ball rolling. The functionality is somewhat similar to a ball-screw mechanism, however it provides a rotational rather than translational output. The geornetry of the classic worm transmission components, the worm and the worm gear, has been modified to render the transmission of motion through a finite number of identical spherical balls that cyclically roll between them. The worm and the gear are no longer in contact, yet, at any instance of time they both contact several balls. The rotation of the worm causes the balls to roll, thus causing the gear to follow the worm rotation, with a given tranmission ratio. The balls are being recycled on a special circulation path enclosed within the worm.

The key feature of the ball-worm is the substitution of the sliding friction with the rolling friction implemented by spherical balls. Several major advantages result from this reduction of friction forces: non-backlash, kinematic precision, high efficiency, increased power transmission capability, and minimal lubrication requirement. Several characteristics of the classic worm transmission still apply, such as the high transmission ratio, the backdrive or non-backdrive configuration. In addition the particular design of the ball recirculation path allows the miniaturization of the transmission assembly. The added characteristics make this transmission suitable for precision miniature mechanisms, such as surgical systems.

Several prototypes have been developed and tested in the URobotics laboratory. Robotic applications of this technology are under development.



DURATION OF EFFICACY OF BIOFEEDBACK EXERCISES AND ELECTRICAL STIMULATION FOR THE GENUINE STRESS INCONTINENCE.


Zafar Khan, and Shehla Shobnam, New York, NY

INTRODUCTION AND OBJECTIVE: We present a study to determine the combine effect of biofeedback exercises and electrical stimulation in-patients with genuine stress incontinence.

METHODS: 100 patients suffering from genuine stress incontinence underwent a biofeedback with Pelvic Floor Exercises and Direct Electrical Stimulation. InCare PRS 8900 equipment with vaginal probe was used. A 45 minutes session twice a week for 6-weeks was carried out. Hence total of 12 sessions was given,

RESULTS: A questionnaire was mailed to all these patients within a year of completion. Patients were asked to categorize the beneficial response at 3, 6, 9, 12 months period. We received response from 38 patients. 9-patients (23.6%) felt that the effect of exercises lasted for 1- 4 months. 3-patients (7.89%) had control of symptoms till 4-8 months, remaining 2 (5.26%) showed positive response for 8-months-1 year. 13 patients (34.21%) remain in good control for more than a year.

CONCLUSION: An assessment of the results is made difficult by the varying methods of the different studies. However, it would appear that in short term at least, 40-70% of the patients showed improvement and 23-44% said they were cured. There are few studies with long-term results. Beyond 1 year the full rate of recovery is between 8.5 and 30% depending on the study, with different selection criteria for patients and interpretation of results, but improvements are noted in 20-50%.



USE OF AN ELECTROSURGICAL SNARE TO PERFORM PARTIAL NEPHRECTOMY: ADVANCES IN DESIGN AND FUNCTION.


William C. Collyer,Jaime Landman, Ephrem O. Olweny, and Ralph V. Clayman,
Department of Urology, Washington University School of Medicine, St. Louis, MO


INTRODUCTION: We describe the development and preliminary data on the application of a novel experimental snare design for partial nephrectomy.

METHODS: A snare was constructed combining high current density arcing for tissue coagulation and vaporization with parenchymal compression for vascular coaptation. Five kidneys in four separate animals underwent laparoscopic mobilization and partial nephrectomy with the snare. No attempt was made to isolate or control the renal vasculature.

RESULTS: In 3 of the 5 kidneys, renal transection was performed over 5 to 10 minutes without blood loss. In the remaining 2 kidneys, renal transection was performed in < 1.5 minutes; there was some minor self-limited bleeding that stopped without the application of any other form of hemostasis. In the two kidneys evaluated, intravenous injection of indigo carmine, revealed no extravasation indicating that the snare had sealed the collecting system.

CONCLUSIONS: laparoscopic partial nephrectomy with the arcing-gap electrosurgical snare is feasible in a porcine model. Initial data suggest that application of the snare alone may produce transection of renal parenchyma with adequate hemostasis and simultaneous closure of the collecting system. Chronic animal studies are underway



AUTOMATED NEEDLE TARGETING FOR ROBOTIC PERCUTANEOUS ACCESS USING PORTABLE FLUOROSCOPY UNITS


Alexandru Patriciu, Dan Stoianovici Ph.D. , Louis Whitcomb, Ph.D., Louis R. Kavoussi M.D. Johns Hopkins University, James Buchanan Brady Urological Institute, Whiting School of Engineering


At previous SUE meetings we presented a robotic system for radiological image guided percutaneous access, the PAKY-RCM. We now augment a specialized image guidance algorithm that facilitates needle targeting through automatic orientation of the RCM robot. Percutaneous needle access is normally performed in the operating room using a portable fluoroscopy unit, the C-Arm. The procedure is extremely challenging due to the lack of volumetric information of the X-ray imager. Three-dimensional information is acquired by using multiple C-Arm views. In the manual procedure, target 'triangulation' is performed by the surgeon while in the presented method it is computerized and followed by automatic needle orientation. The main obstacle in performing C-Arm guided robotic procedures is the unknown orientation of the C-Arm. We addressed this problem by developing an image registration algorithm independent of the imager orientation and positioning, the 'Trajectory Based Registration'.

With this system, the urologist positions the PAKY-RCM robot such that the needle tip is located at the desired skin try point. The C-Arm is oriented to provide unimpeded observation of the target (calyx) and the needle tip. A video capture board is used to acquire the image. While maintaining needle tip location the robot moves the needle on a preset trajectory. A specialized registration algorithm is employed to determine the image-robot orientation by comparing the actual orientation of the needle to its X-ray projection. The surgeon specifies the desired target by pointing it on the computer screen. A similar procedure is then performed for a second C-Arm orientation that is geometrically dissimilar. Based on the data acquired in both views the robot orients the needle so that it extends into the target. The urologist may verify targeting by choosing other C-Arm orientations and controls needle insertion under lateral fluoroscopic observation. The system improves targeting accuracy by providing computerized triangulation and reduces the required surgeon experience for percutaneous procedures. This also reduces the time of the procedure and the radiation exposure. The system is in the final stages of development being successfully tested in the laboratory setting. Clinical experiments and validation will commence in the next future.



ACUTE MORBIDITY REDUCTION USING INTENSITY MODULATED RADIATION THERAPY(IMRT) FOR PROSTATE CARCINOMA.


F Cardel, E. Dectaldo, M. Lennon, E. Mullokandov, G. Gejerman, J. Vitenson,
Departments of Radiation, Oncology and Urology, Hackensack Medical Center, Hackensack, NJ



INTRODUCTION: Three-dimensional conformal radiotherapy (3DCRT) is a technique in which beams of ionizing radiation are individually shaped to conform to the 2 dimensional projection of a target defined from CT or MR] imaging. Despite its name, 3DCRT cannot easily conform to the 3rd dimension of a target volume. Intensity Modulated Radiation Therapy (IMRT) is a revolutionary method of delivering radiation therapy in which a unique multileaf collimator directs pencil thin beams of radiation to a target organ while modulating their intensity. This allows for enhanced conformality in the 3rd dimension delivering a high dose to the target organ while minimizing dose to surrounding tissues. In an attempt to increase delivered dose to the prostate gland while decreasing GI and GU toxicity we have used IMRT in combination with interstitial brachytherapy. We report our experience and compare dose distributions of IMRT verses 3DCRT.

METHODS: Seventy five patients with organ confined prostate cancer were treated with 4500 cGy delivered to the prostate and seminal vesicles followed by a Pd-103 implant. IMRT treatments were generated and delivered using the CORVUS inverse planning system and a MIMic multileaf intensity modulating collimator (NOMOS Corporation; Sewickley, PA). A 3 dimensional treatment planning system was used to generate a corresponding conformal 4 field plan. Prostate, bladder and rectal Dose Volume Histograms were generated and analyzed.

RESULTS: IMRT of the prostate resulted in a 7% higher mean prostate dose while delivering a 9% lower bladder and a 12% lower rectal dose compared with 3DCRT. Prospectively graded RTOG.EORTC acute toxicity were 6% grade 1 GI, 25% grade 1 GU, and 4% grade 2 GU.

CONCLUSION: IMRT can achieve greater conformality allowing for reduced dose to normal tissue and fewer acute side effects. We are presently escalating the delivered prostate dose to 504OcGy.




CIRCUIT MODELING, VALIDATION, AND APPLICATION OF ELECTRICAL IMPEDANCE MEASUREMENTS IN THE RENAL COLLECTING SYSTEM.

George Mitroi, M. D. Don Stoianovici Ph.D. , Alexandru Patriciu ,
William Roberts, M.D., Sumiyo Onda, Louis R. Kovoussi M.D.,
James Buchanan Brady Urological Institute,
Whiting School of Engineering,
University of Medicine and Pharmacy, Craiova, Romania




INTRODUCTION: Percutaneous methods for renal stone removal have become a standard procedure in the urological armamentarium. These procedures are still challenging for the surgeon thus requiring extensive experience. Complications are usually related to the initial needle access making this step one of the most important parts of the procedure. To assist the surgeon in this difficult task we developed and clinically validated a needle sensor for electrical impedance, YIM, that we presented at a previous SUE meeting. We now present an electrical model for impedance measurements performed with the YIM needle in the kidney aimed towards improving the accuracy of measurement. We validate the model in laboratory experiments and assess its application for the confirmation of needle insertion into the collecting system.

METHODS: The YIM needle is a modified trocar needle allowing the measurement of electrical impedance at its tip. For impedance measurements we use a multi-frequency LCR meter (HP 4275) wired to the needle head. The impedance measurement includes resistive, capacitive, and inductive components. The significant component for assessing the nature of the tissue/solution at the needle tip is the resistive component. A model of the electrical system comprising the LCR meter, the YIM needle, and the kidney is required in order to separate the sought resistive component. The model was defined and experimentally verified using standard resistivity solutions. Further experiments were conducted for electrical impedance measurements using urine and porcine kidneys.

RESULTS: Experiments show that the urine presents reduced electrical resistivity on the order of 0.9 n~ 1.4 (m compared to renal tissue that presents higher values of 2.5 n~ 4.6 (m. Several experiments of inserting the needle into porcine kidneys filled with urine at 37(C rendered specific profiles of the resistivity drop while advancing the needle. A sharp decay characterizes the passage of the needle tip into the urine. Moreover, the collecting system tissue exhibits somewhat higher resistivity than the neighboring parenchyma.



The SONY Award Lecture
Intensity Modulated Radiation Therapy (IMRT)
Natural Progression from 3D Conformal Therapy.


G. Gejermen, M.D., and Jack H. Vitenson, M.D. Department of Radiation Oncology,
Department of Urology, Hackensack University Medical Center, Hackensack, NJ


Today's world of urologic oncology is a rapidly changing scene. With the advent of PSA testing, most men now present with early stage disease making them candidates for several different treatment modalities. While radical prostatectomy remains the "gold standard", patients within similar prognostic categories stratified to RP or RT have similar 10-year PSA free survival rates. At the same time, because demographic trends predict greater longevity, many patients no longer opt for watchful waiting and must choose between different definitive options. The evolving scene is made more difficult to interpret as we gain new imaging and radiation technologies as well as neoadjuvant therapies. This is part and parcel of medical advances but it often leaves patients and physicians confused. Radical prostatectomy vs. conventional RT vs. 3D Conformal RT vs. Intensity Modulated RT vs. neutron beam RT are among some of the choices presented to patient and physician alike. These choices do not even take into account the issue of adjuvant androgen deprivation therapy (ADT) and brachytherapy.

In an attempt to clarify some aspects of our evolving therapies, a review of Intensity Modulated Radiation Therapy (IMRT) is presented. IMRT represents fusion technology; a fusion of imaging, compute medicine and medical physics intended to direct curative radiation to a desired target while sparing normal tissues. Our goals should be to understand the benefits of IMRT, learn how to properly use IMRT, design treatment protocols to validate its apparent superiority and learn how best to incorporate IMRT treatment with ADT and brachytherapy.

Dr. Geierman is the Clinical Director of the Department of Radiation Oncology and is also the CoDirector of the Prostate Cancer Institute of New Jersey of the Hackensack University Medical Center. He completed his residency at the Montefiore Medical Center and Weiler Hospital, Albert Einstein College of Medicine in 1995 and continues as a research associate there. His primary research and clinical interest is in finding innovative treatments for prostate cancer.



The Tsi-Gziou Li Memorial Lecture

Optical imaging Study of Human Prostate Tissues.

W. B. Wang, J. Ali, and R. R. Alfano,J. H. Vitenson, and. M. Lombard Institute for Ultrafast Spectroscopy and Lasers, and New York State Center for Advanced Technology for Ultrafast Photonic Materials and Applications,
Department of Physics, The City College of the City University of New York ,Urology and Pathology Departments of Hackensack University Medical Center, NJ


Prostate cancer has a high incidence and mortality rate for men. Current techniques for detection of prostate have limited accuracy. Better methods are needed to develop high resolution and noninvasive techniques to detect early small prostate cancers.

Based on spectral and polarization properties of the light propagated, scattered, absorbed and emitted from turbid media and contrast agents, we have developed spectral polarization imaging methods to enhance the ability to image objects hidden inside turbid media and tissues. A prototype wide-band near infrared (NIR) spectral polarization imaging instrument was built, and has been used for imaging measurements on human prostate tissues at Hackensack University Medical Center (HUMC) under the IRB approval.

In our NIR spectral polarization imaging study of human prostate tissues, the prostate tissues were obtained from four autopsy cases at HUMC, ranging in age from 57 to 70 years, who died of conditions unrelated to the prostate. The prostate tissues were cut into a number of large slices with thickness varied from 1.0 mm to 4.5 mm. Several model samples were made for the imaging measurements with a small piece of foreign object (absorber or dyed prostate tissue) sandwiched by large pieces of prostate tissue layers. The depths of the foreign objects underneath the surface of the host prostate tissues were varied from millimeter to centimeter to obtain the critical depths of different imaging methods.

Different spectral polarization imaging methods, including scattering light polarization difference imaging, scattering light different wavelength imaging, tissue fluorescence different wavelength imaging, and contrast agent fluorescence different wavelength imaging, were performed and compared to obtain the experimental criteria for imaging objects inside prostate tissues. The measured results show that small guest objects with -1 mm diameter hidden inside the host normal prostate tissues at depths of 3.0 mm, 5.0 mm, and 8.5 mm can be imaged and identified using the scattering light imaging, tissue fluorescence imaging, and contrast agent fluorescence imaging methods, respectively. The measured results indicate that the longer wavelength NIR light and emission imaging methods are preferred for detecting deeply hidden objects.

Dr. W.B. Wang received his Ph.D. in Physics from the City University of New York in 1993, and has been working as a member of the research stall of the the Institute of Ultrafast Spectroscopy and Lasers in the City College of New York. His research interest includes tissue optics, optical imaging techniques for medical applications, ultrafasf semiconductor physics, and MOW photovoltaic devices. He has published more than 50 scientific papers in the field of optical imaging and semiconductor physics and devices.

In his presentation, he will introduce the concept of using the spectral and polarization properties of light propagating inside tissues, and present the optical imaging studies on human prostate in-vitro tissues in collaboration with a medical group of Hackensack University Medical Center.






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