ABSTRACTS -Thirteenth Annual Meeting

Saturday, May 30, 1998
San Diego, California


Robotic For Precise Percutaneous Needle Insertion

Dan Stoianovici Ph.D. Jeffrey A. Cadeddu, M.D. , Louis L. Whitcomb, Ph.D.
Russell H. Taylor, Ph.D. . Louis R. Kavoussi M.D.
Johns Hopkins University, The James Buchanan Brady Urological Institute,
Whiting School of Engineering


TWe present a novel robotic system for precise needle insertion under radiological guidance. The system was developed to facilitate percutaneous renal access for surgical interventions and delivery of therapy. The robot has an extremely low profile making it compatible with portable X-ray units (for OR environments) and CT scanners. Using this system the urologist defines the skin insertion site, prescribes the anatomical target using radiological data, controls and confirms the needle orientation, and finally commands needle insertion. The system is comprised of a passive mechanical arm mounted on the OR table, a novel RCM (Remote Center of Motion) robot and a radiolucent needle injector (PAKY). The overall system exhibits three motorized degrees of freedom: one translation accounting for needle insertion and two rotations allowing needle orientation in imager space. These three degrees of freedom are sufficient for accessing any anatomical target while priory setting the skin insertion site. The system offers an unquestionable improvement of needle placement occuracy and procedure time as compared to the classic manual procedure. In addition, the system reduces the radiation exposure to patient and urologist. The reduced number of degrees of freedom of the robot insures patient safety.




An Automated Comprehensive Videourodynamic Report and Test System of Improved Accuracy Incorporating Mathematical Analysis of Multimodal Information

Edward F. Wahl, Ph.D, P.E., Bernard M. Churchill, M.D., F.R.C.S. (C) and Steven Lerman, M. D., Department of Urology, UCLA School of Medicine


A test system generating an integrated comprehensive report combining patient characteristics, cystometrogram and imaging data, known urological information and medical criteria with improved accuracy has been developed and used on 120 patients to date. Patient characteristics of age, height, weight and sex are combined mathematically with urologic knowledge/data bank to produce patient specific background templates which display minimal and mean bladder volumes, infusion rate based on maximum physiologic diuresis and pressure whether safe, questionable, or dangerous. Color is used to add a third dimension to a planer plot. The CMG data collected using specially designed, highly accurate equipment uses averaging and unique filters to remove electronic noise and patient and test artifacts such as coughing. This results in specialized curves each indicating different patient conditions such as compliance, urologic instabilities, and leak point pressures in a more quantifiable manner than heretofore available. Several case examples are reported to demonstrate this. Spot images timed by fluoroscopy and real time system display are delivered as digitized images to the computer memory. The above are analyzed to produce the comprehensive real time monitor and hardcopy reports without operator intervention. The theory, methodology, and mathematics are summarized.




Transcutaneous Neurostimulation and Bladder Filling Activity

Ian K. Walsh, Robin Johnson, Patrick F. Keane and Gordon WG Loughridge,
Department of Urology, Level 3, Belfast City Hospital, Belfast, Northern Ireland.



Modulation of third sacral nerve (S3) activity is effective for irritative voiding dysfunction, but requires the invasive neurostimulator implantation. We studied the effect of transcutaneous S3 neurostimulation on bladder activity during filling. 32 patients with irritative voiding dysfunction (sensory urgency or detrusor instability) underwent filling cystometry at 50ml/min. In the study group (n=16), transcutaneous neurostimulation was then applied to both S3 dermatomes. Current (10mA) was set at 10Hz frequency, 200ms pulse width in continuous mode at maximum tolerable level. Neurostimulation continued throughout a second filling cystometry. The control group (n= 16) underwent second fill without neurostimulation. Bladder volume (ml) and cletrusor pressure (cmH2O) values for second fill cystometry (mean+/-standard error; statistical analysis by Mann-Whitney U nonparametric testing):

 
CYSTOMETRY CONTROL NEUROSTIMULATION p value
First Desire To Void 136+/-2.9 176.9 +/- 2.6 0.009
Pressure At First Desire To Void 10.1 +/-0.4 5.1+/-0.2 0.01
Maximum capacity 307.5 +/- 5.9 461.6+/- 5.4 0.008
End Fill Pressure 40.1+/-2.0 24.2+/-0.6 0.009

Transcutaneous S3 stimulation significantly improves bladder filling activity in patients with irritative voiding dysfunction. This non-invasive, ambulatory treatment may be effective for such patients.



Yim Needle: Confirming Percutaneous Access Through Urinary Impedance

Dan Stoianovici Ph.D. 1,2 . Mohamad E. Allaf B.S., Stephen V. Jackman M.D.', Louis R. Kavoussi M.D., Johns Hopkins University, The James Buchanan Brady Urological Institute, Whiting School of Engineering

Introduction: Image guided percutaneous renal access is required for various minimally invasive urologic operations. Common radiological techniques offer limited means to assess whether successful access was achieved and the depth of needle insertion often relies upon the surgeon's experience. Specifically, in the process of needle insertion the surgeon may overshoot the target without observing that the needle passed through the urinary tract. To overcome this problem we developed a sensor (YIM) to detect urine at the needle tip, hence confirming needle insertion into the urinary tract.
Methods: YIM uses a modified trocar needle allowing the measurement of electrical impedance at its tip. A battery powered purpose built electronic circuit measures this impedance using a low voltage, high frequency oscillator. The circuit triggers if and only if the tip of the needle is immersed into urine (window-comparator on impedance). Ex-vivo experiments were performed using porcine kidneys filled with urine under pressure (50 cm H20) at 370C. Renal access was determined classically (urine flow through the needle) as well as electronically and the results were compared.
Results: For 24 trials the success rate was 91.7% with one false positive and one false negative. The errors were related to technically correctable factors encountered early in the study.
Conclusion: The YIM sensor is accurate and easily provides a reliable and quick confirmation of needle access into the urinary collecting system.



Bladder Mucosa Ablation by Diode Laser

Fumio Nakajima, Shigeki Tokonabe, Tomohiko Asano, Masamichi Hayakawa, Hiroshi Nakamura, Takuya Hayashi, Tsunenori Arai, and Makoto Kikuchi Department of Urology, National Defense Medical College


This study was performed to evaluate the ability of diode laser to ablate bladder pathology and its enhancement by submucosal indocyanine green (ICG) injection. The laser source was Diomed 25 (Diomed Company, UK). The applied power was 5 W (non-contact mode). Excised swine bladder and anesthetized canine bladder were utilized to examine the effect in non-blood circulating and blood circulating condition, respectively, To assess the enhancement effect of ICG, normal saline or ICG solution were injected submucosally immediately before irradiation. The subadventitial temperature was also measured. In non-blood circulating condition, while the laser only minimally coagulated mucosal surface in 180 seconds without ICG pretreatment, ablation was obvious within 10 seconds and the whole mucosal layer was vaporized in 60 seconds with ICG pretreatment. In blood circulating condition, although ICG pretreatment always accelerated ablation, the control bladder was also vaporized probably because of laser absorption by blood stream. Moreover, the subadventitial temperature increase following laser irradiation was suppressed by ICG treatment, suggesting that the laser was absorbed by ICG. These results suggest that diode laser is capable of ablating mucosal pathology of the bladder, and ICG injection facilitates ablation and limit the thermal damage up to the ICG layer.




Bladder Neck Suspension Using Bone Anchors for the
Treatment of Female Stress Incontinence

Mordechay Beyar, Boaz Moskovitz, Elias Issaq, Alexander Condrea, Alexander Kastin, Sarel Halachimi, Joseph Burbura, Shahar Madjar and Ofer Nativ.
Bnai Zion Medical Center, Haifa, Israel


A new technique and related devices for the treatment of female urinary stress incontinence were developed and tested. It involves soft tissue to bone fixation by means of miniature bone anchors and a bone anchor driver. The novel bone anchors are made of a shape-memory nickel titanium alloy (Nitinol) attached to two sutures. It has a sharp conical tip enabling it to easily penetrate the vaginal mucosa and pubic bone without requiring vaginal incisions or bone drilling. Two holes in the anchor's tail are used for threading sutures. Inserted in a straight configuration, the shape memory anchors transform to their original C shape when inserted into the bone medulla and heated to body temperature. This assures excellent anchor fixation to the bone. With the patients in the lithotomy position, the bone anchor driver is introduced into the vagina and pulled towards the posterior surface of the pubic bone. Pressing a button releases the energy stored in the loaded spring inside the driver and drives the bone anchor through the cortex of the pubic bone. Two anchors are positioned lateral to each side of the urethra. Each ipsilateral pairs of sutures are tied together resulting in fixation of the periurethral tissue to the posterior surface of the pubis. The procedure has minimal morbidity and a short learning curve. This procedure was successfully performed in 300 patients world wide.



Teleradiology In Urology: A Comparison of Bandwidth

Mohamad Allaf, Benjamin R. Lee, M.D., Ron Khazan, M.D.,
Stephen Jackman, M.D., Alan W Partin, M.D., Ph.D., and Louis R. Kavoussi, M.D.



There is increasing interest in developing teleradiology systems because of their potential to provide rapid, accurate, and cost effective diagnostic radiographs to off-site physicians. Radiographic image size may average over 10 megabytes of information per film. A limiting factor in clinical application of teleradiology may be the time needed to transmit large files over conventional data lines. To address this issue, a comparison of bandwidth was performed using IVP images over a 28.8 Kb/sec modem, Ethernet network system (~100 kb/sec), ISDN (128 kb/sec) line, and a cable modem (45 Mb/sec). Variables measured included weekday vs. weekend, transfer time length, loss of resolution with compression 20:1, and the effect of the amount of RAM (random access memory) on file transfer. The increased amount of bandwidth available at lower cost may allow transfer of images in a clinically useful timeframe.




Laparoscopic Visual Field: Voice Versus Foot Pedal Interfaces for Control of the AESOP Robot

From the Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, MD. Mohamad E. Allaf, Peter G. Schulam, Stephen V. Jackman, Jeffrey A. Cadeddu, Roland N. Chen, Robert G. Moore and Louis R. Kavoussi

Introduction: in an efort to gain direct control over the laparoscopic visual field, robots are being used to hold the laparoscope. The foot pedal is the current standard controller but has limitations which led to the development of voice control as a more transparent interface. We compared the speed, accuracy, learning curves, durability of learning at two weeks and operator-interface failures of these two interfaces. Methods: A purpose-built robotic laparoscopic camera holder (AESOP, Computer Motion, Goleta CA) was used in a series of set maneuvers with each interface. These were repeated 2 weeks later. Time to complete maneuvers, "pass points," and operator-interface failures were recorded. Results: Foot control was significantly faster and had less operator-interface failures. Voice control was significantly more accurate as measured by "pass points". The foot control learning curve reached a plateau at the third trial while the voice control did not fully plateau. Durability of learning favored the foot control but was not significant.

 

Foot Pedal
Voice
Time for trial completion on day 1 439* sec 9713* sec.
Operator-interface failures per trial 1.40.6 4.81.2*
"Pass points" per trial 6.0+-3.4* 6.83.4*
Durability (% improvement retained at 2 weeks) 82.4% 54.4%

*p<0.05
Conclusion: Currently, the voice control is more accurate and has the advantage of not requiring the surgeon to look away from the operative field. However, it is slower and requires more attention as an interface. As voice recognition software continues to advance, speed and transparency should improve.



Applications of Automated Urinary Sediment Analyzer
for Evaluation of Hematurla


*Shinji Hirakawa , lkuo M ikagawa , Masakazu Fukuda and Tokuhiro Okada
Department of Urology, Tottori University School of Medicine, Yonago,
Japan Toa Medical Electronics Co. Ltd., Kobe, Japan



A newly developed automated urinary sediment analyser (LIF- 100) has been recently employed in our facilities to evaluate patients with hematuria. This analyser uses flowcytometric technology to differentiate components in the urine without centrifugation and demonstrates the results on a display within 72 seconds. The UF-100 can also analyse automatically the morphological profiles of urinary erythrocytes (dysmorphic, isomorphic and mixed). Selective RBC patterns can indicate the origin of urinary red cells (glomerular or non-glomerular origin). In this study, urine specimens from 75 cases with hematuria were analysed by UF-100 and by the real time confocal laser microscope (RCLM) in order to evaluate the morphological patterns of erythrocytes in the urine. The sensitivity, specificity and accuracy for glomerular disease by the UF- 100 were 84.8%, 71.4% and 77.3%, whereas, those for non-glomerular disease were 71.4%,84.8% and 77.3%. On the other hand, the sensitivity, specificity and accuracy for glomerular disease by the RCLM were 72.7%, 95.2% and 85.3%, whereas, those for non-glomerular disease were 73.87o, 90.9% and 81.37o. The current results suggest that the UF- 100 represents an easy and rapid mode for the diagnosis of the origin of urinary erythrocytes.




Development and Clinical Evaluation of Flexible
Ureteroscopes and Accessories


Robert U. Bregman, M.D. and Arthur L. Wollman, M.D., Ph.D., San Diego, CA.


We have been working on this project for 18 years with optical scientists and engineers. Ten prototype and production instruments evolved over the past 15 years in 7.0, 9.0, 10.0, and 11.0 French sizes with.020" to.052"operating channels. 1.4 to 4.0 French diameter surgical accessories have been developed and used with these instruments, as well as rigid ureteroscopes.




Home Bladder Pressure Monitoring: An Update

Margot S. Damaser, Ph.D,
Rehabilitation Research & Development Center, Hines VA Hospital


We have developed a system for measurement of bladder pressures at home by individuals, such as those with spinal cord injury (SCI) or spina bifida (SB) who, use clean intermittent catheterization to empty the bladder. This system provides an easy and inexpensive method for these patients to frequently monitor bladder function. It could supplement urodynamic recordings to enable early identification of high bladder pressures that, if endured chronically, could lead to kidney damage. Over the post two years, we have used an analog pressures gouge to obtain home recordings in 5 SCI and 11 SB patients. We have developed a reliable method for estimating abdominal pressures without a rectal catheter. We have also developed a new digital device and have obtained FDA market approval for home use. In this talk, progress so far and plans for the future will be summarized.




The Usefulness of Suction Effusion Fluid as a Sample for Blood Biochemistry

Fumio Nakajima, Tomohiko Asano, Masamichi Hayakawa, Hiroshi Nakamura
Department of Urology, National Defense Medical College, Tokorozawa, Japan



We have evaluated a new technique to obtain biological sample fluid by applying negative pressure to the skin surface (percutaneous suction method) and determined the usefulness of the fluid as a sample for blood biochemistry. Female mongrel dogs were utilized to evaluate the procedure under general anesthesia. The procedure was started by removing the horny substance covering the skin by stripping. The appropriate intraluminal pressure was 300mgHg and the effusion fluid was obtained at a rate of 0.6 - min/cm2 . The blood biochemistry test of the effusion fluid revealed that molecules of smaller weight as creatinine (Cr) and urea (BUN) showed concentrations very close to those in plasma whereas those of larger weight as proteins and lipids showed a large discrepancy. The six-hour continuous studies demonstrated Cr and BUN levels of the fluid consistent with the plasma and a continuous effusion rate. In uremia models, Cr. and BUN levels in the effusion fluid was close to those of plasma in a wide range (Cr: 0.8 - 15.5 mg/dI, BUN: 10.0 - 295 mg/dI) and showed extremely high correlation (r=).985 and 0.982 respectively). Skin biopsy revealed that the invasiveness of the suction was small and regeneration of the horny substance had started at in a week following the procedure. Our results suggest that the effusion fluid is a reliable sample for plasma Cr and Bun levels, and because of its lower levels of proteins and lipids, it might be a good sample for biochemical measurement using biosensors.




Prediction of Superficial Bladder Cancer
Chemoresponse Using the Comet Assay


Ian K. Walsh, James JA McAteer, Stephanie R. McKeown,
Valerie J. McKelvey-Martin and Robin S. Johnston,
Department of Urology, Belfast City Hospital, Northern Ireland




Objectives: To quantify and predict individual bladder tumor chemoresponse to intravesical (IVCT) by single gel electrophoresis (Comet) assay.


Methodology: Cell suspensions of forty freshly resected superficial bladder tumors were exposed to a panel of standard IVCT agents (doxorubicin, epiubicin, mitomycin and thiotepa). The cells were embedded in agarose, cell membranes were lysed and the nucleoids subjected to alkaline electrophoresis. The DNA was stained with ethidium bromide and nuclear damage was measured by image analysis.


Results: A dose-response curve was derived for each agent using eight tumors. DNA repair kinetics were examined in twelve tumors. When repair occurred, it was complete by 120 minutes. Each of twenty tumors demonstrated a differential, unique response to the panel of agents. 70% of tumors responded to at least one agent. Mitomycin caused the greatest DNA damage in ten (50%) of tumors., thiotepa caused the greatest damage in 307o, doxorubicin in 10% and epirubicin in 10%. These results were statistically significant (MannWhitney U test p<0.01). Correlation with clinical response was 87%.


Conclusion: The Comet assay is an accurate ex vivo method for quantifying the chemoresponse of individual bladder tumors to different agents. The highest in vitro and in vivo chemoresponse was with mitomycin. The comet assay may indicate the most effective agent for managing each individual patient's bladder tumor.




Intraureteral Ultrasound System

Toshikatsu Tanahashi, M.D., Ph.D.,
Department of Urology, Tohoku Kohsai Hospital, Sendai, Japan


The authors have developed a new ultrasound diagnostic system, which visualizes cross sections of the ureter. Several types of scanning method are used for intraluminal examination for cardiac or vascular diseases. We employed a mechanical rotating type probe. The probe is composed of two main parts, e.g. and inner and an outer part. The inner part of the probe is composed of a flexible shaft and an oscillating disk mounted at the very tip of the shaft. The oscillating disk has a flat surface and is a square shape, I mm in size. The oscillating frequency of the disk is 20 MHz. The oscillating disk rotates for a radial scanning; the rotating speed of the disk is 6 to 10 times per second. The outer part is a tube like sheath made of flexible polymer, only 2mm in diameter. The inner part of the probe is completely covered by the sheath. Only the inner part rotates for scanning, so the scanning procedure is safe for patients both mechanically and electrically. The intraureteral probe is inserted into the ureter, using just the manner with retrograde catheterivation into the ureter. The tomograms of the ureter are taken continuously, pushing up the pre from the distal end of the ureter up to renal pelvis and calyces. The tomograms of the ureter are taken again continuously, pulling down the probe from calyx down to the distal end of the ureter. This newly developed intraureteral ultrasonography will give us new information concerning details of cross-section of the urinary system. This method is easy to perform for the urologists, and safe for the patients.




A Novel Method of Surgical Instruction: International Telementoring

Benjamin R. Lee, Jay T. Bishoff , Gunter Janetschek, Pichai Bunyaratavep, Wichcan Kamolpronwijitt Jeffrey Cadeddul, Supoj RatchanW and Louis Kavoussi, James Buchanan Brady Urological Institute, Johns Hopkins Hospital, Baltimore, MD, Department of Urology, Chulalongkom Hospital, Bangkok, Thailand, Department of Urology, University of Innsbruck, Austria, Bangkok General Hospital, Lerdsin General Hospital, Bangkok, Thailand.


Introduction: Telemedicine is the use of communication technologies to deliver health care. Telesurgical telementoriing represents an advanced from of telemedicine, whereby an experienced surgeon can guide and teach practicing surgeons new operative techniques utilizing current video technology, medical robots and high bandwidth telecommunications. Telesurgical laparoscopic telementoriing has successfully been implemented between the Johns Hopkins Bayview Medical Center and the Johns Hopkins Hospital in 27 prior operations. In this previously reported series, telerobotic mentoring was achieved between two institutions 3.5 miles away. We report our experience in performing three international surgical telementoring operations.


Purpose: To determine the clinical utility of international surgical telementoring during laparoscopic surgical procedures.


Method: A laparoscopic adrenalectomy was telementored between Innsbruck, Austria (5,083 miles) and Baltimore. As well, a laparoscopic varicocelectomy and laparoscopic nephrectomy was telemonitored between Bangkok and Baltimore (10,880) miles) both over three ISDN lines (384 kbps).


Results: All procedures were successfully accomplished with an uneventful postoperative course. Remote functions of telestration AESOP (Computer Motion, Inc., Goleta, CA) robot control to manipulate the laparoscope, and electrocautery activation were achieved. Time delay of image transmission was approximately one second.


Conclusion: International telementoring is a viable method that can potentially enhance surgeon education, increase patient access to experienced surgeons and decrease the likelihood of complications due to inexperience with new techniques.




Role of Serum P.S.A. in the Diagnosis of Prostate Cancer

Muhammad Choudhury, M.D.,
Department of Urology, New York Medical College, Valhalla, NY


Routine utilization of serum P.S.A. for early detection and monitoring of men with prostate cancer has resulted in dramatic changes in the day-to-day clinical practice of urology with respect to prostatic diseases. Over the past several years major changes in the use of Prostate Specific Antigen (P.S.A.) have occurred. These changes include the use of age-specific P.S.A. range, P.S.A. density, P.S.A. velocity and most recently use of free P.S.A. in the early detection of prostate cancer. This lecture will present the New York Medical College experience in the use of P.S.A. involving over 400 patients over an eight year period.




Role of Melatonin in Regulation of
Night Time Urinary Frequency

Shehla Shabnam, M.D., Zafar Khan, M.D., New York, NY


Nocturia in men is caused by many factors, frequently it is associated with benign prostatic hypertrophy (13PH). However in many patients even after prostatectomy the symptoms of nocturia were not relived. It has been our observation that nocturia in these patients is due to nocturnal diuresis. The observation in children with enuresis have shown that the defective regulation of vasopressin diurnal rhythm may be at fault. Recent research has shown that diurnal rhythm may be under control of the pineal gland, melatonin being the chief mediator. Our observations of melatonin will be presented.




The Bioengineering and Ergonomic Mechanisms of
Elevation of P.S.A After Abdominal Exercise


Irving M. Bush, M.D., Center for the Study of GU Diseases, West Dundee, IL


Total P.S.A., levels vary more than is generally reported. It is well know that bacterial prostatic inflammation, B.P.H. and middle lobe hypertrophy will elevate P.S.A. In 1989 we showed that medications such as aspirin, guafenesin, testonolactone and antibiotics will also affect levels of total P.S.A. Since then we have used various antibiotics to ameliorate elevated P.S.A.'s to a relative resting state, in an attempt to reduce the number and morbidity of prostatic biopsies. Forty-two men with elevated P.S.A.'s above 4 (4-16) (method) with and without BPH as determined by rectal, ultrasound or intravenous pyelogram were placed on antibiotics (Cephalosporins or Quinolones) for 4 weeks and then retested. If the total P.S.A. levels dropped, antibiotics were continued till 2 stable levels. If P.S.A. levels dropped, antibiotics were administered. At the end of the study period, 80% of the P.S.A.'s were reduced. If the P.S.A.'s were still elevated or there was a suspicion of P.C.A. on subsequent testing, prostatic biopsies were obtained. In 1983 we pointed out that machine type abdominal exercises, certain weight training sit-ups and crunches increases the incidence of prostate-seminal vesiculitis and epididymitis due to prostatic duct and vasal reflux. This urological mechanical problem was defined by the use of ultrasound and CT scans. Recently, 12 patients being followed on the antibiotic protocol developed a paradoxical P.S.A. rise. On questioning, I 1 /12 had performed vigorous abdominal exercise for one to several hours just before the blood drawn. A P.S.A. check after 3 days of exercise abstinence revealed the P.S.A.'s to be lower or at baseline levels. The biomedical engineering mechanisms behind the phenomena will be explored. Is it due to exercise with a full bladder pushing urine through the weak bladder neck sphincter into already dilated prostatic ducts? Would voiding before abdominal exercise, running, bicycling, etc., alleviate the phenomena? is exer cise hazardous to man's health




© Copyright 2003 | All Rights Reserved | Home