Gerhard J. Fuchs

Laparoscopic vesicoureteroplasty in children: Initial case reports

OBJECTIVE To determine the feasibility of performing laparoscopic vesicoureteroplasty in children. METHODS Two pediatric patients, a two-year-old boy and a five-year-old girl, underwent laparoscopic vesicoureteroplasty for vesicoureteral reflux. Operating time was two hours fifteen minutes and three hours fifteen minutes, respectively. RESULTS The reflux was successfully corrected without morbidity, and they required only short hospitalization (23 hours) and exhibited decreased peri- and post-operative pain as well as improved cosmesis. CONCLUSIONS These cases represent the first implementation of this technique in humans. We stress that this is a preliminary report and suggest that this technique deserves further study.

Laparoscopic renal surgery in children.

A total of 17 laparoscopic renal procedures was performed in children, including nephrectomy (10), nephroureterectomy (4), partial nephrectomy (2) and giant renal cyst excision (1). Patient age ranged from 4 months to 11 years (average age 34 months). The average operating time was 2 hours and 15 minutes, ranging from 1 hour 50 minutes to 2 hours 45 minutes. The usual period of hospitalization was 23 hours, with the longest being 36 hours for 2 patients. No complications ensued. Despite the decreased working space in children, laparoscopic renal surgery offers compelling advantages, including short hospitalization, less perioperative and postoperative pain, improved cosmesis, earlier return to normal unrestricted activities and early return to work for the parents. Methods to accomplish renal laparoscopic surgery safely in children are detailed.

Treatment of ureteral calculi by extracorporeal shock-wave lithotripsy UCLA experience

One hundred sixteen patients underwent extracorporeal shock-wave lithotripsy (ESWL) for ureteral stones. In 108 patients, the stones were manipulated pre-ESWL whereas 8 patients underwent ESWL without prior stone manipulation. Ureteral lubrication using a 2% Xylocaine jelly solution greatly facilitated the retrograde advancement of the calculus or the passage of ureteral catheters alongside the stone. ESWL disintegrated all but 4 stones for an overall success rate of 96.6 per cent. It is considered that the combination of retrograde ureteral stone repositioning and ESWL is a highly successful alternative in the management of ureteral calculi.

Transurethral electrovaporization and vapour-resection of the prostate: an appraisal of possible electrosurgical alternatives to regular loop resection.

Within the past decade, several alternatives to loop resection have been introduced into urological practice that have sought to deliver either topical or interstitial heat to obstructive prostatic tissue. The tissue effects of heat are governed by the maximum temperature achieved, the total duration for which the temperature is sustained and the temperature rise time (the rate of increase to the maximum temperature). Tissue is coagulated when the temperature rise is slow and the thermal dose is low. In contrast, a rapid temperature rise to >100uC causes a loss of intracellular water as it boils away. Under these conditions, the power density of the applied energy governs whether cells are desiccated, carbonized or vaporized. A low power density results in cell death by desiccation and carbonization, with delayed sloughing, while a high power density vaporizes cells, producing an instant tissue defect. Transurethral electrovaporization (TUEVAP) and vapour-resection (TUEVRP) of the prostate are new treatments developed through modi®cations of conventional electrosurgical tissue desiccation, using innovative electrode design. They offer the prospect of reduced bleeding and lower morbidity from ̄uid absorption in patients with bothersome LUTS associated with BPH. In clinical practice, effective prostatic electrovaporization in ̄uid depends on various factors, the most important being the active electrode con®guration, the power output characteristics of the radiofrequency (RF) generator and the way in which electrical energy is applied to the tissue by the operator.

Calcification of Ureteral Stent Treated by extracorporeal Shock Wave Lithotripsy

A patient with stones presented with large calcifications of the J ends of a Double-J stent that had been placed in the ureter for an obstructing ureteral stone 1 month previously. The J end located in the renal pelvis was treated with extracorporeal shock wave lithotripsy and the calcification was disintegrated completely. This noninvasive procedure appears to be the method of choice in the treatment of such complications.

Kidney stone formed around refluxedsurgical staple and removed by transureteral endoscopic manipulation

We present a case of a kidney stone that developed around a surgical staple which refluxed up to the kidney following a Bricker urinary diversion and bilateral ureteroileal anastomosis. A GIA stapler had been utilized to construct the ileal conduit. The stone was retrieved by means of flexible ureterorenoscopy through the ileal conduit. To our knowledge, this is the first report of such a complication following construction of an ileal conduit with a stapling device.

Quantitative assessment of variables that influence soft-tissue electrovaporization in a fluid environment☆

OBJECTIVES To evaluate the process of soft-tissue electrovaporization and to study variables that affect tissue clearance rates in a laboratory setting, in order to identify parameters that can optimize transurethral electrovaporization of the prostate. METHODS Fresh bovine skeletal muscle, equivalent in impedance and surface properties to the human prostate, was submerged in 3.3% sorbitol solution and electrovaporized with a grooved monopolar electrode attached to the weighted arm of a linear actuator. The effects of excursion rate, applied mechanical load, power setting, electrode configuration, and generator performance on the volume of tissue removed, were assessed. RESULTS Tissue removal increased significantly when electrode excursion rate was slowed from 25 to 15 mm/s (P < 0.05) and then to 10 mm/s (P < 0.05); when the load was increased from 20 to 50 g (P < 0.005); and when dial power was increased from 120 to 150 W (P < 0.01). Tissue removal was generator dependent. There was no significant difference between the Force 40 and the Force 2 (P > 0.4), but a new computer-controlled constant power output generator (Force FX) did significantly improve tissue vaporization at an equivalent power setting (P < 0.005 and P < 0.01, respectively). Tissue removal was also dependent upon electrode configuration, with the VaporTrode-Grooved Bar removing significantly more tissue than either an ungrooved roller bar of equivalent size or 2-mm smooth roller ball, respectively, both after a single pass (P < 0.001 and P < 0.05) and after five repeated passes (P < 0.05 and P < 0.005). The histologic depth of tissue thermal effect was less than 1 mm, but it was 38% greater for the VaporTrode-Grooved Bar (0.68 mm) than for the standard cutting loop (0.5 mm, P < 0.01). CONCLUSIONS Using a novel method to quantify tissue removal, we have demonstrated that electrode configuration, excursion rate, applied load, power setting, and generator performance are interdependent factors that influence the efficacy of the electrovaporization process in a fluid environment.

A pilot study of energy utilization patterns during different transurethral electrosurgical treatments of the prostate

OBJECTIVES During a prospective randomized study of prostatic and periprostatic heating during transurethral electrosurgical treatment, energy utilization was studied with respect to electrode configuration and prostate size. METHODS Patients were stratified for gland volume (transrectal ultrasound [TRUS] 50 cc or less and more than 50 cc) and randomized to treatment either with loop resection (transurethral resection of the prostate [TURP]) or electrovaporization (transurethral electrovaporization [TUEVAP]. VaporTrode-Grooved Bar, CIRCON ACMI). Power was provided by a radiofrequency unit (Force FX, Valleylab) initially set at 150 W. A passive feed-through system was connected to the patient circuit to record current and voltage at 10 Hz during each activation of the cut mode in real time. RESULTS Patients (6 per group) were well matched for prostate volume (P < 0.57) and operating time (P < 0.33). Power settings were also similar (120 to 190 W). Both total energy utilization (P < 0.025) and energy used per minute of treatment (P < 0.004) were greater for TUEVAP than for TURP. The higher energy deposition per unit time for TUEVAP was not associated with undesirable periprostatic heating. For TURP, more energy was used per unit time for each gram resected in small prostates than in larger glands. Comparing energy consumption per minute per cubic centimeter of prostate, we found a 2:1 ratio between TUEVAP and TURP in large prostates, which increased to 3.4:1 (P < 0.049) in small glands. CONCLUSIONS For the same panel power settings, more energy is deposited at the tissue interface during TUEVAP than during TURP. This extra energy provides better surface hemostasis without undesirable deep heating and can be explained by the larger contact surface and contact time (slower speed of excursion) of the VaporTrode than a regular loop. The novel observation that more energy is required for small prostates during both treatments suggests that these glands have different electrical properties and higher tissue impedance than larger glands.

A SIMPLIFIED METHOD OF URETERAL STENT REMOVAL USING WATERLESS RIGID URETHROSCOPY

Removal of an indwelling ureteral stent can be problematic secondary to discomfort of outpatient cystoscopy, especially if the stent has migrated proximally up the ureter. Also, while the use of stent tethers can diminish this problem, there can be problems if the string is left protruding beyond the meatus and secured to the penis, with penile erection or activity resulting in dislodgement of the stent beyond the urinary sphincter.’ Pain and incontinence often result. While flexible instrumentation has facilitated this process, these endoscopes may not always be available due to cost, malfunction or concurrent use. An additional problem is the exposure of health care personnel to urine and to the irrigation fluid that is used during cystourethroscopy. Special procedures are required to protect the patient and health care personnel from contamination, and the use of a special procedure room with adequate drainage on the table and floor. To avoid these problems, we have devised a simple technique that allows for easy removal of a ureteral stent in the male patient. This technique reduces the use of patient charge items, since air is used to distend the urethra rather than a sterile salt solution, and results in decreased costs for the procedure, as well as decreased risk of contamination to the patient and physician. TECHNIQUE The stent used should have a retrieval string (tether) attached distally but if not the string can be tied on using a suture passed through a distal drainage hole. After the stent 1s placed up the ureter in the standard fashion, the cystoscope is removed, leaving the string dangling out of the penile meatus. The position of the lower curl may be adjusted under endoscopic and fluoroscopic guidance to ensure that the stent is not being dislodged. Mild tension is placed on the string while the penis is telescoped backwards, allowing for the tethering string that lies within the penile urethra to be exposed. Excess string is then cut, thus, leaving no string Protruding from the external meatus. Subsequently, for stent removal or exchange, the string can be grasped with the patient under local anesthetic via rigid urethroscopy. The Technique for ureteral stent removal via waterless, rigid string is usually encountered within the distal or bulbar urethra, thus, avoiding the discomfort that is associated with Passing the cystoscope through the urinary sphincter into the urethroscopy.

Laparoscopic approaches to transitional cell carcinomas of the upper urinary tract.

Traditionally transitional cell tumors of the upper urinary tract are treated by nephroureterectomy. In circumstances where low functional renal reserve necessitates renal parenchymal preservation, endoscopic or percutaneous treatment may be an option for low grade and stage lesions. In this article, the role of laparoscopic surgery as an alternative modality to open surgery is discussed. Techniques of laparoscopic nephroureterctomy are described and different approaches (transperitoneal, retroperitoneal, and gasless hand-assisted) are contrasted. The limitations imposed on laparoscopic treatment by the requirement of adherence to oncological principles of tumor containment and excision of the intramural ureter, are outlined. Laparoscopic nephroureterectomy, although technically demanding, has been shown to be a feasible procedure. Benefits of the laparoscopic approach include shortened hospital stay and early return to daily activities. It is unclear at this time whether these immediate advantages over open surgery will yield comparatively efficacious long term outcomes.