Walter Ludwig Strohmaier

Minimally Invasive PCNL in Patients with Renal Pelvic and Calyceal Stones

Stones of the renal pelvis can be treated either by extracorporeal shock wave lithotripsy (SWL) or percutaneous nephrolithotomy (PCNL). As a low–risk procedure with a longer treatment period, SWL often leads to persistent residual stone fragments, whereas conventional PCNL achieves a higher stone–free rate and allows a shorter treatment period albeit with a somewhat higher surgical risk. To reduce the invasiveness of conventional PCNL, the application of a miniaturised instrument for PCNL (MPCNL) was evaluated. For MPCNL a rigid nephroscope with a calibre of 12 F was developed and used in 19 patients. After puncture of the kidney under ultrasound control and single–step dilatation, a 15 F Amplatz sheath was placed. Data on the stone size and location, stone–free rate, blood transfusions, operating time and complications were recorded. In all patients, the part of the kidney afflicted by the stone was successfully punctured. On average, retreatment rate was 0.7. The mean stone size was 2.4 cm2. The average operating time was 99.2 min. In every case, the absence of residual stones was confirmed radiologically and nephroscopically. Hemorrhages requiring a blood transfusion did not occur. A febrile pyelonephritis occurred as a postoperative complication in one patient (= 5.3%). MPCNL represents an alternative to SWL for renal calculi with a size from 1 to 2 cm located in the renal pelvis and calices, especially the lower calix. The advantages are the short treatment time, the high stone–free rate and the accessibility of lower pole stones which are less amenable to SWL. MPCNL is not suitable for large concrements since the limited sheath diameter would increase the operating time. Due to this limitation, MPCNL represents an extension of the indication for conventional PCNL that it can in no way replace.

Comparison of Extracorporeal Shock Wave Lithotripsy and Ureteroscopy in the Treatment of Ureteral Calculi: A Prospective Study

146 patients whose ureteral stones did not pass spontaneously participated in a prospective study on optimal management. Patients were offered two treatment options: extracorporeal shock wave lithotripsy (ESWL) and ureteroscopy (URS). The stone was treated with the technique preferred by the patient. In case of treatment failure after first-line therapy, patients again could decide on how to proceed. Stone analysis could be obtained from 72.6% patients. ESWL was the primary treatment in 66.4% patients. In 2 patients, ESWL was the secondary treatment after failed URS. URS was the first-line therapy in 33.6% patients. In 29 patients URS was done after failed ESWL. For analgesia, sedoanalgesia or spinal anesthesia were used. Analgesia was required in 74.2% ESWL and 100% URS sessions. Following ESWL, 70.1% patients became stone free. In 29.9% ESWL failed. Distal stones had a higher failure rate than proximal or mid-ureteral calculi. Distal stones treated without success were significantly larger than those treated successfully. Failures were switched to URS. Stone analysis could be obtained in 26 patients with failed ESWL: 23/26 consisted of pure whewellite or mixed whewellite stones. Clinically relevant complications were not observed. After URS, 94.9% of the patients became stone free. In distal stones, the stone-free rate was 97.5%. There was only 1 relevant complication: a proximal ureteral lesion requiring surgical repair. Our study demonstrates that URS is a safe and highly effective treatment option for ureteral stones. In patients with distal ureteral stones, it should be offered as a first-line treatment. When whewellite is expected as the stone mineral, URS is the treatment of choice.

Evaluation of the Acute Scrotum by Color-Coded Doppler Ultrasonography

Color-coded Doppler ultrasonography is a combination of real-time sonography and duplex sonography for noninvasive imaging of arterial and venous blood vessels. In 40 patients with acute onset of scrotal pain this diagnostic procedure was correlated with the findings at surgical exploration: 11 had testicular torsion, 4 hydatid torsion, 13 spontaneous detorsion, 2 blunt scrotal trauma and 10 epididymitis. For testicular torsion color-coded Doppler ultrasonography had a sensitivity of 82% and a specificity of 100%, and for epididymitis the sensitivity was 70% and specificity was 88%. Color-coded ultrasonography readily demonstrates testicular perfusion. In cases of incomplete or early torsion some residual perfusion may be detected leading to false-negative results. Despite this fact, color-coded Doppler ultrasonography currently is the most valuable diagnostic modality in the evaluation of the acute scrotum.

Course of Calcium Stone Disease without Treatment. What Can We Expect

Objectives: The knowledge of the natural history (i.e. the course of the disease without metaphylaxis is the base for establishing rational guidelines for metaphylaxis in urolithiasis. Methods: This review is based on a Medline™ Search (1966–1999) and the proceedings of the Bonn–Vienna and European symposia on urolithiasis. Only 31 references were sufficient for the purpose of this review. Results: In idiopathic calcium stone disease, stone frequency without metaphylaxis is 0.10–0.15 stones per patient per year. The average recurrence rate is 30–40%. Recurrence rate increases with age and observation time. Risk for recurrence is highest during the first 4 years after the first stone episode. More than 50% of all recurrent stone formers have only one recurrence during their lives. 10% of recurrent stone formers have more than 3 recurrences. Risk factors for recurrence are: male sex, multiple and lower calyx stones, early onset, familial history, complications after stone removal. Metabolic evaluation is a poor predictor of the risk for recurrence. Conclusions: Renunciation of metaphylaxis is justified in first stone formers with idiopathic calcium oxalate and apatite stones. All patients, however, should be advised to increase their fluid intake.

Local Microwave Hyperthermia of Benign Prostatic Hyperplasia

Recently, hyperthermia has been used for treatment of benign prostatic hyperplasia. The preliminary results reported were promising. However, apart from patients with total urinary retention, objective voiding parameters have not been reported in detail for patients with prostatism. In a phase II study we treated 30 patients with benign prostatic hyperplasia by local microwave hyperthermia (915 MHz.). The prostate was heated transrectally to 42 to 43C, with the treatment consisting of 8 sessions of 60 minutes each given twice a week. To assess the results of treatment several parameters were determined before and 4 weeks after hyperthermia therapy, including transrectal ultrasound of the prostate with volumetry, urinary flow rate and residual volume. Of the patients 28 could be evaluated and only 2 showed a relevant improvement. Neither the voiding parameters nor the size of the prostate could be changed significantly by hyperthermia. The success rate of 7.1% is even lower than the spontaneous temporary regression rate of benign prostatic hyperplasia. Thus, we believe that hyperthermia cannot be regarded as an effective treatment for benign prostatic hyperplasia comparable to transurethral resection.

Protective Effect of Verapamil on Shock Wave Induced Renal Tubular Dysfunction

In a prospective randomized study, the effects of the calcium entry blocker verapamil on shock wave induced tubular impairment were examined. A total of 24 patients with renal pelvis or caliceal stones undergoing anesthesia-free extracorporeal shock wave lithotripsy (ESWL*) without auxiliary measures was randomly assigned to the verapamil group (12) or the control group (12). Four doses of verapamil (80 mg. each) were given orally starting the night before ESWL. Controls received no medication. To assess renal tubular function the urinary excretion of alpha 1-microglobulin, N-acetyl-beta-glucosaminidase and Tamm-Horsfall protein were determined before, immediately, and 12 and 24 hours after ESWL. After ESWL there was an increase in urinary alpha 1-microglobulin and N-acetyl-beta-glucosaminidase, which was significantly higher in the control than in the verapamil group. Tamm-Horsfall protein, a glycoprotein synthesized by the distal tubules, decreased significantly less in the verapamil group compared to the controls. Our results indicate that verapamil exhibits a protective effect on shock wave induced tubular damage. The underlying mechanisms are not elucidated yet, and direct actions on tubular cells and interference with renal hemodynamics are to be discussed.

Laparoscopic adrenalectomy in urological centres – the experience of the German Laparoscopic Working Group

Study Type – Practice patterns (retrospective cohort)

Ex vivo training model for percutaneous renal surgery

Percutaneous endourological procedures require an advanced level of skills. To facilitate training in the proper technique, simulators are helpful. Non-biological models, useful for learning the basic steps, do not represent the clinical situation in an ideal way. Recently, we developed a porcine urinary tract model for ureteroscopy. Proceeding from this experience, we developed a further ex vivo model for training percutaneous endourological procedures. The kidney with the ureter is dissected off of the retroperitoneal organ package of freshly slaughtered pigs. It is embedded in silicon. The renal pelvis can be filled with saline to simulate hydronephrosis, stones can be implanted for percutaneous nephrolithotomy. This ex vivo model allows training of all percutaneous endourological procedures (e.g. percutaneous nephrostomy, percutaneous lithotomy, endopyelotomy). It is an ideal way to train these techniques, being superior to non-biological models in terms of “tissue feeling” for anatomic relations, and the great variety of procedures that can be trained. Nevertheless, it is readily available and inexpensive.

Porcine Urinary Tract as a Training Model for Ureteroscopy

Objectives: Endourological procedures as ureteroscopy require an advanced level of skills. To facilitate the training of the proper technique, simulators are helpful. Nonbiological models, useful to learn the basic steps, do not represent the clinical situation in an ideal way. We therefore looked for a biological but nevertheless easily available model. Methods: The complete urinary tract is dissected off the retroperitoneal organ package of freshly slaughtered pigs. Results: The porcine urinary tract model allows for training all aspects of diagnostic and therapeutic ureteroscopy including lithotripsy and stenting in a way which is almost identical to the clinical situation in humans. Conclusions: The porcine urinary tract model is an ideal ex vivo model. Concerning ‘tissue feeling’ and anatomic relations, it is superior to nonbiological simulators. Nevertheless, it is quite easily available and inexpensive. In training courses, we have used it with great success.

Arterial blood pressure following different types of urinary stone therapy

Objective: Several studies reported increased blood pressure (BP) values following extracorporeal shock wave lithotripsy (ESWL) treatment of renal stones. It is unclear, however, whether this is due to ESWL, since nephrolithiasis itself increases the relative risk of developing hypertension. Therefore we prospectively studied the BPs of stone patients undergoing different types of treatment.Methods: 252 stone patients (63% males, 37% females, median age 44.3, range 11.7–86.4 years) participated. 168 suffered from uretral stones: 50 underwent ESWL; 40 ureteroscopy, and 78 patients passed stones spontaneously (SP). 84 had renal stones: 60 underwent ESWL; 8 percutaneous nephrolithotomy/open surgery, and 16 no treatment. Systolic (SBP) and diastolic (DBP) BP were measured according to Riva–Rocci prior to, immediately after, and 3, 6, 12, 18 and 24 months after stone therapy.Results: Immediately after SP, SBP decreases, whereas after active stone treatment increases (highest after ESWL) in SBP were seen. DBP was unchanged. During the further follow–up, a gradual increase in BP was observed in all groups. At 24 months in all groups, regardless of the stone location and type of treatment, SBP and DBP were significantly higher than the pretreatment levels (p = 0.000). There was no a difference between renal and ureteral stones, or between the ESWL treatment and the other groups.Conclusion: Renal stone disease itself rather than the type of treatment significantly increases SBP and DBP during a follow–up period of 24 months. The underlying mechanisms remain to be elucidated.