Lothar Hertle

Combined Treatment of Branched Calculi by Percutaneous Nephrolithotomy and Extracorporeal Shock Wave Lithotripsy

Eighty-seven patients with branched renal calculi were treated by a combination of percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy. Stone debulking was achieved by percutaneous nephrolithotomy and residual stone fragments were destroyed by shock wave lithotripsy. Of the patients 70 (80 per cent) required 2 to 3 treatments, 12 (14 per cent) required 4 treatments and 5 (6 per cent) required 5 to 6 treatments. Results after 3 months indicated that 58 patients were free of stones, 3 had recurrent stones and 12 had disintegrated stone particles (less than 3 mm.) in the collecting system, while 13 were lost to followup. One patient had undergone nephrectomy. This treatment plan minimized the disadvantages of either technique when used alone and made open operative intervention unnecessary. Procedural and fluoroscopy times were reduced drastically compared to reported data on percutaneous nephrolithotomy only. We believe that more than 90 per cent of all branched calculi can be treated with this combined technique.

Critical Evaluation of Treatment of Staghorn Calculi by Percutaneous Nephrolithotomy and Extracorporeal Shock Wave Lithotripsy

The combined use of percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy in patients with staghorn calculi has become an established treatment regimen. We evaluated the results of 90 staghorn calculi-bearing kidneys treated with such combination therapy after a mean follow-up of approximately 2 years. A total of 69 kidneys (76.7 per cent) became free of stones at some point after treatment. However, due to stone recurrence this number decreased to 55 kidneys (61.1 per cent) at the end of follow-up. Patients who had undergone a previous open operation on the stone-bearing kidney showed less favorable results than the over-all group. When our results were compared to reported data on open surgery or percutaneous nephrolithotomy alone even better results may have been obtained by such treatment modalities. However, our data indicate that percutaneous stone debulking combined with further destruction of residual stone fragments by shock wave lithotripsy certainly is less invasive than an open operation and provides an alternative to percutaneous treatment alone, which can yield comparable results.

Calcium channel blockade in smooth muscle of the human upper urinary tract. I. Effects on depolarization-induced activation.

The effects of the calcium blockers nifedipine, verapamil, D600 and diltiazem on mechanical activity were studied in isolated preparations of the human upper urinary tract. Two types of activity were used: spontaneous phasic-rhythmic activity in calyceal segments and potassium-induced depolarization in ureteral muscle strips. Nifedipine (10(-6) mol./l.), verapamil, D600 and diltiazem (all 10(-5) mol./l.) completely suppressed spontaneous phasic-rhythmic activity. Elevation of extracellular potassium concentration induced contractions concentration-dependently. A log-linear relationship between the extracellular calcium concentration and the 85 mmol./l. potassium-induced activation was demonstrated. Concentration-response relationships of the compounds were found by activating the muscle strips with 85 mmol./l. potassium in the Tyrode solution. This activation model produced stable and reproducible contractures. The compounds antagonized depolarization-induced activations concentration-dependently, nifedipine being the drug with the lowest EC50 value; its relative potency with reference to papaverine was about 8,000 to 1. The order of potency of the other drugs was in the following sequence: D600 greater than verapamil greater than diltiazem. It is concluded that processes in the human upper urinary tract which are triggered by depolarization (action potential or high potassium concentrations) are highly sensitive to calcium channel blockers.

Calcium Channel Blocker Nisoldipine Limits Ischemic Damage in Rat Kidney

The effects of the calcium channel blocker nisoldipine on renal function after 60 min. normothermic ischemia and contralateral nephrectomy were studied in male Wistar rats. Nisoldipine (300 ppm) was given in a standard diet as well as one hour prior to ischemia (10 mg./kg. orally). Survival, serum urea, serum creatinine, urine volume and creatinine clearance were used to test the effectiveness of the drug. Nisoldipine treatment resulted in the survival of all animals (compared to 66.6 per cent in the untreated group) and improved immediate and long term (14 days) renal function. The drug given post ischemia only was not effective, suggesting that nisoldipine must be present in the kidney during ischemia. The beneficial effects of the drug in postischemic acute renal failure may be attributed in part to effects on postischemic renal hemodynamics. Additional direct effects on ischemic renal epithelial cells, presumably by inhibiting transmembrane calcium fluxes, cannot be excluded.

Calcium Channel Blockade in Smooth Muscle of the Human Upper Urinary Tract. II. Effects on Norepinephrine-Induced Activation

The effects of the calcium channel blockers verapamil and nifedipine on norepinephrine-induced activation were studied in different tissues of the human upper urinary tract. In usually inactive ureteral muscle strips, norepinephrine induced predominantly phasic contractions with only minimal effects on resting tension. In contrast, in isolated segments of the renal calyx and pelvis, irrespective of preexisting spontaneous phasic activity, the same agonist effected a long-lasting tonic contraction. These different types of mechanical activity induced by norepinephrine showed different sensitivities to calcium channel blockers, phasic contractions being potently suppressed while the tonic response was little affected by the drugs. This different pattern of response to norepinephrine and the different sensitivity of the responses to calcium channel blockers suggest different and separate coupling mechanisms between the receptors involved and the calcium pools responsible for initiation of contraction. The existence of different calcium pathways activating the contractile proteins in the human upper urinary tract is postulated.

In vitro studies on human primary obstructed megaureters.

We studied isolated muscle strips from the dilated segments of primary obstructed megaureters from 2 children and 2 adults. The preparations were obtained at ureteral reimplantation procedures and mechanical activity was compared with that of normal ureteral segments obtained at tumor nephrectomies. In contrast to normal ureters, all the preparations of the megaureters of the children showed stable spontaneous phasic activity over several hours. The adult megaureters were inactive. In both tissues a marked tonic, sustained contraction could be induced by norepinephrine. This type of response is found in calyceal and pelvic tissues only in normal upper tracts. Normal ureters responded to norepinephrine with an increase in the frequency of spontaneous phasic contractions. The qualitatively different responses of the megaureters (in comparison to normal ureteral tissue) to alpha-adrenoceptor stimulation may be due to abnormal subcellular distribution of activator calcium in these hypertrophied tissues. The observed in vitro findings may be related to the radiographic observations of impaired and uncoordinated peristalsis in primary obstructed megaureters.

Stimulation of Voltage-Dependent Contractions by Calcium Channel Activator Bay K 8644 in the Human Upper Urinary Tract in Vitro

The effects of calcium agonist Bay K 8644 on mechanical activity were studied in isolated preparations of the human upper urinary tract. Bay K 8644 increased the amplitude of phasic-rhythmic contractions in calyceal segments in a concentration-dependent way. In inactive and unstimulated ureteral muscle strips, Bay K 8644 did not induce contractions. After depolarization of ureteral segments with an extracellular potassium concentration of 48 mmol./l., Bay K 8644 produced a concentration-dependent increase of contractile force and enhanced phasic-rhythmic activity. The EC50 of the drug was 7.23 X 10(8) mol./l. The potassium and calcium concentration-response-curves were shifted to the left and the maximum force development was increased. Tonic contractions induced by norepinephrine in calyceal and pelvic segments were not affected by Bay K 8644, but the tendency for phasic-rhythmic activity was increased. In contrast to calcium-antagonistic dihydropyridines like nifedipine, the dihydropyridine derivative Bay K 8644 displayed completely opposite effects, which are obviously limited to voltage-induced activation. These observations can be explained by assuming that these agents act at sites that are components or are associated with voltage-controlled calcium channels. Occupation of these sites may either increase (Bay K 8644) or decrease (nifedipine) the transmembrane calcium flux into the cell.

Limitierung des ischämischen Nierenschadens durch den Calciumantagonisten Nisoldipin

Die zellularen und molekularen Mechanismen der ischamischen Zellschadigung sind weitgehend unbekannt Aufgrund neuerer Befunde wird allgemein angenommen, das einer ischamiebedingten intrazellularen Akkumulation von Calciumionen eine wichtige Rolle bei der ischamischen Zellschadigung zukommt (Farber 1981).

Four Years of Experience with Ureteroscopy: Technique and Results in More Than 500 Cases

Since the introduction of ureteroscopy in July, 1984, more than 530 procedures have been performed at our department for ureteral stones and various ureteral pathologies.

The MFL 5000: A New Machine for Urological Diagnosis, Endourology, and Extracorporeal Shock-Wave Lithotripsy

In February, 1988, a new lithotripter was installed at our Center: the MFL 5000. This multifunctional lithotripter, developed collaboratively by Dornier and the Philips Company, brings together three areas of application: extracorporeal shock-wave lithotripsy (ESWL), urological diagnosis, and all endourological procedures such as percutaneous nephrostolithotomy and ureterorenoscopy. The table used is similar to a urologic diagnostic table. For the ESWL procedure, one U-arm which can be tilted contains the apparatus for stone location. This can define the anterior-posterior as well as the cranial-caudal projections at 15° to 30°. The U-arm can be rotated 180°, thus allowing percutaneous procedures with an x-ray tube located under the table and an image intensifier above it. This arrangement significantly reduces the x-ray exposure of the patient and urologist.