ISSN:0892-7790    

DOI:10.1089/end.1990.4.1

年代:1990

数据来源: MAL

摘要:

A model for calcium oxalate aggregation was developed using the high-molecular-weight polymer poly (acry lamide). The mechanism for aggregation by this polymer was demonstrated to involve mainly nonelectrostatic hydrogen bonding. With the use of settling studies and turbidity measurements, the effect of extracorporeal shock wave lithotripsy (ESWL) on these aggregates was determined. This effect proved to be a function of aggregate size: the smaller the aggregate, the less effect ESWL had on it. This result can be explained by a force analysis of the ESWL wave: when the distance for the wave to rise to maximal pressure is large relative to the size of the particle, the pressure gradient (related to the force) will never be large. For our machine, the waveform rise takes place over a distance of 306.8 μm. This distance should represent a theoretical minimum for a powerful ESWL effect and correlates well with the minimum size of the stone fragments produced by ESWL. The model described here may be useful for studying the effect of stone therapies on calcium oxalate aggregation, a means for the clinician to predict the probability of fragmenting a stone based on its size, and a means of modifying the ESWL waveform to enable it to break up smaller fragments

ISSN:0892-7790    

DOI:10.1089/end.1990.4.3

年代:1990

数据来源: MAL

摘要:

Ten male pigs underwent balloon dilatation of the right ureter to three times its normal caliber during either infusion of IN saline (0.5,2, or 4 ml/min) or induced diuresis to a urine flow rate of 4 ml/min with the bladder open. There was no significant difference between the resting pelvic pressure (Ppvs) and the Ppvson either the control and the dilated side immediately after dilatation except at a flow rate of 4 ml/min on the dilated side. Also, on the dilated side, the resting Ppvswas normal at 1 week, but there was a statistically significant increase in Ppvs(P = 0.02; Student's t test) when the system was challenged with a saline infusion. At 6 weeks, this obstructive change had disappeared except at a flow rate of 4 ml/min. Histologic and ultrastructural findings were confirmatory, with extensive damage 1 week postdilatation and nearly complete repair by 6 weeks. The results point to the importance of ureteral sten ting after dilatation and imply that patients should delay increasing their fluid intake for approximately 6 weeks. The results also suggest that the dilated ureter heals both by ingrowth of muscle fibers from the edge of the ruptured area and by regeneration by pluripotent fibroblasts.

ISSN:0892-7790    

DOI:10.1089/end.1990.4.15

年代:1990

数据来源: MAL

摘要:

An animal model has been developed to compare the biologic effects of various stone treatment modalities on renal and perirenal tissue. The pig (Suis scrafus) was chosen because its renal anatomy and physiology (including the renin-angiotensin system) are similar to those of humans and because its blood pressure regulation has been well characterized. An indwelling line was implanted in the right carotid artery for blood pressure measurement. None of the treatments (unilateral extracorporeal shock wave lithotripsy [ESWL] with 2000 or 4000 shock waves; percutaneous nephrostomy; open surgery) produced a lasting change in the glomerular filtration rate. Whereas neither 2000 shock waves nor open surgery produced a significant change in the blood pressure, 4000 shock waves caused a significant rise in blood pressure that was reversed by removal of the treated kidney; and percutaneous nephrostomy caused a slight although significant increase in blood pressure that was not reversed by nephrectomy. Although this was only a pilot study designed to test the feasibility of the model, it is significant that nephrogenic hypertension could be created by supraphysiologic doses of shock waves. The use of MRI proved helpful in detecting subclinical alterations in renal and perirenal morphology after all types of treatment. This model should be valuable in defining the roles and effects of stone treatments.

ISSN:0892-7790    

DOI:10.1089/end.1990.4.27

年代:1990

数据来源: MAL

摘要:

Laparoscopic surgery as applied to urology has attracted limited interest from endourologists. In order to explore the feasibility of and gain the technical skills for performing laparoscopic procedures, we selected the female pig as the experimental model. All pigs underwent one or more procedures: translaparoscopic pelvic lymph node sampling, ureteral isolation and ligation, cystostomy and bladder repair, and laparoscopic monitoring of percutaneous cholecystostomy. Each pig underwent a second-look laparoscopic examination 2 to 4 weeks later. Minor complications occurred early in the investigation, but mastery came rapidly. Potential applications of laparoscopic surgery to clinical urology are discussed.

ISSN:0892-7790    

DOI:10.1089/end.1990.4.37

年代:1990

数据来源: MAL

摘要:

To determine whether epidural anesthesia can be avoided in patients undergoing extracorporeal shock wave lithotripsy (ESWL) with the standard Dornier HM3 lithotripter, 33 patients who received monitored anesthesia care (MAC) consisting of intravenous fentanyl and midazolam were compared with 33 who received epidural anesthesia. Only 2 of 31 patients could not tolerate ESWL with its auxiliary procedures under MAC. Preoperative time in the cystoscopy suite was significantly reduced with MAC (17 vs. 33 minutes; P<0.001), as was recovery room time (143 vs. 214 minutes; P<0.001). Our study indicates that ESWL with the standard HM3 lithotripter and most pre-ESWL procedures can be performed successfully and safely under MAC.

ISSN:0892-7790    

DOI:10.1089/end.1990.4.49

年代:1990

数据来源: MAL

摘要:

Ureteropyeloscopy not only is of considerable diagnostic value but also is therapeutically useful. In particular, it is superior to all other procedures available for clarifying the nature of filling defects found at urography. When a ureteral tumor has been discovered, biopsy material can be obtained to determine whether the tumor is malignant before treatment is initiated. In suitable cases, endoscopic endoureteral electroresection can be performed as an alternative to open surgery.

ISSN:0892-7790    

DOI:10.1089/end.1990.4.55

年代:1990

数据来源: MAL

摘要:

We present a method that allows percutaneous resection of renal cysts under local anesthesia using standard urologic instruments. Much as in the method described by Eickenberg, the peripheral wall of the cyst is resected with an ordinary resectoscope. Suction drainage is applied postoperatively for 2 to 3 days. The procedure has been used in 14 patients with obstructive cysts or flank pain. With follow-up averaging 19 months, in six cases, the cysts were reduced in size substantially, and the remaining eight cases showed no evidence of a cyst at follow-up. All patients but one were completely freed from the complaints they suffered prior to treatment.

ISSN:0892-7790    

DOI:10.1089/end.1990.4.61

年代:1990

数据来源: MAL

摘要:

A patient with severe hemophilia Type A (<1% Factor VIII) and thrombocytopenia, chronic active hepatitis, and HIV-positive serology was treated for kidney stones with percutaneous nephrolithotomy (PCNL). Platelets and Factor VIII replacement therapy were administered preoperatively, but bleeding occurred during creation of the nephrostomy tract and obscured the collecting system. The PCNL was therefore done as a second procedure after maturation of the tract, after which the patient was endoscopically free of all stones. We believe this is the first reported case of PCNL in a patient with severe hemophilia.

ISSN:0892-7790    

DOI:10.1089/end.1990.4.67

年代:1990

数据来源: MAL

摘要:

Patients with low ureteral calculi were accepted for treatment in the Dornier HM3 lithotripter if, in the opinion of the treating urologist, the calculus was able to be seen on the X-ray monitors. Using the supine position, 65 patients so selected were treated initially (de novo) with extracorporeal shock wave lithotripsy with a 91% success rate. These results are compared with those of 54 patients similarly selected and treated after lower tract instrumentation (ureteral catheterization, ureteral stent placement, or prior failed ureteroscopy) with an 87% success rate. No complications were encountered in the group treated de novo.

ISSN:0892-7790    

DOI:10.1089/end.1990.4.71

年代:1990

数据来源: MAL