The Journal of stone disease最新文献

This study was designed to evaluate the quality of sedation/analgesia and patient cooperation provided by Patient Controlled Sedation & Analgesia (PCSA) using propofol and fentanyl (Group II) when compared with anesthetist administered propofol/fentanyl (Group I) in 32 ASA I & II patients undergoing ESWL of renal or ureteric stones. Demographics of the patients and the duration of ESWL were similar in both groups. Dose of propofol/fentanyl used during the procedure was significantly higher in Group I patients as compared to group II (p less than 0.05). Interpatient variability in propofol requirement was reflected in both groups in the lack of significant correlation between propofol dose and procedure duration. PCSA provided a marginally higher degree of patient and surgeon satisfaction scores as compared to anesthetist administered propofol/fentanyl. Quick recovery was more consistent in the PCSA group as compared to group I patients.

Our aim was to compare the results of extracorporeal shock wave lithotripsy with the Dornier MPL 9000 for patients with single radiolucent gallstones less than or equal to 20-mm diameter using higher power (kV) and more shock waves during lithotripsy with our results during the Dornier National Biliary Lithotripsy Study using lower power and fewer shock waves. Nineteen patients were treated at higher power (mean +/- SE, 21.0 +/- 0.4 kV) vs 11 patients at lower power (18.8 +/- 0.5 kV). In the higher power group, the actuarial rate for complete clearance of gallstone fragments was 39 +/- 9%, 63 +/- 9% and 78 +/- 9% after 6 weeks, 3- and 6-months follow-up, respectively, versus only 19 +/- 12% after 6 months in the lower power group. We conclude that the use of higher power and more shock waves during extracorporeal shock wave lithotripsy with the MPL 9000 results in fragment clearance rates over 6 months for patients with single gallstones that are significantly higher than those previously achieved in the Dornier National Biliary Lithotripsy Study.

Exposure of mice fibroblasts cell strain 3T3 to high energy shock waves and megavoltage radiotherapy resulted in a reduction in cell viability as determined by trypan-blue exclusion and H3-Thymidine incorporation assays. Electromagnetic shock waves have a higher cytotoxic effect on cell viability than megavoltage radiotherapy, at low and medium levels of energy. Megavoltage radiotherapy has a higher cytotoxic effect on cell viability at high levels of energy, as nucleoside incorporation reveals. The combination of electromagnetic shock waves and megavoltage radiotherapy delivered on cell cultures at medium levels of energy, did not enhance their cytotoxicity when it was compared with their high levels of energy individually.

Seventy-one adult patients underwent ureteroscopy for treatment of ureteral calculi using the disposable shaft semirigid mini-ureteroscope. The ureteroscope has an 8.3F outer diameter with a fiber optic core that allows some flexibility of the shaft. It has a 4.0F working channel that allows simultaneous use of 3F instruments and irrigation. Twenty-three patients had upper ureteral calculi and 48 patients had lower ureteral calculi. Thirty-six patients did not require ureteral dilation and the remainder had minimal dilation to 10-12F. Fifty-one patients underwent laser lithotripsy, 14 patients underwent basket extraction, and six patients had both. Five patients required use of a second flexible ureteroscope. Seventy-seven percent of the patients went home the day of the procedure, 16% stayed one night in the hospital, and the remaining 7% had longer hospital stays. No major complications or infections were noted. Only 11% of the patients required IV or IM narcotics for pain management post-operatively. The stone-free results at 1 month were 96% for lower ureteral calculi and 91% for upper ureteral calculi. We have found this ureteroscope to be similar to other rigid mini-ureteroscopes with some additional advantages. A larger working channel, increased flexibility/steerability, and improved optics make it useful for treating ureteral calculi in the lower ureter in men and the entire ureter in women.

This study was performed to determine the advantages and disadvantages of the two shapes of electrodes (flat and conical) commonly used in electrohydraulic extracorporeal shock wave lithotripters. Hundreds of measurements made on profiles obtained from a piezoelectric pressure gauge in an underwater shock wave research device showed that conical electrodes are more convenient than flat electrodes, since they produce shock waves with larger compressional amplitudes, less misfires and a better reproducibility, having similar widths and rise times. In an attempt to improve the effectiveness and duration of the electrode tips, a new shape was designed that proved to be more reliable and suitable for lithotripsy than the conventional flat or conical electrodes. Experiments with calculi models placed in the focal region of the shock wave generator seem to confirm the results obtained from pressure measurements.

As the general experience with extracorporeal shock wave lithotripsy (ESWL) for renal calculi broadens, it is increasingly evident that the clearance of stone fragments in lower pole calices needs to be improved. The stone-free rate posttreatment for lower caliceal stones is consistently less than that for other upper tract locations. Utilization of a cystoscopically placed cobra catheter for directed irrigation during ESWL with a Dornier HM4 lithotripter resulted in an increase of our lower caliceal stone-free rate to 64% (29/45) at 1 month follow-up and 73% (33/45) at 3 months follow-up compared to 36% (15/42) of randomly selected controls at 1 month (p less than 0.007) and 54% (23/42) at 3 months (p < 0.070). Patients were included in the study if they had a solitary calculus, less than 2 cm in size, located in a normal lower pole calix and had no indwelling stent placed by the referring physician. The cobra catheter was positioned in the appropriate calix with fluoroscopic guidance under intravenous sedation. Statistical analysis was performed using Pearson's Chi-square test. We conclude that the pre-ESWL treatment placement of a cobra catheter into the lower pole calix and intermittent irrigation during the procedure is a useful adjunct in the successful treatment of lower caliceal calculi.

Recently published literature on biliary extracorporeal shock wave lithotripsy (ESWL) has shown that high-energy ESWL utilizing high kV is more effective than the low-energy ESWL and low kV used previously. Prior studies have not reported injury to the gallbladder or adjacent liver following ESWL. Our study evaluated 29 patients that were treated with high kV ESWL. Magnetic resonance imaging (MRI) was used to study the gallbladder and adjacent liver for possible injury resulting from the high-energy treatment. The patients, selected using the Dornier MPL-9000 United States protocol, underwent ESWL using 18-24 kV (average 21 kV). MRI was done both pre and post-ESWL in all 29 patients. Ten patients had a second treatment to reduce fragment size and, subsequently, had an additional MRI examination. Spin echo MRI images were obtained at the level of the gallbladder fossa using a 0.5-Tesla ESATOM RM 5000 (ESAOTE Biomedica, Genva, Italy.) superconductive unit. Both T1- and T2-weighted images were obtained. In 26 patients the hepatic parenchyma was normal post-ESWL. Two patients had a hyperintense region on T1-weighted images post-ESWL that was felt to be related to pericholecystic fat. A third patient had an abnormality detected on T2-weighted images that was thought to be due to hepatic edema or microhemorrhage. No significant changes were shown by laboratory or concurrent ultrasound examinations. Repeat MRI examinations in these three patients were normal. High-energy ESWL appears as safe as low-energy ESWL in the treatment of patients with symptomatic gallstones.

The major limitations of biliary extracorporeal shock wave lithotripsy (ESWL) relate to adequate stone fragmentation and clearance of the stone fragments. We hypothesized the removal of small fragments with concomitant catheter cholecystostomy during ESWL would improve its efficacy. ESWL with aspiration or flushing through three different cholecystostomy catheters was performed on pigs with surgically implanted gallstones. Twenty-two percent and 46% of the pre-ESWL stone weight were aspirated through the 10 and 12 French catheters respectively. The clearance, size, and visualization of fragments was not significantly different between any of the groups. No significant post-mortem tissue or catheter damage was found. Catheter aspiration is a safe and effective method of removing gallstone fragments during biliary ESWL, but it does not improve stone fragmentation, stone clearance, or visualization of other fragments.

In vitro experiments were conducted to determine if differences in targeting would effect stone fragmentation. Ten pairs of twin gallstones were used. The stones in each pair were identical in volume, diameter, radiolucency, and gross shape. One stone from each pair was subjected to shock waves focused at the center of the stone; the other was treated with shock waves targeted at the edge. Lithotripsy was terminated when all fragments were less than 5mm in diameter. The total number of shock waves used for each stone was recorded. In 7 of 10 pairs, fewer shock waves were required to fragment the edge targeted stone than the center targeted stone. In two of the remaining three pairs, equal numbers of shock waves were required for complete fragmentation. The difference between edge targeting and center targeting was shown to be statistically significant using the nonparametric Wilcoxin Signed Rank Test. (1 tailed = p less than 0.02, 2 tailed = p less than 0.04). These findings suggest that the outcome of biliary lithotripsy may be improved by targeting the edge of the stone.

Extracorporeally-perfused rabbit kidneys were exposed to five shock waves at 14 kV on the XL1 Dornier experimental lithotripter (Dornier Medical Systems, Inc., Germering, Germany). While the perfusion flow rate was kept constant, the arterial perfusion pressure was recorded to assess changes in vascular resistance. Immediately after shock wave application, perfusion pressure decreased by 20%-30%, followed by a short, relative pressure rise that did not reach pretreatment values. Fifteen-twenty minutes later, arterial perfusion pressure reattained pretreatment values. Subsequent to treatment, urine flow decreased by greater than 50%. The observed pressure rise was also induced in nontreated kidneys by perfusion with the effluent of treated kidneys indicating that this is based on a humoral mechanism. On the other hand, shock wave application to formalin fixed kidneys only caused a marked decrease in arterial perfusion pressure, suggesting that this effect is due to a pure mechanical interaction of the shock wave also found with denaturated kidneys. The observed decrease of urine flow is probably caused by a decreased filtration rate. Since this was not the case in nontreated kidneys being perfused with the effluent of treated kidneys, the reduction of urine flow after extracorporeal shock wave lithotripsy does not appear to be mediated by a humoral factor, but is more likely a result of the mechanically-induced vasodilation with consecutive decline of the glomerular filtration rate.