The Journal of stone disease最新文献

A new successful approach in treating lower and middle ureteral calculi in situ was undertaken utilizing the Dornier MFL-5000. From August 19, 1989 to February 7, 1990, 46 consecutive cases were treated representing 60 stones (54 lower, 6 middle). The average size of treated stones was 12 mm. Ten cases (21.1%) had two stones and two cases (4.2%) had three stones. Stones were not displaced and no ureteral catheter was used except in one case, a female, 28 years of age, with a lower ureteral stone, where the stone had to be displaced proximally using a double balloon ureteral catheter to follow FDA protocol in order to avoid the ovaries. Minimal IV sedation was required in 97.7% of the patients and only 2.1% required general anesthesia. Different positioning techniques were implemented. One (2.1%) out of 46 cases required retreatment. The average length of stay in the hospital was 1.2 days. No complications occurred to date. Follow-up, 48 hours post-treatment, revealed 94.6% stone-free. At 3 month's follow-up, 100% were stone-free.

Extracorporeal shock wave lithotripsy (ESWL) is the most widely used treatment for renal calculi. Newer second generation lithotripters are being produced, which are considered to be less painful than their prototypes. Thus, the trend in anesthesia for ESWL is away from general endotracheal and regional anesthesia and toward less involved and more easily monitored techniques such as intravenous analgesia (IVA). This report relates our experience with a continuous alfentanil infusion for ESWL treatment of renal calculi with a nonimmersion second generation Dornier HM-4 lithotripter model. Thirty-five patients treated pre-operatively with droperidol and midazolam, followed by a continuous infusion of alfentanil, reported excellent pain relief via a numerical pain score and manifested little, if any, hypertension or tachycardia. Stone fragmentation, fluoroscopy, and recovery time did not differ between patients receiving IVA or general anesthesia. Potential disadvantages of IVA include elevation of transcutaneous CO 2, bradycardia in 14 patients requiring the use of atropine, slightly longer ESWL time, increased number of shocks needed for fragmentation, and a small failure rate, with 11% of patients requiring general anesthesia. With proper patient selection and respiratory monitoring, IVA is highly recommended for ESWL in the treatment of renal calculi.

Despite the extensive use of lithotripsy for treating renal and biliary calculi, there has been little data reported regarding the causes and manifestations of lithotripter failure. The clinical and service records for 145 consecutive treatments performed with the Siemens Lithostar Plus were reviewed. Service record analysis revealed eight failures of shock wave generation during a 10-month period. Six of these failures were subtle and still allowed shock wave generation. There were five in-line ultrasound probe failures during this period. The most useful clinical parameter for predicting lithotripter failure was reduced severity of sonographically evident cavitation bubbles during treatment. Lack of stone fragmentation and unexpectedly low analgesia requirements at high-power levels were less useful in predicting lithotripter failure. All clinical parameters suffered from nonspecificity. Preliminary experience, with an ongoing quality assurance program using a test object hydrophone, suggests this is a useful method of predicting lithotripter function and avoiding compromised treatments.

Extracorporeal shock wave lithotripsy (ESWL) has proven to be effective for the treatment of renal calculi. However, its use for ureteral stones as monotherapy is controversial. In this study, 142 patients underwent in situ ESWL for ureteral stones. Stone fragmentation was achieved in 87.4% of the patients. Stone clearance rate at 3 months was 95.8%, 94.7%, and 94.2% for stones located in upper, middle, and lower ureter, respectively. Efficiency quotient calculated for the overall stone clearance at 15 days, 1 month, and 3 months was 74.6, 71.8, and 71.7, respectively. Treatment was performed in 82.5% of patients as an outpatient procedure. Our data show that in situ monotherapy is an effective and noninvasive method for treating ureteral stones.

The role of cavitation during shock wave exposure was poorly understood until now. Cavitational activity produces severe damage to nearby surfaces due to multiple high-speed liquid jets resulting from bubble collapse. These jet impacts can be made visible by microscopy. For investigating the presence of cavitational processes by shock waves outside and even inside of targets, we have performed the following experiments. Natural gallstones and artificial targets were examined microscopically with regard to the effects of shock pulses. Scanning electron and light microscopical investigations revealed regularly typical and uniform microjet impacts within the fissures and split lines. Since these experiments are the continuation of high-speed films of 10,000 frames/s of shock wave actions on targets, it is most likely that the shock wave produces at first split lines through the stone. Then liquid occupies these cracks. But the following shock waves create within these liquid-filled fissures cavitation and, therefore, cause the disintegration of the targets. It now becomes understandable why biliary lithotripsy is less effective than renal lithotripsy: bile fluid is a high-viscous liquid and, therefore, hinders the disintegration of stones more than low-viscous urine. Intervals between the application of shock waves in biliary lithotripsy, therefore, should improve the treatment results.

Extracorporeal shock wave lithotripsy (ESWL) uses either X-ray fluoroscopy or ultrasound to localize and determine the end point of treatment. We report radiation doses to patients and personnel from the Storz Modulith lithotripter system recently installed in the Lithotripter Centre, St. Thomas' Hospital, London. The mean annual radiation dose to patients and staff was calculated at 0.73 mSv and 4.8 mSv, respectively.

One hundred and six patients were treated with a second generation underwater spark discharge lithotripter (Dornier MPL-9000). During the 15-month study period, Kaplan-Meier analysis predicted a stone clearance rate of 16.5% after 4 months, 37% (7 months), 71% (10 months), and 81% (15 months), respectively. Patients with multiple stones had a 5% probability to be free of stones after 13 months of treatment, when compared to 100% in patients with solitary stones smaller than 2 cm (p less than 0.001). Stones with densities below 100 Hounsfield units (HU) on computed tomography disappeared in 75% of the cases within 13 months. Rim calcified stones were cleared in 100% after 10 months of treatment. Fragmentation efficacy proved to be an essential predictive parameter for stone clearance: a fragment size below 5 mm after extracorporeal shock wave lithotripsy resulted in a 100% stone clearance within 13 months regardless of the initial stone number, size, and density. None of the stones fragmented to pieces of more than 10 mm in diameter could be dissolved within the observation period. Obviously, modern generation electrohydraulic lithotripters are effective in stone fragmentation, thus providing the basis for successful bile acid therapy provided the patients are properly selected.

We examined the cytotoxic effect of shock waves for primary (embryonic chick kidney and thigh muscle) and permanently growing normal and malignant cells (human, rat, and mouse) in suspension. To avoid the influence of different media, the cells were suspended in phosphate buffered saline and shock wave treated. In all cases the acute cytotoxic effect (measured by flow cytometry) was a function of the applied shock waves. The investigated cells differed in their LD 50 values which, however, do not reveal a general difference in sensitivity to shock waves for normal and malignant cells.

Gallstone lithotripsy (GSL) with the Technomed Sonolith 3000 extracorporeal lithotripter was studied in a multisite, international cooperative trial involving the United States, France, and Italy. All participating sites worked under a common protocol to investigate the safety and efficacy of GSL for symptomatic gallstone patients. These collective results are from a mix of 25 academic and community hospital sites using fixed and transportable/mobile versions of the lithotripter. As of November 1, 1990, 661 patients have been treated in this two-arm randomized study (GSL Only vs GSL + Ursodiol [Actigall]). Patients were treated with up to 2,500 shocks per session and only two treatments were allowed. All machines had standardized pressure settings (850 bar nominal) and operator adjustment of output voltage was not allowed. We saw no statistically significantly different results in initial fragmentation between patients pre-loaded with ursodiol for 2 weeks and those treated by GSL alone. Gallbladder clearance rates did vary with the stone number, size, and burden as well as the adequacy of initial fragmentation. In the GSL + Ursodiol Arm of the trial, 46.2% of patients with solitary, 5-to 20-mm calculi are stone-free at 6 months.