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Biomedical subjects

J B Prystowsky

Publications and source records attributed to J B Prystowsky.

24 records · Page 2Linked to original sources
PubMed1992

The effects of ultrasound-guided shock waves during early pregnancy in Sprague-Dawley rats.

Pregnancy is a contraindication to extracorporeal shock wave lithotripsy (ESWL) because of its possible harm to the embryo or fetus caused by shock waves or ionizing radiation. In this study timed-pregnant rats were subjected to shock waves early in gestation using a lithotriptor having ultrasound imaging. In a pilot group undergoing immediate laparotomy, it was determined to what extent the pelvic structures were effected. Then a test group was exposed to shock waves and carried to near term pregnancy along with an identical group of pregnant, sham procedure rats. A laparotomy all were inspected for fetal viability, fetal abnormalities, and maternal organ damage. Fetuses located nearest the focal area of maximum shock wave energy showed lower mean weight than controls. There was no recognizable gross or microscopic fetal damage.

Animals↗
PubMed1992

A performance analysis of an extracorporeal shock wave lithotripter: spatial pressure distribution and the effects of lithotripter voltage, electrode life, and tissue attenuation.

The Dornier MPL-9000 lithotripter was analyzed as a function of lithotripter voltage, electrode efficiency, and bovine muscle attenuation. The maximum pressure at 20 kV measured 65 +/- 4 MPa (mean +/- SD). The region containing 50% of the maximum pressure was a cylindrical volume with a diameter of 2.5 cm and a height of 7 cm. Pressure varied in a linear fashion with lithotripter voltage (r = 0.996). The average pressure produced by an electrode throughout the course of 2,200 shock waves was 78% of its maximum pressure. Shock wave pressure was reduced from 65 +/- 4 MPa to 49 +/- MPa, 44 +/- 3 MPa, and 44 +/- 1 MPa with 1-, 2-, and 3-cm thickness of intervening bovine muscle, respectively. There was a statistically significant decrease in pressure when muscle was interposed, but there was no significant difference in reduction of pressure between 1, 2, and 3 cm of muscle (ANOVA, Newman-Keuls, alpha = 0.01). Frequency spectral analysis revealed the major contribution to the shock wave comes from 0-200 kHz with a peak near 50 kHz. Major frequency intensities were reduced with a decrease in lithotripter voltage, attenuating tissue, and distance away from the center of the focal zone.

Animals↗
PubMed1991

Acute diverticulitis. A complicated problem in the immunocompromised patient.

We reviewed the records of 209 patients with acute diverticulitis treated from 1984 through 1989 to determine if immunocompromised patients have a worse prognosis than nonimmunocompromised patients. Forty immunocompromised patients and 169 nonimmunocompromised patients with acute diverticulitis were identified. Free perforation into the peritoneal cavity occurred in 43% (17/40) of immunocompromised patients and 14% (24/169) of nonimmunocompromised patients. Operations were performed in 58% (23/40) of immunocompromised patients and 33% (55/169) of nonimmunocompromised patients. Postoperative morbidity was 65% (15/23) in immunocompromised patients and 24% (13/55) in nonimmunocompromised patients; postoperative mortality was 39% (9/23) and 2% (1/55), respectively. We conclude that acute diverticulitis in the immunocompromised patient is a complicated problem; there is a greater risk of free perforation and need for surgery than in the nonimmunocompromised patient. Furthermore, the prognosis for immunocompromised patients who undergo surgery is worse than that for nonimmunocompromised patients.

Acute Disease↗
PubMed1990

Extracorporeal shock wave lithotripsy for biliary stones.

Extracorporeal shock wave lithotripsy is a noninvasive technique for treatment of patients with gallbladder and bile duct stones. Selected patients with gallbladder stones can be treated on an outpatient basis without general anesthesia and may return to full activity within 1 or 2 days. Stone-free rates of 40% to 60% at 6 months have been achieved in most reported series with minimal morbidity. Bile duct stone lithotripsy has achieved stone clearance in 80% of patients in whom conventional methods were unsuccessful and therefore constitutes a valuable second-line treatment for these patients.

Bile Duct Diseases↗
PubMed1988

Gastrointestinal endometriosis. Incidence and indications for resection.

Of 1573 consecutive patients with endometriosis diagnosed at laparoscopy or celiotomy, 85 patients (5.4%) had gastrointestinal involvement and 11 patients (0.7%) required bowel resection due to recurrent gastrointestinal symptoms (usually obstructive in nature) and/or suspicion of malignancy. Of 63 patients with gastrointestinal involvement at sites other than the appendix, who did not undergo bowel resection, only two patients had gastrointestinal symptoms at the time of diagnosis (neither patient had obstructive symptoms); follow-up has revealed that only one patient subsequently developed significant gastrointestinal symptoms. Fifteen patients had appendiceal endometriosis, but none had symptoms suggestive of appendicitis. Indications for resection of gastrointestinal endometriosis include the presence of clear-cut obstructive symptoms or the inability to exclude malignancy. The absence of gastrointestinal symptoms appears to be predictive of the absence of clinically significant intestinal endometriosis, and bowel resection is not indicated in the asymptomatic patient. Appendiceal endometriosis appears to be an incidental finding and one that is not clinically important.

Adult↗