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Biomedical subjects

B Finlayson

Publications and source records attributed to B Finlayson.

At least 37 records · Page 2Linked to original sources
PubMed1988

Simulation of ventilatory-induced stone movement and its effect on stone fracture during extracorporeal shock wave lithotripsy.

Because ventilation influences renal movement, we investigated the effect of stone motion on the efficiency of extracorporeal shock-wave lithotripsy (ESWL). Comparisons of the rates of fragmentation of an experimental model of renal calculi were made between simulated high-frequency jet ventilation at 100 breaths/min. with four-mm. stone movement as measured from the fluoroscope screen, conventional mechanical ventilation at 10 breaths/min. with 32-mm. stone movement as measured from the fluoroscope screen, and a static control. Fragmentation did not differ significantly between high-frequency jet ventilation and no ventilation (static control), but was significantly greater with high-frequency jet ventilation than with conventional ventilation.

High-Frequency Jet Ventilation↗
PubMed1988

Combination extracorporeal shock wave lithotripsy and percutaneous extraction of calculi in a renal allograft.

Renal calculi are a well documented although uncommon complication of kidney transplantation and may be associated with significant morbidity in this immunosuppressed population with a single functioning kidney. We describe a patient who presented with 2 episodes of staphylococcal bacteremia associated with a ureteral structure and struvite calculi involving the calices, renal pelvis and proximal ureter of a cadaveric renal allograft. The patient was treated successfully with a combination of extracorporeal shock wave lithotripsy, percutaneous extraction and balloon dilation of the ureteral stricture. Renal transplant function was not altered postoperatively. In selected cases shock wave lithotripsy can be used as effective adjunctive therapy in a renal allograft harboring stones.

Combined Modality Therapy↗
PubMed1987

ESWL: a look from different angles.

Rapid and accurate stone positioning prior to shock wave administration is the key to efficient extracorporeal shock wave lithotripsy (ESWL). On the Dornier HM-3 machine, the operator uses the control panel to move the stone image along the x, y, or z axis, but many operators are uncertain about the direction and speed of the target when the control buttons are activated. Since knowledgeable, full use of ESWL controls probably results in reduced positioning time and x-ray exposure, the angles and relative velocities from simple and complex maneuvers are presented as a didactic aid.

Humans↗
PubMed1987

Pathologic effects of ESWL on canine renal tissue.

The introduction of extracorporeal shock wave lithotripsy (ESWL) has provided an avenue for dealing with many urinary stones noninvasively. The margin of safety for the kidney during shock wave administration is largely undefined. A pilot study was performed where six kidneys in five female mongrel dogs were shocked. Group A kidneys were given 1,776, 4,500, 6,000, or 8,000 shocks, respectively, at 18-24 kV. Group B kidneys received 1,600 and 8,000 shocks (18-24 kV). The number of shocks per electrode ranged from 500 to 4,538 and averaged 2,490. The dogs were sacrificed forty-eight to seventy-two hours (Group A) or twenty-eight to thirty-two days (Group B) post-treatment. Modest damage (hematoma and/or interstitial hemorrhage) was noted in all kidneys. Evidence of permanent change (fibrosis) was noted in both Group B kidneys. Complete necrosis of the kidney was not seen after administration of 8,000 shocks. These preliminary data indicate that lithotripsy can, in some circumstances, produce renal damage in the canine model.

Animals↗
PubMed1987

Acute mechanical dilation of the ureter: an experimental study.

Forty-three kidney donor ureters were mechanically dilated in vitro with Van Buren sounds to an average of 21.2F. Thirty-three of these ureters, with an average pre-dilation diameter of 11.3F, could be dilated an additional average of 10.6F. The average dilated/nondilated diameter ratio in these ureters was 1.9. These experimental data suggest an undilated pelvic ureteral diameter and a manually dilated ureteral diameter of approximately the same size cited in the clinical literature.

Adult↗
PubMed1987

The ureteral access system: a review of the immediate results in 43 cases.

The ureteral access set was used 43 times during an 18-month period between 1984 and 1985. Stones lodged throughout the ureter and in the renal pelvis were extracted with a success rate of 51 per cent. Of the upper tract strictures 92 per cent were dilated successfully. Filling defects were diagnosed in 88 per cent of the cases. Foreign bodies were retrieved, Double-J stents were placed and biopsies were successful in each case. Ureteral perforation in 28 per cent of the cases was caused by the dilator in 8 of 12 (19 per cent over-all). The technique and short-term results are discussed. Long-term followup data are not yet available.

Catheterization↗
PubMed1986

Tobramycin and renal ischemia.

Sprague-Dawley rats were injected with known nephrotoxic doses of tobramycin and then subjected to varying amounts of warm renal ischemia. Analysis of serum creatinine at the time of sacrifice revealed no statistically significant difference among controls and the two doses of tobramycin at any given duration of ischemia. Light microscopy revealed no worsening of tubular necrosis with increasing doses of tobramycin.

Animals↗
PubMed1986

Morphology of urinary stone particles resulting from ESWL treatment.

Fragments of urinary stones resulting from extracorporeal shock wave lithotripsy were examined by light and scanning electron microscopy. Calcium oxalate monohydrate and uric acid stone fragments were homogeneous and regular whereas struvite stone fragments were irregular in shape. Examination of the fractured surfaces revealed that the process of stone fragmentation involved fracture and cleavage of the crystals at some places and their separation from each other at others. In stones whose crystals are organised in layers, for instance calcium oxalate monohydrate and uric acid, crystalline layers separated along the concentric laminations. In struvite stones, which are an agglomeration of struvite and calcium phosphate crystals, major fragmentation occurred along the crystalline interfaces.

Calcium Oxalate↗
PubMed1986

Report of the United States cooperative study of extracorporeal shock wave lithotripsy.

Extracorporeal shock wave lithotripsy effectively fragments urinary calculi in the upper urinary tract and upper ureter. These fragments pass completely by 3 months in 77.4 per cent of the patients with single stones. Risk of obstruction, increased postoperative pain, need for additional urological operations and retained fragments are low for stones less than 1 cm. in size. As the number of stones treated or single stone size increases above 1 cm. the risk for these factors increases. Adjunctive urological surgical management is required in 9 per cent of the patients preoperatively and 8 per cent postoperatively. Only 0.6 per cent of the patients require some type of open operation to resolve the stone problems after extracorporeal shock wave lithotripsy. Hemorrhage, obstruction by fragments, severe pain and urinary infection all constitute known complications and require careful urological management of all patients. Hospitalization averages 2 days after treatment and patients usually return to work within a few days after they are discharged from the hospital.

Adult↗
PubMed1986

Initiation and growth of uroliths.

The urinary concentrating capacity of terrestrial animals often results in a high degree of urinary supersaturation. Supersaturation provides a driving force for rapid precipitation of solids. For some minerals in urine, the balance between supersaturation and presence of inhibitors determines whether crystal growth will occur. If crystals are delayed in their transit through the urinary tract, they may grow to such a size that they cannot readily pass through the ureters or urethra.

Animals↗
PubMed1986

Renal stone disease treated with extracorporeal shock wave lithotripsy: short-term observations in 100 patients.

The immediate posttreatment findings are described for 100 patients who underwent extracorporeal shock wave lithotripsy (ESWL) for renal stone disease. Excretory urography was performed both before and 24-72 hours after ESWL. In 21 patients, stones were completely disintegrated, and stone fragments were passed rapidly. Stones were fragmented but not passed entirely within 24-72 hours in 76 patients. There was no appreciable effect on stones in three patients. In nine of 27 patients who had mild to severe ureteral obstruction caused by stone fragments, relief procedures (retrograde ureteral manipulation or percutaneous stone extraction) were necessary. Overall, 70 patients experienced successful stone disintegration without complications. Continued investigation is needed to determine prevalence of residual calculi, reversibility of acute effects of ESWL on the kidney, and possible development of late hypertension.

Female↗
PubMed1985

Primary liquid intake and urinary stone disease.

This investigation indicates that there are important associations between urinary stone disease and a person's primary liquid intake. Based on data collected from 2295 caucasian male patients from two geographical regions, the Carolinas (both North and South) and the Rockies (including Colorado, Idaho, Nevada, Montana, Utah and Wyoming) an important (p less than 0.01) positive association was found between urinary stone disease and soda (carbonated beverage) consumption within both geographical regions. It was also found that negative associations exist between urinary stone disease and both beer consumption and coffee consumption in the Rockies and that no important associations exist between urinary stone disease and any of milk, water, or tea, when these beverages represent a person's primary liquid intake. Moreover, soda can be viewed almost synonymously as sugared cola, since few subjects had diet sodas or sugared non-cola soda as primary fluid. No cause/effect relationships are implied in this paper.

Adolescent↗