Birdwell Finlayson

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.

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.

Crystal retention by injured urothelium of the rat urinary bladder

Injuries caused by hydrochloric acid or Triton X 100 application to the rat bladder urothelium, and the effects on calcium oxalate crystal retention, were examined by light and scanning electron microscopy. Damage due to either compound resulted in desquamation of urothelial cells. The crystals appeared to be retained by a fibrillar material, some of which was identified as fibrin. Heparin treatment of injured urothelium was found to prevent crystal retention.

Solubility Product of Magnesium Ammonium Phosphate Hexahydrate at Various Temperatures

AbstractThe solubility of magnesium ammonium phosphate hexahydrate (MgNH4PO4·6H2O) was determined in aqueous solution at 25, 35, 38, and 45C. The thermodynamic solubility product was determined at each temperature.

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.

Water Hardness and Urinary Stone Disease

On the macrogeographic scale, a strong negative association exists in the United States between water hardness and urinary stone disease. This investigation studies the association on the microgeographical scale, where it is possible to control for confounding environmental factors. The study was conducted on 2,295 patients from 2 regions: the Carolinas which had soft water and high stone incidence, and the Rockies which had hard water and low stone incidence. Home tap water samples from urinary stone patient hospitalizations were compared with that of controls, concurrent inguinal hernia patient hospitalization. After adjusting for environmental factors, no significant difference (p = 0.59) between the 2 groups was obtained in tap water calcium, magnesium, and sodium concentrations. An incidental but potentially important finding was that those consuming water from a private well had an estimated relative risk of 1.5 (p less than 0.01) compared to those using public water. While no cause-effect relationship is suggested, stone-formers might consider avoiding private well water. On the other hand, water hardness should be a minor concern with respect to stone formation.

Distribution of organic matrix in calcium oxalate renal calculi

SummaryThe quantity of protein and carbohydrate comprising the matrix of calcium oxalate monohydrate (COM) renal stones was found to decrease with distance from the surface of the stone. The average organic concentration of stones 3 to 30 mm in diameter ranged from 5.7% at the surface to 2.7% at the core. This concentration gradient suggests matrix involvement in a “growth front” on stone surfaces with migration of organic material from the “older” interior. The matrix distribution was not readily correlated with density variations or with the presence of hydroxyapatite or calcium oxalate dihydrate. Surface matrix concentrations were greater than amounts predicted by physical adsorption. Electron microscopy confirmed the presence of the organic-rich surface layer and also suggested that increase in stone size occurs predominantly by crystal growth with microcrystal aggregates as growth centers.

An electrophoretic study of calcium oxalate monohydrate

Abstract The electrophoretic behavior of calcium oxalate monohydrate was analyzed in terms of a simple double-layer model. The experimental results with a variety of electrolytes could be described nearly quantitatively with the Nernst-Gouy-Stern double-layer model if reasonable values were chosen for the adjustable parameters. Specific adsorption of ions was analyzed in relation to their location in the double layer and to the strength of the adsorption bonds.

Primary liquid intake and urinary stone disease

This investigation indicates that there are important associations between urinary stone disease and a persons 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 persons 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.

Hawkins-hunter retrograde transcutaneous nephrostomy: A new technique

Retrograde nephrostomy, a new technique to aid in stone management, has been performed successfully in dogs. It has also been used without complication in a human patient to help remove a renal stone percutaneously under local anesthesia. The technique consists of placing a coaxial catheter over a guidewire under fluoroscopy into the exact calyx desired and advancing a long needle out to the skin to establish a transcutaneous tract. The advantages of the technique include increased control and precision of tract placement, efficient working angles for percutaneous stone removal, and the ability to perform the procedure under local anesthesia.