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Biomedical subjects

D P Griffith

Publications and source records attributed to D P Griffith.

At least 55 records · Page 3Linked to original sources

Extracorporeal shockwave lithotripsy monotherapy for large renal calculi.

Extracorporeal shockwave lithotripsy (ESWL) monotherapy with a Dornier HM3 lithotripter was used to treat 199 large (greater than or equal to 3 cm) renal calculi. Calculi were classified as solitary (29), multiple (152) or staghorn (18) with stone-free rates of 55.2, 39.5 and 55.6% respectively. The stone-free rate was not statistically related to stone size, site or multiplicity. Complications occurred in 24 patients (12.8%) and were more common with solitary and staghorn calculi. ESWL is not recommended as primary treatment for most patients with large renal calculi.

Adult↗

A randomized trial of acetohydroxamic acid for the treatment and prevention of infection-induced urinary stones in spinal cord injury patients.

Acetohydroxamic acid is known to inhibit bacterial urease activity, thus, reducing urinary ammonia levels. A double-blind placebo-controlled clinical trial of acetohydroxamic acid was conducted at 12 Veterans Administration spinal cord injury units. A total of 210 male spinal cord injury patients with chronic urea-splitting urinary infection was enrolled for a scheduled followup of 2 years. The study data support the usefulness of acetohydroxamic acid in reducing urinary ammonia. At every followup visit the acetohydroxamic acid patients with stones had decreases in ammonia of 30 to 48 mg. per dh., while the placebo patients had increases in ammonia. Acetohydroxamic acid also retarded stone growth. Patients with stones treated with acetohydroxamic acid exhibited significantly longer intervals from randomization to first stone growth than patients treated with placebo (p less than 0.005, medians 15 versus 9 months). Acetohydroxamic acid reduced significantly the proportion of patients with stone growth at 12 months (33 versus 60 per cent, p equals 0.017). This decrease was diminished at 24 months (42 versus 60 per cent, p equals 0.260). Patient attrition was 31 per cent in the placebo group and 62 per cent in the acetohydroxamic acid group, the latter attrition being primarily owing to patient request because of mild symptoms. Of the acetohydroxamic acid and placebo patients 62 and 29 per cent, respectively, reported drug side effects but all were reversible and no unanticipated or life-threatening reactions occurred.

Ammonia↗

The role of silicone ureteral stents in extracorporeal shock wave lithotripsy of large renal calculi.

Between November 1984 and December 1985 extracorporeal shock wave lithotripsy was used to treat 1,645 kidneys at our institution. A total of 646 kidneys with stone burden greater than 14 mm. was evaluated with regard to the impact of silicone ureteral stents in post-extracorporeal shock wave lithotripsy morbidity. Our results indicate that small stones were pulverized and eliminated with minimum morbidity. Larger stones frequently were associated with post-treatment ureteral obstruction by sand and fragments. Of 283 kidneys with stone burden exceeding 25 mm. pretreatment placement of silicone ureteral stents reduced complications from 26 to 7 per cent and auxiliary procedure rates from 15 to 6 per cent. Silicone ureteral stents protect the kidney from ureteral obstruction, and allow for safe and effective extracorporeal shock wave lithotripsy of large renal calculi.

Catheters, Indwelling↗

Cholesteatoma of the renal pelvis: endoscopic management.

We report 2 cases of renal cholesteatoma, 1 of which was associated with inactive renal tuberculosis and the other with urinary stone disease. Both cases were managed by endourological techniques. The diagnosis of cholesteatoma was suspected at ureteroscopic examination of the renal pelvis and it was confirmed by histological examination of biopsy material in both cases. Treatment consisted of endoscopic extraction of the keratinous debris from the collecting system. In 1 case this was achieved with the ureteroscope and in the other case the nephroscope was used.

Adult↗

Ureteroscopy in management of ureteral calculi.

Transurethral ureteroscopy (TUURS) for the management of ureteral stones was performed in 102 patients. Primary ureteroscopy was performed in 57 patients while in 20 cases the procedure was used for stone manipulation prior to ESWL and in 18 cases after ESWL treatment. In 7 cases, insertion of the instrument was impossible. The overall success rate was 89 per cent (85/95). Success rate in the lower ureter was 93 per cent, in the middle ureter 84 per cent, and in the upper ureter 80 per cent. There were four complications (4%) and open operation was required in 3 patients only (3%). The up-to-date ureteroscopic results suggest that ureteroscopy should be the procedure of choice in the treatment of lower ureteral calculi and a valuable alternative in the treatment of upper ureteral calculi.

Adult↗

PICA/burden: a staging system for upper tract urinary stones.

A staging system is proposed to stratify upper urinary tract stones by their complexity, location and burden. Burden is defined as the sum of the longest axial diameter of all stones. The kidney is divided into 3 cavities (pelvis, branches or infundibula and calices). The ureter is defined according to 4 segments (upper, middle, lower and juxtavesical). Special descriptors (sand, match heads and fragments) are defined. The use of a scoring diagram allows for a concise description of the complexity and burden of stone in each renal and ureteral cavity. The system facilitates computerized stratification of upper tract stones.

Humans↗

Patient and personnel exposure during extracorporeal lithotripsy.

Extracorporeal shock wave lithotripsy (ESWL) has provided a nonsurgical approach to treatment of renal stones. The Dornier lithotripter uses dual image intensified x-ray systems to center the stone before treatment. Three imaging modes are offered: a fluoroscopic mode and two video spot filming modes. The average entrance exposure to the stone side of the typical patient at our facility is 2.6 X 10(-3) C kg-1 (10 R) [range: 0.5-7.7 X 10(-3) C kg-1 (2-30 R)] which is comparable and often much less than that reported for percutaneous lithotripsy. Recommendations are made for minimizing patient exposure. Scattered radiation levels in the lithotripter room are presented. We have determined that Pb protective apparel is not required during this procedure provided x-ray operation is temporarily halted should personnel be required to lean directly over the tub to attend to the patient. If the walls of the ESWL room are greater than 1.83 m (6 feet) from the tub, shielding in addition to conventional construction is not required.

Humans↗

Infection (urease) stones.

Infection-induced stones in man probably form solely as a consequence of urealysis which is catalyzed by the bacterial protein urease. Urease stones composed of struvite and carbonate-apatite may form primarily, or as secondary stones or pre-existent metabolic stones. Struvite stones form and grow rapidly owing to (a) supersaturation of urine with stone forming salts, (b) 'salting out' of poorly soluble organic substances normally dissolved in urine and (c) ammonia-induced destruction of the normally protective urothelial glycosaminoglycan layer. Immature (predominantly organic) matrix stones mature into densely mineralized stones. Curative treatment is possible only by eliminating all of the stone and by eradicating all urinary and parenchymal infection. A variety of operative and pharmaceutical approaches are available. Patient treatment must be individualized inasmuch as some patients are better candidates for one type of treatment than another.

Humans↗

Etiopathogenesis of canine struvite urolithiasis.

Urine must be oversaturated with magnesium ammonium phosphate for struvite uroliths to form. Oversaturation of urine with magnesium ammonium phosphate may be associated with several factors, including urinary tract infections with urease-producing microbes, alkaline urine, diet, and genetic predisposition. Of the urease-producing microbes, staphylococci are most struvitogenic in dogs. The precise mechanisms resulting in formation of sterile struvite uroliths in dogs have not been determined.

Animals↗

Etiopathogenesis, clinical manifestations, and management of canine calcium oxalate urolithiasis.

Calcium oxalate uroliths are commonly called metabolic uroliths because they are sequelae of a variety of metabolic abnormalities that alter the composition of body fluids and urine. Factors incriminated in the etiopathogenesis of calcium oxalate urolithiasis include hypercalciuria, hyperoxaluria, and hyperuricosuria. The predominant type of calcium oxalate urolith encountered in dogs is the monohydrate form; however, the dihydrate form may also occur. Male dogs have been more frequently affected than female dogs. Medical therapy should be formulated with the goal of reducing urine concentration of calculogenic substances.

Allopurinol↗

Medical dissolution of canine struvite uroliths.

Medical therapy is an effective method of canine struvite urolith dissolution. Recommendations include (1) eradication or control of urinary tract infection (if present), (2) use of calculolytic diets, and (3) administration of urease inhibitors to patients with persistent urinary tract infection caused by urease-producing microbes.

Animals↗

Teratogenic effect of acetohydroxamic acid in clinically normal beagles.

Acetohydroxamic acid (AHA), a potent urease inhibitor used for treatment of infection-induced struvite urolithiasis, was teratogenic after administration of 25 mg of AHA/kg of body weight/day orally to 5 clinically normal Beagles from the onset of proestrus until parturition. Thirty pups exposed to AHA in utero developed anomalies of the skeletal system, heart, and ventral midline. Cardiac anomalies included atrial septal defects (20%), ventricular septal defects (3%), and atrial and ventricular septal defects (3%). Skeletal anomalies included coccygeal hemivertebrae and fused coccygeal vertebrae (50%), supernumerary vertebrae (67%), supernumerary ribs (50%), duplicated sternebrae (3%), and lumbar hemivertebrae (3%). Defects of the ventral midline of the abdominal wall occurred in 20% of AHA-exposed pups. Other abnormalities included retarded growth, high neonatal mortality, and a decreased number of circulating RBC, compared with those in 30 control pups born to 5 Beagles given a placebo. Adverse effects of AHA in pregnant Beagles were limited to morphologic alterations (Howell-Jolly bodies, spherocytes, and target cells) in a small number of circulating RBC. Slight neutrophilic leukocytosis and monocytosis occurred between 0 and 30 days of pregnancy in dogs given AHA, compared with those in controls. Seemingly, AHA did not influence fertility, conception rate, or length of gestation.

Abnormalities, Drug-Induced↗