Feline lower urinary tract disorders. Definition of terms and concepts

Lower urinary tract disorders of male and female cats may be caused by a variety of fundamentally different causes. The term Feline urologic syndrome should be abandoned and substituted with descriptive etiopathogenic terms whenever possible. If the underlying cause cannot be identified, the term Idiopathic lower urinary tract disease is recommended.

Renal hemodynamics in patients with obstructive uropathy evaluated by color Doppler sonography

OBJECTIVES

Prior animal studies have shown through direct pressure measurements that there is a definite rise in the renal vascular resistance in obstruction. Therefore intrarenal hemodynamic changes can be determined by the vascular impedance expressed as pulsatility and resistive indexes (PI and RI) obtained from the Doppler waveforms of intrarenal arteries. We investigated whether various degrees of obstruction result in different hemodynamic responses according to color Doppler sonography.

METHODS

22 kidneys with varied degrees of hydronephrosis and 19 normal kidneys were examined. The pulsatility and resistive index of Doppler waveforms from interlobar arteries were obtained. The grade of hydronephrosis was based upon the width of parenchyma.

RESULTS

The mean resistive index in the study and controls were 0.70 +/- 0.07 and 0.60 +/- 0.03, respectively. The difference was significant (p < 0.001). Pulsatility indexes in the study and controls were 1.07 +/- 0.34 and 0.98 +/- 0.23, respectively. The difference was not significant (p > 0.005). Significant difference was also noticed in the parenchymal widths between both groups (p < 0.001).

CONCLUSION

It appeared that intrarenal color Doppler sonography can provide physiologic information reflecting renal vascular resistance status by means of an easily obtained parameter: resistive index.

[Renal colic]

The pathophysiology of renal colic is related to tension exerted on the excretory cavities by an obstruction, generally a stone, causing secretion of prostaglandins which, in turn, increase the renal blood flow and glomerular filtration rate. This results in a vicious circle explaining the effect of fluid restriction and NSAIDs.

Changing patient and stone features for shock wave lithotripsy (SWL) in Turkey

Shock wave lithotripsy (SWL) has made a revolution in the treatment of urolithiasis. Recent reports suggesting that stone features for SWL have changed during the last years have forced us to compare our initial and last 250 patients treated at our ESWL unit in terms of stone and patient characteristics. We found that the number of ureteric stones and small calyceal stones have increased significantly with time whereas the number of larger stones undergoing SWL has decreased significantly. We believe that this change in stone features is caused by the changing trends in the treatment of stone disease by incorporating other therapeutic options and modifying the SWL indications according to patient characteristics We also believe that prophylactic lithotripsy for asymptomatic calyceal stones still remains to be a debatable issue.

Recurrence rates and severity of urinary calculi

During the last ten years, data of urinary calculi was received in 4094 cases on the criterion of "recurrence", whereby the answer was "yes" in 1446 cases. The overall "adjusted relative recurrence rate" (ARRR) is therefore 35.3%. The importance of an exact physical analysis of urinary stones, involving a differentiation of the various Ca oxalates and Ca phosphates, becomes clear looking at the high recurrence rates for the monomineralic stones of the Ca stone class like brushite and weddellite (ARRR = 66.7% and 50.0%, respectively) compared to apatite and whewellite (ARRR = 36.5% and 29.2%, respectively). Dramatic changes in the composition of the recurrent stone were observed only in 12.7% of all cases. The highest ARRR was found in infection stones with a large content of struvite (about 75%), whereas the total recurrence rate of the infection stone class was about 38%. An assessment of the "danger" of a urinary stone taking into account the criteria of "composition" and "prevalence to recur" is given.

Etiology of calcium oxalate nephrolithiasis in rats. II. The role of the papilla in stone formation

In kidneys of healthy rats submitted to a crystal-inducing diet (CID) with ethylene glycol (EG) and NH4Cl, the fate of retained crystals in the papillar region is studied during a recovery period of one, five or ten days, as model system for human nephrolithiasis. Scanning electron microscopy (SEM) shows, at papillary tips bulging into the calycine space, crystal masses covered either by the epithelium or a thin fibrous veil, or by unidentified mobile cuboidal cells. After CID plus one or five days recovery, small sub-epithelial swellings are seen of large sub-epithelial crystals at or around the papillary tip. After CID plus ten days, massive sub-surface crystal-containing micrometer-sized stones are seen in which the presence of calcium is confirmed by X-ray microanalysis. The papillary tip of rats after a re-challenge with an oxalate load from 0.1 vol% EG for twelve or forty-two days shows minor lesions. But a re-challenge with 0.3 vol% EG for thirty-seven days induces large sub-epithelial papillary millimeter-sized stones. The Von Kossa section staining converts the crystals into a black precipitate, but large peri-tubular or peri-vascular calcium deposits are absent. A new hypothesis about the etiology of an inductive calcium oxalate monohydrate nephrolithiasis is formulated which differs from the one proposed by Randall based on his deductive human kidney studies.

[Renal morphology and urodynamic factors for renal stone formation]

Studies on the pathogenesis of urolithiasis have mainly focused on metabolic disorders. However, metabolic disorders alone are not sufficient to explain the problem. In the present study, morphological and urodynamic differences of the upper urinary tract on both the stone and normal side were examined. There were 35 cases of those who had experienced unilateral, recurrent, and/or multiple stone formation. 1. Morphologic study. Study of the pelvic-caliceal system (PCS) revealed significant differences in the following parameters on the stone side as compared with the normal side. The findings were: 1) the number of minor calices (papillaes), Np, was higher; 2) the number of major calices, Nm, was higher; 3) the number of branches, Nb, was higher; 4) the lower calyx radius, 1(2), was longer; 5) the total calyx area, Ac, was larger; 6) the renal pelvic area, Ar, was larger; 7) and the total area, At, was larger. 2. Urodynamic study. Additional study of the urodynamic factors revealed significant differences in the following parameters on the stone side as compared with the normal side. These findings include: 1) the peristaltic frequency in the upper third of the ureter was less; 2) the difference in peristaltic interval was longer and the rhythm of the peristaltic discharge was irregular. However, no significant difference in the contraction pressure was found except in the pelviureteral junction. After furosemide had been administered, the contraction pressure decreased while the peristaltic frequency increased on both sides. Furthermore, it was found that on the stone side the peristaltic interval decreased significantly as well as the rhythm of the peristaltic discharge becoming regular. The results of the two studies indicate that in the same individual the urine flow in the stone side as compared to the of the normal side is either stagnant or inconstant, thereby creating conditions conductive to the formation and growth of stones which become difficult to discharge owing to these same conditions. Therefore, morphological and urodynamic disorders of the upper urinary tract may be considered as factors contributing to stone formation. It appears that the diuretic action is an effective method for preventing stone recurrence and facilitating stone passage.

Urinary tract stones in pregnancy

The presence of stones during an otherwise uneventful pregnancy is a dramatic and potentially serious issue for the mother, the fetus, and the treating physicians alike. The incidence and predisposing factors are generally the same as in nonpregnant, sexually active, childbearing women. Unique metabolic effects in pregnancy such as hyperuricuria and hypercalciuria, changes in inhibitors of lithiasis formation, stasis, relative dehydration, and the presence of infection all have an impact on stone formation. The anatomic changes and physiologic hydronephrosis of pregnancy make the diagnosis and treatment more challenging. Presenting signs and symptoms include colic, flank pain, hematuria, urinary tract infection, irritative voiding, fever, premature onset or cessation of labor, and pre-eclampsia. The initial evaluation and treatment are again similar to those used for the nonpregnant population. The most appropriate first-line test is renal ultrasonography, which may, by itself, allow the diagnosis to be made and provide enough information for treatment. Radiographic studies, including an appropriately performed excretory urogram, give specific information as to size and location of the stones, location of the kidneys, and differential renal function and can be used safely, but the ionizing radiation risks should be considered. All forms of treatment with the exception of extracorporeal shock wave lithotripsy and some medical procedures are appropriate in the pregnant patient. Close coordination by the urologist, the obstetrician, the pediatrician, the anesthesiologist, and the radiologist is required for the appropriate care of these patients.

[Clinical kidney function studies in sheep. III. Pathologic function changes in nephropathies of sheep and in urolithiasis of rams and billy goats]

Examination of renal function have been carried out in sheep with acute prerenal (n = 6), renal (n = 15) or postrenal failure (n = 3), pyelocystitis (n = 4), and in cases of urolithiasis in rams (n = 16) and billy goats (n = 11) respectively. The calculation of parameters was done on the basis of the estimated weight dependent endogenous creatinine excretion. A control group of 56 healthy non pregnant or early pregnant (< 120th day of pregnancy) ewes have been used. The renal creatinine clearance was reduced and the absolute as well as the fractional renal water excretion was enhanced in all groups of sick animals. An elevated fractional excretion of sodium and phosphate could be seen as well. Functional disturbances could be observed in urolithiasis in like manner as in acute renal failure. There was proteinuria, glucosuria, excessive potassium excretion and often decreased plasma concentration of potassium in both syndromes. A hyperkalemia occurred only in the final state of urolithiasis. No clinical outcome of chronic nephropathies could be seen. Mortality of the described acute nephropathies was about 76%. The results of examination were suitable to control the course and restitution of renal function. They were not helpful for differential diagnosis and prognosis of acute renal failure.

Hematuria associated with hypercalciuria and hyperuricosuria: a practical approach

Hematuria is one of the most common urinary abnormalities found in children. When hypercalciuria was identified as a potential etiology of painless hematuria, many questions arose concerning the general importance of this observation. Subsequently, increased uric acid excretion also has been purported to cause hematuria in children. This review traces the history of these observations and describes the clinical characteristics of the clinical syndrome of hematuria associated with hypercalciuria and hyperuricosuria. Diagnostic criteria of excessive urinary excretion of calcium and uric acid are reviewed; differences in urinary calcium and uric acid excretion between infants and older children are emphasized. Aside from urolithiasis, few long-term consequences from hypercalciuria or hyperuricosuria have been identified, although some debate exists concerning the effect of chronic hypercalciuria upon bone mineralization.

[The stimulation of the urodynamics of the upper urinary tract in the combined treatment of urolithiasis]

Sound, vacuum and electrical stimulation of urodynamics on the units Intrafon, Intraton, electric aspirator has been assessed in 311 urolithiasis patients. Sound stimulation of the upper urinary tracts in the presence of ureteroliths improves urodynamics in 88% of cases, in multiple fragments of the stones crashed at impulse lithotripsy in 81.3%. Vacuum exposure of the upper urinary tracts relieves pain in one third of the patients. The highest effect on urodynamics (93.5%) and the concrement dislodgement rate (82.2%) occurred in sound combined with vacuum stimulation. Modification of the direct electrical stimulation of upper urinary tract urodynamics is proposed to recover the tract tonicity. It can be also used in surgical patients with drained tracts for elimination of the stones and fragments as well as for prevention of lithogenesis.

[The use of an impulse magnetic field in the combined therapy of patients with stone fragments in the upper urinary tract]

The paper covers the experiment's details and the results obtained at stimulation of the kidney projection region and upper ureter with remote-controlled impulse magnetic field (IMF). It was found that IMF activates impulse activity of ureteral smooth muscles in 100% of cases. The technique is detailed of managing ureterolith fragments using IMF combined with iodobromine baths. The results of the proposed treatment are given. A single therapeutic course produced effect in 62.9% of the patients.

[Membrane-destabilizing processes as the universal basis of inflammation]

It is established that active pyelonephritis and operative stress are accompanied with structural and functional changes in erythrocytic membranes: cholesterol and its ethers rose in quantity as well as difficulty oxidized phospholipids, cation adenosine triphosphatase activity changed. Being nonspecific, these changes seemed more pronounced in the active phase of chronic pyelonephritis. Minor structural rearrangement of membrane lipids in surgical patients indicated uneventful postoperative period. It is suggested that bacterial inflammation in the kidneys and urinary tracts may be related to the above shifts. The adjuvant use of dimephosphone produced a clear-cut membrane-stabilizing effect clinically reflected by reduced inflammation and improved renal function.

Enteric and mild hyperoxaluria

Enteric hyperoxaluria complicates extensive disease or resection of the small intestine in the presence of an intact colon, and is associated with calcium oxalate nephrolithiasis. In addition to hyperoxaluria these patients have a low urine volume, low urinary ionic strength and hypocitraturia. Many forms of treatment have been recommended, but none has been subjected to a prospective clinical trial. Mild idiopathic hyperoxaluria is reported in 8-50% of idiopathic calcium oxalate stoneformers. Several pathophysiological mechanisms have been proposed, including low dietary calcium and possible oxalate transport defects in the gut and/or the kidney. Mild hyperoxaluria, or a high oxalate:calcium ratio in the urine, may be particularly important risk factors for calcium oxalate stone formation; an approach to the correction of these abnormalities is proposed.

Urethral stones in women. A case report

Urethral stones are encountered rarely in the urethra in women. We report the clinical and urodynamic findings and the management of 17 stones in a urethral diverticulum.

[The gastroenterorenal interrelationships after a single intake of naftusia mineral water]

Clinico-pathophysiological study revealed both reciprocal and direct relations between gastric and renal reactions on "Naftusia". Gastric secretion and diuresis changed in different directions in urological patients and paralleled in gastro-enterological pathology. Correlation between terms of "Naftusia" evacuation from stomach and intestinal absorption of xylose on one side and intensity of diuresis on the other was direct but unsignificant. Direct significant correlation between the influence of "Naftusia" on xylose excretion and diuresis was established.

The morbidity due to lower urinary tract function in spinal cord injury patients

A review is given of 105 patients with a traumatic spinal cord injury. In 93 patients with a minimum follow up of one year the morbidity due to lower urinary tract function was evaluated, based on the situation at their last control visit. The relation was studied between bladder behaviour and the type of urine evacuation and their influence on upper urinary tract problems, urinary tract infections, stone formation and incontinence. Based on the results of this study the most appropriate method for control of bladder behaviour and urine evacuation in spinal cord injured patients is discussed in view of new treatment modalities such as dorsal rhizotomies and the implantation of an anterior sacral root stimulator.

Xanthine calculi presenting at 1 month of age

Xanthinuria is a rare cause of nephrolithiasis and is usually due to an inherited abnormality in purine metabolism. A 5-year 6-month-old boy was assessed for a history of recurrent episodes of renal colic. The child first presented with symptoms due to xanthine calculi at 1 month of age, the youngest presentation we were able to identify. Xanthine calculi, although rare, should be considered in the differential diagnosis of nephrolithiasis and ureterovesical junction obstruction in children. Xanthine calculi should also be considered when symptoms suggestive of urinary tract infection are present but the urine culture is negative, and when an orange-brown sediment is noted in the urine or similar coloured stains are found in the nappy.

Sex-dependent urolithiasis in the portacaval shunt rat. 2. Hormones and stone formation

Sex-dependent stone formation following portacaval shunt (PCS) was investigated in 82 male and 71 female Sprague-Dawley rats. 72.6% of male PCS rats and none of the female PCS rats developed urolithiasis, in 90.2%, potassium-hydrogen-urate stones formed. Hormonal analysis revealed significant alterations in steroid hormones and glucagon postoperatively. Male PCS rats showed a significant decrease in total and free testosterone and an increase in estradiol and glucagon levels. Female PCS rats showed a marked rise in testosterone and glucagon levels as well as a decrease in estradiol plasma levels. Male PCS rats had higher urinary and plasma uric acid concentrations compared to female PCS and sham-operated rats. Loss of testosterone and rise of glucagon in males was correlated with urolithiasis in so far as stone-forming rats had higher concentrations than non-stone-forming PCS rats. Our findings suggest that hormonal alterations might contribute to sex-dependent stone formation in PCS rats.

[Chronobiological approach to renal colic]

The concentration of lithogenic and antilithogenic substances in urine shows circadian fluctuations. With this investigation we intended to verify the presence of a chronobiologic rhythm of colic pain in urinary tract calculosis. Four hundred and forty seven consecutive patients with a clinical symptomatology related to urinary tract colic pain were studied. They were subdivided according to sex and age (297 M, 150 F; > or = 65 ys 29, < 65 ys 428). Urinary and blood chemical analysis and instrumental examinations permitted to confirm the clinical diagnosis. To evaluate the circadian and circannual variability, acute events were grouped into one calendar year by the month and into a ideal day by the hour of occurrence respectively. Chronobiologic analysis was performed utilising Halberg single cosinor test. The results pointed out that the symptomatology related to urinary tract colic pain presents a circadian rhythmicity either in patients as a whole or in single subgroups (males, females, younger or older than 65 ys). Besides no seasonal variability was demonstrated, perhaps because of the mild climate present in the geographic area in which the study was carried on.

Plain radiography, renography, and 99mTc-DMSA renal scintigraphy before and after extracorporeal shock wave lithotripsy for urolithiasis

Eighteen patients were evaluated before and 5 weeks after the first treatment with extracorporeal shock wave lithotripsy (ESWL) using abdominal plain radiography, 131I-hippuran probe renography, and 99mTc-dimercaptosuccinic acid scintigraphy. In 6 patients no urolithiasis was present on the post ESWL plain radiograph, in 7 the size had decreased, and in 5 the stone mass was unchanged. The renograms were within normal range in the 6 patients who were cured by ESWL, whereas this was the case for only 4 of the 12 who still had renal calculi. In 2 patients pelvic stones had descended into the ureter after ESWL, and the renograms indicated obstruction. Another 3 patients had ureteral stones, whereas in the remaining 7 patients only pelvic stones were found on the plain radiographs. In no patient did the scintigrams reveal scars. It is concluded that abdominal plain radiography of the urinary tract and probe renography are complementary and sufficient in the monitoring of patients with urolithiasis post ESWL.