Diuretic Doppler ultrasonography in chronic unilateral partial ureteric obstruction in dogs

Abstract

Objective To compare the effects of diuresis induced by a loop diuretic (frusemide), an osmotic diuretic (mannitol) and a high-osmolar radio-contrast medium (sodium iothalamate) on the intrarenal resistive index (RI) in dogs with chronic unilateral partial ureteric obstruction (UPUO). Materials and methods The split renal clearance and intrarenal RI were estimated in 11 dogs with chronic UPUO. Doppler ultrasonography measurements of the interlobar arteries were obtained before and 10 min after the intravenous infusion of 1 mg/kg frusemide, 1 g/kg mannitol or 20 mL 60% sodium iothalamate. The same experimental protocol was repeated with another drug at 1-week intervals. Results There was a significant difference between the intrarenal RI of obstructed and unobstructed kidneys in the chronic phase of UPUO. While mannitol and sodium iothalamate significantly increased the RI in both kidneys, differences in RI between the kidneys decreased after infusing the two drugs. However, while frusemide insignificantly increased the RI in the obstructed kidney, it decreased the RI in unobstructed one. Consequently, the difference in RI between the kidneys increased significantly after administering frusemide. There were no significant differences in urinary volume after administering each of the drugs. Conclusions As there were no significant differences in the diuretic effects of the drugs, frusemide may have additional effects on the RI of unobstructed kidneys other than diuresis. Frusemide increased the difference between the intrarenal RI of the kidneys and therefore may improve the detection of unilateral urinary obstruction in humans.

Contribution of the renin-angiotensin system to the intrarenal resistive index in chronic unilateral partial ureteral obstruction in dogs

“…Eleven mongrel dogs weighing between 10 and 17 kg were used in this experiment, and all these dogs had been used in our previous study. 8 All procedures were performed under general anesthesia using nitrous oxide, oxygen, and halothane (Takeda, Osaka, Japan) with endotracheal intubation and mechanical ventilation after induction by thiopental sodium (25 mg/kg BW; Dainippon, Osaka, Japan) administrated intravenously.…”

“…6,7 We have also reported that only furosemide but not mannitol and sodium iothalamate increased the difference in RI between obstructed and nonobstructed kidneys; therefore, furosemide may affect RI of nonobstructed kidneys through some mechanism other than diuresis. 8 On the other hand, previous studies of the pathophysiology of obstructive uropathy have revealed the important role of the renin-angiotensin system, [9][10][11][12][13][14] and recently captopril renography has been used for diagnosis of not only renovascular hypertension but also obstructive hydronephrosis. 15,16 Therefore, we hypothesized that angiotensin II might have some effects on the acute change in intrarenal RI in ureteral obstruction, because it has a great vasoconstrictive action and angiotensin II receptor subtypes exist in kidneys.…”

Tavşanlarda Unilateral Parsiyel Üreteral Obstruksiyonda Ekskretör Ürografi, Ultrason Rehberli Perkutan Anterograd Pyelografi ve Renal Doppler Ultrasonografi Tanı Yöntemlerinin Karşılaştırılması: Deneysel Çalışma

“…In addition to the discrimination of obstructive and nonobstructive dilatation, it is also imperative to determine localization and extent of the obstructed area in order to avoid unnecessary surgical intervention 4,5 . The early diagnosis and release of obstruction are critical for preventing irreversible damages in affected kidneys 6 . In diagnosis of ureteral obstruction, various imaging methods are used, such as radiography, excretory urography (EU), ultrasonography (US), Doppler ultra sonography (DUS), computer tomography (CT), magnetic resonance imaging (MRI) and percutan antegrade pyelography 7, 8 .…”

“…In diagnosis of ureteral obstruction, various imaging methods are used, such as radiography, excretory urography (EU), ultrasonography (US), Doppler ultra sonography (DUS), computer tomography (CT), magnetic resonance imaging (MRI) and percutan antegrade pyelography 7, 8 . Excretory urography and renal US are routinely used in evaluating urinary system 6 . Excretory urography is a type of contrast study used to verify and localize urinary tract disease.…”

“…Until recently, it has been reported that none of the imaging methods has capability to evaluate the urinary system both anatomically and physiologically 6 . Although conventional grey-scale US provides only an anatomical depiction of the changes in ureteral obstruction, employment of DUS in obstruction cases provide comprehensive information about kidney diseases and indicate renal morphology as well as changes in renal blood flow under different pathophysiological conditions.…”