Experimental Partial Ureteric Obstruction: Pathophysiological Changes in Upper Tract Pressures and Renal Blood Flow

Ryan, P. C.; Maher, K. P.; Murphy, Bernadette; Hurley, Gail; Fitzpatrick, John M.

doi:10.1016/s0022-5347(17)43297-6

Cited by 57 publications

(22 citation statements)

References 12 publications

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“…Based on our series, the RI in the very acute setting of obstruction most likely will be normal, then after complete obstruction persists the intrarenal diastolic flow diminishes and the RI will rise. This may be due to direct back pressure within the collecting system or possibly the release of vasoactive factors [10,14,19,20].…”

Section: Discussionmentioning

confidence: 99%

New techniques of ultrasound and color Doppler in the prospective evaluation of acute renal obstruction. Do they replace the intravenous urogram?

et al. 1995

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Section: Discussionmentioning

confidence: 99%

New techniques of ultrasound and color Doppler in the prospective evaluation of acute renal obstruction. Do they replace the intravenous urogram?

et al. 1995

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“…14,15 The response of the renal blood flow to the site of urinary obstruction is said to be phasic. [16][17][18][19] At the onset of the obstruction, there is an immediate increase in the renal pelvic pressure, which results in the vasodilatation caused by the vasoconstrictor factors. [20][21][22] As this obstruction continues, there is a vasoconstriction which is caused by the hormonal regulatory systems.…”

Section: Discussionmentioning

confidence: 99%

Mean resistive index as a prognostic tool for hydronephrosis in patients with acute renal colic: a study in a tertiary care

Ravindernath

Reddy

2017

Int J Adv Med

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Background: Uretolithiasis is one of the most common cause of urinary tract obstruction which leads to the admission into the emergency ward. The detection of urolithiasis or acute renal colic is by the radiography, conventional ultrasonography (US) and intravenous urography (IVU). A colour Doppler USG measures this change as a resistive index (RI) of the arcuate arteries at the corticomedullary junction or the interlobar arteries.Methods: 84 patients between the ages 15-50 years, who were admitted to the Emergency department of our hospital with unilateral renal colic were included into our study. Detailed demographic data was collected from all the patients and they were all subjected to a thorough physical and clinical examination. Bladder ultrasound was taken along with color Doppler for all the patients at the time of admission for every 6 hours. Thus, an increased RI index signifies an obstruction without a dilatation.Results: Left flank pain was slightly more than the right flank pain, although this was not found to be significant. Most of the patients were presented with vomiting or nausea and dysuria was seen in 48 patients. there were 41 cases of hydronephrosis in total and all of them were positive for mean RI. The specificity with the mean resistive index with color Doppler was 90%, while the sensitivity was 100%. Around 95% of the prediction was accurate with mean resistive index, with more than 90% efficiency.Conclusions: The mean resistive index is a very good tool for the diagnosis of hydronephrosis, with a very high level of specificity and sensitivity.

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“…15,16 The renal arterial blood flow exhibits a biphasic hemodynamic response to complete urinary obstruction. 1,2,6,17,18 Immediately after the onset of obstruction, an increase in renal pelvic pressure causes diffuse vasodilatation of the renal vascular bed due to release of local prostaglandins. With prolonged complete obstruction, a multitude of complex hormonal regulatory systems reverse the initial vasodilatation and produce diffuse vasoconstriction of the renal vascular bed that may last the duration of obstruction.…”

Section: Discussionmentioning

confidence: 99%

“…[4][5][6]15,19 Renal blood flow decreases in response to chronic partial obstruction of the ureter, which results in decreased urine filtration and subsequent return of intrapelvic pressure to within the normal range. 1 Other factors causing normalization of intrapelvic pressures include increased venous and lymphatic reabsorption of urine and dilatation of the urinary tract proximal to the obstruction. Several authors have reported that the mean RI may not be elevated in patients with partial urinary obstruction.…”

Section: Discussionmentioning

confidence: 99%

Resistive indices in the evaluation of infants with obstructive and nonobstructive pyelocaliectasis.

Vade

Dudiak²,

McCarthy³

et al. 1999

Journal of Ultrasound in Medicine

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onography plays an important role in the identification of the dilated renal collecting system in the infant. Gray scale sonography accurately identifies abnormal dilation of the renal collecting system; however, its value is limited in differentiating obstructive from reflux uropathy.Studies of the pathophysiology of obstruction have shown that obstruction causes an increase in vascular resistance and a subsequent decrease in renal blood flow. 1-3 Platt and coworkers suggested that the decrease in renal blood flow secondary to obstruction could be measured by the RI ([peak systolic velocity -end diastolic velocity]/peak systolic velocity) and provide an accurate, noninvasive method for diagnosing obstructive uropathy. 4 Platt and coworkers noted that when the DRI between the two kidneys is also taken into consideration in the evaluation of unilateral pyelocaliectasis, the accuracy of Doppler sonography in detecting obstructive hydronephrosis is increased. 4 Conclusions regarding the accuracy of the RI using a threshold value of 0.7 and a DRI of 0.08 or greater in the identification of obstructive uropathy in adults have been mixed. [4][5][6][7] Renal RIs are normally higher in children compared to adults up to the age of 10 years, with the highest values in infants under the age of 1 year. [8][9][10][11][12] Received October 17, 1998, from Loyola University Medical Center Diagnosing obstructive uropathy by renal resistive indices calculated from duplex Doppler sonographic waveforms has been supported as well as challenged in the radiology literature relating to adults. Despite reports of normally higher resistive indices in children as compared to adults, two studies have documented high sensitivity and specificity of renal Doppler sonography in the diagnosis of obstructive uropathy in children, using the same discriminatory criterion of a resistive index of 0.7 or greater as used in adults. We evaluated 43 infants with significant or bilateral pyelocaliectasis secondary to both obstructive and unobstructive uropathy and found no significant difference in the mean resistive indices or the mean difference in resistive indices of two kidneys in one patient. We conclude that Doppler sonography in infants has no value in differentiating obstructive from nonobstructive pyelocaliectasis.

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Experimental Partial Ureteric Obstruction: Pathophysiological Changes in Upper Tract Pressures and Renal Blood Flow

Cited by 57 publications

References 12 publications

New techniques of ultrasound and color Doppler in the prospective evaluation of acute renal obstruction. Do they replace the intravenous urogram?

New techniques of ultrasound and color Doppler in the prospective evaluation of acute renal obstruction. Do they replace the intravenous urogram?

Mean resistive index as a prognostic tool for hydronephrosis in patients with acute renal colic: a study in a tertiary care

Resistive indices in the evaluation of infants with obstructive and nonobstructive pyelocaliectasis.

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