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URETERAL OPENING PRESSURE. J Urol 1998. [DOI: 10.1097/00005392-199804000-00082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Fung LC, Churchill BM, McLorie GA, Chait PG, Khoury AE. Ureteral opening pressure: a novel parameter for the evaluation of pediatric hydronephrosis. J Urol 1998; 159:1326-30. [PMID: 9507877 DOI: 10.1016/s0022-5347(01)63609-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE The antegrade nephrostogram is an important tool in the evaluation of the upper urinary tract. However, the information currently provided by a nephrostogram is largely limited to anatomical details. To establish a meaningful pressure-flow parameter that may be incorporated into a routine nephrostogram, we evaluated the ureteral opening pressure (defined as the pressure at which contrast material is first seen beyond the suspected site of obstruction) and correlated these findings with the results of pressure-flow studies performed with an external infusion and/or furosemide induced diuresis. MATERIALS AND METHODS A total of 52 renal units were studied under a prospective pressure-flow study protocol. All patients had grade 3 or 4 hydronephrosis (Society of Fetal Urology classification) and patient age range was 0.2 to 12 years (median 1.1). The suspected sites of obstruction were the ureteropelvic and ureterovesical junctions in 42 and 10 renal units, respectively. With the patient under general anesthesia 22 gauge percutaneous nephrostomy needles were inserted. Pressure-flow studies with an external infusion and/or furosemide induced diuresis were then performed. As the renal pelvic pressure progressively increased during the course of the pressure-flow studies, the renal pelvic pressure at which contrast material was first seen to appear distal to the suspected site of obstruction was recorded as the ureteral opening pressure. Ureteral opening pressures were compared to the results of the pressure-flow studies. RESULTS With a positive test defined as renal pelvic pressure greater than 14 cm. water, positive ureteral opening pressures were associated with positive pressure-flow study results in 100% of the cases, regardless of which form of pressure-flow study was used or where the suspected site of obstruction was located. In contrast, negative ureteral opening pressures had specificities and negative predictive values of only 19 to 57%, depending on the form of the pressure-flow study and the suspected site of obstruction. CONCLUSIONS An elevated ureteral opening pressure was 100% predictive of obstruction and may obviate the need for more elaborate pressure-flow analyses. However, if the ureteral pelvic pressure remained low, the possibility of a potentially significant obstruction could not be definitively eliminated and further evaluation was required.
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Affiliation(s)
- L C Fung
- Department of Surgery, University of Massachusetts Medical School, Worcester, USA
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Fung LC, Atala A. Constant elevation in renal pelvic pressure induces an increase in urinary N-acetyl-beta-D-glucosaminidase in a nonobstructive porcine model. J Urol 1998; 159:212-6. [PMID: 9400483 DOI: 10.1016/s0022-5347(01)64070-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE To clarify the physiological significance of renal pelvic pressure elevations encountered in the evaluation of hydronephrotic kidney we examined the effects of different levels of renal pelvic pressure on the induction of renal injury. MATERIALS AND METHODS A nonobstructive porcine model was created in which the urine drained against a constant predetermined pressure gradient. Renal pelvic pressure of 10, 20 and 40 cm. was created in 2, 2 and 4 animals, respectively. During 18 to 23 hours serial urinary N-acetyl-beta-D-glucosaminidase levels were determined as an indicator of renal tubular injury. Tissue specimens were examined histologically and renal arterial blood flow was monitored. RESULTS Urinary N-acetyl-beta-D-glucosaminidase levels in the kidneys subjected to 10 cm. water remained essentially unchanged. However, at 20 and 40 cm. water statistically significant increases were observed. Similarly, renal arterial blood flow was unchanged at 10 cm. water but it became significantly lower than in controls at 20 and 40 cm. water. Histological evaluation revealed mild to moderate tubular dilatation in the kidneys subjected to 20 and 40 cm. water. CONCLUSIONS Excessively high collecting system pressure induced renal cellular injury, as reflected by an increase in urinary N-acetyl-beta-D-glucosaminidase levels. While renal pelvic pressure up to 10 cm. water appeared to be innocuous, renal cellular injury was evident within as little as 1 hour at renal pelvic pressures 20 cm. water or greater. The degree of N-acetyl-beta-D-glucosaminidase in the urine also correlated with a decrease in renal arterial blood flow.
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Affiliation(s)
- L C Fung
- Department of Urology, Children's Hospital, Boston, Massachusetts 02115, USA
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Pressure Decay Half-life. J Urol 1996. [DOI: 10.1097/00005392-199603000-00075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Fung LC, Khoury AE, McLorie GA, Chait PG, Churchill BM. Pressure decay half-life: a method for characterizing upper urinary tract urine transport. J Urol 1996; 155:1045-9. [PMID: 8583561 DOI: 10.1016/s0022-5347(01)66387-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE We examined the pressure dynamics of hydronephrotic kidneys after elevated renal pelvic pressure developed. MATERIALS AND METHODS A total of 40 patients (44 renal units) 0.2 to 12 years old was evaluated. Transiently elevated renal pelvic pressure was induced with a percutaneous nephrostomy infusion. After renal pelvic pressure increased the infusion was stopped and the subsequent decrease in pressure with time was plotted as a pressure decay curve. The rapidity of the decrease in renal pelvic pressure was then quantitated as a half-life for each pressure decay curve. Pressure decay half-lives were compared to corresponding pressure flow study results and diuretic nuclear renography half-lives. RESULTS Renal units without elevated renal pelvic pressure during infusion at a high physiological flow rate were associated with relatively rapid pressure decay, whereas those with elevated renal pelvic pressure during infusion were associated with much slower pressure decay (p < 0.0001). Diuretic nuclear renography half-lives had no correlation with collecting system pressure dynamics. CONCLUSIONS Pressure decay half-life provides an objective quantitative measure of the relative tendency for elevated renal pelvic pressure to persist. When used in conjunction with other diagnostic modalities, it may be a useful parameter for a comprehensive assessment of the risk of pressure induced injury in hydronephrotic kidneys.
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Affiliation(s)
- L C Fung
- Department of Surgery (Division of Urology), Hospital for Sick Children, Toronto, Ontario, Canada
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Fung LC, Khoury AE, McLorie GA, Chait PG, Churchill BM. Evaluation of pediatric hydronephrosis using individualized pressure flow criteria. J Urol 1995; 154:671-6. [PMID: 7609153 DOI: 10.1097/00005392-199508000-00089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In pursuit of a diagnostic modality better able to assess collecting system urine transport characteristics while operating within physiological ranges, a new set of guidelines for the pressure flow study was proposed. An infusion rate individualized for each patient was chosen based on a calculated estimate of the maximum physiological urine output, adjusted for patient size and age. The upper limit of normal renal pelvic pressure used was 14 cm. water. We evaluated 37 renal units with grade 3 or 4 hydronephrosis with the individualized pressure flow study. Patient age ranged from 0.2 to 12 years (median 1.1). Calculated individualized infusion rates ranged from 1.3 to 12.5 ml. per minute and resulting renal pelvic pressures ranged from 7 to greater than 40 cm. water. In each patient the corresponding renal pelvic pressure resulting from a fixed 10 ml. per minute infusion rate was uniformly equal to or higher than the corresponding individualized study pressures (p < 0.0001). Disagreement between the individualized and fixed rate pressure flow studies was highest in the younger patients. The correlation coefficient between diuretic nuclear renography half-times and individualized pressure flow results was 0.09, indicative of a random association between the 2 variables. By using individualized infusion rates based on the calculated estimate of the maximum physiological urine output, much of the falsely high pressures induced by nonphysiologically high fixed infusion rates in pediatric patients can be avoided.
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Affiliation(s)
- L C Fung
- Department of Surgery, Hospital for Sick Children, Toronto, Ontario, Canada
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Fung LC, Khoury AE, McLorie GA, Chait PG, Churchill BM. Evaluation of Pediatric Hydronephrosis Using Individualized Pressure Flow Criteria. J Urol 1995. [DOI: 10.1016/s0022-5347(01)67130-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Leo C.T. Fung
- Department of Surgery, Division of Urology and Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Antoine E. Khoury
- Department of Surgery, Division of Urology and Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Gordon A. McLorie
- Department of Surgery, Division of Urology and Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Peter G. Chait
- Department of Surgery, Division of Urology and Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Bernard M. Churchill
- Department of Surgery, Division of Urology and Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada
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Steinhausen M, Snoei H, Parekh N, Baker R, Johnson PC. Hydronephrosis: a new method to visualize vas afferens, efferens, and glomerular network. Kidney Int 1983; 23:794-806. [PMID: 6887692 DOI: 10.1038/ki.1983.98] [Citation(s) in RCA: 136] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We have developed a new preparation for in vivo visualization of the glomerular microcirculation, the vas afferens and the vas efferens. This preparation utilizes postischemic hydronephrosis (PIH) to destroy the renal tubular system while preserving a portion of the cortex. In this preparation, glomeruli and associated vasculature remained intact. Observations can be made with either incident light or transillumination. The inner diameter of the vas afferens, measured within 50 microns of the glomerular vascular pole, was 7.9 +/- 0.5 microns (N = 12; SEM) while that of the vas efferens was 7.7 +/- 0.5 microns (N = 12). Both vessels were narrower adjacent to the glomerulus; minimal diameters in this region were 4.5 +/- 0.5 microns (N = 10) and 4.3 +/- 0.5 microns (N = 11), respectively. A specialized round cell, which may act as a sphincter, was seen in the vas efferens. In a second series of experiments, blood velocity was measured in the vas afferens and efferens about 100 microns from the vascular pole. Mean control velocities at these sites were 5.9 +/- 0.9 (N = 14) and 4.6 +/- 1.3 (N = 9) mm X sec-1, respectively; diameters at these same sites were 10.3 +/- 0.6 microns and 11.2 +/- 0.7. During angiotensin II infusion (first series, 0.2 to 0.4 micrograms X min-1 X kg-1, i.v.) the vas efferens in the vicinity of the glomerulus constricted by 22% whereas the corresponding vas afferens showed no consistent response. During angiotensin II infusion, the filtration fraction (GFR/RPF) may, therefore, be elevated by an increased resistance in the vas efferens, particularly at the outflow point of the glomerulus. In the second series of experiments higher dosages of angiotensin II caused vasoconstriction of both vessels, especially at sites more distant from the glomerulus. Furthermore, the new approach is suitable for observing the flow direction within single capillaries of one third to one half of the glomerulus. Therefore, for the first time it is possible to determine the real flow direction in a three-dimensional way.
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Garland HO, Brunt JN, Taylor CJ, Green R. Computerised image analysis of split-drop micropuncture data. Pflugers Arch 1979; 381:11-4. [PMID: 573449 DOI: 10.1007/bf00582325] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A technique is described for rapid and reproducible analysis of split-drop micropuncture sequences recorded on film. Automatic identification of the droplet menisci in each cine frame, and subsequent evaluation is performed by a computerised T.V. image analysis system. In comparison with a more conventional technique, the improvement in reproducibility of the analysis is achieved without loss of accuracy and is accompanied by a three fold increase in speed.
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Steinhausen M, Hill E, Parekh N. Intravital microscopical studies of the tubular urine flow in the conscious rat. Pflugers Arch 1976; 362:261-4. [PMID: 944434 DOI: 10.1007/bf00581179] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A method was developed which allowed microscopical observation of the kidney in conscious and anesthetized rats. The left kidney was freed from surrounding tissue and placed in a plexiglas chamber with a protecting window which was sewed into the skin of left flank. During the experiments the covering glass was removed. Tubular transit time was measured in the conscious state and during inactin anesthesia in control rats as well as in unilaterally nephrectomized rats with compensatory hypertrophy. Transit time of lissamine green within proximal convolutions and Henle's loop increased significantly in both series during anesthesia. Luminal and outer diameters of proximal tubules in control rats were evaluated from microphotogramms of the kidney surface, they did not change due to anesthesia. The results could be mainly explained by a decrease in glomerular filtration rate due to anesthesia. Possible mechanisms are discussed which could explain the observed transit time in Henle's loops and distal convolutions in control and uninephrectomized rats.
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Hierholzer K, Müller-Suur R, Gutsche HU, Butz M, Lichtenstein I. Filtration in surface glomeruli as regulated by flow rate through the loop of Henle. Pflugers Arch 1974; 352:315-37. [PMID: 4475413 DOI: 10.1007/bf00585685] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Steinhausen M, Eisenbach GM, Böttcher W. High-frequency microcinematographic measurements on peritubular blood flow under control conditions and after temporary ischemia of rat kidneys. Pflugers Arch 1973; 339:273-88. [PMID: 4735609 DOI: 10.1007/bf00594163] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Eisenbach GM, Steinhausen M. Micropuncture studies after temporary ischemia of rat kidneys. Pflugers Arch 1973; 343:11-25. [PMID: 4796815 DOI: 10.1007/bf00586571] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Györy AZ. Reexamination of the split oil droplet method as applied to kidney tubules. Pflugers Arch 1971; 324:328-43. [PMID: 5103165 DOI: 10.1007/bf00592461] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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de Rouffignac C, Deiss S, Bonvalet JP. [Determination of the glomerular filtration rate of individual nephrons accessible and inaccessible to micropuncture]. Pflugers Arch 1970; 315:273-90. [PMID: 5461320 DOI: 10.1007/bf00593456] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Kulenkampff C. Verhandlungen �rztlicher Gesellschaften. J Mol Med (Berl) 1970. [DOI: 10.1007/bf01485111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Steinhausen M, Eisenbach GM, Galaske R. A counter-current system of the surface of the renal cortex of rats. Pflugers Arch 1970; 318:244-58. [PMID: 5465177 DOI: 10.1007/bf00593664] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Aukland K, Johannesen J, Kiil F. In vivo measurements of local metabolic rate in the dog kidney. Effect of mersalyl, chlorothiazide, ethacrynic acid and furosemide. Scand J Clin Lab Invest 1969; 23:317-30. [PMID: 5383314 DOI: 10.3109/00365516909081697] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Steinhausen M, Eisenbach GM, Helmstädter V. Concentration of Lissamine green in proximal tubules of antidiuretic and mercury poisoned rats and the permeability of these tubules. Pflugers Arch 1969; 311:1-15. [PMID: 5817285 DOI: 10.1007/bf00588058] [Citation(s) in RCA: 49] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Gertz KH, Braun-Schubert G, Brandis M. [Method of measuring the filtration rate of single glomeruli situated near the surface of the kidney]. Pflugers Arch 1969; 310:109-15. [PMID: 5388300 DOI: 10.1007/bf00586768] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Schnermann J, Levine DZ, Horster M. A direct evaluation of the Gertz hypothesis on single rat proximal tubules in vivo: failure of the tubular volume to be the sole determinant of the reabsorptive rate. Pflugers Arch 1969; 308:149-65. [PMID: 5814034 DOI: 10.1007/bf00587022] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Schnermann J, Wahl M, Liebau G, Fischbach H. Balance between tubular flow rate and net fluid reabsorption in the proximal convolution of the rat kidney. I. Dependency of reabsorptive net fluid flux upon proximal tubular surface area at spontaneous variations of filtration rate. Pflugers Arch 1968; 304:90-103. [PMID: 5748572 DOI: 10.1007/bf00586722] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Wiederholt M, Langer KH, Thoenes W, Hierholzer K. [Functional and morphologic investigation of proximal and distal convolutions of rat kidney under the influence of the split-oil droplet method]. Pflugers Arch 1968; 302:166-91. [PMID: 5748554 DOI: 10.1007/bf00586868] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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