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Urinary Rate Determination by Ureteral Catheterization in Conscious Unoperated Dogs
THE JOURNAL OF UROLOGY
Vol. 64, No. 6, December 1950 Printed in U.S.A.
URINARY RATE DETERMINATION BY URETERAL CATHETERIZATION IN CONSCIOUS UNOPERATED DOGS LOUIS A. TOTH, Ph.D. From the Department of Physiology, Louisiana State University School of 1vledicine, New Orleans, La.
For the determination of urinary rates from each kidney in unanesthetized dogs two methods can be employed. It is possible to exteriorize the orifices of the ureters so that the urine drains to the outside of the body, thus facilitating the quantitative determination of urine output from each kidney. JVIaluf's report is the most recent describing the surgery necessary for the exteriorization of the vesical trigone in bitches. The second method for the quantitative collection of urine from each kidney is by ureteral catheterization following the procedure usually employed clinically. Rmvntree, Fitz and Geraghty mentioned this method but did not elaborate on the procedure. The present report describes the method for the catheterization of one or both ureters in conscious, unoperated dogs. MATERIAL AND ME'I'HODS
Trained female dogs, weighing 12-15 kg., were loosely restrained in a supine position on a dog board. The animals had free access to water previous to the experiment but had been ·without food for 24 hours. A hard rubber urethral catheter was passed into the urinary bladder to empty it and to dilate the urethra. In a dog that has been used for a number of experiments the cystoscope can be passed without preliminary urethral dilation. After the removal of the catheter the cystoscope ·with the observation telescope in the convex sheath was passed into the bladder. No topical anesthetic was used. For the dogs used in the present work a children's cystoscope, 16 F caliber having a capacity for two 6 F catheters, is the instrument of choice. vVith the cystoscope in place the urinary bladder was washed once with ·warm sterile water, the ·washing fluid drained and the bladder distended with 100 cc warm water. A plastic sheet covered the hind quarters of the animal because at times the dog did not retain the distending fluid in the bladder during the catheterization. It was also advisable to have some protective partitions between the dog's hind legs and the observer's face. The ureteral orifices were easily located through the observation telescope because of the wide field of this apparatus. The location of these structures was facilitated in new dogs by injecting 1 cc sterile aqueous 4 per cent indigo carmine solution intramuscularly. After locating the orifices, the bladder was emptied and the observation telescope removed. The catheterizing telescope, with graduated whistle tip catheters in place and filled with water, was introduced into the sheath. The bladder ·was again distended with water. A catheter was passed into the orifice with the aid of the deflector and slowly pushed up into or near the pelvis of the kidney. The second ureter was catheterized likewise. The cystoscope was then removed, leaving the catheters in place by threading them through the instrument as it was 11·ithdrawn from the hladder and 737
738
LOUIS A. TOTH
urethra. The distending fluid remained in the bladder. The urinary rate was determined by observing the drops of urine issuing from the catheters and recording on a kymograph. The instruments and catheters were sterilized by immersing them for 15 minutes in an aqueous solution of 1: 5000 oxycyanide of mercury and rinsing them in sterile water before use. It was found necessary to perform the experiments in a cool room because high temperatures cause the dogs to pant, resulting in bobbing movement of the bladder and making it extremely difficult to pass the catheter into the orifice.
35
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____. UFT UR~TER
D..
o--o Rll",t-lT URETER
IO U) D..
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05
20
40
60
80
100
120
MINUTES
Fm. 1. Urinary rates from catheterized ureters in conscious dogs. Each point on curve is average minute rate for preceding 2-minute period. A, control experiment. B, animal received 23 cc water/kg. by stomach tube at minus 40 minutes. At arrow, animal was given 1/2 cc pituitrin intramuscularly. EXPERIMENTS AND RESULTS
A total of 30 experiments were carried out on 4 dogs. Fifteen experiments were performed on dog B, 10 on dog Q, 3 on dog L and 2 on dog N. The number of times both ureters were catheterized in these animals were 10, 3, 1 and 1 respectively. The results from a representative experiment are presented in figure 1,A, which is a graph of the urinary rates in a dog with both ureters catheterized. The animal was not subjected to any experimentation. It is seen that the rates were quite constant varying between 1 and 3 drops per minute. (This rate can be converted into cubic centimeters by dividing by 33, the number of drops in 1 cc of urine.) The fluctuations in the rates from the two kidneys were alike especially when the output was low. Figure 1,B shows the responses of the 2 kidneys during water diuresis. When the diuresis was pronounced ½cc of pituitrin (Parke, Davis & Co. Obstetrical) was injected intramuscularly to determine how rapidly the rate could be affected. With the urine draining from or near the renal pelvis there was no time lag influencing the effect.
URINARY RATE DETERMINATION
739
DISCUSSION
The primary purpose of this research was to perfect a method whereby urinary output could be determined quantitatively and separately from each kidney in conscious, unoperated dogs. For an animal to be used repeatedly over a long period of time, and with a minimum amount of special care, ureteral catheterization has an advantage over exteriorization of the ureteral orifices. In the latter preparation the urine is wetting the animal's legs and abdomen, and will bring about cutaneous sloughing unless daily attention is given the animal. Maluf recommended treatment with 70 per cent ethyl alcohol once or twice daily to prevent cutaneous necrosis. The danger of an ascending infection in the renal apparatus after ureteral exteriorization is always present. A number of years ago the author transplanted the ureteral papillae to ventrolateral positions in several dogs but was not successful in preventing renal infections. Judging from microscopic examination of the urine, ureteral catheterization has not resulted in any infection in the dogs used in this series over a period of 12 months. That there is some .trauma to the urinary bladder from the passage of the cystoscope, and to the ureteral orifices by the repeated catheterization, is indicated by the appearance of these structures. The bladder wall and the orifices of the ureters were congested after the dogs had been used weekly over a period of time. To decrease the cumulative effects of the trauma the animal should be catheterized at 14-day intervals. Not every attempt at ureteral catheterization, even in the same dog, was successful. The curved course of the ureter in the vesical portion makes it difficult, and at times impossible, to pass a catheter high into the ureter. This difficulty can be overcome to a great extent by selecting dogs in which one finds, by trial, that the catheter can be passed easily. In dog Bin this series, double catheterization was successful in a large percentage of the attempts. The use of a smaller catheter than a No. 6 is not advised. A catheter of this size completely obturates the ureter of a 12-kg. dog and eliminates the danger of leakage into the bladder. In some experiments of this series in which indigo carmine was used, no colored urine was seen leaking into the bladder even though a water diuresis was present. The lumen of a small catheter will also be occluded more easily. In a few experiments the catheter was gradually forced from the ureter by peristaltic activity. The urinary rate did not change significantly; but the regularity of the drops gradually gave way to an intermittency. When the tip entered the bladder a gush of drops came through the catheter. The distending fluid in the bladder, therefore, served 3 purposes: it facilitated the catheterization of the ureters; it helped to prevent leakage of urine around the catheter; and it indicated when the catheter tip entered the bladder. SUMMARY
A procedure is described for ureteral catheterization in conscious unoperated dogs for the quantitative determination of urinary rates from each kidney. REFERENCES MALUF, N. S. R.: Ann. Surg., 130: 43, 1949. ROWNTREE, L. G., FITZ, R. AND GERAGHTY,
J. T.: Arch. Int. Med., 11: 121, 1913.
Vol. 64, No. 6, December 1950 Printed in U.S.A.
URINARY RATE DETERMINATION BY URETERAL CATHETERIZATION IN CONSCIOUS UNOPERATED DOGS LOUIS A. TOTH, Ph.D. From the Department of Physiology, Louisiana State University School of 1vledicine, New Orleans, La.
For the determination of urinary rates from each kidney in unanesthetized dogs two methods can be employed. It is possible to exteriorize the orifices of the ureters so that the urine drains to the outside of the body, thus facilitating the quantitative determination of urine output from each kidney. JVIaluf's report is the most recent describing the surgery necessary for the exteriorization of the vesical trigone in bitches. The second method for the quantitative collection of urine from each kidney is by ureteral catheterization following the procedure usually employed clinically. Rmvntree, Fitz and Geraghty mentioned this method but did not elaborate on the procedure. The present report describes the method for the catheterization of one or both ureters in conscious, unoperated dogs. MATERIAL AND ME'I'HODS
Trained female dogs, weighing 12-15 kg., were loosely restrained in a supine position on a dog board. The animals had free access to water previous to the experiment but had been ·without food for 24 hours. A hard rubber urethral catheter was passed into the urinary bladder to empty it and to dilate the urethra. In a dog that has been used for a number of experiments the cystoscope can be passed without preliminary urethral dilation. After the removal of the catheter the cystoscope ·with the observation telescope in the convex sheath was passed into the bladder. No topical anesthetic was used. For the dogs used in the present work a children's cystoscope, 16 F caliber having a capacity for two 6 F catheters, is the instrument of choice. vVith the cystoscope in place the urinary bladder was washed once with ·warm sterile water, the ·washing fluid drained and the bladder distended with 100 cc warm water. A plastic sheet covered the hind quarters of the animal because at times the dog did not retain the distending fluid in the bladder during the catheterization. It was also advisable to have some protective partitions between the dog's hind legs and the observer's face. The ureteral orifices were easily located through the observation telescope because of the wide field of this apparatus. The location of these structures was facilitated in new dogs by injecting 1 cc sterile aqueous 4 per cent indigo carmine solution intramuscularly. After locating the orifices, the bladder was emptied and the observation telescope removed. The catheterizing telescope, with graduated whistle tip catheters in place and filled with water, was introduced into the sheath. The bladder ·was again distended with water. A catheter was passed into the orifice with the aid of the deflector and slowly pushed up into or near the pelvis of the kidney. The second ureter was catheterized likewise. The cystoscope was then removed, leaving the catheters in place by threading them through the instrument as it was 11·ithdrawn from the hladder and 737
738
LOUIS A. TOTH
urethra. The distending fluid remained in the bladder. The urinary rate was determined by observing the drops of urine issuing from the catheters and recording on a kymograph. The instruments and catheters were sterilized by immersing them for 15 minutes in an aqueous solution of 1: 5000 oxycyanide of mercury and rinsing them in sterile water before use. It was found necessary to perform the experiments in a cool room because high temperatures cause the dogs to pant, resulting in bobbing movement of the bladder and making it extremely difficult to pass the catheter into the orifice.
35
B
~l~I ;:;;;:
25 w20
0
t-
=> z
20
40
60
MINUTES
~,s
..,a:
____. UFT UR~TER
D..
o--o Rll",t-lT URETER
IO U) D..
~
05
20
40
60
80
100
120
MINUTES
Fm. 1. Urinary rates from catheterized ureters in conscious dogs. Each point on curve is average minute rate for preceding 2-minute period. A, control experiment. B, animal received 23 cc water/kg. by stomach tube at minus 40 minutes. At arrow, animal was given 1/2 cc pituitrin intramuscularly. EXPERIMENTS AND RESULTS
A total of 30 experiments were carried out on 4 dogs. Fifteen experiments were performed on dog B, 10 on dog Q, 3 on dog L and 2 on dog N. The number of times both ureters were catheterized in these animals were 10, 3, 1 and 1 respectively. The results from a representative experiment are presented in figure 1,A, which is a graph of the urinary rates in a dog with both ureters catheterized. The animal was not subjected to any experimentation. It is seen that the rates were quite constant varying between 1 and 3 drops per minute. (This rate can be converted into cubic centimeters by dividing by 33, the number of drops in 1 cc of urine.) The fluctuations in the rates from the two kidneys were alike especially when the output was low. Figure 1,B shows the responses of the 2 kidneys during water diuresis. When the diuresis was pronounced ½cc of pituitrin (Parke, Davis & Co. Obstetrical) was injected intramuscularly to determine how rapidly the rate could be affected. With the urine draining from or near the renal pelvis there was no time lag influencing the effect.
URINARY RATE DETERMINATION
739
DISCUSSION
The primary purpose of this research was to perfect a method whereby urinary output could be determined quantitatively and separately from each kidney in conscious, unoperated dogs. For an animal to be used repeatedly over a long period of time, and with a minimum amount of special care, ureteral catheterization has an advantage over exteriorization of the ureteral orifices. In the latter preparation the urine is wetting the animal's legs and abdomen, and will bring about cutaneous sloughing unless daily attention is given the animal. Maluf recommended treatment with 70 per cent ethyl alcohol once or twice daily to prevent cutaneous necrosis. The danger of an ascending infection in the renal apparatus after ureteral exteriorization is always present. A number of years ago the author transplanted the ureteral papillae to ventrolateral positions in several dogs but was not successful in preventing renal infections. Judging from microscopic examination of the urine, ureteral catheterization has not resulted in any infection in the dogs used in this series over a period of 12 months. That there is some .trauma to the urinary bladder from the passage of the cystoscope, and to the ureteral orifices by the repeated catheterization, is indicated by the appearance of these structures. The bladder wall and the orifices of the ureters were congested after the dogs had been used weekly over a period of time. To decrease the cumulative effects of the trauma the animal should be catheterized at 14-day intervals. Not every attempt at ureteral catheterization, even in the same dog, was successful. The curved course of the ureter in the vesical portion makes it difficult, and at times impossible, to pass a catheter high into the ureter. This difficulty can be overcome to a great extent by selecting dogs in which one finds, by trial, that the catheter can be passed easily. In dog Bin this series, double catheterization was successful in a large percentage of the attempts. The use of a smaller catheter than a No. 6 is not advised. A catheter of this size completely obturates the ureter of a 12-kg. dog and eliminates the danger of leakage into the bladder. In some experiments of this series in which indigo carmine was used, no colored urine was seen leaking into the bladder even though a water diuresis was present. The lumen of a small catheter will also be occluded more easily. In a few experiments the catheter was gradually forced from the ureter by peristaltic activity. The urinary rate did not change significantly; but the regularity of the drops gradually gave way to an intermittency. When the tip entered the bladder a gush of drops came through the catheter. The distending fluid in the bladder, therefore, served 3 purposes: it facilitated the catheterization of the ureters; it helped to prevent leakage of urine around the catheter; and it indicated when the catheter tip entered the bladder. SUMMARY
A procedure is described for ureteral catheterization in conscious unoperated dogs for the quantitative determination of urinary rates from each kidney. REFERENCES MALUF, N. S. R.: Ann. Surg., 130: 43, 1949. ROWNTREE, L. G., FITZ, R. AND GERAGHTY,
J. T.: Arch. Int. Med., 11: 121, 1913.