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Experimental Hydronephrosis: Effects of Ureteral Participation
THE JOURNAL OF UROLOGY
Vol. 84, No. 6, December 1960 Printed in U.S.A.
EXPERIMENTAL HYDRONEPHROSIS: EFFECTS OF URETERAL PARTICIPATION OLINTO S. RODRIGUEZ* From the Department of Surgery, Division of Urology, University of California Medical Center, Los Angeles, Cal.
Hydronephrosis has been the object of experimental study for many years. 1 We now know that renal damage associated with hydronephrosis depends upon two factors, the length of time and the extent of the obstruction to normal urinary flow. Studies of lymphatic drainage under conditions of ureteral obstruction have shown an increased lymph flow in the thoracic duct. 2 • 3 When ligature of the renal lymphatics was added to ureteral obstruction, there was greater damage to the kidney than when renal lymphatics were intact. 4 Experimental work described in this paper is focused on the study of possible contributions of the ureter and the ureteral lymphatics to total fluid diversion from a hydronephrotie kidney. Simple experiments were undertaken to study and observe the pathological differences that the kidney and its adjacent structures present when the ureter is included or excluded in complete obstruction of the upper urinary tract. It is the purpose of this paper to report results of some of these experiments.
at the ureterovesical junction (UVJ) in the other animal. A small flank incision was used to place the ligature at the ureteropelvic junction with minimal dissection. The ureterovesical junction was easily approached through a small midline incision. A double ligature of cotton was used in each case. The rabbits tolerated this procedure very well. No wound infection, fever, or decreased appetite was observed. The five pairs of rabbits were sacrificed according to the following schedule: 1 week, 2 weeks, 1 month, 2 months, and 4 months after occlusion of the ureter. Before sacrifice, the animals were anesthetized with nembutal, and the abdominal cavity was opened through a midline incision. When intraperitoneal fluid was present, it was carefully collected and measured. The perirenal and periureteral areas were then observed on both sides through an opening in the posterior peritoneum. Finally, the rabbits were killed with an overdose of nembutal, and the kidneys were compared in the gross and under the microscope after sections were made.
METHOD
RESULT8
In a series of chronic experiments, ten adult rabbits were grouped in five pairs, disregarding sex. In each pair, the left ureter was ligated at the ureteropelvic junction (UPJ) in one animal and
Table 1 presents results obtained from observation of the animals sacrificed at one week and four months following lower and upper ureteral ligation. The degree of hydronephrosis is graded from I (minimum) to IV (maximum). Animals sacrificed after 2 weeks, 1 month, and 2 months of ureteral obstruction at the different levels showed a degree of damage between the above extremes. They will not be detailed here. When the ureter was included in the hydronephrosis (i.e. hydroureteronephrosis), the following changes were observed: 1. In the kidney: Initial enlargement followed by renal atrophy. 2. In the ureter and renal pelvis: Marked dilatation. 3. In the periureteral tissue: Marked edema. 4. In the abdominal cavity: Formation of minimal ascites.
Accepted for publication January 29, 1960. Supported by grants from the Blalock Foundation and The Fund for the Advancement of Urology. * Present address: San Lorenzo 1580, Rosario S.F., Argentina. 1 Hinman, F. and Hepler, A. B.: Experimental hydronephrosis. IV. Simultaneous ligation of the posterior branch of the renal artery and the ureter on the same side. Arch. Surg., 12: 830-853, 1926. 2 Goodwin, W. E. and Kaufman, J. J.: The renal lymphatics and hydronephrosis. Surg. Forum, 6: 632-635, 1956. 3 Murphy, J. J., Myint, M. K., Rattner, W. H., Klaus, R. and Shallow, F.: The lymphatic system of the kidney. J. Urol., 80: 1-6, 1958. 4 Foldi, M. and Romhanyi, G.: Untersuchung iiber den Lymphstrom der Niere. Acta Medica (Academiae Scientiarum Hungaricae), tomus IV, fasciculi 3-4, Budapest, 1953.
704
EXPEIUME:',TAL HYDRONEPHl:WSIS TAHLE
1. Complete iueteral obstruction (upper 1lreter vs. lower ureter) I
Upper Ureter (Ureteropelvic Junction)
I
I----~-~-
-------
I___
One 1veek
Four months
II II
II I
0 0
0 1 cc
Lower Ureter (Ureterovesiral Junctionj One \veek
I
I
Four month~
,,
!
Hydronephrosis Perirenal edema Perinreteral edema. Ascites .. Kidney: Length Width Wall thickness. Capsule .. Pelvic contents. Histolog:-,·: Extrnvasr1tion of blood Fibrotic reaction
I
I-
(I~I;I;-
.
IT~
I
8 cc
II l 4 cc
I 40 mm. 24 mm. 12 mm. loose coagulated blood
43 mm. 24 mm. 10 mm. adherent coagulated blood
marked none
marked marked
Urine of ]my specific gravity was found in the rlilatPd ureter and renal contrast, when the ureter was excluded and the ligation was high, at the LUPteropelvic junction, there was a small initial incr<'asc in the size of the kidney without subsequent change. Edema mm minimal and limited to the perirenal space. In these experiments the contents of the upper ureter and renal pelvis was coagulated blood. Histological study shO\n:cl that damage to the kidney ,ms greater \\'hen the ureter was excluded. This obsen·ation ancl eonclusion is based on the dPgree of bloody extravasation and fibrotie reac, tion found throughout the renal parcnchyma. Results after lower urekrnl ligation suggest that ureteral participation in h,vdronephrosis permits the kidney to function for a longer period of time and that urine escapes via the lymphatics and to the periuretcral tissues and ultimately the abdominal ca,·ity. lllSCUS:-iTOK
Other workers luwe considered the renal lymphatics a,: an additional circulation for the kid,·ah·<'." 5 · 7 • 8 It has been neys, a kind of 5 Gooc1'Yin, W. E. and Kaufman, J. J.: Renal lymphaties, II. Preliminary experiments. J. Urol., 76: 702-707, 1956. "Vest, S. A. and Bnrelare, B.: Peri-ureteritis plastica: A report of four cases. J. Urol., 70: 38-49, Hl53. 7 Goodwin. W. E. and Kaufman, J. J.: The renal lymphatics, I. A review of some of the pertinent liternture. Urol. 8urve)·, 6: 305-329, 195G. 8 Kaufman, J J. and Goodwin, vV. E. · Renal
I I
45 mm. 29 mm. 10 mm. loose urine
loose urine
minimal none
rninirnnl medium
6
observed that uretcral lymphatics may have .,omt: participation in periuretcritiR plastica of un known etiology (retroperitoncal fibroRis) . 15 In trying to relate the precc'C!ing facts we hn asked these questions: 1. Does lower ureteral obstruction initiate safety valve mechanism which inclu.deP. uretern.t dilatation, an increase in renal and ureterat phatic flow, and filtration of urim" through tii(' ureteral wall and outside the renal lymphatics t1; be picked up by other lymphatics in thr rd.roper itoneal space? 2. If so, do lymphatics absorb urine from tlw ah, kidney, ureter, periureteral dominal cavity? Further experiments are in progress to to elucidate some of these points. SU'\IMARY
The question of the importance of the urrkr~ in hydronephrosis is examined and discussed. Preliminary Pxperiments are described in whid: results suggest that urcteral rnits the kidney to function for a longer oi time than if the obstruction were at tli(' nrcternpelvic junction and excluded the uretPr Thc:,1, experiments also show that urine escapes from the urinary tract to the periureternl ti8stws :rncl the abdominal cavity under nmdition~ of low"r Ltreteral obstruction. lymphatics, III. Clinical implications and ments of nature. Ann. Int. 1\Ierl., 49: 1958.
Vol. 84, No. 6, December 1960 Printed in U.S.A.
EXPERIMENTAL HYDRONEPHROSIS: EFFECTS OF URETERAL PARTICIPATION OLINTO S. RODRIGUEZ* From the Department of Surgery, Division of Urology, University of California Medical Center, Los Angeles, Cal.
Hydronephrosis has been the object of experimental study for many years. 1 We now know that renal damage associated with hydronephrosis depends upon two factors, the length of time and the extent of the obstruction to normal urinary flow. Studies of lymphatic drainage under conditions of ureteral obstruction have shown an increased lymph flow in the thoracic duct. 2 • 3 When ligature of the renal lymphatics was added to ureteral obstruction, there was greater damage to the kidney than when renal lymphatics were intact. 4 Experimental work described in this paper is focused on the study of possible contributions of the ureter and the ureteral lymphatics to total fluid diversion from a hydronephrotie kidney. Simple experiments were undertaken to study and observe the pathological differences that the kidney and its adjacent structures present when the ureter is included or excluded in complete obstruction of the upper urinary tract. It is the purpose of this paper to report results of some of these experiments.
at the ureterovesical junction (UVJ) in the other animal. A small flank incision was used to place the ligature at the ureteropelvic junction with minimal dissection. The ureterovesical junction was easily approached through a small midline incision. A double ligature of cotton was used in each case. The rabbits tolerated this procedure very well. No wound infection, fever, or decreased appetite was observed. The five pairs of rabbits were sacrificed according to the following schedule: 1 week, 2 weeks, 1 month, 2 months, and 4 months after occlusion of the ureter. Before sacrifice, the animals were anesthetized with nembutal, and the abdominal cavity was opened through a midline incision. When intraperitoneal fluid was present, it was carefully collected and measured. The perirenal and periureteral areas were then observed on both sides through an opening in the posterior peritoneum. Finally, the rabbits were killed with an overdose of nembutal, and the kidneys were compared in the gross and under the microscope after sections were made.
METHOD
RESULT8
In a series of chronic experiments, ten adult rabbits were grouped in five pairs, disregarding sex. In each pair, the left ureter was ligated at the ureteropelvic junction (UPJ) in one animal and
Table 1 presents results obtained from observation of the animals sacrificed at one week and four months following lower and upper ureteral ligation. The degree of hydronephrosis is graded from I (minimum) to IV (maximum). Animals sacrificed after 2 weeks, 1 month, and 2 months of ureteral obstruction at the different levels showed a degree of damage between the above extremes. They will not be detailed here. When the ureter was included in the hydronephrosis (i.e. hydroureteronephrosis), the following changes were observed: 1. In the kidney: Initial enlargement followed by renal atrophy. 2. In the ureter and renal pelvis: Marked dilatation. 3. In the periureteral tissue: Marked edema. 4. In the abdominal cavity: Formation of minimal ascites.
Accepted for publication January 29, 1960. Supported by grants from the Blalock Foundation and The Fund for the Advancement of Urology. * Present address: San Lorenzo 1580, Rosario S.F., Argentina. 1 Hinman, F. and Hepler, A. B.: Experimental hydronephrosis. IV. Simultaneous ligation of the posterior branch of the renal artery and the ureter on the same side. Arch. Surg., 12: 830-853, 1926. 2 Goodwin, W. E. and Kaufman, J. J.: The renal lymphatics and hydronephrosis. Surg. Forum, 6: 632-635, 1956. 3 Murphy, J. J., Myint, M. K., Rattner, W. H., Klaus, R. and Shallow, F.: The lymphatic system of the kidney. J. Urol., 80: 1-6, 1958. 4 Foldi, M. and Romhanyi, G.: Untersuchung iiber den Lymphstrom der Niere. Acta Medica (Academiae Scientiarum Hungaricae), tomus IV, fasciculi 3-4, Budapest, 1953.
704
EXPEIUME:',TAL HYDRONEPHl:WSIS TAHLE
1. Complete iueteral obstruction (upper 1lreter vs. lower ureter) I
Upper Ureter (Ureteropelvic Junction)
I
I----~-~-
-------
I___
One 1veek
Four months
II II
II I
0 0
0 1 cc
Lower Ureter (Ureterovesiral Junctionj One \veek
I
I
Four month~
,,
!
Hydronephrosis Perirenal edema Perinreteral edema. Ascites .. Kidney: Length Width Wall thickness. Capsule .. Pelvic contents. Histolog:-,·: Extrnvasr1tion of blood Fibrotic reaction
I
I-
(I~I;I;-
.
IT~
I
8 cc
II l 4 cc
I 40 mm. 24 mm. 12 mm. loose coagulated blood
43 mm. 24 mm. 10 mm. adherent coagulated blood
marked none
marked marked
Urine of ]my specific gravity was found in the rlilatPd ureter and renal contrast, when the ureter was excluded and the ligation was high, at the LUPteropelvic junction, there was a small initial incr<'asc in the size of the kidney without subsequent change. Edema mm minimal and limited to the perirenal space. In these experiments the contents of the upper ureter and renal pelvis was coagulated blood. Histological study shO\n:cl that damage to the kidney ,ms greater \\'hen the ureter was excluded. This obsen·ation ancl eonclusion is based on the dPgree of bloody extravasation and fibrotie reac, tion found throughout the renal parcnchyma. Results after lower urekrnl ligation suggest that ureteral participation in h,vdronephrosis permits the kidney to function for a longer period of time and that urine escapes via the lymphatics and to the periuretcral tissues and ultimately the abdominal ca,·ity. lllSCUS:-iTOK
Other workers luwe considered the renal lymphatics a,: an additional circulation for the kid,·ah·<'." 5 · 7 • 8 It has been neys, a kind of 5 Gooc1'Yin, W. E. and Kaufman, J. J.: Renal lymphaties, II. Preliminary experiments. J. Urol., 76: 702-707, 1956. "Vest, S. A. and Bnrelare, B.: Peri-ureteritis plastica: A report of four cases. J. Urol., 70: 38-49, Hl53. 7 Goodwin. W. E. and Kaufman, J. J.: The renal lymphatics, I. A review of some of the pertinent liternture. Urol. 8urve)·, 6: 305-329, 195G. 8 Kaufman, J J. and Goodwin, vV. E. · Renal
I I
45 mm. 29 mm. 10 mm. loose urine
loose urine
minimal none
rninirnnl medium
6
observed that uretcral lymphatics may have .,omt: participation in periuretcritiR plastica of un known etiology (retroperitoncal fibroRis) . 15 In trying to relate the precc'C!ing facts we hn asked these questions: 1. Does lower ureteral obstruction initiate safety valve mechanism which inclu.deP. uretern.t dilatation, an increase in renal and ureterat phatic flow, and filtration of urim" through tii(' ureteral wall and outside the renal lymphatics t1; be picked up by other lymphatics in thr rd.roper itoneal space? 2. If so, do lymphatics absorb urine from tlw ah, kidney, ureter, periureteral dominal cavity? Further experiments are in progress to to elucidate some of these points. SU'\IMARY
The question of the importance of the urrkr~ in hydronephrosis is examined and discussed. Preliminary Pxperiments are described in whid: results suggest that urcteral rnits the kidney to function for a longer oi time than if the obstruction were at tli(' nrcternpelvic junction and excluded the uretPr Thc:,1, experiments also show that urine escapes from the urinary tract to the periureternl ti8stws :rncl the abdominal cavity under nmdition~ of low"r Ltreteral obstruction. lymphatics, III. Clinical implications and ments of nature. Ann. Int. 1\Ierl., 49: 1958.