Scand J Urol Nephrol9: 50-56, 1975
A COMPARISON BETWEEN UROGRAPHY AND RADIOISOTOPE RENOGRAPHY IN THE FOLLOW-UP OF SURGERY FOR HYDRONEPHROSIS Brynjulf Otnes, Kjell Rootwelt and Willy Mathisen
Scand J Urol Nephrol Downloaded from informahealthcare.com by Chinese University of Hong Kong on 02/06/15 For personal use only.
From the Sections of Urology and Nuclear Medicine, Rikshospitalet, Oslo, Norway
(Submitted for publication October 16, 1973)
Abstract. The result of surgical correction of hydm-
nephrosis caused by chronic obstruction at the pyeloureteral junction has been evaluated clinically as well as by urography and body background subtracted renography performed preoperatively and up to 65 months postoperatively. The average follow-up period was 24 months. Twenty-eight patients (29 kidneys) were operated. Clinically 24 patients were improved. Urography showed regress of hydronephrosis and/or improved urinary pelvic drainage in 22 patients, whereas kidney function as judged from renography was improved in only 8 patients. Improvement in all parameters was generally most marked during the first postoperative months. Renographic improvement was seen much more often when the contralateral (non-operated) kidney was abnormal. Thus, kidney function in terms of effective renal plasma flow is rather uninfluenced by hydronephrosis surgery if the contralateral kidney is normal, whereas clinical improvement in urinary drainage is regularly obtained. This improvement in drainage is poorly registered by renography. It is concluded that renography is an important complementary method to urography, but the method cannot replace the radiological methods in the follow-up of hydmnephrosis surgery. Radioisotope renography has been established as a routine method for the evaluation of renal function. It is simple to perform, discomfort t o the patient is minimal and radiation exposure insignificant. The examination may be repeated frequently. The method therefore lends itself to follow-up investigations. The fact that renography does not allow definite etiologic conclusions as to the cause of abnormal tracings is a limitation which is of little concern in the follow-up situation where clinical diagnosis is established and one merely wants t o register improvement or deterioration. With the aim of evaluating the usefulness of isotope renography in the follow-up of surgical corScand J Urol Nephrol9
rection of hydronephrosis caused by obstruction a t the ureteropelvic junction, we have compared pre- and postoperative urography, renography and clinical findings in 28 patients. Such comparative studies have previously been presented by Davies, Jones & Croft (1969) and Johnston & Kathel (1972). These authors, however,, appear to have used relatively crude renographic techniques that do not incorporate correction of the kidney tracings for changing body background activity during monitoring.
METHODS Excretory urography was performed according to stand-
ard methods. Two thirds of the examinations were done in our own hospital, the remainder in a number of different X-ray departments elsewhere. All radiograms have been seen and graded by one examiner (B. 0.). Preoperative classification was based mainly on the state of the calyces and renal papillae (Table I). In comparing pre- and postoperative X-rays, the result was classified as improved, if a better grading or a definite improvement in passage from the pelvis to the ureter could be seen (Fig. I). In one patient, considerable reduction in calyceal dilatation was the only sign of radiological improvement. Table I. Radiological classification of hydroneph-
rosis Grade
I I1 I11 IV
Dilated renal pelvis, normal papillae Dilated renal pelvis, with atrophy of papillae Dilated renal pelvis, with atrophy of papillae and large globular calyces As above, and with considerable thinning of renal cortex and minimal contrast excretion
Scand J Urol Nephrol Downloaded from informahealthcare.com by Chinese University of Hong Kong on 02/06/15 For personal use only.
Urography and radioisotope renography 5 1
Fig. 1 . Preoperative X-ray demonstrates a grade I l l
hydronephrosis. Postoperatively the grading has improved to grade 11. Improved pyeloureteral passage is
Renogrophy was performed in the same laboratory in all cases. The equipment consisted of three Nal (TI) activated crystals 2 x 2 inches with 5 cm cylindrical collimators and a skin-crystal distance of 6 cm. Each detector was connected to a separate pulse height analyzer, rate meter (time constant 3 seconds) and a linear recorder. The patients were normally hydrated and were investigated in the sitting position. '311-Hippuran was injected intravenously at a dose of 0.2 uCi/kg body weight. A detector was placed over each kidney region, the detector being moved during the first 2 minutes after the injection to ensure its position over the maximal activity area. The third detector was placed over the left scapula to record the body background activity. The pulse rate from this detector was automatically subtracted from the pulse rate from the two other detectors, thus body background subtracted curves were registered from the kidney regions. This body background subtracted activity was measured 3 minutes after the injection, and the ratio of the left kidney activity to the sum of the kidney activities was taken to indicate the share of the left kidney in the total renal function. 50k7% for each kidney was considered a normal distribution. After 20 minutes registration the patient walked around for one minute, lied down for approximately 4 minute on each side, and was then again placed in sitting position before the detectors. Inspection of the renogram was directed to comparing the general shapes of the tracings and, where possible,
also seen. Either one of these changes is considered as improvement in the present study.
to measuring the times taken for the kidney tracings to reach a maximum (T,), and the times required for the tracings to fall from the maximum to half that level (Tf) (Fig. 2). In a normal case T, is reached within 6 minutes and Tf is less than 12 minutes. In comparing pre- and postoperative renograms (example in Fig. 3) improvement was considered proven if renographic tracings as well as relative function improved definitely in the presence of unchanged contralateral tracings, whereas further impairment of both parameters was taken as token of deterioration. Marked change in one of the parameters without notable change in the other was also interpreted as significant change. The urograms and renograms were evaluated independently and comparisons not made until definite classification of each had been made. The clinical results were classified as excellent, fair and poor, according to criteria listed in Table 11. They were based on personal examination of the patient in all cases.
MATERIAL During the years 1966-72, 74 patients underwent surgical correction of ureteropelvic obstruction causing hydronephrosis. In 28 of these preoperative renograms had been made. The selection of patients for this examination had been arbitrary, although more examinations had been performed during the later part of the Scand J Urol Nephrol9
52 B . Otnes et a / . 1000
iooo
i Scand J Urol Nephrol Downloaded from informahealthcare.com by Chinese University of Hong Kong on 02/06/15 For personal use only.
I
I
I 20 5
25 20 TIME
is
ia
5
o
(MIN. )
Fig. 2. Renography in a patient with unilateral hydronephrosis. On the affected side (35% of effective renal plasma flow) the activity increases during the whole 25 minutes registration period and T , and T i are not measurable. On the contralateral side the tracing is normal with T,=5 minutes and Tf=8 minutes. t= patient walks and lies down.
period. Follow-up urography, renography and clinical evaluation have been obtained for these 28 patients. The material consists of 10 women and 18 men, aged 12-67 years (average 29) at the time of surgery. The preoperative symptoms were: pain 23, urinary infection 11, hematuria 5, incidental finding during investigation for hypertension 1. Urinary infection and hematuria were the only symptoms in 3 and I patient respectively. Preoperative serum creatinine was normal (less than 1.3 mglla0 ml) in all patients except one, who had bilateral hydronephrosis and creatinine levels of 1.61.8 mg/100 ml. Classification on the basis of urography was hydronephrosis grade I 7, I1 5 , 111 16 and IV 1 kidney. The contralateral kidney was radiologically abnormal in 7 patients, one of whom was operated upon bilaterally for hydronephrosis, and absent in 1 (Table V1, column 5 ) . Rcnography showed preoperative abnormality in all Table 11. Assessment of clinical result Excellent Fair
Asymptomatic, normal unne Minimal symptoms, sterile urine or only minor episodes of infection Persistent symptoms, pyuria, reoperation
Poor ____
~
~~
Scand J Urol Nephrol9
15
10
5
t-
a u n
)
rz $
0
TIME (MN3
Fig. 3. Pre- and postoperative renography in hydronephrotic kidney with postoperative renographic improvement. Tracings over contralateral kidney are not shown. Relative effective plasma flow of kidney increased from 70 to 80%; T , decreased from 7 to 4 minutes and T i from 14 to 5 minutes.
of the 29 kidneys subjected to surgical correction. Only 9 had a measurable T,, 5 a measurable T i . Pathologic relative functional distribution was present in 17 patients, with a wide range from 17 to 100% of total function for the kidney treated. Abnormal renograms were also found in the contralateral kidneys of 10 patients, including the 8 with abnormal or absent contralateral kidney as established radiographically. Thirty operations for hydronephrosis were performed in these 28 patients, as 1 patient was reoperated on the same kidney after 6 years and 1 was operated on both kidneys with an interval of 3 months between operations. The procedures performed were dismembered ureteropyeloplasty (of the Hynes-Anderson type) 25 kidneys, Y-V ureteropyeloplasty 3, ureterolysis alone 1. Nephroplasty (Stewart, 1947; Smith, 1972) was done as an additional procedure in connection with 9 of the pyeloplasty operations, in order to reduce the calyceal volume. (When this had been done, reduction in calyceal volume alone was not considered a sign of improvement in the postoperative evaluation.) At the one reoperation, ureterolysis and nephroplasty were performed. Stones were removed incidentally in 4 patients. F O L L O W - U P AND R E S U L T S Urography, renography and clinical follow-up examinations have been performed at least once in all patients, a n d in 14 the examinations were
Urography and radioisotope renography 53 Table 111. Radiological evaluation of results
Scand J Urol Nephrol Downloaded from informahealthcare.com by Chinese University of Hong Kong on 02/06/15 For personal use only.
Changes in grade Grade Preop. 0 Normal I 7 II 5 Ill 16 IV I
Postop. 4 4 8 12 1
Summary of radiological changes Improved in grade Unchanged in grade, but improved in passage improved in calyceal volume Unchanged
8 kidneys 13
I 7
repeated another 1-3 times. These examinations were done from 1 week to 5 years after the operation, but all patients had at least one set of examination not less than 4 months postoperatively. The three types of examination were done as closely together as possible, often on the same day. In reviewing the patients where more than one postoperative set of examinations had been done, it was apparent that improvement usually occurred during the first months and that the result achieved 3-6 months postoperatively was rarely improved in any form of assessment at later controls. The results in this study are based on the last set of examinations performed, 4-65 months postoperatively (average 24 months). Radiological evaluation (Table 111) showed improvement in 22 kidneys. Seven of these were improved in both grade and passage, the remainder satisfied one of the criteria of improvement. Evaluation of the renograms showed an increase in the number of kidneys with measurable T , from 9 to 13 and with measurable T f from 5 to 7. The average increase in the relative part of total renal function was only from 45.7 to
47.2%, which is not statistically significant (Student’s t-test, paired data, 0.4
A COMPARISON BETWEEN UROGRAPHY AND RADIOISOTOPE RENOGRAPHY IN THE FOLLOW-UP OF SURGERY FOR HYDRONEPHROSIS Brynjulf Otnes, Kjell Rootwelt and Willy Mathisen
Scand J Urol Nephrol Downloaded from informahealthcare.com by Chinese University of Hong Kong on 02/06/15 For personal use only.
From the Sections of Urology and Nuclear Medicine, Rikshospitalet, Oslo, Norway
(Submitted for publication October 16, 1973)
Abstract. The result of surgical correction of hydm-
nephrosis caused by chronic obstruction at the pyeloureteral junction has been evaluated clinically as well as by urography and body background subtracted renography performed preoperatively and up to 65 months postoperatively. The average follow-up period was 24 months. Twenty-eight patients (29 kidneys) were operated. Clinically 24 patients were improved. Urography showed regress of hydronephrosis and/or improved urinary pelvic drainage in 22 patients, whereas kidney function as judged from renography was improved in only 8 patients. Improvement in all parameters was generally most marked during the first postoperative months. Renographic improvement was seen much more often when the contralateral (non-operated) kidney was abnormal. Thus, kidney function in terms of effective renal plasma flow is rather uninfluenced by hydronephrosis surgery if the contralateral kidney is normal, whereas clinical improvement in urinary drainage is regularly obtained. This improvement in drainage is poorly registered by renography. It is concluded that renography is an important complementary method to urography, but the method cannot replace the radiological methods in the follow-up of hydmnephrosis surgery. Radioisotope renography has been established as a routine method for the evaluation of renal function. It is simple to perform, discomfort t o the patient is minimal and radiation exposure insignificant. The examination may be repeated frequently. The method therefore lends itself to follow-up investigations. The fact that renography does not allow definite etiologic conclusions as to the cause of abnormal tracings is a limitation which is of little concern in the follow-up situation where clinical diagnosis is established and one merely wants t o register improvement or deterioration. With the aim of evaluating the usefulness of isotope renography in the follow-up of surgical corScand J Urol Nephrol9
rection of hydronephrosis caused by obstruction a t the ureteropelvic junction, we have compared pre- and postoperative urography, renography and clinical findings in 28 patients. Such comparative studies have previously been presented by Davies, Jones & Croft (1969) and Johnston & Kathel (1972). These authors, however,, appear to have used relatively crude renographic techniques that do not incorporate correction of the kidney tracings for changing body background activity during monitoring.
METHODS Excretory urography was performed according to stand-
ard methods. Two thirds of the examinations were done in our own hospital, the remainder in a number of different X-ray departments elsewhere. All radiograms have been seen and graded by one examiner (B. 0.). Preoperative classification was based mainly on the state of the calyces and renal papillae (Table I). In comparing pre- and postoperative X-rays, the result was classified as improved, if a better grading or a definite improvement in passage from the pelvis to the ureter could be seen (Fig. I). In one patient, considerable reduction in calyceal dilatation was the only sign of radiological improvement. Table I. Radiological classification of hydroneph-
rosis Grade
I I1 I11 IV
Dilated renal pelvis, normal papillae Dilated renal pelvis, with atrophy of papillae Dilated renal pelvis, with atrophy of papillae and large globular calyces As above, and with considerable thinning of renal cortex and minimal contrast excretion
Scand J Urol Nephrol Downloaded from informahealthcare.com by Chinese University of Hong Kong on 02/06/15 For personal use only.
Urography and radioisotope renography 5 1
Fig. 1 . Preoperative X-ray demonstrates a grade I l l
hydronephrosis. Postoperatively the grading has improved to grade 11. Improved pyeloureteral passage is
Renogrophy was performed in the same laboratory in all cases. The equipment consisted of three Nal (TI) activated crystals 2 x 2 inches with 5 cm cylindrical collimators and a skin-crystal distance of 6 cm. Each detector was connected to a separate pulse height analyzer, rate meter (time constant 3 seconds) and a linear recorder. The patients were normally hydrated and were investigated in the sitting position. '311-Hippuran was injected intravenously at a dose of 0.2 uCi/kg body weight. A detector was placed over each kidney region, the detector being moved during the first 2 minutes after the injection to ensure its position over the maximal activity area. The third detector was placed over the left scapula to record the body background activity. The pulse rate from this detector was automatically subtracted from the pulse rate from the two other detectors, thus body background subtracted curves were registered from the kidney regions. This body background subtracted activity was measured 3 minutes after the injection, and the ratio of the left kidney activity to the sum of the kidney activities was taken to indicate the share of the left kidney in the total renal function. 50k7% for each kidney was considered a normal distribution. After 20 minutes registration the patient walked around for one minute, lied down for approximately 4 minute on each side, and was then again placed in sitting position before the detectors. Inspection of the renogram was directed to comparing the general shapes of the tracings and, where possible,
also seen. Either one of these changes is considered as improvement in the present study.
to measuring the times taken for the kidney tracings to reach a maximum (T,), and the times required for the tracings to fall from the maximum to half that level (Tf) (Fig. 2). In a normal case T, is reached within 6 minutes and Tf is less than 12 minutes. In comparing pre- and postoperative renograms (example in Fig. 3) improvement was considered proven if renographic tracings as well as relative function improved definitely in the presence of unchanged contralateral tracings, whereas further impairment of both parameters was taken as token of deterioration. Marked change in one of the parameters without notable change in the other was also interpreted as significant change. The urograms and renograms were evaluated independently and comparisons not made until definite classification of each had been made. The clinical results were classified as excellent, fair and poor, according to criteria listed in Table 11. They were based on personal examination of the patient in all cases.
MATERIAL During the years 1966-72, 74 patients underwent surgical correction of ureteropelvic obstruction causing hydronephrosis. In 28 of these preoperative renograms had been made. The selection of patients for this examination had been arbitrary, although more examinations had been performed during the later part of the Scand J Urol Nephrol9
52 B . Otnes et a / . 1000
iooo
i Scand J Urol Nephrol Downloaded from informahealthcare.com by Chinese University of Hong Kong on 02/06/15 For personal use only.
I
I
I 20 5
25 20 TIME
is
ia
5
o
(MIN. )
Fig. 2. Renography in a patient with unilateral hydronephrosis. On the affected side (35% of effective renal plasma flow) the activity increases during the whole 25 minutes registration period and T , and T i are not measurable. On the contralateral side the tracing is normal with T,=5 minutes and Tf=8 minutes. t= patient walks and lies down.
period. Follow-up urography, renography and clinical evaluation have been obtained for these 28 patients. The material consists of 10 women and 18 men, aged 12-67 years (average 29) at the time of surgery. The preoperative symptoms were: pain 23, urinary infection 11, hematuria 5, incidental finding during investigation for hypertension 1. Urinary infection and hematuria were the only symptoms in 3 and I patient respectively. Preoperative serum creatinine was normal (less than 1.3 mglla0 ml) in all patients except one, who had bilateral hydronephrosis and creatinine levels of 1.61.8 mg/100 ml. Classification on the basis of urography was hydronephrosis grade I 7, I1 5 , 111 16 and IV 1 kidney. The contralateral kidney was radiologically abnormal in 7 patients, one of whom was operated upon bilaterally for hydronephrosis, and absent in 1 (Table V1, column 5 ) . Rcnography showed preoperative abnormality in all Table 11. Assessment of clinical result Excellent Fair
Asymptomatic, normal unne Minimal symptoms, sterile urine or only minor episodes of infection Persistent symptoms, pyuria, reoperation
Poor ____
~
~~
Scand J Urol Nephrol9
15
10
5
t-
a u n
)
rz $
0
TIME (MN3
Fig. 3. Pre- and postoperative renography in hydronephrotic kidney with postoperative renographic improvement. Tracings over contralateral kidney are not shown. Relative effective plasma flow of kidney increased from 70 to 80%; T , decreased from 7 to 4 minutes and T i from 14 to 5 minutes.
of the 29 kidneys subjected to surgical correction. Only 9 had a measurable T,, 5 a measurable T i . Pathologic relative functional distribution was present in 17 patients, with a wide range from 17 to 100% of total function for the kidney treated. Abnormal renograms were also found in the contralateral kidneys of 10 patients, including the 8 with abnormal or absent contralateral kidney as established radiographically. Thirty operations for hydronephrosis were performed in these 28 patients, as 1 patient was reoperated on the same kidney after 6 years and 1 was operated on both kidneys with an interval of 3 months between operations. The procedures performed were dismembered ureteropyeloplasty (of the Hynes-Anderson type) 25 kidneys, Y-V ureteropyeloplasty 3, ureterolysis alone 1. Nephroplasty (Stewart, 1947; Smith, 1972) was done as an additional procedure in connection with 9 of the pyeloplasty operations, in order to reduce the calyceal volume. (When this had been done, reduction in calyceal volume alone was not considered a sign of improvement in the postoperative evaluation.) At the one reoperation, ureterolysis and nephroplasty were performed. Stones were removed incidentally in 4 patients. F O L L O W - U P AND R E S U L T S Urography, renography and clinical follow-up examinations have been performed at least once in all patients, a n d in 14 the examinations were
Urography and radioisotope renography 53 Table 111. Radiological evaluation of results
Scand J Urol Nephrol Downloaded from informahealthcare.com by Chinese University of Hong Kong on 02/06/15 For personal use only.
Changes in grade Grade Preop. 0 Normal I 7 II 5 Ill 16 IV I
Postop. 4 4 8 12 1
Summary of radiological changes Improved in grade Unchanged in grade, but improved in passage improved in calyceal volume Unchanged
8 kidneys 13
I 7
repeated another 1-3 times. These examinations were done from 1 week to 5 years after the operation, but all patients had at least one set of examination not less than 4 months postoperatively. The three types of examination were done as closely together as possible, often on the same day. In reviewing the patients where more than one postoperative set of examinations had been done, it was apparent that improvement usually occurred during the first months and that the result achieved 3-6 months postoperatively was rarely improved in any form of assessment at later controls. The results in this study are based on the last set of examinations performed, 4-65 months postoperatively (average 24 months). Radiological evaluation (Table 111) showed improvement in 22 kidneys. Seven of these were improved in both grade and passage, the remainder satisfied one of the criteria of improvement. Evaluation of the renograms showed an increase in the number of kidneys with measurable T , from 9 to 13 and with measurable T f from 5 to 7. The average increase in the relative part of total renal function was only from 45.7 to
47.2%, which is not statistically significant (Student’s t-test, paired data, 0.4
