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Is ureteric compression still necessary?
Clinical Radiology (1987) 38, 17%180
Is Ureteric Compression Still Necessary? R. R. MAWHINNEY and R. H. S. G R E G SO N
Department of Radiology, Queens Medical Centre, Nottingham
A prospective randomised trial was performed to examine the value of ureteric compression in intravenous urography. Calyceal distension improved during the urogram in 68% of kidneys when compression was used, in contrast to an improvement of 43% in patients not receiving compression. In both heavy patients and those with a large girth a trend towards improved distension was shown but was significant only in the former group.
Although ureteric compression has been employed for over half a century (Ziegler, 1930; Kornblum, 1932) with a variety of compressive devices (Steinert, 1952; Eklof, 1965; Daughtridge, 1965; Rothfield, 1969) the evidence for its value has been more subjective than quantitative (Cimmino, 1965). Powell et al. (1967) produced evidence supporting the use of compression but it has been suggested, because of the high doses of contrast medium now routinely employed or because of artefacts which may be produced (Oosterlinck et al., 1979), that compression may be unnecessary. In Britain, while some centres use it routinely, others consider it unnecessary. We therefore decided to look critically at whether ureteric compression could improve the radiological demonstration of calyceal morphology beyond that obtained by conventional urography without compression.
PATIENTS AND METHODS The study included 79 patients (158 kidneys), 40 of whom received compression while 39 did not. All patients were weighed and their girths measured before the start of the examination. Only patients on whom compression would normally be employed in our hospital were included and therefore children under 16 years of age and patients with renal colic, abdominal pain, a colostomy or an abdominal aneurysm were excluded. Patients with known abnormal renal function were also' excluded. Patients were randomly allocated into either a compression or a non-compression group using random number tables. After control films all patient received 50 ml of sodium iothalamate, 420 mg/ml as a rapid bolus intravenous injection and films were taken after one and five min. Compression using a two balloon system similar to that first described by Steinert (1952) was then applied to both groups. The balloons were lightly inflated without producing compression in the non-compression group and firmly inflated in the compression group. Both groups then had 10 and 15min radiographs of the renal area. In the compression group a full length film was obtained following the 15 min film immediately after compress-
ion release, whereas in the non-compression group full length films were also obtained at both 10 and 15 min. The examination then proceeded normally with further techniques such as a second injection or tomography being performed as necessary. An initial assessment (see results) showed that maximal calyceal distension occurred most frequently at 15 min for the compression group and at 10min for the non-compression group. The 15min renal area film from the compression group and the 10min film from the non-compression group were relabelled as 'X' min. The 5 min film and the film labelled 'X' min from each patient in the series were then presented to an experienced radiologist (RG) for scoring. The compression device was demonstrated on the films in every patient and the interpreting radiologist had no prior knowledge as to whether the patient had received compression or not. Radiographs were scored for calyceal distension on a scale from 1 to 4 for each kidney against a set of standard radiographs (Fig. 1).
RESULTS Patients in the compression group had a mean weight of 67.8kg and a mean girth of 85.9cm. The values for the non-compression group were 69.4 and 88.7 respectively. One of us (RM) initially compared the 10 and 15min films from the same patient to assess which showed maximal calyceal distension. The results are shown in Table 1. Whilst most cases showed no difference, the 15 min film was more often superior in the compression group and, similarly, the 10 min film in the non-compression group. These films were relabelled as 'X' min. The distribution of scores at 5 and at X min is shown in Table 2. One kidney in each group was hydronephrotic and these cases were therefore excluded. It can be seen that scores are higher at X min in the compression group compared with the noncompression group, particularly with respect to the number of kidneys obtaining a score of 3. We also looked at the change in score seen between 5 and Xmin for individual kidneys. 68% of the compression group, but only 43% of the non-compression group, showed an increased score. The results are shown in more detail in Table 3 and demonstrate significantly more improvement in calyceal filling in the compression group than in the non-compression group. Those patients weighing over 75 kg or with a girth measurement of 95cm or greater were also assessed separately. The number of patients in these groups was 22 (28% of total) and 20 (25%) respectively for the compression group and 20 (26%) and 26 (33%) for the non-compression group. The percentage of kid-
180
CLINICAL RADIOLOGY
-B
Table 1 - Comparison of 10 and 15 min films from the same patient
Maximal calyceal distension
10>15
10=15
10<15
Compression group Non-compression group
14% 22%
52% 67%
34% 11%
Table 2 - Distribution of distension scores for compression and noncompression groups at 5 and 'X' min
Compression Score 1 2 3 4
5min 24 51 4 0
Total
Non-compression 'X'min 11 27 37 4
5min 31 39 7 0
79
'X'min 16 44 16 1 77
Variation in scores between groups is not significant at 5 rain but significant at 'X' rain (P<0.01).
D
Table 3 - The change in distension score between 5 and 'X' min for individual kidneys
:,ao
Change in score
Compression
Non-compression
-1 0 +1 +2 +3
8 17 46 7 1
10 34 31 1 1
79
77
Improved score in compression group is significant at P<0.01.
Fig. 1 - Standard radiographs for assessing calyceal distension. (a) Score 1 (b) Score 2 (c) Score 3 (d) Score 4.
neys showing an improved score at 'X' min is shown in Table 4 where the heavy and rotund patients are identified separately. DISCUSSION
The results confirm the ability of compression to improve calyceal distension, though an improvement is not guaranteed. Indeed a decrease in score occurred in eight kidneys (10%) of our series despite the use of compression (Table 3). Whether weight or girth affects the effectiveness of compression is not resolved by this series. In both the heavier and more rotund patients in our group a trend towards improved calyceal distension with compression was shown (Table 4). However numbers in both groups were small and the improvement was only significant in the over 75 kg group. Despite this we would recommend that if compression bands will go round the patient they should be used. The crucial question is of course whether improving calyceal distension improves diagnostic accuracy. This is difficult to answer as a definitive diagnosis based on a method other than the intravenous urogram is obtained only in a minority of cases. As radiologists however we feel more confident in reaching a diagnosis when presented with a pyelogram similar to Fig. 1(c) as opposed to Figs l(a) or (b). Since we have
Table 4 - Kidneys showing a n improved distension score at 'X' min as a percentage of the total
Patients
Compression (%)
Non-Compression (%)
All >75 kg >95 cm
68 68 55
43 (P<0.01) 35 (P<0.05) 35 (P>0.05)
Probabilities calculated by z2test.
shown that compression improves the probability of calyceal distension we consider its use is to be recommended.
REFERENCES
Cimmino, CV (1965). The problem of compression in intravenous pyelography. American Journal of Roentgenology, 93, 484-485. Daughtridge, TG (1965). Ureteral compression device for excretory urography. American Journal of Roentgenology, 95, 431-438. Eklof, O (1965). A simple abdominal compressor for use in intravenous urography. American Journal of Roentgenology, 93, 480-482. Kornbtum, K (1932). Some observations on the use of intravenous urography. American Journal of Roentgenology, 28, 1-11. Oosterlinck, W, Verbaeys, A & De Sy, W (1979). Evidence against routine abdominal compression during excretory urography. Acta Urologica Belgica, 47, 585-589. Powell, T, Lentle, BC, Dew, B, ApSimon, HT & Pitman, RG (1967). Intravenous pyelography. British Journal of Radiology, 40, 30-37. Rothfield, NJH (1969). Balloon compression in excretory urography. Radiology, 92, 645. Steinert, R (1952). Compression apparatus for urography. Acta Radiologica, 38, 212-214. Zeigler, J (1930). Significance and technic of compression of ureter in elimination pyelography. Deutsche Medizinische Wochenschrift, 56, 1772-1775.
Is Ureteric Compression Still Necessary? R. R. MAWHINNEY and R. H. S. G R E G SO N
Department of Radiology, Queens Medical Centre, Nottingham
A prospective randomised trial was performed to examine the value of ureteric compression in intravenous urography. Calyceal distension improved during the urogram in 68% of kidneys when compression was used, in contrast to an improvement of 43% in patients not receiving compression. In both heavy patients and those with a large girth a trend towards improved distension was shown but was significant only in the former group.
Although ureteric compression has been employed for over half a century (Ziegler, 1930; Kornblum, 1932) with a variety of compressive devices (Steinert, 1952; Eklof, 1965; Daughtridge, 1965; Rothfield, 1969) the evidence for its value has been more subjective than quantitative (Cimmino, 1965). Powell et al. (1967) produced evidence supporting the use of compression but it has been suggested, because of the high doses of contrast medium now routinely employed or because of artefacts which may be produced (Oosterlinck et al., 1979), that compression may be unnecessary. In Britain, while some centres use it routinely, others consider it unnecessary. We therefore decided to look critically at whether ureteric compression could improve the radiological demonstration of calyceal morphology beyond that obtained by conventional urography without compression.
PATIENTS AND METHODS The study included 79 patients (158 kidneys), 40 of whom received compression while 39 did not. All patients were weighed and their girths measured before the start of the examination. Only patients on whom compression would normally be employed in our hospital were included and therefore children under 16 years of age and patients with renal colic, abdominal pain, a colostomy or an abdominal aneurysm were excluded. Patients with known abnormal renal function were also' excluded. Patients were randomly allocated into either a compression or a non-compression group using random number tables. After control films all patient received 50 ml of sodium iothalamate, 420 mg/ml as a rapid bolus intravenous injection and films were taken after one and five min. Compression using a two balloon system similar to that first described by Steinert (1952) was then applied to both groups. The balloons were lightly inflated without producing compression in the non-compression group and firmly inflated in the compression group. Both groups then had 10 and 15min radiographs of the renal area. In the compression group a full length film was obtained following the 15 min film immediately after compress-
ion release, whereas in the non-compression group full length films were also obtained at both 10 and 15 min. The examination then proceeded normally with further techniques such as a second injection or tomography being performed as necessary. An initial assessment (see results) showed that maximal calyceal distension occurred most frequently at 15 min for the compression group and at 10min for the non-compression group. The 15min renal area film from the compression group and the 10min film from the non-compression group were relabelled as 'X' min. The 5 min film and the film labelled 'X' min from each patient in the series were then presented to an experienced radiologist (RG) for scoring. The compression device was demonstrated on the films in every patient and the interpreting radiologist had no prior knowledge as to whether the patient had received compression or not. Radiographs were scored for calyceal distension on a scale from 1 to 4 for each kidney against a set of standard radiographs (Fig. 1).
RESULTS Patients in the compression group had a mean weight of 67.8kg and a mean girth of 85.9cm. The values for the non-compression group were 69.4 and 88.7 respectively. One of us (RM) initially compared the 10 and 15min films from the same patient to assess which showed maximal calyceal distension. The results are shown in Table 1. Whilst most cases showed no difference, the 15 min film was more often superior in the compression group and, similarly, the 10 min film in the non-compression group. These films were relabelled as 'X' min. The distribution of scores at 5 and at X min is shown in Table 2. One kidney in each group was hydronephrotic and these cases were therefore excluded. It can be seen that scores are higher at X min in the compression group compared with the noncompression group, particularly with respect to the number of kidneys obtaining a score of 3. We also looked at the change in score seen between 5 and Xmin for individual kidneys. 68% of the compression group, but only 43% of the non-compression group, showed an increased score. The results are shown in more detail in Table 3 and demonstrate significantly more improvement in calyceal filling in the compression group than in the non-compression group. Those patients weighing over 75 kg or with a girth measurement of 95cm or greater were also assessed separately. The number of patients in these groups was 22 (28% of total) and 20 (25%) respectively for the compression group and 20 (26%) and 26 (33%) for the non-compression group. The percentage of kid-
180
CLINICAL RADIOLOGY
-B
Table 1 - Comparison of 10 and 15 min films from the same patient
Maximal calyceal distension
10>15
10=15
10<15
Compression group Non-compression group
14% 22%
52% 67%
34% 11%
Table 2 - Distribution of distension scores for compression and noncompression groups at 5 and 'X' min
Compression Score 1 2 3 4
5min 24 51 4 0
Total
Non-compression 'X'min 11 27 37 4
5min 31 39 7 0
79
'X'min 16 44 16 1 77
Variation in scores between groups is not significant at 5 rain but significant at 'X' rain (P<0.01).
D
Table 3 - The change in distension score between 5 and 'X' min for individual kidneys
:,ao
Change in score
Compression
Non-compression
-1 0 +1 +2 +3
8 17 46 7 1
10 34 31 1 1
79
77
Improved score in compression group is significant at P<0.01.
Fig. 1 - Standard radiographs for assessing calyceal distension. (a) Score 1 (b) Score 2 (c) Score 3 (d) Score 4.
neys showing an improved score at 'X' min is shown in Table 4 where the heavy and rotund patients are identified separately. DISCUSSION
The results confirm the ability of compression to improve calyceal distension, though an improvement is not guaranteed. Indeed a decrease in score occurred in eight kidneys (10%) of our series despite the use of compression (Table 3). Whether weight or girth affects the effectiveness of compression is not resolved by this series. In both the heavier and more rotund patients in our group a trend towards improved calyceal distension with compression was shown (Table 4). However numbers in both groups were small and the improvement was only significant in the over 75 kg group. Despite this we would recommend that if compression bands will go round the patient they should be used. The crucial question is of course whether improving calyceal distension improves diagnostic accuracy. This is difficult to answer as a definitive diagnosis based on a method other than the intravenous urogram is obtained only in a minority of cases. As radiologists however we feel more confident in reaching a diagnosis when presented with a pyelogram similar to Fig. 1(c) as opposed to Figs l(a) or (b). Since we have
Table 4 - Kidneys showing a n improved distension score at 'X' min as a percentage of the total
Patients
Compression (%)
Non-Compression (%)
All >75 kg >95 cm
68 68 55
43 (P<0.01) 35 (P<0.05) 35 (P>0.05)
Probabilities calculated by z2test.
shown that compression improves the probability of calyceal distension we consider its use is to be recommended.
REFERENCES
Cimmino, CV (1965). The problem of compression in intravenous pyelography. American Journal of Roentgenology, 93, 484-485. Daughtridge, TG (1965). Ureteral compression device for excretory urography. American Journal of Roentgenology, 95, 431-438. Eklof, O (1965). A simple abdominal compressor for use in intravenous urography. American Journal of Roentgenology, 93, 480-482. Kornbtum, K (1932). Some observations on the use of intravenous urography. American Journal of Roentgenology, 28, 1-11. Oosterlinck, W, Verbaeys, A & De Sy, W (1979). Evidence against routine abdominal compression during excretory urography. Acta Urologica Belgica, 47, 585-589. Powell, T, Lentle, BC, Dew, B, ApSimon, HT & Pitman, RG (1967). Intravenous pyelography. British Journal of Radiology, 40, 30-37. Rothfield, NJH (1969). Balloon compression in excretory urography. Radiology, 92, 645. Steinert, R (1952). Compression apparatus for urography. Acta Radiologica, 38, 212-214. Zeigler, J (1930). Significance and technic of compression of ureter in elimination pyelography. Deutsche Medizinische Wochenschrift, 56, 1772-1775.