1991, The British Journal of Radiology, 64, 314-317
The most advantageous timing of external ureteric compression during intravenous urography By T. H. Hughes, FRCSEd and A. L Hine, MRCP, FRCR Department of Radiology, Central Middlesex Hospital, Acton Lane, Park Royal, London NW10 7NS, UK
(Received August 1990)
Abstract. The objective of this study was to ascertain the most advantageous time during an intravenous urogram to apply external ureteric compression to gain the greatest calyceal distension. This was a prospective randomized trial of 60 patients, divided into three equal groups with compression applied immediately after injection, at 5 minutes and after the 5 minute film had been viewed. Patients with the usual criteria for avoiding compression were excluded. A statistically significant improvement in calyceal distension occurred when compression was applied at 5 minutes compared with that applied after the 5 minute film had been viewed. No improvement was seen when the compression was applied immediately after injection. We recommend that external ureteric compression should be applied immediately after the 5 minute film.
External ureteric compression became popular shortly after the introduction of excretory urography (Ziegler, 1930). Other techniques include placing the patient in Trendelenburg or using bladder distension (Braasch, 1931). Compression became routine following an early uncompressed film (Kornblum, 1932), with the exclusion of the following groups of patients: painful or tender abdomen, palpable abdominal mass, known abdominal aortic aneurysm, symptoms of ureteric colic, renal failure, age under 12 years, recent surgery and if a limited intravenous urogram (IVU) is indicated. Many reports have since confirmed the value of compression (Beare & Wattenberg, 1950; Harrow & Sloane, 1963; Hamby & Kirsh, 1964; Heetderks et al, 1964; Cimmino, 1965; Powell et al, 1967; Mawhinney & Gregson, 1987). Two main types of apparatus have been described for compression (Steinert, 1952; Eklof, 1965), those that wrap around the patient and allow oblique views and those that attach to the table and prevent patient movement. They have been shown to be equally effective (Daughtridge, 1965). There is no firm agreement as to the most advantageous timing of compression which can vary from immediately after injection (Hattery et al, 1988), immediately after the 5 minute film (Ford & Palubinskas, 1967), or waiting until after the 5 minute film has been viewed (Cattell et al, 1989). Patients and methods
A prospective randomized study was performed. All patients referred for non-emergency IVUs were considered (112 patients) but some were excluded from the trial on the following grounds (52 patients): tender or painful abdomen (five), palpable abdominal mass (two), only one kidney present (three), ultrasound as preferred investigation (five), upper tenth centile for weight (10), Address corrrespondence to: Dr T. H. Hughes, Department of Radiology, The Middlesex Hospital, Mortimer Street, London WIN 8AA, UK. 314
symptoms of ureteric colic (18), renal failure (three), follow-up limited IVUs (six). The remaining 60 patients were randomly assigned to one of three groups of 20: (A) compression applied immediately after injection and the exposure of the nephrogram; (B) compression applied at 5 minutes; (C) compression applied after the 5 minute film had been viewed. All IVUs and the application of external ureteric compression were performed by one radiologist (T.H.). All patients had the departmental standard preparation. The compression device was of the type attached to the table, using a ratchet and band, with foam pads below the band. All patients received 1 ml of iopamidol (Niopam 300 mg/ml) per kilogram. Films were taken immediately, at 5 minutes and at 10 minutes, following contrast medium injection. The examination proceeded normally, with further techniques such as obliques, tomography or second injection as necessary. The distension of the calyceal system for each kidney on the 10 minute film was scored independently by two radiologists unaware of when the compression was applied, using a standard scoring system (Mawhinney & Gregson, 1987) (Fig. 1). Statistical analysis was performed using the %2 test. The time at which the 5 minute film became available for viewing was recorded and was immediately seen by the radiologist (T.H.). Film processing was by a 90 second daylight processor. Results The compression results at 10 minutes are shown in Fig. 2 and the mean value and 95% confidence limits in Table I. This shows a statistically significant improvement (p < 0.05) in the scores 1 and 2 against 3 and 4 in calyceal dilatation if the compression is applied immediately after the 5 minute film rather than waiting for the 5 minute film to be viewed. There is also a trend towards improved distension when compression is applied immediately after injection compared with that after the The British Journal of Radiology, April 1991
Timing of external ureteric compression during IVU
(c) (d) Figure 1. Standard radiographs for assessing calyceal distension: (a) score 1, (b) score 2, (c) score 3, (d) score 4.
315
T. H . Hughes and A. L. Hine Number of kidneys (Total 120).
I
Group A
Group B
Group C
(after Immediate film)
(at S minutes)
(post S minute film viewed)
Score 1
(v. poor)
Compression group. Score 2
Score 4
Score 3
(v. good)
5 minute film has been viewed, but this was not statistically significant. Interobserver agreement was 74% (Fig. 3). Although the interkidney agreement (same patient, right versus left) was 55%, those that disagreed were skewed positively to the right (Fig. 4). The average time from the taking of the 5 minute film to it being available for viewing was 3.8 minutes (range 2-8 minutes). Discussion Recent evidence (Mawhinney & Gregson, 1987) shows that compression is beneficial and in our study compression applied immediately after the 5 minute film gives better distension of the calyceal system than waiting for the 5 minute film to be viewed. Applying compression after the immediate film resulted in no additional improvement in distension. These results
100
were obtained in the best possible situation where the radiologist was immediately on hand to view the 5 minute film, an average of 3.8 minutes later, using a 90 second processor. Without compression the distension is greater at 10 minutes than 15 minutes (Mawhinney & Gregson, 1987) and the most useful films are taken within 15 minutes of injection (Davidson, 1985), indicating that further delay in applying compression is likely to reduce its benefit. We recommend the following IVU sequence: the ~5 minute film is taken to show physiological distension, then compression is applied immediately. The 5 minute film is then viewed and if compression is found to be undesirable (no case in our study) it can be removed, or indeed applied if avoided unnecessarily in the first place, for instance in the case of clinical ureteric obstruction not shown on IVU. Our study confirms the earlier finding (Berger, 1937) that the
No variance >1
Number of kidneys. (Total 120)
-1
Figure 2. Compression results in the three groups.
O
1
AH score minus TH score. Right kidney.
316
HH] Left kidney.
1
i Total.
Figure 3. Inter-observer variance. The British Journal of Radiology, April 1991
Timing of external ureteric compression during IV U Number of kidneys.
(Total 120)
Table I. 95% confidence limits for the degree of calyceal distension in the three groups Group
Difference in score, positive represents Right > Left
Figure 4. Graph showing the variance in the degree of calyceal distension between right and left kidneys in the same patient.
left ureter could not be compressed as well as the right ureter, probably owing to the overlying sigmoid mesocolon. References BEARE, J. B. & WATTENBERG, C. A., 1950. Excretory urography
Mean score (1-4)
95% confidence limits
2.55 2.65 2.44
2.41-2.69 2.54-2.76 2.33-2.54
EKLOF, O., 1965. A simple abdominal compressor for use in intravenous urography. American Journal of Roentgenology, 93, 480-482. FORD, W. H. JR. & PALUBINSKAS, J., 1967. Renal extravasation
during excretory urography using abdominal compression. The Journal of Urology, 97, 983-986. HAMBY, W. M. & KIRSH, I. E., 1964. Urography with ureteral compression. Journal of the American Medical Association, 189, 582-584. HARROW, B. R. & SLOANE, J. A., 1963. Compression and
nephrographic effects during Medical Times, 91, 1203-1211.
intravenous
urography.
HATTERY, R. R., WILLIAMSON M. D. JR., HARTMAN, G. W., LEROY, A. J. & WITTEN, D. M., 1988. Intravenous uro-
versus retrograde urography: ureteral compression technique. Archives of Surgery, 61, 568-582. BERGER, R. A., 1937. Increasing the value of intravenous urography by improvements in technique. American Journal of Roentgenology, 38, 156-161. BRAASCH, W. F., 1931. Intravenous urography. American Journal of Roentgenology and Radiotherapy, 25, 196-208.
J., 1964. An improved method of excretory urography. The Journal of Urology, 92, 75-77. KORNBLUM, K., 1932. Some observations on the use of intravenous urography. American Journal of Roentgenology, 28, 1-11.
CATTELL, W. R., WEBB, J. A. W. & HILSON, A. J. W., 1989. In
MAWHINNEY, R. R. & GREGSON, R. H. S., 1987. Is ureteric
Clinical Renal Imaging (Wiley, Chichester), p. 10. CIMMINO, C. V., 1965. The problem of compression in intravenous pyelography. American Journal of Roentgenology, 93, 484-485. DAUGHTRIDGE, T. G., 1965. Ureteral compression device for excretory urography. American Journal of Roentgenology, 95, 431-438. DAVIDSON, A. J., 1985. Excretory urography. In Radiology of the Kidney (W. B. Saunders, London), pp. 12-21.
Vol. 64, No. 760
graphic technique. Radiology, 167, 593-599. HEETDERKS, D. R. JR., RAPP, R., CORREA, R. J. JR. & LAPIDES,
compression still necessary? Clinical Radiology, 38, 179-180. POWELL, T., LENTLE, B. C., D E W , B., APSIMON, H. T. &
PITMAN, R. G., 1967. Intravenous pyelography. British Journal of Radiology, 40, 30-37. STEINERT, R., 1952. A compression apparatus for urography. Ada Radiologica, 38, 212-214. ZIEGLER, J., 1930. Significance and technique of compression of ureter in elimination pyelography. Deutsche Medizinische Wochenschrift, 56, 1772-1775.
317
The most advantageous timing of external ureteric compression during intravenous urography By T. H. Hughes, FRCSEd and A. L Hine, MRCP, FRCR Department of Radiology, Central Middlesex Hospital, Acton Lane, Park Royal, London NW10 7NS, UK
(Received August 1990)
Abstract. The objective of this study was to ascertain the most advantageous time during an intravenous urogram to apply external ureteric compression to gain the greatest calyceal distension. This was a prospective randomized trial of 60 patients, divided into three equal groups with compression applied immediately after injection, at 5 minutes and after the 5 minute film had been viewed. Patients with the usual criteria for avoiding compression were excluded. A statistically significant improvement in calyceal distension occurred when compression was applied at 5 minutes compared with that applied after the 5 minute film had been viewed. No improvement was seen when the compression was applied immediately after injection. We recommend that external ureteric compression should be applied immediately after the 5 minute film.
External ureteric compression became popular shortly after the introduction of excretory urography (Ziegler, 1930). Other techniques include placing the patient in Trendelenburg or using bladder distension (Braasch, 1931). Compression became routine following an early uncompressed film (Kornblum, 1932), with the exclusion of the following groups of patients: painful or tender abdomen, palpable abdominal mass, known abdominal aortic aneurysm, symptoms of ureteric colic, renal failure, age under 12 years, recent surgery and if a limited intravenous urogram (IVU) is indicated. Many reports have since confirmed the value of compression (Beare & Wattenberg, 1950; Harrow & Sloane, 1963; Hamby & Kirsh, 1964; Heetderks et al, 1964; Cimmino, 1965; Powell et al, 1967; Mawhinney & Gregson, 1987). Two main types of apparatus have been described for compression (Steinert, 1952; Eklof, 1965), those that wrap around the patient and allow oblique views and those that attach to the table and prevent patient movement. They have been shown to be equally effective (Daughtridge, 1965). There is no firm agreement as to the most advantageous timing of compression which can vary from immediately after injection (Hattery et al, 1988), immediately after the 5 minute film (Ford & Palubinskas, 1967), or waiting until after the 5 minute film has been viewed (Cattell et al, 1989). Patients and methods
A prospective randomized study was performed. All patients referred for non-emergency IVUs were considered (112 patients) but some were excluded from the trial on the following grounds (52 patients): tender or painful abdomen (five), palpable abdominal mass (two), only one kidney present (three), ultrasound as preferred investigation (five), upper tenth centile for weight (10), Address corrrespondence to: Dr T. H. Hughes, Department of Radiology, The Middlesex Hospital, Mortimer Street, London WIN 8AA, UK. 314
symptoms of ureteric colic (18), renal failure (three), follow-up limited IVUs (six). The remaining 60 patients were randomly assigned to one of three groups of 20: (A) compression applied immediately after injection and the exposure of the nephrogram; (B) compression applied at 5 minutes; (C) compression applied after the 5 minute film had been viewed. All IVUs and the application of external ureteric compression were performed by one radiologist (T.H.). All patients had the departmental standard preparation. The compression device was of the type attached to the table, using a ratchet and band, with foam pads below the band. All patients received 1 ml of iopamidol (Niopam 300 mg/ml) per kilogram. Films were taken immediately, at 5 minutes and at 10 minutes, following contrast medium injection. The examination proceeded normally, with further techniques such as obliques, tomography or second injection as necessary. The distension of the calyceal system for each kidney on the 10 minute film was scored independently by two radiologists unaware of when the compression was applied, using a standard scoring system (Mawhinney & Gregson, 1987) (Fig. 1). Statistical analysis was performed using the %2 test. The time at which the 5 minute film became available for viewing was recorded and was immediately seen by the radiologist (T.H.). Film processing was by a 90 second daylight processor. Results The compression results at 10 minutes are shown in Fig. 2 and the mean value and 95% confidence limits in Table I. This shows a statistically significant improvement (p < 0.05) in the scores 1 and 2 against 3 and 4 in calyceal dilatation if the compression is applied immediately after the 5 minute film rather than waiting for the 5 minute film to be viewed. There is also a trend towards improved distension when compression is applied immediately after injection compared with that after the The British Journal of Radiology, April 1991
Timing of external ureteric compression during IVU
(c) (d) Figure 1. Standard radiographs for assessing calyceal distension: (a) score 1, (b) score 2, (c) score 3, (d) score 4.
315
T. H . Hughes and A. L. Hine Number of kidneys (Total 120).
I
Group A
Group B
Group C
(after Immediate film)
(at S minutes)
(post S minute film viewed)
Score 1
(v. poor)
Compression group. Score 2
Score 4
Score 3
(v. good)
5 minute film has been viewed, but this was not statistically significant. Interobserver agreement was 74% (Fig. 3). Although the interkidney agreement (same patient, right versus left) was 55%, those that disagreed were skewed positively to the right (Fig. 4). The average time from the taking of the 5 minute film to it being available for viewing was 3.8 minutes (range 2-8 minutes). Discussion Recent evidence (Mawhinney & Gregson, 1987) shows that compression is beneficial and in our study compression applied immediately after the 5 minute film gives better distension of the calyceal system than waiting for the 5 minute film to be viewed. Applying compression after the immediate film resulted in no additional improvement in distension. These results
100
were obtained in the best possible situation where the radiologist was immediately on hand to view the 5 minute film, an average of 3.8 minutes later, using a 90 second processor. Without compression the distension is greater at 10 minutes than 15 minutes (Mawhinney & Gregson, 1987) and the most useful films are taken within 15 minutes of injection (Davidson, 1985), indicating that further delay in applying compression is likely to reduce its benefit. We recommend the following IVU sequence: the ~5 minute film is taken to show physiological distension, then compression is applied immediately. The 5 minute film is then viewed and if compression is found to be undesirable (no case in our study) it can be removed, or indeed applied if avoided unnecessarily in the first place, for instance in the case of clinical ureteric obstruction not shown on IVU. Our study confirms the earlier finding (Berger, 1937) that the
No variance >1
Number of kidneys. (Total 120)
-1
Figure 2. Compression results in the three groups.
O
1
AH score minus TH score. Right kidney.
316
HH] Left kidney.
1
i Total.
Figure 3. Inter-observer variance. The British Journal of Radiology, April 1991
Timing of external ureteric compression during IV U Number of kidneys.
(Total 120)
Table I. 95% confidence limits for the degree of calyceal distension in the three groups Group
Difference in score, positive represents Right > Left
Figure 4. Graph showing the variance in the degree of calyceal distension between right and left kidneys in the same patient.
left ureter could not be compressed as well as the right ureter, probably owing to the overlying sigmoid mesocolon. References BEARE, J. B. & WATTENBERG, C. A., 1950. Excretory urography
Mean score (1-4)
95% confidence limits
2.55 2.65 2.44
2.41-2.69 2.54-2.76 2.33-2.54
EKLOF, O., 1965. A simple abdominal compressor for use in intravenous urography. American Journal of Roentgenology, 93, 480-482. FORD, W. H. JR. & PALUBINSKAS, J., 1967. Renal extravasation
during excretory urography using abdominal compression. The Journal of Urology, 97, 983-986. HAMBY, W. M. & KIRSH, I. E., 1964. Urography with ureteral compression. Journal of the American Medical Association, 189, 582-584. HARROW, B. R. & SLOANE, J. A., 1963. Compression and
nephrographic effects during Medical Times, 91, 1203-1211.
intravenous
urography.
HATTERY, R. R., WILLIAMSON M. D. JR., HARTMAN, G. W., LEROY, A. J. & WITTEN, D. M., 1988. Intravenous uro-
versus retrograde urography: ureteral compression technique. Archives of Surgery, 61, 568-582. BERGER, R. A., 1937. Increasing the value of intravenous urography by improvements in technique. American Journal of Roentgenology, 38, 156-161. BRAASCH, W. F., 1931. Intravenous urography. American Journal of Roentgenology and Radiotherapy, 25, 196-208.
J., 1964. An improved method of excretory urography. The Journal of Urology, 92, 75-77. KORNBLUM, K., 1932. Some observations on the use of intravenous urography. American Journal of Roentgenology, 28, 1-11.
CATTELL, W. R., WEBB, J. A. W. & HILSON, A. J. W., 1989. In
MAWHINNEY, R. R. & GREGSON, R. H. S., 1987. Is ureteric
Clinical Renal Imaging (Wiley, Chichester), p. 10. CIMMINO, C. V., 1965. The problem of compression in intravenous pyelography. American Journal of Roentgenology, 93, 484-485. DAUGHTRIDGE, T. G., 1965. Ureteral compression device for excretory urography. American Journal of Roentgenology, 95, 431-438. DAVIDSON, A. J., 1985. Excretory urography. In Radiology of the Kidney (W. B. Saunders, London), pp. 12-21.
Vol. 64, No. 760
graphic technique. Radiology, 167, 593-599. HEETDERKS, D. R. JR., RAPP, R., CORREA, R. J. JR. & LAPIDES,
compression still necessary? Clinical Radiology, 38, 179-180. POWELL, T., LENTLE, B. C., D E W , B., APSIMON, H. T. &
PITMAN, R. G., 1967. Intravenous pyelography. British Journal of Radiology, 40, 30-37. STEINERT, R., 1952. A compression apparatus for urography. Ada Radiologica, 38, 212-214. ZIEGLER, J., 1930. Significance and technique of compression of ureter in elimination pyelography. Deutsche Medizinische Wochenschrift, 56, 1772-1775.
317
