ONE THOlJSAND RETROGRADE PYELOGRAMS WITH MAN0 PRESSURE RECORDS

By JAMES A. Ross, M.B.E., M.D., F.R.C.S.E. Surgeon, Edinburgh Royal Itifirmury unrl Lritli Hospitul

THE usual ways i n which the radio-opaque solution is injected up the ureter into t l when retrograde pyelography is being carried out are by the examiner’s hand pressure on the injecting syringe, o r by a flask and funnel raised so that the solution runs in by gravity. It is generally agreed that if a syringe is used the injection of the radio-opaque medium must be cautious and the pressure exerted as low as possible. Grave iiijuries to the renal tract such as perforation of the ureter and calyces (Stevens, 1938), rupture of the kidney (Bai-elz, 1936), toxic action of the pyelographic medium (Shapiro and Veseen, 1930) rupture of the renal pelvis (Kindall, 1933), and severe symptoms of reflex nature with anuria (Mooi e, 1939) occasionally occur. The remarkable case of anuria of some sixty hours’ duration following retrograde pyelography with extensive pyelorenal backflow described by Grieve and Lowe (1955) must also be remembered, as it shows what can occasionally happen i n this frequently performed examination. Minor compli- cations, however, such as various forms of pyelorenal backflow and varying degrees of discomfort, are not un- common in retrogrdde pyelography and ctill requii-e attention.

For some time past the present writer has been using a mercury manometer in circuit when performing retrograde pyelography (Ross. 1952, 1953) uith the intention of minimising if possible these minor coinplications (Fig. I ) . An explanatory paragraph is, perhaps, neces- q r y regarding the working of the circuit FIG. 1

‘. injecting syringe, patient’s kidney, and Mercury rnaiioineter h i t h wale in rnlllirnetres uaed tor recording pressure readings i n retrograde pyelogrdphy From the twin-headed

manometer.” Froin the syringe filled screw adapter on the syringe one cdtheter goes to the pdtient and with the radio-opaque solut ion a twill- the other (of eqiidl calibre) 10 the air-lock boitleot the rndnonietei.

headed screw adapter leads to two catheters of equal internal diameter and length, one of which passes to the patient. the other to the manometer. This consists of an air-lock bottle into which the catheter passes through a rubber stopper, and from which another rubber tube passes to the mercury tube. Theoretically the circuit is not an absolutely closed one, because there IS a potential leak between the catheter inside the lumen of the ureter atid the ureteric wall. If a catheter could be devised with a cuff, a “ ureteric Foley,” then the circuit could be closed completely ; but though numerous attempts have been made during the course of this investigation with this end i n view, no suitable catheter has yet been devised. I n actual practice the ureteric catheter fits the normal-sized ureter fairly tightly and no leak of fluid passes down alongside the catheter during the course of the iiijection.

The pressure reading on the manometer scale, before iiijection, has been found to be 0. 2 A 133

I34 B R I T I S H J O U R N A L O F U R O L O G Y

It rises during the course of the injectimi of the solution, which is made, following MacaPpine’s (1949) advice. “ very slowly and intermittently especially when the capacity of the pelvis is being approached.” The height to which the mercury has risen in the manometer is read just after the injection of the required amount of solution, ~t.lien the circuit lrtis come to equilihrium. The reading, in the present series. when 5 to 6 ml. had been injected, was 50 to 55 mm. Hg with an average of 53.6 mm. Hg.

In this series the factor maintaining the circuit in equilibrium at the height of injection has been the pressure of the examiner’s thumb on the plunger of the syringe. After injection the reading on the manometer scale has been found to remain stationary for a considerable time (at least thirty to f ~ r t y seconds), giving ample time for the radiographer to take the X-ray photographs : then when the stabilising agents, the injecting syringe. and examiner’s thumb are removed, the pressure at once falls to 0. The amount of fluid injected into the renal pelvis and ureter is calculated by subtracting the quantity entering the lock bottle, measured at the end of the injection, from the total amount injected from the syringe, measured on the syringe barrel scale. A millilitre scale on the lock bottle, suggested by Dr D. C . Simpson. is now being added to facilitate this measurement.

I n the Diagnostic Theatre, Edinburgh Royal Infirmary, 1,000 pyelographic examinations have now been completed with the mercury manometer in the injecting circuit, in 519 patients (267 males, 252 females), and it is the purpose of this paper to record the impressions obtained from a study of these cases.

In 8 17 retrograde pyelograms (216 males, 205 females) the radio-opaque solution employed was 12.5 per cent. sodium iodide. In sixty-seven (eighteen male, sixteen female) Pyelectan (iodoxyl injection, B.P., Glaxo Laboratories) was added, the solution being made up of equal parts of sodium iodide (12.5 per cent.) and Pyelectan. In the last I16 pyelograms (thirty-three males, thirty-one females) a n antispasmodic, Buscopan (hyoscine N-butylbromide. Pfizer Ltd.) was added to the sodium iodide pyelectan mixture, as described later.

CASES WITH DISCOM FORT Four of the 1,000 pyelograms were performed under general anzesthesia, 996 with local

anzsthesia of the urethra following preliminary sedation. In the 996 pyelograms performed under local anzsthesia of the urethra. forty-nine were accompanied by some degree of discomfort in the renal regions (twenty-nine on the left side, twenty on the right). Ten of these were associated with some degree of pyelorenal backflow (five i n men, five i n women) as described later. Thirty-nine were unaccompanied by backflow, and occurred i n thirty-four patients (five patients having discomfort on both sides). Of these patients, twenty-six were females (thirty readings) and eight were males (nine readings).

The occurrence of pain or discomfort in the renal regions during the course of retrograde pyelography can be very distressing to the patient. It is also particulai-Iy annoying to the examiner, after obtaining careful and successful anzesthesia of the urethra. In some cases the pain is mild and transient, but in others it can be quite severe, lasting for a considerable time after the examination is over. and accompanied by nausea and sometimes vomiting. General anzsthesia does not entirely eliminate the occurrence of pain, as this may develop after the anresthetic has worn off. Pain is considered to be due usually to distension colic of the renal pelvis (Kiil, 1957) and to eliminate this the quantity of solutioii injected is usually kept at the minimnm consistent with obtaining a satisfactory pyelograni. I n the present series injection was usually performed after emptying the renal pelvis by allowing urine to drain down the catheter into a test tube, and the quantity of solution injected, except in hydronephrosis cases, rarely exceeded 7 ml. The average quantity of radio-opaque medium injected into each renal pelvis in the cases in the present series where discomfort was experienced (excluding those with backflow who are discussed later) was 5.4 ml.

ONE THOUSAND RETROGRADE PYELOGRAMS WITH MANOMETRIC PRESSURE KECOKIX 135

In the first 880 readings there were forty-seven with discomfort, that is, in 5.3 per cent. of cases. An attempt was therefore made to improve this percentage by adding an antispasmodic drug to the radio-opaque solution injected into the renal pelvis. I t was felt that this method of administration. if feasible, would be simpler and more convenient than by pa ren ted injection. The drug was Buscopan, which was added to the injection solution and used in 116 pyelograms. Buscopan-" a brand of hyoscine N-butylbromide "-is a spasmolytic which acts primarily bq blocking the parasympathetic ganglia (Kunz, 1953). It counteracts smooth muscle spasm of the gastro-intestinal tract, the biliary ducts and the urinary tract. It is used orally, subcutaneouslj. intramuscularly, o r intravenously as a spasmolytic for painful vesical tenesmus and for relieving pain after retrograde pyelography (Bauei-, 1951 ; Lossl, 1952 ; Jahn, 1953). I t is also used simultaneously with the contrast solution i n excretory pyelography to improve the roentgenological renal diagnosis (Becker, 1955).

Dr F. R. Fletcher, Medical Department, Pfizer Ltd., was " a little doubtful as to the action of Buscopan when applied to a mucosal surface rather than injected into the blood stream." Prior to its use, therefore. he carried out compatibility tests with Buscopan and Pyelectan. N o apparent incompatibility either immediate or delayed was observed (Fletcher, 1956).

A solution was therefore made up as follows for routine pyelograms :- 2 ampoules, each of I ml. capacity containing 0.02 g. Buscopan (i.e.. a total of 40 mg.

1 ampoule, 20 ml. Pyelectan (75 per cent. solution of iodoxyl B.P., Glaxo Laboratories).

As the average amount was 12 ml. injected into each patient (6 ml. on each side, one-tenth of the made-up solution) the dose of Buscopan was one-fifth of an ampoule, o r 4 mg. It was thought advisable to use this small dose in the early trials (the intravenous dose of Buscopan is 20 mg.) before proceeding to a larger dose if necessary.

There were two cases of discomfort in the I16 pyelograms using the solution containing Buscopan described above, that is, in 1-7 per cent. of cases. The average pressure reading with the manometer in the whole series of 1,000 pyelograms was 53.6 mni. Hg. In the 116 pyelograms with Buscopan it was 48.2 mm. Hg ; but the lower percentage of discomfort cases with Buscopan cannot be attributed entirely to this lower pressure because the incidence of discomfort in individual cases was found not to bear any exact relationship to the pressure readings. Some discomfort was noted wi th readings of 15, 18, 20 (in three cases), and 25 nim. Hg. well below the average figure of 53.6. On the other hand, one patient had both pelves injected with a pressure reading of 100 mm. Hg without discomfort. (This case was one in which Buscopan had been used.) Kiil (1957) has also found no obvious correlation between the occurrence cf pain and the IeCel of the distension pressure in his patients.

The reduction of cases with discomfort from 5.3 to 1.7 per cent. would seem to show that the addition of an antispasmodic drug-Buscopan-to the radio-opaque solution injected into the renal pelvis proved a distinct benefit in this series of retrograde pyelograms. As the quantity of Buscopan used was only one-fifth of the recommended intravenous dose. it seems probable that with a higher dose the number of cases of discomfort can be reduced still further. Dr W. A. Bullen, Medical Department. Pfizer Ltd., considers that a dose of 10 mg. in each renal pelvis is quite safe and work oil this is proceeding at present.

Buscopan).

100 ml. 12.5 per cent. iodide.

A quantity of 122 ml. was therefore available for a morning's session.

CASES WITH PYELORENAL BACKFLOW

There were twenty-seven cases of pyelorenal backflow in the 1,000 pyelograms. (This figure includes eight previously recorded (Ross, 1952)). These cases occurred in twenty-four patients, two being bilateral, and in one, backflow occurred at two separate examinations.

136 B R I T I S H J O U R N A L O F U R O L O G Y

Fourteen patients were male, ten female ; and backflow occurred nineteen times on the left side, eight times on the right side.

Pyelorenal backflow, the clinical significance and interpretation of which has recently been reviewed by Politano (1957), is usually recognised as being of four varieties : pyelotubular, pyelo-interstitial, pyelolymphatic, and pyelovenous. This is the classification adopted by Hinman and Lee-Brown (1924) and by Williams (1941). Narath (1940) using a different nomenclature, defines the same varieties as pyelocanicular, pyelosinus transflow, sinolymphatic absorption, and pyelovenous transflow and sinovenous ingression. Lindbom ( 1943), noting that extravasation of the solution out of the renal pelvis takes place almost always a t the fornix of a calyx, employs the term “ fornix backflow,” a refinement in terminology describing the early stage of pyelosinus transflow.

The twenty-seven cases of backflow in the present series were made up as follows :- Pyelo-interstitial backflow (pyeloparenchymatous or pyelosinus transflow) : in fifteen

cases (eight very slight, occurring in one zone of the kidney ; seven were rather more extensive).

Pyelo-interstitial, with accompanying pyelolymphatic backflow : in four cases (one extensive at upper pole and one very extensive in a patient under general anresthesia).

Pyelo-interstitial with accompanying pyelovenous backflow : i n one case ( in a patient under general anresthesia).

Pyelotubular (pyelocanicular) : in two cases (very slight at one pole). Pyelotubular and pyelolymphatic : in one case. Pyelolymphatic alone : in one case (at upper pole). Pyelovenous alone : in two cases. Pyelovenous and pyelolymphatic : i n one case.

The average pressure reading i n these backflow cases was 50.2 mm. Hg, and the average ,quantity of radio-opaque solution used was 6 ml. This pressure reading is well above the figure advised by many authorities as the upper margin of safety-30 mm. Hg (Scott, I933 ; Baretz, 1936 ; Moore, 1939) ; and it is just above the critical figure of 50 mm. Hg beyond which renal damage is t o be expected (Galbraith, 1924). In the present series, however. the figure of 30 mm. Hg was exceeded on most occasions. It is very easy, when using a syringe to inject the radio-opaque solution, to produce high pressures, and with a manometer in circuit it is seen how rapidly a pressure reading approaching 100 mm. Hg can be attained. Using the manometer, therefore, is salutary in helping to keep the pressures down. Even so, the average figure in the present series was 53.6 mm. Hg ; and in the vast ma-jority of these (973) pyelorenal backflow did not occur.

Comparison with the findings of other workers in this field brings out some interesting points. Kohler (1953) recorded 154 cases of backflow in 628 routine retrograde pyelograms, and Rummelhardt (1951) had 125 refluxes in 960 pyelograms. These are much higher figures than in a series previously recorded by the present writer, 2 per cent. in 1,876 pyelograms performed by members of the Diagnostic Theatre Staff, Edinburgh Royal lnfirmary (Ross, 1952). I n a personal series, in the first 547 pyelograms using the manometer the same percentage, 2 per cent., was found (Ross, 1953), and with the number now brought up to 1,000 the figure is 2.7 per cent.

Apart from this feature-the much lower incidence of pyelorenal backflow-other findings require comment.

Pyelo-interstitial, pyelosinus transflow, or pyeloparenchymal backflow is the commonest variety, as to be expected ; the radio-opaque solution passing out of the calyces into the tissues of the renal sinus, and then into the renal parenchyma. One hundred and six of Rummelhardt’s 125 cases of backflow were of this variety, twenty of the present series of twenty-seven. Pyelotubular backflow is much less common. Eighteen of Rummelhardt’s cases were of this variety, three of the present series.

ONE THOUSAND RETROGRADE PYELOGRAMS WITH MANOMETRIC PRESSURE RECORDS I37

Radio-opaque solution extravasated into the renal parenchyma is rapidly absorbed by the lymphatic channels. giving rise to the very characteristic appearance of fine streaks passing medially from the kidney (Higham, 1937; Narath, 1940; Babics and RCnyi-Vamos, 1957). It is therefore to be expected in all cases where there has been leakage of the contrast medium. and it can be seen frequently. I t occurred seven times in the twenty-seven cases under review. in four cases associated with interstitial backflow, orice with pyelotubular, once with pyelovenous, and once alone.

Pyelovenous backflow is not seen as often in the retrograde pyelograms as the other varieties. “ if for no other reason than that the blood flow through the pericalyceal veins dilutes and

A R FG. 2

A, Retrograde pyelogram showing a broad shadow passing medially in the position of the main renal vein, an example of pyelovenous backflow.

B. Pyelogram with fine beaded lines passing medially and downwards. typical of pyelolymphatic backflow.

Considerable pyelo-interstitial backflow is present in both cases

disperses the medium” (Lcmcet, 1953). It occurred three times in the present series, I t is distinguished from the pyelolymphatic backflow by the much broader shadow. contrasted with the fine, sometimes beaded, streaks characteristic of lymphatics (Fig. 2).

The effect of the state of the kidneys themselves is another factor to be considered i n pyelorenal backflow. Rummelhardt noted that in only seven of his 125 cases of reflux was the kidney normal. This is quite different to the finding in the present series. In the twenty-seven cases the kidney was normal i n twenty-four. Nephroptosis was present i n one. pyelitis in one. and a ureteric calculus had been present i n one.

It was thought that the use o f a manometer in circuit, recording the pressure reading in every pyelogram, would give some measure of help in indicating at what point pyelorenal backflow iisually O C C L I ~ S . A study of the 1,000 readings. however, shows that no single critical point can

138 B R I T I S H J O U R N A L O F U R O L O G Y

be demonstrated. Backflow occurred at pressures as low as 15 nim. Hg i n one patient, 20 mm. Hg in another, and 25 mm. Hg in two others ; whereas, i n another patient, radio-opaque solution injected at 100 mm. Hg showed no reflux.

He found that backflow occurred in four cases a t pressures of 60 mm. Hg or less, while in three of his cases there was no backflow even a t pressures of 200 mm. Hg. Scott (1933) also noted that backflow can occur in the range of pressures ordinarily used in making clinical pyelograms. Kiil (1957) found from his investigations that the intrapelvic pressure sufficient to produce reflux may be as low as 20 mm. Hg. He also records that “ in the same way as the intensity of pain is not parallel with the magnitude of the intrapelvic pressure, the production of ruptures of the endothelium is more dependent on the rate of pressure increase,” a point also referred to by the Lancet (1953), sudden increase of pressure being coiisidered likely to produce calyceal rupture and backflow.

The present series, similar to that of Kohler, shows that pain is not a reliable guide to the state of filling of the renal pelvis during retrograde pyelography ; and the onset of pain is n o criterion that backflow has developed. Pain, o r discomfort, occurred in ten cases of backflow (five male, five female) and no discomfort was present in fifteen. Two were under general anzsthesia and did not have pain on regaining consciousness. General anzsthesia eliminates the warning pain indicating that backflow may be occurring, and therefore the backflow may be more extensive than in cases under local anzsthesia. In the present series, of the four patients under general anzsthesia, two had marked backflow. The pressure readings were 80 mm. Hg and 60 mm. Hg, considerably higher than the average.

The cases in which Buscopan was used were noted particularly to see if the local action of such an antispasmodic drug would have any effect on the possible occurrence of backflow. Backflow occurred in two of the 116 cases in whom Buscopan was used, that is, i n 1.7 per cent. In the previous 884 cases backflow occurred in 25 (2.8 per cent.) These figures are suggestive, but a larger series using Buscopan is required before any comment is made.

These findings are similar to those of Kohler (1953).

SUMMARY AND CONCLUSTONS

One thousand retrograde pyelographic examinations have been performed with a mercury manometer in circuit in order to observe the point at which the complications of ( I ) discomfort in the renal regions and (2) pyelorenal backflow occurred.

Discomfort in the renal regions was recorded on forty-nine occasions in 996 pyelograms performed under local antesthesia of the urethra. It occurred at a variable pressure reading, being recorded as low as at 15 mm. Hg in one case, but not occurring at 100 mm. Hg in another. The average quantity of radio-opaque solution injected into each renal pelvis in cases with discomfort Mas 5.4 ml.

I n t h e first 880 readings there were forty-seven cases with discomfort, that is, 5.3 per cent. In the last I16 an antispasmodic drug, Buscopan, was added to the solution injected into the renal pelvis. This reduction from 5.3 to 1.7 pel- cent. would seem to show that Buscopan acted effectively when injected directly into the renal pelvis. As this is a simple method of administration, and eliminates the prick of a needle, it would seem to have some place in retrograde pyelography. The actual dose of Buscopan injected into each renal pelvis in this series was 2 mg. A higher dose, 10 mg., is now being employed.

Pyelorenal backflow occurred i n twenty-seven of the 1,000 pyelograms. This figure, 2.7 per cent., contrasts with Kohler’s 154 cases of backflow in 628 routine retrograde pyelograms (24.5 per cent.) and Rummelhardt’s 125 refluxes in 960 pyelograms (13 per cent.)

The four varieties of pyelorenal backflow-( 1) pyelo-interstitial, (2) pyelotubular, (3) pyelolymphatic, and (4) pyelovenous-were observed in this series. The incidence of these different varieties was similar to that noted by other writers. Pyelo-interstitial is the commonest ;

Discomfort occurred in two of these, that is, 1.7 per cent.

ONE T H O U S A N U RETROGRADE PYELOGRAMS WITH MANOMETRIC PRESSURE RECORIX I39

Rummelhardt had 106 i n 125 cases of backflow, and there were twenty in the twenty-seven cases in the present series.

I n the twenty-seven cases of pyelorenal backflow, twenty-four were in normal kidneys. This finding contrasts with Rummelhardt’s seven normal kidneys i n 125 cases of reflux. In the present series, therefore, backflow was unrelated TO renal pathology.

Pyelorenal backflow occurred at a variable pressure reading. The average reading in these cases was 50.2 mm. Hg, a figure actually lower than that for the whole series, 53.6. The lowest reading at which it was noted was 15 mm. Hg. This finding of variability of the pressure at which reflux occurs is similar to that of Kohler.

I n ten cases of pyelorenal backflow there was some accompanying discomfort, but in fifteen no discomfort was noted. The two cases under general anlesthesia did not complain of discomfort afterwards. Neither the pressure reading nor discomfort was therefore found to be a reliable guide as to the state of filling oT the renal pelvis during retrograde pyelography. or an indication that reflux had occurred. The threshold for pain and discomfort is evidently as variable in the kidney as elsewliei-e in the body i n different persons.

No observation was made in this series as regards any possible fluctuations i n the pressure reading which might have occurred the moment pain was experienced, because as soon as untoward symptoms developed the renal pelvis was emptied by withdrawing the plunger of the syringe. Neither was any observation made regarding a possible sudden fall in the reading when backflow occurred. These are among the points requiring further study. In this series readings were taken with the examiner’s thumb on the plunger of the syringe maintaining the pressure in the circuit. Mr G. F. Murnaglian has suggested a more accurate method. He advises inserting a piece of rubber tubing between the nozzle of the syringe and the double-headed screw adapter, and occluding this with an artery forceps at the end of the injection. This would eliminate the possibility of slight variability of pressure from the examiner’s thumb, and the suggestion has been adopted for the future.

On account of the variability of the pressure readings at which discomfort and backflow Q C C U ~ , it is impossible to define a critical level for the development of these complications. Most urologists, however, would agree with the view expressed by Kiil (1957) : “ The conception that reflux is only produced when the renal pelvis is distended and the intrapelvic pressure increased is in accordance with all available experimental facts.” With a manometer in circuit, therefore, a valuable indicator is available, warning the examiner to keep within moderate limits, for it is surprising what high pressures can be rapidly attained when solutions are injected into the renal pelvis with a hand syringe.

The manometer is of particular value also in cases under general anzsthesia because, though pain occurs in only a proportion of cases of backflow, its absence under general anlesthesia at the time of the pyelogram eliminates the warning which otherwise would be given, and overfilling and backflow readily occur. With the manometer i n circuit, however, the pressure readings are available instead of the patient’s sensations, and the injections can be slowed down or stopped if they are going too high.

Further research in the subject of retrograde pyelography and its complications would be greatly facilitated by the use of cineradiography and the image inlensifier. In conclusion, one may state that the nianonieter as used i n the present series is a simple clinical instrument, not intended to compete with the more elaborate and perfected techniques recently described by Kiil (1957)- but of some value, perhaps, i n routine ~1r01ogy.

I am grateful to M r R. Leslie Stewart for the facilities i n the Diagnostic Theatre, Edinburgh Royal Infirmary. I a150 wish to thank M r H. Bruce Torrance, Department of Surgical Science ; Dr D. C . Simpson, Medical Physics Unit; M r G. F. Murnaghan, Department of Urological Surgery, Edinburgh University ; and M r I. C. K . Tough, for their stimulating and constructive criticism of the work which this paper summarises.

1 40 B R I T I S H J O U R N A L O F U R O L O G Y

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