Renal Arteriography in Hypertension

Transcription

1 29 Section of Radiology 539 In many other cases where the antro-ethmoidal angle is involved the cheek must be turned aside and the whole of the inner wall and floor of the orbit removed. In those cases where there is at any stage clihical evidence of involvement of the orbital tissues, as shown by proptosis or other form of ocular displacement, exenteration of the orbit must be accepted as the logical form of surgical help, although I doubt if one could, in practice, justify destruction of an eye with normal vision. If, as I believe is now the case, a logical and determined effort is made to irradiate effectively the whole of the affected area then the subsequent surgical intervention must be sufficient to expose that area as far as is technically possible. [February 15, 1957] Renal Arteriography in Hypertension By C. J. HODSON, M.R.C.P., F.F.R., D.M.R.E. Deputy Director Radiological Department, University College Hospital, London SoME five years ago when we started investigating the potentialities of radiology in the study of renal changes associated with hypertension our preliminary survey suggested various lines of investigation. One of these was the demonstration by means of arteriography of arterial changes in such kidneys and to this end it was necessary to establish (a) what such arterial changes might be, and (b) how far they might be defined by means of renal arteriography in vivo. This contribution is a brief outline of some of the positive results which have derived from this study. To define the arterial changes we carried out an extensive investigation of the arterial trees of normal and abnormal kidneys of all kinds using the injection of post-mortem and excised specimens with radio-opaque material and subsequent radiographic examination as our method. At the same time we evolved a radiographic technique to define as far as possible the renal arterial and capillary circulation in vivo, carrying out aortography by means of catheterization of a femoral artery, and exposing X-ray films at the rate of one a second, with the radiographic factors adjusted so as to give maximum detail of the renal arterial tree. Generalized renal arterial changes associated with hypertension.-injection of a number of specimens showed that the changes which occur in hypertension are largely those due to degeneration of the walls of the arterial tree. They consist of (1) tortuosity of the finer branches of the arterial tree, (2) diminution in the number of interlobular vessels and arterioles, (3) diminution in the distance between the zone of the arcuate vessels and the surface of the kidney, i.e. a narrowing of the true renal cortex. In the normal arterial tree tortuosity of the vessels is conspicuous by its absence. When early degenerative changes are present the first sign is tortuosity of the branches at the level of the arcuate vessels with a diminution in the number of twigs. In the more advanced cases these changes are accentuated, there being tortuosity of the interlobar vessels and sometimes of the main branches of the renal arteries with again further diminution in the number of peripheral twigs and a decrease in the thickness of the renal cortex. Comparing these findings with the results obtained by renal aortography, tortuosity affecting the main branches, the interlobar branches and, in a good film, the arcuate vessels might be defined. As well, the thickness of the renal cortex can be shown during the capillary or "cortical blush" phase, but the diminution in the number of interlobular vessels is beyond the power of definition in vivo at the moment. In any case it appears that renal arteriography as a means of defining the generalized vascular changes occurring in arteriosclerosis is not likely to be of any great practical value although it certainly may give some evidence in doubtful cases. Renal biopsy appears likely to be an easier and more accurate means of determining these changes during life. Localized changes.-in those cases of hypertension where the disease is not diffuse but is localized to a part of the kidneys or to part of one kidney the underlying pathological condition is usually localized chronic pyelonephritis, or, in a small minority of cases, a lesion of the main renal artery. Other rare conditions may be unilateral hydronephrosis or some form of obstruction to the urinary tract. I intend to deal only with the first two groups of cases. Localized pyelonephritis.-.the structural change in the kidney which can be assessable radiographically is a coarse localized scarring, either atrophy or fibrosis or both, of a relatively

2 540 Proceedings of the Royal Society of Medicine 30 large segment of the kidney substance. This is almost always associated with expansion of the adjacent calyx and is thus represented on the film by a marked localized diminution in thickness of the renal substance with a localized depression of the outline and with "clubbing" of the calyx. This lesion is readily recognizable in an intravenous pyelogram providing the exposure factors are adjusted to demonstrate the renal outlines. In an early case in which this defect was present (Fig. 1) it was considered likely that these A FIG. I. Localized chronic pyelonephritis. Injected specimen. A shows the marked narrowing of renal substance. B, the contracted tissue round the upper calyx appears to be supplied by a very small separate polar branch of the renal artery suggesting that its cause might originally have been a vascular lesion. B FIG. 2.-Localized chronic pyelonephritis. "Cortical blush" phase of aortography showing irregularity of outline of lower pole with areas showing cortical blush interspaced with contracted "ischmmic" areas. contracted areas might be associated with a demonstrable abnormality of a branch of the renal artery. Further cases have not directly supported this idea, or, if such an arterial change has been present, it has been overlaid in the radiographic picture by neighbouring vessels. Arteriography can help in the demonstration of this condition during the "cortical blush" phase of the arteriographic cycle when the scarred region stands out sharply against the normal renal cortex which is rendered more opaque by the contrast medium (Fig. 2). The use of renal arteriography to this end is of very limited value, as experience has shown that these lesions can be diagnosed very readily by intravenous pyelography. Aortography should certainly not be regarded as a routine procedure in this group. 3 cases illustrating the value of arteriography in localized pyelonephritis were demonstrated by slides. In each case aortography added very little to the assessment of the case by means of excretion pyelography. In each case there was a smaller renal artery on the affected side and the areas of scarring were shown to alternate with areas of good cortical vascularization. These results were shown to compare faithfully with the injected kidney after surgical removal (Fig. 3A, B, C, D). Lesions of the main renal artery.-it is in the small but important group of cases where hypertension develops following a lesion of the main renal artery that arteriography comes into its own. The lesion may be thrombosis or embolism, intimal thickening or atheromatous degeneration, aneurysm or pressure from extrinsic causes. It recalls the experimental pioneer work of Goldblatt (1937) in which a temporary rise in blood pressure in experimental animals was obtained by narrowing one, and a permanent rise by narrowing

3 Section of Radiology 541 A B C D FIG. 3.-Localized chronic pyelonephritis: A, Excretory pyelogram. B, Aortogram-cortical blush phase. c, Injected surgical specimen. D, Surgical specimen; showing value of pyelogram in diagnosis. both renal arteries. Examples of this group of cases have been described in increasing numbers in recent years, particularly in American literature, and in which nephrectomy (Thompson and Smithwick, 1952), thrombectomy (Freeman et al, 1954), or by-passing of the lesion by means of arterial grafts (Poutasse et al., 1956) has resulted in relief of hypertension. The changes in the affected kidney vary from a slight diminution in size, Howard et al. (1954), with almost normal histology, to the classical changes of complete or partial

4 542 Proceedings of the Royal Society of Medicine 32 infarction. Radiographically the main finding is a decrease in size of the kidney as a whole, or, in the case of partial infarction, of a portion of the kidney which corresponds to the size of the vessel affected. On intravenous pyelography there may be no appreciable change or a complete absence of excretion on this side. Arteriography is probably the most efficient way of investigating this type of lesion. Not only is it the only means of defining its site and extent but it forms the basis of surgical treatment. Asymmetry of the electrolytic contents of urinary specimens by ureteric catheterization gives some indication of a damaged kidney, the main findings being a diminished flow of urine and a lower sodium concentration on the affected side, but I understand these results are not always reliable. It seems likely that renal asymmetry, as shown radiographically, will turn out to be a valuable primary sign in this condition. In our series of cases 2 may fall into this group. One was a man of 36 years with a blood pressure of 180/130 who had been diagnosed elsewhere as a case of right-sided hydronephrosis due to aberrant renal arteries. Of these one had been tied with the result that the lower pole of his kidney had atrophied. The remainder of this kidney looked almost normal at pyelography. On aortography a moderate short-length stenosis of his right renal artery near its origin was shown, and it was thought that this might be producing an ischemic effect. Hypertension had been present for at least three years and nephrectomy was thought advisable. In fact there was no change in the blood pressure level after operation. The second was a man of 28 years, with a short history of headaches, a blood pressure of 230/145 and grade II retinal changes. His right kidney was slightly smaller than the left, with a normal calycine pattern on pyelography. An ischemic kidney was considered. Aortography showed a marked short-length stenosis of his right renal artery just distal to a small branch artery to the upper pole of the kidney. Beyond the stenosis was a marked dilatation. It was considered, however, that ureteric catheter specimens did not support a diagnosis of ischiemic kidney, and so far surgical treatment has not been attempted. In some of these cases the clinical story points to the nature and side of the lesion and the aortogram may then be a conclusive accessory to diagnosis. In others there may be no helpful clinical sign beyond a recent onset of hypertension in a patient, either young or old, in whom there is no family history. If in such a case the difference between the long axes of the two kidneys measured on an X-ray film is over 1-5 cm., and particularly if such asymmetry is supported by demonstrable generalized narrowing of the renal substance on the smaller side, then this is a strong indication of unilateral disease, and if supported by asymmetry on analysis of ureteric specimen, is a reasonable indication for aortography. These statements are based on an analysis of over seven hundred pyelograms in which one of the most striking findings is the symmetry displayed by normal kidneys and in which asymmetry with a normal pelvicalycine pattern on both sides has been associated in a dramatic way with hypertension. The inference that such asymmetry may result from a lesion to the main renal artery is supported by both experimental and published work and by our own experience. Dangers of aortography in hypertension.-it is too early to be definite as to the dangers of aortography in hypertension. There are the complications inherent in all arterial injections whether by needle or catheter, and presumably when the puncture site is not under one's direct control there is an increased risk of hemorrhage. Apart from this, there is, as yet, no direct evidence that hypertension carries an increased risk to aortography. In a series of 36 cases only one serious complication occurred in a hypertensive woman of 67 years in whom there was a non-functioning kidney on one side and only the one renal artery had been demonstrated on aortography. Following this examination there was a partial suppression of urine for several days during which the blood urea rose to 348 mg. %. After three weeks she was recovering rapidly with treatment and in six weeks her blood urea was normal again. Details of this case will be published after a follow-up. SUMMARY (1) Renal arteriography is likely to be of little value in the general assessment of details of the renal arterial tree in cases of diffuse arteriosclerosis. (2) The "cortical blush" phase of the arteriogram is of limited value in assessing narrowing and irregularity of the renal cortex in localized chronic pyelonephritis. (3) In the small group of cases in which lesions of the aorta or main renal arteries are causing hypertension the accurate assessment of the lesion by means of contrast medium offers a major diagnostic weapon. (4) There may be positive evidence of such a change in an intravenous pyelogram. (5) Apart from a possible increased tendency to hemorrhage in cases where the puncture

5 33 Sedion of Radiology 543 site is not under one's control aortography in cases of hypertension does not appear, as yet, to carry an added risk. REFERENCES FREEMAN, E. F., FRANK, H. L., WALLACE, G. E., and SAMUEL, I. R. (1954) J. Amer. med. Ass., 156, GOLDBLATT, H. (1937) Harvey Lect., 33, 237. How,Au, J. E., BERTHRONG, M., GOULD, D. M., and YENDT, E. R. (1954) Bull. Johns Hopk. Hosp., 94, 81. PoUrASSE, E. F., HuMPHuiEs, A. W., MCCORMACK, L. J., and CORCORAN, A. C. (1956) J. Amer. med. Ass., 161,149. THoMpsoN, J. E., and SM1THWICK, R. A. (1952) Angiology, 3, 493. Renal Phlebography By R. E. STEINER, Ch.M., F.F.R. Director Radiological Department, Hammersmith Hospital, London RENAL vein thrombosis with or without obstruction of the inferior vena cava, has frequently been reported since its original description by Rayer ( ). In the past the condition has been recognized only at necropsy, but with renal phlebography it is now possible to confirm the clinical diagnosis radiologically. Four main clinical types of renal vein obstruction can be recognized: (i) Thrombosis of the inferior vena cava with secondary involvement of the renal veins. (ii) Obstruction of the inferior vena cava due to invasion by malignant neoplasm, or to external pressure with renal vein obstruction. (iii) Primary thrombosis of the renal veins. (iv) Renal vein thrombosis secondary to primary renal disease. Thrombosis of the inferior vena cava is usually due to spread of thrombus from the lower limb or pelvic veins. Primary thrombosis of the renal vein is exceedingly rare except in infancy when the renal blood flow may be reduced due to salt-loss, vomiting, or severe diarrhoea. In a review of 228 cases of renal vein thrombosis by Abeshouse (1945) 40% of the patients were under 2 months old. Renal vein thrombosis secondary to primary renal disease, such as glomerulo- or pyelonephritis (Schr6der, 1926) or renal amyloidosis (Vilk, 1940) can occur as a complication of the renal disorder where the blood flow has been reduced. The indications for renal phlebography have been defined by Harrison et al. (1956), as follows: In patients with proteinuria with or without oedema in association with the following abnormalities: (i) Abdominal wall veins with upward blood flow; (ii) unexplained aedema of the lower trunk associated with proteinuria of less severity than occurs in the nephrotic syndrome; (iii) unexplained pulmonary infarction; (iv) malignant disease; (v) single kidney. THE RADIOLOGICAL INVESTIGATION There are two main methods of approach: either by injection of contrast medium from below through the saphenous vein using 30 ml. of 70% diodone, or by retrograde injection through a cardiac catheter direct into the renal vein using 15 ml. of 50% diodone. In the case of caval thrombosis injection from below is unsatisfactory, as it will only demonstrate a blocked vena cava and the collateral circulation; in those patients, retrograde Mjection through a cardiac catheter which has been threaded under fluoroscopic control through an antecubital vein into the superior vena cava, inferior vena cava, and renal vein, is the method of choice. During the injection a Valsalva manceuvre is carried out to augment retrograde filling of the branches of the vena cava and of the renal veins. The problem of the clinical aspects of renal vein thrombosis and their radiological investigation, together with a large number of illustrations, has already been published elsewhere (Harrison et al., 1956; and Steiner, 1957). REFERENCES ABESHOUSE, B. S. (1945) Urol. cutan. Rev., 49, 661. HARRISON, C. V., MILNE, M. D., and STEINER, R. E. (1956) Quart. J. Med., 25, 285. RAYER, P. ( ) Traite des maladies des reins, Paris, 2, 269; 3, 590. SCHR5DER, J. (1926) Virchows Arch., 262, 634. STEINER, R. E. (1957) Brit. med. Bull., 13, 64. VILK, N. L. (1940) Klin. Med. (Mosk.), 18, 91.