Pyelography in Renal Disease with Hypertension

Abstract

There is no evidence as yet that ordinary “essential” hypertension is curable by any means known to us. Nevertheless, out of a sea of investigative material and conflicting clinical reports in the past thirty years, there has gradually emerged incontrovertible evidence that certain cases of hypertension are related to renal disease, may be curable if recognized before the heightened pressure becomes fixed, and probably depend on relative renal ischemia of still viable parenchyma. It is now possible to select some cases of renal hypertension which are curable by removal or repair of the guilty kidney tissue. Our object in writing this paper is to alert the radiologist to the limitations of the role he can play in helping the clinician select the salvageable patient. It was undertaken subsequent to studies in a series of hypertensive subjects showing that in many instances the excretory pyelogram appeared normal although function on one side was known to be depressed. The radiologist must realize that, in spite of the fact that excretion of the currently employed opaque materials appears equal and of good density on both sides, he may in fact be looking at two kidneys of very different functional capacity, one of which is doing as much as ten times the work of the other. In reporting such a pyelogram, he may unintentionally imply equal function, leading to abandonment of further investigative studies. Although it is probable that few of us actually rely on the intravenous pyelogram as an index to function, the authors believe that most radiologists and the practicing clinicians whom they serve are unaware of the wide functional difference which may exist between the two kidneys in spite of a normal pyelogram. Historical Evidence that there are Salvageable Patients Although Bright (21) in his original article in 1836 recognized the relationship between renal disease and high blood pressure, it was not until almost one hundred years later that Crabtree (22) recorded cases in which a diseased kidney had been removed with consequent relief of associated hypertension. Within two years Ask-Upmark (23) discussed a series of postmortem examinations of hypertensive patients in whom renal disease was found on only one side. Goldblatt's work showing that hypertension could be produced by clamping the renal artery stimulated great interest in the problem. Butler (24) in 1937 for the first time successfully treated hypertension by nephrectomy and recognized it as related to unilateral renal disease. The success of this operation led to an overenthusiastic hope that unilateral nephrectomy might remedy many cases of high blood pressure. In 1948 Homer Smith (3), in a necessarily pessimistic report, reviewed 262 cases of hypertension in which what had appeared to be unilateral renal disease had been treated by nephrectomy with only 19 per cent cure.