CONGENITAL ARTERIOVENOUS ANEURYSM OF THE RENAL ARTERY1 ROBIN PEARSE
AND
R. L. MAcMILLAN
From the Departments of Urology and Pathology, Toronto General Hospital, Toronto, Canada
A well preserved man 60 years of age, without previous warning or other symptoms, found his urine bright red with blood. Twenty-four hours later the blood was sufficient to clot in the bladder and produce some difficulty in micturition. The bladder was irrigated by the patient's physician, through a catheter with some relief, but as the hematuria persisted, arrangements were made to send the patient to Toronto, where he arrived on October 11, 1945, six days after the onset of the bleeding. The hematuria abated considerably during the journey. The patient denied any trauma or violent exercise. Past history was irrelevant except that a small stone had been passed from the right kidney 10 years previously. The blood pressure was 160/60, nonprotein nitrogen 35, urine bloody, specific gravity 1022, no sugar. Abdominal palpation revealed no abnormality, and rectal examination showed only slight adenomatous enlargement of the prostate. Cystoscopy showed a few small recent clots in the bladder, which were washed out, and an old clot adherent to the lip of the left ureteral opening. The prostate was only slightly enlarged, and no stone, tumor or diverticulum could be found. Catheters passed easily to both renal pelves and clear urine, which presently became slightly tinged with blood, probably traumatic in origin, came from the right side. Nothing came spontaneously through the left catheter, but on irrigation a few drops of very thick, bloody fluid were obtained. Plain x-ray films were negative for stone and films exposed after injection of 12.5 per cent sodium iodide were reported upon by the radiologist (Dr. A. C. Singleton) as follows: "The pyelogram shows normal right kidney pelvis with normal major and minor calyces. On the left side there appears a globular pressure defect on the middle and upper calyces, and again between the middle and lower calyces. The findings are in keeping with either a cystic kidney or possibly an early hypernephroma. There can be seen a soft tissue mass anterior to the left kidney pelvis, which appears to be producing pressure upon the kidney pelvis." See figure 1. The hematuria stopped after the pyelogram had been made, and the patient was prepared for transperitoneal nephrectomy, which took place 4 days after his admission to the hospital. Spinal anesthesia (nupercain supplemented by inhalation of cyclopropane and oxygen) was used. The blood pressure was 160/60, pulse 100. An incision was made through the middle third of the left rectus muscle from just above the costal margin to a little below the umbilicus. The peritoneal cavity was opened and the descending colon and small intestine drawn to the midline. 1 Read at annual meeting, Western New York and Ontario Urological Society of the Central Section, American Urological Association, Alexandria Bay, N. Y., September 14, 1946.
235
236
ROBIN PEARSE AND R. L. MACMILLAN
The posterior layer of peritoneum was divided along the white line, the anterior layer of the perirenal fascia incised and the large and small bowel retracted across the midline, exposing the kidney with its blood supply. A large vessel was seen crossing the renal pelvis to enter the hilus. On palpating this vessel a vibratory thrill was felt. A little more dissection disclosed an aneurysm of the renal artery. There being no longer any contraindication to manipulating the kidney, which appeared to be normal, the ureter was clamped, divided and ligated. The kidney was then lifted from its bed and turned forwards. One clamp was. placed on the renal artery proximal to the aneurysm and two on the renal vein. The vascular pedicle was divided and the kidney removed. The renal artery and vein were tied separately and then a third ligature placed around the two vessels. The posterior peritoneum was repaired with catgut, the anterior abdominal wall with buried figure of 8 sutures of stainless steel~wire, and the
Fm. 1. Retrograde urogram
skin with waxed thread. The blood pressure was then 125/75, pulse 95. Five hundred cubic centimeters of blood were given during the operation and 2000 cc glucose in saline afterwards. The patient made. an uneventful recovery. Pathologist's report: At the mesial border of the left kidney, towards the lower edge of the hilus, was a saccular aneurysm 3 cm. in diameter, formed by a dilatation of the lower branch of the renal artery. ,. A small saccule extended from the anterior part of the aneurysm. This saccule communicated freely with the main aneurysm through an opening: l cm. in diameter. Neither aneurysm nor saccule contained blood clot. The wall of the main aneuryslll measured 2 mm. in thickness, it was smooth, whitish, tough and flexible, and its inner surface showed small yellowish patches and flecks of athermna., The wall of the saccule was rigid and contained calcium. I:µ.stde the aneurysm was a further opening 0.5 cm. in diameter communicating: with a large irregular cavity. The lining of this cavity had a glistening surface
ARTER OVENOUS ANEURYSM OF RENAL ARTERY
237
and was very adherent to the underlying renal substance. It was thrown into folds by the pressure of adjacent calyces and contained no atheromatous deposits. The cavity was drained by a main branch of the renal vein. · The above findings .~demonstrated,.~ vehous aneurysm and an arterial aneurysm with an arteriovenous communication. The pressure of th~' venous aneurysm has caused considerable distortion and narrowing of the cortex and pyramids of the lower pole of the kidney. No communication co.uld be found between the renal pelvis and either of the .aneurysm. See figur~ 2.
Fm. 2. A, Posterior aspect of kidney, showing arterial aneurysm. showing arterial and venous aneurysm.
B, Further dissection,
Histologically, the wall of the arterial aneur5 sm consisted of a dense inner layer of collagen and elastic fibres, with an outer layer of loose connective tissue -0ontaining small blood vessels. The venous aneurysm differs in that the dense layer of collagen was narrower and a well defined internal elastic lamina was present. The kidney itself showed a marked increase in peripelvic fat, especially towards the lower pole. The pelvis was slightly dilated. On the surface of the kidney were a few retention cysts varying in diameter up to 0.5 cm. The -0ortex and medulla together measured no more than 2 cm. at any point, and in some areas only 1.3 cm. The capsule was adherent over the lower pole, and in this area there was marked destruction of the medulla.
238
ROBIN PEARSE AND R, L. MACMILLAN COMMENT
Kahle and Schenken recently reported an aneurysm of the renal artery which developed after partial nephrectomy. These authors reviewed the literature and enumerated previous cases, but failed to include one by Levine reported the preceding year. The present case would, therefore, seem to be the eightyfirst in the literature and the first case of congenital renal arterio-venous aneurysm on record. The etiology is obscure; probably a gradual dilatation occurred of one or more of the small cross communication channels, which always are present between large arteries and veins lying in close apposition. Such dilatation would take many years to attain the size of the specimen under discussion. KAHLE, P. J. AND ScHENKEN, LEVINE, B.: J. Urol., 54: 17,
REFERENCES J. R.: J. Urol. 66: 1, 1946. 1945.