Arteriovenous fistulae in rabbit kidney studied by dye-dilution technique and by angiography

Intraoperative balloon catheter control of renal arteriovenous fistula

Renal arteriovenous fistulas have been managed with embolic therapy or surgical excision. In the case of a large, hemodynamically significant shunt sudden occlusion of the renal artery may result in profound circulatory decompensation. We managed such a case with a combined approach. An intra-arterial balloon catheter was inserted into the renal artery under fluoroscopic guidance, with constant monitoring of the central cardiac indexes via a Swan-Ganz line. The balloon was inflated and then released as circulatory changes were corrected. Once the patient was stable we performed a simple nephrectomy. We recommend this combined, controlled approach for the management of large arteriovenous fistulas.

Transcatheter embolotherapy for congenital renal arteriovenous malformations. Long-term follow-up

Transcatheter embolization was performed five times in 3 patients with congenital renal arteriovenous malformations (AVM). The patients were followed for one to seven and a half years. Two patients whose AVM were completely occluded with Gelfoam have been asymptomatic with no evidence of hematuria. A third patient, embolized with Gelfoam and Ivalon without complete occlusion of the AVM, bled ten months after the first procedure, was re-embolized, and later had the AVM removed surgically. Superselective transcatheter embolization should be the initial treatment modality for congenital AVM with the aim to control bleeding and occlude those malformations supplied by the terminal portion of interlobar arteries. Large malformations supplied by multiple feeders may require operative ligation and removal of the AVM when vessels cannot be occluded satisfactorily because of massive shunting.

Blood flow in renal carcinomas evaluated by a dye dilution technique and angiography

In 31 patients with renal carcinoma referred for angiography, rapid sequence angiography was performed in 25. In 18 of the patients determination of renal blood flow and related parameters was made in conjunction with the angiography. Carcinomas with high and medium-high differentiation comprised Group I, while those with medium and poor differentiation constituted Group II. In both groups a positive correlation was demonstrated between the renal blood flow and the tumour area. In group I, positive correlation (t greater than 2) was demonstrated between the vascular volume and the tumour area, between the vascular resistance and the emptying time of the tumour arteries and the normal renal arteries. There was some degree of shunting of blood in all tumours. Comparison of the arterial emptying time of the tumour arteries with the parenchymal arteries does not allow of staging of renal carcinomas. The degree of shunting may be an indication of the degree of malignancy and poor differentiation.

Arteriovenous shunting in carcinomas evaluated by a dye dilution technique

In 19 patients with renal carcinomas determination of the renal blood flow and related parameters were determined. In 10 of the kidneys the renal blood flow was higher than 1700 ml/min, in five kidneys the vascular volume was increased and in all kidneys the appearance time of dye in the renal vein was below normal. It is concluded that AV-shunting is present in all renal carcinomas even if they are hypovascularized or cystic. Underperfusion is supposed to be present in the normal renal parenchyma surrounding the carcinoma. The shunted amount of blood can be fairly large, in the present series up to 3 1/2 litre. The dye dilution technique is suitable for studies of the hemodynamics in renal carcinomas.

Pharmacoangiography in experimental tumours. Evaluation of vasoactive drugs

Pharmacoangiography with four vasoactive drugs was performed in experimental renal and hepatic tumours in rats in order to compare their ability to demonstrate tumour vascularity. Three vasoconstrictors, angiotensin, norepinephrine and vasopressin, and one vasodilator, tolazoline, were tested, vasoconstrictors giving most diagnostic information and the difference in effect among these sometimes being small and probably dose-related. This diagnostic effect is based upon the primitive character of tumour vessels, being unable to react upon a vasoactive stimulus. Angiotensin turned out to be the superior drug which corresponds to clinical experiences of this drug.

Effects of emulsified iodo-lipids. A toxicologic investigation in the rabbit

Two different iodized oil emulsion have been intravascularly injected into rabbits, one with a particle size of 15 mum or more and one with a size of about 1 mum. The effects of the emulsions have been evaluated on the brain, the heart, the kidney, the liver and the circulation. The reactions to the small particle emulsion was minor, especially if administered slowly. The injection site was of critical importance. The safest place for injection was the superior mesenteric artery. If supplied directly to the brain or the heart the emulsions were often deleterious, particularly the coarse one.

Roentgenologic aspects of haematuria

In the roentgenologic investigation of haematuria, urography is the main diagnostic tool, other examinations being only of supplementary value. The main importance of other roentgen examinations is the possibility of excluding certain types of suspected disease as the cause of haematuria, and to demonstrate certain vascular malformations in the kidneys with renal angiography. Urography and cystoscopy should be performed in all patients with haematuria, and the possibility of pathologic conditions in both upper and lower urinary tract must be kept in mind. A large number of overlooked calculi and the finding of unsuspected malignant renal tumors in cases where the urography was performed on an emergency basis, underlines the important fact that "emergency" in these cases only indicates that the patient is an acute distress, not that the examination should be hasty and incomplete, or if so, should be supplemented by a repeat examination under normal conditions.

Effects of vasopressin in experimental nephroangiography

Nephroangiography was performed in 13 rabbits using eight-fold magnification with a 0.05 mm focus. After arginine vasopressin in doses of 0.01 to 1.0 IU the glomeruli were well demonstrated as well as the subcortial arteries and veins and the concentration of contrast medium in arteries and veins increased. At increasing doses of vasopressin the glomeruli were shut off to an increasing degree, beginning at the outer part of the cortex. At 1.0 IU only the juxtamedullary glomeruli functioned.

Renal bloodflow and function in the rabbit after surgical trauma. I. An experimental study

The aim of the present study was to examine the influence of surgical trauma on renal blood flow (RBF) and renal funciotn. The renal vessels were catheterized in lightly anaesthetized rabbits and the dye-dilution technique was used to measure renal blood flow and cardiac output. The renal fraction of the cardiac output (RBF % CO), the total peripherauation of the glomerular and tubular function was made by measuring the extraction of EDTA and of Hippuran. A decrease in the cardiac output was accompanied by a diminution of renal blood flow. Renal blood flow was reduced, regardless of whether surgery or puncture of the kidney was performed, probably due to vasoconstriction in the kidney caused by an increase in sympathetic tonus or in the concentration of plasma catecholamines. Manipulation of the renal artery seemed to stimulate further vasoconstriction in the ipsilateral kidney by a direct effect. The glomerular and tubular function decreased initially, independently of surgical trauma, and it is therefore assumed that the initial renal vasoconstriction includes the afferent arterioles. Renal function was not greatly influenced by handling of the renal artery.