Clinical History
Insufficient central coil embolization of a hypernephroma causing recurrent bleeding
Imaging Findings
The patient was admitted for recurrent hematuria. She was known to suffer from a large inoperable hypernephroma of her right kidney. Three years earlier, she had undergone palliative embolization by use of vascular coils in another institution that had been considered successful then. Hematuria as a leading symptom had disappeared.
Now, the patient was readmitted because of macrohematuria that was thought to be due to further tumor growth. Selective angiography performed via a 5 F Cobra-shaped catheter (Fig. 1) revealed a large hypervascularized mass of the right renal artery which was patent as well as the segmental arteries. A number of coils partly in perfused arteries are visible. It is likely that the embolization effect of coiling had never completed.
Discussion
In order to achieve tumor devascularization also in the peripheral tumor arteries, it was decided to perform combined peripheral and central embolization of the right kidney. After placing a 6 F guiding catheter (Cordis Inc, Roden) within the right renal artery , a 4 F diagnostic vertebral catheter with a large inner lumen of 0.038 in (Cordis Inc) was inserted through the guiding catheter deeply into the main renal artery.
Then, peripheral embolization with one vial of 500 - 710 micron PVA particles (Trufill, Cordis Inc) was performed. After completion, the peripheral small vessels (Fig. 2 a) were occluded.
Central embolization of the main renal arteries was then performed by 2 cc of bucrylate mixed with lipiodol in a ratio of 1 : 1 through the 4 F catheter which was flushed first by 5 cc of glucose 40% to avoid precipitation of the glue within the catheter. To utilize also glue in the catheter, careful injection of glucose was added after administering the bucrylate - lipiodol mixture.
The 4 F catheter was then retrieved through the guiding catheter and after careful aspiration and flushing of the guiding catheter was removed. Angiography performed through a 5 F cobra catheter showed complete occlusion of the renal artery (Fig. 2 b). Radiography shows the radiopaque glue suspension located within the renal artery (Fig. 2 c).
The intervention was terminated, the patient put on antiphlogistic and pain relief medication, hematuria ceased immediately.
Embolization of renal tumors is nowadays limited to patients who have inoperable tumors or are in a state preventing open surgery. Preoperative embolization to reduce blood loss has been widely abandoned.
Tumor embolization should performed as both a peripheral and central embolization. In smaller tumors, for example in patients with solitary kidneys or limited renal function, selective embolization only of the tumor saving nondiseased renal tissue is an option.
Peripheral embolization is performed by particles, ethanol or liquids of lower viscosity. Particles are pretty safe but size of the particles should adapted to the individual situation. If there is a risk of small av tumor shunts, larger particles are recommended to avoid pulmonary embolization of the particles. In case a large av shunt is present, the shunt has to undergo coil occlusion before particles can be injected.
Occlusion of the main renal arteries in addition to particle embolization can be performed either by coils or glue. Bucrylate - lipiodol embolization is safe if a coaxial technique is used. If performed only through a single catheter, some glue may remain adherent at the catheter tip and may dislodge once the catheter is retrieved. In case of a coaxial technique, the outer catheter prevents dislocation to another vessel than the target vessel.
Central embolization in renal tumors is not recommendable because collateral vessels will keep the peripheral tumor arteries open while the main door is occluded by coils which makes a sufficient reintervention difficult or impossible.
Differential Diagnosis List
Combined peripheral and central embolization to palliate an inoperable renal tumor
Final Diagnosis
Combined peripheral and central embolization to palliate an inoperable renal tumor
