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Intrarenal arterial collaterals simulating malignant tumor in traumatic arteriovenous fistula
INTRARENAL
ARTERIAL
SIMULATING
MALIGNANT
TRAUMATIC
U. PATIL,
TUMOR
ARTERIOVENOUS
M. KINKHABWALA, R. DZIADIW,
COLLATERALS IN
FISTULA
M.D.
M.D.
M.D.
From the Departments Kings County Hospital Brooklyn, New York
of Radiology and Urology, and Downstate Medical Center,
ABSTRACT-A case of intrarenal arterial collaterals responsible for pelvicalyceal notching is presented. These resulted from a large traumatic arteriovenous fistula without any identi$able renal artery obstruction. It is possible that they indicated a vasodilatory response to ischemia. The bizzare malignant neovuscularity and early venous_@ling were signijicantly absent, distinguishing them from carcinoma and arteriovenous malformation.
The intrarenal arterial collaterals are rarely seen at renal arteriography even in patients with segmental arterial obstruction. A few cases have been described where the collaterals occurred following either renal trauma or biopsy.lV3 We present an unusual case of extensive intrarenal arterial collaterals which resulted from a large proximal arteriovenous fistula. The unique diagnostic features of the intrarenal collaterals distinguish them from the vessel patterns of the malignant neoplasm and an arteriovenous malformation. Case Report A twenty-two-year-old black man was admitted to Kings County Hospital because of severe headaches and recurrent epistaxis of two years’ duration. A history of a past admission for stab wound on the right side of his back three years ago was available. No history of genitourinary infection or hematuria was obtained. During his hospital stay, his blood pressure fluctuated between 200/130 to 180/95 mm. Hg. Blood count, urinalysis, and other laboratory test results were within normal limits. An intravenous pyelogram and a selective right renal arteriogram were performed. Subsequently the
UROLOGY
/ DECEMBER1974
/ VOLUMEIV,NUMBER6
patient underwent right nephrectomy. Postoperatively his blood pressure dropped, and to date it is normal without medication. Radiologic findings An intravenous pyelogram revealed delayed excretion from the right kidney. A twenty-minute radiograph showed marked notching and irregular marginal impressions involving pelvicalyceal system (Fig. 1A). ,4 selective renal arteriogram showed a prompt opacification of the entire inferior vena cava indicating the presence of a large proximal arteriovenous fistula. Extensive arterial and arteriolar network within the kidney simulated malignant neovascularity. Most of these were seen to be arising from the intralobar and arcuate branches (Fig. 1B). Comment The various extrarenal collateral pathways in main renal artery occlusions are well known.3’4 The intrarenal arterial branches, however, are generally thought to be segmental and “end arteries.” Contrary to this common belief, varied patterns of intrarenal collaterals involving segmental renal artery occlusions due to trauma have recently been described by Meng, Elkin,
715
FIGURE 1. (A) intravenous pyelogram showing marked notching and irregularity of pelvicalyceal system. (B) Selective renal arteriogram revealing prompt opacijication of inferior vena cava due to large arteriovenous jistula and extensive arterial and arteriolar collaterals originating from intralobar and arcuate branches.
and Smith. l Pericalyceal collaterals originate from the intralobar branches and form one of the principal collateral pathways in the segmental renal artery obstruction. They appear as coiled vascular network and often cause notching of the collecting system (Fig. 1A). Less commonly the collaterals also originate from the perforating capsular branches and the vasa recta; these, however, are difficult to see on routine angiogram without utilizing magnification techniques. The most important differential diagnostic problems are arteriovenous malformation and neoplastic neovascularity. The collateral vessels have a typical coiled corkscrew appearance. The characteristic bizarre vessel pattern and tumor staining seen in malignant tumors are absent. Early opacification of veins usually noted in the arteriovenous malformation and the malignant neoplasm is also significantly absent. In our patient, prompt opacification of the inferior vena cava occurred due to a central arteriovenous fistula (Fig. 1B). The collateral vessels commonly appear around the arterial obstruction to maintain the blood flow. However, the trauma and the inflammation can also induce hyperemic dilatation of the existing and the potential collateral vascular channels. 1,3 Even after careful pathologic dissection of the kidney specimen, no renal artery obstruction was identified in this patient. Micro-
716
scopically, areas of dilated arteries and arterioles were seen throughout the kidney. Reactive hyperemia due to ischemic trauma from the massive arteriovenous fistula seems to be responsible for the extensive arterial collaterals. The generalized extent of the arterial collateral network throughout the kidney is unique and not observed in any case previously described in the literature.2,4,5 A probable explanation is that this patient’s entire kidney was subjected to ischemia rather than a small segment of it. Kings County Hospital Center 451 Clarkson Avenue Brooklyn, New York 11203 (DR. KINKHABWALA) References 1. MENG, C., ELKIN, M., and SMITH, T.: Intrarenal arterial collaterals, Radiology 109: 59 (1973). 2. PASTERSHANK, S. P. : Intrarenal collateral circulation, J. Canad. Assoc. Radiol. 21: 105 (1970). 3. THOMAS, S. D., BOGASH, M., PAPKY, G., ~~~POLLACK, . Abnormal renal vasculature and renal trauma, F’Urol. 110: 155 (1973). 4. ABRU-IAMS, H. C., and CORNELL, S. H.: Patterns of collateral flow in renal ischemia, Radiology S4: 1091 (I9W. 5. PAUL, R. E., JR., et al. : Angiographic visualization of renal collateral circulation as a means of detecting and delineating renal ischemia, ibid. 84: 1013 (1965).
UROLOGY
/
DECEMBER
1974
I
VOLUME
IV, NUMBER 6
ARTERIAL
SIMULATING
MALIGNANT
TRAUMATIC
U. PATIL,
TUMOR
ARTERIOVENOUS
M. KINKHABWALA, R. DZIADIW,
COLLATERALS IN
FISTULA
M.D.
M.D.
M.D.
From the Departments Kings County Hospital Brooklyn, New York
of Radiology and Urology, and Downstate Medical Center,
ABSTRACT-A case of intrarenal arterial collaterals responsible for pelvicalyceal notching is presented. These resulted from a large traumatic arteriovenous fistula without any identi$able renal artery obstruction. It is possible that they indicated a vasodilatory response to ischemia. The bizzare malignant neovuscularity and early venous_@ling were signijicantly absent, distinguishing them from carcinoma and arteriovenous malformation.
The intrarenal arterial collaterals are rarely seen at renal arteriography even in patients with segmental arterial obstruction. A few cases have been described where the collaterals occurred following either renal trauma or biopsy.lV3 We present an unusual case of extensive intrarenal arterial collaterals which resulted from a large proximal arteriovenous fistula. The unique diagnostic features of the intrarenal collaterals distinguish them from the vessel patterns of the malignant neoplasm and an arteriovenous malformation. Case Report A twenty-two-year-old black man was admitted to Kings County Hospital because of severe headaches and recurrent epistaxis of two years’ duration. A history of a past admission for stab wound on the right side of his back three years ago was available. No history of genitourinary infection or hematuria was obtained. During his hospital stay, his blood pressure fluctuated between 200/130 to 180/95 mm. Hg. Blood count, urinalysis, and other laboratory test results were within normal limits. An intravenous pyelogram and a selective right renal arteriogram were performed. Subsequently the
UROLOGY
/ DECEMBER1974
/ VOLUMEIV,NUMBER6
patient underwent right nephrectomy. Postoperatively his blood pressure dropped, and to date it is normal without medication. Radiologic findings An intravenous pyelogram revealed delayed excretion from the right kidney. A twenty-minute radiograph showed marked notching and irregular marginal impressions involving pelvicalyceal system (Fig. 1A). ,4 selective renal arteriogram showed a prompt opacification of the entire inferior vena cava indicating the presence of a large proximal arteriovenous fistula. Extensive arterial and arteriolar network within the kidney simulated malignant neovascularity. Most of these were seen to be arising from the intralobar and arcuate branches (Fig. 1B). Comment The various extrarenal collateral pathways in main renal artery occlusions are well known.3’4 The intrarenal arterial branches, however, are generally thought to be segmental and “end arteries.” Contrary to this common belief, varied patterns of intrarenal collaterals involving segmental renal artery occlusions due to trauma have recently been described by Meng, Elkin,
715
FIGURE 1. (A) intravenous pyelogram showing marked notching and irregularity of pelvicalyceal system. (B) Selective renal arteriogram revealing prompt opacijication of inferior vena cava due to large arteriovenous jistula and extensive arterial and arteriolar collaterals originating from intralobar and arcuate branches.
and Smith. l Pericalyceal collaterals originate from the intralobar branches and form one of the principal collateral pathways in the segmental renal artery obstruction. They appear as coiled vascular network and often cause notching of the collecting system (Fig. 1A). Less commonly the collaterals also originate from the perforating capsular branches and the vasa recta; these, however, are difficult to see on routine angiogram without utilizing magnification techniques. The most important differential diagnostic problems are arteriovenous malformation and neoplastic neovascularity. The collateral vessels have a typical coiled corkscrew appearance. The characteristic bizarre vessel pattern and tumor staining seen in malignant tumors are absent. Early opacification of veins usually noted in the arteriovenous malformation and the malignant neoplasm is also significantly absent. In our patient, prompt opacification of the inferior vena cava occurred due to a central arteriovenous fistula (Fig. 1B). The collateral vessels commonly appear around the arterial obstruction to maintain the blood flow. However, the trauma and the inflammation can also induce hyperemic dilatation of the existing and the potential collateral vascular channels. 1,3 Even after careful pathologic dissection of the kidney specimen, no renal artery obstruction was identified in this patient. Micro-
716
scopically, areas of dilated arteries and arterioles were seen throughout the kidney. Reactive hyperemia due to ischemic trauma from the massive arteriovenous fistula seems to be responsible for the extensive arterial collaterals. The generalized extent of the arterial collateral network throughout the kidney is unique and not observed in any case previously described in the literature.2,4,5 A probable explanation is that this patient’s entire kidney was subjected to ischemia rather than a small segment of it. Kings County Hospital Center 451 Clarkson Avenue Brooklyn, New York 11203 (DR. KINKHABWALA) References 1. MENG, C., ELKIN, M., and SMITH, T.: Intrarenal arterial collaterals, Radiology 109: 59 (1973). 2. PASTERSHANK, S. P. : Intrarenal collateral circulation, J. Canad. Assoc. Radiol. 21: 105 (1970). 3. THOMAS, S. D., BOGASH, M., PAPKY, G., ~~~POLLACK, . Abnormal renal vasculature and renal trauma, F’Urol. 110: 155 (1973). 4. ABRU-IAMS, H. C., and CORNELL, S. H.: Patterns of collateral flow in renal ischemia, Radiology S4: 1091 (I9W. 5. PAUL, R. E., JR., et al. : Angiographic visualization of renal collateral circulation as a means of detecting and delineating renal ischemia, ibid. 84: 1013 (1965).
UROLOGY
/
DECEMBER
1974
I
VOLUME
IV, NUMBER 6