- Email: [email protected]
Obstructive ARF caused by an inflammatory abdominal aortic aneurysm
CASE REPORT
Obstructive ARF Caused by an Inflammatory Abdominal Aortic Aneurysm Rosa Sa´nchez, MD, Agustı´n Arroyo, MD, Ricardo Gesto, MD, Marı´a J. Ferna´ndez-Reyes, MD, ´ lvarez-Ude, MD Carmen Mon, MD, and Fernando A ● Inflammatory abdominal aortic aneurysms are rare entities characterized by dense fibrosis typically enveloping the aortic wall and adjacent structures with distinctive clinical features that differentiate them from typical atherosclerotic aneurysms. The inflammatory process can involve the renal excretory pathways, causing ureteral obstruction in 20% of cases. The authors report 2 cases of complete obstructive anuria secondary to inflammatory aneurysms and discuss the most appropriate management for these situations of hydronephrosis. Surgical repair of the aneurysm usually leads to regression of the inflammatory reaction. Am J Kidney Dis 41:E9. © 2003 by the National Kidney Foundation, Inc. INDEX WORDS: Anuria; aortic aneurysm; inflammatory aneurysm; obstructive uropathy; retroperitoneal fibrosis.
T
HE OVERALL incidence of acute obstructive renal failure is difficult to estimate, because a wide and varied range of causes exists, depending on patient age, sex, and associated conditions. In the prospective and multicenter study conducted by Lian˜o et al,1 10% of 748 cases of acute renal failure were found to be secondary to obstructive disease. Obstructive uropathy usually has a bimodal distribution, with a first peak in children, in whom congenital abnormalities play a significant role. The incidence subsequently decreases in adulthood and again increases after the age of 60 to 65 years, mainly in men as a result of prostatic disease. Other possible causes to be considered in middleaged individuals are stones, pelvic neoplasms, and pregnancy in women. Abdominal aortic aneurysms (AAA) should be considered among the causes of obstructive uropathy caused by extrinsic compression of the upper urinary tract above the ureterovesical junction.2 A variant of AAA, called inflammatory abdominal aortic aneurysm (IAAA), is characterized by the presence of an adventitial layer of fibrosis, preferentially located in its anterior and lateral side.3 This fibrotic reaction confers the aneurysm clinical, diagnostic, and prognostic characteristics different from those seen in the more common degenerative or atherosclerotic aneurysm. The clinical differences are attributable to the adherence or entrapment of adjacent structures in the fibrotic component. One of the structures that can become enveloped by the thick fibrotic adventitial layer of the aorta is the ureter. In fact, the first description of such an
aneurysm was made by James in 19354 in a patient with uremia caused by bilateral hydronephrosis. Ureteral involvement is seen in about 20% of cases according to the classical series.5 Bilateral involvement is less common,6 and cases initially manifesting as anuria are exceptional.7-9 We report 2 cases of acute renal failure with anuria caused by bilateral ureteral obstruction caused by IAAAs. The cases were separated in time by several years, and different approaches were used to manage hydronephrosis in each patient, a fact that gives us the opportunity to discuss the different management options. CASE REPORTS
Case 1 A 62-year-old man presented with lower back pain for the previous month, mainly on the left side and irradiating along the ureteral trajectory, associated with asthenia, anorexia, and weight loss (8 kg). The pain had been attributed to renal colic on several occasions. The clinical history found a smoking habit and myocardial infarction 4 years before. The physical examination found a pulsatile periumbilical mass. The laboratory tests showed creatinine levels of 3.8 mg/dL
From the Department of Nephrology, Segovia General Hospital and the Department of Angiology and Vascular Surgery, 12 de Octubre, University Hospital, Madrid, Spain. Received July 9, 2002; accepted in revised form November 6, 2002. Address reprint requests to Rosa Sa´nchez Herna´ndez, MD, Servicio de Nefrologı´a, Hospital General de Segovia, Carretera de A´vila s/n, 40002-Segovia, Spain. E-mail: [email protected]; [email protected] © 2003 by the National Kidney Foundation, Inc. 1523-6838/03/4103-0023$30.00/0 doi:10.1053/ajkd.2003.50136
American Journal of Kidney Diseases, Vol 41, No 3 (March), 2003: E9
1
2
SANCHEZ ET AL
moderate alcohol consumption, mild prostatic syndrome, and colonic diverticulosis. The physical examination showed a pulsatile periumbilical mass and blood pressure values of 170/100 mm Hg. The laboratory findings upon admission included creatinine levels of 10.2 mg/dL (902 mol/L), potassium levels of 6.4 mEq/L (6.4 mmol/L) and a sedimentation rate of 50 mm in the first hour. An ultrasound scan showed grade II/IV bilateral hydronephrosis with an empty bladder and an abdominal aortic aneurysm. The condition was defined as obstructive acute renal failure, and emergency cystoscopy was used to place bilateral double J ureteral catheters. Ascending pyelography confirmed the existence of bilateral proximal ureterohydronephrosis with medial deviation of the ureters. A computed tomography (CT) scan showed an aneurysm involving the infrarenal abdominal aorta and both iliac arteries, with a maximum diameter of 8 cm and abnormal thickening of the aortic wall, characteristic of inflammatory aneurysms (Fig 2). After the recovery of diuresis (after a polyuric phase) and renal function (creatinine, 1.4 mg/dL [124 mol/L]), arteriography was performed, and the patient was subjected to endoaneurismorraphy with interposition of an aortobifemoral Dacron graft. The catheters were removed 30 days later. After a 24-month follow-up, the patient is asymptomatic, with a normal renal function, and no periaortic fibrosis is seen in the control CT, although minimal renal ectasia persists. Fig 1. Intravenous urography showing medial deviation of the right ureter and hydronephrosis.
(336 mol/L) and a sedimentation rate of 60 mm in the first hour, with the rest of the parameters being normal. An abdominal ultrasound scan showed bilateral pyelocaliceal dilation (discrete on the left side and moderate on the right) that was confirmed in an intravenous urography, which also showed medial deviation of the right ureter (Fig 1). A computed tomography (CT) showed an infrarenal abdominal aortic aneurysm 4.5 cm in diameter with the presence of a fibrous band surrounding the aneurysm on its anterior and lateral aspects. With the diagnosis of IAAA, an arteriography was performed to better plan surgical treatment of the aneurysm. During the study phase, renal function worsened progressively to anuria, requiring bilateral ureteral catheterization with a double J catheter. After recovery of renal function, the patient was subjected to endoaneurismorraphy with interposition of an aortobifemoral Dacron graft, together with the release of both ureters (ureterolysis). The postoperative course was uneventful, and the ureteral catheters were removed after 6 days. The patient was discharged after one week with creatinine levels of 1.2 mg/dL (106 mol/L) and died after 12 months of coronary disease. The hydronephrosis and periaortic fibrosis had disappeared previously as evidenced by a CT follow-up study.
Case 2 A 63-year-old man came to the emergency service with anuria for the previous 24 hours, drowsiness, and a poor general condition. His medical history included smoking,
DISCUSSION
The etiology of obstructive acute renal failure includes conditions that may require surgery for effective management. IAAA is a rare variant accounting for 4.5% to 15% of all AAAs.5,10 This form of aneurysm, of unknown etiology, is macroscopically characterized by an increased wall thickness as a consequence of firm and sclerotic fibrosis, with a suggestive histopathologic picture in which 3 observations stand out: thickening of the media and, mainly, adventitial layers, with a lymphoplasmocytic infiltrate; obliterating endarteritis of the vasa vasorum; and fibrosis around the lymphatic and nervous structures.11 This fibrotic reaction confers the aneurysm clinical characteristics different from those of the more common degenerative aneurysm, as a result of the entrapment or adhesion within the fibrotic component of adjacent structures such as duodenum, inferior vena cava, left renal vein, and sigmoid. However, ureteral involvement has the greatest clinical implications, leading to secondary hydronephrosis and a potential impairment of renal function that can evolve toward atrophy if allowed to become chronic. These types of aneurysms may have clinical similarities with retroperitoneal fibrosis. Only 4% of patients
ANURIA AND INFLAMMATORY ANEURYSM
3
Fig 2. CT scan of an inflammatory abdominal aortic aneurysm with the characteristic adventitial fibrosis.
with retroperitoneal fibrosis go on to have aortic aneurysms. Atherosclerotic or degenerative aortoiliac aneurysms rarely cause hydronephrosis, and complete ureteral obstruction is even less common. Moreover, if hydronephrosis occurs, it is usually caused by lateral displacement of the distal ureter at its crossing with the aneurysm of the common iliac or hypogastric arteries. In the case of inflammatory aneurysms, the obstruction lies higher up. Instead of ureteral displacement, the latter becomes entrapped within the aortic wall. For this reason, medial deviation of the ureter in the urographic study is a characteristic finding.5 Other clinical features that differentiate inflammatory from atherosclerotic aneurysms include the greater incidence of pain (lumbar or abdominal) and an increased erythrocyte sedimentation rate. In cases of impaired renal function secondary to obstructive uropathy, initial management should mainly include preferential drainage of kidneys using a rapid decompression technique before the aneurysm is repaired, with the dual objective of not prolonging renal damage12 and improving the general condition of a patient before surgery when aortic clamping is performed. Some controversy has traditionally existed as to the ideal management approach for hydrone-
phrosis in these patients. Some investigators advocate preoperative corticoid therapy to reduce the inflammation and thus improve the hydronephrosis.13 However, this approach may theoretically increase the probability of rupture of the aneurysm caused by thinning of the wall, with a greater risk of infection of vascular prosthesis and the possibility of ureteral rupture. We are of the opinion that in patients with inflammatory aneurysms, steroid therapy should be reserved for cases of hydronephrosis and impaired renal function where the aneurysm cannot be operated on based on anesthetic criteria. Other investigators propose systematic intraoperative ureterolysis, as in our first case.14 However, this is a risky procedure that may increase the intra- and postoperative urologic complications.15 Perhaps the most widely accepted and applied practice currently is conservative management, because many investigators have reported regression of the periaortic fibrosis after surgery of the aneurysm.5,16 The main objective of this report is to point out the existence of an unusual and rarely considered cause of obstructive uropathy. In many cases, simple abdominal palpation can guide the etiologic diagnosis of obstructive acute renal failure. The triad of abdominal pulsatile mass, pain, and hydronephrosis is highly suggestive of an inflammatory aneurysm, with CT being the imaging technique of choice.
4
SANCHEZ ET AL
REFERENCES 1. Lian˜ o F, Pascual J and the Madrid Acute Renal Failure Study Group: Epidemiology of acute renal failure: A prospective multicenter community-based study. Kidney Int 50:811818, 1996 2. Curhan GC, Zeidel ML: Urinary tract obstruction, in The Kidney. Brenner and Rector (ed 5). 1996, pp 1936-1958 3. Walker DI, Bloor K, Williams G, Gillie I: Inflammatory aneurysms of the abdominal aorta. Br J Surg 59:609614, 1972 4. James TGI: Uremia due to aneurysm of the abdominal aorta. Br J Urol 7:157, 1935 5. Pennell RC, Hollier LH, Lie JT, et al: Inflammatory abdominal aortic aneurysms: A thirty-year review. J Vasc Surg 2:859-869, 1985 6. Korzets Z, Witz M, Goldberg E, Rozin M, Lehmann J, Bernheim J: The patient with asymptomatic advanced renal failure obstructive uropathy caused by inflammatory abdominal aortic aneurysm. Nephrol Dial Transplant 13:1835-1837, 1998 7. Friedel WE, Smith TR, Herman JR: Anuria caused by peri-aneurysmal retroperitoneal fibrosis. J Urol 110:516518, 1973 8. Pahira JJ, Wein AJ, Barker CF, et al: Bilateral complete ureteral obstruction secondary to an abdominal aortic aneurysm with perianeurysmal fibrosis: Diagnosis by computed tomography. J Urol 121:103-106, 1979 9. Nevelsteen A, Lacroix H, Stockx L, Baert L, Depuydt
P: Inflammatory abdominal aortic aneurysm and bilateral complete ureteral obstruction: Treatment by endovascular graft and bilateral ureteric stenting. Ann Vasc Surg 13:222224, 1999 10. Fritscchen UV, Malzfeld E, Clasen A, Kortmann H: Inflammatory abdominal aortic aneurysm: A postoperative course of retroperitoneal fibrosis. J Vasc Surg 30:1090-1098, 1999 11. Mcmahon JN, Davies JD, Scott DJA, et al: The microscopic features of inflammatory abdominal aortic aneurysms: Discriminant analysis. Histopathology 16:557-564, 1990 12. Klahr S: Obstructive nephropathy. Kidney Int 54:286300, 1998 13. Soury P, Peillon C, Melki J, Riviere J, Watelet J, Testart J: A propos d’un ane´ urysme inflammatoire de l’aorte abdominal re´ ve´ le´ par une anurie. Ann Chir 49:327-330, 1995 14. Bitsch M, Norgaard HH, Rodero O, Schroeder TV, Lorentzen JE: Inflammatory aortic aneurysms: Regression of fibrosis after aneurysm surgery. Eur J Vasc Endovasc Surg 13:371-374, 1997 15. Lacquet JP, Lacroix H, Nevelsteen A, Suy R: Inflammatory abdominal aortic aneurysm. A retrospective study of 110 cases. Acta Chir Belg 97:286-292, 1997 16. Nitecki SS, Hallet JW Jr, Stanson AW, et al: Inflammatory abdominal aortic aneurysms: A case-control study. J Vasc Surg 23:860-869, 1996
Obstructive ARF Caused by an Inflammatory Abdominal Aortic Aneurysm Rosa Sa´nchez, MD, Agustı´n Arroyo, MD, Ricardo Gesto, MD, Marı´a J. Ferna´ndez-Reyes, MD, ´ lvarez-Ude, MD Carmen Mon, MD, and Fernando A ● Inflammatory abdominal aortic aneurysms are rare entities characterized by dense fibrosis typically enveloping the aortic wall and adjacent structures with distinctive clinical features that differentiate them from typical atherosclerotic aneurysms. The inflammatory process can involve the renal excretory pathways, causing ureteral obstruction in 20% of cases. The authors report 2 cases of complete obstructive anuria secondary to inflammatory aneurysms and discuss the most appropriate management for these situations of hydronephrosis. Surgical repair of the aneurysm usually leads to regression of the inflammatory reaction. Am J Kidney Dis 41:E9. © 2003 by the National Kidney Foundation, Inc. INDEX WORDS: Anuria; aortic aneurysm; inflammatory aneurysm; obstructive uropathy; retroperitoneal fibrosis.
T
HE OVERALL incidence of acute obstructive renal failure is difficult to estimate, because a wide and varied range of causes exists, depending on patient age, sex, and associated conditions. In the prospective and multicenter study conducted by Lian˜o et al,1 10% of 748 cases of acute renal failure were found to be secondary to obstructive disease. Obstructive uropathy usually has a bimodal distribution, with a first peak in children, in whom congenital abnormalities play a significant role. The incidence subsequently decreases in adulthood and again increases after the age of 60 to 65 years, mainly in men as a result of prostatic disease. Other possible causes to be considered in middleaged individuals are stones, pelvic neoplasms, and pregnancy in women. Abdominal aortic aneurysms (AAA) should be considered among the causes of obstructive uropathy caused by extrinsic compression of the upper urinary tract above the ureterovesical junction.2 A variant of AAA, called inflammatory abdominal aortic aneurysm (IAAA), is characterized by the presence of an adventitial layer of fibrosis, preferentially located in its anterior and lateral side.3 This fibrotic reaction confers the aneurysm clinical, diagnostic, and prognostic characteristics different from those seen in the more common degenerative or atherosclerotic aneurysm. The clinical differences are attributable to the adherence or entrapment of adjacent structures in the fibrotic component. One of the structures that can become enveloped by the thick fibrotic adventitial layer of the aorta is the ureter. In fact, the first description of such an
aneurysm was made by James in 19354 in a patient with uremia caused by bilateral hydronephrosis. Ureteral involvement is seen in about 20% of cases according to the classical series.5 Bilateral involvement is less common,6 and cases initially manifesting as anuria are exceptional.7-9 We report 2 cases of acute renal failure with anuria caused by bilateral ureteral obstruction caused by IAAAs. The cases were separated in time by several years, and different approaches were used to manage hydronephrosis in each patient, a fact that gives us the opportunity to discuss the different management options. CASE REPORTS
Case 1 A 62-year-old man presented with lower back pain for the previous month, mainly on the left side and irradiating along the ureteral trajectory, associated with asthenia, anorexia, and weight loss (8 kg). The pain had been attributed to renal colic on several occasions. The clinical history found a smoking habit and myocardial infarction 4 years before. The physical examination found a pulsatile periumbilical mass. The laboratory tests showed creatinine levels of 3.8 mg/dL
From the Department of Nephrology, Segovia General Hospital and the Department of Angiology and Vascular Surgery, 12 de Octubre, University Hospital, Madrid, Spain. Received July 9, 2002; accepted in revised form November 6, 2002. Address reprint requests to Rosa Sa´nchez Herna´ndez, MD, Servicio de Nefrologı´a, Hospital General de Segovia, Carretera de A´vila s/n, 40002-Segovia, Spain. E-mail: [email protected]; [email protected] © 2003 by the National Kidney Foundation, Inc. 1523-6838/03/4103-0023$30.00/0 doi:10.1053/ajkd.2003.50136
American Journal of Kidney Diseases, Vol 41, No 3 (March), 2003: E9
1
2
SANCHEZ ET AL
moderate alcohol consumption, mild prostatic syndrome, and colonic diverticulosis. The physical examination showed a pulsatile periumbilical mass and blood pressure values of 170/100 mm Hg. The laboratory findings upon admission included creatinine levels of 10.2 mg/dL (902 mol/L), potassium levels of 6.4 mEq/L (6.4 mmol/L) and a sedimentation rate of 50 mm in the first hour. An ultrasound scan showed grade II/IV bilateral hydronephrosis with an empty bladder and an abdominal aortic aneurysm. The condition was defined as obstructive acute renal failure, and emergency cystoscopy was used to place bilateral double J ureteral catheters. Ascending pyelography confirmed the existence of bilateral proximal ureterohydronephrosis with medial deviation of the ureters. A computed tomography (CT) scan showed an aneurysm involving the infrarenal abdominal aorta and both iliac arteries, with a maximum diameter of 8 cm and abnormal thickening of the aortic wall, characteristic of inflammatory aneurysms (Fig 2). After the recovery of diuresis (after a polyuric phase) and renal function (creatinine, 1.4 mg/dL [124 mol/L]), arteriography was performed, and the patient was subjected to endoaneurismorraphy with interposition of an aortobifemoral Dacron graft. The catheters were removed 30 days later. After a 24-month follow-up, the patient is asymptomatic, with a normal renal function, and no periaortic fibrosis is seen in the control CT, although minimal renal ectasia persists. Fig 1. Intravenous urography showing medial deviation of the right ureter and hydronephrosis.
(336 mol/L) and a sedimentation rate of 60 mm in the first hour, with the rest of the parameters being normal. An abdominal ultrasound scan showed bilateral pyelocaliceal dilation (discrete on the left side and moderate on the right) that was confirmed in an intravenous urography, which also showed medial deviation of the right ureter (Fig 1). A computed tomography (CT) showed an infrarenal abdominal aortic aneurysm 4.5 cm in diameter with the presence of a fibrous band surrounding the aneurysm on its anterior and lateral aspects. With the diagnosis of IAAA, an arteriography was performed to better plan surgical treatment of the aneurysm. During the study phase, renal function worsened progressively to anuria, requiring bilateral ureteral catheterization with a double J catheter. After recovery of renal function, the patient was subjected to endoaneurismorraphy with interposition of an aortobifemoral Dacron graft, together with the release of both ureters (ureterolysis). The postoperative course was uneventful, and the ureteral catheters were removed after 6 days. The patient was discharged after one week with creatinine levels of 1.2 mg/dL (106 mol/L) and died after 12 months of coronary disease. The hydronephrosis and periaortic fibrosis had disappeared previously as evidenced by a CT follow-up study.
Case 2 A 63-year-old man came to the emergency service with anuria for the previous 24 hours, drowsiness, and a poor general condition. His medical history included smoking,
DISCUSSION
The etiology of obstructive acute renal failure includes conditions that may require surgery for effective management. IAAA is a rare variant accounting for 4.5% to 15% of all AAAs.5,10 This form of aneurysm, of unknown etiology, is macroscopically characterized by an increased wall thickness as a consequence of firm and sclerotic fibrosis, with a suggestive histopathologic picture in which 3 observations stand out: thickening of the media and, mainly, adventitial layers, with a lymphoplasmocytic infiltrate; obliterating endarteritis of the vasa vasorum; and fibrosis around the lymphatic and nervous structures.11 This fibrotic reaction confers the aneurysm clinical characteristics different from those of the more common degenerative aneurysm, as a result of the entrapment or adhesion within the fibrotic component of adjacent structures such as duodenum, inferior vena cava, left renal vein, and sigmoid. However, ureteral involvement has the greatest clinical implications, leading to secondary hydronephrosis and a potential impairment of renal function that can evolve toward atrophy if allowed to become chronic. These types of aneurysms may have clinical similarities with retroperitoneal fibrosis. Only 4% of patients
ANURIA AND INFLAMMATORY ANEURYSM
3
Fig 2. CT scan of an inflammatory abdominal aortic aneurysm with the characteristic adventitial fibrosis.
with retroperitoneal fibrosis go on to have aortic aneurysms. Atherosclerotic or degenerative aortoiliac aneurysms rarely cause hydronephrosis, and complete ureteral obstruction is even less common. Moreover, if hydronephrosis occurs, it is usually caused by lateral displacement of the distal ureter at its crossing with the aneurysm of the common iliac or hypogastric arteries. In the case of inflammatory aneurysms, the obstruction lies higher up. Instead of ureteral displacement, the latter becomes entrapped within the aortic wall. For this reason, medial deviation of the ureter in the urographic study is a characteristic finding.5 Other clinical features that differentiate inflammatory from atherosclerotic aneurysms include the greater incidence of pain (lumbar or abdominal) and an increased erythrocyte sedimentation rate. In cases of impaired renal function secondary to obstructive uropathy, initial management should mainly include preferential drainage of kidneys using a rapid decompression technique before the aneurysm is repaired, with the dual objective of not prolonging renal damage12 and improving the general condition of a patient before surgery when aortic clamping is performed. Some controversy has traditionally existed as to the ideal management approach for hydrone-
phrosis in these patients. Some investigators advocate preoperative corticoid therapy to reduce the inflammation and thus improve the hydronephrosis.13 However, this approach may theoretically increase the probability of rupture of the aneurysm caused by thinning of the wall, with a greater risk of infection of vascular prosthesis and the possibility of ureteral rupture. We are of the opinion that in patients with inflammatory aneurysms, steroid therapy should be reserved for cases of hydronephrosis and impaired renal function where the aneurysm cannot be operated on based on anesthetic criteria. Other investigators propose systematic intraoperative ureterolysis, as in our first case.14 However, this is a risky procedure that may increase the intra- and postoperative urologic complications.15 Perhaps the most widely accepted and applied practice currently is conservative management, because many investigators have reported regression of the periaortic fibrosis after surgery of the aneurysm.5,16 The main objective of this report is to point out the existence of an unusual and rarely considered cause of obstructive uropathy. In many cases, simple abdominal palpation can guide the etiologic diagnosis of obstructive acute renal failure. The triad of abdominal pulsatile mass, pain, and hydronephrosis is highly suggestive of an inflammatory aneurysm, with CT being the imaging technique of choice.
4
SANCHEZ ET AL
REFERENCES 1. Lian˜ o F, Pascual J and the Madrid Acute Renal Failure Study Group: Epidemiology of acute renal failure: A prospective multicenter community-based study. Kidney Int 50:811818, 1996 2. Curhan GC, Zeidel ML: Urinary tract obstruction, in The Kidney. Brenner and Rector (ed 5). 1996, pp 1936-1958 3. Walker DI, Bloor K, Williams G, Gillie I: Inflammatory aneurysms of the abdominal aorta. Br J Surg 59:609614, 1972 4. James TGI: Uremia due to aneurysm of the abdominal aorta. Br J Urol 7:157, 1935 5. Pennell RC, Hollier LH, Lie JT, et al: Inflammatory abdominal aortic aneurysms: A thirty-year review. J Vasc Surg 2:859-869, 1985 6. Korzets Z, Witz M, Goldberg E, Rozin M, Lehmann J, Bernheim J: The patient with asymptomatic advanced renal failure obstructive uropathy caused by inflammatory abdominal aortic aneurysm. Nephrol Dial Transplant 13:1835-1837, 1998 7. Friedel WE, Smith TR, Herman JR: Anuria caused by peri-aneurysmal retroperitoneal fibrosis. J Urol 110:516518, 1973 8. Pahira JJ, Wein AJ, Barker CF, et al: Bilateral complete ureteral obstruction secondary to an abdominal aortic aneurysm with perianeurysmal fibrosis: Diagnosis by computed tomography. J Urol 121:103-106, 1979 9. Nevelsteen A, Lacroix H, Stockx L, Baert L, Depuydt
P: Inflammatory abdominal aortic aneurysm and bilateral complete ureteral obstruction: Treatment by endovascular graft and bilateral ureteric stenting. Ann Vasc Surg 13:222224, 1999 10. Fritscchen UV, Malzfeld E, Clasen A, Kortmann H: Inflammatory abdominal aortic aneurysm: A postoperative course of retroperitoneal fibrosis. J Vasc Surg 30:1090-1098, 1999 11. Mcmahon JN, Davies JD, Scott DJA, et al: The microscopic features of inflammatory abdominal aortic aneurysms: Discriminant analysis. Histopathology 16:557-564, 1990 12. Klahr S: Obstructive nephropathy. Kidney Int 54:286300, 1998 13. Soury P, Peillon C, Melki J, Riviere J, Watelet J, Testart J: A propos d’un ane´ urysme inflammatoire de l’aorte abdominal re´ ve´ le´ par une anurie. Ann Chir 49:327-330, 1995 14. Bitsch M, Norgaard HH, Rodero O, Schroeder TV, Lorentzen JE: Inflammatory aortic aneurysms: Regression of fibrosis after aneurysm surgery. Eur J Vasc Endovasc Surg 13:371-374, 1997 15. Lacquet JP, Lacroix H, Nevelsteen A, Suy R: Inflammatory abdominal aortic aneurysm. A retrospective study of 110 cases. Acta Chir Belg 97:286-292, 1997 16. Nitecki SS, Hallet JW Jr, Stanson AW, et al: Inflammatory abdominal aortic aneurysms: A case-control study. J Vasc Surg 23:860-869, 1996