Ureteral
Obstruction DONALD
Resulting
A. TRACY,’
RONALD
from Vascular L. EISENBERG,
Prosthetic
AND
MARCUS
ureter
was dissected
removed. tunnel
by suturing
American Journal of Roentgenology 1979.132:415-418.
Technique
Case
of the graft.
tion.
Excretory
and
retrograde
urography
(figs.
The
tunnel
not by compression
from
the grafts,
but rather
was
discharged,
serum
creatinine
had
dropped
undertaken
132:415-418,
0 1979 American
Case
because
of the
patient’s
frail
condition.
Ten
March
1979
Ray Society
months
3
A 60-year-old man underwent resection of a thoracoabdominal aontic aneurysm and placement of an aorta-to-common iliac artery bypass graft. Postoperative excretory urography, performed to evaluate renal function, demonstrated hydronephrosis of the left kidney due to ureteral obstruction at the level of 51 The patient did well clinically, although follow-up retrograde excretory urography disclosed persistence of the ureteral
1B)
ureteral obstruction bilaterally at the level of aortography showed occlusion of the right
Roentgen
to 3.0
later, renal function had worsened, serum creatinine levels had risen to 4.9 mg/dl, and the ureteral obstruction had not diminished. Comment. This patient’s ureteral obstruction resulted from either mechanical compression by the graft or retroperitoneal fibrosis.
.
Received April 7, 1978; accepted after revision December 1 1 , 1978. , All authors: Departments of Radiology. University of California School of Medicine, and Veterans Administration Hospital, San Francisco, 94143. Address reprint requests to A. L. Eisenberg. Department of Radiology, University of California, San Francisco, California 94143. AJR
was
mg/dI, and 2 months later to 2.6 mg/dl. During the next 4 months, renal function became worse, and a urinary tract infection developed. Excretory urography demonstrated left ureteral obstruction with hydronephrosis and cortical atrophy of the left kidney. Tomography of the ureter clearly demonstrated the exact site of obstruction (fig. 2), which was thought to be caused by compression from the overlying graft and/or retroperitoneal fibrosis. However, corrective surgery was not
The patient
1A and
laterally.
2
patient
underwent further surgery, in which another bilateral prosthetic aortof’tmoral graft was inserted. The patient was readmitted 6 montis later because of right flank pain and right leg claudicadisc’sed partial the iliac vessels; limb of the graft.
fascia
A 67-year-old man had a ruptured abdominal aontic aneurysm resected and replaced with a bilateral aortoexternal iliac graft. Postoperative complications included acute renal failure, attributed to acute tubular necrosis secondary to both intraoperative hypotension and suprarenal cross-clamping of the aorta for 8 mm. The patient was maintained on hemodialysis for 3 weeks and had serum creatinine levels reaching 6.0 mg/dI. When the
Reports
of the left limb
psoas
graft
causes of postgraft ureteral obstruction-entrapment with resuIting mechanical obstruction of the left ureter between originab and replacement grafts, and obstruction of the right ureter secondary to postsurgical retroperitoneal fibrosis. The surgical technique was designed to prevent recurrence of ureteral obstruction from the retroperitoneal fibrosis.
man experienced left leg claudication 9 months of a bilateral aortofemoral graft. Aortography occlusion
of the original
in a retroperitoneal
slung
of stent catheters demonstrated bilateral clearing of ureteral obstruction and reduced hydronephrosis (fig. 1C). Comment. This unique case demonstrates two different
1
demonstrated
the
and the remnant
was then
by constricting adhesions from surrounding dense retropenitoneal fibrosis. After lysis of the adhesions, the right ureter was slung in the same type of retroperitoneal tunnel as the left. Retrograde excretory urography during postoperative removal
Standard technique for aortofemoral on aortoiliac bypass surgery involves a midline abdominal incision from the xiphoid process to the symphysis pubis, retraction of the intestines, and incision of the netnopenitoneal tissues to expose the distal aorta. If the distal end of the graft is to be anastomosed to the femoral artery, a separate groin incision is made to expose the intended site of anastomosis. For an aortoiliac graft, the original incision is extended to expose the site for iliac anastomosis. Using blunt dissection of the retroperitoneal soft tissues anterior and parallel to the iliac artery, a tunnel is created into which the graft prosthesis is placed. The ureter normally crosses anteriorly to the distal common iliac artery before entering the bladder. Unless cane is taken to make the tunnel for the graft posterior to the ureter by dissecting beneath the posterior panietal penitoneum and cleanly along the anterior surface of the iliac artery, the graft may be positioned anterion rather than posterior to the ureter. In this situation uneteral compression may be anticipated
A 52-year-old after placement
free,
extended from the pelvic brim to the lower pole of the left kidney. On the right side, exploration revealed the right ureter
Uneteral obstruction can produce the serious complications of hydronephrosis, infection, urine extravasation, and fistulas. Important but not previously well necognized causes of such obstruction after vascular bypass surgery are mechanical compression, retnopenitoneal fibrosis, and infection. Only 17 cases of uneteral obstruction after vascular bypass surgery have been described [1-8]. We report four additional cases.
Case
W. HEOGCOCK
The left ureter
to be obstructed
Case
Surgery
At surgery the left ureter was trapped between the remnant of the original graft and the left limb of the replacement graft. The
Four cases of ureteral obstruction are described which were primarily due to compression from an overlying vascular graft and retroperitoneal fibrosis. Infection may also be causal. Excretory urography should be performed routinely after vascular prosthetic surgery to permit early diagnosis of this complication. Ultrasonography may also be helpful in certain cases.
Surgical
Graft
41S
0361 -8o3x/79/1323-041
California S $0.00
American Journal of Roentgenology 1979.132:415-418.
416
Fig. 1 -case hydronephrosis.
TRACY
ET
AL.
MR:132,
March 1979
1 . A and B, Partial bilateral ureteral obstruction where limbs of aortofemoral graft cross and resulting ureterectasis, caliectasis, and C, Postoperative during removal of stent catheters. Ureters in lateral retroperitoneal tunnels. Previous bilateral ureteral obstruction is
diminished.
narrowing. The patient was readmitted 4 years later for painless gross hematuria. Results of renal function tests were normal, but excretory urography (fig. 3A) showed left renal cortical thinning with the persistent partial ureteral obstruction. During the next 18 months, the patient had no further urinary tract symptoms, although excretory urography showed no improvement in renal function. Aortography demonstrated adequate blood flow to both kidneys, indicating that the loss of left renal cortical substance was most likely due to the chronic partial ureteral obstruction. The ureter was found to be compressed by the graft and by the patient’s native left common iliac artery (fig. 3B). Comment. Decreasing renal function in this asymptomatic patient seems to have resulted mainly from direct mechanical compression of the ureter by the overlying graft, although reactive
retroperitoneal
fibrosis
may also have
contributed.
Case 4
A 68-year-old man underwent resection of an abdominal aortic aneurysm and placement of an aortofemoral prosthetic graft. Two weeks after discharge, he returned with flank pain. Excretory urography demonstrated hydronephrosis on the left caused by ureteral obstruction at the level of L5. Follow-up excretory urography 1 month later showed no ureteral obstruction
and
decreased
hydronephrosis.
Follow-up
excretory
urog-
raphy 3 years later showed the left urinary tract to be within normal limits. Five years after the graft surgery, the patient was hospitalized after 3 months of fatigue and pain in the region of the left femoral artery. Excretory urography demonstrated recurrence of the ureteral obstruction at the level of L5 and hydronephrosis of the left kidney. Aortography disclosed the ureteral obstruction at the point where the graft crossed the left ureter. At that time, the patient’s serum creatinine level was 1 .9 mg/dI, and no surgical correction of the ureteral obstruction was attempted Over the next 5 years, excretory urography continued to show left ureteral obstruction with hydrone.
American Journal of Roentgenology 1979.132:415-418.
MR:132,
URETERAL
March 1979
OBSTRUCTION
phrosis, and the patient experienced chronic renal failure with the serum creatinine levels rising to 3.1 mg/dI. Comment. The delayed onset of ureteral obstruction in this patient suggests that the cause was reactive retroperitoneal fibrosis. Discussion
Ureterab obstruction occurring after aortofemonal on aortoiliac bypass surgery can have several causes. The most common is compression of the ureter by an overlying graft limb. In 73% (11 of 15) ofthe reported episodes of uneteral obstruction [1-8], including ours, in which the site was known, the obstruction developed about where the graft crossed a posteriorly positioned ureter. In one of our patients, the ureter was trapped between the remnant of an old graft posteriorly and a newer graft anteriorly, a type of compression not previously neported. Retnopenitoneal fibrosis can also produce unetenal obstnuction after graft surgery [9]. Retnopenitoneal fibrosis always
varying damage,
occurs
after
aortic
bypass
surgery,
the
extent
with the amount of surgically induced tissue residual hematoma, and surrounding inflammatory reaction to the prosthetic graft [4, 7]. In 27% (4 of 15) of the episodes of uneteral obstruction in which the position of the graft was reported, the grafts had been placed posterior to the ureters, and the obstruction was caused by peniunetenic fibrosis alone. Even in cases in which compression of the ureter is the primary cause of obstruction, retnopenitoneal fibrosis may contribute to
AFTER
GRAFT
SURGERY
417
the obstruction by not permitting the ureter to move free of the graft. Although graft infection did not occur among our four patients, it can also cause uneteral obstruction. In five (24%) of the 21 cases, graft infection, either from concomitant peniuretenic fibrosis on from abscess expanding against the ureter, produced obstruction of the ureter. Uretenal intramural fibrosis resulting from constant pounding of the ureter between a pulsatile graft and a stenosed artery has also been postulated as a cause of ureteral obstruction [3]. However, it should be noted that ureteral obstruction has diminished in all cases in which surgical intervention to reposition the unetens and lyse adhesions was undertaken. The most common clinical signs of ureteral obstnuction due to prosthetic bypass graft surgery have been pain (flank, lower back, or abdominal), sepsis, and signs of urinary tract obstruction and chronic renal failure. Hypertension [7], hematunia [3], and chylunia [10] have also been symptoms. In only one instance (case 3) has the unetenal obstruction been demonstrated in an asymptomatic patient. Symptoms referable to ureteral obstruction in the 21 reported cases have occurred as early as 2 weeks and as late as 5 years after surgery. All but four cases were diagnosed within a year of surgery. Those cases diagnosed early were mainly due to direct mechanical obstruction of the ureter by the prosthetic graft. Delays in the development of symptoms have been associated with the complication of netnopenitoneab fibrosis. All of the
418
TRACY
four reported cases of abscess formation about the graft causing uretenal obstruction were diagnosed 3-S months after surgery. the 21 reported patients, 14 were treated surgically, most by graft revision or a ureteral-freeing procedure, although two required nephnectomy. Of the seven who were medically treated all have had persistent uneteral obstruction and chronic renal failure. The incidence of ureteral obstruction after graft sungery has not been assessed because the unilateral hydronephrosis it produces may not cause symptoms [10]. However, in graft patients who have had ureteral obstnuction diagnosed, frequent and serious associated morbidity has occurred, including chronic renal failure and sepsis. Such serious sequelae underscore the need for awareness of ureteral obstruction as a complication of reconstructive vascular surgery. Preservation of the normal anatomic relation of the ureter to the common iliac artery may decrease the incidence of postgraft ureteral obstruction [2-7]. Therefore, during vascular surgery, the ureter should be placed anterior to the prosthetic graft. This maneuver is especially important since the correction of uneteral obstruction involves either reanastomosis of the graft, with the attendant risk of graft occlusion, or division and repositioning of the ureter, with the possibility of graft sepsis produced by extravasation of infected urine. Case 1 had ureteral obstruction due to entrapment between old and new grafts; this indicates, we believe, that an old graft should be completely nesected when a new one is inserted. In patients with obstruction due to retnopenitoneal fibrosis alone who are undergoing lysis of constricting adhesions, we concur with Ross and Goldsmith [11] that, as was done in case 1 an attempt be made to avoid recurrence of uretenal obstruction by placing the ureter laterally. Theoretically, in patients whose physical condition precludes further surgery, steroid therapy might reduce the incidence of obstructing adhesions by limiting the peniunetenic inflammatory reaction induced by the prosthetic graft. However, this mode of therapy needs further evaluation. Excretory unography is the most sensitive procedure for detecting uneteral obstruction and should be performed routinely after reconstructive aortic bypass sunOf
American Journal of Roentgenology 1979.132:415-418.
,
,
gery.
Two
of
our
patients
had
symptoms
of
MR:132,
AL.
March 1979
obstruction before serious complications occur. Excretory urography should be performed without significant delay if the postgnaft patient has any lower urinary tract symptoms or develops urinary tract infection. In all reported cases, uneteral obstruction occurred most commonly at the level of L4-S1 When excretory urography fails to show the ureters in patients with previous graft surgery, tomography may be necessary at the level of L4-Sb to demonstrate the site of obstruction (case fig. 2). Impressions by overlying graft limbs can sometimes be identified radiographically and may exdude other causes of obstruction such as nonopaque calculus. Hydnonephrosis is also commonly seen on excretory unograms in patients with postgraft uretenal obstruction; this occurred in all four of our patients. In patients with sepsis, an adjacent abscess can cause a mass effect on the uneters [1 ] Extravasation of contrast material from the obstructed ureter into fistulous tracts has also occurred [1 5]. In patients hypersensitive to contrast material, ultrasonography can be used to evaluate for hydronephrosis. .
2,
.
,
REFERENCES 1 Shaw AS, Baue AE: Management of sepsis complicating arterial reconstructive surgery. Surgery 53 :75-85, 1963 2. Veith FJ, Hartsuck JM, Cram C: Management of aortoiliac reconstruction complicated by sepsis and hemorrhage. N EngI J Med 270 : 1 389-1 391 1964 3. Lytton B: Ureteral obstruction following aontofemoral bypass grafts. Surgery 59 : 91 8-922, 1966 4. Oorfman LE, Thomford NA: Unusual ureteral injury following aorto-iliac by-pass graft: case report. J Urol 101 :25-27, 1969 .
,
5. Ehrlich AM, Hecht HL, aorto-iliac bypass graft:
RJ: Chyluria following method of radiologic of the literature. J Urol 107:302-303,
6.
7.
8.
unetenal
obstruction within 6 weeks of surgery; thus, excretory urognaphy soon after surgery seems advisable. In 81% (17 of 21) of the reported cases, including ours, the ureteral obstruction occurred within 1 year of surgery; in of 21) of these patients obstruction developed within the first 4 months. Therefore, a second postoperative excretory urogram probably should be obtained within 4 months of surgery to detect silent unilateral 48%
ET
9.
10.
Veenema a unique
diagnosis and review 1972 Petrone AF, Oudzinski PJ, Maniatis W: Ureteral obstruction secondary to aortic femorab bypass. Ann Surg 179 : 192-1 96, 1974 Wallijn E, Renders G, Vereecken L: Urobogical complications following aontofemoral bypass graft. BrJ Urol 47:617621, 1975 Jacobsen ME, Mastio GJ, Berkas EM: Ureteral obstruction as a late complication of abdominal aneurysm resection. J Kans Med Soc 63:516-518, 1962 Wotley RG: Anatomy and physiology of the ureter, in Urology, edited by Blandy J, London, Blackwell Scientific Publications, 1976, pp 568-598 Lytton B, Epstein FH: Obstructive uropathy, in Harrison’s Principles of Internal Medicine, 7th ed New York, McGrawHill, 1974, pp 1409-1411 Ross JC, Goldsmith HJ: The combined surgical and medical treatment of retroperitoneal fibrosis. Br J Surg 58 :422-427, 1971 ,
(10
11 .
Obstruction DONALD
Resulting
A. TRACY,’
RONALD
from Vascular L. EISENBERG,
Prosthetic
AND
MARCUS
ureter
was dissected
removed. tunnel
by suturing
American Journal of Roentgenology 1979.132:415-418.
Technique
Case
of the graft.
tion.
Excretory
and
retrograde
urography
(figs.
The
tunnel
not by compression
from
the grafts,
but rather
was
discharged,
serum
creatinine
had
dropped
undertaken
132:415-418,
0 1979 American
Case
because
of the
patient’s
frail
condition.
Ten
March
1979
Ray Society
months
3
A 60-year-old man underwent resection of a thoracoabdominal aontic aneurysm and placement of an aorta-to-common iliac artery bypass graft. Postoperative excretory urography, performed to evaluate renal function, demonstrated hydronephrosis of the left kidney due to ureteral obstruction at the level of 51 The patient did well clinically, although follow-up retrograde excretory urography disclosed persistence of the ureteral
1B)
ureteral obstruction bilaterally at the level of aortography showed occlusion of the right
Roentgen
to 3.0
later, renal function had worsened, serum creatinine levels had risen to 4.9 mg/dl, and the ureteral obstruction had not diminished. Comment. This patient’s ureteral obstruction resulted from either mechanical compression by the graft or retroperitoneal fibrosis.
.
Received April 7, 1978; accepted after revision December 1 1 , 1978. , All authors: Departments of Radiology. University of California School of Medicine, and Veterans Administration Hospital, San Francisco, 94143. Address reprint requests to A. L. Eisenberg. Department of Radiology, University of California, San Francisco, California 94143. AJR
was
mg/dI, and 2 months later to 2.6 mg/dl. During the next 4 months, renal function became worse, and a urinary tract infection developed. Excretory urography demonstrated left ureteral obstruction with hydronephrosis and cortical atrophy of the left kidney. Tomography of the ureter clearly demonstrated the exact site of obstruction (fig. 2), which was thought to be caused by compression from the overlying graft and/or retroperitoneal fibrosis. However, corrective surgery was not
The patient
1A and
laterally.
2
patient
underwent further surgery, in which another bilateral prosthetic aortof’tmoral graft was inserted. The patient was readmitted 6 montis later because of right flank pain and right leg claudicadisc’sed partial the iliac vessels; limb of the graft.
fascia
A 67-year-old man had a ruptured abdominal aontic aneurysm resected and replaced with a bilateral aortoexternal iliac graft. Postoperative complications included acute renal failure, attributed to acute tubular necrosis secondary to both intraoperative hypotension and suprarenal cross-clamping of the aorta for 8 mm. The patient was maintained on hemodialysis for 3 weeks and had serum creatinine levels reaching 6.0 mg/dI. When the
Reports
of the left limb
psoas
graft
causes of postgraft ureteral obstruction-entrapment with resuIting mechanical obstruction of the left ureter between originab and replacement grafts, and obstruction of the right ureter secondary to postsurgical retroperitoneal fibrosis. The surgical technique was designed to prevent recurrence of ureteral obstruction from the retroperitoneal fibrosis.
man experienced left leg claudication 9 months of a bilateral aortofemoral graft. Aortography occlusion
of the original
in a retroperitoneal
slung
of stent catheters demonstrated bilateral clearing of ureteral obstruction and reduced hydronephrosis (fig. 1C). Comment. This unique case demonstrates two different
1
demonstrated
the
and the remnant
was then
by constricting adhesions from surrounding dense retropenitoneal fibrosis. After lysis of the adhesions, the right ureter was slung in the same type of retroperitoneal tunnel as the left. Retrograde excretory urography during postoperative removal
Standard technique for aortofemoral on aortoiliac bypass surgery involves a midline abdominal incision from the xiphoid process to the symphysis pubis, retraction of the intestines, and incision of the netnopenitoneal tissues to expose the distal aorta. If the distal end of the graft is to be anastomosed to the femoral artery, a separate groin incision is made to expose the intended site of anastomosis. For an aortoiliac graft, the original incision is extended to expose the site for iliac anastomosis. Using blunt dissection of the retroperitoneal soft tissues anterior and parallel to the iliac artery, a tunnel is created into which the graft prosthesis is placed. The ureter normally crosses anteriorly to the distal common iliac artery before entering the bladder. Unless cane is taken to make the tunnel for the graft posterior to the ureter by dissecting beneath the posterior panietal penitoneum and cleanly along the anterior surface of the iliac artery, the graft may be positioned anterion rather than posterior to the ureter. In this situation uneteral compression may be anticipated
A 52-year-old after placement
free,
extended from the pelvic brim to the lower pole of the left kidney. On the right side, exploration revealed the right ureter
Uneteral obstruction can produce the serious complications of hydronephrosis, infection, urine extravasation, and fistulas. Important but not previously well necognized causes of such obstruction after vascular bypass surgery are mechanical compression, retnopenitoneal fibrosis, and infection. Only 17 cases of uneteral obstruction after vascular bypass surgery have been described [1-8]. We report four additional cases.
Case
W. HEOGCOCK
The left ureter
to be obstructed
Case
Surgery
At surgery the left ureter was trapped between the remnant of the original graft and the left limb of the replacement graft. The
Four cases of ureteral obstruction are described which were primarily due to compression from an overlying vascular graft and retroperitoneal fibrosis. Infection may also be causal. Excretory urography should be performed routinely after vascular prosthetic surgery to permit early diagnosis of this complication. Ultrasonography may also be helpful in certain cases.
Surgical
Graft
41S
0361 -8o3x/79/1323-041
California S $0.00
American Journal of Roentgenology 1979.132:415-418.
416
Fig. 1 -case hydronephrosis.
TRACY
ET
AL.
MR:132,
March 1979
1 . A and B, Partial bilateral ureteral obstruction where limbs of aortofemoral graft cross and resulting ureterectasis, caliectasis, and C, Postoperative during removal of stent catheters. Ureters in lateral retroperitoneal tunnels. Previous bilateral ureteral obstruction is
diminished.
narrowing. The patient was readmitted 4 years later for painless gross hematuria. Results of renal function tests were normal, but excretory urography (fig. 3A) showed left renal cortical thinning with the persistent partial ureteral obstruction. During the next 18 months, the patient had no further urinary tract symptoms, although excretory urography showed no improvement in renal function. Aortography demonstrated adequate blood flow to both kidneys, indicating that the loss of left renal cortical substance was most likely due to the chronic partial ureteral obstruction. The ureter was found to be compressed by the graft and by the patient’s native left common iliac artery (fig. 3B). Comment. Decreasing renal function in this asymptomatic patient seems to have resulted mainly from direct mechanical compression of the ureter by the overlying graft, although reactive
retroperitoneal
fibrosis
may also have
contributed.
Case 4
A 68-year-old man underwent resection of an abdominal aortic aneurysm and placement of an aortofemoral prosthetic graft. Two weeks after discharge, he returned with flank pain. Excretory urography demonstrated hydronephrosis on the left caused by ureteral obstruction at the level of L5. Follow-up excretory urography 1 month later showed no ureteral obstruction
and
decreased
hydronephrosis.
Follow-up
excretory
urog-
raphy 3 years later showed the left urinary tract to be within normal limits. Five years after the graft surgery, the patient was hospitalized after 3 months of fatigue and pain in the region of the left femoral artery. Excretory urography demonstrated recurrence of the ureteral obstruction at the level of L5 and hydronephrosis of the left kidney. Aortography disclosed the ureteral obstruction at the point where the graft crossed the left ureter. At that time, the patient’s serum creatinine level was 1 .9 mg/dI, and no surgical correction of the ureteral obstruction was attempted Over the next 5 years, excretory urography continued to show left ureteral obstruction with hydrone.
American Journal of Roentgenology 1979.132:415-418.
MR:132,
URETERAL
March 1979
OBSTRUCTION
phrosis, and the patient experienced chronic renal failure with the serum creatinine levels rising to 3.1 mg/dI. Comment. The delayed onset of ureteral obstruction in this patient suggests that the cause was reactive retroperitoneal fibrosis. Discussion
Ureterab obstruction occurring after aortofemonal on aortoiliac bypass surgery can have several causes. The most common is compression of the ureter by an overlying graft limb. In 73% (11 of 15) ofthe reported episodes of uneteral obstruction [1-8], including ours, in which the site was known, the obstruction developed about where the graft crossed a posteriorly positioned ureter. In one of our patients, the ureter was trapped between the remnant of an old graft posteriorly and a newer graft anteriorly, a type of compression not previously neported. Retnopenitoneal fibrosis can also produce unetenal obstnuction after graft surgery [9]. Retnopenitoneal fibrosis always
varying damage,
occurs
after
aortic
bypass
surgery,
the
extent
with the amount of surgically induced tissue residual hematoma, and surrounding inflammatory reaction to the prosthetic graft [4, 7]. In 27% (4 of 15) of the episodes of uneteral obstruction in which the position of the graft was reported, the grafts had been placed posterior to the ureters, and the obstruction was caused by peniunetenic fibrosis alone. Even in cases in which compression of the ureter is the primary cause of obstruction, retnopenitoneal fibrosis may contribute to
AFTER
GRAFT
SURGERY
417
the obstruction by not permitting the ureter to move free of the graft. Although graft infection did not occur among our four patients, it can also cause uneteral obstruction. In five (24%) of the 21 cases, graft infection, either from concomitant peniuretenic fibrosis on from abscess expanding against the ureter, produced obstruction of the ureter. Uretenal intramural fibrosis resulting from constant pounding of the ureter between a pulsatile graft and a stenosed artery has also been postulated as a cause of ureteral obstruction [3]. However, it should be noted that ureteral obstruction has diminished in all cases in which surgical intervention to reposition the unetens and lyse adhesions was undertaken. The most common clinical signs of ureteral obstnuction due to prosthetic bypass graft surgery have been pain (flank, lower back, or abdominal), sepsis, and signs of urinary tract obstruction and chronic renal failure. Hypertension [7], hematunia [3], and chylunia [10] have also been symptoms. In only one instance (case 3) has the unetenal obstruction been demonstrated in an asymptomatic patient. Symptoms referable to ureteral obstruction in the 21 reported cases have occurred as early as 2 weeks and as late as 5 years after surgery. All but four cases were diagnosed within a year of surgery. Those cases diagnosed early were mainly due to direct mechanical obstruction of the ureter by the prosthetic graft. Delays in the development of symptoms have been associated with the complication of netnopenitoneab fibrosis. All of the
418
TRACY
four reported cases of abscess formation about the graft causing uretenal obstruction were diagnosed 3-S months after surgery. the 21 reported patients, 14 were treated surgically, most by graft revision or a ureteral-freeing procedure, although two required nephnectomy. Of the seven who were medically treated all have had persistent uneteral obstruction and chronic renal failure. The incidence of ureteral obstruction after graft sungery has not been assessed because the unilateral hydronephrosis it produces may not cause symptoms [10]. However, in graft patients who have had ureteral obstnuction diagnosed, frequent and serious associated morbidity has occurred, including chronic renal failure and sepsis. Such serious sequelae underscore the need for awareness of ureteral obstruction as a complication of reconstructive vascular surgery. Preservation of the normal anatomic relation of the ureter to the common iliac artery may decrease the incidence of postgraft ureteral obstruction [2-7]. Therefore, during vascular surgery, the ureter should be placed anterior to the prosthetic graft. This maneuver is especially important since the correction of uneteral obstruction involves either reanastomosis of the graft, with the attendant risk of graft occlusion, or division and repositioning of the ureter, with the possibility of graft sepsis produced by extravasation of infected urine. Case 1 had ureteral obstruction due to entrapment between old and new grafts; this indicates, we believe, that an old graft should be completely nesected when a new one is inserted. In patients with obstruction due to retnopenitoneal fibrosis alone who are undergoing lysis of constricting adhesions, we concur with Ross and Goldsmith [11] that, as was done in case 1 an attempt be made to avoid recurrence of uretenal obstruction by placing the ureter laterally. Theoretically, in patients whose physical condition precludes further surgery, steroid therapy might reduce the incidence of obstructing adhesions by limiting the peniunetenic inflammatory reaction induced by the prosthetic graft. However, this mode of therapy needs further evaluation. Excretory unography is the most sensitive procedure for detecting uneteral obstruction and should be performed routinely after reconstructive aortic bypass sunOf
American Journal of Roentgenology 1979.132:415-418.
,
,
gery.
Two
of
our
patients
had
symptoms
of
MR:132,
AL.
March 1979
obstruction before serious complications occur. Excretory urography should be performed without significant delay if the postgnaft patient has any lower urinary tract symptoms or develops urinary tract infection. In all reported cases, uneteral obstruction occurred most commonly at the level of L4-S1 When excretory urography fails to show the ureters in patients with previous graft surgery, tomography may be necessary at the level of L4-Sb to demonstrate the site of obstruction (case fig. 2). Impressions by overlying graft limbs can sometimes be identified radiographically and may exdude other causes of obstruction such as nonopaque calculus. Hydnonephrosis is also commonly seen on excretory unograms in patients with postgraft uretenal obstruction; this occurred in all four of our patients. In patients with sepsis, an adjacent abscess can cause a mass effect on the uneters [1 ] Extravasation of contrast material from the obstructed ureter into fistulous tracts has also occurred [1 5]. In patients hypersensitive to contrast material, ultrasonography can be used to evaluate for hydronephrosis. .
2,
.
,
REFERENCES 1 Shaw AS, Baue AE: Management of sepsis complicating arterial reconstructive surgery. Surgery 53 :75-85, 1963 2. Veith FJ, Hartsuck JM, Cram C: Management of aortoiliac reconstruction complicated by sepsis and hemorrhage. N EngI J Med 270 : 1 389-1 391 1964 3. Lytton B: Ureteral obstruction following aontofemoral bypass grafts. Surgery 59 : 91 8-922, 1966 4. Oorfman LE, Thomford NA: Unusual ureteral injury following aorto-iliac by-pass graft: case report. J Urol 101 :25-27, 1969 .
,
5. Ehrlich AM, Hecht HL, aorto-iliac bypass graft:
RJ: Chyluria following method of radiologic of the literature. J Urol 107:302-303,
6.
7.
8.
unetenal
obstruction within 6 weeks of surgery; thus, excretory urognaphy soon after surgery seems advisable. In 81% (17 of 21) of the reported cases, including ours, the ureteral obstruction occurred within 1 year of surgery; in of 21) of these patients obstruction developed within the first 4 months. Therefore, a second postoperative excretory urogram probably should be obtained within 4 months of surgery to detect silent unilateral 48%
ET
9.
10.
Veenema a unique
diagnosis and review 1972 Petrone AF, Oudzinski PJ, Maniatis W: Ureteral obstruction secondary to aortic femorab bypass. Ann Surg 179 : 192-1 96, 1974 Wallijn E, Renders G, Vereecken L: Urobogical complications following aontofemoral bypass graft. BrJ Urol 47:617621, 1975 Jacobsen ME, Mastio GJ, Berkas EM: Ureteral obstruction as a late complication of abdominal aneurysm resection. J Kans Med Soc 63:516-518, 1962 Wotley RG: Anatomy and physiology of the ureter, in Urology, edited by Blandy J, London, Blackwell Scientific Publications, 1976, pp 568-598 Lytton B, Epstein FH: Obstructive uropathy, in Harrison’s Principles of Internal Medicine, 7th ed New York, McGrawHill, 1974, pp 1409-1411 Ross JC, Goldsmith HJ: The combined surgical and medical treatment of retroperitoneal fibrosis. Br J Surg 58 :422-427, 1971 ,
(10
11 .
