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Retrospective study of ureteral obstruction following vascular bypass surgery
RETROSPECTIVE STUDY OF URETERAL OBSTRUCTION FOLLOWING VASCULAR BYPASS SURGERY JEFFREY E. KAUFMAN, M.D. C. LOWELL PARSONS, M.D. BARBARA B. GOSINK, M.D. JOSEPH D. SCHMIDT, M.D. From the Sections of Urology and Ultrasound, Veterans Administration Medical Center, and the Division of Urology, Department of Surgery, University of California Medical Center, San Diego, California
ABSTRACT -Although several cases of ureter-al obstruction after vascular bypass surgery for aortoiliac disease have been reported, the incidence of this potentially critical complication has not been established. In this study, 57 selected patients who had undergone vascular bypass surgery were examined with ultrasound for evidence of ureter-al obstruction. Hydronephrosis was discovered in 1 of 57 patients (1.75 per cent) over-all (symptomatic and asymptomatic); no evidence of obstruction was found in the asymptomatic patients. These results fail to corroborate the impression of several investigators that undetected ureteral obstruction may be present in a signiftcant number of patients after vascular bypass surgery.
Abdominal and pelvic vascular lesions are known to cause ureteral obstruction. Since Goodwin and Schumacker’ reviewed this topic in 1947, several cases of ureteral obstruction associated with aortic, iliac, and hypogastric artery aneurysms have been reported. In 1961 Culp and Bernatz* reviewed the urologic aspects of 400 surgically treated cases of abdominal aortic aneurysms without addressing the question of ureteral obstruction following repair. Jacobson, Mastio, and Be&as in 1962’ reported a case of ureteral obstruction following aortoiliac bypass, and several other reports of such cases followed. Most authors suggested that the incidence of this complication might be significant since unilateral obstruction without infection may go unnoticed. Today, although the use of bypass grafts for aortoiliac disease is increasingly common, the incidence of ureteral obstruction after such procedures has not been determined. Our aim was to review the records of vascular surgery
patients at our institution for silent obstruction and thus to determine the over-all incidence of this complication.
Between December, 1976, and December, 1978, 150 aortofemoral or aortoiliac bypass grafts were performed at the University of California-affiliated Veterans Administration Medical Center in San Diego. Of these 150 patients, 117 met the criteria for inclusion in the study. Included in the study were patients whose surgery was done for significant aortic aneurysms as well as those whose surgery was done to correct significant peripheral ischemia. Excluded were patients who had received a Dacron tube graft for an aneurysmectomy and those in whom the distal anastomosis of the bifurcated graft was placed proximal to the ureters. Patients whose surgery was done because of trauma were also excluded.
278
UROLOGY
Material
/
MARCH
and Methods
1932
/
VOLUME
XIX,
NUMBER
3
Operative
technique
In all of the bypass procedures performed, the standard technique was transperitoneal through a midline incision. Tunnels for the iliac limbs of the graft were created by blunt digital dissection under the posterior peritoneum on the anterior surface of the iliac vessels. Since the ureters normally adhere to the peritoneum and are reflected along with it, the grafts were placed in an anatomically correct position posterior to the ureter. Preclotted knitted Dacron bifurcated grafts were used in all cases. In no instance was a ureteral catheter placed preoperatively; only rarely were the ureters isolated or identified. No ureteral injuries were recognized intraoperatively. Preoperative profiles consisted of serum blood urea nitrogen and creatinine measurements, urinalysis, and an evaluation of the upper tract anatomy by excretory urogram, echography, or the excretion phase of an angiogram. Follow-up studies in the postoperative period included repeat serum blood urea nitrogen and creatinine determinations. Follow-up was obtained on 57 of the 117 eligible patients who underwent surgery during this period. Follow-up failures were due to death from unrelated causes, administrative problems, or failures of patients to return for post-surgical care. The charts of those patients who were reviewed for this study but not contacted for follow-up did not suggest any symptoms of obstruction. To determine if ureteral obstruction was present, we screened these 57 patients from two to twenty-four months postoperatively with renal echography (ultrasound), a sensitive and reliable method of determining hydroureteronephrosis.4 Determination of the presence and grade of obstruction was made by members of the radiology staff. Ultrasound
All studies were performed with commercially available gray scale ultrasound equipment using a 3.5 mHz transducer. Patients were requested to void prior to examination. All longitudinal and transverse scans of the kidneys were performed with the patient in the prone position. In addition, right lateral decubitus scans were performed to provide better visualization of the left kidney and left lateral decubitus scans performed to provide better visualization of the right kidney. The degree of hydronephrosis was graded on a scale of O-III using
UROLOGY
/ MARCH1982
/ VOLUMEXIX,NUMBER3
FIGURE 1. Excretory urogram of fifty-two-year-old man after 2 aortoiliac endarterectomies and aortofemoral bypass. Bilateral obstruction at pelvic brim with extravasation on right.
the criteria previously published.4 Grade 0 showed dense central collecting system echoes; grade I showed slight separation of collecting system echoes with a central ovoid sonolucency; grade II showed a rounded central sonolucency with further separation of collecting echoes; grade III showed large portions of the kidney replaced by a sonolucent sac. Results Of 57 patients studied only 1 patient, who was symptomatic, was noted to have ureteral obstruction. In the case presented here the obstruction was bilateral, though greater on one side. In another patient, unilateral grade I hydronephrosis with a midureteral narrowing was discovered on excretory urogram done for lower tract obstructive symptoms eleven days after surgery. He failed later follow-up, however, and was not included in this study. His surgery was uncomplicated, and he had had no prior operation. No cases of ureteral obstruction were discovered in asymptomatic patients
279
TABLE Reference Dorfman and Thornfords
Presenting Symptom
Summary of reported cases in literature
Relation of Graft to Ureter
Results Much
Unknown
Bilateral hydronephrosis (degree unknown)
Steroids
Complete resolution on left, slight improvement on right
Posterior
Severe bilateral hydronephrosis
Slight improvement
Hypertension
Unknown
Right renal artery graft thrombosed; increased creatinine
Anterior
Minimal hnction with severe hydronephrosis on right Left hydronephrosis, no visualization on right
Initially steroids; later, grafts divided and transposed Nephrectomy
Progression until surgery, slight improvement after
Low back pain; hematuria
Anterior
Chyluria
Anterior
Obstnwtive voiding symptoms
Anterior
Obstructive voiding symptoms Obstructive voiding symptoms Rt. flank tenderness; rt. chest pain Right flank pain
Anterior
Initially ureteral catheterization; ureter divided, segment resected, transposed 4 months later Ureterolysis, ureters divided and transposed Ureterolysis, division and transposition Ureter divided and transposed with omental interposition Nephre ureterectomy
Renal failure, urinary tract infection
Anterior
Painless hematuria (asymptomatic initially) Flank pain
Anterior
Rajfer and Smith’s
Anuria,
Posterior
Bilateral ureteral obstruction
Bilateral nephrostomy
Bouterie and Harbach14
Right flank pain
Anterior
Grade II hydronephrosis
Ureterolysis; graft divided and transposed; ureter placed intraperitoneal
Lyttons
Ehrlich
to
Treatment Graft divided and transposed; ureterolysis
et al. ‘I
Anterior ureter
Findings Grade II-III hydronephrosis on right
Wallijn,
Hemahuia; obstructive voiding symptoms Nephrotic syndrome secondary to glomerulonephritis Vague abdominal discomfort
I.
et al. 7
Petrone et al. g
Tracy et al. ‘*
280
uremia
Posterior
Unknown
Anterior on left; unknown on right
Unknown
Bilateral hydronephrosis (greater on rt.) Moderate hydra nephrosis Moderate hydronephrosis Nonfunction on left 2” to obstruction Grade II hydronephrosis on rt. Obstruction on rt. (degree) unknown) Bilateral partial obstruction
Left ureteral obstruction, hydronephrosis, cortical atrophy Hydronephrosis; cortical thinning Hydronephrosis
UROLOGY
/
improved
Resolution
Much improved bilaterally Complete resolution Much
improved
Resolution
Antibiotics
No Change
None
Marked hydronephrosis
Ureters placed in retroperitoneal tunnel; ureterolysis on right None
Reduced hydronephrosis
MARCH
1952
Progressive failure
renal
Progressive parenchymal thinning Initial resolution, delayed recurrence and renal failure Improved renal function Resolution
i
VOLUME
XIX,
NUMBER
3
TABLE Presenting Symptom
Reference Kaufman
et al.
Veith
I.
Relation of Craft to Ureter
Findings
Fever, dysuria, flank pain
Posterior
Bilateral grade II hydronephrosis Left hydra nephrosis “Considerable” bilateral hydronephrosis
Hepatitis
Unknown
Left flank pain, fever and chills
Unknown
Back pain, chills
Unknown
Chills, fever, back pain, urinary frequency Fever
Unknown
Unknown
Right hydronephrosis, ureteral
Right back, abdominal pain
Posterior
Right hydra ureteronephrosis
et al. I5
Shaw and Baue’
Continued
Mild left hydronephrosis Bilateral hydronephrosis
fiShlli3
Jacobson et al. 3
regardless of whether the surgery was done for aneurysms or ischemia. The over-all incidence was 1.75 per cent. Case Report A fifty-two-year-old man had undergone two aortoiliac endartereetomies (in 1970 and 1974). For complaints of recurrent severe claudication he underwent an uncomplicated aortofemoral bypass on July 19, 1978. The surgeon noted that a moderate amount of adhesions made the dissection difficult, but identified the ureters and constructed the retroperitoneal tunnels as previously described. The preoperative urinalysis was negative; blood urea nitrogen was 12 mg. and creatinine 1.3 mg./lOO ml. One year earlier the patient’s excretory urogram had been normal. He did well until postoperative days 3 to 5 when a low-grade fever, dysuria, and bilateral flank pain developed. An excretory urogram revealed bilateral grade II hydronephrosis with extravasation from the right renal pelvis (Fig. 1). Both ureters were obstructed at the level of the pelvic brim. A 7-F ureteral catheter was placed with some difficulty on the right with immediate relief of pain and resolution of fever. No catheter was placed on the left. The catheter was changed to an indwelling 7-F Gibbons catheter
UROLOGY
/
MARCH
1982
/
VOLUME
XIX,
NUMBER
3
Treatment
Results
Ureteral catheter
Improvement
None
Unknown
Retroperitoneal abscess drained initially; nephrostomy and ureter-al reconstruction 6 wk. later Ureteral catheter initially Retroperitoneal abscess drained, graft revised Nephrostomy tube initially, nephrectomy later Ureter resected and stented
Progressive hydronephrosis; recurrent abscess
Death from causes
other
Resolution
Resolution
Resolution
after five days. Follow-up intravenous pyelogram and ultrasound showed complete resolution on the right and much improvement on the left; but when the catheter was removed in early February, 1979, grade II to III hydronephrosis and flank pain recurred, necessitating replacement of the stent. Throughout the episode, there was no change in the blood urea nitrogen or creatinine. Long-term followup is unavailable since the patient died of an acute myocardial infarction on March 21, 1979. Postmortem examination revealed no hydronephrosis. Comment There has existed little evidence to answer the question of how often bypass surgery leads to significant ureteral obstruction, The scarcity of case reports in the literature leads one to presume that it is not a common occurrence, although the reason for this may be that silent obstruction goes undiagnosed. When it does occur, the complication is serious, threatening renal loss, graft infection, and even loss of limb or life.5 Thirty-two obstructed ureters in 24 patients have been reported in the literature (Table 1).3*515 These patients presented from four days
231
to twenty-eight months postoperatively with variable complaints. The most common of these were pain, infection, hematuria, and decreasing renal function, but nephrotic syndrome, l1 hypertension, l1 and chyluria’ have been mentioned. Only 1 patient was completely asymptomatic at the time of diagnosis.12 The literature offers several explanations for the occurrence of the obstruction as well as several possible modes of therapy. The most probable cause of early obstruction, as proposed by Lyttona is mechanical compression of the ureter against the native iliac artery from an anteriorly placed graft, a process that is analogous to the obstruction that occurs in a congenitally anomalous retroiliac ureter. l6 Though the ureter usually adheres to the peritoneum and is reflected anteriorly when a retroperitoneal tunnel is created for graft placement, fibrosis from prior surgery may prevent this. In cases in which the relationship of graft tcr ureter was known, Table I shows that the grafts in 63 per cent (12 of 19) of obstructed ureters were anterior. Preoperative ureteral catheterization and attention to this relationship by vascular surgeons would prevent this. A second mechanism, one accounting for delayed obstruction, is the restriction of postsurgical tissue reaction. Just as in obstruction from perianeurysmal or retroperitoneal fibrosis, encasement prevents normal ureteral peristalsis and results in functional obstruction even though easy passage of a catheter is permitted. ” Similar “fibrosis” may occur when the ureter is devascularized from extensive dissection, especially in the face of generalized atherosclerosis. l3 When obstruction is due to fibrosis or if the patient is a poor surgical risk, management may be undertaken with steroids or ureteral stents. Internal stenting is relatively noninvasive, can remain indwelling for years, and may allow time for fibrosis to diminish or soften and become less restrictive.‘*-21 On the other hand, risks of urinary tract infection, occlusion of the lumen by debris, and poor patient tolerance may necessitate removal of the stent and definitive operative treatment. The surgical approach to repair ureteral obstruction in this setting has been a subject of debate. Lytton’ and others’,’ suggest that division and transposition of the ureterolysis, ureter is the least hazardous method of repair. They believe that the presence of fibrosis leading to difficult mobilization, uncontrollable
bleeding, difficult reanastomosis, and possible thrombosis is too great a risk to justify division of the graft. This is especially true in a wellhealed graft. Although we agree with Lytton, others have pointed out that the risks mentioned are also attendant to division of the ureter.“,14 Moreover, the dissection and mobilization may further compromise the blood supply to the ureter and impair healing. Urine extravasation, which almost certainly occurs, may lead to local fibrosis and possible restricturing, threaten infection, and require an external drain which is contraindicated in the presence of a graft. These risks may be minimized through interposition of omentum or peritoneum between graft and ureter. The division of the ureter should be as far from the graft as possible, and proximal drainage should be used. We have had to intervene surgically in 2 other cases, not included in this series, where the patients presented with obvious symptoms (pain) following a vascular graft procedure. Contrary to speculation, ureteral obstruction after vascular bypass is uncommon (1.75 per cent) and silent obstruction is rare. Nonetheless, since the possible sequelae of obstruction are so serious and echography offers an effective, noninvasive method of evaluation, routine postoperative evaluation should be done in any patient who has undergone vascular bypass surgery.
282
UROLOGY
Division of Urology H-897 225 Dickinson Street San Diego, California 92103 (DR. KAUFMAN) References 1. Goodwin WE, and Schumacker HB Jr: Aneurysm of the hypogastric artery producing urinary tract obstruction, J. Ural. 57: 839 (1947). 2. Culp OS, and Bemak PE: Urologic aspects of lesions in the abdominal aorta, ibid. 86: 189 (1961). 3. Jacobson ME, Mastio GJ, and Be&as EM: Ureteral obstruction as a late complication of abdominal aneurysm resection, J. Kansas Med. Sot. 63: 516 (lSe2). 4. Ellenbogen PH. Scheible FW, Tahrer LB, and Leopold GR: Sensitivity ofr gray scale ultrasound in detecting urinary tract obstruction. AIR 130: 731 (1978). 5. Shaw RS: and Baue AE: Management of sepsis complicating arterial reconstructive surgery, Surgery 53: 75 (1963). 6. Dorfinan LE, and Thomford NR: Unusual ureteral injury following aorto-iliac by-pass .-graft: case report, J. Ural. 101: 25 (1969j: 7. Ehrlich RM. Hecht HL. and Veenema RI: Chvluria following aortoiliac bypass graft, ibid. 197: 362 (1972): . 8. Lytton B: Ureteral obstruction following aortofemoral bypass grafts, Surgery 5% 918 (1966). 9. Petrone AF, D&in& PJ, and Maniatis W: U&end ob-
/
MARCH
1982
i
VOLUME
XIX,
NUMBER
3
struction secondary to aortic femoral bypass, Ann. Surg. 179: 192 (1974). 10. Thornford NR, and Dorfman LF: Ureteral obstruction caused by an aortofemoral bypass prosthesis, Am. J. Surg. 115: 394 (1968). 11. Wallijn E, Renders G, and Vereecken L: Urological complications following aortofemoral bypass graft, Br. J. UroJ. 47: 617 (1975). 12. Tracy DA, Eisenberg RL, and Hedgcock MW: Ureteral obstruction resulting from vascular prosthetic graft surgery, AJR 132: 415 (1979). 13. Rajfer J, and Smith GW: Bilateral ureteral obstruction after repair of-&& aneurysm, J. Urol. 122: 255 (1979). 14. Bouterie RL. and Harbach LB: Ureteral obstruction after aortofemoral bypass surgery. Urology 14: 273 (1979). 15. Veith FJ, Hartsuck JM, and Crane C: Management of
UROLOGY
I
MARCH
1982
/
VOLUME
XIX,
NUMBER
3
aorta-iliac reconstruction complicated by sepsis and hemorrhage, N. Engl. J, Med. 270: 1389 (1964). 16. Corbus BC, Estrem RD, and Hunt W: Retro-iliac ureter, J. Urol. 84: 67 (1966). 17. Jones JH, Ross EJ, Mats LR, Edwards D, and Davies DR: Retrcperitoneal fibrosis, Am. J. Med. 48: 203 (1970). 18. Gibbons RP, Correa RJ Jr, Cummings KB, and Mason JTz Experience with indwelling ureteral stent catheters, J. Urol. 115: 22 (1976). 19. Hepperlen TW, Mardis HK, and Kammandel H: The pigtail ureteral stent in the cancer patient, ibid. 121: 17 (1979). 20. Finney RP: Experience with new double J ureteral catheter stent, ibid. 120: 678 (1978). 21. Zimskind PD, Fetter TR, and Wilkerson JL: Clinical use of long-term indwelling silicone rubber ureteral splints inserted cystoscopically, ibid. 97: 840 (1967).
283
ABSTRACT -Although several cases of ureter-al obstruction after vascular bypass surgery for aortoiliac disease have been reported, the incidence of this potentially critical complication has not been established. In this study, 57 selected patients who had undergone vascular bypass surgery were examined with ultrasound for evidence of ureter-al obstruction. Hydronephrosis was discovered in 1 of 57 patients (1.75 per cent) over-all (symptomatic and asymptomatic); no evidence of obstruction was found in the asymptomatic patients. These results fail to corroborate the impression of several investigators that undetected ureteral obstruction may be present in a signiftcant number of patients after vascular bypass surgery.
Abdominal and pelvic vascular lesions are known to cause ureteral obstruction. Since Goodwin and Schumacker’ reviewed this topic in 1947, several cases of ureteral obstruction associated with aortic, iliac, and hypogastric artery aneurysms have been reported. In 1961 Culp and Bernatz* reviewed the urologic aspects of 400 surgically treated cases of abdominal aortic aneurysms without addressing the question of ureteral obstruction following repair. Jacobson, Mastio, and Be&as in 1962’ reported a case of ureteral obstruction following aortoiliac bypass, and several other reports of such cases followed. Most authors suggested that the incidence of this complication might be significant since unilateral obstruction without infection may go unnoticed. Today, although the use of bypass grafts for aortoiliac disease is increasingly common, the incidence of ureteral obstruction after such procedures has not been determined. Our aim was to review the records of vascular surgery
patients at our institution for silent obstruction and thus to determine the over-all incidence of this complication.
Between December, 1976, and December, 1978, 150 aortofemoral or aortoiliac bypass grafts were performed at the University of California-affiliated Veterans Administration Medical Center in San Diego. Of these 150 patients, 117 met the criteria for inclusion in the study. Included in the study were patients whose surgery was done for significant aortic aneurysms as well as those whose surgery was done to correct significant peripheral ischemia. Excluded were patients who had received a Dacron tube graft for an aneurysmectomy and those in whom the distal anastomosis of the bifurcated graft was placed proximal to the ureters. Patients whose surgery was done because of trauma were also excluded.
278
UROLOGY
Material
/
MARCH
and Methods
1932
/
VOLUME
XIX,
NUMBER
3
Operative
technique
In all of the bypass procedures performed, the standard technique was transperitoneal through a midline incision. Tunnels for the iliac limbs of the graft were created by blunt digital dissection under the posterior peritoneum on the anterior surface of the iliac vessels. Since the ureters normally adhere to the peritoneum and are reflected along with it, the grafts were placed in an anatomically correct position posterior to the ureter. Preclotted knitted Dacron bifurcated grafts were used in all cases. In no instance was a ureteral catheter placed preoperatively; only rarely were the ureters isolated or identified. No ureteral injuries were recognized intraoperatively. Preoperative profiles consisted of serum blood urea nitrogen and creatinine measurements, urinalysis, and an evaluation of the upper tract anatomy by excretory urogram, echography, or the excretion phase of an angiogram. Follow-up studies in the postoperative period included repeat serum blood urea nitrogen and creatinine determinations. Follow-up was obtained on 57 of the 117 eligible patients who underwent surgery during this period. Follow-up failures were due to death from unrelated causes, administrative problems, or failures of patients to return for post-surgical care. The charts of those patients who were reviewed for this study but not contacted for follow-up did not suggest any symptoms of obstruction. To determine if ureteral obstruction was present, we screened these 57 patients from two to twenty-four months postoperatively with renal echography (ultrasound), a sensitive and reliable method of determining hydroureteronephrosis.4 Determination of the presence and grade of obstruction was made by members of the radiology staff. Ultrasound
All studies were performed with commercially available gray scale ultrasound equipment using a 3.5 mHz transducer. Patients were requested to void prior to examination. All longitudinal and transverse scans of the kidneys were performed with the patient in the prone position. In addition, right lateral decubitus scans were performed to provide better visualization of the left kidney and left lateral decubitus scans performed to provide better visualization of the right kidney. The degree of hydronephrosis was graded on a scale of O-III using
UROLOGY
/ MARCH1982
/ VOLUMEXIX,NUMBER3
FIGURE 1. Excretory urogram of fifty-two-year-old man after 2 aortoiliac endarterectomies and aortofemoral bypass. Bilateral obstruction at pelvic brim with extravasation on right.
the criteria previously published.4 Grade 0 showed dense central collecting system echoes; grade I showed slight separation of collecting system echoes with a central ovoid sonolucency; grade II showed a rounded central sonolucency with further separation of collecting echoes; grade III showed large portions of the kidney replaced by a sonolucent sac. Results Of 57 patients studied only 1 patient, who was symptomatic, was noted to have ureteral obstruction. In the case presented here the obstruction was bilateral, though greater on one side. In another patient, unilateral grade I hydronephrosis with a midureteral narrowing was discovered on excretory urogram done for lower tract obstructive symptoms eleven days after surgery. He failed later follow-up, however, and was not included in this study. His surgery was uncomplicated, and he had had no prior operation. No cases of ureteral obstruction were discovered in asymptomatic patients
279
TABLE Reference Dorfman and Thornfords
Presenting Symptom
Summary of reported cases in literature
Relation of Graft to Ureter
Results Much
Unknown
Bilateral hydronephrosis (degree unknown)
Steroids
Complete resolution on left, slight improvement on right
Posterior
Severe bilateral hydronephrosis
Slight improvement
Hypertension
Unknown
Right renal artery graft thrombosed; increased creatinine
Anterior
Minimal hnction with severe hydronephrosis on right Left hydronephrosis, no visualization on right
Initially steroids; later, grafts divided and transposed Nephrectomy
Progression until surgery, slight improvement after
Low back pain; hematuria
Anterior
Chyluria
Anterior
Obstnwtive voiding symptoms
Anterior
Obstructive voiding symptoms Obstructive voiding symptoms Rt. flank tenderness; rt. chest pain Right flank pain
Anterior
Initially ureteral catheterization; ureter divided, segment resected, transposed 4 months later Ureterolysis, ureters divided and transposed Ureterolysis, division and transposition Ureter divided and transposed with omental interposition Nephre ureterectomy
Renal failure, urinary tract infection
Anterior
Painless hematuria (asymptomatic initially) Flank pain
Anterior
Rajfer and Smith’s
Anuria,
Posterior
Bilateral ureteral obstruction
Bilateral nephrostomy
Bouterie and Harbach14
Right flank pain
Anterior
Grade II hydronephrosis
Ureterolysis; graft divided and transposed; ureter placed intraperitoneal
Lyttons
Ehrlich
to
Treatment Graft divided and transposed; ureterolysis
et al. ‘I
Anterior ureter
Findings Grade II-III hydronephrosis on right
Wallijn,
Hemahuia; obstructive voiding symptoms Nephrotic syndrome secondary to glomerulonephritis Vague abdominal discomfort
I.
et al. 7
Petrone et al. g
Tracy et al. ‘*
280
uremia
Posterior
Unknown
Anterior on left; unknown on right
Unknown
Bilateral hydronephrosis (greater on rt.) Moderate hydra nephrosis Moderate hydronephrosis Nonfunction on left 2” to obstruction Grade II hydronephrosis on rt. Obstruction on rt. (degree) unknown) Bilateral partial obstruction
Left ureteral obstruction, hydronephrosis, cortical atrophy Hydronephrosis; cortical thinning Hydronephrosis
UROLOGY
/
improved
Resolution
Much improved bilaterally Complete resolution Much
improved
Resolution
Antibiotics
No Change
None
Marked hydronephrosis
Ureters placed in retroperitoneal tunnel; ureterolysis on right None
Reduced hydronephrosis
MARCH
1952
Progressive failure
renal
Progressive parenchymal thinning Initial resolution, delayed recurrence and renal failure Improved renal function Resolution
i
VOLUME
XIX,
NUMBER
3
TABLE Presenting Symptom
Reference Kaufman
et al.
Veith
I.
Relation of Craft to Ureter
Findings
Fever, dysuria, flank pain
Posterior
Bilateral grade II hydronephrosis Left hydra nephrosis “Considerable” bilateral hydronephrosis
Hepatitis
Unknown
Left flank pain, fever and chills
Unknown
Back pain, chills
Unknown
Chills, fever, back pain, urinary frequency Fever
Unknown
Unknown
Right hydronephrosis, ureteral
Right back, abdominal pain
Posterior
Right hydra ureteronephrosis
et al. I5
Shaw and Baue’
Continued
Mild left hydronephrosis Bilateral hydronephrosis
fiShlli3
Jacobson et al. 3
regardless of whether the surgery was done for aneurysms or ischemia. The over-all incidence was 1.75 per cent. Case Report A fifty-two-year-old man had undergone two aortoiliac endartereetomies (in 1970 and 1974). For complaints of recurrent severe claudication he underwent an uncomplicated aortofemoral bypass on July 19, 1978. The surgeon noted that a moderate amount of adhesions made the dissection difficult, but identified the ureters and constructed the retroperitoneal tunnels as previously described. The preoperative urinalysis was negative; blood urea nitrogen was 12 mg. and creatinine 1.3 mg./lOO ml. One year earlier the patient’s excretory urogram had been normal. He did well until postoperative days 3 to 5 when a low-grade fever, dysuria, and bilateral flank pain developed. An excretory urogram revealed bilateral grade II hydronephrosis with extravasation from the right renal pelvis (Fig. 1). Both ureters were obstructed at the level of the pelvic brim. A 7-F ureteral catheter was placed with some difficulty on the right with immediate relief of pain and resolution of fever. No catheter was placed on the left. The catheter was changed to an indwelling 7-F Gibbons catheter
UROLOGY
/
MARCH
1982
/
VOLUME
XIX,
NUMBER
3
Treatment
Results
Ureteral catheter
Improvement
None
Unknown
Retroperitoneal abscess drained initially; nephrostomy and ureter-al reconstruction 6 wk. later Ureteral catheter initially Retroperitoneal abscess drained, graft revised Nephrostomy tube initially, nephrectomy later Ureter resected and stented
Progressive hydronephrosis; recurrent abscess
Death from causes
other
Resolution
Resolution
Resolution
after five days. Follow-up intravenous pyelogram and ultrasound showed complete resolution on the right and much improvement on the left; but when the catheter was removed in early February, 1979, grade II to III hydronephrosis and flank pain recurred, necessitating replacement of the stent. Throughout the episode, there was no change in the blood urea nitrogen or creatinine. Long-term followup is unavailable since the patient died of an acute myocardial infarction on March 21, 1979. Postmortem examination revealed no hydronephrosis. Comment There has existed little evidence to answer the question of how often bypass surgery leads to significant ureteral obstruction, The scarcity of case reports in the literature leads one to presume that it is not a common occurrence, although the reason for this may be that silent obstruction goes undiagnosed. When it does occur, the complication is serious, threatening renal loss, graft infection, and even loss of limb or life.5 Thirty-two obstructed ureters in 24 patients have been reported in the literature (Table 1).3*515 These patients presented from four days
231
to twenty-eight months postoperatively with variable complaints. The most common of these were pain, infection, hematuria, and decreasing renal function, but nephrotic syndrome, l1 hypertension, l1 and chyluria’ have been mentioned. Only 1 patient was completely asymptomatic at the time of diagnosis.12 The literature offers several explanations for the occurrence of the obstruction as well as several possible modes of therapy. The most probable cause of early obstruction, as proposed by Lyttona is mechanical compression of the ureter against the native iliac artery from an anteriorly placed graft, a process that is analogous to the obstruction that occurs in a congenitally anomalous retroiliac ureter. l6 Though the ureter usually adheres to the peritoneum and is reflected anteriorly when a retroperitoneal tunnel is created for graft placement, fibrosis from prior surgery may prevent this. In cases in which the relationship of graft tcr ureter was known, Table I shows that the grafts in 63 per cent (12 of 19) of obstructed ureters were anterior. Preoperative ureteral catheterization and attention to this relationship by vascular surgeons would prevent this. A second mechanism, one accounting for delayed obstruction, is the restriction of postsurgical tissue reaction. Just as in obstruction from perianeurysmal or retroperitoneal fibrosis, encasement prevents normal ureteral peristalsis and results in functional obstruction even though easy passage of a catheter is permitted. ” Similar “fibrosis” may occur when the ureter is devascularized from extensive dissection, especially in the face of generalized atherosclerosis. l3 When obstruction is due to fibrosis or if the patient is a poor surgical risk, management may be undertaken with steroids or ureteral stents. Internal stenting is relatively noninvasive, can remain indwelling for years, and may allow time for fibrosis to diminish or soften and become less restrictive.‘*-21 On the other hand, risks of urinary tract infection, occlusion of the lumen by debris, and poor patient tolerance may necessitate removal of the stent and definitive operative treatment. The surgical approach to repair ureteral obstruction in this setting has been a subject of debate. Lytton’ and others’,’ suggest that division and transposition of the ureterolysis, ureter is the least hazardous method of repair. They believe that the presence of fibrosis leading to difficult mobilization, uncontrollable
bleeding, difficult reanastomosis, and possible thrombosis is too great a risk to justify division of the graft. This is especially true in a wellhealed graft. Although we agree with Lytton, others have pointed out that the risks mentioned are also attendant to division of the ureter.“,14 Moreover, the dissection and mobilization may further compromise the blood supply to the ureter and impair healing. Urine extravasation, which almost certainly occurs, may lead to local fibrosis and possible restricturing, threaten infection, and require an external drain which is contraindicated in the presence of a graft. These risks may be minimized through interposition of omentum or peritoneum between graft and ureter. The division of the ureter should be as far from the graft as possible, and proximal drainage should be used. We have had to intervene surgically in 2 other cases, not included in this series, where the patients presented with obvious symptoms (pain) following a vascular graft procedure. Contrary to speculation, ureteral obstruction after vascular bypass is uncommon (1.75 per cent) and silent obstruction is rare. Nonetheless, since the possible sequelae of obstruction are so serious and echography offers an effective, noninvasive method of evaluation, routine postoperative evaluation should be done in any patient who has undergone vascular bypass surgery.
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Division of Urology H-897 225 Dickinson Street San Diego, California 92103 (DR. KAUFMAN) References 1. Goodwin WE, and Schumacker HB Jr: Aneurysm of the hypogastric artery producing urinary tract obstruction, J. Ural. 57: 839 (1947). 2. Culp OS, and Bemak PE: Urologic aspects of lesions in the abdominal aorta, ibid. 86: 189 (1961). 3. Jacobson ME, Mastio GJ, and Be&as EM: Ureteral obstruction as a late complication of abdominal aneurysm resection, J. Kansas Med. Sot. 63: 516 (lSe2). 4. Ellenbogen PH. Scheible FW, Tahrer LB, and Leopold GR: Sensitivity ofr gray scale ultrasound in detecting urinary tract obstruction. AIR 130: 731 (1978). 5. Shaw RS: and Baue AE: Management of sepsis complicating arterial reconstructive surgery, Surgery 53: 75 (1963). 6. Dorfinan LE, and Thomford NR: Unusual ureteral injury following aorto-iliac by-pass .-graft: case report, J. Ural. 101: 25 (1969j: 7. Ehrlich RM. Hecht HL. and Veenema RI: Chvluria following aortoiliac bypass graft, ibid. 197: 362 (1972): . 8. Lytton B: Ureteral obstruction following aortofemoral bypass grafts, Surgery 5% 918 (1966). 9. Petrone AF, D&in& PJ, and Maniatis W: U&end ob-
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struction secondary to aortic femoral bypass, Ann. Surg. 179: 192 (1974). 10. Thornford NR, and Dorfman LF: Ureteral obstruction caused by an aortofemoral bypass prosthesis, Am. J. Surg. 115: 394 (1968). 11. Wallijn E, Renders G, and Vereecken L: Urological complications following aortofemoral bypass graft, Br. J. UroJ. 47: 617 (1975). 12. Tracy DA, Eisenberg RL, and Hedgcock MW: Ureteral obstruction resulting from vascular prosthetic graft surgery, AJR 132: 415 (1979). 13. Rajfer J, and Smith GW: Bilateral ureteral obstruction after repair of-&& aneurysm, J. Urol. 122: 255 (1979). 14. Bouterie RL. and Harbach LB: Ureteral obstruction after aortofemoral bypass surgery. Urology 14: 273 (1979). 15. Veith FJ, Hartsuck JM, and Crane C: Management of
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aorta-iliac reconstruction complicated by sepsis and hemorrhage, N. Engl. J, Med. 270: 1389 (1964). 16. Corbus BC, Estrem RD, and Hunt W: Retro-iliac ureter, J. Urol. 84: 67 (1966). 17. Jones JH, Ross EJ, Mats LR, Edwards D, and Davies DR: Retrcperitoneal fibrosis, Am. J. Med. 48: 203 (1970). 18. Gibbons RP, Correa RJ Jr, Cummings KB, and Mason JTz Experience with indwelling ureteral stent catheters, J. Urol. 115: 22 (1976). 19. Hepperlen TW, Mardis HK, and Kammandel H: The pigtail ureteral stent in the cancer patient, ibid. 121: 17 (1979). 20. Finney RP: Experience with new double J ureteral catheter stent, ibid. 120: 678 (1978). 21. Zimskind PD, Fetter TR, and Wilkerson JL: Clinical use of long-term indwelling silicone rubber ureteral splints inserted cystoscopically, ibid. 97: 840 (1967).
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