115
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Urinary Tract Calculi That Form Surgical Staples: A Characteristic Radiologic
on
Appearance :
Barbara
C. Dangman1
Robert
L. Lebowitz
An autostapler
reconstructive beneath
is frequently
urologic
the intestinal
exposed
or
used when
surgery
becomes
bowel
in children.
mucosa.
However,
exposed
through
is interposed
Usually
in the urinary
the metallic
if a portion
of a staple
migration
and
is then
tract during
staples
are buried
is unintentionally bathed
by
urine,
left it can
become the nidus for formation of a calculus. The radiologic studies of 30 patients having surgery of this type in our hospital from 1980 to 1990 were reviewed prospectively, and stones were found to have developed on staples in eight patients. None of the patients had metabolic abnormalities. The stones were easily visible on plain radiographs because they were calcified. They formed in the lumen of the bladder or the bowel segment on the exposed portion of the staple. Thus, the staple was eccentric in the calculus and not central, as is usually the case with a stone forming on a foreign body. This
experience
tive urologic identification. AJR
suggests
surgery
157:115-117,
that
have
stones
forming
a characteristic
on surgical
radiologic
staples
appearance
during
reconstruc-
that may aid in their
July 1991
Patients who have undergone continent urinary diversion or urinary tract “undiversion” often have bowel interposed in the urinary tract [1 -1 0]. When the ileocecal valve is reinforced, or the bowel modified to serve as either an antireflux or continence mechanism, an autostapler is frequently used. If a portion of the staple becomes exposed to urine, it may serve as a nidus for formation of a stone. This type of stone has a characteristic radiologic appearance that has not been described before.
Materials
and Methods 1 980
Between surgical
staples
radiologic
and 1990, approximately used
studies.
for
Those
study. Their radiographs
urinary
tract
30 patients at the Children’s reconstruction.
All
of
these
found
Hospital had metallic patients
to have stones forming on staples and medical records were reviewed.
were
had
the basis
follow-up
for this
Results
. Received October 24, 1990; accepted vision January 23, 1991 .
after re-
Eight patients who had calculi forming on surgical staples were seen. Seven ranged in age from 4+ to 23 years, and one was 41 years old, when their stones were discovered. Their diagnoses included bladder exstrophy in two patients, menlngomyelocele In two, Isolated eplspadlas in one, cloacal exstrophy In one, .
neurogenic
drersHo:pt&,3O0LongwoodAve.,Boston,MA 021 15. Address reprint requests to A. L. Lebowitz.
one. The
0361-803X/91/1571-01
included
0 American
Roentgen
15 Ray Society
creation
.
bladder
most continent
.
.
of uncertain
recent
surgical
ileocecal
of a nonrefluxing
.
cause
in one,
procedures diversion,
jejunocecal
.
bladder
conduit,
and
that
vaginal
had been augmentation
urinary
tract
rhabdomyosarcoma
performed with
undiversion
with sigmoid
with
in
staples colon,
ileoce-
Downloaded from www.ajronline.org by 61.188.184.132 on 10/14/15 from IP address 61.188.184.132. Copyright ARRS. For personal use only; all rights reserved
116
DANGMAN
AND
LEBOWITZ
AJR:157,July
1991
Fig. 1.-41/2-year-old boy with bladder exstrophy, 15 months after continent ileocecal diversion. A routine follow-up sonogram showed stones in conduit. A, Abdominal radiograph reveals three large stones, two with eccentric staples (solid straight arrows), free within lumen of conduit. No staple is present in the third stone (open arrow). A smaller stone is still eccentrically attached to one of staples at suture line (curved arrow).
Stones were removed surgically and conduit was revised. B, Close-up of two lateral stones seen in A shows that one has broken free from its staple, but notch where staple was attached is evident (arrow). Other stone appears to have a central
staple, but staple is characteristically in another
eccentric
projection.
Fig. 2.-8-year-old boy with bladder exstrophy, 31/2 years after Mitrofanoff procedure [12]. Sonography performed because of urinary tract infections showed multiple stones in cecal pouch. Abdominal radiograph showed multiple small calculi forming eccentrically on surgical staples. CT scan shows that a free calculus had refluxed into left kidney. Stones were removed
surgically. Fig.
3.-41-year-old
woman,
after
multiple
surgical continence procedures because of neurogenic dysfunction of bladder of uncertain cause. Most recent procedure was augmentation of colonic loop with jejunum and formation of Kock continent nipple 21/2 years previously. She presented because of spontaneous passage of
a stone. Abdominal
radiograph
calculus that has formed gical staples (arrow). Most endoscopically. Remainder extracorporeal shock-wave
cal interposition, and augmentation of a colonic conduit with construction of a Kock continent nipple [1 1 ]. In seven of the patients, a GIA (gastrointestinal anastomosis) autosuture device (United States Surgical Corporation, Norwalk, CT) was used with stainless steel staples. The eighth patient had surgery at another institution, and the type of staple used was not known. The interval from the surgery until the appearance of stones ranged from 1 5 months to 6 years. Although not all of these stones were subjected to pathologic/ metabolic analysis, the composition of those that were analyzed included magnesium ammonium phosphate hexahydrate (struvite), calcium phosphate (apatite), and ammonium urate. Two of the patients had a history of urinary tract infections around the time of the formation of stones. Only one of the patients had serum calcium and phosphorus levels measured, and these were normal. No metabolic abnormalities were seen in any of the patients. In each of the patients, one or more opaque stones were seen, each with the same characteristic appearance. Each had formed eccentrically around an embedded surgical staple (Figs. 1 -4). The exposed edge of the staple had served as the nidus for the formation of the stone, accounting for the
eccentric position of the without their embedded mucosa and dropped into (Fig. 1 ), and in one case kidney (Fig. 2).
staple. Some staples, had the lumen of such a stone
reveals a large
eccentrically
on sur-
of this was removed was fragmented lithotnpsy.
with
of the stones, with or broken free from the the conduit or bladder had refluxed into the
Discussion Foreign material in the urinary tract that is exposed to urine frequently serves as the nidus for formation of calculi. Surgical staples are no exception, and stones forming on such staples are well known to urologists [1 -1 0, 1 3]. The staples may be either stainless steel or tantalum [2, 5, 1 0, 1 3]. The composition of the stones varies, but is most often struvite, apatite, or magnesium ammonium phosphate [1 -3, 6, 7, 1 3]. The average time until development of the first stone has been reported to be approximately 1 4 months after the surgery during which the staples were used [5]. Surgical procedures that use staples and result in stones have included a variety of large- and small-bowel conduits and end-to-end anastomosis of renal transplants to native ureter [1 3]. Hendren and
AJA:157,July
1991
URINARY
TRACT
CALCULI
AND
SURGICAL
STAPLES
117
Downloaded from www.ajronline.org by 61.188.184.132 on 10/14/15 from IP address 61.188.184.132. Copyright ARRS. For personal use only; all rights reserved
Fig. 4.-81/2-year-old spadias, after urinary
girl with complete
epi-
tract diversion and, most recently, undiversion with augmentation of bladder with ileocecal conduit and reinforcement of ileocecal valve with staples. A, Abdominal radiograph shows that several stones are free in lumen, each with an eccentric staple (straight arrows). Two others are still attached to mucosa (curved arrows). B, Surgical photograph when bladder was open shows stones attached to mucosa and projecting into lumen. Arrow points to eccentric staple of one of these.
r
Hendren [1 4] noted that stone formation on surgical staples used for an antireflux nipple was a relatively common complication among patients who had bladder augmentation. The majority of the reported patients have passed the stones spontaneously through a stoma [1 -3, 5, 7, 1 0], although others have required surgical removal of the stones [6, 9-10, 1 3]. Some have had extracorporeal shock-wave lithotripsy [4]. One patient had impaction of a refluxed stone in the ureter [10]. Virtually all of the reported cases have been in older adolescents and adults. Although previous descriptions have characterized the stapIe as being centrally located within the stone, in fact the characteristic appearance is that of a stone formed eccentrically around the staple. This is related to the pathophysiology of the stone’s formation. When the staples are placed during surgery, they are buried beneath the mucosa and are not exposed to urine. However, with time, part of the staple may migrate through the mucosal surface, and the portion that becomes exposed to urine can then serve as a nidus for formation of a stone. If the stone enlarges, or the staple migrates further, the staple may pull free from the bowel wall, and the stone with the staple attached will fall into the lumen of the conduit or bladder (Fig. 1). Occasionally the stone may fall into the lumen and leave the staple behind (Fig. 1 B). In the majority of cases, such intraluminal stones have passed spontaneously without difficulty or have been removed endoscopically. However, in one reported case [1 0] and in one patient reported here, a stone refluxed into the ureter. It is important for every radiologist who deals with such patients to learn to recognize these calculi, because they are a local problem that is easily managed and are not a sign of some more ominous problem with stasis or metabolic derangement.
“
ACKNOWLEDGMENTS Paulette
Fontaine
H. Colodny
provided
and Elaine Donnelly Figure
4B,
and
typed
Donald
the manuscript, Sucher
took
the
Arnold photo-
graphs.
REFERENCES 1 . Assadnia A, Lee CN, Petre JH, Lyons AC. Two cases of stone formation in ileal conduits after using staple gun for closure of proximal end of isolated loop. J Urol 1972;108:553 2. Bergman SM, Sears HF, Javadpour N. Complication with mechanical stapling device in creation of ileoconduit. Urology 1978;12:71-73 3. Bisson J, Vinson AK, Leadbetter GW. Urolithiasis from stapler anastomosis. Am J Surg 1979;137:280-282 4. Boyd SD, Everett AW, Schiff WM, Fugelso PD. Treatment of unusual Kook pouch urinary calculi with extracorporeal shock wave lithotnpsy. J Urol
1987;139:805-806 5. Brenner M, Johnson DE. Ileal conduit calculi from stapler anastomosis: a long term complication? Urology 1985;26:537-540 6. Cohn MS, Breslin TG, Coulombe AD. An intussuscepted ileal ureter bladder nipple. J Urol 1985;133:849-850 7. Heney NM, Dretler SP, Hensle 1W, Kerr WS. Autosuturing device in intestinal urinary conduits. Urology 1978;1 2:650-653 8. Karamcheti A. O’Donnell WF, Hakala TA, Schwentker FN, Steichen FM. Autosuture ileal conduit construction: experience in 1 1 0 cases. J Urol 1978;1 20:545-548 9. Ward HC. Surgical staples in bladder calculi after caecocystoplasty. Br J Urol 1987;60:375 10. Webster GD, Henry HH, Tomlin EM. Calculus formation and ureteral obstruction after ileal conduit construction using autosuture stapling device. Urology 1987:30:571-573 1 1 . RaIls PW, Barakos JA, Skinner DG, et al. Imaging of the Kook continent ileal urinary reservoir. Radiology 1986;161 :477-483 12. Weingarten JL, Cromie WJ. The Mitrofanoff principle: an alternative form of continent urinary diversion. J Urol 1988;140:1529-1531 13. Motayne GG, Jindal SL, Irvine AH, AbeIe AP. Calculus formation in renal transplant patients. J Urol 1984:132:448-449 14. Hendren WH, Hendren RB. Bladder augmentation: experience with 129 children and young adults. J Urol 1990; 144:445-453
Downloaded from www.ajronline.org by 61.188.184.132 on 10/14/15 from IP address 61.188.184.132. Copyright ARRS. For personal use only; all rights reserved
Urinary Tract Calculi That Form Surgical Staples: A Characteristic Radiologic
on
Appearance :
Barbara
C. Dangman1
Robert
L. Lebowitz
An autostapler
reconstructive beneath
is frequently
urologic
the intestinal
exposed
or
used when
surgery
becomes
bowel
in children.
mucosa.
However,
exposed
through
is interposed
Usually
in the urinary
the metallic
if a portion
of a staple
migration
and
is then
tract during
staples
are buried
is unintentionally bathed
by
urine,
left it can
become the nidus for formation of a calculus. The radiologic studies of 30 patients having surgery of this type in our hospital from 1980 to 1990 were reviewed prospectively, and stones were found to have developed on staples in eight patients. None of the patients had metabolic abnormalities. The stones were easily visible on plain radiographs because they were calcified. They formed in the lumen of the bladder or the bowel segment on the exposed portion of the staple. Thus, the staple was eccentric in the calculus and not central, as is usually the case with a stone forming on a foreign body. This
experience
tive urologic identification. AJR
suggests
surgery
157:115-117,
that
have
stones
forming
a characteristic
on surgical
radiologic
staples
appearance
during
reconstruc-
that may aid in their
July 1991
Patients who have undergone continent urinary diversion or urinary tract “undiversion” often have bowel interposed in the urinary tract [1 -1 0]. When the ileocecal valve is reinforced, or the bowel modified to serve as either an antireflux or continence mechanism, an autostapler is frequently used. If a portion of the staple becomes exposed to urine, it may serve as a nidus for formation of a stone. This type of stone has a characteristic radiologic appearance that has not been described before.
Materials
and Methods 1 980
Between surgical
staples
radiologic
and 1990, approximately used
studies.
for
Those
study. Their radiographs
urinary
tract
30 patients at the Children’s reconstruction.
All
of
these
found
Hospital had metallic patients
to have stones forming on staples and medical records were reviewed.
were
had
the basis
follow-up
for this
Results
. Received October 24, 1990; accepted vision January 23, 1991 .
after re-
Eight patients who had calculi forming on surgical staples were seen. Seven ranged in age from 4+ to 23 years, and one was 41 years old, when their stones were discovered. Their diagnoses included bladder exstrophy in two patients, menlngomyelocele In two, Isolated eplspadlas in one, cloacal exstrophy In one, .
neurogenic
drersHo:pt&,3O0LongwoodAve.,Boston,MA 021 15. Address reprint requests to A. L. Lebowitz.
one. The
0361-803X/91/1571-01
included
0 American
Roentgen
15 Ray Society
creation
.
bladder
most continent
.
.
of uncertain
recent
surgical
ileocecal
of a nonrefluxing
.
cause
in one,
procedures diversion,
jejunocecal
.
bladder
conduit,
and
that
vaginal
had been augmentation
urinary
tract
rhabdomyosarcoma
performed with
undiversion
with sigmoid
with
in
staples colon,
ileoce-
Downloaded from www.ajronline.org by 61.188.184.132 on 10/14/15 from IP address 61.188.184.132. Copyright ARRS. For personal use only; all rights reserved
116
DANGMAN
AND
LEBOWITZ
AJR:157,July
1991
Fig. 1.-41/2-year-old boy with bladder exstrophy, 15 months after continent ileocecal diversion. A routine follow-up sonogram showed stones in conduit. A, Abdominal radiograph reveals three large stones, two with eccentric staples (solid straight arrows), free within lumen of conduit. No staple is present in the third stone (open arrow). A smaller stone is still eccentrically attached to one of staples at suture line (curved arrow).
Stones were removed surgically and conduit was revised. B, Close-up of two lateral stones seen in A shows that one has broken free from its staple, but notch where staple was attached is evident (arrow). Other stone appears to have a central
staple, but staple is characteristically in another
eccentric
projection.
Fig. 2.-8-year-old boy with bladder exstrophy, 31/2 years after Mitrofanoff procedure [12]. Sonography performed because of urinary tract infections showed multiple stones in cecal pouch. Abdominal radiograph showed multiple small calculi forming eccentrically on surgical staples. CT scan shows that a free calculus had refluxed into left kidney. Stones were removed
surgically. Fig.
3.-41-year-old
woman,
after
multiple
surgical continence procedures because of neurogenic dysfunction of bladder of uncertain cause. Most recent procedure was augmentation of colonic loop with jejunum and formation of Kock continent nipple 21/2 years previously. She presented because of spontaneous passage of
a stone. Abdominal
radiograph
calculus that has formed gical staples (arrow). Most endoscopically. Remainder extracorporeal shock-wave
cal interposition, and augmentation of a colonic conduit with construction of a Kock continent nipple [1 1 ]. In seven of the patients, a GIA (gastrointestinal anastomosis) autosuture device (United States Surgical Corporation, Norwalk, CT) was used with stainless steel staples. The eighth patient had surgery at another institution, and the type of staple used was not known. The interval from the surgery until the appearance of stones ranged from 1 5 months to 6 years. Although not all of these stones were subjected to pathologic/ metabolic analysis, the composition of those that were analyzed included magnesium ammonium phosphate hexahydrate (struvite), calcium phosphate (apatite), and ammonium urate. Two of the patients had a history of urinary tract infections around the time of the formation of stones. Only one of the patients had serum calcium and phosphorus levels measured, and these were normal. No metabolic abnormalities were seen in any of the patients. In each of the patients, one or more opaque stones were seen, each with the same characteristic appearance. Each had formed eccentrically around an embedded surgical staple (Figs. 1 -4). The exposed edge of the staple had served as the nidus for the formation of the stone, accounting for the
eccentric position of the without their embedded mucosa and dropped into (Fig. 1 ), and in one case kidney (Fig. 2).
staple. Some staples, had the lumen of such a stone
reveals a large
eccentrically
on sur-
of this was removed was fragmented lithotnpsy.
with
of the stones, with or broken free from the the conduit or bladder had refluxed into the
Discussion Foreign material in the urinary tract that is exposed to urine frequently serves as the nidus for formation of calculi. Surgical staples are no exception, and stones forming on such staples are well known to urologists [1 -1 0, 1 3]. The staples may be either stainless steel or tantalum [2, 5, 1 0, 1 3]. The composition of the stones varies, but is most often struvite, apatite, or magnesium ammonium phosphate [1 -3, 6, 7, 1 3]. The average time until development of the first stone has been reported to be approximately 1 4 months after the surgery during which the staples were used [5]. Surgical procedures that use staples and result in stones have included a variety of large- and small-bowel conduits and end-to-end anastomosis of renal transplants to native ureter [1 3]. Hendren and
AJA:157,July
1991
URINARY
TRACT
CALCULI
AND
SURGICAL
STAPLES
117
Downloaded from www.ajronline.org by 61.188.184.132 on 10/14/15 from IP address 61.188.184.132. Copyright ARRS. For personal use only; all rights reserved
Fig. 4.-81/2-year-old spadias, after urinary
girl with complete
epi-
tract diversion and, most recently, undiversion with augmentation of bladder with ileocecal conduit and reinforcement of ileocecal valve with staples. A, Abdominal radiograph shows that several stones are free in lumen, each with an eccentric staple (straight arrows). Two others are still attached to mucosa (curved arrows). B, Surgical photograph when bladder was open shows stones attached to mucosa and projecting into lumen. Arrow points to eccentric staple of one of these.
r
Hendren [1 4] noted that stone formation on surgical staples used for an antireflux nipple was a relatively common complication among patients who had bladder augmentation. The majority of the reported patients have passed the stones spontaneously through a stoma [1 -3, 5, 7, 1 0], although others have required surgical removal of the stones [6, 9-10, 1 3]. Some have had extracorporeal shock-wave lithotripsy [4]. One patient had impaction of a refluxed stone in the ureter [10]. Virtually all of the reported cases have been in older adolescents and adults. Although previous descriptions have characterized the stapIe as being centrally located within the stone, in fact the characteristic appearance is that of a stone formed eccentrically around the staple. This is related to the pathophysiology of the stone’s formation. When the staples are placed during surgery, they are buried beneath the mucosa and are not exposed to urine. However, with time, part of the staple may migrate through the mucosal surface, and the portion that becomes exposed to urine can then serve as a nidus for formation of a stone. If the stone enlarges, or the staple migrates further, the staple may pull free from the bowel wall, and the stone with the staple attached will fall into the lumen of the conduit or bladder (Fig. 1). Occasionally the stone may fall into the lumen and leave the staple behind (Fig. 1 B). In the majority of cases, such intraluminal stones have passed spontaneously without difficulty or have been removed endoscopically. However, in one reported case [1 0] and in one patient reported here, a stone refluxed into the ureter. It is important for every radiologist who deals with such patients to learn to recognize these calculi, because they are a local problem that is easily managed and are not a sign of some more ominous problem with stasis or metabolic derangement.
“
ACKNOWLEDGMENTS Paulette
Fontaine
H. Colodny
provided
and Elaine Donnelly Figure
4B,
and
typed
Donald
the manuscript, Sucher
took
the
Arnold photo-
graphs.
REFERENCES 1 . Assadnia A, Lee CN, Petre JH, Lyons AC. Two cases of stone formation in ileal conduits after using staple gun for closure of proximal end of isolated loop. J Urol 1972;108:553 2. Bergman SM, Sears HF, Javadpour N. Complication with mechanical stapling device in creation of ileoconduit. Urology 1978;12:71-73 3. Bisson J, Vinson AK, Leadbetter GW. Urolithiasis from stapler anastomosis. Am J Surg 1979;137:280-282 4. Boyd SD, Everett AW, Schiff WM, Fugelso PD. Treatment of unusual Kook pouch urinary calculi with extracorporeal shock wave lithotnpsy. J Urol
1987;139:805-806 5. Brenner M, Johnson DE. Ileal conduit calculi from stapler anastomosis: a long term complication? Urology 1985;26:537-540 6. Cohn MS, Breslin TG, Coulombe AD. An intussuscepted ileal ureter bladder nipple. J Urol 1985;133:849-850 7. Heney NM, Dretler SP, Hensle 1W, Kerr WS. Autosuturing device in intestinal urinary conduits. Urology 1978;1 2:650-653 8. Karamcheti A. O’Donnell WF, Hakala TA, Schwentker FN, Steichen FM. Autosuture ileal conduit construction: experience in 1 1 0 cases. J Urol 1978;1 20:545-548 9. Ward HC. Surgical staples in bladder calculi after caecocystoplasty. Br J Urol 1987;60:375 10. Webster GD, Henry HH, Tomlin EM. Calculus formation and ureteral obstruction after ileal conduit construction using autosuture stapling device. Urology 1987:30:571-573 1 1 . RaIls PW, Barakos JA, Skinner DG, et al. Imaging of the Kook continent ileal urinary reservoir. Radiology 1986;161 :477-483 12. Weingarten JL, Cromie WJ. The Mitrofanoff principle: an alternative form of continent urinary diversion. J Urol 1988;140:1529-1531 13. Motayne GG, Jindal SL, Irvine AH, AbeIe AP. Calculus formation in renal transplant patients. J Urol 1984:132:448-449 14. Hendren WH, Hendren RB. Bladder augmentation: experience with 129 children and young adults. J Urol 1990; 144:445-453
