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129
Technical
Wallstent Misplaced During an Intrahepatic Portosystemic Loop Snare Robert B. Sanchez,1
Anne
C. Roberts,
Karim
Valji,
Note
Transjugular Placement of Shunt: Retrieval with a Steven
Lengle,
and Joseph
J. Bookstein
Expandable metallic stents are important tools in the bronchial [1], bihiary [2, 3], urinary [4], and vascular systems [5, 6], although their use in these systems is still investigative, and their efficacy has yet to be proved. Transjuguhar intrahepatic portosystemic shunt (TIPS) procedures have become feasible since the advent of these stents [6, 7]. As with any procedure, complications may occur, and migration of these stents during placement is possible. We describe the use of a right-angled loop snare to retrieve a Wahlstent that was misplaced during a TIPS procedure.
fourth stent was deployed to bridge the gap. During the placement of the fourth stent, the third stent migrated farther cephahad along the guidewire into the right atrium (Fig. 1 A). A right-angled loop snare (Microvena, Vadnais Heights, MN) was used to retrieve the stent. The loop of the snare was placed over the guidewire, and the catheter containing the snare (except for the protruding loop) was inserted along the side of the guidewire into the 9-French sheath in the jugular vein. The snare was opened and placed around the stent. The loop was then tightened, compressing
Case Report
patient (Fig. 1C).
the
stent
against
the
guidewire
(Fig.
1 B). The
stent
was
then
pulled
back firmly against the distal end of the sheath. The guidewire was removed while firm tension was applied on the loop to prevent escape of the stent. By pulling firmly on the snare, we were able to fold the stent into the access sheath and completely remove it from the
A TIPS procedure was performed in a 43-year-old man with a history of IV drug and alcohol abuse and portal hypertension. A single episode
of
esophageal
variceal
bleeding
caused
a decrease
in his
to 0.22.
The patient was not a surgical candidate because he was a Jehovah’s Witness, which precluded perioperative blood transfusions. After gaining access to the portal venous system via the jugular approach by using a Ring transjugular portography set (Cook, Bloomington, IN), we dilated a tract through the liver and placed two Wallstents (Schneider U.S. Stent Division, Minneapolis, MN). After dilatation to 1 0 mm, the stents failed to overlap, and a third stent was deployed. After dilatation to 10 mm, the third stent migrated cephalad along the guidewire, completely overlapping the second stent and no longer covering the gap between the first two stents. A hematocrit
Received 1
November
Department
requests
18, 1991
of Department
;
accepted
of Radiology
after revision (H-756),
January
University
Discussion TIPS is the equivalent percutaneously.
July 1992 0361-803X/92/1
591-0129
the procedure
shunt that is placed is in its infancy,
initial
results
are favorable, and in experienced hands, the procedure appears to be safe even for patients with liver failure and coagulopathy [6, 7]. One of the potential complications is stent misplacement or migration. The ability to percutaneously
retrieve
misplaced
stents
improves
the
safety
and
efficacyof TIPS procedures.
2, 1992. of California,
San Diego,
Medical
to A. B. Sanchez.
AJR 159:129-130,
of a portacaval
Although
0 American
Roentgen
Ray Society
Center,
225 Dickinson
St., San Diego,
CA 921 03. Address
reprint
Downloaded from www.ajronline.org by 24.107.137.22 on 10/24/15 from IP address 24.107.137.22. Copyright ARRS. For personal use only; all rights reserved
130
SANCHEZ
ET AL.
AJR:159,
July 1992
Fig. 1.-Radiographs show removal of stent during transjugular placement of an intrahepatic portosystemic shunt. A, Two stents can be seen in liver. Third stent is misplaced in right atrium (arrows), but guidewire is still through stents. B, After guldewire removal, stent (arrows) is doubled over as it is removed by snare. C, Stent has been pulled back into sheath and is doubled over and compressed.
It is useful to consider the possible causes of the stent misplacement. We suspect that the inner of two concentric stents will slide relatively easily, while the outer stent is much more restrained by invaginations of hepatic parenchyma. The migration of the third stent occurred despite its having been fully dilated to 1 0 mm within the stents that had previously been dilated to 1 0 mm. Thus, the original overlap of the third stent over the first and second stents was host as the inner third
stent
migrated
easily
within
the
outer
first
two.
We
believe that the third stent migrated because no tissue retamed it in place. The same event probably explained the ease with which this stent migrated farther until it was entirely within the right atrium, while the fourth stent was being placed. Before migration, the distal end was within the second stent, and the stent was probably loose proximally within a large hepatic vein. Although one of us has previously placed many bihiary Wahlstents, this event occurred early in our experience with vascular placement, and the possibility of a technical error cannot be completely excluded. Without the guidewire in place, the stent could have embohized
into the heart
or lungs.
We initially
considered
manip-
ulating the stent over a balloon into the jugular or iliac veins; however, the recipient vein would have been susceptible to thrombosis, and the stent could have been host during repositioning. Technically,snaring and removing the stent by means of snare-loop-over-the-wire
technique
was
quite
simple.
Be-
cause the Wallstent is so flexible and compressible, it was easilypulled back into the sheath and removed. Maintaining
the guidewire across the stent was critical in preventing complete escape of the third stent and in facilitating passage of the snare loop around the stent. When it was finally necessary to remove the guidewire so that the stent could be folded into the sheath, great care was exercised to maintain a tight loop. In conclusion,
it is possible
to have
stent
migration
during
a TIPS procedure. It is important to visualize the position of the stent before the guidewire is removed. If stent migration has occurred, the flexibility of the Walhstent allows snaring and removal via a sheath.
REFERENCES 1 . Simonds AK, Irving JD, Clarke SW, Dick A. Use of expandable metal stents in the treatment of bronchial obstruction. Thorax 1989;44:680-681 2. Lammer J. Biliary endoprostheses. Plastic versus metal stents. Radiol Clin North Am 1990;28:121 1-1 222 3. Neuhaus H, Hagenmuller F, Griebel M, Classen M. Percutaneous cholangioscopic or transpapillary insertion of self-expanding biliary metal stents. Gastrointest Endosc 1991;37:31-37 4. Donald JJ, Rickards D, Milroy EJ. Stricture disease: radiology of urethral stents. Radiology 1991;180:447-450 5. Palmaz JC, Kopp DT, Hayashi H, et al. Normal and stenotic renal arteries: experimental balloon-expandable intraluminal stenting. Radiology 1987; 164:705-708 6. Richter GM, Noeldge G, Roessle M, et al. Transjugular intrahepatic pertosystemic stent shunt (TIPS). Radiology 1990174:1027-1030 7. Roberts JP, Ring E, Lake JA, Stemeck M, Ascher NL. Intrahepatic portecaval shunt for vanceal hemorrhage prior to liver transplantation. Transplantation 1991;52: 160-1 62
129
Technical
Wallstent Misplaced During an Intrahepatic Portosystemic Loop Snare Robert B. Sanchez,1
Anne
C. Roberts,
Karim
Valji,
Note
Transjugular Placement of Shunt: Retrieval with a Steven
Lengle,
and Joseph
J. Bookstein
Expandable metallic stents are important tools in the bronchial [1], bihiary [2, 3], urinary [4], and vascular systems [5, 6], although their use in these systems is still investigative, and their efficacy has yet to be proved. Transjuguhar intrahepatic portosystemic shunt (TIPS) procedures have become feasible since the advent of these stents [6, 7]. As with any procedure, complications may occur, and migration of these stents during placement is possible. We describe the use of a right-angled loop snare to retrieve a Wahlstent that was misplaced during a TIPS procedure.
fourth stent was deployed to bridge the gap. During the placement of the fourth stent, the third stent migrated farther cephahad along the guidewire into the right atrium (Fig. 1 A). A right-angled loop snare (Microvena, Vadnais Heights, MN) was used to retrieve the stent. The loop of the snare was placed over the guidewire, and the catheter containing the snare (except for the protruding loop) was inserted along the side of the guidewire into the 9-French sheath in the jugular vein. The snare was opened and placed around the stent. The loop was then tightened, compressing
Case Report
patient (Fig. 1C).
the
stent
against
the
guidewire
(Fig.
1 B). The
stent
was
then
pulled
back firmly against the distal end of the sheath. The guidewire was removed while firm tension was applied on the loop to prevent escape of the stent. By pulling firmly on the snare, we were able to fold the stent into the access sheath and completely remove it from the
A TIPS procedure was performed in a 43-year-old man with a history of IV drug and alcohol abuse and portal hypertension. A single episode
of
esophageal
variceal
bleeding
caused
a decrease
in his
to 0.22.
The patient was not a surgical candidate because he was a Jehovah’s Witness, which precluded perioperative blood transfusions. After gaining access to the portal venous system via the jugular approach by using a Ring transjugular portography set (Cook, Bloomington, IN), we dilated a tract through the liver and placed two Wallstents (Schneider U.S. Stent Division, Minneapolis, MN). After dilatation to 1 0 mm, the stents failed to overlap, and a third stent was deployed. After dilatation to 10 mm, the third stent migrated cephalad along the guidewire, completely overlapping the second stent and no longer covering the gap between the first two stents. A hematocrit
Received 1
November
Department
requests
18, 1991
of Department
;
accepted
of Radiology
after revision (H-756),
January
University
Discussion TIPS is the equivalent percutaneously.
July 1992 0361-803X/92/1
591-0129
the procedure
shunt that is placed is in its infancy,
initial
results
are favorable, and in experienced hands, the procedure appears to be safe even for patients with liver failure and coagulopathy [6, 7]. One of the potential complications is stent misplacement or migration. The ability to percutaneously
retrieve
misplaced
stents
improves
the
safety
and
efficacyof TIPS procedures.
2, 1992. of California,
San Diego,
Medical
to A. B. Sanchez.
AJR 159:129-130,
of a portacaval
Although
0 American
Roentgen
Ray Society
Center,
225 Dickinson
St., San Diego,
CA 921 03. Address
reprint
Downloaded from www.ajronline.org by 24.107.137.22 on 10/24/15 from IP address 24.107.137.22. Copyright ARRS. For personal use only; all rights reserved
130
SANCHEZ
ET AL.
AJR:159,
July 1992
Fig. 1.-Radiographs show removal of stent during transjugular placement of an intrahepatic portosystemic shunt. A, Two stents can be seen in liver. Third stent is misplaced in right atrium (arrows), but guidewire is still through stents. B, After guldewire removal, stent (arrows) is doubled over as it is removed by snare. C, Stent has been pulled back into sheath and is doubled over and compressed.
It is useful to consider the possible causes of the stent misplacement. We suspect that the inner of two concentric stents will slide relatively easily, while the outer stent is much more restrained by invaginations of hepatic parenchyma. The migration of the third stent occurred despite its having been fully dilated to 1 0 mm within the stents that had previously been dilated to 1 0 mm. Thus, the original overlap of the third stent over the first and second stents was host as the inner third
stent
migrated
easily
within
the
outer
first
two.
We
believe that the third stent migrated because no tissue retamed it in place. The same event probably explained the ease with which this stent migrated farther until it was entirely within the right atrium, while the fourth stent was being placed. Before migration, the distal end was within the second stent, and the stent was probably loose proximally within a large hepatic vein. Although one of us has previously placed many bihiary Wahlstents, this event occurred early in our experience with vascular placement, and the possibility of a technical error cannot be completely excluded. Without the guidewire in place, the stent could have embohized
into the heart
or lungs.
We initially
considered
manip-
ulating the stent over a balloon into the jugular or iliac veins; however, the recipient vein would have been susceptible to thrombosis, and the stent could have been host during repositioning. Technically,snaring and removing the stent by means of snare-loop-over-the-wire
technique
was
quite
simple.
Be-
cause the Wallstent is so flexible and compressible, it was easilypulled back into the sheath and removed. Maintaining
the guidewire across the stent was critical in preventing complete escape of the third stent and in facilitating passage of the snare loop around the stent. When it was finally necessary to remove the guidewire so that the stent could be folded into the sheath, great care was exercised to maintain a tight loop. In conclusion,
it is possible
to have
stent
migration
during
a TIPS procedure. It is important to visualize the position of the stent before the guidewire is removed. If stent migration has occurred, the flexibility of the Walhstent allows snaring and removal via a sheath.
REFERENCES 1 . Simonds AK, Irving JD, Clarke SW, Dick A. Use of expandable metal stents in the treatment of bronchial obstruction. Thorax 1989;44:680-681 2. Lammer J. Biliary endoprostheses. Plastic versus metal stents. Radiol Clin North Am 1990;28:121 1-1 222 3. Neuhaus H, Hagenmuller F, Griebel M, Classen M. Percutaneous cholangioscopic or transpapillary insertion of self-expanding biliary metal stents. Gastrointest Endosc 1991;37:31-37 4. Donald JJ, Rickards D, Milroy EJ. Stricture disease: radiology of urethral stents. Radiology 1991;180:447-450 5. Palmaz JC, Kopp DT, Hayashi H, et al. Normal and stenotic renal arteries: experimental balloon-expandable intraluminal stenting. Radiology 1987; 164:705-708 6. Richter GM, Noeldge G, Roessle M, et al. Transjugular intrahepatic pertosystemic stent shunt (TIPS). Radiology 1990174:1027-1030 7. Roberts JP, Ring E, Lake JA, Stemeck M, Ascher NL. Intrahepatic portecaval shunt for vanceal hemorrhage prior to liver transplantation. Transplantation 1991;52: 160-1 62
