A Simple Catheters’
Method
to Lock
Horacio B. D’Agostino, Eric vanSonnenberg,
Materials
Robert
Malecot
B. Sanchez,
Brian W. Goodacre, Giovanna Casola, Distodgment large-bore
MD MD MD MD MD
From
with
a suture
affixed
Radiology
Catheters and 81.454, 70.454 technology 81.81
1992;
ARCE-BORE
to the
catheterization, Catheters and #{149}Kidney, interven#{149}
182:576-577
Malecot
used routinely for percutaneous
catheters
to maintain nephrotithotomy.
and Methods July
1988
catheters
to March
1991,
with
locking
this
17
were placed in 15 patients. 12 men and three women, aged 36-82 years. The reasons for catheterization were percutaneous nephrostomy and tract dilation (,i = 9), gallbladder drainage (n = 2), bitiary drainage (n = 1), lung abscess drainage (n = 1; two catheters), pancreatic abscess drainage (ii = 1; two catheters), and percutaneous gastrostomy (ii = 1). Malecot catheter sizes were 14 F (ii = 3), 18F(n = 3),and24F(n = 11). The locking mechanism is affixed onto any standard Malecot catheter (Cook Urological, Spencer, Ind) prior to insertion of the tube. A 3-0 silk or nylon suture is stitched to the distal portion of one (and only one) of the wings of the mushroom tip (stitching is preferred to tying the suture). A 0.038-inch floppy J wire is inserted into the catheter until the wire tip exits at the site of the suture. The loose end of the suture is tied to the tip of the guide wire with a surgeon’s knot. The wire is retracted and exits through the hub of the catheter along with the end of the suture. The tied end of the suture is released from the guide wire outside the catheter hub. Once the Malecot catheter has been inserted into the fluid collection or hottow viscera, the suture is retracted with tension, which pulls the solitary wing of the Malecot tight. The lock is maintamed by screwing the connecting tube or a Luer lock adapter into the catheter over the suture (Fig 2). This establishes an effective self-retaining system. The mushroom tip bends toward the retracted sutured limb, and this change in shape can be appreciated fluoroscopicatty (Fig 3). Catheters (14-18 F) were secured to the skin entry site with a
There
distal portion of the mushroom tip is described. In a 32-month period, 17 Malecot catheters with locking mechanisms were placed in 15 patients. One catheter dislodged as a result of suture failure. A variation in design prevented subsequent failure of sutures. This simpte locking mechanism prevents cotlapse of the catheter wings and thereby maintains catheter placement. Index terms: complications, catheterization, tional procedure,
Mushroom-Tip
mechanism
is a major drawback with Malecot catheters. A locking
mechanism
L
Large
are
tracts
Similar catheters percutaneously
occasionally are used in the biliary tract, for abscess drainage, or for gastric feeding. The expanding wings on the Malecot catheter tip offer some degree of stabilization for the catheter, but the wings may close spontaneously and thereby permit the catheter to retract. Dislodgment of these large-bore catheters can have disastrous effects. After we had experience with several patients in whom dislodgment of these catheters resulted in major complications (Fig 1), we devised a method to lock these catheters that effectively eliminates dislodgment.
were
drain-tube attachment device (DTAD; Hollister, Libertyville, Ill); Molnar retention disks (Cook, Bloomington, Ind) to secure 24-F catheters. Adin all cases, 2-inch (5.08-cm) nylon tape was used to form a mesentery around the Malecot catheter and to fasten the catheter shaft to the skin. To unlock the locking mechanism, the connecting tube or the adapter is unscrewed and tension on the suture is released. The Malecot catheter can be removed in the standard fashion by stretching the catheter with an internal stiffener and retracting the whole system over a guide wire. were
used
Figure 1. Computed tomographic scan obtamed in a 25-year-old man with a staghorn calculus shows collapsed catheter wings and dislodgment. A 24-F Malecot catheter had been successfully placed in the collecting system. The patient developed chills and fever in the recovery room. Blood with clots appeared in fluids obtained through the Malecot drainage system. A subcapsular and pennephnic hematoma developed, which eventually led to an operation.
We have recently tested specifically designed prototype locking Matecot catheters (Cook); these have been used for percutaneous nephrostomy with tract dilation and for gallbladder drainage (i = 1 each).
Results
In 14 of 15 patients, the catheter locking system functioned well. One of the 17 locking Malecot catheters dislodged. The distodgment occurred because the tie on the limb was loose and the suture slipped off the wing, therefore disassembling the self-retaining mechanism. After this episode, the suture was stitched rather than tied to the Malecot wing, and no dislodgment or any other problem has occurred. The prototype catheters have functioned welt in the two patients in whom they were used.
ditionatly,
I From the Department of Radiology, University of California San Diego Medical Center, 225 Dickinson St, San Diego, CA 92103 (H.B.D., E.V., R.B.S., B.W.G., CC.) and the Department of Medicine, University of California, San Diego (E.V.). Received June 24, 1991; accepted and revision requested August 16; revision received September 12. Address reprint requests to H.B.D. ( RSNA, 1992
576
#{149} Radiology
Discussion Matecot catheters for a variety
are popular and of drainages. For many urologists, it is the preferred catheter, especially for percutaneous nephrostomy and tract dilation. Because it is thin-walled, the Matecot catheter provides excellent drainage. Although the mushroom tip of a Malecot catheter is designed to “lock,” spontaneous recoil
useful
February
1992
expand.
The
system
locking
larly advantageous ditionally, if the
locking
Other these
b.
Figure
Ad-
wings of the Malecot catheter are collapsed between the staghorn and the collecting system, gentle retraction on the suture may assist in opening the mushroom.
a.
been
is particu-
in this situation.
2. Mechanism stitched to the
of locking Malecot catheter. distal end of one of the Malecot
the catheter hub. (b) Locked Malecot on the suture is maintained
Traction
catheter. by the
(a) Locking mechanism. wings (arrow). The
A 3-0 suture has suture exits through
The wings are locked by pulling connector attachment (arrow).
on the suture.
types
mechanisms
of situations
are
for use in the
pleated
shape of an “accordion” catheter (2) and the two wings of an Amplatz anchor catheter (3). Suture attachments in these catheters are effective in achieving internal fixation. If these drainage tubes are vigorously pulled out, however, they may cause tearing of the organ in which they have been placed. Our locking device for mushroom-tip catheters has the same potential risk. An internal
retention device such as the balloon of a Foley catheter requires that the cavity be spacious enough for both the balloon and the catheter tip. With balloon catheters, however, the balloon may deflate spontaneously dislodgment, may resist
ficult
and create the risk of or conversely, the balloon deflation and become dif-
to remove
If one
(4-6).
chooses
to use a Matecot
cathe-
ter for percutaneous nephrostomy with tract dilation, and if the ureter has been cannulated, a good alternative catheter to the
locking
combination
long tip. This curity by extra
Matecot Malecot
catheter catheter
catheter
offers
is the with added
a se-
purchase within the unnary tract. Currently, we also lock this catheter with one suture. This system is
a.
b.
(a) A standard Malecot catheter placed in the gallbladder dislodged and resulted in bile leak (arrow). (b) The dislodged catheter was replaced with a locking Malecot catheter. The deformity of the tip, caused by tension on the suture, is characteristic and indicates correct tension on the catheter wing. A 7-F gallbladder catheter is adjacent to the Malecot catheter. Figure
3.
our preferred
catheter
nephrostomy
and
locking
design (1) was effective in overcoming the problem of dislodgment. The prototype catheters also have performed well in the first two patients in whom they were used. The locking mechanism for the Malecot catheter is simple to create and has been reliable to date, except in the singte case where the suture was loosely tied. The suture should be stitched in advance while preparing for the proce-
Volume
182
#{149} Number
2
dure, rather than tant not to stitch
tied. It is also importhe suture to the
mushroom tip or to multiple wings; in each of these situations, retraction of the suture will cause obstruction of the catheter lumen. When aligned correctly, the Malecot tip should be slightly asymmetric at fluoroscopy, because of the eccentric position of the suture. A particularly difficult problem with Malecot catheters occurs with percutaneous nephrostomy and tract dilation for large staghorn calculi. When the stone occupies a large volume within the relatively restricted capacity of the collecting system, the catheter may be prone to dislodgment because of the little space left for the Malecot wings to
for percutaneous dilation.
U
Acknowledgment: We thank Marcia Earnshaw for photographic contribution, Ellen Mower for the illustrations, and Cook, Inc., (Bloomington, md) for providing us with prototype catheters.
References 1.
of the mushroom with subsequent dislodgment is an occasional problem that can be serious. Securing the catheter to the skin does not necessarily avoid displacement of the catheter from its organ. Our modification of the Cope
tract
2.
3.
4.
5.
6.
Cope C. Improved anchoring of nephrostomy catheters: loop technique. AIR 1980; 135:402-403. Candi JC, Hawkins IF Jr, Hawkins MC. Single step placement of a self-retaining ‘accordion catheter.” AIR 1984; 143:337-340. Brazzini H, Castaneda-Zuniga WR, Coleman CC, et al. Urostent designs. Semin Intervent Radiol 1987; 4:26-35. Carrett JP. Technical note: methods for deflating retained urinary catheters. Clin Radiol 1989; 40:319. Walters NA, Kilbey J, Rickards D. Technical note: a technique for the removal of retamed balloon bladder catheters. Br J Radiol 1988; 61:320-321. Higgins WL, Mace AH. Puncture of a nondeflatable Foley balloon using ultrasound guidance. Radiology 1984; 151 :801.
Radiology
#{149} 577
Method
to Lock
Horacio B. D’Agostino, Eric vanSonnenberg,
Materials
Robert
Malecot
B. Sanchez,
Brian W. Goodacre, Giovanna Casola, Distodgment large-bore
MD MD MD MD MD
From
with
a suture
affixed
Radiology
Catheters and 81.454, 70.454 technology 81.81
1992;
ARCE-BORE
to the
catheterization, Catheters and #{149}Kidney, interven#{149}
182:576-577
Malecot
used routinely for percutaneous
catheters
to maintain nephrotithotomy.
and Methods July
1988
catheters
to March
1991,
with
locking
this
17
were placed in 15 patients. 12 men and three women, aged 36-82 years. The reasons for catheterization were percutaneous nephrostomy and tract dilation (,i = 9), gallbladder drainage (n = 2), bitiary drainage (n = 1), lung abscess drainage (n = 1; two catheters), pancreatic abscess drainage (ii = 1; two catheters), and percutaneous gastrostomy (ii = 1). Malecot catheter sizes were 14 F (ii = 3), 18F(n = 3),and24F(n = 11). The locking mechanism is affixed onto any standard Malecot catheter (Cook Urological, Spencer, Ind) prior to insertion of the tube. A 3-0 silk or nylon suture is stitched to the distal portion of one (and only one) of the wings of the mushroom tip (stitching is preferred to tying the suture). A 0.038-inch floppy J wire is inserted into the catheter until the wire tip exits at the site of the suture. The loose end of the suture is tied to the tip of the guide wire with a surgeon’s knot. The wire is retracted and exits through the hub of the catheter along with the end of the suture. The tied end of the suture is released from the guide wire outside the catheter hub. Once the Malecot catheter has been inserted into the fluid collection or hottow viscera, the suture is retracted with tension, which pulls the solitary wing of the Malecot tight. The lock is maintamed by screwing the connecting tube or a Luer lock adapter into the catheter over the suture (Fig 2). This establishes an effective self-retaining system. The mushroom tip bends toward the retracted sutured limb, and this change in shape can be appreciated fluoroscopicatty (Fig 3). Catheters (14-18 F) were secured to the skin entry site with a
There
distal portion of the mushroom tip is described. In a 32-month period, 17 Malecot catheters with locking mechanisms were placed in 15 patients. One catheter dislodged as a result of suture failure. A variation in design prevented subsequent failure of sutures. This simpte locking mechanism prevents cotlapse of the catheter wings and thereby maintains catheter placement. Index terms: complications, catheterization, tional procedure,
Mushroom-Tip
mechanism
is a major drawback with Malecot catheters. A locking
mechanism
L
Large
are
tracts
Similar catheters percutaneously
occasionally are used in the biliary tract, for abscess drainage, or for gastric feeding. The expanding wings on the Malecot catheter tip offer some degree of stabilization for the catheter, but the wings may close spontaneously and thereby permit the catheter to retract. Dislodgment of these large-bore catheters can have disastrous effects. After we had experience with several patients in whom dislodgment of these catheters resulted in major complications (Fig 1), we devised a method to lock these catheters that effectively eliminates dislodgment.
were
drain-tube attachment device (DTAD; Hollister, Libertyville, Ill); Molnar retention disks (Cook, Bloomington, Ind) to secure 24-F catheters. Adin all cases, 2-inch (5.08-cm) nylon tape was used to form a mesentery around the Malecot catheter and to fasten the catheter shaft to the skin. To unlock the locking mechanism, the connecting tube or the adapter is unscrewed and tension on the suture is released. The Malecot catheter can be removed in the standard fashion by stretching the catheter with an internal stiffener and retracting the whole system over a guide wire. were
used
Figure 1. Computed tomographic scan obtamed in a 25-year-old man with a staghorn calculus shows collapsed catheter wings and dislodgment. A 24-F Malecot catheter had been successfully placed in the collecting system. The patient developed chills and fever in the recovery room. Blood with clots appeared in fluids obtained through the Malecot drainage system. A subcapsular and pennephnic hematoma developed, which eventually led to an operation.
We have recently tested specifically designed prototype locking Matecot catheters (Cook); these have been used for percutaneous nephrostomy with tract dilation and for gallbladder drainage (i = 1 each).
Results
In 14 of 15 patients, the catheter locking system functioned well. One of the 17 locking Malecot catheters dislodged. The distodgment occurred because the tie on the limb was loose and the suture slipped off the wing, therefore disassembling the self-retaining mechanism. After this episode, the suture was stitched rather than tied to the Malecot wing, and no dislodgment or any other problem has occurred. The prototype catheters have functioned welt in the two patients in whom they were used.
ditionatly,
I From the Department of Radiology, University of California San Diego Medical Center, 225 Dickinson St, San Diego, CA 92103 (H.B.D., E.V., R.B.S., B.W.G., CC.) and the Department of Medicine, University of California, San Diego (E.V.). Received June 24, 1991; accepted and revision requested August 16; revision received September 12. Address reprint requests to H.B.D. ( RSNA, 1992
576
#{149} Radiology
Discussion Matecot catheters for a variety
are popular and of drainages. For many urologists, it is the preferred catheter, especially for percutaneous nephrostomy and tract dilation. Because it is thin-walled, the Matecot catheter provides excellent drainage. Although the mushroom tip of a Malecot catheter is designed to “lock,” spontaneous recoil
useful
February
1992
expand.
The
system
locking
larly advantageous ditionally, if the
locking
Other these
b.
Figure
Ad-
wings of the Malecot catheter are collapsed between the staghorn and the collecting system, gentle retraction on the suture may assist in opening the mushroom.
a.
been
is particu-
in this situation.
2. Mechanism stitched to the
of locking Malecot catheter. distal end of one of the Malecot
the catheter hub. (b) Locked Malecot on the suture is maintained
Traction
catheter. by the
(a) Locking mechanism. wings (arrow). The
A 3-0 suture has suture exits through
The wings are locked by pulling connector attachment (arrow).
on the suture.
types
mechanisms
of situations
are
for use in the
pleated
shape of an “accordion” catheter (2) and the two wings of an Amplatz anchor catheter (3). Suture attachments in these catheters are effective in achieving internal fixation. If these drainage tubes are vigorously pulled out, however, they may cause tearing of the organ in which they have been placed. Our locking device for mushroom-tip catheters has the same potential risk. An internal
retention device such as the balloon of a Foley catheter requires that the cavity be spacious enough for both the balloon and the catheter tip. With balloon catheters, however, the balloon may deflate spontaneously dislodgment, may resist
ficult
and create the risk of or conversely, the balloon deflation and become dif-
to remove
If one
(4-6).
chooses
to use a Matecot
cathe-
ter for percutaneous nephrostomy with tract dilation, and if the ureter has been cannulated, a good alternative catheter to the
locking
combination
long tip. This curity by extra
Matecot Malecot
catheter catheter
catheter
offers
is the with added
a se-
purchase within the unnary tract. Currently, we also lock this catheter with one suture. This system is
a.
b.
(a) A standard Malecot catheter placed in the gallbladder dislodged and resulted in bile leak (arrow). (b) The dislodged catheter was replaced with a locking Malecot catheter. The deformity of the tip, caused by tension on the suture, is characteristic and indicates correct tension on the catheter wing. A 7-F gallbladder catheter is adjacent to the Malecot catheter. Figure
3.
our preferred
catheter
nephrostomy
and
locking
design (1) was effective in overcoming the problem of dislodgment. The prototype catheters also have performed well in the first two patients in whom they were used. The locking mechanism for the Malecot catheter is simple to create and has been reliable to date, except in the singte case where the suture was loosely tied. The suture should be stitched in advance while preparing for the proce-
Volume
182
#{149} Number
2
dure, rather than tant not to stitch
tied. It is also importhe suture to the
mushroom tip or to multiple wings; in each of these situations, retraction of the suture will cause obstruction of the catheter lumen. When aligned correctly, the Malecot tip should be slightly asymmetric at fluoroscopy, because of the eccentric position of the suture. A particularly difficult problem with Malecot catheters occurs with percutaneous nephrostomy and tract dilation for large staghorn calculi. When the stone occupies a large volume within the relatively restricted capacity of the collecting system, the catheter may be prone to dislodgment because of the little space left for the Malecot wings to
for percutaneous dilation.
U
Acknowledgment: We thank Marcia Earnshaw for photographic contribution, Ellen Mower for the illustrations, and Cook, Inc., (Bloomington, md) for providing us with prototype catheters.
References 1.
of the mushroom with subsequent dislodgment is an occasional problem that can be serious. Securing the catheter to the skin does not necessarily avoid displacement of the catheter from its organ. Our modification of the Cope
tract
2.
3.
4.
5.
6.
Cope C. Improved anchoring of nephrostomy catheters: loop technique. AIR 1980; 135:402-403. Candi JC, Hawkins IF Jr, Hawkins MC. Single step placement of a self-retaining ‘accordion catheter.” AIR 1984; 143:337-340. Brazzini H, Castaneda-Zuniga WR, Coleman CC, et al. Urostent designs. Semin Intervent Radiol 1987; 4:26-35. Carrett JP. Technical note: methods for deflating retained urinary catheters. Clin Radiol 1989; 40:319. Walters NA, Kilbey J, Rickards D. Technical note: a technique for the removal of retamed balloon bladder catheters. Br J Radiol 1988; 61:320-321. Higgins WL, Mace AH. Puncture of a nondeflatable Foley balloon using ultrasound guidance. Radiology 1984; 151 :801.
Radiology
#{149} 577
