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Centrally placed external catheters and subcutaneous ports
Centrally Placed External Catheters and Subcutaneous Ports Susan Weeks, MD and Matthew A. Mauro, MD, FACR
Centrally placed external catheters and subcutaneous ports are the original devices designed for long-term central venous access. Their insertion requires three basic procedural steps: (1) access to a vein and catheterization to the right heart, (2) formation of a subcutaneous tunnel (for external catheters) or a subcutaneous pocket (for ports), and (3) catheter insertion. Catheterization from a venous entry site to the right atrium (RA) is generally straightforward but occasionally requires the use of a variety of catheters and guidewires. These techniques are well-known to interventionalists. Tunnel and pocket formation requires basic surgical skills which are readily acquired by the interventional radiologist. Unsuccessful placement of a central device in the operating room is generally not due to an inability to create the tunnel or pocket, but rather an inability to either initially catheterize the RA or to place the final catheter into its desired location. These are the particular areas in which catheter/guidewire manipulative skills pertain and in which interventional radiologists are well-versed. Successful catheterization and final placement of a functional central catheter reaches 100% when performed in an interventional suite. Copyright © 1998 by W.B. Saunders Company
his article discusses the various methods for the insertion
T of centrally placed external catheters and subcutaneous
ports. External catheters include dialysis and apheresis catheters (both temporary and tunneled), tunneled catheters for long-term venous access, and nontunneled intermediate-term small bore catheters such as the Hohn catheter (Bard Access Systems, Salt Lake City, UT).
Dialysis and Apheresis Catheters
location within the RA. The external portion of the 0.018" guidewire is bent. The wire is then withdrawn to the venous entry site and marked a second time to measure overall intravascular length (Fig 1). The correct catheter length can then be chosen. The authors currently use the Medcomp Hemocath silicone double-lumen catheter (Medcomp, Inc, Harleysville, PA). If the left IJV is accessed, the catheter will often migrate superiorly because of the tortuosity of the left brachiocephalic vein, so added length is necessary. The tract is then dilated to one-half French size less than the catheter size, and the catheter is then advanced over a stiff guidewire such that the distal tip terminates within the superior RA. The catheter is then heparinized according to the manufacturer's specifications and sutured in place using nonabsorbable suture material. The catheter is ready for immediate use.
Long-Term Tunneled Catheters Placement of long-term tunneled catheters can be divided into three steps: venous access, tunnel formation, and catheter insertion. For long-term dialysis access, the authors prefer the Hickman Hemodialysis/Apheresis 13.5F round double-lumen catheter (Bard Access Systems). Access into the IJV is achieved, and appropriate intravascular catheter length is measured in the usual fashion. Overall catheter length is then determined, taking into account the length of the subcutaneous tunnel. For instance, if the intravascular length measures 13 cm, then a 15-cm catheter (tip to cuff), may be used, and a 4-cm tunnel created. If a longer tunnel is desired, the next longer-sized catheter is chosen. The cuff should always be located within 2 centimeters of the skin exit site.
Temporary Catheters
Tunnel Formation
Placement of temporary catheters is very straightforward. Access into the internal jugular vein (IJV) is obtained using the techniques described in Dr Sandhu's article titled "Techniques for Conventional Access to Central Veins," in this issue. The right IJV is preferred, as it offers a straight pathway to the right atrium (RA) and catheters tend to function better from this location. 1 The authors use ultrasound guidance and a micropuncture kit to accomplish this. Appropriate intravascular catheter length is measured using the 0.018" mandril guidewire as follows: the tip of the wire is positioned at the desired tip
Tunnel style is divided into supraclavicular and infraclavicular tunnels. For a supraclavicular tunnel, local anesthesia with 1% lidocaine with epinephrine is administered. A dermatotomy is made at the distal aspect of the tract, located above the clavicle and a curved hemostat is used to carefully create the tunnel from venous access site to catheter exit site (Fig 2A). The tunnel should form a gentle angle with the venous access site. The catheter is pulled through the tunnel, flushed, and clamped (Fig 2B). At this point, it is helpful to pull the catheter centrally a bit more so that the cuff is located deeper in the tunnel, several centimeters from the exit site. After the catheter tip is advanced into the RA, it can be withdrawn to the correct location. This maneuver allows removal of any kinks which may be present at the venous entry site, and is faster than manipulating the catheter with a wire. For infraclavicular tunnels, 1% lidocaine with epinephrine is again administered for local anesthesia. A dermatotomy is
From the University of North Carolina, School of Medicine, Department of Radiology,Chapel Hill, NC. Address reprint requests to Susan Weeks, MD, University of North Carolina, School of Medicine, Department of Radiology, CB# 7510 2006 Old Clinic Building, Chapel Hill, NC 27599-7510. Copyright © 1998 by WB. Saunders Company 1089-2516/98/0103-000558.00/0
Techniques in Vascular and Interventional Radiology, Vol 1, No 3 (September), 1998: pp 133-139
133
Fig 1. Intravascular guidewire measurement: Guidewire kink (straight arrow) is made when wire is at the desired location of catheter tip within the RA. The clamp is placed when the wire tip is at the venous entry site (curved arrow). The distance between the kink and clamp represents the intravascular length of catheter required.
made at the distal aspect of the tunnel site located below the clavicle, and a curved hemostat is used to initiate tunnel formation. A tunneling device is usually necessary to complete the tunnel. When forming an infraclavicular tunnel from an IJ approach, a two-step tunnel is preferred (Fig 3). The first step of the tunnel is from the catheter exit site to a point 2 cm superior and lateral to the venous access site. This is created with a tunneling tool, and the catheter is brought through this portion of the tunnel. The second step of the tunnel is created with a hemostat from the venous site to the site where the catheter has exited. The catheter is grasped with the hemostats and brought through to the venous access site. This two-step tunnel ensures a smooth catheter course. Both tunnel styles have their advantages. With supraclavicular tunnels, a very gentle angle is easily created with respect to the venous access site. It is also much easier and faster to form, especially in larger patients. Additionally, later catheter manipulations are much easier compared with the longer infraclavicular tunnel. Infraclavicular tunnels are preferred by the patient in terms of comfort and appearance. There is more flexibility in catheter tip position when longer tunnels are used and longer tunnels may decrease the chance of microorganisms migrating from the catheter exit site to the venous entry site.
Catheter Insertion The transitional dilator is exchanged over a stiff guidewire for an appropriately sized peel-away sheath. It is very important to advance this sheath and dilator over the wire while watching under fluoroscopic guidance to ensure that the sheath is following the line of the wire, thereby avoiding conversion of an intravascular sheath to an extravascular one. Finally, the inner dilator and guidewire are removed simultaneously while pinching the peel-away sheath; this prevents both air embolism and excessive blood loss and is more reliable than asking the patient to suspend respirations. The catheter is immediately advanced into the peel-away sheath until the distal tip terminates in the RA. Before removing the peel-away sheath, the catheter should be checked with fluoroscopy to be certain it is
134
entering the RA, and not the left brachiocephalic vein or another undesirable location. Additionally, if the left IJV is accessed, a hydrophilic guidewire may be required to advance the catheter through a tortuous brachiocephalic vein into the RA. If all measurements are correct, the catheter should be perfectly positioned with the distal tip in the RA, and the cuff located approximately 1 to 2 centimeters from the skin exit site. In those patients in whom it is difficult to maintain adequate catheter flow rates, the Ash Split and Tesio catheter system (Medcomp, Inc) offer alternatives. Insertion of the Ash Split catheter is identical to the technique described for the conventional tunneled hemodialysis catheter. The Tesio catheter system is composed of two separate single-lumen catheters. Therefore, dual venotomies are made within the IJV, approximately 1 to 2 centimeters apart. Two parallel tunnels are created, and the catheters are placed through the tunnels and can be cut to length at their back ends due to a removable hub. The catheters are then individually placed through peel-away sheaths and advanced until both catheters terminate in the RA, the venous catheter tip several centimeters distal to the arterial catheter tip (Fig 4).
Tunneled Catheters for Long-Term Venous Access Catheters such as single-, double-, and triple-lumen Hickman catheters (Bard Access Systems) are placed in a method similar to that used for tunneled dialysis catheters. 2-5 Although the authors have classically used the nondominant-handed subclavian vein for access, they have more recently begun to use the right IJV, because of ease of access and avoidance of potential complications related to vessel thrombosis or stenosis. Additionally, in larger patients, catheter position tends to be more stable via the IJV, as increased chest weight shifts the Hickman to a more proximal location. Consequently, added catheter length is often necessary in these patients to avoid superior migration of the catheter into the superior vena cava (SVC). WEEKS AND MAURO
Fig 2. Supraclavicular tunnel. (A) The patient's head is to the left with the right shoulder in the near field. A short tunnel is created with hemostats from venous access site to the final catheter exit site which is above the clavicle (arrows). (B) The catheter tip is grasped and brought through the tunnel.
Access is obtained through either the IJV or subclavian vein and appropriate intravascular catheter length is measured in standard fashion. A 22G Chiba needle (Cook, Bloomington, IN) is used to introduce anesthetic throughout the planned tunnel course. With subclavian vein (SCV) access, a singlestage tunnel is created, forming a gentle angle with respect to the venous entry site (Fig 5). If the IJV is used, a two-stage tunnel is formed similar to that used in longer dialysis catheter placements. Regardless of the venous access site, the catheter exit site is typically located in a parasternal location at or below the nipple line. The catheter is pulled through the tunnel, flushed and clamped, and the cuff is placed approximately 2 CENTRALLY PLACED CATHETERS AND PORTS
cm from the skin entry site. The catheter is inserted through a peel-away sheath as described previously (Fig 6). Once again, it is important to check with fluoroscopy during advancement of the catheter to ensure that it is directed toward the RA. Also, if the catheter will not advance, it is most likely due to a kink in the sheath (usually at the subclavian-brachiocephalic venous unction), which can be corrected by simply withdrawing the sheath slowly until the catheter can be advanced. Although kinked sheaths frequently occur with right SCV access, they rarely, if ever occur with IJV or left SCV access. Once the catheter is in its final location, it should be flushed and then heparinized according to the manufacturer's specifica-
135
Venou2bACCi~SSite
~
J
A
,
_
.
~
'
.......
CatheterExitSite SecondStage of Tunnel First Stage of Tunnel
I
I IJ
Fig 3. Infraclavicular tunnel, (A) From a skin incision below the clavicle, a tunneling tool is placed and brought out at a point superior and lateral to the venous site. The catheter is brought through this first stage of the tunnel. (B) A hemostat is inserted from the venous access site to the second skin incision. The tip of the catheter is grasped and brought through completing the second stage of the tunnel. (C) Final appearance: A smooth curve is created.
C tions. Nonabsorbable monofilament 3-0 suture material is used to secure the catheter and close the dermatotomy at the venous entry site.
Small Bore Intermediate-Term Catheters At the authors' institution, the most commonly used catheter fitting this description is the Hohn catheter (Bard Access Systems). However, peripherally inserted central catheter
136
(PICC) insertions have replaced Hohn catheter placements to a large degree. Placement of a small bore catheter such as a Hohn is usually very straightforward but can be difficult in patients with excessive soft tissues. After access is achieved into either the SCV or IJV, the tract is dilated over the mandril guidewire, and then the nontapered catheter is advanced over the mandril guidewire until the tip terminates in the superior RA. The authors find this is more easily accomplished using a 0.018" mandril guidewire instead of the more flimsy 0.025" guidewire
WEEKSANDMAURO
Subcutaneous Ports
Fig 4, Twin Tesio system. Two separate venous punctures with parallel tunnels. Venous catheter (straight arrow) is distal to arterial catheter (curved arrow).
provided in the Hohn kit. In those patients with excessive soft tissues, it may be necessary to use a peel-away sheath to successfully advance the catheter into the RA. The catheter is flushed, heparinized, and secured to the skin using nonabsorbable 3-0 suture material, and is ready for use.
For access, the SCV can be used, but the IJV is preferred in larger patients, both for ease and safety concerning venous access, and because the catheter tip is less likely to migrate superiorly. In all patients, use of the IJV avoids possible complications related to vessel stenoses and thrombosis. After standard venous access, ports are inserted by using either preattached ports (attached at the manufacturer or on the table before insertion) or ports in which the attachment of the catheter to the port is made during the insertion procedure. 6 For preattached ports, an intravascular guidewire measurement is performed after venous access. An incision for the port pocket is then made horizontal to the clavicle following local anesthesia with 1% lidocaine with epinephrine. The site of the pocket is patient-dependent and independent of the venous access site. The port should be placed over a firm location on the upper chest wall to facilitate subsequent access. The use of a low profile port versus a regular port is based on the patient's body habitus. A subcutaneous pocket is typically formed below the incision using blunt dissection. The pocket can be formed superior to the incision and this is preferred by some interventionalists because there will be no catheter component located directly under the incision line. Hemostasis is achieved; a disposable cautery device, packing with gauze or vessel ligation using 3-0 or 4-0 absorbable suture may be necessary. A subcutaneous tunnel is then made connecting the venous entry site with the pocket, using either a curved hemostat if the tunnel is short, or a tunneling device if needed. The catheter is pulled through the tunnel, and the port is placed in the pocket. Single stabilizing sutures may be placed on either side of the port using 3-0 absorbable suture (ie, Vicryl; Ethicon, Inc, Somerville, NJ). The port position can then be further secured in the pocket by placement of the access needle through the skin and into the port (Fig 7).
Fig 5. Tunnel for external chest wall catheter via the left subclavian approach. The patient's sternum is to the left and the head is superior, The tunnel is created from the exit site (straight arrow) in a parasternal location to venous access site (curved arrow),
CENTRALLY PLACED CATHETERSAND PORTS
137
Fig 6. The catheter is inserted into a peel-away sheath as the sheath is pinched.
The pocket is closed in a two-layer fashion with both deep and superficial sutures. The pocket is initially closed with a layer of deep inverted interrupted 3-0 absorbable subcnticular sutures. In those patients in whom excellent hemostasis has been achieved, and there is little if any tension on the suture line, the second layer is a running subcuticular stitch using 4-0 absorbable sutures. If there is a concern for oozing into the wound, or tension on the incision, this stitch should not be used, and instead, a layer of 4-0 interrupted monofilament skin sutures is applied, to be removed in 7 days. The catheter is then cut to length and flushed. In addition to removing any air from the port and catheter, this also ensures
appropriate access needle placement. The transition dilator is exchanged over a stiff guidewire for the enclosed peel-away sheath and the catheter is advanced into the RA as previously described. Blood should be aspirated, the catheter flushed, and then heparinized with the appropriate volume of 100 U heparirdmL. If the port is left accessed, it can be used immediately.
Cat
Fig 7. Preattached ports. The catheter is brought through a tunnel from the pocket to the venous access site, trimmed to length, and inserted through a peel-away sheath.
138
Fig 8. Attachable ports. The catheter is inserted immediately after access to the RA is achieved, and the catheter is backtunneled from the venous access site to the port pocket. A clamp is placed on the catheter at the venous access site. The catheter is trimmed and connected to the port. WEEKS AND MAURO
Attachable ports are placed using an alternate method. This may be beneficial in those patients in whom stenoses need to be negotiated, or in larger patients in whom catheter migration secondary to patient size is of concern. Immediately after venous access, the peel-away sheath is placed and the catheter is advanced into the RA while detached from the port. The external portion is clamped (using an atraumatic clamp) to avoid backbleeding. A horizontal incision is made after local anesthesia as before. For the detachable port, the subcutaneous pocket must be located below this incision. A subcutaneous tunnel connecting the pocket with the venous entry site is formed and the catheter is backtunneled through the tunnel to the level of the pocket (Fig 8). An atraumatic clamp is placed on the catheter at the venous access site before backtunneling. The catheter is cut to length and attached to the port. The interventional radiologist should make certain that he or she has enough catheter exposed to easily perform this step; he or she will want to be able to easily grasp the catheter to attach it to the port. The securing collar is then placed across the catheter/port interface, and the atraumatic clamp is released at the venous entry site. Blood is aspirated, and the catheter is
CENTRALLY PLACED CATHETERS AND PORTS
flushed, tt is important to make sure there is no leakage of fluid
at the port/catheter attachment site, The port is then placed into the pocket, reaccessed if needed, secured to the deep fascia, and the pocket is closed as previously described.
References 1. Cimochowski GE, Worley E, Rutherford WE, et al: Superiority of the internal jugular over the subclavian access for temporary dialysis. Nephron 54:154-161, 1990 2. Robertson LJ, Mauro MA, Jaques PF: Radiotogic placement of Hickman catheters. Radiology 170:1007-1009, 1989 3. Mauro MA, Jaques PF: Radiologic placement of long-term central venous catheters: A review. Vasc Interv Radiol 4:127-137, 1993 4. Campbell WE, Mauro MA, Jaques PF: Radiological insertion of long-term venous access devices. Semin Intervent Radiol 1:366-376, 1994 5. Cockburn JF, Eynon CA, Virji N, et al: Insertion of Hickman central venous catheters by using angiographic techniques in patients with hematologic disorders. Am J Roentgeno1159:121-124, 1992 6. Denny DF: Placement and management of tong-term central venous access catheters and ports. Am J Roentgeno1161:385-393, 1993
139
Centrally placed external catheters and subcutaneous ports are the original devices designed for long-term central venous access. Their insertion requires three basic procedural steps: (1) access to a vein and catheterization to the right heart, (2) formation of a subcutaneous tunnel (for external catheters) or a subcutaneous pocket (for ports), and (3) catheter insertion. Catheterization from a venous entry site to the right atrium (RA) is generally straightforward but occasionally requires the use of a variety of catheters and guidewires. These techniques are well-known to interventionalists. Tunnel and pocket formation requires basic surgical skills which are readily acquired by the interventional radiologist. Unsuccessful placement of a central device in the operating room is generally not due to an inability to create the tunnel or pocket, but rather an inability to either initially catheterize the RA or to place the final catheter into its desired location. These are the particular areas in which catheter/guidewire manipulative skills pertain and in which interventional radiologists are well-versed. Successful catheterization and final placement of a functional central catheter reaches 100% when performed in an interventional suite. Copyright © 1998 by W.B. Saunders Company
his article discusses the various methods for the insertion
T of centrally placed external catheters and subcutaneous
ports. External catheters include dialysis and apheresis catheters (both temporary and tunneled), tunneled catheters for long-term venous access, and nontunneled intermediate-term small bore catheters such as the Hohn catheter (Bard Access Systems, Salt Lake City, UT).
Dialysis and Apheresis Catheters
location within the RA. The external portion of the 0.018" guidewire is bent. The wire is then withdrawn to the venous entry site and marked a second time to measure overall intravascular length (Fig 1). The correct catheter length can then be chosen. The authors currently use the Medcomp Hemocath silicone double-lumen catheter (Medcomp, Inc, Harleysville, PA). If the left IJV is accessed, the catheter will often migrate superiorly because of the tortuosity of the left brachiocephalic vein, so added length is necessary. The tract is then dilated to one-half French size less than the catheter size, and the catheter is then advanced over a stiff guidewire such that the distal tip terminates within the superior RA. The catheter is then heparinized according to the manufacturer's specifications and sutured in place using nonabsorbable suture material. The catheter is ready for immediate use.
Long-Term Tunneled Catheters Placement of long-term tunneled catheters can be divided into three steps: venous access, tunnel formation, and catheter insertion. For long-term dialysis access, the authors prefer the Hickman Hemodialysis/Apheresis 13.5F round double-lumen catheter (Bard Access Systems). Access into the IJV is achieved, and appropriate intravascular catheter length is measured in the usual fashion. Overall catheter length is then determined, taking into account the length of the subcutaneous tunnel. For instance, if the intravascular length measures 13 cm, then a 15-cm catheter (tip to cuff), may be used, and a 4-cm tunnel created. If a longer tunnel is desired, the next longer-sized catheter is chosen. The cuff should always be located within 2 centimeters of the skin exit site.
Temporary Catheters
Tunnel Formation
Placement of temporary catheters is very straightforward. Access into the internal jugular vein (IJV) is obtained using the techniques described in Dr Sandhu's article titled "Techniques for Conventional Access to Central Veins," in this issue. The right IJV is preferred, as it offers a straight pathway to the right atrium (RA) and catheters tend to function better from this location. 1 The authors use ultrasound guidance and a micropuncture kit to accomplish this. Appropriate intravascular catheter length is measured using the 0.018" mandril guidewire as follows: the tip of the wire is positioned at the desired tip
Tunnel style is divided into supraclavicular and infraclavicular tunnels. For a supraclavicular tunnel, local anesthesia with 1% lidocaine with epinephrine is administered. A dermatotomy is made at the distal aspect of the tract, located above the clavicle and a curved hemostat is used to carefully create the tunnel from venous access site to catheter exit site (Fig 2A). The tunnel should form a gentle angle with the venous access site. The catheter is pulled through the tunnel, flushed, and clamped (Fig 2B). At this point, it is helpful to pull the catheter centrally a bit more so that the cuff is located deeper in the tunnel, several centimeters from the exit site. After the catheter tip is advanced into the RA, it can be withdrawn to the correct location. This maneuver allows removal of any kinks which may be present at the venous entry site, and is faster than manipulating the catheter with a wire. For infraclavicular tunnels, 1% lidocaine with epinephrine is again administered for local anesthesia. A dermatotomy is
From the University of North Carolina, School of Medicine, Department of Radiology,Chapel Hill, NC. Address reprint requests to Susan Weeks, MD, University of North Carolina, School of Medicine, Department of Radiology, CB# 7510 2006 Old Clinic Building, Chapel Hill, NC 27599-7510. Copyright © 1998 by WB. Saunders Company 1089-2516/98/0103-000558.00/0
Techniques in Vascular and Interventional Radiology, Vol 1, No 3 (September), 1998: pp 133-139
133
Fig 1. Intravascular guidewire measurement: Guidewire kink (straight arrow) is made when wire is at the desired location of catheter tip within the RA. The clamp is placed when the wire tip is at the venous entry site (curved arrow). The distance between the kink and clamp represents the intravascular length of catheter required.
made at the distal aspect of the tunnel site located below the clavicle, and a curved hemostat is used to initiate tunnel formation. A tunneling device is usually necessary to complete the tunnel. When forming an infraclavicular tunnel from an IJ approach, a two-step tunnel is preferred (Fig 3). The first step of the tunnel is from the catheter exit site to a point 2 cm superior and lateral to the venous access site. This is created with a tunneling tool, and the catheter is brought through this portion of the tunnel. The second step of the tunnel is created with a hemostat from the venous site to the site where the catheter has exited. The catheter is grasped with the hemostats and brought through to the venous access site. This two-step tunnel ensures a smooth catheter course. Both tunnel styles have their advantages. With supraclavicular tunnels, a very gentle angle is easily created with respect to the venous access site. It is also much easier and faster to form, especially in larger patients. Additionally, later catheter manipulations are much easier compared with the longer infraclavicular tunnel. Infraclavicular tunnels are preferred by the patient in terms of comfort and appearance. There is more flexibility in catheter tip position when longer tunnels are used and longer tunnels may decrease the chance of microorganisms migrating from the catheter exit site to the venous entry site.
Catheter Insertion The transitional dilator is exchanged over a stiff guidewire for an appropriately sized peel-away sheath. It is very important to advance this sheath and dilator over the wire while watching under fluoroscopic guidance to ensure that the sheath is following the line of the wire, thereby avoiding conversion of an intravascular sheath to an extravascular one. Finally, the inner dilator and guidewire are removed simultaneously while pinching the peel-away sheath; this prevents both air embolism and excessive blood loss and is more reliable than asking the patient to suspend respirations. The catheter is immediately advanced into the peel-away sheath until the distal tip terminates in the RA. Before removing the peel-away sheath, the catheter should be checked with fluoroscopy to be certain it is
134
entering the RA, and not the left brachiocephalic vein or another undesirable location. Additionally, if the left IJV is accessed, a hydrophilic guidewire may be required to advance the catheter through a tortuous brachiocephalic vein into the RA. If all measurements are correct, the catheter should be perfectly positioned with the distal tip in the RA, and the cuff located approximately 1 to 2 centimeters from the skin exit site. In those patients in whom it is difficult to maintain adequate catheter flow rates, the Ash Split and Tesio catheter system (Medcomp, Inc) offer alternatives. Insertion of the Ash Split catheter is identical to the technique described for the conventional tunneled hemodialysis catheter. The Tesio catheter system is composed of two separate single-lumen catheters. Therefore, dual venotomies are made within the IJV, approximately 1 to 2 centimeters apart. Two parallel tunnels are created, and the catheters are placed through the tunnels and can be cut to length at their back ends due to a removable hub. The catheters are then individually placed through peel-away sheaths and advanced until both catheters terminate in the RA, the venous catheter tip several centimeters distal to the arterial catheter tip (Fig 4).
Tunneled Catheters for Long-Term Venous Access Catheters such as single-, double-, and triple-lumen Hickman catheters (Bard Access Systems) are placed in a method similar to that used for tunneled dialysis catheters. 2-5 Although the authors have classically used the nondominant-handed subclavian vein for access, they have more recently begun to use the right IJV, because of ease of access and avoidance of potential complications related to vessel thrombosis or stenosis. Additionally, in larger patients, catheter position tends to be more stable via the IJV, as increased chest weight shifts the Hickman to a more proximal location. Consequently, added catheter length is often necessary in these patients to avoid superior migration of the catheter into the superior vena cava (SVC). WEEKS AND MAURO
Fig 2. Supraclavicular tunnel. (A) The patient's head is to the left with the right shoulder in the near field. A short tunnel is created with hemostats from venous access site to the final catheter exit site which is above the clavicle (arrows). (B) The catheter tip is grasped and brought through the tunnel.
Access is obtained through either the IJV or subclavian vein and appropriate intravascular catheter length is measured in standard fashion. A 22G Chiba needle (Cook, Bloomington, IN) is used to introduce anesthetic throughout the planned tunnel course. With subclavian vein (SCV) access, a singlestage tunnel is created, forming a gentle angle with respect to the venous entry site (Fig 5). If the IJV is used, a two-stage tunnel is formed similar to that used in longer dialysis catheter placements. Regardless of the venous access site, the catheter exit site is typically located in a parasternal location at or below the nipple line. The catheter is pulled through the tunnel, flushed and clamped, and the cuff is placed approximately 2 CENTRALLY PLACED CATHETERS AND PORTS
cm from the skin entry site. The catheter is inserted through a peel-away sheath as described previously (Fig 6). Once again, it is important to check with fluoroscopy during advancement of the catheter to ensure that it is directed toward the RA. Also, if the catheter will not advance, it is most likely due to a kink in the sheath (usually at the subclavian-brachiocephalic venous unction), which can be corrected by simply withdrawing the sheath slowly until the catheter can be advanced. Although kinked sheaths frequently occur with right SCV access, they rarely, if ever occur with IJV or left SCV access. Once the catheter is in its final location, it should be flushed and then heparinized according to the manufacturer's specifica-
135
Venou2bACCi~SSite
~
J
A
,
_
.
~
'
.......
CatheterExitSite SecondStage of Tunnel First Stage of Tunnel
I
I IJ
Fig 3. Infraclavicular tunnel, (A) From a skin incision below the clavicle, a tunneling tool is placed and brought out at a point superior and lateral to the venous site. The catheter is brought through this first stage of the tunnel. (B) A hemostat is inserted from the venous access site to the second skin incision. The tip of the catheter is grasped and brought through completing the second stage of the tunnel. (C) Final appearance: A smooth curve is created.
C tions. Nonabsorbable monofilament 3-0 suture material is used to secure the catheter and close the dermatotomy at the venous entry site.
Small Bore Intermediate-Term Catheters At the authors' institution, the most commonly used catheter fitting this description is the Hohn catheter (Bard Access Systems). However, peripherally inserted central catheter
136
(PICC) insertions have replaced Hohn catheter placements to a large degree. Placement of a small bore catheter such as a Hohn is usually very straightforward but can be difficult in patients with excessive soft tissues. After access is achieved into either the SCV or IJV, the tract is dilated over the mandril guidewire, and then the nontapered catheter is advanced over the mandril guidewire until the tip terminates in the superior RA. The authors find this is more easily accomplished using a 0.018" mandril guidewire instead of the more flimsy 0.025" guidewire
WEEKSANDMAURO
Subcutaneous Ports
Fig 4, Twin Tesio system. Two separate venous punctures with parallel tunnels. Venous catheter (straight arrow) is distal to arterial catheter (curved arrow).
provided in the Hohn kit. In those patients with excessive soft tissues, it may be necessary to use a peel-away sheath to successfully advance the catheter into the RA. The catheter is flushed, heparinized, and secured to the skin using nonabsorbable 3-0 suture material, and is ready for use.
For access, the SCV can be used, but the IJV is preferred in larger patients, both for ease and safety concerning venous access, and because the catheter tip is less likely to migrate superiorly. In all patients, use of the IJV avoids possible complications related to vessel stenoses and thrombosis. After standard venous access, ports are inserted by using either preattached ports (attached at the manufacturer or on the table before insertion) or ports in which the attachment of the catheter to the port is made during the insertion procedure. 6 For preattached ports, an intravascular guidewire measurement is performed after venous access. An incision for the port pocket is then made horizontal to the clavicle following local anesthesia with 1% lidocaine with epinephrine. The site of the pocket is patient-dependent and independent of the venous access site. The port should be placed over a firm location on the upper chest wall to facilitate subsequent access. The use of a low profile port versus a regular port is based on the patient's body habitus. A subcutaneous pocket is typically formed below the incision using blunt dissection. The pocket can be formed superior to the incision and this is preferred by some interventionalists because there will be no catheter component located directly under the incision line. Hemostasis is achieved; a disposable cautery device, packing with gauze or vessel ligation using 3-0 or 4-0 absorbable suture may be necessary. A subcutaneous tunnel is then made connecting the venous entry site with the pocket, using either a curved hemostat if the tunnel is short, or a tunneling device if needed. The catheter is pulled through the tunnel, and the port is placed in the pocket. Single stabilizing sutures may be placed on either side of the port using 3-0 absorbable suture (ie, Vicryl; Ethicon, Inc, Somerville, NJ). The port position can then be further secured in the pocket by placement of the access needle through the skin and into the port (Fig 7).
Fig 5. Tunnel for external chest wall catheter via the left subclavian approach. The patient's sternum is to the left and the head is superior, The tunnel is created from the exit site (straight arrow) in a parasternal location to venous access site (curved arrow),
CENTRALLY PLACED CATHETERSAND PORTS
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Fig 6. The catheter is inserted into a peel-away sheath as the sheath is pinched.
The pocket is closed in a two-layer fashion with both deep and superficial sutures. The pocket is initially closed with a layer of deep inverted interrupted 3-0 absorbable subcnticular sutures. In those patients in whom excellent hemostasis has been achieved, and there is little if any tension on the suture line, the second layer is a running subcuticular stitch using 4-0 absorbable sutures. If there is a concern for oozing into the wound, or tension on the incision, this stitch should not be used, and instead, a layer of 4-0 interrupted monofilament skin sutures is applied, to be removed in 7 days. The catheter is then cut to length and flushed. In addition to removing any air from the port and catheter, this also ensures
appropriate access needle placement. The transition dilator is exchanged over a stiff guidewire for the enclosed peel-away sheath and the catheter is advanced into the RA as previously described. Blood should be aspirated, the catheter flushed, and then heparinized with the appropriate volume of 100 U heparirdmL. If the port is left accessed, it can be used immediately.
Cat
Fig 7. Preattached ports. The catheter is brought through a tunnel from the pocket to the venous access site, trimmed to length, and inserted through a peel-away sheath.
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Fig 8. Attachable ports. The catheter is inserted immediately after access to the RA is achieved, and the catheter is backtunneled from the venous access site to the port pocket. A clamp is placed on the catheter at the venous access site. The catheter is trimmed and connected to the port. WEEKS AND MAURO
Attachable ports are placed using an alternate method. This may be beneficial in those patients in whom stenoses need to be negotiated, or in larger patients in whom catheter migration secondary to patient size is of concern. Immediately after venous access, the peel-away sheath is placed and the catheter is advanced into the RA while detached from the port. The external portion is clamped (using an atraumatic clamp) to avoid backbleeding. A horizontal incision is made after local anesthesia as before. For the detachable port, the subcutaneous pocket must be located below this incision. A subcutaneous tunnel connecting the pocket with the venous entry site is formed and the catheter is backtunneled through the tunnel to the level of the pocket (Fig 8). An atraumatic clamp is placed on the catheter at the venous access site before backtunneling. The catheter is cut to length and attached to the port. The interventional radiologist should make certain that he or she has enough catheter exposed to easily perform this step; he or she will want to be able to easily grasp the catheter to attach it to the port. The securing collar is then placed across the catheter/port interface, and the atraumatic clamp is released at the venous entry site. Blood is aspirated, and the catheter is
CENTRALLY PLACED CATHETERS AND PORTS
flushed, tt is important to make sure there is no leakage of fluid
at the port/catheter attachment site, The port is then placed into the pocket, reaccessed if needed, secured to the deep fascia, and the pocket is closed as previously described.
References 1. Cimochowski GE, Worley E, Rutherford WE, et al: Superiority of the internal jugular over the subclavian access for temporary dialysis. Nephron 54:154-161, 1990 2. Robertson LJ, Mauro MA, Jaques PF: Radiotogic placement of Hickman catheters. Radiology 170:1007-1009, 1989 3. Mauro MA, Jaques PF: Radiologic placement of long-term central venous catheters: A review. Vasc Interv Radiol 4:127-137, 1993 4. Campbell WE, Mauro MA, Jaques PF: Radiological insertion of long-term venous access devices. Semin Intervent Radiol 1:366-376, 1994 5. Cockburn JF, Eynon CA, Virji N, et al: Insertion of Hickman central venous catheters by using angiographic techniques in patients with hematologic disorders. Am J Roentgeno1159:121-124, 1992 6. Denny DF: Placement and management of tong-term central venous access catheters and ports. Am J Roentgeno1161:385-393, 1993
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