Long-term hemodialysis catheter placement Pourchez RetrO?catheter insertion techniques
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《血管的通路杂志》
1.Department of Nephrology and Dialysis, General Hospital, Imperia - Italy
ABSTRACT
none
INTRODUCTION
Provision of an effective and durable vascular access (VA) continues to be a challenge. During the past 10 yrs, catheters have played an increasing role
in dialysis provision. They have obvious advantages over arteriovenous access, such as the relative ease of placement, removal and replacement in experienced hands and the possibility for immediate use. Long-term catheters are meant to be in use for weeks to months, and possibly even years. The cuff and the tunnel provide physical barriers to bacterial invasion; therefore, allowing prolonged catheter use without the risk of infection.
Native arteriovenous fistulas (AVFs) are the preferred access modality for most patients on chronic hemodialysis permanent VA; they have lower complication rates compared to other access types. However, the central venous catheter (CVC) for dialysis remains a necessity for many patients beginning and continuing dialysis therapy. Improving the technological characteristics of the CVC and the safer insertion techniques are, however,
mandatory to minimize early and late complications. We describe a new cuffed CVC insertion technique.
PROCEDURE
Two interventional nephrologists performed the Procedures in an operating theater or an angiography unit. All patients received naropine without epinephrine local anesthesia and under continuous electrocardiographic (ECG) and pulse oximetry monitoring; we do not routinely use conscious sedation
with midazolam per os. Previously, we always recorded superficial presternal V1 leads to verify the subsequent correct CVC position using endocavitary
electrocardiography (EC-ECG). All CVCs were placed in the right internal jugular vein.
CATHETER PLACEMENT
The Pourchez RetrO?catheter (Spire Biomedical Inc., MA, USA) is a radiopaque silicone rubber cuffed double-lumen catheter; its main distinguishing feature is in the design. The Pourchez RetrO?catheter incorporates two O-shaped lumens in the mid body, but splits in two separate distal tips, each with side holes in all directions, and in two separate
proximal tips. This catheter partially reproduces the Ash Split Cath design. The difference from the Ash Split Cath is in the tunneled section, which consists of two separate cannulae and with the absence of stepdown
in diameter at the tip of the removal and return lines; practically, it combines certain characteristics of twin catheters and of Split Cath chronic catheters.
In contrast to double-lumen catheters with an inflow hole facing one direction, the Pourchez RetrO? like the twin catheter and the Ash Split catheter, has side holes arranged in a spiral around the distal cm of the tips (Fig. 1).
Compared to conventional D-shaped designs, Oshaped lumens of the same cross-sectional area provide higher flows at lower pressures, potentially
leading to a more effective fluid delivery. This difference allows subcutaneous tunneling in a craniocaudal direction after insertion in the vein lumen, as in the case of Canaud or Tesio catheters. Unlike other catheters, the Pourchez RetrO?has a kink-resistant body, the result of a carefully selected
combination of design and materials. This characteristic increases catheter placement flexibility and minimizes the need for subsequent intervention
due to kinking. It also eliminates the need for precurved catheter designs (Fig. 2).
The Pourchez RetrO?catheter is very similar to the SchonCath, which consists of two catheters with intravenous and subcutaneous portions identical to the Canaud and Tesio catheters, but without the subcutaneous cuffs. Instead of cuffs, there is a plastic grommet fixing the two catheters together and in position in the subcutaneous space below the primary incision. The Pourchez RetrO?catheter has a small Dacron cuff on the anchoring hub connector; this anchoring hub connector fixes the venous
and arterial catheter lengths from the venotomy to the right atrium (Fig. 3).
Percutaneous insertion
CVC insertion sites include the right and left femoral, subclavian and internal jugular veins. The preferred insertion site for long-term catheters is the right internal jugular vein. The right side is favored because this site offers a direct route to the right atrium and a lower complication rate. There is lower risk of pneumothorax and central venous stenosis, which occurs more frequently with
catheter placement in the left jugular vein, mainly in the subclavian vein. Moreover, there is no risk of damage to the thoracic duct.
First step: internal jugular vein puncture under ultrasound guidance We have used for many years, an ultrasound device specifically designed for CVC placement (Site-Rite, Dimax Corporation, Pittsburg, PA, USA). Several studies have documented an overall improvement in efficiency and a reduction in complication rates when ultrasound guidance is used for CVC insertion. The 1977 Dialysis Outcomes Quality Initiatives (DOQI) recommended 搑eal-time ultrasound guided insertion to reduce insertion related complications?based on both evidence and opinion. Moreover, in difficult cannulation situations or in patients with coagulopathy, initial access to the internal jugular vein is made with a micro puncture set (Medical Component, Harleysville, USA) always under real-time ultrasound guidance. The micro puncture consists of venipuncture using a 21-gauge needle introduced through the needle of a 0.018-inch micro guidewire (Fig. 4).
After a small skin incision at the puncture site (Fig. 5), a 4.5 F sheath-dilator (micro puncture coaxial dilator) is advanced gently over the micro guidewire (Fig. 6).
The micro guidewire is then removed and through the dilator lumen a standard 0.035-inch guidewire is inserted on the outer dilator (Fig. 7).
The guidewire should pass through the needle without any resistance. Any resistance encountered during the passage of the guidewire suggests malposition. Malposition can also occur if, after needle withdrawal, an obstacle is detected in the progression of the guidewire through the subcutaneous tract. In these conditions, it is necessary to avoid
pulling back the guidewire through the needle lumen because of the risk of fragmentation and embolism. The needle and the guidewire must be removed together and, a few minutes after tamponade, a new insertion can be started. The correct guidewire insertion can be checked by EC-ECG. The guidewire is used like an internal exploring electrode. In the case of any doubts, fluoroscopic control is necessary.
Second step: insertion of a second guidewire in the same puncture site
This can be done using the pacemaker technique. A 6-French minisheath-introducer is then advanced over the first wire (Fig. 8); the dilator is removed
(Fig. 9) and another guidewire is inserted through the sheath (Fig. 10). The sheath is then removed. A new EC-ECG registration on the second guidewire
is required.
The catheter kit includes two dilators of different increasing calibers, 14 and 16 F, to be inserted through the guidewire. The maneuver requires the patient to be in the Trendelenburg posture. Dilators do not need to be introduced too deeply due to the risk of venous wall injury. We recommend performing, as mandatory, the push-pull technique: one hand pushes the dilator over the
guidewire while the outer pulls the guidewire through the dilator. If there is any doubt as to the location of the dilator or the guidewire does not move freely through the dilator, the device should not be advanced further and the fluoroscope should be used for verify proper positioning. Uncontrolled dilator or catheter tip advancement can be avoided. After the final dilatation, the one-puncture technique and the dilation of the soft tissue and vein result
in significant bleeding.
Fourth step: a) Catheter insertion with peel-away Typically, an introducer sheath is used when inserting a tunneled catheter in a large central vein because the large diameter, soft, silastic or polyurethane mod catheters are too compliant to traverse the skin and subcutaneous tissue. The peel-away sheath introducer is a rigid system composed of a dilator and a sheath 損eel away? Therefore, the peel-away introducer should be inserted
using the same caution concerning the guidewire and the dilator procedure. Once the dilator-sheath complex overcomes the soft tissue resistance
(superficial and median cervical fasciae and venous wall), it is then slightly advanced in the vein. For the right internal jugular vein, the dilator and
guidewire can be removed together. For catheter placement on the left side or in the subclavian vein, it is always safer to leave the guidewire in place. Remove the dilator from the previously inserted sheath and insert the distal tips of the catheter in and through the sheath. This maneuvre requires rapid execution, inviting the patient to stop breathing, pinching the sheath between
the finger and the thumb of the clinician抯 hand, to prevent blood loss and air embolism. As soon as the catheter occludes the sheath, the clinician can release the sheath. Gently and slowly, pull the peel-away sheath out of the vessel.
b) Sheathless technique
Using an over-the-wire technique to insert the tunneled catheter eliminates the requirement for an introducer sheath. Since the Pourchez RetrOTM
catheter is too compliant to traverse the skin and subcutaneous tissue, to facilitate the passage in the venous system, two rigid plastic mandril wires are
inserted in the two catheter lumens to harden the device (Fig. 12).
Initially, resistance could be met as the catheter passes through the soft tissues (Figs. 13, 14), but a slight torquing of the catheter will aid its passage (Figs. 15, 16).
Previous careful dilation of the subcutaneous tunnel is essential for insertion without peel-away.
Catheter position
The final position of the tips of the catheter should be in the mid right atrium. For checking the proper positioning of the catheter, we routinely use EC-ECG registration. Fluoroscopy is necessary only in particular cases: previous central venous catheterization, left internal jugular vein insertion
and central venous thrombosis. After insertion, catheter function should be evaluated by placing a 10 ml syringe on each of the catheter hubs, rapidly withdrawing blood into the syringe.
The tunneling steps
Before tunneling, it is necessary to widen the incision, to perform a blunt dissection of the subcutaneous tissue, making a subcutaneous pocket, so
that the catheter anchoring hub can be embedded well and free of kinks (Figs. 19a, b, c, d).
After local anesthesia (Fig. 21), the tunneling device with the two catheters is then passed from the insertion site subcutaneously to the exit site (Figs. 22-26).
Care must be exercised to avoid damaging the catheter tips during the tunneling procedure. After insertion, catheter function should be evaluated using the so-called 搕hree T test? Check the TIP to ensure that the two tips are in the right atrium using fluoroscopy or EC-ECG, check the TOP to rule out in the unlikely event any kinks and, finally, check the TUG by placing a 20 ml syringe on each of the proximal ends of the catheter. A full 6 sec blood aspiration corresponds to a 200 ml/min flow rate. Once the flow is satisfactory, both lumens are flushed with heparinized saline. At the conclusion of the procedure, the citrate lock is applied. The catheter lumens are filled with the amount of citrate solution designated on the arterial and venous extensions. If any problems are identified, they should be corrected before the patient leaves the procedure room (Fig. 27).
COMMENTS
1. Who should insert permanent CVCs? Experienced physicians, nephrologists, surgeons or interventional radiologists.
2. Preferred insertion site of the tunneled, cuffed catheter is the right internal jugular vein. Use of the right internal jugular vein, ultrasound guidance to assist cannulation and intratrial ECG registration allows successful long-term catheter positioning without the use of fluoroscopy.
3. Fluoroscopy may not be necessary for permanent CVC insertion in patients without a history of prior catheterization or venous abnormalities.
4. The sheathless technique should significantly reduce potential problems associated with sheath/dilator insertion, such as air embolism, vessel trauma and excess bleeding.
REFERENCES
1. Work J. Chronic catheter placement. Semin Dial 2001; 14: 436-40.
2. Schwab S, Besarab A, Beathard G, Brouwer D, Etheredge E, Hartigan M, Levine M, McCann R, Sherman R, Trerotola S. NKF-DOQI clinical practice guidelines for vascular access. Am J Kidney Dis 2000; 37 (supp1 1): S169.
3. Patel A, Hofkin S, Ball D, Cohen G, Smith D. Sheathless technique of Ash Split-Cath insertion. J Vasc Interv Radiol 2001; 12: 376-8.
4. Butterly D, Schwab S. Catheter access for hemodialysis: an overview. Semin Dial2001; 14: 411-5.
5. Fox K, Roach D J, Berman SS. Central venous catheters: selection and placement. In Berman SS, ed. Vascular access in clinical practice. New York: Basel, M Dekker, Inc, 2002; 271-321.(F. Cavatorta, S. Galli1, )
ABSTRACT
none
INTRODUCTION
Provision of an effective and durable vascular access (VA) continues to be a challenge. During the past 10 yrs, catheters have played an increasing role
in dialysis provision. They have obvious advantages over arteriovenous access, such as the relative ease of placement, removal and replacement in experienced hands and the possibility for immediate use. Long-term catheters are meant to be in use for weeks to months, and possibly even years. The cuff and the tunnel provide physical barriers to bacterial invasion; therefore, allowing prolonged catheter use without the risk of infection.
Native arteriovenous fistulas (AVFs) are the preferred access modality for most patients on chronic hemodialysis permanent VA; they have lower complication rates compared to other access types. However, the central venous catheter (CVC) for dialysis remains a necessity for many patients beginning and continuing dialysis therapy. Improving the technological characteristics of the CVC and the safer insertion techniques are, however,
mandatory to minimize early and late complications. We describe a new cuffed CVC insertion technique.
PROCEDURE
Two interventional nephrologists performed the Procedures in an operating theater or an angiography unit. All patients received naropine without epinephrine local anesthesia and under continuous electrocardiographic (ECG) and pulse oximetry monitoring; we do not routinely use conscious sedation
with midazolam per os. Previously, we always recorded superficial presternal V1 leads to verify the subsequent correct CVC position using endocavitary
electrocardiography (EC-ECG). All CVCs were placed in the right internal jugular vein.
CATHETER PLACEMENT
The Pourchez RetrO?catheter (Spire Biomedical Inc., MA, USA) is a radiopaque silicone rubber cuffed double-lumen catheter; its main distinguishing feature is in the design. The Pourchez RetrO?catheter incorporates two O-shaped lumens in the mid body, but splits in two separate distal tips, each with side holes in all directions, and in two separate
proximal tips. This catheter partially reproduces the Ash Split Cath design. The difference from the Ash Split Cath is in the tunneled section, which consists of two separate cannulae and with the absence of stepdown
in diameter at the tip of the removal and return lines; practically, it combines certain characteristics of twin catheters and of Split Cath chronic catheters.
In contrast to double-lumen catheters with an inflow hole facing one direction, the Pourchez RetrO? like the twin catheter and the Ash Split catheter, has side holes arranged in a spiral around the distal cm of the tips (Fig. 1).
Compared to conventional D-shaped designs, Oshaped lumens of the same cross-sectional area provide higher flows at lower pressures, potentially
leading to a more effective fluid delivery. This difference allows subcutaneous tunneling in a craniocaudal direction after insertion in the vein lumen, as in the case of Canaud or Tesio catheters. Unlike other catheters, the Pourchez RetrO?has a kink-resistant body, the result of a carefully selected
combination of design and materials. This characteristic increases catheter placement flexibility and minimizes the need for subsequent intervention
due to kinking. It also eliminates the need for precurved catheter designs (Fig. 2).
The Pourchez RetrO?catheter is very similar to the SchonCath, which consists of two catheters with intravenous and subcutaneous portions identical to the Canaud and Tesio catheters, but without the subcutaneous cuffs. Instead of cuffs, there is a plastic grommet fixing the two catheters together and in position in the subcutaneous space below the primary incision. The Pourchez RetrO?catheter has a small Dacron cuff on the anchoring hub connector; this anchoring hub connector fixes the venous
and arterial catheter lengths from the venotomy to the right atrium (Fig. 3).
Percutaneous insertion
CVC insertion sites include the right and left femoral, subclavian and internal jugular veins. The preferred insertion site for long-term catheters is the right internal jugular vein. The right side is favored because this site offers a direct route to the right atrium and a lower complication rate. There is lower risk of pneumothorax and central venous stenosis, which occurs more frequently with
catheter placement in the left jugular vein, mainly in the subclavian vein. Moreover, there is no risk of damage to the thoracic duct.
First step: internal jugular vein puncture under ultrasound guidance We have used for many years, an ultrasound device specifically designed for CVC placement (Site-Rite, Dimax Corporation, Pittsburg, PA, USA). Several studies have documented an overall improvement in efficiency and a reduction in complication rates when ultrasound guidance is used for CVC insertion. The 1977 Dialysis Outcomes Quality Initiatives (DOQI) recommended 搑eal-time ultrasound guided insertion to reduce insertion related complications?based on both evidence and opinion. Moreover, in difficult cannulation situations or in patients with coagulopathy, initial access to the internal jugular vein is made with a micro puncture set (Medical Component, Harleysville, USA) always under real-time ultrasound guidance. The micro puncture consists of venipuncture using a 21-gauge needle introduced through the needle of a 0.018-inch micro guidewire (Fig. 4).
After a small skin incision at the puncture site (Fig. 5), a 4.5 F sheath-dilator (micro puncture coaxial dilator) is advanced gently over the micro guidewire (Fig. 6).
The micro guidewire is then removed and through the dilator lumen a standard 0.035-inch guidewire is inserted on the outer dilator (Fig. 7).
The guidewire should pass through the needle without any resistance. Any resistance encountered during the passage of the guidewire suggests malposition. Malposition can also occur if, after needle withdrawal, an obstacle is detected in the progression of the guidewire through the subcutaneous tract. In these conditions, it is necessary to avoid
pulling back the guidewire through the needle lumen because of the risk of fragmentation and embolism. The needle and the guidewire must be removed together and, a few minutes after tamponade, a new insertion can be started. The correct guidewire insertion can be checked by EC-ECG. The guidewire is used like an internal exploring electrode. In the case of any doubts, fluoroscopic control is necessary.
Second step: insertion of a second guidewire in the same puncture site
This can be done using the pacemaker technique. A 6-French minisheath-introducer is then advanced over the first wire (Fig. 8); the dilator is removed
(Fig. 9) and another guidewire is inserted through the sheath (Fig. 10). The sheath is then removed. A new EC-ECG registration on the second guidewire
is required.
The catheter kit includes two dilators of different increasing calibers, 14 and 16 F, to be inserted through the guidewire. The maneuver requires the patient to be in the Trendelenburg posture. Dilators do not need to be introduced too deeply due to the risk of venous wall injury. We recommend performing, as mandatory, the push-pull technique: one hand pushes the dilator over the
guidewire while the outer pulls the guidewire through the dilator. If there is any doubt as to the location of the dilator or the guidewire does not move freely through the dilator, the device should not be advanced further and the fluoroscope should be used for verify proper positioning. Uncontrolled dilator or catheter tip advancement can be avoided. After the final dilatation, the one-puncture technique and the dilation of the soft tissue and vein result
in significant bleeding.
Fourth step: a) Catheter insertion with peel-away Typically, an introducer sheath is used when inserting a tunneled catheter in a large central vein because the large diameter, soft, silastic or polyurethane mod catheters are too compliant to traverse the skin and subcutaneous tissue. The peel-away sheath introducer is a rigid system composed of a dilator and a sheath 損eel away? Therefore, the peel-away introducer should be inserted
using the same caution concerning the guidewire and the dilator procedure. Once the dilator-sheath complex overcomes the soft tissue resistance
(superficial and median cervical fasciae and venous wall), it is then slightly advanced in the vein. For the right internal jugular vein, the dilator and
guidewire can be removed together. For catheter placement on the left side or in the subclavian vein, it is always safer to leave the guidewire in place. Remove the dilator from the previously inserted sheath and insert the distal tips of the catheter in and through the sheath. This maneuvre requires rapid execution, inviting the patient to stop breathing, pinching the sheath between
the finger and the thumb of the clinician抯 hand, to prevent blood loss and air embolism. As soon as the catheter occludes the sheath, the clinician can release the sheath. Gently and slowly, pull the peel-away sheath out of the vessel.
b) Sheathless technique
Using an over-the-wire technique to insert the tunneled catheter eliminates the requirement for an introducer sheath. Since the Pourchez RetrOTM
catheter is too compliant to traverse the skin and subcutaneous tissue, to facilitate the passage in the venous system, two rigid plastic mandril wires are
inserted in the two catheter lumens to harden the device (Fig. 12).
Initially, resistance could be met as the catheter passes through the soft tissues (Figs. 13, 14), but a slight torquing of the catheter will aid its passage (Figs. 15, 16).
Previous careful dilation of the subcutaneous tunnel is essential for insertion without peel-away.
Catheter position
The final position of the tips of the catheter should be in the mid right atrium. For checking the proper positioning of the catheter, we routinely use EC-ECG registration. Fluoroscopy is necessary only in particular cases: previous central venous catheterization, left internal jugular vein insertion
and central venous thrombosis. After insertion, catheter function should be evaluated by placing a 10 ml syringe on each of the catheter hubs, rapidly withdrawing blood into the syringe.
The tunneling steps
Before tunneling, it is necessary to widen the incision, to perform a blunt dissection of the subcutaneous tissue, making a subcutaneous pocket, so
that the catheter anchoring hub can be embedded well and free of kinks (Figs. 19a, b, c, d).
After local anesthesia (Fig. 21), the tunneling device with the two catheters is then passed from the insertion site subcutaneously to the exit site (Figs. 22-26).
Care must be exercised to avoid damaging the catheter tips during the tunneling procedure. After insertion, catheter function should be evaluated using the so-called 搕hree T test? Check the TIP to ensure that the two tips are in the right atrium using fluoroscopy or EC-ECG, check the TOP to rule out in the unlikely event any kinks and, finally, check the TUG by placing a 20 ml syringe on each of the proximal ends of the catheter. A full 6 sec blood aspiration corresponds to a 200 ml/min flow rate. Once the flow is satisfactory, both lumens are flushed with heparinized saline. At the conclusion of the procedure, the citrate lock is applied. The catheter lumens are filled with the amount of citrate solution designated on the arterial and venous extensions. If any problems are identified, they should be corrected before the patient leaves the procedure room (Fig. 27).
COMMENTS
1. Who should insert permanent CVCs? Experienced physicians, nephrologists, surgeons or interventional radiologists.
2. Preferred insertion site of the tunneled, cuffed catheter is the right internal jugular vein. Use of the right internal jugular vein, ultrasound guidance to assist cannulation and intratrial ECG registration allows successful long-term catheter positioning without the use of fluoroscopy.
3. Fluoroscopy may not be necessary for permanent CVC insertion in patients without a history of prior catheterization or venous abnormalities.
4. The sheathless technique should significantly reduce potential problems associated with sheath/dilator insertion, such as air embolism, vessel trauma and excess bleeding.
REFERENCES
1. Work J. Chronic catheter placement. Semin Dial 2001; 14: 436-40.
2. Schwab S, Besarab A, Beathard G, Brouwer D, Etheredge E, Hartigan M, Levine M, McCann R, Sherman R, Trerotola S. NKF-DOQI clinical practice guidelines for vascular access. Am J Kidney Dis 2000; 37 (supp1 1): S169.
3. Patel A, Hofkin S, Ball D, Cohen G, Smith D. Sheathless technique of Ash Split-Cath insertion. J Vasc Interv Radiol 2001; 12: 376-8.
4. Butterly D, Schwab S. Catheter access for hemodialysis: an overview. Semin Dial2001; 14: 411-5.
5. Fox K, Roach D J, Berman SS. Central venous catheters: selection and placement. In Berman SS, ed. Vascular access in clinical practice. New York: Basel, M Dekker, Inc, 2002; 271-321.(F. Cavatorta, S. Galli1, )