# Tunneled Central Venous Catheter and Port Placement

## Types of Long-Term Central Venous Access

| Feature | Tunneled Dialysis Catheter | Hickman/Broviac | Implantable Port |
|---------|---------------------------|-----------------|------------------|
| Size | 12-16 Fr | Variable (single to triple lumen) | Single or dual lumen |
| External component | Yes (catheter exits skin) | Yes (catheter exits skin) | None (fully subcutaneous) |
| Cuff | Dacron cuff in tunnel | Dacron cuff in tunnel | None (port sutured to fascia) |
| Access method | Direct hub connection | Direct hub connection | Huber needle through skin |
| Infection rate | Moderate | Moderate | Lowest |
| Typical use | Hemodialysis | Chemo, TPN, long-term ABx | Chemo, intermittent infusions |
| Maintenance | Regular dressing changes | Regular dressing changes | Monthly flushes when not in use |
| Removal | Bedside procedure | Bedside procedure | Minor surgical procedure |

### Tunneled Dialysis Catheters

Tunneled dialysis catheters are large-bore (12-16 Fr), dual-lumen catheters designed for high-flow hemodialysis at rates of 300 to 450 mL/min. A Dacron cuff is positioned in the subcutaneous tunnel, approximately 2 to 3 cm from the skin exit site. This cuff promotes tissue ingrowth that anchors the catheter and creates a barrier against infection. Common brands include the Palindrome, Ash Split Cath, and Mahurkar. Tip designs vary among split-tip, step-tip, and symmetric tip configurations, each engineered to minimize recirculation of dialyzed blood.

### Hickman/Broviac Lines

Hickman and Broviac lines are tunneled, cuffed catheters used for long-term intravenous access -- typically for chemotherapy, total parenteral nutrition, or prolonged antibiotic courses. The Hickman catheter has a larger bore and is available in dual or triple lumen configurations, while the Broviac is smaller and often used in pediatric patients. Because both have an external catheter segment, they require regular dressing changes and cap maintenance.

### Implantable Ports (Port-a-Cath)

Implantable ports are completely subcutaneous systems consisting of a catheter connected to a reservoir (port body) implanted in a subcutaneous pocket. The port is accessed percutaneously through the skin using a non-coring Huber needle. Ports offer a lower infection rate than tunneled catheters, better cosmesis, and allow activities such as swimming and bathing. On the other hand, they require needle access for each use and necessitate a surgical procedure for both implantation and explantation. Ports come in single-lumen and dual-lumen versions, with low-profile options for slim patients and power-injectable models compatible with CT contrast administration.

## Anatomy and Access Planning

### Preferred Venous Access

The right internal jugular vein is preferred because it provides the shortest, most direct path to the SVC-RA junction. The left internal jugular vein is an acceptable alternative, though the catheter must traverse the left brachiocephalic vein, creating a longer course with potential for kinking at the venous confluence. The subclavian vein is used for ports (its cosmetic pocket location is advantageous) but should be avoided in dialysis patients because of the risk of stenosis that could compromise future arteriovenous fistula creation. The external jugular vein serves as an alternative when the IJV and subclavian are unavailable.

### Pre-Procedure Imaging

A chest radiograph should be obtained to assess for mediastinal abnormality and prior device hardware. Ultrasound confirms target vein patency, size, and compressibility. In patients with prior central lines, prior radiation, or end-stage renal disease, CT venography or MR venography should be considered to assess central venous patency. Stenotic or occluded venous segments must be identified and avoided.

## Technique

### Tunneled Dialysis Catheter Placement

The procedure begins with ultrasound-guided access to the internal jugular vein using micropuncture technique. A wire is advanced to the IVC-RA junction under fluoroscopic guidance. The tunnel length is determined by laying the catheter on the chest surface from the venotomy site to the desired exit site, typically on the anterior chest wall below the clavicle. A subcutaneous tunnel is created using a tunneling tool from the exit site to the venotomy site, and the catheter is passed through this tunnel with the Dacron cuff positioned approximately 2 cm from the exit site.

The access is upsized, and a peel-away sheath is placed. The catheter is advanced through the sheath into the SVC. The sheath is peeled away, and tip position is confirmed fluoroscopically at the cavoatrial junction. Both lumens are aspirated and flushed to confirm blood return. The exit site is secured with a suture, which is removed at 2 to 3 weeks once the cuff has incorporated into the surrounding tissue.

### Port Placement

Port placement begins with ultrasound-guided access to the IJV or subclavian vein. A subcutaneous pocket is created on the anterior chest wall, usually in the infraclavicular region over the pectoralis fascia. The pocket should be just large enough for the port body, and dissection is carried down to the pectoralis fascia for stable placement. A subcutaneous tunnel is then created from the pocket to the venotomy site, and the catheter is passed through this tunnel.

The catheter is cut to the appropriate length, measured from the venotomy to the cavoatrial junction, and connected to the port body. The connection is locked securely. The port is placed in the pocket and sutured to the pectoralis fascia to prevent flipping, a phenomenon known as Twiddler syndrome. The catheter is advanced through a peel-away sheath, and tip position is confirmed at the cavoatrial junction. The port is accessed with a Huber needle to verify function by aspiration and flushing. The pocket is closed in two layers: deep dermal and skin.

## Tip Positioning

The ideal tip position for both tunneled catheters and ports is at the cavoatrial junction (CAJ). For dialysis catheters, a tip in the right atrium is acceptable and may improve flow rates. Fluoroscopic confirmation should show the tip at or just below the carina on a PA view. For left-sided access, the operator must ensure the catheter crosses the left brachiocephalic vein smoothly without acute angulation.

## Management of Catheter Dysfunction

### Fibrin Sheath

Fibrin sheath formation is the most common cause of tunneled catheter dysfunction. A fibrin sleeve forms around the catheter, creating a one-way valve effect where the catheter can infuse but cannot aspirate, or vice versa. Treatment options include intraluminal alteplase (tPA) instillation at 2 mg per lumen with a 30 to 60 minute dwell time, fibrin sheath stripping (in which a snare catheter is advanced from a femoral venous approach to capture the catheter tip and strip the sheath by pulling the snare over the catheter surface), and catheter exchange over a wire with fibrin sheath disruption.

### Thrombotic Occlusion

Intraluminal thrombus is treated with tPA instillation. Catheter-related DVT is managed with anticoagulation, with catheter removal if the line is no longer needed or if infection is suspected. Central venous stenosis may require venoplasty or stenting.

### Catheter Malposition

Tip migration occurs when the catheter tip moves out of its ideal position, commonly into the azygos vein, contralateral brachiocephalic vein, or high SVC. This may require repositioning or exchange. Pinch-off syndrome occurs when a catheter placed through the subclavian vein is compressed between the clavicle and first rib, which can lead to catheter fracture and embolization.

### Catheter-Related Infection

Exit site infection presents with local erythema and drainage and is treated with antibiotics and local care. Tunnel infection, marked by erythema and tenderness along the tunnel tract, usually requires catheter removal. Catheter-related bloodstream infection (CRBSI) is evaluated with peripheral and catheter blood cultures. Antibiotic lock therapy may salvage some tunneled catheters, but removal is often necessary. Port pocket infection, presenting with erythema and fluctuance over the port, requires port explantation.

<image>Illustration showing the anatomy of a tunneled dialysis catheter in situ. The catheter enters the right internal jugular vein, traverses a subcutaneous tunnel across the anterior chest, with the Dacron cuff positioned 2 cm from the skin exit site. The catheter tip is shown at the cavoatrial junction. Labels identify the exit site, subcutaneous tunnel, Dacron cuff, venotomy site at the IJV, SVC, and catheter tip at the RA junction. An inset magnifies the Dacron cuff showing early tissue ingrowth.</image>

<image>Step-by-step illustration of implantable port placement. Four panels: (1) Subcutaneous pocket created over the pectoralis fascia with the port body held for size comparison; (2) Subcutaneous tunnel created from the pocket to the IJV venotomy site with catheter threaded through; (3) Port body connected to the catheter and sutured to the pectoralis fascia within the pocket; (4) Completed port with pocket closed, showing a Huber needle accessing the port through the skin, with fluoroscopic inset confirming catheter tip at the cavoatrial junction.</image>

<image>Illustration of fibrin sheath stripping technique. Three panels: (1) Femoral venous access with a snare catheter advanced to the SVC where a tunneled dialysis catheter with fibrin sheath is present; (2) The snare captures the tip of the tunneled catheter; (3) The snare is pulled distally along the catheter, stripping the fibrin sheath from the catheter surface, with debris fragments shown being cleared into the bloodstream.</image>

## Clinical Pearls

Right IJV access is preferred for all tunneled catheters and ports when possible because it offers the most direct course to the SVC. Subclavian vein access should never be used for dialysis catheters, as the risk of subclavian vein stenosis jeopardizes future AVF or AVG creation. The port body should always be sutured to the pectoralis fascia to prevent Twiddler syndrome.

A properly positioned Dacron cuff at 2 cm from the exit site reduces both infection and accidental catheter dislodgement. For catheter dysfunction, tPA instillation should be tried first before pursuing more invasive options such as fibrin sheath stripping. Tip position at the cavoatrial junction should be confirmed fluoroscopically in every case. Documentation of catheter type, tip position, tunnel trajectory, and any intraoperative issues is important for future reference and catheter management.

## References

- SIR Clinical Practice Guidelines on Tunneled Central Venous Catheter Placement, JVIR, 2021
- SIR Clinical Practice Guidelines on Implantable Port Placement, JVIR, 2019
- KDOQI Clinical Practice Guidelines for Vascular Access, NKF, 2019 update
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- Defined by ACR-SIR Practice Parameter for Radiologic Management of Central Venous Access, 2021