Long-term venous access

The use of multidrug chemotherapy and bone marrow transplantation in cancer treatment has made the utilization of reliable, long-term venous access (LTVA) an essential component of cancer therapy. The placement of LTVA devices not only permits the delivery of these complex therapeutic regimens but also drastically improves patients’ quality of life.

Indications

No definitive guidelines are available for utilization of central venous access. There are several important factors to consider when deciding upon LTVA device placement:

• the frequency and duration of therapy
• the frequency of blood draws
• the nature of therapy (eg, delivering vesicating agents into a central vein decreases the risk of extravasation)
• the need for supportive therapies (eg, total parenteral nutrition or systemic antibiotics)
• the need for stem-cell collection, plasmapheresis, and bone marrow reinfusion
• patient preference.

Patient selection

LTVA should always be considered an elective procedure. Therefore, before an LTVA device is placed, the patient should have recovered from acute infections and the treatment of complications. If there is an absolute need for immediate central venous access before such times, a temporary percutaneous central venous access catheter can be placed. A history of vascular access catheter insertion, deep venous thrombosis of an upper extremity or central vein, thoracic surgery, neck surgery, irradiation, or mediastinal and thoracic disease should alert the surgeon to possible changes in normal venous drainage.

Physical examination, documenting the integrity of the skin, changes in the skin secondary to previous surgical treatment and reconstruction, sites of previous central venous access catheter insertions, evidence of venous obstruction (presence of venous collaterals in the skin of the chest, unilateral arm swelling, or superior vena cava syndrome), and pulmonary reserve, should be performed in every patient. If there is any evidence of venous obstruction or a history of multiple central venous access catheters, the physical examination should be complemented with a formal venous imaging study.

Duplex Doppler ultrasonography can visualize the patency and flow of the neck and arm veins. Intrathoracic veins and the right atrium are not well visualized by duplex Doppler ultrasonography but are better visualized with transesophageal echocardiography. This can be utilized preoperatively or intraoperatively.

CT and MRI are useful for documenting the presence of thrombosis and the patency of major intrathoracic veins.

Venography is still the gold standard for studying venous anatomy. Venography should be performed whenever the clinical situation warrants it and noninvasive venous imaging studies fail to provide a definitive diagnosis. This can be utilized preoperatively or intraoperatively.

Chest radiography can disclose important information (such as the presence of pleural effusions, lung metastases, mediastinal adenopathy, and mediastinal tumors) that can modify selection of a site for LTVA placement.

Contraindications and precautions

Neutropenia A neutrophil count < 1,000/mm³ is a relative contraindication to the placement of an LTVA device, since patients with neutropenia may have a higher incidence of septic episodes. The use of prophylactic antibiotics may reduce the incidence of infection in patients with a low absolute neutrophil count (ANC).

Thrombocytopenia and platelet dysfunction are frequently encountered in the cancer patient. Preoperative platelet transfusion to approximately 50,000/mL may allow the catheter to be safely placed with a reduction in the risk of bleeding complications. In those patients with thrombocytopenia refractory to platelet transfusions, venous cutdown may be a safer approach for catheter placement.

Clotting factor abnormalities Many cancer patients have abnormalities in their clotting factors secondary to malnutrition or chemotherapy. Correction with vitamin K or fresh frozen plasma may be necessary.

Active infection The presence of an active infection represents an absolute contraindication to the placement of an LTVA device. In those patients with an active infection who require long-term antibiotic treatment, a temporary central venous access catheter or a peripherally inserted central venous catheter is preferable.

LTVA device selection

Two types of LTVA devices are available. There are tunneled external catheters that have skin surface access (Hickman, Broviac, Groshong, Quinton). Likewise, there are subcutaneous implanted ports (Port-A-Cath, Infusaport). Both types of central venous access devices are available with different lumen diameters and numbers. Peripherally placed central venous access devices, such as the PAS (peripherally accessed system) port or PICC (peripherally inserted central catheter), have become popular because of their ease of placement. PICC devices can be placed by specially trained nursing personnel. Important differences between tunneled external catheters and subcutaneous implanted ports are outlined in Table 1.

General considerations An important general consideration in the selection of an appropriate LTVA device is that the infusion flow resistance depends on the catheter length and lumen diameter. Likewise, catheters with a split valve at the tip (Groshong catheter) are less reliable for blood drawing.