Insertion of Central Venous Access Ports in Interventional Radiology:

A Pictorial Review of the Surgical Aspects of Port Insertion

Brian Turley, MD and Philip Johnson, MD

Insertion of central venous access ports has traditionally been performed by surgeons in the operating room. However, in recent years this procedure is being performed more commonly by interventional radiologists in the vascular procedure (angiography) suite. Two of the factors responsible for this change in practice are the introduction of new port designs intended for insertion into peripheral veins, and issues of medical cost containment in this new era of managed care. Because of their expertise in image-guided vascular catheterization techniques, interventional radiologists can perform peripheral port insertions more quickly, at considerably lower cost, and with fewer complications and catheter misplacements .

The purpose of this communication is to review the surgical aspects of peripheral port insertion. While these minor surgical techniques may be unfamiliar to some interventional radiologists, most will find them to be relatively simple and easily mastered.

The first step of the procedure is to identify a satisfactory venous entry site with a contrast study of the extremity including its central venous drainage. In the majority of cases, the basilic vein 10 to 15 cm above the antecubital fossa provides an ideal site because of the size of the vein in that location and the abundance and laxity of the overlying soft tissues. After selecting an appropriate entry site the entire arm is prepped with Betadine and sterile drapes are applied leaving the proposed entry site exposed [1]. The vein is then opacified and punctured using a 21 ga needle under fluoroscopic guidance [2]. Alternatively, the puncture may be made under sonographic guidance using a probe with a sterile cover. Following puncture an 0.018" guide wire is inserted and advanced well into the vein. The area distal to the puncture site is widely infiltrated with local anesthetic [3] and the needle is removed leaving the guide wire in place [4].

Begin preparation of the pocket by making a 2.5 to 3 cm transverse skin incision [5]. Centering the incision on the venous puncture site (guide wire) will avoid kinking the catheter once the port is in place, and will also allow the shaft strength of the catheter to resist its migration back into an overly generous pocket. Extend the incision entirely through the dermis to the subcutaneous layer which is recognizable in most patients by the presence of fatty tissue. Perform blunt dissection with a Kelly or mosquito forceps to create a subcutaneous pocket extending approximately 4 to 5 cm distally [6]. The pocket should also be undermined along the proximal margin of incision so that the guide wire is entirely free of the dermis. We find it useful to complete the blunt dissection by inserting a finger and working it down to the base of the pocket. The finger will break up any remaining fibrous connections between the skin and subcutaneous tissues while simultaneously gauging the adequacy of the pocket [7].

Check the pocket size by inserting the port [8]. A snug fit is desirable, but, if the pocket is too tight, erosion of the overlying skin may occur; if too loose, an anchoring suture will be required to prevent the port from rotating. The completed pocket should be flushed liberally with saline to remove any remaining thrombus and/or tissue debris. Next, insert a peel-away or vascular sheath over the guide wire [9], pass the catheter through the sheath, and advance it into the superior vena cava [10]. Remove the sheath and position the catheter tip at the junction of the superior vena cava and right atrium using fluoroscopy. To trim the excess catheter length, grasp the catheter between thumb and forefinger as it exits the wound [11]. The width of the fingers gripping the catheter is a good approximation of the length needed to enter the reservoir pocket. Withdraw the catheter slightly to maintain a firm grip and divide it cutting perpendicular to the catheter shaft using sharp Iris scissors.

Attach the catheter [12] to the reservoir according to the manufacturer's directions [13]. Note: Attachment mechanisms differ greatly among the various manufacturers. Always review the package insert before placing an unfamiliar port. Prior to inserting the reservoir into the pocket, access it with a Huber needle and inspect the catheter attachment for leaks by aspirating and injecting saline [14].

When the connection is satisfactory, remove the Huber needle and insert the reservoir into the pocket [15]. If required, anchoring sutures should be placed, but left untied, prior to inserting the port. During catheter attachment and insertion of the reservoir into the pocket, some of the catheter will be unavoidably withdrawn from the vein. Once the reservoir is in place, use smooth forceps to gently tease the redundant catheter back through the venotomy.

Re-access the reservoir in its pocket using a right angled Huber needle [16]. This needle will be left in place during wound closure to help stabilize the reservoir. The right angled needle presents less of an obstacle during suturing than the straight variety. Inspect the catheter attachment while injecting saline into the reservoir to ascertain that it did not become dislodged while the port was being inserted into the pocket. If the attachment is secure, proceed to wound closure.

The skin should be closed with interrupted synthetic suture material or with a resorbable subcuticular suture. We prefer a vertical mattress (everted edges) using 4-0 prolene [17]. If nonresorbable suture material is used the patient is instructed to return in 7 to 10 days for suture removal. Caution must be exercised during closure to avoid piercing the catheter with the needle. While the wound is being closed an assistant or nurse flushes the port thoroughly with saline and the system is heparinized per the manufacturer's recommendations.

If the port is to be used within the next 24 hours the access needle is capped and left in place [18]. A dry gauze dressing is placed over the site for 1 week. Avoid occlusive dressings such as Tegaderm except to secure the Huber needle in place when the port is left accessed for immediate use [19].

Although we do give prophylactic intravenous antibiotics during the procedure, we do not use antibiotic ointment on the wound. However, some authors do recommend using iodophor ointment. An Ace-wrap is placed on the arm for the first 24-48 hours to help reduce bruising. The patient is instructed to keep a clean, dry gauze over the site for one week, and to avoid immersing the extremity in water. General patient instructions are:

• No blood pressure measurements on port arm
• No blood draws from port arm (except from the port itself)
• Port to be flushed with heparin after each use and every 4 weeks when not in use