Vascular Access

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CHAPTER 1 Vascular Access

Deborah F. Billmire

Step 1: Surgical Anatomy

♦ The six central veins include the internal jugular, subclavian, and femoral veins. In most children, these are symmetric and paired.
♦ Children with congenital heart disease, splenia syndromes, and variants of esophageal atresia have an increased incidence of anatomic variants in the subclavian veins that are relevant to central access procedures (Fig. 1-1).
♦ Children with congenital heart disease and situs abnormalities have an increased incidence of variants of the inferior vena cava that are relevant (Fig. 1-2).
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Figure 1-1

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Figure 1-2

Step 2: Preoperative Considerations

♦ What is the purpose of the access, and could therapy be achieved without central access?
♦ How long will the access be needed, and would a nontunneled or tunneled line be more appropriate?
♦ Does the patient have current evidence of infection?
♦ Does the patient have clinical indicators of coagulopathy or receive any medications that impact coagulation status?
♦ Has the patient had previous central lines that may have resulted in venous thrombosis?
♦ Can the patient be taken to the operating room so that optimal sterile conditions and fluoroscopy will be available?

Step 3: Operative Steps

1 General Concepts

♦ In general, insertion of most central lines in children is best achieved in the operating room with the patient under anesthesia and using fluoroscopy. It is not uncommon, however, to be asked to provide a central line in the emergency room or intensive care unit for an unstable patient who requires immediate access and is not stable enough for transport.
♦ In these patients, the use of bedside Doppler examination or ultrasound may be helpful in assessing position and patency of veins. This is particularly useful in children who have had multiple previous central lines. With Doppler probe, a good venous signal that varies with respiration suggests patency of the jugular and femoral systems, and the path of the signal may be mapped out using a skin marker. Good augmentation of the venous signal with compression of the leg also suggests patency of the femoral system.
♦ Bedside ultrasound may also demonstrate a patent vein that can be mapped using a skin marker or observed directly during venipuncture if a sterile probe is available.
♦ Operative records should be reviewed for information regarding previous placement of central lines.
♦ Regardless of the method or site of placement, a confirming radiographic image of the final result should be obtained.
♦ Catheter size and number of lumens should be minimized to reduce risk of thrombosis and infection.

2 Temporary Central Lines

♦ Temporary lines are inserted by percutaneous Seldinger technique directly into the vein and are generally acceptable for 2 to 3 weeks.
♦ The vein is accessed percutaneously using a thin-walled needle. After aspiration of nonpulsatile venous blood, the wire is advanced well into the vein.
♦ Fluoroscopy is done to confirm proper wire placement in the central vein.
♦ If venous blood is obtained, but the wire does not advance easily and fluoroscopy is available, contrast solution may be injected either through the needle or after replacing the needle over the wire with an angiocatheter and confirming continued ability to aspirate blood. This may demonstrate previously unrecognized thrombosis or congenital anatomic variants. If fluoroscopy is not available, repeat venipuncture, or an alternative site is needed.
♦ Once the wire has easily passed, the dilator is placed over the wire just deep enough to allow the tip of the dilator to pass through the skin and soft tissues. The wire should remain inserted well beyond the tip of the dilator.
♦ The dilator is removed, and the preflushed catheter is placed to an appropriate depth.
♦ Precautions against venous embolism should be used at all sites.
♦ Ability to aspirate blood and flush easily in all lumens should be confirmed before securing the line in place.

3 Tunneled Central Lines

♦ Tunneled lines are preferred for access anticipated to be longer than 2 to 3 weeks.
♦ These lines end as external catheters or as subcutaneous reservoirs (Fig. 1-3).
♦ Percutaneous or cutdown technique may be used.
♦ The entry site is enlarged enough to allow the catheter tubing to be brought from a separate exit site.
♦ The exit site should be chosen several centimeters away in a location that will create a smooth pathway and a convenient place for the dressing.
♦ The catheter may be either pulled through the tunnel antegrade with a blunt probe or pushed through the lumen of a Frazier tip sucker that is passed retrograde down the tunnel (Fig. 1-4).
♦ The cuff is positioned 1 cm above the exit site to allow for later removal without the need for additional incision.
♦ Once the catheter is tunneled to the exit site, it is cut to length.
♦ For percutaneous access, the peelaway or obturator sheath is advanced over the wire with fluoroscopic assistance (Fig. 1-5).
♦ The obturator and wire are removed, and the catheter is advanced down the sheath (Fig. 1-6).
♦ The sheath is peeled away, and fluoroscopy is used again to confirm the proper course and position of the catheter (Fig. 1-7).
♦ Ability to aspirate and flush the catheter is confirmed.
♦ The entry-site wound is closed with subcuticular monofilament suture.
♦ A single nonabsorbable monofilament suture is used to secure the catheter at the exit site after confirming ability to aspirate and flush all lumens.
♦ For subcutaneous reservoirs, the reservoir should be placed in a flat location and secured to the fascia.
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Figure 1-3

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Figure 1-4

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Figure 1-5

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Figure 1-6

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Figure 1-7

4 Access by Anatomic Site

Neck

♦ The available sites in the neck include the internal jugular and external veins (Fig. 1-8). The external jugular is accessed by cutdown technique and the internal jugular by either cutdown or percutaneous method.
♦ The patient is positioned with a transverse roll beneath the shoulders to achieve mild extension, and the head is turned slightly to the side opposite the planned access. Skin preparation should include the anterior chest and both sides of the neck.
♦ For all neck sites, the patient is placed in Trendelenburg position.
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Figure 1-8

External Jugular Cutdown

♦ Most usable external jugular veins are visible on inspection. The vein overlies the sternocleidomastoid muscle. A small transverse incision is made in midneck directly over the visible vein.
♦ With a minimal amount of blunt dissection, the vein is identified and fine absorbable ties are passed for proximal and distal control.
♦ When the catheter is brought through the tunnel, care is taken to ensure that the tubing enters the neck incision in a gentle arc instead of a sharp turn that will kink the catheter.
♦ The tubing is cut to length by following the expected course from the incision, to the clavicle, to the midline, and to the angle of Louis. A bevel is made to facilitate introduction into the vein.
♦ The distal ligature is tied. It is helpful to place a few drops of lidocaine on the vessel to reduce vasospasm. An anterior venotomy is made, and the catheter is threaded into the vein.
♦ Occasionally the catheter will be difficult to pass at the subclavian junction. In this situation it is often helpful to withdraw the catheter until the bevel is seen, rotate it 180 degrees, and repass the catheter.
♦ Confirmation of the catheter in the superior vena cava by fluoroscopy should be obtained, and the catheter should aspirate and flush easily.
♦ The proximal tie is ligated around the catheter and vein, and the neck wound is closed.
♦ The catheter is secured at the exit site.

Internal Jugular Cutdown

♦ Preparation and position are similar to that for external jugular cutdown. If the procedure was initiated as an external jugular and the vein is not suitable, the same incision can be extended slightly for better exposure.
♦ Blunt dissection should be carried through the sternocleidomastoid muscle. If this is done between the sternal and clavicular heads, dissection is minimized and the vein is visible just deep to the muscle.
♦ Careful blunt dissection is done to isolate the vein, and proximal and distal control is achieved using silk ties. If a visible facial branch is seen, this may be controlled and is used as the point of access to the vein. In small neonates, this branch may be too small or angled for convenient use.
♦ The catheter is drawn through the tunnel to the neck wound, taking care to make a gentle arc.
♦ The catheter length is chosen as a path directly from the incision to the angle of Louis and cut with a slight bevel.
♦ There is no need to ligate the vein in almost all patients, including small premature infants. The stay sutures are placed under traction, and a pursestring suture of 6-0 Prolene is placed on the anterior wall of the vein.
♦ A small venotomy is made, and the catheter is introduced and threaded into the vein.
♦ Fluoroscopy is done to confirm catheter position, and ability to aspirate and flush the catheter is assured.
♦ The pursestring suture is tied down securely, but ability to slide the catheter at the venotomy site is confirmed.
♦ The muscle is closed over the arc of the catheter to minimize mobility of the catheter. The subcutaneous tissue and skin are closed.
♦ The catheter is secured at the exit site.

Internal Jugular, Percutaneous

♦ In adolescent patients, it is sometimes helpful to have the patient elevate the head from the bed before anesthesia is administered. The separate heads of the sternocleidomastoid muscle are more easily seen, and the triangular space formed by their adjacent bundles is visible for marking. This can be particularly helpful when placing the larger hemodialysis catheters.
♦ The patient is positioned supine with a generous transverse roll beneath the shoulders and the neck well extended. The head is turned to the opposite side.
♦ If ultrasound or Doppler is not used, the palpable carotid pulse serves as a landmark. The needle enters the skin at the apex of the muscular triangle lateral to the pulse at a 30-degree angle from the skin and is slowly advanced while aspirating. The trajectory should follow a course aiming at the ipsilateral nipple. When venous blood is obtained, the wire is placed through the needle, and fluoroscopy is used to confirm venous position.
♦ For a tunneled line, the exit site is planned for a flat area on the anterior chest wall below the clavicle.

Subclavian Vein, Percutaneous

♦ In children, the subclavian vein is the most commonly used percutaneous access. The right side is preferable, if possible. The left side may be used if there is a recent history of infected right-side line, ventriculoperitoneal shunt, venous occlusion, or difficulty in accessing the right side.
♦ The patient is positioned supine in Trendelenburg with a transverse roll beneath the shoulder to achieve a neutral position of the shoulders. The neck is extended with the head in the midline.
♦ Skin preparation should include both sides of the chest and the neck.
♦ By palpation, the “crook” of the clavicle is identified. The needle is introduced through the skin just lateral to the crook and directed at the inferior margin of the clavicle. As soon as the needle is under the margin of the clavicle, the tip should be aimed at the sternal notch and slowly advanced using continuous suction. The trajectory of the needle should be parallel with the floor, and no pressure on the needle should be needed to maintain position (Fig. 1-9).
♦ When venous blood is obtained, the wire should be passed through the needle with fluoroscopic confirmation of venous position.
♦ If the wire passes to the opposite subclavian vein, withdraw the tip of the wire back to the ipsilateral subclavian, place a finger in the sternal notch, and press downward to distort the innominate junction and advance the wire.
♦ If the wire passes to the ipsilateral jugular, withdraw the tip back to the ipsilateral subclavian, rotate the head to the ipsilateral side, press downward with a finger at the base of the neck just medial to the sternocleidomastoid, and advance the wire.
♦ For tunneled lines, the exit site is most commonly on the anterior chest wall. For active toddlers, it is sometimes helpful to exit on the upper back by tunneling over the shoulder (Fig. 1-10).
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Figure 1-9

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Figure 1-10

Femoral Vein

♦ The femoral vein is used less often because of concerns regarding contamination in infants and toddlers and concern about kinking and obstruction in patients who are old enough to sit. It is more likely to be used in emergent situations in the intensive care unit or in patients with a coagulopathy. Access by cutdown or percutaneous technique is possible (Fig. 1-11).
♦ Femoral cutdown via the saphenous vein

image The patient is placed supine with the hips flat.
image A wide preparation is done to include both groins and the abdomen up to the umbilicus.
image A small transverse incision is made medial to the pulse 1 cm below the inguinal ligament in infants and 2 to 3 cm below the inguinal ligament in children or adolescents.
image Dissection is carried down through subcutaneous tissue to identify the saphenous vein.
image The vein is isolated and controlled proximally and distally with fine absorbable ties. Lidocaine is dripped onto the vessel to reduce spasm.
image A tunneled line of matched size is brought through a separate exit site to the incision. In most cases, it is advantageous to have the tunnel on the abdominal wall so that the exit site is above the diaper.
image The vein is ligated distally, and a small venotomy is made.
image The catheter is trimmed to length (incision to costal margin) and introduced through the venotomy.
image Fluoroscopy is used to confirm position in the inferior vena cava below the diaphragm.
image The catheter should aspirate and flush easily.
image The proximal tie is ligated around the vein and catheter.
image The incision is closed in layers with absorbable suture.
image The catheter is secured at the exit site with monofilament suture and a secure sterile dressing is applied.

♦ Percutaneous femoral access

image Puncture the skin 1 or 2 cm below the inguinal ligament and medial to the palpable pulse. The needle should be angled 30 degrees above the skin, and the trajectory should point toward the umbilicus. Advance slowly, aspirating continually until venous blood is obtained. The wire is advanced under fluoroscopic guidance into the inferior vena cava.
image The catheter is secured at the exit site with monofilament suture, and a secure sterile dressing is applied.

image

Figure 1-11

Step 4: Postoperative Care

♦ A confirming radiographic image should be done after all access procedures either with fluoroscopy or plain radiography.

Arterial Access

Radial Artery

♦ The radial artery is the most frequently accessed peripheral artery.
♦ Before cannulation, an Allen’s test should be done to confirm patency of collateral circulation. The radial and ulnar arteries are compressed simultaneously, followed by release of the ulnar compression. If the collateral circulation is adequate, the hand will become pink.
♦ The hand should be taped to a padded arm board with a roll under the wrist to aid in extension.
♦ The area is prepped with antiseptic. Using palpation of the pulse medial to the radial head or ultrasound guidance, the artery is accessed percutaneously with a 22- or 24-gauge angiocatheter, depending on the size of the patient. The catheter is advanced.
♦ The angiocatheter is secured with tape, leaving the fingers exposed for monitoring.
♦ The line should be removed as soon as it is no longer needed and should be removed promptly if there is any evidence of ischemia.

Posterior Tibial Artery

♦ The posterior tibial artery is a peripheral access site that is often used in small infants. It is palpable just posterior to the medial malleolus at the ankle.
♦ The foot is restrained on a padded armboard with a roll under the ankle and the foot in gentle plantar flexion.
♦ The area is prepared with antiseptic. Using palpation of the pulse posterior to the medial malleolus or ultrasound guidance, a 22- or 24-gauge angiocatheter is used to access the artery and is then advanced.
♦ The catheter is taped in place, leaving the toes exposed for monitoring.
♦ The line should be removed as soon as it is no longer needed and should be removed promptly if there is any evidence of ischemia.

Step 5: Pearls and Pitfalls

♦ Tunneled silicone catheters that remain intravascular but become malpositioned with the tip in the internal jugular or opposite subclavian vein in many cases may be repositioned without return to the operating room. Under fluoroscopy, a burst injection of normal saline with volume limited to 2 to 5 mL through a Luer lock syringe may “flip” the tip back to proper position in the superior vena cava. Success of this technique has been seen with catheter sizes ranging from 2.7 to 7 French.
♦ “Pinch-off sign” occurs when a subclavian catheter is inserted medially, causing compression of the catheter between the clavicle and first rib. This is visible on x-ray as a compressed segment of the catheter. It is associated with increased risk of catheter fracture with leakage or embolization.
♦ Cardiac tamponade, although rare, may occur during placement of a central line by any approach or as a delayed complication from catheter migration. Any unexplained, abrupt change in cardiopulmonary status should raise suspicion of this problem, even if the chest x-ray is unchanged.
♦ Femoral lines placed by percutaneous or cutdown technique may enter the lumbar venous plexus through the ascending lumbar veins. This may be suspected on plain x-ray by a catheter path in the midline overlying the spine and confirmed by a lateral film showing the catheter path posterior to the vertebral bodies.

Bibliography

Aitken DR, Minton JP. The “pinch-off sign”: A warning of impending problems with permanent subclavian catheters. Am J Surg. 1984;148:633-636.

Bagwell CE, Salzberg AM, Sonnino RE, et al. Potentially lethal complications of central venous catheter placement. J Pediatr Surg. 2000;35(5):709-713.

Lavandosky G, Gomez R, Montes J. Potentially lethal misplacement of femoral central venous catheters. Crit Care Med. 1996;24(5):893-896.

Mowery N, Billmire DF, Schamberger M, et al. Incidence of persistent left superior vena cava in esophageal atresia. J Pediatr Surg. 2006;41:484-486.

Singer RL, Wolfson PJ. Experience with umbilical artery cutdowns in neonates. Pediatr Surg Int. 1990;5:295-297.

Skandalakis JE. The superior and inferior venae cavae. In: Skandalakis JE, Gray SW, editors. Embryology for surgeons. 2nd ed. Baltimore: Williams & Wilkins; 1994:1032-1051.

Van Engelenburg KCA, Festen C. Cardiac tamponade: A rare but life-threatening complication of central venous catheters in children. J Pediatr Surg. 1998;33:1822-1824.

Warner BW, Ryckman FC. A simple technique to redirect malpositioned Silastic central venous catheters. J Parenter Enter Nutr. 1992;16(5):473-476. 1992

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