Vascular Access

Abstract

For the busy pediatric surgeon, vascular access issues arise frequently and often unexpectedly. One should be technically proficient and familiar with the various venous access options, indications, and complications.

Appendices

Summary Points

Expertise in establishing peripheral IV access is a useful skill.

The umbilical vein access is a reliable route that can provide excellent venous access for up to 10 days.

The peripherally inserted central catheter (PICC) is ideal for short-term, central venous access for antibiotics or parenteral nutrition.

The gold standard for insertion of percutaneous central lines has always been guidance by surface anatomy landmarks. The subclavian, internal jugular, and femoral venous approaches account for the majority of central line insertions.

In some institutions the most commonly placed line is the cuffed tunneled central line.

The subcutaneous venous access port is associated with high quality of life scores: the infection rate is generally lower than for tunneled catheters, but once infected the infection is more difficult to clear.

Differential Diagnosis

• Long-term access for parenteral nutrition

• Chemotherapy

• Ongoing need for blood component therapy

• Plasmaphoresis/hemodialysis

• Need for frequent blood sampling

Parental Preparation

Complications of central venous access include infection, bleeding, arrhythmia, injury to adjacent structures (artery, nerve, thoracic duct), infection, thrombosis, pulmonary embolism, and pneumothorax.

Life-threatening complications are rare but not unheard of.

Editor’s Comment

Pediatric surgeons have traditionally been considered the ultimate experts in securing all forms of vascular access in children, a role partially usurped of late by interventional radiologists and the nurse IV specialist. Nevertheless, the pediatric should strive to be the “go-to” person for difficult vascular access, including percutaneous, incisional, and rare surgical techniques. This comes with several important responsibilities: availability at all hours; a genuine willingness to accommodate the needs of the child and their caregivers; the technical proficiency to provide even difficult access safely and efficiently; and meticulous attention to every detail of the insertion technique, dressings, and postoperative use and care of the line. It is important to approach each line in every patient as a true life line and one that, if it becomes infected or stops working, can make for a miserable or dangerous situation.

Percutaneous access to central veins is a veritable art form that experienced surgeons are able to perform safely on the basis of anatomic landmarks alone; however, there are increasing calls from others, primarily regulatory outsiders, but also skeptical colleagues in Radiology and Anesthesiology, who assume that this “blind” approach is inherently unsafe and feel that every one of these procedures should be done with ultrasound guidance. The femoral approach is not nearly as straightforward in children as it is in adults. The femoral vein lies close to and somewhat behind the artery, increasing the risk of arterial injury. Before a large cannula is placed, absolute confirmation that the guide wire is in the vein is essential – femoral artery injury can cause limb ischemia and not infrequently results in leg amputation. Femoral venous catheters are also associated with an increased risk of thromboembolic complications, infection, catheter malfunction, and activity restriction and should therefore be considered the access of last resort.

A cutdown approach to any vein is generally avoidable except in an emergency or when image guidance is unavailable. Most children have four good choices for percutaneous central venous access in the neck and chest: the internal jugular and subclavian veins. The entire anterior neck and chest should routinely be sterilely prepared when placing a central line so that all are available every time. The right internal jugular vein is the best choice in small children as the risk of subclavian thrombosis is relatively high and could become an issue in adulthood should the patient be at high risk for renal insufficiency and require a shunt. The safest approach is between the two heads of the sternocleidomastoid muscle: the vein is surprisingly superficial and can be entered with the needle at nearly a right angle to the skin. Carotid artery injury is rare, but in children the subclavian artery tends to arch up into the neck above the clavicle, placing it at risk of injury. The catheter should then be tunneled below the platysma and in such a way that all turns are smooth and without kinks. The catheter tip should ideally be at the cavo-atrial junction, which looks like the uppermost portion of the atrium on X-ray. This point is usually within two vertebral bodies below the carina and can be measured relative to the guide wire under fluoroscopy or on the basis of superficial landmarks (nipple, third intercostal space), which are notoriously inaccurate. Another option is to err on the long side and check length while the peel-away sheath is still in place. This way the catheter can be retrieved, trimmed, and placed back through the sheath. The neck incision is closed with a deep-dermal absorbable stitch and cyanoacrylate skin adhesive. The cuff of the catheter should be placed within 2 cm of the chest incision but it is better to pull it up higher and then bring it down to its proper location so that it is being held back by the fibrous septae in the subcutaneous fat. This helps to prevent accidental dislodgement before the cuff sets.

The subclavian vein is easily identified in most children but the window for safe access is relatively small: lateral to the intersection of the clavicle and first rib but medial to where the subclavian artery is at risk for injury. The best place is usually just lateral to the palpable first rib, with the needle aimed just above the sternal notch. No shoulder roll, or at most a very small one that only slightly exaggerates the normal anatomy, is best. In infants and small children, the arms can be pulled gently downward with hypoallergenic tape to the diaper or lower extremities. The anterior aspect of the shoulder should be left exposed, allowing the needle to travel in a plane parallel to the chest wall without the hub getting caught in the drapes. Pneumothorax should be rare if the tip of the needle passes close to the clavicle and the shaft of the needle is parallel to the chest. Catching the periostium of the clavicle is a well-known complication that should be avoided. Again, the catheter should be tunneled below the platysma (which extends down onto the upper chest) so that the catheter is not too close to the skin where it can be punctured with a suture needle or erode through the skin. Ports should be placed on the upper chest, medial for boys, slightly more lateral for girls, and always in the space between the Scarpa fascia and the pectoralis fascia – too superficial and skin erosion is a problem, too deep and the port is in the muscle.

As PICC lines become ever more popular, placement of the tunneled line in the premature newborn is a dying art. The procedure must often be completed without an assistant. Gather all instruments and disposables ahead of time and always use strict aseptic technique. The patient must be intubated, sedated, and immobilized. Percutaneous access to the subclavian vein is possible in infants more than 1,500 g but very difficult in smaller infants. The external jugular vein is unreliable due to its acute angle of insertion into the internal jugular in more than half of infants and is best avoided. The facial vein is ideal but not always easily identified. An incision placed in the uppermost skin crease just posterior and inferior to the angle of the mandible will usually reveal the vein, but if not present, the internal jugular is easily found a little deeper. Avoiding injury to the vagus nerve, control the IJV proximally and distally but do not ligate it. After tunneling a 2.7 F silastic catheter and cutting it to length with a sharp tapered point, create a venotomy with 19-gauge needle and the catheter should slide right in without back-bleeding. If fluoroscopy is not available, the catheters must be confirmed to be central by plain x-ray and then repositioned if not in the right position.