King Edward Memorial Hospital - Departments: Radiology

A three year-old-boy, a known case of Non-Hodgkin's Lymphoma was on chemotherapy since three months. The chemotherapy was given through a Hickmann's catheter via the transjugular route. While injecting the chemotherapeutic agent for the second cycle through the catheter, there was extravasation of the drug in the subcutaneous tract. A radiograph of the chest including the lower neck done to evaluate the status of the catheter position revealed the broken distal tip of the catheter to be in left pulmonary trunk (Fig.1).

Fig 1

The child was referred to us for percutaneous transvascular retrieval of the broken catheter fragment from pulmonary trunk. Under fluoroscopy, the mobile fragment was seen to be migrating from right to left pulmonary trunk and vice a versa. The cannulation of the main pulmonary trunk was done with 4F head hunter catheter through the right transfemoral vein route .A 2.5F basket retriever catheter was introduced co -axially through the head hunter catheter into the right pulmonary artery. The fragment was engaged in the basket after repeated attempts. (Fig. 2) This fragment was securely held and withdrawn under fluoroscopy guidance. (Fig. 3) Final percutaneous retrieval was done without a venotomy after removal of the sheath (Fig 4)


Fig 2	Fig 3

Fig 4

DISCUSSION

Percutaneous retrieval of an intravascular foreign body is a standard method of treatment that obviates the need for major surgical procedures. Although intravascular foreign bodies do embolize in the aorta and some arterial branches, it is most frequently seen in the venous and right heart system.

Centrally positioned venous catheters are often placed for providing the venous access for administration of hypertonic intravenous alimentation fluid, long term antibiotic therapy, pressure monitoring and as a route for cancer chemotherapeutic agents in pediatric patients.

Fracture of these catheters with migration of fragments into the vena cava or its tributaries, right heart, or pulmonary artery is an unpredictable and potentially serious complication. The final position of the fragment within the cardiovascular system depends on a number of factors. - The route of entry and (if migratory) on gravity and position of the patient at the time of the accident, the length and stiffness of the material and the flow patterns of the vessel or cardiac chamber containing it. These are associated with complications such as infection, pulmonary abscess, dysrhythmias leading to sudden death; thrombosis with superior vena cava syndrome, erosions in contiguous structures and right atrial perforation.

A number of retrieval techniques to remove the intravascular foreign bodies have been described.

(a) Loop snare technique - This is done with a guide wire like device folded in half at its midsection and inserted through the catheter .It is flexible, loop size is easily changed, and percutaneous removal without cut down and venotomy is frequently possible.

(b) Helical basket technique -This is particularly useful in children, since they have the smallest outside diameter of all devices. They have an advantage in retrieval of fragments within smaller vessel, since the spiral struts would fill the vessel wall to wall and simplify fragment entrapment.

(c) Hook-tip guidewire or catheters technique - It can be formed ad hoc and used to engage lengths of intravascular debris lacking an accessible free end. Tip -deflector guide systems can be useful, although final removal from vein of access has usually required a cut down and venotomy.

(d) Grasping foreceps technique - Bronchoscopic forceps are of limited value because of their rigidity and shorter length and carry considerable risk of perforation.

(e) Balloon catheters technique - Simple balloon tipped catheters can be used percutaneously to move intravascular foreign bodies into more favourable positions for conventional catheter recovery. Balloons can also be used to prevent undesired distal embolization of foreign bodies during their recovery from pulmonary or systemic arteries.

The complication rate is remarkably low. Distal embolisation, transient arrhythmias are reported complications associated with percutaneous retrieval.

Percutaneous intravasular forgein body retrieval is relatively simple, safe, with few possible complications in comparison with the surgical procedure and should be attempted before surgery.