[MIRS-IR Vol II:5; 8/20/98]

Endovascular Retrieval of a Central Venous Catheter Fragment

Todd Bostwick, MD

Introduction
Central venous catheters are used extensively for chemotherapy, parenteral nutrition, and long term antibiotics. A potential complication with the use of central venous catheters is fracture or breakage of the catheter with the intravascular fragment migrating centrally as a foreign body embolus. It has been variously estimated that this complication occurs with a frequency of approximately 1/1000-2/1000 (1). Most often the intravascular fragment becomes lodged within the right heart where it may produce an arrhythmia or compromise a valve. Less frequently, the intravascular fragment lodges more distally within a pulmonary artery with the risk of causing a pulmonary infarction.

There are several endovascular techniques available for retrieving intravascular foreign bodies including endovascular forceps and retrieval baskets similar to those used in the biliary system and urinary tract. However, the most commonly used devise for intravascular catheter fragment retrieval is an endovascular snare introduced via a catheter as originally described by Curry (2). Although forceps can be used to engage any portion of the fragment, they are difficult to control under fluoroscopic guidance and they may produce significant vascular injury. Snares and baskets have an advantage in that when opened they fill the cross section of the vessel, but these devices, particularly snares, require that one end of the catheter fragment be free in the vessel. While forceps may have a tenuous grasp, snares and baskets have the ability to firmly grasp and secure the catheter fragment allowing it to be pulled out through the percutaneous access site without the need for a cut down onto the peripheral vessel into which the fragment has been withdrawn.

This report describes a case where a twelve-centimeter long catheter fragment impacted within the left pulmonary artery was initially freed using a pigtail catheter and subsequently removed through the right femoral vein using a snare technique.

Case Presentation
The patient is a 41-year-old female with breast cancer and an indwelling right subclavian Infuse-A-Port catheter which had been in place approximately one year. Apart from a weekly flushing with normal saline the catheter had been unused since completion of her last course of chemotherapy three months previously. A routine chest radiograph revealed a twelve-centimeter long fragment of the distal central venous catheter had broken off and become lodged within the left pulmonary artery with the fragment straddling the left upper and lower pulmonary arteries (figure 1). The patient was asymptomatic but recalled an episode of rapid, bounding, irregular heart palpitations lasting for two days approximately one month earlier. Routine flushing of the catheter on the day of presentation was accompanied by burning and discomfort in the right shoulder. No blood could be aspirated from the port, but this had been the case for over a month.

The patient was referred to our service for intravascular retrieval of the catheter fragment as it represented a potential nidus for thrombus formation or infection. There was also concern that the fragment would cause a significant pulmonary infarct if clot formed around it or if the fragment migrated more distally.

Procedure
The patient's right femoral vein was percutaneously accessed using a micropuncture technique. An 8 Fr 80 centimeter length braided sheath (Arrow) was then advanced into the right atrium over a guide wire. A 100 centimeter long 5 Fr Glidecath (Medi-tech) and Bentson guide wire (Cook) were introduced through the sheath and manipulated through the right heart into the left main pulmonary artery. The sheath was then advanced over the Glidecath into the left main pulmonary artery. The Glidecath was then exchanged for a 10 mm Amplatz snare (Microvena). Attempts to snare the inferior aspect of the catheter fragment within the descending left pulmonary artery were unsuccessful as the tip of the catheter fragment was impacted in the vessel (figure 2). The snare was manipulated to the superior tip of the catheter, but it too was impacted and a similar problem was encountered. Therefore, the snare was exchanged for a 6 Fr pigtail catheter (Cook). The pigtail was formed around the mid-point of the catheter fragment and fixed using a deflector wire (Cook) (figure 3). The pigtail catheter was then withdrawn over the entwined catheter fragment, freeing the superior end of the fragment and repositioning it into the left main pulmonary artery. With a tip of the fragment now accessible, the pigtail catheter was exchanged for the 10 mm Amplatz snare and the catheter fragment was easily captured (figure 4).

The snare with the secured catheter fragment was withdrawn through the tricuspid valve, right atrium, and into the IVC. At this point the snare and captured catheter fragment were advanced into the right subclavian vein and the snare repositioned near the middle of the catheter. This was done in case the captured catheter fragment should break during manipulation and removal. Positioning the snare in the middle reduced the risk of a new fracture producing an embolic fragment too small to recapture. The snare and captured catheter fragment were then withdrawn into the right femoral vein. A Bentson wire was placed in side-by-side fashion through the sheath and passed into the IVC as a safety wire (figure 5). The vascular sheath and snared catheter fragment were then withdrawn as a unit out through the skin of the right groin (figure 6). Fluoroscopic examination of the IVC, heart and pulmonary arteries revealed no residual or additional catheter fragments. The Bentson wire was then removed and hemostasis obtained with manual pressure. The patient was awake throughout the procedure and required only local anesthetic at the groin puncture site and minimal sedation (Versed 1 mg. IV) at the start of the procedure. The entire procedure, from the initial access of the femoral vein to extraction of the fragment through the skin, was twenty-one minutes in duration.

Discussion
Several minimally invasive endovascular retrieval techniques can be used to recover intravascular fragments from fractured or broken central venous catheters. The most commonly used technique involves using an intravascular snare to capture and secure the catheter fragment. The snare has the advantage of being able to secure the captured fragment tightly enough that it can be removed through the percutaneous access site without the need of a cut-down. However, a disadvantage of the snare is that at least one end of the catheter must be free and accessible to the snare loop. This case required the initial use of a pigtail catheter to manipulate the fragment into a favorable position that facilitated subsequent capture and removal. Since the captured fragment is doubled over in the snare, its cross section is often larger than the internal diameter of the vascular sheath. Consequently, it is frequently necessary to remove the catheter fragment and sheath as a unit. However, such fragments may be quite brittle and subject to additional breakage when tension is applied to the snare. Therefore, it is generally advisable to place a safety wire to secure access in the event of fragmentation and embolization during removal.