AP portable chest radiograph demonstrates hyperinflated lungs and evidence of left lower lobe volume loss. An antecedent median sternotomy and mitral valve replacement has been performed. The right-sided PICC line courses from the right upper extremity into the brachiocephalic and superior vena caval systems. The PICC line then follows an anomalous course into the right atrium, across the midline via a patent foramen ovale into the left atrium with the distal tip of the catheter in the prosthetic mitral valve.
Differential Diagnosis
PICC line crossing into left atrium via other intra-atrial septal defects
Discussion
PICC Lines
As the clinical indications for and frequency of PICC insertions continue to increase, so does therecognition of anomalous line placements and complications related to their use. Between 5-32% of initial PICC line deployments are incorrectly placed. Potential explanations for PICC linemalpositioning may include aberrant venous anatomy or collateral pathways, tortuous venous pathways, venous obstruction or stenosis, previous vascular surgery, underlying neoplasia, chest wall deformity, obesity and technical errors related to incorrect measuring or trimming of the catheter itself. Anomalous PICC line placements include but are not limited to: inadvertent placement into the ipsilateral or contralateral jugular and brachiocephalic venous systems, azygos vein, right atrium, inferior vena cava, and redundant coiling in the axillae. The Association for Vascular Access (1998) Position Statement recommends that the most appropriate location for the tip of the PICC line is in the lower 1/3 of the superior vena cava in close proximity to the junction of the superior vena cava and right atrium. This case illustrates a unique but unusual example of a PICC line gaining access to the left atrium via a patent foramen ovale.
Patent Foramen Ovale
Embryologically, the foramen ovale is a “hole” normally present in the atrial septum which allows blood to freely flow from the right atrium directly to the left atrium allowing blood to bypass the developing fetal lungs. At birth, when the infant first begins to breathe, left atrial pressures increase, causing a flap of atrial tissue to impose itself over the foramen ovale, effectively closing this “hole”. Now blood flows from the right atrium directly into the right ventricle and the lungs for oxygenation. For poorly understoond reasons, in about 1 out of every 4 normal adults (25% of the population), the above described tissue flap fails to seal off the ovale or “hole”. In such circumstances, when the pressure in the right atrium becomes intermittently higher than that in the left atrium (e.g., during a cough or valsalva) the foramen ovale opens up, and once again blood can flow from the right atium directlly into the left. This is referred to as a patent foramen ovale (PFO). PFO is most often diagnosed by echocardiography with employement of a “bubble study.”
Management
PICC Line
Patent Forman Ovale
Selected Readings
www.avainfo.org/website/navdispatch.asp?id=105683
www.wales.nhs.uk/sites3/.../ComplicationmanagmentofPICCs.pdf
Torbey E, Thompson PD. Patent Foramen Ovale: Thromboembolic Structure or Incidental Finding. Conn Med 2011; 75(2): 97-105. Review
Khattab AA, Windecker S, Juni P, et al. Randomized Clinical Trial Comparing Percutaneous Closure of Patent Foramen Ovale (PFO) using the Amplatzer PFO Occluder with Medical Treatment in Patients wit Cryptogenic Embolism (PC-Trial): rationale and Design. Trials 2011; 28; 12:56.