Do linograms aid decision making in the management of malfunctioning tunnelled central venous catheters in paediatric patients?

Abstract

• In most cases linograms add little to managing malfunctioning tunnelled CVCs. • Plain radiography will detect abnormally positioned tunnelled CVCs. • Linograms should only be performed after specialist review in a select group. Dynamic fluoroscopic imaging with contrast injection (also known as a linogram), is a commonly used imaging modality to determine tunnelled central venous catheter (tunnelled CVC) patency when malfunction is suspected; the commonest abnormality detected is an occlusive or non-occlusive fibrin sheath. If detected, some interventional radiologists can perform fibrin sheath removal, though recent studies suggest the benefit following this is short term. This study therefore aimed to evaluate whether linograms impacted upon clinical practice. Retrospective review of all tunnelled CVC linograms performed at a tertiary paediatric centre from Oct 2015–2018. The study indications, outcomes, prior investigations and subsequent tunnelled CVC management were reviewed. A total of 142 tunnelled CVC linograms were performed. Indications were: difficulties aspirating (47.1%), flushing (16.1%), suspected extravasation (19.7%) and symptoms indicating infection (21.1%). Abnormal linograms were most likely found in the presence of suspected extravasation (92.8%); infective symptoms had the lowest pickup rate (10% abnormal). 43 linograms (30.1%) were reported as abnormal and 95 (66.9%) normal. 66 patients (46.5%) underwent tunnelled CVC replacement of which 23 had a normal linogram (34.8% of lines replaced). 18 (12.7%) patients had abnormal line position identified (4.2% on a radiograph, 8.5% on linogram). Linograms are no replacement for specialist review, and in the absence of interventional fibrin sheath removal availability, they add little to the management of tunnelled CVC complications. Malpositioned tunnelled CVCs can be identified on plain radiography, and normal linograms do not remove the need for replacement. Our new protocol recommends: radiograph to check position, trialling anti-fibrinolytic therapy and review by the Vascular Access Team. Linograms are now reserved for a select group of patients: those with diagnostic uncertainty following specialist review, expected difficulty in tunnelled CVC replacement, or in circumstances where fibrin sheath removal may be a possibility, and short-term benefit favoured.