Unexpected course of left leg percutaneous silastic catheters

Three cases of unrecognised, malpositioned saphenous vein percutaneous silastic catheters (PSCs) were identified among 21 saphenous vein PSCs placed over a 13 month period in one neonatal intensive care unit. All had been inserted in the left leg, and the inserting practitioner failed to identify malpositioning of the PSC tip on a frontal abdominal view obtained with contrast (fig 1A). Radiologists later identified the probable abnormal position based on the course of the PSC, and lateral views of the abdomen on the same day of insertion showed the superficial position of the catheter tip in the anterior abdominal wall (fig 1B).

Figure 1 (A) Frontal abdominal view of malpositioned saphenous vein percutaneous silastic catheter inserted in the left leg. (B) Lateral views of the abdomen on the day of insertion showing the superficial position of the tip in the anterior abdominal wall of the catheter shown in (A) (C) Frontal abdominal view of an appropriately positioned catheter.

A literature review showed that most of the reported serious complications secondary to malpositioning of saphenous lines occurred with a PSC inserted via the left leg.1,2,3,4,5,6 Chen et al1 reported one new and three previously reported cases of paraplegia secondary to tracking of a PSC into the lumbar venous plexus from a left saphenous vein. Odaibo et al2 and Kelly et al3 reported serious neurological and respiratory complications in preterm infants from parenteral nutrition fluid in the cerebrospinal fluid via left leg PSCs. Baker and Imong4 reported abdominal wall necrosis as a complication of PSC via a left saphenous vein with the tip in a superficial abdominal vessel, and Coit and Kamitsuka5 reported similar findings, but had one case from a right leg, as did Cartwright .6

Healthcare providers need to be aware of the expected projection of a normally placed saphenous PSC. The appropriate course of the left leg PSC line passes from the left femoral and iliac veins, gradually ascending and becoming more medial until joining the inferior vena cava over the right to mid spine at the L5 or L4 level. It then ascends over the right side of the spine or slightly to the right of the spine (fig 1C). Lines that end below the L5 level are not likely to be in the inferior vena cava. Lines that ascend to the left of the spine may be in an anomalous inferior vena cava but may be in a vertebral vein, in an anterior abdominal wall vessel, in the aorta, or extravascular.

We believe that tracking of the PSC line into an anterior abdominal wall vein can be subtle on the frontal abdominal radiograph, and serious catheter malposition related complications can be prevented by careful comparison with the expected course on the anterior‐posterior projection (fig 1C). If uncertain, a lateral abdominal radiograph to verify the catheter course and tip location is needed.