Catheters

Fractures of catheters

Fracture of a central venous catheter due to compression between the clavicle and the adjacent first rib has been reported [ ]. A “pinched-off sign” on X-ray indicates the need to remove the catheter, because of a significant risk of subsequent fracture, which has an incidence of 0.9%. Catheters lying anterior to the subclavian vein between the clavicle and the first rib are liable to be compressed and to fracture subsequently. This is a potentially life-threatening complication that can be averted by correct placing of the central venous catheter and by immediate chest radiography to search for evidence of catheter kinking or compression.

Totally implantable venous devices are being increasingly used in patients who require long-term continuous parenteral drug therapy, especially in cancer chemotherapy. Inevitably there have been complications, including catheter fracture, as a consequence of “pinched-off” syndrome [ ].

• A 67-year-old woman was provided with a totally implantable venous device in the right subclavian vein by the Seldinger technique with a peel-away sheath. The device was used for a course of chemotherapy. After about 1 month there was subcutaneous extravasation of the drug. A chest X-ray showed that the silicone catheter had fractured below the clavicle and the distal portion of the catheter had embolized into the right atrium. The fragments were removed.

This “pinched-off” effect appears to be due to narrowing of the catheter as it passes over the first rib and beneath the clavicle, when using the Seldinger technique, but it is usually only observed after long-term use. The authors recommended that the cephalic cut-down (Seldinger) technique is best avoided.

Migration of catheters

Migration of a catheter caused failure of parenteral nutrition in a baby [ ].

• A premature small-for-dates girl (34 weeks gestation, birth weight 1000 g) received parenteral nutrition for necrotizing enterocolitis. On day 7, among several septic spots that developed on the skin, an abscess developed on the left shoulder and ruptured spontaneously, leaving a superficial ulcer with purulent discharge. This was cleaned daily with isotonic saline and covered with gauze. On day 11, the blood glucose fell to 1.3 mmol/l and 10% glucose was given. Four further episodes of hypoglycemia during the next 12 hours were similarly treated. Over the next 12 hours the baby became lethargic, hypothermic, and apneic. Her blood glucose remained low (0.9–1.6 mmol/l). Several hours later she became bradycardic and hypotensive. It was then noticed that her bed linen was wet, and some fluid was seen trickling from the ulcer on her shoulder. A chest X-ray showed that the catheter tip had migrated to the left cephalic vein adjacent to the site of the ulcer. Despite attempted resuscitation she died.

The authors speculated that the catheter tip had spontaneously migrated because the ulcer on the left shoulder had eroded deeply to form a venocutaneous fistula with the left cephalic vein. Continuous leakage of parenteral nutrition fluid through the fistula was soaked up by the gauze pads used to cover the ulcer, preventing early recognition of the problem.

Observational studies

The results of a study of Dialock/CLS have been reported in 70 patients (29 men, 41 women; mean age at implantation 63 (range 30–88) years), of whom 42 had no infection (45 when infections occurring within 30 days after implantation were omitted) [ ]. Excluding these early events, 25 patients had a total of 30 infections. The majority (22 events in 20 patients) were pocket infections. The first seven of these pocket infections caused loss of the Dialock. After local treatment with gentamicin no further devices were lost through pocket infection. No infections were recorded during the last 3 months, although the expected rate calculated on the basis of previous occurrences would have been about four. This may have been related to increased nursing care.

Continuous venous access for extended periods is commonly required in patients with cancer for chemotherapy delivery. Transcutaneously tunnelled central venous lines provide one means for the administration of such therapy, although they account for significant costs and morbidity [ ]. In a prospective study, 923 central venous tunnelled catheters in 791 patients were evaluated for devise-specific events. The most important adverse events included 11 insertion complications. Subsequent to placement, a proven or suspected devise-specific complication occurred in 540 lines. For every 10 000 catheter days there were 17.6 episodes of infection, 8.1 thrombotic complications, 6.9 instances of catheter breakage, 3.5 accidental or inadvertent cases of catheter displacement, and 0.6 device leaks. The devices were in position for a median of 365 days, but the median duration of device-specific complications was 167 days, reflecting a highly significant device salvage rate after complications. The authors concluded that central lines can be placed safely for use in long-term administration of cancer chemotherapy. Factors determining outcome are related to where the device is placed as well as the patient’s disease.