PMC3350231_01
Chest X-ray showing the "sheared" (black arrow) central venous catheter and the "tracheal bronchus" (white arrow).
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fig1
Upon close examination, the CVC appeared to have been sheared (Figure 1), and, incidentally, the right upper lobe bronchus arising from the trachea (tracheal bronchus).
(a) Fluoroscopic image showing the right subclavian CVC with the guidewire and the ipsilateral internal jugular CVC and (b) the undamaged CVC upon removal. CVC: central venous catheter.
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fig2
After appropriate aseptic precautions, a guidewire was gently inserted through the right subclavian CVC (suspected to have been sheared) until the J-tip was just beyond the tip of the CVC (Figure 2(a)). Examination of the withdrawn CVC showed no abnormalities whatsoever (Figure 2(b)). 
The possible mechanism of central venous catheter shear by the guidewire.
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fig3
We inserted the guidewire via the distal port of the CVC and then inserted the "J-tip" into the opening of the middle port (Figure 3(a)) and tried to pull it out through the proximal end of the distal port. We were unable to dislodge the "J-tip" from the opening of the middle port even after applying considerable traction on the guidewire, and the loop became smaller and tighter as the traction increased (Figure 3(b)). However, the CVC was not sheared even though the guidewire was damaged with application of extreme traction! We repeated the same after inserting the "J-tip" into the opening of the proximal port (Figure 3(c)).