Internal jugular venous valve: Well known but mostly neglected.

Sir,

Internal jugular vein (IJV) cannulation is a very common procedure performed to obtain central venous access for various indications such as haemodynamic monitoring, administration of inotropes, total parenteral nutrition, chemotherapeutic drugs and haemodialysis. However, the procedure involves numerous complications such as arterial puncture, pneumothorax and malpositioning of the catheter tip.[1] Among all complications, malpositioning has the reported incidence ranging from <1% to >60%.[2] Although ultrasound, electrocardiogram guidance and real-time X-ray imaging have dramatically reduced the incidence of malposition of needles, guidewires and catheters, significant number of catheter misplacements can still occur.

We report a case of misdirection of a central venous pressure (CVP) catheter in a 43-year-old male who was brought to the casualty in shock due to severe sepsis. After resuscitation, in view of CVP monitoring and inotropes infusion, a 7 Fr triple lumen central venous catheter was inserted via right IJV under ultrasound guidance and the catheter was fixed at 13 cm. After connecting the transducer to the monitor, there were normal CVP waveform and free aspiration of the venous blood. However, the chest X-ray revealed that the catheter had rotated 180° at clavicle level and directed upward [Figure 1a]. Subsequent ultrasound of the neck showed bicuspid valve in the IJV at the level of clavicle which was missed during the procedure which prevented the entry of guidewire into right brachiocephalic vein [Figure 1b].

Figure 1

(a) Chest X-ray anteroposterior view showing malpositioned central venous pressure catheter, (b) ultrasound of the neck showing internal jugular venous valve

Although there are many reports concerning the presence and clinical significance of competent jugular venous valves, many physicians are still unaware of the presence of the valves in the IJV. Harvey had mentioned that edges of the valves in the jugular veins hang downward and prevent blood from rising upward.[3] In an autopsy study done by Furukawa et al., it was found that 96.7% of the cases had bilateral IJV valve, and position of 53.4% valves was directly posterior to the clavicle, in which 72% of the valves were bicuspid[3] such as in our case. This valve prevents a sudden increase in the IJV pressure during coughing or positive pressure ventilation and may thus protect the brain from an acute increase in intra-thoracic pressure.[4] Functional or morphological incompetence or absence of the IJV valves may cause cough headache, cerebral morbidity after positive end-expiratory pressure ventilation and some types of cerebrovascular diseases.[5] The presence of valve can lead to various complications during IJV cannulation. As the IJV valve may be situated slightly above the clavicle at the base of the neck, Imai et al. raised the concern that the valve may be injured in clinical situations when the IJV is cannulated at the lower neck for the insertion of a central venous catheter and can lead to incompetency of the valve.[6]

In our case, the central venous catheter got rotated through 180° and turned upward probably because of the resistance due to a bicuspid valve which was missed during cannulation. Hence, it becomes necessary to trace the catheter tip using ultrasound during cannulation to avoid such complications. It is hard to diagnose a malpositioned catheter using clinical methods as the CVP tracing and backflow of blood remain normal. There are also chances of misinterpretation of CVP as the catheter tip is far away from its usual position, i.e., at the junction of superior vena cava and right heart.

Hence, we suggest that whenever possible, ultrasound should be used before cannulation for identification of the vein and presence of valves during cannulation to confirm the catheter position and after the procedure to rule out malposition of the catheter tip.

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Conflicts of interest

There are no conflicts of interest.