Main

Sir,

Intraoperative central venous cannulation permits rapid administration of intravenous fluids and assessment of changes in intravascular volume. The right internal jugular vein has several advantages as a cannulation site, having a predictable anatomy, a high success rate in adults and children, and being easily accessible.1 Complications of cannulation at this site include air embolism, pneumothorax, and brachial plexus damage. The most common complication is haematoma formation, which can result from puncture of the carotid artery.2 Horner's syndrome has rarely been described as a complication. We present a case of Horner's syndrome following unsuccessful internal jugular cannulation and successful external jugular venous cannulation.

Case report

A 6-year-old girl was admitted for debridement of wounds under general anaesthesia. Sites for venous access were limited as she previously had bilateral below-knee and below-elbow amputations following meningococcal septicaemia. Intraoperatively right internal jugular vein cannulation was not successful. Access was gained to the right external jugular vein. In the recovery ward, the patient's mother immediately noticed a right ptosis and a ‘large left pupil’. On returning to the ward, the patient was reported to have a ‘large left pupil’ by medical staff. The child had not complained of headache or severe neck discomfort. Questioning and the patient records revealed that the patient had a history of strabismic ambylopia. No signs suggestive of Horner's syndrome had been noticed previously at the ophthalmic clinic or by the patient's mother. On ophthalmic examination, a right-sided ptosis and miosis were noted. Pupils were both reactive to light and there was a full range of eye movements. The anisocoria was noted to be greater in the dark. No heterochromia iridis was present. A diagnosis of right Horner's syndrome was made. There were no localising signs other than the presence of the external jugular venous cannula. Ultrasound scan 1 day later of right-sided neck vessels revealed no evidence of carotid dissection or haematoma. After 18 days, the anisocoria and ptosis had improved.(Figure 1, Figure 2)

Figure 1
figure 1

External jugular venous line in situ, day 3 post-operately.

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Figure 2
figure 2

Ultrasound scan of right neck vessels; no arterial dissection or haematoma evident.

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Comment

Horner's syndrome results from interruption of the normal sympathetic nervous supply to the eye. The sympathetic nervous supply to the eye originates in the hypothalamus, and during its course passes up the cervical part of the sympathetic trunk. The sympathetic trunk is embedded in the carotid sheath, a condensation of deep cervical fascia. The internal jugular vein, common and internal carotid arteries, and the vagus nerve are also found in the carotid sheath. Normally, the internal jugular vein lies lateral to the internal carotid artery. The external jugular vein descends obliquely across the superficial aspect of the sternocleidomastoid muscle and pierces the deep cervical fascia just above the clavicle to enter the subclavian vein.3 The cervical sympathetic trunk normally lies medial to the internal jugular vein, and therefore a needle should not normally encounter the sympathetic trunk en route to the vein. It has been suggested that damage to the sympathetic trunk can occur during internal jugular venous cannulation caused by excess rotation of the head and neck, which disturbs the normal anatomical relation.4 The ansa subclavia is the most anterior nerve bundle of those connecting the middle and inferior cervical ganglia of the sympathetic chain and is said to be a direct posterior relation of the internal jugular vein around the level of the cricoid cartilage. Haematoma can damage the ansa subclavia.5 Haematoma could also compromise the blood supply to the superior cervical ganglion.6 However, ultrasound in this case provided no evidence for haematoma formation. The needle may, therefore, have directly traumatised the sympathetic trunk. In the present case, internal jugular venous cannulation was unsuccessful. This may suggest that either abnormal anatomical relations were present or that there was a greater than normal degree of exploration of the region with the tip of the cannula during attempted cannulation. In previous reports on Horner's syndrome following internal jugular venous cannulation in adults, there were several attempts to place the line incorrectly.7,8

Conclusion

If difficulties are encountered during internal jugular venous cannulation in children, the possibility of abnormal anatomical relation should be borne in mind, and the degree of excursion of the tip of the cannula minimised. Horner's syndrome resulting from direct trauma to the sympathetic chain, as seems the likely aetiology in the present case, may recover spontaneously. Conversely, acute ipsilateral Horner's syndrome, particularly in postoperative or intensive care patients in whom pupils are observed to assess neurological function, may be due to recent attempts at internal jugular venous cannulation, even if an internal jugular venous line is not present.