Introduction

A false aneurysm (or pseudoaneurysm) is a breach in the vascular wall leading to an extravascular haematoma that freely communicates with the intravascular space. This is in contrast to a true aneurysm which is bounded by all the layers of the vessel wall.

A pseudoaneurysm may arise as a result of an adjacent infective process, injury to the arterial wall or septic embolisation from a distant source. ₁ Many cases of pseudoaneurysms due to tuberculosis have been reported. Some arising from the Aorta (Thoracic and Abdominal), some from the femoral and only a few cases arising in the carotid system. ₂,₃,₄,₅,₆ It has been agreed that tuberculous aneurysms are extremely rare ₇ and even more so when relating to the carotid system.

Case Report

A fifty one year old male presented with a swelling on the right side of the neck with a sinus just below it, discharging serosanguinous fluid for the previous three days. The patient's medical history dates back three years when he was diagnosed with sputum positive pulmonary tuberculosis and was started on anti tuberculous therapy (CATEGORY 1, DOTS) ₈ but he defaulted after two months. Two years ago he noticed a swelling on the right side of his neck which after a while developed a sinus discharging serous fluid. Two weeks back, he became febrile on and off and along with that he noticed that the sinus was discharging a serosanguinous fluid. There was no evident history suggestive of any upper aero digestive tract malignancy. Patient was a known smoker and alcoholic. He was also hypertensive but was not on any regular treatment.

On examination, he was pale and ill nourished. There was a 4x3 cm swelling on the right side of his neck over the upper one third of the sternocleidomastoid suggestive of a lymph node mass. The swelling was non pulsatile. The skin over the swelling revealed a sinus with exuberant granulation tissue. There were no other swellings in the neck or elsewhere. Other systems were within normal limits.

We admitted the patient for evaluation after which he had an episode of bleeding from the sinus of about 25 ml. A vascular etiology was thought of and a Doppler study of the neck revealed a pseudoaneurysm of the common carotid artery extending superficially to the skin surface, with a thrombus in the lateral wall.

Within minutes of the procedure there was a torrential bleeding from the site of the sinus. The bleeding was controlled by compression, and patient resuscitated by using plasma expanders and blood transfusion. After stabilising the patient hemodynamically, he was taken for an emergency CT Angiogram which confirmed the diagnosis but placed the aneurysm distal to the bifurcation of the Common Carotid artery at the Internal Carotid artery.

Figure 1

Figure 1: CT Angiogram demonstrating the aneurysm and the site of leak.

He was shifted immediately to the operating room as he developed a rebleed from the sinus. The neck was explored under general anaesthesia with a longitudinal incision along the anterior border of the sternocleidomastoid. The field was obscured by continuous bleed from the aneurysm which stopped once the Common Carotid was clamped. Diffuse bloody ooze was seen from the edematous tissues around the aneurysm. The common carotid, internal and external carotid were dissected and looped above and below the mass. The neck of the aneurysm or the carotid bifurcation could not be dissected due to dense adhesions of the mass at the site. As it was impossible to repair the aneurysm, we interrupted its flow by ligating the ICA (at the neck of the aneurysm). Ligation has been reported as an effective treatment for ruptured carotid aneurysms. ₃ Multiple 1x1 cm lymph nodes were found in the field which were sampled and sent for histopathology. Seven units of whole blood and 5 units of fresh frozen plasma and platelets were transfused. Post operatively there were no neurological deficits but the patient developed pneumonia from which he recovered. He was kept in intensive care for five days. His blood pressure was high and was controlled with Metaprolol and Nimodipine. Histopathology of lymph nodes showed evidence of tuberculosis. The patient was started on anti tubercular treatment. The patient was followed up and is in good health.

Figure 2

Figure 2: Post operative photograph following suture removal. The sinus can be visualised clearly.

Discussion

Tuberculosis, with an aneurysm of the carotid artery, has, in the previous reported cases, presented with a pulsatile neck swelling. ₂ This particular case in which a sinus resulting from tuberculous lymphadenopathy that extended to involve the surrounding arteries and weakened the walls is probably the first such reported incident. The serosanguinous discharge with which the patient came to us was first interpreted as coming from the wall of the sinus due to granulation tissue formation.

The first instance of bleeding led us to suspect a vascular etiology and before an elective line of management could be formulated we were faced with an emergency. In carotid aneurysms due to other causes, the elective line of management includes exclusion of the diseased segment of the vessel with interposition of a prosthetic graft. In cases of ruptured carotid aneurysms reported earlier, ligation of the carotid has been the treatment of choice. ₃ There have been a few instances of hemiplegia, unilateral loss of vision or aphasia, but the Circle of Willis was intact and the collaterals took over in this patient.

Conclusion

Tuberculosis is still a very common disease. Untreated or ineffectively treated Tuberculosis can manifest with myriad complications. It should be considered as a differential diagnosis in an atypical presentation of any disease in our part of the world. Carotid ligation, in this case, was undertaken as a life saving measure. What has been rightly said about uncommon presentations of a common disease rings true in this case. An aneurysm should be considered as an underlying possibility in any neck swelling.

Correspondence to

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