Ruptured pseudo-aneurysm of the cervical internal carotid artery in a child (a case report).
A ruptured cervical internal carotid artery pseudo-aneurysm is an exceedingly rare lesion seen in children. An extensive review of literature failed to reveal a report of a successfully treated case.
A 7-year-old boy had a sudden onset of high-grade fever and in two days developed bilateral neck swellings. The investigations done at this time, showed elevated total count with shift to the left and an elevated E.S.R. The child was put on antibiotics (drug and dose not known) and tracheostomy was done for laryngeal stridor. The swelling on the left side of the neck regressed but the one on the right side persisted. The examination of the oral cavity revealed a doubtful right-sided peritonsillar abscess. An attempt was made to drain the abscess into the oral cavity. The drainage did not reveal any pus but instead there was bloody fluid. Following the drainage, the child had a bout of bleeding through the mouth, which was self-limiting and was managed with blood transfusions. This boy was then referred to the King Edward Memorial Hospital.
Physical examination revealed a pale cheerful lad with no acute distress. The boy was not febrile and other vital parameters were stable. The neck revealed an irregular, ovoid, partially compressible swelling measuring about 3 cm x 4 cm x 5 cm in dimensions with expansile pulsations and bruit, situated on the right side in the region of the carotid triangle. Also seen in the neck was a mature tracheostomy tract with a tube and normal skin overlying the swelling. Oral examination revealed the same swelling as a bulge on the lateral oropharyngeal wall on the right side. Other significant physical findings included normal heart sounds without any murmur and no focal neurological deficit.
Haematological investigations showed anaemia, elevated total count and E. S. R. Blood culture was negative. Doppler ultrasonography of the neck showed a 4 cm x 3 cm pseudo-aneurysm with turbulent flow arising close to the bifurcation of the right common carotid artery without any evidence of a thrombus. The transfemoral bilateral carotid angiogram showed a saccular aneurysm arising from the right internal carotid artery, just near its origin. (See [Figure - 1]). Angiogram also revealed that the cerebral circulation is maintained after compressing right common carotid artery.
While an elective surgery was being planned, the pseudo-aneurysm ruptured into the oral cavity and because of the excessive uncontrollable blood loss the child had to undergo an emergency surgery. The aneurysmal sac, seen to he arising from the right internal carotid artery just beyond the bifurcation of the common carotid artery, was excised and the internal carotid artery was ligated proximally and distally.
The pathology report stated that the cystic structure had irregular surface with areas of haemorrhage. Microscopic section showed bands of necrotic tissue and haemorrhage with scattered neutrophils without any elastic tissue or lamina (confirmed by special stains). No bacteria were recovered. In the immediate post-operative period there was an evidence of paresis of marginal mandibular branch of facial nerve and Homer's syndrome. The tracheostomy was gradually weaned off and the child was discharged three weeks later. One month after discharge the facial weakness had improved but Horner's syndrome persisted and there was no other neurological deficit. The patient was asked to follow-up regularly.
Aneurysms have been known from the earliest times as pulsatile swellings, whose dangers were well appreciated judging from Galen's description of the "bright red blood that spurted forth with much violence". In 1757, William Hunter had defined distinction between true and false aneurysm. In 1885, Osler introduced the term 'mycotic' aneurysm.
Of a series of approximately 8,500 operations for arterial aneurysm, spanning a 21 year period, only 37 were performed for extracranial carotid aneurysm . A total of 6 carotid aneurysms were found at the Mayo Clinic from 1936 to 1963. Beall et al collected only 7 cases of carotid artery aneurysm in approximately 2,300 operations performed for aneurysm of all parts of extracranial systems. Reid found 12 cases in 30 years at the Johns Hopkins Hospital. An extensive review of literature failed to reveal such a report in a child.
The aneurysm of the intracranial carotid arteries are much more common. The common carotid artery at its bifurcation is the most commonly reported site of aneurysm formations in the extracranial carotid system, the internal carotid artery is the next most common and the external carotid artery is the least common location.
There are several causes of extracranial carotid aneurysm and the relative frequency of each has changed over the past few years years-syphilis and local infection were most common sixty years ago. Instead atherosclerosis, trauma and previous surgery are now believed to be responsible for the majority of extracranial carotid aneurysms . There are many reports of pseudo-aneurysm as a complication of adjacent infection. Infected lymph nodes, osteo-myelitis and abscesses are few of the many sources of infection leading to arterial involvement. Prior to the development of antibiotics, many carotid aneurysms resulted from local cervical or pharyngeal infections - this is obviously not a common problem any more today.
When peripheral pseudo-aneurysms are not associated with bacterial endocarditis, the flora is Staphylococcus and the entero-bacteriae most commonly encountered are Klebsiella, Proteus, Escherichia coli, Pseudomonas and Clostridium in addition to anaerobic organisms, bacteroids and peptostreptococcus. Aneurysms infected with Gram negative organisms have a rupture rate of 83% as compared to 10% for Gram positive organisms . The infection in mycotic aneurysm may be slow and smouldering, and the findings may be that of any non-infected aneurysm. Basically, a mycotic aneurysm should be suspected in patients presenting with aneurysm, a fever of undetermined origin and leucocytosis. Positive blood cultures definitely are of a confirmatory value, but are very rarely found because of antibiotic administration. Duplex scans and angiograms confirm the presence of an aneurysm, show the exact location of the lesion and are important in planning appropriate future of operative treatment.
Shipley et al classic paper emphasized that the aneurysms of the internal carotid artery are present in the throat, whereas those of common carotid artery are present in the neck. The level at which the common carotid bifurcates also influences the point of appearance. In quite a few cases many of the internal carotid aneurysms have been noticed initially because of the haemorrhage from the pharynx, which can be massive and lead to suffocation and result death, though not always.
The treatment of extracranial carotid aneurysms has evolved with speciality of vascular surgery. In 1552, Ambriose Pare published the first account of operative ligation of common carotid artery to control bleeding from a lacerated artery. Astley Cooper performed the first common carotid ligation for an aneurysm in 1805 - unfortunately his patient died 13 days later. Cooper later accomplished the first successful treatment of cervical carotid aneurysm by proximal ligation. This was coupled occasionally with distal ligation and extirpation. The subsequent encouraging development of reconstructive vascular technique has eliminated ligation as a procedure of choice. Never the less, ligation of vessels may still be necessary if rupture has occurred. Ligation results in thrombosis from the level of interruption up to the origin of ophthalmic artery. However, among the patients treated in this manner, nearly 30-60% develop neurological deficit and almost half of these do not survive at all. A substantial number of patients develop hemiplegia within hours to days later, which probably represents propagation of thrombus.
A mycotic aneurysm is an aneurysm that is due to infection of the arterial wall. In most cases of such affliction the bacteria causing infection, cannot be identified. Although pathological examinations of the specimen, in our case did not give clear diagnosis, the findings were more or less compatible with mycotic disease. Because of these and many other considerations and the fact that the patient had fever and bilateral tender neck swellings, we concluded that the cause of aneurysm may not be anything other than mycotic.
How true is the statement of Winslow made over 60 years ago - “The true nature of these mycotic aneurysm often was not discovered until an unsuspecting physician drained a 'peritonsillor abscess' only to be met with a gush of blood”.
We wish to thank the Dean, Seth GS Medical College, King Edward Memorial Hospital for giving us permission to publish this case report.