Repair of a true extracranial internal carotid artery aneurysm with transposition surgery in a pediatric patient: A rare case

Introduction

Extracranial carotid artery aneurysms are very rarely seen in population. In literature, there are very few cases found with regard to this disease occurring in childhood. Extracranial carotid artery aneurysm constitutes only 0.5% to 1.9% of all the carotid operations and 4% of all peripheral aneurysms in adults.^{1, 2} Patients usually complain of painless mass in the neck. Painless cervical mass is the common complaint at admission. In etiology, traumas, accidents, atherosclerosis, infections, surgery from the cervical region and peritonsillar abscess are generally responsible for extracranial carotid artery aneurysm. However, congenital cases have been rarely reported. Since the extracranial carotid artery aneurysms are very rare in childhood, the morphology, anatomy, physiology and other features of the lesions have not been well discussed. Almost all of the articles are case reports in the literature. We have found only one publication with a long-term follow-up and results. In this publication, a series consisting of four patients was reported; there was no symptom in three of the patients during the 25-year follow-up period, and residual hemiparesis was observed in only one patient. ³ We present a 10-year-old girl with a congenital left internal carotid artery aneurysm and a treatment management.

Case report

A 10-year-old girl was admitted to the cardiovascular surgery outpatient clinic with a swelling on the left side of the neck. Physical examination revealed a 3 × 5 cm painless and pulsatile mass on the left side of neck and minimal ptosis in her left eye. Other physical examination findings were normal. It was learned from the family that the patient was born vaginally, at term, with low birthweight (1900 g), in hospital and mother used antiemetics, gastric protection drugs and painkillers during pregnancy. The patient had no history of any operation, hospitalization, trauma, or accident. This mass was noticed by the patient one year ago and it grew. Routine laboratory tests were normal. Carotid artery colored Doppler ultrasonography showed an internal carotid artery aneurysm of approximately 6.1 × 2.4 × 2.2 cm in diameter, which began at the level of left common carotid artery bifurcation, expanding to the superior. In order to determine the location, size, and type of the aneurysm, the patient underwent a three-dimensional reconstruction contrast-enhanced computed tomography (CT). CT angiography showed 64 × 21×21 mm (caudocranial ×anteriorposterior × transvers) fusiform aneurysmal dilatation (dolichoectasia) beginning from the carotid artery bifurcation and extending to the superior, and a second aneurysmal dilatation with a diameter of approximately 14 mm was observed. Because of the compression effect of the lesions, the left external carotid artery and internal jugular vein were displaced laterally and proximally, and the left lobe of the thyroid gland was displaced medially (Figure 1). Written informed consent was obtained from the patient and parents. Operation was started after vital monitoring, and near infrared spectroscopy (NIRS) monitoring was performed. The aneurysm was released through the distal and proximal. External carotid artery was prolonged and elongated medially due to the aneurysm. A second aneurysm sac was seen at the cranial direction, which was separated by a fibrous band from the large aneurysm sac. The normal segment of the internal carotid artery was reached approximately 1 cm after the second aneurysm sac (Figure 2). After the aneurysm sac was completely excised, the internal carotid artery was not suitable for end-to-end anastomosis due to the gap between proximal and distal part. Then, we decided to use the external carotid artery and cut it before the facial branch and transposed it to the internal carotid artery and end-to-end anastomosis was performed. Then at the external carotid artery distal part, end-to-end anastomosis was performed in the carotid bifurcation approximately 0.5 cm in the proximal internal carotid artery segment. Pathological and microbiological samples were taken from the aneurysm sac. The patient was followed up in the intensive care unit for 24 h. No neurologic or motor function loss or dysfunction was observed. No reproduction was detected in the microbiologic specimen. After the intensive care follow-up, the patient was transferred to service; she did not have any postoperative complication and was discharged from the hospital at the third postoperative without any complications.

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Figure 1.

Aneurysm seen in three-dimensional reconstruction contrast-enhanced computed tomography.

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Figure 2.

(a) Preoperative appearance and (b) postoperative appearance.

Discussion

Extracranial carotid artery aneurysm is a rarely seen disease in childhood. Congenital, infective, mycotic, connective tissue diseases and post-traumatic causes are most common etiologic factors. Atherosclerosis and secondary causes of carotid artery surgery are the most common causes in adults. Overall, post-traumatic causes and fibromuscular dysplasia-induced aneurysms are increasing in recent years. Connective tissue diseases and inflammatory diseases such as Marfan syndrome, Ehler-Danlos syndrome, Kawasaki syndrome, Behçet's disease are well-known clinical entities which are associated with increased risk of aneurysms. Except these, parafarangial abscess after ear-nose-throat infections, blunt neck traumas and iatrogenically developed extracranial carotid artery aneurysms have been reported.^{4, 5}

We could find few cases of children with extracranial carotid aneurysm in the literature. Interestingly, most of these patients had a history of tonsillectomy.^6–8 There was no tonsillectomy history or any history of surgery in our case. It has been reported in previous publications that low birthweight is a risk factor for cardiovascular disease. ⁹ We think that low birthweight may be a factor in etiology as in our case. Patients with carotid artery aneurysm are usually admitted with painless, localized neck and a day-to-day growing pulsatile mass. History and physical examination are important for diagnosis, but not enough for the choice of treatment method. Therefore, invasive or non-invasive imaging methods are needed. Imaging methods such as colored Doppler ultrasonography, contrast-enhanced computed tomography, contrast-enhanced magnetic resonance imaging, and digital subtraction angiography are useful and effective to select the treatment method. ¹⁰

The management of external carotid artery aneurysms in adults is well known, whereas in pediatric patients, this situation is more confused. The reason is due that this disease is very rare in childhood.

If extracranial carotid artery aneurysms are not treated, rupture, thromboembolism, Horner syndrome and death can occur. Therefore, carotid artery aneurysms should be treated. ¹¹

Surgical and interventional treatment methods could be performed for extracranial carotid artery aneurysms.

The resection of the aneurysm sac and end-to-end anastomosis, resection of the aneurysm sac and venous or synthetic graft interposition, ligation with extra-intracranial bypass, bypass with venous or synthetic grafts or only ligation treatments can be performed in open surgery.^12–14 Resection and end-to-end anastomosis technique are suitable for only half of the patients. In our case, the resection of the aneurysm sac and transposition of the external carotid artery to the internal carotid artery using end-to-end anastomosis technique were performed. Interventional treatment is a preferred method in patient groups where surgical access is not suitable because of aneurysm extending to the base of the skull. In this situation, the most preferred technique is coil embolization. ¹⁵ In addition to coil embolization, cases treated with stent graft have also been reported. ¹⁶

Thus, the localization and size of the aneurysm are important in the selection of appropriate treatment method especially in childhood extracranial carotid artery aneurysms. For this reason, all the stages before surgery should be carefully evaluated and should help in the intraoperative decision. We believe that the surgical technique which we applied in our case will be useful in similar cases.