Some pitfalls in the diagnosis of pituitary tumours: the importance of carotid angiography

ICA agenesis with transcavernous anastomosis: a systematic review

PURPOSE

To present two cases of Internal Carotid Artery (ICA) agenesis and conduct a systematic review to assess for associations with other anomalies and intracranial aneurysms.

METHODOLOGY

We performed a retrospective review of published cases of patients with ICA agenesis with intercavernous anastomosis in MEDLINE database on August 2022 using search terms "internal carotid artery", "agenesis" and "transcavernous anastomosis". We also included two cases of ICA agenesis with type D collateral that we encountered.

RESULTS

Total of 45 studies that included 47 patients and two of our cases resulted in 49 patients. Only 70% of studies reported the location of a collateral vessel of which more than two-thirds were on the floor of sella. More than half of the vessels connected cavernous segments of ICA. A1 segment ipsilateral to the side of ICA agenesis was absent in most of the cases but was not true for all cases. Aneurysm was seen in more than one-quarter of the patients. It can also mimic microadenoma as in prior reported cases as well as in one of our cases.

CONCLUSION

ICA agenesis with type D collateral is a rare anomaly but clinically relevant due to the increased risk of an aneurysm or mimic microadenoma or false alarm for occlusion of ICA but knowledge of this rare variant can help in better management of these patients.

Congenital absence of internal carotid artery with intercavernous anastomosis: Case report and systematic review of the literature

The absence of an internal carotid artery is a rare congenital anomaly. In the absence of the internal carotid artery, collateral circulations develop through the circle of Willis, persistent embryonic arteries or transcranial collaterals of the external carotid artery. Six pathways of collateral circulation have been described. Intercavernous anastomosis is between cavernous segments of the bilateral internal carotid arteries and is rarely seen. Patients with an absence of the internal carotid artery can be completely asymptomatic. However, these patients can present with subarachnoid hemorrhage or stroke accompanying cerebral aneurysm or abnormal collateral. We combined our case with 33 previous publications to form a retrospective series including 35 cases of unilateral internal carotid artery agenesis with intercavernous anastomosis.

Left internal carotid artery agenesis with trans-sellar collateral and a right aortic arch: Case report

We present a case of unilateral internal carotid artery (ICA) agenesis with trans-sellar anastomosis associated with a right aortic arch, and discuss the embryonic development and clinical implications of this condition. A 26-year-old woman without significant medical history was referred to our hospital complaining of tinnitus. She denied any other symptoms, and examination did not reveal any other neurological deficits. Radiological examinations showed agenesis of the right ICA with trans-sellar anastomosis, and a right aortic arch. This vascular configuration reflects the anatomical homology with avian vascular structure. Recognition of this anomaly has important implications for clinical situations, such as the planning of carotid or transsphenoidal surgery, the management of thromboembolic disease, and the surveillance and detection of associated cerebral aneurysms.

Agenesis of the internal carotid artery with transcavernous anastomosis presenting with an anterior communicating artery aneurysm--a case report and review of the literature

Arterial communication between cavernous segments of the carotid arteries associated with unilateral agenesis of the internal carotid artery (ICA) is extremely rare. We herein present a case of unilateral ICA agenesis with transcavernous anastomosis that presents with an anterior communicating artery (ACoA) aneurysm, and discuss its embryogeny and clinical implications. A 55-year-old woman with no significant medical history was admitted to our hospital for further examination of agenesis of the left ICA, which was detected in a routine medical examination. She was free of clinical symptoms and had no neurological deficits. Radiological evaluation revealed agenesis of the left ICA with transcavernous anastomosis. Moreover, an incidental multilobulated aneurysm was detected at the ACoA. She underwent microsurgical clipping for this aneurysm, and the post-operative course was uneventful. Investigation of collateral pathways helps our understanding of the segmental nature of carotid artery development. Recognition of this anomaly also has important implications in the surveillance and detection of associated cerebral aneurysms.

Magnetic resonance imaging of the sella turcica and parasellar region. A clinical-radiographic evaluation with computed tomography

Thirty-one magnetic resonance (MR) scans and computed tomography (CT) scans were obtained on 25 patients in whom lesions involving the sella turcica or parasellar region were clinically suspected. Surgical pathologic studies were available in 19 cases. Twenty-two of the MR scans were of diagnostic value equivalent to that of the corresponding CT studies. In two small meningiomas, an empty sella, and a sphenoid-middle fossa tumor, MR technology failed to delineate the pathologic process adequately. In the remaining five patients, MR either more convincingly demonstrated the pathologic anatomy or yielded diagnostic information not present in the CT study. In view of the absence of ionizing radiation, high degree of tissue contrast and spatial resolution, and multiplanar capability, magnetic resonance scanning will probably become the initial imaging modality of choice in patients suspected of harboring sellar and parasellar tumors.

Trans-sphenoidal surgery for suprasellar pituitary adenomas

The introduction of the trans-sphenoidal approach has not only made intrasellar tumours removable, but has proved also to be a safe method for ablation of suprasellar tumour extension. Experiences with 154 suprasellar pituitary adenomas in a series of 278 trans-sphenoidal operations are presented. Results are compared to those in the literature, suggesting that this technique is possible also for higher risk elderly patients.