Abstract
INTRODUCTION AND IMPORTANCE: Exceptionally, aneurysms from the posterior genu of the cavernous internal carotid artery (ICA) can rupture, resulting in subarachnoid hemorrhage (SAH). We reported such a case and provided another case with an unruptured aneurysm as a control to confirm the rarity of the ruptured aneurysm from the posterior genu of the cavernous ICA. CASE PRESENTATION: Case 1: This was a 46-year-old female with SAH. Computed tomography angiography (CTA) and digital subtraction angiography (DSA) confirmed that an aneurysm from the posterior genu of the right cavernous ICA had expanded into the intradural space and ruptured; the aneurysm was coiled completely. Postoperatively, she died from cerebral ischemia due to vasospasm. Case 2: This was a 59-year-old female with SAH. CTA and DSA revealed six aneurysms, including two mirror-like aneurysms from the bilateral anterior communicating artery (AcomA), two tandem aneurysms from the posterior genu of the left cavernous ICA, and two aneurysms from the bilateral anterior cavernous ICAs. After coiling the two tandem aneurysms from the posterior genu of the left cavernous ICA, the bilateral AcomA aneurysms were clipped, and rupture of the right AcomA aneurysm was confirmed. Follow-up CTA showed complete clipping of the bilateral AcomA aneurysms. Her Glasgow Outcome Scale score was 5. Endovascular treatment for residual aneurysms is planned for the future. CLINICAL DISCUSSION: As shown in these two cases, the aneurysm from the posterior genu of the cavernous ICA can rupture, resulting in SAH; however, the rupture of other aneurysms must be excluded. CONCLUSION: Once a ruptured aneurysm from the posterior genu of the cavernous ICA was confirmed, EVT was considered an alternative treatment.