A Case of Aneurysmal SAH and Stanford Type A Acute Aortic Dissection: A Case Report.

A 47-year-old woman lost consciousness for 1 min and was in an agitated state at home; she was subsequently transferred to our hospital. Her medical history included breast cancer, gastric cancer, Cronkhite-Canada syndrome, childhood asthma, and endometriosis. Her vital signs were as follows: heart rate: 72 bpm, blood pressure: 141/93 mmHg, body temperature: 35.8°C, respiratory rate: 24/min, and the Glasgow Coma Scale score was 10 (E2V3M5). She had no symptoms other than the episode of unconsciousness and no complaints of headache or chest pain. Head computed tomography (CT) on arrival revealed diffuse SAH (Fisher Group III; Hunt and Kosnik Grade III) ( Fig. 1a ). CT angiography (CTA) revealed 2 aneurysms: a 3-mm aneurysm with 2 blebs at the right internal carotid artery/posterior communicating artery bifurcation (IC-PC) and a 4-mm aneurysm at the right paraclinoid segment (C2-C3 junction) ( Fig. 1b and c ). Thoracic CTA, which is routinely performed at our hospital to inspect the access route for interventional radiology (IVR), revealed Stanford type A aortic dissection extending from the ascending aorta to the descending aorta, and also affecting the brachiocephalic artery ( Fig. 2 ). Our cardiac surgeons determined this lesion as an acute dissection, considering the thin flap of dissection presented on CTA. Although IVR for the cerebral aneurysms was considered, a femoral/brachial approach was not an option because the aortic dissection involved the brachiocephalic artery. Therefore, we decided to perform surgical clipping and TAR. The clipping procedure was performed via a right frontotemporal approach. We removed the anterior clinoid process via an epidural approach. Then, we clipped both aneurysms, and the subarachnoid space was thoroughly irrigated with saline to remove as much hematoma as possible. Intraoperative observation confirmed that the IC-PC aneurysm was the ruptured aneurysm ( Fig. 3 ). Complete hemostasis was achieved during surgery, as confirmed by postoperative CT, before administering heparin ( Fig. 4 ). Subsequently, TAR was performed by cardiac surgeons under systemic heparinization, which is inevitable for extracorporeal circulation. Head computed tomography (CT) and CT angiography (CTA) on arrival. (a) Head CT revealed diffuse subarachnoid hemorrhage (SAH) (Fisher Group III). (b, c) Three-dimensional CTA with volume rendering (VR). The anterior clinoid process is marked by an asterisk (*). CTA revealed aneurysms at the right internal carotid artery/posterior communicating artery bifurcation (IC-PC) (solid thin arrow) and the right paraclinoid (dashed thin arrow). The right IC-PC aneurysm measured 3 mm in size, with two blebs. The right paraclinoid aneurysm measured 4 mm in size. (c) Head CTA with VR (posterolateral view). The wide arrow indicates the direction to view Figure 1 (b). Chest computed tomography angiography (CTA) on arrival. Chest CTA revealed acute aortic dissection (AAD) extending from the ascending aorta to the descending aorta. (a-c) The dissection also extended to the brachiocephalic artery (arrow). 1: ascending aorta. 2: descending aorta. 3: brachiocephalic artery. *False lumen of the AAD. Surgical view of neck clipping (right frontotemporal approach). (a) We removed the anterior clinoid process (1) from the epidural space. (b) Clip applied to the internal carotid artery/posterior communicating artery bifurcation (IC-PC) aneurysm. (c) Clip applied to the paraclinoid aneurysm. The surface of this aneurysm did not show a rupture point, which suggested that the IC-PC aneurysm was the ruptured aneurysm. 1: Anterior clinoid process. 2: IC-PC aneurysm. 3: Right IC. 4: Paraclinoid aneurysm. 5: Anterior clinoid process. *: Clip applied to the IC-PC aneurysm. Postoperative computed tomography (CT). (a, b) Head CT (axial view) after surgical clipping showing the absence of postoperative bleeding. (c, d) Postoperative chest CT angiography (CTA) (sagittal view) showing that the aorta was replaced without problems. Postoperatively, clazosentan was administered to prevent vasospasm and delayed ischemic neurological deficit. We also adjusted the patient's hydration status to prevent water retention and vasospasm. Because a large amount of fluid was administered during TAR, we administered diuretics after the surgery. The total amount of water remaining in the patient's body stabilized 4 days after the surgery, and we aimed to maintain the same level thereafter. The postoperative course was uneventful, and the patient was discharged home 35 days after the surgery (modified Rankin Scale score: 2). She had no significant neurological deficits but had gait instability owing to muscle weakness, which disappeared 3 months later (90-day modified Rankin Scale score: 1).

Author Masahiro Toda is one of the Editorial Board members of the Journal. This author was not involved in the peer-review or decision-making process for this paper. Takuya Enomoto and Katsuhiro Mizutani are co-first authors.

Both SAH and Stanford type A AAD are fatal and emergent diseases with well-established standard treatments. However, because the coexistence of these 2 pathologies is extremely rare, with only one previously reported case, 3 ) a standard therapeutic strategy for this specific condition has not been established. The reported case by Inamasu et al. 3 ) was treated by IVR since both the left and right common carotid artery was spared from the dissection. We could not follow their therapeutic strategy since our patient had a dissection affecting the right carotid artery. Given the conflicting aspects of their respective treatments, reporting the treatment and clinical management of patients with both conditions is crucial. Regarding the order of surgery, it was necessary to consider systemic heparinization targeting an activated clotting time of 500 secs during TAR. Because it is impossible to heparinize while a ruptured aneurysm is not secured, we decided to treat the SAH first. Although IVR was considered, it was impossible to access the SAH from either the femoral or brachial approach because of dissection extending from the aorta to the brachiocephalic artery. Access by direct puncture to the carotid artery was a possible option, but we abandoned this approach because of the bleeding risk during heparinization. Therefore, we performed surgical clipping. Because it was difficult to determine which aneurysm had ruptured from the radiological evaluation, we attempted to treat both aneurysms. We put the greatest effort into controlling bleeding to reduce the risk of heparinization during subsequent cardiac surgery. The typical management for TAR is to administer large volumes of intravenous fluids to compensate for intraoperative fluid loss, followed by postoperative diuretic therapy to reduce excess fluid. Proper postoperative fluid control alleviates cardiac workload and lowers the risk of pulmonary edema, facilitating extubation. In contrast, the standard postoperative SAH management traditionally favors relatively large-volume fluid administration to sustain the cerebral perfusion pressure. However, this approach contradicted the fluid management strategy required after TAR, as mentioned. The recently marketed drug, clazosentan, may help address this conflicting situation. This drug is an endothelin receptor type A selective agonist and a strong vasodilator that prevents vasospasm and delayed ischemic neurological deficit. Because of its adverse effect of causing water retention, less fluid control (fluid administration rate: <1 mL/kg/hr) 4 ) than that with traditional management has been recommended. 5 ) This strategy is also beneficial for postoperative TAR management. Postoperative blood pressure management is not mentioned in the guidelines for either SAH or AAD. 6 , 7 ) Generally, with SAH, blood pressure is controlled to a low level until postoperative day 1 owing to concerns about postsurgical bleeding. Thereafter, blood pressure is maintained at a higher level to prevent cerebral vasospasm. In contrast, blood pressure is usually controlled at a low level to reduce cardiac burden and postoperative bleeding after TAR. We decided to control systolic blood pressure in the mid-range of ideal blood pressure for both diseases. Whether the coexistence of SAH and AAD is a coincidence is intriguing. When simply multiplying the incidence rate of each pathology, the probability of a person having both conditions is approximately 2 in 10 billion individuals. 1 , 2 ) This suggests that such a clinical situation should be exceedingly rare, occurring at a frequency of approximately one person per year across the entire global population. In contrast, the coexistence rate of intracranial aneurysms and AAD was significantly higher (12.96%) than in healthy controls (1.85%). In addition, the mean diameter of the aneurysms is significantly larger in patients with AAD (5.79 mm) than in healthy controls (3.04 mm). Moreover, aneurysm size more than 7 mm is significantly more common in patients with AAD (28.6%) than in healthy controls (5.3%). 8 ) Although the coexistence rate of SAH and AAD is extremely rare, these data suggest that patients with AAD can experience SAH more often than healthy controls without AAD. In our patient, a systemic genetic disorder may have been implicated in the current pathology. The gastroenterologist managing the patient's gastric cancer noted a possible association between gastric malignancy and dissecting aortic aneurysm. However, because the patient declined genetic testing, the hypothesis remains unconfirmed. Juvenile polyposis syndrome-hereditary hemorrhagic telangiectasia (JPS-HHT) is a genetic disorder caused by a mutation in the SMAD4 gene. The condition is characterized by multiple polyps in the stomach and intestines, an increased risk of gastric and colorectal cancer, aortic aneurysms and dissections, recurrent epistaxis, telangiectasias, and arteriovenous malformations in the brain, liver, and lungs. 9 ) Given its involvement in transforming growth factor-beta signaling pathways, JPS-HHT shares potential similarities with Marfan syndrome and Loeys-Dietz syndrome. 9 , 10 ) To date, no studies have established a direct link between JPS-HHT and cerebral aneurysms. Nevertheless, given that SMAD4 mutations compromise vascular integrity, it is plausible that patients with JPS-HHT may also be at risk for cerebral aneurysms. Another possible explanation for the coexistence of SAH and AAD is hypertension. However, our patient had no history of hypertension, and her blood pressure remained normal throughout the hospitalization. Thus, we believe that hypertension was not the underlying cause in this case. We presented a rare case of concurrent SAH and AAD, a clinical scenario that is exceedingly uncommon and lacks a well-established treatment protocol. In this case, we believe that prioritizing surgical clipping of the SAH (if endovascular repair was not feasible), carefully managing fluid therapy according to the patient's clinical course, and maintaining blood pressure within a near-normal range were important factors in achieving a favorable outcome.

Subarachnoid hemorrhage (SAH) and Stanford type A acute aortic dissection (AAD) are both life-threatening conditions that require urgent treatment. The incidence rates of SAH and AAD are 6.1 (95% confidence interval, 4.9-7.5) per 100,000 persons 1 ) and 3.5 (95% confidence interval, 2.4-4.6) per 100,000 persons, 2 ) respectively. Since the typical treatment and postoperative management of these conditions can significantly impact each other, determining the optimal operative strategy and perioperative management can be particularly challenging. Although the simultaneous occurrence of these 2 conditions is considered extremely rare, it is worthwhile to accumulate such reports. Here, we report a case of concurrent SAH and AAD, successfully treated with neck clipping and total arch replacement (TAR).

All authors have no conflict of interest.