[Idiopathic subarachnoid hemorrhage; comparison of different bleeding patterns and long-term outcome]

The diagnostic yield of repeat computed tomography angiography in cases of spontaneous subarachnoid haemorrhage after negative initial digital subtraction angiography

Purpose

It is currently unclear how useful repeat computed tomography angiography (CTA) is in spontaneous subarachnoid haemorrhage (SAH) patients after negative initial digital subtraction angiography (DSA). The purpose of this study is to assess the yield of repeat CTA for the detection of causative vascular lesions in patients with SAH in whom there has been a negative initial DSA.

Material and methods

This observational retrospective study was carried out from January 2013 to July 2022 at a single institution. Analysis of the SAH pattern on unenhanced CT showed that patients were divided into perimesencephalic SAH and diffuse SAH groups. A repeat CTA was performed on all spontaneous SAH patients who had a nega-tive initial CTA and DSA within a 2-week period. An interventional neuroradiologist and a diagnostic radiologist examined all images to search for causative vascular abnormalities.

Results

Forty-seven patients were included in our study, with a median age of 55 years and a range of 28-81 years. Thirty-seven had diffuse SAH (66%), and 16 had perimesencephalic SAH (34%). The repeat CTA revealed 2 causa-tive vascular lesions (a right PICA aneurysm and a mycotic aneurysm) in 2 separate patients (yield of 4.3%), both of whom had diffuse SAH (yield of 6.5%). In retrospect, none of these vascular lesions were evident in the initial CTA and DSA. No evidence of re-bleeding was observed in the follow-up period.

Conclusions

It is beneficial to repeat CTA when evaluating patients with diffuse SAH who initially present with nega-tive initial DSA. For occult aneurysms, the diagnostic yield of the follow-up CTA is 6.5%.

Endovascular Management of Hemorrhagic Stroke

Significant advances in endovascular neurosurgery tools, devices, and techniques are changing the approach to the management of acute hemorrhagic stroke. The endovascular treatment of intracranial aneurysms emerged in the early 1990s with Guglielmi detachable coils, and since then, it gained rapid popularity that surpassed open surgery. Stent-assisted coiling and balloon remodeling techniques have made the treatment of wide-necked aneurysms more durable. With the introduction of flow diverters and flow disrupters, many aneurysms with complex geometrics can now be reliably managed. Arteriovenous malformations and fistulae can also benefit from endovascular therapy by embolization using n-butyl cyanoacrylate (NBCA), Onyx, polyvinyl alcohol (PVA), and coils. In this article, we describe the role of endovascular treatment for the most common causes of intracerebral and subarachnoid hemorrhages, particularly ruptured aneurysms and vascular malformations.

Dural Venous Sinus Variations in Idiopathic Subarachnoid Hemorrhage: A New Indicator of the Venous Origin with Diagnostic Usefulness?

OBJECTIVE

Venous hypertension associated with a primitive basal vein of Rosenthal (BVR) has been noted as the most likely cause of idiopathic subarachnoid hemorrhage (iSAH). Other types of venous drainage variations have been scarcely studied but may further explain the cases not associated with a BVR anomaly. Our aim was to investigate if dural venous sinus (DVS) anomalies are related with iSAH.

METHODS

A total of 76 patients diagnosed with iSAH were identified from a prospectively maintained database and their angiographic findings compared with 76 patients diagnosed with aneurysmal subarachnoid hemorrhage.

RESULTS

On top of the BVR variations, our data showed a higher prevalence of transverse sinus hypoplasia (47.4% vs. 28.9%; P = 0.019), superior petrosal sinus hypoplasia (32.9% vs. 13.2%; P = 0.003), and clival plexus hyperplasia (65.8% vs. 43.4%; P = 0.005) in patients with iSAH. Analyzing by total number of angiograms, the iSAH group showed also a higher prevalence of inferior petrosal sinus hyperplasia (36.2% vs. 25%; P = 0.003). Of the patients with iSAH without a primitive BVR, 84% harbored ≥1 perimesencephalic DVS variation and the overall number of venous drainage variations was significantly higher in patients with iSAH.

CONCLUSIONS

In addition to the well-documented BVR anomalies, there seems to be a significant relationship of other DVS variations in patients with iSAH. Transverse sinus hypoplasia, superior petrosal sinus hypoplasia, inferior petrosal sinus hyperplasia, and clival plexus hyperplasia were significantly more frequent in patients with iSAH. The presence of ≥3 of those variations would increase the suspicion of a nonaneurysmatic subarachnoid hemorrhage and could help avoid a second angiogram.

[Patients with subarachnoid haemorrhage in poor grade neurological status: Study of prognostic factors]

OBJECTIVE

To evaluate and predict factors influencing prognosis and/or clinical outcome at 6 months in patients with spontaneous subarachnoid haemorrhage, World Federation of Neurosurgical Societies (WFNS) grades iv and v.

MATERIAL AND METHODS

This was a retrospective study of a consecutive series of 394 patients admitted to our hospital with clinical and radiological diagnosis of spontaneous subarachnoid haemorrhage, from 1 January 1999 to 30 June 2009. We selected 121 patients who met the criteria of being in WFNS grades iv or v before treatment; 3 patients were excluded due to loss of tracking. The outcome variable was assessed 6 months after the event using the Glasgow Outcome Scale. A P value<.05 was considered statistically significant.

RESULTS

One hundred and twenty-one patients were included in the statistical analysis. The average age of the patients in the series was 54 years (14-92). Patients who had a mean Glasgow Coma Scale lower than 7 points (P<.0001), those who were grade v (P<.0001) in the pre-treatment WFNS scale and those with pupillary disorder (P=.002) had a worse clinical outcome. Likewise, those with associated intraparenchymal hematoma (P=.020) and those not receiving any treatment (P=.020) were also associated with a poor clinical outcome. These results were statistically significant.

CONCLUSIONS

Patients admitted with a WFNS grade v and/or presenting pupil disorder and/or intraparenchymal hematoma were associated with worse clinical outcomes.

Endoscopic third ventriculostomy for hydrocephalus after perimesencephalic subarachnoid hemorrhage: initial experience in three patients

BACKGROUND

To review the outcome after endoscopic third ventriculostomy (ETV) for symptomatic, persistent hydrocephalus in three patients with perimesencephalic angiographically negative subarachnoid hemorrhage (PNH) who were dependent on an external ventricular drain (EVD).

METHODS

All patients initially presented with severe headache, nuchal rigidity, confusion and lethargy (Hunt-Hess Grade II or III), and persistent, EVD-dependent hydrocephalus. Cranial CT images in each revealed acute hydrocephalus and perimesencephalic hemorrhage pattern with a heavy clot burden (Fisher grade 3). A 3D-CT angiogram on admission and two four-vessel cerebral angiograms failed to demonstrate a bleeding source. All three patients failed trial EVD clamping, with clinical deterioration and elevated intracranial pressure (ICP). ETV was performed with a 0-degree endoscope in a 4.6-mm irrigating sheath using an endoscopic-coring/"cookie-cut" technique. An EVD was left in place for postoperative ICP monitoring but was clamped.

RESULTS

ETV was accomplished in all patients. In one case, a tiny basilar tip aneurysm was seen during the endoscopic procedure. Intraoperatively, the prepontine cistern revealed dense, degraded blood products. Postprocedure ICP measurements were reduced to normal range. Clinical improvement, normal ICP readings, and/or radiographic evidence of resolution of hydrocephalus allowed uneventful removal of the EVD within 36-48 h post-ETV in all patients. All remained headache-free, with a normal neurological examination, during a follow-up period of 10, 11, and 12 months, respectively.

CONCLUSION

To our knowledge, this is the first report of ETV for PNH with hydrocephalus and the first report of a basilar tip microaneurysm seen intraoperatively during ETV. ETV is a viable treatment option for refractory hydrocephalus secondary to a perimesencephalic pattern of subarachnoid hemorrhage (SAH). Its early application can avoid placement of a ventriculoperitoneal shunt, curtail the extended use of an EVD, and reduce the associated infection risks. Despite thorough angiographic investigation for an aneurysmal cause of SAH, a "microaneurysm" of the basilar artery was found at ETV. No complication or rebleeding was encountered.

Comparison between perimesencephalic nonaneurysmal subarachnoid hemorrhage and subarachnoid hemorrhage caused by posterior circulation aneurysms

OBJECT

Some authors have questioned the need to perform cerebral angiography in patients presenting with a benign clinical picture and a perimesencephalic pattern of subarachnoid hemorrhage (SAH) on initial computerized tomography (CT) scans, because the low probability of finding an aneurysm does not justify exposing patients to the risks of angiography. It has been stated, however, that ruptured posterior circulation aneurysms may present with a perimesencephalic SAH pattern in up to 10% of cases. The aim of the present study was twofold: to define the frequency of the perimesencephalic SAH pattern in the setting of ruptured posterior fossa aneurysms, and to determine whether this clinical syndrome and pattern of bleeding could be reliably and definitely distinguished from that of aneurysmal SAH.

METHODS

Twenty-eight patients with ruptured posterior circulation aneurysms and 44 with nonaneurysmal perimesencephalic SAH were selected from a series of 408 consecutive patients with spontaneous SAH admitted to the authors' institution. The admission unenhanced CT scans were evaluated by a neuroradiologist in a blinded fashion and classified as revealing a perimesencephalic SAH or a nonperimesencephalic pattern of bleeding. Of the 28 patients with posterior circulation aneurysms, five whose grade was I according to the World Federation of Neurosurgical Societies scale were classified as having a perimesencephalic SAH pattern on the initial CT scan. The data show that the likelihood of finding an aneurysm on angiographic studies obtained in a patient with a perimesencephalic SAH pattern is 8.9%. Conversely, ruptured aneurysms of the posterior circulation present with an early perimesencephalic SAH pattern in 16.6% of cases.

CONCLUSIONS

This study supports the impression that there is no completely sensitive and specific CT pattern for a nonaneurysmal SAH. In addition, the authors believe that there is no specific clinical syndrome that can differentiate patients who have a perimesencephalic SAH pattern caused by an aneurysm from those without aneurysms. Digital subtraction angiography continues to be the gold standard for the diagnosis of cerebral aneurysms and should be performed even in patients who have the characteristic perimesencephalic SAH pattern on admission CT scans.