Surgical management of aneurysmal subarachnoid hemorrhage

Major intraoperative aneurysm rupture may increase the risk of cerebral infarction following surgical clipping of unruptured intracranial aneurysms

OBJECTIVE

Intraoperative aneurysm rupture (IAR) could cause a poor outcome. This study aimed to investigate the relationship between IARs and postoperative cerebral infarctions (CIs).

METHOD

We retrospectively reviewed patients with asymptomatic unruptured intracranial aneurysms (UIAs) who received microsurgical clipping in two neurosurgical centers from January 2016 to June 2019. A propensity score matching was done to constitute a cohort. The data were collected regarding the clinical and radiological characteristics. The CI at 1-2 weeks and the functional outcome at two weeks after clipping were recorded. Differences between IAR patients with CIs and without CIs were compared. The relationship between the IARs and postoperative CIs was investigated by using logistic regression analysis.

RESULTS

This study yielded 96 UIAs patients, including 48 patients undergoing IARs and 48 patients not. Twenty patients with CIs at 1-2 weeks after clipping were identified. The rate of CIs in patients undergoing IARs was higher than that in patients not undergoing IARs (OR, 2.88; p = 0.038); moreover, the mRS was also worse in patients undergoing IARs (OR, 1.58; p = 0.015). For patients undergoing IARs, the significance was found in ischemic cerebrovascular disease (OR, 6.40; p = 0.048), Essen stroke risk score (OR, 2.14; p = 0.026), and severity of intraoperative rupture (OR, 5.63; p = 0.023). The multivariate logistic analysis demonstrated the major IARs (OR, 6.09; CI, 1.18-31.53; p = 0.031) as the independent risk factor related to postoperative CI.

CONCLUSION

IARs could increase the risk of postoperative CIs and worsen the functional outcome, and major IAR was the independent risk factor related to the postoperative CIs.

Combined endovascular and microsurgical management of complex cerebral aneurysms

Cerebral aneurysms are associated with a 50% mortality rate after rupture and patients can suffer significant morbidity during subsequent treatment. Neurosurgical management of both ruptured and unruptured aneurysms has evolved over the years. The historical practice of using microsurgical clipping to treat aneurysms has benefited in the last two decades from tremendous improvement in endovascular technology. Microsurgery and endovascular therapies are often viewed as competing treatments but it is important to recognize their individual limitations. Some aneurysms are considered complex, due to several factors such as aneurysm anatomy and a patient’s clinical condition. A complex aneurysm often cannot be completely excluded with a single approach and its successful treatment requires a combination of microsurgical and endovascular techniques. Planning such an approach relies on understanding aneurysm anatomy and thus should routinely include 3D angiographic imaging. In patients with ruptured aneurysms, endovascular coiling is a well-tolerated early treatment and residual aneurysms can be treated with intervals of definitive clipping. Microsurgical clipping also can be used to reconstruct the neck of a complex aneurysm, allowing successful placement of coils across a narrow neck. Endovascular techniques are assisted by balloons, which can be used in coiling and testing parent vessel occlusion before sacrifice. In some cases microsurgical bypasses can provide alternate flow for planned vessel sacrifice. We present current paradigms for combining endovascular and microsurgical approaches to treat complex aneurysms and share our experience in 67 such cases. A dual microsurgical–endovascular approach addresses the challenge of intracranial aneurysms. This combination can be performed safely and produces excellent rates of aneurysm obliteration. Hybrid angiographic operating-room suites can foster seamless and efficient complementary application of these two modalities.

Safety of early endovascular catheterization and intervention through extracranial-intracranial bypass grafts

Object

The goal of this study was to demonstrate feasibility and evaluate technical aspects of early endovascular access through extracranial-intracranial (EC-IC) bypass grafts.

Methods

Patients undergoing endovascular interventions through the graft in the acute postoperative period following EC-IC bypass are presented. Results, complications, and technical nuances are reviewed.

Results

Fourteen endovascular procedures were performed in 5 patients after EC-IC bypass for ruptured aneurysms in 4 patients and posterior circulation ischemia in 1 patient. In 2 patients, a saphenous vein graft (SVG) was used to bypass the common carotid artery (CCA) to the middle cerebral artery (MCA). One patient underwent a superficial temporal artery (STA)–MCA bypass, and in 2 other patients the STA stump was connected to the intracranial circulation via an interposition SVG. The interval from surgery to endovascular intervention spanned 2–18 days; the indication was intracranial vasospasm in all patients. One case involved angioplasty of the proximal anastomosis on postoperative Day 14. All other interventions entailed proximal access through the bypass conduit for intraarterial infusion of vasodilators. Significant vasospasm of the STA itself was encountered in 2 patients during endovascular manipulation, and it was treated with intraarterial nitroglycerin. There were no cases of anastomotic disruption.

Conclusions

Endovascular catheterization and intervention involving a recent EC-IC bypass is feasible. The main limitation in this series was catheter-induced vasospasm involving the STA. A vein graft may be the more appropriate option in patients with subarachnoid hemorrhage who may require subsequent endovascular intervention for vasospasm.

Artifact quantification and tractography from 3T MRI after placement of aneurysm clips in subarachnoid hemorrhage patients

Background

The application of advanced 3T MRI imaging techniques to study recovery after subarachnoid hemorrhage (SAH) is complicated by the presence of image artifacts produced by implanted aneurysm clips. To characterize the effect of these artifacts on image quality, we sought to: 1) quantify extent of image artifact in SAH patients with implanted aneurysm clips across a range of MR sequences typically used in studies of volumetry, blood oxygen level dependent signal change (BOLD-fMRI), and diffusion-weighted imaging (DW-MRI) and 2) to explore the ability to reconstruct white matter pathways in these patients.

Methods

T1- and T2-weighted structural, BOLD-fMRI, and DW-MRI scans were acquired at 3T in two patients with titanium alloy clips in ACOM and left ACA respectively. Intensity-based planimetric contouring was performed on aligned image volumes to define each artifact. Artifact volumes were quantified by artifact/clip length and artifact/brain volume ratios and analyzed by two-way (scan-by-rater) ANOVAs. Tractography pathways were reconstructed from DW-MRI at varying distances from the artifacts using deterministic methods.

Results

Artifact volume varied by MR sequence for length (p = 0.007) and volume (p < 0.001) ratios: it was smallest for structural images, larger for DW-MRI acquisitions, and largest on fMRI images. Inter-rater reliability was high (r = 0.9626, p < 0.0001), and reconstruction of white matter connectivity characteristics increased with distance from the artifact border. In both patients, reconstructed white matter pathways of the uncinate fasciculus and inferior fronto-occipital fasciculus were clearly visible within 2 mm of the artifact border.

Conclusions

Advanced 3T MR can successfully image brain tissue around implanted titanium aneurysm clips at different spatial ranges depending on sequence type. White matter pathways near clip artifacts can be reconstructed and visualized. These findings provide a reference for designing functional and structural neuroimaging studies of recovery in aSAH patients after clip placement.

Applications of multislice CT angiography in the surgical clipping and endovascular coiling of intracranial aneurysms

Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage (SAH). The aim of our study was to assess the clinical usefulness of multislice computed tomography angiography (CTA) in the surgical and endovascular treatment of intracranial aneurysms. A total of 195 cases with 206 intracranial aneurysms underwent CTA. Fifty (24%) aneurysms underwent surgical clipping while 156 (76%) aneurysms underwent endovascular coiling. In the five missed aneurysms at digital substraction angiography and the nine aneurysms with mass intracerebral hematomas, surgical treatment was successfully performed based on 16-slice CTA alone, and the other 36 aneurysms were clipped on the main basis of the CTA. The intraoperative findings correlated well with the CTA findings and all aneurysms were clipped successfully. Sixteen-slice CTA image information has been shown to determine the choice of aneurysm therapy and assist the surgical and endovascular treatment of intracranial aneurysms.