Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5776_Библиотеки_им_академика_М_И_Перельмана

Here we report fi ndings from a patient who suff ered a SAH. Overall, SAHs are relatively uncommon, as only 15% of all strokes are hemorrhagic, about half of which are classifi ed as SAH (intracerebral bleeds make up the other half). Though it varies geographically and ethnically, the incidence of SAH ranges between 3 and 25 per 100,000. More frequently found in women (3:2 ratio), SAH can manifest at any age and has a peak incidence between 40 and 60 years. Approximately 80% of SAHs are caused by a ruptured aneurysm and the remaining 20% are non­aneurysmatic, nontraumatic (e.g., perimesencephalic and prepontine) bleeds, arteriovenous malformations (fi stu- las and angiomas), amyloid angiopathy, intracranial dis­sections, vasculitis, coagulation disorders, related to illicit drugs, and rarely cerebral venous thrombosis.

secondary etiologies should be considered—namely, re­versible cerebral vasoconstriction syndrome (see Case 36), arterial dissection (see Case 11), cerebral venous thrombo­sis (see Case 29), intracranial hemorrhage, ischemic stroke (rarely), spontaneous intracranial hypotension, pituitary apoplexy, posterior reversible encephalopathy syndrome (PRES), and intracranial infections.

• Grade I: Asymptomatic or mild headache and slight

nuchal rigidity.

defi cit except cranial nerve palsy.

Noncontrast cranial CT remains the fi rst-line method of choice for diagnosing SAH. Its accuracy depends on the time since symptom onset. Within 6 hours of hem­orrhage, modern CT yields a sensitivity and specifi city of 100% (Perry et al 2011). The sensitivity decreases contin­uously with time, reaching <60% after 1 week (van Gijn et al 1982). MRI is an alternative approach if CT is not diagnostic. Its sensitivity is similar to CT within the fi rst hours, but is notably higher in the more subacute stage (da Rocha et al 2006). A lumbar puncture is required for patients with nondiagnostic CT or MRI scans who have a history or symptoms suggestive of SAH. TCCS cannot con­fi dently visualize a fresh SAH within the cisterns.

2013). DSA remains the gold standard for SAH aneurysm assessment, but its benefi t for CTA-negative patients is controversial (Agid et al 2010). In addition to its diag­nostic benefi ts for both single and multiple aneurysms, DSA also enables optimal treatment strategy evaluation— i.e., determination of interventional and surgical a p p r o a c h e s — a s i t f a c i l i t a t e s a s s e s s m e n t o f a n e u r y s m c o n ­fi guration and may show small arteries arising from the aneurysm. DSA has been reported to detect symptomatic aneurysms in the acute SAH phase with a sensitivity of >98% (Westerlaan et al 2007). Aneurysm detection rates, if not detected on initial DSA, remain low (1–2%) in patients for whom DSA is repeated. This is particularly true if SAHs are restricted to the prepontine or perimesencephalic re­gions, as these are considered to be of venous origin, i.e., nonaneurysmatic (Alén et al 2008, Sabatino et al 2014). Correspondingly, no aneurysms were detected in a study that analyzed patients using follow-up DSA (Huttner et al

45). However, TCCS sensitivity is too low for primary as­sessment.

occurred more frequently in the clipping group, where­as rebleeding was signifi cantly higher in the coiling group (2.9% versus 0.9%). The absolute rate of rebleeding, however, was very low (2 versus 0 patients in 1 year). Long-term follow-up from 6 to 14 years and a mean of 9 years confi rmed a low rebleeding rate in both treatment groups and a lower mortality rate in the endovascular group. Additionally, the rate of patients with function­al independence was similar (83% in the endovascular group versus 82% in the neurosurgical group) (Molyneux et al 2009). The benefi t of interventional treatment— i.e., higher rate of disability-free survival and lower percentage of death or dependence—remained after a follow-up period of 10–18.5 years (sample size of 1,644 patients) (Molyneux et al 2015). As a consequence, the main policy should be to primarily treat using endovas­cular coiling if both techniques are an option. Aneurysm site, patient age, comorbidity, SAH grade, presence of ICH, quality of collaterals, and local circumstances (e.g., neurosurgical or interventional availability and compe­tence) are important variables and may favor a surgical approach. A clear surgical option is available in distally located aneurysms, such as the MCA bifurcation or peri­callosal artery, because surgical access is good but cath­eter access is often limited. Also, a wide aneurysm neck, arterial branches rising directly out of the aneurysmal sac, and accompanying relevant ICH may favor a surgical approach whereas posterior circulation aneurysms usual­ly require endovascular intervention (Steiner et al 2013). Our patient had previously undergone surgical treatment, 17 years ago after a fi rst SAH. At that time coil treatment was not established. Due to the aneurysm confi guration, no clipping was possible and therefore the aneurysm was wrapped, but this did not prevent rebleeding.

TCCS can be considered superior to TCD because of the additional visualization of the basal cerebral arteries, parenchyma, ventricles, and cisterns which permits a more reliable identifi cation of the insonated vessel seg- ment, especially regarding the more distal branches and the possibility of angle-corrected fl ow velocity meas- urements if appropriate. Accordingly, TCCS has a higher sensitivity when diagnosing arterial narrowing ≥50%, although similar sensitivities were observed regarding moderate VS (vessel narrowing <50%) (Swiat et al 2009). A second study observed TCCS superiority regarding not only the MCA but also the ICA (Proust et al 1999). Based on our own experience with both methods, we strongly recommend using TCCS instead of TCD.

threshold of 90 cm/s in the

However, the high proportion of false negatives may also be caused by aff ected distal branches (Sloan et al

segment (Rogge et al 2008), and the P3 and P4 branch­es of the PCA (Frid et al 2015). Blood fl ow velocities in these arterial segments can be assumed to be lower than in the main stems, based on the lower perfusion area. Ultrasound data of VS peripheral vessel assessment are scarce. One TCCS study including 47 SAH patients detect­ed an M2-MCA VS in 1 out of 10 patients which was the only reasonable explanation for DID (Mursch et al 2000). In our own DSA-correlated TCCS study with 57 patients looking only for VS in the M1 and M2 segments, we de­fi ned M2-MCA VS as non-angle-corrected fl ow velocities exceeding two standard deviations of the reported peak systolic fl ow velocity in healthy subjects and found a low- er sensitivity/specifi city for M2-MCA VS (65%/87%) than for M1-MCA VS (96%/73%). DSA showed a vessel narrow­ing >25% limited to the M1 segment in 60.3% and to the M2 segment in17.5%; 22.2% had VS involving both seg­ments (Connolly et al 2014). Of note, the variability of dis­tal branches and their curved and more vertically orient­ed courses make reliable fl ow velocity assessments more diffi cult than in the main stem of at least of the MCA.