Diagnostic usefulness of intraoperative ultrasonography for unexpected severe brain swelling in ultra-early surgery for ruptured intracranial aneurysms

Demonstrative study of brain anatomical landmarks by intraoperative ultrasound imaging

Objectives

Intraoperative use of ultrasound in brain surgery needs good understanding of the brain anatomy in ultrasound images. This study aims to compare ultrasound imaging of brain anatomical landmarks during surgery to perioperative computed tomography (CT), and perioperative magnetic resonance imaging (MRI) as demonstration for encouraging usage as low cost, available and hazardless device.

Methods

In total; 350 patients were subjected to brain surgeries under ultrasound guidance using 2.5–8 megahertz (MHZ) transducers, at neurosurgery department Zagazig university hospital from January 2012 to January 2019. Brain anatomical landmarks were compared between ultrasound images, and perioperative images for safe, and confident surgeries.

Results

Various intracranial anatomical landmarks could be well-demonstrated by ultrasound through the open fontanel, or once the skull was opened, and during surgical work in real time fashion, facilitating surgical procedures, and avoiding complications.

Conclusion

Real-time ultrasound is of great help during brain surgeries in delineating brain anatomical landmarks as well as MRI, and CT brain. The growing learning standard of intraoperative ultrasound (IOUS) use makes brain surgery more simple with avoiding brain shift problems, radiation exposure, and high cost of other intraoperative modalities.

Contemporary Management of Increased Intraoperative Intracranial Pressure: Evidence-Based Anesthetic and Surgical Review

Increased intracranial pressure (ICP) is frequently encountered in the neurosurgical setting. A multitude of tactics exists to reduce ICP, ranging from patient position and medications to cerebrospinal fluid diversion and surgical decompression. A vast amount of literature has been published regarding ICP management in the critical care setting, but studies specifically tailored toward the management of intraoperative acute increases in ICP or brain bulk are lacking. Compartmentalizing the intracranial space into blood, brain tissue, and cerebrospinal fluid and understanding the numerous techniques available to affect these individual compartments can guide the surgical team to quickly identify increased brain bulk and respond appropriately. Rapidly instituting measures for brain relaxation in the operating room is essential in optimizing patient outcomes. Knowledge of the efficacy, rapidity, feasibility, and risks of the various available interventions can aid the team to properly tailor their approach to each individual patient. In this article, we present the first evidence-based review of intraoperative management of ICP and brain bulk.

Intraoperative premature rupture of middle cerebral artery aneurysms: risk factors and sphenoid ridge proximation sign

OBJECTIVE This study was an investigation of surgical cases of a ruptured middle cerebral artery (MCA) aneurysm that was conducted to identify the risk factors of an intraoperative premature rupture. METHODS Among 927 patients with a ruptured intracranial aneurysm who were treated over an 8-year period, the medical records of 182 consecutive patients with a ruptured MCA aneurysm were examined for cases of a premature rupture, and the risk factors were then investigated. The risk factors considered for an intraoperative premature rupture of an MCA aneurysm included the following: patient age; sex; World Federation of Neurosurgical Societies clinical grade; modified Fisher grade; presence of an intracerebral hemorrhage (ICH); location of the ICH (frontal or temporal); volume of the ICH; maximum diameter of the ruptured MCA aneurysm; length of the preaneurysmal M₁ segment between the carotid bifurcation and the MCA aneurysm; and a sign of sphenoid ridge proximation. The sphenoid ridge proximation sign was defined as a spatial proximation < 4 mm between the sphenoid ridge and the rupture point of the MCA aneurysm, such as a daughter sac, irregularity, or dome of the aneurysm, based on the axial source images of the brain CT angiography sequences. RESULTS A total of 11 patients (6.0%) suffered a premature rupture of the MCA aneurysm during surgery. The premature rupture occurrences were classified according to the stage of the surgery, as follows: 1) craniotomy and dural opening (n = 1); 2) aspiration or removal of the ICH (n = 1); 3) retraction of the frontal lobe (n = 1); 4) dissection of the sphenoid segment of the sylvian fissure to access the proximal vessel (n = 4); and 5) perianeurysmal dissection (n = 4). The multivariate analysis with a binary logistic regression revealed that presence of a sphenoid ridge proximation sign (p < 0.001), presence of a frontal ICH associated with the ruptured MCA aneurysm (p = 0.019), and a short preaneurysmal M₁ segment (p = 0.043) were all statistically significant risk factors for a premature rupture. Plus, a receiver operating characteristic curve analysis revealed that a preaneurysmal M₁ segment length ≤ 13.3 mm was the best cutoff value for predicting the occurrence of a premature rupture (area under curve 0.747; sensitivity 63.64%; specificity 81.66%). CONCLUSIONS Patients exhibiting a sphenoid ridge proximation sign, the presence of a frontal ICH, and/or a short preaneurysmal M₁ segment are at high risk for an intraoperative premature rupture of a MCA aneurysm. Such high-risk MCA aneurysms have a superficial location close to the arachnoid in the sphenoidal compartment of the sylvian fissure and have a rupture point directed anteriorly.

Formal protocol for emergency treatment of ruptured intracranial aneurysms to reduce in-hospital rebleeding and improve clinical outcomes

OBJECT

While the incidence of a recurrent hemorrhage is highest within 24 hours of subarachnoid hemorrhage (SAH) and increases with the severity of the clinical grade, a recurrent hemorrhage can occur anytime after the initial SAH in patients with both good and poor clinical grades. Therefore, the authors adopted a 24-hour-a-day, formal protocol, emergency treatment strategy for patients with ruptured aneurysms to secure the aneurysms as early as possible. The incidences of in-hospital rebleeding and clinical outcomes were investigated and compared with those from previous years when broadly defined early treatment was used (<3 days of SAH).

METHODS

During an 11-year period, a total of 1224 patients with a ruptured aneurysm were managed using a strategy of broadly defined early treatment between 2001 and 2004 (Period B, n=423), a mixture of early or emergency treatment between 2005 and 2007, and a formal emergency treatment protocol between 2008 and 2011 (Period A, n=442). Propensity score matching was used to adjust the differences in age, sex, modified Fisher grade, World Federation of Neurosurgical Societies (WFNS) clinical grade at admission, size and location of a ruptured aneurysm, treatment modality (clip placement vs coil embolization), and time interval from SAH to admission between the two time periods. The matched cases were allotted to Group A (n=280) in Period A and Group B (n=296) in Period B and then compared.

RESULTS

During Period A under the formal emergency treatment protocol strategy, the catheter angiogram, endovascular coiling, and surgical clip placement were started at a median time from admission of 2.0 hours, 2.9 hours, and 3.1 hours, respectively. After propensity score matching, Group A showed a significantly reduced incidence of in-hospital rebleeding (2.1% vs 7.4%, p=0.003) and a higher proportion of patients with a favorable clinical outcome (modified Rankin Scale score 0-3) at 1 month (87.9% vs 79.7%, respectively; p=0.008). In particular, the patients with good WFNS grades in Group A experienced significantly less in-hospital rebleeding (1.7% vs 5.7%, respectively; p=0.018) and better clinical outcomes (1-month mRS score of 0-3: 93.8% vs 87.7%, respectively; p=0.021) than the patients with good WFNS grades in Group B.

CONCLUSIONS

Patients with ruptured aneurysms may benefit from a strategy of emergency application of surgical clip placement or endovascular coiling due to the reduced incidence of recurrent bleeding and improved clinical outcomes.

Controversies in the anesthetic management of intraoperative rupture of intracranial aneurysm

Despite great advancements in the management of aneurysmal subarachnoid hemorrhage (SAH), outcomes following SAH rupture have remained relatively unchanged. In addition, little data exists to guide the anesthetic management of intraoperative aneurysm rupture (IAR), though intraoperative management may have a significant effect on overall neurological outcomes. This review highlights the various controversies related to different anesthetic management related to aneurysm rupture. The first controversy relates to management of preexisting factors that affect risk of IAR. The second controversy relates to diagnostic techniques, particularly neurophysiological monitoring. The third controversy pertains to hemodynamic goals. The neuroprotective effects of various factors, including hypothermia, various anesthetic/pharmacologic agents, and burst suppression, remain poorly understood and have yet to be further elucidated. Different management strategies for IAR during aneurysmal clipping versus coiling also need further attention.