Early surgery-related complications after aneurysm clip placement: an analysis of causes and patient outcomes

Treatment of ruptured intracranial aneurysms with parent artery flow diverter devices: A comprehensive systematic review and meta-analysis

BACKGROUND

Surgical clipping and endovascular coiling are well-established treatments for acutely ruptured intracranial aneurysms leading to acute subarachnoid hemorrhage (aSAH). However, these modalities have limitations, particularly in cases involving wide-necked, bifurcating, or dissecting aneurysms. Flow diverter (FD) devices, initially used for unruptured aneurysms, have emerged as an alternative treatment for ruptured aneurysms despite concerns about hemorrhagic complications.

AIMS

This study aimed to perform a comprehensive systematic review and meta-analysis to assess the efficacy and safety of parental artery FD devices in treating ruptured intracranial aneurysms.

METHODS

A systematic search was conducted in Medline, Embase, and Cochrane databases from inception to July 2024. The inclusion criteria focused on studies involving patients with acutely ruptured aneurysms treated with parental artery FDs, with or without adjunctive coiling. Studies were required to report clear, stratified data specific to the population of interest, and include more than five patients. Exclusion criteria included studies on non-ruptured aneurysms, intrasaccular flow diversion devices, or previously clipped aneurysms treated with FD. Data extraction was performed independently by two authors, and statistical analysis included single proportion analysis with 95% confidence intervals under a random-effects model, using R Studio. The primary outcome was the rate of aneurysm occlusion at follow-up.

SUMMARY OF REVIEW

A total of 60 studies encompassing 1300 patients were included. The primary outcome analysis revealed a 90% (95% CI: 87-92%; I2 = 51%) rate of total occlusion at follow-up. Subgroup analysis indicated an occlusion rate of 89% for anterior circulation aneurysms and 96% for posterior circulation aneurysms. Intraoperative complications occurred in 6% of cases, while postoperative complications were observed in 13%. Rebleeding rates were low at 1%, with a 2% need for retreatment. Good functional outcomes (mRS ⩽ 2) were achieved in 82% of patients, and the overall mortality rate was 4%.

CONCLUSIONS

FD devices demonstrated high rates of aneurysm occlusion and favorable functional outcomes in patients with acutely ruptured intracranial aneurysms. However, the low mortality rate and favorable outcomes observed may reflect selection bias toward patients with less severe SAH. Despite a modest complication rate, the overall safety and efficacy of FD devices suggest they may be a viable alternative to traditional treatments for specific aneurysm types. Further studies, including a broader spectrum of SAH severities, are warranted to optimize their use in clinical practice.

Effectivity and safety of endovascular coiling versus microsurgical clipping for aneurysmal subarachnoid hemorrhage: A systematic review and meta-analysis

BACKGROUND

There is an ongoing lack of consensus among clinicians regarding on the optimal aneurysmal subarachnoid hemorrhage (aSAH) management approach between endovascular coiling and microsurgical clipping.

METHODS

Comprehensive literature search for randomized controlled trials (RCTs) was conducted in Medline and Cochrane databases until January 1st, 2023 without language constraints. Effectivity outcomes included one-year mortality, one-year poor outcomes, and one-year complete aneurysmal occlusion, while safety outcomes comprised the incidence of vasospasms, rebleeding, post-operative complications, and cerebral ischemia.

RESULTS

Eight RCTs, involving 3585 aSAH patients, underwent comprehensive quantitative analysis. Among them, 1792 underwent endovascular coiling and 1773 patients had microsurgical clipping. Regarding effectivity, the rates of one-year mortality (OR: 0.79, 95% CI: 0.61-1.03, p = 0.08) exhibited no significant difference. However, endovascular coiling demonstrated an inferior one-year complete aneurysmal occlusion rate (OR: 0.33, 95% CI: 0.21-0.53, p < 0.00001), although with significantly lower rates of poor outcomes (OR: 0.68, 95% CI: 0.57-0.81, p < 0.00001) compared to the microsurgical clipping group. As for safety, endovascular coiling group exhibited lower rates of vasospasm (OR: 0.58, 95% CI: 0.36-0.92, p = 0.02), post-operative complications (OR: 0.40, 95% CI: 0.23-0.71, p = 0.02), and cerebral ischemia (OR: 0.36, 95% CI: 0.20-0.63, p = 0.0004). No significant effect on the incidence of rebleeding was observed (OR: 1.09, 95% CI: 0.73-1.63, p = 0.68).

CONCLUSIONS

Endovascular coiling proves superior and safer for aSAH patients, but consideration of resources, patient condition, and surgeon preferences is crucial for selecting the optimal approach.

The influence of contralateral circulation on computational fluid dynamics of intracranial arteries: simulated versus measured flow velocities

BACKGROUND

This study aimed to retrospectively evaluate the influence of contralateral anterior circulation on computational fluid dynamics (CFD) of intracranial arteries, by comparing the CFD values of flow velocities in unilateral anterior circulation with the measured values from phase-contrast magnetic resonance angiography (PC-MRA).

METHODS

We analyzed 21 unilateral anterior circulation models without proximal stenosis from 15 patients who performed both time-of-flight MRA (TOF-MRA) and PC-MRA. CFD was performed with the inflow boundary condition of a pulsatile flow of the internal carotid artery (ICA) obtained from PC-MRA. The outflow boundary condition was given as atmospheric pressure. Simulated flow velocities of the middle cerebral artery (MCA) and anterior cerebral artery (ACA) from CFD were compared with the measured values from PC-MRA.

RESULTS

The velocities of MCA were shown to be more accurately simulated on CFD than those of ACA (Spearman correlation coefficient 0.773 and 0.282, respectively). In four models with severe stenosis or occlusion of the contralateral ICA, the CFD values of ACA velocities were significantly lower (< 50%) than those measured with PC-MRA. ACA velocities were relatively accurately simulated in the models including similar diameters of both ACAs.

CONCLUSION

It may be necessary to consider the flow condition of the contralateral anterior circulation in CFD of intracranial arteries, especially in the ACA.

RELEVANCE STATEMENT

Incorporating the flow conditions of the contralateral circulation is of clinical importance for an accurate prediction of a rupture risk in Acom aneurysms as the bidirectional flow and accurate velocity of both ACAs can significantly impact the CFD results.

KEY POINTS

• CFD simulations using unilateral vascular models were relatively accurate for MCA. • Contralateral ICA steno-occlusion resulted in an underestimation of CFD velocity in ACA. • Contralateral flow may need to be considered in CFD simulations of ACA.

Outcomes and complications of cerebral aneurysms operated on by eyebrow incision according to aneurysm type and location

OBJECTIVE

Trans-eyebrow supraorbital aneurysmal neck clipping, also known as keyhole surgery, have many advantages of minimal invasive surgery. However, there are few studies on whether there is a difference in keyhole surgery according to the location of the aneurysm, and how the complications after keyhole approach differ from the conventional approach. The authors investigated the surgical outcome of keyhole aneurysmal surgery for clarify the characteristics of keyhole surgery.

METHODS

A retrospective study was performed with review of medical records and images of patients with anterior circulation aneurysm undergoing aneurysmal clipping with keyhole surgery. The patient's clinical condition, imaging, surgical condition, and outcome were investigated.

RESULTS

As a result of analysis about the location of the aneurysm, middle cerebral artery (MCA) aneurysm group had a longer operation time than internal carotid artery and anterior cerebral artery aneurysm groups, but there was no significant difference in complication rate. The olfactory dysfunction occurred more than that of conventional surgery and occurred less in MCA aneurysm group than others. Scalp sensory change in the surgical site was more common in patients with unruptured aneurysms.

CONCLUSION

By accurately investigating the frequency and severity of complications associated with trans-eyebrow aneurysmal neck clipping surgery, it can help to select a surgical approach considering risk versus benefit. In addition, patient's satisfaction can be increased by providing information to patients and caregivers in advance about the outcome of this approach and the anticipated complications.

Headache persisting after aneurysmal subarachnoid hemorrhage: A narrative review of pathophysiology and therapeutic strategies

OBJECTIVE

This narrative review of the literature concerns persistent headache attributed to past non-traumatic subarachnoid hemorrhage (SAH), based off demographic and clinical features, what are pathophysiologic mechanisms by which these headaches occur, which medical and interventional treatments have the most evidence for pain alleviation, and what pre-clinical evidence is there for emerging treatments for these patients.

BACKGROUND

Following initial stabilization and treatment of spontaneous SAH, most commonly due to aneurysmal rupture, headache in the immediate inpatient setting and persisting after discharge are an important cause of morbidity. These headaches often receive heterogenous treatment of uncertain efficacy, and the risk factors and pathophysiology of their development has received little study.

METHODS

A narrative review of current literature discussing post-SAH headache was conducted using a literature search in PubMed with search term combinations including "post subarachnoid hemorrhage pain", "subarachnoid hemorrhage headache", and "post subarachnoid hemorrhage headache". Clinical studies mentioning headache after SAH and/or treatment in the abstract/title were included through March, 2022.

RESULTS AND CONCLUSION

Post-SAH headaches are shown to decrease quality of life, have a multi-modal pathophysiology in their occurrence, and only a select few medications (reviewed herein) have been demonstrated to have efficacy in alleviation of these headaches, while also harboring possible risks including vasospasm and re-bleeding. An effective treatment paradigm of these headaches will include trials of evidence-based therapeutics, rapid reduction of opioid medications if not effective, and consideration of multi-modal pain control strategies including nerve blocks.

Staged treatment for ruptured wide-neck intracranial aneurysm with intentional partial coiling in the acute phase followed by definitive treatment

Background:

Evidence supports endovascular coiling for ruptured intracranial aneurysms (RIAs). However, in some cases, it is difficult to achieve complete occlusion by coiling, such as with wide-neck aneurysms. We report our experience with intentional staged RIA treatment using targeted endovascular coiling at the rupture point in the acute phase, followed by delayed stent-assisted coiling, flow diverter stenting, or surgical clipping.

Methods:

Consecutive patients with RIAs treated between April 2015 and June 2021 were retrospectively investigated. Clinical characteristics, treatment complications, and patient outcomes data were collected.

Results:

Among 108 RIAs treated in our hospital, 60 patients underwent initial coiling; 10 patients underwent staged treatment. The aneurysm locations were the anterior communicating artery (n = 5), internal carotid-posterior communicating artery (n = 3), internal carotid-paraclinoid (n = 1), and vertebral artery-posterior inferior cerebellar artery (n = 1). The mean ± standard deviation aneurysmal diameter was 9.6 ± 5.4 mm and the mean aspect ratio was 1.2 ± 0.7. As the second treatment to obliterate blood flow to the neck area, we performed five stent-assisted coiling, two flow-diverter stentings, and three surgical clippings. Only one minor perioperative complication occurred. The median duration between the first and second treatments was 18 days (range, 14– 42 days). Good clinical outcome (modified Rankin scale score 0–2) at 90 days was achieved in 5 (50%) cases. The median follow-up duration was 6.5 months (range, 3–35 months); no rerupture occurred.

Conclusion:

Intentional staged treatment with a short time interval for RIA was effective and feasible.

Long-Term Risk of Ischemic Stroke among Elderly Survivors of Non-Traumatic Subarachnoid Hemorrhage

INTRODUCTION

Non-traumatic subarachnoid hemorrhage (SAH) is associated with poor long-term functional outcomes, but the risk of ischemic stroke among SAH survivors is poorly understood.

OBJECTIVES

The aim of this study was to evaluate the risk of ischemic stroke among survivors of SAH.

METHODS

We performed a retrospective cohort study using claims data from Medicare beneficiaries from 2008 to 2015. The exposure was a diagnosis of SAH, while the outcome was an acute ischemic stroke, both identified using previously validated ICD-9-CM diagnosis codes. We used Cox regression analysis adjusting for demographics and stroke risk factors to evaluate the association between SAH and long-term risk of ischemic stroke.

RESULTS

Among 1.7 million Medicare beneficiaries, 912 were hospitalized with non-traumatic SAH. During a median follow-up of 5.2 years (IQR, 2.7-6.7), the cumulative incidence of ischemic stroke was 22 per 1,000 patients per year among patients with SAH, and 7 per 1,000 patients per year in those without SAH. In adjusted Cox models, SAH was associated with an increased risk of ischemic stroke (HR, 2.0; 95% confidence interval, 1.4-2.8) as compared to beneficiaries without SAH. Similar results were obtained in sensitivity analyses, when treating death as a competing risk (sub HR, 3.0; 95% CI, 2.8-3.3) and after excluding ischemic stroke within 30 days of SAH discharge (HR, 1.5; 95% CI, 1.1-2.3).

CONCLUSIONS

In a large, heterogeneous national cohort of elderly patients, survivors of SAH had double the long-term risk of ischemic stroke. SAH survivors should be closely monitored and risk stratified for ischemic stroke.

Safety and Clinical Outcome of Good-Grade Aneurysmal Subarachnoid Hemorrhage in Non-Intensive Care Units

BACKGROUND

While patients with good grade aneurysmal subarachnoid hemorrhage are routinely admitted in intensive care units, critical care capacity in low-middle income countries (LMICs) is limited. In this study, we report the outcomes of good-grade SAH (Hunt and Hess grades I & II) patients admitted in ICU and non-ICU settings at a center in the Philippines and determine if site of care is predictive of outcome.

METHODS

We performed a retrospective study of all adults diagnosed with good-grade SAH in a five-year period. Patients were analyzed according to three groups based on site of care: Group A (>50% of length of stay in ICU), Group B (>50% of LOS in non-ICU), and Group C (100% of LOS in non-ICU). The primary outcome measures were in-hospital mortality and mRS score at discharge. The secondary outcome measures were complication rate and LOS.

RESULTS

A total of 242 patients was included in the cohort, which had a mean age of 51.16 years and a female predilection (64%). The rates of in-hospital mortality and favorable functional outcome at discharge were 0.82% and 93.8%, respectively, with no difference across groups. Delayed cerebral ischemia and infection were more frequently diagnosed in ICUs (p < 0.001), while rebleeding occurred more commonly in non-ICUs (p = 0.02). The median LOS was significantly longer in patients who developed complications.

CONCLUSIONS

Admission of good-grade aneurysmal SAH patients in non-ICU settings did not adversely affect both in-hospital mortality and functional outcome at discharge. Prospective, randomized studies may lead to changes in pattern of ICU utilization which are critical for LMICs.

Adverse intraoperative events during surgical repair of ruptured cerebral aneurysms: a systematic review

Compared with endovascular techniques, clipping of ruptured cerebral aneurysms has been shown to associate with increased morbidity in several studies. Despite this, clipping remains the preferred option for many aneurysms. The objective of this study is to describe the reported adverse events of open repair of ruptured cerebral aneurysms and their impact on patient outcome. The PubMed, Embase and Cochrane databases were searched between June 1999 and June 2019 to identify original studies of at least 100 patients undergoing surgical repair of ruptured cerebral aneurysms and in which adverse event rates were reported. Thirty-six studies reporting adverse events in a total of 12,410 operations for repair of ruptured cerebral aneurysms were included. Surgical adverse events were common with 36 event types reported including intraoperative rupture (median rate of 16.6%), arterial injury (median rate of 3.8%) and brain swelling (median rate 5.6%). Only 6 surgical events were statistically shown to associate with poor outcomes by any author and for intraoperative rupture (the most frequently analysed), there was an even split between authors finding a statistical association with poor outcome and those finding no association. Even with modern surgical techniques, the technical demands of surgical aneurysm repair continue to lead to a high rate of intraoperative adverse events. Despite this, it is not known which of these intraoperative events are the most important contributors to the poor outcomes often seen in these patients. More research directed towards identifying the events that most drive operative morbidity has the potential to improve outcomes for these patients.

A Propensity Score-Matched Comparison of Readmission Rates Associated With Microsurgical Clipping and Endovascular Treatment of Ruptured Intracranial Aneurysms

BACKGROUND

In the treatment of aneurysmal subarachnoid hemorrhage (aSAH), microsurgical clipping, and endovascular therapy (EVT) with coiling are modalities for securing the ruptured aneurysm. Little data is available regarding associated readmission rates. We sought to determine whether readmission rates differed according to treatment modality for ruptured intracranial aneurysms.

METHODS

The Nationwide Readmissions Database (NRD) was used to identify adults who experienced aSAH and underwent clipping or EVT. Primary outcomes of interest were the incidences of 30- and 90-day readmissions (30dRA, 90dRA). Propensity score matching was used to generate matched pairs based on age, comorbidities, hospital volume, and hemorrhage severity.

RESULTS

We identified 13,623 and 11,160 patients who were eligible for 30dRA and 90dRA analyses, respectively. Among the patients eligible for 30dRA and 90dRA, we created 4282 and 3518 propensity score-matched pairs, respectively. There was no difference in the incidence of 30dRA (12.4% for clipping versus 11.2% for EVT; P = .094). However, 90dRA occurred more frequently after clipping (22.5%) compared to EVT (19.7%; P = .003). Clipping was associated with poor outcome after 30dRA (odds ratio [OR] = 1.51, 95% confidence interval [CI] 1.21-1.88, P < .001) and after 90dRA (OR = 1.60, 95% CI 1.34-1.91, P = .001). Mean duration to readmission and cost of readmission did not vary, but clipping was associated with longer lengths of stay during readmission.

CONCLUSIONS

Microsurgical clipping of ruptured aneurysms is associated with a greater incidence of 90dRA, but not 30dRA, compared to EVT. Poor outcomes after readmission are more common following clipping.

Causes of poor outcome in patients admitted with good-grade subarachnoid haemorrhage

BACKGROUND

Surgical risk in patients with unruptured aneurysms is well known. The relative impact of surgery and natural history of subarachnoid haemorrhage (SAH) on patients in good clinical condition (World Federation of Neurological Surgeons [WFNS] grades 1 and 2) is less well quantified. The aim of this study was to determine causes of poor outcome in patients admitted in good grade SAH.

METHODS

A retrospective study of prospectively collected data among WFNS-1 and -2 patients: demographics, SAH and aneurysm-related data, surgical complications and outcome as assesed by the Glasgow Outcome Scale (GOS). Causes of poor outcome (GOS 1-3) were determined.

RESULTS

During a 7-year period (2009-15), 56 patients with SAH WFNS-1 (39 patients) or WFNS-2 (17 patients) were treated surgically (21 men, 35 women; mean age, 52.4 years). According to the Fisher scale, 19 patients were grade 1 or 2; 37 patients were grade 3 or 4. Most aneurysms were located at anterior communicating (26) or middle cerebral (15) artery. Altogether, 11 patients (19.6%) achieved GOS 1-3. This was attributed to SAH-related complications in six patients (rebleeding, vasospasm), surgery in four patients (postoperative ischaemia in two, haematoma and ventriculitis in one patient each), grand-mal seizure with aspiration in one patient. Age over 60 years (p = 0.017) and presence of hydrocephalus (p < 0.001) were statistically significant predictors of poor GOS; other variables (e.g. sex, Fisher grade, aneurysm size or location, use of temporary clips, intraoperative rupture, vasospasm) were not significant.

CONCLUSIONS

Patients admitted in good-grade SAH achieve favourable outcome following surgical aneurysm repair in the majority of cases. Negative factors include age over 60 years and presence of hydrocephalus. Aneurysm surgery following good-grade SAH still carries a small but significant risk similar to that shown in large multi-institutional trials.

Aneurysmal Surgery in the Presence of Angiographic Vasospasm: An Outcome Assessment

Background and Purpose:

The timing of aneurysmal surgery for patients presenting within the period at risk for vasospasm (VS) is controversial. The goal of this study is to review our experience of surgically treated patients in the presence of angiographic VS.

Materials and Methods:

From 1990-2004, 894 consecutive patients presented with an aneurysmal subarachnoid hemorrhage (SAH) and were treated with a policy of early surgery. We retrospectively analyzed the patients that had pre-operative angiographic VS. In this study, symptomatic VS was diagnosed when a decreased level of consciousness and/or focal deficit occurred after SAH in the presence of angiographic VS without confounding factors. Functional outcome was assessed three months after SAH using the Glasgow Outcome Scale.

Results:

Of the 40 patients studied, 62.5% were in good clinical grade Hunt & Hess (H&H 1-2) on admission; 25%, intermediate grade (H&H 3); 12.5%, poor grade (H&H 4-5). Surgery was performed 24 hours or less after initial angiography in 87.5% of patients and less than 48 hours in 97.5%. Pre-operative symptomatic VS was diagnosed in 25%. Postoperatively, angiographic VS was documented in 87.2%. Of the 30% of patients that presented post-operative symptomatic VS, 66.7% also demonstrated pre-operative symptomatic VS. The functional outcome was favorable in 92.5% of the studied patients. Two deaths occurred in patients presenting pre-operative early radiological and symptomatic VS.

Conclusion:

Aneurysmal surgery, especially between 3-12 days following SAH, in the presence of asymptomatic pre-operative angiographic VS can be associated with a good outcome. Early surgery is not contra-indicated and might enable optimal treatment of VS.

Whole-brain CT perfusion combined with CT angiography for ischemic complications following microsurgical clipping and endovascular coiling of ruptured intracranial aneurysms

Ischemic complications associated with microsurgical clipping and endovascular coiling affects the outcome of patients with intracranial aneurysms. We prospectively evaluated 58 intracranial aneurysm patients who had neurological deterioration or presented with poor grade (Hunt-Hess grades III and IV), aneurysm size >13 mm and multiple aneurysms after clipping or coiling. Thirty patients had ischemic complications (52%) as demonstrated by whole-brain CT perfusion (WB-CTP) combined with CT angiography (CTA). Half of these 30 patients had treatment-associated reduction in the diameter of the parent vessels (n=6), ligation of the parent vessels or perforating arteries (n=2), and unexplained or indistinguishable vascular injury (n=7); seven of these 15 (73%) patients suffered infarction. The remaining 15 patients had disease-associated cerebral ischemia caused by generalized vasospasm (n=6) and focal vessel vasospasm (n=9); six of these 15 (40%) patients developed infarction. Three hemodynamic patterns of ischemic complications were found on WB-CTP, of which increased time to peak, time to delay and mean transit time associated with decreased cerebral blood flow and cerebral blood volume were the main predictors of irreversible ischemic lesions. In conclusion, WB-CTP combined with CTA can accurately determine the cause of neurological deterioration and classify ischemic complications. This combined approach may be helpful in assessing hemodynamic patterns and monitoring operative outcomes.

Agreement of measured and calculated serum osmolality during the infusion of mannitol or hypertonic saline in patients after craniotomy: a prospective, double-blinded, randomised controlled trial

Background

Mannitol and hypertonic saline are used to ameliorate brain edema and intracranial hypertension during and after craniotomy. We hypothesized that the agreement of measured and calculated serum osmolality during the infusion of hypertonic saline would be better than mannitol. The objective was to determine the accuracy of serum osmolality estimation by different formulas during the administration of hyperosmolar agent.

Methods

A prospective, randomized, double-blinded, controlled trial was conducted in a 30-bed neurosurgical intensive care unit at a university hospital. Thirty-five adult patients requiring the use of hyperosmolar agents for prevention or treatment of brain edema after elective craniotomy were enrolled, and randomly assigned 1:1 to receive 125 mL of either 20 % mannitol (mannitol group) or 3.1 % sodium chloride solution (hypertonic saline group) in 15 min. Serum osmolality, serum sodium and potassium concentration, blood urea nitrogen and blood glucose concentration were measured during the study period. The primary outcome was the agreement of measured and estimated serum osmolality during the infusion of the two experimental agents. We used Bland and Altman’s limits of agreement analysis to clarify the accuracy of estimated serum osmolality. Bias and upper and lower limits of agreement of bias were calculated.

Results

For each formula, the bias was statistically lower in hypertonic saline group than mannitol group (p < 0.001). Within group comparison showed that the lowest bias (6.0 [limits of agreement: −18.2 to 30.2] and 0.8 [−12.9 to 14.5] mOsml/kg in mannitol group and hypertonic saline group, respectively) was derived from the formula ‘2 × ([serum sodium] + [serum potassium]) + [blood urea nitrogen] + [blood glucose]’.

Conclusions

Compared to mannitol, a better agreement between measured and estimated serum osmolality was found during the infusion of hypertonic saline. This result indicates that, if hypertonic saline is chosen to prevent or treat brain edema, calculated serum osmolality can be used as a reliable surrogate for osmolality measurement.

Trial registration

ClinicalTrials.gov identifier: NCT02037815

Correlation of measured and calculated serum osmolality during mannitol or hypertonic saline infusion in patients after craniotomy: a study protocol and statistical analysis plan for a randomised controlled trial

INTRODUCTION

Brain oedema is a major complication after craniotomy. Hyperosmolar agents have been used as the medical treatment for this condition. Measurement and estimation of serum osmolality during hyperosmolar agent infusion is of clinical importance to evaluate clinical efficacy, adjust dosage and avoid side effects. However, several studies have shown that calculated serum osmolality may lead to a systematic bias compared with direct measurement. In the present study, mannitol or hypertonic saline (HS) will be used in patients after elective craniotomy. We aim to determine the accuracy of serum osmolality estimation during the application of hyperosmolar agent.

METHODS AND ANALYSIS

The study is a prospective, randomised, double-blinded, controlled, parallel-group design. Adult patients requiring the use of hyperosmolar agents for the prevention or treatment of postoperative brain oedema are enrolled and assigned randomly to one of the two treatment study groups, labelled as 'M group' and 'HS group'. Patients in the M and HS groups receive intravenous infusion of 125 mL of either 20% mannitol or 3.1% sodium chloride solution, respectively. Data will be collected immediately before the infusion of study agents, 15, 30, 60, 120, 240 and 360 min after the start of infusion of experimental agents, which includes serum osmolality, concentration of serum sodium, potassium, urea and glucose. Serum osmolality will be measured by means of freezing point depression. Estimated serum osmolality will also be calculated by using four formulas published previously. Osmole gap is calculated as the difference between the measured and the estimated values. The primary endpoint is the correlation of measured and estimated serum osmolality during hyperosmolar agent infusion.

ETHICS AND DISSEMINATION

The study was approved by the International Review Board (IRB) of Beijing Tiantan Hospital, Capital Medical University. Study findings will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT02037815.

Assessment of the clipping efficacy of intracranial aneurysms: analysis of the employed methodology in relation to case difficulty

OBJECTIVE

To assess intracranial aneurysms clipping efficacy (CE) employing different angiographic techniques in relation to the case difficulty.

METHOD

In the past 6 years, 152 patients harboring 179 aneurysms who underwent surgical clipping in our department were angiographically examined to confirm aneurysm occlusion. Intraoperative angiography (IA), post-operative conventional (PCA) and three-dimensional angiography were single or sequentially performed based on the surgeon's concern about case difficulty. The percentage of visualized angiographic abnormalities (PVAA) assessing CE and their impact on corrective treatment were retrospectively analysed.

RESULTS

The PVAA of IA was 67.8% (19 of 28 aneurysms). Eighteen of them (eight aneurysm remnants, four parent vessel stenosis, two distal branch occlusions and five clip slippage phenomena) underwent immediate corrective treatment (clip reposition in 11 cases, complementary clipping in three cases and combined treatment in four cases). The impact on corrective treatment was 94.7%. The PVAA of PCA was 18.4% (33 of 179 aneurysms). Fifteen patients presented aneurysm remnants, six presented parent vessel stenosis, five presented distal branch occlusions and seven presented clip slippage phenomena. The impact of this technique on corrective treatment was 15.1% (five of 33 angiographic abnormalities). In only one case, PCA demonstrated an aneurysm remnant which was missed on IA. Twenty patients were additionally examined with three-dimensional angiography. The impact on corrective treatment of three-dimensional angiography was 25% (five of 20 examined patients with angiographic abnormalities).

CONCLUSION

In pre-selected difficult cases, IA provides high PVAA and increased impact on corrective treatment. In non-selected patients, PCA shows low PVAA and reduced impact on corrective treatment. The complementary assessment with multiplanar three-dimensional angiography increases the impact on corrective treatment and facilitates decisions about the final case management.

Patterns in neurosurgical adverse events: open cerebrovascular neurosurgery

OBJECT

As part of a project to devise evidence-based safety interventions for specialty surgery, we sought to review current evidence concerning the frequency of adverse events in open cerebrovascular neurosurgery and the state of knowledge regarding methods for their reduction. This review represents part of a series of papers written to consolidate information about these events and preventive measures as part of an ongoing effort to ascertain the utility of devising system-wide policies and safety tools to improve neurosurgical practice.

METHODS

The authors performed a PubMed search using search terms "cerebral aneurysm", "cerebral arteriovenous malformation", "intracerebral hemorrhage", "intracranial hemorrhage", "subarachnoid hemorrhage", and "complications" or "adverse events." Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to be included to maximize the range of rates of occurrence for the reported adverse events.

RESULTS

The review revealed hemorrhage-related hyperglycemia (incidence rates ranging from 27% to 71%) and cerebral salt-wasting syndromes (34%-57%) to be the most common perioperative adverse events related to subarachnoid hemorrhage (SAH). Next in terms of frequency was new cerebral infarction associated with SAH, with a rate estimated at 40%. Many techniques are advocated for use during surgery to minimize risk of this development, including intraoperative neurophysiological monitoring, but are not universally used due to surgeon preference and variable availability of appropriate staffing and equipment. The comparative effectiveness of using or omitting monitoring technologies has not been evaluated. The incidence of perioperative seizure related to vascular neurosurgery is unknown, but reported seizure rates from observational studies range from 4% to 42%. There are no standard guidelines for the use of seizure prophylaxis in these patients, and there remains a need for prospective studies to support such guidelines. Intraoperative rupture occurs at a rate of 7% to 35% and depends on aneurysm location and morphology, history of rupture, surgical technique, and surgeon experience. Preventive strategies include temporary vascular clipping. Technical adverse events directly involving application of the aneurysm clip include incomplete aneurysm obliteration and parent vessel occlusion. The rates of these events range from 5% to 18% for incomplete obliteration and 3% to 12% for major vessel occlusion. Intraoperative angiography is widely used to confirm clip placement; adjuncts include indocyanine green video angiography and microvascular Doppler ultrasonography. Use of these technologies varies by institution.

DISCUSSION

A significant proportion of these complications may be avoidable through development and testing of standardized protocols to incorporate monitoring technologies and specific technical practices, teamwork and communication, and concentrated volume and specialization. Collaborative monitoring and evaluation of such protocols are likely necessary for the advancement of open cerebrovascular neurosurgical quality.

Management of patients with aneurismal subarachnoid hemorrhage and associated symptomatic vasospasm on presentation

Rebleeding and symptomatic vasospasm (VS) are the major causes of subsequent morbidity and mortality in patients surviving a subarachnoid hemorrhage (SAH). Although most patients present rapidly after the bleed, some may seek medical attention in a delayed fashion due to non-resolving or worsening headaches or new neurological deficits, requiring treatment during the period at risk for VS. Such patients may either present asymptomatic radiological VS on their diagnostic angiogram or present symptomatic VS confirmed on angiogram. A similar situation may occur in patients presenting within the first 48 hours after SAH with very early angiographic VS. Deciding on the optimal timing and modality of treatment in such patients with SAH and symptomatic VS on presentation is controversial. Only six observational studies that specifically assessed aneurysm treatment in the presence of symptomatic VS have been published to date. We reviewed the published literature on the management of ruptured intracranial aneurysms in the presence of symptomatic VS and suggest avenues for future studies.

Causes of neurological deficits following clipping of 200 consecutive ruptured aneurysms in patients with good-grade aneurysmal subarachnoid haemorrhage

BACKGROUND

The surgical risk of unruptured aneurysms is well quantified. Although the outcomes for ruptured aneurysms are also well described, due to the concurrent morbidity from the natural history of the haemorrhage, the relative contributions of surgery and natural history to outcome following aneurysmal subarachnoid haemorrhage (SAH) is not. Our aim was to quantify these risks.

METHODS

This was a retrospective case note and radiological review of 200 patients with aneurysmal World Federation of Neurological Surgeons grade 1 or 2 SAH, treated with surgical clipping over a period of 3 years. Cases were reviewed to establish the incidence of surgical complications. Outcome was assessed at 3-month follow-up on Glasgow outcome score and the influence of surgical complications on this was assessed.

RESULTS

Thirty-seven patients suffered a surgical complication (19%). Over one half (19/37) were due to a vascular injury and 13 of those resulted in an unfavourable outcome (7% of all operations). The remainder of the patients who suffered a surgical complication (18/37) included those with direct brain injury, cranial nerve injury, post-operative haematoma and bone flap infection. Of those, only two cases resulted in poor outcome (1% of operations). In total, 22 patients had an unfavourable outcome (11%). In 15 (8%), surgical complications were deemed the major contributory factor.

CONCLUSIONS

Overall, surgically treated good-grade SAH has a good outcome. The majority of poor outcomes are due to surgical complications and most of these are vascular. Careful preservation of perforators and accurate clip placement remain the key factors in determining outcome in surgically treated good-grade SAH.

Surgical management of blood blister-like aneurysms of the internal carotid artery

OBJECTIVE

To present a review of the literature and a case series of blood blister-like aneurysms (BBA) to show that an adapted direct surgical approach enables treatment of BBA with a low complication rate.

METHODS

A retrospective review was performed of patients treated for a ruptured BBA of the internal carotid artery (ICA) at Hôpital Notre-Dame from 2005-2009. Clinicoradiologic data and intraoperative videos were analyzed. Outcome was assessed using the modified Rankin scale (mRS).

RESULTS

This series includes 7 patients (4 women and 3 men) with a mean age of 44.7 (range 30-61). All patients presented with subarachnoid hemorrhage (SAH). Four angiograms were initially negative. Diameter of BBA ranged from 1.1-8.2 mm. No intraoperative or postoperative aneurysm rupture occurred in this series. Although angiograms showed expected mild stenosis of the ICA after clipping, no clinical or radiologic cerebral infarctions were observed. The outcome was favorable in all patients.

CONCLUSIONS

Recognition of BBA is essential for proper management. An appropriate neurosurgical strategy has enabled a significant reduction in perioperative aneurysm rupture compared with previous reports and obtains excellent functional results.

Intraoperative computed tomography angiography with computed tomography perfusion imaging in vascular neurosurgery: feasibility of a new concept

OBJECT

In vascular neurosurgery, there is a demand for intraoperative imaging of blood vessels as well as for rapid information about critical impairment of brain perfusion. This study was conducted to analyze the feasibility of intraoperative CT angiography and brain perfusion mapping using an up-to-date multislice CT scanner in a prospective pilot series.

METHODS

Ten patients with unruptured aneurysms underwent intraoperative scanning with a 40-slice sliding-gantry CT scanner. Multimodal CT acquisition was obtained in 8 patients consisting of dynamic perfusion CT (PCT) scanning followed by intracranial CT angiography. Two of these patients underwent CT angiography and PCT 2 times in 1 session as a control after repositioning cerebral aneurysm clips. In another 2 patients, CT angiography was performed alone. The quality of all imaging obtained was assessed in a blinded consensus reading performed by an experienced neurosurgeon and an experienced neuroradiologist. A 6-point scoring system ranging from excellent to insufficient was used for quality evaluation of PCT and CT angiography.

RESULTS

In 9 of 10 PCT data sets, the quality was rated excellent or good. In the remaining case, the quality was rated insufficient for diagnostic evaluation due to major streak artifacts induced by the titanium pins of the head clamp. In this particular case, the quality of the related CT angiography was rated good and sufficient for intraoperative decision making. The quality of all 12 CT angiography data sets was rated excellent or good. In 1 patient with an anterior communicating artery aneurysm, PCT scanning led to a repositioning of the clip because of an ischemic pattern of the perfusion parameter maps due to clip stenosis of an artery. The subsequent PCT scan obtained in this patient revealed an improved perfusion of the related vascular territory, and follow-up MR imaging showed only minor ischemia of the anterior cerebral artery territory.

CONCLUSIONS

Intraoperative CT angiography and PCT scanning were shown to be feasible with short acquisition time, little interference with the surgical workflow, and very good diagnostic imaging quality. Thus, these modalities might be very helpful in vascular neurosurgery. Having demonstrated their feasibility, the impact of these methods on patients' outcomes has now to be analyzed prospectively in a larger series.

Usefulness of preoperative three-dimensional computed tomographic angiography with two-dimensional computed tomographic imaging for rupture point detection of middle cerebral artery aneurysms

OBJECTIVE

We report the technique of three-dimensional computed tomographic (CT) angiography with a two-dimensional CT image aiding in the early operation of ruptured middle cerebral artery aneurysms. This combined image allows the prediction of the rupture point in the aneurysm and may reduce the risk of rupture during early clipping surgery.

METHODS

The findings for 14 patients with 14 middle cerebral artery ruptured aneurysms who underwent subsequent early clipping were analyzed. The average aneurysm size was 8.5 mm, and there were two large and one giant aneurysms. CT examinations were performed by means of a multidetector CT scanner (Aquilion M16; Toshiba Medical Systems, Tokyo, Japan) and reconstructed with a workstation (ZIO M900 QUADRA; Amin Co., Ltd., Tokyo, Japan). We constructed an operating view through three-dimensional CT angiography for a lateral transsylvian approach with a two-dimensional CT image (nonshaded volume-rendering image), which was perpendicular to the direction of the surgical approach. Using this combined image, we predicted the rupture point of the aneurysm and successfully performed clipping surgery through a lateral transsylvian approach. Rupture points were confirmed at the time of surgery. Rupture points of 13 out of 14 aneurysms appeared as we expected, but one differed; all aneurysms were successfully clipped. Thirteen of the 14 patients could be clipped without rupture at surgery, but the remaining patient experienced rupture just after craniotomy.

CONCLUSION

The combination of three-dimensional CT angiography and two-dimensional CT images may help improve the surgical outcome by indicating aneurysmal rupture points, leading to the prevention of rupture.

Current Indications for Aneurysm Surgery

Treatment of cerebral aneurysm has changed greatly over the last several years. Although surgery was the treatment of choice for decades, coiling is coming into more prevalent use now. This article highlights when each modality should be used.

Reversibility of extensive hemispheric cytotoxic cerebral edema following subarachnoid hemorrhage

INTRODUCTION

Cerebral edema, as assessed by computer-assisted tomography, has been proposed as a prognosis factor of poor outcome following aneurysmal subarachnoid hemorrhage. However, this radiological finding might wrongly influence the decision to maintain or withdraw treatment in critically ill patients.

CASE REPORT

We present the case of a 63-year-old female presenting with poor clinical grade after an aneurysmal rupture that developed extensive right hemispheric cytotoxic edema. With appropriate treatment, the brain edema progressively resolved and the clinical state improved.

CONCLUSION

We discuss the importance of recognizing the possible reversibility of such extensive hemispheric edema and its relevance to patient management.

Endovascular management of intracerebral and subarachnoid hemorrhage

Significant advances in neuroendovascular devices and techniques are changing the approach to the management of acute hemorrhagic stroke. Greater numbers of aneurysms can now be treated using a wide array of platinum coils. Intracranial stents and balloon remodeling have made possible the treatment of wide-necked aneurysms. Microcatheters have been developed with better tractability to traverse tortuous vessels and access vascular lesions. With more than an estimated 100,000 patients with aneurysms treated worldwide, coil embolization has an excellent safety profile and level of outcome, with similar or better results compared with surgical clipping in select patient populations. Arteriovenous malformations and fistulae may also benefit from endovascular treatment by embolization using n-butyl cyanoacrylate or coils. In this article, we describe the endovascular role for the most common causes of intracerebral and subarachnoid hemorrhages, with special attention toward ruptured aneurysms and vascular malformations.