Impact of Young Age on the Presentation of Saccular Intracranial Aneurysms: Population-Based Analysis of 4082 Patients

Neurosurgery, Volume 82, 2018, 815–823

Formation and rupture of saccular intracranial aneurysms (sIAs) may have different pathobiologies in patients with younger age at first diagnosis of sIA disease.
OBJECTIVE: To study the phenotype of sIA disease and formation of new (de novo) sIAs in patients below 40 yr.
METHODS: A population-based cohort study was conducted in 613 young (<40 yr) sIA patients with first diagnosis between 1980 and 2014 and total angiographic follow-up of 3768 yr.
RESULTS: Of the 613 sIA patients <40 yr, 508 had aneurysmal subarachnoid hemorrhage (sIA-SAH) and 105 unruptured sIA(s) at first sIA diagnosis. Hypertension was 2 times less common among <40 than >40-yr-old patients (unruptured and ruptured). Smoking was very prevalent in <40-yr-old patients (33% in SAH, 68% unruptured). SAH patients <40 yr more often had family history of sIA, and lower PHASES scores (age omitted, P < .001). Ruptured sIAs were small (<7 mm) in 33% of 39 to 30 yr patients, in 44% of 29 to 20 yr patients, and 57% of <19 yr patients. Their shape was irregular in 90%, 94%, and 95%, respectively. Smoking history (hazard ratio [HR] 2.8, 95% confidence interval [CI] 1.2-7.0), family history for sIAs (HR 3.1, 95% CI 1.3-7.7), and age at presentation (HR .91 per year, 95% CI .85-.98) were risk factors for de novo sIA formation, diagnosed in 4% even after 20 yr (median 11.8 yr).
CONCLUSION: Smoking and family history are risk factors for sIA formation and aneurysmal SAH at young age. Young aneurysmal SAH patients had lower PHASES scores and often rupture from a small sIA, suggesting need for more aggressive management.

Supraorbital approach through eyebrow skin incision for aneurysm clipping

Acta Neurochirurgica (2018) 160:1155–1158

Surgery has been in a huge development where the aim is to achieve same or better results with less complication in a less invasive way; these minimal approaches can be applied in a very safe way to aneurysmal neurosurgery.

Method Images are studied to optimize the patient positioning and the surgical roadmap. After the positioning, the skin incision, craniotomy, and dura incision are performed and intradural lesion is reached. A watertight closure is performed under the microscope.

Conclusion The keyhole approach requires some adaption from the side of the surgeon and can be performed only in cases envisioned to have no increased risk for the patient.

Surgical clipping of vertebrobasilar junction aneurysms through a far-lateral transcondylar approach

Acta Neurochirurgica (2018) 160:1149–1153

Vertebrobasilar junction aneurysms occur rarely, but have a higher rupture rate than supratentoral aneurysms, and higher morbidity and mortality. Their location ventral to the neuroaxis makes them a challenging surgical lesion.

Methods In this paper, we share our experience with the surgical technique for the management of these complex aneurysms.

Conclusion An in-depth understanding of the anatomy of these aneurysms, careful preoperative planning, and a meticulous surgical technique, including knowledge of every detail of the procedure—positioning, an advanced skull base technique, and careful aneurysm dissection and clipping—is essential for a successful outcome of the surgery.

CircumferentialWall Enhancement on Magnetic Resonance Imaging is Useful to Identify Rupture Site in Patients with Multiple Cerebral Aneurysms

Neurosurgery 82:638–644, 2018

Identification of rupture sites in patients with multiple intracranial aneurysms is largely based on aneurysm size, location, and shape. Finding circumferential enhancement along the aneurysm wall (CEAW) on magnetic resonance (MR) vessel wall imaging was recently shown to be indicative of ruptured aneurysm.

OBJECTIVE: To investigate the hypothesis that a higher degree of CEAW would identify the site of rupture in patients with multiple aneurysms.

METHODS: We prospectively performed quantitative analysis of CEAW in consecutive patients with both aneurysmal subarachnoid hemorrhage and multiple aneurysms (26 patientswith a total of 62 aneurysms), usingMR vesselwall imaging. Three-dimensional T1-weighted fast spin-echo sequenceswere obtained before and after injection of contrast media, and the wall enhancement index (WEI) was calculated. Aneurysm characteristics (size, location, irregular shape, aspect ratio [neck-to-dome length/neck width], and WEI) were compared between ruptured and unruptured aneurysms. Odds ratios with 95% confidence intervals for ruptures were calculated with conditional univariable logistic regression analysis. Analyses were repeated after adjustment for aneurysm size.

RESULTS: Large aneurysm size, high aspect ratio, WEI (above the median values), and irregular shape were significantly associated with aneurysm rupture. After adjustment for aneurysm size, WEI (adjusted odds ratio: 8.8; 95% confidence interval, 1.1-72.6) as well as irregular shape and aspect ratio showed a strong association with rupture.

CONCLUSION: CEAW is associated with rupture of intracranial aneurysm independent of aneurysm size and patient characteristics. Contrast-enhanced MR vessel wall imaging helps to identify the site of rupture in patients with multiple aneurysms.

Microsurgery Simulator of Cerebral Aneurysm Clipping with Interactive Cerebral Deformation Featuring a Virtual Arachnoid

Operative Neurosurgery 14:579–589, 2018

A virtual reality simulator for aneurysmal clipping surgery is an attractive research target for neurosurgeons. Brain deformation is one of the most important functionalities necessary for an accurate clipping simulator and is vastly affected by the status of the supporting tissue, such as the arachnoid membrane. However, no virtual reality simulator implementing the supporting tissue of the brain has yet been developed.

OBJECTIVE: To develop a virtual reality clipping simulator possessing interactive brain deforming capability closely dependent on arachnoid dissection and apply it to clinical cases.

METHODS: Three-dimensional computer graphics models of cerebral tissue and surrounding structureswere extracted frommedical images.We developed a new method formodifiable cerebral tissue complex deformation by incorporating a nonmedical imagederived virtual arachnoid/trabecula in a process called multitissue integrated interactive deformation (MTIID). MTIID made it possible for cerebral tissue complexes to selectively deform at the site of dissection. Simulations for 8 cases of actual clipping surgery were performed before surgery and evaluated for their usefulness in surgical approach planning.

RESULTS: Preoperatively, each operative field was precisely reproduced and visualized with the virtual brain retraction defined by users. The clear visualization of the optimal approach to treating the aneurysmvia an appropriate arachnoid incision was possiblewith MTIID.

CONCLUSION: A virtual clipping simulatormainly focusing on supporting tissues and less on physical properties seemed to be useful in the surgical simulation of cerebral aneurysm clipping. To our knowledge, this article is the first to report brain deformation based on supporting tissues.

KEYWORDS: Virtual reality, Clipping, Aneurysm, Deformation, Arachnoid, Simulation

 

Stereotactic radiosurgery alone or combined with embolization for brain arteriovenous malformations

J Neurosurg 128:1338–1348, 2018

Embolization of brain arteriovenous malformations (AVMs) prior to stereotactic radiosurgery (SRS) has been reported to negatively affect obliteration rates. The goal of this systematic review and meta-analysis was to compare the outcomes of AVMs treated with embolization plus SRS (E+SRS group) and those of AVMs treated with SRS alone (SRS group).

METHODS A literature review was performed using PubMed to identify studies with 10 or more AVM patients and obliteration data for both E+SRS and SRS groups. A meta-analysis was performed to compare obliteration rates between the E+SRS and SRS groups.

RESULTS Twelve articles comprising 1716 patients were eligible for analysis. Among the patients with radiological follow-up data, complete obliteration was achieved in 48.4% of patients (330/681) in the E+SRS group compared with 62.7% of patients (613/978) in the SRS group. A meta-analysis of the pooled data revealed that the obliteration rate was significantly lower in the E+SRS group (OR 0.51, 95% CI 0.41–0.64, p < 0.00001). Symptomatic adverse radiation effects were observed in 6.6% (27/412 patients) and 11.1% (48/433 patients) of the E+SRS and SRS groups, respectively. The annual post-SRS hemorrhage rate was 2.0%–6.5% and 0%–2.0% for the E+SRS and SRS groups, respectively. The rates of permanent morbidity were 0%–6.7% and 0%–13.5% for the E+SRS and SRS groups, respectively.

CONCLUSIONS Arteriovenous malformation treatment with combined embolization and SRS is associated with lower obliteration rates than those with SRS treatment alone. However, this comparison does not fully account for differences in the initial AVM characteristics in the E+SRS group as compared with those in the SRS group. Further studies are warranted to address these limitations.

Circumferential Wall Enhancement on Magnetic Resonance Imaging is Useful to Identify Rupture Site in Patients with Multiple Cerebral Aneurysms

Neurosurgery 82:638–644, 2018

Identification of rupture sites in patients with multiple intracranial aneurysms is largely based on aneurysmsize, location, and shape. Finding circumferential enhancement along the aneurysm wall (CEAW) on magnetic resonance (MR) vessel wall imaging was recently shown to be indicative of ruptured aneurysm.

OBJECTIVE: To investigate the hypothesis that a higher degree of CEAW would identify the site of rupture in patients with multiple aneurysms.

METHODS: We prospectively performed quantitative analysis of CEAW in consecutive patients with both aneurysmal subarachnoid hemorrhage and multiple aneurysms (26 patientswith a total of 62 aneurysms), usingMR vesselwall imaging. Three-dimensional T1-weighted fast spin-echo sequenceswere obtained before and after injection of contrast media, and the wall enhancement index (WEI) was calculated. Aneurysm characteristics (size, location, irregular shape, aspect ratio [neck-to-dome length/neck width], and WEI) were compared between ruptured and unruptured aneurysms. Odds ratios with 95% confidence intervals for ruptures were calculated with conditional univariable logistic regression analysis. Analyses were repeated after adjustment for aneurysm size.

RESULTS: Large aneurysm size, high aspect ratio, WEI (above the median values), and irregular shape were significantly associated with aneurysm rupture. After adjustment for aneurysm size, WEI (adjusted odds ratio: 8.8; 95% confidence interval, 1.1-72.6) as well as irregular shape and aspect ratio showed a strong association with rupture.

CONCLUSION: CEAW is associated with rupture of intracranial aneurysm independent of aneurysm size and patient characteristics. Contrast-enhanced MR vessel wall imaging helps to identify the site of rupture in patients with multiple aneurysms.

 

Median Supraorbital Keyhole Approach for Clipping Ruptured Distal Anterior Cerebral Artery Aneurysm

World Neurosurg. (2018) 112:73-76

The minimally invasive approach to distal anterior cerebral artery (DACA) aneurysms has not gained much acceptance due to difficulties associated with the conventional frontal paramedian approach. The more proximal basal interhemispheric approach, however, necessitates extensive dissection of soft tissues. We describe a novel minimally invasive median supraorbital keyhole craniotomy with a basal interhemispheric approach for clipping a ruptured DACA aneurysm.

METHODS: A 62-year-old patient presented with subarachnoid hemorrhage. Computed tomography angiography revealed a DACA aneurysm. The surgical technique involved a keyhole craniotomy made via an eyebrow incision extending between the supraorbital notches, and flush with the anterior cranial fossa. The dura was opened at the anterior part, the falx was cut, an interhemispheric dissection was carried out, adequate proximal control was obtained, and the aneurysm neck was dissected and clipped. A relevant review of the literature was carried out.

RESULTS: The patient recovered well, with no residual aneurysm or forehead numbness, with good cosmesis. Compared with the previously described “keyhole unilateral interhemispheric” approaches, our technique has less likelihood of encountering bridging veins; easier cisternal cerebrospinal fluid release, making it feasible even in swollen brain; better proximal vascular control; and trajectory toward the neck rather than dome.

CONCLUSION: The median supraorbital keyhole approach is a minimally invasive technique sufficient for clipping most DACA aneurysms, with easier access, better proximal control, and good cosmesis.

Flow diverter devices in ruptured intracranial aneurysms

J Neurosurg 128:1037–1043, 2018

In this single-center series, the authors retrospectively evaluated the effectiveness, safety, and midterm follow-up results of ruptured aneurysms treated by implantation of a flow diverter device (FDD).

METHODS The records of 17 patients (12 females, 5 males, average World Federation of Neurosurgical Societies score = 2.9) who presented with subarachnoid hemorrhage (SAH) due to the rupture of an intracranial aneurysm treated with an FDD were retrospectively reviewed. Of 17 ruptured aneurysms, 8 were blood blister–like aneurysms and the remaining 9 were dissecting aneurysms. The mean delay between SAH and treatment was 4.2 days. Intraprocedural and periprocedural morbidity and mortality were recorded. Clinical and angiographic follow-up evaluations were conducted between 6 and 12 months after the procedure.

RESULTS None of the ruptured aneurysms re-bled after endovascular treatment. The overall mortality rate was 12% (2/17), involving 2 patients who died after a few days because of complications of SAH. The overall morbidity rate was 12%: 1 patient experienced intraparenchymal bleeding during the repositioning of external ventricular drainage, and 1 patient with a posterior inferior cerebellar artery aneurysm developed paraplegia due to a spinal cord infarction after 2 weeks. The angiographic follow-up evaluations showed a complete occlusion of the aneurysm in 12 of 15 surviving patients; of the 3 remaining cases, 1 patient showed a remnant of the aneurysm, 1 patient was retreated due to an enlargement of the aneurysm, and 1 patient was lost at the angiographic follow-up.

CONCLUSIONS FDDs can be used in patients with ruptured aneurysms, where conventional neurosurgical or endovascular treatments can be challenging.

Surgical Drains in Chronic Subdural Hematoma Surgery: From the Cheapest to the Most Expensive Drains

World Neurosurg. (2018) 112:284-286

Among the various neurosurgical techniques currently being used in chronic subdural hematoma (CSDH) surgery, bur hole craniostomy is the most popular worldwide. Recent studies have strongly recommended that a drain be placed after surgical evacuation of a hematoma, and a broad spectrum of preformed surgical drains is widely available for this purpose. If preformed drains are unavailable, a surgeon-made drain can be used and various methods are available to develop a drain in the operating room.

METHODS: Using a case report, we demonstrate how to develop a surgeon-made drain. Next, we retrospectively screened for subdural drain usage in consecutive patients undergoing bur hole drainage for CSDH at Adiyaman University Hospital between January 2017 and April 2017, and data from only those patients in whom a surgeon-made drain was used were included for analyses.

RESULTS: A 74-year-old male was operated with the diagnosis of CSDH. Assembly of a surgeon-made drain was explained step by step. Our review identified 6 unilateral and 2 bilateral cases in which 10 surgeon-made drains were used. Mean age of the patients was 72, and mean follow-up period was 7 months, 23 days. No instances of infection or drain-related complications had been recorded. The recurrence rate was 0%, and the average drainage period was 3.4 days.

CONCLUSIONS: In case of unavailability of a preformed drain, a surgeon-made drain can be used during CSDH surgery. Different methods are available and can be further diversified using various combinations of simple medical materials.

Delayed treatment of ruptured brain AVMs: is it ok to wait?

J Neurosurg 128:999–1005, 2018

Despite a hemorrhagic presentation, many patients with arteriovenous malformations (AVMs) do not require emergency resection. The timing of definitive management is not standardized in the cerebrovascular community. This study was designed to evaluate the safety of delaying AVM treatment in clinically stable patients with a new hemorrhagic presentation. The authors examined the rate of rehemorrhage or neurological decline in a cohort of patients with ruptured brain AVMs during a period of time posthemorrhage.

METHODS Patients presenting to the authors’ institution from January 2000 to December 2015 with ruptured brain AVMs treated at least 4 weeks posthemorrhage were included in this analysis. Exclusion criteria were ruptured AVMs that required emergency surgery involving resection of the AVM, prior treatment of AVM at another institution, or treatment of lesions within 4 weeks for other reasons (subacute surgery). The primary outcome measure was time from initial hemorrhage to treatment failure (defined as rehemorrhage or neurological decline as a direct result of the AVM). Patientdays were calculated from the day of initial rupture until the day AVM treatment was initiated or treatment failed.

RESULTS Of 102 ruptured AVMs in 102 patients meeting inclusion criteria, 7 (6.9%) failed the treatment paradigm. Six patients (5.8%) had a new hemorrhage within a median of 248 days (interquartile range 33–1364 days). The total “at risk” period was 18,740 patient-days, yielding a rehemorrhage rate of 11.5% per patient-year, or 0.96% per patient-month. Twelve (11.8%) of 102 patients were found to have an associated aneurysm. In this group there was a single (8.3%) new hemorrhage during a total at-risk period of 263 patient-days until the aneurysm was secured, yielding a rehemorrhage risk of 11.4% per patient-month.

CONCLUSIONS It is the authors’ practice to rehabilitate patients after brain AVM rupture with a plan for elective treatment of the AVM. The present data are useful in that the findings quantify the risk of the authors’ treatment strategy. These findings indicate that delaying intervention for at least 4 weeks after the initial hemorrhage subjects the patient to a low (< 1%) risk of rehemorrhage. The authors modified the treatment paradigm when a high-risk feature, such as an associated intracranial aneurysm, was identified.

The impact of nTMS mapping on treatment of brain AVMs

Acta Neurochirurgica (2018) 160:567–578

The treatment of brain arteriovenous malformations (BAVMs) is still contrarily discussed. Despite the debatable results of the ARUBA trial, most BAVMs still require treatment depending on the Spetzler-Martin (SM) grading. Since size is measurable and venous drainage is visible, the determination of eloquence is comparably crucial but not fully objective. The present bicentric cohort study aims to examine the influence of preoperative navigated transcranial magnetic stimulation (nTMS) motor and language mapping data on decision-making for or against surgical treatment of BAVMs.

Methods The influence of data from nTMS on decision-making for or against treatment of BAVMs was examined by confirming/falsifying presumed motor or language eloquence.

Results The results of nTMS mappings changed the SM grading in nine cases. In six cases, the SM grading changed to a lower grade (= falsified eloquence); in three cases, the SM grading changed to a higher grade due to nTMS mappings (= unexpected eloquence). Out of all 34 cases, indication for surgery was supported by nTMS mappings in 15 cases (7 motors, 8 languages). In six cases, the decision against surgery was made based on nTMS mappings (three motors, three languages).

Conclusion In 21 of 34 cases (62%), nTMS was a supportive argument. We could show that nTMS motor and language data can be used for a more objective decision-making regarding the treatment of BAVMs and for a more detailed SM grading regarding the rating of eloquence.

Aneurysm wall enhancement on magnetic resonance imaging as a risk factor for progression of unruptured vertebrobasilar dissecting aneurysms after reconstructive endovascular treatment

J Neurosurg 128:747–755, 2018

The recurrence rate of vertebrobasilar dissecting aneurysms (VBDAs) after reconstructive endovascular treatment (EVT) is relatively high. The aneurysm wall enhancement on high-resolution MRI (HRMRI) reportedly predicts an unsteady state of an intracranial aneurysm. The authors used HRMRI to investigate the relationship between wall enhancement on HRMRI and progression of VBDAs after reconstructive EVT.

METHODS From January 2012 to December 2015, patients with an unruptured VBDA who underwent reconstructive EVT were enrolled in this study. Preoperative enhanced HRMRI was performed to evaluate radiological characteristics. The relationships between aneurysm wall enhancement and various potential risk factors were statistically analyzed. Follow-up angiographic examination was performed with digital subtraction angiography and conventional HRMRI. Cox regression analysis was performed to identify predictors of VBDA progression after reconstructive EVT.

RESULTS Eighty-two patients (12 women and 70 men, mean age 53.48 ± 9.23 years) with 83 VBDAs were evaluated in the current study. The average maximum diameter of the VBDAs was 11.30 ± 7.90 mm. Wall enhancement occurred in 43 VBDAs (51.81%). Among all 83 VBDAs, 62 (74.70%) were treated by stent-assisted coil embolization and 21 (25.30%) by stenting alone. The mean duration of imaging follow-up among all 82 patients was 10.55 months (range 6–45 months), and 15 aneurysms (18.07%) exhibited progression. The statistical analysis indicated no significant differences in age, sex, risk factors (high blood pressure, smoking, diabetes mellitus, and a high cholesterol level), VBDA stage, or VBDA size between enhanced and unenhanced VBDAs. Univariate Cox regression analysis showed that both the maximum diameter of the VBDAs and wall enhancement were associated with recurrence (p < 0.05). Multivariate Cox proportional hazard regression analysis showed that the maximum diameter of the VBDAs and wall enhancement on HRMRI were independent risk factors for aneurysm progression (p < 0.05).

CONCLUSIONS Aneurysm size and wall enhancement on HRMRI can predict the progression of VBDAs after reconstructive EVT.

Outcomes of Elective Cerebral Aneurysm Treatment Performed by Attending Neurosurgeons after Night Work

Neurosurgery 82:329–334, 2018

The association between long work hours and outcomes among attending surgeons remains an issue of debate.

OBJECTIVE: To investigate whether operating emergently the night before an elective case was associated with inferior outcomes among attending neurosurgeons.

METHODS:We executed a cohort study with unruptured cerebral aneurysm patients,who underwent endovascular coiling or surgical clipping from 2009 to 2013 and were registered in the Statewide Planning and Research Cooperative Systemdatabase. We investigated the association of treatment by surgeons performing emergency procedures the night before with outcomes of elective cerebral aneurysm treatment using an instrumental variable analysis.  RESULTS:Overall, 4700 patients underwent treatment for unruptured cerebral aneurysms. Therewas no difference in inpatient mortality (adjusted difference, –0.7%; 95% confidence interval [CI], –1.4% to 0.02%), discharge to a facility (adjusted difference, –0.1%; 95% CI, –1.2% to 1.2%), or length of stay (adjusted difference, –0.58; 95% CI, –1.66 to 0.50) between patients undergoing elective cerebral aneurysm treatment by surgeons who performed emergency procedures the night before, and those who did not.

CONCLUSION: Using a comprehensive patient cohort in New York State for elective treatment of unruptured cerebral aneurysms, we did not identify an association of treatment by surgeons performing emergency procedures the night before, with mortality, discharge to a facility, or length of stay. Our study had 80% power to detect differences inmortality (our primary outcome), as small as 4.1%. The results of the present study do not support the argument for regulation of attending work hours.

Transcondylar approach for resection of lateral medullary cavernous malformation

Acta Neurochir (2018) 160:291–294

Resection of a medullary cavernous malformation requires aggressive exposure, but there is controversy on how much occipital condyle can be safely removed during the transcondylar approach.

Method We describe and demonstrate the use of the transcondylar approach to a medullary cavernous malformation, with emphasis on adequate surgical exposure while preserving the atlanto-occipital joint.

Conclusions Despite conservative handling of the occipital condyle, craniocervical stability may vary in patients after transcondylar surgery. A “dynamic” computer tomography, with views of the atlanto-occipital joint at each end-rotational extreme, may be the best postoperative assessment tool to evaluate the stability of the craniocervical junction.

Brainstem Cavernous Malformations: Surgical Indications Based on Natural History and Surgical Outcomes

World Neurosurg. (2018) 110:55-63

Cavernous malformations (CMs) are uncommon lesions occurring in the central nervous system, with an incidence of approximately 0.5% in the general population and constituting 5%e10% of all intracranial vascular malformations. Among CMs, prevalence within the brainstem as reported in the literature has ranged from 4% to 35%. With their precarious location and potentially devastating clinical events, brainstem CMs have attracted attention from neurosurgeons, and with these surgeons’ unrelenting efforts, the microsurgical techniques to treat these lesions in the brainstem have greatly improved in recent decades. Although surgical outcomes reported in the literature have been satisfying, surgical intervention has become increasingly contraindicated because of the tendency for a benign clinical course in brainstem CMs, after weighing this fact against the high risk of surgical morbidity. Thus, it is advisable to operate on patients with symptomatic lesions abutting the pial or ependymal surface of the brainstem or where lesions are accessible to safe entry zones, which have caused more than 1 significantly symptomatic hemorrhage and can be defined as aggressive. However, treatment remains controversial for deep-seated lesions away from the surface of the brainstem or lesions that are inaccessible to safe entry zones. Other treatments, such as radiosurgery and medication, are still debatable, which might be as an alternative for lesions amenable to but at high risk with surgery.

Surgical approach to posterior inferior cerebellar artery aneurysms

Acta Neurochir (2018) 160:295–299

The far-lateral is a standardised approach to clip aneurysms of the posterior inferior cerebellar artery (PICA). Different variants can be adopted to manage aneurysms that differ in morphology, topography, ruptured status, cerebellar swelling and surgeon preference.

Method We distinguished five paradigmatic approaches aimed to manage aneurysms that are: proximal unruptured; proximal ruptured requiring posterior fossa decompression (PFD); proximal ruptured not requiring PFD; distal unruptured; distal ruptured.

Conclusions Preoperative planning in the setting of PICA aneurysm surgery is of paramount importance to perform an effective and safe procedure, to ensure an adequate PFD and optimal proximal control before aneurysm manipulation.

ABC/2 Method Does not Accurately Predict Cerebral Arteriovenous Malformation Volume

Neurosurgery 82:220–225, 2018

Stereotactic radiosurgery (SRS) is a treatment option for cerebral arteriovenous malformations (AVMs) to prevent intracranial hemorrhage. The decision to proceed with SRS is usually based on calculated nidal volume. Physicians commonly use the ABC/2 formula, based on digital subtraction angiography (DSA), when counseling patients for SRS.

OBJECTIVE: To determine whether AVM volume calculated using the ABC/2 method on DSA is accuratewhen compared to the exact volume calculated from thin-cut axial sections used for SRS planning.

METHODS: Retrospective search of neurovascular database to identify AVMs treated with SRS from 1995 to 2015. Maximum nidal diameters in orthogonal planes on DSA images were recorded to determine volume using ABC/2 formula. Nidal target volume was extracted from operative reports of SRS. Volumes were then compared using descriptive statistics and paired t-tests.

RESULTS: Ninety intracranial AVMs were identified. Median volume was 4.96 cm3 [interquartile range (IQR) 1.79-8.85] with SRS planning methods and 6.07 cm3 (IQR 1.3-13.6) with ABC/2 methodology. Moderate correlation was seen between SRS and ABC/2 (r = 0.662; P<.001). Paired sample t-tests revealed significant differences between SRS volume and ABC/2 (t = –3.2; P = .002). When AVMs were dichotomized based on ABC/2 volume, significant differences remained (t = 3.1, P = .003 for ABC/2 volume < 7 cm3; t = –4.4, P < .001 for ABC/2 volume > 7 cm3).

CONCLUSION: The ABC/2 method overestimates cerebral AVM volume when compared to volumetric analysis from SRS planning software. For AVMs > 7 cm3, the overestimation is even greater. SRS planning techniques were also significantly different than values derived from equations for cones and cylinders.

Effectiveness of endoscopic surgery for supratentorial hypertensive intracerebral hemorrhage: a comparison with craniotomy

J Neurosurg 128:553–559, 2018

The goal of this study was to investigate the effectiveness and practicality of endoscopic surgery for treatment of supratentorial hypertensive intracerebral hemorrhage (HICH) compared with traditional craniotomy.

METHODS The authors retrospectively analyzed 151 consecutive patients who were operated on for treatment of supratentorial HICH between January 2009 and June 2014 in the Department of Neurosurgery at Chinese PLA General Hospital. Patients were separated into an endoscopy group (82 cases) and a craniotomy group (69 cases), depending on the surgery they received. The hematoma evacuation rate was calculated using 3D Slicer software to measure the hematoma volume. Comparisons of operative time, intraoperative blood loss, Glasgow Coma Scale score 1 week after surgery, hospitalization time, and modified Rankin Scale score 6 months after surgery were also made between these groups.

RESULTS There was no statistically significant difference in preoperative data between the endoscopy group and the craniotomy group (p > 0.05). The hematoma evacuation rate was 90.5% ± 6.5% in the endoscopy group and 82.3% ± 8.6% in the craniotomy group, which was statistically significant (p < 0.01). The operative time was 1.6 ± 0.7 hours in the endoscopy group and 5.2 ± 1.8 hours in the craniotomy group (p < 0.01). The intraoperative blood loss was 91.4 ± 93.1 ml in the endoscopy group and 605.6 ± 602.3 ml in the craniotomy group (p < 0.01). The 1-week postoperative Glasgow Coma Scale score was 11.5 ± 2.9 in the endoscopy group and 8.3 ± 3.8 in the craniotomy group (p < 0.01). The hospital stay was 11.6 ± 6.9 days in the endoscopy group and 13.2 ± 7.9 days in the craniotomy group (p < 0.05). The mean modified Rankin Scale score 6 months after surgery was 3.2 ± 1.5 in the endoscopy group and 4.1 ± 1.9 in the craniotomy group (p < 0.01). Patients had better recovery in the endoscopy group than in the craniotomy group. Data are expressed as the mean ± SD.

CONCLUSIONS Compared with traditional craniotomy, endoscopic surgery was more effective, less invasive, and may have improved the prognoses of patients with supratentorial HICH. Endoscopic surgery is a promising method for treatment of supratentorial HICH. With the development of endoscope technology, endoscopic evacuation will become more widely used in the clinic. Prospective randomized controlled trials are needed.

 

Brainstem arteriovenous malformations: lesion characteristics and treatment outcomes

J Neurosurg 128:126–136, 2018

Brainstem arteriovenous malformations (AVMs) are rare lesions that are difficult to diagnose and treat. They are often more aggressive in their behavior when compared with their supratentorial counterparts. The consequence of a brainstem hemorrhage is often devastating, and many patients are in poor neurological status at presentation. The authors examine the factors associated with angiographically confirmed cure and those affecting management outcomes for these complex lesions.

METHODS This was a retrospective analysis of data gathered from the prospectively maintained Stanford AVM database. Lesions were grouped based on their location in the brainstem (medulla, pons, or midbrain) and the quadrant they occupied. Angiographic cure was dichotomized as completely obliterated or not, and functional outcome was dichotomized as either independent or not independent at last follow-up.

RESULTS Over a 23-year period, 39 lesions were treated. Of these, 3 were located in the medulla, 14 in the pons, and 22 in the midbrain. At presentation, 92% of the patients had hemorrhage, and only 43.6% were functionally independent. Surgery resulted in the best radiographic cure rates, with a morbidity rate of 12.5%. In all, 53% of patients either improved or remained stable after surgery. Absence of residual nidus and female sex correlated with better outcomes.

CONCLUSIONS Brainstem AVMs usually present with hemorrhage. Surgery offers the best chance of cure, either in isolation or in combination with other modalities as appropriate.