Takeya Watabe

Intraoperative near-infrared indocyanine green–videoangiography (ICG–VA) and graphic analysis of fluorescence intensity in cerebral aneurysm surgery

We present our preliminary experience with intraoperative near-infrared indocyanine green-videoangiography (ICG-VA) and analysis of blood flow dynamics using fluorescence intensity assessment in cerebral aneurysm clipping surgery. Thirty-nine patients with 43 intracranial aneurysms underwent microsurgical clipping. Intraoperative ICG-VA was performed before and after clip application. An infrared fluorescence module integrated into a surgical microscope was used to visualize fluorescence in the surgical field and we recorded the emitted fluorescent light. An integrated analytical visualization tool simultaneously analyzed the video sequence and converted it into an intensity diagram, which allowed an objective evaluation of the results rather than the subjective assessment of fluorescence using ICG-VA. Overall, ICG-VA was performed 137 times. Incomplete clipping was detected in four patients, which allowed suitable adjustment to completely obliterate the aneurysm. In 12 patients, perforators arising close to, or from, the aneurysmal neck were identified in the surgical field. In three patients, the ICG-VA intensity diagram provided valuable information leading to modification of the primary surgical maneuver. ICG-VA provides high resolution images allowing real-time assessment of the blood flow in the parent artery and arterial branches, including the perforators. The intensity diagram is useful for providing a more objective record of the hemodynamics than the traditional ICG-VA, which relies more on subjective assessment and may allow interobserver variability. We conclude that ICG-VA, combined with the intensity diagram, can reduce the morbidity and complications associated with aneurysm clipping and improve patient outcomes.

Clinical characteristics and risk factors of chronic subdural haematoma associated with clipping of unruptured cerebral aneurysms

Chronic subdural haematoma (CSDH) is an uncommon but potentially serious complication of clipping unruptured cerebral aneurysms. We conducted a study to identify the patients who are at risk of developing postoperative CSDH. The data from 713 consecutive patients who underwent clipping of unruptured anterior circulation aneurysms were reviewed, and risk factors correlated with CSDH were identified by multivariate regression analysis of demographic variables. Fifteen patients (2.1%) developed CSDH after the surgery. Advanced age (odds ratio [OR] 1.151, 95% confidence interval [CI] 1.051-1.261) and male gender (OR 3.167, 95% CI 1.028-9.751) were correlated with CSDH. Subsequently, all 713 patients were quadrichotomized on the basis of gender and age, with 70 years as the cut-off value for age. The frequency of CSDH in men <70 years of age was 1.3% and that in men ≥70 years of age was 15.1%, with risk of CSDH was significantly higher in the older men (OR 13.39; 95% CI: 3.42-52.44). The frequency of CSDH in women <70 years of age was 0.6% and that in women ≥70 years of age was 3.7%. As in men, the risk of CSDH was significantly higher in the older women (OR 6.69, 95% CI 1.10-40.73). The interval between the aneurysm clipping and CSDH development was 0.5-6 months, suggesting that clinical observation should be continued up to 6 months after surgery. Although prognosis for patients with a postoperative CSDH complication is generally favourable, the risk of CSDH should be taken into account when considering elective clipping of unruptured aneurysms in patients ≥70 years of age.

Decompressive Hemicraniectomy for Malignant Hemispheric Stroke in the Elderly: Comparison of Outcomes between Individuals 61-70 and .70 Years of Age

BACKGROUND Malignant hemispheric infarction is a life-threatening condition with a high mortality rate. Decompressive hemicraniectomy (DHC) is frequently a life-saving procedure that has shown the highest grade of evidence for patients 18 to 60 years of age. However, the efficacy of DHC in patients>60 years of age has rarely been investigated. METHODS A retrospective study was conducted in a single academic institution. Surrogates of patients with clinical signs of impending brain herniation despite standard medical therapy were offered the option of DHC regardless of age or the side of the lesion. The clinical data from 18 patients>60 years of age who underwent DHC for malignant hemispheric infarction in our institution were analyzed. Patients were classified into the following 2 groups: 61-70 and >70 years of age, and their demographics and surgical outcomes were compared. The variables compared included the male:female ratio, side of the lesion, type of stroke, site of vascular occlusion, use of thrombolytic therapy, National Institutes of Health Stroke Scale score, stroke onset-to-DHC interval, duration of hospital stay, infectious complications, and 90-day mortality rate. RESULTS There were no significant intergroup differences in any of the demographic variables evaluated. However, the 30-day mortality rate was significantly higher in the group that was >70 years of age (0% v 60%; P=.01) than in the group that was 61 to 70 years of age. CONCLUSIONS We suggest that the efficacy of DHC in malignant hemispheric stroke patients between 61 and 70 years of age be further investigated in future randomized trials. By contrast, it appears unlikely that patients>70 years of age would benefit from DHC.

Preliminary evaluation of the role of surgical microscope-integrated intraoperative FLOW 800 colored indocyanine fluorescence angiography in arteriovenous malformation surgery

OBJECTIVE To discuss the role of FLOW 800 innovative software for analytical color visualization and objective evaluation of fluorescence videos obtained by microscope-integrated intraoperative indocyanine green (ICG) fluorescence angiography in arteriovenous malformations (AVM) surgery. MATERIALS AND METHODS Microscope-integrated intraoperative FLOW 800 was used and evaluated in three consecutive AVM surgeries over a period of two months. The role of FLOW 800 to distinguish feeding arteries from arterialized veins and other arteries was evaluated. Its advantages and limitations over conventional intraoperative ICG angiography were evaluated. RESULTS This software was found to be useful in identifying arterial feeders, arterialized veins and other arteries in all the three patients and it gives additional information on the status of AVM before and after clipping suspected feeders which is sometimes difficult to interpret on conventional ICG angiography. CONCLUSION Flow 800 is a reliable and useful addition to microscope-integrated color ICG video angiography. Although its role is limited in deep-seated AVMs, if properly dissected and exposed it can give useful information which can be easily interpretable and reproducible.

Transvenous Embolization for Carotid-Cavernous Fistula in a Patient with Vascular Type of Ehlers-Danlos Syndrome—Direct Superior Ophthalmic Vein Approach: Case Report

The vascular type of Ehlers-Danlos syndrome (vEDS) is an autosomal dominant hereditary disease characterized by connective tissue fragility throughout the body, including the arteries, viscera, and gastrointestinal tract. We report a case in which we performed transvenous embolization (TVE) via direct superior ophthalmic vein (SOV) approach to treat a direct carotid-cavernous fistula (CCF) in a patient with Ehlers-Danlos syndrome (EDS). The patient was a 37-year-old woman who developed tinnitus in her left ear and a headache during examination in the outpatient clinic of another hospital in order to make a definitive diagnosis of vEDS, and she was referred to our hospital and examined. Based on the results of all of the studies she was diagnosed with a CCF. Conservative treatment was attempted, but was not very effective. Because of progressing aphasia, TVE was performed via the SOV direct cut. There were no intraoperative or postoperative complications. It has been reported that cerebral angiography is generally contraindicated in vEDS and that the morbimortality associated with endovascular treatment is very high. When performing treatment it is necessary to be sufficiently aware of the risks it entails.

Intraoperative rupture in the surgical treatment of patients with intracranial aneurysms.

Intraoperative rerupture (IOR) during clipping of cerebral aneurysms is a difficult complication of microneurosurgery. The aim of this study was to evaluate the incidence of IOR and analyze the strategies for controlling profound hemorrhage. A total of 165 patients with unruptured intracranial aneurysms and 46 patients with subarachnoid hemorrhage (SAH) treated surgically between April 2010 and March 2011, were reviewed. The data were collected with regard to age, sex, presence of symptoms, confounding factors and strategy for controlling intraoperative hemorrhage was analyzed in terms of location of aneurysms, timing of rupture and severity of IOR. 211 patients with 228 aneurysms were treated in this series. There were a total of six IORs which represented an IOR rate of 2.84% per patient and 2.63% per aneurysm. The highest ruptures rates occurred in patients with internal carotid artery aneurysms (25%). Surgeries in the group with ruptured aneurysms had a much higher rate of IOR compared with surgeries in the group with unruptured aneurysms. Of the six IOR aneurysms, one occurred during predissection, four during microdissection and one during clipping. One was major IOR, three were moderate and two were minor. Intraoperative rupture of an intracranial aneurysm can be potentially devastating in vascular neurosurgery. Aneurysm location, presence of SAH and surgical experience of the operating surgeon seem to be important factors affecting the incidence of IOR.

Surgical treatment of patients with unruptured intracranial aneurysms

We present our experience with elective microsurgical clipping of unruptured intracranial aneurysms (UIA) and analyze this management. A total of 150 patients with UIA were reviewed and data were collected with regard to age, sex, presence of symptoms, location and size of the aneurysms, surgical complications and postoperative 1 year outcomes. Aneurysm size was assessed either by three-dimensional CT angiography or digital subtraction angiogram. Glasgow Outcome Scale was used to assess clinical outcomes. One hundred and fifty patients with 165 aneurysms were treated in this series. The mean size of the UIA was 5.6mm. Eighty aneurysms (48.5%) were less than 5mm in size, and 73 (44.2%) were from 5 to 10mm. Ten (6.1%) of the aneurysms were large and two (1.2%) were giant. One hundred and forty-three were asymptomatic and seven were symptomatic before surgery. The outcome was good in 147 patients (98%), and only three patients (2%) had a treatment-related unfavorable outcome. Five patients experienced transient neurological deficits and one patient experienced permanent neurological deficits. Overall 98.7% of the treated aneurysms were satisfactorily obliterated. Wound complications were seen only in three patients. In conclusion, UIA pose a significant challenge for neurosurgeons, where a delicate balance between benefits and possible risks must be weighed. If the requisite expertise is available, they can be treated surgically with low morbidity and a good outcome at specialized neurovascular centers.

Recent advances in diagnostic approaches for sub-arachnoid hemorrhage

Sub-arachnoid hemorrhage (SAH) has been easily one of the most debilitating neurosurgical entities as far as stroke related case mortality and morbidity rates are concerned. To date, it has case fatality rates ranging from 32-67%. Advances in the diagnostic accuracy of the available imaging methods have contributed significantly in reducing morbidity associated with this deadly disease. We currently have computed tomography angiography (CTA), magnetic resonance angiography (MRA) and the digital subtraction angiography (DSA) including three dimensional DSA as the mainstay diagnostic techniques. The non-invasive angiography in the form of CTA and MRA has evolved in the last decade as rapid, easily available, and economical means of diagnosing the cause of SAH. The role of three dimensional computed tomography angiography (3D-CTA) in management of aneurysms has been fairly acknowledged in the past. There have been numerous articles in the literature regarding its potential threat to the conventional “gold standard” DSA. The most recent addition has been the introduction of the fourth dimension to the established 3D-CT angiography (4D-CTA). At many centers, DSA is still treated as the first choice of investigation. Although, CT angiography still has some limitations, it can provide an unmatched multi-directional view of the aneurysmal morphology and its surroundings including relations with the skull base and blood vessels. We study the recent advances in the diagnostic approaches to SAH with special emphasis on 3D-CTA and 4D-CTA as the upcoming technologies.

Surgical navigation-assisted endoscopic biopsy is feasible for safe and reliable diagnosis of unresectable solid brain tumors

Stereotactic biopsy has been validated for tissue sampling of deep-seated lesions that cannot be easily resected via open craniotomy. However, some inherent problems including the inability to directly observe the lesion and difficulty in confirming hemostasis limit its usefulness. To overcome these issues, we used the endoscope in brain tumor biopsy, for not only intraventricular tumors but also intraparenchymal tumors. The rigid scope was used in association with a surgical navigation system for intraparenchymal lesions via a transcortical route. There were no useful anatomical landmarks when the trajectory to the lesions was decided; therefore, surgical navigation system was required for the transcortical procedures. The endoscopic procedure described here was attempted in 21 cases of intraparenchymal lesions between January 2007 and February 2012. A definitive diagnosis was obtained in all cases, and genetic analysis was performed when required. Serious postsurgical hemorrhage or neurological deficits were not observed in any cases. Endoscopic surgery provides a clear view of the target and makes it easier to differentiate tumor tissue from normal brain tissue. Moreover, the endoscope helped to confirm hemostasis during the procedure. Thus, endoscopic biopsy has the potential to contribute toward safe and reliable diagnosis of brain tumors.

Contralateral approach to unruptured superior hypophyseal artery aneurysms.

OBJECTIVE To evaluate the feasibility and limitations of the contralateral approach to unruptured superior hypophyseal artery (SHA) aneurysms. METHODS Data regarding eight cases of superior hypophyseal artery aneurysms operated on by a contralateral pterional approach at our center from January 2008 to September 2010 were collected and evaluated retrospectively. Of these eight cases, six were male and two were female. The mean age was 57.1 years (range 28 years to 77 years). All the aneurysms were unruptured; five were on right side and three were on left side. The surgical technique and outcome of patients were reviewed. RESULTS All aneurysms were successfully clipped without complication and patency of all superior hypophyseal arteries was preserved. Postoperative three-dimensional computed tomography angiography revealed residual aneurysm in only one case. None of the patients had deterioration of visual acuity or field after surgery. The contralateral pterional approach was found to be appropriate for fully exposing the aneurysmal dome and neck without retraction of the optic nerve or the carotid artery in five cases. Slight retraction of the optic nerve was required in two cases, and significant manipulation of the optic nerve was required in one case. CONCLUSIONS The contralateral pterional approach for clipping of unruptured superior hypophyseal artery aneurysms is technically feasible and safe in a select group of patients where optimal results can be achieved without significant retraction of near by neurovascular structures.