[Indication and Technique of Ventriculo:Atrial Shunt for Normal Pressure Hydrocephalus].

The type of shunt surgery with the best outcome and lowest complication rate has not been established. Ventriculo-atrial(V-A)shunts have almost been abandoned as the first choice of surgery. However, the V-A shunt has many advantages; the operative site is narrower than in other types of shunt surgery, and intra-atrial pressure is lower than intra-abdominal pressure, which may guarantee constant cerebrospinal fluid flow and less malfunction. Since this procedure has been neglected, devices of V-A shunt are scarce. Furthermore, the technique to insert an atrial catheter into the jugular vein is not commonly performed by general neurosurgeons. Herein, we introduce a simple method of V-A shunt for general neurosurgeons.

Endoscopic Approach to Cerebellar and Large Putaminal Bleed.

OBJECTIVE: To highlight the basic points of brain endoscopic procedure for Cerebellar and Large Putaminal Hemorrhage to achieve repeatability and reproducibility in the results among the new brain endoscopic surgeons. METHOD: Sharing the experience of 10 years as an endoscopic surgeon to bring out the basic insight into the method, challenges, points which need special attention during the surgery and discussion of recent advancements in the endoscopic equipment for safe surgery. CONCLUSION: Procedure of endoscopic evacuation of brain hematoma is simple with learning curve. In the beginning new endoscopic surgeons should operate in the presence of experience surgeon. They should follow standard technique to achieve the good surgical outcome and uniformity in the result every time they perform the surgery.

Endoscopic Approach to Subcortical (Lobar) Hemorrhage.

OBJECTIVE: To highlight the basic points of brain endoscopic procedure for Subcortical (Lobar) Hemorrhage to achieve repeatability and reproducibility in the results among the new brain endoscopic surgeons. METHOD: Sharing the experience of 10 years as an endoscopic surgeon to bring out the basic insight into the method, challenges, points which need special attention during the surgery and discussion of recent advancements in the endoscopic equipment for safe surgery. CONCLUSION: Procedure of endoscopic evacuation of brain hematoma is simple with learning curve. In the beginning new endoscopic surgeons should operate in the presence of experience surgeon. They should follow standard technique to achieve the good surgical outcome and uniformity in the result every time they perform the surgery.

Endoscopic Approach to Putaminal Bleed.

OBJECTIVE: To highlight the basic points of brain endoscopic procedure for Putaminal Bleed to achieve repeatability and reproducibility in the results among the new brain endoscopic surgeons. METHOD: Sharing the experience of 10 years as an endoscopic surgeon to bring out the basic insight into the method, challenges, points which need special attention during the surgery and discussion of recent advancements in the endoscopic equipment for safe surgery. CONCLUSION: Procedure of endoscopic evacuation of brain hematoma is simple with learning curve. In the beginning new endoscopic surgeons should operate in the presence of experience surgeon. They should follow standard technique to achieve the good surgical outcome and uniformity in the result every time they perform the surgery.

Endoscopic Approach to Thalamic and Intraventricular Hemorrhage.

OBJECTIVE: To highlight the basic points of brain endoscopic procedure for Thalamic and Intraventricular Hemorrhage to achieve repeatability and reproducibility in the results among the new brain endoscopic surgeons. METHOD: Sharing the experience of 10 years as an endoscopic surgeon to bring out the basic insight into the method, challenges, points which need special attention during the surgery and discussion of recent advancements in the endoscopic equipment for safe surgery. CONCLUSION: Procedure of endoscopic evacuation of brain hematoma is simple with learning curve. In the beginning new endoscopic surgeons should operate in the presence of experience surgeon. They should follow standard technique to achieve the good surgical outcome and uniformity in the result every time they perform the surgery.

Adenosine-induced Flow Arrest to Facilitate Intracranial Complex Aneurysm Clip Ligation: Review of the Literature.

Complex intracranial aneurysms (CIAs) rank high among the most technically demanding neurosurgical pathologies. Microsurgery and clip ligation can be challenging in CIAs as circumferential visualization of the aneurysm, parent vessels, branches, perforators, and other neurovascular structures is important to prevent residual aneurysms or strokes from vessel or perforator occlusion. Decompression of the aneurysm sac is often required for CIAs. We reviewed the literature and PubMed advanced search showed 13 results of adenosine-induced flow arrest to facilitate intracranial complex aneurysm clip ligation which included three independent case reports and ten cases in a case series from 1999 to May 2016. Few case series have described the use of adenosine in intracranial aneurysm surgery. Satisfactory aneurysm decompression was achieved in all cases, and all aneurysms were clipped successfully. We recommend that adenosine cardiac arrest is a relatively novel method for decompression of intracranial aneurysms to facilitate clip application. With appropriate safety precautions, it is a reasonable alternative method when temporary clipping of proximal vessels is not desirable or not possible.

Computational Fluid Dynamics Analysis and Correlation with Intraoperative Aneurysm Features.

INTRODUCTION: There are many controversies about computational fluid dynamics (CFD) findings and aneurysm initiation, growth, and ultimate rupture. The aim of our work was to analyze CFD data in a consecutive series of patients and to correlate them with intraoperative visual aneurysm findings. METHODS: Hemoscope software (Amin, Ziosoft Corporation, Minato ward, Tokyo, Japan) was used to process images from 17 patients who underwent clipping of 18 aneurysms. Pressure (P), wall shear stress (WSS) gradient and vectors, normalized WSS, and streamlines (SL) direction and velocity were assessed. CFD data were compared to intraoperative visual findings. A total of 39 aneurysm wall areas were assessed. RESULTS: Red, thin aneurysm wall areas were more often associated with low WSS. However, the association of low WSS with high P, diverging WSS vectors, direct impact of SL, and high SL velocity more frequently matched with yellow, atherosclerotic aneurysm walls. CONCLUSIONS: Low WSS alone is not sufficient to determine the thickness of an aneurysm wall. Its association with other parameters might enable one to distinguish preoperatively atherosclerotic, thick areas (high P, diverging WSS vectors, high flow velocity) from thin areas with higher rupture risk (parallel WSS vectors, lower flow velocity). The changing balance between these parameters can modify the features and the risk of rupture of aneurysm wall over time.

Intraoperative Rupture Cerebral Aneurysm and Computational Flow Dynamics.

Intraoperative aneurysmal rupture (IAR) is the most fearsome complication of aneurysm surgery. IAR associates with high morbidity and mortality. In recent years, we have many studies regarding using computational fluid dynamics (CFD) in aneurysm surgery. CFD helps in calculating the velocity of blood flowing in the aneurysm sac, the pressure in the aneurysm sac, and wall shear stress (WSS). CFD also helps in predicting nature of aneurysm wall and thus may warn about different intraoperative microscopy findings in aneurysms. Using its application, surgeon may become more careful in doing microsurgical sharp dissection. A 40-year-old female admitted with diagnosis of unruptured anterior communicating artery aneurysm. CFD analysis demonstrated high intra-aneurysmal pressure and divergent WSS in dome. During sharp dissection, there was intraoperative rupture aneurysm twice which was managed with cotton tamponade and glue and temporary clipping aneurysm. Indocyanine green video angiography showed working parent arteries and nonfunctioning aneurysm. After operation, the patient recovered fully and had a modified Rankin score of 1. This case demonstrated importance of preoperative planning of aneurysm surgery using CFD analysis. IAR is associated with an increased risk for an unfavorable outcome. Accurate preoperative planning with studying flow dynamics and structure of aneurysm may help in use sharp microsurgical dissection more cautiously.

State-of-art in surgical treatment of dissecting posterior circulation intracranial aneurysms.

Vertebrobasilar (VB) intracranial dissecting aneurysms (IDAs) pose difficult therapeutic issues and are especially among the most difficult to manage surgically. There are, however, some cases where selective aneurysm obliteration by endovascular approach is impossible or is associated with an unacceptable risk of morbidity. This is particularly true when the aneurysm is dissecting, giant, or has a large neck. In such cases, surgical treatment may be the only alternative. Optimal management of these lesions is therefore challenging and treatment decisions have to be made on a case-by-case basis. Ideal treatment should be a complete surgical excision of the lesion; however, this procedure might only be possible after distal and proximal vessel wall occlusion which might not be tolerated by the patient depending on the location of the aneurysm. Therefore, formulation of recommendations concerning the surgical strategy remains still difficult due to inconsistency of surgical outcomes. The literature describing surgical strategy of VB IDAs is varying in quality and content, and many studies deal with only a few patients. In the presented review, the authors summarize the current knowledge on the incidence, pathogenesis, clinical presentation, and diagnostic procedures with special emphasis on surgical treatment of IDAs in posterior circulation.

Surgical treatment of large and giant cavernous carotid aneurysms.

Cavernous carotid aneurysms (CCAs) are uncommon pathologic entities. Extradural place and the skull base location make this type of an aneurysm different in clinical features and treatment techniques. Direct aneurysm clipping is technically difficult and results in a significant postoperative neurological deficit. Therefore, several techniques of indirect surgical treatment were developed with different surgical outcomes, such as proximal occlusion of internal carotid artery (ICA) or trapping with or without bypass (superficial temporal artery-middle cerebral artery bypass or high-flow bypass). High-flow bypass with proximal ICA occlusion seems to be the most appropriate surgical treatment for CCA because of the high rate of symptom improvement, aneurysm thrombosis, and minimal postoperative complications. However, in cases of CCA presented with direct carotid-cavernous fistula, the appropriate surgical treatment is high-flow bypass with aneurysm trapping, which the fistula can be obliterated immediately after surgery.

Dual-Image Videoangiography During Intracranial Microvascular Surgery.

OBJECTIVE: Indocyanine green videoangiography (ICG-VA) is a valuable tool to assess vessel and aneurysm patency during neurovascular surgical procedures. However, ICG-VA highlights vascular structures, which appear white over a black background. Anatomic relationships are sometimes difficult to understand at first glance. Dual-image videoangiography (DIVA) enables simultaneous visualization of light and near-infrared fluorescence images of ICG-VA. METHODS: The DIVA system was mounted on an OPMI Pentero Flow 800 intraoperative microscope. DIVA was used during microsurgical procedures on 5 patients who were operated for aneurysm clipping and superficial temporal artery-middle cerebral artery bypass. RESULTS: DIVA provides real-time simultaneous visualization of aneurysm and vessels and surrounding structures including brain, nerves, and surgical clips. Although visual contrast between vessels and background is higher with standard black-and-white imaging, DIVA makes it easier to understand anatomic relationships between intracranial structures. DIVA also provides better vision of the depth of field. CONCLUSIONS: DIVA has the potential to become a widely used intraoperative tool to check patency of intracranial vessels. It should be considered as an adjunct to standard ICG-VA for better understanding of vascular anatomy in relation to surrounding structures and can have an impact on decision making during surgery.

State-of-Art Surgical Treatment of Dissecting Anterior Circulation Intracranial Aneurysms.

Intracranial dissecting aneurysms (IDAs) are an important cause of subarachnoid hemorrhage, stroke, or compression of intracranial structures. Since the availability of endovascular treatment and the advantage of intraprocedural anticoagulation, an endovascular strategy has become the mainstay of their therapy. But in some cases selective aneurysm obliteration by the endovascular approach is impossible or associated with an unacceptable risk of morbidity. This is particularly true when the IDA is a blood blister-like aneurysm or when dissection affects peripheral branches of the internal carotid artery. The literature dealing with surgical treatment of IDAs in the anterior circulation is heterogeneous, and formulation of general recommendations concerning the surgical strategy remains difficult. The aim of this study was to conduct a systematic review of the current knowledge on incidence, pathogenesis, clinical presentation, and diagnostic procedures with a special emphasis on the surgical treatment of intracranial dissections of anterior circulation.

Surgical treatment of unruptured dissecting intracranial aneurysms of vertebral-posterior inferior cerebellar artery region.

A lack of published surgical experience and higher symptomatic recurrence than previously recognized prompted the authors to present their experience with the surgical treatment of unruptured intracranial dissecting aneurysms (UIDAs). Hospital records, neuroimaging studies, operative reports, and follow-up records were retrospectively reviewed. All patients underwent surgical exploration of the lesion with proximal clipping of the parent artery through a far-lateral suboccipital craniotomy with or without partial condylar resection. The surgical treatment of vertebral artery-posterior inferior cerebellar artery UIDAs has acceptable risk regarding perioperative mortality and morbidity. The incidence of aneurysmal recurrence or the need for retreatment seems to be less than that associated with anticoagulation/antiplatelet therapy or endovascular treatment.

Comparison of computational fluid dynamics findings with intraoperative microscopy findings in unruptured intracranial aneurysms- An initial analysis.

CONTEXT: The increase in the detection of unruptured cerebral aneurysms has led to management dilemma. Prediction of risk based on the size of the aneurysm is not always accurate. There is no objective way of predicting rupture of aneurysm so far. Computational fluid dynamics (CFDs) was proposed as a tool to identify the rupture risk. AIMS: To know the correlation of CFD findings with intraoperative microscopic findings and to know the relevance of CFD in the prediction of rupture risk and in the management of unruptured intracranial aneurysms. SETTINGS AND DESIGN: A prospective study involving nine cases over a period of 6 months as an initial analysis. SUBJECTS AND METHODS: Both males and females were included in the study. Preoperative analysis was performed using computed tomography angiogram, magnetic resonance imaging in all cases and digital substraction angiogram in some cases. Intraoperatively microscopic examination of the aneurysm wall was carried out and images recorded. The correlation was done between microscopic and CFD images. RESULTS: Seven cases were found intraoperatively to have a higher risk of rupture based on the thinning of the wall. Two cases had an atherosclerotic wall. All cases had low wall shear stress (WSS).Only two cases with atherosclerotic wall had a correlation with low WSS. CONCLUSIONS: While the pressure measured with CFD technique is a good predictor of rupture risk, the WSS component is controversial. Multicentric trials involving a larger subset of population are needed before drawing any definite conclusions. On-going development in the CFD analysis may help to predict the rupture chances accurately in future.