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.

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.

The application of intraoperative near-infrared indocyanine green videoangiography and analysis of fluorescence intensity in cerebrovascular surgery.

OBJECTIVE: To evaluate the usefulness and limitations of the intraoperative near-infrared (NIR) indocyanine green videoangiography (ICG-VA) and analysis of fluorescence intensity in cerebrovascular surgery. METHODS: Forty-eight patients received ICG-VA during various surgical procedures from May 2010 to August 2010. Included among them were 45 cases of cerebral aneurysms and 3 cases of cerebral arteriovenous malformations (AVMs). The infrared fluorescence module integrated into the surgical microscope was used to visualize fluorescent areas in the surgical field. An integrated analytical visualization tool constantly analyzed the fluorescence video sequence and generated it in the form of an intensity diagram for objective interpretation. RESULTS: Overall, the procedure of ICG VA was done 158 times in 48 patients. There was no adverse effect of ICG dye. In cerebral aneurysm cases, the images obtained were of high resolution. In 4 cases, incomplete clipping was detected by ICG-VA and allowed suitable adjustment to completely obliterate the aneurysm. In 3 aneurysm cases, the intensity diagram of ICG VA provided valuable information. ICG-VA identified the feeding arteries, the draining veins, and nidus in all 3 AVM cases, which was confirmed by an immediate analysis of fluorescence intensity. CONCLUSIONS: ICG-VA provides high resolution images allowing real-time assessment of the blood flow in surgical field. The intensity analysis function, in addition, is a useful adjunct to improve the accuracy of the clipping and decrease the complication rates in cerebral aneurysm cases. In cerebral AVM cases, with the help of color map and intensity diagram function, the superficial feeders, drainers, and nidus can be identified easily.

Retrograde suction decompression assisted clipping of large and giant cerebral aneurysms: our experience.

OBJECTIVE: The aim of this study was to present our experience with retrograde suction decompression in clipping of large and giant cerebral aneurysms and analyze its advantages and pitfalls. METHODS: A retrospective analysis of 27 patients with large and giant intracranial aneurysms treated by suction decompression assisted clipping between November 2005 and February 2010 was done. The surgical technique and the outcome of patients were reviewed. RESULTS: All aneurysms were successfully clipped, and postoperative 3-D CTA or DSA revealed no major branch occlusion or residual aneurysm. There was no surgical mortality in both giant and large aneurysm groups. CONCLUSION: Retrograde suction decompression is a successful adjunct to clipping of large and giant cerebral aneurysms.

Assessment of incomplete clipping of aneurysms intraoperatively by a near-infrared indocyanine green-video angiography (Niicg-Va) integrated microscope.

OBJECTIVE: The objective of this article was to assess the clinical use and the completeness of clipping with total occlusion of the aneurysmal lumen, real-time assessment of vascular patency in the parent, branching and perforating vessels, intraoperative assessment of blood flow, image quality, spatial resolution and clinical value in difficult aneurysms using near infrared indocyanine green video angiography integrated on to an operative Pentero neurosurgical microscope (Carl Zeiss, Oberkochen Germany). MATERIALS AND METHODS: Thirteen patients with aneurysms were operated upon. An infrared camera with near infrared technology was adapted on to the OPMI Pentero microscope with a special filter and infrared excitation light to illuminate the operating field which was designed to allow passage of the near infrared light required for excitation of indocyanine green (ICG) which was used as the intravascular marker. The intravascular fluorescence was imaged with a video camera attached to the microscope. ICG fluorescence (700-850 nm) from a modified microscope light source on to the surgical field and passage of ICG fluorescence (780-950 nm) from the surgical field, back into the optical path of the microscope was used to detect the completeness of aneurysmal clipping RESULTS: Incomplete clipping in three patients (1 female and 2 males) with unruptured complicated aneurysms was detected using indocyanine green video angiography. There were no adverse effects after injection of indocyanine green. The completeness of clipping was inadequately detected by Doppler ultrasound miniprobe and rigid endoscopy and was thus complemented by indocyanine green video angiography. CONCLUSION: The operative microscope-integrated ICG video angiography as a new intraoperative method for detecting vascular flow, was found to be quick, reliable, cost-effective and possibly a substitute or adjunct for Doppler ultrasonography or intraoperative DSA, which is presently the gold standard. The simplicity of the method, the speed with which the investigation can be performed, the quality of the images, and the outcome of surgical procedures have all reduced the need for angiography. This technique may be useful during routine aneurysm surgery as an independent form of angiography and/or as an adjunct to intraoperative or postoperative DSA.

Anterior communicating artery aneurysms: an overview.

AComA aneurysms are most commonly found at the A1-A2 junction on the dominant side. The angle of the arteries at the bifurcation and the direction of blood flow are factors of hemodynamic stress in the apical region where these aneurysms often develop. They exist at the bifurcation of dominant A1, A2 and AComA and usually point in the direction away from the dominant A1. They are more prone to rupture and demonstrate the highest incidence of post-operative morbidity among anterior circulation aneurysms. Consideration of aneurysm morphology may be used to guide approaches in AComA aneurysms. Resection of the gyrus rectus in combination with a pterional approach was popularized by Yasargil and it became the standard for treatment or exposure of AComA aneurysms, although other skull base approaches are also widely used. Clip selection is of extreme importance and the preservation of blood flow to the perforators should be emphasized. Adequate dissection and exposure of the entire "H" complex prior to clipping is the key to a successful outcome. Separating the perforators from the neck or dome of the artery and preserving the parent vessel presents a substantial challenge to the surgeon when the aneurysm is behind the parent artery, making it difficult to achieve a good outcome.

A classification of unruptured middle cerebral artery bifurcation aneurysms that can help in choice of clipping technique.

Middle cerebral artery (MCA) aneurysms comprise 20-25% of all intracranial aneurysms. The majority of middle cerebral artery aneurysms are treated by microsurgical clipping. Most of the classifications of aneurysms at present are based on size, location or pathology which are effective for the description but are less useful in preoperative planning and also in deciding on the technique or type of clip application. The aim of our study was to examine the morphological features of unruptured MCA bifurcation aneurysms which influence the techniques of clipping of these aneurysms and to attempt to subclassify unruptured middle cerebral artery aneurysms based on their preoperative 3D CTA and intraoperative characteristics so as to help in the intraoperative choice of technique and clip application, respectively. Preoperative 3D CT angiography and intraoperative images along with the record of technique and type of clips used for 141 unruptured MCA aneurysms operated at our center were studied retrospectively. Unruptured MCA bifurcation aneurysms could be subclassified into 5 types based on the similarities in their morphological features which influenced the techniques of clipping as recorded from their preoperative 3D CTA and intraoperative view. These types and the distinctive feature of each type are described. The various techniques of clipping are discussed based on these subgroups. The groups outlined make possible the establishment of a common technical approach to clipping within the groups. This classification, based on preoperative 3D CTA and intraoperative morphological features of the aneurysm and parent vessels, helps in the intraoperative choice of technique and type of clip application to tackle these lesions.

The "Multi Clip" method in unruptured complex middle cerebral artery aneurysms--a case series.

This study aims to analyze the feasibility, indications and applicability of the "Multi Clip" method for accurate and complete clipping in patients with unruptured complex middle cerebral artery aneurysms. In this series, we achieved precise clipping in all cases without any intraoperative complications. On the basis of our work, we classified the necessity for multi-clipping into 3 categories: 1) precise clipping, 2) perforator preservation, and 3) reconstruction. The outcome in all patients was excellent. In conclusion, the "Multi Clip" method is a safe and an efficient procedure in cases of difficult unruptured middle cerebral artery aneurysms, where optimal neck closure cannot be obtained by single clipping.

Prediction of impending rupture in aneurysms using 4D-CTA: histopathological verification of a real-time minimally invasive tool in unruptured aneurysms.

The authors describe the use of a 4D-CT angiogram to predict impending rupture in intact aneurysms, as a real-time, less invasive imaging technique. Histopathological verification and immunostaining of the bleb site performed on the study population reveals the significant predictive value of this tool. The point of maximum amplitude of pulsation of the aneurysm wall in unison with the RR interval of the electrocardiogram determines the potential rupture point. This helps in prioritizing the intervention for unruptured aneurysm cases, provides an effective screening of the high-risk population, and aids preoperative planning of clip application.

Normal perfusion pressure breakthrough in arteriovenous malformation surgery: the concept revisited with a case report.

The pathophysiological mechanisms and the salient features of normal perfusion pressure breakthrough (NPPB) are discussed on the basis of an operated case of arteriovenous malformation.

Assessing Prognosis of Areas of Acute Cerebral Ischemia Using Perfusion CT.

SUMMARY: Vascular recanalization by the vascular reconstruction method can dramatically improve ischemic symptoms in patients with acute cerebral ischemia. However, this treatment method is frequently associated with haemorrhagic complications. The indications for this therapeutic approach have been described in a number of studies in the literature. The present paper discusses the possibility of assessing the prognosis of ischemic areas using perfusion CT (PCT) by comparing the results obtained before and after thrombolytic therapy. Twenty-six patients underwent vascular reconstruction at our hospital between July 2002 and March 2004. Of these patients, six who underwent PCT before treatment and showed adequate recanalization following vascular reconstruction were included in the present study. PCT images were obtained using the first-pass bolus-tracking method with a 16-row multislice helical CT scanner. Areas of cerebral ischemia were evaluated by CT before and after vascular reconstruction. A region of interest was placed in the area showing low density in CT images before vascular reconstruction. The mean average CBF (mL/min/100 g), CBV (mL/100 g), and MTT (s) values were calculated in areas with and without cerebral infarction after vascular reconstruction. The %CBF, % CBV, and %MTT values relative to the normal side were evaluated with reference to the time until recanalization. Transarterial vascular reconstruction resulted in full recanalization in four patients and partial recanalization in two. The mean time from onset to recanalization was 284.7 +/- 63.27 minutes and was not longer than six hours in any patient. The patient prognosis results in terms of GOS were GR in two patients, MD in three patients, and SD in one patient. Based on comparison of the time after examination to recanalization, the %CBF showed a significant positive correlation in the salvaged area (Y = 47.321 + 2.491 x %CBF:R(2) = 0.792, p < 0.05). A significant correlation was not observed in %CBV, but %MTT showed a significant negative correlation (Y = 269.45 - 0.356 x %MTT:R(2) = 0.794, p < 0.05). The %CBF and %MTT results obtained by PCT performed before transarterial vascular reconstruction suggest that it may be possible to estimate the time before vascular reconstruction and the relationship with prognosis. These findings are expected to help ensure the appropriate application of vascular reconstruction and to provide useful information for developing optimal therapeutic protocols, thus reducing complications. In addition, because the results are based on the time after examination, the appropriate therapeutic approach can be determined even when the time of onset of ischemia is uncertain.

Micromanipulator: effectiveness in minimally invasive neurosurgery.

Minimally invasive surgeries by innovative approaches are practiced in all fields. The evolution of microneurosurgery has revolutionized the results in neurosurgery. Use of endoscopes and navigation has made microsurgery less invasive. Another development to make minimally invasive microneurosurgery further lesser invasive is the use of micromanipulator. The use and effectiveness of manually controlled micromanipulator system is presented. The manually controlled micromanipulator system consists of three parts, i.e., a basic micromanipulator, manipulator supporting device and the manual control. The micromanipulator fitted in supporting device is arranged before the start of surgery. The supporting device used is pneumatically driven powered endoscopic holding device (Mitaka Kohki Co., Tokyo) In maximum number of times we used the system for endoscopic assisted cerebrovascular microneurosurgery. In a span of two months we used it in thirty aneurysm clipping surgeries. The endoscope fitted in system has three ranges of motions (forward/backward, upside/down and sideways). We use MACHIDA rigid endoscope with internal diameter of 2.7 mm (smallest diameter endoscope available). Special features of this endoscope are accurate visualization at a deeper plane, stable movements and availability of single focus point for long time. All these features are valuable during pre- and postoperative clipping observation. The aim of development of micromanipulator system was to further reduce invasiveness. A significant improvement in manual dexterity is possible when working through the micromanipulator interface, which dampens human physiological tremor. The physiological tremor would render the manual dexterity unsafe at the end of lever arm of long instruments. Thus, the use endoscope becomes practical. The minimally invasive microneurosurgery can be further made lesser invasive by use of micromanipulator and we are convinced that this will facilitate more accurate and promising results in microneurosurgery.

Surgical strategies for treatment of giant or large intracranial aneurysms: our experience with 139 cases.

Giant or large intracranial aneurysms are the vascular neurosurgeon's greatest challenge. At our department, we have treated one hundred and thirty nine patients with giant or large intracranial aneurysms between 1975 and 2001. These included 37 partially thrombosed giant aneurysms. 75 aneurysms were giant (> 2.5 cm) and 64 were large aneurysms (2-2.5 cm). Three-dimensional computed tomography angiograms were performed in patients besides MRI angiography and digital subtraction angiography. These were found to be very valuable in the preoperative assessment of surgical anatomy of the aneurysm with respect to the branch arteries and perforators origin besides knowing the relations to the skull base. With our experience in surgical treatment of these 139 cases, we find that the basic technique is trapping and evacuation and not just clipping of the aneurysm neck but also reconstruction of the artery bearing the aneurysm, especially with wide-necked aneurysms. Use of multiple clipping, tandem clipping or dome clipping as per the intraoperative situation, is very helpful in dealing with giant aneurysms as also is the use of different types of clips like fenestrated clip with straight clip (combination clipping), booster clip, dome clips etc. While selecting surgical strategy for partially thrombosed giant aneurysm, securing the neck is most important. If the neck is too narrow to reconstruct, aneurysmectomy with anastomosis is one of the surgical strategies. An extracranial intracranial bypass should be considered in cases where clipping or parent artery ligation is expected to be associated with compromise of cerebral circulation.