Ahmad Hafez

Taming the cavernous sinus: technique of hemostasis using fibrin glue.

OBJECTIVE Improved understanding of the microsurgical anatomy of the cranial base region has made surgery in and through the cavernous sinus safer. However, continuous venous oozing that occurs during cavernous sinus surgery can cause significant blood loss and poor visualization. We describe a technique that will help minimize cavernous sinus bleeding and improve the safety of the surgical steps. METHODS The lateral wall of the cavernous sinus is exposed. Cavernous sinus access windows between the V1 and V2 branches of the trigeminal nerve and posterior to the clinoidal internal carotid artery are used to inject fibrin glue into the different cavernous sinus compartments. Postoperative follow-up cerebral angiography in basilar apex aneurysms clipped using the transcavernous approach were evaluated for cavernous sinus patency during the venous phase. RESULTS Fibrin glue injection between V1 and V2 obliterated the lateral cavernous sinus compartment. Fibrin glue injection posterior to the clinoidal segment of the internal carotid artery obliterated the medial compartment of the cavernous sinus. These steps were used in 217 surgical procedures (95 benign and 9 malignant neoplastic lesions; 113 aneurysms). There were no significant clinical side effects. Follow-up angiographic controls of basilar aneurysms operated on via the transcavernous approach consistently showed the reestablishment of flow within the cavernous sinus as early as 2 to 3 months postoperatively. CONCLUSION Presently, the use of hemostatic agents and the better understanding of the microsurgical anatomy of the cranial base and cavernous sinus enable us to tame the cavernous sinus and operate in and around it with a high degree of safety.

A5 segment aneurysm of the anterior cerebral artery, imbedded into the body of the corpus callosum: A case report

Background: The A5 segment aneurysms of the anterior cerebral artery are rare, approximately 0.5% of all intracranial aneurysms. They are small with a wide base located in the midline, with the domes mostly projecting upward or backward. Case Description: The authors describe a unique case of A5 segment aneurysm, with the dome embedded into the body of the corpus callosum. This 41-year-old female was admitted to the neurology department for possible multiple sclerosis investigation. Computed tomography angiogram (CTA) revealed a 4-mm right-sided pericallosal artery aneurysm, with rare configuration, which was caudally projected, embedded into the body of the corpus callosum. Considering the family history, patient underwent a prophylactic ligation surgery. The postoperative CT and CTA showed no complication and successful occlusion of the aneurysm with no ischemia or hemorrhage in the corpus callosum. Conclusion: To the best of our knowledge, this is the first case of an aneurysm with this configuration. Our rare case of A5 segment aneurysm demonstrates the importance of planning of the surgery, choosing the appropriate approach, and knowing the detailed anatomy of the region, as well as the necessity of microsurgical clipping of small unruptured AdistAs.

Simple training tricks for mastering and taming bypass procedures in neurosurgery

Background: Neurosurgeons devoted to bypass neurosurgery or revascularization neurosurgery are becoming scarcer. From a practical point of view, “bypass neurosurgeons” are anastomosis makers, vessels technicians, and time-racing repairers of vessel walls. This requires understanding the key features and hidden tricks of bypass surgery. The goal of this paper is to provide simple and inexpensive tricks for taming the art of bypass neurosurgery. Most of these tricks and materials described can be borrowed, donated, or purchased inexpensively. Methods: We performed a review of relevant training materials and recorded videos for training bypass procedures for 3 years between June 2014 and July 2017. In total, 1,300 training bypass procedures were performed, of which 200 procedures were chosen for this paper. Results: A training laboratory bypass procedures is required to enable a neurosurgeon to develop the necessary skills. The important skills for training bypass procedures gained through meticulous practice to be as reflexes are coordination, speed, agility, flexibility, and reaction time. Bypassing requires synchronization between the surgeons gross movements, fine motoric skills, and mental strength. The suturing rhythm must be timed in a brain–body–hand fashion. Conclusion: Bypass-training is a critical part of neurosurgical training and not for a selected few. Diligent and meticulous training can enable every neurosurgeon to tame the art of bypass neurosurgery. This requires understanding the key features and hidden tricks of bypass surgery, as well as uncountable hours of training. In bypass neurosurgery, quality and time goes hand in hand.

Anatomic Features of Paraclinoid Aneurysms: Computed Tomography Angiography Study of 144 Aneurysms in 136 Consecutive Patients

BACKGROUND Paraclinoid aneurysms are among the most challenging aneurysms to treat. Computed tomography (CT) angiography helps in evaluating the radiological characteristics of these aneurysms next to bony structures. OBJECTIVE To present the CT angiography characteristics of paraclinoid aneurysms in order to better understand such pathology. METHODS The study examined CT angiography-based anatomical characteristics obtained retrospectively from 136 patients with 144 paraclinoid aneurysms selected from single-defined catchment populations in Finland. We examined the diameters of the parent artery (internal carotid artery), the location of the aneurysm, its dimensions (width, height, neck), and aneurysm wall irregularity. RESULTS We analyzed 144 paraclinoid aneurysms in 136 patients admitted to the hospital during 2000-2014. Multivariable analysis reveals that rupture aneurysms have the following radiological features: aneurysm larger than 5 mm in diameter (P = .006), irregular wall (P = .046), superior location, larger aspect ratio (P = .039), and neck wider than parent artery (P < .001). CONCLUSION Smaller diameter of the internal carotid artery and superior location, as well as a large and irregular aneurysm wall, are radiological characteristics of ruptured paraclinoid aneurysms, which CT angiography can measure easily.

Delayed Migration of Fractured K-wire Causing Vertebral Artery Invagination After Anterior Atlantoaxial Fixation: A Case Report

BACKGROUND Most of the physicians attention during spinal surgery, when using wires and screws, is toward the avoidance of injuries of critical structures (nerves and vessels). When such wires are broken during surgery, the most important point is to take them out safely or, if it is impossible, to leaf them in secure place and follow the patient closely. Migrations of broken Kirschner wire (K-wire) are well known in literature; however, to the best of our knowledge, migration of a fractured K-wire during anterior atlantoaxial fixation of cervical spine has not been reported in the literature. CASE DESCRIPTION We report a case in which a fractured K-wire was imbedded in the lateral mass of C1 for 3 years and then migrated to endanger the dominant right vertebral artery. By using posterior approach and drilling right part of posterior arch of C1, we manage to secure the vertebral artery. The broken K-wire was extracted successfully. In our case, with optimal follow-up, the burred wire inside hard bone was moved in delayed fashion to come out of the bone, grooving the dominant vertebral artery. CONCLUSIONS Our recommendation is to inspect the K-wire before using it and to try retrieve as much as possible when removing it.

Perimesencephalic subarachnoid hemorrhage with a positive angiographic finding: case report and review of the literature

The vast majority of perimesencephalic subarachnoid hemorrhage cases are reported as negative-finding etiologies. Recently, high-resolution images allowed us to overcome the previous difficulty of finding the source of bleeding, which underlies the concept of a “negative finding”. We discovered a venous etiology, hidden behind the tip of the basilar artery; namely, the lateral pontine vein. Here, we review the literature on perimesencephalic subarachnoid hemorrhage and on venous aneurysm. We highlight this type of aneurysm as a candidate source of perimesencephalic hemorrhage. This case may change our way of dealing with what we have termed a negative finding of subarachnoid hemorrhage.

The impact of neurosurgical procedure on cognitive resources: Results of bypass training

Background: Neurosurgeons are exposed to unavoidable distractions in their natural operating environment. Distractions can affect both the surgeons concentration and the safety and duration of the surgery. Such distraction can be studied by applying a simultaneous cognitive task during a surgical procedure. Methods: We used a previously described cognitive task: a forward (DF) and backward digit (DB) repetition task to interfere with the surgeons attention during a training bypass. A pilot study was performed to find suitable digit repetition lengths. For the main experiment, we used four-digit strings. The test task was alternated across two consecutive sutures (n = 153, 8 bypasses), followed by two consecutive control sutures without digit repetition. The duration and the number of correct answers for the digit repetition task were compared to a baseline digit repetition without simultaneous surgery. Results: During the bypass surgery, digit repetitions (especially DB) became slower (P < 0.0001). More errors were made during DB compared to DF only during simultaneous bypass (P < 0.0001). However, we found no effect of digit repetition tasks on individual suture times (P = 0.823). Conclusions: The ability to engage in simultaneous tasks while performing surgery is diminished. A surgeon with extensive training can withstand external distraction without an effect on performance; however, this is achieved by partially ignoring the simultaneous task. Our data support that during surgery other cognitive tasks should be avoided to ensure safety.

Characteristics and Long-Term Outcome of 127 Children With Cerebral Arteriovenous Malformations

BACKGROUND Population-based long-term data on pediatric patients with cerebral arteriovenous malformations (AVMs) are limited. OBJECTIVE To clarify the characteristics and long-term outcome of pediatric patients with AVM. METHODS A retrospective analysis was performed on 805 consecutive brain AVM patients admitted to a single center between 1942 and 2014. The patients were defined as children if they were under 18 yr at admission. Children were compared to an adult cohort. Changing patterns of presentation were also analyzed by decades of admission. RESULTS The patients comprised 127 children with a mean age of 12 yr. The mean follow-up time was 21 yr (range 0-62). Children presented more often with intracerebral hemorrhage (ICH) but less often with epilepsy than adults. Basal ganglia, cerebellar, and posterior paracallosal AVMs were more common in pediatric than in adult patients. Frontal and temporal AVMs, in contrast, were more common in adult than in pediatric patients. As the number of incidentally and epilepsy-diagnosed AVMs increased, ICH rates dropped in both cohorts. In total, 22 (82%) pediatric and 108 (39%) adult deaths were assessed as AVM related. After multivariate analysis, small AVM size and surgical treatment correlated with a favorable long-term outcome. CONCLUSION Hemorrhagic presentation was more common in children than in adults. This was also reflected as lower prevalence of epileptic presentation in the pediatric cohort. Lobar and cortical AVM locations were less frequent, whereas deep and cerebellar AVMs were more common in children. Hemorrhagic presentation correlated negatively with incidentally and epilepsy-diagnosed AVMs. In children, AVM was a major cause of death, but in adults, other factors contributed more commonly to mortality.

The Application of the Novel Grading Scale (Lawton-Young Grading System) to Predict the Outcome of Brain Arteriovenous Malformation

Abstract BACKGROUND A supplementary grading scale (Supplemented Spetzler-Martin grade, Supp-SM) was introduced in 2010 as a refinement of the SM system to improve preoperative risk prediction of brain arteriovenous malformations (AVMs). OBJECTIVE To determine the ability to predict surgical outcomes using the Supp-SM grading scale. METHODS This retrospective study was conducted on 200 patients admitted to the Helsinki University Hospital between 2000 and 2014. The validity of the Supp-SM and SM grading systems was compared using the area under the receiver operating characteristic (AUROC) curves, with respect to the change between preoperative and early (3-4 mo) as well as final postoperative modified Rankin Scale (mRS) scores. RESULTS The performance of the Supp-SM was superior to that of the SM grading scale in the early follow-up (3-4 mo): AUROC = 0.57 (95% confidence interval [CI]: 0.49-0.65) for SM and AUROC = 0.67 (95% CI: 0.60-0.75) for Supp-SM. The Supp-SM performance continued improving over SM at the late follow-up: AUROC = 0.63 (95% CI: 0.55-0.71) for SM and AUROC = 0.70 (95% CI: 0.62-0.77) for Supp-SM. The perforating artery supply, which is not part of either grading system, plays an important role in the early follow-up outcome (P = .008; odds ratio: 2.95; 95% CI: 1.32-6.55) and in the late follow-up outcome (P < .001; odds ratio: 5.89; 95% CI: 2.49-13.91). CONCLUSION The Supp-SM grading system improves the outcome prediction accuracy and is a feasible alternative to the SMS, even for series with higher proportion of high-grade AVMs. However, perforators play important role on the outcome.

Role of Damage Associated Molecular Pattern Molecules (DAMPs) in Aneurysmal Subarachnoid Hemorrhage (aSAH)

Aneurysmal subarachnoid hemorrhage (aSAH) represents only a small portion of all strokes, but accounts for almost half of the deaths caused by stroke worldwide. Neurosurgical clipping and endovascular coiling can successfully obliterate the bleeding aneurysms, but ensuing complications such as cerebral vasospasm, acute and chronic hydrocephalus, seizures, cortical spreading depression, delayed ischemic neurological deficits, and delayed cerebral ischemia lead to poor clinical outcomes. The mechanisms leading to these complications are complex and poorly understood. Early brain injury resulting from transient global ischemia can release molecules that may be critical to initiate and sustain inflammatory response. Hence, the events during early brain injury can influence the occurrence of delayed brain injury. Since the damage associated molecular pattern molecules (DAMPs) might be the initiators of inflammation in the pathophysiology of aSAH, so the aim of this review is to highlight their role in the context of aSAH from diagnostic, prognostic, therapeutic, and drug therapy monitoring perspectives. DAMPs represent a diverse and a heterogenous group of molecules derived from different compartments of cells upon injury. Here, we have reviewed the most important DAMPs molecules including high mobility group box-1 (HMGB1), S100B, hemoglobin and its derivatives, extracellular matrix components, IL-1α, IL-33, and mitochondrial DNA in the context of aSAH and their role in post-aSAH complications and clinical outcome after aSAH.