Hal S. Meltzer

Intraoperative Assessment of Aneurysm Clip Placement by Intravenous Fluorescein Angiography

Clip occlusion of intracranial aneurysms can be difficult, and intraoperative misadventures are still fairly frequent. Many complications are caused by improper clip placement. Intraoperative conventional arteriography is time consuming and requires expensive image-intensifying equipment. As an alternative, we have found that the bolus intravenous administration of fluorescein produces the necessary intra-arterial dye concentration for the direct visualization of the perforating medium and large arteries in proximity to a clipped aneurysm. The technique is straightforward, requiring little additional operating time and an inexpensive set of disposable optical filters. No adverse reactions to fluorescein have been observed.

Review of bone substitutes.

Bone substitutes are being increasingly used in craniofacial surgery and craniomaxillofacial trauma. We will review the history of the biomaterials and describe the ideal characteristics of bone substitutes, with a specific emphasis on craniofacial reconstruction. Some of the most commonly used bone substitutes are discussed in more depth, such as calcium phosphate and hydroxyapatite ceramics and cements, bioactive glass, and polymer products. Areas of active research and future directions include tissue engineering, with an increasing emphasis on bioactivity of the implant.

Pediatric Acute Hemorrhagic Leukoencephalitis: Report of a Surviving Patient and Review

Acute hemorrhagic leukoencephalitis (AHLE) is a rare, fulminant CNS demyelinating condition usually diagnosed at autopsy. We report the clinical, laboratory, radiographic, and pathologic features of the first nonfatal case of pediatric AHLE confirmed by brain biopsy. Pathologic diagnosis of this condition may be critical to exclude more-common processes and to expedite the decision to administer high-dose corticosteroid therapy, which is potentially lifesaving.

Robotic Virtual Endoscopy∶ Development of a Multidirectional Rigid Endoscope

INTRODUCTION: The use of neuroendoscopy has increased in the past 20 years. Despite an increase in the number of indications for use, novel adjuncts and modifications to existing endoscopes remain all but nonexistent. We introduce a robotic virtual endoscope with applications for neurosurgery that could serve as a novel step in the evolution of future endoscopic technologies. METHODS: Over the past 8 years, we have worked on the construction of a prototype endoscope with three degrees of freedom that was designed to allow for enhanced safety while maximizing the benefits of virtual field rendition and robotic control. We have developed a prototype to examine a cerebral ventricular model in vitro that functions via either a direct video- or computer-based interface. RESULTS: Assessment of viewing angulation with robotic feedback has verified the accuracy of the prototype. Models support the ability of the endoscope to localize regions identified via a software interface. CONCLUSION: The endoscope is a rigid virtual robotic endoscope that provides complete visual coverage of a three-dimensional space by controlling an adjustable viewing direction with three degrees of freedom.

Nonsyndromic craniosynostosis: current treatment options.

The significance and etiology of abnormal skull shape have been under investigation since ancient times. Nonsyndromic, or isolated, craniosynostosis predominates and is defined as suture fusion that creates functional impairments related to local effects of the fusion. The purpose of this article is to present our current approach to patients with nonsyndromic craniosynostosis, outlining the place of both open, conventional approaches and newer, minimally invasive, endoscopic assisted craniosynostosis correction.

Complications associated with prolonged hypertonic saline therapy in children with elevated intracranial pressure.

Objectives: Safe upper limits for therapeutic hypernatremia in the treatment of intracranial hypertension have not been well established. We investigated complications associated with hypernatremia in children who were treated with prolonged infusions of hypertonic saline. Design: Retrospective chart analysis. Setting: PICU in university-affiliated children’s hospital. Patients: All children from 2004 to 2009 requiring intracranial pressure monitoring (external ventricular drain or fiberoptic intraparenchymal monitor) for at least 4 days who were treated with hypertonic saline infusion for elevated intracranial pressure and did not meet exclusion criteria. Intervention: Continuous hypertonic saline infusion on a sliding scale was used to achieve target sodium levels that would keep intracranial pressure less than 20 mm Hg once the conventional therapies failed. Measurements and Main Results: Eighty-eight children met inclusion criteria. Etiologies of elevated intracranial pressure included trauma (n = 48), ischemic or hemorrhagic stroke (n = 20), infection (n = 8), acute disseminated encephalomyelitis (n = 5), neoplasm (n = 2), and others (n = 5). The mean peak serum sodium was 171.3 mEq/L (range, 150–202). The mean Glasgow Outcome Score was 2.8 (± 1.1) at time of discharge from the hospital. Overall mortality was 15.9%. Children with sustained (> 72 hr) serum sodium levels above 170 mEq/L had a significantly higher occurrence of thrombocytopenia (p < 0.001), renal failure (p < 0.001), neutropenia (p = 0.006), and acute respiratory distress syndrome (p = 0.029) after controlling for variables of age, gender, Pediatric Risk of Mortality score, duration of barbiturate-induced coma, duration of intracranial pressure monitoring, vasopressor requirements, and underlying pathology. Children with sustained serum sodium levels greater than 165 mEq/L had a significantly higher prevalence of anemia (p < 0.001). Conclusions: Children treated by continuous hypertonic saline infusion for intracranial hypertension whose serum sodium levels exceeded certain thresholds experienced significantly more events of acute renal failure, thrombocytopenia, neutropenia, anemia, and acute respiratory distress syndrome than those whose sodium level was maintained below these thresholds.

Immediate cranial vault reconstruction with bioresorbable plates following endoscopically assisted sagittal synostectomy.

Minimally invasive, endoscopically assisted strip craniectomy has been successfully used for early treatment of craniosynostosis. Building on the introduction of the endoscopic technique by Vicari 2 and combining strip synostectomy with postoperative helmet molding , Barone and Jimenez have reported excellent results in patients with sagittal synostosis. By operating as early as possible, these authors have produced comparable results to standard cranial vault reshaping with less blood loss, shorter operating times and earlier discharge from the hospital. The disadvantage of their procedure is the prolonged need for postoperative helmet therapy. Vicari in a recent update of his technique claims similar results can be achieved without using a postoperative helmet. However, in our opinion, in more severe cases of scaphocephaly, complete correction may not be accomplished with synostectomy alone. Herein, we describe an improvement in the endoscopic technique that permits more definitive head shape changes and immediate reconstruction of the scaphocephalic deformity. By utilizing extensive cranial osteotomies and wedge ostectomies in concert with rigid fixation using bioresorbable devices (MacroPore, Inc., San Diego, CA), immediate cranial reconstruction can be achieved in selected patients with sagittal synostosis who undergo the endoscopic assisted technique.

Bacterial adhesion to surfactant-modified silicone surfaces.

OBJECTIVEVentricular shunt infections are a major contributor to morbidity in patients being treated for hydrocephalus. The majority of these infections are from Staphylococcus epidermidis. Prevention of bacterial adhesion to the silicone surface of a ventricular catheter could decrease shunt infections. We studied the effectiveness of a surfactant and/or 2% iodine prewash on preventing bacterial adhesion to Silastic catheter material. METHODSIn a laboratory setting, various concentrations of a surfactant, Poloxamer-188 (P188), and a bactericidal agent, iodine, were compared against a control solution in their ability to prevent bacterial adhesion of S. epidermidis to a silicone surface. Silicone wafers were soaked for 1 hour in the test solution, then inoculated and incubated with S. epidermidis for 24 hours. Bacterial counts were then obtained and compared. RESULTSThe most effective method tested in this study was 20% P188, which allowed only 3.02% bacterial adhesion compared with 22.2% bacterial adhesion in the control (P < 0.001). P188 at a 10% concentration or 20% mixed with iodine had the next most effective inhibition. Of the germicidal solutions, a 5-ppm solution of iodine was the most effective. The most ineffective method tested was 2 ppm iodine, which allowed 13.2% bacterial adhesion CONCLUSIONUse of a surfactant and/or a germicidal will provide some protection against bacteria attaching to silicone surfaces before they are surgically implanted. The use of a surfactant soak of 20% P188 or iodine at a concentration of 5 ppm before inoculation with S. epidermidis significantly decreased the bacterial adhesion to silicone wafers. This finding has relevance to clinical practice because it highlights a simple step undertaken before implanting a ventricular catheter that could reduce the adhesion rate of the most common contaminant of these catheters. This step may become an important factor in decreasing infection rates in shunt-dependent patients.

Comparison of open versus minimally invasive craniosynostosis procedures from the perspective of the parent

Craniosynostosis, or the premature closure of the sutures of the skull, has historically been repaired in an open manner and included extensive cranial reconstruction. In recent years, technological advancements have given surgeons the ability to perform repairs with minimal surgical invasion. With the advent of endoscopy and bioresorbable plates, recent reports [J Craniofac Surg 2002;13(4):578-82] have emphasized attempts at decreased morbidity. Recently, researchers have been able to compare the results of traditional open and minimally invasive techniques in 45 craniosynostosis cases, demonstrating decreased operating room time, blood loss, transfusions, complications, and hospital stay in minimally invasive patients [Clin Plast Surg 2004;31(3):429-42]. Many of the parameters comparing the 2 types of procedures are easily quantified and comparable, but a variety of other considerations, such as the parents reaction to the stress of surgery, arise. The purpose of this study was to compare the effects of these surgical procedures on the parents level of stress at the time of operation. To accomplish this, we measured stress postoperatively using the Parenting Stress Index-Short Form. Subjects undergoing surgical treatment of craniosynostosis were placed into 2 groups: open versus minimally invasive. To test for confounding factors, subjects were subcategorized for sex, parents sex, ethnicity, and parents marital status. Analysis of our data reveals a statistically significant decrease in total stress in the households of minimally invasive patients.

Emotional and psychological impact of delayed craniosynostosis repair

IntroductionAmong children with craniosynostosis, there exists an interesting dynamic involving parents’ preconceptions of craniosynostosis and its repair, influenced in large part by differing cultural perspectives. In a time in which we are understanding how critical a child’s early formative years are in influencing his/her emotional and psychological development, the authors describe one medical aspect involved in that dynamic process.Materials and methodsThe authors reviewed their cumulative experience at the Children’s Hospital San Diego between January 2000 and June 2004 and identified nine children with significant craniofacial deformities and, for one reason or another, had delayed surgical repair.DiscussionThe authors have found that by age 6, parents will often bring their children back to their physician and insist on surgical correction. The significant motivating factor in most of these cases stems from teasing by classmates with respect to head shape. In this manuscript, we report and discuss some of the emotional and psychological issues associated with delayed craniosynostosis repair. Often times, these issues are overlooked or underemphasized in the overall surgical care of such patients.