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Robert M. Friedlander and Christopher S. Ogilvy

✓ Fenestration of the proximal anterior cerebral artery (A1 segment) is a rare occurrence. This vascular anomaly is often associated with aneurysms and other abnormalities. The current article describes the case of a 33-year-old man who presented with a subarachnoid hemorrhage secondary to a ruptured aneurysm originating from the proximal end of an A1 fenestration. This patient also had a contralateral A1 fenestration as well as an azygos anterior cerebral artery. This is the first report of such an unusual vascular anatomy. The literature is reviewed and possible embryological mechanisms are discussed.

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Srinivas Chivukula, Ramesh Grandhi, and Robert M. Friedlander

Two key discoveries in the 19th century—infection control and the development of general anesthesia—provided an impetus for the rapid advancement of surgery, especially within the field of neurosurgery. Improvements in anesthesia and perioperative care, in particular, fostered the development of meticulous surgical technique conducive to the refinement of neuroanatomical understanding and optimization of neurosurgical procedures and outcomes. Yet, even dating back to the earliest times, some form of anesthesia or perioperative pain management was used during neurosurgical procedures. Despite a few reports on anesthesia published around the time of William Morton's now-famous public demonstration of ether anesthesia in 1846, relatively little is known or written of early anesthetics in neurosurgery. In the present article the authors discuss the history of anesthesia pertaining to neurosurgical procedures and draw parallels between the refinements and developments in anesthesia care over time with some of the concomitant advances in neurosurgery.

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Kai U. Frerichs, Philip E. Stieg, and Robert M. Friedlander

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Vallabh Janardhan, Robert Friedlander, Howard Riina, and Philip Edwin Stieg

Object

A decision to treat incidental intracranial aneurysms (IIAs) relies on understanding the risks of treatment and weighing them against the those of aneurysm rupture. Whereas the natural history of IIAs is currently being studied, the risks associated with treating IIAs and factors associated with poor outcome need to be clearly established.

Methods

In a consecutive series of 125 patients, 160 IIAs were treated either surgically (152 cases) or endovascularly (eight cases). Postprocedural morbidity was defined as a new neurological deficit associated with a score greater than or equal to 3 on the modified Rankin Scale or a score of less than 24 on the Mini-Mental Status Examination. Logistic regression analysis was used to identify predictors of postprocedural morbidity from retrospectively collected data on demographic, clinical, and radiographic characteristics.

Treatment of IIAs was not associated with any mortality and was associated with postprocedural morbidity in 17 (13.6%) of 125 patients (early outcome) and eight (6.4%) of patients (late outcome). In the logistic-regression model, treatment of aneurysms (≥13 mm) and posterior circulation aneurysms were independently associated with postprocedural morbidity. In patients in whom postprocedural neurological deficits developed, 12 (70.6%) of 17 and four (23.5%) of 17 patients harbored aneurysms with broad or calcified necks, respectively. Age, comorbidities, multiple aneurysms, specific aneurysm location, and history of subarachnoid hemorrhage related to a different aneurysm were not significantly associated with poor outcome.

Conclusions

The authors found that IIAs can be safely and effectively treated without causing mortality and with a lower morbidity rate than previously reported. A combination of radiographic variables may be helpful in identifying patients at risk for postprocedural morbidity.

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Yoshiaki Takamiya, Robert M. Friedlander, Harold Brem, Amy Malick, and Robert L. Martuza

✓ The effectiveness of AGM-1470, a potent, fungal-derived inhibitor of angiogenesis, in suppressing the neovascularization and growth of human Schwann cell tumors was tested in six schwannomas, seven neurofibromas, and one neurofibrosarcoma. Tumor fragments from surgical specimens were implanted into the subrenal capsule of 348 nude mice (nu/nu). Seven days after implantation, the tumors were measured and vascularity was graded. The animals were then randomly assigned to one of two groups, to receive either saline (control group) or systemic AGM-1470 treatment. After 2 to 6 weeks of treatment, tumor size and degree of vascularity were recorded. In the six different schwannomas implanted into 138 mice, the average vascular grade in the control group after 2 weeks of treatment increased from 2.2 to 3.2 (+1.0), while in the AGM-1470-treated group it decreased from 2.2 to 1.7 (−0.5) (p < 0.01). In the seven different neurofibromas implanted into 158 mice, the change in the average vascular grade in control and AGM-1470-treated animals was +0.5 and −1.0, respectively (p < 0.01). In the one neurofibrosarcoma implanted into 52 mice, the change in average vascular grade in each group during the 6-week treatment period was +1.9 and −1.0, respectively (p < 0.01). Neurofibrosarcoma growth after 6 weeks of AGM-1470 treatment was only 8.5% of the growth found in the control animals (p < 0.01). This study determined that AGM-1470 is effective in inhibiting angiogenesis and the growth of human nerve-sheath tumors.

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Ezequiel Goldschmidt, Amir H. Faraji, Brian T. Jankowitz, Paul Gardner, and Robert M. Friedlander

Near-infrared (NIR) light is commonly used to map venous anatomy in the upper extremities to gain intravenous access for line placement. In this report, the authors describe the use of a common and commercially available NIR vein finder to delineate the cortical venous anatomy prior to dural opening.

During a variety of cranial approaches, the dura was directly visualized using an NIR vein finder. The NIR light source allowed for recognition of the underlying cortical venous anatomy, dural sinuses, and underlying pathology before the dura was opened. This information was considered when tailoring the dural opening. When the dura was illuminated with the NIR vein finder, the underlying cortical and sinus venous anatomy was evident and correlated with the observed cortical anatomy. The vein finder was also accurate in locating superficial lesions and pathological dural veins. A complete accordance in the findings on the pre– and post–dural opening images was observed in all cases.

This simple, inexpensive procedure is readily compatible with operative room workflow, necessitates no head fixation, and offers a real-time image independent of brain shift.

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Jason Sheehan, Dale Ding, and Robert M. Starke

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Nitin Agarwal, Ahmed Kashkoush, Michael M. McDowell, William R. Lariviere, Naveed Ismail, and Robert M. Friedlander

OBJECTIVE

Ventricular shunt (VS) durability has been well studied in the pediatric population and in patients with normal pressure hydrocephalus; however, further evaluation in a more heterogeneous adult population is needed. This study aims to evaluate the effect of diagnosis and valve type—fixed versus programmable—on shunt durability and cost for placement of shunts in adult patients.

METHODS

The authors retrospectively reviewed the medical records of all patients who underwent implantation of a VS for hydrocephalus at their institution over a 3-year period between August 2013 and October 2016 with a minimum postoperative follow-up of 6 months. The primary outcome was shunt revision, which was defined as reoperation for any indication after the initial procedure. Supply costs, shunt durability, and hydrocephalus etiologies were compared between fixed and programmable valves.

RESULTS

A total of 417 patients underwent shunt placement during the index time frame, consisting of 62 fixed shunts (15%) and 355 programmable shunts (85%). The mean follow-up was 30 ± 12 (SD) months. The shunt revision rate was 22% for programmable pressure valves and 21% for fixed pressure valves (HR 1.1 [95% CI 0.6–1.8]). Shunt complications, such as valve failure, infection, and overdrainage, occurred with similar frequency across valve types. Kaplan-Meier survival curve analysis showed no difference in durability between fixed (mean 39 months) and programmable (mean 40 months) shunts (p = 0.980, log-rank test). The median shunt supply cost per index case and accounting for subsequent revisions was $3438 (interquartile range $2938–$3876) and $1504 (interquartile range $753–$1584) for programmable and fixed shunts, respectively (p < 0.001, Wilcoxon rank-sum test). Of all hydrocephalus etiologies, pseudotumor cerebri (HR 1.9 [95% CI 1.2–3.1]) and previous shunt malfunction (HR 1.8 [95% CI 1.2–2.7]) were found to significantly increase the risk of shunt revision. Within each diagnosis, there were no significant differences in revision rates between shunts with a fixed valve and shunts with a programmable valve.

CONCLUSIONS

Long-term shunt revision rates are similar for fixed and programmable shunt pressure valves in adult patients. Hydrocephalus etiology may play a significant role in predicting shunt revision, although programmable valves incur higher supply costs regardless of initial diagnosis. Utilization of fixed pressure valves versus programmable pressure valves may reduce supply costs while maintaining similar revision rates. Given the importance of developing cost-effective management protocols, this study highlights the critical need for large-scale prospective observational studies and randomized clinical trials of ventricular shunt valve revisions and additional patient-centered outcomes.

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Nitin Agarwal, Ahmed Kashkoush, Michael M. McDowell, William R. Lariviere, Naveed Ismail, and Robert M. Friedlander

OBJECTIVE

Ventricular shunt (VS) durability has been well studied in the pediatric population and in patients with normal pressure hydrocephalus; however, further evaluation in a more heterogeneous adult population is needed. This study aims to evaluate the effect of diagnosis and valve type—fixed versus programmable—on shunt durability and cost for placement of shunts in adult patients.

METHODS

The authors retrospectively reviewed the medical records of all patients who underwent implantation of a VS for hydrocephalus at their institution over a 3-year period between August 2013 and October 2016 with a minimum postoperative follow-up of 6 months. The primary outcome was shunt revision, which was defined as reoperation for any indication after the initial procedure. Supply costs, shunt durability, and hydrocephalus etiologies were compared between fixed and programmable valves.

RESULTS

A total of 417 patients underwent shunt placement during the index time frame, consisting of 62 fixed shunts (15%) and 355 programmable shunts (85%). The mean follow-up was 30 ± 12 (SD) months. The shunt revision rate was 22% for programmable pressure valves and 21% for fixed pressure valves (HR 1.1 [95% CI 0.6–1.8]). Shunt complications, such as valve failure, infection, and overdrainage, occurred with similar frequency across valve types. Kaplan-Meier survival curve analysis showed no difference in durability between fixed (mean 39 months) and programmable (mean 40 months) shunts (p = 0.980, log-rank test). The median shunt supply cost per index case and accounting for subsequent revisions was $3438 (interquartile range $2938–$3876) and $1504 (interquartile range $753–$1584) for programmable and fixed shunts, respectively (p < 0.001, Wilcoxon rank-sum test). Of all hydrocephalus etiologies, pseudotumor cerebri (HR 1.9 [95% CI 1.2–3.1]) and previous shunt malfunction (HR 1.8 [95% CI 1.2–2.7]) were found to significantly increase the risk of shunt revision. Within each diagnosis, there were no significant differences in revision rates between shunts with a fixed valve and shunts with a programmable valve.

CONCLUSIONS

Long-term shunt revision rates are similar for fixed and programmable shunt pressure valves in adult patients. Hydrocephalus etiology may play a significant role in predicting shunt revision, although programmable valves incur higher supply costs regardless of initial diagnosis. Utilization of fixed pressure valves versus programmable pressure valves may reduce supply costs while maintaining similar revision rates. Given the importance of developing cost-effective management protocols, this study highlights the critical need for large-scale prospective observational studies and randomized clinical trials of ventricular shunt valve revisions and additional patient-centered outcomes.

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Ahmed Kashkoush, Nitin Agarwal, Ashley Ayres, Victoria Novak, Yue-Fang Chang, and Robert M. Friedlander

OBJECTIVE

The preoperative scrub has been shown to lower the incidence of surgical site infections (SSIs). Various scrubbing and gloving techniques exist; however, it is unknown how specific scrubbing technique influences SSI rates in neurosurgery. The authors aimed to assess whether the range of scrubbing practice in neurosurgery is associated with the incidence of SSIs.

METHODS

The authors conducted a retrospective review of a prospectively maintained database to identify all 90-day SSIs for neurosurgical procedures between 2012 and 2017 at one of their teaching hospitals. SSIs were classified by procedure type (craniotomy, shunt, fusion, or laminectomy). Surveys were administered to attending and resident physicians to understand the variation in scrubbing methods (wet vs dry, iodine vs chlorhexidine, single vs double glove). The chi-square followed by multivariate logistic regression analyses were utilized to identify independent predictors of SSI.

RESULTS

Forty-two operating physicians were included in the study (18 attending physicians, 24 resident physicians), who performed 14,200 total cases. Overall, SSI rates were 2.1% (296 SSIs of 14,200 total cases) and 2.0% (192 of 9,669 cases) for attending physicians and residents, respectively. Shunts were independently associated with an increased risk of SSI (OR 1.7 [95% CI 1.3–2.1]), whereas laminectomies were associated with a decreased SSI risk (OR 0.4 [95% CI 0.2–0.8]). Wet versus dry scrub (OR 0.9 [95% CI 0.6–1.4]), iodine versus chlorhexidine (OR 0.6 [95% CI 0.4–1.1]), and single- versus double-gloving (OR 1.1 [95% CI 0.8–1.4]) preferences were not associated with SSIs.

CONCLUSIONS

There is no evidence to suggest that perioperative infection is associated with personal scrubbing or gloving preference in neurosurgical procedures.