Browse

You are looking at 1 - 10 of 112 items for

  • Refine by Access: all x
  • By Author: Kulkarni, Abhaya V. x
Clear All
Free access

Brandon G. Rocque, Hailey Jensen, Ron W. Reeder, Abhaya V. Kulkarni, Ian F. Pollack, John C. Wellons III, Robert P. Naftel, Eric M. Jackson, William E. Whitehead, Jonathan A. Pindrik, David D. Limbrick Jr., Patrick J. McDonald, Mandeep S. Tamber, Todd C. Hankinson, Jason S. Hauptman, Mark D. Krieger, Jason Chu, Tamara D. Simon, Jay Riva-Cambrin, John R. W. Kestle, Curtis J. Rozzelle, and

OBJECTIVE

Endoscopic third ventriculostomy (ETV) is an option for treatment of hydrocephalus, including for patients who have a history of previous treatment with CSF shunt insertion. The purpose of this study was to report the success of postshunt ETV by using data from a multicenter prospective registry.

METHODS

Prospectively collected data in the Hydrocephalus Clinical Research Network (HCRN) Core Data Project (i.e., HCRN Registry) were reviewed. Children who underwent ETV between 2008 and 2019 and had a history of previous treatment with a CSF shunt were included. A Kaplan-Meier survival curve was created for the primary outcome: time from postshunt ETV to subsequent CSF shunt placement or revision. Univariable Cox proportional hazards models were created to evaluate for an association between clinical and demographic variables and subsequent shunt surgery. Postshunt ETV complications were also identified and categorized.

RESULTS

A total of 203 children were included: 57% male and 43% female; 74% White, 23% Black, and 4% other race. The most common hydrocephalus etiologies were postintraventricular hemorrhage secondary to prematurity (56, 28%) and aqueductal stenosis (42, 21%). The ETV Success Score ranged from 10 to 80. The median patient age was 4.1 years. The overall success of postshunt ETV at 6 months was 41%. Only the surgeon’s report of a clear view of the basilar artery was associated with a lower likelihood of postshunt ETV failure (HR 0.43, 95% CI 0.23–0.82, p = 0.009). None of the following variables were associated with postshunt ETV success: age at the time of postshunt ETV, etiology of hydrocephalus, sex, race, ventricle size, number of previous shunt operations, ETV performed at time of shunt infection, and use of external ventricular drainage. Overall, complications were reported in 22% of patients, with CSF leak (8.6%) being the most common complication.

CONCLUSIONS

Postshunt ETV was successful in treating hydrocephalus, without subsequent need for a CSF shunt, in 41% of patients, with a clear view of the basilar artery being the only variable significantly associated with success. Complications occurred in 22% of patients. ETV is an option for treatment of hydrocephalus in children who have previously undergone shunt placement, but with a lower than expected likelihood of success.

Restricted access

Han Yan, Nathan A. Shlobin, Youngkyung Jung, Kristina K. Zhang, Nebras Warsi, Abhaya V. Kulkarni, and George M. Ibrahim

OBJECTIVE

The nucleus accumbens (NAcc) of the ventral striatum is critically involved in goal- and reward-based behavior. Structural and functional abnormalities of the NAcc or its associated neural systems are involved in neurological and psychiatric disorders. Studies of neural circuitry have shed light on the subtleties of the structural and functional derangements of the NAcc across various diseases. In this systematic review, the authors sought to identify human studies involving the NAcc and provide a synthesis of the literature on the known circuity of the NAcc in healthy and diseased states, as well as the clinical outcomes following neuromodulation.

METHODS

A systematic review was conducted using the PubMed, Embase, and Scopus databases. Neuroimaging studies that reported on neural circuitry related to the human NAcc with sample sizes greater than 5 patients were included. Demographic data, aim, design and duration, participants, and clinical and neurocircuitry details and outcomes of the studies were extracted.

RESULTS

Of 3591 resultant articles, 123 were included. The NAcc and its corticolimbic connections to other brain regions, such as the prefrontal cortex, are largely involved in reward and pain processes, with distinct functional circuitry between the shell and core in healthy patients. There is heterogeneity between clinical studies with regard to the NAcc indirect targeting coordinates, methods for postoperative confirmation, and blinded trial design. Neuromodulation studies provided promising clinical results in the context of addiction and substance misuse, obsessive-compulsive disorder, and mood disorders. The most common complications were impaired memory or concentration, and a notable serious complication was hypomania.

CONCLUSIONS

The functional diversity of the NAcc highlights the importance of studying the NAcc in healthy and pathological states. The results of this review suggest that NAcc neuromodulation has been attempted in the management of diverse psychiatric indications. There is promising, emerging evidence that the NAcc may be an effective target for specific reward- or pain-based pathologies with a reasonable risk profile.

Restricted access

Grace M. Thiong’o, Thomas Looi, James T. Rutka, Abhaya V. Kulkarni, and James M. Drake

OBJECTIVE

Early adaptors of surgical simulation have documented a translation to improved intraoperative surgical performance. Similar progress would boost neurosurgical education, especially in highly nuanced epilepsy surgeries. This study introduces a hands-on cerebral hemispheric surgery simulator and evaluates its usefulness in teaching epilepsy surgeries.

METHODS

Initially, the anatomical realism of the simulator and its perceived effectiveness as a training tool were evaluated by two epilepsy neurosurgeons. The surgeons independently simulated hemispherotomy procedures and provided questionnaire feedback. Both surgeons agreed on the anatomical realism and effectiveness of this training tool. Next, construct validity was evaluated by modeling the proficiency (task-completion time) of 13 participants, who spanned the experience range from novice to expert.

RESULTS

Poisson regression yielded a significant whole-model fit (χ2 = 30.11, p < 0.0001). The association between proficiency when using the training tool and the combined effect of prior exposure to hemispherotomy surgery and career span was statistically significant (χ2 = 7.30, p = 0.007); in isolation, pre-simulation exposure to hemispherotomy surgery (χ2 = 6.71, p = 0.009) and career length (χ2 = 14.21, p < 0.001) were also significant. The mean (± SD) task-completion time was 25.59 ± 9.75 minutes. Plotting career length against task-completion time provided insights on learning curves of epilepsy surgery. Prediction formulae estimated that 10 real-life hemispherotomy cases would be needed to approach the proficiency seen in experts.

CONCLUSIONS

The cerebral hemispheric surgery simulator is a reasonable epilepsy surgery training tool in the quest to increase preoperative practice opportunities for neurosurgical education.

Restricted access

David S. Hersh, Jonathan E. Martin, Ruth E. Bristol, Samuel R. Browd, Gerald Grant, Nalin Gupta, Todd C. Hankinson, Eric M. Jackson, John R. W. Kestle, Mark D. Krieger, Abhaya V. Kulkarni, Casey J. Madura, Jonathan Pindrik, Ian F. Pollack, Jeffrey S. Raskin, Jay Riva-Cambrin, Curtis J. Rozzelle, Jodi L. Smith, and John C. Wellons III

OBJECTIVE

Long-term follow-up is often recommended for patients with hydrocephalus, but the frequency of clinical follow-up, timing and modality of imaging, and duration of surveillance have not been clearly defined. Here, the authors used the modified Delphi method to identify areas of consensus regarding the modality, frequency, and duration of hydrocephalus surveillance following surgical treatment.

METHODS

Pediatric neurosurgeons serving as institutional liaisons to the Hydrocephalus Clinical Research Network (HCRN), or its implementation/quality improvement arm (HCRNq), were invited to participate in this modified Delphi study. Thirty-seven consensus statements were generated and distributed via an anonymous electronic survey, with responses structured as a 4-point Likert scale (strongly agree, agree, disagree, strongly disagree). A subsequent, virtual meeting offered the opportunity for open discussion and modification of the statements in an effort to reach consensus (defined as ≥ 80% agreement or disagreement).

RESULTS

Nineteen pediatric neurosurgeons participated in the first round, after which 15 statements reached consensus. During the second round, 14 participants met virtually for review and discussion. Some statements were modified and 2 statements were combined, resulting in a total of 36 statements. At the conclusion of the session, consensus was achieved for 17 statements regarding the following: 1) the role of standardization; 2) preferred imaging modalities; 3) postoperative follow-up after shunt surgery (subdivided into immediate postoperative imaging, delayed postoperative imaging, routine clinical surveillance, and routine radiological surveillance); and 4) postoperative follow-up after an endoscopic third ventriculostomy. Consensus could not be achieved for 19 statements.

CONCLUSIONS

Using the modified Delphi method, 17 consensus statements were developed with respect to both clinical and radiological follow-up after a shunt or endoscopic third ventriculostomy. The frequency, modality, and duration of surveillance were addressed, highlighting areas in which no clear data exist to guide clinical practice. Although further studies are needed to evaluate the clinical utility and cost-effectiveness of hydrocephalus surveillance, the current study provides a framework to guide future efforts to develop standardized clinical protocols for the postoperative surveillance of patients with hydrocephalus. Ultimately, the standardization of hydrocephalus surveillance has the potential to improve patient care as well as optimize the use of healthcare resources.

Restricted access

Anastasia Arynchyna-Smith, Curtis J. Rozzelle, Hailey Jensen, Ron W. Reeder, Abhaya V. Kulkarni, Ian F. Pollack, John C. Wellons III, Robert P. Naftel, Eric M. Jackson, William E. Whitehead, Jonathan A. Pindrik, David D. Limbrick Jr., Patrick J. McDonald, Mandeep S. Tamber, Brent R. O’Neill, Jason S. Hauptman, Mark D. Krieger, Jason Chu, Tamara D. Simon, Jay Riva-Cambrin, John R. W. Kestle, Brandon G. Rocque, and

OBJECTIVE

Primary treatment of hydrocephalus with endoscopic third ventriculostomy (ETV) and choroid plexus cauterization (CPC) is well described in the neurosurgical literature, with wide reported ranges of success and complication rates. The purpose of this study was to describe the safety and efficacy of ETV revision after initial ETV+CPC failure.

METHODS

Prospectively collected data in the Hydrocephalus Clinical Research Network Core Data Project registry were reviewed. Children who underwent ETV+CPC as the initial treatment for hydrocephalus between 2013 and 2019 and in whom the initial ETV+CPC was completed (i.e., not abandoned) were included. Log-rank survival analysis (the primary analysis) was used to compare time to failure (defined as any other surgical treatment for hydrocephalus or death related to hydrocephalus) of initial ETV+CPC versus that of ETV revision by using random-effects modeling to account for the inclusion of patients in both the initial and revision groups. Secondary analysis compared ETV revision to shunt placement after failure of initial ETV+CPC by using the log-rank test, as well as shunt failure after ETV+CPC to that after ETV revision. Cox regression analysis was used to identify predictors of failure among children treated with ETV revision.

RESULTS

The authors identified 521 ETV+CPC procedures that met their inclusion criteria. Ninety-one children underwent ETV revision after ETV+CPC failure. ETV revision had a lower 1-year success rate than initial ETV+CPC (29.5% vs 45%, p < 0.001). ETV revision after initial ETV+CPC failure had a lower success rate than shunting (29.5% vs 77.8%, p < 0.001). Shunt survival after initial ETV+CPC failure was not significantly different from shunt survival after ETV revision failure (p = 0.963). Complication rates were similar for all examined surgical procedures (initial ETV+CPC, ETV revision, ventriculoperitoneal shunt [VPS] placement after ETV+CPC, and VPS placement after ETV revision). Only young age was predictive of ETV revision failure (p = 0.02).

CONCLUSIONS

ETV revision had a significantly lower 1-year success rate than initial ETV+CPC and VPS placement after ETV+CPC. Complication rates were similar for all studied procedures. Younger age, but not time since initial ETV+CPC, was a risk factor for ETV revision failure.

Free access

Jason Chu, Hailey Jensen, Richard Holubkov, Mark D. Krieger, Abhaya V. Kulkarni, Jay Riva-Cambrin, Curtis J. Rozzelle, David D. Limbrick Jr., John C. Wellons III, Samuel R. Browd, William E. Whitehead, Ian F. Pollack, Tamara D. Simon, Mandeep S. Tamber, Jason S. Hauptman, Jonathan Pindrik, Robert P. Naftel, Patrick J. McDonald, Todd C. Hankinson, Eric M. Jackson, Brandon G. Rocque, Ron Reeder, James M. Drake, John R. W. Kestle, and

OBJECTIVE

Two previous Hydrocephalus Clinical Research Network (HCRN) studies have demonstrated that compliance with a standardized CSF shunt infection protocol reduces shunt infections. In this third iteration, a simplified protocol consisting of 5 steps was implemented. This analysis provides an updated evaluation of protocol compliance and evaluates modifiable shunt infection risk factors.

METHODS

The new simplified protocol was implemented at HCRN centers on November 1, 2016, for all shunt procedures, excluding external ventricular drains, ventricular reservoirs, and subgaleal shunts. Procedures performed through December 31, 2019, were included (38 months). Compliance with the protocol, use of antibiotic-impregnated catheters (AICs), and other variables of interest were collected at the index operation. Outcome events for a minimum of 6 months postoperatively were recorded. The definition of infection was unchanged from the authors’ previous report.

RESULTS

A total of 4913 procedures were performed at 13 HCRN centers. The overall infection rate was 5.1%. Surgeons were compliant with all 5 steps of the protocol in 79.4% of procedures. The infection rate for the protocol alone was 8.1% and dropped to 4.9% when AICs were added. Multivariate analysis identified having ≥ 2 complex chronic conditions (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.26–2.44, p = 0.01) and a history of prior shunt surgery within 12 weeks (OR 1.84, 95% CI 1.37–2.47, p < 0.01) as independent risk factors for shunt infection. The use of AICs (OR 0.70, 95% CI 0.50–0.97, p = 0.05) and vancomycin irrigation (OR 0.36, 95% CI 0.21–0.62, p < 0.01) were identified as independent factors protective against shunt infection.

CONCLUSIONS

The authors report the third iteration of their quality improvement protocol to reduce the risk of shunt infection. Compliance with the protocol was high. These updated data suggest that the incorporation of AICs is an important, modifiable infection prevention measure. Vancomycin irrigation was also identified as a protective factor but requires further study to better understand its role in preventing shunt infection.

Restricted access

Han Yan, Lior M. Elkaim, Flavia Venetucci Gouveia, Joelene F. Huber, Jurgen Germann, Aaron Loh, Juan Carlos Benedetti-Isaac, Paresh K. Doshi, Cristina V. Torres, David J. Segar, Gavin J. B. Elias, Alexandre Boutet, G. Rees Cosgrove, Alfonso Fasano, Andres M. Lozano, Abhaya V. Kulkarni, and George M. Ibrahim

OBJECTIVE

Individuals with autism spectrum disorder (ASD) may display extreme behaviors such as self-injury or aggression that often become refractory to psychopharmacology or behavioral intervention. Deep brain stimulation (DBS) is a surgical alternative that modulates brain circuits that have yet to be clearly elucidated. In the current study the authors performed a connectomic analysis to identify brain circuitry engaged by DBS for extreme behaviors associated with ASD.

METHODS

A systematic review was performed to identify prior reports of DBS as a treatment for extreme behaviors in patients with ASD. Individual patients’ perioperative imaging was collected from corresponding authors. DBS electrode localization and volume of tissue activated modeling were performed. Volumes of tissue activated were used as seed points in high-resolution normative functional and structural imaging templates. The resulting individual functional and structural connectivity maps were pooled to identify networks and pathways that are commonly engaged by all targets.

RESULTS

Nine patients with ASD who were receiving DBS for symptoms of aggression or self-injurious behavior were identified. All patients had some clinical improvement with DBS. Connectomic analysis of 8 patients (from the systematic review and unpublished clinical data) demonstrated a common anatomical area of shared circuitry within the anterior limb of the internal capsule. Functional analysis of 4 patients identified a common network of distant brain areas including the amygdala, insula, and anterior cingulate engaged by DBS.

CONCLUSIONS

This study presents a comprehensive synopsis of the evidence for DBS in the treatment of extreme behaviors associated with ASD. Using network mapping, the authors identified key circuitry common to DBS targets.

Free access

William E. Whitehead, Jay Riva-Cambrin, John C. Wellons III, Abhaya V. Kulkarni, David D. Limbrick Jr., Vanessa L. Wall, Curtis J. Rozzelle, Todd C. Hankinson, Patrick J. McDonald, Mark D. Krieger, Ian F. Pollack, Mandeep S. Tamber, Jonathan Pindrik, Jason S. Hauptman, Robert P. Naftel, Chevis N. Shannon, Jason Chu, Eric M. Jackson, Samuel R. Browd, Tamara D. Simon, Richard Holubkov, Ron W. Reeder, Hailey Jensen, Jenna E. Koschnitzky, Paul Gross, James M. Drake, and John R. W. Kestle

OBJECTIVE

The primary objective of this trial was to determine if shunt entry site affects the risk of shunt failure.

METHODS

The authors performed a parallel-design randomized controlled trial with an equal allocation of patients who received shunt placement via the anterior entry site and patients who received shunt placement via the posterior entry site. All patients were children with symptoms or signs of hydrocephalus and ventriculomegaly. Patients were ineligible if they had a prior history of shunt insertion. Patients received a ventriculoperitoneal shunt after randomization; randomization was stratified by surgeon. The primary outcome was shunt failure. The planned minimum follow-up was 18 months. The trial was designed to achieve high power to detect a 10% or greater absolute difference in the shunt failure rate at 1 year. An independent, blinded adjudication committee determined eligibility and the primary outcome. The study was conducted by the Hydrocephalus Clinical Research Network.

RESULTS

The study randomized 467 pediatric patients at 14 tertiary care pediatric hospitals in North America from April 2015 to January 2019. The adjudication committee, blinded to intervention, excluded 7 patients in each group for not meeting the study inclusion criteria. For the primary analysis, there were 229 patients in the posterior group and 224 patients in the anterior group. The median patient age was 1.3 months, and the most common etiologies of hydrocephalus were postintraventricular hemorrhage secondary to prematurity (32.7%), myelomeningocele (16.8%), and aqueductal stenosis (10.8%). There was no significant difference in the time to shunt failure between the entry sites (log-rank test, stratified by age < 6 months and ≥ 6 months; p = 0.061). The hazard ratio (HR) of a posterior shunt relative to an anterior shunt was calculated using a univariable Cox regression model and was nonsignificant (HR 1.35, 95% CI, 0.98–1.85; p = 0.062). No significant difference was found between entry sites for the surgery duration, number of ventricular catheter passes, ventricular catheter location, and hospital length of stay. There were no significant differences between entry sites for intraoperative complications, postoperative CSF leaks, pseudomeningoceles, shunt infections, skull fractures, postoperative seizures, new-onset epilepsy, or intracranial hemorrhages.

CONCLUSIONS

This randomized controlled trial comparing the anterior and posterior shunt entry sites has demonstrated no significant difference in the time to shunt failure. Anterior and posterior entry site surgeries were found to have similar outcomes and similar complication rates.

Free access

Jay Riva-Cambrin, Abhaya V. Kulkarni, Robert Burr, Curtis J. Rozzelle, W. Jerry Oakes, James M. Drake, Jessica S. Alvey, Ron W. Reeder, Richard Holubkov, Samuel R. Browd, D. Douglas Cochrane, David D. Limbrick, Robert Naftel, Chevis N. Shannon, Tamara D. Simon, Mandeep S. Tamber, Patrick J. McDonald, John C. Wellons III, Thomas G. Luerssen, William E. Whitehead, and John R. W. Kestle

OBJECTIVE

In pediatric hydrocephalus, shunts tend to result in smaller postoperative ventricles compared with those following an endoscopic third ventriculostomy (ETV). The impact of the final treated ventricle size on neuropsychological and quality-of-life outcomes is currently undetermined. Therefore, the authors sought to ascertain whether treated ventricle size is associated with neurocognitive and academic outcomes postoperatively.

METHODS

This prospective cohort study included children aged 5 years and older at the first diagnosis of hydrocephalus at 8 Hydrocephalus Clinical Research Network sites from 2011 to 2015. The treated ventricle size, as measured by the frontal and occipital horn ratio (FOR), was compared with 25 neuropsychological tests 6 months postoperatively after adjusting for age, hydrocephalus etiology, and treatment type (ETV vs shunt). Pre- and posttreatment grade point average (GPA), quality-of-life measures (Hydrocephalus Outcome Questionnaire [HOQ]), and a truncated preoperative neuropsychological battery were also compared with the FOR.

RESULTS

Overall, 60 children were included with a mean age of 10.8 years; 17% had ≥ 1 comorbidity. Etiologies for hydrocephalus were midbrain lesions (37%), aqueductal stenosis (22%), posterior fossa tumors (13%), and supratentorial tumors (12%). ETV (78%) was more commonly used than shunting (22%). Of the 25 neuropsychological tests, including full-scale IQ (q = 0.77), 23 tests showed no univariable association with postoperative ventricle size. Verbal learning delayed recall (p = 0.006, q = 0.118) and visual spatial judgment (p = 0.006, q = 0.118) were negatively associated with larger ventricles and remained significant after multivariate adjustment for age, etiology, and procedure type. However, neither delayed verbal learning (p = 0.40) nor visual spatial judgment (p = 0.22) was associated with ventricle size change with surgery. No associations were found between postoperative ventricle size and either GPA or the HOQ.

CONCLUSIONS

Minimal associations were found between the treated ventricle size and neuropsychological, academic, or quality-of-life outcomes for pediatric patients in this comprehensive, multicenter study that encompassed heterogeneous hydrocephalus etiologies.

Free access

Jessica R. Lane, Paddy Ssentongo, Mallory R. Peterson, Joshua R. Harper, Edith Mbabazi-Kabachelor, John Mugamba, Peter Ssenyonga, Justin Onen, Ruth Donnelly, Jody Levenbach, Venkateswararao Cherukuri, Vishal Monga, Abhaya V. Kulkarni, Benjamin C. Warf, and Steven J. Schiff

OBJECTIVE

This study investigated the incidence of postoperative subdural collections in a cohort of African infants with postinfectious hydrocephalus. The authors sought to identify preoperative factors associated with increased risk of development of subdural collections and to characterize associations between subdural collections and postoperative outcomes.

METHODS

The study was a post hoc analysis of a randomized controlled trial at a single center in Mbale, Uganda, involving infants (age < 180 days) with postinfectious hydrocephalus randomized to receive either an endoscopic third ventriculostomy plus choroid plexus cauterization or a ventriculoperitoneal shunt. Patients underwent assessment with the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III; sometimes referred to as BSID-III) and CT scans preoperatively and then at 6, 12, and 24 months postoperatively. Volumes of brain, CSF, and subdural fluid were calculated, and z-scores from the median were determined from normative curves for CSF accumulation and brain growth. Linear and logistic regression models were used to characterize the association between preoperative CSF volume and the postoperative presence and size of subdural collection 6 and 12 months after surgery. Linear regression and smoothing spline ANOVA were used to describe the relationship between subdural fluid volume and cognitive scores. Causal mediation analysis distinguished between the direct and indirect effects of the presence of a subdural collection on cognitive scores.

RESULTS

Subdural collections were more common in shunt-treated patients and those with larger preoperative CSF volumes. Subdural fluid volumes were linearly related to preoperative CSF volumes. In terms of outcomes, the Bayley-III cognitive score was linearly related to subdural fluid volume. The distribution of cognitive scores was significantly different for patients with and those without subdural collections from 11 to 24 months of age. The presence of a subdural collection was associated with lower cognitive scores and smaller brain volume 12 months after surgery. Causal mediation analysis demonstrated evidence supporting both a direct (76%) and indirect (24%) effect (through brain volume) of subdural collections on cognitive scores.

CONCLUSIONS

Larger preoperative CSF volume and shunt surgery were found to be risk factors for postoperative subdural collection. The size and presence of a subdural collection were negatively associated with cognitive outcomes and brain volume 12 months after surgery. These results have suggested that preoperative CSF volumes could be used for risk stratification for treatment decision-making and that future clinical trials of alternative shunt technologies to reduce overdrainage should be considered.