Search Results

You are looking at 1 - 10 of 17 items for

  • Author or Editor: Stephen Gannon x
  • All content x
Clear All Modify Search
Free access

Ranbir Ahluwalia, Chelsea Kiely, Jarrett Foster, Stephen Gannon, Alyssa L. Wiseman, Chevis N. Shannon, and Christopher M. Bonfield

OBJECTIVE

The authors sought to assess the prevalence and severity of positional posterior plagiocephaly (PPP) in the pediatric population at a tertiary care center.

METHODS

The authors conducted a retrospective review of 1429 consecutive patients aged 2 months to 18 years who presented with head trauma and a negative CT scan in 2018. The cohort was stratified by age. The cranial vault asymmetry index (CVAI) was calculated at the superior orbital rim. Asymmetry was categorized according to the following CVAI scores: mild (3.5%–7%), moderate (7%–12%), and severe (> 12%). Patients were grouped by age to assess PPP at different stages of head development: group 1, 2–5 months; group 2, 6–11 months; group 3, 12–23 months; group 4: 2–4 years; group 5, 5–8 years; group 6, 9–12 years; and group 7, 13–18 years. Patients with a history of shunted hydrocephalus, craniosynostosis, skull surgery, or radiographic evidence of intracranial trauma were excluded.

RESULTS

The overall cohort prevalence of PPP was 24.8% (354 patients). PPP prevalence was higher among younger patients from groups 1–3 (40.4%, 33.5%, and 0.8%, respectively). There was a continued decline in PPP by age in groups 4–7 (26.4%, 20%, 20%, and 10.8%, respectively). Mild cranial vault asymmetry was noted most often (78.0%, 276 patients), followed by moderate (19.5%, 69 patients) and severe (2.5%, 9 patients). There were no patients in group 6 or 7 with severe PPP.

CONCLUSIONS

PPP is prevalent in pediatric populations and most commonly presents as a case of mild asymmetry. Although there was an overall decline of PPP prevalence with increasing age, moderate asymmetry was seen in all age groups. No patients in the cohort had severe asymmetry that persisted into adolescence.

Free access

Andrew T. Hale, David P. Stonko, Amber Brown, Jaims Lim, David J. Voce, Stephen R. Gannon, Truc M. Le, and Chevis N. Shannon

OBJECTIVE

Modern surgical planning and prognostication requires the most accurate outcomes data to practice evidence-based medicine. For clinicians treating children following traumatic brain injury (TBI) these data are severely lacking. The first aim of this study was to assess published CT classification systems in the authors’ pediatric cohort. A pediatric-specific machine-learning algorithm called an artificial neural network (ANN) was then created that robustly outperformed traditional CT classification systems in predicting TBI outcomes in children.

METHODS

The clinical records of children under the age of 18 who suffered a TBI and underwent head CT within 24 hours after TBI (n = 565) were retrospectively reviewed.

RESULTS

“Favorable” outcome (alive with Glasgow Outcome Scale [GOS] score ≥ 4 at 6 months postinjury, n = 533) and “unfavorable” outcome (death at 6 months or GOS score ≤ 3 at 6 months postinjury, n = 32) were used as the primary outcomes. The area under the receiver operating characteristic (ROC) curve (AUC) was used to delineate the strength of each CT grading system in predicting survival (Helsinki, 0.814; Rotterdam, 0.838; and Marshall, 0.781). The AUC for CT score in predicting GOS score ≤ 3, a measure of overall functionality, was similarly predictive (Helsinki, 0.717; Rotterdam, 0.748; and Marshall, 0.663). An ANN was then constructed that was able to predict 6-month outcomes with profound accuracy (AUC = 0.9462 ± 0.0422).

CONCLUSIONS

This study showed that machine-learning can be leveraged to more accurately predict TBI outcomes in children.

Free access

Emily W. Chan, Stephen R. Gannon, Chevis N. Shannon, Jeffrey E. Martus, Gregory A. Mencio, and Christopher M. Bonfield

OBJECTIVE

Adolescent idiopathic scoliosis (AIS), the most common type of scoliosis, often presents immediately prior to a woman’s childbearing years; however, research investigating the impact of AIS on women’s health, particularly pregnancy delivery outcomes, is sparse, with existing literature reporting mixed findings. Similarly limited are studies examining the change in scoliotic curve during or after pregnancy. Therefore, this study aims to determine 1) the impact of scoliotic curvature on obstetric complications (preterm births, induction of labor, and urgent/emergency caesarean section delivery), 2) regional anesthetic decision making and success during delivery for these patients, and 3) the effect of pregnancy on curve progression.

METHODS

Records of all pregnant patients diagnosed with AIS at the authors’ institution who delivered between January 2002 and September 2016 were retrospectively reviewed. Demographic information, pre- and postpartum radiographic Cobb angles, and clinical data for each pregnancy and delivery were recorded and analyzed. The Wilcoxon rank-sum test and the Wilcoxon signed-rank test were used for statistical analyses.

RESULTS

Fifty-nine patients (84 deliveries) were included; 14 patients had undergone prior posterior spinal fusion. The median age at AIS diagnosis was 15.2 years, and the median age at delivery was 21.8 years. Overall, the median major Cobb angle prior to the first pregnancy was 25° (IQR 15°–40°). Most births were by spontaneous vaginal delivery (n = 45; 54%); elective caesarean section was performed in 17 deliveries (20%). Obstetric complications included preterm birth (n = 18; 21.4%), induction of labor (n = 20; 23.8%), and urgent/emergency caesarean section (n = 12; 14.0%); none were associated with severity of scoliosis curve or prior spinal fusion. Attempts at spinal anesthesia were successful 99% of the time (70/71 deliveries), even among the patients who had undergone prior spinal fusion (n = 13). There were only 3 instances of provider refusal to administer spinal anesthesia. In the subset of 11 patients who underwent postpartum scoliosis radiography, there was no statistically significant change in curve magnitude either during or immediately after pregnancy.

CONCLUSIONS

The results of this study suggest that there was no effect of the severity of scoliosis on delivery complications or regional anesthetic decision making in pregnant patients with AIS. Moreover, scoliosis was not observed to progress significantly during or immediately after pregnancy. Larger prospective studies are needed to further investigate these outcomes, the findings of which can guide the prenatal education and counseling of pregnant patients with AIS.

Full access

Babatunde J. Akinpelu, Scott L. Zuckerman, Stephen R. Gannon, Ashly Westrick, Chevis Shannon, and Robert P. Naftel

OBJECTIVE

Isolated transverse and spinous process fractures (TPFx and SPFx) in the thoracic and/or lumbar region have been deemed clinically insignificant in the adult population. This same rule is often applied to the pediatric population; however, little evidence exists in this younger group. The goal of this study was to describe the clinical, radiographic, and long-term data on isolated TPFx and SPFx in an exclusively pediatric population.

METHODS

A retrospective chart review at Monroe Carell Jr. Children's Hospital at Vanderbilt University identified 82 pediatric patients with isolated TPFx and/or SPFx following a traumatic event between January 2000 and December 2013. Patient demographic information, presenting symptoms, radiographic characteristics, and follow-up data were collected. Follow-up was used to determine the outcome (presence of neurological deficits) of such injuries via complete physical examination and, when available, radiographic evidence.

RESULTS

In the 82 identified patients, the mean age was 15.5 ± 3.1 years (mean is expressed ± SD throughout), with 72 injuries (87.8%) resulting from a motor vehicle, motorcycle, or all-terrain vehicle accident. There was a mean of 1.7 ± 1.0 fractured vertebral levels involved and a mean of 1.8 ± 1.1 fractures was identified per patient. Seventy-one patients (86.6%) needed bedside pain control, 7 (8.5%) were prescribed a brace, and 4 patients (4.9%) received a collar. Physical therapy was recommended for 12 patients (14.6%). A total of 84.1% had follow-up, and the mean length of follow-up was 19 ± 37 months. No patients had true neurological deficits at presentation or follow-up as a result of their isolated fractures, whereas 95.1% had other associated system injuries.

CONCLUSIONS

These data shows that there is no appreciable long-term complication associated with isolated thoracic and/or lumbar TPFx and/or SPFx in an exclusively pediatric population. Because these fractures are, however, associated with high-energy blunt trauma, they often result in associated soft-tissue or other skeletal injury. All pediatric patients in the cohort benefited from conservative management and aggressive treatment of their comorbidities.

Full access

Silky Chotai, Bradley S. Guidry, Emily W. Chan, Katherine D. Sborov, Stephen Gannon, Chevis Shannon, Christopher M. Bonfield, John C. Wellons III, and Robert P. Naftel

OBJECTIVE

Readmission and return to operating room after surgery are increasingly being used as a proxy for quality of care. Nearly 60% of these readmissions are unplanned, which translates into billions of dollars in health care costs. The authors set out to analyze the incidence of readmission at their center, to define causes of unplanned readmission, and to determine the preoperative and surgical variables associated with readmissions following pediatric neurosurgery.

METHODS

A total of 536 children who underwent operations for neurosurgical diagnoses between 2012 and 2015 and who were later readmitted were included in the final analysis. Unplanned readmissions were defined to have occurred as a result of complications within 90 days after index surgery. Patient records were retrospectively reviewed to determine the primary diagnosis, surgery indication, and cause of readmission and return to operating room. The cost for index hospitalization, readmission episode, and total cost were derived based on the charges obtained from administrative data. Bivariate and multivariable analyses were conducted.

RESULTS

Of 536 patients readmitted in total, 17.9% (n = 96) were readmitted within 90 days. Of the overall readmissions, 11.9% (n = 64) were readmitted within 30 days, and 5.97% (n = 32) were readmitted between 31 and 90 days. The median duration between discharge and readmission was 20 days (first quartile [Q1]: 9 days, third quartile [Q3]: 36 days). The most common reason for readmission was shunt related (8.2%, n = 44), followed by wound infection (4.7%, n = 25). In the risk-adjusted multivariable logistic regression model for total 90-day readmission, patients with the following characteristics: younger age (p = 0.001, OR 0.886, 95% CI 0.824–0.952); “other” (nonwhite, nonblack) race (p = 0.024, OR 5.49, 95% CI 1.246–24.2); and those born preterm (p = 0.032, OR 2.1, 95% CI 1.1–4.12) had higher odds of being readmitted within 90 days after discharge. The total median cost for patients undergoing surgery in this study cohort was $11,520 (Q1: $7103, Q3: $19,264). For the patients who were readmitted, the median cost for a readmission episode was $8981 (Q1: $5051, Q3: $18,713).

CONCLUSIONS

Unplanned 90-day readmissions in pediatric neurosurgery are primarily due to CSF-related complications. Patients with the following characteristics: young age at presentation; “other” race; and children born preterm have a higher likelihood of being readmitted within 90 days after surgery. The median cost was > $8000, which suggests that the readmission episode can be as expensive as the index hospitalization. Clearly, readmission reduction has the potential for significant cost savings in pediatric neurosurgery. Future efforts, such as targeted education related to complication signs, should be considered in the attempt to reduce unplanned events. Given the single-center, retrospective study design, the results of this study are primarily applicable to this population and cannot necessarily be generalized to other institutions without further study.

Free access

Michael C. Dewan, Jaims Lim, Clinton D. Morgan, Stephen R. Gannon, Chevis N. Shannon, John C. Wellons III, and Robert P. Naftel

OBJECTIVE

Endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC) offers an alternative to shunt treatment for infantile hydrocephalus. Diagnosing treatment failure is dependent on infantile hydrocephalus metrics, including head circumference, fontanel quality, and ventricle size. However, it is not clear to what degree these metrics should be expected to change after ETV/CPC. Using these clinical metrics, the authors present and analyze the decision making in cases of ETV/CPC failure.

METHODS

Infantile hydrocephalus metrics, including bulging fontanel, head circumference z-score, and frontal and occipital horn ratio (FOHR), were compared between ETV/CPC failures and successes. Treatment outcome predictive values of metrics individually and in combination were calculated.

RESULTS

Forty-four patients (57% males, median age 1.2 months) underwent ETV/CPC for hydrocephalus; of these patients, 25 (57%) experienced failure at a median time of 51 days postoperatively. Patients experiencing failure were younger than those experiencing successful treatment (0.8 vs 3.9 months, p = 0.01). During outpatient follow-up, bulging anterior fontanel, progressive macrocephaly, and enlarging ventricles each demonstrated a positive predictive value (PPV) of no less than 71%, but a bulging anterior fontanel remained the most predictive indicator of ETV/CPC failure, with a PPV of 100%, negative predictive value of 73%, and sensitivity of 72%. The highest PPVs and specificities existed when the clinical metrics were present in combination, although sensitivities decreased expectedly. Only 48% of failures were diagnosed on the basis all 3 hydrocephalus metrics, while only 37% of successes were negative for all 3 metrics. In the remaining 57% of patients, a diagnosis of success or failure was made in the presence of discordant data.

CONCLUSIONS

Successful ETV/CPC for infantile hydrocephalus was evaluated in relation to fontanel status, head growth, and change in ventricular size. In most patients, a designation of failure or success was made in the setting of discordant data.

Full access

Lucy He, Stephen Gannon, Chevis N. Shannon, Brandon G. Rocque, Jay Riva-Cambrin, and Robert P. Naftel

OBJECTIVE

The success of endoscopic third ventriculostomy with choroid plexus cauterization may have associations with age, etiology of hydrocephalus, previous shunting, cisternal scarring, and possibly aqueduct patency. This study aimed to measure interrater reliability among surgeons in identifying cisternal scarring and aqueduct patency.

METHODS

Using published definitions of cistern scarring and aqueduct patency, 7 neuroendoscopists with training from Dr. Warf in Uganda and 7 neuroendoscopists who were not trained by Dr. Warf rated cistern status from 30 operative videos and aqueduct patency from 26 operative videos. Interrater agreement was calculated using Fleiss' kappa coefficient (κ). Fisher's 2-tailed exact test was used to identify differences in the rates of agreement between the Warf-trained and nontrained groups compared with Dr. Warf's reference answer.

RESULTS

Aqueduct status, among all raters, showed substantial agreement with κ = 0.663 (confidence interval [CI] 0.626–0.701); within the trained group and nontrained groups, there was substantial agreement with κ = 0.677 (CI 0.593–0.761) and κ = 0.631 (CI 0.547–0.715), respectively. The identification of cistern scarring was less reliable, with moderate agreement among all raters with κ = 0.536 (CI 0.501–0.571); within the trained group and nontrained groups, there was moderate agreement with κ = 0.555 (CI 0.477–0.633) and κ = 0.542 (CI 0.464–0.620), respectively. There was no statistically significant difference in the amount of agreement between groups compared with Dr. Warf's reference.

CONCLUSIONS

Regardless of training with Dr. Warf, all neuroendoscopists could identify scarred cisterns and aqueduct patency with similar reliability, emphasizing the strength of the published definitions. This makes the identification of this risk factor for failure generalizable for surgical decision making and research studies.

Free access

Michael C. Dewan, Jaims Lim, Stephen R. Gannon, David Heaner, Matthew C. Davis, Brandy Vaughn, Joshua J. Chern, Brandon G. Rocque, Paul Klimo Jr., John C. Wellons III, and Robert P. Naftel

OBJECTIVE

It has been suggested that the treatment of infant hydrocephalus results in different craniometric changes depending upon whether ventriculoperitoneal shunt (VPS) placement or endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC) is performed. Without an objective and quantitative description of expected changes to the infant cranium and ventricles following ETV/CPC, asserting successful treatment of hydrocephalus is difficult. By comparing infants successfully treated via ETV/CPC or VPS surgery, the authors of this study aimed to define the expected postoperative cranial and ventricular alterations at the time of clinical follow-up.

METHODS

Patients who underwent successful treatment of hydrocephalus at 4 institutions with either VPS placement or ETV/CPC were matched in a 3:1 ratio on the basis of age and etiology. Commonly used cranial parameters (including head circumference [HC], HC z-score, fontanelle status, and frontooccipital horn ratio [FOHR]) were compared pre- and postoperatively between treatment cohorts. First, baseline preoperative values were compared to ensure cohort equivalence. Next, postoperative metrics, including the relative change in metrics, were compared between treatment groups using multivariate linear regression.

RESULTS

Across 4 institutions, 18 ETV/CPC-treated and 54 VPS-treated infants with hydrocephalus were matched and compared at 6 months postoperatively. The most common etiologies of hydrocephalus were myelomeningocele (61%), followed by congenital communicating hydrocephalus (17%), aqueductal stenosis (11%), and intraventricular hemorrhage (6%). The mean age at the time of CSF diversion was similar between ETV/CPC- and VPS-treated patients (3.4 vs 2.9 months; p = 0.69), as were all preoperative cranial hydrocephalus metrics (p > 0.05). Postoperatively, the ventricle size FOHR decreased significantly more following VPS surgery (−0.15) than following ETV/CPC (−0.02) (p < 0.001), yielding a lower postoperative FOHR in the VPS arm (0.42 vs 0.51; p = 0.01). The HC percentile was greater in the ETV/CPC cohort than in the VPS-treated patients (76th vs 54th percentile; p = 0.046). A significant difference in the postoperative z-score was not observed. With both treatment modalities, a bulging fontanelle reliably normalized at last follow-up.

CONCLUSIONS

Clinical and radiographic parameters following successful treatment of hydrocephalus in infants differed between ETV/CPC and VPS treatment. At 6 months post-ETV/CPC, ventricle size remained unchanged, whereas VPS-treated ventricles decreased to a near-normal FOHR. The HC growth control between the procedures was similar, although the final HC percentile may be lower after VPS. The fontanelle remained a reliable indicator of success for both treatments. This study establishes expected cranial and ventricular parameters following ETV/CPC, which may be used to guide preoperative counseling and postoperative decision making.

Free access

Silky Chotai, Emily W. Chan, Travis R. Ladner, Andrew T. Hale, Stephen R. Gannon, Chevis N. Shannon, Christopher M. Bonfield, Robert P. Naftel, and John C. Wellons

OBJECTIVE

The aim of this study was to determine the timeline of syrinx regression and to identify factors mitigating syrinx resolution in pediatric patients with Chiari malformation type I (CM-I) undergoing posterior fossa decompression (PFD).

METHODS

The authors conducted a retrospective review of records from pediatric patients (< 18 years old) undergoing PFD for the treatment of CM-I/syringomyelia (SM) between 1998 and 2015. Patient demographic, clinical, radiological, and surgical variables were collected and analyzed. Radiological information was reviewed at 4 time points: 1) pre-PFD, 2) within 6 months post-PFD, 3) within 12 months post-PFD, and 4) at maximum available follow-up. Syrinx regression was defined as ≥ 50% decrease in the maximal anteroposterior syrinx diameter (MSD). The time to syrinx regression was determined using Kaplan-Meier analysis. Multivariate analysis was conducted using a Cox proportional hazards model to determine the association between preoperative, clinical, and surgery-related factors and syrinx regression.

RESULTS

The authors identified 85 patients with CM-I/SM who underwent PFD. Within 3 months post-PFD, the mean MSD regressed from 8.1 ± 3.4 mm (preoperatively) to 5.6 ± 2.9 mm within 3 months post-PFD. Seventy patients (82.4%) achieved ≥ 50% regression in MSD. The median time to ≥ 50% regression in MSD was 8 months (95% CI 4.2–11.8 months). Using a risk-adjusted multivariable Cox proportional hazards model, the patients who underwent tonsil coagulation (n = 20) had a higher likelihood of achieving ≥ 50% syrinx regression in a shorter time (HR 2.86, 95% CI 1.2–6.9; p = 0.02). Thirty-six (75%) of 45 patients had improvement in headache at 2.9 months (IQR 1.5–4.4 months).

CONCLUSIONS

The maximum reduction in syrinx size can be expected within 3 months after PFD for patients with CM-I and a syrinx; however, the syringes continue to regress over time. Tonsil coagulation was associated with early syrinx regression in this cohort. However, the role of surgical maneuvers such as tonsil coagulation and arachnoid veil identification and sectioning in the overall role of CM-I surgery remains unclear.

Restricted access

Andrew T. Hale, Stephen R. Gannon, Shilin Zhao, Michael C. Dewan, Ritwik Bhatia, Michael Bezzerides, Amanda N. Stanton, Robert P. Naftel, Chevis N. Shannon, Sumit Pruthi, and John C. Wellons III

OBJECTIVE

The authors aimed to evaluate clinical, radiological, and surgical factors associated with posterior fossa tumor resection (PFTR)–related outcomes, including postoperative complications related to dural augmentation (CSF leak and wound infection), persistent hydrocephalus ultimately requiring permanent CSF diversion after PFTR, and 90-day readmission rate.

METHODS

Pediatric patients (0–17 years old) undergoing PFTR between 2000 and 2016 at Monroe Carell Jr. Children’s Hospital of Vanderbilt University were retrospectively reviewed. Descriptive statistics included the Wilcoxon signed-rank test to compare means that were nonnormally distributed and the chi-square test for categorical variables. Variables that were nominally associated (p < 0.05) with each outcome by univariate analysis were included as covariates in multivariate linear regression models. Statistical significance was set a priori at p < 0.05.

RESULTS

The cohort consisted of 186 patients with a median age at surgery of 6.62 years (range 3.37–11.78 years), 55% male, 83% Caucasian, and average length of follow-up of 3.87 ± 0.25 years. By multivariate logistic regression, the variables primary dural closure (PDC; odds ratio [OR] 8.33, 95% confidence interval [CI] 1.07–100, p = 0.04), pseudomeningocele (OR 7.43, 95% CI 2.23–23.76, p = 0.0007), and hydrocephalus ultimately requiring permanent CSF diversion within 90 days of PFTR (OR 9.25, 95% CI 2.74–31.2, p = 0.0003) were independently associated with CSF leak. PDC versus graft dural closure (GDC; 35% vs 7%, OR 5.88, 95% CI 2.94–50.0, p = 0.03) and hydrocephalus ultimately requiring permanent CSF diversion (OR 3.30, 95% CI 1.07–10.19, p = 0.0007) were associated with wound infection requiring surgical debridement. By multivariate logistic regression, GDC versus PDC (23% vs 37%, OR 0.13, 95% CI 0.02–0.87, p = 0.04) was associated with persistent hydrocephalus ultimately requiring permanent CSF diversion, whereas pre- or post-PFTR ventricular size, placement of peri- or intraoperative extraventricular drain (EVD), and radiation therapy were not. Furthermore, the addition of perioperative EVD placement and dural closure method to a previously validated predictive model of post-PFTR hydrocephalus improved its performance from area under the receiver operating characteristic curve of 0.69 to 0.74. Lastly, the authors found that autologous (vs synthetic) grafts may be protective against persistent hydrocephalus (p = 0.02), but not CSF leak, pseudomeningocele, or wound infection.

CONCLUSIONS

These results suggest that GDC, independent of potential confounding factors, may be protective against CSF leak, wound infection, and hydrocephalus in patients undergoing PFTR. Additional studies are warranted to further evaluate clinical and surgical factors impacting PFTR-associated complications.