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Joshua M. Beckman, Ernest K. Amankwah, Lisa L. Tetreault and Gerald F. Tuite

OBJECT

The application of concentrated topical antibiotic powder directly to surgical wounds has been associated with a reduction in wound infection in cardiac, spinal, and deep brain stimulator surgery. As a result of these findings, the corresponding author began systematically applying concentrated bacitracin powder directly to wounds during shunt surgery more than 5 years ago. The object of this study was to evaluate the effectiveness of concentrated bacitracin powder applied directly to wounds prior to closure during cranial shunt surgery and to evaluate the association between shunt infection and other risk factors. A single surgeon’s cranial shunt surgery experience, equally divided between periods during which antibiotic powder was and was not applied, was studied to assess the effect of concentrated bacitracin powder application on shunt infection rates.

METHODS

This retrospective cohort study included all patients who underwent a cranial shunting procedure at All Children’s Hospital performed by a single surgeon (G.F.T.) from 2001 to 2013. The surgeon applied bacitracin powder to all shunt wounds prior to closure between 2008 and 2013, whereas no antibiotic powder was applied to wounds prior to 2008. Both initial and revision shunting procedures were included, and all procedures were performed at a large children’s hospital (All Children’s Hospital). The primary outcome measure was shunt infection, which was defined using clinical criteria previously used by the Hydrocephalus Clinical Research Network. The association between bacitracin powder use and shunt infection was estimated using hazard ratios (HRs) and 95% CIs from Cox proportional hazard regression models.

RESULTS

A total of 47 infections out of 539 shunt operations occurred during the study period, resulting in an overall infection rate of 8.7%. Procedures performed before the use of concentrated bacitracin powder was instituted resulted in a 13% infection rate, whereas procedures performed after systematic use of bacitracin powder had been adopted experienced a 1% infection rate. Bacitracin powder use was associated with a reduced risk of shunt infection in univariate analysis (HR 0.11, 95% CI 0.03–0.34, p = 0.0002) and also in multivariate analysis (HR 0.12, 95% CI 0.04–0.41, p = 0.0006) when controlling for covariates that were associated with infection from the univariate analysis. The presence of a tracheostomy or a gastrostomy tube was also found to be independently associated with shunt infection in multivariate analysis (HR 3.15, 95% CI 1.05–9.50, p = 0.04, and HR 2.82, 95% CI 1.33–5.96, p = 0.007, respectively).

CONCLUSIONS

This study suggests, for the first time, that the systematic application of concentrated bacitracin powder to surgical wounds prior to closure during shunt surgery may be associated with a reduction in cranial shunt infection. This initial finding requires validation in a large prospective study before widespread application can be advocated.

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Joshua M. Beckman, Ernest K. Amankwah, Lisa L. Tetreault, Sharon A. Perlman and Gerald F. Tuite

OBJECT

There has been renewed interest in the application of concentrated antibiotic powder to surgical wounds as a method to decrease infection rates. While there is substantial medical literature describing the effectiveness and complications associated with vancomycin and gentamycin powders, very little has been reported regarding the safety and effectiveness of bacitracin powder in surgical wounds. In this paper the authors report their detailed analysis of potential bacitracin powder-related complications in a population of pediatric patients who underwent shunt surgery.

METHODS

A detailed retrospective analysis was completed of all CSF shunt surgeries performed by the corresponding author at a large children’s hospital between 2001 and 2013. This cohort consisted of many patients who were the subject of a previous report that showed the use of bacitracin powder in shunt wounds potentially decreased infection rates. Data were collected regarding the most common known complications of bacitracin, i.e., anaphylaxis, wound healing difficulties, and renal dysfunction. Data were stratified by typical demographic, medical, and surgical variables, including whether bacitracin powder was applied to wounds prior to closure.

RESULTS

A total of 597 patients were reviewed in the analysis: 389 underwent surgery without bacitracin powder and 208 had concentrated bacitracin powder applied to the wounds prior to closure. The application of bacitracin powder was not associated with anaphylaxis (n = 0 both groups) or with an increase in wound breakdown (n = 5 in the control group, n = 0 in the bacitracin powder group) or renal dysfunction (creatinine/estimated glomerular filtration rate) using both comparative and multivariate analyses between the 2 groups. The sample size evaluating renal function was significantly lower (range 6–320) than that of anaphylaxis and wound breakdown analysis because only clinical values acquired during the routine care of these patients were available for analysis. The only significant difference in demographics was the more frequent use of intrathecal vancomycin and gentamycin in patients who received bacitracin powder (n = 1 for controls, n = 21 for bacitracin powder). In the multivariate analysis, only 1 factor, surgery performed on a premature infant within the first 3 months of life, was independently associated with a change in creatinine at 3 months (creatinine decreased by 0.18) compared with the level before surgery (p < 0.0001). Bacitracin powder was not a significant factor.

CONCLUSIONS

To the authors’ knowledge, this is the first study to systematically analyze the potential complications of concentrated bacitracin powder applied to surgical wounds. The use of topical bacitracin powder in CSF shunt wounds was not associated with anaphylaxis, wound breakdown, or renal dysfunction. Further study using standardized protocols is necessary before widespread use can be recommended.

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Stephen L. Reintjes, Ernest K. Amankwah, Luis F. Rodriguez, Carolyn C. Carey and Gerald F. Tuite

OBJECT

Fusion rates are high for children undergoing posterior cervical fusion (PCF) and occipito-cervical fusion (OCF). Autologous bone has been widely used as the graft material of choice, despite the risk of donor-site morbidity associated with harvesting the bone, possibly because very low fusion rates were reported with posterior allograft cervical fusions in children several decades ago. Higher overall fusion rates using allograft in adults, associated with improvements in internal fixation techniques and the availability of osteoinductive substances such as bone morphogenetic protein (BMP), have led to heightened enthusiasm for the use of bank bone during pediatric PCF. A systematic review was performed to study factors associated with successful bone fusion, including the type of bone graft used.

METHODS

The authors performed a comprehensive PubMed search of English-language articles pertaining to PCF and OCF in patients less than 18 years old. Of the 561 abstracts selected, 148 articles were reviewed, resulting in 60 articles that had sufficient detail to be included in the analysis. A meta-regression analysis was performed to determine if and how age, fusion technique, levels fused, fusion substrate, BMP use, postoperative bracing, and radiographic fusion criteria were related to the pooled prevalence estimates. A systematic review of the literature was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement.

RESULTS

A total of 604 patients met the specific inclusion and exclusion criteria. The overall fusion rate was 93%, with a mean age of 9.3 years and mean follow-up of 38.7 months. A total of 539 patients had fusion with autograft (94% fusion rate) and 65 patients with allograft (80% fusion rate). Multivariate meta-regression analysis showed that higher fusion rates were associated with OCF compared with fusions that excluded the occiput (p < 0.001), with the use of autograft instead of allograft (p < 0.001), and with the use of CT to define fusion instead of plain radiography alone. The type of internal fixation, the use of BMP, patient age, and the duration of follow-up were not found to be associated with fusion rates in the multivariate analysis.

CONCLUSIONS

Fusion rates for PCF are high, with higher rates of fusion seen when autograft is used as the bone substrate and when the occiput is included in the fusion construct. Further study of the use of allograft as a viable alternative to autograft bone fusion is warranted because limited data are available regarding the use of allograft in combination with more rigid internal fixation techniques and osteoinductive substances, both of which may enhance fusion rates with allograft.

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Gerald F. Tuite, Ethan G. Polsky, Yves Homsy, Margaret A. Reilly, Carolyn M. Carey, S. Parrish Winesett, Luis F. Rodriguez, Bruce B. Storrs, Sarah J. Gaskill, Lisa L. Tetreault, Denise G. Martinez and Ernest K. Amankwah

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Gerald F. Tuite, Ethan G. Polsky, Yves Homsy, Margaret A. Reilly, Carolyn M. Carey, S. Parrish Winesett, Luis F. Rodriguez, Bruce B. Storrs, Sarah J. Gaskill, Lisa L. Tetreault, Denise G. Martinez and Ernest K. Amankwah

OBJECTIVE

Xiao et al. and other investigators have studied an intradural somatic-to-autonomic (e.g., L-5 to S3–4) nerve transfer as a method to create a reflex arc to allow bladder emptying in response to cutaneous stimulation (the Xiao procedure). In previous clinical studies of patients with spinal dysraphism who underwent the Xiao procedure, high success rates (70%–85%) were reported for the establishment of a “skin-CNS-bladder” reflex arc that allows spontaneous, controlled voiding in children with neurogenic bladder dysfunction. However, many of these studies did not use blinded observers, did not have control groups, and/or featured only limited follow-up durations.

METHODS

A randomized, prospective, double-blind trial was initiated in March 2009, enrolling children with myelomeningocele (MM), lipomyelomeningocele (LMM), and neurogenic bladder dysfunction who were scheduled for spinal cord detethering (DT) for the usual indications. At the time of DT, patients were randomized between 2 arms of the study: half of the patients underwent a standard spinal cord DT procedure alone (DT group) and half underwent DT as well as the Xiao procedure (DT+X group). Patients, families, and study investigators, all of whom were blinded to the surgical details, analyzed the patients' strength, sensory function, mobility, voiding, and urodynamic bladder function before surgery and at regular intervals during the 3-year follow-up.

RESULTS

Twenty patients were enrolled in the study: 10 underwent only DT and the other 10 underwent DT+X. The addition of the Xiao procedure to spinal cord DT resulted in longer operative times (p = 0.024) and a greater chance of wound infection (p = 0.03). Patients in both treatment arms could intermittently void or dribble small amounts of urine (< 20% total bladder capacity) in response to scratching in dermatomes T-9 through S-2 using a standardized protocol, but the voiding was not reproducible and the volume voided was not clinically useful in any patient. Voiding in response to scratching was not more frequent in patients who underwent DT+X compared with those who underwent only DT. Bladder contractions in response to scratching occurred in both treatment arms at various intervals after surgery, but they were not more reproducible or more frequent in the patients who underwent the Xiao procedure than in the patients who did not. No patient in either treatment arm was continent of urine before, during, or after the study.

CONCLUSIONS

Patients with MM and LMM who underwent the Xiao procedure during spinal cord DT were no more likely to be able to void, to control their urination, to achieve continence, or to have a demonstrable urodynamic bladder contraction in response to cutaneous stimulation than patients who underwent only spinal cord DT. This study, in the context of disappointing results reported in other recent studies of the Xiao procedure, raises doubts about the clinical applicability of this procedure in humans until further basic science research is performed.