Syed F. Abbas, Morgan P. Spurgas, Benjamin S. Szewczyk, Benjamin Yim, Ashar Ata and John W. German
Minimally invasive posterior cervical decompression (miPCD) has been described in several case series with promising preliminary results. The object of the current study was to compare the clinical outcomes between patients undergoing miPCD with anterior cervical discectomy and instrumented fusion (ACDFi).
A retrospective study of 74 patients undergoing surgery (45 using miPCD and 29 using ACDFi) for myelopathy was performed. Outcomes were categorized into short-term, intermediate, and long-term follow-up, corresponding to averages of 1.7, 7.7, and 30.9 months, respectively. Mean scores for the Neck Disability Index (NDI), neck visual analog scale (VAS) score, SF-12 Physical Component Summary (PCS), and SF-12 Mental Component Summary (MCS) were compared for each follow-up period. The percentage of patients meeting substantial clinical benefit (SCB) was also compared for each outcome measure.
Baseline patient characteristics were well-matched, with the exception that patients undergoing miPCD were older (mean age 57.6 ± 10.0 years [miPCD] vs 51.1 ± 9.2 years [ACDFi]; p = 0.006) and underwent surgery at more levels (mean 2.8 ± 0.9 levels [miPCD] vs 1.5 ± 0.7 levels [ACDFi]; p < 0.0001) while the ACDFi patients reported higher preoperative neck VAS scores (mean 3.8 ± 3.0 [miPCD] vs 5.4 ± 2.6 [ACDFi]; p = 0.047). The mean PCS, NDI, neck VAS, and MCS scores were not significantly different with the exception of the MCS score at the short-term follow-up period (mean 46.8 ± 10.6 [miPCD] vs 41.3 ± 10.7 [ACDFi]; p = 0.033). The percentage of patients reporting SCB based on thresholds derived for PCS, NDI, neck VAS, and MCS scores were not significantly different, with the exception of the PCS score at the intermediate follow-up period (52% [miPCD] vs 80% [ACDFi]; p = 0.011).
The current report suggests that the optimal surgical strategy in patients requiring dorsal surgery may be enhanced by the adoption of a minimally invasive surgical approach that appears to result in similar clinical outcomes when compared with a well-accepted strategy of ventral decompression and instrumented fusion. The current results suggest that future comparative effectiveness studies are warranted as the miPCD technique avoids instrumented fusion.
Daniel M. Sciubba, R. Morgan Stuart, Matthew J. McGirt, Graeme F. Woodworth, Amer Samdani, Benjamin Carson and George I. Jallo
The majority of shunt infections occur within 6 months of shunt placement and chiefly result from perioperative colonization of shunt components by skin flora. Antibiotic-impregnated shunt (AIS) systems have been designed to prevent such colonization. In this study, the authors evaluate the incidence of shunt infection after introduction of an AIS system in a population of children with hydrocephalus.
The authors retrospectively reviewed all pediatric patients who had undergone cerebrospinal fluid (CSF) shunt insertion at their institution over a 3-year period between April 2001 and March 2004. During the 18 months prior to October 2002, all CSF shunts included standard, nonimpregnated catheters. During the 18 months after October 2002, all CSF shunts included antibiotic-impregnated catheters. All patients were followed up for 6 months after shunt surgery, and all shunt-related complications, including shunt infection, were evaluated. The independent association of AIS catheter use with subsequent shunt infection was assessed via multivariate proportional hazards regression analysis.
A total of 211 pediatric patients underwent 353 shunt placement procedures. In the 18 months prior to October 2002, 208 (59%) shunts were placed with nonimpregnated catheters; 145 (41%) shunts were placed with AIS catheters in the 18 months after October 2002. Of patients with nonimpregnated catheters, 25 (12%) experienced shunt infection, whereas only two patients (1.4%) with antibiotic-impregnated catheters experienced shunt infection within the 6-month follow-up period (p < 0.01). Adjusting for intercohort differences via multivariate analysis, AIS catheters were independently associated with a 2.4-fold decreased likelihood of shunt infection.
The AIS catheter significantly reduced incidence of CSF shunt infection in children with hydrocephalus during the early postoperative period (< 6 months). The AIS system used is an effective instrument to prevent perioperative colonization of CSF shunt components.
Andrew W. Grande, P. Colby Maher, Chad J. Morgan, Ondrej Choutka, Benjamin C. Ling, Timothy C. Raderstorf, Edward J. Berger and Charles Kuntz IV
The standard treatment for lumbosacral tethered cord syndrome (TCS) in adults is surgical detethering. In patients with recurrent TCS, additional detethering operations are associated with increased risk of complications and subsequent scar formation. The authors studied the effect of undertaking a vertebral column subtraction osteotomy (VCSO) at the thoracolumbar junction to shorten the vertebral column and reduce neural element tension.
A model of TCS, developed in fresh-frozen human cadavers, was evaluated in three experiments. In Experiment 1, VCSO of 20 to 25 mm was performed at the T11–12 level. The vertebral column was sequentially shortened and the reduction in tension was measured separately in the terminal filum and the L-1 to S-3 or S-4 nerve roots. In Experiments 2 and 3 the reduction in tension was measured in the spinal cord after a VCSO and after simulating a traditional detethering operation.
Vertebral column shortening produced tension reduction in all experiments. Tension decreased to less than 0.6 g in the terminal filum, L1–S3/4 nerve roots, and spinal cord after closure of a 20- to 25-mm VCSO. The mean ± standard deviation of the Δtension/Δdistance was −0.242 ± 0.019 g/mm for the terminal filum, −0.246 ± 0.019 g/mm for the lumbar nerve roots, and −0.216 ± 0.040 g/mm for the sacral nerve roots. A simulated traditional detethering operation required significant neural element release (detethering) to achieve spinal cord tension reduction equivalent to VCSO.
A VCSO significantly reduced neural tension at the thoracolumbar junction. This novel procedure may provide an alternative to traditional surgical detethering when scarring is excessive and the risk of complications and retethering are high.
Jetan H. Badhiwala, Brij Karmur, Lior M. Elkaim, Naif M. Alotaibi, Benjamin R. Morgan, Nir Lipsman, Philippe De Vloo, Suneil K. Kalia, Andres M. Lozano and George M. Ibrahim
Although deep brain stimulation (DBS) is an accepted treatment for childhood dystonia, there is significant heterogeneity in treatment response and few data are available to identify ideal surgical candidates.
Data were derived from a systematic review and individual patient data meta-analysis of DBS for dystonia in children that was previously published. Outcomes were assessed using the Burke-Fahn-Marsden Dystonia Rating Scale for movement (BFMDRS-M) and for disability (BFMDRS-D). The authors used partial least squares, bootstrapping, and permutation statistics to extract patterns of contributions of specific preoperative characteristics to relationship with distinct outcomes, in all patients and in patients with primary and secondary dystonia separately.
Of 301 children undergoing DBS for dystonia, 167 had primary dystonia, 125 secondary dystonia, and 9 myoclonus dystonia. Three dissociable preoperative phenotypes (latent variables) were identified and associated with the following: 1) BFMDRS-M at last follow-up; 2) relative change in BFMDRS-M score; and 3) relative change in BFMDRS-D score. The phenotype of patients with secondary dystonia, with a high BFMDRS-M score and truncal involvement, undergoing DBS at a younger age, was associated with a worse postoperative BFMDRS-M score. Children with primary dystonia involving the trunk had greater improvement in BFMDRS-M and -D scores. Those with primary dystonia of shorter duration and proportion of life with disease, undergoing globus pallidus DBS, had greater improvements in BFMDRS-D scores at long-term follow-up.
In a comprehensive, data-driven, multivariate analysis of DBS for childhood dystonia, the authors identified novel and dissociable patient phenotypes associated with distinct outcomes. The findings of this report may inform surgical candidacy for DBS.
Paul Gigante, Michael M. McDowell, Samuel S. Bruce, Genevieve Chirelstein, Claudia A. Chiriboga, Joseph Dutkowsky, Elizabeth Fontana, Joshua Hyman, Heakyung Kim, Dean Morgan, Toni S. Pearson, Benjamin D. Roye, David P. Roye Jr., Patricia Ryan, Michael Vitale and Richard C. E. Anderson
Randomized clinical trials have established that lumbar selective dorsal rhizotomy (SDR) reduces lower-extremity tone and improves functional outcome in children with spastic cerebral palsy. Significant data exist to support a secondary effect on upper-extremity function in patients with upper-extremity spasticity. The effects of SDR on upper-extremity tone, however, are not well characterized. In this report, the authors sought to assess changes in upper-extremity tone in individual muscle groups after SDR and tried to determine if these changes could be predicted preoperatively.
The authors retrospectively reviewed 42 children who underwent SDR at Columbia University Medical Center/Morgan Stanley Children's Hospital of NewYork-Presbyterian between 2005 and 2011. Twenty-five had upper-extremity spasticity. All underwent pre- and postoperative examination for measuring tone (Modified Ashworth Scale) and assessing functional outcome. Follow-up examinations with therapists were performed at least once at a minimum of 2 months postoperatively (mean 15 months).
In the upper extremities, 23 (92%) of 25 patients had improvements of at least 1 Ashworth point in 2 or more independent motor groups on the Modified Ashworth Scale, and 12 (71%) of 17 families surveyed reported increases in motor control or spontaneous movement. The mean Modified Ashworth Scale scores for all upper-extremity muscle groups demonstrated an improvement from 1.34 to 1.22 (p < 0.001). Patients with a mean preoperative upper-extremity tone of 1.25–1.75 were most likely to benefit from reduction in tone (p = 0.0019). Proximal and pronator muscle groups were most likely to demonstrate reduced tone.
In addition to improvements in lower-extremity tone and function, SDR has demonstrable effects on upper extremities. Greater than 90% of our patients with elevated upper-extremity tone demonstrated reduction in tone in at least 2 muscle groups postoperatively. Patients with a mean Modified Ashworth Scale upper-extremity score of 1.25–1.75 may encounter the greatest reduction in upper-extremity tone.