Benjamin Yim, M. Reid Gooch, John C. Dalfino, Matthew A. Adamo and Tyler J. Kenning
Cerebrospinal fluid shunting can effectively lower intracranial pressure and improve the symptoms of idiopathic intracranial hypertension (IIH). Placement of ventriculoperitoneal (VP) shunts in this patient population can often be difficult due to the small size of the ventricular system. Intraoperative adjuvant techniques can be used to improve the accuracy and safety of VP shunts for these patients. The purpose of this study was to analyze the efficacy of some of these techniques, including the use of intraoperative CT (iCT) and frameless stereotaxy, in optimizing postoperative ventricular catheter placement.
The authors conducted a retrospective review of 49 patients undergoing initial ventriculoperitoneal shunt placement for the treatment of IIH. The use of the NeuroPEN Neuroendoscope, intraoperative neuronavigation, and iCT was examined. To analyze ventricular catheter placement on postoperative CT imaging, the authors developed a new grading system: Grade 1, catheter tip terminates optimally in the ipsilateral frontal horn or third ventricle; Grade 2, catheter tip terminates in the contralateral frontal horn; Grade 3, catheter terminates in a nontarget CSF space; and Grade 4, catheter tip terminates in brain parenchyma. All shunts had spontaneous CSF flow upon completion of the procedure.
The average body mass index among all patients was 37.6 ± 10.9 kg/m2. The NeuroPEN Neuroendoscope was used in 44 of 49 patients. Intraoperative CT scans were obtained in 24 patients, and neuronavigation was used in 32 patients. Grade 1 or 2 final postoperative shunt placement was achieved in 90% of patients (44 of 49). In terms of achieving optimal postoperative ventricular catheter placement, the use of iCT was as effective as neuronavigation. Two patients had their ventricular catheter placement modified based on an iCT study. The use of neuronavigation significantly increased time in the operating room (223.4 ± 46.5 vs 190.8 ± 31.7 minutes, p = 0.01). There were no shunt infections in this study.
The use of iCT appears to be equivalent to the use of neuronavigation in optimizing ventricular shunt placement in IIH. Additionally, it may shorten operating room time and limit overall costs.
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.