Noninvasive electrical stimulation as an adjunct to fusion procedures: a systematic review and meta-analysis

OBJECTIVE

Noninvasive electrical stimulation represents a distinct group of devices used to augment fusion rates. However, data regarding outcomes of noninvasive electrical stimulation have come from a small number of studies. The goal of this systematic review and meta-analysis was to determine outcomes of noninvasive electrical stimulation used as an adjunct to fusion procedures to improve rates of successful fusion.

METHODS

PubMed, Embase, and the Cochrane Clinical Trials database were searched according to search strategy and PRISMA guidelines. Random-effects meta-analyses of fusion rates with the three main modalities of noninvasive electrical stimulation, capacitively coupled stimulation (CCS), pulsed electromagnetic fields (PEMFs), and combined magnetic fields (CMFs), were conducted using R version 4.1.0 (The R Foundation for Statistical Computing). Both retrospective studies and clinical trials were included. Animal studies were excluded. Risk-of-bias analysis was performed with the Risk of Bias 2 (RoB 2) and Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tools.

RESULTS

Searches of PubMed, Embase, and the Cochrane Clinical Trials database identified 8 articles with 1216 participants meeting criteria from 213 initial results. There was a high overall risk of bias identified for the majority of randomized studies. No meta-analysis could be performed for CCS as only 1 study was identified. Meta-analysis of 6 studies of fusion rates in PEMF did not find any difference between treatment and control groups (OR 1.89, 95% CI 0.36-9.80, p = 0.449). Meta-analysis of 2 studies of CMF found no difference in fusion rates between control and treatment groups (OR 0.90, 95% CI 0.07-11.93, p = 0.939). Subgroup analysis of PEMF was limited given the small number of studies and patients, although significantly increased fusion rates were seen in some subgroups.

CONCLUSIONS

This meta-analysis of clinical outcomes and fusion rates in noninvasive electrical stimulation compared to no stimulation did not identify any increases in fusion rates for any modality. A high degree of heterogeneity between studies was noted. Although subgroup analysis identified significant differences in fusion rates in certain groups, these findings were based on a small number of studies and further research is needed. This analysis does not support routine use of these devices to augment fusion rates, although the data are limited by a high risk of bias and a small number of available studies.

2D versus 3D Endoscopy: Head-to-Head Comparison in a Simulated Model of Endoscopic Endonasal Dural Suturing

Objective Endonasal dural suturing (EDS) has been reported to decrease the incidence of cerebrospinal fluid fistula. This technique requires handling of single-shaft instrumentation in the narrow endonasal corridor. It has been proposed that three-dimensional (3D) endoscopes were associated with improved depth perception. In this study, we sought to perform a comparison of two-dimensional (2D) versus 3D endoscopy by assessing surgical proficiency in a simulated model of EDS.

Materials and Methods Twenty-six participants subdivided into groups based on previous endoscopic experience were asked to pass barbed sutures through preset targets with either 2D (Storz Hopkins II) or 3D (Storz TIPCAM) endoscopes on 3D-printed simulation model. Surgical precision and procedural time were measured. All participants completed a Likert scale questionnaire.

Results Novice, intermediate, and expert groups took 11.0, 8.7, and 5.7 minutes with 2D endoscopy and 10.9, 9.0, and 7.6 minutes with 3D endoscopy, respectively. The average deviation for novice, intermediate, and expert groups (mm) was 5.5, 4.4, and 4.3 with 2D and 6.6, 4.6, and 3.0 with 3D, respectively. No significant difference in procedural time or accuracy was found in 2D versus 3D endoscopy. 2D endoscopic visualization was preferred by the majority of expert/intermediate participants, while 3D endoscopic visualization by the novice group.

Conclusion In this pilot study, there was no statistical difference in procedural time or accuracy when utilizing 2D versus 3D endoscopes. While it is possible that widespread familiarity with 2D endoscopic equipment has biased this study, preliminary analysis suggests that 3D endoscopy offers no definitive advantage over 2D endoscopy in this simulated model of EDS.

Stenting in High-Grade Internal Carotid Artery Stenosis: 2-Dimensional Operative Video

Carotid artery stenosis is implicated in up to 40% of all ischemic strokes. Accordingly, symptomatic, high-grade carotid artery stenosis portends an especially high risk of future stroke. Intervention via open or endovascular approaches drastically reduces this risk. Under the appropriate conditions, carotid artery stenting serves as a safe and effective alternative to carotid endarterectomy. We present the case of a 57-yr-old male with symptomatic, high-grade stenosis of his right internal carotid artery, for whom a history of radiation to the head and neck represented a relative contraindication to carotid endarterectomy, and thus endovascular treatment with angioplasty and stenting was performed. Informed consent was obtained prior to the procedure. Intraprocedurally, stent delivery past the area of stenosis proved somewhat challenging. However, by employing several nuanced maneuvers, we utilized our guiding catheter in a nonconventional manner in order to successfully perform the procedure. As the field of neuroendovascular surgery evolves, each case provides us unique lessons, which in turn expands our interventional capabilities and adds to the armamentarium of neuroendovascular techniques. We present this surgical video both as a means to provide a general overview of carotid artery stenting, and to share a lesson learned through the implementation of an interesting technical nuance.

Super-Pedicle Osteotomy for Correction of Focal Thoracolumbar Kyphosis

BACKGROUND

Focal thoracolumbar kyphotic deformities require operative correction through osteotomies to restore normal spinal balance. Traditional osteotomies, such as the pedicle subtraction osteotomy, that are often used in the lumbar spine are less useful in the thoracolumbar region. The super-pedicle osteotomy is a pedicle-sparing wedge osteotomy that can be used for correction of kyphosis in patients with thoracolumbar deformities.

METHODS

A retrospective review was conducted of 9 consecutive cases using the super-pedicle technique. Clinical data regarding patient age at presentation, etiology of deformity, symptoms, neurological status at presentation, American Society of Anesthesiologists class, type of surgery performed, estimated blood loss during surgery, and complications up to last follow-up were recorded. The primary parameter of interest was the angle at the planned osteotomy site before and after correction.

RESULTS

Nine patients with an average age of 64 years were included. All 9 patients had focal thoracic kyphosis either at T11-T12 or T12-L1. All patients underwent thoracolumbar operations with super-pedicle osteotomies at their main level of kyphosis. Estimated blood loss was 600 mL. Average correction at the osteotomy site as measured on preoperative and postoperative radiographs was 31°. At an average follow-up of 338 days, no patients experienced rod fracture, but 1 patient required extension of fusion for proximal junctional kyphosis.

CONCLUSIONS

In this small series of patients with thoracolumbar kyphosis, the super-pedicle osteotomy technique was clinically useful. More robust examination is required to determine the safety, utility, and durability of this osteotomy technique.