Transcutaneous electrical nerve stimulation for the treatment of acute postoperative pain following spine surgery: a scoping review.

OBJECTIVE: Given the ubiquity and severity of postoperative pain following spine surgery, developing adequate pain management modalities is critical. Transcutaneous electrical nerve stimulation (TENS) is a promising noninvasive modality that is well studied for managing postoperative pain following a variety of surgeries, but data on using TENS for pain management in the acute postoperative period of spine surgery are limited. Therefore, this review aimed to recapitulate the existing evidence for the use of TENS in postoperative pain management for spine surgery and explore the potential of this modality moving forward. METHODS: A scoping review was conducted according to 2020 PRISMA guidelines. Two independently operating reviewers then conducted a systematic search of PubMed, Embase, and Scopus databases to identify studies that reported the use of TENS for the treatment of acute postoperative pain following spine surgery. The following data were abstracted from included studies: study type, sample size, demographics, surgery details, comparison group, assessment parameters, timing of postoperative assessment, TENS technical characteristics, relevant findings, length of hospital stay, complications with TENS, and notable limitations. RESULTS: Nine hundred thirty-two publications were screened, resulting in 6 studies included in this review, all of which were prospective clinical trials. The publication dates ranged from 1980 to 2011. Spine surgery types varied; the most common was posterior lumbar interbody fusion. No studies evaluated pain control in cervical- or thoracic-only surgeries. All 6 studies evaluated the level of postoperative pain directly. Five of the 6 studies that directly examined postoperative pain reported lower levels of pharmacological analgesia usage in the TENS groups compared with controls, with 4 of these studies reporting this difference as statistically significant. Length of hospital stay was evaluated in 2 studies, both of which reported decreases in mean length of stay, but these differences were not significant. Notably, every study reported distinct TENS administration parameters while also reporting similar results. CONCLUSIONS: This review concludes that TENS is effective at reducing postoperative pain in spine surgery. Further investigation is needed regarding the optimal settings for TENS administration, as well as efficacy in the thoracic and cervical spine.

Development and validation of an artificial intelligence model to accurately predict spinopelvic parameters.

OBJECTIVE: Achieving appropriate spinopelvic alignment has been shown to be associated with improved clinical symptoms. However, measurement of spinopelvic radiographic parameters is time-intensive and interobserver reliability is a concern. Automated measurement tools have the promise of rapid and consistent measurements, but existing tools are still limited to some degree by manual user-entry requirements. This study presents a novel artificial intelligence (AI) tool called SpinePose that automatically predicts spinopelvic parameters with high accuracy without the need for manual entry. METHODS: SpinePose was trained and validated on 761 sagittal whole-spine radiographs to predict the sagittal vertical axis (SVA), pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), T1 pelvic angle (T1PA), and L1 pelvic angle (L1PA). A separate test set of 40 radiographs was labeled by four reviewers, including fellowship-trained spine surgeons and a fellowship-trained radiologist with neuroradiology subspecialty certification. Median errors relative to the most senior reviewer were calculated to determine model accuracy on test images. Intraclass correlation coefficients (ICCs) were used to assess interrater reliability. RESULTS: SpinePose exhibited the following median (interquartile range) parameter errors: SVA 2.2 mm (2.3 mm) (p = 0.93), PT 1.3° (1.2°) (p = 0.48), SS 1.7° (2.2°) (p = 0.64), PI 2.2° (2.1°) (p = 0.24), LL 2.6° (4.0°) (p = 0.89), T1PA 1.1° (0.9°) (p = 0.42), and L1PA 1.4° (1.6°) (p = 0.49). Model predictions also exhibited excellent reliability at all parameters (ICC 0.91-1.0). CONCLUSIONS: SpinePose accurately predicted spinopelvic parameters with excellent reliability comparable to that of fellowship-trained spine surgeons and neuroradiologists. Utilization of predictive AI tools in spinal imaging can substantially aid in patient selection and surgical planning.

Conservative management of intraventricular migration of a gelatin sponge: illustrative case.

BACKGROUND: Gelatin sponges, such as Gelfoam, are used as hemostatic agents during surgery and are generally absorbed over the course of 4-6 weeks in most body cavities. The time course of the dissolution of Gelfoam sponges within the cerebral ventricles has not been described. OBSERVATIONS: The authors present a case of intraventricular migration of Gelfoam after ventriculoperitoneal shunt placement in a 6-week-old infant. The infant was imaged regularly after ventriculoperitoneal shunt placement, and the Gelfoam sponge persisted within the ventricles on all images until 11 months after surgery. At no time during follow-up did the patient have any symptoms of hydrocephalus requiring retrieval of the sponge or shunt revision. LESSONS: This is the first case describing time until absorption of a gelatin sponge within the ventricle and successful conservative management.

Predictors of favorable quality of life outcome following kyphoplasty and vertebroplasty.

OBJECTIVE: In 2009, 2 randomized controlled trials demonstrated no improvement in pain following vertebral augmentation compared with sham surgery. However, a recent randomized trial demonstrated significant pain relief in patients following vertebroplasty compared to controls treated with conservative medical management. This study is a retrospective review of prospectively collected patient-reported quality of life (QOL) outcomes. The authors hypothesized that vertebral augmentation procedures offer a QOL benefit, but that this benefit would be diminished in patients with a history of depression and/or in patients undergoing vertebral augmentation at more than 1 level. METHODS: Multivariable linear regression was used to identify predictors of postoperative pain assessed using the Pain Disability Questionnaire (PDQ), Patient Health Questionnaire 9 (PHQ-9), and EQ-5D scores. Eleven candidate predictors were selected a priori: age, sex, smoking history, coronary artery disease, depression, diabetes, procedure location (thoracic, lumbar), BMI, prior spine surgery, procedure indication (metastases, osteoporosis/osteopenia, other), and number of levels (1, 2, 3, or more). RESULTS: A total of 143 patients were included in the study. For each 10-year increase in age, postoperative PDQ scores decreased (improved) by 9.7 points (p < 0.001). Patients with osteoporosis/osteopenia had significantly higher (worse) postoperative PDQ scores (+17.97, p = 0.028) than patients with metastatic lesions. Male sex was associated with higher (worse) postoperative PHQ-9 scores (+2.48, p = 0.010). Compared to single-level augmentation, operations at 2 levels were associated with significantly higher PHQ-9 scores (+2.58, p = 0.017). Current smokers had significantly lower PHQ-9 scores (-1.98, p = 0.023) than never smokers. No predictors were associated with significantly different EQ-5D score. CONCLUSIONS: Variables associated with worse postoperative PDQ scores included younger age and osteoporosis/osteopenia. Variables associated with decreased (better) postoperative PHQ-9 scores included female sex, single operative vertebral level, and positive smoking status (i.e., current smoker). These clinically relevant predictors may permit identification of patients who may benefit from vertebral augmentation.

Techniques for placement of stereotactic electroencephalographic depth electrodes: Comparison of implantation and tracking accuracies in a cadaveric human study.

OBJECTIVE: Stereotactic electroencephalography (SEEG) is used for the evaluation and identification of the epileptogenic zone (EZ) in patients suffering from medically refractory seizures and relies upon the accurate implantation of depth electrodes. Accurate implantation is critical for identification of the EZ. Multiple electrodes and implantation systems exist, but these have not previously been systematically evaluated for implantation accuracy. This study compares the accuracy of two SEEG electrode implantation methods. METHODS: Thirteen "technique 1" electrodes (applying guiding bolts and external stylets) and 13 "technique 2" electrodes (without guiding bolts and external stylets) were implanted into four cadaver heads (52 total of each) according to each product's instructions for use using a stereotactic robot. Postimplantation computed tomography scans were compared to preimplantation computed tomography scans and to the previously defined targets. Electrode entry and final depth location were measured by Euclidean coordinates. The mean errors of each technique were compared using linear mixed effects models. RESULTS: Primary analysis revealed that the mean error difference of the technique 1 and 2 electrodes at entry and target favored the technique 1 electrode implantation accuracy (P < 0.001). Secondary analysis demonstrated that orthogonal implantation trajectories were more accurate than oblique trajectories at entry for technique 1 electrodes (P = 0.002). Furthermore, deep implantations were significantly less accurate than shallow implantations for technique 2 electrodes (P = 0.005), but not for technique 1 electrodes (P = 0.50). SIGNIFICANCE: Technique 1 displays greater accuracy following SEEG electrode implantation into human cadaver heads. Increased implantation accuracy may lead to increased success in identifying the EZ and increased seizure freedom rates following surgery.