Dorsal Root Ganglion Stimulation as a Salvage Therapy Following Failed Spinal Cord Stimulation.

INTRODUCTION: Spinal cord stimulation (SCS) can provide long-term pain relief for various chronic pain conditions, but some patients have no relief with trial stimulation or lose efficacy over time. To "salvage" relief in patients who do not respond or have lost efficacy, alternative stimulation paradigms or anatomical targets can be considered. Dorsal root ganglion stimulation (DRG-S) has a different mechanism of action and anatomical target than SCS. OBJECTIVES: We assessed DRG-S salvage therapy outcomes in patients who did not respond to SCS or had lost SCS efficacy. MATERIALS AND METHODS: We retrospectively included consecutive patients from 2016 to 2020 who were salvaged with DRG-S after failed SCS trials (<50% pain reduction) or who had lost efficacy after permanent SCS. We compared numerical rating scale (NRS) pain, Oswestry disability index (ODI), health-related quality of life (EuroQol five-dimensions five-level), and oral morphine equivalent (OME) opioid requirements before DRG-S salvage and at patients' last follow-up. RESULTS: A total of 60 patients who had failed SCS were salvaged with DRG-S. The mean age was 56 ± 12 years, and the most common diagnoses were complex regional pain syndrome (n = 24) and failed back surgery syndrome (n = 24). The most common failed modalities included tonic (n = 32), Burst (n = 18), and high-frequency (n = 10) SCS. The median follow-up duration of salvage DRG-S was 34 months. With DRG-S, NRS decreased (8.7 ± 1.2 to 3.8 ± 2.1), and OME declined (median 23 mg to median 15 mg), whereas EuroQol 5D scores increased (0.40 ± 0.15 to 0.71 ± 0.15), and ODI improved (64 ± 14% to 31 ± 18%) (all p < 0.05). CONCLUSIONS: DRG-S can be used in patients with chronic pain who have previously failed to receive persistent benefit from SCS.

A paramedian approach for dorsal root ganglion stimulation placement developed to limit lead migration and fracture.

INTRODUCTION: Dorsal root ganglion stimulation (DRG-S), has demonstrated superiority in the treatment of complex regional pain syndrome and causalgia. Lead migration and fracture impact DRG-S therapeutic stability. Lead anchoring reduces DRG-S lead migration without increasing lead fracture. Lead fracture may be related to lead entrapment in the superficial fascial plane. A novel medialized approach for lead placement and anchoring is presented to address these issues. METHODS: We suggest an alternative technique for implanting percutaneous DRG-S leads at the T10-L5 levels. RESULTS: A novel medialized ipsilateral technique for lead placement and anchoring for single, bilateral, and adjacent segment placement is presented. The Tuohy needle puncture site is medial to the pedicle and adjacent to the spinous process, two vertebral levels caudad to the target foramen. Trajectory is maintained in the sagittal plane, to access the caudad interlaminar space near the midline. This technique allows for ipsilateral or contralateral lead placement. After epidural access, the introducer sheath is rotated toward the targeted foramen and advanced. The guidewire followed by the lead is passed, and once lead position is confirmed, tension "S" loops are created, followed by anchoring to the deep fascia. CONCLUSION: We describe a new paramedian technique for DRG-S lead placement. We propose it will decrease DRG-S complication rates through anchoring to reduce migration and by avoiding the fascial planes thought to be responsible for fracture. Long-term outcomes applying our proposed techniques are required for determining the true impact, however, early anecdotal results suggest that these new techniques are favorable.

Evaluation of an Intrathecal Drug Delivery Protocol Leads to Rapid Reduction of Systemic Opioids in the Oncological Population.

Objective: The article that follows is purposed at demonstrating how IT opioid plus bupivacaine achieves sustained acceptable pain relief while simultaneously rapidly reducing oral morphine equivalents (OME). Background: Cancer patients represent a population with significant morbidity, pain, and limited life expectancy. It is, therefore, vital to achieve satisfactory analgesia quickly and safely. To date, there is limited data in the literature that discusses efficacy of combined intrathecal (IT) medication therapy in reducing systemic opioids in the oncological population. Methods: This was a retrospective analysis that reviewed cancer pain patients from day of IT pump implantation through the six-month postoperative time point. A cohort of 50 oncological patients who had intrathecal drug delivery systems (IDDSs) implanted at Memorial Sloan Kettering Cancer Center between 2017 and 2019 were studied. Median OMEs were the primary modality of analysis for this review. Mean visual analogue scale scores were secondarily reviewed. Results: Median OMEs decreased from 503 preoperative to 105 at six months postoperative time point. Median time to discharge was 6.5 days. Unfortunately, due to malignant mortality, 27 patients did not make it to the 6-month postoperative time point. Discussion: IDDSs with opioid plus bupivacaine represent a safe and efficient route toward expeditious pain relief and decreased OMEs in the cancer pain population.

Evaluation of Fixed Intrathecal Bupivacaine Infusion Doses in the Oncologic Population.

OBJECTIVES: Intrathecal drug delivery systems (IDDS) are an important method of pain control for patients with refractory oncologic pain. Local anesthetics such as bupivacaine have been infused either alone or with opioids. While effective, bupivacaine can cause adverse effects such as numbness, weakness, and urinary retention. This study looks to establish a safe and efficacious fixed bupivacaine dosing algorithm in intrathecal pumps for cancer patients. MATERIALS AND METHODS: A bupivacaine dosing algorithm was developed using data from 120 previous patients who underwent IDDS placement at Memorial Sloan Kettering Cancer Center. The outcomes were then evaluated for 43 subsequent patients who were treated with bupivacaine IDDS according to our aforementioned algorithm. RESULTS: Our data show that in patients treated with our bupivacaine guideline, visual analog pain scale scores decreased by 59% and oral morphine equivalence decreased by 70% from the period between IDDS implantation until discharge from the MSKCC hospital. However, 16.3% of our patients had bupivacaine-related side effects. CONCLUSIONS: For oncological patients, our data and experience support the initiation of intrathecal bupivacaine at the following doses: 5 mg/day for catheter tips in the cervical spine, 8 mg/day for catheter tips at T1-4, and 10 mg/day for catheter tips at T5-8. Given the higher likelihood of adverse effects in catheters at T9-12 and the lumbar spine, we start at 8 mg/day with close follow-up of the patient. Initiating these doses allow our patients to safely reach adequate analgesia faster, with a shorter hospitalization and quicker return to anti-cancer therapy.

The Use of L2 and L3 Lumbar Sympathetic Blockade for Cancer-Related Pain, an Experience and Recommendation in the Oncologic Population.

OBJECTIVE: The sympathetic nervous system has a recognized role in transmission of pain, and the lumbar sympathetic blockade is intended to provide analgesia. We share our experiences of lumbar sympathetic blockade in the treatment of cancer-related pain. METHODS: We performed a retrospective analysis of patients with cancer-related pain in the back, abdomen, pelvis, or legs treated at Memorial Sloan Kettering Cancer Center between 2000 and 2018 undergoing lumbar sympathetic blockade at L2 or L3. Blocks were accomplished by injection of local anesthetic or local anesthetic with steroid under fluoroscopy. We measured numerical rating scale scores, percent relief, and relief time. The primary end point was defined as "effective" or "ineffective" pain relief. Effective pain relief was defined as ≥30% relief for at least one day. RESULTS: We identified 124 data points of lumbar sympathetic blockade at L2 or L3, of which 57 were with complete data and used for analysis. Peri-injection, 42 data points had active disease whereas 15 were in remission. Lumbar sympathetic blockade was 67% effective in the back pain cohort, 82% effective in the abdominopelvic pain cohort, and 75% effective in the leg pain cohort. Seventeen data points went on to neurolysis, two to neuromodulation, and eight to intrathecal pump implantation. CONCLUSIONS: Lumbar sympathetic blockade is effective for back, abdominopelvic, and leg pain related to cancer and its treatments. Future research should be aimed at refining its role within multimodal pain management.

Validation of the recently developed Total Disability Index: a single measure of disability in neck and back pain patients.

OBJECTIVE: Neck and back pain are highly prevalent conditions that account for major disability. The Neck Disability Index (NDI) and Oswestry Disability Index (ODI) are the two most common functional status measures for neck and back pain. However, no single instrument exists to evaluate patients with concurrent neck and back pain. The recently developed Total Disability Index (TDI) combines overlapping elements from the ODI and NDI with the unique items from each. This study aimed to prospectively validate the TDI in patients with spinal deformity, back pain, and/or neck pain. METHODS: This study is a retrospective review of prospectively collected data from a single center. The 14-item TDI, derived from ODI and NDI domains, was administered to consecutive patients presenting to a spine practice. Patients were assessed using the ODI, NDI, and EQ-5D. Validation of internal consistency, test-retest reproducibility, and validity of reconstructed NDI and ODI scores derived from TDI were assessed. RESULTS: A total of 252 patients (mean age 55 years, 56% female) completed initial assessments (back pain, n = 115; neck pain, n = 52; back and neck pain, n = 55; spinal deformity, n = 55; and no pain/deformity, n = 29). Of these patients, 155 completed retests within 14 days. Patients represented a wide range of disability (mean ODI score: 36.3 ± 21.6; NDI score: 30.8 ± 21.8; and TDI score: 34.1 ± 20.0). TDI demonstrated excellent internal consistency (Cronbach's alpha = 0.922) and test-retest reliability (intraclass correlation coefficient = 0.96). Differences between actual and reconstructed scores were not clinically significant. Subanalyses demonstrated TDI's ability to quantify the degree of disability due to back or neck pain in patients complaining of pain in both regions. CONCLUSIONS: The TDI is a valid and reliable disability measure in patients with back and/or neck pain and can capture each spine region's contribution to total disability. The TDI could be a valuable method for total spine assessment in a clinical setting, and its completion is less time consuming than that for both the ODI and NDI.

When is compensation for lumbar spinal stenosis a clinical sagittal plane deformity?

BACKGROUND CONTEXT: Degenerative lumbar stenosis (DLS) patients have been reported to lean forward in an attempt to provide neural decompression. Spinal alignment in patients with DLS may resemble that of adult spinal deformity (ASD). No previous studies have compared and contrasted the compensatory mechanisms of DLS and ASD patients. PURPOSE: This study aimed to determine the differences in compensatory mechanisms between DLS and ASD patients with increasing severity of sagittal spinopelvic malalignment. Contrasting these compensatory mechanisms may help determine at what severity sagittal malalignment represents a clinical sagittal deformity rather than a compensation for neural compression. STUDY DESIGN/SETTING: This is a retrospective clinical and radiological review. PATIENT SAMPLE: Baseline x-rays in patients without spinal instrumentation, with the clinical radiological and diagnoses of DLS or ASD, were assessed for patterns of spinopelvic compensatory mechanisms. Patients were stratified by sagittal vertical axis (SVA) according to the Scoliosis Research Society-Schwab [SRS-Schwab] classification. OUTCOME MEASURES: Radiographic spinopelvic parameters were measured in the DLS and ASD groups, including SVA, pelvic incidence-lumbar lordosis mismatch (PI-LL), T1 spinopelvic inclination (T1SPi), T1 pelvic angle (TPA), and pelvic tilt (PT). METHODS: The two diagnosis cohorts were propensity-matched for PI and age. Each group contained 125 patients and was stratified according to the SRS-Schwab classification. Regional spinopelvic,lower limb, and global alignment parameters were assessed to identify differences in compensatory mechanisms between the two groups with differing degrees of deformity. No funding was provided by any third party in relation to carrying out this study or preparing the manuscript. RESULTS: With mild to moderate malalignment (SRS-Schwab groups "0," or "+" for PT, PI-LL, or SVA), DLS patients permit anterior truncal inclination and recruit posterior pelvic shift instead of pelvic tilt to maintain balance, while providing relief of neurologic symptoms. Adult spinal deformity patients with mild to moderate deformity recruit pelvic tilt earlier than DLS patients. With moderate to severe malalignment, no significant difference was found in compensatory mechanisms between DLS and ASD patients. CONCLUSIONS: Patients with DLS permit mild to moderate deformity without recruiting compensatory mechanisms of PT, reducing truncal inclination and thoracic hypokyphosis to achieve neural decompression. However, with moderate to severe deformity, their desire for upright posture overrides the desire for neural decompression, evident by the adaptation of compensatory mechanisms similar to that of ASD patients.

Variability Over Time of Preoperative Sagittal Alignment Parameters: Radiographic and Clinical Considerations.

STUDY DESIGN: Retrospective review. OBJECTIVE: To evaluate preoperative variability in radiographic sagittal parameters in adult spinal deformity (ASD). SUMMARY OF BACKGROUND DATA: In ASD surgical planning, deformity magnitude is determined from preoperative radiographs. There are no studies evaluating the clinical relevance and timing to repeat radiographs during interval clinic visits and timing to repeat radiograph for preoperative planning. METHODS: A total of 139 patients with ASD with minimum two preoperative full-body spine x-rays were included. Cervical, thoracic, lumbar, pelvic, and hip/knee sagittal alignment parameters were analyzed using dedicated spine measurement software. Patients were grouped by time intervals between x-rays: A: 8 weeks or lesser, B: 10 to 20 weeks, and C: 21 weeks or more. Changes in sagittal parameters were correlated to age and deformity magnitude (T1 pelvic angle or pelvic tilt [PT] >20°). RESULTS: The cohort had mean age 59 years, mean body mass index 27, 30% men, 95 patients with no prior spine surgery, and 44 patients at minimum 9 months since prior spine surgery. There were 25 patients in group A, 38 in B, and 71 in C. All radiographic measures showed good time-based consistency at intervals less than 21 weeks (groups A and B). Group C had significant increases in PT (1.5°) and hip extension (2.1°) (P < 0.05). These changes were greater in group C patients with previous surgery (PT 3.7°; P < 0.006, hip extension 3.2°; P < 0.025). Greater interval changes in parameters were also associated with higher magnitudes of deformity and younger patient ages. CONCLUSION: All sagittal radiographic parameters were statistically consistent at intervals of less than 21 weeks. In patients with more than 21 weeks between interval x-rays, change in PT was greater than the standard error of measurement for patients with prior surgery or severe deformity. Consideration should be made to obtain new x-rays for patients with ASD when the interval between clinical visits exceeds 5 months. LEVEL OF EVIDENCE: 4.

Developing the Total Disability Index Based on an Analysis of the Interrelationships and Limitations of Oswestry and Neck Disability Index.

STUDY DESIGN: Retrospective. OBJECTIVE: This study assessed the feasibility of combining Oswestry and Neck Disability Index (ODI and NDI) into 1 shorter "Total Disability Index" (TDI) from which reconstructed scores could be computed. SUMMARY OF BACKGROUND DATA: ODI and NDI are not pure assessments of disability related to back and neck, respectively. Because of similarities/redundancies of questions, ODI scores may be elevated in neck-pain patients and the converse is true for NDI in back-pain patients. METHODS: Spine patients completed ODI and NDI, and complaints were recorded as back pain (BP), neck pain (NP), or both (BNP). Questionnaire scores were compared across cohorts via descriptives and Spearman (ρ) correlations. In exploring the feasibility of merging ODI/NDI, TDI was constructed from 9 ODI and 5 NDI items. Extracting questions from TDI, reconstructed 9-item rODI and 10-item rNDI indices were formed and compared with true ODI/NDI. RESULTS: There were a total of 1207 patients: 741 BP, 134 NP, and 268 BNP. Mean ODI was 37 ±â€Š21 and mean NDI was 32 ±â€Š21. Patients with concurrent BP and NP had significantly more disability. Seventy-eight patients of 134 (58%) patients with NP only had at least "moderate disability" by ODI and 297 of 741 (40%) patients with back pain only, had at least "moderate disability" by NDI. ODI versus NDI correlation was ρ = 0.755; ODI versus reconstructed rODI correlated at ρ = 0.985, and NDI versus reconstructed rNDI correlated at ρ = 0.967 (P < 0.01). CONCLUSION: Elevated ODI/NDI scores in patients with isolated complaints show that disability in 1 region affects scores on both surveys. This study constructed a 14-item TDI that represents every domain of ODI/NDI with exception of ODI "Sex Life." From this TDI, reconstructed scores correlated near perfectly with true scores. TDI provides a more global assessment of spinal disability and is a questionnaire that reduces the time burden to patients. The TDI allows for simultaneous assessment of back, neck, and global spinal disability.

Patient preferences and bariatric surgery procedure selection; the need for shared decision-making.

BACKGROUND: Bariatric surgery is the most effective treatment for patients suffering from obesity-related comorbidities. There is little data regarding how patients choose one particular bariatric procedure over another. This study aimed to better define the relationship between preferences of patients considering bariatric surgery and the procedure patients undergo. METHODS: A bilingual questionnaire was administered to all prospective patients seen between March 1 and August 31, 2012. The questionnaire assessed basic knowledge of bariatric surgery (based on the information seminar) as well as patient preferences of the various outcomes and complications for sleeve gastrectomy, gastric bypass, and gastric banding. RESULTS: One hundred seventy-two patients completed the questionnaire. Fifty-eight percent of patients chose "maximum weight loss" as the most important outcome, and 65 % chose "leak" as the most concerning complication. Subgroup analysis of patients with diabetes revealed that 58 % chose "curing diabetes" as the most important outcome. Nineteen percent of patients were either not sure which procedure they wanted or changed their decision after consultation with the surgeon. CONCLUSIONS: The decision to choose one bariatric procedure over another is complex and is based on factors beyond absolute patient preferences. Although maximum weight loss is a commonly reported preference for patients seeking bariatric surgery, patients with diabetes are more focused on diabetes remission. Most patients have already decided which procedure to undergo prior to surgeon consultation. Patients may benefit from shared decision making, which integrates patient values and preferences along with current medical evidence to assist in the complex bariatric surgery selection process.