A Meta-analysis of the Impact of Bariatric Surgery on Back Pain

Differences in Psychological Health and Weight Loss after Bariatric Metabolic Surgery between Patients with and without Pain Syndromes

PURPOSE

Chronic pain and obesity often co-occur, negatively affecting one another and psychological wellbeing. Pain and psychological wellbeing improve after bariatric metabolic surgery (BMS), however, it is unknown whether psychological wellbeing improves differently after weight loss between patients with and without chronic pain. We investigated whether weight loss is associated with greater psychological wellbeing and functioning change after BMS, comparing patients with and without preoperative pain syndromes.

METHODS

Depression, health-related quality of life, self-esteem, self-efficacy to exercise and controlling eating behaviours, physical activity, and food cravings were measured before and 24 months after BMS among 276 patients with obesity. The presence of preoperative chronic pain syndromes was examined as a moderator for the relationship between 24-month weight loss and changes in psychological outcomes.

RESULTS

Chronic pain syndromes were present among 46% of patients. Weight loss was associated with greater improvement in health-related quality of life, self-efficacy to exercise and controlling eating behaviours, self-esteem and greater amelioration in food cravings. Pain syndromes only moderated negatively the relationship between the postoperative weight loss and change in self-efficacy to control eating behaviours (b = -0.49, CI [-0.88,-0.12]).

CONCLUSION

Patients with and without chronic pain showed similar improvements in weight and psychological wellbeing and behaviours after BMS. The relationship between weight loss and the improvement of self-efficacy to control eating behaviours was weaker among patients with chronic pain syndrome. Further work, measuring pain severity over time, is needed to shed light on the mechanism underlying pain and postoperative change in psychological wellbeing and weight loss.

Predictors of Chronic Pain 6 Months and 1 Year After Bariatric Surgery

BACKGROUND

Obesity and chronic pain (CP) represent serious, interrelated global public health concerns that have a profound impact on individuals and society. Bariatric surgery is increasing in popularity and has been proven safe and efficacious, providing long-term weight loss and improvements in many obesity-related co-morbidities. A decrease in CP is often a motivation for bariatric surgery. The purpose of this study was to investigate the changes in CP postoperatively and to examine the relationship between psychosocial measures and pain.

METHODS

A total of 155 adult bariatric surgery patients were recruited and completed self-report measures for CP severity and interference, neuropathic pain, anxiety, depression, emotion regulation and perceived social support at three timepoints preoperative and 6 and 12 months postoperative.

RESULTS

Pain significantly decreased between preoperative and postoperative timepoints, and preoperative pain was the most significant predictor of postoperative pain. Preoperative CP was correlated with anxiety (p < 0.05) and depression (p < 0.01) at 6 months postoperatively and perceived social support (p < 0.01) at 1 year postoperatively. However, regression analyses with psychological variables were not significant.

CONCLUSION

CP decreases after bariatric surgery, but further research with larger sample sizes is needed to establish whether psychosocial characteristics impact this outcome.

Effects of BMI on SI joint fusion outcomes: examining the evidence to improve insurance guidelines

BACKGROUND CONTEXT

Obesity is increasing. Previous studies have demonstrated an association between obesity and adverse events after lumbar fusion. There is limited evidence on the effect of obesity on minimally invasive SI joint fusion (SIJF) outcomes.

PURPOSE

The purpose of this study was to investigate the impact of obesity on patient-reported outcomes in patients undergoing SIJF surgery using triangular titanium implants (TTI).

STUDY DESIGN

Retrospective cohort study based on four prospective clinical trials (INSITE [NCT01681004], SIFI [NCT01640353], iMIA [NCT01741025], and SALLY [NCT03122899]).

PATIENT SAMPLE

Adult patients ≥18 years of age who underwent minimally invasive surgery (MIS) sacroiliac joint (SIJ) fusion between 2012 and 2021.

OUTCOME MEASURES

Visual analog scale (VAS Pain), Oswestry Disability Index (ODI).

METHODS

Participants were classified using the National Institutes of Health body mass index (BMI). Patients with a BMI of 30 to 39 with no significant comorbidity are considered obese, patients with a BMI of 35 to 39 with a significant comorbidity or a BMI of 40 or greater are considered morbidly obese. All subjects underwent either minimally invasive SIJ fusion with TTI or nonsurgical management (INSITE and iMIA studies only). All subjects completed SIJ pain scale scores (measured with a 100-point VAS) and disability scores (measured with ODI) at baseline and at scheduled visits to 24 months. Repeated measures analysis of variance was used to examine the impact of BMI category on score changes.

RESULTS

In the SIJF group, mean SIJ pain improved at 24 months by 53.3 points (p<.0001). Over the 24-month follow-up period, BMI category did not impact mean improvement in SIJ pain scale score (repeated measures analysis of variance (ANOVA) p=.44). In the SIJF group, mean ODI at 24 months improved by 25.8 points (p<.0001). BMI category did not impact mean improvement in ODI (ANOVA p=.60). In the nonsurgical management (NSM) group, mean improvements in SIJ pain scale and ODI were clinically small (8.7 and 5.2 points, respectively) and not affected by BMI category (ANOVA p=.49 and .40).

CONCLUSION

This study demonstrates similar benefits and risks of minimally invasive SIJ fusion with TTI across all BMI categories. This analysis suggests that obese patients benefit from minimally invasive SIJ fusion and should not be denied this procedure based solely on elevated BMI.

Bariatric surgery and COVID-19 outcomes: a systematic review and meta-analysis

BACKGROUND

Obesity and its associated complications have a negative impact on human health. Metabolic and bariatric surgery (MBS) ameliorates a series of clinical manifestations associated with obesity. However, the overall efficacy of MBS on COVID-19 outcomes remains unclear.

OBJECTIVES

The objective of this article is to analyze the relationship between MBS and COVID-19 outcomes.

SETTING

A meta-analysis.

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library databases were searched to retrieve the related articles from inception to December 2022. All original articles reporting MBS-confirmed SARS-CoV-2 infection were included. Outcomes including hospital admission, mortality, intensive care unit (ICU) admission, mechanical ventilation utilization, hemodialysis during admission, and hospital stay were selected. Meta-analysis with fixed or random-effect models was used and reported in terms of odds ratios (ORs) or weighted mean differences (WMDs) along with their 95% confidence intervals (CIs). Heterogeneity was assessed with the I2 test. Study quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

A total of 10 clinical trials involving the investigation of 150,848 patients undergoing MBS interventions were included. Patients who underwent MBS had a lower risk of hospital admission (OR: .47, 95% CI: .34-.66, I2 = 0%), mortality (OR: .43, 95% CI: .28-.65, I2 = 63.6%), ICU admission (OR: .41, 95% CI: .21-.77, I2 = 0%), and mechanical ventilation (OR: .51, 95% CI: .35-.75, I2 = 56.2%) than those who did not undergo surgery, but MBS did not affect hemodialysis risk or COVID-19 infection rate. In addition, the length of hospital stay for patients with COVID-19 after MBS was significantly reduced (WMD: -1.81, 95% CI: -3.11-.52, I2 = 82.7%).

CONCLUSIONS

Our findings indicate that MBS is shown to improve COVID-19 outcomes, including hospital admission, mortality, ICU admission, mechanical ventilation, and hospital stay. Patients with obesity who have undergone MBS infected with COVID-19 will have better clinical outcomes than those without MBS.

Effect of Body Mass Index on Paddle Lead Spinal Cord Stimulator Safety Implantation for Chronic Pain Management

OBJECTIVE

Spinal cord stimulators (SCS) represent an effective treatment for patients with chronic pain issues. This study examines extremely obese patients (body mass index [BMI] ≥40) as appropriate surgical candidates for paddle lead SCS trial via partial thoracic laminectomy and whether obesity impacts implantation safety.

METHODS

A retrospective review of patients treated with partial thoracic laminectomy and paddle lead SCS trial between October 1, 2016 and September 30, 2019 was performed. The primary outcome was implantation safety (complication rate within minimum of 90 days) in patients with extreme obesity (BMI ≥40) compared with patients with BMI <40 and secondary outcome was effectiveness (successful trial leading to final implantation). Seventy-three patients underwent SCS trial.

RESULTS

Four (5.48%) patients developed complications with only 1 patient in the BMI ≥40 cohort (not statistically significant). Overall trial success rate was 82.2% (60/73) with statistically significant higher success rates among patients with a BMI ≥40 (93.3% vs. 74.4%, P = 0.0183).

CONCLUSIONS

We conclude that paddle lead SCS trial in extremely obese patients is reasonable to offer with the expectation of similar safety concerns as those for patients with a lower BMI.

Pain is adversely related to weight loss maintenance following bariatric surgery

BACKGROUND

Pain and obesity are frequently co-morbid health conditions; thus, it is unsurprising that pain is commonly experienced by individuals seeking bariatric surgery. While pain is generally reduced in the short-term after surgery, there is also variability in pain outcomes and less is known about how unresolved or recurring pain may relate to long-term weight loss and weight loss maintenance.

OBJECTIVES

This study evaluated trajectories of pain scores through 7 years following bariatric surgery and whether higher pain levels related to poorer weight loss and greater weight regain.

SETTING

Data were collected from 3 university hospitals, 1 private not-for-profit research institute, and 1 community hospital.

METHODS

Self-report measures of pain and weight change data were utilized for 1702 adults seeking Roux-en-Y gastric bypass surgery from the Longitudinal Assessment for Bariatric Surgery (LABS) cohort. A series of linear mixed models examined trajectories of pain scores and the concurrent predictive relationship between pain and weight outcomes from pre-surgery through 7 years post-surgery.

RESULTS

Overall bodily-, hip-, and knee-pain improved through 2 years, deteriorated from 2-5 years, and then slightly improved from 5-7 years following surgery (P < .001). Greater pain was concurrently associated with less weight loss and greater weight regain over time (P ≤ .006).

CONCLUSION

Pain is evident in the long-term following bariatric surgery and associated with suboptimal weight outcomes. More research is needed to identify mechanisms underlying this relationship, which may ultimately help develop appropriate pain assessment and treatment strategies to ensure optimal post-surgery outcomes.

Network Meta-Analysis of Metabolic Surgery Procedures for the Treatment of Obesity and Diabetes

Background

Metabolic surgery is part of a well-established treatment intensification strategy for obesity and its related comorbidities including type 2 diabetes (T2DM). Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG) and one-anastomosis gastric bypass (OAGB) are the most commonly performed metabolic surgeries worldwide, but comparative efficacy is uncertain. This study employed network meta-analysis to compare weight loss, T2DM remission and perioperative complications in adults between RYGB, SG and OAGB.

Methods

MEDLINE, EMBASE, trial registries were searched for randomised trials comparing RYGB, SG and OAGB. Study outcomes were excess weight loss (at 1, 2 and 3–5 years), trial-defined T2DM remission at any time point and perioperative complications.

Results

Twenty randomised controlled trials were included involving 1803 patients investigating the three metabolic surgical interventions. RYGB was the index for comparison. The excess weight loss (EWL) demonstrated minor differences at 1 and 2 years, but no differences between interventions at 3–5 years. T2DM remission was more likely to occur with either RYGB or OAGB when compared to SG. Perioperative complications were higher with RYGB when compared to either SG or OAGB. Two-way analysis of EWL and T2DM remission against the risk of perioperative complications demonstrated OAGB was the most positive on this assessment at all time points.

Conclusion

OAGB offers comparable metabolic control through weight loss and T2DM remission to RYGB and SG whilst minimising perioperative complications.

Registration number: CRD42020199779 (https:// www.crd.york.ac.uk/PROSPERO)

Graphical abstract

Changes in Back Pain Scores after Bariatric Surgery in Obese Patients: A Systematic Review and Meta-Analysis

Bariatric surgery produces significant and quantifiable reductions in back pain. However, there is a lack of information on the association of weight changes after bariatric surgery with changes in pain score. We aim to evaluate the impact of bariatric surgery on back pain in obese patients and to address the association between changes in body mass index (BMI) and pain score. In obese patients eligible for bariatric surgery, the changes in pre- and post-operative pain scores, assessed by the Numeric Rating Pain Scale (NPS) or Visual Analogue Scale (VAS), were considered as primary outcomes. Mean difference (MD) and their 95% confidence intervals (CI) were evaluated. Eight cohort studies were included in the analysis of 298 obese patients undergoing bariatric surgery. All studies showed a reduction in back pain, with a mean change of -2.9 points in NPS and of -3.8 cm in VAS. There was a significant reduction in back pain (NPS: (MD = -3.49) (95% CI = -3.86, -3.12); VAS: MD = -3.75, (95% CI = -4.13, -3.37)) and BMI (MD = -12.93, (95% CI = -13.61, -12.24)) following bariatric surgery. No significant relationship between BMI change and decrease in clinical scores could be established. However, it was evident that bariatric surgery had a significant effect on back pain scores in severely obese patients. Ideally, a prospective study including spinal imaging, inflammatory markers, a longer follow-up period, and larger study groups with a randomized control group needs to be performed.

Regional Variation in Unmet Need for Metabolic Surgery in England: a Retrospective, Multicohort Analysis

Metabolic surgery provision is severely limited despite extensive supportive trial evidence. This study estimated the eligible population and the unmet need for metabolic surgery within English regions. Health Survey for England, National Diabetes Audit and population estimates were used to estimate the metabolic surgery eligible population by English region. Hospital Episode Statistics data was examined for metabolic surgery procedure volume by region (2013-2019). Regression analysis examined factors associated with metabolic surgery eligibility. 7.3% of the English population is potentially eligible for metabolic surgery; equivalent to 3.21 million people. Only 0.20% of the eligible English population receive metabolic surgery per year (regional variation 0.08-0.41%). The metabolic surgery eligible population was more likely to be female, older, have fewer educational qualifications and live in more deprived areas.