Psoas Muscle Index as a Predictor of Perioperative Outcomes in Geriatric Patients Undergoing Spine Surgery.

STUDY DESIGN: Single-center retrospective study. OBJECTIVE: The objective of this study was to evaluate the association of psoas muscle mass defined sarcopenia with perioperative outcomes in geriatric patients undergoing elective spine surgery. METHODS: We included geriatric patients undergoing thoracolumbar spinal surgery. Total psoas surface area (TPA) was measured on preoperative axial computerized tomography or magnetic resonance imaging at the L3 vertebra and normalized to the L3 vertebral body area. Patients were divided into quartiles by normalized TPA, and the fourth quartile (Q4) was compared to quartiles 1-3 (Q1-3). Outcomes included perioperative transfusions, length of stay (LOS), delirium, pseudoarthrosis, readmission, discharge disposition, revision surgery, and mortality. RESULTS: Of the patients who met inclusion criteria (n = 196), the average age was 73.4 y, with 48 patients in Q4 and 148 patients in Q1-3. Q4 normalized TPA cut-off was <1.05. Differences in Q4 preoperative characteristics included significantly lower body mass index, baseline creatinine, and a greater proportion of females (Table 1). Q4 patients received significantly more postoperative red blood cell and platelet transfusions and had longer ICU LOS (P < .05; Table 2). There was no difference in intraoperative transfusion volumes, delirium, initiation of walking, discharge disposition, readmission, pseudoarthrosis, or revision surgery (Tables 2 and 3). Mortality during follow-up was higher in Q4 but was not statistically significant (P = .075). CONCLUSION: Preoperative TPA in geriatric patients undergoing elective spine surgery is associated with increased need for intensive care and postoperative blood transfusion. Preoperative normalized TPA is a convenient measurement and could be included in geriatric preoperative risk assessment algorithms.

Perioperative Factors Associated With Chronic Opioid Use After Spine Surgery.

STUDY DESIGN: Retrospective case control. OBJECTIVES: The purpose of the current study is to determine risk factors associated with chronic opioid use after spine surgery. METHODS: In our single institution retrospective study, 1,299 patients undergoing elective spine surgery at a tertiary academic medical center between January 2010 and August 2017 were enrolled into a prospectively collected registry. Patients were dichotomized based on renewal of, or active opioid prescription at 3-mo and 12-mo postoperatively. The primary outcome measures were risk factors for opioid renewal 3-months and 12-months postoperatively. These primarily included demographic characteristics, operative variables, and in-hospital opioid consumption via morphine milligram equivalence (MME). At the 3-month and 12-month periods, we analyzed the aforementioned covariates with multivariate followed by bivariate regression analyses. RESULTS: Multivariate and bivariate analyses revealed that script renewal at 3 months was associated with black race (P = 0.001), preoperative narcotic (P < 0.001) or anxiety/depression medication use (P = 0.002), and intraoperative long lumbar (P < 0.001) or thoracic spine surgery (P < 0.001). Lower patient income was also a risk factor for script renewal (P = 0.01). Script renewal at 12 months was associated with younger age (P = 0.006), preoperative narcotics use (P = 0.001), and ≥4 levels of lumbar fusion (P < 0.001). Renewals at 3-mo and 12-mo had no association with MME given during the hospital stay or with the usage of PCA (P > 0.05). CONCLUSION: The current study describes multiple patient-level factors associated with chronic opioid use. Notably, no metric of perioperative opioid utilization was directly associated with chronic opioid use after multivariate analysis.

Perioperative Optimization of Senior Health in Spine Surgery: Impact on Postoperative Delirium.

BACKGROUND: Delirium is a common postoperative complication in geriatric patients, especially in those with underlying risk factors. Multicomponent nonpharmacologic interventions are effective in preventing delirium, however, implementation of these measures is variable in perioperative care. The aim of our study was to assess the impact of our Perioperative Optimization of Senior Health Program (UTSW POSH) on postoperative delirium in patients undergoing elective spine surgery. STUDY DESIGN: The UTSW POSH program is an interdisciplinary perioperative initiative involving geriatrics, surgery, and anesthesiology to improve care for high-risk geriatric patients undergoing elective spine surgery. Preoperatively, enrolled patients (n = 147) were referred for a geriatric assessment and optimization for surgery. Postoperatively, patients were co-managed by the primary surgical team and the geriatrics consult service. UTSW POSH patients were retrospectively compared to a matched historical control group (n = 177) treated with usual care. Main outcomes included postoperative delirium and provider recognition of delirium. RESULTS: UTSW POSH patients were significantly older (75.5 vs 71.5 years; P < .001), had more comorbidities (8.02 vs 6.58; P < .001), and were more likely to undergo pelvic fixation (36.1% vs 17.5%; P < .001). The incidence of postoperative delirium was lower in the UTSW POSH group compared to historical controls, although not statistically significant (11.6% vs 19.2%; P = .065). Delirium was significantly lower in patients who underwent complex spine surgery (≥4 levels of vertebral fusion; N = 106) in the UTSW POSH group (11.7% vs 28.9%, P = .03). There was a threefold increase in the recognition of postoperative delirium by providers after program implementation, (76.5% vs 23.5%; P = .001). CONCLUSIONS: This study suggests that interdisciplinary care for high-risk geriatric patients undergoing elective spine surgery may reduce the incidence of postoperative delirium and increase provider recognition of delirium. The benefit may be greater for those undergoing larger procedures.

Generation of model tissues with dendritic vascular networks via sacrificial laser-sintered carbohydrate templates.

Sacrificial templates for patterning perfusable vascular networks in engineered tissues have been constrained in architectural complexity, owing to the limitations of extrusion-based 3D printing techniques. Here, we show that cell-laden hydrogels can be patterned with algorithmically generated dendritic vessel networks and other complex hierarchical networks by using sacrificial templates made from laser-sintered carbohydrate powders. We quantified and modulated gradients of cell proliferation and cell metabolism emerging in response to fluid convection through these networks and to diffusion of oxygen and metabolites out of them. We also show scalable strategies for the fabrication, perfusion culture and volumetric analysis of large tissue-like constructs with complex and heterogeneous internal vascular architectures. Perfusable dendritic networks in cell-laden hydrogels may help sustain thick and densely cellularized engineered tissues, and assist interrogations of the interplay between mass transport and tissue function.