ABSTRACT
BACKGROUND: The postoperative length of stay (LOS) is an important prognostic indicator for patients undergoing instrumented spinal fusion surgery. Increased LOS can be associated with higher infection rates, higher incidence of venous thromboembolisms, and a greater frequency of hospital-acquired delirium. The day of surgery and early postoperative mobilization following single-level posterior thoracolumbar stabilizations may impact the LOS. In this study, we evaluated the effects of weekday (Monday-Thursday) versus weekend (Friday-Sunday) surgery and postoperative rehabilitation services on LOS following primarily transforaminal lumbar interbody fusion (TLIF) for degenerative spondylolisthesis (DS). METHODS: In this single-institution retrospective chart review, we identified 198 adults who received a one-level thoracolumbar instrumented fusion through a posterior only approach (2017-2019). The majority of these patients underwent TLIF for DS. A zero truncated negative binomial model was used for predictors of the primary outcome of LOS (weekday of surgery, duration of operation, first or repeat surgery, and physical therapy/ occupational therapy [PT/OT] evaluation). Covariates were sex, age, and body mass index. RESULTS: We found that operative duration, repeat surgery, and in-hospital PT/OT all significantly increased the LOS (P < 0.05). Furthermore, those undergoing weekday surgery (Monday-Thursday) had 1.29 times longer LOS than those on the weekend (Friday-Sunday), but this did not reach statistical significance (P = 0.09). CONCLUSION: In our patient sample, duration, repeat surgery, and in-hospital PT/OT increased the LOS following primarily TLIF for DS. The increased LOS in these cases is likely due to higher overall disease burden and case complexity. In addition, those patients with a greater likelihood of extended recovery and ongoing neurologic deficits are more likely to have PT/OT evaluations. Notably, LOS was not significantly impacted by the day of surgery at our institution.
ABSTRACT
The mesocorticolimbic system is comprised of dopaminergic neurons in the ventral tegmental area (VTA) and their projection targets in the ventral striatum, amygdala, prefrontal cortex, and hippocampus, among others. Regulation of dopamine transmission within this system is achieved in part through a negative feedback mechanism via dopamine D2 autoreceptors located on somatodendrites and terminals of VTA dopaminergic neurons. Dysregulation of this mechanism has been implicated in addiction and other psychiatric disorders, although the biological bases for these associations are unclear. In order to elucidate the functional consequences of VTA D2 receptor dysregulation, this study investigated alterations in local cerebral glucose utilization throughout the brain following Drd2 knockdown in the VTA. Male Sprague-Dawley rats received bilateral injections of lentivirus encoding shRNAs against the rat dopamine D2 receptor, scrambled shRNA or phosphate buffered saline. The autoradiographic 2-[14C]deoxyglucose metabolic mapping procedure was conducted 22â¯days post-infection. Brains were sectioned for autoradiography and glucose utilization was measured across distinct regions throughout the brain. Local cerebral glucose utilization was found to be elevated in the Drd2 knockdown group as compared to control groups. These greater levels of metabolic activity following Drd2 knockdown in the VTA were observed not only in the mesocorticolimbic system and associated dopamine pathways, but also in a global pattern that included many areas with far less concentrated VTA dopamine inputs. This suggests that even a partial Drd2 deletion in the VTA can have widespread consequences and impact information flow in diverse networks that process sensory, cognitive, motor and emotional information.
