Autografting is the gold standard in the repair of peripheral nerve injuries that are not amenable to end-to-end coaptation. However, because autografts result in donor-site defects and are a limited resource, an effective substitute would be valuable. In a rat model, we compared isografts with Integra NeuraGen (NG) nerve guides, which are a commercially available type I collagen conduit, with processed rat allografts comparable to AxoGen's Avance human decellularized allograft product. In a 14-mm sciatic nerve gap model, isograft was superior to processed allograft, which was in turn superior to NG conduit at 6 weeks postoperatively (P < 0.05 for number of myelinated fibers both at midgraft and distal to the graft). At 12 weeks, these differences were no longer apparent. In a 28-mm graft model, isografts again performed better than processed allografts at both 6 and 22 weeks; regeneration through the NG conduit was often insufficient for analysis in this long graft model. Functional tests confirmed the superiority of isografts, although processed allografts permitted successful reinnervation of distal targets not seen in the NG conduit groups. Processed allografts were inherently non-immunogenic and maintained some internal laminin structure. We conclude that, particularly in a long gap model, nerve graft alternatives fail to confer the regenerative advantages of an isograft. However, AxoGen processed allografts are superior to a currently available conduit-style nerve guide, the Integra NeuraGen. They provide an alternative for reconstruction of short nerve gaps where a conduit might otherwise be used.

IMPORTANCE Chronic pain is common among the elderly and is associated with cognitive deficits in cross-sectional studies; the population-level association between chronic pain and longitudinal cognition is unknown. OBJECTIVE To determine the population-level association between persistent pain, which may reflect chronic pain, and subsequent cognitive decline. DESIGN, SETTING, AND PARTICIPANTSCohort study with biennial interviews of 10 065 community-dwelling older adults in the nationally representative Health and Retirement Study who were 62 years or older in 2000 and answered pain and cognition questions in both 1998 and 2000. Data analysis was conducted between June 24 and October 31, 2016.EXPOSURES "Persistent pain," defined as a participant reporting that he or she was often troubled with moderate or severe pain in both the 1998 and 2000 interviews. MAIN OUTCOMES AND MEASURESCoprimary outcomes were composite memory score and dementia probability, estimated by combining neuropsychological test results and informant and proxy interviews, which were tracked from 2000 through 2012. Linear mixed-effects models, with random slope and intercept for each participant, were used to estimate the association of persistent pain with slope of the subsequent cognitive trajectory, adjusting for demographic characteristics and comorbidities measures in 2000 and applying sampling weights to represent the 2000 US population. We hypothesized that persistent pain would predict accelerated memory decline and increased probability of dementia. To quantify the impact of persistent pain on functional independence, we combined our primary results with information on the association between memory and ability to manage medications and finances independently. RESULTSOf the 10 065 eligible HRS sample members, 60% were female, and median baseline age was 73 years (interquartile range, 67-78 years). At baseline, persistent pain affected 10.9% of participants and was associated with worse depressive symptoms and more limitations in activities of daily living. After covariate adjustment, persistent pain was associated with 9.2% (95% CI, 2.8%-15.0%) more rapid memory decline compared with those without persistent pain. After 10 years, this accelerated memory decline implied a 15.9% higher relative risk of inability to manage medications and an 11.8% higher relative risk of inability to manage finances independently. Adjusted dementia probability increased 7.7% faster (95% CI, 0.55%-14.2%); after 10 years, this translates to an absolute 2.2% increase in dementia probability for those with persistent pain.CONCLUSIONS AND RELEVANCE Persistent pain was associated with accelerated memory decline and increased probability of dementia.

Quantitative histomorphometry is the current gold standard for objective measurement of nerve architecture and its components. Many methods still in use rely heavily upon manual techniques that are prohibitively time consuming, predisposing to operator fatigue, sampling error, and overall limited reproducibility. More recently, investigators have attempted to combine the speed of automated morphometry with the accuracy of manual and semi-automated methods. Systematic refinements in binary imaging analysis techniques combined with an algorithmic approach allow for more exhaustive characterization of nerve parameters in the surgically relevant injury paradigms of regeneration following crush, transection, and nerve gap injuries. The binary imaging method introduced here uses multiple bitplanes to achieve reproducible, high throughput quantitative assessment of peripheral nerve. Number of myelinated axons, myelinated fiber diameter, myelin thickness, fiber distributions, myelinated fiber density, and neural debris can be quantitatively evaluated with stratification of raw data by nerve component. Results of this semi-automated method are validated by comparing values against those obtained with manual techniques. The use of this approach results in more rapid, accurate, and complete assessment of myelinated axons than manual techniques.

BackgroundEnhanced Recovery After Surgery (ERAS) pathways have been shown in multiple surgical disciplines to improve outcomes, including reduced opioid consumption, length of stay, and post-operative nausea and vomiting (PONV). However, very few studies describe the application of ERAS to breast surgery and even fewer describe ERAS for outpatient surgery. We describe the implementation and efficacy of an Enhanced Recovery After Surgery (ERAS) pathway for total skin-sparing mastectomy with immediate reconstruction in an outpatient setting.MethodsWe implemented an evidence-based, multimodal ERAS pathway for all patients undergoing total skin-sparing mastectomy surgery with immediate reconstruction at a single 23-h stay surgery center. Highlights of the ERAS pathway included: preoperative acetaminophen, gabapentin, and scopolamine; regional anesthesia for the breast (Pectoral blocks type 1 and 2 or paravertebral block); and intraoperative dexamethasone and ondansetron. This retrospective study included all American Society of Anesthesiology (ASA) Class 1–3 patients undergoing total skin-sparing mastectomy surgery with immediate reconstruction between July 2013 and April 2016. We compared 96 patients who were in the ERAS pathway (ERAS group) to a retrospective cohort of 276 patients (Pre group). The primary outcome was total perioperative opioid consumption. Secondary outcomes were highest postoperative pain scores, incidence of PONV, and length of stay.ResultsPatients in the ERAS group had significantly lower total perioperative opioid consumption compared to the Pre group (mean (SD): 111.4 mg (46.0) vs. 163.8 mg (73.2) oral morphine equivalents, p < 0.001). Patients in the ERAS group also had a lower incidence of PONV (28% vs. 50%, p < 0.001). Patients in the ERAS group reported less pain in the recovery room, with a two-point decrease in highest pain score (median [interquartile range (IQR)]: 4 [2,6] in ERAS group vs. 6 [4,7] in Pre group, p < 0.001). There was no clinically significant difference in length of stay (median [IQR]: 1144 min [992, 1259] in ERAS group vs. 1188 [1058, 1344] in Pre group, p = 0.006).ConclusionImplementation of an ERAS pathway for total skin-sparing mastectomy with reconstruction that incorporates regional anesthesia is feasible in a 23-h-stay hospital. Patients in the ERAS pathway had improved post-operative analgesia and reduced post-operative nausea and vomiting.Electronic supplementary materialThe online version of this article (10.1186/s12871-018-0505-9) contains supplementary material, which is available to authorized users.

Background Postoperative delirium in the intensive care unit (ICU) is a frequent complication after cardiac or thoracic surgery and is associated with increased morbidity and mortality. Methods In this single-center substudy of the BAG-RECALL trial (NCT00682825) we screened patients after cardiac or thoracic surgery in the ICU twice daily for delirium using the Confusion Assessment Method for the ICU. The primary outcome was the incidence of delirium in patients who had been randomized to intraoperative Bispectral Index (BIS)-guided and end-tidal anesthetic concentration-guided depth of anesthesia protocols. As a secondary analysis, a Bayesian stochastic search variable selection strategy was used to rank a field of candidate risk factors for delirium, followed by binary logistic regression. Results Of 310 patients assessed, 28/149 (18.8%) in the BIS group and 45/161 (28.0%) in the end-tidal anesthetic concentration group developed postoperative delirium in the ICU (odds ratio 0.60, 95% confidence interval 0.35-1.02, p=0.058). Low average volatile anesthetic dose, intraoperative transfusion, ASA physical status, and EuroSCORE were identified as independent predictors of delirium. Discussion A larger randomized study should determine whether brain monitoring with BIS or an alternative method decreases delirium after cardiac or thoracic surgery. The association between low anesthetic concentration and delirium is a surprising finding and could reflect that patients with poor health are both more sensitive to the effects of volatile anesthetic drugs and are also more likely to develop postoperative delirium. Investigation of candidate methods to prevent delirium should be prioritized in view of the established association between postoperative delirium and adverse patient outcomes.