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Volumetric muscle loss (VML) is traumatic, degenerative, or surgical loss of skeletal muscle that exceeds the regenerative capacity of the remaining muscle, thus resulting in impaired muscle function. In humans, the loss of 30% or more mass of any one muscle will result in permanent structural and functional loss. Current VML repair treatments are limited by donor site morbidity and graft tissue availability, necessitating alternative muscle graft sources. To address this need, our lab has fabricated tissue-engineered skeletal muscle units (SMUs) for implantation into a 30 % VML model in the tibialis anterior (TA) muscle of rat. Previous results showed that after 28 days in vivo, muscle with a 30% VML repaired with our SMUs produced significantly more force than muscle with acute VML. But repair with our SMU did not fully restore muscle force production to that of native muscle. Thus, we hypothesized that more time for in vivo tissue regeneration would allow for greater force recovery. Therefore, the purpose of this study was to examine the long-term (3-month) effects of our SMUs on a 30% VML repair. We also assessed the effects of reinnervation by redirecting a branch of the peroneal nerve to the repair site. Thirty-nine, 2-month old female F344 rats were separated into a nonsurgical control group (n=5) and four surgical experimental groups (VML Only, n=5; VML+Nerve Redirect, n=6; VML+SMU, n=5; VML+SMU+ Nerve Redirect, n=8). Experimental rats were allowed a 3-month recovery period post-surgery before undergoing in situ force testing of the surgical (left) TA. The left TA of the control animals also underwent in situ force testing. Finally, the surgical (left) and contralateral (right) TAs of the experimental animals, as well as the left TA of the control animals, were explanted for histological analysis. Results for specific force showed that while all groups recovered specific forces similar to that of native muscle, the two SMU groups had significantly higher specific forces, on average, compared to the uninjured control group. Histological staining showed small muscle fibers in the repair site in animals that received an SMU. The average cross-sectional area of the native fibers just outside the area of repair (or the equivalent area in control animals) was not significantly different between groups, indicating that hypertrophy of remaining fibers did not contribute to the recovery of force following the VML. Our results suggest that following a 30% VML of the TA muscle, all surgical groups were able to recover TA mass, maximum tetanic and specific force production. Thus, creating a 30% VML in the TA in a rat model is not enough a sufficient VML to produce the sustained VML seen in humans following similar 30% loss of muscle volume.

A right-sided pneumonectomy after induction therapy for non-small cell lung cancer (NSCLC) has been shown to be associated with significant perioperative risk. We examined the effect of laterality on long-term survival after induction therapy and pneumonectomy using the National Cancer Data Base.Perioperative and long-term outcomes of patients who underwent pneumonectomy after induction chemotherapy, with or without radiotherapy, from 2004 to 2014 in the National Cancer Data Base were evaluated using multivariable Cox proportional hazards modeling and propensity score-matched analysis.During the study period, 1,465 patients (right, 693 [47.3%]; left, 772 [52.7%]) met inclusion criteria. Right-sided pneumonectomy was associated with significantly higher 30-day (8.2% [57 of 693] vs 4.2% [32 of 772], p0.01) and 90-day mortality (13.6% [94 of 693] vs 7.9% [61 of 772], p0.01), and right-sided pneumonectomy was a predictor of higher 90-day mortality (odds ratio, 2.23; p0.01). However, overall 5-year survival between right and left pneumonectomy was not significantly different in unadjusted (37.6% [95% confidence interval {CI}, 0.34 to 0.42] vs 35% [95% CI, 0.32 to 0.39], log-rank p = 0.94) or multivariable analysis (hazard ratio, 1.07; 95% CI, 0.92 to 1.25; p = 0.40). A propensity score-matched analysis of 810 patients found no significant differences in 5-year survival between the right-sided versus left-sided groups (34.7% [95% CI, 0.30 to 0.40] vs 34.1%, [95% CI, 0.29 to 0.39], log-rank p = 0.86).In this national analysis, right-sided pneumonectomy after induction therapy was associated with a significantly higher perioperative but not worse long-term mortality compared to a left-sided procedure.

Background: Postoperative cognitive dysfunction (POCD), a syndrome of cognitive deficits occurring 1–12 months after surgery primarily in older patients, is associated with poor postoperative outcomes. POCD is hypothesized to result from neuroinflammation; however, the pathways involved remain unclear. Unbiased proteomic analyses have been used to identify neuroinflammatory pathways in multiple neurologic diseases and syndromes but have not yet been applied to POCD. Objective: To utilize unbiased mass spectrometry-based proteomics to identify potential neuroinflammatory pathways underlying POCD. Methods: Unbiased LC-MS/MS proteomics was performed on immunodepleted cerebrospinal fluid (CSF) samples obtained before, 24 hours after, and 6 weeks after major non-cardiac surgery in older adults who did (n = 8) or did not develop POCD (n = 6). Linear mixed models were used to select peptides and proteins with intensity differences for pathway analysis. Results: Mass spectrometry quantified 8,258 peptides from 1,222 proteins in > 50%of patient samples at all three time points. Twelve peptides from 11 proteins showed differences in expression over time between patients with versus without POCD (q

BACKGROUND: Perioperative neurocognitive disorders (PND) are common complications in older adults associated with increased 1-year mortality and long-term cognitive decline. One risk factor for worsened long-term postoperative cognitive trajectory is the Alzheimer’s Disease (AD) genetic risk factor APOE4. APOE4 is thought to elevate AD risk partly by increasing neuroinflammation, which is also a theorized mechanism for PND. Yet, it is unclear whether modulating apoE4 protein signaling in older surgical patients would reduce PND risk or severity. OBJECTIVES: MARBLE is a randomized, blinded, placebo-controlled phase II sequential dose escalation trial designed to evaluate perioperative administration of an apoE mimetic peptide drug, CN-105, in older adults (age ≥60 years). The primary aim is evaluating the safety of CN-105 administration, as measured by adverse event (AE) rates in CN-105 versus placebo-treated patients. Secondary aims include assessing perioperative CN-105 administration feasibility and its efficacy for reducing postoperative neuroinflammation and PND severity. METHODS: 201 patients undergoing non-cardiac, non-neurological surgery will be randomized to control or CN-105 treatment groups and receive drug or placebo before and every six hours after surgery, for up to three days after surgery. Chart reviews, pre- and postoperative cognitive testing, delirium screening, and blood and CSF analyses will be performed to examine effects of CN-105 on perioperative adverse event rates, cognition, and neuro-inflammation. Trial results will be disseminated by presentations at conferences and peer-reviewed publications. CONCLUSION: MARBLE is a transdisciplinary study designed to measure CN-105 safety and efficacy for preventing PND in older adults and to provide insight into the pathogenesis of these geriatric syndromes.

Purpose To report the prevalence of ocular surface dysfunction in patients presenting for cataract surgery evaluation. Setting Duke University Eye Center and Weill Cornell Ophthalmology, single-physician practices. Design Prospective case series. Methods Consecutive patients presenting for cataract surgery evaluation were identified. Patient information including demographics, medical history, slitlamp findings, tear osmolarity, and tear matrix metalloproteinase-9 (MMP-9) levels were recorded. Patients were considered to have ocular surface dysfunction if any of the following outcomes were present: visually significant abnormal corneal surface examination, positive MMP-9 test, or abnormal osmolarity values (>307 mOsm/L or >7 mOsm/L intereye difference). Patient symptoms were recorded using the ocular surface disease index (OSDI) or Symptom Assessment iN Dry Eye questionnaires. Results There were 120 patients (69% women), mean age 69.5 years ± 8.4 (SD). Abnormal osmolarity was found in 68 patients (56.7%), and abnormal MMP-9 in 76 patients (63.3%). Clinical findings showed that 47 patients (39.2%) had positive corneal staining on presentation, 9 patients (7.5%) had epithelial basement membrane dystrophy, and 2 patients (1.6%) had Salzmann nodules. Questionnaire data showed 54 (54.0%) of 100 patients reported symptoms suggestive of ocular surface dysfunction. In the asymptomatic group of 46 patients, 39 (85%) had at least 1 abnormal tear test (osmolarity or MMP-9) and 22 (48%) had both tests abnormal. Overall, 96 (80%) of 120 patients had at least 1 abnormal tear test result suggestive of ocular surface dysfunction and 48 patients (40%) had 2 abnormal results. Conclusions Objective ocular surface dysfunction findings were common among patients presenting for cataract surgery, yet many presented undiagnosed. Clinicians should be aware of this high prevalence and consider screening with tear testing before surgery.

OBJECTIVE: The objective of this study was to evaluate the impact of the video-assisted thoracoscopic (VATS) approach on the outcomes of patients who underwent pneumonectomy. METHODS: The effect of the surgical approach on perioperative complications and survival in patients who underwent pneumonectomy for non-metastatic non-small cell lung cancer (NSCLC) across 3 institutions (2000-2016) was assessed using multivariable logistic regression, Cox proportional hazard analysis and propensity-score matching. Completion pneumonectomies were excluded from this study and an “intent-to-treat” analysis was performed. RESULTS: During the study period, 359 patients met inclusion criteria and underwent pneumonectomy for non-metastatic NSCLC: 124 (35%) VATS and 235 (65%) thoracotomy. Perioperative mortality (VATS 7% [n=9] vs open 8% [n=19]; p=0.75) and morbidity (VATS 28% [n=35] vs open 28% [n=65], p=0.91) were similar between the groups, even after multivariable adjustment. Using a VATS approach, there was a significantly greater number of lymph nodes (p < 0.001) and N2 stations dissected (p < 0.001). Further, there was a significantly shorter chest tube duration for the VATS group (VATS 1.2±1.4 days vs open 1.5±1.4 days, p = 0.01). VATS showed similar 5-year survival when compared with thoracotomy in unadjusted analysis (47% [95% CI: 36-56] vs 33% [95% CI: 27-40]; p = 0.19), even after multivariable adjustment (HR = 0.76 [95% CI: 0.50-0.1.18]; p=0.23). In a propensity-score matched analysis that balanced patient characteristics, there were no significant differences found in overall survival between the two groups (p=0.69). CONCLUSION: Although the role of VATS pneumonectomy will likely become clearer as more surgeons report results, this multicenter study suggests that the VATS approach for pneumonectomy can be performed safely, with at least equivalent oncologic outcomes compared to thoracotomy.

Volumetric muscle loss (VML) is a loss of skeletal muscle that results in a sustained impairment of function and is often accompanied by physical deformity. To address the need for more innovative repair options, our laboratory has developed scaffold-free, multiphasic tissue-engineered skeletal muscle units (SMUs) to treat VML injuries. In our previous work, using the concept of the "body as a bioreactor", we have shown that implantation promotes the maturation of our SMUs beyond what is possible in vitro. Thus, in this study we sought to better understand the effect of implantation on the maturation of our SMUs, including the effects of implantation on SMU force production and cellular remodeling. We used an ectopic implantation so that we could more easily dissect the implanted tissues post-recovery and measure the force contribution of the SMU alone and compare it to pre-implantation values. This study also aimed to scale up the size of our SMUs to enable the replacement of larger volumes of muscle in our future VML studies. Overall, implantation resulted in extensive maturation of the SMUs, as characterized by an increase in force production, substantial integration with native tissue, innervation, vascularization, and the development of structural organization similar to native tissue.

Damage to peripheral nerve tissue may cause loss of function in both the nerve and the targeted muscles it innervates. This study compared the repair capability of engineered nerve conduit (ENC), engineered fibroblast conduit (EFC), and autograft in a 10-mm tibial nerve gap. ENCs were fabricated utilizing primary fibroblasts and the nerve cells of rats on embryonic day 15 (E15). EFCs were fabricated utilizing primary fibroblasts only. Following a 12-week recovery, nerve repair was assessed by measuring contractile properties in the medial gastrocnemius muscle, distal motor nerve conduction velocity in the lateral gastrocnemius, and histology of muscle and nerve. The autografts, ENCs and EFCs reestablished 96%, 87% and 84% of native distal motor nerve conduction velocity in the lateral gastrocnemius, 100%, 44% and 44% of native specific force of medical gastrocnemius, and 63%, 61% and 67% of native medial gastrocnemius mass, respectively. Histology of the repaired nerve revealed large axons in the autograft, larger but fewer axons in the ENC repair, and many smaller axons in the EFC repair. Muscle histology revealed similar muscle fiber cross-sectional areas among autograft, ENC and EFC repairs. In conclusion, both ENCs and EFCs promoted nerve regeneration in a 10-mm tibial nerve gap repair, suggesting that the E15 rat nerve cells may not be necessary for nerve regeneration, and EFC alone can suffice for peripheral nerve injury repair.

Skeletal muscle is the largest organ of human body with several important roles in everyday movement and metabolic homeostasis. The limited ability of small animal models of muscle disease to accurately predict drug efficacy and toxicity in humans has prompted the development in vitro models of human skeletal muscle that fatefully recapitulate cell and tissue level functions and drug responses. We first review methods for development of three-dimensional engineered muscle tissues and organ-on-a-chip microphysiological systems and discuss their potential utility in drug discovery research and development of new regenerative therapies. Furthermore, we describe strategies to increase the functional maturation of engineered muscle, and motivate the importance of incorporating multiple tissue types on the same chip to model organ cross-talk and generate more predictive drug development platforms. Finally, we review the ability of available in vitro systems to model diseases such as type II diabetes, Duchenne muscular dystrophy, Pompe disease, and dysferlinopathy.

Evaluation of potential grafts to improve upon current strategies for abdominal wall (AW) repair in small animal models typically involves mechanical testing using methods that currently are inadequate to assess physiologically relevant parameters. This study introduces burst inflation testing as a more relevant assessment of the mechanical integrity of the AW compared to traditional tensile testing. AWs were excised from 14 healthy adult Fischer 344 rats and tested using either a custom burst inflation device or an Instron tensile testing system. Modulus outcomes from both testing methods were compared. Mechanical analyses of native AW using burst and tensile testing methods resulted in similar average tissue moduli, but with the burst test, there was significantly less variability among specimens. The burst test had greater repeatability compared to tensile testing and has the ability to test repaired AWs without compromising the integrity of the repair site, making it a useful tool for assessing graft repairs.

Volumetric muscle loss (VML) is the traumatic, degenerative, or surgical loss of muscle tissue, which may result in function loss and physical deformity. To date, clinical treatments for VML--the reflected muscle flap or transferred muscle graft--are limited by tissue availability and donor site morbidity. To address the need for more innovative skeletal muscle repair options, our laboratory has developed scaffoldless tissue-engineered skeletal muscle units (SMUs), multiphasic tissue constructs composed of engineered skeletal muscle with engineered bone-tendon ends, myotendinous junctions, and entheses, which in vitro can produce force both spontaneously and in response to electrical stimulation. Though phenotypically immature in vitro, we have shown that following 1 week of implantation in an ectopic site, our muscle constructs develop vascularization and innervation, an epimysium-like outer layer of connective tissue, an increase in myosin protein content, formation of myofibers, and increased force production. These findings suggest that our engineered muscle tissue survives implantation and develops the interfaces necessary to advance the phenotype toward adult muscle. The purpose of this study was to evaluate the potential of our SMUs to restore muscle tissue to sites of acute VML. Our results indicate that our SMUs continue to mature in vivo with longer recovery times and have the potential to repair VML sites by providing additional muscle fibers to damaged muscles. We conclude from this study that our SMUs have the potential to restore lost tissue volume in cases of acute VML.

Objective: Over 200,000 incisional hernia repairs are performed each year in the United States at a cost of over $2.5 billion. Currently, hernias are repaired using either alloplastic meshes or sof...