Outcomes of hypothalamic oxytocin neuron-driven cardioprotection after acute myocardial infarction.

Altered autonomic balance is a hallmark of numerous cardiovascular diseases, including myocardial infarction (MI). Although device-based vagal stimulation is cardioprotective during chronic disease, a non-invasive approach to selectively stimulate the cardiac parasympathetic system immediately after an infarction does not exist and is desperately needed. Cardiac vagal neurons (CVNs) in the brainstem receive powerful excitation from a population of neurons in the paraventricular nucleus (PVN) of the hypothalamus that co-release oxytocin (OXT) and glutamate to excite CVNs. We tested if chemogenetic activation of PVN-OXT neurons following MI would be cardioprotective. The PVN of neonatal rats was transfected with vectors to selectively express DREADDs within OXT neurons. At 6 weeks of age, an MI was induced and DREADDs were activated with clozapine-N-oxide. Seven days following MI, patch-clamp electrophysiology confirmed the augmented excitatory neurotransmission from PVN-OXT neurons to downstream nuclei critical for parasympathetic activity with treatment (43.7 ± 10 vs 86.9 ± 9 pA; MI vs. treatment), resulting in stark improvements in survival (85% vs. 95%; MI vs. treatment), inflammation, fibrosis assessed by trichrome blue staining, mitochondrial function assessed by Seahorse assays, and reduced incidence of arrhythmias (50% vs. 10% cumulative incidence of ventricular fibrillation; MI vs. treatment). Myocardial transcriptomic analysis provided molecular insight into potential cardioprotective mechanisms, which revealed the preservation of beneficial signaling pathways, including muscarinic receptor activation, in treated animals. These comprehensive results demonstrate that the PVN-OXT network could be a promising therapeutic target to quickly activate beneficial parasympathetic-mediated cellular pathways within the heart during the early stages of infarction.

Open thoracic surgical implantation of cardiac pacemakers in rats.

Genetic engineering and implantable bioelectronics have transformed investigations of cardiovascular physiology and disease. However, the two approaches have been difficult to combine in the same species: genetic engineering is applied primarily in rodents, and implantable devices generally require larger animal models. We recently developed several miniature cardiac bioelectronic devices suitable for mice and rats to enable the advantages of molecular tools and implantable devices to be combined. Successful implementation of these device-enabled studies requires microsurgery approaches that reliably interface bioelectronics to the beating heart with minimal disruption to native physiology. Here we describe how to perform an open thoracic surgical technique for epicardial implantation of wireless cardiac pacemakers in adult rats that has lower mortality than transvenous implantation approaches. In addition, we provide the methodology for a full biocompatibility assessment of the physiological response to the implanted device. The surgical implantation procedure takes ~40 min for operators experienced in microsurgery to complete, and six to eight surgeries can be completed in 1 d. Implanted pacemakers provide programmed electrical stimulation for over 1 month. This protocol has broad applications to harness implantable bioelectronics to enable fully conscious in vivo studies of cardiovascular physiology in transgenic rodent disease models.

A transient, closed-loop network of wireless, body-integrated devices for autonomous electrotherapy.

Temporary postoperative cardiac pacing requires devices with percutaneous leads and external wired power and control systems. This hardware introduces risks for infection, limitations on patient mobility, and requirements for surgical extraction procedures. Bioresorbable pacemakers mitigate some of these disadvantages, but they demand pairing with external, wired systems and secondary mechanisms for control. We present a transient closed-loop system that combines a time-synchronized, wireless network of skin-integrated devices with an advanced bioresorbable pacemaker to control cardiac rhythms, track cardiopulmonary status, provide multihaptic feedback, and enable transient operation with minimal patient burden. The result provides a range of autonomous, rate-adaptive cardiac pacing capabilities, as demonstrated in rat, canine, and human heart studies. This work establishes an engineering framework for closed-loop temporary electrotherapy using wirelessly linked, body-integrated bioelectronic devices.

Photocurable bioresorbable adhesives as functional interfaces between flexible bioelectronic devices and soft biological tissues.

Flexible electronic/optoelectronic systems that can intimately integrate onto the surfaces of vital organ systems have the potential to offer revolutionary diagnostic and therapeutic capabilities relevant to a wide spectrum of diseases and disorders. The critical interfaces between such technologies and living tissues must provide soft mechanical coupling and efficient optical/electrical/chemical exchange. Here, we introduce a functional adhesive bioelectronic-tissue interface material, in the forms of mechanically compliant, electrically conductive, and optically transparent encapsulating coatings, interfacial layers or supporting matrices. These materials strongly bond both to the surfaces of the devices and to those of different internal organs, with stable adhesion for several days to months, in chemistries that can be tailored to bioresorb at controlled rates. Experimental demonstrations in live animal models include device applications that range from battery-free optoelectronic systems for deep-brain optogenetics and subdermal phototherapy to wireless millimetre-scale pacemakers and flexible multielectrode epicardial arrays. These advances have immediate applicability across nearly all types of bioelectronic/optoelectronic system currently used in animal model studies, and they also have the potential for future treatment of life-threatening diseases and disorders in humans.

Fully implantable and bioresorbable cardiac pacemakers without leads or batteries.

Temporary cardiac pacemakers used in periods of need during surgical recovery involve percutaneous leads and externalized hardware that carry risks of infection, constrain patient mobility and may damage the heart during lead removal. Here we report a leadless, battery-free, fully implantable cardiac pacemaker for postoperative control of cardiac rate and rhythm that undergoes complete dissolution and clearance by natural biological processes after a defined operating timeframe. We show that these devices provide effective pacing of hearts of various sizes in mouse, rat, rabbit, canine and human cardiac models, with tailored geometries and operation timescales, powered by wireless energy transfer. This approach overcomes key disadvantages of traditional temporary pacing devices and may serve as the basis for the next generation of postoperative temporary pacing technology.

Cholecystectomy Outcomes in the Veterans Affairs Surgical Quality Improvement Program (2006-2017).

Background: Cholecystectomy trends and outcomes have been reported extensively in the private sector. Despite being one of the most common procedures performed in the United States, there is a paucity of reports on the trends and outcomes of laparoscopic and open cholecystectomy in the veteran population. Materials and Methods: Veterans who underwent laparoscopic or open cholecystectomy from 2006 to 2017 were identified using current procedural terminology codes from the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database. Multivariable analyses were used to compare laparoscopic and open outcomes. The primary outcome was mortality, and secondary outcomes were postoperative complications and length of stay (LOS). Results: In the VASQIP database, 53,901 patients underwent laparoscopic cholecystectomy and 8011 patients underwent open cholecystectomy during the study period. The laparoscopic approach increased from 82.0% (2006-2008) to 91.9% (2015-2017). Postoperatively, the open group had a significantly higher morbidity rate (15.4% versus 3.8%, P < .001). The 30-day mortality rate and mean LOS were also significantly higher in the open cholecystectomy group (P < .001). Earlier year of operation, diabetes diagnosis, and open approach significantly increased the likelihood of postoperative morbidity (P < .05). Conclusions: Similar to the private sector, minimally invasive cholecystectomy in the Veterans Health Administration (VHA) has increased over the last two decades. Diabetes was present in a significant percentage of the veteran population and was a predictor of all postoperative complications. Finally, the clinical outcomes in the VHA are comparable with those documented in the private sector.

Outcomes of Paraesophageal Hernia Repair: Analysis of the Veterans Affairs Surgical Quality Improvement Program Database.

BACKGROUND: While there have been many outcome studies on paraesophageal hernia repair in the civilian population, there is sparse recent data on the veteran population. This study analyzes the mortality and morbidities of veterans who underwent paraesophageal hernia repair in the Veterans Affairs Surgical Quality Improvement Program database. METHODS: Veterans who underwent paraesophageal hernia repair from 2010 to 2017 were identified using Current Procedural Terminology codes. Multivariable analysis was used to compare laparoscopic and open, including abdominal and thoracic approaches, groups. The outcomes were postoperative complications and mortality. RESULTS: There were 1607 patients in the laparoscopic group and 366 in the open group, with 84.1% men and mean age of 61 years. Gender and body mass index did not influence the type of surgical approach. The mortality rates at 30 and 180 days were 0.5% and 0.7%, respectively. Postoperative complications, including reintubation (2.2%), pneumonia (2.0%), intubation > 48 h (2.0%), and sepsis (2.0%) were higher in the open group (15.9% versus 7.2%, p < 0.001). The laparoscopic group had a significantly shorter length of stay (4.3 versus 9.6 days, p < 0.001) and a lower percentage of return to surgery within 30 days (3.9% versus 8.2%, p < 0.001) than the open group. The ratio of open versus laparoscopic paraesophageal hernia repairs varied significantly by different Veterans Integrated Services Network regions. CONCLUSIONS: Veterans undergoing laparoscopic paraesophageal hernia repair experience similar outcomes as patients in the private sector. Veterans who underwent laparoscopic paraesophageal hernia repair had significantly less complications compared to an open approach even after adjusting for patient comorbidities and demographics. The difference in open versus laparoscopic practices between various regions requires further investigation.

Impact of Timing of Smoking Cessation on 30-Day Outcomes in Veterans Undergoing Lobectomy for Cancer.

The adverse effects of tobacco use on postoperative outcomes are well documented. While smoking cessation is associated with overall improvement in long-term survival for lung cancer patients, the effects of cessation shortly before lung surgery are unclear. This study compares 30-day outcomes after lobectomy between active smokers, recent quitters, and nonsmokers. Patients who underwent lobectomy for cancer at national Veterans Affairs medical centers from 2012 to 2018 were retrospectively identified in the Veterans Affairs Surgical Quality Improvement Program database. The sample was stratified into 3 groups: smokers within 2 weeks of surgery ("active smokers"), those who quit between 2 weeks and 3 months prior to surgery ("recent quitters"), and "nonsmokers." Propensity score matching was performed to compare groups. Of 5715 patients who met inclusion criteria, 2696 were nonsmokers, 774 were recent quitters, and 2245 were active smokers. After propensity matching, 572 patients comprised each group. Compared to recent quitters, active smokers had 48% higher odds of suffering a pulmonary complication (95% confidence interval [CI]: 1.03-2.14; P = 0.035) and 72% higher odds of suffering multiple complications (CI: 1.07-2.76; P = 0.026). Relative to nonsmokers, active smokers had 81% higher odds of pulmonary complications (CI: 1.34-2.65; P = 0.003). No differences were detected in outcomes comparing recent quitters to nonsmokers. Veterans undergoing lobectomy for cancer who quit 2 weeks before surgery had less pulmonary complications than active smokers. Recent quitters have similar outcomes to nonsmokers. Surgeons should therefore encourage patients to quit smoking, including just prior to lung surgery.

Complications and Management of the Thoracic Endovascular Aortic Repair.

Endovascular treatment in thoracic aortic diseases has increased in use exponentially since Dake and colleagues first described the use of a home-made transluminal endovascular graft on 13 patients with descending thoracic aortic aneurysm at Stanford University in the early 1990s. Thoracic endovascular aneurysm repair (TEVAR) was initially developed for therapy in patients deemed unfit for open surgery. Innovations in endograft engineering design and popularization of endovascular techniques have transformed TEVAR to the predominant treatment choice in elective thoracic aortic repair. The number of TEVARs performed in the United States increased by 600% from 1998 to 2007, while the total number of thoracic aortic repairs increased by 60%. As larger multicenter trials and meta-analysis studies in the 2000s demonstrate the significant decrease in perioperative morbidity and mortality of TEVAR over open repair, TEVAR became incorporated into standard guidelines. The 2010 American consensus guidelines recommend TEVAR to be "strongly considered" when feasible for patients with degenerative or traumatic aneurysms of the descending thoracic aorta exceeding 5.5 cm, saccular aneurysms, or postoperative pseudoaneurysms. Nowadays, TEVAR is the predominant treatment for degenerative and traumatic descending thoracic aortic aneurysm repair. Although TEVAR has been shown to have decreased early morbidity and mortality compared with open surgical repair, endovascular manipulation of a diseased aorta with endovascular devices continues to have significant risks. Despite continued advancement in endovascular technique and devices since the first prospective trial examined the complications associated with TEVAR, common complications, two decades later, still include stroke, spinal cord ischemia, device failure, unintentional great vessel coverage, access site complications, and renal injury. In this article, we review common TEVAR complications with some corresponding radiographic imaging and their management.

Hybrid Repair of Chronic Stanford Type B Aortic Dissection with Expanding Arch Aneurysm.

PURPOSE: The management of patients with chronic Stanford type B aortic dissection who develop complications requires intervention without clear guidelines. Chronic aortic dissection is difficult to treat and often leads to significant morbidity and mortality. We report a complex case of chronic Stanford type B aortic dissection (TBAD) with an expanding false lumen aneurysm and distal fenestrations that required a multi-stage hybrid repair. TECHNIQUE: The patient first underwent a median sternotomy for the ascending aorta to the innominate artery and innominate artery to the left carotid artery bypass, followed by a left carotid to left axillary artery bypass. Due to continued aneurysmal growth, the patient ultimately underwent total cervical and abdominal aortic debranching as well as thoracic and abdominal endovascular grafting with iliac excluders. The patient recovered well after the surgery and had no further expansion of the aneurysm at 12-month follow up. CONCLUSION: Endovascular repairs have been the mainstay of chronic TBAD repair, but hybrid approaches may be necessary for difficult repairs. A multi-stage hybrid repair approach has been successful in a patient who had a chronic type B aortic dissection with aneurysmal degeneration that failed medical management.

Preoperative Factors Associated with Appendiceal Tumors in Nonelective Appendectomy.

Background: The rates of incidental appendiceal neoplasms after appendectomy performed for acute appendicitis is <2%. To date, no large studies have investigated the preoperative risk factors or imaging findings associated with incidental appendiceal tumors that present as appendicitis. Our study aims to identify preoperative factors that are associated with an increased risk of appendiceal tumors in patients who present with signs and symptoms of acute appendicitis. Materials and Methods: Using the targeted appendectomy American College of Surgeons National Surgical Quality Improvement Program database, we identified patients who underwent nonelective appendectomy for acute appendicitis in 2016. Patients with final pathology consistent with a tumor were compared with those with only appendicitis. A nonmatched case/control method was used to pull a random sample from the appendicitis cohort using a 1:4 ratio (tumor: acute appendicitis) to obtain adequate power for comparison. Preoperative patient variables and imaging findings were investigated using stepwise logistic regression to identify variables associated with appendiceal tumor. Results: Following multivariate analysis, preoperative imaging read of "indeterminate" and "not consistent with appendicitis," female gender, increased age, and lower preoperative white blood cell (WBC) count were significant predictors of tumor causing symptoms of appendicitis. The odds of having tumor pathology were significantly increased in patients with preoperative imaging of "indeterminate" and "not consistent with appendicitis." The odds of having tumor pathology were 82% higher for females than for males, increased by 2% for every 1-year increase in age, and increased by 3% for every one-unit decrease in WBC count. Conclusion: While incidental appendiceal tumors can present as acute appendicitis, 3 patient variables and one imaging finding were identified that may increase suspicion for appendiceal tumors. Consideration should be given to patients with these associated risk factors for additional preoperative consultation in addition to the potential for intraoperative pathology consultation.

Long-term Outcomes of Coronary Artery Bypass Grafting in Veterans with Left Main Coronary Artery Disease.

BACKGROUND: Studies of the civilian population with left main coronary artery disease (LMCAD) who underwent coronary artery bypass grafting (CABG) have shown 2% to 4.2% 30-day mortality. However, there is a lack of reporting from the veteran population. Here we analyze the outcomes of veterans with LMCAD who underwent CABG by a single surgeon at a single Veterans Affairs Medical Center (VAMC). METHODS: Veterans who underwent isolated CABG between 1998 to 2018 at a VAMC were further divided into a group with significant left main coronary artery disease (LMCAD) of stenosis greater than or equal to 50% and a group without left main coronary artery stenosis (non-LMCAD). The primary outcome was mortality. Secondary outcomes included postoperative complications. Multivariable regression analysis and Kaplan-Meier survival analysis were used to compare the two cohorts. RESULTS: The demographics and comorbidities are similar between the two cohorts except for higher average age and percentage of stroke in the LMCAD group (n = 509) compared to non-LMCAD (n = 927). Perioperative complications are comparable between the two groups except for increased length of stay (LOS) in the LMCAD group (12.9 ± 15.9 days versus 10.9 ± 9.0 days in non-LMCAD, P < .001). 30-day mortality in the LMCAD group is 4.1% versus 1.4% in non-LMCAD. However, Kaplan-Meier curves show no significant difference in adjusted overall survival throughout 15 years between the groups (P = .560). CONCLUSION: Veterans with LMCAD who underwent CABG have similar postoperative complications compared to non-LMCAD group. The 30-day mortality is higher in the LMCAD group; however, there is no difference in long-term survival.

Long-Term Outcomes of Coronary Artery Bypass Grafting in Veterans with Ischemic Cardiomyopathy.

BACKGROUND: The Surgical Treatment for Ischemic Heart Failure (STICH) trial showed that surgical revascularization in ischemic cardiomyopathy (ICM) patients improves long-term mortality compared with medical treatment alone. This study examines how veterans with ICM undergoing revascularization fare against patients without ICM; it also examines the outcomes in the veteran population. METHODS: This is a retrospective review of a single-center database. From 2000 to 2018, 1,461 patients underwent isolated coronary artery bypass grafting (CABG). Two-hundred-one patients with an ejection fraction less than 35% were classified as the ICM cohort. The primary outcome was mortality. Secondary outcomes included postoperative complications. Subgroup analysis was performed within the ICM cohort comparing off-pump CABG (OPCAB) versus on-pump CABG (ONCAB). RESULTS: ICM patients had a higher incidence of myocardial infarction (MI), diabetes, chronic kidney disease (CKD), and preoperative intra-aortic balloon pump (IABP) use. The non-ICM cohort was more functionally independent. OPCAB was performed in 80.1% of ICM and 66.3% of non-ICM cohorts. There was no statistical difference between ICM and non-ICM cohorts in 30-day mortality (OR 1.94[0.79 - 4.75], P = .15). The ICM cohort had an increased 5-year mortality (OR 1.75[1.14 - 2.69], P = .01) and 10-year mortality (OR 1.71[1.09 - 2.67], P = .02). The ICM cohort showed improved, although not statistically significant, short-term mortality with OPCAB compared with ONCAB (3.1% versus 12.5%, OR 0.31[0.05 - 1.82], P = .20). CONCLUSION: Veterans with ICM undergoing CABG demonstrated similar short-term survival compared with non-ICM veterans. The long-term survival in the ICM cohort still is inferior to patients without ICM. There is a trend toward improved short-term survival in patients with ICM undergoing OPCAB.

Influence of Age on Cardiac Surgery Outcomes in United States Veterans.

OBJECTIVE: Heart disease is still the leading cause of death for both men and women in the United States, and the rate of cardiovascular disease in veterans is even higher than in civilians. This study examines age-related outcomes for veterans undergoing cardiac surgeries at a single institution. METHODS: We included all veterans undergoing coronary artery bypass grafting (CABG) and/or valve surgery between 1997 to 2017 at a single Veterans Affairs (VA) medical center. We stratified this cohort into 4 age groups: ≤59 years old, 60-69 years old, 70-79 years old, and ≥80 years old. Outcomes in age groups were compared using standard statistical methods with the ≤59 years old group as reference. RESULTS: A total of 2,301 patients underwent open cardiac procedures at our institution. The frequency of simultaneous CABG and valve operations increased with age. Usage of cardiopulmonary bypass versus off-pump CABG and operative time was not associated with age. Increased pulmonary and renal complications as well as rates of postoperative arrhythmias all were associated with increasing age. There was no statistically significant difference in 30-day mortality. However, multivariable analysis adjusted for covariates showed all-cause mortality significantly was increased with older age groups (aHR ≥80 years old: 2.94 [2.07-4.17], P < .01; aHR 70-79 years old: 2.15 [1.63-2.83], P < 0.01, with ≤59 years old as reference). CONCLUSIONS: Older patients may have comparable perioperative mortality as their younger counterparts. However, age still is a significant predictor of all-cause mortality, pulmonary and renal complications, and postoperative arrhythmia, and should be considered as a major factor in preoperative risk assessment.

30-Day outcomes and predictors of complications after Puestow procedure.

BACKGROUND: A lateral pancreaticojejunostomy, or a Puestow procedure, is used in chronic pancreatitis with ductal dilation and pain. The current literature on the Puestow is sparse. This study examines outcomes of Puestow procedures nationwide. METHODS: Using ACS-NSQIP database, patients who underwent a Puestow procedure from 2010 to 2016 were identified. Univariate analysis and multivariable regression models were used to identify predictors of mortality and morbidities. Covariates included in the regression models were chosen based on clinical significance. RESULTS: The cohort included 524 patients. The 30-day mortality rate was 1.2%(n = 6). At least one major complication occurred in 19.1% of patients including death (1.2%), major organ dysfunction (8.2%), pulmonary embolism (1.3%), and surgical site infections (13.0%). Diabetes, COPD, and transfusions were the strongest predictors of complications. CONCLUSIONS: The Puestow procedure is an acceptable treatment modality with low rates of morbidity and mortality. Minimizing transfusions and optimizing pulmonary status may improve 30-day outcomes.

Attending Specialization and 30-Day Outcomes Following Laparoscopic Bariatric Surgery: an Analysis of the ACS-MBSAQIP Database.

BACKGROUND: Surgeon and hospital volume are factors that have been shown to impact outcomes following bariatric surgery. Nevertheless, there is a paucity of literature investigating surgeon training on bariatric surgery outcomes. The purpose of our study was to determine if bariatric specialty training leads to improved short-term outcomes following laparoscopic bariatric surgery using the American College of Surgeons Metabolic and Bariatric Surgery Accreditation Quality Improvement Program (ACS-MBSAQIP) database. METHODS: All patients undergoing first-time, elective, laparoscopic bariatric surgery from 2015 to 2016 were identified within the ACS-MBSAQIP database. Patients were divided into two groups based on the type of bariatric procedure performed and the surgeon performing the procedure. Thirty-day outcomes were compared between the groups using multivariable logistic regression analysis. RESULTS: A total of 140,340 patients met inclusion criteria. Higher risk patients with more associated comorbidities underwent bariatric surgery by a metabolic and bariatric surgeon. After controlling for these differences, patients who underwent Roux-en-Y gastric bypass (RYGB) had similar 30-day irrespective of the surgeon performing the procedure while patients who underwent sleeve gastrectomy (SG) by a metabolic and bariatric surgeon (MBS) had improved 30-day outcomes. CONCLUSION: Surgeon type is associated with 30-day morbidity and mortality outcomes for SG but not for RYGB. These differences in 30-day morbidity and mortality outcomes may be facilitated by institutional factors, surgeon experience, and participation in bariatric surgery accredited centers. Standardization of the perioperative process for both surgeons and institutions may improve 30-day morbidity and mortality outcomes for all patients who undergo laparoscopic bariatric surgery.

National trends in total vs subtotal gastrectomy for middle and distal third gastric cancer.

BACKGROUND: To identify trends in total and subtotal gastrectomy for middle and distal third gastric adenocarcinoma in the U.S. METHODS: NCDB was queried for patients with stage 0-III middle or distal gastric adenocarcinoma treated with total or subtotal gastrectomy. Statistical analysis including cox proportional hazards model was performed to examine overall survival by stage. RESULTS: 1,628 (85%) underwent subtotal gastrectomy and 283 (15%) underwent total. 1113 patients (58%) had distal tumors and 798 (42%) had middle tumors. Total gastrectomy patients more often had poor tumor grade (60% vs 50%,p < 0.01), larger size (46.3 mm vs 37.8 mm,p < 0.0001), had positive nodes (3.6 ± 5.9 vs 2.2 ± 4.1,p < 0.0001), underwent chemoradiation (13% vs 6%,p < 0.0001), and were higher clinical stage (p < 0.05). An overall survival curve showed an adjusted HR of 2.7 for total vs subtotal gastrectomy at clinical stage 3 (p < 0.05). CONCLUSIONS: Total gastrectomy is performed for larger, more aggressive tumors with higher stage. Subtotal gastrectomy may have a survival benefit for stage III gastric cancers.

Flexible and Transparent Metal Oxide/Metal Grid Hybrid Interfaces for Electrophysiology and Optogenetics.

Flexible and transparent microelectrodes and interconnects provide the unique capability for a wide range of emerging biological applications, including simultaneous optical and electrical interrogation of biological systems. For practical biointerfacing, it is important to further improve the optical, electrical, electrochemical, and mechanical properties of the transparent conductive materials. Here, high-performance microelectrodes and interconnects with high optical transmittance (59-81%), superior electrochemical impedance (5.4-18.4 Ω cm2), and excellent sheet resistance (5.6-14.1 Ω sq-1), using indium tin oxide (ITO) and metal grid (MG) hybrid structures are demonstrated. Notably, the hybrid structures retain the superior mechanical properties of flexible MG other than brittle ITO with no changes in sheet resistance even after 5000 bending cycles against a small radius at 5 mm. The capabilities of the ITO/MG microelectrodes and interconnects are highlighted by high-fidelity electrical recordings of transgenic mouse hearts during co-localized programmed optogenetic stimulation. In vivo histological analysis reveals that the ITO/MG structures are fully biocompatible. Those results demonstrate the great potential of ITO/MG interfaces for broad fundamental and translational physiological studies.

Wireless, battery-free, fully implantable multimodal and multisite pacemakers for applications in small animal models.

Small animals support a wide range of pathological phenotypes and genotypes as versatile, affordable models for pathogenesis of cardiovascular diseases and for exploration of strategies in electrotherapy, gene therapy, and optogenetics. Pacing tools in such contexts are currently limited to tethered embodiments that constrain animal behaviors and experimental designs. Here, we introduce a highly miniaturized wireless energy-harvesting and digital communication electronics for thin, miniaturized pacing platforms weighing 110 mg with capabilities for subdermal implantation and tolerance to over 200,000 multiaxial cycles of strain without degradation in electrical or optical performance. Multimodal and multisite pacing in ex vivo and in vivo studies over many days demonstrate chronic stability and excellent biocompatibility. Optogenetic stimulation of cardiac cycles with in-animal control and induction of heart failure through chronic pacing serve as examples of modes of operation relevant to fundamental and applied cardiovascular research and biomedical technology.

The effect of bougie size and distance from the pylorus on dehydration after laparoscopic sleeve gastrectomy: an analysis of the ACS-MBSAQIP database.

BACKGROUND: Dehydration is the most common cause of readmission after laparoscopic sleeve gastrectomy (SG). Bougie size and distance from the pylorus, both of which have been associated with rates of dehydration postoperatively, varies by surgeon and across institutions. OBJECTIVES: To determine if there is an association between bougie size or distance from the pylorus on the rate of dehydration after laparoscopic SG. SETTING: American College of Surgeons Metabolic and Bariatric Surgery Accreditation Quality Improvement Program database. METHODS: All patients undergoing first-time, elective laparoscopic SG from 2015-2016 were identified. The association of bougie size and distance from the pylorus on the rate of dehydration within the first 30 days postoperatively was investigated. RESULTS: The inclusion criteria were met by 170,751 patients. The most commonly used bougie size was 36 Fr and the most common distance from the pylorus at which the gastric sleeve was started was 5 cm. Patients were divided into 4 groups based on bougie size and distance from the pylorus (Group 1: bougie size <36 Fr, pylorus distance <4 cm; Group 2: bougie size ≥36 Fr, pylorus distance <4 cm; Group 3: bougie size ≥36 Fr, pylorus distance ≥4 cm; and Group 4: bougie size <36 Fr, pylorus distance ≥4 cm). Patients in Group 4 were significantly less likely than any other group to experience dehydration-related complications. CONCLUSION: Both distance from the pylorus and bougie size are significantly associated with dehydration-related complications after SG. Consideration should be made for standardizing these technical aspects of SG to help reduce the rate of postoperative dehydration and hospital readmission.