Photonic chip-based low-noise microwave oscillator.

Numerous modern technologies are reliant on the low-phase noise and exquisite timing stability of microwave signals. Substantial progress has been made in the field of microwave photonics, whereby low-noise microwave signals are generated by the down-conversion of ultrastable optical references using a frequency comb1-3. Such systems, however, are constructed with bulk or fibre optics and are difficult to further reduce in size and power consumption. In this work we address this challenge by leveraging advances in integrated photonics to demonstrate low-noise microwave generation via two-point optical frequency division4,5. Narrow-linewidth self-injection-locked integrated lasers6,7 are stabilized to a miniature Fabry-Pérot cavity8, and the frequency gap between the lasers is divided with an efficient dark soliton frequency comb9. The stabilized output of the microcomb is photodetected to produce a microwave signal at 20 GHz with phase noise of -96 dBc Hz-1 at 100 Hz offset frequency that decreases to -135 dBc Hz-1 at 10 kHz offset-values that are unprecedented for an integrated photonic system. All photonic components can be heterogeneously integrated on a single chip, providing a significant advance for the application of photonics to high-precision navigation, communication and timing systems.

Integrated optical frequency division for microwave and mmWave generation.

The generation of ultra-low-noise microwave and mmWave in miniaturized, chip-based platforms can transform communication, radar and sensing systems1-3. Optical frequency division that leverages optical references and optical frequency combs has emerged as a powerful technique to generate microwaves with superior spectral purity than any other approaches4-7. Here we demonstrate a miniaturized optical frequency division system that can potentially transfer the approach to a complementary metal-oxide-semiconductor-compatible integrated photonic platform. Phase stability is provided by a large mode volume, planar-waveguide-based optical reference coil cavity8,9 and is divided down from optical to mmWave frequency by using soliton microcombs generated in a waveguide-coupled microresonator10-12. Besides achieving record-low phase noise for integrated photonic mmWave oscillators, these devices can be heterogeneously integrated with semiconductor lasers, amplifiers and photodiodes, holding the potential of large-volume, low-cost manufacturing for fundamental and mass-market applications13.

Binding and dimerization of PGLa peptides in anionic lipid bilayer studied by replica exchange molecular dynamics.

The 21-residue PGLa peptide is well known for antimicrobial activity attributed to its ability to compromize bacterial membranes. Using all-atom explicit solvent replica exchange molecular dynamics with solute tempering, we studied PGLa binding to a model anionic DMPC/DMPG bilayer at the high peptide:lipid ratio that promotes PGLa dimerization (a two peptides per leaflet system). As a reference we used our previous simulations at the low peptide:lipid ratio (a one peptide per leaflet system). We found that the increase in the peptide:lipid ratio suppresses PGLa helical propensity, tilts the bound peptide toward the bilayer hydrophobic core, and forces it deeper into the bilayer. Surprisingly, at the high peptide:lipid ratio PGLa binding induces weaker bilayer thinning, but deeper water permeation. We explain these effects by the cross-correlations between lipid shells surrounding PGLa that leads to a much diminished efflux of DMPC lipids from the peptide proximity at the high peptide:lipid ratio. Consistent with the experimental data the propensity for PGLa dimerization was found to be weak resulting in coexistence of monomers and dimers with distinctive properties. PGLa dimers assemble via apolar criss-cross interface and become partially expelled from the bilayer residing at the bilayer-water boundary. We rationalize their properties by the dimer tendency to preserve favorable electrostatic interactions between lysine and phosphate lipid groups as well as to avoid electrostatic repulsion between lysines in the low dielectric environment of the bilayer core. PGLa homedimer interface is predicted to be distinct from that involved in PGLa-magainin heterodimers.

Can Risk-Based Thromboprophylaxis Practice Guidelines be Safely Used in Esophagectomy Cases? Experience of an Academic Health System.

BACKGROUND: Venous thromboembolism (VTE) occurs in 3-11% of esophagectomy patients and is associated with increased mortality and morbidity. The use of validated VTE risk assessment tools and compliance with recommended practice guidelines remains unclear. In this study, we seek to determine the use of Caprini guideline indicated VTE prophylaxis and its effect on VTE and bleeding complications following esophagectomy. METHODS: Esophagectomy cases were identified from the Mayo Clinic electronic health records. Caprini score and VTE prophylaxis regimen received were determined retrospectively. VTE prophylaxis was identified as appropriate or inappropriate based on the Caprini score and prophylaxis received preoperative, during hospitalization, and after hospital discharge. Study cohorts were compared by Pearson Chi-square test, Fisher's Exact test, Kruskal-Wallis test, and logistic regression models. Stata/MP 16.1 was used for analysis. Odds ratios and 95% confidence intervals were reported for logistic regression models. A p-value < 0.05 was considered significant. RESULTS: Four hundred and fifty-six esophagectomy cases were analyzed. The median Caprini score was thirteen. Appropriate prophylaxis resulted in a 6.9-fold reduction in inpatient VTE. All 30- and 90-day post-discharge VTEs occurred in those not receiving Caprini guideline-indicated VTE prophylaxis. Inpatient, 30- and 90-day post-discharge bleeding rates were 7.68%, 0.91%, and 2.11%, respectively; however, bleeding was not increased with receipt of appropriate prophylaxis. CONCLUSION: In this esophagectomy cohort, Caprini guideline indicated VTE prophylaxis resulted in reduced inpatient VTE events without increasing bleeding complications. Risk-based VTE prevention measures should be considered in this patient cohort known to be at heightened risk for postoperative VTE.

Replica Exchange with Hybrid Tempering Efficiently Samples PGLa Peptide Binding to Anionic Bilayer.

We evaluated the utility of a variant of the replica exchange method, a replica exchange with hybrid tempering (REHT), for all-atom explicit water biomolecular simulations and compared it with a more traditional replica exchange with the solute tempering (REST) algorithm. As a test system, we selected a 21-mer antimicrobial peptide PGLa binding to an anionic DMPC/DMPG lipid bilayer. Application of REHT revealed the following binding mechanism. Due to the strong hydrophobic moment, the bound PGLa adopts an extensive helical structure. The binding free energy landscape identifies two major bound states, a metastable surface bound state and a dominant inserted state. In both states, positively charged PGLa amino acids maintain electrostatic interactions with anionic phosphate groups by rotating the PGLa helix around its axis. PGLa binding causes an influx of anionic DMPG and an efflux of zwitterionic DMPC lipids from the peptide proximity. PGLa thins the bilayer and disorders the adjacent fatty acid tails. Deep invasion of water wires into the bilayer hydrophobic core is detected in the inserted peptide state. The analysis of charge density distributions indicated that peptide positive charges are nearly compensated for by lipid negative charges and water dipole ordering, whereas ions play no role in peptide binding. Thus, electrostatic interactions are the key energetic factor in binding cationic PGLa to an anionic DMPC/DMPG bilayer. Comparison of REHT and REST shows that due to exclusion of lipids from tempered partition, REST lags behind REHT in peptide equilibration, particularly, with respect to peptide insertion and helix acquisition. As a result, REST struggles to provide accurate details of PGLa binding, although it still qualitatively maps the bimodal binding mechanism. Importantly, REHT not only equilibrates PGLa in the bilayer faster than REST, but also with less computational effort. We conclude that REHT is a preferable choice for studying interfacial biomolecular systems.

Redo fundoplication vs. Roux-en-Y gastric bypass conversion for failed anti-reflux surgery: which is better?

INTRODUCTION: Different techniques have been proposed for reoperation after failed anti-reflux surgery. However, there is no consensus on which should be preferred. We aim to report and compare the outcomes of different revisional techniques for failed anti-reflux surgery. METHODS: We performed a retrospective analysis of patients who underwent redo fundoplication (RF) or Roux-en-Y gastric bypass (RYGB) conversion after a failed fundoplication at our institution between 2016 and 2021. The primary outcome was long-term presence of reflux or dysphagia following revisional surgery. Secondary outcomes included 30-day perioperative complications as well as long-term use of anti-reflux medication and radiographic recurrence of hiatal hernia (HH). RESULTS: A total of 165 (median age 63 years, 73.9% female) patients were included. RF was performed in 120 (73 Toupet and 47 Nissen), RYGB in 38, and 7 patients had fundoplication takedown alone. The RYGB group had a significantly higher BMI, and more prior revisional surgeries compared to the other groups. Median operative time and length of stay were longer for RYGB. Twenty (12.1%) patients experienced postoperative complications, with the highest incidence in the RYGB group. Reflux and dysphagia improved significantly for the whole cohort, with the greatest improvement noted with reflux in the RYGB group (89.5% with preoperative reflux vs. 10.5% with postoperative reflux, p = < .001). On multivariable regression we found that prior re-operative surgery was associated with persistent reflux and dysphagia, whereas RYGB conversion was protective against reflux. CONCLUSION: Conversion to RYGB may offer superior resolution of reflux than RF, especially for obese patients.

Proton Therapy With Concurrent Chemotherapy for Thoracic Esophageal Cancer: Toxicity, Disease Control, and Survival Outcomes.

Purpose: When treating esophageal cancer with radiation therapy, it is critical to limit the dose to surrounding structures, such as the lung and/or heart, as much as possible. Proton radiation therapy allows a reduced radiation dose to both the heart and lungs, potentially reducing the risk of cardiopulmonary toxicity. Here, we report disease control, survival, and toxicity outcomes among patients with esophageal cancer treated with proton radiation therapy and concurrent chemotherapy (chemoradiation therapy; CRT) with or without surgery. Materials and Methods: We enrolled 17 patients with thoracic esophageal carcinoma on a prospective registry between 2010 and 2021. Patients received proton therapy to a median dose of 50.4-GyRBE (range, 50.4-64.8) in 1.8-Gy fractions.Acute and late toxicities were graded per the Common Terminology Criteria for Adverse Events, version 4.0 (US National Cancer Institute, Bethesda, Maryland). In addition, disease control, patterns of failure, and survival outcomes were collected. Results: Nine patients received preoperative CRT, and 8 received definitive CRT. Overall, 88% of patients had adenocarcinoma, and 12% had squamous cell carcinoma. With a median follow-up of 2.1 years (range, 0.5-9.4), the 3-year local progression-free, disease-free, and overall survival rates were 85%, 66%, and 55%, respectively. Two patients (1 with adenocarcinoma and 1 with squamous cell carcinoma) recurred at the primary site after refusing surgery after a complete clinical response to CRT. The most common acute nonhematologic and hematologic toxicities, respectively, were grades 1 to 3 esophagitis and grades 1 to 4 leukopenia, both affecting 82% of patients. No acute cardiopulmonary toxicities were observed in the absence of surgical resection. Reagarding surgical complications, 3 postoperative cardiopulmonary complications occurred as follows: 1 grade 1 pleural effusion, 1 grade 3 pleural effusion, and 1 grade 2 anastomotic leak. Two severe late CRT toxicities occurred: 1 grade 5 tracheoesophageal fistula and 1 grade 3 esophageal stenosis requiring a feeding tube. Conclusion: Proton radiation therapy is a safe, effective treatment for esophageal cancer with increasing evidence supporting its role in reducing cardiopulmonary toxicity.

Combined Sleeve Gastrectomy with Liver Transplant in Patients with Obesity: a Feasibility Study.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) associated with obesity is one of the leading causes of liver failure requiring transplant, yet guidelines for the management of obesity in these scenarios are not always followed. In order to decrease incidence of NASH in the new liver, we studied the feasibility of simultaneous liver transplant and bariatric surgery. MATERIALS AND METHODS: We retrospectively identified patients who underwent simultaneous liver transplant and sleeve gastrectomy at our hospital site between November 24, 2019, and April 14, 2022. Demographics, surgical data, postoperative adverse events, and weight loss data were collected. RESULTS: Ten patients met inclusion criteria. Mean body mass index (BMI) at the time of transplant was 43.1 ± 5.3 kg/m2, and mean length of hospital stay was 10.8 ± 5.22 days. Within 30 days after surgery, 7 patients reported adverse effects, and 2 were readmitted. Mean BMI at 6-month follow-up was 30.6 ± 2.5 kg/m2. Mean percentage excess weight (in pounds) loss was 48.1 ± 11.4%, 58.6 ± 8.9%, and 66.1 ± 15.3% at 3-, 6-, and 12-month follow-up, respectively. Three patients had an increase in weight at 12-month follow-up when compared to 6-month follow-up. Most patients required fewer comorbidity-related medications, and none reported adverse effects related to sleeve gastrectomy. CONCLUSIONS: Bariatric surgery at the time of liver transplant is safe and has minimal adverse effects. Results include substantial postoperative weight loss, improvement in comorbidities, and decreased risk of NASH in the new liver. Further studies with larger cohorts are required to confirm the findings of this study.

Mechanisms of Binding of Antimicrobial Peptide PGLa to DMPC/DMPG Membrane.

PGLa belongs to a class of antimicrobial peptides showing strong affinity to anionic bacterial membranes. Using all-atom explicit solvent replica exchange molecular dynamics with solute tempering, we studied binding of PGLa to a model anionic dimyristoylphosphatidylcholine/dimyristoylphosphatidylglycerol (DMPC/DMPG) bilayer. Due to a strong hydrophobic moment, PGLa upon binding adopts a helical structure and two distinct bound states separated by a significant free energy barrier. In these states, the C-terminus helix is either surface bound or inserted into the bilayer, whereas the N-terminus remains anchored in the bilayer. Analysis of the free energy landscape indicates that the transition between the two states involves a C-terminus helix rotation permitting the peptide to preserve the interactions between cationic Lys amino acids and anionic lipid phosphorus groups. We calculated the free energy of PGLa binding and showed that it is mostly governed by the balance between desolvation of PGLa positive charges and formation of electrostatic PGLa-lipid interactions. PGLa binding induces minor bilayer thinning but causes pronounced lipid redistribution resulting from an influx of DMPG lipids into the binding footprint and efflux of DMPC lipids. Our in silico results rationalize the S-state detected in NMR experiments.

Outcomes of Enhanced Recovery After Surgery Protocols Versus Conventional Management in Patients Undergoing Bariatric Surgery.

Background: Enhanced recovery after surgery (ERAS) pathways focus on decreasing surgical stress and promoting return to normal function for patients undergoing surgical procedures. The aim of our study was to evaluate the impact of an ERAS protocol on outcomes of patients undergoing primary sleeve gastrectomy and Roux-en-Y gastric bypass. Outcomes included hospital length of stay (LOS), and management of postoperative pain and postoperative nausea and vomiting (PONV) measured by pain medications and antiemetic use, respectively. Incidence of 90-day emergency department (ED) visits, readmissions, and complications were also analyzed. Methods: A retrospective review was performed from October 1, 2016 to October 31, 2018 of patients enrolled in the ERAS versus the conventional pathway. Patient baseline characteristics, pain and nausea scores, LOS, and postoperative outcome variables were collected. Results: Non-ERAS (n = 193) and ERAS (n = 173) groups had similar patient characteristics. Fewer ERAS patients required postoperative opioids and antiemetics (P < .01), with a significant difference in postoperative nausea control in favor of ERAS patients (P < .05). There was a decreasing trend in median LOS (2 versus 1, P = .28), 90-day postoperative readmissions (10.4% versus 8.1%, P = .47), and major adverse events (5.2% versus 1.7%, P = .07) after ERAS implementation. The ED visits and postoperative need for intravenous fluid for dehydration were significantly lower in the ERAS group (P = .01). Conclusion: Implementation of ERAS pathway for bariatric surgery was associated with less opioid usage, PONV, ED visits, and postoperative need for intravenous fluids, without increasing LOS, 90-day readmission or rates of adverse effects.

Chronic Wounds: Evaluation and Management.

Chronic wounds are those that do not progress through a normal, orderly, and timely sequence of repair. They are common and are often incorrectly treated. The morbidity and associated costs of chronic wounds highlight the need to implement wound prevention and treatment guidelines. Common lower extremity wounds include arterial, diabetic, pressure, and venous ulcers. Physical examination alone can often guide the diagnosis. All patients with a nonhealing lower extremity ulcer should have a vascular assessment, including documentation of wound location, size, depth, drainage, and tissue type; palpation of pedal pulses; and measurement of the ankle-brachial index. Atypical nonhealing wounds should be biopsied. The mainstay of treatment is the TIME principle: tissue debridement, infection control, moisture balance, and edges of the wound. After these general measures have been addressed, treatment is specific to the ulcer type. Patients with arterial ulcers should be immediately referred to a vascular surgeon for appropriate intervention. Treatment of venous ulcers involves compression and elevation of the lower extremities, plus exercise if tolerated. Diabetic foot ulcers are managed by offloading the foot and, if necessary, treating the underlying peripheral arterial disease. Pressure ulcers are managed by offloading the affected area.

Preoperative high respiratory quotient correlates with lower weight loss after bariatric surgery.

BACKGROUND: The respiratory coefficient (RQ), as determined by indirect calorimetry (IC), classifies diet as being carbohydrate rich (RQ = 0.7-0.8), fat rich (RQ = 0.9-1.0), or overfeeding (RQ > 1). We hypothesized that preoperative RQ may be associated with weight-loss outcomes after bariatric surgery. METHODS: From 2016 to 2018, 137 obese patients were enrolled in a Bariatric Registry and underwent dietary and behavioral counseling, followed by preoperative IC. Resting energy expenditure (REE) and RQ of all patients was measured. Patients were classified as over-feeders (OF; 42, 31%) with RQ > 1 or non-over-feeders (NOF; 95, 69%) with RQ < 1. At baseline, there was no difference between groups in gender [female: 105 (76.6%), male: 32 (23.4%)], body mass index (BMI; OF: 46.8 ± 7.8 vs. NOF: 44.8 ± 7.4 kg/m2, p = 0.40), or baseline REE (OF: 1897 ± 622 vs. NOF: 1874 ± 579, p = 0.74), although OF were younger [mean age (OF: 47.1 ± 13.0 years vs. NOF: 43.1 ± 13.4; p = 0.009). At 6-month follow-up 94 patients [53.28%; OF: 35 (83%) vs. NOF: 59 (62%), p = 0.016] were seen and 48 [35.03%; OF: 23 (55%) vs. NOF: 25 (59%), p = 0.001] at 12-month follow-up. On preoperative psychological assessment, OF had a significantly higher rate of childhood neglect (OF: 28 (47.46%) vs. NOF: 40 (28.99%); p = 0.01). RESULTS: At 1 year postoperatively, the OF had a significantly higher BMI (OF: 34.3 ± 6.5 vs. NOF: 29.3 ± 5.1 kg/m2, p = 0.009). Differences in weight were not significant at 6-month (OF: 36.0 ± 6.5 vs. NOF: 33.5 ± 5.9 kg/m2, p = 0.07). There was no difference between type of operation and RQ group (RYGB; OF: 55 (75%) vs. NOF: 18 (25%) and SG; OF: 40 (62%) vs. NOF: 24 (38%), p = 0.14), nor in BMI loss after operation. CONCLUSION: Evidence of overfeeding in the preoperative period prior to bariatric surgery is associated with higher resultant BMI at 1 year. Calculation of the RQ with IC has prognostic significance in bariatric surgery, and calculation of REE based on assumed normal RQ potentiates error. It is unclear if overfeeding is purely behavioral or secondary to potentially reversible metabolic etiology.

Squamous Cell Carcinoma in Lichen Planus of the Esophagus.

Cancer arising in lichen planus of the esophagus (LPE) is extremely rare. We report 2 elderly female patients with LPE who developed squamous cell carcinoma. Both underwent laparoscopic ischemic gastric preconditioning followed 2 weeks later by 3-field esophagectomy. Final pathological stages were carcinoma in situ and pT3N2, respectively. No adjuvant therapy was given. The patient with in situ cancer has no evidence of recurrence at 24 months. The second patient opted to follow up locally and died 8 months later. LPE should be closely monitored for malignant degeneration. Esophagectomy should be considered when malignancy is detected.

Strategies for surgical remediation of the multi-fundoplication failure patient.

BACKGROUND: Outcomes are not well studied in patients undergoing remediation for multi-fundoplication failure, that is, two or more prior failed fundoplications. Re-operation must balance reflux control and restoration of the ability to eat with the challenge of reconstructing a distorted hiatus and GE junction. The purpose of this study is to present our experience with surgical remediation for multi-fundoplication failure. METHODS: Medical records were retrospectively reviewed of 91 patients who underwent third time or more esophagogastric operation for fundoplication failure at a single institution from 2007 to 2016. Dysphagia was present in 56% and heartburn in 51%. Median number of prior operations was 2 with range up to 6. Anatomic failure consisted of slipped wrap in 26 cases, wrap herniation in 23, hiatal stenosis in 24, hiatal mesh complication in 8, and wrap dehiscence in 10. Operative approaches generally followed an institutional algorithm and consisted of hiatal hernia repair with: re-do fundoplication in 55%, takedown of fundoplication alone in 24%, Roux-en-Y gastrojejunostomy in 14%, and GE junction resection in 7%. Laparoscopic approach was successful in 81%. RESULTS: Mean duration of operations was 217 min and median length of stay was 3 days. The complication rate was 13%, with 7% undergoing unplanned early re-operation. Patients were followed for mean 11 months, and recurrent hiatal hernia was detected in 13%. Late re-operation was performed in 6% for recurrent hiatal hernia. Recurrent reflux symptomatology resolved in 93%. Dysphagia resolved in 84%. There were no significant differences in outcomes with regard to number of prior operations, operative approach, BMI, or age. CONCLUSIONS: There is no single best approach to remediation in the multi-fundoplication failure patient. Re-do fundoplication is appropriate in over half of patients. Reoperation for multi-fundoplication failure can be performed via minimally invasive approach with excellent remediation of symptoms, low morbidity, and low recurrence rates.

Short-Term Outcomes Predict Long-Term Satisfaction in Patients Undergoing Laparoscopic Magnetic Sphincter Augmentation.

INTRODUCTION: Laparoscopic magnetic sphincter augmentation (MSA) has been shown to be efficacious therapy for gastroesophageal reflux disease (GERD) refractory to maximal medical management. Herein, we present our experience with this procedure and an analysis of our outcomes. MATERIALS AND METHODS: Medical records were retrospectively reviewed of 98 patients who underwent laparoscopic MSA for GERD at a single institution from 2012 to 2016. Symptoms were assessed with gastroesophageal reflux disease-health-related quality of life (GERD-HRQL) questionnaire. Objective testing included pH testing, manometry, endoscopy, and upper GI series. Postimplantation interventions were recorded. Median follow-up was 46 months. RESULTS: Median preoperative DeMeester score was 32 (interquartile range 21-46). Esophagitis was present in 18%. Hiatal hernia was present in 59%. Operation required full hiatal dissection in 16%. There were no intraoperative complications. Mean hospital stay postimplantation was 18 hours. Reoperative intervention with device explant was necessary in 5 cases, one of which was for intraluminal device erosion. Median GERD-HRQL scores were 25 preoperatively, 8 in short-term follow-up at median 1 month, and 5 in long-term follow-up at median 46 months. Improvement in GERD-HRQL scores was statistically significant with both short and long term compared with preoperative (P < .05), but no different between short- and long-term follow-up. Daily bothersome dysphagia was present in 19 patients preoperatively and in 9 at long-term follow-up. CONCLUSIONS: Laparoscopic MSA is associated with excellent outcomes with decrease in GERD-HRQL scores in short term that are durable to longer term follow-up, and with low rates of new-onset dysphagia.

The Spectrum of Surgical Remediation of Transoral Incisionless Fundoplication-Related Failures.

AIM: To evaluate outcomes of surgical remediation for symptomatic or anatomic failure after a transoral incisionless fundoplication (TIF). METHODS: This retrospective study was performed on 11 patients who underwent a remedial operation following TIF failure between June 2011 and September 2016 at the Mayo Clinic in Florida for persistent foregut symptoms. Upper gastrointestinal workup characterized 1 patient as having normal post-TIF anatomy and 10 as having anatomic failure. Ambulatory pH testing was performed in 7 patients and was abnormal in all. All patients underwent a laparoscopic takedown of the prior endoscopic fundoplication and removal of all accessible polypropylene T-fasteners. RESULTS: All patients had esophageal salvage and have not required a reoperation. Anatomical findings included hiatal hernia (7), esophageal diverticulum (2), hiatal mesh erosion of esophagus (1), long-segment esophageal stricture (1), and normal anatomy (1). Remedial operations included laparoscopic explant of fasteners in all patients with conversion to fundoplication (7), resection/imbrication of esophageal diverticulum (2), Heller myotomy (1), and mesh explant and complex esophageal repair (1). Mean operative time was 177 minutes and median length of stay 3 days (range 2-13 days). At mean follow-up of 10.7 months (range 1-42 months), 7 patients had persistent complaints. Esophagogastroduodenoscopy was repeated in these 7 patients and was normal (n = 3), mild stenosis requiring dilation (n = 2), Los Angeles grade B esophagitis (n = 1), and Barrett's esophagus (n = 1). CONCLUSION: Anatomic distortion of the distal esophagus after TIF can be significant, making subsequent operations complex. After remedial surgery, few patients will continue to have troublesome symptoms such as dysphagia.

Correction to: Endoscopic and surgical management of nonampullary duodenal neoplasms.

This article was updated to correct the author listing for Carlos Roberto Simons-Linares.

Endoscopic and surgical management of nonampullary duodenal neoplasms.

BACKGROUND: Sporadic nonampullary duodenal neoplasms (SNADN) can have malignant potential for which endoscopic and surgical resections are offered. We report combined gastroenterologic and surgical experience for treatment of SNADN, including endoscopic mucosal resection (EMR) and pancreas-preserving partial duodenectomy (PPPD). METHODS: We retrospectively reviewed 121 consecutive patients, who underwent 30 PPPDs and 91 EMRs for mucosal and submucosal SNADN. Decision to undergo EMR or surgical resection was based on expert endoscopist and surgeon discretion including multidisciplinary tumor board review. Main outcomes were recurrence rate of neoplasia and adverse events requiring hospital admission or prolonged care. EMRs were performed with submucosal lifting followed by snare resection. PPPD included total duodenectomy, supra-ampullary PPPD for neoplasms proximal to the ampulla, and infra-ampullary PPPD for lesions distal to the ampulla. Follow-up data were available for 65% of EMR and 73% of surgical patients. RESULTS: Surgically resected neoplasia was larger with more advanced neoplasia and submucosal lesions. En bloc resection was achieved in all surgical resections and in 53% of EMRs. Post-EMR, mucosal and submucosal neoplasia recurred in 32 and 0%, respectively, including five neoplasms (26%) after an initial negative esophagogastroduodenoscopy. All recurrences were treated endoscopically. Complications occurred in 14 endoscopically and eight surgically treated patients, none requiring surgical intervention. CONCLUSIONS: Post-EMR patients had higher recurrence of mucosal neoplasia, whereas submucosal neoplasms, mainly carcinoid, did not recur. Polyp size and positive resection margin were not associated with neoplasia recurrence. Patients with SNADN could benefit from a multidisciplinary approach to stratify the optimal treatment based on local expertise.

The argument for peroral endoscopic myotomy in treatment of achalasia.

Although there has been debate regarding the optimal procedure to palliate dysphagia in patients with achalasia, emerging reports of longer term follow-up of patients after peroral endoscopic myotomy (POEM) suggest that the POEM procedure is efficacious in relief of dysphagia, and that there is infrequent need for subsequent procedures for treatment of failure or reflux. The number of centers in the United States of America performing POEM for esophageal achalasia continues to increase. This report assess the current knowledge of technical issues of POEM, outcomes after POEM and the status of POEM centers in the U.S.A., and presents the argument for surgeons to participate in the practice of POEM.

Laparoscopic Sleeve Gastrectomy for Morbid Obesity in Patients After Orthotopic Liver Transplant: a Matched Case-Control Study.

INTRODUCTION: Obesity is frequently encountered in patients with orthotopic liver transplant (OLT). The role of bariatric surgery is still unclear for this specific population. The aim of this study was to review our experience with laparoscopic sleeve gastrectomy (LSG) after OLT. MATERIAL AND METHODS: We performed a retrospective case-control study of patients undergoing LSG after OLT from 2010 to 2016. OLT-LSG patients were matched by age, sex, body mass index (BMI), and year to non-OLT patients undergoing LSG. Demographics, operative variables, postoperative events, and long-term weight loss with comorbidity resolution were collected and compared between cases and controls. RESULTS: Of 303 patients undergoing LSG, 12 (4%) had previous OLT. They were matched to 36 non-OLT patients. No difference was found between groups in the American Society of Anesthesiologists class, mean operative time, or postoperative morbidity. The non-OLT group, however, had a significantly shorter mean hospital stay than the OLT group (1.7 vs 3.1 days; P < .001). There were no conversions to open procedures. For patients with long-term follow-up, change in BMI after LSG was similar between the groups, but the non-OLT patients had significantly more excess body weight loss at 2 years (53.7 vs 45.2%; P < .001). Similar resolution of comorbid conditions was noted in both groups. LSG caused no changes in dosage of immunosuppressive medications, and no liver complications occurred. CONCLUSION: LSG after OLT in appropriately selected patients appears to have similar outcomes to LSG in non-OLT patients.