The "double-fired" gastro-jejunostomy as a form of improved efficiency during Whipple procedure.

BACKGROUND: Gastro-jejunostomy (GJ) after pylorus-resecting pancreatoduodenectomy (PD) is most commonly performed in a hand-sewn fashion. Intestinal stapled anastomosis are reported to be as effective as hand-sewn in terms of patency and risk of leakage in other indications. However, the use of a stapled gastro-jejunostomy hasn't been fully assessed in PD. The aim of the present technical report is to evaluate functional outcomes of stapled GJ during PD, its associated effect on operative time and related complications. METHODS: The institutional database for pancreatic duct adenocarcinoma (PDAC) was retrospectically reviewed. Pylorus resecting open PD without vascular or multivisceral resections were considered for the analysis. The incidence of clinically significant delayed gastric emptying (DGE from the International Stufy Group of Pancreatic Surgery (ISGPS) grade B and C), other complications, operative time and overall hospitalization were evaluated. RESULTS: Over a 10-years study period, 1182 PD for adenocarcinoma were performed and recorded in the database. 243 open Whipple procedures with no vascular and with no associated multivisceral resections were available and constituted the study population. Hand-sewn (HS) anastomosis was performed in 175 (72 %), stapled anastomosis (St) in 68 (28 %). No significant differences in baseline characteristics were observed between the two groups, with the exception of a higher rate of neoadjuvant chemotherapy in the HS group (74 % St vs. 86 % HS, p = 0.025). Intraoperatively, a significantly reduced median operative time in the St group was observed (248 min St vs. 370 mins HS, p < 0.001). Post-operatively, rates of clinically relevant delayed gastric emptying (7 % St vs. 14 % HS, p = 0.140), clinically relevant pancreatic fistula (10 % St, 15 % HS, p = 0.300), median length of stay (7 days for each group, p = 0.289), post-pancreatectomy hemorrhage (4.4 % St vs. 6.3 % HS, p = 0.415) and complication rate (22 % St vs. 34 % HS, p = 0.064) were similar between groups. However, readmission rates were significantly lower after St GJ (13.2 % St vs 29.7 % HS, p = 0.008). CONCLUSION: Our results indicate that a stapled GJ anastomosis during a standard Whipple procedure is non-inferior to a hand-sewn GJ, with a comparable rate of DGE and no increase of gastrointestinal related long term complications. Further, a stapled GJ anastomosis might be associated with reduced operative times.

Predictors of Adverse Events in the Surgical Treatment of Adult Distal Humerus Fractures.

The purpose of this study was to identify surgical complications after distal humerus fracture fixation as well as correlations between these complications and patient variables. A total of 132 patients underwent open reduction and internal fixation of traumatic distal humerus fractures between October 2011 and June 2018. Included were adult patients who underwent surgical fixation and had more than 6 months of follow-up. Excluded were patients with inadequate radiographic imaging, less than 6 months of follow-up, and previous distal humerus surgery. Multivariate logistic regression models controlling for age and body mass index were used to determine preoperative factors predictive of postoperative complications. A total of 73 patients were included in this analysis. Surgical complications were reported for 17 patients. Reoperation was required for 13 patients. Open injury at presentation was predictive of delayed union. Predictors of subsequent elbow surgery included younger age, polytrauma, open fracture, and ulnar nerve injury at the time of injury. Radial nerve injury at the time of presentation was also a risk factor for postoperative radial nerve symptoms. Predictors of postoperative heterotopic ossification included older age. Thirty-one patients had an olecranon osteotomy during their open reduction and internal fixation and none went on to nonunion. There were 13 patients with ulnar nerve complications. Of these patients, 3 had undergone an ulnar nerve transposition. None of the other studied variables were predictors of complications, malunion, or nonunion at latest follow-up. Although open reduction and internal fixation is effective in treating distal humerus fractures, its complications cannot be overlooked. Open fractures are more likely to go on to delayed union. Ulnar nerve injury, open fracture, and polytrauma were predictive for reoperation. Older patients were less likely to have subsequent surgery but more likely to develop heterotopic ossification. By identifying at-risk patients, managing physicians can better prognosticate and counsel patients on their recovery. [Orthopedics. 2023;46(6):352-357.].

PSEUDOMONAL CHOROIDAL ABSCESS AFTER ROUTINE PARS PLANA VITRECTOMY IN AN IMMUNOSUPPRESSED PATIENT.

PURPOSE: To describe an unusual case of pseudomonal choroidal abscess which developed after a routine pars plana vitrectomy in an immunosuppressed patient. METHODS: Case report. A 61-year-old woman with a history of rheumatoid arthritis and ulcerative colitis on abatacept underwent pars plana vitrectomy. A few days after the patient's operation, a partially serous choroidal detachment was identified. Her choroidal detachment increased in size despite prednisone therapy, and she was taken to the operating room for repeat vitrectomy and choroidal drainage. Intraoperatively, there was no significant intraocular inflammation, but purulent whitish material was expressed during external choroidal drainage which grew Pseudomonas aeruginosa. RESULTS: The patient was given intravenous antibiotics. Systemic infectious workup was negative for blood and urine cultures. The patient was transitioned to oral antibiotics, but had persistent eye pain after discharge and vision remained at count fingers. A computed tomography orbit scan with contrast showed persistent choroidal abscess, and intravitreal ceftazidime injections were administered. The patient's subjective pain resolved within several days of the first intravitreal injection; repeat ultrasound also showed interval resolution of the choroidal elevation. One year after the resolution of her choroidal abscess, her visual acuity was Snellen 20/250 in the affected eye. CONCLUSION: Isolated choroidal bacterial abscess is a possible, but rare, complication of pars plana vitrectomy. Although visual prognosis is poor, especially for pseudomonal choroidal abscesses, aggressive treatment with timely choroidal drainage, systemic antibiotics, and intravitreal antibiotics may allow recovery of some ambulatory vision.

Outcomes and Cost Comparison Between Generic and Conventional Cephalomedullary Nails in the Treatment of Peritrochanteric Femur Fractures.

INTRODUCTION: Although generic orthopaedic implants have been available for several years, there has been slow adoption of this cost-saving option. We hypothesize equivalent outcomes between generic and conventional cephalomedullary nails (CMN) in the treatment of peritrochanteric femur fractures. METHODS: We evaluated 419 patients undergoing CMN for peritrochanteric femur fracture with a minimum 6-month follow-up. Demographic data, radiographic assessment, and clinical outcomes were compared. RESULTS: Ninety patients were treated with generic implants and 329 patients with conventional implants. The overall complication rate was 7.0%, with a revision surgery rate of 5.4%. No significant differences were seen in demographic variables or surgical factors. Although there was an increased incidence of postoperative infections with conventional nails (P = 0.045), no significant differences were seen in other complications. CONCLUSION: At our institution, generic nails cost approximately 38% less than their conventional counterparts. There seems to be no increased rate of implant-associated complications with the use of generic CMNs, although allowing for notable cost savings.

Parental Leave Policy for Ophthalmology Residents: Results of a Nationwide Cross-Sectional Study of Program Directors.

BACKGROUND: Many residents become parents during residency and the adequacy of parental leave is integrally related to resident wellness. OBJECTIVE: To understand current parental leave policies in ophthalmology residency programs and program director perceptions of the impact of parental leave on trainees. DESIGN: Cross-sectional study. SETTING: Multicenter among all U.S. ophthalmology residency programs. PARTICIPANTS: Ophthalmology residency program directors during the 2017 to 2018 academic year. RESULTS: Sixty-eight percent (82/120) program directors participated in this study. The majority of programs had written maternity leave policies (89%) and partner leave policies (72%). The typical duration of maternity leave taken ranged from 4 to 6 weeks while typical partner leave duration taken ranged from 1 day to 2 weeks. Residents who take leave may need to extend training at 72% of programs. Program directors perceived that parental leave negatively impacts resident scholarly activities and surgical skills and volume. Male program directors, relative to female program directors, perceived that becoming a childbearing parent negatively impacts resident dedication to patient care. Program directors raised concerns including local support and policy, extension of residency, impact on residents, impact on programs, consistency and fairness, and desire for national policy change. CONCLUSIONS: Parental leave practices vary significantly among ophthalmology training programs with residents typically taking less leave than permitted. Program directors are challenged to accommodate parental leave while balancing resident training and wellness for all trainees in their program.

Risk factors and outcomes of conversion in minimally invasive distal pancreatectomy: a systematic review.

PURPOSE: The reported conversion rates for minimally invasive distal pancreatectomy (MIDP) range widely from 2 to 38%. The identification of risk factors for conversion may help surgeons during preoperative planning and patient counseling. Moreover, the impact of conversion on outcomes of MIDP is unknown. METHODS: A systematic review was conducted as part of the 2019 Miami International Evidence-Based Guidelines on Minimally Invasive Pancreas Resection (IG-MIPR). The PubMed, Cochrane, and Embase databases were searched for studies concerning conversion to open surgery in MIDP. RESULTS: Of the 828 studies screened, eight met the eligibility criteria, resulting in a combined dataset including 2592 patients after MIDP. The overall conversion rate was 17.1% (range 13.0-32.7%) with heterogeneity between studies associated with the definition of conversion adopted. Only one study divided conversion into elective and emergency conversion. The main indications for conversion were vascular involvement (23.7%), concern for oncological radicality (21.9%), and bleeding (18.9%). The reported risk factors for conversion included a malignancy as an indication for surgery, the proximity of the tumor to vascular structures in preoperative imaging, higher BMI or visceral fat, and multi-organ resection or extended resection. Contrasting results were seen in terms of blood loss and length of stay in comparing converted MIDP and completed MIDP patients. CONCLUSION: The identified risk factors for conversion from this study can be used for patient selection and counseling. Surgeon experience should be considered when contemplating MIDP for a complex patient. Future studies should divide conversion into elective and emergency conversion.

Does Intentional Support of Degree Programs in General Surgery Residency Affect Research Productivity or Pursuit of Academic Surgery? A Multi-Institutional Study.

OBJECTIVE: To determine whether pursuit of an advanced degree during dedicated research time (DRT) in a general surgery residency training program impacts a resident's research productivity. DESIGN: A retrospective, multi-institutional cohort study. SETTING: General surgery residency programs that were approved to graduate more than 5 categorical residents per year and that offered at least 1 year of DRT were contacted for participation in the study. A total of 10 general surgery residency programs agreed to participate in the study. PARTICIPANTS: Residents who started their residency between 2000 and 2012 and spent at least one full year in DRT (n = 511) were included. Those who completed an advanced degree were compared on the following parameters to those who did not complete one: total number of papers, first-author papers, the Journal Citation Reports impact factors of publication (2018, or most recent), and first position after residency or fellowship training. RESULTS: During DRT, 87 (17%) residents obtained an advanced degree. The most common degree obtained was a Master of Public Health (MPH, n = 42 (48.8%)). Residents who did not obtain an advanced degree during DRT published fewer papers (median 8, [interquartile range 4-12]) than those who obtained a degree (9, [6-17]) (p = 0.002). They also published fewer first author papers (3, [2-6]) vs (5, [2-9]) (p = 0.002) than those who obtained a degree. Resident impact factor (RIF) was calculated using Journal Citation Reports impact factor and author position. Those who did not earn an advanced degree had a lower RIF (adjusted RIF, 84 ± 4 vs 134 ± 5, p < 0.001) compared to those who did. There was no association between obtaining a degree and pursuit of academic surgery (p = 0.13) CONCLUSIONS: Pursuit of an advanced degree during DRT is associated with increased research productivity but is not associated with pursuit of an academic career.

A Comparison of Whole Genome Sequencing of SARS-CoV-2 Using Amplicon-Based Sequencing, Random Hexamers, and Bait Capture.

Genome sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is increasingly important to monitor the transmission and adaptive evolution of the virus. The accessibility of high-throughput methods and polymerase chain reaction (PCR) has facilitated a growing ecosystem of protocols. Two differing protocols are tiling multiplex PCR and bait capture enrichment. Each method has advantages and disadvantages but a direct comparison with different viral RNA concentrations has not been performed to assess the performance of these approaches. Here we compare Liverpool amplification, ARTIC amplification, and bait capture using clinical diagnostics samples. All libraries were sequenced using an Illumina MiniSeq with data analyzed using a standardized bioinformatics workflow (SARS-CoV-2 Illumina GeNome Assembly Line; SIGNAL). One sample showed poor SARS-CoV-2 genome coverage and consensus, reflective of low viral RNA concentration. In contrast, the second sample had a higher viral RNA concentration, which yielded good genome coverage and consensus. ARTIC amplification showed the highest depth of coverage results for both samples, suggesting this protocol is effective for low concentrations. Liverpool amplification provided a more even read coverage of the SARS-CoV-2 genome, but at a lower depth of coverage. Bait capture enrichment of SARS-CoV-2 cDNA provided results on par with amplification. While only two clinical samples were examined in this comparative analysis, both the Liverpool and ARTIC amplification methods showed differing efficacy for high and low concentration samples. In addition, amplification-free bait capture enriched sequencing of cDNA is a viable method for generating a SARS-CoV-2 genome sequence and for identification of amplification artifacts.

Accuracy of Intraocular Lens Formulas in Eyes With Keratoconus.

PURPOSE: To evaluate the refractive accuracy of current intraocular lens (IOL) formulas in eyes with keratoconus. DESIGN: Retrospective case series. METHODS: Preoperative optical biometry, Pentacam topography, and postoperative outcomes were collected from eyes with keratoconus that had uncomplicated cataract surgery between 2014 and 2018 at a single institution. Exclusion criteria include postoperative best-corrected spectacle visual acuity worse than 20/40, multifocal lens, prior ophthalmic surgeries, and prior ocular trauma. The Hoffer Q, SRK/T, Holladay I, Holladay II, Haigis, and Barrett Universal II formulas were analyzed in each eye stratified by keratoconus severity. RESULTS: A total of 73 eyes were included. All formulas had a positive mean predicted error ranging from 0.10 to 4.38 diopters (D). The Barrett Universal II formula had the lowest median absolute error for stage I (n = 46, 0.445 D) and II (n = 22, 0.445 D) eyes, and the highest percentage of eyes with predicted error within ±0.50 D for both stage I (52%) and II (50%) eyes. In stage III eyes (n = 5), the Haigis formula had the lowest median predicated error (1.90 D) and the highest percentage of eyes with predicted error within ±0.50 D (40%). Corneal power measured by optical biometers was higher than measurements by Pentacam keratometry. CONCLUSIONS: All formulas tend to have a hyperopic surprise. The Barrett Universal II formula was the most accurate for mild to moderate disease. Pentacam keratometry may help avoid hyperopic outcomes.

Transverse Velocities with the Moving Lens Effect.

Gravitational potentials that change in time induce fluctuations in the observed cosmic microwave background (CMB) temperature. Cosmological structure moving transverse to our line of sight provides a specific example known as the moving lens effect. Here, we explore how the observed CMB temperature fluctuations, combined with the observed matter overdensity, can be used to infer the transverse velocity of cosmological structures on large scales. We show that near-future CMB surveys and galaxy surveys will have the statistical power to make a first detection of the moving lens effect, and we discuss applications for the reconstructed transverse velocity.

Author Correction: Reconstruction of cysteine biosynthesis using engineered cysteine-free enzymes.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Ability of Ophthalmology Residents to Self-Assess Their Performance Through Established Milestones.

OBJECTIVES: Accurate self-assessment is an important aspect of practice-based learning and improvement and a critical skill for resident growth. The Accreditation Council for Graduate Medical Education mandates semiannual milestones assessments by a clinical competency committee (CCC) for all ophthalmology residents. There are six core competencies: patient care (PC), medical knowledge, systems-based practice, practice-based learning and improvement, professionalism, and interpersonal communication skills. These competencies are assessed by the milestones rubric, which has detailed behavioral anchors and are also used for trainee self-assessments. This study compares resident self-assessed (SA) and faculty CCC milestones scores. DESIGN: Residents completed milestones self-assessments prior to receiving individual score reports from the CCC. Correlation coefficients were calculated comparing the SA and CCC scores. In addition, statistical models were used to determine predictors of disparities and differences between the SA and CCC scores. SETTING: Wilmer Eye Institute, Johns Hopkins Hospital. PARTICIPANTS: Twenty-one residents in the Wilmer Ophthalmology Residency program from July 2014 to June 2016. RESULTS: Fifty-seven self-assessments were available for the analysis. For each resident's first assessment, SA and CCC scores were strongly correlated (r ≥ 0.6 and p < 0.05) for four milestones, and not correlated for the remaining 20 milestones. In multivariable models, the SA and CCC scores are less disparate for medical knowledge and systems-based practice competencies compared to practice-based learning and improvement. Higher year of training, PC and professionalism competencies were predictive of statistically significant resident overestimation of scores relative to the CCC. In addition, higher CCC scores predicted statistically significant lower SA-CCC disparities and differences. SA-CCC differences did not lower to a significant extent with repeated assessments or modification to the end-of-rotation evaluation forms. CONCLUSIONS: Self-assessments by ophthalmology residents are not well-correlated with faculty assessments, emphasizing the need for improved and frequent timely feedback. Residents have the greatest difficulty self-assessing their professionalism and PC competency. In general, senior residents and underperforming residents have more inaccurate self-assessments.

Reconstruction of cysteine biosynthesis using engineered cysteine-free enzymes.

Amino acid biosynthesis pathways observed in nature typically require enzymes that are made with the amino acids they produce. For example, Escherichia coli produces cysteine from serine via two enzymes that contain cysteine: serine acetyltransferase (CysE) and O-acetylserine sulfhydrylase (CysK/CysM). To solve this chicken-and-egg problem, we substituted alternate amino acids in CysE, CysK and CysM for cysteine and methionine, which are the only two sulfur-containing proteinogenic amino acids. Using a cysteine-dependent auxotrophic E. coli strain, CysE function was rescued by cysteine-free and methionine-deficient enzymes, and CysM function was rescued by cysteine-free enzymes. CysK function, however, was not rescued in either case. Enzymatic assays showed that the enzymes responsible for rescuing the function in CysE and CysM also retained their activities in vitro. Additionally, substitution of the two highly conserved methionines in CysM decreased but did not eliminate overall activity. Engineering amino acid biosynthetic enzymes to lack the so-produced amino acids can provide insights into, and perhaps eventually fully recapitulate via a synthetic approach, the biogenesis of biotic amino acids.

Detecting Patchy Reionization in the Cosmic Microwave Background.

Upcoming cosmic microwave background (CMB) experiments will measure temperature fluctuations on small angular scales with unprecedented precision. Small-scale CMB fluctuations are a mixture of late-time effects: gravitational lensing, Doppler shifting of CMB photons by moving electrons [the kinematic Sunyaev-Zel'dovich (KSZ) effect], and residual foregrounds. We propose a new statistic which separates the KSZ signal from the others, and also allows the KSZ signal to be decomposed in redshift bins. The decomposition extends to high redshift and does not require external data sets such as galaxy surveys. In particular, the high-redshift signal from patchy reionization can be cleanly isolated, enabling future CMB experiments to make high-significance and qualitatively new measurements of the reionization era.

Selective inhibition of small-diameter axons using infrared light.

Novel clinical treatments to target peripheral nerves are being developed which primarily use electrical current. Recently, infrared (IR) light was shown to inhibit peripheral nerves with high spatial and temporal specificity. Here, for the first time, we demonstrate that IR can selectively and reversibly inhibit small-diameter axons at lower radiant exposures than large-diameter axons. We provide a mathematical rationale, and then demonstrate it experimentally in individual axons of identified neurons in the marine mollusk Aplysia californica, and in axons within the vagus nerve of a mammal, the musk shrew Suncus murinus. The ability to selectively, rapidly, and reversibly control small-diameter sensory fibers may have many applications, both for the analysis of physiology, and for treating diseases of the peripheral nervous system, such as chronic nausea, vomiting, pain, and hypertension. Moreover, the mathematical analysis of how IR affects the nerve could apply to other techniques for controlling peripheral nerve signaling.

Diabetic and idiopathic gastroparesis is associated with loss of CD206-positive macrophages in the gastric antrum.

BACKGROUND: Animal studies have increasingly highlighted the role of macrophages in the development of delayed gastric emptying. However, their role in the pathophysiology of human gastroparesis is unclear. Our aim was to determine changes in macrophages and other cell types in the gastric antrum muscularis propria of patients with diabetic and idiopathic gastroparesis. METHODS: Full thickness gastric antrum biopsies were obtained from patients enrolled in the Gastroparesis Clinical Research Consortium (11 diabetic, 6 idiopathic) and 5 controls. Immunolabeling and quantitative assessment was done for interstitial cells of Cajal (ICC) (Kit), enteric nerves protein gene product 9.5, neuronal nitric oxide synthase, vasoactive intestinal peptide, substance P, tyrosine hydroxylase), overall immune cells (CD45) and anti-inflammatory macrophages (CD206). Gastric emptying was assessed using nuclear medicine scintigraphy and symptom severity using the Gastroparesis Cardinal Symptom Index. RESULTS: Both diabetic and idiopathic gastroparesis patients showed loss of ICC as compared to controls (Mean [standard error of mean]/hpf: diabetic, 2.28 [0.16]; idiopathic, 2.53 [0.47]; controls, 6.05 [0.62]; P=.004). Overall immune cell population (CD45) was unchanged but there was a loss of anti-inflammatory macrophages (CD206) in circular muscle (diabetic, 3.87 [0.32]; idiopathic, 4.16 [0.52]; controls, 6.59 [1.09]; P=.04) and myenteric plexus (diabetic, 3.83 [0.27]; idiopathic, 3.59 [0.68]; controls, 7.46 [0.51]; P=.004). There was correlation between the number of ICC and CD206-positive cells (r=.55, P=.008). Enteric nerves (PGP9.5) were unchanged: diabetic, 33.64 (3.45); idiopathic, 41.26 (6.40); controls, 46.80 (6.04). CONCLUSION: Loss of antral CD206-positive anti-inflammatory macrophages is a key feature in human gastroparesis and it is associates with ICC loss.

Robustness, flexibility, and sensitivity in a multifunctional motor control model.

Motor systems must adapt to perturbations and changing conditions both within and outside the body. We refer to the ability of a system to maintain performance despite perturbations as "robustness," and the ability of a system to deploy alternative strategies that improve fitness as "flexibility." Different classes of pattern-generating circuits yield dynamics with differential sensitivities to perturbations and parameter variation. Depending on the task and the type of perturbation, high sensitivity can either facilitate or hinder robustness and flexibility. Here we explore the role of multiple coexisting oscillatory modes and sensory feedback in allowing multiphasic motor pattern generation to be both robust and flexible. As a concrete example, we focus on a nominal neuromechanical model of triphasic motor patterns in the feeding apparatus of the marine mollusk Aplysia californica. We find that the model can operate within two distinct oscillatory modes and that the system exhibits bistability between the two. In the "heteroclinic mode," higher sensitivity makes the system more robust to changing mechanical loads, but less robust to internal parameter variations. In the "limit cycle mode," lower sensitivity makes the system more robust to changes in internal parameter values, but less robust to changes in mechanical load. Finally, we show that overall performance on a variable feeding task is improved when the system can flexibly transition between oscillatory modes in response to the changing demands of the task. Thus, our results suggest that the interplay of sensory feedback and multiple oscillatory modes can allow motor systems to be both robust and flexible in a variable environment.