Management of symptomatic, asymptomatic, and recurrent hiatal hernia: a systematic review and meta-analysis.

BACKGROUND: The surgical management of hiatal hernia remains controversial. We aimed to compare outcomes of mesh versus no mesh and fundoplication versus no fundoplication in symptomatic patients; surgery versus observation in asymptomatic patients; and redo hernia repair versus conversion to Roux-en-Y reconstruction in recurrent hiatal hernia. METHODS: We searched PubMed, Embase, CINAHL, Cochrane Library and the ClinicalTrials.gov databases between 2000 and 2022 for randomized controlled trials (RCTs), observational studies, and case series (asymptomatic and recurrent hernias). Screening was performed by two trained independent reviewers. Pooled analyses were performed on comparative data. Risk of bias was assessed using the Cochrane Risk of Bias tool and Newcastle Ottawa Scale for randomized and non-randomized studies, respectively. RESULTS: We included 45 studies from 5152 retrieved records. Only six RCTs had low risk of bias. Mesh was associated with a lower recurrence risk (RR = 0.50, 95%CI 0.28, 0.88; I2 = 57%) in observational studies but not RCTs (RR = 0.98, 95%CI 0.47, 2.02; I2 = 34%), and higher total early dysphagia based on five observational studies (RR = 1.44, 95%CI 1.10, 1.89; I2 = 40%) but was not statistically significant in RCTs (RR = 3.00, 95%CI 0.64, 14.16). There was no difference in complications, reintervention, heartburn, reflux, or quality of life. There were no appropriate studies comparing surgery to observation in asymptomatic patients. Fundoplication resulted in higher early dysphagia in both observational studies and RCTs ([RR = 2.08, 95%CI 1.16, 3.76] and [RR = 20.58, 95%CI 1.34, 316.69]) but lower reflux in RCTs (RR = 0.31, 95%CI 0.17, 0.56, I2 = 0%). Conversion to Roux-en-Y was associated with a lower reintervention risk after 30 days compared to redo surgery. CONCLUSIONS: The evidence for optimal management of symptomatic and recurrent hiatal hernia remains controversial, underpinned by studies with a high risk of bias. Shared decision making between surgeon and patient is essential for optimal outcomes.

Introductory Video as a Supplemental Application for General Surgery Residency Candidates: Concept, Implementation, Preliminary Outcomes, and Future Directions.

OBJECTIVE: The residency selection process has changed dramatically over the past several years, primarily due to the COVID-19 pandemic causing a transition to virtual interviews and limiting sub-internship opportunities. Another new major change is the transition of the USMLE Step 1 examination from a numerical score to pass/fail as of January 2022. In anticipation of this major change, our program asked applicants to submit a short video clip expressing their interest. PARTICIPANTS: Review of each of the videos was completed by three members of the admission committee and each reviewer was required to complete formal implicit bias training prior to reviewing the videos. RESULTS: Over 1200 general surgery residency applications were received via the Electronic Residency Application Service (ERAS) for the 2022-2023 application cycle. 286 applicants were selected for a formal interview invitation and asked to submit a 2-minute introductory video. In response, 222 (77.62%) of the 286 cohort submitted introductory videos. 210 of these videos (94.59%) were submitted within the first week. The average length of the videos submitted was 105.10 seconds. CONCLUSION: Using optional introductory videos as a supplemental application has helped to narrow the applicant pool and identify individuals to offer interviews.

Colonic Trichobezoar Causing Acute Large Bowel Obstruction.

A trichobezoar is a solid mass of undigested hair that accumulates in the gastrointestinal tract that is typically associated with trichotillomania and trichophagia. Most documented cases are reported to be found in the stomach and small intestine. We report a case of a complete large bowel and small bowel obstruction secondary to a trichobezoar in an 81-year-old male with abdominal pain for one month. He presented to the emergency department with sudden onset nausea, vomiting, constipation, and severe abdominal pain, prompting him to come to the emergency department. CT demonstrated a mechanical obstruction with a transition point at the splenic flexure with pneumatosis. He was taken for urgent exploratory laparotomy, where a colotomy was made and the obstructive intraluminal mass in the transverse colon was identified and removed, and a transverse colostomy was matured. Subsequent pathology revealed the mass as hair and fecal material, confirming a diagnosis of colonic obstruction due to trichobezoar.

Capsaicin pre-treatment provides neurovascular protection against neonatal hypoxic-ischemic brain injury in rats.

Capsaicin, a transient receptor potential vanilloid 1 (TRPV1) agonist, has recently been shown to provide neuroprotection against brain injury in experimental adult models of cerebral ischemia. Accordingly, in this study, we investigated the way in which capsaicin-mediated TRPV1 modulation could attenuate damage in an experimental hypoxic-ischemic (HI) neonatal brain injury model. The Rice-Vannucci method was used in 10-day-old rat pups by performing unilateral carotid artery ligation followed by 2 h of hypoxia (8% O2 at 37°C). Capsaicin was administered intraperitoneally (0.2 mg/kg or 2.0 mg/kg) at 3 h pre-HI or 1 h post-HI. Post assessment included measurement of infarction volume at 24 and 72 h in addition to an assessment of the vascular dynamics of the middle cerebral artery (MCA) at 6 h post-HI. The results indicated that pre-treatment with capsaicin reduced infarction volume significantly with either low-dose or high-dose treatment. Pre-treatment also improved myogenic tone and decreased apoptotic changes in the distal MCA. We concluded that capsaicin pre-treatment may provide neurovascular protection against neonatal HI.

A practical methodology to improve the dosimetric accuracy of MR-based radiotherapy simulation for brain tumors.

PURPOSE: To investigate the dosimetric accuracy of synthetic computed tomography (sCT) images generated by a clinically-ready voxel-based MRI simulation package, and to develop a simple and feasible method to improve the accuracy. METHODS: 20 patients with brain tumor were selected to undergo CT and MRI simulation. sCT images were generated by a clinical MRI simulation package. The discrepancy between planning CT and sCT in CT number and body contour were evaluated. To resolve the discrepancies, an sCT specific CT-relative electron density (RED) calibration curve was used, and a layer of pseudo-skin was created on the sCT. The dosimetric impact of these discrepancies, and the improvement brought about by the modifications, were evaluated by a planning study. Volumetric modulated arc therapy (VMAT) treatment plans for each patient were created and optimized on the planning CT, which were then transferred to the original sCT and the modified-sCT for dose re-calculation. Dosimetric comparisons and gamma analysis between the calculated doses in different images were performed. RESULTS: The average gamma passing rate with 1%/1 mm criteria was only 70.8% for the comparison of dose distribution between planning CT and original sCT. The mean dose difference between the planning CT and the original sCT were -1.2% for PTV D95 and -1.7% for PTV Dmax, while the mean dose difference was within 0.7 Gy for all relevant OARs. After applying the modifications on the sCT, the average gamma passing rate was increased to 92.2%. Mean dose difference in PTV D95 and Dmax were reduced to -0.1% and -0.3% respectively. The mean dose difference was within 0.2 Gy for all OAR structures and no statistically significant difference were found. CONCLUSIONS: The modified-sCT demonstrated improved dosimetric agreement with the planning CT. These results indicated the overall dosimetric accuracy and practicality of this improved MR-based treatment planning method.

Selective cell propagation via micropatterning of a thermally-activated hydrogel.

The ability to selectively propagate specific cells is fundamentally important to the development of clonal cell populations. Current methods rely on techniques such as limiting dilution, colony picking, and flow cytometry to transfer single cells into single wells, resulting in workflows that are low-throughput, slowed by propagation kinetics, and susceptible to contamination. Here, we developed a method, called selective laser gelation (SLG), to micropattern hydrogels in cell culture media in order to encapsulate specific cells to selectively arrest their growth. This process relies on the inverse gelation of methylcellulose, which forms a hydrogel when heated rather than cooled. Local heating using an infrared laser enables hydrogel micropatterning, while phase transition hysteresis retains the hydrogel after laser excitation. As a demonstration, we used this approach to selectively propagate transgenic CHO cells with increased antibody productivity. More generally, hydrogel micropatterning provides a simple and non-contact method for selective propagation of cells based on features identified by imaging.

Development and validation of risk prediction models for COVID-19 positivity in a hospital setting.

OBJECTIVES: To develop: (1) two validated risk prediction models for coronavirus disease-2019 (COVID-19) positivity using readily available parameters in a general hospital setting; (2) nomograms and probabilities to allow clinical utilisation. METHODS: Patients with and without COVID-19 were included from 4 Hong Kong hospitals. The database was randomly split into 2:1: for model development database (n = 895) and validation database (n = 435). Multivariable logistic regression was utilised for model creation and validated with the Hosmer-Lemeshow (H-L) test and calibration plot. Nomograms and probabilities set at 0.1, 0.2, 0.4 and 0.6 were calculated to determine sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: A total of 1330 patients (mean age 58.2 ± 24.5 years; 50.7% males; 296 COVID-19 positive) were recruited. The first prediction model developed had age, total white blood cell count, chest x-ray appearances and contact history as significant predictors (AUC = 0.911 [CI = 0.880-0.941]). The second model developed has the same variables except contact history (AUC = 0.880 [CI = 0.844-0.916]). Both were externally validated on the H-L test (p = 0.781 and 0.155, respectively) and calibration plot. Models were converted to nomograms. Lower probabilities give higher sensitivity and NPV; higher probabilities give higher specificity and PPV. CONCLUSION: Two simple-to-use validated nomograms were developed with excellent AUCs based on readily available parameters and can be considered for clinical utilisation.

Radioactive seed localization of nonpalpable breast lesions in an academic comprehensive cancer program community hospital setting.

Wire localized excision (WLE) has been a long-standing method for localization of nonpalpable breast lesions. Disadvantages of this method include difficulty locating the wire tip in relation to borders of the lesion, imprecise placement of the wire, and the need to place the wire shortly before scheduled surgery. These shortcomings may lead to a high positive margin rate requiring re-excision to obtain clear margins for breast cancer. Radioactive seed localized excision (RSLE) of nonpalpable breast lesions has been advocated as a safe and effective alternative to WLE. The primary endpoints of the study were to compare re-excision rates between WLE and RSLE of nonpalpable breast lesions and to determine if there were any differences in volume of tissue removed. One hundred three patients were included in a retrospective review of localized breast excisions done by a single surgeon. Forty-four patients underwent WLE between April 2007 and February 2009. Fifty-nine patients underwent RSLE between September 2009 and January 2012. Margins were considered to be clear if at least 1 mm of normal tissue was obtained from the circumferential periphery of the lesion in question. RSLE resulted in a re-excision rate of 17 versus 55 per cent re-excision rate for wire localization (P < 0.001). Excision volume was greater for patients having wire localization (P = 0.074). RSLE is an effective technique for excision of nonpalpable breast lesions in the community setting. This technique allows for accurate localization and appears to allow for smaller volume of tissue to be excised.

The hyperbaric oxygen preconditioning-induced brain protection is mediated by a reduction of early apoptosis after transient global cerebral ischemia.

We hypothesized that the brain-protective effect of hyperbaric oxygen (HBO) preconditioning in a transient global cerebral ischemia rat model is mediated by the inhibition of early apoptosis. One hundred ten male Sprague-Dawley (SD) rats (300-350 g body weight) were allocated to the sham group and three other groups with 10 min of four-vessel occlusion, untreated or preconditioned with either 3 or 5 hyperbaric oxygenations. HBO preconditioning improved neurobehavioral scores and reduced mortality, decreased ischemic cell change, reduced the number of early apoptotic cells and hampered a conversion of early to late apoptotic alterations. HBO preconditioning reduced the immunoreactivity of phosphorylated p38 in vulnerable neurons and increased the expression of brain derived neurotrophic factor (BDNF) in early stage post-ischemia. However, preconditioning with 3 HBO treatments proved less beneficial than with 5 HBO treatments. We conclude that HBO preconditioning may be neuroprotective by reducing early apoptosis and inhibition of the conversion of early to late apoptosis, possibly through an increase in brain BDNF level and the suppression of p38 activation.

Development and validation of a new technique for assessing lumbar spine motion.

STUDY DESIGN: Dynamic lumbar flexion-extension motions were assessed by an electrogoniometer and a videofluoroscopy unit simultaneously. OBJECTIVE: To develop and validate a new technique for the assessment of lumbar spine motion. SUMMARY OF BACKGROUND DATA: Spine instability, a clinical condition that is common but difficult to diagnose, has been suggested to involve a characteristic change in the relation between vertebrae during motion. Assessment of lumbar instability using functional radiographs is controversial. Information regarding dynamic spine kinematics in vivo is limited. METHODS: A lumbar spine motion analysis system was developed, and its reliability was assessed. Simultaneous total flexion range of motion and segmental motion of the lumbar spine were assessed in 30 healthy volunteers. Lumbar images were captured in 10 degrees intervals during flexion-extension. Intervertebral flexion-extension of each vertebral level was calculated. RESULTS: In flexion, the lumbar vertebrae flexed with a descending order from L1 to L5 throughout the motion. Conversely, the concavity of lumbar lordosis increased steadily in extension. No statistically significant difference in the pattern of motion was found between genders. CONCLUSIONS: The results from this study showed that the newly developed technique is reliable. It may have potential value for evaluating spine instability in clinical practice.