A realistic combined exposure scenario: effect of microplastics and atrazine on Piaractus mesopotamicus.

Microplastics, considered emerging environmental contaminants resulting from plastic degradation, are discovered in diverse aquatic ecosystems and can be unintentionally ingested by fish. Therefore, it is essential to characterize their interaction with other contaminants, such as agrochemicals, in aquatic environments. This study aimed to assess histological, enzymatic, and genotoxic biomarkers in juvenile pacú (Piaractus mesopotamicus) exposed to polyethylene (PE) microplastic particles and the herbicide atrazine, individually or combined, for 15 days. Four treatments were used: a negative control (CON), PE in the fish diet (0.1% w/w, FPE), atrazine through water (100 µg L-1, ATZ), and the mixture (ATZ+FPE). Results confirmed histological alterations in gills (edema and lamellar fusion) and liver (necrotic areas and congestion) of fish exposed to ATZ and ATZ+FPE. The number of goblet cells increased in the posterior intestine of fish under ATZ+FPE compared to CON and FPE. Enzyme activities (CAT, GST, AChE, and BChE) significantly increased in ATZ+FPE compared to CON. However, no genotoxic effect was demonstrated. These findings provide insights into the complex impacts of simultaneous exposure to atrazine and microplastics, emphasizing the need for continued research to guide effective environmental management strategies against these contaminants that represent a risk to aquatic organisms.

MR Imaging of the Cerebral Aneurysmal Wall for Assessment of Rupture Risk.

The evaluation of unruptured intracranial aneurysms requires a comprehensive and multifaceted approach. The comprehensive analysis of aneurysm wall enhancement through high-resolution MRI, in tandem with advanced processing techniques like finite element analysis, quantitative susceptibility mapping, and computational fluid dynamics, has begun to unveil insights into the intricate biology of aneurysms. This enhanced understanding of the etiology, progression, and eventual rupture of aneurysms holds the potential to be used as a tool to triage patients to intervention versus observation. Emerging tools such as radiomics and machine learning are poised to contribute significantly to this evolving landscape of diagnostic refinement.

Optimisation of sugar and solid biofuel co-production from almond tree prunings by acid pretreatment and enzymatic hydrolysis.

Almond pruning biomass is an important agricultural residue that has been scarcely studied for the co-production of sugars and solid biofuels. In this work, the production of monosaccharides from almond prunings was optimised by a two-step process scheme: pretreatment with dilute sulphuric acid (0.025 M, at 185.9-214.1 â„ƒ for 0.8-9.2 min) followed by enzyme saccharification of the pretreated cellulose. The application of a response surface methodology enabled the mathematical modelling of the process, establishing pretreatment conditions to maximise both the amount of sugar in the acid prehydrolysate (23.4 kg/100 kg raw material, at 195.7 â„ƒ for 3.5 min) and the enzymatic digestibility of the pretreated cellulose (45.4%, at 210.0 â„ƒ for 8.0 min). The highest overall sugar yield (36.8 kg/100 kg raw material, equivalent to 64.3% of all sugars in the feedstock) was obtained with a pretreatment carried out at 197.0 â„ƒ for 4.0 min. Under these conditions, moreover, the final solids showed better properties for thermochemical utilisation (22.0 MJ/kg heating value, 0.87% ash content, and 72.1 mg/g moisture adsorption capacity) compared to those of the original prunings.

Effect of olive leaf phytochemicals on the anti-acetylcholinesterase, anti-cyclooxygenase-2 and ferric reducing antioxidant capacity.

In this study, the phytochemical profile of fifty olive leaves (OL) extracts from Spain, Italy, Greece, Portugal, and Morocco was characterized and their anti-cholinergic, anti-inflammatory, and antioxidant activities were evaluated. Luteolin-7-O-glucoside, isoharmnentin, and apigenin were involved in the acetylcholinesterase (AChE) inhibitory activity, while oleuropein and hydroxytyrosol showed noteworthy potential. Secoiridoids contributed to the cyclooxygenase-2 inhibitory activity and antioxidant capacity. Compounds such as oleuropein, ligstroside and luteolin-7-O-glucoside, may exert an important role in the ferric reducing antioxidant capacity. It should be also highlighted the role of hydroxytyrosol, hydroxycoumarins, and verbascoside concerning the antioxidant activity. This research provides valuable insights and confirms that specific compounds within OL extracts contribute to distinct anti-cholinergic, anti-inflammatory, and anti-oxidative effects.

Acid insoluble lignin material production by chemical activation of olive endocarps for an efficient furfural adsorption-removal from aqueous solutions.

The present work describes a protocol of chemical activation, with acid catalyst, of olive endocarps to obtain acid insoluble lignin-rich materials with high capacities for the adsorption of furfural present in aqueous media. During biomass activation, factors such as acid concentration, reaction time and temperature, solid/liquid ratio and the presence of water extractives strongly affected both the surface characteristics of the treated bioadsorbents and their capacities for furfural retention (percentage increase close to 600% with respect to the crude biomass). Once a treated solid with good adsorbent properties was obtained, the optimal conditions for adsorption were found: stirring speed 80 rpm, temperature 303 K and adsorbent load 7.5 g solid/50 cm3. Kinetic study indicated the pseudo-second order model provided the best fit of the experimental data. At 303 K, the equilibrium adsorption capacities values ranged from 2.27 mg g-1 to 29.29 mg g-1, for initial furfural concentrations between 0.49 g dm-3 and 12.88 g dm-3. Freundlich model presented the best isotherm (R2 = 0.996 and SE = 4.7%) providing KF and n values of 0.115 (mg g-1) (mg dm-3)-n and 0.610, respectively. Since physical interactions predominate in the adsorption of furfural on chemically activated olive endocarps, the furfural removal process could have occurred reversibly on the heterogeneous surface of the bioadsorbents.

Tigertriever in the treatment of acute ischemic stroke with underlying intracranial atherosclerotic disease.

BACKGROUND: The Tigertriever device offers a unique feature that enables gradual control of the radial expansion. We sought to evaluate the safety and efficacy of the Tigertriever device in patients with large vessel occlusion (LVO) and underlying intracranial atherosclerotic disease (ICAD). The patients were part of the TIGER trial. METHODS: The presence of underlying ICAD was determined by a core imaging laboratory using CT angiography and digital subtraction angiography. The primary outcomes included successful reperfusion, puncture to reperfusion time, and complications associated with the use of the Tigertriever device. Patients underwent mechanical thrombectomy with the Tigertriever device for up to three passes, and alternative devices were employed for subsequent passes. RESULTS: A total of 160 patients were enrolled in the TIGER trial, and 32 patients had ICAD. Among the patients with ICAD, 78% achieved successful reperfusion within three passes of the Tigertriever device, without requiring rescue therapy. Additionally, a first pass effect was observed in 46.8%. The median time from puncture to reperfusion was 22 minutes. There were no device-related complications. The National Institutes of Health Stroke Scale (NIHSS) score at 24 hours was significantly reduced, from an average of 17 at baseline to 8. At the 3 month follow-up, 50% of patients achieved a modified Rankin Scale score of ≤2. CONCLUSION: Endovascular therapy (EVT) with the Tigertriever device for LVO in patients with underlying ICAD is effective and safe. When compared with historical data from other devices employed in similar cases, we observed a high rate of successful reperfusion, along with a shorter puncture to reperfusion time.

Dural Arteriovenous Fistulas With Cognitive Impairment: Angiographic Characteristics and Treatment Outcomes.

BACKGROUND AND OBJECTIVES: Anecdotal cases of rapidly progressing dementia in patients with dural arteriovenous fistulas (dAVFs) have been reported in small series. However, large series have not characterized these dAVFs. We conducted an analysis of the largest cohort of dAVFs presenting with cognitive impairment (dAVFs-CI), aiming to provide a detailed characterization of this subset of dAVFs. METHODS: Patients with dAVFs-CI were analyzed from the CONDOR Consortium, a multicenter repository comprising 1077 dAVFs. A propensity score matching analysis was conducted to compare dAVFs-CI with Borden type II and type III dAVFs without cognitive impairment (controls). Logistic regression was used to identify angiographic characteristics specific to dAVFs-CI. Furthermore, post-treatment outcomes were analyzed. RESULTS: A total of 60 patients with dAVFs-CI and 60 control dAVFs were included. Outflow obstruction leading to venous hypertension was observed in all dAVFs-CI. Sinus stenosis was significantly associated with dAVFs-CI (OR 2.85, 95% CI: 1.16-7.55, P = .027). dAVFs-CI were more likely to have a higher number of arterial feeders (OR 1.56, 95% CI 1.22-2.05, P < .001) and draining veins (OR 2.05, 95% CI 1.05-4.46, P = .004). Venous ectasia increased the risk of dAVFs-CI (OR 2.38, 95% CI 1.13-5.11, P = .024). A trend toward achieving asymptomatic status at follow-up was observed in patients with successful closure of dAVFs (OR 2.86, 95% CI 0.85-9.56, P = .09). CONCLUSION: Venous hypertension is a key angiographic feature of dAVFs-CI. Moreover, these fistulas present at a mean age of 58 years-old, and exhibit a complex angioarchitecture characterized by an increased number of arteriovenous connections and stenosed sinuses. The presence of venous ectasia further exacerbates the impaired drainage and contributes to the development of dAVFs-CI. Notably, in certain cases, closure of the dAVF has the potential to reverse symptoms.

The Cognitive Profile of Elderly Patients With Mild Traumatic Brain Injury: A Role for Cognitive Reserve?

OBJECTIVE: To assess cognitive status in elderly patients with mild traumatic brain injury (mTBI) in the subacute phase, examine the role of cognitive reserve, and investigate associations with cognitive complaints, mental distress, and functional outcomes. SETTING: A level 1 trauma center in the Netherlands. PARTICIPANTS: A total of 52 individuals with mTBI and 42 healthy controls. DESIGN: A prospective observational cohort study. MAIN MEASURES: Neuropsychological assessment in the subacute phase (2 weeks to 6 months post-injury) to objectively measure the cognitive functioning, the Head Injury Symptom Checklist for subjective cognitive complaints, the Hospital Anxiety and Depression Scale for anxiety and depression, the Cognitive Reserve Index questionnaire for cognitive reserve, the Community Integration Questionnaire for community integration, and the Glasgow Outcome Scale Extended for functional outcome. RESULTS: Cognitive impairments were observed in memory (P < .001) and attention, processing speed and executive control (P < .001). Cognitive reserve was not associated with neuropsychological test performance, except for one test measuring working memory. The relationship between injury severity and cognitive outcome was not moderated by cognitive reserve. Elderly patients reported significantly more complains than healthy controls regarding forgetfulness, concentration problems, and slowness. Complaints of concentration were associated with cognitive impairment. All cognitive complaints were significantly correlated with mental distress. CONCLUSIONS: Cognitive impairments may be present in elderly patients in the subacute phase after mTBI, and these impairments were not significantly associated with cognitive reserve. This suggests that cognitive reserve might not serve as a protective factor against the effects of mTBI in the elderly. Concentration complaints may serve as a specific indicator for cognitive impairment, while complaints of memory and mental slowness may represent more generic indicators of mental distress. These findings highlight the importance of careful screening in older adults with mTBI, guiding clinicians toward specific treatment targets encompassing cognitive impairment, diminished mental well-being, or both.

Morphological characteristics of brain aneurysms among age groups.

BACKGROUND: Patient's age is an important factor in determining the risk of aneurysm rupture. However, there is limited data on how aneurysm morphology differs among age groups. We studied morphological characteristics of brain aneurysms among age groups in a large cohort. METHODS: Aneurysms from the Stroke Thrombectomy and Aneurysm Registry (STAR) were analyzed. The following parameters were included: location, size, neck, width, height, aspect ratio, and regular versus irregular morphology. The risk of rupture presentation was estimated using logistic regression. RESULTS: A total of 1407 unruptured and 607 ruptured saccular aneurysms were included. The most common locations of ruptured aneurysms in patients younger than 70 years-old were the middle cerebral artery (MCA) and the anterior communicating artery (ACOM). The most common location of ruptured aneurysms in patients older than 70 years-old were the posterior communicating artery (PCOM) and ACOM. The size of unruptured aneurysms increased with age (p < .001). Conversely, the size of ruptured aneurysms was similar among age groups (p = .142). Unruptured and ruptured aneurysms became more irregular at presentation with older age (p < .001 and p .025, respectively). Irregular morphology and location were associated with rupture status across all age groups in multivariate regression. CONCLUSIONS: Younger patients have small unruptured and ruptured aneurysms, and ruptured aneurysms are mostly located in the MCA and ACOM. Older patients have larger and more irregular unruptured aneurysms, and ruptured aneurysms are mostly located in the PCOM and ACOM. An irregular morphology increases the risk of rupture in all age groups.

Exploring the Antioxidant, Neuroprotective, and Anti-Inflammatory Potential of Olive Leaf Extracts from Spain, Portugal, Greece, and Italy.

The leaves of the olive tree (Olea europaea L.) are one of the major solid wastes from the olive industry. Globally, the European Union is the largest producer of olive by-products, with Spain, Italy, Greece, and Portugal accounting for almost the entire production. Many questions remain to be solved concerning olive leaves (OL), including those related to possible differences in composition and/or biological activities depending on their geographical origin. In the present work, OL from Spain, Italy, Greece, and Portugal have been characterized according to their phytochemical profile, antioxidant capacity, neuroprotective activity, and anti-inflammatory effects. The Spanish and Italian OL samples presented the highest antioxidant and neuroprotective activities, while the Greek OL showed the lowest. These results were strongly associated with the content of oleoside methyl ester and p-hydroxybenzoic acid for the Spanish and Italian samples, respectively, whereas the content of decarboxymethyl elenolic acid dialdehyde form (hydrated) was negatively associated with the mentioned biological activities of the Greek samples. No country-related effect was observed in the anti-inflammatory activity of OL. Comprehensively, this work could provide a useful tool for manufacturers and R&D departments in making environmentally friendly decisions on how OL can be used to generate nutraceutical products based on the composition and origin of this by-product.

Diagnostic performance of contrast-enhanced ultrasound in diagnosing hepatic artery occlusion after liver transplantation: A systematic review and meta-analysis.

INTRODUCTION: Hepatic artery occlusion (HAO) is a significant complication post-liver transplantation. Doppler ultrasound (DUS) has been widely used as an initial screening test for detecting HAO; however, its performance is often not sufficient. Although other diagnostic tests such as computed tomography angiography (CTA), magnetic resonance angiography (MRA), and angiogram are more accurate, they are invasive and have several limitations. Contrast-enhanced ultrasound (CEUS) is an emerging tool for detecting HAO; however, the results from previous studies were limited due to a small number of patients. Therefore, we aimed to evaluate its performance by performing a meta-analysis. METHOD: We performed a systemic review and meta-analysis of studies evaluating the performance of CEUS for the detection of HAO in an adult population. A literature search of EMBASE, Scopus, CINAHL, and Medline was conducted through March 2022. Pooled sensitivity, specificity, log diagnostic odd ratio (LDOR), and area under summary receiver operating curve (AUC) were calculated. Publication bias was assessed by Deeks' funnel plot. RESULT: Eight studies were included, with 434 CEUS performed. Using a combination of CTA, MRA, angiography, clinical follow-up, and surgery as the gold standard, the sensitivity, specificity, and LDOR of CEUS for detection of HAO were .969 (.938, .996), .991 (.981, 1.001), and 5.732 (4.539, 6.926), respectively. AUC was .959. The heterogeneity between studies appeared universally low, and no significant publication bias was found (p = .44). CONCLUSION: CEUS appeared to have an excellent performance for the detection of HAO and could be considered as an alternative when DUS is non-diagnostic or when CTA, MRA, and angiogram are not feasible.

Workplace bullying and sexual harassment among general surgery residents in Colombia / Acoso laboral y sexual en residentes de cirugía general en Colombia

INTRODUCTION: Workplace bullying and sexual harassment are concerns among general surgery residents in Colombia. OBJETIVE: To explore the prevalence and impact of workplace bullying and sexual harassment incidents among general surgery residents in Colombia. MATERIALS AND METHODS: This nationwide study was conducted in 2020. Residents selfrated their exposure to workplace bullying and to sexual harassment in the forms of gender harassment, unwanted sexual attention, and sexual coercion. We analyzed demographic variables, perpetrator's characteristics, and differences between victims and non-victims. RESULTS: The study included 302 residents. It found that 49% of general surgery residents in Colombia suffered from workplace bullying and 14.9% experienced sexual harassment. The main forms of sexual harassment were gender harassment (47%) and unwanted sexual attention (47%). Women reported significantly higher rates of being sexually harassed. Surgeons were the main perpetrators of sexual harassment. CONCLUSIONS: Workplace bullying and sexual harassment are frequent events in general surgery residency in Colombia. These findings suggest the need for interventions to improve the educational culture of surgical departments and decrease the prevalence of these behaviors.

Introducción: El acoso laboral y el acoso sexual son preocupaciones en la formación quirúrgica. Objetivo: Exploramos la magnitud de estos problemas entre los residentes de cirugía general en Colombia. Materiales y métodos: se realizó un estudio nacional en junio de 2020. Los residentes autoevaluaron su exposición a la intimidación y el acoso sexual en forma de acoso de género, atención sexual no deseada y coerción sexual. Se analizaron variables demográficas y perpetradores entre víctimas y no víctimas. Resultados: Se incluyeron un total de 302 residentes. Las tasas de acoso laboral y sexual fueron del 49% y 14,9%, respectivamente. Las principales formas de acoso sexual correspondieron al acoso de género (47%) y la atención sexual no deseada (47%). El acoso sexual fue significativamente mayor entre las mujeres. Los cirujanos fueron los principales perpetradores. Conclusiones: El acoso laboral y el acoso sexual son frecuentes en la formación quirúrgica en Colombia. Estos hallazgos conducen a intervenciones para mejorar la cultura educativa de los departamentos quirúrgicos para disminuir la prevalencia de estos comportamientos.

Workplace bullying and sexual harassment among general surgery residents in Colombia / Acoso laboral y sexual en residentes de cirugía general en Colombia

Introduction. Workplace bullying and sexual harassment are concerns among general surgery residents in Colombia. Objective. To explore the prevalence and impact of workplace bullying and sexual harassment incidents among general surgery residents in Colombia. Materials and methods. This nationwide study was conducted in 2020. Residents selfrated their exposure to workplace bullying and to sexual harassment in the forms of gender harassment, unwanted sexual attention, and sexual coercion. We analyzed demographic variables, perpetrator's characteristics, and differences between victims and non-victims. Results. The study included 302 residents. It found that 49% of general surgery residents in Colombia suffered from workplace bullying and 14.9% experienced sexual harassment. The main forms of sexual harassment were gender harassment (47%) and unwanted sexual attention (47%). Women reported significantly higher rates of being sexually harassed. Surgeons were the main perpetrators of sexual harassment. Conclusions. Workplace bullying and sexual harassment are frequent events in general surgery residency in Colombia. These findings suggest the need for interventions to improve the educational culture of surgical departments and decrease the prevalence of these behaviors.

Introducción. El acoso laboral y el acoso sexual son preocupaciones en la formación quirúrgica. Objetivo. Exploramos la magnitud de estos problemas entre los residentes de cirugía general en Colombia. Materiales y métodos. Se realizó un estudio nacional en junio de 2020. Los residentes autoevaluaron su exposición a la intimidación y el acoso sexual en forma de acoso de género, atención sexual no deseada y coerción sexual. Se analizaron variables demográficas y perpetradores entre víctimas y no víctimas. Resultados. Se incluyeron un total de 302 residentes. Las tasas de acoso laboral y sexual fueron del 49% y 14,9%, respectivamente. Las principales formas de acoso sexual correspondieron al acoso de género (47%) y la atención sexual no deseada (47%). El acoso sexual fue significativamente mayor entre las mujeres. Los cirujanos fueron los principales perpetradores. Conclusiones. El acoso laboral y el acoso sexual son frecuentes en la formación quirúrgica en Colombia. Estos hallazgos conducen a intervenciones para mejorar la cultura educativa de los departamentos quirúrgicos para disminuir la prevalencia de estos comportamientos.

Evaluation of ocular blood flow in the assessment of symptomatic carotid stenosis.

BACKGROUND AND PURPOSE: The degree of internal carotid artery (ICA) stenosis determined by criteria from the North American Symptomatic Carotid Endarterectomy Trial (NASCET) is not the most accurate index to assess distal flow compromise. Distal ICA perfusion is also determined by factors such as tandem carotid stenosis and collateral circulation. Quantification of end-organ ocular perfusion using non-invasive laser speckle flowgraphy (LSFG) may provide insights into distal ICA flow. This study prospectively assessed the degree of ICA flow using LSFG. METHODS: Eighteen patients with symptomatic carotid stenosis underwent LSFG evaluation. LSFG was used to extract ocular blood flow metrics recorded simultaneously in the retina, choroid, and optic nerve head. The following ocular flow parameters were measured with LSFG: mean blur rate (MBR), flow acceleration index (FAI), and rising rate (RR). Syngo iFlow perfusion imaging was used to objectively quantify contrast flow in the ICA and brain parenchyma during digital subtraction angiography. Time to peak (TTP) and contrast delay were extracted from seven different regions of interest (ROIs). RESULTS: MBR, FAI, and RR were correlated with NASCET degree of stenosis. FAI and RR also improved after stenting. TTP improved after stenting in three ROIs. A moderate negative correlation was observed between FAI and contrast delay. CONCLUSIONS: LSFG non-invasively quantifies end-organ blood flow distal to the ICA origin. LSFG metrics have the potential to quantify end-organ perfusion and determine if a proximal carotid stenosis is symptomatic.

Transgastric laparoscopic polypectomy in giant gastric polyps not susceptible of endoscopic management: novel surgical technique and case series.

BACKGROUND: The identification of gastric polyps incidentally in endoscopies of the upper digestive tract has increased its incidence, varying between 0.5% and 23%. 10% of these polyps have symptoms, 40% are hyperplastic. We allow ourselves to propose a laparoscopic technique for the management of giant hyperplastic polyps associated with a pyloric syndrome, not susceptible to endoscopic resection. METHOD: A series of patients approached by laparoscopic transgastric polypectomy due to the giant gastric polyps associated with pyloric syndrome, in Bogotá, Colombia, from January 2015 to December 2018. RESULTS: Seven patients, 85% female, with an average age of 51 years, who were admitted for pyloric syndrome and were taken to laparoscopic management, with an average surgical time of 42 min, intraoperative bleeding 7-8 cc, tolerance to the oral route 24 hours, no conversion, without mortality. CONCLUSIONS: Transgastric polypectomy for the management of benign giant gastric polyps that cannot be resected endoscopically turns out to be a feasible method, with a low rate of complications and without mortality.

ANTECEDENTES: La identificación de pólipos gástricos de manera incidental en endoscopias de vías digestivas altas ha aumentado su incidencia, que varía entre el 0.5% y el 23%. El 10% de estos pólipos presentan síntomas y el 40% son hiperplásicos. Nos permitimos proponer una técnica laparoscópica para el manejo de los pólipos hiperplásicos gigantes asociados a síndrome pilórico no susceptibles de resección endoscópica. MÉTODO: Serie de pacientes llevados a polipectomía transgástrica laparoscópica por hallazgo de pólipos gástricos gigantes asociados a síndrome pilórico, en Bogotá, Colombia, de enero de 2015 a diciembre de 2018. RESULTADOS: Un total de siete pacientes, el 85% de sexo femenino, con edad promedio de 51 años, ingresaron por síndrome pilórico y fueron llevados a manejo laparoscópico, con un tiempo quirúrgico promedio de 42 minutos, sangrado intraoperatorio de 7-8 cc, tolerancia a la vía oral a las 24 horas, no conversión, sin mortalidad. CONCLUSIONES: La polipectomía transgástrica para el manejo de pólipos gástricos gigantes benignos que no pueden ser resecados por vía endoscópica resulta ser un método factible, con una baja tasa de complicaciones y sin mortalidad.

Utility of repeat colonoscopy within 1 year: a patient-level analysis.

Patients undergo colonoscopies for colorectal cancer screening and for the evaluation of gastrointestinal symptoms. Analysis of large administrative databases has demonstrated that some patients undergo repeat colonoscopies at intervals inconsistent with current recommendations, but these studies do not provide patient-level details. The medical records of 110 patients undergoing repeat colonoscopies within 1 year of their index colonoscopies at a tertiary care hospital-based endoscopy center were retrospectively reviewed to determine patient demographics, gastrointestinal symptoms, and endoscopic findings. Thirty-five patients had poor bowel preparations, and 11 patients had a history of colorectal cancer. Thirty-four patients had polyps identified during their index colonoscopies, and 28 patients had no polyps identified during their index colonoscopies. Eleven patients in the nonpolyp group had new endoscopic findings identified during the repeat colonoscopies. Twenty patients who had polyps identified on their index colonoscopies had 44 polyps identified on repeat colonoscopies. Repeat colonoscopies within 1 year occurred relatively infrequently in this endoscopy center. Indications included poor bowel preparation with incomplete studies, colonic polyps with incomplete resection, multiple polyps resulting in the possibility of missed polyps, and new gastrointestinal symptoms.