Abdominal X-ray Imaging Research Articles

Neodymium magnets migrated into an internal supravesical hernia: a rare case of foreign body ingestion in children

BackgroundForeign body (FB) ingestion is a common event in children. The management of the ingested FB depends on the location, type, number, size of the FBs, patient age, and symptoms. Although most FBs pass spontaneously through the gastrointestinal tract without causing serious injuries, the ingestion of multiple high-powered magnetic pieces, especially neodymium magnets (NMs) increases the risks of morbidity and mortality. Supravesical hernia (SH) is rarely occurs in children, and few studies have reported SH in pediatric patients. We report an extremely rare case of ingested NMs that migrated into an internal SH in a pediatric patient.Case presentationA 3-year-old boy who had accidentally swallowed two NMs 3 days ago presented with vomiting and lower abdominal pain. X-ray imaging and computed tomography (CT) suspected the presence of a 1.0-cm radiopaque FB located in the terminal ileum dorsal side of the bladder. Although his abdominal pain was gradually getting better after oral feeding, repeat abdominal X-ray imaging showed that the FB was in a stagnant in position. Therefore, surgical intervention was planned to remove the FB 1 week after his admission. Under general anesthesia, laparoscopic and fluoroscopic examinations were performed and the cecum was found adhered to the retroperitoneum between the right medial umbilical fold and the right wall of the urinary bladder. The FB was presumed to be located at the tip of the incarcerated cecum in the retroperitoneal space. Peritoneum incision was started near the medial inguinal fossa, and the Retzius space was opened in a manner similar to the transabdominal pre-peritoneal approach for inguinal hernia repair. Consequently, the patient was diagnosed with internal SH with FB migration. The incarcerated cecum was pulled out, which revealed intestinal wall perforation. The FB remained in the retroperitoneal space in the pelvic cavity. The FB was easily removed using intestinal forceps and identified as combined two NMs. The postoperative course was good, and the patient was discharged on postoperative day 5.ConclusionsWe experienced an extremely rare case of a pediatric patient who swallowed multiple NMs that migrated into an internal SH, and the laparoscopic minimally invasive removal was successful.

Parieto-occipital ERP indicators of gut mechanosensation in humans

Understanding the neural processes governing the human gut-brain connection has been challenging due to the inaccessibility of the body’s interior. Here, we investigated neural responses to gastrointestinal sensation using a minimally invasive mechanosensory probe by quantifying brain, stomach, and perceptual responses following the ingestion of a vibrating capsule. Participants successfully perceived capsule stimulation under two vibration conditions (normal and enhanced), as evidenced by above chance accuracy scores. Perceptual accuracy improved significantly during the enhanced relative to normal stimulation, which was associated with faster stimulation detection and reduced reaction time variability. Capsule stimulation induced late neural responses in parieto-occipital electrodes near the midline. Moreover, these ‘gastric evoked potentials’ showed intensity-dependent increases in amplitude and were significantly correlated with perceptual accuracy. Our results replicated in a separate experiment, and abdominal X-ray imaging localized most capsule stimulations to the gastroduodenal segments. Combined with our prior observation that a Bayesian model is capable of estimating computational parameters of gut-brain mechanosensation, these findings highlight a unique form of enterically-focused sensory monitoring within the human brain, with implications for understanding gut feelings and gut-brain interactions in healthy and clinical populations.

AB129. SOH23ABS_101. The evaluation of compliance with iRefer guidelines for abdominal imaging and the discovery of new pathologic findings on the abdominal X-ray (AXR) performed

Background: Attendance of adult patients to the emergency department (ED) with acute abdominal pain is a frequent event. Abdominal X-ray (AXR) imaging is commonly the choice of investigation but previous studies have suggested that AXR plays a small role in assessment because of its low diagnostic yield and limited contribution to direct clinical decision making. As per iRefer radiology guideline, there are four indications of requesting an X-ray that are shown to be clinically relevant and thus minimizing the unnecessary radiation in non-indicated tests: Clinical suspicion of bowel obstruction, foreign body ingestion, renal colic and acute exacerbation of inflammatory bowel disease.

Urinary Stones Segmentation in Abdominal X-Ray Images Using Cascaded U-Net Pipeline With Stone-Embedding Augmentation and Lesion-Size Reweighting Approach

In this research, we proposed a two-stage pipeline for segmenting urinary stones. The first stage U-Net generated the map localizing the urinary organs in full abdominal x-ray images. Then, this map was used for creating partitioned images input to the second stage U-Net to reduce class imbalance and was also used in stone-embedding augmentation to increase a number of training data. The U-Net model was trained with the combination of real stone-contained images and synthesized stone-embedded images to segment urinary stones on the partitioned input images. In addition, we proposed to use an inverse weighting method in the focal Tversky loss function in order to rebalance lesion size. The U-Net model using our proposed pipeline produced a 71.28% pixel-wise <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> score and a 69.82% region-wise <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> score, which were higher than 2.88% and 7.63%, respectively, by a baseline method. Experimental results showed that the proposed method improved urinary stone segmentation results, especially for small stones and stones in uncommon locations.

Peritonite meconial relacionada à doença hepática materna: relato de caso

Meconium peritonitis has been associated with cystic fibrosis, congenital infections, and bowel disease. A growing number of reports have also associated it with maternal liver disease. This report describes the case of a preterm newborn with meconium peritonitis born from a woman with liver disease and presents a review of the literature on the subject. A male preterm newborn weighing 2595g was admitted to the Neonatal Intermediate Care Unit due to an obstetric ultrasound scan performed at 31 weeks and 3 days of gestation showing calcifications of various sizes throughout his abdomen. His mother had autoimmune hepatitis and sclerosing cholangitis. Postnatal abdominal x-ray images showed calcifications in the liver and right paracolic gutter and abdomen ultrasound scans showed large peritoneal calcifications in the hepatic and splenic capsules and in the pouch of Morrison, in addition to calcifications in the right scrotum.

The use of carglumic acid in hyperammonemia secondary to bacterial overgrowth in lately diagnosed Hirschsprung disease

Hirschsprung disease is associated with significant bacterial proliferation and colonic dysbiosis leading to life threating hyperammonemia. In this report, we highlight the use of carglumic acid; a synthetic ammonia scavenger in hyperammonemia secondary to bacterial overgrowth in Hirschsprung disease. A 33-month-old female patient with a history of delayed passage of meconium presented with constipation, vomiting, abdominal distention, and an altered level of consciousness. Physical examination revealed a puffy face, non-pitting edema and distended, rigid, non-tender abdomen with faint bowel sounds. Further investigations showed anemia, hypoalbuminemia, hyperammonemia, prolonged prothrombin time and partial thromboplastin time alongside a normal liver enzymes panel. Abdominal X-ray imaging revealed severely dilated bowel loops reassembling obstruction and impending perforation. A lower gastrointestinal contrast study revealed a classical picture of Hirschsprung disease with a transition zone at the rectosigmoid. Urgent surgical intervention was performed resecting the distended part of the sigmoid colon applying an end colostomy with a distal end closure was done. The diagnosis of Hirschsprung disease was confirmed histopathologically. The patient was started on oral antibiotics and carglumic acid 600 mg q12h for the state of hyperammonemia and the unavailability of sodium benzoate. After its administration the ammonia levels dropped from 302 μmol/L to a nadir of 46 μmol/L. Taking into consideration our case carglumic acid proved to be an effective ammonia scavenger in such cases.

One-year safety and effectiveness of the Alto abdominal stent graft in the ELEVATE IDE trial

ObjectiveThis study reports the results of a prospective, multicenter trial designed to evaluate the safety and effectiveness of the polymer based Endologix Alto Stent Graft System in treating abdominal aortic aneurysms (AAAs), with sealing 7 mm below the top of the fabric in aortic neck diameters from 16 to 30 mm. MethodsSeventy-five patients were treated with Alto devices between March 2017 and February 2018 in 16 centers in the United States for infrarenal AAAs (max diameter ≥5.0 cm in diameter or size increase by 0.5 cm in 6 months or diameter ≥1.5 times the adjacent normal aorta). Patients were followed for 30 days, 6 months, and 1 year by clinical evaluation and computed tomography and abdominal x-ray imaging. Treatment success was defined as technical success and freedom from AAA enlargement, migration, type I or III endoleak, AAA rupture or surgical conversion, stent graft stenosis, occlusion, kink, thromboembolic events, and stent fracture attributable to the device requiring secondary intervention through 12 months. Preoperative characteristics, perioperative variables, follow-up clinical evaluations, and radiographic examination results through the first 1 year were analyzed. ResultsThe mean patient age was 73 years, with 93% of patients being male. The 30-day major adverse event rate was 5.3%. At 1 year, the primary endpoint was met with a treatment success rate of 96.7%. Through 1-year post-treatment, all-cause mortality was 4.0%. No AAA-related mortality occurred. AAA enlargement was 1.6%, type I endoleak rate was 1.4%, with 100% freedom from type III endoleaks, device migration, device fracture, stent occlusion, or AAA rupture. The device-related secondary intervention rate was 2.7%. ConclusionsThis prospective study demonstrates the Endologix Alto is safe and effective in treating AAAs with appropriate anatomy at 1 year. The safety endpoint is met by a 5.3% 30-day major adverse event rate, whereas the effectiveness endpoint is met by a treatment success rate of 96%.

Imaging in a Patient with Recent Cesarean Section and Acute Right Lower Quadrant Pain Due to Torsion OF Ovarian Teratoma – Diagnostic Challenges

Abstract Introduction: Ovarian teratomas are common pathology, manifested by various clinical and imaging findings, as well as different complications. The differential diagnosis can be challenging in cases with acute right lower quadrant (ARLQ) pain. Aim: to present typical imaging findings in this pathology and possible pitfalls in their interpretation, focusing on a case with torsion of ovarian teratoma. Methods: We describe a case of a 41-yearold female patient with a recent Cesarean section and a history of kidney stones and previous appendectomy, who presented with acute right lower quadrant pain. Her pregnancy was uneventful. The plain abdominal X-ray, ultrasound and computer tomography images revealed air-fluid levels, a fecaloma in the ascending colon and a pelvic mass of unclear origin, misinterpreted as a foreign body or postoperative complication. Results: The patient underwent a surgical procedure that revealed an ovarian teratoma torsion. A right adnexectomy was performed. The diagnosis was confirmed by histological examination. Conclusion: An excellent knowledge of the imaging findings in the diseases presented with ARLQ pain is of vital importance, however patient’s co-morbidities and recent surgical procedures may hinder the correct interpretation.

Method of determining technique from weight and height to achieve targeted detector exposures in portable chest and abdominal digital radiography.

This study presents a methodology to develop an X‐ray technique chart for portable chest and abdomen imaging which utilizes patient data available in the modality worklist (MWL) to reliably achieve a predetermined exposure index (EI) at the detector for any patient size. The method assumes a correlation between the patients’ tissue equivalent thickness and the square root of the ratio of the patient's weight to height. To assess variability in detector exposures, the EI statistics for 75 chest examinations and 99 abdominal portable X‐ray images acquired with the new technique chart were compared to those from a single portable unit (chest: 3877 images; abdomen: 200 images) using a conventional technique chart with three patient sizes, and to a stationary radiography room utilizing automatic exposure control (AEC) (chest: 360 images; abdomen: 112 images). The results showed that when using the new technique chart on a group of portable units, the variability in EI was significantly reduced (p < 0.01) for both AP chest and AP abdomen images compared to the single portable using a standard technique chart with three patient sizes. The variability in EI for the images acquired with the new chart was comparable to the stationary X‐ray room with an AEC system (p > 0.05). This method could be used to streamline the entire imaging chain by automatically selecting an X‐ray technique based on patient demographic information contained in the MWL to provide higher quality examinations to clinicians by eliminating outliers. In addition, patient height and weight can be used to estimate the patients’ tissue equivalent thickness.

Improvement of Urinary Stone Segmentation Using GAN-Based Urinary Stones Inpainting Augmentation

A urinary stone is a type of abnormality that occurs frequently in the urinary system. An automated segmentation of urinary stones is important for assisting medical doctors in early diagnosis and further treatment. While deep learning techniques are effective for image segmentation, they require a large number of datasets to achieve high accuracy. We proposed a GAN-based augmentation technique for creating synthetic images based on stone and non-stone mask inputs in order to improve the segmentation network’s performance by increasing the number and diversity of training data. The synthetic training images were generated from stone-contained images and stone-free images using existing stone ground truth and corresponding stone location maps, respectively. To segment urinary stones from full abdominal x-ray images, we trained the MultiResUnet model using both original stone-contained and our proposed synthetic samples. The proposed method obtained a 69.59% pixel-wise <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> score and a 68.14% region-wise <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> score, which achieved an improvement of 2.12% and 2.13%, respectively, over a model trained with only the original stone-contained dataset.

Quality by Design Enabled Anti-hypertensive Floating Drug Delivery System by Risk Assessment and Design of Experiment (DoE) - In Vitro - In Vivo Correlation Studies

Background: The present research aimed to develop and optimize extended-release floating tablets of Sacubitril and Valsartan by Quality by Design (QbD) approach. Methods: Risk analysis by formulation assessment and process parameters showed that optimizing the levels of the polymer will minimize the high risk to meet the target profile. A two (2) level three (3) full factorial experimental design along with midpoints was carefully chosen for optimization and statistical analysis. Based on the literature, the independent and dependent variables were selected. Results: HPMC K100, Carbopol 934P had a positive effect, Ethyl cellulose with the negative effect on Floating time, Drug release at 2 h, Drug release at 12 h and, t50% responses. Drug release kinetics followed the first-order release with Higuchi and fickian diffusion. Contour and overlay plots were utilized for an assortment of design space and optimized formula. ANOVA results of all the factors exhibited significance at p &lt; 0.05. Abdominal X-ray imaging of the optimized tablets on a healthy rabbit’s stomach confirmed the floating behavior for more than 12 h. In vivo pharmacokinetic studies in rabbits have shown that the optimized formulation exhibited prolonged and extended drug release with improved Cmax, tmax, AUCo-t, and t1/2 of test product when compared to marketed product. IVIVC model was developed by using dissolution data of in vitro and pharmacokinetics data of in-vivo by deconvolution method (Wagner-Nelson method). Conclusion: The Quality by Design implementation in the formulation and optimization abridged the number of trials to produce a cost-effective formula. In vivo studies have demonstrated that the formula was successfully developed with extended floating time (12 h) and drug release by risk analysis and experimental designs. Level A correlation was observed, which confirmed a good correlation between in vitro and in vivo data.

Design and Characterization of Combinational Domperidone-Famotidine Floating Drug Delivery System - In vitro and In vivo studies

Introduction: The drawbacks assosiated with oral administration of drugscan be controlled or minimized by gastro retentive formulations that remain buoyant within the stomach for an extended time by providing prolonged gastric retention and releasethe drug in an exceedingly extended manner thereby improving bioavailability. The current research was to develop and optimize Domperidone and Famotidine floating tablets with extended release by Quality by Design approach.&#x0D; Method: Based on QTPP (Quality Target Product Profile), CQAs (Critical Quality Attributes)wereidentified. Risk analysis by the evaluation of formulation and process parameters showed that optimizing the levels of polymers could reduce high risk to achieve the target profile. A 23factor experimental design with midpoints was selected for statistical analysis and optimization.&#x0D; Results: HPMC K100 and Carbopol 934P had a positive effect while ethyl cellulose demonstrated a negative effect on the selected responses. Drug release kinetics followed the first-order release with Higuchi diffusion and Fickian diffusion. Optimized formula satisfying all the required parameters was selected and evaluated. The predicted response values were in close agreement with experimental response values. Abdominal X-ray imaging after oral administration of the tablets on a healthy rabbit’s stomach confirmed the extended floating behavior with shorter lag time. In vivo, pharmacokinetic studies in rabbits revealed that the optimized formulation exhibited prolonged drug release with enhanced Cmax, tmax, AUCo-t, and t1/2 of an optimized product when compared to the marketed product.&#x0D; Conclusions: It has been concluded that the application of Quality by Design in the formulation and optimization reduced the number of trials to produce a cost-effective formula.

Radiographic Imaging to Evaluate Food Passage Rate in Preterm Piglets as a Model for Preterm Infants.

Objectives and study: Gut motility in infants mature with increasing post-menstrual age and is affected by numerous hormonal, immunological and nutritional factors. However, it remains unclear how age and diet influence gut motility and its relation to feeding intolerance and gastric residuals in preterm neonates. Using preterm piglets as a model for infants, we investigated if contrast passage rate, as determined by X-ray contrast imaging, is affected by gestational age at birth, advancing postnatal age and different milk diets.Methods: Contrast passage rate was evaluated using serial abdominal X-ray imaging on postnatal day 4 and 18 in preterm and near-term piglets fed infant formula, colostrum or intact bovine milk, with or without added fortifier (total n = 140).Results: Preterm piglets had a faster small intestinal passage rate of contrast solution at day 4 of life than near-term piglets (SIEmpty, hazard ratio (HR): 0.52, 95%CI [0.15, 0.88], p < 0.01). Formula fed piglets at day 4 had a faster passage rate of contrast to caecum (ToCecum, HR: 0.61, 95%CI [0.25,0.96], p = 0.03), and through the colon region (CaecumToRectum, p < 0.05, day 4) than colostrum fed preterm piglets. The time for contrast to leave the stomach, and passage through the colon in day 4 preterm piglets were slower than in older piglets at day 18 (both, p < 0.05). Adding a nutrient fortifier increased body growth, gastric residuals, intestinal length and weight, but did not affect any of the observed passage rates of the contrast solution.Conclusion: Serial X-ray contrast imaging is a feasible method to assess food passage rate in preterm piglets. Contrast passage rate through different gut segments is affected by gestational age at birth, postnatal age, and milk diet. The preterm piglet could be a good model to investigate clinical and dietary factors that support maturation of gut motility and thereby feeding tolerance and gut health in preterm infants.

Automatic detection of body packing in abdominal X-ray images

Abstract Objectives It is difficult and time-consuming to detect narcotic drugs concealed within human bodies by visual assessment of X-ray images . This study aimed to describe a method for automatic detection of concealed drugs based on abdominal X-ray transmission images. Methods 43 X-ray images from suspects during border inspection are used in this study. Image features were extracted from both the directional fractal dimension and the gray level to form feature vectors. An unbalanced data preprocessing method was implemented before training to minimize the false alarms. A support vector machine model was applied for training and final classification. Results The proposed method yielded a 97.7% classification accuracy and a 96.1% sensitivity in 43 image cases, which were superior to the method without unbalanced data process resulting in a 95.3% classification accuracy and a 92.3% sensitivity. Conclusions This fast, computer-based X-ray transmission image processing method can be used in the field inspection for rapid, automatic detection of body packing.

Bile Stained Vomiting in Neonates: Radiological and Surgical Correlation

Abstract Background: Bile stained vomiting in neonates is fre-quently encountered clinical symptom in pediatric practice. It is very important to examine them and exclude or confirm surgical condition. Aim of Study: This work is advocated to illustrate the spectrum of radiological findings in neonates with bile stained vomiting and correlate them with surgical data. Patients and Methods: All included neonates presented with bile stained vomiting were referred to Diagnostic Radi-ology Department at Sohag University Hospitals. Abdominal X-ray, abdominal ultrasound, Doppler and contrast imaging were done to identify the surgical causes of bilious vomiting with clinical and surgical correlation. The patients were treated surgically in Pediatric Surgery Unit at Sohag University Hospitals. Patients with bilious vomiting caused by non-surgical causes were excluded. Results: Our study included 31 bile stained vomiting neonates with age range from one day to 30 days and with male sex predominance (17 boys and 14 girls). Four patients were found to have necrotizing enterocolitis, 5 cases with mid-gut volvulus, 3 cases were found to have distal duodenal atresia, one case with duodenal stenosis, 5 cases with jejunal atresia, 4 cases with ileal atresia, 2 cases with congenital bands, 2 cases with complicated congenital inguinal hernias, 2 cases with meconium plug, 1 case with neonatal intussus-ception, 1 case with iatrogenic clamping of umbilical hernia and 1 case with anal stenosis. Imaging techniques were diagnostic in most of the cases and correlate with surgical findings. Conclusion: Bile stained vomiting in the newborn usually indicative of surgical conditions and needs surgical consulta-tion. Imaging studies are of utmost important to investigate and diagnose these cases before surgery.

Review of the need for Abdominal X-rays in the diagnosis of acute abdominal pain- An Emergency Department Perspective

There has been a significant debate over the use of AXR as an adjunct to the diagnosis of the acute abdomen. There are only a few numbers of clinical indications for this modality of imaging, and there has been a concerted effort from the Royal College of Radiologist (RCR) to ensure that there is a reduction in the number of AXR being performed. Evidence Acquisition To study the most frequent presentation of abdominal pain to accident and emergency requiring abdominal X-ray imaging. To understand the correlation between the clinical indication for the imaging and the subsequent findings as reported by the Radiologist. To assess whether further imaging was done and if these yielded any benefit. To assess for change once interventions were instituted. Method Phase 1-100 patients were selected at random from the patients presenting with abdominal pain to Ayr Accident and Emergency during July 2014. As previously stated, the indication for the AXR was explored with any follow-up imaging that was performed. Phase 2 was carried out for the patients presenting with abdominal pain in months of December 2019- January 2020. The same methodology was used with 100 patients to investigate the indications for AXR imaging as per Phase 1, any significant findings in relation to the clinical query and the further use of other imaging modalities. The clinical indications for the imaging were also studied and audited against the IRMER and the RCR guidelines, taking into consideration any changes in the guidelines from the time of Phase 1. Results/Measures Phase1 - It was seen than in 56 cases out of the 100 cases AXR was the only imaging done with no follow-up imaging. In 44 cases there was follow up imaging with other modalities. It was also noted that only in 20 cases the indication matched with the radiological findings whilst in the vast 80% of cases there was no correlation between the indication and imaging findings. Phase 2- As can be seen, there was an improvement in the indication put in the request with a significant reduction of 7% in the? perforation? obstruction as an indication. There was also a significant reduction in the number of AXR done for renal calculi related cases (11% vs 4%). There was, however, increases in both surgery-related and acute onset abdominal pain-related cases. One of the main limitations of this form of comparison is that this only represents a cohort of patients and may not be representative of the actual trend in requesting AXR. Discussion The practice of medicine is ever-changing, and the realities of medico-legal consequences are becoming part of the way we are practising today. The tendency to over investigate and practice defensively is increasing, and this is shown clearly through this audit study Conclusion There can be more that can be done to reduce the number of AXR that are done for abdominal pain. It should be noted that there is no role for AXR in the diagnosis of undifferentiated abdominal pain. All clinicians requesting AXR should review the need for the same prior to proceeding due to the unnecessary exposure in the vast majority of cases.

Use of X-ray to Assess Fecal Loading in Patients with Gastrointestinal Symptoms.

There is currently no gold standard for evaluating stool burden in the colon for patients with gastrointestinal symptoms. We aim to examine the relationship between fecal loading on single view abdominal X-ray imaging and gastrointestinal symptoms such as constipation, diarrhea, bloating, and accidental bowel leakage in adult outpatients. This retrospective, cross-sectional study examined patients seen at University of Michigan from 2005 to 2017. Chart review of demographic information, reported gastrointestinal symptoms, past medical history, and abdominal radiographic imaging was performed. Bivariate analysis was performed to assess associations between these characteristics and fecal loading. Factors independently associated with fecal loading were identified using logistic regression. Significance was established at p < 0.05. In total, 319 patients who had an X-ray were included in the final analysis, with 84.0% demonstrating fecal loading on the initial X-ray and most reporting constipation as a symptom (n = 214, 84.3%, p = 0.0334). In logistic regression, a chief complaint of constipation had higher odds of being associated with fecal loading on X-ray compared to diarrhea (adjusted OR 6.41; CI 1.51-27.24, p = 0.0118). Bloating as a reported symptom was statistically significant with an adjusted OR of 2.56 (CI 1.10-5.96, p = 0.0286). Constipation (as a chief complaint) and bloating (as a symptom) were associated with fecal loading on X-ray imaging, while accidental bowel leakage and diarrhea were not.

The ideal position of the peritoneal dialysis catheter is not always ideal.

Peritoneal catheter dysfunction is a frequent complication of peritoneal dialysis (PD). Traditionally, dysfunction has been attributed to catheter malposition, but whether the location of the catheter tip in the small pelvis really determines proper function is unclear. We reviewed 900 abdominal X-ray images of PD patients from a 7-year period in two PD units that use different catheter types (straight and Swan Neck Curled). In 52% of the images, the dialysis catheter tip was located in the ideal position in the small pelvis and in 48% in other sites. Peritoneal catheter function was normal at the time of imaging in 87% of those with ideal catheter tip position, and in 74% of those with other than ideal position. The tip was located in small pelvis in 35% of images performed during catheter dysfunction and in 56% of those performed during normal catheter function. There were no differences between two catheter types. The positive predictive value of abdominal X-ray images to predict catheter function was 26%, and the negative predictive value 87%. We also found a significant positive correlation between polycystic kidney disease and normal catheter function. In contrast, obese patients were more likely to have catheter malfunction. Previous abdominal surgery was not associated with catheter dysfunction. Our data showed a higher probability of normal function of peritoneal catheters whose tips were located in the small pelvis. However, also malpositioned catheters generally functioned well, and malpositioning of the PD catheter did not in itself explain its malfunction.

Development of a gastroretentive delivery system for acyclovir by 3D printing technology and its in vivo pharmacokinetic evaluation in Beagle dogs.

Gastroretentive (GR) systems are designed to prolong gastric residence time to allow sustained absorption and improve the oral bioavailability of drugs with a narrow absorption window in the upper part of the gastrointestinal tract. The present study aimed to develop a GR system for acyclovir using 3D printing technology and evaluate its in vivo pharmacokinetics after oral administration in Beagle dogs. The system consisted of a gastro-floating device, which can float in the gastric fluid, prepared by a fused deposition modeling 3D printer and conventional acyclovir sustained-release (SR) tablet. The acyclovir SR tablet was inserted to the floating device to allow sustained release of the drug in the stomach. The buoyancy and sustained-release property of the developed GR system were determined using an in vitro dissolution test, in vivo pharmacokinetic study, and abdominal X-ray imaging in Beagle dogs. The in vivo dissolution profiles of the GR system were also predicted based on the in vivo pharmacokinetic data using a population pharmacokinetic (POP-PK) model. In the dissolution test, the sustained-release characteristic of the GR system was identified with a time corresponding to 80% dissolution (T80) of 2.52 h. Following oral administration of the GR system, the time to reach the maximum concentration (Tmax) of acyclovir was significantly prolonged, whereas the maximum concentration (Cmax) decreased and the area under the curve increased compared with those obtained after the administration of immediate-release and SR tablets, indicating prolonged absorption. By X-ray imaging, we showed that the developed GR system stayed in the stomach for more than 12 h. The POP-PK model successfully described the observed plasma concentration-time data and predicted the in vivo biphasic dissolution profiles of the GR system, which was significantly different from the in vitro dissolution. The developed GR system could be applied to various drugs and had great prospects in the design and development of novel controlled-release formulations.

Acute colonic pseudo-obstruction after cesarean section: a retrospective analysis of 11 cases

Objective To summary the risk factors, clinical characteristics and treatment of acute colonic pseudo-obstruction (ACPO) after cesarean section(CS). Methods The case group enrolled 11 patients who were diagnosed with ACPO after cesarean section in the First Affiliated Hospital of University of Science and Technology of China from January 2006 to January 2018. Another 55 patients without ACPO after CS, performed within two weeks' difference from the case group, were randomly selected as the control group. Clinical data of all subjects were analyzed retrospectively. Potential clinical risk factors were statistically analyzed. T test, Chi-square test and logistic regression analysis were used for statistical analysis. Results In the case group, the abdominal distension presented on 2 d (n=1), 3 d (n=7), 4 d (n=2) and 17 d (n=1) respectively after CS, and all cases experienced abdominal pain and nausea. Vomiting was reported in some cases. Plain abdominal X-ray images revealed pneumocolon with colon pouch. The maximum diameter of cecum was 6 to 12 cm. Air-liquid levels were observed in two patients. All patients underwent fasting, gastrointestinal decompression, intravenous fluid infusion, correction of electrolyte imbalance, hypertonic saline enema and prophylactic antibiotic treatment. The disease condition lasted two to six days in these patients. Conservative treatment was successful in eight patients and failed in the other three who later went for operations. The maximum cecal diameters in the three patients who underwent surgery were all ≥9 cm, among whom one case progressed quickly and laparotomy was tempted to rule out mechanical intestinal obstruction. In this case, the pressure was successfully reduced by placing a thoracic catheter through the anus after the failure of intestinal puncture trying to release the gases. One patient underwent colostomy due to positive signs of peritoneal irritation after a failure of four-day conservative treatment. One patient suffered a relapse after having been treated conservatively for five days, and then underwent surgeries of resection of ileocecum, distal closure of the colon ascendens plus terminal ileostomy due to intestinal perforation. Multivariate logistic regression analysis showed that higher postoperative leukocyte count (OR=1.38, 95%CI: 1.12-1.71, P=0.003) and postoperative body temperature >38 ℃ (OR=6.47, 95%CI: 1.06-39.61, P=0.044) were the risk factors for ACPO after CS. Conclusions Elevated leukocyte count and body temperature >38 ℃ were two high-risk factors for ACPO after CS. ACPO is characterized by acute onset, and the first choice is conservative management. Active surgical treatment would be required if conservative treatment fails, especially when the maximum diameter of the cecum is ≥ 9 cm, which may increase the incidence of intestinal necrosis or perforation. Key words: Cesarean section; Postoperative complications; Colonic pseudo-obstruction; Intestinal perforation