Intra-abdominal Diseases Research Articles

Size-dependent translocation and lymphatic transportation of polymeric nanocarriers post intraperitoneal administration

Intraperitoneal (i.p.) administered nanomedicine has been widely applied in the clinical treatment of intra-abdominal diseases and preclinical pharmacological investigations. However, current understandings about the in vivo fate of i.p.-administered drug remains controversial owing to lack of reliable investigation tools. This work presents a nanoparticle-labeling strategy based on aggregation-caused quenching (ACQ) probes in the second near-infrared (NIR-II) window, which can eliminate the interference of unbound probes and allow for non-invasive tracking of nanoparticles in deep tissues. Our results strongly evidence a size-dependent absorption and biodistribution of the i.p.-administered polymeric nanocarriers (PNs) with particle sizes ranging from 30 to 1000 nm both in vivo and ex vivo, and moreover provide a clear visualization of lymphatic transportation and lymph node retention of integral PNs. Importantly, our findings suggest that small particles (≤30 nm) are favorable in systemic therapies due to their rapid absorption and high concentration (>19 %ID mL−1) in circulation, while large particles (over 1000 nm) are meant for localized treatment of abdominal diseases. Besides, the high retention of 200 nm nanoparticles within lymph nodes indicates their promising role in cancer vaccines and lymphatic diseases including lymph node metastasis.

Multi-omics approach for understanding the response of Bacteroides fragilis to carbapenems

BackgroundThe prevalence of Bacteroides fragilis isolates resistant to first-line beta-lactam drugs is increasing, resulting in reduced treatment efficacy. Investigating the bacterial transcriptome and proteome can uncover links between bacterial genes and resistance mechanisms. In this study, we experimentally assessed in vitro the transcriptional and proteomic profiles of B. fragilis exposed to SICs of meropenem, an effective antimicrobial agent, collected from patients with intra-abdominal diseases at Astana City Hospital, Kazakhstan. MethodsB. fragilis was cultured in brain heart infusion broth and sub-cultured every 48 h for 8 days in media with and without meropenem. Total RNA was extracted from the liquid cultures using a commercial RNeasy mini kit, and strand-specific RNA sequencing (RNA-seq) was performed on the DNBSEQ platform. Raw RNA-seq data were retrieved from BioProject No. PRJNA531645 and uploaded to the NCBI Sequence Read Archive (accession no. SRX22081155). Proteins of B. fragilis were extracted and separated using sodium dodecyl sulphate–polyacrylamide gel electrophoresis, followed by analysis of the eluted peptides using liquid chromatography–tandem mass spectrometry. Cluster analysis utilised the Database for Annotation, Visualisation, and Integrated Discovery. ResultsThe subinhibitory concentration (SIC) of meropenem was determined to be 0.5 μg/L (minimum inhibitory concentration: 1). Mapping of reads to the reference genome identified 2477 expressed genes in all B. fragilis BFR KZ01 samples. Ten differentially expressed genes (DEGs) were common across comparison groups during and post-antibiotic exposure (wMEM vs. MEM2 and MEM2 vs. rMEM8); however, no substantially enriched Gene Ontology terms were identified. The cluster analysis highlighted a significant enrichment cluster (W-0560 oxidoreductase) of DEGs following antibiotic withdrawal. In total, 859 B. fragilis proteins were identified, with the expressions of three proteins, 3-oxoacyl-[acyl carrier protein] reductase, acetyl-CoA carboxylase biotin carboxylase subunit, and beta-ketoacyl-ACP synthase III, being upregulated in the enriched protein folding category. Notably, chaperone proteins such as FKBP-type peptidyl-prolyl cis-trans isomerases (involved in the cis-trans isomerisation of prolyl peptide bonds) and GroES (a co-chaperone functioning with GroEL) were also identified. ConclusionsUnder the influence of low doses of antibiotics defense mechanisms are activated which contribute to the emergence of resistance. These results provide insight into the response of B. fragilis to meropenem exposure, mainly at the SIC, contributing to the understanding bacterial survival strategies under stress conditions.

POSSIBILITIES OF ENDOPORTAL INFUSION THERAPY FOR INTRA-ABDOMINAL SURGICAL INFECTIONS COMPLICATED BY ACUTE INTESTINAL FAILURE

The purpose of this study was to evaluate the effectiveness of EIT for intra-abdominal infections complicated by acute intestinal failure. Materials and Methods: The authors modified the technique of catheterization of the right gastroepiploic vein to conduct prolonged endoportal infusion therapy. The modification allows for easy surgery and successful removal of the catheter upon completion of endoportal infusion therapy. This operation is possible using video laparoscopic access. An antihypoxic agent, an antibiotic, and a hepatoprotector were given as an endoportal bolus. The technique was carried out on 24 patients with various purulent-inflammatory diseases of the abdominal organs complicated by acute intestinal failure. The results were compared with a group of 24 patients treated with traditional methods. Research Results: As a result of the study, it turned out that in the main group, indicators returned to normal according to the systems for assessing the severity of the condition (APACHE II and abdominal index) and signs of intestinal failure (EMFC) on the day 5 of treatment. At the same time, in the comparison group, these changes occurred only on the day 7 of treatment (p≤0.05). The values of enzymes reflecting the state of the intestinal wall, as well as indicators of cellular immunity were normalized by day 3 in the main group, and by day 7 in the comparison group (p≤0.05). Conclusion: The proposed EIT technology can serve as a good supplement to the treatment of patients with intra-abdominal purulent-inflammatory diseases complicated by acute intestinal failure. It prevents bacterial translocation into the portal system and thus reduces the risk of generalized infection and multiple organ failure.

Liver Abscess Caused by Klebsiella Pneumoniae, Series of Cases with Different Management

Abstract We present two cases of liver abscess caused by Klebsiella pneumoniae with different management, one of them resolved under antibiotherapy without theraputic drainage. Klebsiella pneumoniae is a gram-negative, lactose-fermenting, rod-shaped bacterium that is part of natural intestinal flora and one of the common causes of nosocomial infections. The liver is one of the viscera in which abscesses frequently occur and is associated with intraabdominal or hepatobiliary diseases. The first patient was admitted to „Prof. Dr. Agrippa Ionescu” Hospital with sepsis due to liver abcess. The CT examination revealed a liver lesion in segments VI-VII, limited by a hypodense margin with fluid-parafluid content (with maximal axial diameters 54/32 mm), without any other focal hepatic lesions. Laboratory workup revealed neutrophilia and lymphopenia, anemia, trombocytopenia, increased inflammatory syndrome, a high level of procalcitonin and blood cultures positives with Klebsiella pneumoniae sensitive. Based on the information presented, the diagnosis established was liver abscess caused by Klebsiella pneumoniae with favorable outcome under initial empirical antibiotherapy with Vancomycin and Meropenem, de-escalated later to I.V. Ceftriaxone, due to the result of the antibiogram. At the 14 day mark, an abdominal CT reveals a slight dimentional progression. Percutaneous ecographic guided drainage was considered but the patient denied it.The patient was released with the antibiotherapy recomandation of 14 more days of orally administered Cefixime. After 4 weeks of antibiotherapy treatment, the patient is ecographically reassesed. The liver abscess is observed to have achieved complete remission without drainage, despite the classical literature recommended protocol. The second case, a male patient admitted with sepsis due to multiple liver abscess (the largest one 100/50 mm with negative blood cultures and unfavorable outcome, despite maximal empirical therapy. Percutaneous ecographic guided drainage was performed and Klebsiella pneumoniae was isolated from the drainage samples .Under target antibiotherapy with Ertapenem for 4 weeks the outcome was very good with complete resolution of the hepatic lesions. Hepatic abscess is associated with a high mortality rate and several complications, despite its low incidence. Prompt recognition is important for effective management and achieving good outcomes. Usually, the liver abscess is treated by either percutaneous drainage or surgical drainage in combination with antibiotics.The key to succesful outcomes is early diagnosis, institution of appropriate therapy and attentive evolution monitoring.More prospective trials with large cohorts are needed to refine our understanding of this serious condition.

USG and CT-guided cytomorphological profile of FNAC in deep-seated lesions

Abstract Introduction: Ultrasound and computed tomography-guided fine needle aspiration cytology play an important role in the diagnosis of deep-seated lesions such as intra-abdominal and intrathoracic diseases. Objective: To evaluate the efficacy of ultrasound (USG) and computed tomography (CT)-guided FNAC in the diagnosis of abdominal and intrathoracic lesions for one year, from January 2021 to December 2021. Materials And Methods: The study included 58 intraabdominal and 45 intrathoracic lesions. Cytological findings were correlated to clinical and radiographic data to arrive at a definitive diagnosis. Results: Fine needle aspiration cytology was performed at various anatomical sites: liver (24 patients), colon (9 patients), gallbladder (5 patients), ovary (6 cases), spleen (3 cases), mesentery (3 cases), omentum ( 3 cases), cecum (2 cases), pancreas (1 case), subhepatic lesions (1 case), lung (43 cases), mediastinum (2 cases). The most common intra-abdominal disease was metastatic adenocarcinoma of the liver (14 patients), and the most common intrathoracic disease was lung adenocarcinoma (18 patients). Conclusion: Ultrasound and computed tomography-guided fine needle cytology is an excellent method for deep diagnosis in the abdominal and thoracic cavity.

Effects of rhubarb peony decoction combined with antibiotics in treating pediatric periappendiceal abscess.

Rhubarb peony decoction (RPD) is a formula of traditional Chinese medicine that has been widely used to treat intra-abdominal inflammatory diseases. To investigate the therapeutic efficacy of RPD in pediatric periappendiceal abscess, patients who received intravenous antibiotics alone were compared with those treated with intravenous antibiotics combined with RPD. A retrospective review of children with periappendiceal abscess who received conservative treatment in our hospital between January 2013 and April 2022 was performed. The patients were divided into an intravenous antibiotic group (the control group) and an intravenous antibiotic combined with RPD group (the intervention group). Interval appendectomy (IA) was generally performed 10-12 weeks after conservative treatment. The primary outcome was the cure rate of conservative treatment, while the secondary outcomes included the recurrence rate, days of total intravenous antibiotic use, length of hospital stay (LOS), postoperative complications, and liver injury caused by RPD. A total of 142 patients (77 girls and 65 boys) were included, 52 in the control group and 90 in the intervention group. The two groups were similar in demographic data and clinical characteristics (P > 0.05). The mean total course of RPD in the intervention group was 11.82 days. The intervention group had a significantly higher cure rate than the control group (93.33% vs. 80.77%, P = 0.029), and the length of total intravenous antibiotic use (P = 0.150), LOS (P = 0.077), recurrence rate (9.52% vs. 4.76%, P = 0.439), as well as the operation time (P = 0.101), LOS (P = 0.572), and postoperative complications (P = 0.549) were not significantly different between the two groups when the patients received IA. No patient had a liver injury caused by RPD during the treatment. Intravenous antibiotics combined with RPD demonstrated high effectiveness and safety for treating pediatric periappendiceal abscess.

Evaluation of the Diagnostic Performance of mNGS in Detecting Intra-Abdominal Infections of the Emergency Department Patients.

Intra-abdominal infections (IAI) are gradually becoming common in the emergency department, though the incidence is low and the prognosis is fair, as the symptoms are similar to other intra-abdominal diseases, rapid and accurate diagnosis of the causative agents is essential for clinical management. This study aimed to evaluate the diagnostic performance of metagenomic next-generation sequencing (mNGS) in detecting IAI in the emergency department. This was a retrospective, single-centered study including patients admitted to the emergency department from January 1st, 2021 to August 31st, 2022 with diagnosis of IAI. The comparison between mNGS and microbial culture using paracentesis fluid samples was performed to evaluate the diagnostic performance of mNGS for IAI. Meanwhile, paracentesis fluid and peripheral blood mNGS were compared to explore the sample specificity. Further, the microbial community structure of the patients with pyogenic liver abscesses (PLA) was analyzed. Thirty-four IAI patients including 23 with pyogenic liver abscesses (PLA), 3 with parapancreatic abscesses, and 8 with other IAI were included in this study. Compared with the conventional microbial culture of paracentesis fluid, mNGS using paracentesis fluid detected more positive cases of IAI (93.75% vs 81.25%), and identified more species of pathogens, especially in obligate anaerobes and viral pathogens. Peripheral blood mNGS presented a relatively high consistency with the paracentesis fluid mNGS (91% mutual positive). The microbial community structure of PLA patients with diabetes is less diverse than that of those without diabetes. Patients with diabetes are at high risk of PLA caused by Klebsiella pneumonia. mNGS has advantages in detecting IAI in the emergency department, and peripheral blood mNGS can be a non-invasive choice for early diagnosis.

ROLE OF DIAGNOSTIC LAPAROSCOPY IN PATIENTS WITH CHRONIC RIGHT ILIAC FOSSA PAIN: A PROSPECTIVE OBSERVATIONAL STUDY

Abdominal pain of longer duration is associated with poor quality of life and signicant level of depressive symptoms. Chronic right iliac fossa pain with normal radiological and laboratory ndings is common indication for diagnostic laparoscopy by general surgeon. In case of diagnostic uncertainty, laparoscopy may help to avoid unnecessary laparotomy and provide accurate diagnosis. Diagnostic laparoscopy is a minimally invasive method for the diagnosis of intra-abdominal diseases through direct inspection of intra-abdominal organs. Diagnostic laparoscopy also allows tissue biopsy, culture acquisition, and a variety of therapeutic interventions. Laparoscopic ultrasonography can also be performed during diagnostic laparoscopy to evaluate organs that are not amenable to direct visual inspection

Upper Gastrointestinal Bleeding Due to a Left Gastric Artery Pseudoaneurysm: A Case Series.

Left gastric artery (LGA) pseudoaneurysm presenting with upper gastrointestinal (UGI) bleeding is rare but fatal, unless treated. We aimed to describe the clinical and endoscopic features of patients with UGI bleeding due to LGA pseudoaneurysms. We performed a computerized search of our hospital's de-identified clinical data warehouse to identify patients with UGI bleeding due to an LGA pseudoaneurysm between 2000 and 2020. Patients' electronic medical records and data on esophagogastroduodenoscopy and digital subtraction angiography were reviewed retrospectively. Of 26 patients with an LGA pseudoaneurysm, six patients had UGI bleeding related to an LGA pseudoaneurysm. No patients had previous vascular diseases or pancreatitis. One patient had liver cirrhosis and a history of radiofrequency ablation for hepatocellular carcinoma, one had colon cancer, two had undergone abdominal surgeries, one had received chemoradiotherapy for renal cell carcinoma, and one had no intraabdominal diseases. Symptoms were hematemesis in two, hematochezia in the other two, and melena in the remaining two patients. Esophagogastroduodenoscopy showed a pulsating bulge in the ulcer in two and a large Dieulafoy's lesion-like structure in four patients. All patients achieved hemostasis by angioembolization. LGA pseudoaneurysm should be suspected in UGI bleeding if a large Dieulafoy's lesion-like structure or a pulsating bulge in the ulcer is found at the lesser curvature of the gastric body on endoscopy and if the patient has any intra-abdominal inflammatory disease.

Abdominal pain in children with intraabdominal purulent diseases and acute complications of type I diabetes mellitus: a non-systematic review

Annotation. The prevalence of type I diabetes mellitus (T1DM) among children in Ukraine reached 9105 patients in 2018 and continues to rise. Differential diagnosis of abdominal pain in ketoacidosis and intraabdominal purulent diseases is an important factor contributing to prompt and appropriate management of such patients. We analyzed the prevalence of T1DM in different age groups and specific features of abdominal pain related to its complications and concomitant intraabdominal purulent diseases in childhood in this article. Scientific research for the period from 2008 to 2021 was carried out according to the primary search strategy “type I diabetes mellitus” (T1DM, pediatric, children, prevalence), “ketoacidosis” (ketoacidosis, diabetic ketoacidosis, children), “abdominal pain” (acute abdominal pain, children), “acute appendicitis” (acute appendicitis, pediatric, children) and the combination of AND/OR in the scientometric databases MEDLINE (PubMed), Scopus, Web of Science. The leading role in the pathogenesis of pain belongs to electrolyte imbalance (acidosis) arising from the accumulation of intermediate products of fat oxidation. Abdominal pain in intraabdominal purulent diseases includes visceral, somatic parietal, and irradiating elements. The coincidence of onset peaks of intraabdominal purulent diseases, accompanied by acute abdominal pain and T1DM in this population requires the development of a standardized algorithm for the differential diagnosis of these pathologies.

A study of incidental appendectomy during diagnostic laparoscopy performed to evaluate the causes of lower abdominal pain

Background: Diagnostic laparoscopy is a minimally invasive method for the diagnosis of intra-abdominal diseases by direct inspection of intra-abdominal organs whenever there is a diagnostic dilemma even after routine diagnostic workup. Incidental appendectomy is defined as the removal of a clinically normal appendix during non-appendiceal surgery. The study is performed to evaluate the causes of lower abdominal pain during diagnostic laparoscopy and to determine the benefits of incidental appendectomy.Methods: This study, performed at the department of surgery, B. J. medical college, Ahmedabad from May 2012 to October 2014 is a prospective study. Incidental appendectomy was performed during diagnostic laparoscopy in 30 patients with abdominal pain. Criteria such as symptomatology, aetiology of pain as found on laparoscopy, post-operative pain relief and complications were analysed.Results: Nearly two third of the patients who presented with intractable lower abdominal pain were females. Mesenteric lymphadenopathy was the commonest per-operative finding affecting half of the patients, followed by adhesions present in about one quarter of the patients. Gynaecological conditions represented about one third of the cases. All, except one patient, had satisfactory pain relief and no complications of incidental appendectomy over a one year follow up.Conclusions: We conclude that diagnostic laparoscopy is a very good and accurate tool to diagnose the causes of abdominal pain and should be routinely used where radiological investigations are inconclusive. Incidental appendectomy indeed has many advantages when performed in an appropriate age group and proper setting.

Clinical characteristics and microbiology of nosocomial enterococcal bloodstream infections in a tertiary-level hospital: a retrospective study, 2007–2019

Enterococci are important pathogens causing nosocomial bloodstream infections (BSIs) and cannot be treated with appropriate timely empirical antibiotics due to their natural resistance to many kinds of antibiotics. To analyse the clinical characteristics and microbiological features of nosocomial bloodstream infections caused by enterococci. The clinical characteristics and microbiological features of nosocomial enterococcal BSI patients in Xiamen University Zhongshan Hospital were examined in a case-controlled retrospective study. All patient information was collected through an electronic surveillance system. A total of 199 cases were identified as nosocomial enterococcal BSIs over a period of 13 years. The incidence of BSIs fluctuated from 0.21% to 0.81%. In the distribution of wards, enterococcal BSIs in hepatobiliary surgery ranked first. Intra-abdominal diseases (odds ratio: 3.36; 95% confidence interval: 2.15-5.27; P < 0.001), chemotherapy history (4.37; 2.06-9.25; P < 0.001), and urinary catheterization (2.34; 1.52-3.61; P < 0.001) were risk factors for nosocomial enterococcal BSI acquisition. Vancomycin-resistant enterococci and linezolid-insensitive enterococci strains were not found. Patients with a history of intra-abdominal disease, chemotherapy and urinary catheterization are at higher risk of nosocomial enterococcal bloodstream infections. The enterococcus strains were still sensitive to commonly used antibiotics.

The technology of artificial pneumoperitoneum CT and its application in diagnosis of abdominal adhesion

To retrospectively analyze the use of artificial pneumoperitoneum in CT scans, to explore its operation methods and technical points, and to lay the foundation for the widespread application of artificial pneumoperitoneum in CT. A total of 331 patients who underwent artificial pneumoperitoneum with CT angiography from January 1, 2013, to November 1, 2019, were recruited. All patients underwent standardized artificial pneumoperitoneum in the horizontal, left and right lateral, and prone positions during CT thin-layer scans of the abdomen and 3D reconstruction. Taking the surgical results as the gold standard, and using kappa test to verify the consistency of surgical results and imaging results. In all 331 patients, 43 patients had a normal peritoneal space, and 288 patients had an abnormal peritoneal space. And only 22 patients developed complications of subcutaneous emphysema, accounting for 6.6% of all 331 patients. In terms of the postoperative results, 28 were normal, and 303 were abnormal. The sensitivity, specificity and accuracy of CT diagnosis of abdominal adhesions using artificial pneumoperitoneum were 100%, 95.04%, and 95.46%, respectively. According to the Kappa consistency test, the imaging diagnosis from the CT scan with artificial pneumoperitoneum had a high consistency with the surgical results (kappa = 0.796, P < 0.05). The technique of artificial pneumoperitoneum CT is safe, reliable, highly practical, and proficient for obtaining good imaging results. It provides a good imaging basis for the diagnosis of intra-abdominal diseases, especially intra-abdominal adhesions.

Acetazolamide-eluting biodegradable tubular stent prevents pancreaticojejunal anastomotic leakage

Postoperative pancreatic fistula at the early stage can lead to auto-digestion, which may delay the recovery of the pancreaticojejunal (PJ) anastomosis. The efficacy and safety of an acetazolamide-eluting biodegradable tubular stent (AZ-BTS) for the prevention of self-digestion and intra-abdominal inflammatory diseases caused by pancreatic juice leakage after PJ anastomosis in a porcine model were investigated. The AZ-BTS was successfully fabricated using a multiple dip-coating process. Then, the drug amount and release profile were analyzed. The therapeutic effects of AZ were examined in vitro using two kinds of pancreatic cancer cell lines, AsPC-1 and PANC-1. The efficacy of AZ-BTS was assessed in a porcine PJ leakage model, with animals were each assigned to a leakage group, a BTS group and an AZ-BTS group. The overall mortality rates in these three groups were 44.4%, 16.6%, and 0%, respectively. Mean α-amylase concentrations were significantly higher in the leakage and BTS groups than in the AZ-BTS group on day 2–5 (p < 0.05 each all). The luminal diameters and areas of the pancreatic duct were significantly larger in the leakage group than in the BTS and AZ-BTS groups (p < 0.05 each all). These findings indicate that AZ-BTS can significantly suppress intra-abdominal inflammatory diseases caused by pancreatic juice leakage and also prevent late stricture formation at the PJ anastomotic site in a porcine model.

Enteral insufficiency syndrome: current provisions about the terminology, pathogenesis and treatment (review of literature)

An analytical review of the literature on the pathogenesis of disorders of the motor-evacuation function of the intestine, which underlies the enteral insufficiency syndrome (EIS), which develops in various acute intra-abdominal surgical diseases, is presented. On the basis of a multivariate analysis of literature data, various pathogenetic mechanisms of enteric dysfunctions caused by morphological and structural changes in the wall of the small intestine, violations of its local defense mechanisms are described. The essence of the modern concept of the pathogenesis of enteral insufficiency – enteral distress syndrome (EDS) according to the literature is presented. According to new views, EDS is a combination of various pathogenetic mechanisms that are formed as a result of dysregulation and destabilization of biological membranes of tissue structures of the intestinal wall (especially its mucous membrane) and a violation of the functional and metabolic status of the intestine, developing in acute surgical diseases of the abdominal organs. Recognition of the validity of the concept will allow unifying the terminology and creating more evidence-based and generally accepted teaching about the nature of EIS.

Analysis of Bacteroides fragilis Clinical Strains Isolated in Kazakhstan.

Our aim was to study the nucleotide sequences of 9 previously undescribed strains of B. fragilis collected from patients with intra-abdominal diseases at city hospitals in Nur-Sultan, Kazakhstan.

Importance of Radiologists in Optimizing Outcomes for Older Americans with Acute Abdomen

BackgroundPatients presenting with acute abdominal pain often undergo a computed tomography (CT) scan as part of their diagnostic workup. We investigated the relationship between availability, timeliness, and interpretation of CT imaging and outcomes for life-threatening intra-abdominal diseases or “acute abdomen,” in older Americans. MethodsData from a 2015 national survey of 2811 hospitals regarding emergency general surgery structures and processes (60.1% overall response, n = 1690) were linked to 2015 Medicare inpatient claims data. We identified beneficiaries aged ≥65 admitted emergently with a confirmatory acute abdomen diagnosis code and operative intervention on the same calendar date. Multivariable regression models adjusted for significant covariates determined odds of complications and mortality based on CT resources. ResultsWe identified 9125 patients with acute abdomen treated at 1253 hospitals, of which 78% had ≥64-slice CT scanners and 85% had 24/7 CT technicians. Overnight CT reads were provided by in-house radiologists at 14% of hospitals and by teleradiologists at 66%. Patients were predominantly 65-74 y old (43%), white (88%), females (60%), and with ≥3 comorbidities (67%) and 8.6% died. STAT radiology reads by a board-certified radiologist rarely/never available in 2 h was associated with increased odds of systemic complication and mortality (adjusted odds ratio 2.6 [1.3-5.4] and 2.3 [1.1-4.8], respectively). ConclusionsDelays obtaining results are associated with adverse outcomes in older patients with acute abdomen. This may be due to delays in surgical consultation and time to source control while waiting for imaging results. Processes to ensure timely interpretation of CT scans in patients with abdominal pain may improve outcomes in high-risk patients.

Abstract 5351: FLASH irradiation enhances the therapeutic index of abdominal radiotherapy in mice

Abstract Radiation therapy is the most effective cytotoxic cancer therapy available for the treatment of localized tumors. However, radiation-induced toxicity to normal tissues limits the radiation dose and therefore the curative potential of radiotherapy. In particular, the highly radiosensitive intestine greatly limits the use of radiation for patients with intra-abdominal tumor diseases including women with ovarian cancer. Here we sought to investigate the safety and efficacy of FLASH radiation therapy in the treatment of widespread ovarian cancer peritoneal metastases. We performed abdominal irradiation on healthy and ovarian tumor-bearing mice at conventional (CONV, (0.07 Gy/sec)) or FLASH (200 Gy/sec) dose rates and examined gut function by stool counts, DNA damage in crypt cells by γ-H2AX staining, cell death and proliferation by TUNEL/ caspase-3 staining and BrdU immunohistochemistry respectively. We report that ultrahigh dose rate FLASH irradiation causes significantly less radiation-induced intestinal injury in both healthy and tumor-bearing mice compared to CONV dose rate irradiation. Abdominal FLASH reduced the mortality from gastrointestinal syndrome, preserved gut function and epithelial integrity as reflected by their stool counts and FITC-Dextran analysis. In addition, we found decreased cell death and enhanced proliferation of crypt base columnar cells (CBCs) following FLASH irradiation in comparison to CONV irradiation. We also detected reduced number of γ-H2AX foci in crypt cells indicating less DNA damage and/or increased DNA repair after FLASH compared to CONV irradiation. Importantly, FLASH and CONV irradiation have similar efficacy in the reduction of ovarian cancer peritoneal metastases. These findings suggest that FLASH irradiation has biological advantages compared to conventional dose rate irradiation in reducing radiation-induced intestinal injury within the irradiation field and therefore may be an effective strategy to enhance the therapeutic index of radiotherapy for the treatment of abdominal and pelvic tumor disease. Citation Format: Suchitra Natarajan, Karen Levy, Jinghui Wang, Stephanie Chow, Joshua Eggold, Phoebe Loo, Rakesh Manjappa, Frederick M. Lartey, Emil Schüler, Lawrie Skinner, Marjan Rafat, Ryan Ko, Anna Kim, Duaa Al Rawi, Rie von Eyben, Oliver Dorigo, Kerriann M. Casey, Edward E. Graves, Karl Bush, Amy S. Yu, Albert C. Koong, Peter G. Maxim, Billy W. Loo, Erinn B. Rankin. FLASH irradiation enhances the therapeutic index of abdominal radiotherapy in mice [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5351.

Increased risk of perforated appendicitis in patients with schizophrenia and dementia: A population-based case-control study.

Previous studies have suggested that patients with psychotic or mental disorders are relatively pain insensitive, resulting in difficulties in the diagnosis of acute intra-abdominal diseases requiring emergency surgeries. We aimed to evaluate whether central nervous system (CNS) or mental disorders are associated with perforated appendicitis in patients with acute appendicitis.We conducted a population-based case-control study using Taiwan's National Health Insurance Research database. Patients aged >18 years who had been hospitalized with a diagnosis of acute appendicitis between 2000 and 2013 were identified. After 1:1 matching for age and sex, 2792 patients with perforated appendicitis (case group) and 2792 patients with nonperforated appendicitis (control group) were included. CNS disorders, mental disorders, pain control medication, and several comorbidities were analyzed for the odds of appendiceal perforation with 95% confidence interval (CI) using the multivariable logistic regression model.Schizophrenia and dementia were associated with a high risk of appendiceal rupture in patients with acute appendicitis, with an adjusted odds ratio of 2.01 for dementia (95% CI: 1.19–3.39, P = .009) and 4.8 for schizophrenia (95% CI: 1.62–14.19, P = .005). Other factors, such as other CNS disorders, comorbidities, and pain control medication, were not associated with the risk of perforated appendicitis.Dementia and schizophrenia are associated with perforated appendicitis in patients with acute appendicitis. This might be owing to altered pain perception, difficult symptom expression, and delayed hospitalization. Further studies are still needed to determine the underlying mechanism and confirm the causality.

Is the presence of echo-rich periportal cuffing in the liver indicator for abdominal inflammation in pediatric patients?

Hyperechoic/echo-rich periportal cuffing (ErPC) is defined as an increase in echogenicity relative to the adjacentliver parenchyma. Thickening in the periportal area may occur with proliferation of bile ducts, hemorrhage, oedema, fibrosis,inflammatory changes or a combination of these. The aim of this study is to determine which intraabdominal inflammatory diseases are associated with the presence of ErPC in the pediatric population and to calculate the sensitivity and specificity of this finding. In this prospective study 200 consecutive children who underwent abdominal ultrasonography (US) were included: group 1, the patient group (100 children with appendicitis, gastroenteritis, mesenteric lymphadenitis, intestinal infection, terminal ileitis and invagination as cause of intra-abdominal inflammation) and group 2, the control group (100 children). The ErPC was positive in 74 (74%) cases in the patient group and in 3 (3%) in the control group. According to final diagnoses, we found ErPC in most of patients with gastroenteritis (16/17), perforated appendicitis (10/11), mesenteric lymphadenitis (5/6) and acute appendicitis (27/37). The sensitivity of ErPC in indicating intra-abdominal inflammation was 0.80 and its specificity was 0.87. No significant correlation between ErPC and age, gender and CRP was found but a moderate and significant positive correlation between ErPC and WBC (p=0,010; r=0.255) was detected. Very good concordance between observers in terms of the presence of ErPC on abdominal US was found (concordance 97% and kappa 0.93). We consider that the presence of ErPC in pediatric patients, when evaluated alongside clinical and laboratory findings, has a high sensitivity and specificity for inflammatory intra-abdominal pathology.