Abdominal manifestations of cystic fibrosis in children

The Etiology of Cholelithiasis in Children and Adolescents-A Literature Review

The incidence of gallstone disease has increased in recent years. The pathogenesis of cholelithiasis is not fully understood. The occurrence of the disease is influenced by both genetic and environmental factors. This article reviews the literature on cholelithiasis in children, with the exception of articles on hematological causes of cholelithiasis and cholelithiasis surgery. The aim of this review is to present the latest research on the pathogenesis of gallstone disease in children. The paper discusses the influence of all factors known so far, such as genetic predisposition, age, infections, medications used, parenteral nutrition, and comorbidities, on the development of gallstone disease. The course of cholelithiasis in the pediatric population is complex, ranging from asymptomatic to life-threatening. Understanding the course of the disease and predisposing factors can result in a faster diagnosis of the disease and administration of appropriate treatment.

Surgical considerations in cystic fibrosis: what every general surgeon needs to know

Cystic fibrosis (CF) is a complex multiorgan disease, which often affects the gastrointestinal tract. With improved CF specific therapies and multidisciplinary management, patients with CF are now living longer with a median life expectancy of around 50 years. This increased life expectancy has resulted in corresponding increase in presentations of the CF patient with comorbid surgical conditions that were never important considerations. Investigations and management of these conditions, such as distal intestinal obstruction syndrome and colorectal cancer warrant good clinical understanding of the unique challenges that CF patients present including chronic immunosuppression, impaired respiratory function and their multi-organ dysfunction. The purpose of this review is to provide general surgeons with a contemporary update on the CF related surgical issues as they are likely to become increasingly involved in the care of these complex patients and form an integral part of the multidisciplinary team.

Changing paradigms in the treatment of gastrointestinal complications of cystic fibrosis in the era of cystic fibrosis transmembrane conductance regulator modulators

Cystic fibrosis (CF) - although primarily a lung disease - also causes a variety of gastrointestinal manifestations which are important for diagnosis, prognosis and quality of life. All parts of the gastrointestinal tract can be affected by CF. Besides the well-known pancreatic insufficiency, gastroesophageal reflux disease, liver disease and diseases of the large intestine are important pathologies that impact on prognosis and also impair quality of life. Diagnosis and management of gastrointestinal manifestations will be discussed in this review. Since optimisation of CF therapy is associated with a significantly longer life-span of CF patients nowadays, also gastrointestinal malignancies, which are more common in CF than in the non-CF population need to be considered. Furthermore, novel evidence on the role of the gut microbiome in CF is emerging. The introduction of cystic fibrosis transmembrane conductance regulator (CFTR) protein modulators gives hope for symptom alleviation and even cure of gastrointestinal manifestations of CF.

Evaluation of children and adolescent with cystic fibrosis by pancreatic elastography

BACKGROUND

Cystic fibrosis (CF) is an autosomal recessively inherited disease. Clinical findings vary by age of the patient, the organ systems involved, and the severity of the CFTR gene mutation. Pancreatic and liver involvement is prominent and exocrine pancreatic insufficiency is observed in the majority of patients. Point shear wave elastography (pSWE) is a non-invasive method that can quantitatively determine tissue elasticity and stiffness. In this study, the morphological evaluation of the pancreas was performed using the pSWE technique in pediatric patients diagnosed with CF. The effectiveness of this method for the early detection of pancreatic insufficiency was investigated.

METHODS

Fifty-five patients with CF (24 girls, 31 boys) and 60 healthy children (29 girls, 31 boys) without any chronic diseases and who were suitable for the pSWE examination were included in the study.

RESULTS

The mean value of pSWE was 1.12 ± 0.16 in the healthy group and 0.97 ± 0.16 in the patients with cystic fibrosis. There was a statistically significant difference between the two groups (P < 0.001). Significant negative correlations were found between pSWE and age (r = -0.319; P = 0.018), height (r = -0.293; P = 0.03), serum glucose (r = -0.346; P = 0.01), HbA1C (r = -0.592; P = 0.02), and duration of the disease (r = -0.806; P < 0.001).

CONCLUSIONS

Investigating pancreatic elasticity and detecting pancreatic insufficiency using pSWE (a simple, inexpensive, and non-invasive method) in the early period before overt laboratory and clinical symptoms of EPI appear can contribute positively to long-term results in young patients with CF.

Case report of compound CFTR variants in Korean siblings with cystic fibrosis: importance of differentiating cystic fibrosis from inflammatory bowel disease

The prevalence of cystic fibrosis (CF) is considerably lower in Asian populations compared with that of Caucasians. Cases of CF are typically due to mutations in the CF transmembrane conductance regulator gene with autosomal recessive inheritance. Here, we report two cases of newly diagnosed CF in Korea-a 13-year-old boy and his 5-year-old brother. The older brother was admitted to our hospital for evaluation and treatment of recurrent abdominal pain, frequent diarrhea, and failure to thrive. Fecal calprotectin (FC) was elevated, and when combining this with his clinical presentation, inflammatory bowel disease (IBD) or eosinophilic gastroenteritis (EoGE) was the first impression of his disease. Several ulcerative lesions were observed on ileocolonoscopy. However, incidental findings of suspicious bronchiectatic lesions were observed on plain radiography, which were confirmed by chest computed tomography. Moreover, diffuse bowel wall thickening with pancreatic atrophy was also incidentally detected by computed tomography of the abdomen. Comprehensively, these findings were highly suggestive of CF. Therefore, diagnostic exome sequencing was conducted, which revealed compound heterozygous variants of c.263T>G (p.Leu88*) and c.2977G>T (p.Asp993Tyr) in the CF transmembrane conductance regulator gene. Although symptoms in the younger brother were not as prominent as the older brother, genetic test was also conducted, which revealed the same mutation. We report the identification of a novel variant, p.Asp993Tyr, in siblings with Korean heritage. Although CF is rare in Koreans, it should be included in the differential diagnosis of IBD.

Dystrophin in the Neonatal and Adult Rat Intestine

Background: Gastrointestinal (GI) complaints are frequently noted in aging dystrophinopathy patients, yet their underlying molecular mechanisms are largely unknown. As dystrophin protein isoform 71 (Dp71) is particularly implicated in the development of smooth muscle cells, we evaluated its distribution in the neonatal and adult rat intestine in this study. Methods: Dp71 expression levels were assessed in the proximal (duodenum, jejunum and ileum) and distal (caecum, colon and rectum) intestine by Western blotting and qPCR. In addition, the cellular distribution of total Dp was evaluated in the duodenum and colon by immunohistochemical colocalization studies with alpha-smooth muscle actin (aSMA), Hu RNA binding proteins C and D (HuC/HuD) for neurons and vimentin (VIM) for interstitial cells. Results: In neonatal and adult rats, the distal intestine expressed 2.5 times more Dp71 protein than the proximal part (p < 0.01). This regional difference was not observed in Dp71 mRNA. During both stages, Dp-immunoreactivity was predominant in the muscularis propria, where it co-localized with aSMA and HuC/HuD. Conclusions: In neonatal and adult rats, Dp71 was expressed highest in the distal intestine. Together with the observation that Dp may be expressed by myenteric neurons, this warrants a paradigm shift in the treatment of GI comorbidities.

[Abdominal imaging in cystic fibrosis]

CLINICAL ISSUE

Abdominal complications are often the first indications for cystic fibrosis (CF), a multiorgan disease. A broad range of abdominal manifestations are associated with the disease, including gastrointestinal abnormalities (such as meconium ileus in newborns and distal intestinal obstruction syndrome in older children) and hepatobiliary alterations (e.g., cholelithiasis, microgallbladder, hepatosteatosis, biliary cirrhosis). A characteristic finding is pancreatic involvement, which leads to exocrine and over the course of time to endocrine insufficiency.

STANDARD RADIOLOGICAL METHODS

Ultrasonography is the preferred and often sole modality for a precise diagnosis of abdominal CF manifestations. However, all imaging modalities can be used, depending on the pathology: X‑ray, fluoroscopic examinations, computed tomography, magnetic resonance imaging (also with application of magnetic resonance cholangiopancreatography).

METHODICAL INNOVATIONS/PERFORMANCE

Scoring systems are useful for standardized diagnostics. Sonographic findings, described using a scoring system, correlate with clinical symptoms, such as pancreatic lipomatosis with abdominal pain (p = 0.018), flatulence (p = 0.006), and gastroesophageal reflux (p = 0.006).

EVALUATION/PRACTICAL RECOMMENDATIONS

A standardized approach with structured reporting is important due to the numerous abdominal CF manifestations. To enable precise follow-up analyses, scoring systems based on sonographic findings are excellent.

A comparative study of the pancreas in pediatric patients with cystic fibrosis and healthy children using two-dimensional shear wave elastography

PURPOSE

To compare sonographic parameters of the pancreas between healthy children and pediatric cystic fibrosis (CF) patients with pancreatic involvement using shear wave elastography (SWE) and to investigate the efficacy of SWE in the diagnosis of pancreatic involvement in pediatric CF patients.

METHODS

The pancreas was evaluated in 38 patients with CF and 38 healthy children using conventional B-mode ultrasonography (US) and two-dimensional (2D)-SWE.

RESULTS

The pancreatic 2D-SWE values of the CF group were significantly lower than those of the healthy control group (1.01 ± 0.16 vs. 1.31 ± 0.01 m/s for the head, 1.03 ± 0.05 vs. 1.28 ± 0.08 m/s for the pancreatic body, and 1.02 ± 0.05 vs. 1.30 ± 0.10 m/s for the tail; p < 0.005 for all the comparisons). When the threshold values were obtained for the pancreatic head, body, and tail segments for the differentiation of the CF patients and healthy controls, the sensitivity of the test was determined as 81.5%, 76.3%, and 73.3%, respectively, and the specificity as 97.3%, 100%, and 100%, respectively. When the patients were divided into two groups based on the presence of B-mode US characteristics (homogeneity, sharp demarcation, and hyperechoic pancreas), there was a significant difference in the 2D-SWE values of the pancreatic head between the patients with and the patients without these characteristics (p = 0.048 for homogeneity, p = 0.021 for sharp demarcation, and p = 0.006 for hyperechoic pancreas).

CONCLUSION

The measurement of 2D-SWE values was found to be an easily applicable non-invasive test with high sensitivity and specificity for the demonstration of changes in the pancreas of pediatric CF patients.

Cystic fibrosis liver disease: A condition in need of structured transition and continuity of care

Liver disease affects one-third of patients with cystic fibrosis (CF) and it is one of the major causes of morbidity and mortality in these patients. Historically considered a disease of childhood, its impact is now seen more often in adulthood. The heterogeneous pattern of CF liver disease and its rapid progression to cirrhosis remain a diagnostic challenge and new questions pertaining to the nature of liver involvement have recently been raised. Non-invasive measures to stratify the severity of liver involvement are increasingly used to predict clinical outcomes. A single treatment, ursodeoxycholic acid, has been used to slow progression of liver disease while recent advances in the field of CF treatments are promising. Management of portal hypertension remains challenging but outcomes after liver transplantation are encouraging. While many questions remain unanswered, a growing number of CF patients reach adulthood and will require care for CF liver disease.

Non-Cystic Fibrosis-Related Meconium Ileus: GUCY2C-Associated Disease Discovered through Rapid Neonatal Whole-Exome Sequencing

Meconium ileus is caused by cystic fibrosis; however, mutations in the GUCY2C gene also cause this disease. We report non-cystic fibrosis meconium ileus in an infant of non-Middle Eastern origin with compound heterozygous mutations in GUCY2C.

Meconium Ileus

Cystic fibrosis is one of the most common inheritable traits in Caucasians. Meconium ileus and its potential complications are the most likely reasons that these patients will need surgical care. Surgical intervention is usually needed in the neonatal period but may also be required later in life. This article discusses the various ways cystic fibrosis can affect the gastrointestinal tract. Both the operative and nonoperative management of complicated and uncomplicated meconium ileus are discussed in the neonatal period as well as long-term issues, such as distal intestinal obstructive syndrome, fibrosing colonopathy, and rectal prolapse, all of which may be seen in older children and adults.

A pictorial review of diagnostic pitfalls of developmental anomalies and variants in pancreatic imaging

Developmental anomalies and anatomic variants of the pancreas vary widely, and most of them are encountered incidentally during radiologic evaluation. However, some of these anomalies and variants are potentially pathologic and may cause various clinical presentations in childhood or adulthood. The early identification of these entities in various imaging modalities including ultrasound, computed tomography (CT), and magnetic resonance (MR) imaging would be valuable in making correct diagnoses and, in turn, preventing unnecessary additional procedures. In order to differentiate these entities, it is fundamental to understand the embryologic development and normal anatomical structure of the pancreas. In this article, we review the embryology and normal anatomy of the pancreas, and diagnostic pitfalls of developmental anomalies and anatomic variants in various pancreatic imaging modalities.

Ultrasound of the pediatric appendix

Appendicitis is the most common pediatric surgical emergency. Ultrasound (US) receives the highest appropriate rating scale in children with right lower quadrant pain suspected to have appendicitis. The US exam of the appendix has improved since Puylaert pioneered the technique of graded compression in 1986. In this article, we review ultrasonography of the pediatric appendix as it pertains to the normal appendix, acute appendicitis and the different sonographic manifestations. We also briefly describe technical optimization of image acquisition, common pitfalls and differential diagnoses.

Abdominal symptoms in cystic fibrosis and their relation to genotype, history, clinical and laboratory findings

BACKGROUND & AIMS

Abdominal symptoms (AS) are a hallmark of the multiorgan-disease cystic fibrosis (CF). However, the abdominal involvement in CF is insufficiently understood and, compared to the pulmonary manifestation, still receives little scientific attention. Aims were to assess and quantify AS and to relate them to laboratory parameters, clinical findings, and medical history.

METHODS

A total of 131 patients with CF of all ages were assessed with a new CF-specific questionnaire (JenAbdomen-CF score 1.0) on abdominal pain and non-pain symptoms, disorders of appetite, eating, and bowel movements as well as symptom-related quality of life. Results were metrically dimensioned and related to abdominal manifestations, history of surgery, P. aeruginosa and S. aureus colonization, genotype, liver enzymes, antibiotic therapy, lung function, and nutritional status.

RESULTS

AS during the preceding 3 months were reported by all of our patients. Most common were lack of appetite (130/131) and loss of taste (119/131) followed by abdominal pain (104/131), flatulence (102/131), and distention (83/131). Significantly increased AS were found in patients with history of rectal prolapse (p = 0.013), distal intestinal obstruction syndrome (p = 0.013), laparotomy (p = 0.022), meconium ileus (p = 0.037), pancreas insufficiency (p = 0.042), or small bowel resection (p = 0.048) as well as in patients who have been intermittently colonized with P. aeruginosa (p = 0.006) compared to patients without history of these events. In contrast, no statistically significant associations were found to CF-associated liver disease, chronic pathogen colonization, lung function, CF-related diabetes, and nutritional status.

CONCLUSION

As the complex abdominal involvement in CF is still not fully understood, the assessment of the common AS is of major interest. In this regard, symptom questionnaires like the herein presented are meaningful and practical tools facilitating a wider understanding of the abdominal symptoms in CF. Furthermore, they render to evaluate possible abdominal effects of novel modulators of the underlying cystic fibrosis transmembrane (conductance) regulator (CFTR) defect.

Expression of Cystic Fibrosis Transmembrane Conductance Regulator in Ganglia of Human Gastrointestinal Tract

CF is caused by mutations of the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) which is an anion selective transmembrane ion channel that mainly regulates chloride transport, expressed in the epithelia of various organs. Recently, we have demonstrated CFTR expression in the brain, the spinal cord and the sympathetic ganglia. This study aims to investigate the expression and distribution of CFTR in the ganglia of the human gastrointestinal tract. Fresh tissue and formalin-fixed paraffin-embedded normal gastrointestinal tract samples were collected from eleven surgical patients and five autopsy cases. Immunohistochemistry, in situ hybridization, laser-assisted microdissection and nested reverse transcriptase polymerase chain reaction were performed. Expression of CFTR protein and mRNA was detected in neurons of the ganglia of all segments of the human gastrointestinal tract examined, including the stomach, duodenum, jejunum, ileum, cecum, appendix, colon and rectum. The extensive expression of CFTR in the enteric ganglia suggests that CFTR may play a role in the physiology of the innervation of the gastro-intestinal tract. The presence of dysfunctional CFTRs in enteric ganglia could, to a certain extent, explain the gastrointestinal symptoms frequently experienced by CF patients.

Gastrointestinal, Pancreatic, and Hepatobiliary Manifestations of Cystic Fibrosis

Pulmonary disease is the primary cause of morbidity and mortality in people with cystic fibrosis (CF), but significant involvement within gastrointestinal, pancreatic, and hepatobiliary systems occurs as well. As in the airways, defects in CFTR alter epithelial surface fluid, mucus viscosity, and pH, increasing risk of stasis through the various hollow epithelial-lined structures of the gastrointestinal tract. This exerts secondary influences that are responsible for most gastrointestinal, pancreatic, and hepatobiliary manifestations of CF. Understanding these gastrointestinal morbidities of CF is essential in understanding and treating CF as a multisystem disease process and improving overall patient care.

Imaging of Cystic Fibrosis and Pediatric Bronchiectasis

1. CT is superior to pulmonary function tests and chest radiography for the assessment and monitoring of cystic fibrosis (CF)-related lung disease and, also, of pediatric bronchiectasis not caused by CF (hereafter referred to as non-CF bronchiectasis). 2. Low-dose CT protocols that impart radiation doses similar to those used in chest radiography are feasible for the surveillance of patients with bronchiectasis. 3. Chest radiography is still most commonly used as the first-line imaging examination of choice for the assessment of acute complications related to bronchiectasis. 4. Pulmonary MRI, with or without the use of inhaled hyperpolarized gas, can be performed to obtain functional information, and, in dedicated centers, it may yield imaging results comparable to those obtained by CT. 5. Gastrointestinal and pancreaticobiliary manifestations of CF are observed with greater frequency in adults, because of increased life expectancy.

Ultrasound of paediatric appendicitis and its secondary sonographic signs: providing a more meaningful finding

Sonography is an important clinical tool in diagnosing appendicitis in children as it can obviate both exposure to potentially harmful ionising radiation from computed tomography scans and the need for unnecessary appendicectomies. This review examines the diagnostic accuracy of ultrasound in the identification of acute appendicitis, with a particular focus on the the utility of secondary sonographic signs as an adjunct or corollary to traditionally examined criteria. These secondary signs can be important in cases where the appendix cannot be identified with ultrasound and a more meaningful finding may be made by incorporating the presence or absence of secondary sonographic signs. There is evidence that integrating these secondary signs into the final ultrasound diagnosis can improve the utility of ultrasound in cases where appendicitis is expected, though there remains some conjecture about whether they play a more important role in negative or positive prediction in the absence of an identifiable appendix.

Gastrointestinal Manifestations of Cystic Fibrosis

Gastrointestinal symptoms of cystic fibrosis are the most important non-pulmonary manifestations of this genetic illness. Pancreatic manifestations include acute and chronic pancreatitis as well as pancreas insufficiency resulting in malnutrition. Complications in the gastrointestinal lumen are diverse and include distal intestinal obstruction syndrome (DIOS), meconium ileus, intussusception, and constipation; biliary tract complications include focal biliary cirrhosis and cholangiectasis. The common pathophysiology is the inspissation of secretions in the hollow structures of the gastrointestinal tract. Improved survival of CF patients mandates that the adult gastroenterologist be aware of the presentation and treatment of pancreatic, luminal, and hepatobiliary CF complications.

Ultrasound echo-intensity predicts severe pancreatic affection in cystic fibrosis patients

Background

Pancreatic destruction affects the majority of patients with cystic fibrosis. We aimed to relate ultrasound findings to exocrine pancreatic function and cystic fibrosis genotype.

Methods

Patients with cystic fibrosis and a matched group of healthy controls were included. We performed transabdominal ultrasound, and recorded echo intensities of the pancreas and parenchymal characteristics according to endoscopic ultrasound based Rosemont criteria.

Results

We included 39 patients and 29 healthy controls. The cystic fibrosis patients were grouped according to exocrine pancreatic function; Cystic fibrosis, insufficient (n = 20) and sufficient (n = 19). Echo intensity measures and visual score demonstrated hyper-echogenicity in the pancreas insufficient group compared to the pancreas sufficient groups (p<0.001). Ductal and parenchymal changes were not prevalent in any of the groups.

Conclusion

The hyper-echoic pancreas was the most frequent ultrasonographic finding in exocrine pancreas insufficient cystic fibrosis patients. Pancreatic echo levels correlated to pancreatic phenotype.

Ferret and pig models of cystic fibrosis: prospects and promise for gene therapy

Large animal models of genetic diseases are rapidly becoming integral to biomedical research as technologies to manipulate the mammalian genome improve. The creation of cystic fibrosis (CF) ferrets and pigs is an example of such progress in animal modeling, with the disease phenotypes in the ferret and pig models more reflective of human CF disease than mouse models. The ferret and pig CF models also provide unique opportunities to develop and assess the effectiveness of gene and cell therapies to treat affected organs. In this review, we examine the organ disease phenotypes in these new CF models and the opportunities to test gene therapies at various stages of disease progression in affected organs. We then discuss the progress in developing recombinant replication-defective adenoviral, adeno-associated viral, and lentiviral vectors to target genes to the lung and pancreas in ferrets and pigs, the two most affected organs in CF. Through this review, we hope to convey the potential of these new animal models for developing CF gene and cell therapies.

Sonography of the pediatric gastrointestinal system

Sonography is a commonly used modality for the investigation of abdominal symptoms in the pediatric population. It is a highly sensitive, readily available imaging modality that does not require ionizing radiation, iodinated contrast material, or anesthesia and can be performed at the bedside if necessary. Abdominal ultrasound is therefore often the first examination performed. This article presents an overview of the ultrasound characteristics of some of the most frequently encountered pathologies as well as some more rarely encountered entities. Our aim was to present a series of characteristic images of a wide gamut of pediatric abdominal conditions. The goal was to familiarize the reader with key sonographic features of both congenital and acquired gastrointestinal pathologies in children, making them more easily recognizable.

Cystic fibrosis transmembrane conductance regulator dysfunction in VIP knockout mice

Vasoactive intestinal peptide (VIP), a neuropeptide, controls multiple functions in exocrine tissues, including inflammation, and relaxation of airway and vascular smooth muscles, and regulates CFTR-dependent secretion, which contributes to mucus hydration and local innate defense of the lung. We had previously reported that VIP stimulates the VPAC1 receptor, PKCϵ signaling cascade, and increases CFTR stability and function at the apical membrane of airway epithelial cells by reducing its internalization rate. Moreover, prolonged VIP stimulation corrects the molecular defects associated with F508del, the most common CFTR mutation responsible for the genetic disease cystic fibrosis. In the present study, we have examined the impact of the absence of VIP on CFTR maturation, cellular localization, and function in vivo using VIP knockout mice. We have conducted pathological assessments and detected signs of lung and intestinal disease. Immunodetection methods have shown that the absence of VIP results in CFTR intracellular retention despite normal expression and maturation levels. A subsequent loss of CFTR-dependent chloride current was measured in functional assays with Ussing chamber analysis of the small intestine ex vivo, creating a cystic fibrosis-like condition. Interestingly, intraperitoneal administration of VIP corrected tissue abnormalities, close to the wild-type phenotype, as well as associated defects in the vital CFTR protein. The results show in vivo a primary role for VIP chronic exposure in CFTR membrane stability and function and confirm in vitro data.

Gastrointestinal pathology in juvenile and adult CFTR-knockout ferrets

Cystic fibrosis (CF) is a multiorgan disease caused by loss of a functional cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel in many epithelia of the body. Here we report the pathology observed in the gastrointestinal organs of juvenile to adult CFTR-knockout ferrets. CF gastrointestinal manifestations included gastric ulceration, intestinal bacterial overgrowth with villous atrophy, and rectal prolapse. Metagenomic phylogenetic analysis of fecal microbiota by deep sequencing revealed considerable genotype-independent microbial diversity between animals, with the majority of taxa overlapping between CF and non-CF pairs. CF hepatic manifestations were variable, but included steatosis, necrosis, biliary hyperplasia, and biliary fibrosis. Gallbladder cystic mucosal hyperplasia was commonly found in 67% of CF animals. The majority of CF animals (85%) had pancreatic abnormalities, including extensive fibrosis, loss of exocrine pancreas, and islet disorganization. Interestingly, 2 of 13 CF animals retained predominantly normal pancreatic histology (84% to 94%) at time of death. Fecal elastase-1 levels from these CF animals were similar to non-CF controls, whereas all other CF animals evaluated were pancreatic insufficient (<2 μg elastase-1 per gram of feces). These findings suggest that genetic factors likely influence the extent of exocrine pancreas disease in CF ferrets and have implications for the etiology of pancreatic sufficiency in CF patients. In summary, these studies demonstrate that the CF ferret model develops gastrointestinal pathology similar to CF patients.

Paediatric ultrasonography of the liver, hepatobiliary tract and pancreas

In the field of paediatric radiology ultrasonography (US) is the most versatile imaging tool available. Children in general, by virtue of their body composition, are excellent candidates for US exams in whom abdominal anatomy and pathology can be visualised in great detail. The fact that during the US study a clinical history can be obtained strongly adds to the value of the US exam. This does require investment in time and expertise and ideally a paediatric radiologist performing the exam. In this review the role of ultrasonography (US) of the liver, biliary tract and pancreas in children is discussed.

Gastrointestinal surgery in cystic fibrosis: a 20-year review

OBJECTIVES

The purpose of this study was to evaluate outcomes of the surgical management for meconium ileus (MI) and Distal Intestinal Obstruction Syndrome (DIOS) in Cystic Fibrosis (CF).

METHODS

Children born between 1990 and 2010 were identified using a regional CF database. Retrospective case note analysis was performed. Outcome measures for MI were mortality, relaparotomy rate, length of stay (LOS), time on parental nutrition (TP), and time to full feeds (TFF). Outcome measures for DIOS were: age of onset, number of episodes, and need for laparotomy.

RESULTS

Seventy-five of 376 neonates presented with MI. Fifty-four (92%) required laparotomy. Contrast enema decompression was attempted in nineteen. There were no post-operative deaths. Thirty-nine (72%) neonates with MI were managed with stomas. LOS was longer in those managed with stomas (p=0.001) and in complex MI (p=0.002). Thirty-five patients were treated for DIOS. Twenty-five patients were managed with gastrograffin. Ten patients underwent surgical management of DIOS. Overall, MI did not predispose to later development of DIOS. There was a significantly greater incidence of laparotomy for DIOS in children who had MI.

CONCLUSION

The proportion of neonates with complex meconium ileus was high (49%) and may explain the infrequent utilisation of radiological decompression. Complex MI or management with stomas both significantly increase LOS. Re-laparotomy rate is high (22%) in MI irrespective of the type of management. DIOS is not a benign condition, particularly when the child has had previous abdominal surgery. Early referral to a surgical team is essential in these children.

Beyond acute appendicitis: imaging and pathologic spectrum of appendiceal pathology

While acute appendicitis is a common and important clinical problem, a variety of other disease processes can affect the appendix. Simple and perforated appendicitis, tip appendicitis, and stump appendicitis share a common clinical presentation including anorexia, right lower quadrant pain, and fever. By imaging, most cases of acute appendicitis exhibit luminal dilation, wall thickening, and periappendiceal inflammatory stranding. In tip appendicitis, these changes are isolated to the distal appendix, often with an obstructing appendicolith. Perforated appendicitis can exhibit mural discontinuity, periappendiceal abscess, and/or extraluminal appendicoliths. After appendectomy, the appendiceal remnant or "stump" can become inflamed, often necessitating repeat surgery. Inflammatory bowel disease can involve the terminal ileum, secondarily involving the appendix, or may primarily involve the appendix. Patient symptoms can be chronic in such cases, and mucosal hyperenhancement is a pronounced imaging feature. In asymptomatic patients without appendiceal inflammation, the appendix can be dilated by intraluminal material such as inspissated succus in cystic fibrosis or mucus from benign appendiceal mucocele. Finally, neoplasms such as typical appendiceal carcinoid tumor and mucinous adenocarcinoma can involve the appendix. Carcinoids are often small and incidentally discovered at pathologic examination, while malignant mucinous adenocarcinoma tends to present with advanced disease including pseudomyxoma peritonei. Cecal cancers can also obstruct the appendiceal lumen and cause acute appendicitis; an astute radiologist can recognize this prospectively and facilitate definitive resection (right hemicolectomy) at the time of surgery. Attention to mural features, cecal configuration, and periappendiceal inflammation is essential to the correct prospective diagnosis of complicated appendicitis and less common appendiceal pathologies.

Fibrosis reduces severity of acute-on-chronic pancreatitis in humans

BACKGROUND & AIMS

Acute pancreatitis (AP) and chronic pancreatitis (CP) share etiologies, but AP can be more severe and is associated with a higher rate of mortality. We investigated features of CP that protect against severe disease. The amount of intrapancreatic fat (IPF) is increased in obese patients and fibrosis is increased in patients with CP, so we studied whether fibrosis or fat regulate severity of AP attacks in patients with CP.

METHODS

We reviewed records from the University of Pittsburgh Medical Center/Presbyterian Hospital Autopsy Database (1998-2008) for patients with a diagnosis of AP (n = 23), CP (n = 35), or both (AP-on-CP; n = 15). Pancreatic histology samples from these patients and 50 randomly selected controls (no pancreatic disease) were analyzed, and IPF data were correlated with computed tomography data. An adipocyte and acinar cell Transwell coculture system, with or without collagen type I, was used to study the effects of fibrosis on acinar-adipocyte interactions. We studied the effects of nonesterified fatty acids (NEFAs) and adipokines on acinar cells in culture.

RESULTS

Levels of IPF were significantly higher in nonobese patients with CP than in nonobese controls. In patients with CP or AP-on-CP, areas of IPF were surrounded by significantly more fibrosis than in controls or patients with AP. Fat necrosis-associated peri-fat acinar necrosis (PFAN, indicated by NEFA spillage) contributed to most of the necrosis observed in samples from patients with AP; however, findings of peri-fat acinar necrosis and total necrosis were significantly lower in samples from patients with CP or AP-on-CP. Fibrosis appeared to wall off the fat necrosis and limit peri-fat acinar necrosis, reducing acinar necrosis. In vitro, collagen I limited the lipolytic flux between acinar cells and adipocytes and prevented increases in adipokines in the acinar compartment. This was associated with reduced acinar cell necrosis. However, NEFAs, but not adipokines, caused acinar cell necrosis.

CONCLUSIONS

Based on analysis of pancreatic samples from patients with CP, AP, or AP-on-CP and in vitro studies, fibrosis reduces the severity of acute exacerbations of CP by reducing lipolytic flux between adipocytes and acinar cells.

Reduction of intussusception: defining a better index of successful non-operative treatment

The reported non-operative reduction rate for intussusception is usually the proportion of attempted non-operative (radiological) reductions that succeed, which we term the "selective reduction rate." This value shows wide variation that may result from selection bias that is difficult to quantify because data regarding primary operative treatment are frequently lacking. The proportion of patients with late clinical presentation or pathological lead points can also distort the apparent efficacy of non-operative treatment. We found no definitions of outcome measures in the literature or practice guidelines to inform analysis. Based on analysis of our own audit data we derived a "composite reduction rate" from first principles that can account for variations in radiological and surgical treatment thresholds that might bias other measures of successful non-operative treatment. This index is the proportion of intussusceptions not requiring resection that are successfully reduced non-operatively. We propose that the composite reduction rate be used as a key component of standardised multidisciplinary outcome reporting for intussusception rather than the selective reduction rate. The reduced bias and confounding would allow fairer comparisons and lead to better outcome standards.

A pilot study of the characterization of hepatic tissue strain in children with cystic-fibrosis-associated liver disease (CFLD) by acoustic radiation force impulse imaging

BACKGROUND

Progressive fibrotic alterations of liver tissue represent a major complication in children with cystic fibrosis. Correct assessment of cystic-fibrosis-associated liver disease (CFLD) in clinical routine is a challenging issue. Sonographic elastography based on acoustic radiation force impulse imaging (ARFI) is a new noninvasive approach for quantitatively assessing in vivo elasticity of biological tissues in many organs.

OBJECTIVE

To characterize ARFI elastography as a diagnostic tool to assess alteration of liver tissue elasticity related to cystic fibrosis in children.

MATERIALS AND METHODS

ARFI elastography and B-mode US imaging were performed in 36 children with cystic fibrosis. The children's clinical history and laboratory parameters were documented. According to the findings on conventional US, children were assigned to distinct groups indicating severity of hepatic tissue alterations. The relationship between US findings and respective elastography values was assessed. Additionally, differences between ARFI elastography values of each US group were statistically tested.

RESULTS

Children with sonomorphologic characteristics of fibrotic tissue remodeling presented significantly increased values for tissue elasticity. Children with normal B-mode US or discrete signs of hepatic tissue alterations showed a tendency toward increased tissue stiffness indicating early tissue remodeling.

CONCLUSION

Assessment of children with CFLD by means of ARFI elastography yields adequate results when compared to conventional US. For detection of early stages of liver disease with mild fibrotic reactions of hepatic tissue, ARFI elastography might offer diagnostic advantages over conventional US. Thus, liver stiffness measured by means of elastography might represent a valuable biological parameter for evaluation and follow-up of CFLD.

Beyond acute appendicitis: imaging of additional pathologies of the pediatric appendix

Primary acute appendicitis is by far the most common pathological condition affecting the appendix. There are differential diagnoses, however, when an abnormal appendix is found by imaging. The purpose of this paper is to highlight the imaging and clinical manifestations of less common appendiceal abnormalities in children. Familiarity with these alternative diagnoses might be particularly helpful in guiding management of the child whose clinical presentation is not typical for primary acute appendicitis.

Managing treatment complexity in cystic fibrosis: challenges and opportunities

Cystic fibrosis (CF) is a complex, chronic, multisystem disease for which there is currently no cure. Nonetheless, advances in management have led to dramatic improvements in patient survival. With this development, new issues have arisen for CF patients and their care providers, including an increased symptom burden and increased frequency of co-morbidities as patients reach older ages, leading to the need for a highly complicated and time-consuming regimen of treatments. Such high symptom and treatment burden often leads to non-adherence and low levels of competence with administration of therapy, both of which may have detrimental impacts on CF outcomes. Optimal management is also hindered by other patient-related factors, including inadequacies in disease education which may lead to issues with self-management. This is particularly important during the transition from parent-directed therapy to independent self-management that occurs during adolescence and early adulthood. Clinicians are also faced with a considerable challenge when selecting interventions for individual patients; although the paradigm of aggressive care necessitates a wide range of therapies, there is a limited evidence base with which to compare available therapeutic regimens. Novel pharmacological agents are being developed to target the underlying cause of CF, while non-pharmacological interventions aim to improve competence and maximize adherence and health outcomes. Comparative effectiveness research is needed to simplify management and facilitate the implementation of appropriate treatment strategies.

New animal models of cystic fibrosis: what are they teaching us?

PURPOSE OF REVIEW

Cystic fibrosis is the first human genetic disease to benefit from the directed engineering of three different species of animal models (mice, pigs, and ferrets). Recent studies on the cystic fibrosis pig and ferret models are providing new information about the pathophysiology of cystic fibrosis in various organ systems. Additionally, new conditional cystic fibrosis transmembrane conductance regulator (CFTR) knockout mice are teaching unexpected lessons about CFTR function in surprising cellular locations. Comparisons between these animal models and the human condition are key to dissecting the complexities of disease pathophysiology in cystic fibrosis.

RECENT FINDINGS

Cystic fibrosis pigs and ferrets have provided new models to study the spontaneous development of disease in the lung and pancreas, two organs that are largely spared overt spontaneous disease in cystic fibrosis mice. New cystic fibrosis mouse models are now interrogating CFTR functions involved in growth and inflammation at an organ-based level using conditional knockout technology. Together, these models are providing new insights on the human condition.

SUMMARY

Basic and clinical cystic fibrosis research will benefit greatly from the comparative pathophysiology of cystic fibrosis mice, pigs, and ferrets. Both similarities and differences between these three cystic fibrosis models will inform pathophysiologically important mechanisms of CFTR function in humans and aid in the development of both organ-specific and general therapies for cystic fibrosis.

[Usefulness of ultrasonography in children with right iliac fossa pain]

Acute pain in the right iliac fossa is common in children. It can arise from a wide variety of gastrointestinal and genitourinary processes that make up the differential diagnosis with acute appendicitis. In this article, we describe the most representative findings of these processes on ultrasonography. We emphasize the characteristics that enable these processes to be differentiated from acute appendicitis.

Nonvisualization of fetal gallbladder increases the risk of cystic fibrosis

OBJECTIVE

The aim of our study is to evaluate the prevalence of cystic fibrosis (CF) in fetuses referred for genetic testing because of ultrasonographic sign (nonvisualized fetal gallbladder--NVFGB).

METHOD

We reviewed the results of CFTR gene analysis over the period 2002 to 2009 in all consecutive cases referred because of NVFGB in Western France. We correlated these data with the presence of a more classical ultrasonographic finding (fetal echogenic bowel - FEB).

RESULTS

Cystic fibrosis was diagnosed in 5 of the 37 fetuses with NVFGB (13.5%, 95% confidence interval (CI): [2.5%; 24.5%]) and in only 9 of the 229 other cases referred because of FEB (3.9%, 95% CI: [3.2%; 14.7%]). In our series, all CF-affected fetuses with NVFGB also had FEB. The risk of CF was 11.6-fold higher in fetuses with both indications (NVFGB + FEB) than in fetuses with isolated FEB (45.5% vs 3.9%, RR = 11.6, 95% CI: [4.7%; 28.8%], p = 0.0001). We also estimated that the residual risk of CF was less than 1 in 68 (1.5%) when a single mutation was identified in the fetus by our molecular protocol.

CONCLUSION

Ultrasonographic evidence of NVFGB is an additional risk factor for CF in cases with FEB.

Comparative biology of cystic fibrosis animal models

Animal models of human diseases are critical for dissecting mechanisms of pathophysiology and developing therapies. In the context of cystic fibrosis (CF), mouse models have been the dominant species by which to study CF disease processes in vivo for the past two decades. Although much has been learned through these CF mouse models, limitations in the ability of this species to recapitulate spontaneous lung disease and several other organ abnormalities seen in CF humans have created a need for additional species on which to study CF. To this end, pig and ferret CF models have been generated by somatic cell nuclear transfer and are currently being characterized. These new larger animal models have phenotypes that appear to closely resemble human CF disease seen in newborns, and efforts to characterize their adult phenotypes are ongoing. This chapter will review current knowledge about comparative lung cell biology and cystic fibrosis transmembrane conductance regulator (CFTR) biology among mice, pigs, and ferrets that has implications for CF disease modeling in these species. We will focus on methods used to compare the biology and function of CFTR between these species and their relevance to phenotypes seen in the animal models. These cross-species comparisons and the development of both the pig and the ferret CF models may help elucidate pathophysiologic mechanisms of CF lung disease and lead to new therapeutic approaches.

Guidelines for the diagnosis and management of distal intestinal obstruction syndrome in cystic fibrosis patients

Complete or incomplete intestinal obstruction by viscid faecal material in the terminal ileum and proximal colon - distal intestinal obstruction syndrome (DIOS) - is a common complication in cystic fibrosis. Estimates of prevalence range from 5 to 12 episodes per 1000 patients per year in children, with higher rates reported in adults. DIOS is mainly seen in patients with pancreatic insufficiency, positive history of meconium ileus and previous episodes of DIOS. DIOS is being described with increasing frequency following organ transplantation. Diagnosis is based on suggestive symptoms with a right lower quadrant mass confirmed on X-ray. The main differential is chronic constipation. Treatment consists of rehydration combined with stool softening laxatives or gut lavage with balanced electrolyte solutions. Rapid fluid shifts have been described following osmotic agents. Avoiding dehydration and optimizing pancreatic enzyme dosage may reduce the chance of further episodes. Prophylactic laxative therapy is widely used, but is not evidence-based.

Hepatobiliary and pancreatic imaging in children-techniques and an overview of non-neoplastic disease entities

Imaging plays a major role in the diagnostic work-up of children with hepatobiliary or pancreatic diseases. It consists mainly of US, CT and MRI, with US and MRI being the preferred imaging modalities because of the lack of ionizing radiation. In this review the technique of US, CT and MRI in children will be addressed, followed by a comprehensive overview of the imaging characteristics of several hepatobiliary and pancreatic disease entities most common in the paediatric age group.

Pathophysiological preconditions promoting mixed "black" pigment plus cholesterol gallstones in a DeltaF508 mouse model of cystic fibrosis

Gallstones are frequent in patients with cystic fibrosis (CF). These stones are generally "black" pigment (i.e., Ca bilirubinate) with an appreciable cholesterol admixture. The pathophysiology and molecular mechanisms for this "mixed" gallstone in CF are unknown. Here we investigate in a CF mouse model with no overt liver or gallbladder disease whether pathophysiological changes in the physical chemistry of gallbladder bile might predict the occurrence of "mixed" cholelithiasis. Employing a DeltaF508 mouse model with documented increased fecal bile acid loss and induced enterohepatic cycling of bilirubin (Am J Physiol Gastrointest Liver Physiol 294: G1411-G1420, 2008), we assessed gallbladder bile chemistry, morphology, and microscopy in CF and wild-type mice, with focus on the concentrations and compositions of the common biliary lipids, bilirubins, Ca(2+), and pH. Our results demonstrate that gallbladder bile of CF mice contains significantly higher levels of all bilirubin conjugates and unconjugated bilirubin with lower gallbladder bile pH values. Significant elevations in Ca bilirubinate ion products in bile of CF mice increase the likelihood of supersaturating bile and forming black pigment gallstones. The risk of potential pigment cholelithogenesis is coupled with higher cholesterol saturations and bile salt hydrophobicity indexes, consistent with a proclivity to cholesterol phase separation during pigment gallstone formation. This is an initial step toward unraveling the molecular basis of CF gallstone disease and constitutes a framework for investigating animal models of CF with more severe biliary disease, as well as the human disease.