Review of the abdominal manifestations of cystic fibrosis in the adult patient

Intraluminal causes of mechanical small bowel obstruction: CT findings and diagnostic approach

Intraluminal causes of small bowel obstruction (SBO) are less common than mural or extrinsic etiologies. This review categorizes intraluminal causes of SBO into four broad categories to provide a diagnostic framework for radiologic interpretation: 1) ingested contents, 2) bowel stasis, 3) inflammatory causes, and 4) neoplasms. Ingested materials can result in SBO when individual or accumulated contents are too large to pass, such as in the case of foreign bodies or bezoars. Bowel stasis causing SBO can be secondary to abnormal bowel function, such as in cystic fibrosis, reduced transit of contents at sites of narrowing such as surgical anastomoses, or the formation of enteroliths in diverticula which may subsequently dislodge and result in luminal obstruction. Inflammatory causes of SBO include strictures or fistulas that allow foreign bodies (such as gallstones) formed outside the bowel to enter the bowel lumen and cause obstruction. Finally, neoplasms can present as endophytic masses that occlude the bowel lumen through a ball-valve mechanism or serve as a lead point for intussusception. Recognizing the imaging features that are suggestive of intraluminal SBO is critical for accurate diagnosis and timely patient care.

Imaging of cystic fibrosis manifestations in the abdomen

Cystic fibrosis is a common inherited autosomal recessive disease affecting 35,000 persons in the United States. It is caused by mutations of the cystic fibrosis transmembrane regulator (CFTR) gene, located on the long arm of chromosome 7.This protein carries chlorine in the membranes of epithelial cells of exocrine glands. Mutations in the CFTR gene results in production of abnormally viscous mucus. Although it primarily affects the lungs, cystic fibrosis is a multisystem disease with involvement of extra thoracic organs including the liver, pancreas, kidneys and digestive tract.With advances in the management of cystic fibrosis resulting in improved life expectancy, cystic fibrosis patients are surviving into adulthood and extrapulmonary disease has become more commonplace. It is essential that radiologists are aware of the spectrum of potential manifestations of cystic fibrosis to allow accurate diagnosis.The purpose of this manuscript is to provide an overview of the pathophysiology and imaging findings of abdominal entities unique to patients with cystic fibrosis. We will present a wide spectrum of renal, pancreatic, gastrointestinal, hepatobiliary and post-transplant cases describing the typical findings that will assist radiologists in providing a timely diagnosis for patients with cystic fibrosis.

Presentation, characteristics and management of obstructive intestinal conditions in cystic fibrosis

Objective

Constipation and distal intestinal obstruction syndrome (DIOS) are common gastrointestinal manifestations of cystic fibrosis (CF). The primary aim was to describe the characteristics of constipation and DIOS hospitalisations in a paediatric and adult CF service over a 12-year period. The secondary aims were to determine the proportion of constipation and DIOS presentations which met the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) CF Working Group definitions and to describe management strategies of both conditions.

Method

A retrospective study of children and adults with CF who were admitted with a primary diagnosis of constipation or DIOS between 1 January 2011 and 31 December 2022. ESPGHAN definitions for constipation and DIOS were retrospectively applied to all admissions to determine if the primary medical diagnosis met ESPGHAN criteria.

Results

During the 12-year study period, 42 hospitalisations for constipation were recorded in 19 patients, and 33 hospitalisations for DIOS were recorded in 23 patients. 88.10% of constipation episodes met ESPGHAN definitions, compared with 3.0% of DIOS episodes. Constipation and DIOS were primarily treated with polyethylene glycol (PEG). The use of sodium amidotrizoate meglumine enemas was significantly higher in the DIOS group (p=0.045). Those admitted with DIOS were significantly less likely to be recommended a weaning dose of PEG (p=0.018).

Conclusion

Children and adults with CF are more commonly admitted for the management of constipation than DIOS. There is considerable variation in diagnostic and therapeutic practice, and this study highlights the need to enhance the translation and adoption of existing best-practice guidelines.

Diagnosis, Management, and Prognosis of Cystic Fibrosis-Related Liver Disease in Children

Cystic fibrosis (CF) is a multifaceted disorder predominantly investigated for its pulmonary manifestations, yet patients with CF also exhibit a spectrum of extrapulmonary manifestations, notably those involving the hepatobiliary system. The latter constitutes the third leading cause of morbidity and mortality in individuals with CF. Cystic fibrosis-related liver disease (CFLD), with an escalating prevalence, manifests diverse clinical presentations ranging from hepatomegaly to cirrhosis and hepatopulmonary syndrome. Consequently, early detection and appropriate management are imperative for sustaining the health and influencing the quality of life of CF patients afflicted with CFLD. This review aims to consolidate existing knowledge by providing a comprehensive overview of hepatobiliary manifestations associated with CF. It delineates the clinical hepatobiliary manifestations, diagnostic methodologies, incorporating minimally invasive markers, and therapeutic approaches, encompassing the impact of novel CFTR modulators on CFLD. Given the exigency of early diagnosis and the intricate management of CFLD, a multidisciplinary team approach is essential to optimize care and enhance the quality of life for this subset of patients. In conclusion, recognizing CF as more than solely a pulmonary ailment, the authors underscore the imperative for further clinical investigations to establish a more robust evidence base for CFLD management within the continuum of this chronic disease.

Cystic Fibrosis in an Adolescent: A "Miranda Warning" Against Blaming TB-A Case-Based Scholarly Update

Cystic fibrosis (CF) is a multisystem disorder that occurs as a result of autosomal recessive congenital transmission of CF transmembrane conductance regulator (CFTR) gene mutation on chromosome 7. Because it is considered a disease of the Caucasian pediatric population or due to lack of awareness, it is rarely considered in developing countries like ours. This case report presents the first case of cystic fibrosis ever reported in Ethiopia and possibly East Africa, that of a 17-year-old female diagnosed with the disease following a CT scan of her abdomen and chest. She was initially misdiagnosed and treated for tuberculosis (TB) as she was a chronic cougher. Perhaps due to epidemiological evidence, there is an obstinate tendency of blaming tuberculosis (TB) for almost every case of chronic cough with fibro-bronchiectatic lung parenchymal changes in Ethiopia. Once a diagnosis of TB is posted on such patients, their diagnosis remains in the circle of TB reinfection, relapse or resistance, followed by multiple phases of anti-mycobacterial drugs. This could lead to hazardous implications, including unnecessary prolonged anti-mycobacterial treatments, possibility of developing drug resistance, and mismanagement-related patient morbidity. This patient's chest and abdominal CT findings, including bronchiectasis, hepatic steatosis, pancreatic lipomatosis, micro-gallbladder and proximal colonic wall thickening, led to the diagnosis of CF. This article, presenting the first documented case of CF in the region, is meant to be a helpful reminder for clinicians and radiologists to also consider presumably "rare" illnesses like CF rather than blaming TB for every chronic cough and highlights the importance of abdominal CT features in the diagnosis of CF.

Diagnosis and Management of Gastrointestinal Manifestations in Children with Cystic Fibrosis

Cystic fibrosis (CF) is primarily known for its pulmonary consequences, which are extensively explored in the existing literature. However, it is noteworthy that individuals with CF commonly display gastrointestinal (G-I) manifestations due to the substantial presence of the cystic fibrosis transmembrane conductance regulator (CFTR) protein in the intestinal tract. Recognized as pivotal nonpulmonary aspects of CF, G-I manifestations exhibit a diverse spectrum. Identifying and effectively managing these manifestations are crucial for sustaining health and influencing the overall quality of life for CF patients. This review aims to synthesize existing knowledge, providing a comprehensive overview of the G-I manifestations associated with CF. Each specific G-I manifestation, along with the diagnostic methodologies and therapeutic approaches, is delineated, encompassing the impact of innovative treatments targeting the fundamental effects of CF on the G-I tract. The findings underscore the imperative for prompt diagnosis and meticulous management of G-I manifestations, necessitating a multidisciplinary team approach for optimal care and enhancement of the quality of life for affected individuals. In conclusion, the authors emphasize the urgency for further clinical studies to establish a more robust evidence base for managing G-I symptoms within the context of this chronic disease. Such endeavors are deemed essential for advancing understanding and refining the clinical care of CF patients with G-I manifestations.

A novel free-breathing abdominal RAVE T2/T1 hybrid MRI sequence in patients with cystic fibrosis: Preliminary results

OBJECTIVES

Patients with cystic fibrosis (CF) increasingly require imaging for the diagnosis of abdominal complications. We prospectively evaluated the image quality and signal-to-noise ratio (SNR) of a modern radial volumetric encoding (RAVE) T2/T1 hybrid sequence for abdominal magnetic resonance imaging (MRI). RAVET2/T1 is a three-dimensional radial sequence with fat saturation and blood flow suppression that acquires T2- and T1-weighted contrasts in one scan in an identical slice position during free-breathing.

METHODS

Sixteen CF patients underwent axial T2 HASTE (1000 ms/93 ms TR/TE), T1 DIXON (6.8 ms/2.4 ms/4.8 ms TR/TE1/TE2), and RAVE T2/T1 hybrid sequence (1200 ms/1.7 ms/3.3 ms/4.9 ms/102 ms TR/TE1/TE2/TE3/TE4) of the upper abdomen at 1.5 Tesla. The SNR values in six different regions were assessed and compared using the Wilcoxon signed-rank test. The image quality criteria were rated on a 5-point Likert scale.

RESULTS

In all regions, the SNR was significantly higher in the T2 weighted aspect of the RAVE T2/T1 hybrid sequence compared to T2 HASTE (p < 0.05) and significantly lower in the T1 weighted in-phase aspect of the RAVE T2/T1 hybrid sequence compared to the T1 DIXON sequence (p < 0.05). Qualitatively the T2 weighted aspect of the RAVE T2/T1 hybrid sequence was rated significantly higher than the T2 HASTE in 6 of 7 categories (p < 0.05) and the T1 weighted in-phase aspect of the RAVE T2/T1 hybrid sequence was rated significantly higher than the T1 DIXON in 2 of 6 categories (p < 0.05).

CONCLUSIONS

The abdominal radial RAVE T2/T1 hybrid sequence provided higher image quality and SNR than the T2HASTEsequence. Together with increased robustness against motion artifacts, the RAVE T2/T1 hybrid sequence appears to be a good tool for abdominal imaging in CF patients.

Endoscopic Ultrasound Finding of Diffuse Echogenicity in the Pancreas, Is It Relevant?

BACKGROUND/OBJECTIVES

Diffuse echogenicity of the pancreas, a commonly discovered finding on endoscopic ultrasound (EUS), is often of undetermined significance. The goal of this study was to characterize the clinical picture and pancreatic function in patients who incidentally present with this endosonographic finding.

METHODS

This was a case-control study comparing consecutive adult patients with diffuse echogenicity of the pancreas found on EUS to those who did not have known pancreas disease. Demographic and clinical data were extracted from the electronic medical record. The primary endpoint was exocrine pancreatic insufficiency (EPI) defined as fecal elastase (FE-1) < 200 μg/g.

RESULTS

A total of 166 patients were included in this study. There were 89 patients who had diffuse echogenicity of the pancreas on EUS and FE-1 testing. There were 77 control patients with chronic diarrhea who did not have known pancreas disease but did have FE-1 testing. EPI was significantly more likely in the fatty pancreas group compared to the control group (47% vs 6%, p < 0.001). There was also a significantly greater proportion of smokers in the fatty pancreas group compared to the control group (42% vs 17%, p = 0.002). There were no other differences in baseline characteristics between the two groups, including prevalence of chronic pancreatitis by Rosemont classification. On multiple logistic regression analysis controlling for multiple variables, smoking (OR 2.26, 95% CI 1.15-4.43) and NAFLD (OR 3.99, 95% CI 1.09-14.70) had significant associations with EPI.

CONCLUSIONS

This study found a significantly greater amount of patients who had diffuse echogenicity of the pancreas on EUS to also have EPI. This is compared to a control group of patients without known pancreas disease. This prevalence was found in the absence of a significant association with chronic pancreatitis on EUS based on Rosemont classification. Future controlled studies are required to further investigate this relationship.

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.

Hepatic manifestations of systemic disease: an imaging-based review

The liver is responsible for many processes that maintain human metabolic homeostasis and can be affected by several pediatric systemic diseases. In this manuscript, we explore key pathological findings and imaging features across multiple modalities of a spectrum of congenital, metabolic and autoimmune disorders. Strengthening the radiologists' knowledge regarding potential hepatic manifestations of these systemic diseases will ultimately lead to improved care for pediatric patients.

Animal Models and Their Role in Understanding the Pathophysiology of Cystic Fibrosis-Associated Gastrointestinal Lesions

The life expectancy of cystic fibrosis (CF) patients has greatly increased over the past decade, and researchers and clinicians must now navigate complex disease manifestations that were not a concern prior to the development of modern therapies. Explosive growth in the number of CF animal models has also occurred over this time span, clarifying CF disease pathophysiology and creating opportunities to understand more complex disease processes associated with an aging CF population. This review focuses on the CF-associated pathologies of the gastrointestinal system and how animal models have increased our understanding of this complex multisystemic disease. Although CF is primarily recognized as a pulmonary disease, gastrointestinal pathology occurs very commonly and can affect the quality of life for these patients. Furthermore, we discuss how next-generation genetic engineering of larger animal models will impact the field's understanding of CF disease pathophysiology and the development of novel therapeutic strategies.

[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.

Clinical characteristics and prediction of the asymptomatic phenotype of pneumatosis intestinalis in critically ill patients: a retrospective observational study

Aim

The differences in clinical characteristics between benign asymptomatic and symptomatic pneumatosis intestinalis (PI) remain unknown. This study aimed to reveal the clinical characteristics of PI in critically ill patients.

Methods

This was a retrospective observational study undertaken between 2013 and 2017 in a single facility. Patients with PI were enrolled. Pneumatosis intestinalis was diagnosed using computed tomography, and clinical data were collected. Pathologic PI refers to PI with bowel ischemia. Asymptomatic PI refers to PI with a benign etiology.

Results

There were 17 patients with pathologic PI and 31 with asymptomatic PI. Pathologic PI was detected at day 4 of hospital stay, and asymptomatic PI was detected at day 30 of hospital stay (P < 0.01). The symptoms that were different between pathologic and asymptomatic PI were acute diarrhea (18% and 65%, P = 0.01), C‐reactive protein level elevation (9.9 and 2.1 mg/dL, P = 0.01), and systemic inflammatory reaction syndrome (100% and 13%, P < 0.01). Computed tomography findings showed a difference in the occurrence of ascites collection (94% versus 23%, P < 0.01) and PI of the ascending colon (47% versus 80%, P = 0.02). Hospital mortality of pathologic PI was 88%, whereas all patients with benign PI survived. The positive likelihood ratio of acute diarrhea with PI of the ascending colon to diagnose benign PI was 7.33 (1.11–48.5).

Conclusions

Pneumatosis intestinalis of the ascending colon that occurs in the post‐intensive care phase with a poor inflammatory reaction, acute diarrhea, and no ascites collection could be benign. In other cases, bowel ischemia should be promptly ruled out.

Non-neoplastic cholangiopathies: an algorithmic approach

Cholangiopathies are chronic diseases that affect the bile ducts, comprising a heterogeneous group of progressive and potentially fatal entities. The diagnosis of these diseases is a great challenge for radiologists because of the overlapping of their clinical, biochemical, and imaging findings. Nevertheless, identifying the precise etiology is crucial, given that the therapeutic options are distinct and influence the prognosis of the patient. The purpose of this review article is to discuss some of the non-neoplastic causes of cholangiopathies and to provide a useful diagnostic algorithm.

The Efficacy of MRI in the diagnostic workup of cystic fibrosis-associated liver disease: A clinical observational cohort study

PURPOSE

To identify independent imaging features and establish a diagnostic algorithm for diagnosis of cystic fibrosis (CF)-associated liver disease (CFLD) in CF patients compared to controls using gadoxetic acid-enhanced MRI.

METHODS

A total of 90 adult patients were enrolled: 50 with CF, 40 controls. The CF group was composed of two subgroups: a retrospective test subgroup (n = 33) and a prospective validation subgroup (n = 17). Controls (patients with normal liver enzymes and only benign focal liver lesions) were divided accordingly (27:13). MRI variables, including quantitative and qualitative parameters, were used to distinguish CFLD from controls using clinical symptoms, laboratory tests and Debray criteria. Disease severity was classified according to Child-Pugh and Albumin-Bilirubin (ALBI) scores. Fifteen qualitative single-lesion CF descriptors were defined. Two readers independently evaluated the images. Univariate statistical analysis was performed to obtain significant imaging features that differentiate CF patients from controls. Through multivariate analysis using chi-squared automatic interaction detector (CHAID) methodology the most important descriptors were identified. Diagnostic performance was assessed by receiver-operating characteristic (ROC) analysis.

RESULTS

Three independent imaging descriptors distinguished CFLD from controls: (1) presence of altered gallbladder morphology; (2) periportal tracking; and (3) periportal fat deposition. Prospective validation of the classification algorithm demonstrated a sensitivity of 94.1% and specificity of 84.6% for discriminating CFLD from controls. Disease severity was well associated with the imaging features.

CONCLUSIONS

A short unenhanced MRI protocol can identify the three cardinal imaging features of CFLD. The hepatobiliary phase of gadoxetic acid-enhanced MRI can define CFLD progression.

KEY POINTS

• Using a multivariate classification analysis, we identified three independent imaging features, altered gallbladder morphology (GBAM), periportal tracking (PPT) and periportal fat deposition (PPFD), that could diagnose CFLD with high sensitivity, 94.1 % (95% CI: 71.3-99.9) and moderate specificity, 84.6 % (95% CI: 54.6-98.1). • Based upon the results of this study, gadoxetic acid-enhanced MRI with DWI is able to diagnose early-stage CFLD, as well as its progression.

Association of fatty pancreas with pancreatic endocrine and exocrine function

Aim

The purpose of this study was to clarify whether fatty pancreas might lead to impaired pancreatic endocrine or exocrine function.

Material and methods

The study involved 109 participants who had undergone the glucagon stimulation test and N-benzoyl-L-tyros-p-amino benzoic acid (BT-PABA) test to assess pancreatic function as well as unenhanced abdominal computed tomography (CT). Pancreatic endocrine impairment was defined as ΔC peptide immunoreactivity less than 2 [mmol/L] in the glucagon stimulation test, and pancreatic exocrine impairment was defined as a urinary PABA excretion rate less than 70% on the BT-PABA test. We defined as the mean CT value of pancreas / CT value of spleen (P/S ratio) as a marker to assess fatty pancreas. We analyzed the association between fatty pancreas and pancreatic impairment using the logistic regression model. The odds ratio (OR) is shown per 0.1 unit.

Results

Pancreatic endocrine function was impaired in 33.0% of the participants, and 56.9% of those were regarded as having pancreatic exocrine impairment. The P/S ratio was significantly correlated with pancreatic endocrine impairment in univariate analysis (OR = 0.61, 95% confidence interval (CI) = 0.43–0.83, P = 0.0013) and multivariate analysis (OR = 0.38, 95% CI = 0.22–0.61, P < .0001) for all participants. Similar significant relationships were observed in both univariate (OR = 0.70, 95% CI = 0.49–0.99, P = 0.04) and multivariate (OR = 0.39, 95% CI = 0.21–0.66, P = 0.0002) analyses for the participants without diabetes (n = 93). The amount of pancreatic fat was not associated with exocrine impairment in univariate analysis (OR = 0.80, 95% CI = 0.59–1.06, P = 0.12).

Conclusion

Fatty pancreas was associated with pancreatic endocrine impairment but did not have a clear relationship with pancreatic exocrine impairment.

Acute and chronic non-pulmonary complications in adults with cystic fibrosis

INTRODUCTION

Cystic fibrosis (CF) is a genetic disease that primarily affects the respiratory system and often leads to respiratory failure and premature death. Although pulmonary complications contribute to 85% of deaths, non-pulmonary complications are responsible for significant morbidity and mortality in adults with CF. Areas covered: This review summarizes acute and chronic non-pulmonary complications in CF patients, with emphasis on emerging complications and in the context of the current growth and aging of the CF adult population. It also addresses the potential benefits of CF transmembrane conductance regulator modulator therapy. Complications that occur after solid organ (e.g. lung and/or liver) transplantation have been excluded. The review is based on an extensive search of the available literature, using PubMed and international guidelines, and on the authors' clinical experience. Expert commentary: Acute non-pulmonary complications have been well described but should be recognized and managed carefully. Managing chronic non-pulmonary complications is an important and changing aspect of CF patient care, particularly with the emergence of novel complications in adults. Early detection of non-pulmonary complications is essential to the development of prevention and treatment strategies that aim to further improve the survival and health status of adult CF patients.

Functional insufficiency of the pancreas and the metabolic activity of the microbiota in cystic fibrosis adults patients

In order to optimize the therapy, the functional state of the pancreas (P) and the peculiarities of metabolic activity of intestinal microbiota in adults with cystic fibrosis (CF) were assessed. Materials and methods. 14 CF patients (20-34 years, 7 men, 7 women) were enrolled. In 8 patients, the diagnosis was confirmed in the first year of life on the basis of clinical data, positive sweat test, 5 had genetic confirmation. In 4 patients, the diagnosis was confirmed at the age of 8-13 years and 2 patients aged 18, 27 years. In this group, genetic confirmation was in 4 subjects. In addition to general clinical studies, the level of C-peptide in blood, elastase and the concentration of short chain fatty acids in feces was determined. Results and discussion. Of elastase feces in 9 patients was 5.5±4.7 icg/g, that is revealed severe exocrine insufficiency of the pancreas and in 5 patients the elastase level was normal and amounted to 402±124 icg/g. Deployed the clinical picture of diabetes mellitus was observed in 3 patients. Metabolic activity of the colon microflora as a whole was reduced, the sum of the concentration of short-chain fatty acids (ΣCn) was 6.03±4.11 mg/g at a rate of 10.61±5.11 (p

Point shear wave elastography of the pancreas in patients with cystic fibrosis: a comparison with healthy controls

PURPOSE

Manifestations of cystic fibrosis in the pancreas are gaining in clinical importance as patients live longer. Conventional ultrasonography and point shear wave elastography (pSWE) imaging are non-invasive and readily available diagnostic methods that are easy to perform. The aim of this study was to perform conventional ultrasonography and obtain pSWE values in the pancreases of patients with cystic fibrosis and to compare the findings with those of healthy controls.

METHODS

27 patients with cystic fibrosis (13 women/14 men; mean age 27.7 ± 13.7 years; range 9-58 years) and 60 healthy control subjects (30 women/30 men; mean age 30.3 ± 10.0 years; range 22-55 years) underwent examinations of the pancreas with conventional ultrasound and pSWE imaging.

RESULTS

Patients with cystic fibrosis have an echogenic pancreatic parenchyma. We found cystic lesions of the pancreas in six patients. pSWE imaging of the pancreatic parenchyma gave significantly lower shear wave velocities in patients with cystic fibrosis than in the control group (1.01 m/s vs 1.30 m/s; p < 0.001).

CONCLUSIONS

Using pSWE imaging in vivo, we have shown that the pancreas is considerably softer in patients with cystic fibrosis than in a healthy control population.

Cystic Fibrosis Kidney Disease: 10 Tips for Clinicians

Increased longevity in people with cystic fibrosis (CF) means that more people are surviving long enough to develop kidney complications. Nephrologists and their colleagues now face a steep learning curve as many of them encounter patients with CF related kidney disease (CFKD) for the first time. This article presents perspectives from a medical sociologist with CF on what renal health professionals should know about people with CFKD. It outlines challenges that people with CFKD as they age, framing these struggles as opportunities for clinicians to help these unique patients achieve and maintain their best possible quality of life.

Pediatric Rectal Prolapse

Rectal prolapse is a common and self-limiting condition in infancy and early childhood. Most cases respond to conservative management. Patients younger than 4 years with an associated condition have a better prognosis. Patients older than 4 years require surgery more often than younger children. Multiple operative and procedural approaches to rectal prolapse exist with variable recurrence rates and without a clearly superior operation. These include sclerotherapy, Thiersch's anal cerclage, Ekehorn's rectopexy, laparoscopic suture rectopexy, and posterior sagittal rectopexy.

The Clinical Implications of Fatty Pancreas: A Concise Review

Fatty pancreas is a newly recognized condition which is poorly investigated until today as compared to nonalcoholic fatty liver disease. It is characterized by pancreatic fat accumulation and subsequent development of pancreatic and metabolic complications. Association of fatty pancreas have been described with type 2 diabetes mellitus, acute and chronic pancreatitis and even pancreatic carcinoma. In this review article, we provide an update on clinical implications, pathogenesis, diagnosis, treatment and outcomes.

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.

Fat-containing Retroperitoneal Lesions: Imaging Characteristics, Localization, and Differential Diagnosis

The complex anatomy of the retroperitoneum is reflected in the spectrum of neoplastic and nonneoplastic conditions that can occur in the retroperitoneum and appear as soft-tissue masses. The presence of fat within a retroperitoneal lesion is helpful in refining the differential diagnosis. Fat is easily recognized because of its characteristic imaging appearance. It typically is hyperechoic at ultrasonography and demonstrates low attenuation at computed tomography (-10 to -100 HU). Magnetic resonance imaging is a more ideal imaging modality because it has better soft-tissue image contrast and higher sensitivity for depicting (a) microscopic fat by using chemical shift imaging and (b) macroscopic fat by using fat-suppression techniques. Whether a lesion arises from a retroperitoneal organ or from the soft tissues of the retroperitoneal space (primary lesion) is determined by examining the relationship between the lesion and its surrounding structures. Multiple imaging signs help to determine the organ of origin, including the "beak sign," the "embedded organ sign," the "phantom (invisible) organ sign," and the "prominent feeding artery sign." Adrenal adenoma is the most common adrenal mass that contains microscopic fat, while myelolipoma is the most common adrenal mass that contains macroscopic fat. Other adrenal masses, such as pheochromocytoma and adrenocortical carcinoma, rarely contain fat. Renal angiomyolipoma is the most common fat-containing renal mass. Other fat-containing renal lesions, such as lipoma and liposarcoma, are rare. Fatty replacement of the pancreas and pancreatic lipomas are relatively common, whereas pancreatic teratomas are rare. Of the primary retroperitoneal fat-containing lesions, lipoma and liposarcoma are common, while other lesions are relatively rare. (©)RSNA, 2016.

Fatty Pancreas: Should We Be Concerned?

The metabolic consequences of visceral fat deposition are well known, and the presence of intrapancreatic fat (IPF) has been recognized for decades. However, our knowledge about the distribution of fat in the pancreas and its clinical implications is in a nascent stage. Various terms have been proposed to describe IPF; for the purpose of this narrative review, we chose the general term fatty pancreas. Herein, we describe the radiologic, endoscopic, and histopathologic aspects of diagnosing fatty pancreas and provide an overview of the diseases associated with this condition. Our purpose is to highlight diagnostic challenges and identify specific clinical questions that would benefit from further study. As evident in this review, IPF is associated with various metabolic diseases, pancreatitis, pancreatic cancer, and precancer-yet establishing causality needs careful, further study.

Imaging the Abdominal Manifestations of Cystic Fibrosis

Cystic fibrosis (CF) is a multisystem disease with a range of abdominal manifestations including those involving the liver, pancreas, and kidneys. Recent advances in management of the respiratory complications of the disease has led to a greater life expectancy in patients with CF. Subsequently, there is increasing focus on the impact of abdominal disease on quality of life and survival. Liver cirrhosis is the most important extrapulmonary cause of death in CF, yet significant challenges remain in the diagnosis of CF related liver disease. The capacity to predict those patients at risk of developing cirrhosis remains a significant challenge. We review representative abdominal imaging findings in patients with CF selected from the records of two academic health centres, with a view to increasing familiarity with the abdominal manifestations of the disease. We review their presentation and expected imaging findings, with a focus on the challenges facing diagnosis of the hepatic manifestations of the disease. An increased familiarity with these abdominal manifestations will facilitate timely diagnosis and management, which is paramount to further improving outcomes for patients with cystic fibrosis.

Exploring the metabolic syndrome: Nonalcoholic fatty pancreas disease

After the first description of fatty pancreas in 1933, the effects of pancreatic steatosis have been poorly investigated, compared with that of the liver. However, the interest of research is increasing. Fat accumulation, associated with obesity and the metabolic syndrome (MetS), has been defined as "fatty infiltration" or "nonalcoholic fatty pancreas disease" (NAFPD). The term "fatty replacement" describes a distinct phenomenon characterized by death of acinar cells and replacement by adipose tissue. Risk factors for developing NAFPD include obesity, increasing age, male sex, hypertension, dyslipidemia, alcohol and hyperferritinemia. Increasing evidence support the role of pancreatic fat in the development of type 2 diabetes mellitus, MetS, atherosclerosis, severe acute pancreatitis and even pancreatic cancer. Evidence exists that fatty pancreas could be used as the initial indicator of "ectopic fat deposition", which is a key element of nonalcoholic fatty liver disease and/or MetS. Moreover, in patients with fatty pancreas, pancreaticoduodenectomy is associated with an increased risk of intraoperative blood loss and post-operative pancreatic fistula.

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.

Relevance of 3D Cholangiography and Transient Elastography to Assess Cystic Fibrosis-Associated Liver Disease?

Background. Cystic fibrosis-associated liver disease (CFLD) is a major cause of death. The objective of our retrospective study was to describe the relevance of magnetic resonance imaging (MRI) and liver stiffness measurement (LSM) for CFLD evaluation. Methods. All cystic fibrosis adult patients evaluated by MRI and LSM were included. MR signs of portal hypertension (PHT), dysmorphia, or cholangitis were collected and LSM expressed in kPa and Metavir. Results. Of 25 patients, 52% had abnormal MRI. Median LSM was 5.7 kPa (3.4–9.9). Three patients had F2 score and one had F3 score. In patients with PHT, LSM was 7.85 kPa (3.7–9.9) compared to 5 (3.4–7.5) in others, p = 0.02. In patients with abnormal liver function tests, 50% had increased LSM (≥F2), whereas 94% with normal tests had normal LSM (p = 0.04). Seven patients had abnormal MRI despite normal ultrasonography. Conclusions. MRI and LSM provide useful information on CFLD and may help to screen patients with PHT.

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.

On the mechanism of gating defects caused by the R117H mutation in cystic fibrosis transmembrane conductance regulator

KEY POINTS

Two functional abnormalities of cystic fibrosis transmembrane conductance regulator (CFTR), a 25% reduction of the single-channel conductance (g) and a ∼13-fold lower open probability (Po ), were found with the R117H mutation that is associated with mild forms of cystic fibrosis. Characterizations of the gating defects of R117H-CFTR led to the conclusion that the mutation decreases Po by perturbing the gating conformational changes in CFTR's transmembrane domains (TMDs) without altering the function of the nucleotide binding domains (NBDs). Nonetheless, gating of the R117H-CFTR can be improved by a variety of pharmacological reagents supposedly acting on NBDs such as ATP analogues, or TMDs (e.g. VX-770 or nitrate). These reagents potentiate synergistically R117H-CFTR gating to a level that allows accurate assessments of its gating deficits. Our studies not only elucidate the mechanism underpinning gating dysfunction of R117H-CFTR, but also provide a mechanistic understanding of how VX-770 ameliorates the gating defects in the R117H mutant.

ABSTRACT

Cystic fibrosis (CF) is caused by loss-of-function mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene encoding a phosphorylation-activated, but ATP-gated chloride channel. In the current study, we investigated the mechanism responsible for the gating defects manifested in R117H-CFTR, an arginine-to-histidine substitution at position 117 of CFTR that is associated with mild forms of CF. We confirmed previous findings of a 25% decrease of the single-channel conductance (g) in R117H-CFTR, but found a ∼13-fold lower open probability (Po ). This dramatic gating deficit is not due to dysfunctional nucleotide binding domains (NBDs) as the mutation does not alter the apparent affinity for ATP, and the mutant channels respond to ATP analogues in a similar manner as wild-type CFTR. Furthermore, once ATP hydrolysis is abolished, the R117H mutant can be trapped in a prolonged 'burst opening' conformation that is proposed to be equipped with a stable NBD dimer. On the other hand, our results support the conclusion that the R117H mutation decreases Po by perturbing the gating conformational changes in CFTR's transmembrane domains as even when NBDs are kept at a dimerized configuration, Po is reduced by ∼10-fold. Moreover, our data demonstrate that a synergistic improvement of R117H-CFTR function can be accomplished with a combined regiment of VX-770 (Ivacaftor), nitrate ion (NO3 (-) ) and N(6) -(2-phenylethyl)-2'-deoxy-ATP (d-PATP), which almost completely rectifies the gating defect of R117H-CFTR. Clinical implications of our results are discussed.

Cystic fibrosis from the gastroenterologist's perspective

Cystic fibrosis is a life-limiting, recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Increased survival outcomes and the multisystem nature of the disease, including the involvement of hepatobiliary and gastrointestinal tracts, now require the need for more extensive knowledge and expertise in cystic fibrosis among gastroenterologists. Manifestations are either a direct consequence of the primary defect in cystic fibrosis or a secondary complication of the disease or therapy. Adult patients with cystic fibrosis also have an increased risk of malignancy in the gastrointestinal and pancreatico-biliary tracts compared with the general population. Novel treatments that target the basic defects in the CFTR protein have emerged, but to date not much is known about their effects on the gastrointestinal and hepatobiliary systems. The introduction of such therapies has provided new opportunities for the application of intestinal endpoints in clinical trials and the understanding of underlying disease mechanisms that affect the gut in cystic fibrosis.

Bowel ultrasound imaging in patients with cystic fibrosis: Relationship with clinical symptoms and CFTR genotype

BACKGROUND

Ultrasound imaging is used to assess bowel abnormalities in gastrointestinal diseases. We aimed to assess the rate of predefined bowel ultrasound signs and their relationship with gastrointestinal symptoms and the cystic fibrosis transmembrane conductance regulator (CFTR) genotype in cystic fibrosis patients in regular follow-up.

METHODS

Prospective study of 70 consecutive patients with cystic fibrosis and 45 controls who underwent abdominal ultrasound; pertinent findings were related to gastrointestinal symptoms and, in cystic fibrosis patients, to pancreatic status, malabsorption degree, lipase intake, CFTR genotype (classified as severe or mild against functional class of CFTR mutations).

RESULTS

96% patients showed at least one abnormal bowel ultrasound sign. Most frequent signs were lymph node enlargement (64%), bowel loop dilatation (55%), thick corpuscular intraluminal content (49%), bowel wall hypervascularization (26%), thickened bowel wall (22%) and intussusception (17%). Patients with recurrent abdominal pain showed more bowel wall hypervascularization than patients without recurrent pain (47% vs. 19%, respectively; p = 0.02) and intussusception (58% vs. 17%, respectively; p < 0.01). Genotype was not associated to specific bowel ultrasound signs. Patients with bowel loop intussusception showed greater lipase intake than those without intussusception (8.118 ± 2.083 vs. 5.994 ± 4.187, respectively; p < 0.01).

CONCLUSION

Cystic fibrosis patients present a higher rate of bowel ultrasound abnormalities than controls. Bowel ultrasound abnormalities are associated with abdominal symptoms.

Pneumatosis intestinalis with obstructing intussusception: A case report and literature review

Pneumatosis intestinalis (PI) often represents a benign condition that should not be considered as an argument for surgery. We report a patient with PI and obstructing intussusception who underwent urgent colectomy and review the literatures regarding PI with intussusception. A 20-year-old man presented at our hospital with a 3-d intermittent lower abdominal pain history. He underwent steroid therapy for membranoproliferative glomerulonephritis for 4 years. Computed tomography revealed ascending colon intussusception with air within the wall. Intraoperative colonoscopy revealed numerous soft polypoid masses with normal overlying mucosa and right hemicolectomy was performed. Histological examination of colonic wall sections revealed large cysts in the submucosal layer. The pathological diagnosis was PI. Nine cases of intussusception associated with primary PI have been reported. Although primary PI often represents a benign condition that should not be considered as an argument for surgery, if the case involves intussusception and obstruction, emergent laparotomy should be considered.

Gastrointestinal manifestations of systemic disease: a multimodality review

Systemic diseases have many different presentations, including imaging findings in the bowel. Recognizing the imaging findings in these diseases is important in making the correct diagnosis. Although certain imaging features overlap, knowledge of specific findings along with the clinical presentation aid in narrowing the differential or in making an imaging diagnosis. The pictorial review will focus on the gastrointestinal manifestations of systemic diseases, including amyloidosis, angiotensin converter enzyme inhibitor-induced angioedema, celiac sprue, distal intestinal obstruction syndrome, graft-versus-host disease, hemolytic uremic syndrome, hemophilia, Henoch-Schönlein purpura, intestinal lymphangiectasia, mastocytosis, scleroderma, systemic lupus erythematosus, Wegener's granulomatosis, and Whipple's disease. The aforementioned diseases can be subdivided based upon the underlying process leading to the disease. The diseases discussed are categorized into autoimmune, infiltrative, treatment related, congenital/hereditary, and infectious etiologies.

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.

Cystic Fibrosis below the Diaphragm: Abdominal Findings in Adult Patients

Cystic fibrosis (CF) is the most common lethal autosomal recessive disease in the white population. Mutation of the CF transmembrane conductance regulator gene on chromosome 7 results in production of abnormally viscous mucus and secretions in the lungs of patients with CF. A similar pathologic process occurs in the gastrointestinal tract, pancreas, and hepatobiliary system. Inspissated mucus causes luminal obstruction and resultant clinical and radiologic complications associated with the disease process. Pancreatic involvement can result in exocrine and endocrine insufficiency, pancreatic atrophy, fatty replacement, or lipomatous pseudohypertrophy. Acute and chronic pancreatitis, pancreatic calcification, cysts, and cystosis also occur. Hepatic manifestations include hepatic steatosis, focal biliary and multilobular cirrhosis, and portal hypertension. Biliary complications include cholelithiasis, microgallbladder, and sclerosing cholangitis. The entire digestive tract can be involved. Distal ileal obstruction syndrome, intussusception, appendicitis, chronic constipation, colonic wall thickening, fibrosing colonopathy, pneumatosis intestinalis, gastroesophageal reflux, and peptic ulcer disease have been described. Renal manifestations include nephrolithiasis and secondary amyloidosis. The educational objectives of this review are to reveal the abdominal manifestations of CF to facilitate focused analysis of cross-sectional imaging in adult patients. Life expectancy in patients with CF continues to improve because of a combination of aggressive antibiotic treatment, improved emphasis on nutrition and physiotherapy, and development of promising new CF transmembrane conductance regulator modulators. As lung function and survival improve, extrapulmonary conditions, including hepatic and gastrointestinal malignancy, will be an increasing cause of morbidity and mortality. Awareness of the expected abdominal manifestations of CF may assist radiologists in identifying acute inflammatory or neoplastic conditions. (©)RSNA, 2015.

Cystic fibrosis: unenhanced CT description of the appendix in asymptomatic adults

OBJECTIVE

The purpose of this study was to describe the unenhanced CT appearance of the appendix in adults with cystic fibrosis.

SUBJECTS AND METHODS

Among adults with cystic fibrosis undergoing follow-up at our hospital, 71 patients (35 women, 36 men; mean age, 33 years; range, 18-59 years) without a history of appendectomy or current abdominal pain were prospectively included in this study and underwent unenhanced abdominopelvic MDCT. Two readers coded visualization of the appendix, measured the diameter of the appendix, and described the attenuation of its contents in relation to the intestinal wall. They also coded the presence of colonic wall redundancy, pancreatic fatty replacement, and cirrhosis. Lung transplant status and CFTR gene mutations were recorded. Analysis of variance, linear regression analysis, Student t test, and Pearson test were used.

RESULTS

The appendix was detected in all patients. The mean diameter was recorded as 10.6 ± 3.5 mm. The mean diameter was larger when the appendix contained hyperattenuating material (p = 0.001). There was no association between diameter and the other coded CT findings (p = 0.076-0.466), transplant status (p = 0.788), or CFTR mutation (p = 0.078). In 75% of the patients, the appendix contained hyperattenuating material with a higher proportion in homozygous ΔF508 mutation (p = 0.029) without any significant effect of the other CT features (p = 0.056-0.392), or transplant status (p = 1.000).

CONCLUSION

The appendix is larger in adults with cystic fibrosis than in those without it and appears hyperattenuating at unenhanced CT in 75% of patients, more commonly in those with ΔF508 homozygous mutation.

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.

Pneumatosis Intestinalis Predictive Evaluation Study (PIPES): a multicenter epidemiologic study of the Eastern Association for the Surgery of Trauma

BACKGROUND

Pneumatosis intestinalis (PI) is associated with numerous adult conditions, ranging from benign to life threatening. To date, series of PI outcomes consist of case reports and small retrospective series.

METHODS

We conducted a retrospective multicenter study, involving eight centers, of PI from January 2001 to December 2010. Demographics, medical history, clinical presentation, and outcomes were collected. Primary outcome was the presence of pathologic PI defined as confirmed transmural ischemia at surgery or the withdrawal of clinical care and subsequent mortality. Forward logistic regression and a regression tree analysis was used to generate a clinical prediction rule for pathologic PI.

RESULTS

During the 10-year study period, 500 patients with PI were identified. Of this number, 299 (60%) had benign disease, and 201 (40%) had pathologic PI. A wide variety of variables were statistically significant predictors of pathologic PI on univariate comparison. In the regression model, a lactate of 2.0 or greater was the strongest independent predictor of pathologic PI, with hypotension or vasopressor need, peritonitis, acute renal failure, active mechanical ventilation, and absent bowel sounds also demonstrating significance. Classification and regression tree analysis was used to create a clinical prediction rule. In this tree, the presence of a lactate value of 2.0 or greater and hypotension/vasopressor use had a predictive probability of 93.2%.

CONCLUSION

Discerning the clinical significance of PI remains a challenge. We identified the independent predictors of pathologic PI in the largest population to date and developed of a basic predictive model for clinical use. Prospective validation is warranted.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

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.

Gastrointestinal surgery in adult patients with cystic fibrosis

OBJECTIVE

Gastrointestinal conditions requiring surgical intervention are becoming increasingly frequent in adults with cystic fibrosis (CF) as life expectancy increases. In addition, patients with CF are at risk of specific gastrointestinal complications associated with their disease. This includes distal intestinal obstruction syndrome (DIOS), which may affect up to 15% of patients, and can present diagnostic and therapeutic challenges. The aim of this study was to determine the nature and frequency of general surgical procedures undertaken in a large cohort of adult CF patients so as to guide future care.

DESIGN

The medical records of all surviving adult CF patients followed at a large tertiary referral centre in the UK were scrutinised and details retrieved on those who had undergone abdominal surgery after the age of 16 years.

RESULTS

A total of 377 patients with CF were identified from the prospectively held database. Thirty-three patients had undergone 43 abdominal operations. The median age at surgery was 22.7 years (range 16-58 years). The three most commonly performed operations were: surgery for DIOS (n=9); cholecystectomy (n=8) and fundoplication (n=6). A past history of surgically treated meconium ileus at birth was a significant risk factor for requiring surgery for DIOS as an adult.

CONCLUSIONS

The treatment of DIOS-related complications is one of the main reasons for abdominal surgery in the adult CF population. The general surgical community needs to be increasingly aware of the existence of disease-related gastrointestinal conditions in adult CF patients so that treatment can be optimised.

Ileal smooth muscle dysfunction and remodeling in cystic fibrosis

Patients with cystic fibrosis (CF) often suffer from gastrointestinal cramps and intestinal obstruction. The CF transmembrane conductance regulator (CFTR) channel has been shown to be expressed in vascular and airway smooth muscle (SM). We hypothesized that the absence of CFTR expression alters the gastrointestinal SM function and that these alterations may show strain-related differences in the mouse. The aim of this study was to measure the contractile properties of the ileal SM in two CF mouse models. CFTR(-/-) and CFTR(+/+) mice were studied on BALB/cJ and C57BL/6J backgrounds. Responsiveness of ileal strips to electrical field stimulation (EFS), methacholine (MCh), and isoproterenol was measured. The mass and the cell density of SM layers were measured morphometrically. Finally, the maximal velocity of shortening (Vmax) and the expression of the fast (+)insert myosin isoform were measured in the C57BL/6J ileum. Ileal hyperreactivity was observed in response to EFS and MCh in CFTR(-/-) compared with CFTR(+/+) mice in C57BL/6J background. This latter observation was not reproduced by acute inhibition of CFTR with CFTR(inh)172. BALB/cJ CFTR(-/-) mice exhibited a significant increase of SM mass with a lower density of cells compared with CFTR(+/+), whereas no difference was observed in the C57BL/6J background. In addition, in this latter strain, ileal strips from CFTR(-/-) exhibited a significant increase in Vmax compared with control and expressed a greater proportion of the fast (+)insert SM myosin isoform with respect to total myosin. BALB/cJ CFTR(-/-) ilium had a greater relaxation to isoproterenol than the CFTR(+/+) mice when precontracted with EFS, but no difference was observed in response to exogeneous MCh. In vivo, the lack of CFTR expression induces a different SM ileal phenotype in different mouse strains, supporting the importance of modifier genes in determining intestinal SM properties.

Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in pancreatitis

BACKGROUND

The pancreas is one of the primary organs affected by dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein. While exocrine pancreatic insufficiency is a well-recognized complication of cystic fibrosis (CF), symptomatic pancreatitis is often under-recognized.

RESULTS

The aim of this review is to provide a general overview of CFTR mutation-associated pancreatitis, which affects patients with pancreatic sufficient CF, CFTR-related pancreatitis, and idiopathic pancreatitis. The current hypothesis regarding the role of CFTR dysfunction in the pathogenesis of pancreatitis, and concepts on genotype-phenotype correlations between CFTR and symptomatic pancreatitis will be reviewed. Symptomatic pancreatitis occurs in 20% of pancreatic sufficient CF patients. In order to evaluate genotype-phenotype correlations, the Pancreatic Insufficiency Prevalence (PIP) score was developed and validated to determine severity in a large number of CFTR mutations. Specific CFTR genotypes are significantly associated with pancreatitis. Patients who carry genotypes with mild phenotypic effects have a greater risk of developing pancreatitis than patients carrying genotypes with moderate-severe phenotypic consequences at any given time.

CONCLUSIONS

The genotype-phenotype correlation in pancreatitis is unique compared to other organ manifestations but still consistent with the complex monogenic nature of CF. Paradoxically, genotypes associated with otherwise mild phenotypic effects have a greater risk for causing pancreatitis; compared with genotypes associated with moderate to severe disease phenotypes. Greater understanding into the underlying mechanisms of disease is much needed. The emergence of CFTR-assist therapies may potentially play a future role in the treatment of CFTR-mutation associated pancreatitis.