Colonic diverticulitis in adolescents: an index case and associated syndromes

Genetic, epigenetic and environmental factors in diverticular disease: systematic review

BACKGROUND

Diverticulosis is a normal anatomical variant of the colon present in more than 70% of the westernized population over the age of 80. Approximately 3% will develop diverticulitis in their lifetime. Many patients present emergently, suffer high morbidity rates and require substantial healthcare resources. Diverticulosis is the most common finding at colonoscopy and has the potential for causing a significant morbidity rate and burden on healthcare. There is a need to better understand the aetiology and pathogenesis of diverticular disease. Research suggests a genetic susceptibility of 40-50% in the formation of diverticular disease. The aim of this review is to present the hypothesized functional effects of the identified gene loci and environmental factors.

METHODS

A systematic literature review was performed using PubMed, MEDLINE and Embase. Medical subject headings terms used were: 'diverticular disease, diverticulosis, diverticulitis, genomics, genetics and epigenetics'. A review of grey literature identified environmental factors.

RESULTS

Of 995 articles identified, 59 articles met the inclusion criteria. Age, obesity and smoking are strongly associated environmental risk factors. Intrinsic factors of the colonic wall are associated with the presence of diverticula. Genetic pathways of interest and environmental risk factors were identified. The COLQ, FAM155A, PHGR1, ARHGAP15, S100A10, and TNFSF15 genes are the strongest candidates for further research.

CONCLUSION

There is increasing evidence to support the role of genomics in the spectrum of diverticular disease. Genomic, epigenetic and omic research with demographic context will help improve the understanding and management of this complex disease.

Diverticulitis Familiality: A Statewide Case-Control Study

BACKGROUND

The etiology of diverticulitis is multifactorial and poorly understood. We estimated the familiality of diverticulitis using the Utah Population Database, a statewide database linking medical records with genealogy data.

STUDY DESIGN

We identified patients with diverticulitis diagnosed between 1998 and 2018 and age- and sex-matched controls in the Utah Population Database. Risk of diverticulitis in family members of patients and controls was calculated using multivariable Poisson models. We performed exploratory analyses to determine the association of familial diverticulitis with severity of disease and age of onset.

RESULTS

The study population included 9,563 diverticulitis patients (with 229,647 relatives) and 10,588 controls (with 265,693 relatives). Relatives of patients were more likely to develop diverticulitis (incidence rate ratio [IRR] 1.5, 95% CI 1.4 to 1.6) compared with relatives of controls. There was an elevated risk of diverticulitis among first-degree (IRR 2.6, 95% CI 2.3 to 3.0), second-degree (IRR 1.5, 95% CI 1.3 to 1.6), and third-degree relatives of patients (IRR 1.3, 95% CI 1.2 to 1.4). Complicated diverticulitis was more common among relatives of patients compared with relatives of controls (IRR 1.6, 95% CI 1.4 to 1.8). Age at diverticulitis diagnosis was similar between groups (relatives of patients 0.2 years older than relatives of controls, 95% CI -0.5 to 0.9).

CONCLUSIONS

Our results indicate that the first-, second-, and third-degree relatives of diverticulitis patients are at elevated risk of developing diverticulitis. This information may aid surgeons in counseling patients and family members about diverticulitis risk and can inform the development of future risk-stratification tools. Further work is needed to clarify the causal role and relative contribution of various genetic, lifestyle, and environmental factors in the development of diverticulitis.

Acute Right-Sided Abdominal Pain in an Adolescent: Expect the Unexpected

Acute right lower quadrant (RLQ) abdominal pain is a common presenting complaint in the emergency department (ED). The most common cause is acute appendicitis, generally requiring surgical intervention. We present a rare cause of RLQ abdominal pain mimicking acute appendicitis.

Evaluation of molecular and genetic predisposing parameters at diverticular disease of the colon

BACKGROUND

Diverticular disease (DD) refers to the presence of diverticula throughout the gastrointestinal (GI) tract, mainly along colon. DD might evolve into diverticulitis that is accompanied by severe clinical presentation, which includes abscess formation, perforation, stricture, obstruction and/or fistula.

AIM

The aim of the present review is to summarize the role of molecular and genetic factors in DD development, as well as their possible contribution towards new prognostic indicators, diagnostic algorithms and new therapeutic approaches.

METHODS AND RESULTS

Except from common predisposing parameters, several genetic mutations, immune factors, neurotransmitters, hormones and protein dysfunctions have been associated to the early onset of DD symptoms, pathogenesis and prognosis of the disease. Specific structural changes in the colonic wall, altered matrix composition and compromised motility have been verified as possible pathogenic factors for the development of DD. Dysregulation in peristaltic activity and reduced ability of the longitudinal muscle to relax following contraction has been also associated with DD evolution. In addition, it has been suspected that genetic defects combined with alterations in intestinal microbiota might play an important role in diverticulitis presentation.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery

AIM

There is a requirement for an expansive and up to date review of the management of emergency colorectal conditions seen in adults. The primary objective is to provide detailed evidence-based guidelines for the target audience of general and colorectal surgeons who are responsible for an adult population and who practise in Great Britain and Ireland.

METHODS

Surgeons who are elected members of the Association of Coloproctology of Great Britain and Ireland Emergency Surgery Subcommittee were invited to contribute various sections to the guidelines. They were directed to produce a pathology-based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. Each author was asked to provide a set of recommendations which were evidence-based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after two votes were included in the guidelines.

RESULTS

All aspects of care (excluding abdominal trauma) for emergency colorectal conditions have been included along with 122 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence-based summary of the current surgical knowledge in the management of emergency colorectal conditions and should serve as practical text for clinicians managing colorectal conditions in the emergency setting.

Genetic Risk Factors for Diverticular Disease-Emerging Evidence

Diverticular disease is traditionally understood as an environmental disease caused by diet and constipation. However, genes are increasing understood to play a role in pathogenesis. Twin studies suggest a substantial component of individual risk is due to heritable factors. Association of diverticular disease with other traits suggests an underlying biological mechanism and recently genome-wide association studies have described the genetic architecture underlying this complex phenotype. These studies suggest a new paradigm for understanding this common surgical disease.

Abdominal Symptoms and Colonic Diverticula in Marfan’s Syndrome: A Clinical and Ultrasonographic Case Control Study

Background: Marfan’s syndrome (MFS) seems to be frequently associated with colonic diverticulosis, but the prevalence of diverticula and symptoms evocative of diverticular disease in this population are still unknown. Methods: This prospective case control study included 90 consecutive patients with MFS, 90 unselected controls, and 90 asymptomatic subjects. The clinical characteristics, including lower gastrointestinal symptoms, and ultrasonographic features of the bowel, including diverticula and thickening of the muscularis propria of the sigmoid colon, were investigated. In addition, the genotype of MFS patients was assessed. The characteristics of patients and controls were compared using parametric tests. Results: Complaints of abdominal symptoms were made by 23 (25.6%) patients with MFS and 48 (53%) control subjects (p < 0.01). Constipation and bloating were reported less frequently by MFS patients than controls (constipation: 13.3% vs. 26.6%, p = 0.039; bloating: 3.3% vs. 41.1%, p < 0.0001), while other symptoms were not significantly different. Sigmoid diverticulosis was detected in 12 (12.3%) patients with MFS, as well as in 3 (3.3%) asymptomatic healthy subjects and 4 (4.4%) random controls (p = 0.0310). The genetic variants of MFS were not correlated with symptoms or diverticula. Conclusion: Patients with MFS have a greater prevalence of diverticula, although less abdominal symptoms, compared to the general population. Symptoms and diverticula in MFS are not correlated with any genetic variant.

European Society of Coloproctology: guidelines for the management of diverticular disease of the colon

AIM

The goal of this European Society of Coloproctology (ESCP) guideline project is to give an overview of the existing evidence on the management of diverticular disease, primarily as a guidance to surgeons.

METHODS

The guideline was developed during several working phases including three voting rounds and one consensus meeting. The two project leads (JKS and EA) appointed by the ESCP guideline committee together with one member of the guideline committee (WB) agreed on the methodology, decided on six themes for working groups (WGs) and drafted a list of research questions. Senior WG members, mostly colorectal surgeons within the ESCP, were invited based on publication records and geographical aspects. Other specialties were included in the WGs where relevant. In addition, one trainee or PhD fellow was invited in each WG. All six WGs revised the research questions if necessary, did a literature search, created evidence tables where feasible, and drafted supporting text to each research question and statement. The text and statement proposals from each WG were arranged as one document by the first and last authors before online voting by all authors in two rounds. For the second voting ESCP national representatives were also invited. More than 90% agreement was considered a consensus. The final phrasing of the statements with < 90% agreement was discussed in a consensus meeting at the ESCP annual meeting in Vienna in September 2019. Thereafter, the first and the last author drafted the final text of the guideline and circulated it for final approval and for a third and final online voting of rephrased statements.

RESULTS

This guideline contains 38 evidence based consensus statements on the management of diverticular disease.

CONCLUSION

This international, multidisciplinary guideline provides an up to date summary of the current knowledge of the management of diverticular disease as a guidance for clinicians and patients.

Novel swine model of colonic diverticulosis

The pathophysiology of colonic diverticulosis has not been completely understood. The development of appropriate animal models is essential to study diverticular disease. To date, no large animal models are available for this disease condition. The objective of this study was to develop a swine model by damaging the colon wall, combined with or without a low-fiber diet to mimic the pathogenesis of diverticulosis. To create a weakness on the colon wall, collagenase was applied in vivo to degrade the collagen in the colon wall. Three groups of Yucatan minipigs were included. Group 1 (n = 12) underwent collagenase injection (CI) with a low-fiber diet for 6 mo, group 2 (n = 8) underwent CI alone with a standard swine diet for 6 mo, and group 3 (n = 12) received a low-fiber diet alone for 6 mo. We found that diverticulosis occurred in 91.7% (11 of 12) of pigs in the CI + diet group and 100% (8 of 8) in CI-alone group. Moreover, around 30-75% of colon CI spots for each pig developed diverticular lesions. Diet alone for 6 mo did not induce diverticulosis. The endoscopic and histological examinations revealed the formation of multiple wide-mouthed diverticular lesions along the descending colon. Our results provide convincing evidence of the high efficacy of the reduced colon wall strength caused by CI in the development of a swine model of diverticulosis. Low-fiber diet consumption for 6 mo had no influence on the generation time or incidence rate of diverticulosis. In this model, digestion of the collagen in the colonic wall is sufficient to cause diverticulosis. NEW & NOTEWORTHY Effective large animal models of diverticulosis are currently lacking for the study of diverticular disease. This study marks the first time that a swine model of diverticulosis was developed by damaging colon wall structure, combined with or without a low-fiber diet. We found that a defect of colon wall could result in colon diverticular lesions within 6 mo in swine. This animal model mimicking the pathological process of diverticulosis is of great clinical value.

Maternal Uniparental Disomy 14 (UPD14) Identified by Clinical Exome Sequencing in an Adolescent with Diverticulosis

Pediatric diverticular disease is extremely rare, with most cases associated with connective tissue disorders. We report an adolescent boy with syndromic features who presented with acute complicated sigmoid diverticulitis. Clinical exome sequencing analysis detected a 6.5-Mb region of homozygosity on chromosome 14, consistent with partial maternal uniparental disomy. Analysis of this region did not identify rare homozygous variants but included several imprinted genes that were candidates for the observed phenotypes. The pediatric clinical presentation of diverticulosis in this patient has not been previously described in maternal uniparental disomy of chromosome 14 and adds to the phenotypic spectrum of the syndrome.

Animal Models of Diverticulosis: Review and Recommendations

Diverticulosis is a structural alteration of the colon tissue characterized by the development of pouch-like structures called diverticula. It afflicts a significant portion of the population in Western countries, with a higher prevalence among the elderly. Diverticulosis is believed to be the result of a synergetic interaction between inherent tissue weakness, diet, colonic microstructure, motility, and genetic factors. A validated etiology has, however, not yet been established. Non-surgical treatment is currently lacking due to this poor understanding, and surgical colon resection is the only long-term solution following recurrent complications. With rising prevalence, the burden of diverticulosis on patients and hospital resources has increased over the past several years. More efficient and less invasive treatment approaches are, thus, urgently needed. Animal models of diverticulosis are crucial to enable a preclinical assessment and evaluation of such novel approaches. This review discusses the animal models of diverticulosis that have been proposed to date. The current models require either a significant amount of time to develop diverticulosis, present a relatively low success rate, or seriously deteriorate the animals' systemic health. Recommendations are thus provided to address these pitfalls through the selection of a suitable animal and the combination of multiple risk factors for diverticulosis.

Diverticular disease is associated with benign intra-abdominal cystic disease

BACKGROUND

Diverticular disease (DD) and hepatic and renal cysts have been linked with defects in collagen and dysfunctional matrix metalloproteinases.

METHODS

Consecutive abdominal computed tomography scans between January-July 2015 were prospectively studied to determine a correlation between visceral cysts and DD. Patients with a sigmoid colectomy for pathology other than DD and scans in which DD and/or solid organs were not fully visualized were excluded. A subgroup analysis was performed on youthful DD patients (<55 years of age, n = 32) vs. older controls (>55, n = 213).

RESULTS

238 DD patients (50.8% male) and 369 controls (40.5% male, p = .02) were included. Incidence of visceral cystic disease in DD patients vs. controls was 71.4% vs. 22.5% (p < 0.00001). Renal cysts, present in 53.4% of the DD patients and 18.7% of the controls (p < .00001), were more common than hepatic cysts in both groups. Hepatic cyst prevalence was 8.8 vs. 2.4% (p = .0008). In the subgroup analysis, cystic disease was present in 56.2% of youthful DD patients vs. 29.1% of older controls (p = .004).

CONCLUSIONS

A significant association between cystic disease and DD was demonstrated overall and in subgroup analysis inclusive of youthful DD patients and older controls. These findings suggest a global defect in connective tissue integrity in DD patients.

Diverticulitis and Crohn's disease have distinct but overlapping tumor necrosis superfamily 15 haplotypes

BACKGROUND

Diverticulitis (DD) and Crohn's disease (CD) have overlapping features including bowel structuring, inflammation, and infection. Tumor necrosis superfamily 15 (TNFSF15) is an immunoregulatory, anti-angiogenic gene. CD has been previously associated with a haplotype of five TNFSF15 single-nucleotide polymorphism alleles: rs3810936 (G allele), rs6478108 (A), rs6478109 (G), rs7848647 (G), and rs7869487 (A). We aimed to determine the TNFSF15 risk haplotype for DD versus controls with a subgroup analysis of youthful DD patients (aged ≤55 y) versus older controls (aged ≥55 y).

METHODS

A total of 148 diverticulitis patients (90 aged ≤55 y) and 200 controls (87 aged ≥55 y) were genotyped using our custom-designed Illumina Veracode microarray chip. Genotypes from rs3810936, rs6478108, rs6478109, rs7848647, rs7869487 and two additional TNFSF15 single nucleotide polymorphisms, rs3810936 and rs11554257, were analyzed. PHASE version 2.1, R with HaploStats and the Broad Institute's Haploview program were used for statistics and imputed haplotype frequency. Permutation corrected for multiple comparisons.

RESULTS

The CD GAGGA haplotype was significantly associated with diverticulitis (P = 0.03) in the all DD versus all controls comparison. A second haplotype, rs6478108 (A), rs6478109 (G), rs7869487 (A), and rs4263839 (G), was also associated with DD in this cohort (P = 0.025). A third haplotype rs6478108 (A), rs6478109 (G), rs7848647 (G) and rs7869487 (A), rs4263839 (G) was demonstrated in the DD < 55 versus controls >55 comparison (P = 0.045).

CONCLUSIONS

Distinct but overlapping TNFSF15 haplotypes were demonstrated in diverticulitis patients versus healthy controls when compared with the known Crohn's risk haplotype suggesting similar but distinct genetic predispositions. This study strengthens the role for a genetic predisposition to diverticulitis that involves the TNFSF15 gene.

Management of sigmoid diverticulitis: an update

The role, indications and modalities of elective resection for sigmoid diverticulitis remain the cause of fierce debate. During the past two decades clinicians have increasingly recognized that: (1) young patients (<50) are no more at risk to develop more aggressive course of the disease; and (2) patients who present initially with a first uncomplicated attack are no more at risk for developing subsequent complicated diverticulitis requiring emergency surgery. Hence, the previously well-recognized indications (based upon age of the patients or the number of attacks) are no longer valid. Yet, the number of sigmoid resections performed for diverticulitis in industrialized countries is increasing, which seems to indicate that in many cases, uncomplicated sigmoid diverticulitis progressively evolves towards a chronic symptomatic condition, which significantly impacts upon the patients' quality of life. The aims of this review are twofold: (1) to identify which disease presentation still represents good indications for elective laparoscopic sigmoid resection; and (2) to summarize the technical aspects of surgery for a benign condition, such as diverticular disease.

Perisigmoid Abscess Leading to a Diagnosis of Ehlers-Danlos Syndrome Type IV

The Ehlers-Danlos syndromes (EDS) are a group of connective tissue disorders characterized by triad of joint hypermobility, skin extensibility, and tissue fragility. Ehlers-Danlos syndrome type IV places patients at risk for life-threatening, spontaneous, vascular or visceral rupture due to reduced or abnormal secretion of type III collagen. We present an adolescent male who was found to have a perisigmoid abscess with a fistula connecting to adjacent sigmoid colon secondary to undiagnosed EDS type IV. Conservative management with antibiotics and bowel rest was pursued to allow for elective resection for his acute complicated diverticulitis at a safer time.

Management of diverticular disease

Diverticular disease is a common condition in Western countries and the incidence and prevalence of the disease is increasing. The pathogenetic factors involved include structural changes in the gut that increase with age, a diet low in fibre and rich in meat, changes in intestinal motility, the concept of enteric neuropathy and an underlying genetic background. Current treatment strategies are hampered by insufficient options to stratify patients according to individual risk. One of the main reasons is the lack of an all-encompassing classification system of diverticular disease. In response, the German Society for Gastroenterology and Digestive Diseases (DGVS) has proposed a classification system as part of its new guideline for the diagnosis and management of diverticular disease. The classification system includes five main types of disease: asymptomatic diverticulosis, acute uncomplicated and complicated diverticulitis, as well as chronic diverticular disease and diverticular bleeding. Here, we review prevention and treatment strategies stratified by these five main types of disease, from prevention of the first attack of diverticulitis to the management of chronic complications and diverticular bleeding.

Surgical diverticulitis is not associated with defects in the expression of wound healing genes

PURPOSE

The development of diverticuli may represent defects in collagen vascular tissue integrity possibly from a genetic predisposition. We evaluated the tissue expression of wound healing genes in sigmoid tissue from youthful patients undergoing surgery for diverticulitis and thus would more likely suffer from a genetic predisposition (SD mean age 39 ± 0.9) versus controls in the form of patients over the age of 50 (mean age 52.9 ± 10.5 years) without evidence of diverticular disease.

METHODS

The mRNA expression of 84 genes associated with the extracellular matrix, cellular adhesion, growth factors, inflammatory cytokines, and signal transduction was evaluated in 16 SD and 15 control tissues using a Qiagen Wound Healing Array. Vitronectin, the gene protein with the highest potential significance on raw analysis, was further investigated using a Taqman assay with an additional 11 SD (total n = 27) and four control (total n = 19) samples. Statistics were by Student's t and Mann-Whitney tests with Bonferroni correction.

RESULTS

No significant differences in mRNA expression between the SD and control tissue in the 84 measured genes were demonstrated after correction. Vitronectin mRNA expression was downregulated 2.7-fold in SD tissue vs. tissue from non-neoplastic control patients (p = 0.001 raw/0.08 corrected). However, on vitronectin TaqMan analysis, no difference in expression was seen in SD vs. all controls or in all subset comparisons.

CONCLUSIONS

The lack of significant alteration in mRNA expression of traditionally associated wound healing genes/proteins in young SD patients suggests that such genes play a minor role in the genetic predisposition to youthful diverticulitis.

Risk Factors for the Development of an Incisional Hernia after Sigmoid Resection for Diverticulitis: An Analysis of 33 Patient, Operative and Disease-associated Factors

Incisional hernia (IH) is a relatively common sequelae of sigmoidectomy for diverticulitis. The aim of this study was to investigate factors that may predict IH in diverticulitis patients. Two hundred and one diverticulitis patients undergoing sigmoidectomy between January 2002 and December 2012 were identified (mean follow-up 5.15 ± 2.33 years). Patients with wound infections were excluded. Thirteen patient-associated, three diverticular disease-related, and 17 operative variables were evaluated in patients with and without IH. Volumetric fat was measured on pre-operative CTs. Fischer's exact, χ2, and Mann–Whitney tests and multivariate regression analysis were used for statistics. Thirty-four (17%) patients had an IH. On multivariate analysis, wound packing (OR 3.4, P = 0.017), postoperative nonwound infection (OR 7.4, P = 0.014), and previous hernia (OR 3.6, P = 0.005) were as independent predictors of IH. Fifteen of 34 (44%) patients who developed a hernia had a history of prior hernia. Of 33 potential risk factors analyzed, including smoking, chronic obstructive pulmonary disease, and obesity, the only patient factor present preoperatively associated with increased risk of a postsigmoidectomy hernia after multivariate analysis was a history of a previous hernia. Preoperative identification of patients with a history of hernia offers the opportunity to employ measures to decrease the likelihood of IH.

Risk Factors for Diverticulosis, Diverticulitis, Diverticular Perforation, and Bleeding: A Plea for More Subtle History Taking

Background

Diverticulosis is a very common condition. Around 20% of diverticula carriers are believed to suffer from diverticular disease during their lifetime. This makes diverticular disease one of the clinically and economically most significant conditions in gastroenterology. The etiopathogenesis of diverticulosis and diverticular disease is not well understood. Epidemiological studies allowed to define risk factors for the development of diverticulosis and the different disease entities associated with it, in particular diverticulitis, perforation, and diverticular bleeding.

Methods

A comprehensive literature search was performed, and the current knowledge about risk factors for diverticulosis and associated conditions reviewed.

Results

Non-controllable risk factors like age, sex, and genetics, and controllable risk factors like foods, drinks, and physical activity were identified, as well as comorbidities and drugs which increase or decrease the risk of developing diverticula or of suffering from complications. In naming risk factors, it is of utmost importance to differentiate between diverticulosis and the different disease entities.

Conclusion

Risk factors for diverticulosis and diverticular disease may give a clue towards the possible etiopathogenesis of the conditions. More importantly, knowledge of comorbidities and particularly drugs conferring a risk for development of complicated disease is crucial for patient management.

Morphologic Basis for Developing Diverticular Disease, Diverticulitis, and Diverticular Bleeding

Diverticula of the colon are pseudodiverticula defined by multiple outpouchings of the mucosal and submucosal layers penetrating through weak spots of the muscle coat along intramural blood vessels. A complete prolapse consists of a diverticular opening, a narrowed neck, and a thinned diverticular dome underneath the serosal covering. The susceptibility of diverticula to inflammation is explained by local ischemia, translocation of pathogens due to retained stool, stercoral trauma by fecaliths, and microperforations. Local inflammation may lead to phlegmonous diverticulitis, paracolic/mesocolic abscess, bowel perforation, peritonitis, fistula formation, and stenotic strictures. Diverticular bleeding is due to an asymmetric rupture of distended vasa recta at the diverticular dome and not primarily linked to inflammation. Structural and functional changes of the bowel wall in diverticular disease comprise: i) Altered amount, composition, and metabolism of connective tissue; ii) Enteric myopathy with muscular thickening, deranged architecture, and altered myofilament composition; iii) Enteric neuropathy with hypoganglionosis, neurotransmitter imbalance, deficiency of neurotrophic factors and nerve fiber remodeling; and iv) Disturbed intestinal motility both in vivo (increased intraluminal pressure, motility index, high-amplitude propagated contractions) and in vitro (altered spontaneous and pharmacologically triggered contractility). Besides established etiologic factors, recent studies suggest that novel pathophysiologic concepts should be considered in the pathogenesis of diverticular disease.

Changing views on diverticular disease: impact of aging, obesity, diet, and microbiota

The development of colonic diverticulosis is a common aging change in industrialized nations. While most patients have asymptomatic diverticulosis, around one in five develops symptomatic diverticular disease. This is characterized by recurrent abdominal pain and disturbed bowel habit. Some of the pain episodes are prolonged and are due to acute diverticulitis, which itself may be complicated by abscess, perforation, fistulation, or stricture formation. Risk factors favouring the development of symptomatic diverticular disease include obesity, smoking and diets low in fiber but high in red meat and animal fat. What determines the transition from asymptomatic diverticulosis to symptomatic diverticular disease is unclear but neuromuscular changes following acute diverticulitis may be responsible in some cases. The severity of symptoms generated depends on cerebral pain processing which is influenced by psychosocial factors. These are important considerations in deciding optimal patient management. Prior theories of the cause of diverticulosis suggested that constipation was an important cause, but new data challenge this and has provoked new ideas. Underlying mechanisms causing diverticulosis include weakening of the colonic wall and/or degenerative changes in the enteric nerves. Dietary induced changes in microbiota and the host inflammatory response may underlie the subsequent development of acute/chronic diverticulitis and its sequela.

[Anatomy and pathogenesis of diverticular disease]

BACKGROUND

Although diverticular disease is one of the most frequent gastrointestinal disorders the pathogenesis is not yet sufficiently clarified.

OBJECTIVES

The aim is to define the anatomy and pathogenesis of diverticular disease considering the risk factors and description of structural and functional alterations of the bowel wall.

METHODS

This article gives an appraisal of the literature, presentation and evaluation of classical etiological factors, analysis and discussion of novel pathogenetic concepts.

RESULTS

Colonic diverticulosis is defined as an acquired out-pouching of multiple and initially asymptomatic pseudodiverticula through muscular gaps in the colon wall. Diverticular disease is characterized by diverticular bleeding and/or inflammatory processes (diverticulitis) with corresponding complications (e.g. abscess formation, fistula, covered and open perforation, peritonitis and stenosis). Risk factors for diverticular disease include increasing age, genetic predisposition, congenital connective tissue diseases, low fiber diet, high meat consumption and pronounced overweight. Alterations of connective tissue cause a weakening of preformed exit sites of diverticula and rigidity of the bowel wall with reduced flexibility. It is assumed that intestinal innervation disorders and structural alterations of the musculature induce abnormal contractile patterns with increased intraluminal pressure, thereby promoting the development of diverticula. Moreover, an increased release of pain-mediating neurotransmitters is considered to be responsible for persistent pain in chronic diverticular disease.

CONCLUSIONS

According to the present data the pathogenesis of diverticular disease cannot be attributed to a single factor but should be considered as a multifactorial event.

The TNFSF15 gene single nucleotide polymorphism rs7848647 is associated with surgical diverticulitis

OBJECTIVE

To determine if single nuclear polymorphisms (SNPs) in the TFNSF15 gene play a role in patients requiring surgery for diverticulitis.

BACKGROUND

A role for a genetic predisposition in diverticulitis is suggested by its association with hereditary connective tissue disorders, youthful onset in some patients, and the observation of families with multiple affected individuals. The TNFSF15 gene has been associated with other inflammatory diseases affecting the colon such as medically refractory ulcerative colitis (UC), aggressive Crohn's disease (CD), and pouchitis after restorative proctocolectomy.

METHODS

In the discovery phase of this study, 21 sporadic surgical diverticulitis (SD) patients (9 female, mean age = 52 ± 5) and 5 individuals from a single family with surgically managed diverticulitis [familial diverticulitis (FD), 4 female, mean age = 51.1 ± 7] were studied. SD patients were age and sex matched with 3 separate groups of healthy, CD and UC control patients. All patients were genotyped for 5 known TNFSF15-associated SNPs. The SNP discovered to be associated with diverticulitis (rs7848647) was then confirmed in a separate test group composed of 34 additional patients (20 female, mean age 57.7 ± 2) who also underwent surgical treatment for diverticulitis. These patients were age matched to a new control cohort of patients having no history of diverticulitis (26 female). Patients were genotyped using a TaqMan assay. In the discovery phase, logistical regression on matched subjects was performed to determine an association of TNFSF SNP with diverticulitis versus the control groups. In the test phase, significance for the rs7848647 SNP was assessed by the Fischer's exact test.

RESULTS

In the discovery phase, the TNFSF15 SNP rs7848647 was significantly associated with SD (p = 0.0003) versus all control groups studied. The risk allele for this SNP (G substituted for A) was found in all SD patients. The homozygous GG allele was found in 62% (13/21) of SD patients versus only 5% (1/21) of healthy controls (p = 0.001) and 24% (10/42) of all UC + CD controls (p = 0.002). All 5 members of the FD cohort were homozygous for the at-risk "G" allele. In the test group, the homozygous GG genotype was found in 56% of SD patients compared with 17% of healthy controls (p = 0.006). Risk of SD seemed to increase with number of the G alleles with 8% of SD patients having AA homozygosity, 35% of SD patients having AG heterozygosity, and 56% of SD patients having GG homozygosity.

CONCLUSIONS

The SNP rs7848647 associated with the TNFSF15 gene is associated with surgical diverticulitis. This finding suggests a fundamental role for TNFSF15, a T-cell receptor gene involved in T-cell maturation, in the pathophysiology of diverticulitis requiring surgery. This SNP may be a marker of diverticular disease severity that might assist in surgical decision making.

Colonic wall changes in patients with diverticular disease - is there a predisposition for a complicated course?

BACKGROUND

The aim of this study was to evaluate colonic wall changes and enteric neuropathy in patients with either uncomplicated (UDD) or complicated diverticular disease (CDD). Furthermore, we evaluated the presence of an anatomic sphincter at the rectosigmoid junction (RSJ).

METHODS

Samples of colonic tissue from fifteen patients with UDD, fifteen patients with CDD and fifteen patients as control were collected. Collagen quotient I/III was measured with the Sirius-red test, expression of MMP-1, MMP-13, innervation (S100), proliferation (Ki67) and apoptosis (TUNEL) in the colonic wall were investigated by immunohistochemical studies. Furthermore, measurements of the different layers were performed to investigate the RSJ.

RESULTS

Patients with either UDD or CDD had lower collagen I/III quotients compared to the control group, significant for CDD (p = 0.007). For MMP-1 and MMP-13 only a slight increase for patients with CDD was found. The percentage of proliferating (Ki67) and apoptotic (TUNEL) cells was significantly higher for patients with CDD than in the control group (p = 0.016; p = 0.037). Upon investigating the S100-expression a significant reduce in glial cells density was found in the myenteric and mucosal plexus for both groups (UDD and CDD) compared to the control group. Measurements of the different colon layers oral, aboral and at the RSJ revealed equal values.

CONCLUSIONS

This study has shown that colonic wall changes and enteric neuropathy seem to play a role in the pathogenesis of colonic diverticulosis. None of our results suggest a predisposition for a complicated diverticular disease. Furthermore, the presence of an anatomic sphincter at the rectosigmoid junction could not be detected.

Review article: The pathogenesis and management of acute colonic diverticulitis

BACKGROUND

Acute diverticulitis, defined as acute inflammation associated with a colonic diverticulum, is a common emergency presentation managed by both surgeons and physicians. There have been advances in both the medical and the surgical treatments offered to patients in recent years.

AIM

To review the current understanding of the aetiology and treatment of acute diverticulitis.

METHODS

A search of PubMed and Medline databases was performed to identify articles relevant to the aetiology, pathogenesis and management of acute diverticulitis.

RESULTS

There are 75 hospital admissions per year for acute diverticulitis per 100,000 of the population in the United States. Recent reports suggest a 26% increase in admissions over a 7-year period. Factors predisposing to the development of acute diverticulitis include obesity, smoking, diet, lack of physical activity and medication use such as aspirin and nonsteroidal anti-inflammatory drugs. The condition is associated with a low mortality of about 1% following medical therapy, rising to 4% in-hospital mortality in those requiring surgery. There is limited evidence on the efficacy of individual antibiotic regimens, and antibiotic treatment may not be required in all patients. The rates of recurrence reported for patients with acute diverticulitis following medical management vary from 13% to 36%. The surgical management of those patients who fail medical treatment has moved towards a laparoscopic nonresectional approach; however, the evidence supporting this is limited.

CONCLUSIONS

Further high-quality randomised controlled trials are required of both medical and surgical treatments in patients with acute diverticulitis, if management is to be evidence-based.

Diverticulitis in a child with Williams syndrome: a case report and review of the literature

Diverticulitis is rare in pediatric patients and often associated with a more complicated course than that seen with adult patients. Certain syndromes, such as Williams syndrome, have been associated with an increase incidence of diverticular disease. We describe a 9-year-old boy with Williams syndrome who presented with rectal bleeding secondary to sigmoid diverticulitis. This case represents the youngest known patient with diverticulitis. Patients with this disorder who present with chronic or recurrent abdominal pain should be evaluated for diverticular disease and its potential complications.

Long-term follow-up after an initial episode of diverticulitis: what are the predictors of recurrence?

PURPOSE

The purpose of our study was to determine the clinical and CT predictors of recurrent disease after a first episode of diverticulitis that was successfully managed nonoperatively.

METHODS

We retrospectively analyzed 954 consecutive patients who presented to our institution with diverticulitis from 2002 to 2008. Patients were identified with International Classification of Diseases, 9th Revision/Current Procedural Terminology codes. Patients were excluded if they had subsequent colectomy based on the first attack (n = 81), or if the attack they had between 2002 and 2008 was not their first attack (n = 201). We evaluated CT variables chosen by a panel of expert gastrointestinal radiologists. These radiologists reviewed the available published literature for CT imaging characteristics thought to predict diverticulitis severity. CT variables (n = 20) were determined by prospective reevaluation of scans by blinded study radiologists. Clinical variables (n = 43) were coded based on a retrospective chart review. Univariate analysis of variables in relation to recurrent disease was performed by a log-rank test of Kaplan-Meier estimates. Multivariate analysis was performed using Cox proportional hazards modeling. Variables with P < .2 on univariate analysis were included in a stepwise selection algorithm.

RESULTS

The study population included 672 patients; mean age, 61 ± 15 years; mean follow-up, 42.8 ± 24 months. The index presentation of diverticulitis was most commonly located in the sigmoid colon (72%), followed by descending colon (33%), right colon (5%), and transverse colon (3%). Overall recurrence at 5 years was 36% by (95% CI 31.4%-40.6%) Kaplan-Meier estimate. Complicated recurrence (fistula, abscess, free perforation) occurred in 3.9% (95% CI 2.2%-5.6%) of patients at 5 years by Kaplan-Meier estimate. Family history of diverticulitis (HR 2.2, 95% CI 1.4-3.2), length of involved colon >5 cm (HR 1.7, 95% CI 1.3-2.3), and retroperitoneal abscess (HR 4.5, 95% CI 1.1-18.4) were associated with diverticulitis recurrence. Right colon disease (HR 0.27, 95% CI 0.09-0.86) was associated with freedom from recurrence.

CONCLUSION

Although diverticulitis recurrence is common following an initial attack that has been managed medically, complicated recurrence is uncommon. Patients who present with a family history of diverticulitis, long segment of involved colon, and/or retroperitoneal abscess are at higher risk for recurrent disease. Patients who present with right-sided diverticulitis are at low risk for recurrent disease. These findings should be taken into consideration when counseling patients regarding the potential benefits of prophylactic colectomy.