This review summarizes the relevant literature regarding imaging of suspected diverticulitis as an etiology for left lower quadrant pain, and imaging of complications of acute diverticulitis. The most common cause of left lower quadrant pain in adults is acute sigmoid or descending colonic diverticulitis. Appropriate imaging triage for patients with suspected diverticulitis should address the differential diagnostic possibilities and what information is necessary to make a definitive management decision. Patients with diverticulitis may require surgery or interventional radiology procedures because of associated complications, including abscesses, fistulas, obstruction, or perforation. As a result, there has been a trend toward greater use of imaging to confirm the diagnosis of diverticulitis, evaluate the extent of disease, and detect complications before deciding on appropriate treatment. Additionally, in the era of bundled payments and minimizing health care costs, patients with acute diverticulitis are being managed on an outpatient basis and rapid diagnostic imaging at the time of initial symptoms helps to streamline and triage patients to the appropriate treatment pathway. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Young patients are thought to have a more severe disease course and a higher rate of recurrent diverticulitis. However, these understandings are mainly based on studies with important limitations. This review aimed to clarify the true natural history of acute diverticulitis in young patients compared to elderly patients. PubMed and MEDLINE were searched for studies reporting outcomes on disease severity or recurrences in young and elderly patients with a computed tomography-proven diagnosis of acute diverticulitis. Twenty-seven studies were included. The proportion of complicated diverticulitis at presentation (21 studies) was not different for young patients (age cut-off 40-50 years) compared to elderly patients [risk ratio (RR) 1.19; 95% confidence interval 0.94-1.50]. The need for emergency surgery (11 studies) or percutaneous abscess drainage (two studies) yielded comparable results for both groups with a RR of 0.93 (95% confidence interval 0.70-1.24) and 1.65 (95% confidence interval 0.60-4.57), respectively. Crude data on recurrent diverticulitis rates (12 studies) demonstrated a significantly higher RR of 1.47 (95% confidence interval 1.20-1.80) for young patients. Notably, no association between age and recurrent diverticulitis was found in the studies that used survival analyses, taking length of follow-up per age group into account. In conclusion, young patients do not have a more severe course of acute diverticulitis. Published data on the risk of recurrent diverticulitis in young patients are conflicting, but those with the most robust design do not demonstrate an increased risk. Therefore, young patients should not be treated more aggressively nor have a lower threshold for elective surgery just because of their age.

A preoperative reliable classification system between clinical and computed tomography (CT) findings to better plan surgery in acute complicated diverticulitis (ACD) is lacking. We studied the inter-observer agreement of CT scan data and their concordance with the preoperative clinical findings and the adherence with the intraoperative status using a new classification of diverticular disease (CDD).

152 patients operated on for acute complicated diverticulitis (ACD) were retrospectively enrolled. All patients were studied with CT scan within 24 h before surgery and CT images were blinded reanalyzed by 2 couples of radiologists (A/B). Kappa value evaluated the inter-observer agreement between radiologists and the concordance between CDD, preoperative clinical findings and findings at operation. Univariate and multivariate analysis were used to evaluate the predicting values of CT classification and CDD stage at surgery on postoperative outcomes.

Overall inter-observer agreement for the CDD was high, with a kappa value of 0.905 (95% CI = 0.850-0.960) for observers A and B, while the concordance between radiological and surgical findings was weak (kappa values = 0.213 and 0,248, respectively and 95% CI = 0.106 to 0.319 and 95% CI = 0.142 to 0.355, respectively). When overall morbidity, mortality and the need of a terminal colostomy were considered as main endpoints no concordance was observed between surgical and radiological findings and the CDD (P=NS).

The need for a more accurate classification of ACD, able to better stage this emergency, and to provide surgeons with reliable information for the best treatment is advocated.

In Western countries, the incidence of acute diverticulitis (AD) is increasing. Patients with uncomplicated diverticulitis can undergo a standard antibiotic treatment in an outpatient setting. The aim of this systematic review was to assess the safety and efficacy of the management of acute diverticulitis in an outpatient setting.

A literature search was performed on PubMed, Scopus, Embase, Central and Web of Science up to September 2018. Studies including patients who had outpatient management of uncomplicated acute diverticulitis were considered. We manually checked the reference lists of all included studies to identify any additional studies. Primary outcome was the overall failure rates in the outpatient setting. The failure of outpatient setting was defined as any emergency hospital admission in patients who had outpatient treatment for AD in the previous 60 days. A subgroup analysis of failure was performed in patients with AD of the left colon, with or without comorbidities, with previous episodes of AD, in patients with diabetes, with different severity of AD (pericolic air and abdominal abscess), with or without antibiotic treatment, with ambulatory versus home care unit follow-up, with or without protocol and where outpatient management is a common practice. The secondary outcome was the rate of emergency surgical treatment or percutaneous drainage in patients who failed outpatient treatment.

This systematic review included 21 studies including 1781 patients who had outpatient management of AD  including 11 prospective, 9 retrospective and only 1 randomized trial. The meta-analysis showed that outpatient management is safe, and the overall failure rate in an outpatient setting was 4.3% (95% CI 2.6%-6.3%). Localization of diverticulitis is not a selection criterion for an outpatient strategy (p 0.512). The other subgroup analyses did not report any factors that influence the rate of failure: previous episodes of acute diverticulitis (p = 0.163), comorbidities (p = 0.187), pericolic air (p = 0.653), intra-abdominal abscess (p = 0.326), treatment according to a registered protocol (p = 0.078), type of follow-up (p = 0.700), type of antibiotic treatment (p = 0.647) or diabetes (p = 0.610). In patients who failed outpatient treatment, the majority had prolonged antibiotic therapy and only few had percutaneous drainage for an abscess (0.13%) or surgical intervention for perforation (0.06%). These results should be interpreted with some caution because of the low quality of available data.

The outpatient management of AD can reduce the rate of emergency hospitalizations. This setting is already part of the common clinical practice of many emergency departments, in which a standardized protocol is followed. The data reported suggest that this management is safe if associated with an accurate selection of patients (40%); but no subgroup analysis demonstrated significant differences between groups (such as comorbidities, previous episode, diabetes). The main limitations of the findings of the present review concern their applicability in common clinical practice as it was impossible to identify strict criteria of failure.

The management of uncomplicated (Modified Hinchey Classification Ia) acute diverticulitis (AD) has become increasingly conservative, with a focus on symptomatic relief and supportive management. Clear criteria for patient selection are required to implement this safely. This retrospective study aimed to identify risk factors for severe clinical course in patients with uncomplicated AD.

Patients admitted to General Surgery at two New Zealand tertiary centres over a period of 18 months were included. Univariate and multivariate analyses were carried out in order to identify factors associated with a more severe clinical course. This was defined by three endpoints: need for procedural intervention, admission >7 days and 30-day readmission; these were analysed separately and as a combined outcome.

Uncomplicated AD was identified in 319 patients. Fifteen patients (5%) required procedural intervention; this was associated with SIRS (OR 3.92). Twenty-two (6.9%) patients were admitted for >7 days; this was associated with patient-reported pain score >8/10 (OR 5.67). Thirty-one patients (9.8%) required readmission within 30 days; this was associated with pain score >8/10 (OR 6.08) and first episode of AD (OR 2.47). Overall, 49 patients had a severe clinical course, and associated factors were regular steroid/immunomodulator use (OR 4.34), pain score >8/10 (OR 5.9) and higher temperature (OR 1.51) and CRP ≥200 (OR 4.1).

SIRS, high pain score and CRP, first episode and regular steroid/immunomodulator use were identified as predictors of worse outcome in uncomplicated AD. These findings have the potential to inform prospective treatment decisions in this patient group.

To determine the application of clinical practice guidelines for the current management of diverticulitis and colorectal surgeon specialist consensus in Australia and New Zealand.

A survey was distributed to 205 colorectal surgeons in Australia and New Zealand, using 22 hypothetical clinical scenarios.

The response rate was 102 (50%). For 19 guideline-based scenarios, only 11 (58%) reached consensus (defined as > 70% majority opinion) and agreed with guidelines; while 3 (16%) reached consensus and did not agree with guidelines. The remaining 5 (26%) scenarios showed community equipoise (defined as less than/equal to 70% majority opinion). These included diagnostic imaging where CT scan was contraindicated, management options in the failure of conservative therapy for complicated diverticulitis, surgical management of Hinchey grade 3, proximal extent of resection in sigmoid diverticulitis and use of oral mechanical bowel preparation and antibiotics for an elective colectomy. The consensus areas not agreeing with guidelines were management of simple diverticulitis, management following the failure of conservative therapy in uncomplicated diverticulitis and follow-up after an episode of complicated diverticulitis. Fifty-percent of rural/regional based surgeons would perform an urgent sigmoid colectomy in failed conservative therapy of diverticulitis compared to only 8% of surgeons city-based (Fisher's exact test P = 0.016). In right-sided complicated diverticulitis, a greater number of those in practice for more than ten years would perform an ileocecal resection and ileocolic anastomosis (79% vs 41%, P < 0.0001).

While there are areas of consensus in diverticulitis management, there are areas of community equipoise for future research, potentially in the form of RCTs.

Acute diverticulitis occurs in up to 25% of patients with diverticulosis. The majority of cases are mild or uncomplicated and it has become a frequent reason for consultation in the emergency department. On the basis of the National Inpatient Sample database from the USA, 86% of patients admitted with diverticulitis were treated with medical therapy. However, several recent studies have shown that outpatient treatment with antibiotics is safe and effective. The aim of this systematic review is to update the evidence published in the outpatient treatment of uncomplicated acute diverticulitis. We performed a systematic review according to the PRISMA guidelines and searched in MEDLINE and Cochrane databases all English-language articles on the management of acute diverticulitis using the following search terms: 'diverticulitis', 'outpatient', and 'uncomplicated'. Data were extracted independently by two investigators. A total of 11 articles for full review were yielded: one randomized controlled trial, eight prospective cohort studies, and two retrospective cohort studies. Treatment successful rate on an outpatient basis, which means that no further complications were reported, ranged from 91.5 to 100%. Fewer than 8% of patients were readmitted in the hospital. Intolerance to oral intake and lack of family or social support are common exclusion criteria used for this approach, whereas severe comorbidities are not definitive exclusion criteria in all the studies. Ambulatory treatment of uncomplicated acute diverticulitis is safe, effective, and economically efficient when applying an appropriate selection in most reviewed studies.

Diverticulosis of the colon is a common disease with an increasing incidence in Western Countries. It represents a significant burden for National Health Systems in terms of costs. Most people with diverticulosis remain asymptomatic, about one quarter of them will develop an episode of symptomatic diverticular disease and up to 5% an episode of acute diverticulitis (AD). AD shows an increasing prevalence. Recently, progresses have been reached about the etiology, pathogenesis, natural course of diverticular disease and its complications; improvements about the diagnosis and treatment of AD have been achieved. However, the treatment options are not well defined because of a lack of solid evidence: there are few systematic reviews and well conducted trials to guide decision-making in the treatment of AD and in the prevention of its recurrences. This review describes the recent evidence about diagnosis, treatment and prevention of AD.

Acute uncomplicated diverticulitis is traditionally managed by inpatient admission for bowel rest, intravenous fluids and intravenous antibiotics. In recent years, an increasing number of publications have sought to determine whether care might instead be conducted in the community, with earlier enteral feeding and oral antibiotics. This systematic review evaluates the safety and efficacy of such an ambulatory approach.

Medline, Embase and Cochrane Library databases were searched. All peer-reviewed studies that investigated the role of ambulatory treatment protocols for acute uncomplicated diverticulitis, either directly or indirectly, were eligible for inclusion.

Nine studies were identified as being suitable for inclusion, including one randomised controlled trial, seven prospective cohort studies and one retrospective cohort study. All, except one, employed imaging as part of their diagnostic criteria. There was inconsistency between studies with regards to whether patients with significant co-morbidities were eligible for ambulatory care and whether bowel rest therapy was employed. Neither of these variables influenced outcome. Across all studies, 403 out of a total of 415 (97 %) participants were successfully treated for an episode of acute uncomplicated diverticulitis using an outpatient-type approach. Cost savings ranged from 35.0 to 83.0 %.

Current evidence suggests that a more progressive, ambulatory-based approach to the majority of cases of acute uncomplicated diverticulitis is justified. Based on this evidence, the authors present a possible outpatient-based treatment algorithm. An appropriately powered randomised controlled trial is now required to determine its safety and efficacy compared to traditional inpatient management.

Severity of acute diverticulitis (AD) has traditionally been assessed using the Hinchey classification; however, this classification is predominantly a surgical one. The Neff classification provides an alternative classification based on CT findings. The aim of this study was to evaluate a modification of the Neff classification to select patients presenting with early-stage AD to receive outpatient management.

All patients with AD, presenting to a single unit, were prospectively studied. All patients underwent emergency abdominal CT and were assigned a Neff stage, including a modification (mNeff) to Neff Stage I. The Neff stages used were: Stage 0, uncomplicated diverticulitis; Diverticula, thickening of the wall, increased density of the pericolic fat; Stage I, locally complicated (our modification included substages Ia (localized pneumoperitoneum in the form of air bubbles) and Ib (local abscess); Stage II, complicated with pelvic abscess; Stage III, complicated with distant abscess; and Stage IV, complicated with other distant complications. Patients who presented with Stage 0 or Stage Ia were selectively managed as outpatients. Patients with comorbidity or the presence of the systemic inflammatory response syndrome (SIRS) were excluded.

Between February 2010 and January 2013, 205 patients (mean age 59 years; age range 25-90 years) presented with AD. One-hundred and forty-nine met the radiological criteria for potential outpatient treatment. After applying the exclusion criteria, 68 were eventually assigned to an outpatient programme. Sixty-four (94%) successfully completed the outpatient treatment protocol; four patients were readmitted.

Our mNeff classification allowed selected patients with AD to be successfully managed in an outpatient programme.

The incidence of acute left-sided colonic diverticulitis (ACD) is increasing in the Western world. To improve the quality of patient care, a guideline for diagnosis and treatment of diverticulitis is needed.

A multidisciplinary working group, representing experts of relevant specialties, was involved in the guideline development. A systematic literature search was conducted to collect scientific evidence on epidemiology, classification, diagnostics and treatment of diverticulitis. Literature was assessed using the classification system according to an evidence-based guideline development method, and levels of evidence of the conclusions were assigned to each topic. Final recommendations were given, taking into account the level of evidence of the conclusions and other relevant considerations such as patient preferences, costs and availability of facilities.

The natural history of diverticulitis is usually mild and treatment is mostly conservative. Although younger patients have a higher risk of recurrent disease, a higher risk of complications compared to older patients was not found. In general, the clinical diagnosis of ACD is not accurate enough and therefore imaging is indicated. The triad of pain in the lower left abdomen on physical examination, the absence of vomiting and a C-reactive protein >50 mg/l has a high predictive value to diagnose ACD. If this triad is present and there are no signs of complicated disease, patients may be withheld from further imaging. If imaging is indicated, conditional computed tomography, only after a negative or inconclusive ultrasound, gives the best results. There is no indication for routine endoscopic examination after an episode of diverticulitis. There is no evidence for the routine administration of antibiotics in patients with clinically mild uncomplicated diverticulitis. Treatment of pericolic or pelvic abscesses can initially be treated with antibiotic therapy or combined with percutaneous drainage. If this treatment fails, surgical drainage is required. Patients with a perforated ACD resulting in peritonitis should undergo an emergency operation. There is an ongoing debate about the optimal surgical strategy.

Scientific evidence is scarce for some aspects of ACD treatment (e.g. natural history of ACD, ACD in special patient groups, prevention of ACD, treatment of uncomplicated ACD and medical treatment of recurrent ACD), leading to treatment being guided by the surgeon's personal preference. Other aspects of the management of patients with ACD have been more thoroughly researched (e.g. imaging techniques, treatment of complicated ACD and elective surgery of ACD). This guideline of the diagnostics and treatment of ACD can be used as a reference for clinicians who treat patients with ACD.

Initial conservative management may be the mainstay of therapy for uncomplicated right colonic diverticulitis. However, definitive treatment guidelines have not yet been established. In this study, we assessed the efficacy of outpatient management versus inpatient management for preventing recurrence of this condition.

Between 2007 and 2009, a total of 103 patients were consecutively enrolled at the first attack of uncomplicated right colonic diverticulitis. In this prospective observational study, 40 patients underwent an outpatient management regimen consisting of oral antibiotics (for 4 days), and 63 patients underwent an inpatient management regimen that included bowel rest and intravenous antibiotics (for 7-10 days). The treatment was selected by the patient. Failure to respond to therapy and the incidence of recurrence of this condition were assessed.

Both groups of patients were treated successfully, and their symptoms were relieved. The patients were followed up for a median time of 21 months. Of the 40 patients with short-term oral antibiotic therapy on an outpatient basis, disease recurrence was observed in 4 patients (10%). Of these four patients, one underwent surgery and the remaining three were treated nonoperatively. Of the 63 patients on inpatient management, recurrence was observed in 7 patients (11%). Of these seven patients, one underwent surgery and the remaining six were treated nonoperatively.

Outpatient management with short-term oral antibiotic therapy for the treatment of uncomplicated right colonic diverticulitis is as effective as inpatient management in regard to preventing disease recurrence.

It is often postulated that younger patients with acute sigmoid diverticulitis (SD) have an increased risk of perforation which constitutes an indication for early surgery. The aim of this study was to correlate the severity of sigmoid diverticulitis with patient age in order to check the surgical indication in younger patients.

Patients with acute SD from January 1998 to June 2009 were included. Two age groups were distinguished: group I (GI) ≤40 years in age and group II (GII) >40 years. The perforation risk associated with first episode SD was determined by multivariate analysis. SD was classified according to Hansen and Stock (H/S).

In the total cohort of 959 patients, including 86 in GI (8.9%) and 873 in GII (91.1%) 468 had a first episode, with 64 in GI (13.7%) and 404 in GII (86.3%). The proportion of first episodes was 74.4% in GI and 46.3% in GII (p<0.001). The perforation risk did not differ (H/S IIb: 29.7% in GI vs. 29.2% in GII, p=0.938; H/S IIc: 25% in GI vs. 25% in GII, p=1). Treatment regimes were (GI vs. GII) emergency operations 25% vs. 25% (p=1), elective operations 17.2% vs. 10% (p=0.096) and conservative treatment 57.8% vs. 64.9% (p=0.276).

First episodes of SD were more frequent in younger patients (≤40) and did not involve a higher risk of perforation. The indication for treatment of acute SD should not be based on age but on the severity of inflammation and the individual situation of patients.

There is controversy over whether sigmoid diverticulitis (SD) is more aggressive with a higher risk of perforation in younger than in older patients. The aim of this study was to assess the clinical presentation and outcome of patients ≤40 and >40 years old with acute diverticulitis.

Consecutive admissions of all patients with acute SD were prospectively recruited from January 1998 to June 2010.

A total of 1,019 patients were included: 513 (69 ≤40 years and 444 >40 years) presented with their first episode, while 506 (20 ≤40 years, 486 >40 years) had a prior history of SD. The percentage of patients with severe SD did not differ between the two age groups either for the first (covered perforation, 30.4% vs. 29.5%, p = 0.875; free perforation, 26.1% vs. 23.9%, p = 0.69) or for the recurrent episode (covered perforation, 15% vs. 8.2%, p = 0.287; free perforation, 5% vs. 4.1%, p = 0.846). Furthermore, the rate of emergency surgery did not differ between both age groups either for the first (26.1% vs. 23.9%, p = 0.690) or the recurrent episode (5% vs. 4.1%, p = 0.846). No differences in the rate of Hartmann's procedure (52.6% vs. 68.3%, p = 0.180) and failure of conservative treatment (3.4% vs. 4.9%, p = 0.607) were observed between younger and older patients.

Acute SD in younger patients is not more aggressive and has no higher risk of perforation or need for emergency surgery compared to older patients.

Patients with uncomplicated diverticulitis and comorbidity are usually hospitalized. We analyze the efficacy and safety of treating these patients in Hospital at Home.

Prospective study since January 2007 to December 2009. Patients were transferred to the Hospital at Home after 12-24h at Emergency Department Observation Ward. All patients were treated with intravenous antibiotic until clinical condition improved.

176 patients were diagnosed with uncomplicated diverticulitis at the Emergency Department. 18% of them (33) had comorbidity. Twenty four patients were transferred to the Hospital at Home (seventeen patients had cardiopathy, four diabetes mellitus and three chronic renal failure). Mean age was 73.4 years. All patients had abdominal pain and 29.1% fever; 45.8% presented with leucocytosis. 20.8% had a previous history of diverticulitis. Mean stay of patients was 9 days. All patients had a favorable course. The home treatment was successfully completed in 100% of patients. 95% of the patients expressed their satisfaction with this type of treatment.

Treatment of patients with uncomplicated diverticulitis and comorbidity at home after a short period of observation in Hospital is safe and effective.

Medical treatment of uncomplicated acute diverticulitis is not standardized, and there is an enormous diversity in clinical practice. Our aim was to demonstrate that uncomplicated diverticulitis can be managed with orally administered amoxicillin plus clavulanic acid and a short hospital admission.

A prospective randomized trial was established to compare patients with uncomplicated diverticulitis who received oral antibiotic after a short course of intravenous antibiotic with those who received intravenous antibiotic for a longer period. The antibiotic treatment consisted of amoxicillin plus clavulanic acid 1 g every 8 h. We included 50 patients, 25 in each group. Patients in group 1 began oral antibiotic as soon as they improved and were discharged the day after. Patients in group 2 received intravenous antibiotic for 7 days. Both groups received oral antibiotic at discharge. The endpoint of the study was "failure of treatment," which was defined as the impossibility of discharging on the expected day, emergency admission, or hospital readmission.

Both groups were comparable in patient demographics and clinical characteristics. Most patients clearly improved between 24 and 48 h after admission. There were no significant differences between the groups when comparing failure of treatment. Treatment of patients in group 1 represented a savings in hospitalization costs of 1,244<euro> per patient.

Most patients with uncomplicated diverticulitis can be managed safely with oral antibiotic; thus, a very short hospital stay is a safe option.

Evidence supporting outpatient treatment with oral antibiotics in patients with uncomplicated diverticulitis is limited. Our aim was to evaluate the safety and efficacy of an ambulatory treatment protocol in patients with uncomplicated acute diverticulitis.

All patients diagnosed with uncomplicated diverticulitis based on abdominal computed tomography findings from June 2003 to December 2008 were considered for outpatient treatment. Admission was indicated in patients not able to tolerate oral intake and those with comorbidity or without adequate family support. Treatment consisted of oral antibiotics for 7 days (amoxicillin-clavulanic or ciprofloxacin plus metronidazole in patients with penicillin allergy). Patients were seen again at between 4 and 7 days after starting treatment to confirm symptom improvement.

Ninety-six patients were diagnosed with uncomplicated acute diverticulitis and 26 presented at least one criterion for admission. Ambulatory treatment was initiated in 70 (73%) patients. Only two (3%) required admission because of persisting abdominal pain and vomiting, respectively. Intravenous antibiotics resolved the inflammatory process in both cases. In the remaining 68 (97%), ambulatory treatment was completed without complication.

Ambulatory treatment of uncomplicated acute diverticulitis is safe, effective and applicable to most patients with tolerance to oral intake and without severe comorbidity and having appropriate family support.

This study was designed to evaluate whether the computed tomography (CT) reflects the extent of the inflammation in sigmoid diverticulitis (SD) in order to draw conclusions for selecting the appropriate treatment.

Two hundred four patients who underwent resection for SD from January 2003 to December 2008 were included. The preoperative CT stage was compared with intraoperative and histological findings. Patients were classified into phlegmonous (Hansen-Stock IIa), abscess-forming (HS IIb), and free perforated (HS IIc) forms of SD. Patients with a recurrent type of diverticulitis were excluded.

In the phlegmonous type (HS IIa; n = 75), we found a correlation with the preoperative stage in 52% (intraoperative) and 56% (histological), an understaging in 12% (intraoperative) and 11% (histological), and an overstaging in 36% (intraoperative) and 33% (histological). In the abscess-forming type (HS IIb, Hinchey I/II; n = 87), we found conformity in 92% (intraoperative) and 90% (histological), understaging in 3% (intraoperative) and 0% (histological), and overstaging in 5% (intraoperative) and 10% (histological). In the presence of a free perforation (HS IIc, Hinchey III/IV; n = 42), we saw conformity in 100% (intraoperative and histological). The positive predictive value for correctly diagnosing of phlegmonous type (HS IIa), abscess-forming type (HS IIb), and free perforation (HS IIc) by CT was intraoperatively (histologically) 52% (56), 92% (90), and 100% (100), respectively.

The CT is one of the most accurate methods for staging in SD. However, in the phlegmonous type (HS IIa), it leads to an overestimation of the findings in every third patient. It must be clarified whether this pronounced low inflammation should really be regarded as a complicated form of SD. In contrast, the abscess-forming (HS IIb) and free perforated (HS IIc) type of complicated SD is very well reflected by CT.

Many patients with acute diverticulitis can be managed as outpatients, but the success rate of this approach has not been thoroughly studied. We analyzed a large cohort of patients treated on an outpatient basis for an initial episode of acute diverticulitis to test our hypothesis that outpatient treatment of acute diverticulitis is highly effective.

We analyzed patients within the Kaiser Permanente Southern California system (from 2006 to 2007) who were diagnosed with an initial episode of diverticulitis during an emergency room visit and subsequently discharged home. Each patient underwent a computed tomography (CT) scan for diagnosis or for confirmation of a diagnosis, and each radiologic report was evaluated regarding the presence of free fluid, phlegmon, perforation, and abscess. Treatment failure was defined as a return to the emergency room or an admission for diverticulitis within 60 days of the initial evaluation.

Our study included 693 patients, of whom 54% were women, the average age was 58.5 years, and 6% failed treatment. In multivariate analysis, women (odds ratio, 3.08 [95% CI, 1.31-7.28]) and patients with free fluid on CT scan (odds ratio, 3.19 [95% CI, 1.45-7.05]) were at significantly higher risk for treatment failure. Age, white blood cell count, Charlson score, and duration of antibiotics were not significant predictive factors.

In a retrospective analysis, among a cohort of patients who were referred for outpatient treatment, we found that such treatment was effective for the vast majority (94%) of patients. Women and those with free fluid on CT scan appear to be at higher risk for treatment failure.

The indications for prophylactic surgery for phlegmonous and covered perforated type of acute sigmoid diverticulitis (SD) are currently matters of debate, and a more conservative approach has been advocated. However, it has not yet been clarified to what extent CT findings indicative of acute SD correlate with histological findings, and it is still uncertain how these findings change in the time interval between initial antibiotic treatment and late elective surgery. The aim of this study was to record time-course changes of inflammation in phlegmonous and abscess-forming diverticulitis after conservative treatment in order to check the indication for surgery.

This study included all patients who underwent surgery for CT morphologically phlegmonous and covered perforated SD from January 2002 to June 2007. Two groups were formed to record time-course changes: early elective surgery (7-10 days after antibiotic treatment) and late elective surgery (4-6 weeks after conservative treatment). Exclusion criteria were emergency interventions, free perforations (Hinchey III and IV), recurrent inflammations, and contrast allergy. The extent of the inflammation recorded preoperatively by CT scan was compared with histological findings.

A total of 257 patients (142 male and 115 female; mean age, 56.6 years) underwent surgery (116 early elective and 141 late elective) for phlegmonous and covered perforated SD. Phlegmonous SD was seen in 127 cases and covered perforated SD in 130 cases. In the phlegmonous type of SD, early surgery led to conformity with the preoperative stage in 56%, to more extensive findings in 11%, and to subsided inflammation in 33%. Late surgery led to conformity in 0% and to signs of subsided inflammation in 100%. In the covered perforated type of SD, early surgery led to conformity in 90%, to subsided inflammation in 10%, and to milder manifestation in 0%. In contrast, late surgery here led to conformity in 26% of the cases and to subsided inflammation in 74%. Considerable histological changes can be detected under conservative therapy. The acute inflammation subsides under antibiotic therapy as awaited. It must be clarified whether the phlegmonous form of SD should, in principal, be regarded as an indication for surgery, since it shows early and nearly complete regression of the inflammation. Otherwise, the covered perforated type of SD still shows marked inflammatory changes after conservative therapy in a high percentage of patients and should thus preferably be treated by surgery. However, the clinical appearance of the patient with sigmoid diverticulitis still remains the most important part of decision making.

Patients who undergo a Hartmann's procedure may not be offered a reversal due to concerns over the morbidity of the second procedure. The aims of this study were to examine the morbidity post reversal of Hartmann's procedure.

Patients who underwent a Hartmann's procedure for acute diverticulitis (Hinchey 3 or 4) between 1995 and 2006 were studied. Clinical factors including patient comorbidities were analysed to elucidate what preoperative factors were associated with complications following reversal of Hartmann's procedure.

One hundred and ten patients were included. Median age was 70 years and 56% of the cohort were male (n = 61). The mortality and morbidity rate for the acute presentation was 7.3% (n = 8) and 34% (n = 37) respectively. Seventy six patients (69%) underwent a reversal at a median of 7 months (range 3-22 months) post-Hartmann's procedure. The complication rate in the reversal group was 25% (n = 18). A history of current smoking (p = 0.004), increasing time to reversal (p = 0.04) and low preoperative albumin (p = 0.003) were all associated with complications following reversal.

Reversal of Hartmann's procedure can be offered to appropriately selected patients though with a significant (25%) morbidity rate. The identification of potential modifiable factors such as current smoking, prolonged time to reversal and low preoperative albumin may allow optimisation of such patients preoperatively.