Management of acute perianal abscess: is surgeon specialization associated with improved outcomes?

BACKGROUND: Acute surgical units (ASU) are increasingly being adopted and in our system are staffed by colorectal and non-colorectal general surgeons. This study aims to evaluate whether surgeon specialization was associated with improved outcomes in perianal abscess. METHODS: Patients with perianal abscess admitted to the ASU between 2016 and 2020 were identified from a prospective database and their medical records reviewed. Patients with IBD, treatment for fistula-in-ano within the preceding year, or perianal sepsis of non-cryptoglandular origin were excluded. Patients admitted under an ASU colorectal (CR) consultant were compared with those under a non-CR general surgeon in a retrospective cohort study. Primary outcome was perianal abscess recurrence. For those without initial fistula, hazard of recurrent abscess or fistula was analysed. Multivariable Cox PH regression analysis was performed. RESULTS: Four-hundred and eight patients were included (150 CR, 258 non-CR). The CR group more frequently had a fistula identified at index operation (34.0% versus 10.9%, P < 0.0001). However, Cox multivariable analysis found no difference in hazard of recurrent abscess between groups (HR 1.12, 95% CI 0.65-1.95, P = 0.681)). Abscess recurred in 18.7% CR and 15.5% non-CR. Subsequent fistula developed in 14.7% in both groups. For patients without initial fistula, there was no difference between groups in hazard of recurrent abscess or fistula (HR 1.18, 95% CI 0.69-2.01, P = 0.539). CONCLUSION: Surgeon specialization was not associated with improved outcomes for ASU patients with perianal abscess, albeit with potential selection bias. CR surgeons were more proactive identifying fistulas; this raises the possibility that drainage alone may be adequate treatment.

Overall survival comparing laparoscopic to open surgery for right-sided colon cancer: propensity score inverse probability weighting population study.

BACKGROUND: This retrospective cohort study reports on overall survival and short-term complications, comparing laparoscopic to open resection for right-sided colon cancers. It is one of the largest studies in the field with generalizable population-level results. METHOD: This study on right sided colon cancers used prospectively collected administrative data linked to a death registry over 5 years from 2014 to 2018. Exclusion criteria were private patients, patients aged less than 10 years, synchronous and metachronous cancers. Propensity score weighting was used to balance cohorts and Cox proportional hazards regression was used to assess the hazard of death. In addition, logistic regression analysis was used to assess secondary outcomes. For completeness, unweighted data was similarly analysed. RESULTS: There were 3603 patients identified for the analysis: 1729 open patients and 1874 laparoscopic patients. Cox proportional hazards regression analysis of the weighted data showed no evidence of a statistically significant effect of laparoscopic surgery compared to open surgery on overall survival for right-sided colon cancers (HR 0.86, 95% CI 0.71-1.04, P = 0.112). The weighted data showed lower odds of prolonged length of stay, return to theatre and discharge destination other than home in the laparoscopic cohort compared to the open cohort. There was no difference in inpatient mortality. Unweighted results were similar. CONCLUSION: This study validates the use of laparoscopic surgery for right-sided colon cancer, showing similar long-term overall survival and inpatient mortality compared to open surgery. It is superior to open surgery for the short-term outcomes of LOS, return to theatre and discharge destination other than home.

Use of Temporary Abdominal Closure in Non-Trauma Surgery: A Cohort Study.

BACKGROUND: Damage control surgery in trauma is widely used but the evidence for the use of laparostomy in non-trauma abdominal emergencies is limited. This study aimed to characterise outcomes in emergency abdominal surgery by comparing laparostomy to one-stage laparotomy for patients of similar illness severity. METHODS: A retrospective study of adult patients requiring emergency abdominal surgery and post-operative intensive care stay was performed between 2016 and 2020 at a major Australian metropolitan hospital. Case selection was from a prospectively maintained database, and case notes were reviewed. Patients having delayed abdominal closure were compared with those having one-stage abdominal closure. The primary outcome was odds of in-hospital mortality. The secondary outcomes included intensive care unit length of stay (LOS), overall hospital LOS, definitive stoma rate and discharge destination. Multivariable logistic regression analysis was performed to adjust for potentially confounding variables. RESULTS: Two hundred and eighteen patients met inclusion criteria (80 laparostomy and 138 non-laparostomy). The most common indications for laparostomy were bowel ischaemia (41.3%), sepsis (26.3%) and physiological instability (22.5%). There was no evidence of difference in odds of in-hospital mortality between groups (adjusted OR = 1.67, CI: 0.85-3.28; p = 0.138). Patients requiring laparostomy had a slightly longer median ICU LOS (4 vs. 3 days; p < 0.001), similar median hospital LOS (19 vs. 14 days, p = 0.245) and similar discharge destination. There was no difference in stoma rate (35.0% vs. 35.5%). CONCLUSION: Compared with standard one-stage laparotomy, laparostomy resulted in similar odds of in-hospital mortality in emergency abdominal surgery patients requiring intensive care.

T-stage downstaging of locally advanced rectal cancer after neoadjuvant chemoradiotherapy is not associated with reduced recurrence after adjusting for tumour characteristics.

BACKGROUND AND OBJECTIVES: Prior studies examining prognostic outcomes of locally advanced rectal adenocarcinomas achieving a complete pathological response following neoadjuvant chemoradiotherapy (nCRT) did not adjust for adverse prognostic factors in multivariate analyses and account for magnetic resonance imaging tumour staging inaccuracy pre-nCRT. We aimed to clarify prognostic outcomes in mT3 rectal adenocarcinomas with ypT-downstaging post-nCRT in robust adjusted analyses. METHODS: Retrospective analysis of prospectively-collected clinical data from 528 mT3 rectal adenocarcinomas ≤12 cm from the anal verge, any N-stage, no metastases, post-nCRT following total mesorectal excision (TME). Recurrence outcomes (local and distant combined) of tumours with complete ypT-downstaging (ypT0) post-nCRT before TME compared with no ypT-downstaging (≥ypT3) were examined using multivariate Cox regression, adjusting for confounders and accounting for pre-nCRT mT3-staging inaccuracy using bootstrapping. RESULTS: Complete ypT-downstaging was achieved in of 17.6% tumours and correlated strongly with complete pathological response. Complete ypT-downstaging was not associated with reduced recurrence hazards compared with no ypT-downstaging (hazard ratio = 0.60; 95% confidence interval [CI]: 0.23-1.56; p = 0.30). Lymphovascular invasion (LVI) and ypN+ve increased recurrence hazards by 1.8-fold (95% CI: 1.10-2.79; p = 0.02) and 2.3-fold (95% CI: 1.48-3.54; p = 0.0002), respectively. CONCLUSION: Complete ypT-downstaging was not associated with reduced recurrence after adjusting for confounders and accounting for mT3-staging inaccuracy, even in the absence of adverse prognostic factors (ypN+, LVI).

Hospital Acquired Infections in Surgical Patients: Impact of COVID-19-Related Infection Prevention Measures.

BACKGROUND: Hospital acquired infections are common, costly, and potentially preventable adverse events. This study aimed to determine the effect of the COVID-19 pandemic-related escalation in infection prevention and control measures on the incidence of hospital acquired infection in surgical patients in a low COVID-19 environment in Australia. METHOD: This was a retrospective cohort study in a tertiary institution. All patients undergoing a surgical procedure from 1 April 2020 to 30 June 2020 (COVID-19 pandemic period) were compared to patients pre-pandemic (1 April 2019-30 June 2019). The primary outcome investigated was odds of overall hospital acquired infection. The secondary outcome was patterns of involved microorganisms. Univariable and multivariable logistic regression analysis was performed to assess odds of hospital acquired infection. RESULTS: There were 5945 admission episodes included in this study, 224 (6.6%) episodes had hospital acquired infections in 2019 and 179 (7.1%) in 2020. Univariable logistic regression analysis demonstrated no evidence of change in odds of having a hospital acquired infection between cohorts (OR 1.08, 95% CI 0.88-1.33, P = 0.434). The multivariable regression analysis adjusting for potentially confounding co-variables also demonstrated no evidence of change in odds of hospital acquired infection (OR 0.93, 95% CI 0.74-1.16, P = 0.530). CONCLUSION: Increased infection prevention and control measures did not affect the incidence of hospital acquired infection in surgical patients in our institution, suggesting that there may be a plateau effect with these measures in a system with a pre-existing high baseline of practice.

Is increasing nodal count associated with improved recurrence-free and overall survival following standard right hemicolectomy for colon cancer?

BACKGROUND AND OBJECTIVES: Increasing lymph node harvest for right-sided colon cancer is associated with improved overall survival (OS), but most relevant studies failed to report the extent of resection. We examined the association between increasing lymph node count with standard right hemicolectomy according to nodal status and prognostic outcomes in right-sided tumors. METHODS: Retrospective analysis of prospectively collected clinical data from patients with proximal colonic adenocarcinomas (n = 1390) following right hemicolectomy. Associations between lymph node counts (0-12 vs. 13-15, 16-20, and >20) and recurrence-free survival (RFS) and OS were examined using multivariate Cox modeling adjusted for confounders. RESULTS: We found no association between increasing nodal count and RFS, regardless of nodal status. In the absence of nodal metastases, increasing nodal count (16-20 and >20 vs. 0-12 nodes) was associated with 57% (95% confidence interval [CI]: 0.21-0.89) and 52% (95% CI: 0.24-0.95) improved OS, respectively. In the presence of nodal metastases, increasing nodal count was not associated with OS. Adjuvant chemotherapy did not modify this effect. CONCLUSION: Increasing nodal count (>15 nodes) with right hemicolectomy was not associated with improved RFS. Improved OS was only found for node-negative tumors, casting some doubt on the benefits of resecting more lymph nodes in the presence of nodal metastases.

Beyond Graft Survivl: A National Cohort Study Quantifying the Impact of Increasing Kidney Donor Profile Index on Recipient Outcomes 1 Year Post-transplantation.

Background: The reporting of a locally validated kidney donor profile index (KDPI) began in Australia in 2016. Across diverse populations, KDPI has demonstrated utility in predicting allograft survival and function. A metric that incorporates both elements may provide a more comprehensive picture of suboptimal recipient outcomes. Methods: A retrospective cohort study of adult kidney transplant recipients in Australia (January 2009 to December 2014) was conducted. Conventional recipient outcomes and a composite measure of suboptimal outcome (1-y allograft failure or estimated glomerular filtration rate [eGFR] <30 mL/min) were evaluated across KDPI intervals (KDPI quintiles and 5-point increments in the KDPI 81-100 cohort). The impact of increasing KDPI on allograft function (1-y eGFR) and a suboptimal outcome was explored using multivariable regression models, adjusting for potential confounding factors. Results: In 2923 donor kidneys eligible for analysis, median KDPI was 54 (interquartile range [IQR], 31-77), and Kidney Donor Risk Index was 1.39 (IQR, 1.03-1.67). The median 1-y eGFR was 52.74 mL/min (IQR, 40.79-66.41 mL/min). Compared with the first quintile reference group, progressive reductions in eGFR were observed with increasing KDPI and were maximal in the fifth quintile (adjusted ß-coefficient: -27.43 mL/min; 95% confidence interval, -29.44 to -25.42; P < 0.001). A suboptimal outcome was observed in 359 recipients (12.3%). The adjusted odds for this outcome increased across quintiles from a baseline of odds ratio of 1.00 (first quintile) to odds ratio of 11.68 (95% confidence interval, 6.33-21.54, P < 0.001) in the fifth quintile cohort. Conclusions: Increases in donor KDPI were associated with higher probabilities of a suboptimal outcome and poorer baseline allograft function, particularly in the KDPI > 80 cohort. These findings may inform pretransplant discussions with potential recipients of high-KDPI allografts.

Colorectal cancer databases and registries in Australia: what data is available?

BACKGROUND: There are multiple data sources relating to colorectal cancer (CRC) nationwide. Prospective clinical cancer databases, population-based registries and linked administrative data are powerful tools in clinical outcomes research and provide real-world perspective on cancer treatments. This study aims to review the different Australian data sources for CRC from the perspective of conducting comparative research studies using a PICO (patient, intervention, comparison, outcome) framework. METHODS: Data dictionaries from the different data sources were evaluated for the types of exposure and outcome variables contained to highlight their differing research utility. RESULTS: State or territory-based cancer registries contain limited histology, cancer staging and treatment detail. They enable investigation of population-level patterns in overall survival (OS) of cancer patients with different demographics. Prospective clinical cancer databases contain more detail, especially surgical. Their strength is in auditing short-term surgical outcomes. They vary in the amount of data collected for other cancer treatments and completion of follow up data. Linked administrative databases have broad population coverage but less surgical detail. They provide population-level data on treatment patterns, short-term outcome measures and OS, as well as long-term surgical outcomes such as identifying patients who did not undergo stoma reversal. These databases cannot assess disease-free survival. CONCLUSION: Of the various CRC data sources within Australia, linked administrative databases have the potential to provide the widest population coverage combined with the broadest range of exposures and outcomes, and arguably the most research utility.

Delayed ileostomy closure increases the odds of Clostridium difficile infection.

AIM: A diverting ileostomy is typically performed to divert intestinal contents in high-risk colorectal anastomoses. Ileostomy closure is associated with high rates of postoperative Clostridium difficile infection (CDI). Risk factors for the development of CDI are unclear; however, a correlation has been observed with delayed closure. This study aimed to assess the odds of developing CDI in patients who had a delay to reversal of ileostomy, compared to those who had no delay. METHODS: A retrospective cohort study was conducted of patients undergoing reversal of ileostomy between 2010 and 2019 at a single tertiary centre. A delay to reversal of ileostomy was defined if the procedure was performed at >365 days following the index procedure. CDI was defined as the presence of Clostridium difficile toxin associated with diarrhoea. Univariable logistic regression analysis was performed to estimate odds of CDI for each covariable, comparing patients who had a delay to reversal of ileostomy with those who did not. Multivariable logistic regression analysis was used to adjust for the potential confounding effects of covariables. RESULTS: Of 195 patients, 11 (5.6%), developed postoperative CDI. Multivariable analysis showed that delay to reversal of ileostomy was associated with a nearly 7-fold increase in odds of CDI (OR = 6.95, CI: 1.06-81.6; p-value = 0.03). CONCLUSION: A delay to reversal of ileostomy of >365 days was associated with a higher incidence of CDI postoperatively. Careful consideration should be given to the timing of reversal and appropriate preoperative counselling of patients.

Impact of hospital geographic remoteness on overall survival after colorectal cancer resection using state-wide administrative data.

BACKGROUND: This study aimed to use administrative data (AD) linked to the Victorian death index (VDI) to report on overall long-term survival following colorectal cancer (CRC) surgery, comparing regional to metropolitan hospitals. METHODS: A retrospective cohort study using prospectively gathered AD linked to VDI. The primary outcome was overall survival (OS). Outcomes were adjusted for potential confounders via multivariable Cox proportional hazard regression analysis. RESULTS: Total of 17 533 patients: 12 879 metropolitan patients, 3835 inner regional patients and 719 outer regional patients. Multivariable Cox regression, adjusted for the effects of age, ASA score, Charlson score, position of tumour, mode of access, admission type, lymph node metastases, distant metastases, return to theatre, length of stay, HDU admission and discharge destination showed no difference in OS comparing CRC resection patients from inner or outer regional hospitals to metropolitan ((HR 1.02, 95% CI 0.95-1.09, P = 0.59) and (HR 0.97, 95% CI 0.85-1.11, P = 0.68) respectively). CONCLUSION: This is the largest and most detailed study concerning OS after CRC resection involving Victorian public hospitals. There was no difference in OS following CRC resection when inner or outer regional hospitals were compared to metropolitan hospitals in Victoria. The study demonstrated the utility of AD with validated algorithms, linked to death data for reporting CRC survival outcomes.

Impact of hospital geographic remoteness on short-term outcomes after colorectal cancer resection using state-wide administrative data.

BACKGROUND: This study aimed to use validated coding algorithms, applied to a central repository of administrative data (AD), to report on short-term outcomes following resection for colorectal cancer (CRC) comparing regional to metropolitan Victorian hospitals. METHODS: This is a retrospective cohort study using prospectively gathered AD. The primary outcome was prolonged length of stay (LOS). Secondary outcomes were: inpatient mortality, return to theatre, discharge destination and need for mechanical ventilation/intensive care unit support. Outcomes were adjusted for potential confounders via multivariable logistic regression analysis. RESULTS: This study of 18 470 patients found strong evidence for lower odds of prolonged LOS (odds ratio (OR) 0.53, 95% confidence interval (CI) 0.48-0.58, P ≤ 0.001) and inpatient mortality (OR 0.67, 95% CI 0.49-0.91, P = 0.01) in inner regional hospital compared with metropolitan hospitals. For outer regional hospitals, there was strong evidence of decreased odds of prolonged LOS (OR 0.64, 95% CI 0.52-0.77, P = <0.001) and return to theatre (OR 0.67, 95% CI 0.47-0.95, P = 0.03). CONCLUSION: This is the largest and most detailed study concerning short-term outcomes following CRC resection in Victorian public hospitals. Inner and outer regional centres had similar or better short-term outcomes than metropolitan hospitals after CRC resection. AD with validated algorithms serves as a large accurate database to report on CRC outcomes.

Laparoscopic Compared With Open Resection for Colorectal Cancer and Long-term Incidence of Adhesional Intestinal Obstruction and Incisional Hernia: A Systematic Review and Meta-analysis.

BACKGROUND: Incisional hernia and adhesional intestinal obstruction are important complications of laparoscopic and open resection for colorectal cancer. This is the largest systematic review of comparative studies on this topic. OBJECTIVE: This study aimed to investigate whether laparoscopic surgery decreases the incidence of incisional hernia and adhesional intestinal obstruction compared to open surgery for colorectal cancer. DATA SOURCES: Online databases PubMed, EMBASE, and the Cochrane Library were searched. Abstracts from the annual meetings of the American Society of Colon and Rectal Surgeons and the European Society of Coloproctology were performed to cover gray literature. STUDY SELECTION: We included both randomized and nonrandomized comparative studies. INTERVENTIONS: Laparoscopic resection was compared to open resection for patients with colorectal cancer. MAIN OUTCOMES MEASURES: The primary outcomes measured were incisional hernia and adhesional intestinal obstruction. RESULTS: Fifteen studies met inclusion criteria (6 randomized comparative studies/9 nonrandomized comparative studies); 84,172 patients. Meta-analysis showed decreased odds of developing incisional hernia in the laparoscopic cohort (OR, 0.79; 95% CI, 0.66-0.95; p = 0.01) but no difference in requirement for surgery (OR, 1.07; 95% CI, 0.64-1.79; p = 0.79). Similarly, there were decreased odds of developing adhesional intestinal obstruction in the laparoscopic cohort (OR, 0.81; 95% CI, 0.72-0.92, p = 0.001), but no difference in requirement for surgery (OR, 0.84; 95% CI, 0.53-1.35; p = 0.48). LIMITATIONS: Incisional hernia and adhesional intestinal obstruction were poorly defined in many studies. CONCLUSION: Laparoscopic surgery is associated with decreased odds of incisional hernias and adhesional intestinal obstructions compared with open surgery for colorectal cancer.

Neoadjuvant Chemoradiotherapy and Tumor Recurrence in Patients with Early T-Stage Cancer of the Lower Rectum.

BACKGROUND: The role neoadjuvant chemoradiotherapy (nCRT) plays in oncological outcomes in early T-stage rectal cancer is uncertain. The present work aims to clarify prognostic outcomes by estimating the effect of nCRT on tumor recurrence prior to major surgery compared with major surgery alone. PATIENTS AND METHODS: Prospectively collected data were retrospectively analyzed for patients diagnosed with localized rectal adenocarcinoma ≤ 8 cm from the anal verge, with final histopathology ≤ T2 (≤ ypT2/≤ pT2), regardless of magnetic resonance imaging staging, between 1990 and 2017. As the effect of nCRT on recurrence varied over time, thereby violating the Cox proportional hazards assumption, the effect of nCRT on recurrence hazards was estimated using a time-varying multivariate Cox model over two separate time intervals (≤ 1 year and > 1 year postsurgery) by nCRT. RESULTS: Long-course nCRT was associated with a 5.6-fold increase in the hazard of recurrence ≤ 1 year postsurgery [hazard ratio (HR) 5.6; 95% confidence interval (CI) 1.2-24.9; P = 0.02], but there was no increase in recurrence hazards > 1 year (HR 0.84; 95% CI 0.4-2.0; P = 0.70). In subgroup analysis restricted to ≤ mrT2/≤ ypT2 and ≤ pT2 tumors (omitting > mrT2 tumors), the effect of nCRT on recurrence no longer varied over time, indicating that tumor heterogeneity was responsible for the observed increased recurrence hazards ≤ 1 year postsurgery; That is, > mrT2 tumors that were downstaged to ≤ ypT2 after nCRT were responsible for the time-varying effects of nCRT and increased recurrence hazards ≤ 1 year postsurgery. Subsequently, no difference was found in prognostic outcomes either with or without nCRT before surgery in the homogeneous population of ≤ mrT2/≤ ypT2 and ≤ pT2 tumors. CONCLUSIONS: No evidence was found to indicate that nCRT prior to surgery reduces tumor recurrence in early T-stage lower rectal cancer compared with surgery alone.

Impact of anastomotic leak on recurrence and survival after colorectal cancer surgery: a BioGrid Australia analysis.

BACKGROUND: There is conflicting evidence regarding the oncological impact of anastomotic leak following colorectal cancer surgery. This study aims to test the hypothesis that anastomotic leak is independently associated with local recurrence and overall and cancer-specific survival. METHODS: Analysis of prospectively collected data from multiple centres in Victoria between 1988 and 2015 including all patients who underwent colon or rectal resection for cancer with anastomosis was presented. Overall and cancer-specific survival rates and rates of local recurrence were compared using Cox regression analysis. RESULTS: A total of 4892 patients were included, of which 2856 had completed 5-year follow-up. The overall anastomotic leak rate was 4.0%. Cox regression analysis accounting for differences in age, sex, body mass index, American Society of Anesthesiologists score and tumour stage demonstrated that anastomotic leak was associated with significantly worse 5-year overall survival (χ 2 = 6.459, P = 0.011) for colon cancer, but only if early deaths were included. There was no difference in 5-year colon cancer-specific survival (χ 2 = 0.582, P = 0.446) or local recurrence (χ 2 = 0.735, P = 0.391). For rectal cancer, there was no difference in 5-year overall survival (χ 2 = 0.266, P = 0.606), cancer-specific survival (χ 2 = 0.008, P = 0.928) or local recurrence (χ 2 = 2.192, P = 0.139). CONCLUSION: Anastomotic leak may reduce 5-year overall survival in colon cancer patients but does not appear to influence the 5-year overall survival in rectal cancer patients. There was no effect on local recurrence or cancer-specific survival.

Combined treatment approach to chronic anal fissure with associated anal fistula.

BACKGROUND: Anal fistula in association with chronic anal fissure (fissure-fistula) is infrequently described. Recognizing this association and managing both components may help prevent some treatment failures seen with chronic anal fissure. This study aims to report on the outcomes of 20 consecutive patients with fissure-fistula managed with fistulotomy and injection of botulinum A toxin. METHODS: The study is a retrospective, observational study, assessing the success of symptom resolution following fistulotomy with botulinum A toxin, in patients identified as having a chronic anal fissure with associated anal fistula. The study included all patients with this condition treated with combination treatment by a single surgeon at a tertiary care hospital between January 2013 and January 2016. RESULTS: Twenty patients with fissure-fistula treated with fistulotomy and botulinum toxin A were identified. The median cohort age was 44 years (range 25-78), with a predominance of males (80%) and posterior fissure position (80%). The most common presenting symptoms were anal pain (70%), rectal bleeding (55%), anal discharge (35%) and anal pruritus (35%). Mean follow-up was 10.5 weeks and all patients who attended follow-up appointments reported resolution of symptoms. There were no cases of incontinence and none of the cohort required further surgical intervention for the condition. CONCLUSION: Chronic anal fissure with associated anal fistula can be successfully managed with fistulotomy and injection of botulinum toxin A. Further studies would be helpful in determining if recognition and management of the fistula component in isolation with fistulotomy is as effective as fistulotomy plus botulinum A toxin.

International Variation in Emergency Operation Rates for Acute Diverticulitis: Insights into Healthcare Value.

BACKGROUND: International comparison of outcomes of surgical diseases has become a global focus because of widespread concern over surgical quality, rising costs and the value of healthcare. Acute diverticulitis is a common disease potentially amenable to optimization of strategies for operative intervention. The aim was to compare the emergency operative intervention rates for acute diverticulitis in USA, England and Australia. METHODS: Unplanned admissions for acute diverticulitis were found from an international administrative dataset between 2008 and 2014 for hospitals in USA, England and Australia. The primary outcome measured was emergency operative intervention rate. Secondary outcomes included inpatient mortality and percutaneous drainage rate. Multivariable analysis was performed after development of a weighted comorbidity scoring system. RESULTS: There were 15,150 unplanned admissions for acute diverticulitis. The emergency operative intervention rates were 16, 13 and 10% for USA, England and Australia. The percutaneous drainage rate was highest in USA at 10%, while the mortality rate was highest in England at 2.8%. The propensity for emergency operative intervention was higher in USA (OR 1.45, p < 0.001) and England (OR 1.49, p < 0.001) than in Australia. The risk of 7-day mortality was higher in England than in Australia (OR 2.79, p < 0.001). Percutaneous drainage was associated with reduced 7-day mortality risk. CONCLUSION: Australia has a lower propensity for emergency operative intervention, while England has a greater risk of mortality for acute diverticulitis. International variations raise the issue of healthcare value in terms of differing resource use and outcomes.