Population level analysis of diagnostic laparoscopy versus normal appendicectomy for acute lower abdominal pain

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

BACKGROUND

Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis.

METHODS

A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16-45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis).

RESULTS

Some 5345 patients across 154 UK hospitals were identified, of which two-thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut-off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut-off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent).

CONCLUSION

Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision-making by identifying adults in the UK at low risk of appendicitis were identified.

A Population-Based Cohort Study of Emergency Appendectomy Performed in England and New York State

BACKGROUND

To compare selected outcomes (30-day reoperation and total length of hospital stay) following emergency appendectomy between populations from New York State and England.

METHODS

This retrospective cohort study used demographic and in-hospital outcome data from Hospital Episode Statistics (HES) and the New York Statewide Planning and Research Cooperative System (SPARCS) administrative databases for all patients aged 18+ years undergoing appendectomy between April 2009 and March 2014. Univariate and adjusted multivariable logistic regression were used to test significant factors. A one-to-one propensity score matched dataset was created to compare odd ratios (OR) of reoperations between the two populations.

RESULTS

A total of 188,418 patient records, 121,428 (64.4%) from England and 66,990 (35.6%) from NYS, were extracted. Appendectomy was completed laparoscopically in 77.7% of patients in New York State compared to 53.6% in England (P < 0.001). The median lengths of hospital stay for patients undergoing appendectomy were 3 (interquartile range, IQR 2-4) days versus 2 (IQR 1-3) days (P < 0.001) in England and New York State, respectively. All 30-day reoperation rates were higher in England compared to New York State (1.2 vs. 0.6%, P < 0.001), representing nearly a twofold higher risk of 30-day reoperation (OR 1.88, 95% CI 1.64-2.14, P < 0.001). As the proportion of appendectomy completed laparoscopically increased, there was a reduction in the reoperation rate in England (correlation coefficient -0.170, P = 0.036).

CONCLUSIONS

Reoperations and total length of hospital stay is significantly higher following appendectomy in England compared to New York State. Increasing the numbers of appendectomy completed laparoscopically may decrease length of stay and reoperations.

Appendicitis in a deployed military setting: diagnosis, management and impact on the fighting force

BACKGROUND

Acute appendicitis is a principal cause of abdominal pain worldwide and most common in young men who constitute the majority of the deployed fighting force. Diagnostic accuracy is paramount to prevent unnecessary intervention, morbidity and force impact.

METHOD

A consecutive series of appendicectomies, performed over 28 months on deployment in Afghanistan, was evaluated to assess the negative appendicectomy (NA) rate, explore the impact of CT on the rates of NA and assess the impact of appendicectomy on manpower in the deployed workforce.

RESULTS

In Afghanistan, the operative NA rate was 9.6%, whereas the histological NA rate was 20.5%. CT was widely used in Afghanistan (36%) and there was a significant reduction in NA rates if CT was performed preoperatively (6.25% vs 26%, p=0.02).

CONCLUSIONS

Diagnostic imaging will be limited in future conflicts and reliance on clinical judgement will be necessary. Military clinicians may need to accept higher rates of NA, as prolonged observation may not be possible. CT scanning should be used to a greater extent when available. A conservative management strategy for appendicitis with appropriate antibiotics should be considered in the event of delayed transfer to a surgical facility.