Appendicitis a common disease n Suspicion of appendicitis 300/100.000 inh/year n Large variations in use of: - laboratory examination - in-hospital observation with repeat examination - diagnostic imaging - laparoscopic vs open appendectomy - non-surgical treatment n Large variations on costs and outcome 1
Untreated appendicitis - a ticking bomb? Balance between perforation - negative appendectomi Proportion perforations (%) 30 20 10 Velanovich 1992 0 10 20 30 40 Proportion negative appendectomies (%) focusing on the negative appendectomy rate is inappropriate. Rather, the primary focus should be upon the perforation rate. 2
Appendectomies in Jönköping, 1970 to 2006 Proportions By an improved clinical diagnosis (no diagnostik imaging or laparoscopy) we have seen a decreasing proportion of negative appendectomies. Increasing proportion of perforation Are we putting our patients at risk? Numbers per 100.000 inhabitants 95% decrease in number of negative appendectomies Unchanged number of perforations 60% decrease in number of non-perforated appendicitis Incidence per 100.000 inh Proportion (%) 30 20 10 0 250 200 150 100 50 Negative Perforation 1970-1974 1975-1979 1980-1984 1985-1989 2002-2006 Year period Perforated Non/perforated Not inflamed R Andersson et al. BMJ 1994 0 1970-1974 1975-1979 1980-1984 1985-1989 2002-2006 Time period Wide indications for surgery does not prevent perforations but detects more cases of appendicitis that would otherwise resolve Incidence per 100.000 inh 240 200 160 120 80 40 Perforated Non perforated 0 0 20 40 60 80 100 Incidence of negative explorations per 100.000 inh R Andersson et al. BMJ 1994 Review of 7 studies, n=53,143 3
Diagnostic laparoscopy on wide indications detects more appendicitis cases that would otherwise resolve Early laparoscopy vs conventional treatment in patients with right iliac fossa pain Early Conventional Decadt et al, 1999 laparoscopy management p-value Number patients 59 61 - - operated 59 17 - - appendicitis 23 8 0.002 Morino et al, 2006 Number patients 53 51 - - operated 53 20 - - appendicitis 16 3 0.003 Resolving appendicitis is common! n Many cases of appendicitis goes undetected n Not all patients with appendicitis need treatment n Increased use of diagnostic imaging will result in increased detection of appendicitis 4
Appendectomy rate per100.000 inh. Swedish hospitals 2004-2008 Perforated Non-perforated Negative Other diagnoses Incidence per 100 000 inh 0 50 100 150 Routine imaging compared to selective imaging Comparison of two hospitals in Sweden 1990 1995 2000 2005 2010 Danderyds hospital Ryhov hospital Non-perforated Non-perforated Perforated Perforated Negative Negative 5
Increasing incidence of appendicitis in the USA from the middle of the 1990s Livingstone et al, Ann Surg 2007 Imaging for the diagnosis of appendicitis Rao The radiologist makes the diagnosis better and cheaper 6
Imaging has good diagnostic properties Ultrasound CT 35 studies Sens 0.75 Spec 0.94 ROC area 0.95 20 studies Sens 0.94 Spec 0.93 ROC area 0.98 But how does it compare with clinical diagnosis? n Restrospective studies comparing patients that had imaging with those who did not! - selection bias 7
But how does it compare with clinical diagnosis? n Comparison of provisional clinical diagnosis with final diagnosis after imaging - provisional diagnosis is provisional! - clinical presentation changes with time Toorenvliet BR et al 2010 But how does it compare with clinical diagnosis? n Retrospective studies comparing outcomes in the pre- and post-imaging era - was imaging the only intervention? - are the patients comparable? 8
Increased use of CT - no impact on outcome Rao s report in NEJM Okt 1996-mars1998 108 CT examinations 106 operations 16 not inflamed (15%) April 1998- sept 1999 1035 CT examinations 120 operations 16 not inflamed (13%) Mc Donald G, Am Surg 2001 Frei et al, Am J Emerg Med 2008;26:39-44 9
july1992- sept1995 1997 p-value Observation period, months 39 12 CT scans 0 329 Operations 493 209 Proportion negative 20% 7% <0.001 Proportion perforated 22% 14% 0.038 Recalculated as numbers per month: Negative 2.5 1.3 0.01 Perforerated 2.2 2.3 ns Non-perforated 7.9 13.8 <0.001 Increased use of CT leads to more operations! Randomised trials: Ultrasound compared with clinical diagnosis n Randomised controlled trial of ultrasonography in diagnosis of acute appendicitis, incorporating the Alvarado score. Douglas C et al. BMJ 2000 160 patients had US and 142 conventional management (observation) - US has high sensitivity (0.95) and specificity (0.89) - no effect on proportion of negative appendectomy (9 vs 11%, p=0.59) - more appendicitis cases in US group (46 vs 39%, p=0.23) n.. US could lead to an increase in therapeutic operations by correctly diagnosing appendicitis in patients who may have recovered during a period of observation. n graded compression ultrasonography has not been shown to produce better outcomes than clinical diagnosis alone. 10
Randomised trials: CT compared with clinical diagnosis n Walker et al, Am J Surg 2000. 128 patients with suspicion of appendicitis - proportion of operations was the same (57 vs 57%) - slightly more appendicitis cases after CT scan (54 vs 46%) - fewer negative appendectomies (3 vs 11%, p=0.09) CT scan should be routinely performed for every patient whom the surgeon suspects of having appendicitis n Hong et al, Surg Inf 2003. 182 patients with indeterminate Alvarado score - no difference in negative appendectomy (8 vs 14%, p=0.50) Computed tomography should not be considered the standard of care for the diagnosis of appendicitis. n Lopez et al, Am Surg 2007. 90 women in childbearing age - no difference in negative appendectomy (5 vs 12%, p=0.62) CT in women of childbearing age who presented with right lower quadrant was not significantly different from clinical assessment STRAPP-score study Baseline registration N=1793 Intervention Lecture on the use of AIR score 25 hospitals Total 4468 patients Implementation of AIR-score and algorithm N=2675 Score <5 Observation at home N=996 Score 5-8 Randomisation N=1078 Score>8 Operation N=262 Imaging N=548 Repeat scoring 4-8 hours of observation N=530 11
STRAPP-score study Preliminary results Number of randomised patients with AIR score 5-8 Observation Imaging p-value Negative appendectomy 30 29 0.80 Non-perforated appendicitis 194 235 0.04 Perforated appendicitis 24 26 0.87 Appendicitis abscess 13 12 0.78 Other diagnosis 10 4 0.111 Not operated 259 242 0.127 Total 530 548 Conclusion n Randomized trials does not support that diagnostic imaging is better than clinical assessment for diagnosing acute appendicitis! n The routine use of diagnostic imaging in patients with suspicion of appendicitis may lead to more (unnecessary) operations for resolving appendicitis! n We need to better define the role of imaging in the algoritm for the managament of patients with suspicion of appendicitis. 12