1

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

2

Untreated appendicitis - a ticking bomb?

0 10 20 30 40 Proportion negative appendectomies (%)

20

10

30

Prop

ortio

n per

forati

ons (

%)

Velanovich 1992

Balance between perforation - negative appendectomi

” …focusing on the negative appendectomy rate is inappropriate. Rather, the primary focus should be upon the perforation rate.”

3

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?

Appendectomies in Jönköping, 1970 to 2006

Numbers per 100.000 inhabitants 95% decrease in number of negative appendectomies Unchanged number of perforations 60% decrease in number of non-perforated appendicitis

Pro

porti

on (%

)

1970-1974 1975-1979 1980-1984 1985-1989 2002-2006Time period

0

50

100

150

200

250

PerforatedNon/perforatedNot inflamed

Inci

denc

e pe

r 100

.000

inh

R Andersson et al. BMJ 1994

1970-1974 1975-1979 1980-1984 1985-1989 2002-2006 Year period

0

10

20

30 Negative Perforation

Wide indications for surgery does not prevent perforations but detects more cases of appendicitis that would otherwise resolve

R Andersson et al. BMJ 1994 Review of 7 studies, n=53,143

Incidence of negative explorations per 100.000 inh

0

40

80

120

160

200

240

0 20 40 60 80 100

Perforated Non perforated

Inci

denc

e pe

r 100

.000

inh

4

Diagnostic laparoscopy on wide indications detects more appendicitis cases that would otherwise resolve

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

Early laparoscopy vs conventional treatment in patients with right iliac fossa pain

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

5

0 50 100 150 200

Karlskoga Norrt‰lje Ljungby Lycksele Skellefte UmeÂDanderyds Torsby Hˆ glandsV‰sterviks ÷ stersunds Ystads V‰xjˆ Kung‰lvs Visby Hudiksvalls Sˆ dersjukhKiruna Nykˆ pings L‰ns KalmarFalu ÷ rebroS:t Gˆ rans V‰rnamo Mora NU sjukvÂrdenVarbergs Karolinska Akademiska V‰sterÂs Karlstads AlingsÂs ÷ rnskˆ ldsviks Huddinge Sundsvalls Skaraborgs Lindesbergs Hels ingborgs S‰sjukvÂrdenLundSol lef te Link ˆ pingSˆ dert‰lje Arvika G‰vle Sunderbyns SahlgrenskaHalms tads M‰larKristianstads MASG‰llivare RyhovBlekinge

PerforatedNon-perforatedNegativeOther diagnoses

Appendectomy rate per100.000 inh. Swedish hospitals 2004-2008

Routine imaging compared to selective imaging Comparison of two hospitals in Sweden

0 50

10

0 15

0 In

cide

nce

per 1

00 0

00 in

h

1990 1995 2000 2005 2010

Non-perforated Non-perforated Perforated Perforated Negative Negative

Danderyds hospital Ryhov hospital

6

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

7

USappendicitSummary  ROC  Curve

1  -­‐  Specificity

Sensitivity

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CTappendicitSummary  ROC  Curve

1  -­‐  Specificity

Sensitivity

   0    0

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Imaging has good diagnostic properties

35 studies Sens 0.75 Spec 0.94 ROC area 0.95

20 studies Sens 0.94 Spec 0.93 ROC area 0.98

Ultrasound CT

But how does it compare with clinical diagnosis?

n  Restrospective studies comparing patients that had imaging with those who did not! - selection bias

8

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?

9

Increased use of CT - no impact on outcome

Mc Donald G, Am Surg 2001

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%)

Rao´s report in NEJM

Frei et al, Am J Emerg Med 2008;26:39-44

10

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.

11

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

Score>8 Operation

N=262

Score 5-8 Randomisation

N=1078

Score <5 Observation at home

N=996

Implementation of AIR-score and algorithm N=2675

Imaging N=548

Repeat scoring 4-8 hours of observation

N=530

25 hospitals Total 4468 patients

12

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.