Diagnosis and treatment of acute appendicitis - RePub - Erasmus

123 Pages·2005·1.52 MB·English

Diagnosis and treatment of
acute appendicitis
G. Kazemier

Diagnosis and treatment of acute appendicitis
Diagnose en behandeling van appendicitis acuta
Proefschrift
ter verkrijging van de graad van doctor aan de
Erasmus Universiteit Rotterdam
op gezag van de rector magnifi cus
Prof.dr. S.W.J. Lamberts
en volgens besluit van het College voor Promoties.
De openbare verdediging zal plaatsvinden op
woensdag 23 februari 2005 om 11.45 uur
door
Geert Kazemier
Geboren te Rotterdam
PROMOTIECOMMISSIE
Promotor: Prof.dr. H.J. Bonjer
Overige leden: Prof.dr. M.A. Cuesta
Prof.dr. E.J. Kuipers
Prof.dr. H.W. Tilanus
Copromotor: Dr. J.F. Lange
CONTENTS
Chapter 1 Introduction and outline 7
Chapter 2 Diagnosis and treatment of acute appendicitis through the years: 13
time to change course?
Chapter 3 Surgical validation of unenhanced helical CT in acute appendicitis 29
Chapter 4 Interobserver variability in computed tomography scanning for 39
suspected acute appendicitis
Chapter 5 Technical aspects of laparoscopic appendectomy. 49
How I do it; level 4 evidence in a nutshell
Chapter 6 Securing the appendiceal stump in laparoscopic appendectomy: 57
evidence for routine stapling?
Chapter 7 Laparoscopic versus open appendectomy; 69
a randomized clinical trial
Chapter 8 Meta-analysis of trials comparing laparoscopic and 81
open appendectomy
Chapter 9 Laparoscopic appendectomy in The Netherlands 95
Chapter 10 Summary and implications of this thesis 101
Chapter 11 Dutch summary 107
Appendix 113

Chapter 1
Introduction and outline

Introduction and outline 9
INTRODUCTION
Diagnosing patients with suspected acute appendicitis remains a challenge to the clinician.
In the Western world, the lifetime risk of acute appendicitis is 7 per cent for females and 9
per cent for males. However, the chance of undergoing an appendectomy during lifetime
is much higher; 23 per cent in females and 12 per cent in males. The discrepancy between
frequency of appendectomy and acute appendicitis refl ects the number of incidental and
unnecessary appendectomies. To prevent unnecessary appendectomies, diagnostic accuracy
demands improvement. Clinical investigation, a thermometer, and some laboratory results
are simply not enough to diagnose acute appendicitis accurately in all cases. In this era of
ultrasonography, computed tomography and laparoscopy it appears logical to apply these
diagnostic tools to assist the often puzzled clinician. Is it justifi ed to incur more costs or
expose patients to radiation just to diagnose acute appendicitis and are these tools really
better than the hands of an experienced surgeon?
It is obvious that treatment of acute appendicitis implies removal of the infl amed appendix.
However, since no diagnostic modality is 100 per cent accurate, the surgical procedure
includes diagnostic aspects as well. When McBurney described the possibility of performing
an appendectomy through a gridiron incision in 1884, this was a minimally invasive
approach compared to the usual midline laparotomy. His gridiron incision carried one major
disadvantage: it hampered access to the other quadrants of the abdominal cavity in case the
appendix was not infl amed. It took almost 100 years before the laparoscopic appendectomy
challenged McBurney’s operation. This novel technique combines a safe way to remove the
infl amed appendix imposing less trauma to the abdominal wall and allows for an inspection
of the entire abdominal cavity. Nevertheless, is laparoscopic appendectomy really the superior
technique and worth the extra operative time and training? Many surgeons tend to doubt
this, particularly in The Netherlands.
This thesis addresses questions regarding diagnosis and treatment of acute appendicitis
in adults and provides some of the answers. It provides scientifi c evidence to modify the
approach to a disease that affects annually 16,000 people in The Netherlands.
OUTLINE OF THIS THESIS
The optimal method to diagnose and treat acute appendicitis has been topic of much debate
during the past century. Particularly in the past two decades, introduction of diagnostic
modalities such as helical computed tomography (CT) and laparoscopy and wider application
of laparoscopic appendectomy have created an abundance of clinical studies. In chapter 2
this literature is reviewed to answer two key questions:
- What is the current state of the art diagnosis and treatment of acute appendicitis?
- What evidence can be culled to support different diagnostic and treatment modalities?
CT yields a high accuracy for acute appendicitis. This factor combined with the increasing
availability of helical CT scanners has resulted in a wide application of this diagnostic
procedure. However, enteral and intravenous contrast enhancement is often considered to
be mandatory to establish high accuracy. In chapter 3, the question is answered:
- Can unenhanced CT be used as a diagnostic tool in patients with suspected acute
appendicitis?
Implementation of routine CT scanning in patients with acute appendicitis requires 24
hours radiological expertise because these patients present at any time of day and they
require prompt and accurate diagnosis and treatment. Consequently, the assessment of
patients with suspected acute appendicitis and interpretation of US and CT scans are done
by in house staff. Chapter 4 addresses the following question:
- What is the impact of experience of radiologists on accuracy of CT scanning in patients with
suspected acute appendicitis?
Treatment of acute appendicitis has undergone major changes as well. Removal of
the infl amed appendix is obviously still the goal, but the technique has changed with the
introduction of minimally invasive techniques in general surgery. In chapter 5, the operative
1 technique of laparoscopic appendectomy is described. This chapter is defi nitely not based on
er
apt a high level of evidence but describes tips and tricks from the author’s personal experience
h
C
with laparoscopic appendectomy and answers the following question:
10
- What is the optimal operative technique for laparoscopic appendectomy?
Technically, the procedure is straight forward except for securing the appendiceal stump.
This can be done with pre-knotted loops or laparoscopic linear staplers. Both techniques
have shown to be safe but both entail potential drawbacks. Linear staplers are expensive,
they require a 12 mm port for introduction and leave metal staplers on the stump and in the
abdominal cavity, which have been shown to lead potentially to short bowel obstruction or
pseudo-polyps. Endoloops on the other hand are associated with more intense manipulation
of the stump and they can slip, which can potentially lead to more deep and superfi cial
postoperative infections and they cannot be placed safely over the cecum if the base of the
appendix is involved in the infl ammation. Complications solely attributable to stump closure
are rare, which means that large studies are required to show superiority of either fashion. In
chapter 6, data are pooled from the literature to overcome this sample size problem and to
answer the following question:
- What is the optimal fashion to secure the appendiceal stump in laparoscopic appendectomy?
During the advent of laparoscopic appendectomy, there was much scepticism whether
the already ‘minimally invasive’ grid iron incision could be improved. There were also safety
concerns about the potential negative effects of a CO pneumoperitoneum in patients with
2
perforated appendicitis and generalised peritonitis. In chapter 7, these issues are dealt with