Acute appendicitis: proposal of a new comprehensive grading system based on clinical, imaging and laparoscopic findings
Gomes et al. World Journal of Emergency Surgery
Acute appendicitis: proposal of a new comprehensive grading system based on clinical, imaging and laparoscopic findings
Carlos Augusto Gomes 0
Massimo Sartelli 2
Salomone Di Saverio 1
Luca Ansaloni 6
Fausto Catena 5
Federico Coccolini 6
Kenji Inaba 4
Demetrios Demetriades 3 4
Felipe Couto Gomes 8
Camila Couto Gomes 7
0 Surgery Department, Therezinha de Jesus University Hospital, Medical and Health Science School, Surgery Unit, Federal University of Juiz de Fora (UFJF), Rua Senador Salgado Filho 510 / 1002, Bairro Bom Pastor, Juiz de Fora , Minas Gerais 36021-660 , Brasil
1 Trauma Surgery Unit, Maggiore Hospital , Bologna , Italy
2 Department of Surgery, Macerata Hospital , Macerata , Italy
3 Department of Surgery (K.I.), Keck School of Medicine of University of Southern California , Los Angeles, CA , USA
4 University of California , San Francisco , USA
5 Emergency Surgery Department, Maggiore Parma Hospital , Parma , Italy
6 General Surgery I, Papa Giovanni XXIII Hospital , Bergamo , Italy
7 Internal Medicine Departament, Monte Sinai Hospital , Juiz de Fora, Minas Gerais , Brazil
8 Internal Medicine Departament, Therezinha de Jesus University Hospital, Medical and Health Science School , Juiz de Fora , Brazil
Advances in the technology and improved access to imaging modalities such as Computed Tomography and laparoscopy have changed the contemporary diagnostic and management of acute appendicitis. Complicated appendicitis (phlegmon, abscess and/ or diffuse peritonitis), is now reliably distinguished from uncomplicated cases. Therefore, a new comprehensive grading system for acute appendicitis is necessary. The goal is review and update the laparoscopic grading system of acute appendicitis and to provide a new standardized classification system to allow more uniform patient stratification. During the last World Society of Emergency Surgery Congress in Israel (July, 2015), a panel involving Acute Appendicitis Experts and the author's discussed many current aspects about the acute appendicitis between then, it will be submitted a new comprehensive disease grading system. It was idealized based on three aspect of the disease (clinical and imaging presentation and laparoscopic findings). The new grading system may provide a standardized system to allow more uniform patient stratification for appendicitis research. In addition, may aid in determining optimal management according to grade. Lastly, what we want is to draw a multicenter observational study within the World Society of Emergency Surgery (WSES) based on this design.
Appendicitis; Appendectomy; Laparoscopy; Treatment; Classification
Appendicitis is the most common cause of an acute
surgical abdomen, with an estimated lifetime prevalence of
7–8 %. Despite advances in diagnosis and treatment, it is
still associated with significant morbidity (10 %) and
mortality (1–5 %) [
]. The clinical history and physical
examination represent the most important tools for early
diagnosis of the disease. The overall accuracy for
diagnosing acute appendicitis is approximately 90 %, with a
falsenegative appendectomy rate of 10 %. This is more frequent
in atypical cases, especially in women of childbearing age,
because the symptoms often overlap with others
]. Recently 182 patients with suspicion of acute
appendicitis were stratified to low, intermediate, and high
probability of appendicitis by two different clinical scores
(AIR / Alvarado) and by an experienced surgeon. The AIR
score was especially good at identifying patients with high
probability of appendicitis with a specificity of 0.97 for all
appendicitis and 0.92 for advanced appendicitis,
compared with 0.91 and 0.77, respectively, for the surgeon
and Alvarado score. Therefore, in this series, the AIR
score had both higher sensitivity and specificity than
the Alvarado score and the experienced surgeon in the
clinical diagnosis of the disease .
The clinical scores represent an excellent and useful tool
for pre-operative diagnosis of acute appendicitis, but
regardless its accuracy it cannot be applied as a grading
system for acute appendicitis, especially attempting to
distinguish different complicated grades of the disease
]. As we know, novel scoring systems are being
described and introduced into clinical practice, based on
clinical and imaging (CT and/or US). In addition, less
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invasive management options including percutaneous
drainage, non-operative treatment and minimally invasive
surgery are available [
Three imaging modalities are available in difficult
cases of acute appendicitis: Ultrasound (US), Computed
Tomography (CT), and Magnetic Resonance Imaging
(MRI). Trans-abdominal ultrasound should be the first-line
imaging test. Although there is a higher radiation burden,
abdominal CT is superior to US and may be required in
patients with an equivocal US or if perforation is suspected.
Low-dose unenhanced CT is equivalent to standard-dose
CT with intravenous contrast agents in the detection of the
five signs of acute appendicitis (thickened appendiceal wall
greater than 2 mm, cross-sectional diameter greater than
6 mm, increased pericolic fat density, abscess, and
]. However, as pointed out by Saar, despite all
available technologies, it remains very difficult to achieve a
false negative appendectomy rates less than 10 % [
Operative versus non-operative treatment
Both open appendectomy and laparoscopic appendectomy
are acceptable techniques and can be used interchangeably.
The laparoscopic treatment of uncomplicated grades of
acute appendicitis is well established and represent the
approach of first choice some time ago. However,
wellconducted trials to help guide the treatment for all
complicated grades of acute appendicitis are limited, especially by
the presence of bias and methodological flaws. However,
the safety and efficacy of laparoscopy in the treatment of
these cases is well established too [
A recent meta-analysis by Varadhan et al. 2015 [
assessed four randomized controlled trials about safety
and efficacy of antibiotics compared with appendectomy
for treatment of uncomplicated acute appendicitis
]. The primary outcome measure was the incidence
of complications and secondary outcome was the efficacy
of treatment. 900 patients (470 antibiotic treatment, 430
appendectomy) met the inclusion criteria. Antibiotic
treatment was associated with a 63 % (277/438) success rate at
1 year. Meta-analysis of complications showed a relative
risk reduction of 31 % for antibiotic treatment compared
with appendectomy. The authors concluded that
antibiotics are both effective and safe as primary treatment for
patients with uncomplicated acute appendicitis. Initial
antibiotic treatment deserves consideration as a primary
treatment option for early-uncomplicated appendicitis.
Similarly, the study NOTA (Non Operative Treatment
for Acute Appendicitis), assessed the safety and efficacy of
antibiotic treatment for suspected acute uncomplicated
appendicitis and monitored the long-term follow-up of
non-operated patients. One hundred fifty-nine patients
with suspected appendicitis were enrolled and underwent
non-operative management with amoxicillin / clavulanate.
The follow-up period was 2 years. Short-term (7 days)
non-operative failure rate was 11.9 %. All patients with
initial failures were operated within 7 days. At 15 days, no
recurrences were recorded. After 2 years, the overall
recurrence rate was 13.8 %. The authors concluded that
antibiotics for suspected acute appendicitis are safe and
effective and may avoid unnecessary appendectomy,
reducing operation rate, surgical risks, and overall costs [
Although interesting and reducing the false negative
appendectomy rate, both studies also contain methodological
flaws, like the patients recruitment, surgery approach
(laparotomy/laparoscopy), different antibiotics prescription
and images diagnostic method criteria (CT scan /
Ultrasound). In addition, the success rate of 63 % is very low and
the relative risk of complication reduction very high.
Therefore, the laparoscopic treatment of non-complicated acute
appendicitis may show much less complication rates and
represent the treatment of choice with acceptable false
negative appendectomy rate about 10 % [
As a rule, the acute appendicitis diagnosis was established
according to the transmural appendix inflammation
(neutrophilic infiltration of the mucosa, submucosa, and
muscularis propria). The histologic assessment also defined the
difference between endoappendicitis (neutrophils within
mucosa and mucosal ulceration) and periappendicitis
(inflammation restricted to serosa and sub-serosa) [
Why to propose a new acute appendicitis grading
The laparoscopic grading system of acute appendicitis
proposed by Gomes et al. [
] is limited by its exclusive
focus on just the intraoperative aspects (Table 1).
Complicated grades (phlegmon, abscess and/or diffuse
peritonitis), are now reliably distinguished from
uncomplicated cases by clinical and imaging findings. Because
the treatment options for these complicated cases of
acute appendicitis includes non-operative modalities, a
new comprehensive grading system for acute
appendicitis is necessary (Table 2).
It was idealized a grading system for acute appendicitis
that incorporates clinical presentation, imaging and
laparoscopic findings. The goal of this new grading system
is to provide a standardized classification to allow more
uniform patient stratification for appendicitis research
and to aid in determining optimal management
according to grade (Table 2).
New acute appendicitis grading system
Grade- 0 (normal looking)
The grade 0 refers to the non-rare situation surgeon may
faces, when the patient has a clinical diagnosis of acute
appendicitis and laparoscopy shows a macroscopically
“normal looking appendix”. In such case, if the appendix
looks normal on laparoscopy but another disease is found
to be the cause of the patient’s symptom, then the appendix
should be left in situ [
]. The 10-year follow-up by van
Dalen et al. [
], demonstrated the safety of this approach
in women. The situation is more complicated when the
appendix shows no signs of inflammation and no other
disease can be found (Fig. 1). Weighting the disadvantages of a
negative appendectomy against the risk of overestimating a
case of appendicitis is difficult. If symptoms and signs are
typical for appendicitis, most surgeons still consider advised
to perform an appendectomy, because in early appendicitis,
the inflammation may be limited to intramural layers [
In surgical cases of pelvic endometriosis, surgeons need
to preoperatively inform that appendix is found frequently
involved, regardless the presence of concurrent symptoms
or gross finding of the appendix. Furthermore, surgeons
should take into account the possibility of performing an
incidental appendectomy [
Note: Proposal for a new acute appendicitis grading system based on clinical,
imaging and laparoscopic findings. (±) = Presence or absence of
fibrinous exudate Gomes et al. (2015).
Gomes et al. in 2012, published a series of 186 patients
who underwent a laparoscopic appendectomy, according to
the Laparoscopic Grading System for Acute Appendicitis
(Table 1). This grading system has been developed to
stratify the disease according to the inflammatory findings
occurring within the appendix and the abdominal cavity.
The impact of the grade on surgical site infection was also
]. This score was externally validated in a
cohort of 112 consecutive cases of complicated acute
appendicitis patients by Di Saverio et al, where all patients
had Gomes scores II–V and the scores were correlated with
the outcomes [
]. Based on this series the safety and
efficacy of laparoscopy compared to open appendectomy was
also examined. The laparoscopic grading system was useful
in stratify the disease; contributing and highlights some
aspects, whose laparotomy could not be able to show at the
same amplitude (Fig. 2) [
In addition, Gomes et al. documented an unusual
situation. About 10 % of the patients where appendix presented
with hyperemia, edema and fibrin exudates had a significant
plasma exudation into the abdominal cavity. The study of
the exudates diagnosed the presence of gram-negative
bacteria in 10 % of the analyzed samples. These data could
explain, at least partially, that acute appendicitis may get
complicated with development of postoperative peritonitis
and intra-abdominal abscesses after simple appendectomies,
especially when antimicrobial prophylaxis was not
administrated. Excessive plasma exudation in the absence of necrosis
and/or perforation of resected appendices could be explained
by bacterial translocation and plasma transudation [
Grade- 2A and 2B (necrosis)
Complicated appendicitis refers to gangrenous and/or
perforated appendix, which may lead to abscess formation
and degrees of peritonitis [
]. Therefore, these grades by
definition are complicated cases of acute appendicitis.
Nevertheless, the specific grade study, showed that in the
grade 2A, the necrosis was an isolated phenomenon,
restricted to the appendix, without or with minimal local
exudation (Fig. 3). The majority of patients had an
uneventful recovery and were discharged in the next
postoperative day. More importantly, they had a clinical course
similar to those with non-complicated appendicitis (grade
0, 1). They received short course antimicrobial therapy (3
to 5 days) and post-operative complication was a rare
event. By the way, recent observational cohort study from
van Rossem et al. showed that after appendectomy for
complicated appendicitis, 3 days of antibiotic treatment is
equally effective as 5 days in reducing postoperative
About 3.2 % there was presence of necrosis involving the
appendicular base, at the level of its insertion on cecal wall
(grade 2B). This condition makes the operation even more
difficult and requires experience from the surgical team
with intra-corporeal suturing, mainly when endostapler is
not routinely used, justifying a new specific grade, which is
rarely studied during laparoscopic appendectomy.
Nowadays, this grade represents the most important situation,
where the endostapler is used to closure the appendiceal
stump in the Service. In the other grades the appendicular
stump could be closure of different ways (endostapler,
endoloop, metallic and polymeric clip and others one). We
prefer its management by T-400 metallic endoclip, which
is less expensive and have demonstrated safety and
effectiveness in a prospective observational study [
addition, it is oriented operating the patients under Day
Hospital way. The study of Alvarez and Voitk [
be highlighted because, according the authors, in the
ambulatory management of acute appendicitis (Day Hospital),
the patients discharge is occurring less than 24 h after
Fig. 5 Acute appendicitis complicated with inflammatory tumor and an
abscess less than 5 cm, managed by laparoscopic approach (Grade 3B)
appendectomy and this recommendation was adopted for
grades 0,1, 2 [
Grade- 3A - 3B - 3C (perforated - inflammatory tumor)
As it is already well known, sometimes the inflammation of
the appendix may be enclosed by the patient’s own defense
mechanisms, by the formation of an inflammatory
phlegmon or a circumscribed abscess of different diameter, often
presenting some days after the onset of symptoms [
fact, an inflammatory tumor in the right lower quadrant
represents a spectrum, at least of three physiopathology
stages of the acute appendicitis, very similar to what
happens in the acute diverticulitis of sigmoid colon: phlegmon,
inflammatory tumor with <5-cm abscesses and
inflammatory tumor >5-cm abscess (Fig. 4). Thus, once again, such
patients should not be considered as a whole, without
distinction, since they have different aspects with regard to,
physiopathology, treatment, complications, disease
recurrence and prognosis. Moreover, according to Stefanidis et
al 2008, acute abdominal pain lasting less than 7 days [
Therefore, assuming that we are evaluating patients with
acute and subacute disease, since mostly patients classified
within these grades, had the onset of symptoms occurring
into seven or more days. These patients receive long
course (5–10 days) antimicrobial therapy according their
clinical post-operative recovery (Fig. 5).
Grade- 4 (perforate - diffuse peritonitis)
Controversy exists regarding the laparoscopic approach
in the treatment of acute appendicitis complicated with
diffuse peritonitis. The chance of potential surgical
complications is high and consequently the outcomes are
poorly documented. Our literature review found only
two articles investigating the issue [
]. Although the
results seems to favor the use of laparoscopy, only a
large multi-institutional study with appropriate design
will be able to answer this question (Fig. 6).
In summary, the new appendicitis grading system is based
on three aspects of the disease. The clinical, imaging and
laparoscopic findings and could be tested in multicenter
observational study within the World Society of
Emergency Surgery, in order to assess its actual practicality. It
will enable the creation of homogeneous groups of patients
with disease in the same well-defined stage. Ultimately, the
goal of this grading system is to aid in determining optimal
management according to grade, and to provide a
standardized classification system to allow more uniform
patient stratification for appendicitis research.
The authors have no conflicts of interest ties or financial funding source’ to
CAG, MS, SDS: conception design and coordination and helped to draft the
manuscript, acquisition of data, analysis and interpretation of data, entire
manuscript reviewer. FC, FC, LA: Participated in the sequence alignment
and revising it critically for important intellectual content; KI, DD: Participated in
the sequence alignment, design and revising it critically for important intellectual
content; FCG, CCG: have made substantial contributions in the graphic art and
contribution in the manuscript conception and revision. All authors read and
approved the final manuscript.
Manuscript produced at Surgery and Internal Medicine Unit. Monte Sinai
Hospital, Juiz de Fora, Minas Gerais, Brazil.
*Presented in part at last World Society of Emergency Surgery (WSES)
Congress, 2015 in Jerusalem – Israel.
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