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Diagnosis and Treatment ofAcute AppendicitisJMAJ 46(5): 217–221, 2003

Hiroshi ISHIKAWA

Department of Surgery, Sasebo Municipal Hospital

Abstract: The diagnosis and treatment of acute appendicitis are described withemphasis on the significance of ultrasonography, computed tomography (CT), andlaparoscopic appendectomy. The diagnosis of acute appendicitis has traditionallybeen made by physical examination and blood tests. However, use of ultra-sonography and CT as well as these conventional methods makes more precisediagnosis possible. These imaging modalities are useful for determining whethersurgery is necessary. Ultrasonography is easy to perform and minimally invasive,making it essential for diagnosis. This examination can visualize hypertrophy, dis-turbance, and disruption of the layered structure of the appendiceal wall, accumu-lation of purulent fluid, and the presence of a fecolith in the appendix. In catarrhalappendicitis, the wall of the appendix consists of three layers. In phlegmonousappendicitis, these layers become unclear, and in gangrenous appendicitis, thelayered structure is lost. CT is superior to ultrasonography in objectivity, but isunable to depict the layers of the appendiceal wall. It is useful for demonstratingperiappendiceal fat, ascites, and abscess formation, and for determining whetheran operation is necessary based on these findings. Laparoscopic appendectomyis one of the choices for obese patients, young women, and patients in whom acondition other than acute appendicitis is suspected.

Key words: Acute appendicitis; Imaging diagnosis;Abdominal ultrasonography; Laparoscopic appendectomy

Introduction

Acute appendicitis is one of the most com-mon conditions treated by emergency opera-tion. Physicians from a wide range of medicalspecialties including internal medicine and pe-

diatrics, as well as surgeons, encounter patientswith this condition in their daily practice. Whenit presents with typical symptoms, it is relativelyeasy to diagnose and treat. In young children,elderly persons, and those presenting with vari-ous atypical symptoms, however, the diagnosis

This article is a revised English version of a paper originally published inthe Journal of the Japan Medical Association (Vol. 127, No. 5, 2002, pages 747–750).The Japanese text is a transcript of a lecture originally aired on October 8, 2001, by the Nihon ShortwaveBroadcasting Co., Ltd., in its regular program “Special Course in Medicine”.

� Acute Appendicitis

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H. ISHIKAWA

may be delayed and treatment may becomedifficult.

The diagnosis and treatment of acute appen-dicitis, particularly the diagnostic role of imag-ing modalities such as ultrasonography andcomputed tomography (CT), and the thera-peutic role of laparoscopic appendectomy (anew surgical procedure for this disease) aredescribed in the following article.

Pathology of Acute Appendicitis

The cause of appendicitis is considered to beobstruction of the appendiceal lumen and thesubsequent onset of bacterial infection. Lumi-nal obstruction can be produced by variousmechanisms and it results in the retention ofmucus. If bacterial infection supervenes, theintraluminal pressure increases, leading tointerruption of lymphatic flow and the develop-ment of appendiceal edema. This process leadsto acute appedicitis characterized by distensionof the appendix and vascular congestion, whichis designated as catarrhal appendicitis. If thiscondition progresses further, appendiceal edemaand vascular congestion become pronouncedwith the formation of multiple abscesses in thewall and purulent fluid on the serosal surface.This condition is designated as phlegmonous

appendicitis. If it progresses further and causeslocal circulatory dysfunction, this will result ininfarction opposite the junction between themesoappendix and appendix, where the bloodsupply is inadequate. As a result, the appendixbecomes congested dark red with black necroticareas, a condition that is designated as gangre-nous appendicitis. If perforation of the necroticwall occurs, appendicitis becomes complicatedby perforative peritonitis. Usually, peritonitis islocalized, being confined to the ileocecal region.In young children, however, the omentum isnot fully developed, so the clinical course isoften complicated by diffuse peritonitis.

Diagnosis of Acute Appendicitis

1. Clinical manifestationsAbdominal pain, fever, and anorexia are clas-

sical symptoms. Pain occurs in the upper abdo-men at first. It then moves slowly and localizesto the right lower quadrant. In many cases, afever of around 38°C is present.

2. Findings on physical examinationPhysical examination is the most useful

method for diagnosing appendicitis and fordetermining whether an operation is necessary.Tenderness can be elicited at various pointsin the right lower quadrant of the abdomen,including McBurney’s, Lanz’s, and Munro’spoints (Fig. 1). Among the indications for sur-gical treatment, the presence of peritoneal irri-tation is critical. Operation is indicated whenBlumberg’s sign is positive (the pain elicitedby steadily increasing pressure at the site oftenderness increases on abrupt release of thepressure), and when Rosenstein’s sign is elic-ited (tenderness in the right lower quadrantincreases when the patient moves from thesupine position to a recumbent posture on theleft side). As a matter of course, the detectionof abdominal muscular guarding and tender-ness on rectal examination are among the sur-gical indications.

� McBurney’s point � Lanz’s point � Munro’s point

�

�

�

Fig. 1 Points at which tenderness can be elicited inacute appendicitis

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3. Laboratory testsThe white blood cell count (WBC) and CRP

are of diagnostic value. The WBC usually exceeds10,000/mm3. In severe cases associated withdiffuse peritonitis, however, the WBC may bedecreased rather than increased, so care mustbe taken. Although the CRP rises in appendi-citis, the increase is not necessarily associatedwith the severity of inflammation.

4. Imaging diagnosisPlain abdominal radiographs show no par-

ticular evidence of appendicitis. If an air-fluidlevel is seen in the lower abdomen, however,localized peritonitis should be suspected. Ultra-sonography and CT scanning are of diagnos-tic value, and provide useful information fordetermining whether or not appendectomy isnecessary.(1) Abdominal ultrasonography

Because this minimally invasive examinationis easy to perform and can be repeated, it isessential for diagnosing acute appendicitis. Anormal appendix is usually not imaged by ultra-sonography. When it is involved by inflamma-tion and enlarges, however, it can be visualized.The features of appendicitis include hyper-

trophy of the appendiceal wall, disturbance ofthe normal layered structure, destruction of thewall, and purulent fluid or fecaliths within theappendiceal lumen.1) In catarrhal appendicitis,the wall of the appendix shows three layers,while this layered structure becomes unclearin phlegmonous appendicitis. No layered struc-ture is depicted in the more advanced gangre-nous appendicitis (Fig. 2). The periappendicealaccumulation of fluid suggests abscess forma-tion secondary to perforation. A high periappen-diceal echo suggests the aggregation of the omen-tum and other tissues that have been affectedby inflammation. If some of these findings arerecognized, an operation is indicated.

Kojima et al. divided appendicitis into threetypes depending on the ultrasonographic find-ings.2) The classification depended on the fea-tures of the high echo bands representing thesubmucosal layer, as described by Yuasa et al.,3)

as well as the presence or absence of a visual-ized appendix and the length of the shorterdiameter of the appendix (Table 1). The ultra-sonographic pattern was type I in 76% of patientswith catarrhal appendicitis, while it was type IIin 82% of patients with phlegmonous appendi-citis and type III in 94% of patients with gan-

a. Catarrhal appendicitisThe arrow indicates the longaxis of the appendix.

Fig. 2 Ultrasonographic features of each type of appendicitis1)

b. Phlegmonous appendicitisThe arrow indicates an indistinctlayered structure.

c. Gangrenous appendicitisThe arrow indicates a fecalith.

220 JMAJ, May 2003—Vol. 46, No. 5

grenous appendicitis. They concluded that, theseverity of appendicitis could be assessed bypreoperative ultrasonography, so that unneces-sary appendectomy could be avoided.

As described above, ultrasonography is anindispensable modality because it can be usedto both diagnose appendicitis and assess itsseverity.(2) Abdominal CT

CT is superior to ultrasonography in somerespects, because its findings are more objec-tive and it is not affected by the presence ofintestinal gas. The diagnosis of appendicitis byCT depends on hypertrophy of the appendicealwall, enlargement of the appendix, periappen-diceal abscess formation, the presence of afecalith, increased density of periappendicealadipose tissue, and/or the presence of ascitesin the pouch of Douglas.1) CT can depict anenlarged appendix, but cannot visualize thestructure of the wall unlike ultrasonography.

Thus, ultrasonography is superior to CT forassessing the severity of appendicitis depend-ing on the mural changes.

Management of Acute Appendicitis

1. Medical therapyCatarrhal appendicitis should be treated con-

servatively. It is diagnosed by physical exami-nation, blood tests, ultrasonography, and CT, oris characterized by tenderness without perito-neal irritation. On ultrasonography, the appen-dix cannot be visualized or is not enlarged if itis detected. Patients with catarrhal appendicitisshould generally be hospitalized for treatmentwith antibiotics, bed rest, intravenous fluids,

and nil orally. For outpatient management,antibiotics are administered and the course isfollowed closely.

2. Surgical therapyPhlegmonous or more advanced appendi-

citis should be treated surgically. Ultrasono-graphic findings are the most important factorfor deciding whether surgery is necessary. Inaddition to the symptoms of phlegmonousappendicitis described above in the section ondiagnosis, the presence of ascites or an abscessindicates the necessity for surgery. Among theabdominal findings on physical examination,the presence of peritoneal irritation is critical.If this is positive, an operation is indicated.

In the field of surgery for acute appendicitis,laparoscopic appendectomy is attracting muchattention (Fig. 3). This procedure has becomeestablished in Japan and other countries.Although its usefulness has been graduallyaccepted, whether it is superior to conventionalopen appendectomy remains controversial, soit is not yet considered to be a standard therapyfor acute appendicitis. The advantages anddrawbacks of this procedure are describednext. For the technical details that are notdescribed in this article, see the relevant text-books and reports.

For the patient, the advantages of laparo-scopic appendectomy are reported to includedecreased postoperative pain, faster recoveryof muscle tone, earlier return to normal activi-ties, minimal scarring, a low risk of woundinfection, no ventral hernia, and a reduced riskof postoperative adhesions.4) On the other hand,conventional open appendectomy seldom causes

H. ISHIKAWA

Table 1 Classification of Acute Appendicitis According to Ultrasonographic Findings

Pathological diagnosis Layer structure of Submucosal layerthe appendiceal wall

Type I Catarrhal Clear No hypertrophyType II Phlegmonous Indistinct HypertrophiedType III Gangrenous Disrupted Indistinct and partly lost

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problematic postoperative pain, scarring, orventral hernia. In other words, the laparoscopicand open procedures may only be different intheir degree of difficulty.

From the standpoint of the surgeon, laparo-scopy is useful to rule out appendicitis inpatients with confusing symptoms. Also, if adiagnosis of appendicitis is established, wide-ranging examination of the peritoneal cavitybecomes possible. Furthermore, intraperitonealcleansing of the site can be done under visionon the monitor. It has even been reported thata drain could be inserted and placed appro-priately under laparoscopic vision.4)

Drawbacks of laparoscopic appendectomyinclude the necessity for general anesthesia,the need for special apparatus including aninsufflator to create pneumoperitonium, theneed for more staff including surgeons andanesthesiologists, and the risk of complicationsdue to special procedures for laparoscopic sur-gery such as peritoneal insufflation and inser-

tion of trocars.The greatest merit of laparoscopic appen-

dectomy is being “minimally invasive.” Becauseconventional open appendectomy is alreadyrelatively simple and not so invasive, however,this merit itself is not highly attractive. Inparticular cases, such as obese patients, youngfemale patients seeking a better cosmetic out-come, and patients with suspected appendicitiswho may have other conditions, it would seemthat laparoscopic appendectomy may be useful.

Conclusion

The diagnosis and management of acuteappendicitis have been described with a focuson some current issues. For diagnosis, findingson ultrasonography and CT are important.For management, laparoscopic appendectomyshould be considered as a possible choice ifthere are indications for this procedure.

REFERENCES

1) Yamashita, Y., Nishino, Y. and Hirakawa, K.:Radiographic diagnosis of acute appendicitis,a disease commonly treated by emergency sur-gery. Establishment of the diagnosis depend-ing on characteristic findings. Shokaki Geka(Intestinal Surgery) 2000; 23: 1903–1910. (inJapanese)

2) Kojima, K., Fujita, T., Imanari, Y. et al.: Use-fulness of ultrasonography in acute appen-dicitis. Nichi Rin Ge I Kaishi 1993; 54: 2524–2528. (in Japanese)

3) Yuasa, H.: Ultrasonographic Diagnosis ofAppendicitis. 1st ed., Herusu Shuppan, Tokyo,1986; pp.36–37. (in Japanese)

4) Kano, N. and Yamakawa, T.: Various problemsrelated to laparoscopic appendectomy andacute appendicitis. Shokaki Geka (IntestinalSurgery) 1996; 19: 455–464. (in Japanese)

5) Kano, N., Kusanagi, H., Kasama, K. et al.: Roleof laparoscopic appendectomy in the diag-nosis and management of appendicitis: Fromthe standpoint of advocating limited indica-tions for laparoscopic appendectomy. Geka(Surgery) 1998; 60: 423–426. (in Japanese)

Anesthetic unit Anesthesiologist

First assistantsurgeon

Nurse

Instrument table

Monitor

Second assistant surgeon

(to manipulate the laparoscope)

Surgeon

InsufflatorApparatus for

rinsing and aspiration

Electric knife

Lamp

Fig. 3 Illustration of the arrangement of personnel andapparatus for laparoscopic appendectomy4)