Table 1. Distribution of patients by age group.

Figure 1. Distribution of patients by sex.

During the study period, 12,000 abdominal and abdominopelvic ultrasounds were performed in the department, and 51 cases of appendicitis were diagnosed, representing a frequency of 0.425% of cases. The most represented age group was between 15 and 25 years (Table 1). Males were the most represented sex, at 66%, with a sex ratio of 1.94 (Figure 1). Nearly 2% of patients had one or more previous surgical interventions for other pathologies and 2% of patients had one or more drug treatments for chronic pathology. Physicians were the primary prescribers in 68.4% of cases, compared to 31.6% for nurses.

Pain in the right iliac fossa was the most frequently observed clinical sign in 35.3% of cases (Table 2).

Table 2. Distribution of patients according to clinical data.

In our study, 42 of the 51 patients examined tested positive for acute appendicitis on ultrasound. Among the 42 patients who underwent surgery, 4 had recovered from appendiceal abscesses and 1 had a rectosigmoid tumor. The most frequent location of the appendix was mesocecal (72.5% of cases), followed by laterocecal location (21.6% of cases) and retrocecal location (5.9% of cases). We did not observe any subhepatic or pelvic locations. The mean anteroposterior diameter of the appendix was 10.23 mm (range 7 - 18 mm), and the mean wall thickness was 3.71 mm (range 3 - 5 mm). All patients experienced pain at McBurney’s point upon passage of the ultrasound probe, an incompressible appendix, and inflammation of the periappendiceal fat. Appendiceal sclerotherapy was found in 3.9% of cases, and right iliac fossa lymphadenopathy in 25.5% of cases. Color Doppler ultrasound revealed increased abdominal wall hyperemia in 65% of cases. Intraperitoneal fluid effusion was the most frequently associated sign, occurring in 17.7% of cases. The most common complication detected by ultrasound was appendiceal abscess in 11.8% of cases, followed by peritonitis due to appendiceal perforation in 3.9% of cases and appendiceal phlegmon in 2% of cases. There is a significant correlation between ultrasound findings and surgery. Therefore, ultrasound is a reliable examination for the diagnosis of appendicitis. The sensitivity rate of ultrasound for acute appendicitis was 100%, and the specificity was 64.28%. The positive predictive value was 88.09%, and the negative predictive value was 100%. Ultrasound performance was 97% in acute appendicitis and 95% in complications such as abscesses and peritonitis. However, we observed the limitations of ultrasound in staging (distinguishing between acute appendicitis and abscesses).

The surgeons were informed of the ultrasound results in all cases (100% of cases). Patients were operated on the same day between 2 and 6 hours. After surgery, simple acute appendicitis was the most common diagnosis (72.5%), and the most frequent complication was appendiceal abscess (19.6%), followed by peritonitis due to appendiceal perforation (3.9%). Rectosigmoid tumor was found in 2% of cases (Figures 2-4).

Figure 2. Abdominal ultrasound showing parietal thickening, increased anteroposterior diameter, and infiltration of the periappendicular fat suggestive of acute appendicitis (A), and agglutination of the loops around a thickened appendix with infiltration of the periappendicular fat suggestive of an appendiceal phlegmon (B). Image (C) shows the surgical specimen from the acute appendicitis case after surgery.

Figure 3. Echographie abdominale en coupes longitudinale (B) et transversale (A) objectivant une collection à contenu liquidien renfermant des fins échos en regard appendicite inflammatoire associé à des adénomégalies coelio-mésentériques: Abcèsappendiculaire. L’image (C) montre la pièce opératoire de l’abcès appendiculaire après chirurgie.

Figure 4. Abdominal ultrasound in transverse and longitudinal sections (A, B and C) highlighting a fluid collection in the RIF containing fine echoes suspended around a thick appendix with parietal rupture associated with celiac-mesenteric lymphadenopathy suggestive of peritonitis on perforation of appendiceal abscess with the photo of the operative specimen of the perforated appendix after surgery (D).

Our study included 51 cases of appendicitis diagnosed by ultrasound and correlated with the surgical appearance in the radiology and medical imaging department of the KALALE clinic, out of 12,000 abdominal and abdominopelvic ultrasounds, representing a prevalence of 0.425% of cases. These results were comparable to those of CHIPPONI J et al., who found 0.6% of cases.[3] The most represented age group was 15 - 25 years, with a mean age of 26.41 years and a range from 6 to 80 years. This mean age was consistent with those reported in the literature [15]-[17], which found mean ages of 24, 25, and 27.08 years, respectively. These findings demonstrate that appendicitis is a condition that occurs much more frequently in young people. In our series, males were the most represented, accounting for 66% of patients, with a male-to-female ratio of 1.94. This is consistent with several studies in the literature reporting a male predominance, with a male-to-female ratio ranging from 1.05 to 3.2 [18]-[21]. Although some authors suspect anatomical and hormonal factors, with an increased risk in men, the exact reasons for this male predominance are not yet clearly explained by science.

Pain was present in all our patients and localized to the right iliac fossa in 35.3% of cases. This predominance of pain in the right iliac fossa was also found in the literature [15][16], with 71.4% and 70% of cases, respectively. This high frequency of pain in the right iliac fossa could be explained by the normal anatomical location of the appendix. According to Simpson, the pain should ideally be located at McBurney’s point, which corresponds to the base of the appendix [22]. The most frequent location of the appendix was mesocecal, accounting for 72.5% of cases. A study conducted in Senegal [21] found a result very similar to mine, with 66.66% of cases of appendicitis being mesocecal.

In our study, the appendix was incompressible in 100% of cases. This sign suggestive of appendicitis on ultrasound was found in the majority of studies, notably in Löfvenberg F and CHINBO [17][23]; PUYLAERT noted that 89% of patients had an incompressible appendix.

This sign (incompressibility) of the appendix under the influence of the probe in the right iliac fossa (pain at McBurney’s point) was the first diagnostic criterion for acute appendicitis on ultrasound [24]. Indeed, it is important to specify that the incompressibility of the appendix strengthens the diagnostic suspicion. The transverse diameter of the appendix was between 7 and 18 mm in 100% of cases. This finding was consistent with the literature [11][16][25]-[27]. However, this clinical sign, accepted as relevant for the diagnosis of appendicitis, is not significant outside of a clinical context. The appendiceal wall thickness was between 3 and 5 mm in 100% of cases. A wall thickness greater than 3 mm corresponds to the pathological threshold described [11]. This sign is one of the direct signs of acute appendicitis and reflects mucosal congestion. The increase in wall thickness is largely related to inflammatory processes and can be reduced in cases of ischemia. Wall hyperemia was found in 65% of cases in our series. Our results were similar to those of Bergeron E et al., who found parietal hyperemia in 71.72% of their patients [28]. Wall hyperemia is an important criterion in acute appendicitis, but it may be absent in the gangrenous stage [16]. The periappendiceal fat was hyperechoic or infiltrated in 100% of patients in our series. This infiltration was frequently reported in the literature [11][15][17][23] and considered a major criterion in the diagnosis of acute appendicitis. The Kouame study in Ivory Coast revealed a positive predictive value of 95.8% for indirect signs of appendicitis on ultrasound and a sensitivity of 83.9% for the combination of the three indirect signs, which are: hypertrophy of the periappendiceal fat, pain elicited by firm examination of the right iliac fossa, and localized hypokinesis of the bowel loops [28]. Appendiceal scleracolith was found in 3.9% of cases in our series. Our results were lower than those of Chinbo, who reported scleracolith in 11% of patients [23]. It is not a sufficient indicator to diagnose appendicitis, as it is found in patients with healthy appendices [11][25]. However, its presence is a predictive sign because it can lead to secondary inflammation with a risk of perforation. A periappendiceal fluid collection was found in 17.7% of cases in our series. Our results were similar to those of Elleuch, who found periappendiceal effusion in 20% of patients. Löfvenberg F and Bergeron E found 16% and 28.68%, respectively [17][28]. It is an indirect sign, the presence of which can have several interpretations. If it becomes echogenic, it may suggest periappendicular suppuration or peritonitis [15][17][29]. If it extends to the pouch of Douglas or between the loops of the bowel, it may suggest early peritonitis [15][17][29]. Ultrasound had a sensitivity of 100% and a specificity of 64.28%, a positive predictive value (PPV) of 88.09%, and a negative predictive value (NPV) of 100%. The sensitivity of ultrasound in our study was higher than that of M. Mor Tall and Bergeron E et al., who found 96.84% and 92.32%, respectively; however, the specificity remained lower than those found in their studies, at 91.03% and 92.04% of cases. The low specificity was explained by the fact that this clinical form serves as a “catch-all” where all uncertain ultrasound diagnoses or more serious surgical diagnoses (abscess, phlegmon, peritonitis) that were missed by ultrasound were collected [17][28]. However, when ultrasound does diagnose an abscess, it is always correct (PPV = 100%). For peritonitis and phlegmons of appendiceal origin, we found: a sensitivity of 100%, a specificity of 100%, a PPV of 100%, and a NPV of 100%. Our results were comparable to those of Rothrock SG, who found a sensitivity of 96.77% and a PPV of 96.77% [16]. Performance is perfect (100%) when ultrasound clearly identifies peritonitis or phlegmon. Thus, ultrasound, due to its sensitivity and specificity, proves to be a very valuable examination in acute appendicitis. The performance of expert hands reaches a rate of up to 98%, making it possible to confirm or rule out the diagnosis of acute appendicitis in doubtful cases. False positives in appendiceal ultrasound at the Kalale Clinic encompass causes such as resolving appendicitis, ileal Crohn’s disease, adnexal pathologies, mesenteric adenitis, and anatomical variations in caliber. False negatives are mainly explained by an atypically positioned appendix, focal inflammation, early perforation, patient obesity, or significant intestinal distension. The study’s limitations lie in its single-center design, sample size, potential selection bias, and non-standardized operator-dependent nature.

In our study, surgery corrected 5 diagnoses, representing 9.80% of cases. The sensitivity of ultrasound was low (60%), as demonstrated by the surgical intervention, which identified 40% of the abscesses (4 cases) missed by ultrasound.