Open access peer-reviewed chapter
Abstract
Acute appendicitis is the most common cause of acute abdomen in children. One-third of patients are under the age of 18 years, with a peak of incidence during puberty. The particular issues of acute appendicitis in childhood are discussed in this chapter. Anatomical variations, such as malrotation, affect clinical presentation during this period. Complicated appendicitis is a rule in children of preschool age. The theoretical basis of etiology of acute appendicitis is discussed as well. While the prevailing theory considered inflammation secondary to obstruction of the appendiceal lumen, during the last two decades, primary infection is gaining ground as the initial trigger of appendicitis. Finally, therapeutic options are discussed, as non-operative treatment is the new issue in non-complicated appendicitis, while operative options have been enhanced with the advent of laparoscopy.
Keywords
- acute appendicitis
- children
- primary infection
- causes
- treatment
1. Introduction
Acute appendicitis is one of the most common diagnostic and therapeutic issues in pediatric patients. The fact that there are still children with peritonitis, in the era of highly accurate diagnostic modalities, constitutes a challenge for the present generation of clinicians and researchers. The pediatric population is per se a different world, with specific particularities and needs. The scope of the present chapter is to bring to light these particularities, providing incentives for novel ideas against this universal infectious and surgical disease.
2. Embryology, anatomy, and physiology
The appendix forms the last segment of the cecum and begins to differentiate during the 8th week of gestation. During maturation of the primitive intestine, the appendix does not follow the growth of the cecum, which is 4.5 times bigger than the appendix at birth and continues to increase in size until it becomes 8.5 bigger in adults. Throughout the development of the cecum in the gestational life, the appendix along with the anterior colic taenia moves toward the midline of the cecum. In 15% of the population, there is not such a movement, and the appendix presents a funnel shape. Intestinal villi can be observed between the 4th and 5th month of gestation but vanish before birth. At the 7th month of fetal life, lymphatic nodules appear. They increase in number until puberty, and then a decline is noticed. After the 60th year of life, there is no lymphatic tissue in the appendix in the majority of population, while often the lumen of the appendix vanishes completely [1, 2]. Many claim that the appendix is a vestigial organ without a precise function, while others that it is part of the GALT (Gut-Associated Lymphoid Tissue) system, containing M cells, which can produce IgA in response to antigens [3].
The location of the appendix is usually retrocecal (20–74%). Some believe that this happens, because of the rotation of the right colon and cecum around their longitudinal axis [4], while others believe that the appendix is found more often in a retrocecal position as a result of its formation and shaping during the descent of the cecum [5]. There are also the pelvic (3.7–58%), pre-ileal (1–50.9%), post-ileal (0.4–14.8%), paracolic (2.9–8%), and retrocolic (1.25–9%) locations [6].
Since the cecum does not possess a true mesentery, initially, it was believed that this was applicable for the appendix too. However, there is a mesoappendix, which contains the appendicular artery. The mesoappendix is a small mesenteric fold, originating from the posterior surface of the mesentery of the distal part of the ileum. Occasionally, the mesoappendix is shorter than the appendix itself, and for that reason, the appendix presents a curve in its longitudinal axis.
The appendicular artery originates from the ileocolic artery, which arises from the colic artery, being usually a solitary one. Nonetheless, it has been reported that appendicular blood supply is multiple, with arteries originating from the anterior and posterior cecal arteries and from the ileocecal artery [2]. From these arteries, collateral blood vessels create, through various anastomoses, a blood network as an alternative blood supply. Such a network is responsible for the multiple variations of the vascularization of the appendix depicted in human anatomy atlases. The appendicular veins run through the mesoappendix and, after merging with the cecal veins, create the ileocolic vein, which drains into the right colic vein. The lymphatic vessels of the appendix through a series of lymph nodes of the appendicular, ileocolic, and superior mesenteric artery drain in the Haller’s tripod lymph nodes.
The appendix is innervated by the sympathetic and the parasympathetic systems. The first derives from the superior mesenteric ganglia and from those of Haller’s tripod, while the latter originates from the pneumogastric nerve. The knowledge of the different innervation of the visceral and parietal peritoneum is very important to comprehend the distinct kind of pain in case of inflammation in the peritoneal cavity. Initially, inflammation in the right iliac fossa, through the sympathetic innervation of the visceral peritoneum, will create a dull, light pain around the umbilicus. Once the inflammation affects the parietal peritoneum, the characteristic, sharp, continuous pain in the low right abdominal quadrant will emerge, due to sensory nerve fibers, which arise from the 8th thoracic nerve.
3. Congenital malformations
Absence of the appendix is a rarity [7]. An ectopic position of the appendix is a part of congenital malformations affecting the formation of the gastrointestinal tract such as malrotation or situs inversus. A non-fixed cecum with a long mesentery may result in an appendix far away from the right iliac fossa. Surgeons have described lumbar appendicitis, while others found the appendix in the thorax in diaphragmatic hernia [8, 9].
Duplication of the appendix is another uncommon anomaly. The most famous classification of this anomaly is that of Cave and Wallbridge, according to which there can be a partial or total duplication of the appendix with or without the duplication of the cecum and, even, a horseshoe appendix [10]. Diverticula of the appendix have been reported [11]. Ectopic pancreatic, gastric, and esophageal tissues have been found in the appendiceal mucosa [12].
4. Incidence
Acute appendicitis is the most common cause of acute abdomen. In the developed world, 5.7–50 per 100,000 inhabitants are affected by acute appendicitis every year [13]. The incidence of acute appendicitis is declining [14] and presents seasonal variation [15] and significant differences between developed and developing countries. The lifetime risk for acute appendicitis in Europe is 8%, in the USA 9%, and 2% in Africa [16]. One-third of patients with appendicitis are younger than 18 years old, with a peak incidence between the ages of 11 and 12 years [17]. Perforation rates vary from 16% to 40%, occurring more frequently in younger age groups (40–57%) and in patients older than 50 years (55–70%) [18].
It is well known, especially for children, that there may be an atypical presentation of the pain in acute appendicitis, with signs and symptoms, which not only are different from those of the adult population, overlapping with symptoms characteristic for other diseases, and creating a vast catalog of differential diagnosis [19]. This is particularly true for children younger than 5 years old, resulting in erroneous or delayed diagnosis in 5.9–84% of the cases and consequently in complicated appendicitis in 5–51% of the patients. Surprisingly, in children younger than 3 years, the incidence of perforated appendicitis is reported up to 100% [20]. On the other hand, overdiagnosis and consequently unnecessary appendicectomy can reach 23% regarding both child and adult population [21].
5. Etiology and pathophysiology
It is common knowledge that the obstruction of the lumen of the appendix is the main cause of acute appendicitis. However, such an obstruction cannot always be explained [22]. Researchers showed that microbial infection is the main cause of the obstruction of the appendiceal lumen, a fact that explains the presence of acute appendicitis in clusters with seasonal variations and the rare presentation of the disease in rural areas of developing countries [23, 24]. Obstruction can be caused by a foreign body (seed, pin, jewel, etc.), by a carcinoid of the appendix, parasites (
Obstruction will result in the formation of a “closed” enteric loop and, finally, the perforation of the appendix and the presence of peritonitis. The lumen of a normal appendix can accommodate 0.1 mL of contents, but a volume of 0.5 mL of mucus can raise the intraluminal pressure of the appendix to 60 cm H2O [26]. The appendix can continue to produce mucus even with an intraluminal pressure of 93 cm H2O [17]. In such an environment, microorganisms can proliferate rapidly, and as a result, the pressure inside the lumen of the appendix increases even more, compromising initially the function of the lymphatic vessels. The wall of the appendix becomes thicker until there is venous stasis. At a certain point, the arterial blood supply shall decrease, starting from the antimesenteric side of the organ, causing necrosis and, ultimately, perforation.
Histopathological findings have shown scars on the wall of the appendix, indicating older inflammation of the appendix, which did not result in perforation. Thus, some believe that appendicitis can regress without treatment [27].
In order to classify the severity of the inflammation, grading systems have been adopted. One of the most famous is the laparoscopic classification. This grading system correlates the macroscopic appearance with the histopathological examination and the biochemical analysis of the peritoneal fluid. The resulting score includes normal looking appendix (grade 0), hyperemia and edema (grade 1), fibrinous exudate (grade 2), segmental necrosis (grade 3A), base necrosis (grade 3B), abscess (grade 4A), regional peritonitis (grade 4B), and diffuse peritonitis (grade 5) [24]. Grades 1–2 are characterized as non-complicated appendicitis, while grades 3–5 as complicated [28].
The necessary period of time that acute appendicitis evolves to peritonitis due to perforation of the wall depends on various factors such the gender, the age, the body mass index, and concurrent diseases. Although there is no precise rule, theoretically, the rupture of the appendix occurs 24–36 h since the onset of the first symptoms, and the formation of an abscess after 2–3 days [29].
6. Diagnosis
Although acute appendicitis is a well-known pathological entity for centuries, its early diagnosis is still a challenge, especially if the patient is a child. Despite technological innovations and the use of specialized hematological tests and imaging methods, the percentage of prompt diagnosis has not changed during the last decades. Furthermore, children compose a very unique population, since they often cannot provide accurate information nor cooperate adequately [30], resulting in late diagnosis with increased chance of peritonitis.
For this reason, the combination of a detailed history, a thorough physical examination, and appropriate laboratory tests is necessary for a prompt diagnosis. Moreover, repeating the clinical examination and the laboratory analysis, especially performed by the same physician for every single case, is probably the best way to avoid a late or erroneous diagnosis, particularly for the pediatric population for the mentioned reasons.
6.1 Clinical signs and symptoms
Initially, patients with acute appendicitis present mild symptoms for the gastrointestinal system, such as loss of appetite, dyspepsia, and changes of bowel movements. However, the main and first symptom of appendicitis is abdominal pain. Thus, if a severe symptom precedes pain, other pathologies should be taken in consideration [17]. Most studies claim that anorexia occurs at the same time with pain [26]. This is especially true for the pediatric population. Many surgeons concur that a child who is hungry rarely suffers from acute appendicitis.
At first, the pain is localized at the periumbilical area and is described as dull and not very intense. It can be continuous or intermittent. Although it is not a precise rule, after a few hours, due to the irritation of the parietal peritoneum, it migrates to the right iliac fossa and more specifically at the McBurney point, which is found in the proximal third of the imaginary line that connects the anterior superior iliac spine with the umbilicus. Except McBurney point, on the same imaginary line between the anterior superior iliac crest and the umbilicus, two other points have been described as a sign of acute appendicitis, the Morris (Kummel) and the Monro point. Accordingly, in the proximal third of the straight line between the right and left iliac fossa, another pressure point that emits pain is called the Lanz point, while in the same line, but at the right rim of the rectus abdominis muscle, the Clado point.
In addition, the exact position of the appendix can affect not only the location of the abdominal pain, as described, but also its intensity. For example, a retrocecal inflamed appendix can produce pain at a later stage compared with a pre-ileal one, mainly in the right lateral abdominal area and even in the lumbar area.
Certain maneuvers can be used, to trigger pain, which will give suspicion to an inflamed appendix. The pain felt at the right iliac fossa, with the continuous palpation of the left iliac fossa and the migration of the palpation in the direction of the left colic curve, is called the Rovsing sign. The pain sensed in the right abdominal area, after the abrupt cessation of a deep palpation, is known as the Blumberg or rebound sign, not to be confused with the pain felt during the percussion of the same area, called Mandel-Razdolski sign. Both are indicative of peritoneal inflammation. Other signs are the Sitkovskiy (Rosenstein) and Bartomier/Michelson signs. The first is observed when tenderness in the right lower quadrant increases as the patient moves from the supine position to a recumbent posture on the left side. The second regards increased pain during palpation of the right iliac region, as the person being examined lies on their left side compared with the supine position. Obturator sign is defined the discomfort felt by the patient on the slow internal movement of the hip joint while the knee is flexed, because of an inflamed pelvic appendix that contacts the nearby obturator muscle. In case of retrocolic appendicitis overlying the right psoas muscle, the pain elicited by the posterior flexion of the right thigh while lying on the left side is called the psoas sign. Finally, Dunphy and Rotter signs are positive, when pain is felt at the right iliac fossa while the patient is trying to cough and during rectal examination, respectively. The last one means that the inflamed appendix presents probably a direction toward the pelvis.
The position of the appendix is, also, responsible for symptoms that have no relation to the right iliac fossa. For example, dysuria or diarrhea can be present in case of pelvic or retrocolic appendicitis, respectively. A retrocolic inflamed appendix, especially in patients with a non-fixated cecum or a cecum in high position near the liver, can create abscess in the subhepatic area, causing the formation of fluid in the thorax and consequently empyema. Such a condition, although infrequent, is seen mostly in children [31].
It is very important to distinguish between voluntary and involuntary contraction of the abdominal wall, especially in children. The first is a defensive mechanism caused by the fear of the coming palpation while the latter indicates inflammation of the visceral peritoneum.
Patients with acute appendicitis tend to minimize their movements, in order to sooth the pain. During ambulation, they flex the thorax and knees, and they bend laterally toward the right side in order to diminish the pressure of the abdominal muscles and consequently the pain. For the same reason, on the examination table, children may flex their knees to their thorax, assuming a fetal position.
Another important symptom is fever, initially low, and as the inflammation is aggravating, the temperature overcomes 38.5°C. A high temperature since the beginning of symptoms is a sign of an early complicated appendicitis or, more commonly, another disease.
Although vomit is a symptom of all patients with acute appendicitis, it is one of the characteristic symptoms of children, especially of preschoolers, having a neurological etiology, and not caused by obstruction.
Of course, all the symptoms and signs can present in a variety of combinations. The extremely increased probability of complicated appendicitis with high fever, severe vomiting, early intestinal obstruction, and dehydration, in children younger than 3 years, seems to be caused by the low percentage of intraperitoneal fat and the underdeveloped omentum, which cannot confine the expansion of the inflammation and limit the purulent leakage of a ruptured appendix [32].
6.2 Laboratory examinations
The most used blood tests for the diagnosis of acute appendicitis are the count of white blood cells (WBC), the percentage of neutrophils, and the value of the c-reactive protein (CRP), a glycoprotein produce by the liver, as a response to any acute infection. There are many biomarkers used for the diagnosis and even the staging of acute appendicitis in children, among them bilirubin, procalcitonin, calprotectin, aptoglobin, interleukine-8, and serum urokinase-type plasminogen activator receptor [30, 33, 34, 35].
All the above hematological biomarkers, taken in consideration alone or in combinations, present a vast range of specificity and sensitivity; however, none of them can diagnose and/or define the severity of the appendicitis with absolute precision. According to modern international guidelines, the various biochemical markers are only a promising predictive tool for the diagnosis of acute appendicitis [36].
These guidelines affirm that children with pain in the right iliac fossa, WBC more than 16,000/mm3 and CRP more than 10 mg/L, have a high probability for acute uncomplicated appendicitis [36]. Without being a precise rule, greater values of WBC and CRP are indicative of a ruptured appendix. It is important to remember that combined values of WBC, neutrophil count, and CRP within the normal range, are against the possibility of acute appendicitis [37]. To achieve an early and accurate diagnosis, the biomarkers should be taken in consideration always in accordance with the clinical examination and the imaging methods.
6.3 Imaging techniques
The most used imaging methods are simple radiography imaging, ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI).
Despite the fact that an X-ray is not very important for the diagnosis of the acute appendicitis, it can, however, show indirect evidence of an inflamed appendix, such as a non-structural scoliosis with the curvature toward the right side, in order to alleviate the pain. The absence of the psoas muscle in a simple radiograph is a sign of fluid due to inflammation in the area. Fecal stasis and intestinal obstruction can be easily observed through an X-ray. Radiopaque urinary stones give an easy diagnosis of urolithiasis, while a radiopaque fecalith is very specific in highlighting an obstructed appendiceal lumen. We must not forget that an X-ray of the thorax is crucial in the diagnosis of right-sided pneumonia, which can have as initial symptom the pain in the right abdomen.
Ultrasound is considered the first line imaging method for the diagnosis of acute appendicitis in children. Researchers report a range of specificity and sensitivity of 55–96% and 85–98%, respectively [38, 39]. The fact that this technique is economic, fast, and without radiation makes it the optimal investigation tool for the pediatric population. Ultrasound can measure the length and the diameter of the appendix, detect fluid, stones, fecaliths, air-fluid levels, and abscesses. Besides the appendix, ultrasound can give information about most of the intraperitoneal organs and exclude pathologies that make part of the differential diagnosis of the appendicitis, such as ovarian or epiploic torsion and extrauterine pregnancy. This imaging method has been very helpful in reducing overdiagnosis and consequently unnecessary appendicectomies. However, ultrasound has certain limitations. Firstly, it is an operator-dependent technique, meaning that experience is very important. Secondly, the presence of gas in the intestinal loops and obese patients may reduce its accuracy [40]. Finally, in many medical facilities, the necessary equipment is not always available on a 24-h basis.
FAST (focused assessment with sonography for trauma) is a kind of ultrasound used in trauma. With FAST as a starting point, POCUS (point-of-care ultrasound) was invented. This is a new type of ultrasound that uses a portable device and has already been introduced in the routine examination of many different medical specialties, especially in the emergency departments.
CT is another imaging method for the diagnosis of the acute appendicitis. With this technique, the inspection of the whole intraperitoneal cavity and the retroperitoneal space is possible. It can easily measure not only the diameter, but also the thickness of the appendix, which is considered pathological if greater than 1 mm. It can, also, detect the inflamed fat tissue with more accuracy compared with the ultrasound and can differentiate acute appendicitis from an inflamed Meckel diverticulum. Its accuracy is 90–98% with a specificity of 85–94% and a sensitivity of 92–97%.
To perform a CT, the use of the necessary radiocontrast can create an allergic reaction, and, also, a certain dose of anesthesia is needed, especially for the younger children. However, the main limitation of this imaging method in children is the presence of ionizing radiation. During the international congress for the creation of the guidelines for the diagnosis and treatment of acute appendicitis, there was a strong debate concerning the application of the CT in the pediatric population. Some affirm that the CT with low radiation (2 mSv instead of the normal 4.44 mSv) can be used safely in children with good results in children [41]. It is universally accepted that the use of ionizing radiation for the visualization of the appendix in children must be used a third-line imaging procedure when other routine clinical and laboratory tests are inconclusive [36].
MRI is an excellent diagnostic method for the diagnosis of acute appendicitis due to the absence of any harmful radiation. Studies showed that MRI has analogous specificity and sensitivity as a CT [42]. However, it is more expensive than the ultrasound and the CT. Moreover, it depends a lot on local availability of the equipment and expertise of the personnel. Likewise, the presence of an anesthesiologist is essential for the completion of the diagnostic test. International guidelines suggest the use of MRI as the preferable imaging method for the visualization of the appendix in children, after ultrasound, based on local resources, to avoid the ionizing radiation of a CT [36]. Some also affirm that an appropriate clinical and/or staged algorithm based on US/MRI implementation with a sensitivity up to 98% and a specificity up to 97% can reduce the use of CT [43].
7. Scoring systems
Scoring systems provide an easy instrument for the diagnosis of acute appendicitis. They are predictive tools that take in consideration clinical symptoms, signs, and laboratory test values [44]. In all scoring systems for every feature a specific point is ascribed, in case of positive feedback. The sum will attribute to a specific possibility of acute appendicitis. Each of these predictive tools has a different specificity and sensitivity. The most known scoring systems are the Alvarado score (ALV), Adult Inflammatory Score (AIR), the Adult Appendicitis Score (AAS), the Samuel’s Pediatric Appendicitis Score (PAS), and the RIPASA (Raja Isteri Pengiran Anak Saleha Appendicitis) scoring system [45, 46, 47, 48, 49]. This last one, initially, was used for the prediction of acute appendicitis in the Asia population. The most used of them in children are the Alvarado and the PAS. PAS is very similar to the Alvarado, although it considers the pain elicited during percussion or coughing more important than leukocytosis. Even though many studies report the importance of these two scoring systems for the diagnosis of acute appendicitis in children, a systematic review of the literature has proven that PAS and ALV over-diagnose the disease by 35% and 32%, respectively. Also, both failed to achieve the predictive performance of the CRP [50]. As mentioned, children in preschool age have atypical symptoms and more complications. In this age group, ALV and PAS present lower scores in comparison with older children [51]. Thus, many have started to use the AIR, which includes fewer symptoms, but takes into consideration the CRP. This scoring system seems to have a better predictive ability for the diagnosis of appendicitis than ALV and PAS [52]. The use of PAS in children demonstrated a specificity of 89% in female adolescents and 78% for the rest of the patients, while the prognostic value was low in both groups [53].
Regarding the severity of the inflammation of the appendix in the pediatric population and the presence of complications, the three features of the ALV with the higher sensitivity, for complicated appendicitis, were the fever, the leukocytosis, and the pain in the right lower quadrant (88.6%, 82.3%, and 79.7% respectively), while the best predictive value for a ruptured appendix was presented by the rebound tenderness [54].
These scoring systems are very helpful, primarily for the exclusion of acute appendicitis, but should not be solely used for the diagnosis of the disease in children [36].
8. Treatment
8.1 Non-operative management
During the last decade, many studies reported that the treatment of acute non-complicated appendicitis is possible without the need of operation in adults and children. Especially for children, only 19% of the patients present a rupture appendix [36, 55]. The success rate for non-operative management with antibiotics was found between 89.2% and 97% of the cases and during a follow-up of 8 weeks up to 4 years, the effectiveness of this conservative treatment was 75.7–79% [56, 57]. Moreover, a systematic review of 2019, which put in comparison appendicectomy to conservative treatment in children with uncomplicated appendicitis, showed that non-operative management (a cure within 2 weeks of intervention) was successful in 58–100% of the cases, with 0.1–31.8% recurrence at 1 year [58], without increasing the risk of complications [59, 60]. With non-operative initial management for simple appendicitis in children, the reported outcomes include less morbidity, fewer disability days, and lower costs when compared with surgery [61].
On the other hand, some argue that conservative management is not as effective as surgery in all pediatric patients with appendicitis, although it seems that such a statement is true if conservative treatment is, also, applied in children with a fecalith in the lumen of the appendix [62]. In fact, the only exception to conservative treatment in non-complicated appendicitis is the presence of an appendicolith. These patients present a high rate of failure and should not be treated conservatively [63, 64, 65].
Most surgeons agree that in case of non-complicated appendicitis, if operative management is decided, there are not differences regarding complications, between early and delayed treatment. Indeed, perforation of the appendix, small bowel obstruction, and surgical site infections did not seem to have higher rates in children who enter the operation room with a delay of a few hours, compared with those with an early appendicectomy [66, 67, 68, 69]. On the other hand, complicated cases should be treated promptly, in order to avoid complications [70, 71]. According to the international guidelines, delayed appendicectomy, until 24 h after the presentation of symptoms, is safe and does not increase the risks of complications. Complicated cases should be treated with surgery no more than 8 h after admission to the hospital [36].
A debate exists on the optimal treatment in children with abscess or phlegmon. Meta-analyses have shown that although early appendectomy was associated with reduced length of hospital stay, children treated conservatively presented lower rates of complications and readmissions [72, 73]. Some believe that children treated with antibiotics and percutaneous drainage of an abscess can, also, avoid interval appendicectomy [74].
There is evidence that interval appendicectomy is not always necessary after successful conservative treatment of an abscess in the pediatric population. In a systematic review, the rate of recurrence after conservative management of complicated appendicitis in a mixed population of children and adults was 12%, and interval appendicectomy prevented the relapse of the disease in only one of eight patients [75]. The (CHINA) study, a multicenter, open-label, randomized controlled study at 19 specialist pediatric surgery centers, 17 of which were in the United Kingdom, one in Sweden, and one in New Zealand, showed that more than three-quarters of children could avoid appendectomy during early follow-up after successful NOM of an appendix mass. The proportion of children with recurrent acute appendicitis was 12%, and the proportion of children with severe complications related to interval appendicectomy was 6% [76]. Taking into consideration that in patients over 40 years, the risk of neoplasms is quite high (17%) [77], the international guidelines recommend a non-operative approach to children and young adults with complicated appendicitis, reserving appendectomy for patients who develop recurrence of the disease or recurrent symptoms [36].
The best non-operative treatment for uncomplicated appendicitis is the use of antibiotics. For simple appendicitis in adults, there is evidence of remission even without antibiotic therapy [78, 79], but no studies have been done for this purpose in children. The treatment with antibiotics for simple appendicitis follows the empiric regimens for non-critically ill patients with community-acquired intra-abdominal infections as advised by the 2017 WSES guidelines [80]. These are amoxicillin/clavulanate 6-hourly or ceftriaxone 24-hourly + metronidazole 6-hourly or cefotaxime 8-hourly + metronidazole 6-hourly. In patients with beta-lactam allergy, the antibiotic therapy should consist of ciprofloxacin + metronidazole 6-hourly or moxifloxacin 24-hourly. In patients at risk for infection with community-acquired ESBL-producing Enterobacteriaceae, ertapenem once a day or tigecycline in full dose initially and then every 12 h is the best option. Antibiotic therapy should consist of, at least, 48 h intravenous administration followed by oral intake for 7–10 days [36, 81].
8.2 Operative management
Surgical treatment has been the cornerstone for the definitive therapy of acute appendicitis. Claudius Amyand (1660–1740) performed in 1735 the first appendicectomy on an 11-year-old patient, although the initial diagnosis was right inguinal hernia (containing the perforated appendix) with a fistula to the right thigh [82]. Nowadays, laparoscopic operation is the first option in most medical centers, while robotic surgery seeming to be the next step in the minimal invasive surgical treatment.
Reviews of the literature have shown that a single dose of broad-spectrum antibiotics, given preoperatively, from 0 to 60 min before incision, is effective in decreasing the rate of complications, with no apparent difference concerning the severity of the inflammation of the appendix [36, 83, 84].
International guidelines suggest that for non-complicated appendicitis in children, postoperative therapy with antibiotics does not offer any advantage. For complicated cases, the most common regimen administered postoperatively is ampicillin, clindamycin (or metronidazole), and gentamicin for 7 days after surgery. Alternatively, ceftriaxone with metronidazole, or ticarcillin-clavulanate plus gentamicin, can be used [85]. In rates of efficacy, the use of metronidazole is superfluous, when broad-spectrum antibiotics such as aminopenicillins with β-lactam inhibitors or carbapenems and select cephalosporins are administered [86]. Some argue that double antibiotic therapy for pediatric patients has the same efficacy and is more cost-effective than triple therapy, but more evidence is needed [87]. It is widely accepted that children with complicated appendicitis can, safely, switch to oral antibiotics, as soon as 48 h after appendicectomy, without presenting increased rates of complications or readmission. Such regimen with oral antibiotics, also, showed no difference in length of stay but reduced hospital charges [36, 88, 89, 90].
Open appendicectomy is performed using, mostly, the McBurney incision. The laparoscopic technique is used with the same efficacy and safety for the removal of the appendix in children, regardless of the severity of the disease.
The laparoscopic technique follows the same basic principles of the open surgery, with the main difference being the cost, because of the special equipment. Furthermore, the cosmetic result is better with the laparoscopic method. It is widely accepted that laparoscopic appendectomy is associated with lower postoperative pain, lower incidence of complications, fewer days of hospitalization, and higher quality of life in children, regardless of the severity of the inflammation [36, 91, 92].
The argument on the use of drains in children with complicated appendicitis did not result in statistically significant differences between the drain and no drain groups in the rate of intra-abdominal abscesses, surgical site infections, and bowel obstruction. However, drains were statistically associated with an increased requirement for antibiotic and analgesic medication, fasting time, operative time, and length of hospital stay, and for that reason, are not recommended [36, 93].
9. Conclusion
In our times, the acute appendicitis is considered a disease with low morbidity, especially for the complicated cases, and mortality is minimal. Antibiotics, which used to play an important, but secondary role, especially in the postoperative treatment, nowadays have become the best option for the treatment of uncomplicated and certain complicated cases. The only problem remaining is the early and accurate diagnosis of the disease, which, even with various modern diagnostic modalities, remains still a challenge in the pediatric population.
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