Treatment of Complicated Appendicitis

Abstract

Acute complicated appendicitis is defined as the presence of any of the four findings; visible hole, diffuse fibrinopurulent exudate, intra-abdominal abscess, and extraluminal fecalith. Different scoring systems such as appendicitis severity index (APSI) use different clinical and radiological parameters to diagnose complicated appendicitis. Surgical treatment is preferred over conservative treatment. Though previous studies showed open method is best for complicated appendicitis, present studies have shown that laparoscopic method also has similar results as open in terms of development of surgical site infection (superficial, deep or organ space), postoperative prolonged ileus or postoperative hospital stay. Intraoperatively irrigation of the peritoneal cavity is preferred over suction only method but is not statistically significant. Drain placement is not recommended. Postoperative antibiotics should be given for 3–6 days. Tazobactam—Piperacillin is an antibiotic of choice. Postoperative complications include surgical site infection, intra-abdominal abscess, and adhesive intestinal obstruction.

1. Introduction

Complicated appendicitis (CA) is a controversial topic in acute appendicitis. The definition is not standard and universal, diagnosis is difficult, management is not definite with high chance of complication, and worse outcome with increased cost. This chapter aims to summarize and standardize the topic.

2. Definition

Cameron et al. defined CA in the pediatric population as presence of any of the four findings: visible hole, diffuse fibrinopurulent exudate, intra-abdominal abscess, and extraluminal fecalith [1]. Many have accepted perforated appendicitis, gangrenous appendicitis, and suppurative appendicitis as CA [2, 3].

Maxime et al. did a video survey analysis in 2019 in a classification of appendicitis on the basis of laparoscopic findings given by Gomez et al. in 2012 with 85% concordance between surgeons hence good reproducibility which is shown in Table 1 [4, 5].

Grade	Laparoscopic findings
0	Normal looking appendix
1	Hyperemia and edema
2	Fibrinous exudate
3A	Segmental necrosis
3B	Base necrosis
4A	Abscess
4B	Regional peritonitis
5	Diffuse peritonitis

Table 1.

Grading of complicated appendicitis [4].

Histological grading was given by Pieper in 1981 which is shown in the Table 2 [6]. Later in 2022 Kadi et al. showed different histological findings in acute appendicitis recorded as acute hemorrhagic appendicitis, acute appendicitis with gangrene, acute necrotizing appendicitis, acute appendicitis with perforation, and acute suppurative appendicitis. The most common was acute suppurative appendicitis and least common was acute hemorrhagic appendicitis [7].

Type of inflammation	Histological criteria
Appendicitis with minor inflammation	Focal acute inflammation in the mucosa
Phlegmonous	Polymorphonuclear infiltration of the entire appendiceal wall without evidence of necrosis
Gangrenous	Phlegmonous type but presence of necrosis
Appendicitis with perforation	Rupture of the appendiceal wall to the serosal surface
Periappendicitis	Inflammation in the serosa, eventually affecting the longitudinal muscular layer

Table 2.

Histological criteria of appendicitis [6].

The incidence of perforated appendicitis ranges from 8.7 to 12.6% [7, 8] and gangrenous appendicitis is 2.55% [7]. There is a tendency of increasing incidence of CA in extremes of age [9]. During COVID the management of appendicitis was changed as non-operative management was mostly adopted which had some impact on the increase in incidence of complicated appendicitis due to delay in treatment. Many studies have shown increased incidence of complicated appendicitis in adults as well as children during COVID [2, 10].

It may be thought that CA can arise when uncomplicated appendicitis is not managed. However a study done by Livingstone showed that there is no relation between negative appendectomy and perforation rate suggesting that perforated and non-perforated appendicitis have different pathophysiology [11]. Clinical presentation of CA can vary from right lower quadrant pain to generalized abdominal pain and examination findings can vary from right lower quadrant tenderness to features of generalized tenderness [12].

3. Diagnosis

Diagnosing CA can be challenging at times. Alvarado scoring system is used initially and then ultrasound of abdomen and pelvis is done. Ultrasound is a good radiological tool to differentiate complicated from uncomplicated appendicitis. Increased appendiceal diameter, periappendiceal fat inflammation, presence of an appendicolith and a suspected perforation are discriminatory markers [13]. WSES guidelines say to perform computed tomography when the ultrasound findings are inconclusive or in a patient >40 years of age [14]. The overall CT sensitivity, specificity, and accuracy for differentiation of complicated from uncomplicated appendicitis were 87.2%, 75.7%, and 81.1%, respectively. The most sensitive CT findings of complicated appendicitis were mucosal enhancement defect and moderate-to-severe periappendiceal fat stranding [13]. Phlegmon, fluid collection, extraluminal appendicolith, periappendiceal air, and small bowel dilatation had specificity of 98.1–100% [3]^.

The CA must be distinguished from uncomplicated appendicitis and at times it is challenging. Scoring system is created to distinguish CA from uncomplicated appendicitis to help manage the cases. Atema et al. created a scoring system using clinical and imaging features. Clinical and radiological features included age, body temperature, duration of symptoms, white blood cell counts, C-reactive protein level, and presence of extraluminal free air, periappendiceal fluid, and appendicolith shown in Table 3 [15].

Features/points scored	Clinical and CT features	Clinical and ultrasound features
Age >/= 45 yrs	2	2
Body temperature
</= 37	0	0
37.1–37.9	2	2
>/= 38.0	4	4
Duration of symptoms >/= 48 h	2	2
WBC count >13,000/dl	2	2
C-reactive protein (mg/l)
<50	0	0
51–100	2	4
>100	3	5
Extraluminal free air on imaging	5	—
Periappendiceal fluid on imaging	2	2
Appendicolith on imaging	2	2
Maximum score	22	19

Table 3.

Clinical and radiological scoring for complicated appendicitis [15].

Hyponatremia is regarded as a risk factor for development of CA [16]. According to Oba et al. old age, larger body mass index, smoking, and medication with antidiabetic drugs, oral corticosteroids, oral antiplatelet drugs, and oral anticoagulant drugs are independent risk factors for CA [17]. Duration of chief complaint, history of constipation, having history of visit to health facilities without surgical intervention for their current problem and fever are also considered as risk factors for CA [18]. Pelvic appendix may be a new risk factor associated with CA [19]. However appendix length was not considered as a risk factor [20].

Different scoring systems predict the severity of appendicitis. One of the commonly used scoring systems, the Alvarado scoring system helps to diagnose acute appendicitis but is not helpful to grade the severity of acute appendicitis [21]. Appendicitis severity index (APSI) uses different clinical and radiological parameters to diagnose complicated appendicitis. Three clinical (age ≥ 52 years, body temperature ≥ 37.5°C, duration of symptoms ≥48 h) and four computed tomography (CT) findings (appendix diameter ≥ 14 mm, presence of periappendiceal fluid, extraluminal air, perityphlitic abscess) are used and score of ≥4 is predicted as complicated appendicitis [22]. Another scoring system called Sunshine appendicitis grading system score (SAGS) uses intraoperative findings to grade the severity of appendicitis shown in Table 4 [23].

SAGS score	Intraoperative findings
0	No appendicitis
1	Simple appendicitis (any of the following)
	I. Infected appendix
	II. Thickened appendix
	III. Serous free fluid
2	Purulent appendicitis (any of the following)
	I. Pus localized to right iliac fossa
	II. Right paracolic gutter
	III. Pelvis
3	Purulent appendicitis with four quadrant contamination
4	Perforated appendix (any of the following)
	I. Free fecalith, feces
	II. Fecal staining
	III. Visible hole in appendix

Table 4.

SAGS score [23].

4. Management

The optimum management of CA is a subject of controversy. Conservative treatment is one of the treatment options for acute appendicitis. In conservative treatment patients are given antibiotics and kept nil per oral and observed till the pain subsides. It was majorly performed before the surgery was practiced and during the COVID. The effective rate of conservative treatment in uncomplicated appendicitis is 95.2% and in complicated appendicitis is 83.4%. The complication rate of conservative treatment in uncomplicated appendicitis is 3.5% and in complicated appendicitis is 12.1% [24].

A meta-analysis conducted by Simillis et al. discussed conservative management of complicated appendicitis has been associated with decreased complication and reoperation compared to acute appendectomy and has almost similar hospital stay [25]. Delayed operative management may be associated with a reduction in the need of extended resection appendectomy, shorter operative time, and a trend toward reduced mortality. But it may also be associated with an increased length of in-hospital stay and short-term morbidity [26]. Similarly in pediatric age group appendicular abscess and perforated appendix are better managed with non-operative management, conversely free perforated appendix showed lower complication rate and readmission when treated with surgery [27]. However, a study conducted by Vasos et al. in 2019 states immediate surgery is associated with shorter duration of hospital stay, whereas postoperative complication was not affected by treatment of choice [28]. Most of the patients with appendicoliths had to undergo surgery despite being on antibiotics [29] and CA had more chances of having appendicolith than uncomplicated appendicitis [30]. Endoscopic therapy of acute appendicitis helps to clear appendicolith by stenting appendix and is being considered as a treatment option in case of uncomplicated appendicitis but study for its role in complicated appendicitis is yet to be performed [31, 32].

Surgery was regarded as gold standard treatment for more than a century because of its low incidence of postoperative complications, early recovery, and short hospital stay. Emergency surgery is mandated when the patient develops generalized peritonitis. Surgery is also considered a better option in pregnancy and it is associated with a lower rate of maternal and fetal complications. Failed non-operative management was associated with higher maternal and fetal complication rate [33]. Surgery is the only option with no scope for conservative treatment for complicated appendicitis caused by foreign body ingestion such as toothpick [34].

Open surgery had been the gold standard until the last 20 years when laparoscopic appendectomy became a preferred option for most of the surgeons because of its advantages like less pain, lower wound infection rate, and short recovery period [35]. However laparoscopic appendectomy has similar intra-abdominal abscess rate, readmission, and reoperation rate [36]. According to Jung Oh et al. single incision laparoscopic appendectomy (SILA) is also a feasible option for complicated appendicitis as there was no difference in operative time and postoperative infectious complication but hospital stay and drain insertion rate was significantly lower compared to conventional laparoscopic appendectomy [37]. Though laparoscopic appendectomy is gold standard, in low and middle human development index countries like Nepal open appendectomy is still more commonly practiced. Also some studies have shown that open appendectomy is preferred for CA. Foster et al. showed that open surgery is preferred in patients with intra-abdominal abscess [38].

Sun et al. showed that peritoneal irrigation is associated with lower rate of intra-abdominal abscess, shorter hospital stay, and earlier anal exsufflation compared to suction only group in patients with CA [39]. But these findings were not significant according to a meta-analysis. There is increased intraoperative time with irrigation. Also there is an increased chance of intra-abdominal abscess with irrigation in the pediatric population [40]. Hence peritoneal irrigation though preferred has no added advantage in preventing development of intra-abdominal abscess and surgical site infection in both adult and pediatric population [14]. Drain placement is not shown to decrease the rate of intra-abdominal abscess formation. Hence drain is not necessary after appendectomy; rather it can increase risk of postoperative complications such as fistula, surgical site infection (SSI), bowel obstruction, ileus, and length of hospital stay [41, 42].

Post-operative antibiotics are indicated in case of CA. However, the duration is not specified. Less than or equal to 5 days of antibiotics is seen to have more intra-abdominal abscess hence >5 days of antibiotics is preferred. But the duration of antibiotics can be individualized based on the response of the patient [43]. Panshin et al. recommended 3–6 days of antibiotics [44]. Longer duration of antibiotics was not associated with a low rate of complication [45]. For the pediatric population antibiotics can be stopped before postoperative day 7, on the day of discharge [46].

Antibiotics should be chosen wisely for CA as there is significant increased risk of complication in co-amoxiclav resistant E.coli. Also complication rate is increased when pseudomonas is not covered [47]. Routine intraoperative bacterial culture can be done to select antibiotics of choice [48]. Piperacillin—Tazobactam is considered antibiotic of choice to cover the resistant group [49]. Triple regimen consisting of ampicillin, metronidazole, and gentamicin and monotherapy consisting of amoxycillin and clavulanic acid can be the alternative antibiotics [50].

There is a high chance of postoperative complication associated with complicated appendicitis. Postoperative complications include surgical site infection (SSI), intra-abdominal abscess, adhesive intestinal obstruction. SSI can occur in as high as 30.4% and serious complications like intra-abdominal collection and adhesive intestinal obstruction can occur in 13.48% cases [51]. Compared to uncomplicated appendicitis, complicated appendicitis have longer operative duration, greater blood loss, longer hospital stay [52].

5. Conclusions

Complicated appendicitis should be treated with surgery. Intraoperatively irrigation of the peritoneum should be done. Drain is not recommended and postoperatively antibiotics should be continued till 3–6 days.

Conflict of interest

No.

Notes

Pratima Gautam = https://orcid.org/0000-0003-3939-3705

Prakash Mainali = https://orcid.org/0000-0001-6307-5497

Sunil Kumar Das = https://orcid.org/000-0002-6568-5149

Sandeep Bhattarai https://orcid.org/0000-0002-7907-6766