POSTOPERATIVE COMPLICATION

The overall complication rate differs a little between open and LA, and is reported to vary between 8.3% to 13.2% and 2.9% to 7.4% for open and laparoscopic surgery, respectively (259,281). The main advantages of laparoscopic over open surgery are decreased risk of wound infection (OR 0.43; CI 0.34-0.54), and lower incidence of postoperative pain, whereas

a rate of intra-abdominal abscesses is higher in laparoscopic surgery (OR 1.87; CI 1.19-2.93) (264).

In addition, length of hospital stay and readmission rates is reported to be lower after LA compared to OA, even in a patient with perforated appendicitis (253,282).

A large register complication study from Finland reported that two most common claims for complications were wound infection (27%) and abscess (12%) for open surgery, and abscess (21%) and intestinal perforation (13%) for laparoscopic surgery (283). The most common clime for intraoperative complication for both groups was bleeding, 15% and 29%

for OA and LA, respectively (283). The rate of infection complications increases in cases of perforated appendicitis (263,282). In addition, the duration of preoperative symptoms over the 36h, and the age of a patient seem to correlate positively with the incidence of postoperative septic complications (284).

Mortality

Appendectomy is a relatively safe operation. Although, AE for non-perforated appendicitis is not an entirely harmless procedure, with 2.5-fold excess in the 30-day mortality rate compared with the general population (285). The rate of mortality and morbidity is related to the stage of disease, and patient age (125,248,285,286). Emergency appendectomies are still considered the most common approach for treating AA, with mortality rates of 0.5-2.4% and 0.07-0.7% for patients with and without perforation, respectively (14,99,248,287).

Mortality is higher in older age groups. Kraemer et al. found that mortality for patients

<50 and >50 years old was 0.2% vs 2.9% for uncomplicated AA, and 1.8% vs. 2.8% for complicated appendicitis, respectively (99). In Finland, the post-AE mortality rate was found to be 0.21% with a rapid increase in age groups older than 60 years of age (288).

Morbidity

Overall postappendectomy complication rates are typically around 5-15% for AA without perforation and reach up to 30% for perforated AA (99,185,286). The morbidity rate rises to over 70% in elderly patients with perforated appendicitis (289).

In a study from Sweden, they showed that if the diagnosis at the time of surgery, done for suspected appendicitis, was not related to appendix, there was a higher morbidity. This finding led to the conclusion that greater diagnostic effort is warranted for elderly patients before subjecting them to an urgent AE (248). Moreover, there were no significant differences noted in the overall morbidity and mortality in patients operated at <12h, 12-24h, and >24h from time of surgical admission (199). Interestingly, black people, supposed to be an independent predictor of morbidity after AE, are reported to have a 1.5 times higher risk of postoperative complications (290).

Published results indicate that there is no difference in the overall morbidity rate for the removal of a normal appendix in patients suspected of having AA (124,125). Hale et al.

found that the overall complication rate after AE was 5% and there was no difference in complication rates between removal of normal appendix or inflamed (4% vs. 3%, respectively), whereas the complication rate associated with perforated appendicitis was 12% (124).

Wound infection

The rate of postoperative wound infection is determined by intraoperative wound contamination. Rates of infection vary from < 5% in simple appendicitis to 20% in cases with perforation and gangrene (291,292). The use of perioperative antibiotics has been shown to decrease the rates of postoperative wound infections (292). According to large meta-analyses the incidence of the wound infection after the open surgery is significantly higher than that of laparoscopic surgery (262,293). The method of the wound closure with

absorbable or not-absorbable sutures does not seem to have an effect to incidence of wound infection (294).

Abscess

Nevertheless, the rate of intra-abdominal abscesses is reported to be higher after a laparoscopic operation (253,291). The incidence is found to be less than 2%, and it is not affected by the length of post-operative antibiotic treatment (291,295). A surgical site abscess may form in the postoperative period after removal of an infected appendix especially after perforation. The patient presents with swinging pyrexia, and the diagnosis can be confirmed by ultrasonography or computed tomography scanning (203,204).

Antibiotic treatment combined with a radiologically guided drainage of collection with a pigtail drain is recommended. Additionally, open or per rectal drainage may be needed for a pelvic abscess (296).

2.10 SUMMARY

AA can occur at any age, although it is quite rare in infants and in the elderly. There are remarkable variations in the incidence of the disease among various ethnic groups and countries. The clinician must appreciate that the anatomic location of the appendix determines the presentation of symptoms and signs during an episode of appendicitis. The close contact with the parietal peritoneum determines the ordinary clinical picture of appendicitis. The organ may provide immune-mediated maintenance of gut flora within the organ, especially during episodes of severe diarrhea. Increased use of advanced diagnostic techniques such as laparoscopy, CT and US have led to a significant reduction (from 20-30% to 5-10%) of unnecessary operations and have also reduced the mortality rate.

According to the latest findings, an antibiotic treatment can be considered a safe first-line therapy in patients with uncomplicated AA and with no signs of peritonitis. Consequently, the treatment principles of AA may need a re-evaluation to determine whether it should be individualized based on which form of the disease is present.