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Introduction
Acute appendicitis is one of the main surgical pathologies in the population1, the estimated incidence is 9.4-11 por 10,000 person-years, with a lifetime incidence of 7-9%2. Approximately 4-20% of patients will present with periappendiceal abscess or phlegmon3. Actually, the main established treatment is appendectomy; some centers apply open appendectomy and or laparoscopic appendectomy for complicated appendicitis. Patients who had appendectomy for complicated appendicitis are more likely to develop post-operative complications such as intraperitoneal abscess (abdominal or pelvic) or wound infection4. Complicated appendicitis has a mortality rate of less than 1%5. There are several methods applied to prevent or decrease the incidence of these post-operative complications. These methods are the insertion of intra-abdominal drain after the surgery, use of antibiotics, delayed wound closure, and laparoscopic technique6. Typically, abdominal drainage is most familiar. Drains usually are well tolerated but can lead to bleeding, fistula formation, or intra-abdominal abscesses7, but drain failure is reported in previous studies ranging from 4.5% to 26% in adults with intra-abdominal abscesses associated with appendicitis8. Nowadays, the use of intra-abdominal drain after open appendectomy for acute complicated appendicitis is an issue in discussion. Through the development of this study, we will describe the use of drains and establish their relationship with post-operative complications and thus propose the best surgical approach for our patients.
Methods
This was a retrospective, observational cohort study. Records were obtained from patients admitted to Hospital Sergio Bernales during the year 2014, with complicated appendicitis (localized peritonitis, generalized peritonitis, and abscessed appendicular plastron) who underwent emergency surgery. The registration UIN of the study is the research registry 4054. The sample size was 50 patients without drains, chosen for convenience, and 100 patients with drains due to complicated acute appendicitis. A pairing by date, age and sex, and diagnosis in order to avoid any vias the match was made by date, age, sex and diagnosis in order to avoid bias. Patients without drains were operated by a single surgeon; while patients with drains were operated by 10 different surgeons. The treatment of the appendicular base was dependent on its state of the base, in some cases only to free stump, invagination, or raffia of the base. Patients with drains had cavity drying in case of localized peritonitis and cavity lavage after generalized peritonitis; the drains were placed in the right colic parietal space and the rectovesical space. No sample of peritoneal fluid was taken in most cases. The abdominal drains were laminar (Penrose), which were removed when the drainage volume was less 10-20 ml/day. In the post-operative period, if the patient presented with fever or clinical deterioration, an ultrasound study was performed in search of residual abscesses, or the antibiotic scheme was changed. We did not consider the body mass index. The inclusion criteria were patients of both sexes, older than 18 years of age, diagnosis of complicated peritonitis due to acute appendicitis, complete clinical history, and exclusion criteria were patients younger than 18 years, hemorrhagic diathesis or oral anticoagulation, pregnancy, immunocompromised, laparoscopic appendectomy, and incomplete clinical records.
Statistical analysis
The data were collected by three general surgeons and validated by expert judgment. p < 0.05 was considered statistically significant, calculating the corresponding 95% confidence intervals (CI). The statistical methods used were Chi-square and Student's t-test. All the information was analyzed using the statistical program Statistical Package for the Social Sciences 18. The study had the approval from the Ethics Committee of the “Sergio E. Bernales” Hospital and the postgraduate section of the Faculty of Medicine from The San Martín de Porres University.
Results
The study identified 150 patients with open emergency appendectomy for complicated appendicitis during the period of study. A total of 50 patients without drains were chosen for convenience and 100 patients with drains due to complicated acute appendicitis during 2014. The mean age of the unexposed (patients without drains) and exposed (patients with drains) was 36.76 (15-70) and 35.00 (15-72), respectively. The predominant sex in both groups was male 30 (60%) and 60 (60%) without drains and drains. When assessing clinical characteristics of the patients, we found that disease time was 41 (10-144) h, for patients without drains and 61.2 (10-144) h for patients with drains, symptoms, and signs with similar proportions. Analysis of Chi-square and odds ratio (OR) showed no difference between the two groups in the symptoms and signs. Both groups were similar in the blood count, according to the Chi-square test. Once the diagnosis was made, antibiotic prophylaxis was indicated (Table 1). The pre-operative diagnosis was acute appendicitis complicated with generalized peritonitis 16 (32%) and 26 (26%) for patients without drains and drains. The other group acute appendicitis complicated with localized peritonitis 34 (68%) and 74 (74%) for patients without drains and drains, respectively. No differences were found between the two groups in the pre-operative diagnosis in the Chi-square and OR tests. The post-operative diagnosis was acute appendicitis with generalized peritonitis, acute appendicitis with localized peritonitis, and acute appendicitis with abscessed appendicular plastron 13 (26%) and 26 (26%); 31 (62%) and 62 (62%); and 6 (12%) and 12 (12%) for patients without drains and drains, respectively. The operative time was 1.46 h (1.0-2.5) and 1.66 (1-3) for patients without drains and drains, respectively, the difference is significant (p < 0.001) (Table 2).
Table 1 Disease characteristics. Use of drains and post-operative complications in secondary peritonitis for acute appendicitis on complicated
| Sign and symptoms | Withou drains | With drains | p |
|---|---|---|---|
| Disease time (h) | 42.5 (20-96) | 44.3 (24-96) | 0.560 |
| Simptoms | |||
| Murphy cronology (%) | 39 (78) | 79 (79) | 1.000 |
| Vomiting chronology (%) | 43 (86) | 92 (92) | 0.260 |
| Liquid depositions chronology (%) | 21 (42) | 44 (44) | 0.860 |
| Temperature | 37.6 (36.5-39) | 37.6 (36-39.2) | 0.860 |
| Ecography | |||
| Appendicitis suspect (%) | 20 (40) | 40 (40) | 0.910 |
| Appendicular plastron (%) | 10 (20) | 40 (40) | |
| Blood count Leukocytes | 15.6 (10.9-19.0) | 15.3 (10.0-19.0) | 0.450 |
Table 2 Disease, pre and post-operative time. Use of drains and post-operative complications in secondary peritonitis for acute appendicitis
| Without drains | With drains | p | |
|---|---|---|---|
| Post-operative diagnosis | |||
| Generalized peritonitis | 13 (26%) | 26 (26%) | 1.000 |
| Localized peritonitis | 31 (62%) | 62 (62%) | |
| Abscess apendicular plastron | 6 (12%) | 12 (12%) | |
| Wait and operative time Pre-operative wait time (H): | 11.4 (4.5-23) | 10.24 (3-30) | 0.001 |
| Operative time | 1.46 horas (1.0-2.5) | 1.66 horas (1-3) |
Post-operative complications
After the post-operative period, one patient (2%) went to the intensive care unit, with favorable evolution. Post-operative fever was more prevalent in the group with drains OR 3.4 95% CI (1.4-7.9). The antibiotic rotation was performed in 11 (22%) and 27 (27%) patients without drains and drains. The hospitalization time was 7.3 days (3-20) and 8.8 days (3-35) for patients without drains and with drains, respectively, (p = 0.01). Among the complications, the results in the Chi-square analysis; surgical site infection was present in 13 (26%) and 29 (29%) patients without drains and drains, the result was not significant. In turn, evisceration Grade III + residual collection was presented in the group of patients without drains 3 (6%), the results were significant p = 0.036. Thus, there is a relationship between evisceration Grade III and residual collection; however, we cannot establish if it is a risk factor, to elucidate this incognita we need to increase the sample size. Abdominal eventration was present in 4 (4%) patients with drains; the result was not significant, the risk factor was not evaluable; Scrotal abscess was also observed in 2 (2%) patients with drains, the results were not significant. The enterocutaneous fistula was present in 6 (6%) of the patients with drains; the results were not significant. Surgical reoperation and exploratory laparotomy were performed in 3 (6%) of patients without drains and 1 (1%) of patients with drains; the results were not significant. There was no mortality (Table 3).
Table 3 Post-operative complications. Use of drains and post-operative complications in secondary peritonitis for acute appendicitis
| Wihtout drains (%) | With drains (%) | p | |
|---|---|---|---|
| Surgical site infections | 13 (26) | 29 (29) | 0.847 |
| Evisceration grade III + residual collection | 3 (6.0) | - | 0.036 |
| Abdominal eventration | - | 4 (4.0) | 0.302 |
| Scrotal abscess | - | 2 (2.0) | 0.553 |
| Enterocutaneous fistula | - | 6 (6.0) | 0.179 |
| Exploratory laparotomy | 3 (6.0) | 1 (1.0) | 0.108 |
Discussion
The study found that the no insertion of abdominal drainage after open appendectomy at an emergency service for complicated appendicitis has relation with evisceration more residual collection (p = 0.036); had no significant effect on development of surgical site infection (p < 0.05); then intra-abdominal drains prevent post-operative residual abscess, nonetheless do not prevent or significantly decrease the incidence of development of wound infection. The function of the abdominal drain is to prevent the collection of inflammatory materials, drainage of already formed collection, by doing first and second function, it may reduce bacterial invasion and colonization at the site of surgery and thus decrease the incidence of surgical site infection8,9. However, the evidence report some disadvantages such as blockage or obstruction of drain with consequent failure of its function, existence of drain inside the human body may be recognized as foreign body which can initiate inflammatory response and may interfere with surgical site healing and insertion of intra-abdominal drain can increase the duration of patient's stay in the hospital with subsequent extra cost8,10,11. The difference in the period of hospital stay was longer for the drainage group versus without drains (p = 0.001), the mean length of stay for the non-drainage group was 7.3 days, while for the drainage group was 8.8 days. The main reason for the prolonged stay in the group of drains would be the drain care and the criteria for their retirement according to the evolution of the patient. According to the literature, the use of drains in uncomplicated acute appendicitis is not recommended12. There is currently no consensus on the use of drains in complicated acute appendicitis; there are two meta-analyses10,11 and cohort studies that do not recommend the use of drains8-10,12; although others are not conclusive13. Li et al., after an meta-analyses about the use of intra-abdominal drains to prevent intraperitoneal abscess after open appendectomy for complicated appendicitis, found six randomized clinical trials and 521 participants, he concluded that there is insufficient evidence to determine the effects of abdominal drainage and no drainage on intraperitoneal abscess at 14 days or for wound infection at 14 days with a low-quality evidence. The increased risk of 30-day overall complication rate (morbidity) in the drainage group was rated as very low-quality evidence. Therefore, the effect of abdominal drainage on the prevention of intra-peritoneal abscess or wound infection after open appendicectomy is uncertain for patients with complicated appendicitis; also, the increased rates for overall complication rate and hospital stay for the drainage group compared to no drainage group are not clear14. Abdulhamid and Sarker made a cohort retrospective study that includes perforated appendicitis with localized abscess formation only, the study concludes that abdominal drain after open emergency appendectomy for complicated appendicitis did not bring any considerable advantage in terms of prevention or significant reduction of post-operative intraperitoneal abscess and wound infection, even its use prolongs the hospital stay and doubled the cost of operation15. Beek et al., in a cohort retrospective study, concluded that peritoneal drains seem to reduce overall complication rate, re-interventions rate, and readmission rate in patients treated with perforated appendicitis16. Most studies in favor of the use of drains are not recent and have a smaller sample size17. Our study is in favor of the use of drains; although it includes all types of complicated acute appendicitis with localized, generalized and abscess due to appendicitis; nonetheless, the hospital stay was more prolonged for the drain group, similar most studies8-12. According to the European Association of Endoscopic Surgery, routine use of drains does not reduce the incidence of abscesses. The use of abdominal drainage after open appendectomy for perforated appendicitis is controversial. Our study found that use of drains decrease the abdominal abscess and surgical site infections, although the difference was significative (p < 0.001), it did not represent a risk factor. Despite the limitations of a retrospective study based on a single hospital, these results support the need for evidence for any clinical improvement using abdominal drainage in patients undergoing open appendectomy for complicated appendicitis.
