Methods
We performed a retrospective review of all patients who underwent appendectomy at the Division of General Surgery of Civil Hospital of Ragusa, Italy, between May 2008 and May 2012. The study was performed in accordance to the ethical principles of the Declaration of Helsinki and has been approved by the Ethics committee of ASP of Ragusa (local health authority). The study included 230 patients with diagnosis of acute appendicitis obtained by clinical assessment and confirmed by laboratory blood tests and imaging (US or computed tomography) when deemed necessary. Patients younger than 12 years and patients with preoperative clinical evidence of bowel perforation were excluded. For each patient the age, gender, American Society of Anesthesiologist (ASA) risk score, duration of symptoms, white blood cell (WBC) value upon admission, and previous abdominal surgeries were recorded. Depending on the intra-operative evaluation, the cases of acute appendicitis were divided into uncomplicated or complicated if phlegmon with peri-appendiceal abscess, gangrene, or perforation were noted during surgery. According to the surgical approach performed, the patients were divided into two cohorts, LA group and OA group. Mean operative time, intra-operative and postoperative complications, mean duration of postoperative ileus, and average length of hospital stay were recorded for each group. The total hospital costs were calculated as a mean for each group. The cost for each patient was assessed taking into account the length of time that the operating room was used for surgery, the cost of the material used during the surgery, and the cost of the hospital stay. Cases of conversion from laparoscopic to open appendectomy were included in the LA group.
All laparoscopic procedures were performed by two experienced laparoscopic surgeons (VM, VA), who approached all cases laparoscopically according to a standardized technique that involves the use of three trocars, two 10 mm and one 5 mm. After bipolar coagulation and division with scissors of the mesoappendix, two endoscopic loop ligatures were applied at the base of the appendix; the appendix was then divided and extracted with a bag. All the appendectomies of the open group were performed with McBurney's incision by other surgeons who preferred this approach a priori. After ligation and division with scissors of the mesoappendix, the base of appendix was ligated with an absorbable tie and the appendix was divided with a scalpel. The appendiceal stump was inverted within the lumen of the cecum using a purse-string suture. Abdominal incision was extended when deemed necessary by the surgeon. Selection bias was minimized because the choice of the surgical approach was not determined by the characteristics of the patient.
The results were analyzed using the t Student test for comparison of data measured as quantitative variables which were age, duration of symptoms, white blood cell count value at the time of hospitalization, operative time, duration of postoperative ileus, length of hospital stay, and total hospital costs. The statistical significance of difference between the categorical variables such as gender, ASA risk score, previous abdominal surgery, uncomplicated and complicated appendicitis, and postoperative complications was calculated using the Chi-square test with Yates correction and Fisher exact test, when appropriate. A p Value < 0.05 was considered statistically significant. Statistical analysis were performed with SPSS computer software (SPSS 21 for MacOS, SPSS Inc., Chicago, IL, USA).