In spite of the worldwide effort to decrease and treat obesity, the increasing prevalence rates have been concerning many countries.1–6 This preoccupation rises especially when severe obesity is analyzed. In this type of obesity, the only long-term effective treatment is surgery.7–10
Despite the low rates of infectious complications, the exponential increase of numbers of bariatric surgery makes us deal more and more with this kind of patient. Postoperative infections continue to represent a great challenge for surgeons and health professionals. The incidence rate of surgical infection varies from surgeon to surgeon, from hospital to hospital, from one kind of surgery to another, and, especially, from patient to patient.11–13 The aim of this chapter is to discuss some features of essential importance in the physiopathology, prophylaxis, and treatment of postoperative infection in bariatric surgery.
The attempt to prevent the real risk of the patient to develop a postoperative infectious complication has been a reason for a big effort by the scientific community. Patients with a high risk for postoperative infection could be submitted to different types of surgical preparation and management.
In this way, the SENIC Project (Hooton and colleagues14) published, in 1981, the result of a multicentric analysis of 58,498 operated patients, identifying risk factors, to develop a valuation index. Evaluating risk factors, the authors have made a statistical analysis through the CHAID system (chi-square automatic interaction detection). The examined risk factors were age, gender, time of surgery, abdominal surgery, previous infection, immunodeficiency, preoperative stay, intrinsic risk of the surgery and preexisting pathology. Therefore, this index was applied in 59,352 operated patients in the period between 1975 and 1976. They previewed 73% of the infections.
In 1985, Haley and colleagues,15 trying to simplify this methodology and analyzing the same data of the SENIC Project, reduced to a number of four the risk factors and studied them using a system of multiple regression. With this methodology, Haley and colleagues have previewed 69% of the postoperative infections. The four risk factors were contamination level (if the surgery was contaminated or infected), abdominal surgery, extended surgery (more than 2 hours), and the existence of more than three diagnoses or comorbidities in the patient.
In 1987, Christou and colleagues16 also proposed a methodology of prognostic evaluation of the infection. They have analyzed in this proposal, through a logistic system of multiple regression, the contamination level of the surgery, serum albumin, age, cutaneous retarded sensibility test, and the time of surgery. The authors did not quantify the risk of the patient to have infection. The aim was to determine values that added together would show the chances of the patient to become infected after the surgical act. The final equation would be
where DTH score = logarithm expression of cutaneous reaction to hypersensibility test; surgery contamination = clean = 1; potential cont. = 2; ...