The purpose of this study is to monitor and compare peri-operative problems and outcomes of reconstructive surgery with microvascular free flaps in the head and neck region between groups of patients treated with perioperative antibiotics and a group of patients without antibiotics.

Study Design and Patient Recruitment All clinical investigations have been conducted according to the principles expressed in the Declaration of Helsinki. Patient consent was written. Any patient who required reconstructive surgery for oncological reasons within the oral cavity with microvascular free flaps was eligible. Patients receiving preoperative neoadjuvant or previous adjuvant radiation therapy in their medical history were not included in this study as the protocols available are not comparable in doses and effect on the irradiated tissue.14 A prospective study was initiated from July of 2007 to June 2012. All patients were prospectively evaluated.

Postoperative Care The investigators standard regimen was to keep the patient sedated for one night on the intensive care unit and then transfer to the surgical ward. The specific intravenous antibiotic therapy was started 30 minutes before the operation and administered for 10 days.

Data Analysis Recorded parameters included: age, sex, preoperative medical history, American society of Anesthesiologists classification of preoperative status 15, diagnosis, stage of disease, defect localisation, type of microvascular free flap, choice of recipient vessels, flap success, rate and number of operative revisions, primary or secondary reconstruction, type of previous treatment (radiation or surgery), type of previous neck dissection (if any), microvascular complications, the total operative time, wound healing disturbances subdivided into dehiscence and infection at the neck, region of reconstruction, or donor site, and prophylactic antibiotic agent, if used. Infection was defined as a purulent discharge at the wounds.

Descriptive statistics for quantitative variables are given as the mean ± standard deviation. The data were analyzed with the "Statistical Package for the Social Sciences" software (IBM® SPSS® Statistics for Windows, Version 22.0; IBM Corp., Armonk, NY, USA). Figures are generated with SPSS and Microsoft® Office Excel (Microsoft Excel for Windows, release 11.0, 2003, Microsoft Corporation, Redmond, WA, USA). Multiple linear regression analyses were used to determine factors independently associated with the dependent variable wound infection or wound healing disturbances. 95% confidence intervals (95% CI) are also given. Differences were considered to be statistically significant for a two-sided p-value of less than 0.05.

Inclusion Criteria:

• Any patient who required reconstructive surgery for oncological reasons within the oral cavity with microvascular free flaps.

Exclusion Criteria:

• Healthy humans.
• Patients receiving preoperative neoadjuvant or previous adjuvant radiation therapy in their medical history.