Effect of treated infection on microvascular anastomosis

Effect of Salivary Fistulas on Free Flap Failure: A Laboratory and Clinical Investigation

OBJECTIVES

Infection is associated with free flap failure in patients undergoing microvascular flap reconstruction. This study investigates the association between infection arising from salivary fistulas, microvascular thrombosis, and free flap failure.

STUDY DESIGN

Prospective laboratory investigation and retrospective clinical investigation.

METHODS

The effect of saliva-induced infection on the patency of microvascular thrombosis was studied in an experimental animal model and in a clinical series of patients undergoing free flap reconstruction of the head and neck. In the laboratory phase of this study, rat femoral artery anastomoses were inoculated with freshly collected rat saliva to simulate a postoperative salivary fistula. The incidence of femoral artery thrombosis was determined. In the clinical arm of this study, the incidence of salivary fistulas and resulting clinical outcome in 588 head and neck free flap reconstructions were examined.

RESULTS

In the animal experiment, arterial patency was 95% after 10 days for both the control group and the salivary contamination group. In the clinical series, 24 patients developed salivary fistulas during the postoperative period. No cases of microvascular thrombosis were attributed to salivary fistula formation.

CONCLUSIONS

Postoperative salivary fistulas do not appear to be strongly associated as a contributory factor toward free flap failure in head and neck reconstruction. On the basis of our current understanding of this condition, we describe a rational approach for management of patients who develop salivary fistulas after microvascular head and neck reconstruction.

Operative complications and the management of intraoperative flow failure

Free flap flow failure can be either that of an artery and/or vein(s). One approach is to ascertain precisely which vessel(s) is compromised, then figure out whether the problem is on the patient's side or the flap side or at the anastomosis itself. A well perfused patient can minimize a patient-side problem. An anastomotic problem can be revised with or without adding a graft. There is potential to avoid further anastomotic problems with the use of some form of anticoagulant. Problems on the flap side, if limited, can be dealt with by resection or repair. Anticoagulants may be of value. Occasionally, another free flap is needed.