Important considerations in patient selection for free-flap reconstruction include age, comorbidities, and functional needs. Older patients are more likely to have comorbid factors that may increase their risk of exposure to prolonged anesthesia, affect wound healing, and decrease their tolerance for donor site morbidity. Some patients may not need the additional functional advantages gained from free-flap reconstruction. The risks and benefits of free-flap reconstruction must be considered for each individual patient.
Preoperative planning and communication with the anesthesia, nursing, and other involved surgical teams facilitate an efficient and well-executed surgical procedure. The tissue defect, functional needs of the patient, or both must be anticipated so that the optimal free flap is selected. Factors to be considered are donor tissue characteristics and composition, the length of pedicle, color match, soft tissue bulkiness, and the functional disability of the donor site. Communication about the patient's intraoperative position and the preservation of adequate recipient vessels in the head and neck for anastomosis should also be relayed with the appropriate teams.
Although careful preoperative planning, patient selection, and flap design are important factors in free-tissue transfers, a meticulous microvascular technique is essential for the successful insetting and revascularization of tissue units. Critical to the execution of microvascular techniques are proper instruments, an operating microscope, and the expertise of microvascular surgeons who are trained in the techniques of vessel selection, handling, and preparation.
As a rule, vessel handling should be minimal to decrease the risk of trauma or injury. Vessels should be handled by the adventitia because direct contact with the intima may cause spasm, endothelial damage, and thrombosis, all with the potential of compromising blood flow to and from the transferred tissue. Vessels in the donor vascular pedicle are skeletonized, freeing the arteries from the veins within the vascular pedicle. Atraumatic vascular clamps are then placed. The ends of the vessels are transected and irrigated intermittently with dilute heparinized saline solution to prevent thrombosis. Finally, the excess adventitia is removed from the vessels to expose the media; adventitia trapped in the lumen at the suture line may initiate clot formation.
After both donor and recipient vessels are prepared, arterial anastomosis is followed by venous anastomosis. End-to-end anastomosis is the most commonly used technique, using appropriately sized monofilament sutures (8–0, 9–0, or 10–0). The end-to-side technique is used when there is a significant size mismatch between vessels (>3:1) or when the internal jugular vein is the recipient vessel. Significant tension should not exist at the suture line and vessels should be sutured to lie without twists or kinks.