ORN is a severe complication of head and neck cancer treatment that requires prompt recognition, surgical intervention and appropriate antibiotic management. Microvascular free flap reconstruction is an essential component of ORN treatment.
Surgical repair of ORN tissue poses challenges including preoperative radiation-induced tissue fibrosis, bacterial colonization and intimal fibrosis of vascular anastomosis. Postoperative complications include infection, fistula formation and exposure of hardware.
Surgical Technique
Osteoradionecrosis of the jaws is a serious late side effect in patients with head and neck cancer treated by radiation therapy (RT). When left untreated, it may lead to severe complications such as exposed necrotic bone with painful ulceration, perioral infection and mastication or swallowing difficulties.
Aggressive surgical resection and immediate reconstruction using free flaps are recommended as the standard of care to prevent progression of ORN to later stages. However, free flap reconstruction of advanced ORN is challenging due to the hostile surgical environment with necrotic bone, fibrosis and infection and a limited number of suitable vessels for anastomosis.
To overcome these limitations, we have developed a comprehensive approach for managing complex ORN defects including segmental mandibulectomy, microsurgical reconstruction with fibular free flap and oral rehabilitation with dental implants to restore mastication, swallowing and speech functions.
Our results demonstrated that free flap reconstruction of advanced ORN can be performed safely in a variety of flap configurations. A new classification scheme to aid in defect selection was also developed.
We have found the fibular free flap to be a particularly useful technique for reconstructing ORN and MRONJ defects because it offers sufficient bone length and good soft tissue coverage to restore oral function and mastication. In addition, the pedicle length of this flap is sufficient to reach the transverse cervical vessels in most cases for anastomosis.
However, ORN patients present unique challenges to free flap surgery including a hostile surgical environment with vascular compromise from radiation damage and a contaminated surgical field with debris and bacteria. Additionally, the recurrence of neoplasm is a constant concern in these patients. The use of antibiotics to treat postoperative infections in these patients is critical and requires careful consideration. Because culture results frequently do not grow typical polymicrobial anaerobic oral flora, antibiotics should be changed to those that are effective against the specific organisms growing in the wound. This will require close cooperation between the oral surgeon and infectious medicine department. In the right hands, this approach can be successfully implemented and lead to satisfactory outcomes.
Donor Site Selection
The donor site is an important consideration for patients undergoing free flap microsurgery. Morbidity at the anatomical location from which tissue is harvested can result in physical complications and negatively impact patient quality of life (QoL).
The extent of morbidity varies depending on the anatomical site and flap type used. This is due to the varying anatomy and vascular supply of the different anatomical sites and flap types, resulting in different changes in objective function.
During free flap surgery, the surgeon should ensure the viability of the underlying bone by inspecting the periosteum for any necrotic or non-viable areas of bone. The periosteum is a dense fibrous membrane with a rich vascular supply, and it provides nutrients to the outer cortex of the bone. This prevents the avascular necrosis that can occur in osseous defects.
In addition, virtual surgical planning (VSP) has been shown to improve flap alignment resulting in a decrease in rates of malunion or nonunion and subsequent hardware extrusion. VSP also assists in determining the appropriate plate size and shape, reducing operative time. This can be accomplished by using software that creates patient-specific cutting guides and plates that match the dimensions of healthy bone, thereby improving osseointegration and preventing sequalae.
Virtual Surgical Planning
VSP is a computer-based method for surgical planning in craniomaxillofacial surgery, which involves the skull and facial bones. It allows surgeons to plan their surgeries in more detail and improve the results of these procedures.
VSP combines several technologies, including medical imaging, 3D modeling and manufacturing, computer-assisted design and 3D printing, and predictive modeling. These techniques help surgeons optimize their surgical plans and create customized instruments and equipment. In addition, they can also assist with the diagnosis and treatment of conditions such as congenital malformations or traumatic injuries.
This process begins with the clinical evaluation of the patient. Next, the patient’s data is transferred to a 3D computer model. This data is used to generate articulated casts and 3D models of the patients’ anatomy. These models are used to perform model surgery and to prepare for the actual procedure. Finally, the surgeon can use these models to develop a plan for the implant placement.
Virtual surgical planning can be used for a variety of surgical procedures, but it is most commonly used in orthognathic surgery to treat jaw deformities. It can help to improve the symmetry of the facial structure and decrease the amount of adjustment needed during the postoperative period. It can also be used to diagnose and plan for other types of orthodontic treatment.
While VSP is an effective tool, it does have some limitations. First, it can be time-consuming and expensive. Surgeons may need to take several images of the patient, and the software can take a while to process the data and produce accurate models. In addition, surgeons must carefully select landmarks to ensure that their data are aligned properly.
A newer type of VSP called prediction-based surgical planning addresses some of these problems. This approach uses a closed loop architecture, which enables the surgeon to use predictive models to assist with decision making. This can reduce the time required for VSP and improve the accuracy of the outcome.
Despite these limitations, virtual surgical planning is still a powerful tool for improving surgical outcomes and the efficiency of craniomaxillofacial operations. As a result, it should be considered by every surgeon who performs these types of procedures.