Considerations surrounding reconstruction after resection of musculoskeletal sarcomas
ABSTRACT
The defects left by resection of bone and soft-tissue sarcomas often require reconstructive surgery to provide adequate wound coverage, preserve limb function, and optimize cosmetic results. Immediate reconstruction should always be considered after resection with a negative margin, and should be attempted whenever possible. The choice of reconstructive method and tissue flap depends on multiple factors, including body site, donor site morbidity, functional requirements, size of the vascular pedicle, and aesthetics. Preoperative planning before the resection should anticipate the defect size and resulting functional and cosmetic deficits; the success of such planning depends on a collaborative approach between the teams performing the primary resection and the reconstruction. Vigilant postoperative care and flap monitoring is key to avoiding flap or graft failure, hematoma, infection, and other reconstruction-related complications.
POSTOPERATIVE CARE
Postoperative care following reconstruction after sarcoma resection requires a dedicated and trained team, particularly if a free flap is used for reconstruction.
Clinical evaluation of flaps includes color, temperature, and capillary refill. In cases of microsurgical reconstruction, postoperative care should include hourly examination of audible Doppler signals, at least for the first 36 hours. Free flap complications develop primarily in the first 24 hours, but they can occur during initial mobilization of the patient after a long period of bed rest. The surgical team should be aware of the potential problems and be able to act fast if necessary to reestablish blood flow to the flap.
In addition to flap monitoring, immobilization of the patient after surgery is extremely important. Postoperative swelling to the extremity should be avoided. Patients should be placed on bed rest until the postoperative swelling has subsided and the flap has adhered to the wound bed. Our protocol includes strict bed rest for about 7 days, followed by several days of dangling the extremity for short periods to ensure that dependent positioning will not alter the blood supply. A physical therapist should be involved to assist with crutches or a wheelchair. The patient should receive prophylactic anticoagulation during the resting period, in light of the high risk of deep vein thrombosis and pulmonary embolism. A compressive garment should be used to prevent lymphedema.
COMPLICATIONS ASSOCIATED WITH FLAPS
Once the flap is raised, it can still fail as a result of tension at insetting, inadequate blood flow, twisting of the pedicle, hematoma and/or infection, or the patient’s condition (eg, coagulopathy, poor nutritional status, anemia). Failure to correctly evaluate the direction of arterial flow, whether anterograde or retrograde, can cause flap loss. Instruments such as Doppler ultrasonographic equipment can be used to help to determine the flow. Partial or complete occlusion of the vascular pedicle can occur for several reasons (eg, twisting of the pedicle), and the consequences are disastrous if not recognized in time. If a pedicle problem is suspected in the case of a free flap, the patient should be taken to the operating room immediately and the flap should be explored. Rupture of the vascular anastomosis can occur as a result of technical problems, tension, and (in rare cases) infection.
Hematomas can cause mass effect, limit the venous return, and lead to flap necrosis. Hematoma formation also releases free radicals that can contribute to flap necrosis. Prevention is achieved through meticulous hemostasis. If a hematoma is suspected, the wound should be explored and the hematoma evacuated and washed out with normal saline.
The presence of an infected wound bed can also damage a flap by increasing its metabolic demand and causing the flap to be compromised by the infection itself. It is usually best to wait until the infection is controlled before planning the reconstruction.
Partial flap losses, skin graft losses, and wound dehiscence also are possible. Most of the time these require wound care, and patients’ nutrition and general health should be optimized to help the healing process. In the case of partial or complete flap loss, a new flap is often required and should be planned at a proper time.
CONCLUSIONS
Soft-tissue reconstruction following musculoskeletal sarcoma resection can be as simple as allowing the wound to heal by itself, which is less ideal, or as complex as coverage with a microsurgical osteocutaneous free flap. Limb salvage for sarcomas of the lower extremity has demonstrated good final functional outcomes without adversely affecting the oncologic results. Moreover, patients feel better psychologically and have higher quality of life.18,19
We believe that soft-tissue coverage after a wide resection is the most critical factor for avoiding postoperative complications of the tumor resection, such as infection or fractures. For this reason, we recommend the use of well-vascularized coverage at the time of the initial operation, if possible. Careful preoperative planning is especially important. We believe that reconstruction following musculoskeletal sarcoma resection can be done effectively only by using a team approach. Every such team should include, at minimum, an orthopedic surgeon and a reconstructive surgeon, with the mix of other providers dictated by the individual case.
