Saad, Adam M.D.; Winters, Ryan M.D.; Wise, M. Whitten M.D.; Dupin, Charles L. M.D.; St.Hilaire, Hugo D.D.S., M.D.
New Orleans, La.
From the Division of Plastic Surgery, Louisiana State University Health Sciences Center; and the Department of Otolaryngology, Tulane School of Medicine.
Received for publication May 20, 2012; accepted March 19, 2013.
Abstract presented at the 2012 Senior Residents Conference, in Tampa, Florida, January 18 through 21, 2012; the 55th Annual Meeting of the Southeastern Society of Plastic Surgeons, in Amelia Island, Florida, June 2 through 6, 2012; and the 2013 American Society of Reconstructive Microsurgeons Annual Meeting, in Naples, Florida, January 12 through 15, 2013.
Disclosure: The authors have no financial interests to disclose.
Hugo St. Hilaire, D.D.S., M.D., 1542 Tulane Avenue, Room 734, New Orleans, La. 70112, firstname.lastname@example.org
The use of virtual surgical planning for simple immediate mandibular reconstruction has recently been reported.1,2 This technology has the potential to facilitate complicated craniomaxillofacial reconstruction in patients with extensive zones of injury, where native tissue remnants may be compromised by irradiation, multiple surgical entry, or inflammation.3 For these reasons, complex osteocutaneous maxillofacial reconstruction requiring multiple osteotomies, multiple free flaps, and with an extensive zone of injury can be fraught with complications and difficulty.4 Often, the remnants of native mandible or midface are malpositioned, and restoration of the preinjury skeletal anatomy will require manipulation of those segments in addition to restoring resected or destroyed tissue.5
We seek to extend the use of virtual planning to complex maxillofacial reconstruction to simplify the inset of osteocutaneous flaps and to improve the outcomes in these difficult patients. We are presenting our early experience with 10 consecutive patients. Establishment of clinical indications for the use of this methodology, and clinical guidelines, will assist in the identification of patients at risk who may benefit from its application.
PATIENTS AND METHODS
This study was approved by the institutional review board at our institution. A retrospective chart review was undertaken for all patients with complex maxillofacial reconstruction performed at our institution with the use of virtual surgical planning. Charts were reviewed retrospectively, and the initial 10 patients with at least two of the following inclusion criteria were included in the study:
1. Multiple osteotomies required of the osseous flap.
2. Need for multiple simultaneous free flaps.
3. History of osteoradionecrosis or radiation therapy to the head and neck.
4. High-velocity ballistic injury with significant tissue loss.
Appropriate computed tomographic scans of the maxillofacial region and of the donor site of the bone-containing flaps were obtained for all patients. Virtual surgical planning using Synthes Proplan CMF (Synthes GmbH, Oberdorf, Switzerland) was then undertaken with the reconstructive surgeon. The patient’s preinjury native anatomy was restored virtually, and the bone-containing flaps were virtually inset. Jigs and cutting guides were created and plates were prebent using a stereolithic model generated from the preoperative virtual planning. After exposure and preparation of the recipient site, the flaps were harvested and osteotomies were performed using the prefabricated jigs. The prebent plates were inset, followed by the flap(s). Postoperative computed tomographic scans were obtained to evaluate the reconstruction. Postoperative photographs were taken of all patients at approximately 1 year after reconstruction.
Ten consecutive patients who met the inclusion criteria underwent virtual planning and subsequent reconstruction using the prefabricated jigs and plates (Table 1). Six patients had a history of osteoradionecrosis of the mandible requiring resection and reconstruction; three patients had sustained gunshot wounds to the face with loss of skin, soft tissue, and bone; and one had severe osteomyelitis of the mandible requiring total mandibular reconstruction. Six patients underwent free osteocutaneous fibula and additional fasciocutaneous free flap surgery for partial mandibular or maxillary reconstruction, one underwent bilateral free osteocutaneous fibula flap surgery for total mandibular reconstruction, one underwent bilateral free osteocutaneous fibula flap and fasciocutaneous free flap surgery for hemimandible and maxillary reconstruction, and one patient underwent free osteocutaneous fibula flap surgery for mandibular reconstruction. Two patients underwent chimeric flaps, one based on the peroneal artery and the other on the subscapular system, for total maxillary reconstruction. There were a total of six condyle/ramus reconstructions in five patients. There were no intraoperative complications associated with the flap harvest, use of the jigs, or inset of the flap. Postoperative complications included one fasciocutaneous flap loss and one postoperative wound infection. Postoperative computed tomographic scans showed excellent contour of the osseous flaps. There was good adaptation of the plates to the native bone and osseous flaps. All free flaps were viable at 3-month follow-up, and all patients had functional mandibular range of motion.
A 58-year-old man with a history of squamous cell carcinoma of the floor of the mouth had been treated with local resection and postoperative radiation therapy. Approximately 4 years later, he developed osteoradionecrosis, initially treated with hyperbaric oxygen therapy. He subsequently underwent a segmental mandibular resection with fibular free flap reconstruction. This was complicated by exposure of the hardware and loss of the bone component of the flap. On presentation to our clinic, the patient had exposed neomandible and a chronic draining wound from the lateral mandible (Fig. 1). Results of biopsy of the mandible showed osteoradionecrosis with no recurrence of cancer. Extensive radiation damage was present at the affected neck.
The recurrence of the disease was most likely the result of inadequate débridement and resection. It was determined that the patient would require a more extensive resection, including the condyle/ramus unit extending to the contralateral parasymphysis. A free osteocutaneous fibular flap was performed for the bony reconstruction and to reline the floor of the mouth and vestibule. An additional free fasciocutaneous flap would be required to provide stable soft-tissue coverage of the neck. After appropriate computed tomographic scans were obtained, the virtual surgical planning was performed (Fig. 1). The stereolithographic models, jigs, and cutting guides were then created, and the plates were prebent to fit the model. The patient underwent resection and reconstruction with no complications. Postoperative photographs and computed tomographic scans demonstrated good inset and contour of the flaps and appropriate mandibular range of motion (Fig. 1).
A 36-year-old man had sustained a gunshot wound to his anterior maxilla and face. He had subtotal loss of his anterior maxilla and upper lip. He had undergone multiple reconstructive procedures at other institutions in the 5 years since his injury. Reconstructive procedures included multiple nonvascularized bone grafts and two free forearm flaps. On presentation to our clinic, he had a large oronasal fistula and oral incompetence and was unhappy with his aesthetic results (Fig. 2). The preoperative computed tomographic scan demonstrated the lack of a maxilla (Fig. 2). It was determined that the patient would require significant bone for maxillary reconstruction, and skin to separate the oral and nasal cavities. Virtual surgical planning was undertaken using a free fibula osteocutaneous flap (Fig. 2). The reconstructive procedure was performed with no complications. The postoperative computed tomographic scan demonstrated the maxillary reconstruction stabilized with a precontoured mandibular reconstruction plate. Anterior projection of the midface was accomplished with the bony and soft-tissue reconstruction (Fig. 2). The oronasal fistula was repaired with the skin island and the patient is now able to tolerate an oral diet.
A 56-year-old man sustained a self-inflicted shotgun blast to the anterior face (Fig. 3). Computed tomographic scans showed loss of the anterior mandible and maxilla and loss of the inferior orbital rims bilaterally (Fig. 3). After several débridements, there was extensive loss of the skin and subcutaneous tissue of the anterior face. The reconstructive plan included restoration of the inferior orbital rims, maxilla, and mandible to provide a stable framework for soft-tissue reconstruction. Virtual surgical planning was undertaken. It showed that one free osteocutaneous fibular flap would be required to reconstruct the inferior orbital rims and maxilla (Fig. 3). Another free osteocutaneous fibular flap would be required to reconstruct the mandible and mucosal lining of the floor of the mouth (Fig. 3). In addition, another free fasciocutaneous flap would be required to replace the skin and soft tissues of the anterior mandible. The reconstruction of the orbital rims and maxilla was particularly challenging because it required an ostectomy of the fibula while maintaining the vascular pedicle. Estimation of the amount of bone to be removed was facilitated by virtual surgical planning. Postoperative photographs and computed tomographic scans show that the patient now has a stable bony framework with reconstruction of his facial pillars (Fig. 3). This will ensure and facilitate a long-lived nasal and soft-tissue reconstruction that he will undergo in the near future.
Large osteocutaneous defects of the head and neck pose significant challenges to the reconstructive surgeon.5,6 The loss of large sections of native tissue, composed of multiple tissue types, exacerbates the difficulties already present in restoration of form and function to this complex region. The extensive loss of the bony skeleton is particularly difficult to reconstruct.5,6 The facial skeleton provides the platform on which to reconstruct the unique soft-tissue structures of the face. Free flap osteocutaneous reconstruction, especially with the free fibula, allows this platform to be rebuilt; however, it can be difficult to precisely replicate the contour of the bones of the face with the fibula.7 Multiple osteotomies are required to allow the fibula to match the preinury facial skeleton. The difficulty lies is determining exactly where and at what angulation to make the closing osteotomies. In addition, loss or distortion of preinjury anatomy can make it difficult to determine the exact bony requirement for reconstruction.
Because of the loss of normal anatomical landmarks for dissection and reconstruction, and because of suboptimal quality of remaining tissue as a result of irradiation, chronic infection, or ballistic injury, the use of multiple simultaneous free flaps may be required for adequate reconstruction in these patients. The use of multiple free flaps adds time and difficulty to the reconstruction and also carries the added potential for complications.
Virtual surgical planning is an emerging tool wherein high-resolution three-dimensional computed tomographic scans are translated into stereolithographic models that allow fabrication of intraoperative surgical guides and templates preoperatively.8–10 Positive outcomes using this technology are reported in simple, immediate reconstruction, and we sought to extend the utility of this technology to more complex cases.1,2 Use of this technology should allow for more precise estimates on required bony components for reconstruction and for enhancing our ability to make exact osteotomies to better match the contour of the facial skeleton. Based on our initial experience, a set of clinical indications for the use of virtual surgical planning has been devised (Table 2).
The use of this technology in such scenarios offers several advantages. Virtual surgical planning has proven effective in reconstruction of maxillary defects as well, and is particularly suited to situations where both maxilla and mandible need reconstruction.10 Although the use of simultaneous free flaps for massive oromandibular defects has been described, the optimal functional reconstruction of simultaneous maxillary and mandibular defects is not well known.11 When considering two, or even three, simultaneous free flaps for reconstruction of the same area, the precise layout of said flaps is essential, and the ability to virtually see preoperatively how they must be inset greatly facilitates the actual reconstruction.12
In patients with significant loss of domain from prior resection or injury, the preoperative modeling allows restoration of the prior anatomy and positioning of the grafts so that the vascular pedicle is in a favorable position and the skin paddle is oriented intraorally (or otherwise, as desired), thus allowing the surgeon to identify areas in need of additional coverage, often in the form of another flap, preoperatively. This also allows the surgeon to precisely determine the length of the osseous portion of the flap required for adequate reconstruction. When the native anatomy is distorted by trauma or irradiation, the required bony component of the free flap can be underestimated. By restoring the preinjury anatomy using virtual surgical planning, the latter can be avoided. The cutting jigs can be fashioned in such a way as to use the section of fibula with the optimal bone stock to match for remaining native bone. It also decreases the amount of time spent shaping the osseous portion of the flap.1 The cutting jigs and precontoured plates allow for precise cuts to be made and guard against overresection of the native or donor bone.
The use of this technology not only facilitates shaping of the bone-containing flap but also reduces ischemia time. This allows us to perform the contouring under ischemia, on the back table. Nevertheless, the option to perform osteotomies and fasten plates to the graft in situ before dividing the vascular pedicle can shorten ischemia time.8,13,14 Similarly, once the surgeon is familiar with the use of the technology, the learning curve is shortened because the principles of its use are identical from case to case. This should serve to further shorten both ischemic and operative times as the surgeon gains experience and also improve outcomes in these complex reconstructions.
We recognize multiple shortcoming of this retrospective study. To provide stronger support for this emerging technology, a comparative analysis of the outcome would be optimal. Unfortunately, because of the heterogeneity and complexity of the patients presented, a match comparison is virtually impossible.
A cost-effective analysis would be beneficial in establishing stronger indication for virtual surgical planning; however, again because of the heterogeneity of the group, this is not possible. In theory, saving time in the operating room should reduce the overall cost of surgery. This technology allows the case to be more streamlined and should result in shorter cases. The stereolithographic models used in our study are commonplace in craniofacial surgery. They are used in severe trauma cases and in congenital cranial malformations. In our study, their cost ranged from $2500 to $4000. The cutting guides ranged in cost from $400 to $800. We used between two and four guides per case. There is no cost associated with the virtual planning meeting. To minimize the financial burden on the health care system, we follow strict criteria for use of this technology (Table 2).
Despite the lack of definitive data evaluating the financial impact of the use of virtual surgical planning, it is clear to us that this technology simplifies complex reconstruction. We do feel that no price tag can be assigned to predictability and streamlining.
Use of virtual surgical planning allows for complex maxillofacial reconstruction with multiple simultaneous free flaps to be performed reliably and successfully. The use of prefabricated jigs and precontoured plates eases osteocutaneous flap molding and inset to better match the contours of the facial skeleton, allowing for a more complex procedure to be successful.
The patients provided written consent for the use of their images.
This study was funded by the Louisiana State University Health Sciences Center Division of Plastic Surgery.
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