of them were able to standardize its use. 5-9 Nowadays, the free osteofaciocutaneous fibula flap is considered suitable for short segments of bone def

Transcription

1 Segmental mandible defect reconstruction used to be one of the most difficult tasks in maxillo-facial surgery. Due to particularities of each patient and despite a large variety of surgical techniques available for such cases, the choice of the most suitable method remains an important issue. In the past few years microsurgical techniques are considered the golden standard for mandible reconstruction. One of the best advances in this area is represented by the free fibula transfer. The free fibula flap was developed by Taylor in In 1983 Chen and Yan reported the reconstruction of composite defects by a free fibular osteocutaneous flap, and a year later Yoshimura found that the bone viability may be assessed by skin inspection due to the availability of the septocutaneous branches of the peroneal artery. 2,3 Relatively later after its first introduction, Hidalgo (1989) used the free fibula for reconstruction of mandible defects associated with lesions of the floor of the mouth. 4 Since then the fibula was adopted by various authors and some 43

2 of them were able to standardize its use. 5-9 Nowadays, the free osteofaciocutaneous fibula flap is considered suitable for short segments of bone defects, associated or not with external skin replacement, floor of mouth defects or buccal mucosa defects or for hemi mandible reconstruction. 6,7 Its use is limited only in large through and through defects, where the defects concerns more the soft tissue than the bone. In our center the mandible reconstruction was limited to traditional methods simple bone grafting or titanium splints. Collaboration between oromaxillofacial (OMF) and plastic surgery departments lead us to perform more complex surgeries in order to improve our oncological and functional outcomes. change the preoperative plans. For all the subsequent cases the arteriography became routine. We used exclusively osteofasciocutaneous flaps. The skin paddle was planned without Doppler evaluation of the septocutaneous vessels. In all the cases the donor lower leg was ipsilateral with the defect. The flap dissection was performed under tourniquet through lateral approach. 10 The peroneal vessels were dissected up to their origin. For faithful reconstruction of the mandible profile we applied one to three segmental osteotomies in five cases. All the shaping osteotomies were applied before vascular pedicle sectioning. (Fig.1) Between December 2002 and December 2004 we performed seven free fibula transfers, five in men and two in women. In six cases segmental mandible resection was used for surgical treatment of squamous cell carcinoma of the gum invading the mandible and in the remaining one for treatment of a mandibular central giant cell granuloma. Primary mandibular reconstruction was performed in all cases except one for which a secondary reconstruction was imposed due to an extensive squamous cell carcinoma of the gum with lower lip invasion. In the first operation we performed contiguous mandible bone resection, followed by lower lip extirpation and submental, submandibular and bilateral supra-omohyoid lymph node dissection. Mandible reconstruction was obtained using a titanium splint. Defect of the floor of the mouth was filled using a pectoralis major muscle myocutaneous flap and lower lip reconstruction was achieved with a deltopectoral fasciocutaneous flap. After four years of tumor-free follow-up we decided secondary mandible reconstruction using the free osteo-fasciocutaneous fibula flap. In all the cases we adopted a two team approach plastic and OMF surgeon. While the OMF surgeons performed the head and neck dissection and tumor resection, the plastic surgery team performed the flap dissection, the receptor vessels dissection, and vascular anastomosis. Both teams participated at the bone reshaping and the final closure. The size of the defect (bone and skin) was assessed preoperatively using CT scan (no 3D reconstruction or cast models). In the first three cases we did not perform preoperative arteriography. In the third case we found an anatomical anomaly (the peroneal artery originated in the lower third of the lower leg) which forced us to Three mandibles were immobilized with titanium miniplates and four with titanium reconstructive splints. (Fig. 2) The length of the bone transfer ranged from 4 23 cm. For aesthetical considerations the vascular bone graft was fixed at the inferior border of the mandible in all cases, this being considered one of the main factors for faithful maintenance of the facial shape. 6 44

3 We performed peroneal vessel anastomosis to superior thyroid artery in three cases, facial artery in two cases and lingual artery in two cases respectively. Vein anastomosis was performed to the external jugular veins in four cases and to the thyro-lingofaryngo-facial trunk in three cases respectively. Endto-end vascular anastomosis was used for all patients. All the microvascular anastomosis were performed as previously described under loupes only 4x magnification with 7.0 or 8.0 sutures.11 The patients were hospitalized for three weeks. For the first two weeks feeding was allowed with soft diet through naso-gastric tube. Lower limb was immobilized with a cast for the same period. All the flap transfers were successful. We noted two cases with full skin paddle necrosis; however healing was obtained without the need of a second surgical intervention. For three patients the oncologists used postoperative radiotherapy. (Fig. 3) In the patient who underwent secondary mandible reconstruction, radiotherapy was used as a preoperatory procedure. At 6-48 month follow up, we did not notice any significant difficulty in both feeding and speech in any case. None of the patient received implants for dental rehabilitation. Healing at the donor site proceeded spontaneously for all patients except one case for which it was necessary a secondary skin grafting. We registered no other significant post-surgical morbidity at the donor site (pain, foot instability, fractures). 45

4 46 There are various methods available for reconstruction of segmental mandibular defects: nonvascularized bone grafts, titanium reconstructive splints or microsurgical techniques that allow the use of vascularized bone. Among these modern methods the fibula, iliac crest and the scapular flaps have a certain role in mandible reconstruction. Free rib or radius has only a limited place. First to perform mandible reconstruction using a free fibula transfer was Hidalgo.4 In 1991 he also realized that this technique could be applied for most of the mandible reconstructions.6 Fibula has a double vascularization, both endosteal and periostal. Taylor (1975), and Jones (1988) could not find any viability difference between flaps with or without preserved endosteal vessels.1,12 This aspect is of particular importance, since it makes possible to perform multiple segmental osteotomies without jeopardizing bone viability thanks to its periostal vascularization. Such freedom is very important for mandible shape reconstruction. Fibula free flap is used for mandible defects reconstruction in oncology, osteomyelitis as well as for the treatment of comminuted fractures in selected edentulous patients with severely atrophic mandible There is no length restriction. The 25 cm available exceed the span of any mandible defect to be reconstructed.15 The flap has a long vascular pedicle (up to 8 cm) and vessels have a large caliber (2-3 mm the artery and 3-4 mm the vein). Their caliber allows the loupes only magnification in free transfers in adults.11,16 There are four types of vascular distribution of the peroneal artery: type A - in 90 % of the cases the peroneal artery is branch of the posterior tibial artery; type B (1%) - it arises from anterior tibial artery; type C (1%) - it is a branch of the popliteal artery; type D (8%) it takes the place of the posterior tibial artery.17although some authors do not advocate regular assessment of the lower leg vascularization, this data and our early experience convinced us that arteriography should be mandatory when planning the operation. Moreover, on 52 consecutive patients schedule for fibular flaps Kessler performed angiographic assessment of the arterial blood supply of the foot.18 Only 21 patients had a patent three-vessel supply to both feet. Thirtyone patients (59%) had anatomic and atherosclerotic anomalies. We consider their results as a strong argument for our opinion. Doppler examination might represent a less invasive alternative, but our experience is limited.

5 Fibula is a bone with regular shape and constant thickness along its length and its characteristic segmental blood supply allows a great freedom for the osteotomies number and position. If the osteotomies are performed before the vascular pedicle ligation the ischemia time is shorter and the chances to transfer a viable bone are increasing. We increase the flap dissection and preparing time (3 hours) in the aim to decrease the ischemia time (1 1 ½ hours). Free fibula flap in mandible reconstruction allows a good three-dimensional shaping especially for the mandibular basilar edge. However, the thickness of the fibula bone does not give the liberty of simultaneous reconstruction of both basilar edge and alveolar bone. If this aspect is less important for elderly edentulous patients, for patients having normal dentition the absence of alveolar bone has the consequence of no mechanical support for the lower lip or the soft tissues of the jugal region. 19 There are several procedures specially developed to overcome the lack of alveolar bone that leads to facial asymmetries due to lip or cheek ptosis on the operated side. Jones used a double fibular flap ( double barrel ) folded in such a way to allow reconstruction of both basal mandibular edge as well as alveolar bone. 12 The main disadvantage is the fact that the fibular fragment is too voluminous with respect to alveolar bone reconstruction needs. In this way the bone may fill the vestibular cul-de-sac and induce ulcerations. To overcome these problems, Lee obtained alveolar bone reconstruction using a vascularized fibular segment to reconstruct the inferior basal portion of the neomandible, while a non-vascularized residual fibular segment was used to simulate the superior alveolar portion. 19 The double barrel - type flap is not suitable for multiple mandible osteotomies; this disadvantage disappears for non-vascularized fibular bone flaps. To obtain a corresponding height of fibular bone Chiapasco proposes bone distraction. 20 Although we do not have experience in children, the flap is reported as fast and very efficient in remodeling of the transplanted bone. Captier considers that there is no low age limit for the use of free fibula. 21 Although our experience is limited it is our belief that, whenever possible, is better to keep the mandible head, this allowing for an optimal maintenance of the temporomandibular joint function. When mandibular condyle has to be removed, Sieg considers as a better option the inclusion of proximal fibular condyle for temporo-mandibular joint reconstruction. 22 However, due to the fact that fibular condyle is bigger than the mandibular one, this technique is suitable only for primary reconstructions, the appearance of fibrosis making difficult to accommodate the condylian head inside the glenoid fossa during secondary procedures. Moreover, in order to assure fibular head viability we have to consider that the vascularization of the proximal peroneal epiphysis and of the proximal two thirds of the diaphysis is from the anterior tibial artery, and one needs another approach in flap dissection. 23 One of the most important issues in our experience was the type of the bone fixation. While the plastic surgeons preferred the miniplates, the OMF surgeon favored the reconstruction plates. The miniplates are easy to manipulate and offer an easy and safe fixation. However, especially in anterior mandibular defects, it is difficult to maintain the occlusal plane as requested by the OMF Surgeon. Finally, in order to maintain the occlusal relation we used the reconstruction plates. These were molded over the mandible before the segmental resection in order to obtain the accurate template for the shape. The plate is taken to the donor leg for fibular bone shaping and fixation. Finally the complex bone-template is transferred and fixed to the mandible according to the previous plan. (Fig 4) The fibula has enough thickness and resistance to allow dental implants. However in our series none of the patient was interested in further improving the functional outcome. Team approach is the keystone of our management. (Table 1) 47

6 While the OMF surgeons performed the head and neck dissection and tumor resection, the plastic surgery team performed the flap dissection, and vascular anastomosis. Both teams participated in osteotomies and bone fixation. A special comment deserves the preparation of the vessels in the receptor area. Apart from the neck dissection the final vascular preparation should be performed either by the surgeon who is doing the vascular anastomosis or by a team trained in appropriate vascular preservation and handling. The free fibula osteofasciocutaneous free flap tends to become the standard option for mandible reconstruction in our experience. All types of defects are suitable: tumor excision, pot traumatic defects, and osteomyelitis and post radiotherapy defects. The foreseen advantages are the possibility to perform wide and safe resection and the better functional outcome. The associated morbidity at the donor site is minimal and the technique gives the opportunity of two-team approach. Medium term results were satisfactory in all cases, both from oncological and aesthetic point of view. Mandible shape reconstruction was obtained using titanium reconstruction plates. More refinements have to be added of our technique. First, we have to eliminate the cases with skin paddle necrosis; secondly, we have to find the most suitable solution for alveolar bone reconstruction; and thirdly, we have to shorten the operative time by a better preoperative evaluation. 1. Taylor GI, Miller GD, Ham FJ. The free vascularized bone graft: a clinical extension of microvascular techniques. Plast Reconstr Surg 1975;55: Chen ZW, Yan W. The study and clinical application of the osteocutaneous flap of fibula. Microsurgery 1983;4: Yoshimura M, Imura S, Shimamura K, et al. Peroneal flap for reconstruction in the extremity: preliminary report. Plast Reconstr Surg 1984;74: Hidalgo DA. Fibula free flap: A new method of mandible reconstruction. Plast Reconstr Surg. 1989;84: Wei FC, Chen HC, Chuang CC, et al. Fibular osteoseptocutaneous flap: anatomic study and clinical application. Plast Reconstr Surg. 1986;78: Hidalgo DA. Aesthetic improvements in free-flap mandible reconstruction. Plast Reconstr Surg. 1991;88: Hidalgo DA. Fibula Free flap in mandible reconstruction. Microsurgery 1994;15: Chen YBT, Chen HC, Hahn LH. Major mandibular reconstruction with vascularized bone grafts: indications and donor tissue. Microsurgery 1994;15: Yang KC, Leung JKW, Chen JS. Double paddle peroneal tissue transfer for orormandibular reconstruction. Plast Reconstr Surg. 2000;106: Wei FC, Seah CS, Tsai YC, et al. Fibula oseteoseptocutaneous flap for reconstruction of composite mandibular defects. Plast Reconstr Surg 194;93: Pieptu D, Luchian S. Loupes-only microsurgery. Microsurgery 2003;23: Jones NF, Swartz WM, Mears DC, et al. The double-barrel free vascularized fibular bone graft. Plast Reconstr Surg. 1988;81: Lemière E, Maes JM, Raoul JM, et al. Ostéomyélite mandibulaire diffuse chronique. Rev Stomatol Chir Maxillofacial. 2000;101: Zide MF, Ducic Y. Fibula microvascular free tissue reconstruction of severely comminuted atrophic mandible fracture - case report. J Cranio-Maxillofac Surg. 2003; 31: Cordeiro PG, Disa JJ, Hidalgo DA, et al. Reconstruction of the mandible with osseous free flaps: a 10-year experience with 150 consecutive patients. Plast Reconstr Surg. 1999;104: Serletti JM, Deuber MA, Guidera PM, et al. Comparison of the operating microscope and loupes for free microvascular tissue transfer. Plast Reconstr Surg. 1995;95: Strauch B, Yu H-L. Atlas of microvascular surgery. Thieme Medical Publishers, New York 1993, p Kessler P, Wiltfang J, Schultze-Mosgau S, et al. The role of angiography in lower extremity using free vascularized fibular transplants for mandible reconstruction. J Cranio Maxillofac Surg. 2001;33: Lee JH, Kim MJ, Choi WS, et al. Concomitant reconstruction of mandibular basal and alveolar bone with a free fibular flap. Int J Oral Maxillofac Surg 2004;33: Chiapasco M, Brusati R, Galioto S. Distraction osteogenesis of a fibular revascularized flap for improvement of oral implant positioning in a tumor patient: a case report. J Oral Maxillofac Surg 2000;58: Captier G, Montoya P, Duche E, et al. Synovialosarcome de la mandibule chez l enfant. Rev Stomatol Chir Maxillofac. 1999;100: Sieg P, Zieron JO, Bierwolf S, et al. Defect-related variations in mandibular reconstruction using fibula grafts. A review of 96 cases. Brit J Oral Maxillofac Surg 2002;40: Taylor GI, Wilson KR, Rees MD, et al. The anterior tibial vessels and their role in epiphiseal and diapyseal transfer of the fibula: experimental study and clinical applications. Br J Plast Surg 1988;41: