Heterotopic Ossification of the Vascular Pedicle after Maxillofacial Reconstructive Surgery Using Fibular Free Flap: Introducing New Classification and Retrospective Analysis

Pedicle ossification after fibular flap reconstruction of maxillary defects: A case report and literature review

Key Clinical Message

The phenomenon of vessel pedicle ossification is a noteworthy aspect of the repair and reconstruction of maxillofacial defects. Imaging findings typically reveal high-density shadows within the vascular pedicle pathway, which may be managed through conservative observation or surgical intervention as deemed appropriate.

Abstract

Vessel pedicle ossification is a relatively uncommon complication associated with the reconstruction of oral and maxillofacial tissue defects using free tissue flap repair. In this paper, we report a case of pedicle ossification and conduct a comprehensive review of previous literature. A 39-year-old man presented with a limited ability to open his mouth 6 months after fibular flap reconstruction of the mandible. Plain film X-ray and computed tomography (CT) indicated pedicle ossification. Two years after the initial operation, the restriction in the patient's ability to open his mouth had not worsened, although there were more pronounced radiographic abnormalities.

Heterotopic Ossification After Reconstruction with Free Fibula Flap - an Ambiguous Mishap

Heterotopic ossifications (HO) are rare, yet, well reported complications after free flap transfer. We present a case of HO that occurred within a month, and has not been previously described in the literature. This serves as a reminder that bony hard swellings proximal to the free flap within a month should raise the suspicion of HO.

Complete Extensive Heterotopic Ossification of the Entire Free Fibula Flap Vascular Pedicle in Maxillary Reconstruction

INTRODUCTION

Heterotopic ossification is a pathologic extra-skeletal bone formation as a form of aberrant repair process with acquired or genetic etiologies. In plastic surgery, it has been well-described in the burn and trauma patients. Rarely, it can happen along the vascular pedicle of free tissue transfer, and when it happens, it is most commonly in head and neck reconstruction.

CASE PRESENTATION

Here we present a case of complete extensive heterotopic ossification of the entire vascular pedicle from the anastomosis to the bone in an osteocutaneous free fibula flap (FFF). The fibula was used as a 2-segment reconstruction for a maxillary defect resulting from a self-inflicted gunshot wound. The skin paddle was used to reconstruct the anterior palatal defect.

DISCUSSION

Heterotopic ossification of the FFF vascular pedicle is most reported in the head and neck reconstruction cases. It is rare, but when it happens, it occurs earlier, more commonly, and more extensively in cases of maxillary reconstruction than in cases of mandibular reconstruction. Flap loss due to this sequela has not been reported, and surgical debridement is indicated only when symptomatic.

CONCLUSION

Heterotopic ossification of an FFF vascular pedicle is a rare but well-described entity. The periosteal bone formation capacity preservation after revascularization of the flap is thought to be one of the major etiologies of this phenomenon. Hence, some have suggested a modification in the harvesting technique of the FFF that could mitigate return to the operating room, especially when it is for maxillary reconstruction in the trauma patient. Keywords: Keywords: free fibula flap, heterotopic ossification, maxillary reconstruction, mandibular reconstruction.

Stylomandibular False Ankylosis: An Unusual Complication After Vascularized Iliac Crest Flap for Mandibular Reconstruction

Stylomandibular fusion is a poorly documented and rare complication of maxillofacial surgical procedures. This case report describes a patient presenting with stylomandibular false ankylosis following mandibular reconstruction. A 59-year-old female patient underwent segmental mandibular resection and reconstruction for a defect resulting from ameloblastoma surgery using an iliac crest free flap. A styloid fracture was detected postoperatively, and the patient was managed conservatively. In the third postoperative year, the patient presented with marked limitation of oral gape. A diagnosis of stylomandibular false ankylosis was made, and the patient underwent an ostectomy of the aberrant bone, with improved mouth opening. The abnormal union between the styloid process and the mandible is a previously unreported complication in the use of iliac crest free flaps. This case report emphasizes the importance of being vigilant for stylomandibular false ankylosis, especially when there is a restriction of oral aperture postoperatively following reconstructive procedures involving bone flaps.

Classification of pedicle ossification after maxillofacial reconstruction with bony free flap: An observational study

INTRODUCTION

Maxillofacial reconstruction with bony free flap is a classical technique. However, pedicle ossification after such reconstruction is a misunderstood complication that is rarely reported in the literature. It is usually manifested as trismus, neck pain, and hard swelling, but it is predominantly asymptomatic and, thus, mainly incidentally discovered at a later stage. The aim of our study is to propose a classification for pedicle ossification based on both radiological features and vascular calcification progression. We also describe a case of metachronous ossification after two fibula free flap procedures.

MATERIAL & METHODS

Our observational study includes all patients from our unit who underwent maxillofacial reconstruction with bony free flap from 2003 to 2018. We collected all cases of pedicle ossifications identified during the follow-up and described the radiological status of each one to categorise them in different groups and propose a classification scheme for the same.

RESULTS

Radiological and histological analysis showed a progressive three-step evolution of pedicle ossification, starting from the media, progressing into the lumen, and then reaching completion in the extravascular region. The final stage was observed in all symptomatic patients.

CONCLUSION

Pedicle ossification is a progressive process that passes through three successive histological stages that may be associated with factors such as smooth muscle cell phenotype modification [1]. This complication may lead to more severe clinical symptoms and may require surgery for removal of the calcification.

Partial and Total Flap Failure after Fibula Free Flap in Head and Neck Reconstructive Surgery: Retrospective Analysis of 180 Flaps over 19 Years

Fibula free flap (FFF) is widely used in head and neck reconstructive surgery and is considered as a standard and therapy of choice after ablative cancer surgery. The aim of this retrospective monocenter study was to determine the success rates of fibula free flaps for jaw reconstruction after ablative tumor surgery. The disease course of patients who underwent jaw reconstructive surgery with FFF from January 2002 to June 2020 was evaluated regarding the flap success rate. Flap failure was analyzed in detail and categorized into two groups: partial flap failure (PFF) and total flap failure (TFF). A total of 180 free fibular flaps were performed over the last 19 years and a total of 36 flap failures were recorded. TFF occurred in n = 20 (56.6%) and PFF in n = 16 cases (44.4%) cases. No statistically significant differences were found concerning patients' age at flap transfer, sex, BMI, ASA-Score, preoperative non-virtual or virtual surgical planning (non-VSP vs. VSP), and time of reconstruction (immediately vs. delayed). Duration of hospitalization shows statistically significant differences between both groups (p = 0.038), but no differences concerning operating time and duration on Intensive Care Unit (ICU). Partial flap failure appears to be underreported in literature. Sub- and complete failure of the skin paddle leads to clinical complaints like uncovered bone segments and plate exposure. Partial or complete FFF failure lead to infections on the recipient site and prolonged wound healing and therefore may cause a delay of the beginning of adjuvant radiation therapy (RT). PFF of hard tissue can be induced by RT.