Reconstruction with fibular osteocutaneous free flap in patients with mandibular osteoradionecrosis

Outcomes of free flap reconstruction for mandibular ORN: Systematic review and meta-analysis

OBJECTIVE

This study aims to evaluate the success rates and complications associated with different free flap donor sites used in surgical reconstruction for mandibular osteoradionecrosis, providing insights to aid clinical decision-making.

DATA SOURCES

MEDLINE, Embase, Cochrane, and Web of Science.

REVIEW METHODS

Comprehensive database searches were conducted up to October 2023. Three independent reviewers screened articles per PRISMA guidelines. This review is registered with PROSPERO (CRD42023456929). Meta-analysis, using inverse variance statistical method and a random effects model, was performed with OpenMeta software (Version 10.12, Brown University, USA). Study quality was assessed via the methodological index for non-randomized studies (MINORS).

RESULTS

Nineteen full-text articles met inclusion criteria, encompassing 397 patients and 424 free flap procedures. Patients averaged 54.8 years old; 27.5 % were female. Squamous cell carcinoma was the main radiation indication (83.1 %). Flap types included fibula (63 %), iliac crest (36 %), scapula (3.7 %), and radial forearm (3.5 %). Symptoms of osteoradionecrosis appeared on average four years post-radiation therapy, with a mean dose of 6346 cGy. Pooled postoperative complication rate was 22.5 % (95 % CI 0.165-0.284, I2:48%). Radial forearm flaps had the lowest complication rate (13.5 %, 95 % CI 0.026-0.295, I2:0%), while scapula flaps had the highest (34.9 %, 95 % CI 0.039-0.66, I2:40.3 %). Fibula flaps had the lowest failure rate (3.3 %, 95 % CI 0.003-0.025, I2:0%), while iliac crest flaps had the highest (11.9 %, 95 % CI 0.022-0.260, I2:60.4 %).

CONCLUSION

The fibula is the preferred flap for mandibular reconstruction due to its low failure rate. Radial forearm flaps show the fewest complications. More robust, multi-institutional prospective studies are needed.

Is immediate dental implant in fibula free flap beneficial for implant survival and osteoradionecrosis in jaw reconstruction?

OBJECTIVES

This study aimed to compare the risk of osteoradionecrosis and implant survival in oral cancer patients undergoing immediate dental implants during jaw reconstruction, termed "Jaw in a Day" (JIAD), with those receiving no implants or delayed implants (non-JIAD).

PATIENTS & METHODS

Clinicopathologic data were collected from prospectively enrolled JIAD patients (n = 10, 29 implants) and retrospectively from non-JIAD patients (n = 117, 86 implants). Survival analyses were performed to assess implant survival and osteoradionecrosis-free survival.

RESULTS

Osteoradionecrosis occurred in 0 % of JIAD cases compared to 19.3 % in non-JIAD cases without implants and 71.4 % in non-JIAD cases with delayed implants (p = 0.008). Osteoradionecrosis-free survival was significantly better in the JIAD group than the non-JIAD group (p = 0.0059). Implants in the JIAD group all survived regardless of radiation therapy (29/29, 100 %) and 95.1 % (58/61) of implants survived in delayed implants in non-irradiated fibula without radiotherapy. Meanwhile, only 11 of 25 implants placed in irradiated fibula flaps survived, even when the implants were placed after a median time interval of 624 days after radiotherapy, and none of them were earlier than 360 days. The survival analysis revealed a significant difference (p < 0.0001).

CONCLUSION

JIAD appears to offer superior outcomes in terms of implant survival and osteoradionecrosis prevention compared to delayed implant placement. Placing implants in irradiated fibula, even after years, significantly poses high risk of implant failure and osteoradionecrosis. JIAD represents a promising approach for optimal rehabilitation, particularly in oral cancer patients requiring postoperative radiotherapy. Proper positioning and orientation of implants and flaps are crucial for implant survival.

Prevention and Management of Osteoradionecrosis in Patients With Head and Neck Cancer Treated With Radiation Therapy: ISOO-MASCC-ASCO Guideline

PURPOSE

To provide evidence-based recommendations for prevention and management of osteoradionecrosis (ORN) of the jaw secondary to head and neck radiation therapy in patients with cancer.

METHODS

The International Society of Oral Oncology-Multinational Association for Supportive Care in Cancer (ISOO-MASCC) and ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. PubMed, EMBASE, and Cochrane Library databases were searched for randomized controlled trials and observational studies, published between January 1, 2009, and December 1, 2023. The guideline also incorporated systematic reviews conducted by ISOO-MASCC, which included studies published from January 1, 1990, through December 31, 2008.

RESULTS

A total of 1,539 publications were initially identified. There were 487 duplicate publications, resulting in 1,052 studies screened by abstract, 104 screened by full text, and 80 included for systematic review evaluation.

RECOMMENDATIONS

Due to limitations of available evidence, the guideline relied on informal consensus for some recommendations. Recommendations that were deemed evidence-based with strong evidence by the Expert Panel were those pertaining to best practices in prevention of ORN and surgical management. No recommendation was possible for the utilization of leukocyte- and platelet-rich fibrin or photobiomodulation for prevention of ORN. The use of hyperbaric oxygen in prevention and management of ORN remains largely unjustified, with limited evidence to support its practice.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

Prevalence of free flap failure in mandibular osteoradionecrosis reconstruction: a systematic review and meta-analysis

Our study aimed to estimate the prevalence of total free flap failure following free flap reconstruction for mandibular osteoradionecrosis (mORN) and assess the impact of potential moderators on this outcome. A comprehensive systematic literature search was independently conducted by two reviewers using the Medline, Scopus, Web of Science and Cochrane Library databases. Quality assessment of the selected studies was performed, and prevalence estimates with 95% confidence intervals (CI) were calculated. Outlier and influential analyses were conducted, and meta-regression analyses was employed to investigate the effects of continuous variables on the estimated prevalence. Ultimately, forty-six eligible studies (involving 1292 participants and 1344 free flaps) were included in our meta-analysis. The findings of our study revealed a prevalence of 3.1% (95% CI 1.3-5.4%) for total free flap failure after reconstruction for mORN. No study was identified as critically influential, and meta-regression analysis did not pinpoint any potential sources of heterogeneity. These findings provide valuable insights for researchers and serve as a foundation for future investigations into the management of mandibular osteoradionecrosis and the prevention of free flap failure in this context.

Development of an experimental model for radiation-induced inhibition of cranial bone regeneration

Background

Radiation therapy is widely employed in the treatment of head and neck cancer. Adverse effects of therapeutic irradiation include delayed bone healing after dental extraction or impaired bone regeneration at the irradiated bony defect. Development of a reliable experimental model may be beneficial to study tissue regeneration in the irradiated field. The current study aimed to develop a relevant animal model of post-radiation cranial bone defect.

Methods

A lead shielding block was designed for selective external irradiation of the mouse calvaria. Critical-size calvarial defect was created 2 weeks after the irradiation. The defect was filled with a collagen scaffold, with or without incorporation of bone morphogenetic protein 2 (BMP-2) (1 μg/ml). The non-irradiated mice treated with or without BMP-2-included scaffold served as control. Four weeks after the surgery, the specimens were harvested and the degree of bone formation was evaluated by histological and radiographical examinations.

Results

BMP-2-treated scaffold yielded significant bone regeneration in the mice calvarial defects. However, a single fraction of external irradiation was observed to eliminate the bone regeneration capacity of the BMP-2-incorporated scaffold without influencing the survival of the animals.

Conclusion

The current study established an efficient model for post-radiation cranial bone regeneration and can be applied for evaluating the robust bone formation system using various chemokines or agents in unfavorable, demanding radiation-related bone defect models.

Identification of predisposing factors for osteonecrosis of the jaw after marginal mandibulectomy in the surgical management of oral squamous cell carcinoma

BACKGROUND

The aim of this study is to evaluate osteonecrosis of the jaw (ONJ) with the extent of marginal mandibulectomy.

METHODS

Between January 2006 and December 2012, 3087 patients undergoing ablative resection were consecutively enrolled. Among them, 345 cases undergoing marginal mandibulectomy were retrospectively reviewed.

RESULTS

The occurrence of ONJ was 5.51% and associated with body mass index, overall stage, diabetes, concomitant mandibulotomy, and radiotherapy (P = 0.023, 0.033, 0.009, 0.016, and 0.006, respectively). As for bone parameters based on radiological measurements after marginal mandibulectomy, resected bone height, remaining bone height to original bone height ratio, and resected bone height to original bone height ratio were associated with ONJ. In multivariate logistic analyses, concomitant mandibulotomy, radiotherapy, diabetes, resected bone height of >14.5 mm, resected bone height to original bone height ratio of >49.5%, and remaining bone height to original bone height ratio of <53.5% indicated higher risks for ONJ (adjusted HR: 4.345, 4.152, 4.079, 3.402, 3.541, and 3.211; P = 0.018, 0.013, 0.009, 0.021, 0.018, and 0.043, respectively).

CONCLUSIONS

This study demonstrated the predisposing factors and parameters associated with ONJ with marginal mandibulectomy; more caution is necessitated in performing marginal mandibulectomy in patients with multiple risks to prevent ONJ.