Free Flap Transfer For Head And Neck Reconstruction In Pediatric Patients

This study aims to analyze and identify the factors influencing survival of free flap transfer in pediatric head and neck reconstruction,to evaluate the long-term outcomes and midface symmetry following mandibular reconstruction with vascularized free fibula flap in pediatric patients.This study consists of three parts:Part Ⅰ Free Flap Transfer for Pediatric Head and Neck Reconstruction:What Factors Influence Flap Survival?Objectives:The objective of this study is to identify the factors that influence free flap survival after head and neck reconstructive surgery in pediatric patients.Patients and methods:One hundred thirty consecutive cases of head and neck reconstruction with free flaps in pediatric patients at the Department of Oral and Maxillofacial Surgery at Peking University School and Hospital of Stomatology between 1999 and 2017 were reviewed.The procedures were performed by a single head and neck reconstructive team.Patients’ demographic and surgical patient data with possible associations with free flap survival were recorded.Relevant influencing factors were determined using the univariate analysis and logistic regression analysis.Results:There were 135 free flap transfers performed in 130 patients,with an overall success rate of 95.6%.Free flap failure occurred in 6 flaps(4.4%).Arterial crisis was the main cause of flap failure.The overall complication rate was 10.8%.Patient age(5-9 years old;odds ratio,13.397;95%confidence interval,1.167-153.838;P=0.037)was a statistically significant risk factor influencing free flap survival.Types of free flap,defect region,recipient artery and surgery time were not associated with free flap outcome.Conclusions:Free flap transfer for head and neck reconstruction in pediatric patients is safe and reliable.However,special attention should be paid to pediatric patients under 9 years of age when performing head and neck reconstruction.Part Ⅱ Long-term Outcomes of Pediatric Mandibular Reconstruction Using Vascularized Free Fibula FlapObjectives:The objective of this study is to evaluate the long-term outcomes of mandibular reconstruction with vascularized fibula flap in pediatric patients.Patients and methods:Consecutive cases of mandibular reconstruction with vascularized free fibula flaps in pediatric patients at the Department of Oral and Maxillofacial Surgery at Peking University School and Hospital of Stomatology between 1999 and 2017 were reviewed.Postoperative computed tomography(CT)data of the patients were collected at 1 week,6 months,1 year,2 years,3 years above,and after the age of 18 years.The length and height of the fibula flap and the length of the remaining mandible were evaluated by measuring the three-dimensional CT data using ProPlan CMF 3.0 software at each postoperative follow-up point.Lower limb function was evaluated using the Enneking evaluation scale.Facial symmetry was self-evaluated and scored.Statistical analysis was performed on the data.Results:Twelve patients were included in this study.The male to female rate was 2:1,mean age was 12.3±2.5 years old(range,7-14 years old),and mean duration for follow-up was 81.8±49.0 months(range,40-224 months).All free fibula flaps were successful.There were no other severe complications reported in recipient and donor site.The CT measurement results showed growth in the neomandible reconstructed with fibula flap,the length of the neomandibular ramus and the remaining mandible(P<0.05).The length of the neomandibular body and the height of the fibula flap remained stable(P>0.05).Eight patients were followed up to over 18 years old,and the CT measurement results after 18 years old showed that the profile of mandible was basically symmetrical(P>0.05).All patients were satisfied with their postoperative facial symmetry.Enneking evaluation scores showed good recovery of lower limb functions.Conclusions:Vascularized free fibula flap for mandibular reconstruction in pediatric patients is safe and reliable while providing good cosmetic and functional outcomes as it demonstrated positive growth with the mandible.Part Ⅲ Will the symmetrical growth of the midface be affected after mandibular defects reconstruction with free fibula flap in pediatric patients?Objectives:The objective of this study is to evaluate the symmetry of the midface after pediatric mandibular defects reconstruction with free fibula flap.Patients and methods:Consecutive cases of mandibular reconstruction with vascularized free fibula flaps in pediatric patients at the Department of Oral and Maxillofacial Surgery at Peking University School and Hospital of Stomatology between 1999 and 2017 were collected.Postoperative CT data of the patients were collected at 1 week,6 months,1 year,2 years,3 years above,and after the age of 18 years.Midfacial symmetrical was evaluated by three-dimensional cephalometric using ProPlan CMF 3.0 software at each postoperative follow-up time.The post-operative midface symmetry was compared in horizontal,vertical and sagittal aspects.Paired t test was used for statistical analysis.Results:Nine patients were included in this study.The male to female rate was 2:1,mean age was 12.8±2.2 years old(range,8-14 years old),and mean duration for follow-up was 89.1±55.2 months(range,40-224 months).The CT measurement results showed:there was no statistical in the average distances from Orbitale(Or),Frontozygomatic suture point(Fm),Zygoma(Zy),or Zygomaticomaxillary suture point(Zm)to Mid-Sagittal plane(MSP)between the affected and unaffected side(P>0.05);there was no statistical in the average distances from Pterygomaxillary fissure point(Pt)to Horizontal plane(HP)between the affected and unaffected side(P>0.05);the average distance from Upper first molar point(U6)to HP of affected side was longer than unaffected side from 1 year after surgery(P<0.05);the average distance from Pt to Coronal plane(CP)of affected side was shorter than unaffected side in cases of post-operative 3 years above(P<0.05).Emerging adulthood,the average distance from U6 to HP of affected side was longer than unaffected side,and the average distance from Pt to CP of affected side was shorter than unaffected side(P<0.05),but there was no statistically significant difference between the other two measurement items(P>0.05).Conclusions:Mandibular reconstruction with free fibula flap in pediatric patients can avoid midface deformity to a certain extent.With the cranio-maxillofacial growth and development,the midfacial height of the affected side was slightly increased than that of the unaffected side,the maxillary length of the affected side was slightly reduced than that of the unaffected side,and the midfacial width of the two sides was basically symmetrical.