Survival of vascularized osseous flaps in mandibular reconstruction: A network meta-analysis

Vascularized iliac crest free flap in maxillofacial reconstruction: Pearls and pitfalls from 437 clinical application

OBJECTIVE

The vascularized iliac crest free (VICF) flap has been a cornerstone in maxillofacial reconstruction for decades. This study aims to provide a framework for guiding and managing maxillofacial reconstruction using the VICF flap, highlighting key techniques and potential pitfalls to optimize outcomes and reduce practice variability.

METHODS

A retrospective review was conducted on 437 patients (439 flaps) who underwent maxillofacial reconstruction with VICF flaps. The study summarized current practices, challenges, and strategies for successful flap application. Data were collected from electronic medical records and postoperative follow-ups.

RESULTS

The overall success rate of VICF flap transplantation was 98.4 %. Of the 439 VICF flaps, 37 were myo-osteocutaneous, 47 were myo-osseous, and 355 were osseous. Computer-assisted techniques (CATs) were used in 64.5 % (282/437) of cases. The average University of Washington Quality of Life score was 83.38, and the Harris Hip Score averaged 93.34. The incidence of serious complications was low, with 6 % (17/285) of patients reporting moderate-to-severe pain and 8.4 % (24/285) experiencing incisional hernia. Additionally, 11.9 % (34/285) of patients have completed implant-supported restoration.

CONCLUSION

VICF flaps offer significant morphological advantages and ample bone quantity for reconstruction; however, they are associated with some postoperative complications. With advancements in CAT and the application of chimeric perforator flaps, VICF can be successfully used to address most maxillofacial defects, including those caused by benign and malignant tumors in the neck, especially in cases with good vascular supply.

Learning curve in mandibular reconstruction with vascularized iliac crest free flap: a cumulative sum analysis

The repair of mandibular defects is challenging due to the functional and structural complexity of the mandible. The aim of this study was to evaluate the learning curve of mandibular reconstruction using a vascularized iliac crest free flap (ICFF) performed by a single surgeon. This retrospective study used the cumulative sum (CUSUM) method to analyse the operation times of 60 patients who underwent mandibular reconstruction surgery with an ICFF between 2013 and 2022. The results showed that the learning curve could be divided into two phases according to the turning point: phase 1 comprised cases 1-17 and phase 2 comprised cases 18-60. The operation time and length of hospital stay were significantly longer in phase 1 than in phase 2, while there was no significant difference in the flap failure rate or follow-up outcomes between the two phases. In summary, the learning curve of mandibular reconstruction with an ICFF stabilized after approximately 17 cases.

Training of Oral and Maxillofacial Surgery Residents in Virtual Surgical Planning: A Feasibility Study Comparing Open-Source Freeware and Commercially Available Software for Mandibular Reconstruction with Fibula Free Flap

Study Design: This is an experimental feasibility study. Objective: The objective was to analyze the potential of open-source freeware (OSF) to train residents in virtual surgical planning (VSP) and compare this workflow with commercially available software (CAS). Methods: A workflow for mandibular reconstruction with a fibular free flap (FFF) was developed in 3D-Slicer® and Blender® and compared to our clinical workflow in Materialise Mimics Innovation Suite version 25 (Materialise InPrint®, ProPlan CMF® and 3-Matic®). Five CMF residents, inexperienced in VSP, were trained to use both the OSF and CAS workflows and then performed four planning sessions on OSF and CAS. The duration (minutes) and the amount of mouse clicks (MCs) of every step in the workflow were recorded. Afterwards, the experience with VSP was investigated with the System Usability Scale (SUS) and a self-developed questionnaire. Results: The total VSP time with CAS took 91 ± 15 min and needed 2325 ± 86 MCs compared to 111 ± 26 min and 1876 ± 632 MCs for OSF, respectively. The questionnaire had an 80% response rate. The SUS for CAS was 67.5 compared to 50 for OSF. The participants believe it is extremely valuable to learn VSP during their training and to be able to perform VSP as a surgeon. Conclusion: We believe OSF can be a cost-effective alternative compared to CAS for the training of surgical residents to gain insight in complex surgeries and to better understand CAD limitations and possibilities.

An Innovative Methodology: The Submental Island Flap Offers Enhanced Soft Tissue Coverage to the Vascularized Iliac Crest Flap

The vascularized iliac crest flap has garnered widespread acclaim within the field of mandibular reconstruction attributable to its sufficient bone mass and congruent curved morphology. However, when the precise orientation of the iliac crest is imperative during mandibular reconstruction and there exists an accompanying defect within the oral soft tissue, the indispensability of an additional flap to facilitate concurrent defect repair becomes evident. In such instances, the submental island flap emerges as an exemplary candidate.

Delayed reconstruction of the combat-related mandibular defects with non-vascularized iliac crest grafts: Defining the optimal conditions for a positive outcome in the retrospective study

BACKGROUND

Reconstruction of mandibular defects caused by combat injuries is challenging for clinicians due to soft tissue defects and high complication risk. This study evaluated the outcomes of mandibular continuous defects reconstruction with non-vascularized iliac crest graft (NVICG) in patients with combat injuries.

MATERIAL AND METHODS

Patients with continuous mandibular defects acquired by high-velocity agents, who received NVICG reconstruction with or without microvascular-free soft tissue or regional flaps, were included in the study. The outcome variable was graft loss due to postoperative complications or full (more than 90 %) resorption. The primary predictor variable was soft tissue defect in the recipient area. The secondary predictor variable was the length of the defect. Variables related to patients, defect site, surgery, and other complications were also evaluated. Statistical analysis was performed with the usage of independent sample t-test, Pearson's chi-squared and Fisher's exact tests with a significance level of P < 0.05 RESULTS: The study included 24 patients with 27 mandibular defects. Overall, the general success rate of reconstructions was 59.3 %. Soft tissue defects were significantly associated with graft failure and other complications (p < 0.05), which were mostly related to soft tissue defects. The graft success rate was only 14.3 % even in minor soft tissue defects. In turn, in reconstructions with sufficient soft tissue coverage, the graft survived in 75.0 % of the cases. In addition, patients with more delayed reconstruction had significantly fewer graft failures than those with earlier surgery (p < 0.05). No associations were found between defect size and complications.

CONCLUSION

The sufficient soft tissue coverage is essential in the reconstruction of mandibular defects caused by combat injuries. Also, minor soft tissue defects should be covered with soft tissue flaps to avoid complications and graft loss in these specific injuries. Even large defects can be reconstructed with NIVICG if the soft tissue coverage is sufficient.

In vivo endocultivation of CAD/CAM hybrid scaffolds in the omentum majus in miniature pigs

PURPOSE

Correction of bony mandibular defects is a challenge in oral and maxillofacial surgery due to aesthetic and functional requirements. This study investigated the potential of a novel hybrid scaffold for bone regeneration and degradation assessment of the ceramic within the omentum majus over 6 months and the extent to which rhBMP-2 as a growth factor, alone or combined with a hydrogel, affects regeneration.

MATERIALS AND METHODS

In this animal study, 10 Göttingen minipigs each had one scaffold implanted in the greater omentum. Five animals had scaffolds loaded with a collagen hydrogel and rhBMP-2, and the other five animals (control group) had scaffolds loaded with rhBMP-2 only. Fluorochrome injections and computed tomography (CT) were performed regularly. After 6 months, the animals were euthanized, and samples were collected for microCT and histological evaluations.

RESULTS

Fluorescent and light microscopic and a CT morphological density evaluation showed continuous bone growth until week 16 in both groups. Regarding the ratio of bone attachment to the Zr02 support struts, the rhBMP-2 loaded collagen hydrogel group showed with 63% a significantly higher attachment (p > 0.001) than the rhBMP-2 control group (49%).

CONCLUSION

In this study, bone growth was induced in all omentum majus specimens until post-operative week 16. Furthermore, hydrogel and rhBMP-2 together resulted in better bone-scaffold integration than rhBMP-2 alone. Further studies should investigate whether implantation of the scaffolds in the jaw after an appropriate period of bone regeneration leads to a stable situation and the desired results.

The Complications of Osseous Reconstruction in the Head and Neck: A Systematic Review and Meta-analysis

OBJECTIVE

To compare the postoperative complications of the fibular free flap (FFF), scapula free flap (SFF), and osteocutaneous radial forearm free flap (OCRFFF) following osseous reconstruction in the head and neck.

DATA SOURCES

PUBMED, EMBASE, Cochrane.

REVIEW METHODS

A literature search and systematic review were performed using the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. A meta-analysis of proportions was conducted using a random effects model to compare operative time and postoperative complications.

RESULTS

The systematic review identified 26 studies comparing at least 1 variable of interest. The odds ratio estimates favored reduced rates of flap failure with the OCRFFF when compared to FFF (0.7, confidence interval [CI]: 0.29-1.11, P < .001), while FFF and SFF were similar. The mean difference estimates for operative time significantly favored FFF over SFF (-51.04 minutes, CI: -92.73 to -9.35, P = .016) and OCRFFF over FFF (66.77 minutes, CI: 52.74-80.8, P < .001). The FFF was more prone to hardware exposure, longer hospital stays, and donor site complications. Recipient wound complications and fistula rates were similar for all flap types.

CONCLUSION

Depending on the clinical context, the OCRFFF, FFF, and SFF are all robust options for reconstruction in the head and neck. The OCRFFF is associated with a reduced rate of flap failure and shorter operative times. The SFF requires longer operative times, although significant variation was observed between institutions. The FFF has broad reconstructive indications but is associated with more perioperative and long-term complications.

Multi-factor early monitoring method based on D-dimer for iliac crest flap loss

BACKGROUND

In recent years, the utilization of autogenous vascularized iliac crest flap for repairing jaw defects has seen a significant rise. However, the visual monitoring of iliac bone flaps present challenges, frequently leading to delayed detection of flap loss. Consequently, there's a urgent need to develop effective indicators for monitoring postoperative complications in iliac crest flaps.

METHODS

A retrospective analysis was conducted on 160 patients who underwent vascularized iliac crest flap transplantation for jawbone reconstruction from January 2020 to December 2022. We investigated the changes in D-dimer levels among patients with or without postoperative complications. Additionally, multivariable logistic regression analysis was performed to explore potential individual risk factors, including surgical duration, age, pathology type, absolute and relative D-dimer levels, and gender, culminating in the development of a nomogram.

RESULTS

On the first day following surgery, patients who experienced thrombosis exhibited a substantial increase in plasma D-dimer levels, reaching 3.75 mg/L, 13.84 times higher than the baseline. This difference was statistically significant (P < 0.05) compared to patients without postoperative complications. Furthermore, the nomogram we have developed and validated effectively predicts venous thrombosis, assigning individual risk scores to patients. This predictive tool was assessed in both training and validation cohorts, achieving areas under the curve (AUC) of 0.630 and 0.600, with the 95% confidence intervals of 0.452-0.807 and 0.243-0.957, respectively.

CONCLUSIONS

Our study illustrates that postoperative plasma D-dimer levels can serve as a sensitive biomarker for monitoring thrombosis-induced flap loss. Moreover, we have developed a novel prediction model that integrates multiple factors, thereby enhancing the accuracy of early identification of patients at risk of thrombosis-associated flap loss. This advancement contributes to improving the overall management and outcomes of such procedures.

Short dental implants in microvascular free flap DCIA: A case report

Placing dental implants in microvascular bone free flaps used for reconstructing the mandible or maxilla has been previously reported. However, there is scarce information available on the restorative protocol using short dental implants placed in a deep circumflex iliac artery (DCIA) microvascular free flap and the rationale behind it. This case report describes a 18-year-old patient referred to the hospital for numbness and dull pain of the left mandible, which she observed for three months. The patient underwent mandible resection and reconstruction using the DCIA free flap due to "giant cell lesion" on the left side of the mandibular angle. Short dental implants were placed and prosthetic reconstruction of the dentition involved in the resection was performed in a young patient with two integrated abutment crowns. The placement of short dental implants did not negatively affect the vascular pedicle and vitality of free flap. In our case report, two years after the healing, excellent aesthetic and function were accomplished with the DCIA flap followed by restoration with short implants.

Short and Extra Short Dental Implants in Osseous Microvascular Free Flaps: A Retrospective Case Series

There is limited information regarding implant and prosthetic survival after osseous microvascular free flap (OMFF). This case series aims to describe the placement of short and extra short implants in osseous microvascular free flaps to support prostheses, and present an up to 40-month retrospective follow-up. Short and extra short dental implants were placed in six fibula free flaps (FFF) and in two microvascular deep circumflex iliac artery (DCIA) flaps. In total, 27 short and extra short dental implants have been placed into two different types of free flaps. Kaplan-Meyer (K-M) survival analyses were performed to evaluate the survival and success outcomes of implants and prostheses. Out of the eight patients reconstructed with free flap, five were rehabilitated with prostheses, one patient has a temporary prosthesis, and two patients are in the process of prosthetic rehabilitation. Twenty-seven implants were followed up for up to 40 months, and K-M analyses showed 100% implant survival probability (95% confidence interval: 100%), while the implant success probability was 91.0% (95% confidence interval: 68.6-97.7%). Short and extra short dental implants placed in OMFF presented high survival and success rates in a retrospective case series after up to 40 months.

Tenants of Mandibular Reconstruction in Segmental Defects

The premises of mandibular reconstruction are the restoration of occlusion and mandibular contour for the purpose of preserving the facial identity, oral airway, and effective speech and mastication. Establishing functional occlusion is the primary tenant in all mandibular reconstruction. In cases of segmental defects, particularly in dentate regions of the mandible, there has been a paradigm shift over the past two decades in how surgeons are approaching the restoration of load-bearing mandibular continuity with capacity for dental implantation. Here we discuss considerations for deciding the most effective method of reconstruction in segmental defects.

Outcome Assessment after Reconstruction of Tumor-Related Mandibular Defects Using Free Vascularized Fibular Flap-A Clinical Study

The objective of this study was to analyze the outcomes of the free vascularized fibular flap in the reconstruction of mandibular defects, and to assess the oral health impact profile of these patients before surgery and after oral rehabilitation. Patients requiring reconstruction of defects greater than 6 cm were selected for this study. The defect size and type, the size of the required skin paddle, the need for second flaps, the intraoperative complications, and the type of closure were documented. Patients were evaluated postoperatively for function, aesthetics, and donor- or reconstruction-site complications. The validated oral health impact profile (OHIP-14) questionnaires were filled before and after surgery and after dental rehabilitation. This study included 11 cases of squamous-cell carcinomas, 2 cases of malignant nerve sheath tumors, and 1 case each of malignant melanoma, ameloblastoma, giant-cell tumor, osteosarcoma, and chondrosarcoma. The analysis revealed a significant association (p = 0.030) of gender with free vascular flap complications, while no significant association (p > 0.05) was found when donor- and recipient- site complications, as well as the type of resection (Brown’s classification), were compared with free vascular flaps. Moreover, the total OHIP-14 scores for patients before surgery, after surgery, and after dental rehabilitation were 12.03 ± 1.34, 10.66 ± 1.41, and 08.33 ± 0.62, respectively. The oral health-related quality of life was markedly improved after the reconstruction of the mandibular defects with free vascularized fibular flap and dental rehabilitation. The overall success rate of fibular flap in our study was 72.2%, which is lower than that reported in the literature. This may be attributed to the fact that almost all of our cases included large segmental defects that extended across the midline of the mandible.