Virtual surgical planning in fibula free flap head and neck reconstruction: A systematic review and meta-analysis

Long-term outcomes in virtual surgical planning for mandibular reconstruction: A cost-effectiveness analysis

OBJECTIVE

This study is an economic evaluation comparing virtual surgical planning (VSP) utilization to free hand mandibular reconstruction (FHR) for advanced oral cavity cancer, for which the cost effectiveness remains poorly understood. The proposed clinical benefits of VSP must be weighed against the additional upfront costs.

METHODS

A Markov decision analysis model was created for VSP and FHR based on literature review and institutional data over a 35-year time horizon. Model parameters were derived and averaged from systematic review and institutional experience. VSP cost and surgical time saving was incorporated. We accounted for long-term risks including cancer recurrence and hardware failure/exposure. We calculated cost in US dollars and effectiveness in quality-adjusted-life-years (QALYs). A health care perspective was adopted, discounting costs and effectiveness at 3%/year. Deterministic and probabilistic sensitivity analyses tested model robustness.

RESULTS

In the base case scenario, total VSP strategy cost was $49,498 with 8.37 QALYs gained while FHR cost was $42,478 with 8.27 QALY gained. An incremental cost-effectiveness ratio (ICER), or the difference in cost/difference in effectiveness, for VSP was calculated at $68,382/QALY gained. VSP strategy favorability was sensitive to variations of patient age at diagnosis and institutional VSP cost with one-way sensitivity analysis. VSP was less economically favorable for patients >75.5 years of age or for institutional VSP costs >$10,745. In a probabilistic sensitivity analysis, 55% of iterations demonstrated an ICER value below a $100,000/QALY threshold.

CONCLUSIONS/RELEVANCE

VSP is economically favorable compared to FHR in patients requiring mandibular reconstruction for advanced oral cancer, but these results are sensitive to the patient's age at diagnosis and the institutional VSP cost. Our results do not suggest if one "should or should not" use VSP, rather, emphasizes the need for patient selection regarding which patients would most benefit from VSP when evaluating quality of life and long-term complications. Further studies are necessary to demonstrate improved long-term risk for hardware failure/exposure in VSP compared to FHR.

Primary Management of Operable Locally Advanced Oral Cavity Squamous Cell Carcinoma: Current Concepts and Strategies

INTRODUCTION

Locally advanced oral cavity carcinoma (LAOCSCC) is primarily treated with surgery followed by radiotherapy with or without chemotherapy.

METHODS

A review of literature using PubMED was performed for studies reporting the management of LAOCSCC. Based on the reviewed literature and opinions of experts in the field, recommendations were made.

RESULTS

Studies have shown that outcomes following resection of T4a and infranotch (inferior to mandibular notch) T4b are comparable. We discuss the concept of compartmental resection of LAOCSCC and issues concerning the management of the neck. Further, patients who refuse or are unable to undergo surgery can be treated with chemoradiotherapy with uncertain outcomes. The role of neoadjuvant chemotherapy has shown promise for organ (mandibular) preservation in a select subset of patients.

CONCLUSION

The management strategy for LAOCSCC should be determined in a multidisciplinary setting with emphasis on tumor control, functional preservation, and quality of life of the patient.

Functional and esthetic outcomes of virtual surgical planning versus the conventional technique in mandibular reconstruction with a free fibula flap: A retrospective study of 24 cases

This study aimed to compare the functional and esthetic results in patients following mandibular reconstruction with a free fibula flap (FFF) by virtual surgical planning (VSP) versus the conventional technique. Patients who had undergone mandibular reconstruction with a FFF by VSP or the conventional technique were retrospectively assessed. The two groups were compared regarding functional and esthetic variables with appropriate scales preoperatively, intraoperatively, and postoperatively. Twenty-four patients were evaluated in two groups: conventional (n = 8) and VSP (n = 16). The mean amount of mandibular asymmetry was 2.62 mm (SD = 1.59) in the conventional group and 1.19 mm (SD = 1.32) in the VSP group. Of the patients who underwent conventional surgery, 12.5% had mandibular asymmetry of <2 mm and 87.5% had asymmetry of 2-5 mm. Of the VSP patients, 61.5% had mandibular asymmetry of <2 mm and 38.5% had mandibular asymmetry of 2-5 mm (p = 0.03). The mean difference in size of mandibular angle on the surgical and control sides was not significantly different between the two groups (p = 0.62). The difference in mean length of the mandibular body on the surgical side relative to the control side was not significant between the two groups (p = 0.75). Differences in functional variables between the two groups were not significant. Within the limitation of the study, it seems that the VSP technique resulted in better facial symmetry and superior esthetic outcomes compared with the conventional technique.

Cost-effective Solution for Maxillofacial Reconstruction Surgery with Virtual Surgical Planning and 3D Printed Cutting Guides Reduces Operative Time

Background: This study aimed to explore a low-cost solution for virtual surgical planning/3D printed surgical guides in a training hospital, assessing the impact on intraoperative time and bleeding. Material and Methods: We included a total of 13 patients. 8 who underwent maxillofacial reconstruction surgery with fibula-free flap utilizing virtual surgical planning/3D printed guides (VP/SG), and 5 using conventional surgery (CS) from 2017 to 2020. The surgical time, bleeding, length of hospital stay, and comorbidities were collected and compared in two groups. We recorded the average cost for the complete surgical planning and 3D printed guides. We applied a qualitative survey to the surgeons involved in the surgical procedures. Results The mean surgical time in the VP/SG group was 8.16 ± 2.7, compared to the CS group 12.5 ± 3.8, showing a 4.34 hours difference with statistical significance (p = 0.033). Patients from the CS group had a higher bleeding volume of 921 ± 467.6 mL VS 760 ± 633.8 mL in the VP/SG group. The average cost for the complete surgical planning and 3D printed guides was 914.44 ± 46.39 USD. All the surgeons who answered the survey preferred to perform the procedure utilizing the virtual planning/3D printed guides. Conclusions Virtual planning and 3D printed surgical guides have the potential to reduce operation time in maxillofacial reconstruction.

Deep Circumflex Iliac Artery Flap Reconstruction in Brown Class I Defect of the Mandible Using a Three-Component Surgical Template System

BACKGROUND

Computer-assisted surgery is widely used in mandibular reconstruction, but the process is not well described for cases using the deep circumflex iliac artery flap (DCIA) as the donor site. This study aimed to present a DCIA-based three-component surgical template system (3-STS) in patients with a mandibular Brown class I defect.

METHODS

This retrospective cohort study compared clinical outcomes of mandibular reconstruction with DCIA flap using 3-STS or conventional surgical templates. The primary outcome of the study was the accuracy of reconstruction, and the secondary outcomes included surgical time and bone flap ischemia time. Surgery-related parameters and functional outcomes were also recorded and compared.

RESULTS

Forty-four patients (23 in the 3-STS group and 21 in the control group) between 2015 and 2021 were included. Compared with the control group, the 3-STS group had higher accuracy of reconstruction, indicated by lower deviation in absolute distance (1.45 ± 0.76 mm versus 2.02 ± 0.89 mm; P = 0.034), and less deviation in coronal and sagittal angles (0.86 ± 0.53 degree versus 1.27 ± 0.59 degrees, P = 0.039; and 2.52 ± 1.00 degrees versus 3.25 ± 1.25 versus, P = 0.047) between preoperative and postoperative computed tomographic imaging. Surgical time and bone flap ischemia time were significantly reduced in the 3-STS group compared with the control group (median time, 385 minutes versus 445 minutes and 32 minutes versus 53 minutes, respectively; P < 0.001). In addition, masseter attachment was preserved in the 3-STS group but not in the control group. No differences were found in adverse events or other clinical variables.

CONCLUSION

The 3-STS can improve accuracy, simplify intraoperative procedures to increase surgical efficiency, and preserve functionality in mandibular reconstruction for Brown class I defects.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Realizing in-house algorithm-driven free fibula flap set up within 24 hours: a pilot study evaluating accuracy with open-source tools

Objective

This study aims to critically evaluate the effectiveness and accuracy of a time safing and cost-efficient open-source algorithm for in-house planning of mandibular reconstructions using the free osteocutaneous fibula graft. The evaluation focuses on quantifying anatomical accuracy and assessing the impact on ischemia time.

Methods

A pilot study was conducted, including patients who underwent in-house planned computer-aided design and manufacturing (CAD/CAM) of free fibula flaps between 2021 and 2023. Out of all patient cases, we included all with postoperative 3D imaging in the study. The study utilized open-source software tools for the planning step, and three-dimensional (3D) printing techniques. The Hausdorff distance and Dice coefficient metrics were used to evaluate the accuracy of the planning procedure.

Results

The study assessed eight patients (five males and three females, mean age 61.75 ± 3.69 years) with different diagnoses such as osteoradionecrosis and oral squamous cell carcinoma. The average ischemia time was 68.38 ± 27.95 min. For the evaluation of preoperative planning vs. the postoperative outcome, the mean Hausdorff Distance was 1.22 ± 0.40. The Dice Coefficients yielded a mean of 0.77 ± 0.07, suggesting a satisfactory concordance between the planned and postoperative states. Dice Coefficient and Hausdorff Distance revealed significant correlations with ischemia time (Spearman's rho = -0.810, p = 0.015 and Spearman's rho = 0.762, p = 0.028, respectively). Linear regression models adjusting for disease type further substantiated these findings.

Conclusions

The in-house planning algorithm not only achieved high anatomical accuracy, as reflected by the Dice Coefficients and Hausdorff Distance metrics, but this accuracy also exhibited a significant correlation with reduced ischemia time. This underlines the critical role of meticulous planning in surgical outcomes. Additionally, the algorithm's open-source nature renders it cost-efficient, easy to learn, and broadly applicable, offering promising avenues for enhancing both healthcare affordability and accessibility.

Identifying Factors of Operative Efficiency in Head and Neck Free Flap Reconstruction

Importance

Head and neck oncological resection and reconstruction is a complex process that requires multidisciplinary collaboration and prolonged operative time. Numerous factors are associated with operative time, including a surgeon's experience, team familiarity, and the use of new technologies. It is paramount to evaluate the contribution of these factors and modalities on operative time to facilitate broad adoption of the most effective modalities and reduce complications associated with prolonged operative time.

Objective

To examine the association of head and neck cancer resection and reconstruction interventions with operative time.

Design, Setting, and Participants

This large cohort study included all patients who underwent head and neck oncologic resection and free flap-based reconstruction in Calgary (Alberta, Canada) between January 1, 2007, and March 31, 2020. Data were analyzed between November 2021 and May2022.

Interventions

The interventions that were implemented in the program were classified into team-based strategies and the introduction of new technology. Team-based strategies included introducing a standardized operative team, treatment centralization in a single institution, and introducing a microsurgery fellowship program. New technologies included use of venous coupler anastomosis and virtual surgical planning.

Main Outcomes and Measures

The primary outcome was mean operative time difference before and after the implementation of each modality. Secondary outcomes included returns to the operating room within 30 days, reasons for reoperation, returns to the emergency department or readmissions to hospital within 30 days, and 2-year and 5-year disease-specific survival. Multivariate regression analyses were performed to examine the association of each modality with operative time.

Results

A total of 578 patients (179 women [30.9%]; mean [SD] age, 60.8 [12.9] years) undergoing 590 procedures met inclusion criteria. During the study period, operative time progressively decreased and reached a 32% reduction during the final years of the study. A significant reduction was observed in mean operative time following the introduction of each intervention. However, a multivariate analysis revealed that team-based strategies, including the use of a standardized nursing team, treatment centralization, and a fellowship program, were significantly associated with a reduction in operative time.

Conclusions

The results of this cohort study suggest that among patients with head and neck cancer, use of team-based strategies was associated with significant decreases in operative time without an increase in complications.

Mandibular reconstructions with free fibula flap using standardized partially adjustable cutting guides or CAD/CAM technique: a three- and two-dimensional comparison

Background

Mandibular reconstruction with the fibula free flap (FFF) is performed freehand, CAD/CAM-assisted, or by using partially adjustable resection/reconstruction aids. The two latter options represent the contemporary reconstructive solutions of the recent decade. The purpose of this study was to compare both auxiliary techniques with regard to feasibility, accuracy, and operative parameters.

Methods and materials

The first twenty consecutively operated patients requiring a mandibular reconstruction (within angle-to-angle) with the FFF using the partially adjustable resection aids between January 2017 and December 2019 at our department were included. Additionally, matching CAD/CAM FFF cases were used as control group in this cross-sectional study. Medical records and general information (sex, age, indication for surgery, extent of resection, number of segments, duration of surgery, and ischemia time) were analyzed. In addition, the pre- and postoperative Digital Imaging and Communications in Medicine data of the mandibles were converted to standard tessellation language (.stl) files. Conventional measurements - six horizontal distances (A-F) and temporo-mandibular joint (TMJ) spaces - and the root mean square error (RMSE) for three-dimensional analysis were measured and calculated.

Results

In total, 40 patients were enrolled (20:20). Overall operation time, ischemia time, and the interval between ischemia time start until end of operation showed no significant differences. No significant difference between the two groups were revealed in conventional measurements of distances (A-D) and TMJ spaces. The Δ differences for the distance F (between the mandibular foramina) and the right medial joint space were significantly lower in the ReconGuide group. The RMSE analysis of the two groups showed no significant difference (p=0.925), with an overall median RMSE of 3.1 mm (2.2-3.7) in the CAD/CAM and 2.9 mm (2.2-3.8) in the ReconGuide groups.

Conclusions

The reconstructive surgeon can achieve comparable postoperative results regardless of technique, which may favor the ReconGuide use in mandibular angle-to-angle reconstruction over the CAD/CAM technique because of less preoperative planning time and lower costs per case.

Managing Oromandibular Hardware Failure after Free Flap Surgery

Hardware failure after oromandibular reconstruction using free tissue transfer can delay additional therapies directed at cancer treatment and prevent patients from returning to normal oral function. Understanding and strict adherence to principles of rigid fixation is critical in preventing complications. Early surgical intervention for hardware exposure as well as utilization of locoregional flaps may prevent the need for more extensive revision surgery.

Application of a vascularized bone free flap and survival rate of dental implants after transplantation: A systematic review and meta-analysis

PURPOSE

As maxillofacial surgical techniques have advanced, vascularized bone free flap transplantation has become the standard treatment for repairing maxillofacial defects. In this meta-analysis, we summarize the survival rates of implants after VBFF surgery for maxillary and mandibular reconstructions and investigate the factors affecting patient outcomes.

METHODS

The PubMed, Embase, and Wanfang databases were searched up to May 31, 2022. The results of the treatment effect are presented as the risk ratio or odds ratio, using 95% confidence intervals. Statistical significance was calculated at α = 0.05 (two-tailed z tests).

RESULTS

35 studies were included in our analysis. The results revealed a 3-year and 5-year implant survival rate of 95.2% and 85.4% in VBFFs, respectively. The location of jaw defects (maxilla or mandible) or timing of implantation was not found to have a statistically significant influence on the survival rate. However, statistically significant differences were observed in the failure of implants placed in irradiated bone tissue.

CONCLUSIONS

Statistically significant differences were not found in the implant survival rate between simultaneous and delayed implantation, or between maxillary and mandibular defects. However, dental implants placed in irradiated flaps tended to have a lower survival rate than those surgically placed in non-irradiated flaps.

Osseous Union after Jaw Reconstruction with Fibula-Free Flap: Conventional vs. CAD/CAM Patient-Specific Implants

This is a monocentric, retrospective study of patients who underwent successful immediate or delayed maxilla or mandible reconstructions with FFF from January 2005 to December 2021. Panoramic radiograph, computed tomography scans, and cone-beam CTs were analyzed concerning the osseous union of the intersegmental junctions between maxillary or mandibular native jaw and fibular bone. The primary parameter was to estimate the status of osseous union according to osteosynthesis type. A total number of 133 patients (PSI: n = 64, non-PSI: n = 69) were included in the present study. The mean age was 56.7 ± 14.0 (Range: 14.7−82.7); the primary diagnosis was in 105 patients a malignant (78.9%) and in 20 patients a benign (15.0%) tumor. Mandible reconstruction was performed on 103 patients (77.4%), and on 30 patients (22.6%), maxilla reconstruction was performed. The radiographic images provided a rate of incomplete osseous union (IOU) of about 90% in both groups in the first 6 months. Imaging between 6 and 12 months reveals an IOU rate in the non-PSI group of 46.3% vs. 52.5% in the PSI group, between 12 and 24 months, an IOU rate of 19.6% vs. 26.1%, between 24 and 36 months 8.9% vs. 21.7%, and after 36 months the IOU rate decreases to 4.2% vs. 18.2%. Multivariate logistic regression shows that only osteosynthesis type (OR = 3.518 [95%-CI = 1.223−10.124], p = 0.02) and adjuvant radiotherapy (OR = 4.804 [95%-CI = 1.602−14.409], p = 0.005) are independent risk factors for incomplete osseous union. Cox regression revealed that the variables plate-system (Hazard ratio, HR = 5.014; 95 %-CI: 1.826−3.769; p = 0.002) and adjuvant radiotherapy (HR = 5.710; 95 %-CI: 2.066−15.787; p < 0.001) are predictors for incomplete osseous union. In our study, the rate of incomplete bony fusion was significantly higher in the PSI group. Jaw-to-fibula apposition zones were significantly more affected than intersegmental zones. In multivariate analysis, a combination of osteosynthesis with PSI and adjuvant radiotherapy could be identified as a risk constellation for incomplete ossification.

The Amsterdam UMC protocol for computer-assisted mandibular and maxillary reconstruction; A cadaveric study

OBJECTIVES

In this cadaveric study, the accuracy of CAS guided mandibular and maxillary reconstruction including immediate dental implant placement in different Brown defect classes is assessed.

MATERIALS AND METHODS

The virtual planning and surgical procedure was conducted according to a newly proposed Amsterdam UMC reconstruction protocol. Postoperative evaluation was performed according to a previously proposed evaluation guideline.

RESULTS

Fourteen mandibular and 6 maxillary reconstructions were performed. Average mandibular angle deviations were 1.52°±1.32, 1.85°±1.58, 1.37°±1.09, 1.78°±1.37, 2.43°±1.52 and 2.83°±2.37, respectively for the left and right axial angles, left and right coronal angles and left and right sagittal angles. A total of 62 dental implants were placed in neomandibles with an average dXYZ values of 3.68 ± 2.21 mm and 16 in neomaxillas with an average dXYZ values of 3.24 ± 1.7 mm.

CONCLUSION

Promising levels of accuracy were achieved for all mandibular angles. Dental implant positions approached the preoperative preferred positions well, within the margin to manufacture prosthetic devices.

A Comprehensive Approach for Measuring Spatial Deviations of Computer-Assisted Mandibular Reconstruction

BACKGROUND

Computer-assisted surgery has become the mainstream in mandibular reconstruction, but the lack of a standard measuring approach for spatial deviations of mandible hinders postoperative verification and the comparison of different subjects. This study aims to set up a comprehensive approach for measuring spatial deviations of computer-assisted mandibular reconstruction.

METHODS

A systematic review was conducted to extract all measurements for computer-assisted mandibular reconstruction. Thereafter, eligible measurements were included in the authors' comprehensive approach, which categorized the measurements according to different anatomical structures and landmarks.

RESULTS

A total of 80 studies were included in the authors' systematic review, and 31 measurements were extracted. The authors established a comprehensive panel of anatomical landmarks to facilitate measurement, including parts, points, lines, planes, and angles. These measurements encompassed spatial deviations of the overall mandible, condyle, gonial angle, bone grafts, midline, surgical plate, osteotomy, and miscellaneous indicators. A calculation spreadsheet was developed to collect landmarks and compute deviations automatically with built-in formulas. Finally, a simplified panel of measurements was recommended for spatial deviations of mandibular reconstruction.

CONCLUSIONS

A comprehensive approach for measuring spatial deviations of computer-assisted mandibular reconstruction was established. Future studies will confirm this approach as an effective and scientific system for postoperative verification of computer-assisted mandibular reconstruction.

A Comparative Study of Analog Preoperative Planning Versus Virtual Preoperative Planning for Mandibular Reconstruction With Fibula Free Flap

ABSTRACT

Mandibular reconstruction is a challenging procedure, especially in cancer patients with defects that are greater than 6 cm. Free vascularized fibular flap is the gold standard treatment in these cases since it allows three-dimensional restoration of the lost segments after ablative surgery in addition to providing the possibility of a subsequent implant-supported rehabilitation improving the functional and aesthetic outcomes of the surgery.To obtain accurate results, preoperative planning must be done with detail. Approaches for the preoperative planning include both the conventional analog planning and the virtual planning that are valid alternatives in meeting the trans-surgical requirements.This study makes a comparative analysis of 2 clinical cases with a diagnosis of squamous cell carcinoma that were reconstructed using a vascularized fibular free flap. The first case was planned using the conventional analog method whereas the second case was planned using the virtual planning approach.The impact of virtual planning and conventional analog planning on preoperative planning time, ischemia period, and total surgical time is analyzed according to the experience obtained in the cases presented. In addition, the authors described the technique used for each planning method along with a literature review in which the results are contrasted and discussed.

Impact of Periosteal Branches and Septo-Cutaneous Perforators on Free Fibula Flap Outcome: A Retrospective Analysis of Computed Tomography Angiography Scans in Virtual Surgical Planning

Background

Virtual surgical planning (VSP) for jaw reconstruction with free fibula flap (FFF) became a routine procedure and requires computed tomography angiography (CTA) for preoperative evaluation of the lower limbs vascular system and the bone. The aim of the study was to assess whether the distribution and density of periosteal branches (PB) and septo-cutaneous perforators (SCP) of the fibular artery have an impact on flap success.

Method

This retrospective clinical study assessed preoperative CTA of the infra-popliteal vasculature and the small vessel system of 72 patients who underwent FFF surgery. Surgical outcome of flap transfer includes wound healing, subtotal, and total flap loss were matched with the segmental vascular supply.

Result

A total of 72 patients (28 females, 38.9 %; 44 males, 61.1 %) fulfilled the study inclusion criteria. The mean age was 58.5 (± 15.3 years). Stenoses of the lower limbs’ vessel (n = 14) were mostly detected in the fibular artery (n = 11). Flap success was recorded in n = 59 (82.0%), partial flap failure in n = 4 (5.5%) and total flap loss in n = 9 (12.5%). The study found a mean number (± SD) of 2.53 ± 1.60 PBs and 1.39 ± 1.03 SCPs of the FA at the donor-site. The proximal FFF segment of poly-segmental jaw reconstruction showed a higher rate of PB per flap segment than in the distal segments. Based on the total number of prepared segments (n = 121), 46.7% (n = 7) of mono-, 40.4% (n = 21) of bi-, and 31.5 % (n = 17) of tri-segmental fibula flaps were at least supplied by one PB in the success group. Overall, this corresponds to 37.2% (45 out of 121) of all successful FFF. For total flap loss (n = 14), a relative number of 42.9% (n = 6) of distinct supplied segments was recorded. Wound healing disorder of the donor site was not statistically significant influenced by the detected rate of SCP.

Conclusion

In general, a correlation between higher rates of PB and SCP and the flap success could not be statistically proved by the study sample. We conclude, that preoperative PB and SCP mapping based on routine CTA imaging is not suitable for prediction of flap outcome.

Practice patterns of virtual surgical planning: Survey of the reconstructive section of the American Head and Neck Society

PURPOSE

Virtual surgical planning (VSP), with custom made implants and guides represents a recent major advance. Nonetheless, knowledge related to practice patterns is limited. The purpose of this study was to provide data from the AHNS Reconstruction Section related to practice patterns, perceived value of VSP, as well as elucidate specific situations which represent high value for the application of VSP.

MATERIALS AND METHODS

A multi-center web-based survey consisting of 30 questions regarding practice patterns related to VSP practices delivered via email to 203 members of the AHNS Reconstructive Surgery Section at institutions across North America.

RESULTS

There was a 34% response rate (70/203). A majority of the respondents (96%) used VSP in approximately 50% of their mandibular reconstruction cases, and in 42% of maxillary cases. 46% reported using patient specific implants >75% of cases. Respondents estimated that ~17% of patients received dental implant reconstruction. The majority of respondents (71.0%) did not know the cost of VSP at their institution. The remaining respondents indicated the average cost was $6680 per case. VSP was felt to be necessary as a teaching tool by 55.9%.

CONCLUSIONS

Our results demonstrate that a majority of respondents frequently utilize VSP in their practice for head and neck reconstruction. Complex, multi-unit reconstructions were felt to offer the greatest value when utilizing VSP. Future work should focus on increasing the rates of dental implant reconstruction in this population, optimizing value of VSP with careful case selection, and understanding the educational value and costs of these platforms.

In-House, Open-Source 3D-Software-Based, CAD/CAM-Planned Mandibular Reconstructions in 20 Consecutive Free Fibula Flap Cases: An Explorative Cross-Sectional Study With Three-Dimensional Performance Analysis

Background

Mandibular reconstruction is conventionally performed freehand, CAD/CAM-assisted, or by using partially adjustable resection aids. CAD/CAM-assisted reconstructions are usually done in cooperation with osteosynthesis manufacturers, which entails additional costs and longer lead time. The purpose of this study is to analyze an in-house, open-source software-based solution for virtual planning.

Methods and Materials

All consecutive cases between January 2019 and April 2021 that underwent in-house, software-based (Blender) mandibular reconstruction with a free fibula flap (FFF) were included in this cross-sectional study. The pre- and postoperative Digital Imaging and Com munications in Medicine (DICOM) data were converted to standard tessellation language (STL) files. In addition to documenting general information (sex, age, indication for surgery, extent of resection, number of segments, duration of surgery, and ischemia time), conventional measurements and three-dimensional analysis methods (root mean square error [RMSE], mean surface distance [MSD], and Hausdorff distance [HD]) were used.

Results

Twenty consecutive cases were enrolled. Three-dimensional analysis of preoperative and virtually planned neomandibula models was associated with a median RMSE of 1.4 (0.4–7.2), MSD of 0.3 (-0.1–2.9), and HD of 0.7 (0.1–3.1). Three-dimensional comparison of preoperative and postoperative models showed a median RMSE of 2.2 (1.5–11.1), MSD of 0.5 (-0.6–6.1), and HD of 1.5 (1.1–6.5) and the differences were significantly different for RMSE (p < 0.001) and HD (p < 0.001). The difference was not significantly different for MSD (p = 0.554). Three-dimensional analysis of virtual and postoperative models had a median RMSE of 2.3 (1.3–10.7), MSD of -0.1 (-1.0–5.6), and HD of 1.7 (0.1–5.9).

Conclusions

Open-source software-based in-house planning is a feasible, inexpensive, and fast method that enables accurate reconstructions. Additionally, it is excellent for teaching purposes.

Interdisciplinary management of skull base surgery

Skull base surgery remains one of the challenging areas in the field of cranio-maxillofacial surgery, otolaryngology and neurosurgery. Subsequent reconstruction of bone and soft tissue are an essential component to restore function and appearance after ablative surgery. Establishment of interdisciplinary tumor boards with presentation of the individual patient cases have become standard. Multiplanar reconstruction using MRI or CT imaging techniques combined with virtual 3D planning allow precise planning of the procedures. Intraoperative navigation helps for complete resection of malignant findings with safety margins; surgical approaches provide a good overview of the surgical site. Reconstruction using local flaps have a low complication rate with equally reliable results in reconstruction of small tissue defects. Free flap surgery makes reconstruction of large tissue defects possible. Alloplastic materials are alternatively used for reconstruction of bone defects. Based on selected patients, treatment algorithms and standard surgical procedures in extracerebral skull base surgery will be illustrated. Current techniques and new approaches will be discussed with emphasize on hard and soft tissue reconstruction.

Conformity of the Virtual Surgical Plan to the Actual Result Comparing Five Craniofacial Procedure Types

BACKGROUND

The "accuracy" of virtual surgical planning across multiple procedure types is not known. The authors aimed to compare the planned outcome from virtual surgical planning to the actual postoperative outcome for five craniofacial procedure types performed by a single surgeon: implant cranioplasty, cranial vault remodeling, orthognathic surgery, mandible reconstruction, and mandibular distraction.

METHODS

Stereolithography formats were obtained from virtual surgical planning and compared to postoperative computed tomographic scans for consecutive patients who underwent one of the five procedure types. Volumetric renderings of the operated bony region of interest were overlaid and compared using a Boolean operation to compute conformity (as a percentage of the region of interest). Conformity across procedure type was analyzed using analysis of variance and post hoc Bonferroni analysis, where appropriate.

RESULTS

One hundred thirty patients were included (51.5 percent male and 49.5 percent female; mean age, 27 years; 59 orthognathic surgery, 32 cranial vault remodeling, 16 mandible reconstruction, 12 mandibular distraction, and 11 implant cranioplasty patients). The highest tier of conformity was obtained for implant cranioplasty (median, 76.8 ± 10.3 percent) and mandible reconstruction (mean, 69.4 ± 11.2 percent), followed by orthognathic surgery (mean, 55.0 ± 7.3 percent) and mandibular distraction (median, 41.9 ± 20.3 percent), followed by cranial vault remodeling (mean, 22.2 ± 12.1 percent) (p < 0.001 between tiers and p > 0.05 among tiers).

CONCLUSIONS

Virtual surgical planning resulting in custom permanent implants and intraoperative guides provides more predictable results compared to virtual surgical planning used for procedures involving higher degrees of skeletal repositioning and postoperative movement (i.e., mandibular distraction and nonrigid cranial vault remodeling). In cases with expectedly lower conformity, excellent outcomes can be achieved with sound intraoperative judgment.

The Challenges and Perspectives of the Integration Between Virtual and Augmented Reality and Manual Therapies

Virtual reality (VR) and augmented reality (AR) have been combined with physical rehabilitation and psychological treatments to improve patients' emotional reactions, body image, and physical function. Nonetheless, no detailed investigation assessed the relationship between VR or AR manual therapies (MTs), which are touch-based approaches that involve the manipulation of tissues for relieving pain and improving balance, postural stability and well-being in several pathological conditions. The present review attempts to explore whether and how VR and AR might be integrated with MTs to improve patient care, with particular attention to balance and to fields like chronic pain that need an approach that engages both mind and body. MTs rely essentially on touch to induce tactile, proprioceptive, and interoceptive stimulations, whereas VR and AR rely mainly on visual, auditory, and proprioceptive stimulations. MTs might increase patients' overall immersion in the virtual experience by inducing parasympathetic tone and relaxing the mind, thus enhancing VR and AR effects. VR and AR could help manual therapists overcome patients' negative beliefs about pain, address pain-related emotional issues, and educate them about functional posture and movements. VR and AR could also engage and change the sensorimotor neural maps that the brain uses to cope with environmental stressors. Hence, combining MTs with VR and AR could define a whole mind-body intervention that uses psychological, interoceptive, and exteroceptive stimulations for rebalancing sensorimotor integration, distorted perceptions, including visual, and body images. Regarding the technology needed to integrate VR and AR with MTs, head-mounted displays could be the most suitable devices due to being low-cost, also allowing patients to follow VR therapy at home. There is enough evidence to argue that integrating MTs with VR and AR could help manual therapists offer patients better and comprehensive treatments. However, therapists need valid tools to identify which patients would benefit from VR and AR to avoid potential adverse effects, and both therapists and patients have to be involved in the development of VR and AR applications to define truly patient-centered therapies. Furthermore, future studies should assess whether the integration between MTs and VR or AR is practically feasible, safe, and clinically useful.

Spatial deviations of the temporomandibular joint after oncological mandibular reconstruction

Spatial deviations of the temporomandibular joint (TMJ) after oncological mandibular reconstruction are important to the aesthetic and functional rehabilitation. The aim of this study was to clarify whether and how three dimensionally (3D) printed patient-specific surgical plates, and the preservation of the condyle or ramus, affect spatial deviations of the TMJ. A total of 33 patients who underwent mandibular reconstruction via computer-assisted surgery were included. Regarding absolute deviations, patients in the 3D-printed plate group showed smaller TMJ deviations compared to those in the conventional plate group. There was no difference in absolute deviations of the TMJ regardless of whether the condyle or ramus was preserved. Regarding physiological deviations, the impact on the contralateral TMJ was smaller in the 3D-printed plate group. Patients with both the condyle and ramus removed had significantly higher deviations of the condyle and joint space. In summary, 3D-printed patient-specific surgical plates improved the spatial accuracy of the TMJ. Under physiological conditions, TMJ deviations on the operated side were mainly affected by the preservation of the condyle. Removal of both the condyle and ramus caused more severe spatial interference to the TMJ; this should be further confirmed.

Short and long-term outcomes of three-dimensional printed surgical guides and virtual surgical planning versus conventional methods for fibula free flap reconstruction of the mandible: Decreased nonunion and complication rates

BACKGROUND

To determine whether virtual surgical planning and three-dimensional printed cutting guides (3D/VSP) improved radiographic bone union compared to conventional methods (CM) in fibula free flap (FFF) reconstruction of the mandibles.

METHODS

Retrospective study from the years 2000-2018 at a tertiary hospital. Osseous union was evaluated by a radiologist blinded to each patient's treatment.

RESULTS

Two hundred sixty patients who underwent FFF tissue transfer, 28 with VSP and 3D cutting guides. Bony union was not achieved in 46 (20%) patients who underwent CM compared to 1 (4%) of patients with VSP and guides (p = 0.036). FFF complication was significantly higher in CM with 87 patients (38%) compared to three patients (11%) in 3D/VSP (p = 0.005). Median time to bony union for patients who underwent CM was 1.4 years compared to 0.8 years in 3D/VSP.

CONCLUSIONS

3D/VSP reduced the rate of radiographic nonunion and flap-related complications in FFF reconstruction for mandibular defects.

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.

Risk Factors for Plate Extrusion After Mandibular Reconstruction With Vascularized Free Flap

PURPOSE

Plate extrusion after mandibular reconstruction is a complication that imposes significant morbidity on the patient. The goal of this study is to estimate the incidence of plate extrusion after mandible reconstruction with a vascularized free flap and to identify the factors associated with plate extrusion.

METHODS

This was a retrospective cohort study involving patients who underwent mandibular reconstruction from October 2008 to July 2019 at LAC + USC or Keck Hospital of USC. Inclusion criteria were age ≥ 18 years, single-stage mandibular reconstruction with vascularized free flap, and follow-up of at least 12 months. Relevant demographic, intraoperative, and postoperative data were collected. The primary outcome was postoperative plate extrusion within the 12-month follow-up. Descriptive, univariate, and multivariate analyses were performed. Statistical significance was set at P ≤ .05.

RESULTS

A total of 102 patients were included in this study. The majority received a fibula free flap (90%) for a malignant neoplasm (76%). All patients had at least 12 months of follow-up. The rate of plate extrusion was 16%, with the majority of those patients undergoing plate removal (69%). After adjusting for postoperative fistula, soft tissue, and length of hospitalization, we found that any history of smoking (odds ratio = 12.8; confidence interval, 1.57 to 104.2), number of osteotomies (odds ratio 3.07; confidence interval, 1.09 to 8.6), flap nonviability (odds ratio = 18.2; confidence interval, 2.22 to 148.8) were associated with plate extrusion on multivariate analysis. Postoperative soft tissue infection approached significance.

CONCLUSIONS

This study demonstrates that smoking history, number of osteotomies, and flap nonviability are associated with plate extrusion after mandible reconstruction. Performing fewer osteotomies when possible to avoid excessively small flap bone segments and minimizing postoperative complications may improve long-term outcomes after mandibular reconstruction.

The Predictive Hole Technique: A Technical Note

We describe a novel technique in which predictive holes, normally unique to patient-specific plates, may be utilized with off the shelf stock plates. This allows for the numerous benefits of predictive holes in mandibular reconstruction while negating the added cost of a custom milled plate. Three case examples are presented for technique illustration.

[Digitalization and use of artificial intelligence in microvascular reconstructive facial surgery]

BACKGROUND

When using digitalization and artificial intelligence (AI), large amounts of data (big data) are produced, which can be processed by computers and used in the field of microvascular-reconstructive craniomaxillofacial surgery (CMFS).

OBJECTIVE

The aim of this article is to summarize current applications of digitalized medicine and AI in microvascular reconstructive CMFS.

MATERIAL AND METHODS

Review of frequent applications of digital medicine for microvascular CMFS reconstruction, focusing on digital planning, navigation, robotics and potential applications with AI.

RESULTS

The broadest utilization of medical digitalization is in the virtual planning of microvascular transplants, individualized implants and template-guided reconstruction. Navigation is commonly used for ablative tumor surgery but less frequently in reconstructions. Robotics are mainly employed in the transoral approach for tumor surgery of the hypopharynx, whereas the use of AI is still limited even if possible applications would be automated virtual planning and monitoring systems.

CONCLUSION

The use of digitalized methods and AI are adjuncts to microvascular reconstruction. Automatization approaches and simplification of technologies will provide such applications to a broader clientele in the future; however, in CMFS, robotic-assisted resections and automated flap monitoring are not yet the standard of care.

Fibula free flap in maxillomandibular reconstruction. Factors related to osteosynthesis plates' complications

The aim of this paper is to identify risk factors associated with the development of osteosynthesis plates' related complications in fibula free flap reconstructions. This is a case series study of consecutive fibula free flaps. Clinical and radiological variables were recorded. Patient outcomes were evaluated with special attention to osteosynthesis plates' related complications; these included plate exposure, plate fracture, loosening of screws, non-union, bone resorption, oro-cutaneous fistulas, and bone exposure. We have done a descriptive analysis, univariate analysis, and multivariate logistic regression model to explore possible risk factors for osteosynthesis plates' related complications. Data analysis was performed using R software (version 3.5.0). 111 fibula free flaps were studied. 29 patients (26.1%) developed osteosynthesis plates' related complications. The mean time to osteosynthesis plates' related complications was 22 months; range (1-120); the median and mode were 12 months. Patients with preoperative radiotherapy (34% vs 14%, p = 0.021), and secondary reconstruction (31% vs 15%, p = 0.053) had a higher incidence of osteosynthesis plates' related complications. In the univariate analysis, "preoperative radiotherapy" (OR 3.07, 95%CI = 1.139-8.242, p = 0.025) and "extraoral soft-tissue defect" (OR 2.907, 95%CI = 1.032-8.088, p = 0.042) were risk factors for osteosynthesis plates' related complications. We have observed an interaction effect: patients with mandibular Brown's classes III + IV and "secondary reconstruction" have a higher risk for osteosynthesis plates' related complications; more than 47.30 times compared to Brown's class I and "primary reconstruction" (p = 0.026). Different factors may contribute to the development of osteosynthesis plates' related complications. Our study adds important information about these. Patients with higher risk of developing complications should be informed that a second intervention to remove the plates might be necessary.

[3D-assisted mandibular reconstruction: A technical note of fibula free flap with preshaped titanium plate]

The purpose of this technical note is to illustrate a simple and economical preoperative method for preshaping a reconstructive titanium plate in a fibula free flap (FFF) by using 3D printing of a virtually reconstructed mandible haptic model. The whole process consisted in creating a 3D model of the patient's mandible based on a CT-scan using a combination of free software (3Dslicer and ITK-snap), and simulating the surgical osteotomies and reconstruction, and print it as a guide for bending a reconstruction titanium plate. Reconstruction is performed using virtual cubes (1 to 3 cubes, according the number of FFF osteotomies). This virtual lab work is performed using 3D Builder® (Microsoft, Redmond) software. This technique allows obtaining an optimal plate application on the bony fragments. It facilitates reconstructive surgery with good functional (putting the patient back in an optimal dental occlusion based on the native maxilla) and aesthetic results. This technical note presents a simple and economical preoperative fabrication of a reconstructive plate through freeware and a low-cost 3D printer accessible to all surgeons.

Virtual surgical planning and cone beam computed tomography in reconstruction of head and neck tumors - pilot study

&lt;b&gt;Introduction:&lt;/b&gt; The aim of the study was to prove that a combination of visual surgical planning (VSP) and cone beam computed tomography (CBCT) is an optimal technique in fibular free flap reconstructions after complex tumor resections in the head and neck region and that it leads to better functional and aesthetic outcomes. &lt;br&gt;&lt;b&gt;Material and method:&lt;/b&gt; Six patients (3 females, 3 males) with head and neck tumors were included in the study. The region concerned midface in 2 cases and mandible in 4 patients. On the basis of computed tomography of the head, fibular free flap (FFF) reconstruction was planned with the VSP technique. The 3D-printed models were prepared. At the beginning of the operation and a few minutes after the reconstruction, an xCAT CBCT by XORAN was performed. Minor corrections of the angles of the reconstructed bony parts were made where needed. The time of the operation was assessed for each case. Functional and cosmetic results were evaluated in a 1-year follow-up. &lt;br&gt;&lt;b&gt;Results:&lt;/b&gt; The mean time of operation was 6 hours and 48 minutes, which was approximately 1hour and 40 minutes less than standard reconstructive surgery. Functional recovery was achieved in all patients. Aesthetic result was unsatisfactory for 2 patients due to insufficient soft tissue masses of FFF. &lt;br&gt;&lt;b&gt;Conclusions:&lt;/b&gt; The authors claim that intraoperative CBCT imaging, regardless of the cost, improves the accuracy of aesthetic outcome of reconstructive surgeries based on VSP, especially in the region of the midface and the mandible. Further studies on a higher number of subjects are required.

CAD-CAM vs conventional technique for mandibular reconstruction with free fibula flap: A comparison of outcomes

INTRODUCTION

Mandibular reconstruction always pose a challenge to the reconstructive surgeon. With the use of Computer aided designing and computer aided manufacturing (CAD-CAM) it is now possible to reconstruct mandibular defects to near normal configuration with good function and aesthetic outcomes.

AIMS/OBJECTIVES

To compare the efficacy of CAD-CAM technique vs conventional technique in mandibular reconstruction with free fibula flap.

MATERIALS AND METHODS

40 consecutive patients that required mandibular reconstruction using free fibula flap were included in the study. All patients were treated using CAD-CAM technique and then compared retrospectively with 40 patients treated with conventional technique. Comparison was done between total intraoperative time, aesthetic outcome and post-operative occlusion.

RESULTS

Total intraoperative time in the CAD-CAM group was significantly reduced (562 min) as compared to the conventional group (662 min). Patients in the CAD-CAM group also obtained a better Aesthetic score (3.6/5) when compared to the conventional group (2.5/5). Postoperative malocclusion was noted in 1 patient in the CAD-CAM group as opposed to 6 patients in the conventional group.

CONCLUSION

Use of CAD-CAM technology in mandibular reconstruction with free fibula flap offers reduced surgical time with precise and accurate reconstruction that produces better functional and aesthetic outcomes.