Osteomyocutaneous fibular flap harvesting: Computer-assisted planning of perforator vessels using Computed Tomographic Angiography scan and cutting guide

Development of a Cutting Guide for Osteocutaneous Radial Forearm Free Flap Harvest

OBJECTIVES

The osteocutaneous radial forearm free flap (OCRFFF) is used for the reconstruction of bony head and neck defects. Being a weight-bearing bone, precise harvesting of the radius is required to maintain structural integrity, postoperative forearm function, and to prevent postoperative fracture. A radius cutting guide may allow head and neck surgeons to be more precise and confident in performing bony harvest, and may improve allocation of orthopedic specialist resources.

METHODS

A custom radius cutting guide was developed in an iterative process with six head and neck surgeons and one hand surgeon. Following design approval, a prospective feasibility study was conducted. Patient-specific cutting guides were created using pre-operative upper-extremity computed tomography (CT) scans. The length and cross-sectional width of harvested radius bone were measured. The length of time using the guide was recorded. Providers were surveyed to assess their perception of cutting guide utility.

RESULTS

A total of eight patients were enrolled, and the cutting guide was used successfully in seven patients. The mean length of the radius harvested was 77.1 ± 13.8 mm. The mean cross-sectional width of the radius planned for harvest was 11.7 ± 1.7 mm. The mean width of the bone harvested was 12.1 ± 1.2 mm, with a mean difference of + 0.81 mm. The mean total time using the guide was 12.94 min (range 10.0-20.1 min). Survey respondents (n = 7) agreed that the guide did not interfere with their ability to harvest radius bone (mean response 9.0 ± 1.3) and that they would utilize the guide in practice (9.4 ± 1.1).

CONCLUSIONS

Patient-specific cutting guides for OCRFFF harvest are feasible and may improve head and neck reconstructive surgeons' comfort with harvest.

LEVEL OF EVIDENCE: 3

Adjustable Single-Osteotomy Fibular Free Flap for Anterior Mandibular Defects in Irradiated Head and Neck Cancers-A Case Series

Objective: Reconstructing the anterior mandible in patients with irradiated and contracted soft tissues remains challenging despite advances in computer-assisted design and three-dimensional printing. Unpredictable soft-tissue changes reduce the effectiveness of these technologies. This paper explores an alternative using a single-adjustable-osteotomy fibula flap technique. Methods: A retrospective study was performed on patients with anterior segmental mandibular defects due to recurrent tumors, secondary reconstruction, or osteoradionecrosis and previously received radiotherapy who represented the highest risk of soft tissue complexity while limiting the utility of computer technology. All patients underwent mandible reconstruction using the adjustable, single-osteotomy fibula method, which eliminated the need for computer-assisted design. We evaluated the effectiveness and outcome. Results: From 2016 to 2023, 11 patients were included in this study. The median patient age was 58 (ranging 49-65) years. Included patients had either recurrent tumors (n = 6), secondary reconstruction needs (n = 3), or mandibular osteoradionecrosis (n = 2). No complete flap failures occurred. Five of six patients with recurrent cancer required two skin island fibular flaps for intraoral and external defect repair. One patient experienced partial skin paddle loss requiring an additional free flap, and another had plate exposure requiring removal after bone union was achieved. Conclusions: The adjustable single-osteotomy fibula flap technique offers a reliable alternative for anterior mandibular reconstruction in complex cases. This approach demonstrates advantages in surgical simplicity and flexibility while maintaining acceptable outcomes. However, careful patient selection and consideration of defect extent remain crucial for success.

Factors affecting anastomosis failure in microvascular fibula flap reconstruction of the maxillofacial region: a systematic review and meta-analysis

This systematic review and meta-analysis evaluates the contributory factors and failure rates in anastomosis during microvascular fibula flap reconstruction in maxillomandibular regions. A comprehensive search strategy was employed across databases including MEDLINE, Web of Science, EMBASE, Scopus, Cochrane's CENTRAL, as well as grey literature sources, and manual searches of noteworthy journals, covering studies from inception up to April 2023. The inclusion criteria targeted retrospective or prospective cohort and clinical studies that investigated functional and dental rehabilitation outcomes in human subjects undergoing maxillofacial reconstruction using microvascular fibula flaps. Exclusion criteria encompassed case-control studies, alternative reconstruction method research, and animal-based investigations. The study's findings revealed a cumulative vascular failure rate of 6%. Subsequent analysis delineated the primary causes of this failure, attributing 3% to venous thrombosis, 1% to arterial thrombosis, and less than 1% to blood vessel compression due to hematoma. However, notable heterogeneity across the studies indicates substantial variability in vascular failure rates reported. These results of our review and meta-analysis underscore the intricate factors impacting anastomosis success, such as anastomosis technique, recipient vessel quality, the choice between couplers.

The clinical application and anatomical analysis of proximal peroneal artery perforator in free fibula flap based on CTA

BACKGROUND

The vascularized free fibular flap is increasingly recognized as the standard technique for the repair of complex soft tissue and hard tissue defects in oral and maxillofacial surgery. Conventionally, the vascular supply to the skin island is derived from the distal perforators of the peroneal artery. However, complications may arise if these distal perforators are either absent or damaged during surgical procedures, highlighting the necessity to employ the proximal peroneal perforators as an alternative. This study aims to investigate the anatomical characteristics-including the presence, distribution, and origin-of proximal peroneal perforators through computed tomography angiography (CTA) prior to surgical intervention. A secondary objective is to confirm their viability when distal perforators are unavailable or when dual-skin paddles are needed.

METHODS

A comprehensive review was conducted involving 50 patients who underwent CTA examinations. Three-dimensional reconstruction of DICOM data was utilized to document the presence, quantity, location, and variations of proximal perforators. Relative positions of the origin points were measured, and the distances from these points to the fibula were calculated. Additionally, 11 studies were included in which a proximal perforator was successfully used to prepare a free fibula chimeric myocutaneous flap for the reconstruction of maxillofacial defects.

RESULTS

Among the 100 lower limbs evaluated, a successful identification rate of 98% for proximal perforators was achieved via CTA. Of those identified, 70% were found to originate from the fibular artery, 22% branched concurrently with it, and 8% emerged prior to the point of emergence of the fibular artery. Analysis through curve fitting indicated that the origin points of proximal perforators were predominantly located approximately 13.17 mm below the origin of the fibular artery, with their endpoints projecting about 123.9 mm below the fibular head.

CONCLUSIONS

The high prevalence of proximal peroneal perforators identified in this population, along with their relatively stable anatomical positions, suggests their significant surgical potential. In scenarios where the distal peroneal perforator is absent or suffers intraoperative injury, the proximal peroneal perforator can serve as a reliable alternative for preparing a free fibula osteal flap combined with a proximal peroneal perforator skin paddle.

Closure of the osteocutaneous fibula flap donor site with a tonearm (propeller) flap: Anatomic considerations and surgical indications

BACKGROUND

Skin graft is frequently used for donor site closure after osteocutaneous fibula free flap (OCFFF) harvest when primary closure is not possible. Partial skin graft loss requiring wound care is a common complication. The purposes of this prospective study were to investigate the perforator anatomy for local propeller or tonearm flap closure and compare the outcomes to those of skin graft closure.

METHODS

All patients undergoing OCFFF for head and neck reconstruction from February 2022 to October 2023 were considered for the tonearm flap. Intraoperative perforator anatomy was prospectively recorded. Surgical techniques and criteria for tonearm flap reconstruction were described. A minimum follow-up period of 6 months was required. Outcome measures included the rate of flap success and wound complications.

RESULTS

Forty consecutive patients were included. The tonearm flap was not possible in 16 patients (40%) due to unfavorable perforator anatomy and 2 patients underwent primary closure. All successful tonearm flaps were eccentrically designed on a proximal lower leg perforator, located 13.5 ± 1.99 cm from the fibular head. Most proximal perforators were musculocutaneous through the soleus muscle (n = 20, 90.9%), whereas the rest were septocutaneous (n = 2, 9.1%), originating from the peroneal artery. Three patients experienced distal partial flap loss; one required an additional skin graft. Only half of the skin graft cohort (n = 99, 50.8%) achieved complete skin graft take. The average skin graft loss was 34.3%, and wound care was required for an average period of 51.6±52.8 days.

CONCLUSIONS

The study findings demonstrate that local tonearm flaps, when anatomically feasible, can be successfully performed with superior outcomes compared to skin graft closures.

The Role of Computed Tomography Angiography in Perforator Flap Planning

Preoperative computed tomography angiography (CTA) for perforator free flaps is accurate, precise, and reliable in mapping perforator anatomy that can be used in the intraoperative domain. CTA holds important clinical value as a tool in surgical decision making and surgical innovation, enabling reconstructive surgeons to tailor complex flap designs for extensive defects. Integration into existing infrastructure for virtual surgical planning is feasible, and future efforts to characterize the association of preoperative CTA with postoperative outcomes and cost-analyses for perforator flaps are warranted.

Identification of peroneal artery perforators using non-contrast-enhanced T2prep multi-shot gradient echo planar imaging MRA

The purpose of this study was to investigate the spatial resolution of non-contrast-enhanced (CE) T2prep multi-shot gradient echo planar imaging (MSG-EPI) magnetic resonance angiography (MRA) required to identify peroneal artery perforators and demonstrate its effectiveness in preoperative simulation. Twenty-six legs of 13 volunteers were scanned using non-CE T2prep MSG-EPI-MRA at three spatial resolutions: 1.0-, 0.8-, and 0.6-mm isotropic voxels. The location and number of peroneal artery perforators that could be candidates for free fibula flaps were identified by consensus among three plastic surgeons. Surgeons distinguished between septocutaneous and musculocutaneous perforators using MRA, and confirmed the accuracy of their presence and identification using ultrasonography (US). The ability to detect hypoplasia or stenosis of the anterior tibial, posterior tibial, and peroneal arteries was evaluated by confirming the consistency between the MRA and US results. The number of cutaneous perforators identified using MRA and confirmed using US was 39, 51, and 52 at each respective resolution. The discrimination accuracies between septocutaneous and musculocutaneous perforators were 92.3%, 96.1%, and 96.2%. The number of identified septocutaneous perforators was 1.3 ± 0.6, 1.6 ± 0.8, and 1.7 ± 0.8 at 1.0-, 0.8-, and 0.6-mm data, respectively. All the MRA results, including hypoplasia and stenosis, were consistent with the US results. Non-CE T2prep MSG-EPI-MRA with a spatial resolution of 0.8 mm or less shows promise for identifying septocutaneous perforators of the peroneal artery, suggesting its potential as an alternative to conventional imaging methods for the preoperative planning of free fibula osteocutaneous flap transfers.

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.

Comparison of the efficacy of low-molecular-weight heparin and fondaparinux sodium after total knee arthroplasty: a retrospective cohort study

BACKGROUND

Low-molecular-weight heparin (LMWH) and fondaparinux sodium (FPX) are routinely used to prevent deep vein thrombosis (DVT) after total knee arthroplasty (TKA). In this study, we compared the effects of these agents in preventing post-TKA DVT.

METHODS

Clinical data of patients who underwent unilateral TKA for unicompartmental knee osteoarthritis at the Ningxia Medical University General Hospital between September 2021 and June 2022 were retrospectively analyzed. Based on the anticoagulation agent used, the patients were divided into LMWH and FPX groups (34 and 37 patients, respectively). Changes in perioperative coagulation-related indicators, d-dimer and platelet count, perioperative complete blood count, amount of blood loss, lower-limb DVT, pulmonary embolism, and allogeneic blood transfusion were determined.

RESULTS

Intergroup differences in d-dimer or fibrinogen (FBG) levels before and 1 or 3 days after surgery were not significant (all p > 0.05); within-group pairwise comparisons indicated significant differences (all, p < 0.05). Intergroup differences in preoperative prothrombin time (PT), thrombin time, activated partial PT, and international normalized ratio were not significant (all p > 0.05), whereas significant differences were detected on postoperative days 1 and 3 (all p < 0.05). Intergroup differences in platelet counts before and 1 or 3 days after surgery were not significantly different (all p > 0.05). Pairwise comparisons of hemoglobin and hematocrit levels between patients in the same group before and 1 or 3 days after surgery revealed significant differences in both groups (all p < 0.05); however, intergroup differences were not significant (all p > 0.05). Although intergroup differences in visual analog scale (VAS) scores before and 1 or 3 days after surgery were not significant (p > 0.05), we detected significant intragroup differences in VAS scores before and 1 or 3 days after surgery (p < 0.05). The treatment cost ratio was significantly lower in the LMWH group than in the FPX group (p < 0.05).

CONCLUSION

Both LMWH and FPX can effectively prevent DVT after TKA. There are some suggestive signals that FPX may have more beneficial pharmacological effects and clinical significance, while LMWH is cheaper and therefore more economical.

Thrombophilia and Preoperative Deep Venous Thrombosis and Their Effect on Free Flap Survival: A Scoping Review

Background: A proper preoperative planning is essential to prevent flap failure. However, venous workup for flaps has not been commonly performed or utilized as a preoperative screening tool. A scoping review was conducted to explore preoperative venous system screening, including deep vein thrombosis diagnosis, and its effect on flap survival rate. This review identified existing gaps of knowledge and emphasized potential research areas for future studies. Methods: Two independent reviewers searched 3 electronic databases from inception to September 2020. Retrieved appropriate articles were selected systematically by title, abstract, and full review of the article. Studies were included if they enrolled patients who had thrombophilia or deep venous thrombosis (DVT) preoperatively and had undergone a free flap reconstruction. For eligible studies, the following information was extracted: basic demographics (sex, age, comorbidities), preoperative scans type, free flap type, clotting mode (causes), wound type, and flap survival. Results: Seventeen articles were found eligible for this review. Traumatic aetiology was found in 63 (33.6%) patients, while 124 (66.3%) patients had a non-traumatic aetiology. Preoperative screening for patients with non-traumatic aetiology was reported in 119 patients. In these patients, the flap survived in 107 (89.91%) patients. Four studies investigating patients with traumatic DVT aetiology, 60 patients (out of 63) had a preoperative computed tomography angiography or duplex. Those patients had 100% flap survival rates. Conclusion: Further investigations are required to identify venous thrombosis incidence in patients with non-traumatic thrombosis aetiology as this cohort of patients is at high risk of flap failure. Finally, the prognostic validity of available preoperative screening tools to identify high-risk patients should be assessed, such as imaging techniques, which would include venous duplex scanning, may prevent failure in free flap surgery.

Limitations of Computed Tomography Angiography in Preoperative Planning of Peroneus Brevis Rotational Flap

The distally based peroneus brevis (PB) rotational flap has been shown to be a reliable method of coverage of distal third tibial wounds. The flap is perfused via retrograde flow from distal PB perforators located within 8 cm of the lateral malleolus. The ability to assess patency of these vessels preoperatively facilitates surgical planning, and computed tomography angiography (CTA) has been used for perforator assessment of other lower extremity flaps. The purpose of the present study is to establish the potential utility of standard CTA for locating distal PB perforators by examining uninjured lower extremities.

Methods

Twenty-five patients who underwent bilateral lower extremity CTAs using standard lower extremity protocol were retrospectively identified. Axial two-dimensional images were scanned craniocaudally using our institution's standard CT image viewing software, Merge Radsuite (Merge Healthcare, Hartland, Wis.).

Results

The average location of distal-most PB perforators identified on CT angiogram was 13.1 ± 5.1 cm proximal to the distal fibula, or 34.5% ± 13.5% of total fibular length. Standard CTA was only able to locate a pedicle within 8 cm of the lateral malleolus (20.9% of fibular length) in three of 25 patients (12%).

Conclusions

Previous studies have described a reliable pedicle within 8 cm of the distal fibular tip upon which to design a distally based PB rotational flap. The absence of such perforators in the CT angiogram suggests that standard CT angiogram is not a reliable technique for identifying the patency of such perforators when evaluating the utility of a distally based PB flap.

Vascularized Fibula TMJ Reconstruction: A Report of Five Cases featuring Computerized Patient-specific Surgical Planning

BACKGROUND

Mandibular defects involving the condyle represent a complex reconstructive challenge for restoring proper function of the temporomandibular joint because it requires precise bone graft alignment, or alloplastic materials, for complete restoration of joint function. The use of computerized patient-specific surgical planning (CPSSP) technology can aid in the anatomic reconstruction of mandibular condyle defects with a vascularized free fibula flap without the need for additional adjuncts. The purpose of this study was to analyze clinical and functional outcomes after reconstruction of mandibular condyle defects using only a free fibula graft with the assistance of virtual surgery techniques.

METHODS

A retrospective review was performed to identify all patients who underwent mandibular reconstruction utilizing CPSSP with only a free fibula flap without any temporomandibular joint adjuncts after a hemimandibulectomy with total condylectomy.

RESULTS

From 2018 to 2021, five patients underwent reconstruction of mandibular defects involving the condyle with CPSSP technology and preservation of the native temporomandibular articulating disk. The average age was 62 years (range, 44-73 years). The average follow-up period was 29.2 months (range, 9-46 months). Flap survival was 100% (N = 5). The maximal interincisal opening range for all patients was 22-45 mm with no lateral deviation or subjective joint pain. No patients experienced progressive joint hypomobility or condylar migration.

CONCLUSION

The use of CPSSP technology can aid in the anatomic reconstruction of mandibular condyle defects with a vascularized free fibula flap through precise planning and intraoperative manipulation with optimal functional outcomes.

Computed tomography angiography-aided individualized anterolateral thigh flap design in the reconstruction of oral and maxillofacial soft tissue defects

PURPOSE

To evaluate a novel method and computed tomography angiography (CTA) for locating anterolateral thigh flap (ALTF) perforators to design individualized ALTFs to reconstruct maxillofacial soft tissue defects.

STUDY DESIGN

This study comprised a group of 36 patients (CTA group) with malignant oral and maxillofacial tumors who underwent CTA and who received individualized ALTFs and a group of 28 patients (control group) with the same condition but without preoperative CTA examination and with nonindividualized ALTFs. ALTFs in the CTA group were designed and harvested using the locating device and CTA, whereas ALTFs in the control group were designed and harvested according to each surgeon's experience.

RESULTS

Fifty perforators were located and 36 ALTFs harvested in the CTA group. In the control group, 34 perforators were located and 28 ALTFs harvested. Less time was required to locate the perforators in the CTA group. Moreover, the CTA group had a higher flap survival rate and better patient satisfaction regarding the postoperative aesthetics and phonetic and swallowing functions.

CONCLUSIONS

The results suggest that CTA and the locating device can be used to accurately locate ALTF perforators and that this method aids in the design and harvesting of individualized ALTFs to achieve good functional and aesthetic outcomes.

Augmented Reality to Assist Skin Paddle Harvesting in Osteomyocutaneous Fibular Flap Reconstructive Surgery: A Pilot Evaluation on a 3D-Printed Leg Phantom

Background

Augmented Reality (AR) represents an evolution of navigation-assisted surgery, providing surgeons with a virtual aid contextually merged with the real surgical field. We recently reported a case series of AR-assisted fibular flap harvesting for mandibular reconstruction. However, the registration accuracy between the real and the virtual content needs to be systematically evaluated before widely promoting this tool in clinical practice. In this paper, after description of the AR based protocol implemented for both tablet and HoloLens 2 smart glasses, we evaluated in a first test session the achievable registration accuracy with the two display solutions, and in a second test session the success rate in executing the AR-guided skin paddle incision task on a 3D printed leg phantom.

Methods

From a real computed tomography dataset, 3D virtual models of a human leg, including fibula, arteries and skin with planned paddle profile for harvesting, were obtained. All virtual models were imported into Unity software to develop a marker-less AR application suitable to be used both via tablet and via HoloLens 2 headset. The registration accuracy for both solutions was verified on a 3D printed leg phantom obtained from the virtual models, by repeatedly applying the tracking function and computing pose deviations between the AR-projected virtual skin paddle profile and the real one transferred to the phantom via a CAD/CAM cutting guide. The success rate in completing the AR-guided task of skin paddle harvesting was evaluated using CAD/CAM templates positioned on the phantom model surface.

Results

On average, the marker-less AR protocol showed comparable registration errors (ranging within 1-5 mm) for tablet-based and HoloLens-based solution. Registration accuracy seems to be quite sensitive to ambient light conditions. We found a good success rate in completing the AR-guided task within an error margin of 4 mm (97% and 100% for tablet and HoloLens, respectively). All subjects reported greater usability and ergonomics for HoloLens 2 solution.

Conclusions

Results revealed that the proposed marker-less AR based protocol may guarantee a registration error within 1-5 mm for assisting skin paddle harvesting in the clinical setting. Optimal lightening conditions and further improvement of marker-less tracking technologies have the potential to increase the efficiency and precision of this AR-assisted reconstructive surgery.

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.

Procedure Increasing the Accuracy of Modelling and the Manufacturing of Surgical Templates with the Use of 3D Printing Techniques, Applied in Planning the Procedures of Reconstruction of the Mandible

The application of anatomical models and surgical templates in maxillofacial surgery allows, among other benefits, the increase of precision and the shortening of the operation time. Insufficiently precise anastomosis of the broken parts of the mandible may adversely affect the functioning of this organ. Applying the modern mechanical engineering methods, including computer-aided design methods (CAD), reverse engineering (RE), and rapid prototyping (RP), a procedure used to shorten the data processing time and increase the accuracy of modelling anatomical structures and the surgical templates with the use of 3D printing techniques was developed. The basis for developing and testing this procedure was the medical imaging data DICOM of patients treated at the Maxillofacial Surgery Clinic of the Fryderyk Chopin Provincial Clinical Hospital in Rzeszów. The patients were operated on because of malignant tumours of the floor of the oral cavity and the necrosis of the mandibular corpus, requiring an extensive resection of the soft tissues and resection of the mandible. Familiarity with and the implementation of the developed procedure allowed doctors to plan the operation precisely and prepare the surgical templates and tools in terms of the expected accuracy of the procedures. The models obtained based on this procedure shortened the operation time and increased the accuracy of performance, which accelerated the patient’s rehabilitation in the further course of events.

The two-handed template for planning fibular free flap reconstruction of the head and neck

Fibular free flap reconstruction of head and neck defects is complex, and the anatomic relationships among components of the fibular flap pose challenges to reconstructive surgeons. Various techniques have been employed in planning for fibular free flap procedures, but these are often cumbersome and difficult to implement in clinically. We devised a simplistic tool for pre-operative leg selection, wherein the surgeon uses two hands to represent the various components of the fibular flap. The senior author has used this method to aid in leg selection for fibular free flaps. In all cases, utilization of this technique allowed for appropriate leg selection relative to the location of the vascular pedicle and posterior crural septum. The two-handed template for fibular free flap reconstruction is a simple, reproducible, and affordable tool that can aid reconstructive surgeons when they are planning to use a fibular flap.

Computed Tomography Angiography (CTA) before Reconstructive Jaw Surgery Using Fibula Free Flap: Retrospective Analysis of Vascular Architecture

Computed tomography angiography (CTA) is widely used in preoperative evaluation of the lower limbs' vascular system for virtual surgical planning (VSP) of fibula free flap (FFF) for jaw reconstruction. The present retrospective clinical study analysed n = 72 computed tomography angiographies (CTA) of lower limbs for virtual surgical planning (VSP) for jaw reconstruction. The purpose of the investigation was to evaluate the morphology of the fibular bone and its vascular supply in CTA imaging, and further, the amount and distribution of periosteal branches (PB) and septo-cutaneous perforators (SCPs) of the fibular artery. A total of 144 lower limbs was assessed (mean age: 58.5 ± 15.3 years; 28 females, 38.9%; 44 males, 61.1%). The vascular system was categorized as regular (type I-A to II-C) in 140 cases (97.2%) regarding the classification by Kim. Absent anterior tibial artery (type III-A, n = 2) and posterior tibial artery (type III-B, n = 2) were detected in the left leg. Stenoses were observed mostly in the fibular artery (n = 11), once in the anterior tibial artery, and twice in the posterior tibial artery. In total, n = 361 periosteal branches (PBs) and n = 231 septo-cutaneous perforators (SCPs) were recorded. While a distribution pattern for PBs was separated into two clusters, a more tripartite distribution pattern for SCPs was found. We conclude that conventional CTA for VSP of free fibula flap (FFF) is capable of imaging and distinguishing SCPs and PBs.

Impact of Planning Method (Conventional versus Virtual) on Time to Therapy Initiation and Resection Margins: A Retrospective Analysis of 104 Immediate Jaw Reconstructions

Simple Summary

Computer-aided design and manufacturing of osseous reconstructions are currently widely used in jaw reconstructive surgery, providing an improved surgical outcome and decreased procedural stumbling block. However, data on the influence of planning time on the time-to-surgery initiation and resection margin are missing in the literature. This retrospective, monocentric study compares process times from the first patient contact in hospital, time of in-house or out-of-house biopsy for tumor diagnosis and surgical therapy of tumor resection, and immediate reconstruction of the jaw with free fibula flaps (FFF). Two techniques for reconstruction are used: Virtual surgical planning (VSP) and non-VSP. A total of 104 patients who underwent FFF surgery for immediate jaw reconstruction from 2002 to 2020 are included. The study findings fill the gaps in the literature and obtain clear insights based on the investigated study subjects.

Abstract

Virtual surgical planning (VSP) and patient-specific implants are currently increasing for immediate jaw reconstruction after ablative oncologic surgery. This technique contributes to more accurate and efficient preoperative planning and shorter operation time. The present retrospective, single-center study analyzes the influence of time delay caused by VSP vs. conventional (non-VSP) reconstruction planning on the soft and hard tissue resection margins for necessary oncologic safety. A total number of 104 cases of immediate jaw reconstruction with free fibula flap are included in the present study. The selected method of reconstruction (conventionally, non-VSP: n = 63; digitally, VSP: n = 41) are analyzed in detail. The study reveals a statistically significant (p = 0.008) prolonged time to therapy initiation with a median of 42 days when the VSP method compared with non-VSP (31.0 days) is used. VSP did not significantly affect bony or soft tissue resection margin status. Apart from this observation, no significant differences concerning local tumor recurrence, lymph node, and distant metastases rates are found according to the reconstruction method, and affect soft or bone tissue resection margins. Thus, we conclude that VSP for immediate jaw reconstruction is safe for oncological purposes.

Osteosarcoma of the Jaws: A Literature Review

Osteosarcoma of the jaws (OSJ) is a relatively rare disease, accounting for between 2% and 10% of all cases of osteosarcoma. It is morphologically and radiologically identical to the trunk and extremity variant, but distinct in several crucial aspects. The lesion is characterized by sarcomatous cells which produce a variable amount of osteoid bone. It arises centrally within the bone and can be subdivided into osteoblastic, chondroblastic and fibroblastic subtype, depending on the predominant cell type. Radiographically, these tumors display a spectrum of bone changes from well-demarcated borders to lytic bone destruction with indefinite margins and variable cortical bone erosion or, in some cases, images of sclerotic bone. Therapeutic options for OSJ include surgery, chemotherapy and radiotherapy, which are employed according to age of the patient, histological classification and localization of the tumor. Today, there is no general consensus in the treatment guidelines for the OSJ though surgery represents the key to the treatment. The main prognostic factor deeply influencing the patient's prognosis remains the complete tumor resection with negative surgical margins. The aim of the present review is to describe state of the art regarding diagnostic and surgical treatment aspects of the primary osteosarcoma of the jaws.

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.

Use of Kinesiography to Assess Mandibular Function Following Segmental Resection and Microvascular Reconstruction

Mandibular reconstruction has attained adequate morphological outcomes. However, some patients encounter difficulties in oral function and limited mandibular movements. An objective: evaluation has seldom featured actual kinetic measurements after mandibular reconstruction.Thirty patients who underwent mandibular reconstruction using bony free flap were enrolled in the study. Twenty-two patients were recruited after surgery and compared to a control group of 8 healthy subjects; 8 patients underwent both pre and postoperative evaluations. For each patient, a kinesiographic scan was obtained, recording maximum mouth opening, maximal laterality, and maximal protrusion.All postoperative kinesiographic evaluations were performed at least 6 months after surgery to ensure complete healing. In the first group of 22 patients, all measured movements were less than those of healthy controls, in particular maximum mouth opening. In the second study group (pre and postoperative evaluation), the postsurgical values did not achieve the control ones, but were no less than the preoperative values, granting adequate functional outcomes.The kinesiograph appears useful for objectively recording the functional outcomes in patients who have undergone mandibular reconstruction. The postoperative jaw movements were acceptable, ensuring a sufficient functional recovery.

Combination of CAD/CAM and Augmented Reality in Free Fibula Bone Harvest

Supplemental Digital Content is available in the text.

The CAD/CAM technology for mandibular reconstruction has improved the results in terms of outcomes in restoring mandibular complex defects. Augmented reality (AR) represents an evolution of the navigation-assisted surgery. This technology merges the images of the virtual planning with the anatomy of the patient, representing in this way an enhanced scene for the surgeon’s eye. AR can also display in a single scene additional information for the surgeon. Despite of classical navigation, this scenario can be obtained with marker-less registration method, without using reference points or fiducial markers. This technologic evolution together with the large use in our experience of CAD/CAM protocol for mandibular reconstruction we developed this feasibility study to evaluate the possibility of using a marker-less image registration system. Moreover, we tried to evaluate the overlaying of the virtual planning and its reproducibility using AR. We performed a case series of 3 consecutive patients who underwent mandibular reconstruction using AR-assisted fibular free flap harvesting applying our digital workflow. Once launched, the mobile app installed on our tablet, the registration is performed according to a shape recognition system of the leg of the patient, rendering in real time a superimposition of the anatomy of the bony, vascular, and skin of the patient and also the surgical planning of the reconstruction. AR-assisted fibular free flap harvesting was performed. We believe that AR can be a prospective improving technology for mandibular complex reconstruction.

Computer-assisted surgery for reconstruction of complex mandibular defects using osteomyocutaneous microvascular fibular free flaps: Use of a skin paddle-outlining guide for soft-tissue reconstruction. A technical report

INTRODUCTION

We present our pre-operative virtual planning of complex mandibular reconstruction with a microvascular fibular composite free flap and its harvesting using our novel cutaneous positioning guide based on the perforator vessels for our soft tissue reconstructive surgery.

TECHNICAL REPORT

We applied our protocol to 42 consecutive patients needing mandibular composite reconstruction. All patients were preoperatively studied with a CTA scan to evaluate the fibular pattern of vascularization and the perforator vessels three-dimensional path and position. Computer assisted surgery (CAS) was performed: a skin paddle outlining guide (SPOG) was designed to reproduce the shape and area of the planned soft tissue resection. CTA measurements and in vivo findings were compared. After performing the CTA, we classified the viable perforators in High Perforators, Medium Perforators and Low Perforators. The average diameter of the perforator vessels was 3 mm. The average difference between the measurements performed on the CTA and the intra-operative measures was 1, 4 mm. The SPOG was based on calf proximal and distal diameters. The anatomical fitting of the guide was obtained thanks to two customized flanges that embrace circumferentially the proximal and distal portions of the leg. The SPOG encompassed appropriate skin/leg regions, allowing the surgeon to localise the required perforator vessel.

CONCLUSIONS

CTA protocol appears to be a valuable approach to asses and virtually simulate composite mandibular reconstructions. The SPOG seems to be a valuable tool to reproduce intra-operatively the planned soft tissue area to be reconstructed.

Accuracy of CAD/CAM mandibular reconstruction: A three-dimensional, fully virtual outcome evaluation method

PURPOSE

Computer-aided design/computer-aided manufacturing (CAD/CAM) methods for mandibular reconstruction have improved both functional and morphological results. We evaluated the accuracy of the CAD/CAM method for mandibular reconstruction and assessed the quantitative and qualitative reproducibility of virtual preoperative planning.

MATERIALS AND METHODS

A total of 34 consecutive patients treated with mandibular reconstruction using the CAD/CAM method between January 2011 and October 2017 were included in this study. The accuracy of the reconstruction was assessed using the automated Hausdorff distance function of the simulation software, which set the postoperative mesh as the target. This made it possible to calculate the minimum error, the maximum error, and the mean error for each reconstruction in exactly the same way and with the same settings as the difference between the postoperative mesh and virtual planning. Finally, the coloured quality mapper function was applied to superimposition of the STL files, allowing us to visually render the obtained data on differences between preoperative planning and surgical outcome.

RESULTS

The average mean error obtained after performing an accuracy evaluation of our reconstructions was 1 mm (range 0.4-2.46 mm). Based on the colour map areas, the maximum error was located in the symphysis area. The body and ramus areas showed the greatest accuracy in terms of planning reproducibility.

CONCLUSION

This is the first study to assess the three-dimensional reproducibility of virtual planning using the CAD/CAM method for mandibular reconstruction, in a homogeneous sample of 34 cases. Our data suggest that CAD/CAM microvascular reconstruction can result in a very high degree of reproducibility. This occurs in complex areas as well as the condylar region and in the case of extensive mandibular reconstructions.

Computed Tomographic Angiography Perforator Localization for Virtual Surgical Planning of Osteocutaneous Fibular Free Flaps in Head and Neck Reconstruction

Virtual surgical planning (VSP), computer-aided design and computer-aided modeling, and 3-dimensional printing are 3 distinct technologies that have become increasingly employed in head and neck oncology and microvascular reconstruction. Although each of these technologies have long been utilized for treatment planning in other surgical disciplines such as craniofacial surgery, trauma surgery, temporomandibular joint surgery, and orthognathic surgery, its widespread use in head and neck reconstructive surgery remains a much more recent advent. In response to the growing trend of VSP being used for the planning of fibular free flaps in head and neck reconstruction, some surgeons have questioned the technology's implementation based upon its perceived inadequacy in addressing other reconstructive considerations beyond hard tissue anatomy. Detractors of VSP for head and neck reconstruction highlight its lack of capability in accounting for multiple reconstructive factors, such as recipient vessel selection, vascular pedicle reach, need for dead space obliteration, and skin paddle perforator location. It is with this premise in mind that we report a simple technique for anatomically localizing peroneal artery perforators during VSP for osteocutaneous fibular free flaps in which both bone and a soft tissue skin paddle are required for ablative reconstruction. The technique allows for anatomic perforator localization during the VSP session based solely upon data existent within the preoperative computed tomographic angiography (CTA) and it does not require any modifications to preoperative clinical workflows. It is the authors' presumption that many surgeons in the field are unaware of this planning capability within the context of modern VSP for head and neck reconstruction. The primary purpose of this manuscript is to introduce and further familiarize surgeons with the technique of CTA perforator localization as a method of improving intraoperative fidelity for VSP of osteocutaneous fibular free flaps.