Current role of the iliac crest flap in mandibular reconstruction

Evaluating the length, diameter, and stenosis of deep circumflex iliac artery and neighboring arteries based on digital subtraction angiography

BACKGROUND

The vascularized iliac bone crest flap offers excellent usable bone in terms of volume and quality. Its nourishing vessel, the deep circumflex iliac artery (DCIA), although relatively short, is reliable vessel. Digital subtraction angiography presents still the gold standard for diagnostic purpose. However, computed tomography (CT) and magnetic resonance imaging (MRI) angiography is used for preoperative planning with low morbidity. The purpose of this study is to evaluate the gainable information using digital subtraction angiography (DSA) as compared to other imaging modalities.

MATERIALS AND METHODS

We evaluated information gainable from standard DSA of 130 consecutive patients (average age was 69.5 years [range 18-90 years]) concerning topography, dimension, and condition of the vessel wall. We looked for differences considering gender and side.

RESULTS

DCIA could not be followed in the periphery constantly in all cases due to the small, illustrated field. Arteriosclerotic changes showed to be very low in DCIA as compared to the neighboring vessels. Diabetes mellitus and smoking had a significant impact on vessel condition. DCIA branched off into its main two branches early after 40 mm (11%), after 40-60 mm (30%), or late after 60 mm (59%). DCIA showed to be least affected by different risk factors that reported to affect the vessel condition.

CONCLUSIONS

We present additional detailed topographic anatomy of DCIA and its variation that can be used intraoperative guide to harvest the flap and teaching purpose. Standard DSA delivers valuable preoperative data regarding stenosis in addition to the topographic anatomy of the flap pedicle. However, imaging of the distal parts of the DCIA, nourishing the skin paddle is limited by the detector field used. For a full imaging of both DCIAs from the origin to the perforators, the intraarterial injection of contrast medium, as applied in DSA, could be combined with different imaging modalities like CT-angiography.

Effectiveness of computer-assisted virtual planning, cutting guides and pre-engineered plates on outcomes in mandible fibular free flap reconstructions: a systematic review protocol

OBJECTIVE

The objective of this review is to synthesize the best available evidence on the outcomes of mandibular fibular free flap (MFFF) reconstructions using computer-assisted techniques versus traditional freehand techniques.

INTRODUCTION

Fibular free flaps are the most commonly used free flap for mandible reconstruction and are considered best practice for mandible reconstructions following resection of head and neck cancers. There are several reported advantages of computer-assisted MFFF reconstructions, including increased accuracy, decreased operation time, decreased ischemia time, decreased overall cost and improved patient outcomes. It is important to assess the advantages and potential harms of these techniques in a systematic review.

INCLUSION CRITERIA

Eligible studies will consider patients of all ages undergoing MFFF reconstruction. Studies will compare computer-assisted techniques to traditional freehand techniques for the primary outcomes of flap failure, patient-reported outcomes and bony resection margin status. Studies published in English from 2008 will be included. Experimental, quasi-experimental, prospective and retrospective cohort, case-control and analytical cross-sectional studies will be considered.

METHODS

MEDLINE, Embase, Scopus and the Cochrane Central Register of Controlled Trials will be searched. Gray literature sources will include Google Scholar and the World Health Organization International Clinical Trials Registry Platform. Two independent reviewers will screen titles and abstracts, assess full-text papers against the inclusion criteria, evaluate methodological quality using standardized critical appraisal instruments and extract data using a customized form. If possible, data will be pooled for statistical meta-analysis, and a Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Summary of Findings will be presented.

Comparison of Complicated and Simple Guiding Templates in Mandibular Reconstruction Using Vascularized Iliac Crest Flap

Objective

This study aims to compare the degree of accuracy achieved in mandibular reconstruction between complicated guiding templates (CGT) and simple guiding templates (SGT), to evaluate the necessity to spend more time to design complicated templates prior to surgery.

Methods

The preoperative virtual surgery plan (VSP) was used to simulate the osteotomy and accurate mandibular reconstruction strategy. Then the guiding templates were designed and printed to transfer the VSP into the real operation. Between July 2013 and November 2014, we used the SGT in 13 L-type mandibular defect reconstructions utilising vascularized iliac crest bone (VICB). From March 2015 to March 2018, we used CGT in 14 L-type mandibular defects, also reconstructing with VICB. The indicators of mandibular symmetry, midline deviation, alveolar height loss, bone conjunction gap, and operation time were analyzed and compared between the two groups.

Results

The overall bone graft success rate was 100% (27/27) between all patients. The SGT and CGT groups showed similar symmetry (1.01 ± 0.03 vs. 1.03 ± 0.04, P = 0.11) and mandibular midline displacement (1.0 ± 0.7 mm vs. 1.2 ± 0.8 mm, P=0.29). The CGT group showed less alveolar height deficiency than the SGT group (3.0 ± 2.4 mm vs. 7.8 ± 6.8 mm, P=0.01) and lesser bony conjunction gap between the graft and the mandible (1.6 ± 0.7 mm vs. 2.4 ± 1.2 mm, P = 0.02). The average operation time was significantly lower in the CGT group than in the SGT group (340.5 ± 74 min vs. 391.9 ± 41.7 min, P = 0.02).

Conclusion

In the simple mandibular reconstruction, the time-consuming CGT did not significantly improve the symmetry and midline displacement compared to SGT, but it demonstrated less reduction (increased preservation) in alveolar height and decreased the size of the bone conjunction gap. And in addition, CGT also reduced the average operation time and simplified intraoperative procedures compared with SGT.

Mandibular reconstruction with a prefabricated free vascularized fibula and implant-supported prosthesis based on fully three-dimensional virtual planning

Because optimal reconstruction of maxillofacial defects requires functional rehabilitation, the current study demonstrates the successful secondary reconstruction of a large mandibular continuity defect using a fully digitally planned prefabricated free vascularized fibula with immediate implant-supported prosthodontic restoration. A 56-year-old man presented with a large mandibular continuity defect after resection of an enlarged squamous cell carcinoma arising from the floor of the mouth. For secondary reconstruction, the shape of the neomandible and implant position for support of the lower prosthesis were planned virtually. The combined cutting and drilling guide was printed in 3 dimensions. In a 2-step surgical approach, first, the implants were inserted into the fibula and covered with a split-thickness skin graft to form a neogingiva. In a second operation, the fibula was harvested, osteotomized, and fixed with the denture on the preinserted implants. The fibula was placed to its final position guided by the occlusion. Using three-dimensional virtual backward planning, it was feasible to perform a mandibular reconstruction with immediate prosthetic rehabilitation.

Modified osteomyocutaneous iliac crest flaps transplantation

The paper aims to improve the operative technique of osteomyocutaneous iliac crest flap harvesting, further minimise morbidity of donor site, and improve the effect of recipient site reconstruction. From March 2005 to March 2011, 55 cases of osteomyocutaneous iliac crest flap harvested by different methods were performed to reconstruct the defects of the extremities. Twenty-nine cases were reconstructed with a traditional deep circumflex iliac artery osteomusculocutaneous flap. Twenty-six cases were repaired with modified osteomyocutaneous iliac crest flaps. In 29 cases with a traditional DCIA osteomusculocutaneous flap, two cases showed the injured lateral femoral cutaneous nerve. Flapnecrosis was significant in two cases. Arterial compromise occurred in one case 5 days after operation completion and led to flap failure. Three flaps developed postoperative venous congestion, but only one flap received re-exploration. In the other two cases, some stitches were removed for decompression. All three flaps survived. In two cases, marginal flap necrosis occurred, but no secondary skin grafting was required. In 26 cases with modified flap transplantation, one case showed the injured lateral femoral cutaneous nerve. All flaps survived totally. Osseous integration was achieved in all 55 cases in 3 ∼ 9 months after operation. The modified osteomyocutaneous iliac crest flap technique enhances flap safety, provides the additional advantages of reducing donor-site morbidity, and improves the recipient-site contour.

Accuracy of using computer-aided rapid prototyping templates for mandible reconstruction with an iliac crest graft

Background

This study aimed to evaluate the accuracy of surgical outcomes in free iliac crest mandibular reconstructions that were carried out with virtual surgical plans and rapid prototyping templates.

Methods

This study evaluated eight patients who underwent mandibular osteotomy and reconstruction with free iliac crest grafts using virtual surgical planning and designed guiding templates. Operations were performed using the prefabricated guiding templates. Postoperative three-dimensional computer models were overlaid and compared with the preoperatively designed models in the same coordinate system.

Results

Compared to the virtual osteotomy, the mean error of distance of the actual mandibular osteotomy was 2.06 ± 0.86 mm. When compared to the virtual harvested grafts, the mean error volume of the actual harvested grafts was 1412.22 ± 439.24 mm³ (9.12% ± 2.84%). The mean error between the volume of the actual harvested grafts and the shaped grafts was 2094.35 ± 929.12 mm³ (12.40% ± 5.50%).

Conclusions

The use of computer-aided rapid prototyping templates for virtual surgical planning appears to positively influence the accuracy of mandibular reconstruction.

Single versus dual venous anastomoses of the free fibula osteocutaneous flap in mandibular reconstruction: a retrospective study

OBJECTIVE

The present study was to compare the success rates of single venous anastomosis with dual venous anastomoses of the free fibula osteocutaneous flap in mandibular reconstruction.

PATIENTS AND METHODS

Retrospective review of all cases of mandibular reconstruction using free fibula osteocutaneous flaps performed by a single surgeon in our department during the period January 2005 to April 2012. All the flaps were harvested and transplanted by the standard protocols. Microvascular anastomosis of either one or two veins was performed. In addition to routine clinical evaluation, the viability of the flap was evaluated by a portable Doppler at the tenth day after surgery.

RESULTS

Two hundred and one free fibula osteocutaneous flaps were performed during this time period. Single venous anastomosis was performed in 112 flaps and dual venous anastomoses were performed in 89 flaps. The overall incidence of vascular thrombosis was 3%, and the success rate of the transplantation was 98.5%. Six cases developed vascular thrombosis postoperatively. One was arterial thrombosis that occurred 12 hours after initial operation in the dual venous anastomoses group. Three venous thrombosis occurred 24 hr after the operation in the single venous anastomosis group. In dual venous anastomoses group, two venous thrombosis occurred 3-4 days after initial operation and attempt to salvage failed in both the cases. Fisher's exact test showed that there was no significant difference of the success rate between single and dual anastomoses groups (P = 0.59).

CONCLUSIONS

There is no difference in success rates between single venous anastomosis and dual venous anastomoses for mandibular reconstruction with free fibula osteocutaneous flap.

Free fibular flap with periosteal excess for mandibular reconstruction

BACKGROUND

In microvascular transfer of fibular osteocutaneous flap for mandible reconstruction after cancer ablation, good bone union is necessary to allow timely radiation therapy after surgery. As the area of bone contact between fibula and the original mandible at the edge of the mandibular defect is small, a periosteal excess at both ends of the fibula covering the bone junction can be used to increase the chance of bone union. The purpose of this study is to investigate whether a periosteal excess surrounding both ends of the fibula flap can provide better blood supply and, therefore, ensure bone union and wound healing at 6 weeks after surgery and before radiation therapy initiation.

PATIENTS AND METHODS

The transfer of fibular osteocutaneous flap with periosteal excess was only applied to reconstruct segmental mandibular defects. As a consequence, only cases in which osteotomy of fibula was not performed were included in this study. A total of 34 fibular flaps without osteotomies were performed between 2000 and 2008; 17 with and 17 without the periosteal excess. The bone union was evaluated in terms of osseous callus formation using X-rays and CT three-dimensional images at 6 weeks after surgery, and results were assessed by three independent radiologists.

RESULTS

There was a significant difference between reconstructions with and without the periosteal excess in terms of bone union (P = 0.022). With reference to postoperative complications, the group reconstructed without periosteal excess presented a higher number of complications, mainly consisting of partial and total flap necrosis, respectively six (35.29%) and two (11.76%) cases. In the group reconstructed with periosteal excess, no loss of the skin island has occurred. A significant difference was observed in terms of partial flap necrosis (P = 0.024), while the other complications did not reveal a statistically significant difference (P > 0.05).

CONCLUSIONS

The use of a periosteal excess at both ends of the fibula flap provides better blood supply and is, therefore, able to ensure good bone healing and skin paddle survival regardless of the radiotherapy.

Implant mandibular rehabilitation postoncologic segmental resection: a clinical report

In cases of reconstruction of a discontinuity defect of the mandible, the surgeon has a major responsibility to maximize function as well as cosmetics and to preserve quality of life, restoring mastication, speech, and appearance. Treatment of mandibular discontinuity defects is a complex process and, among other methods, includes the use of free vascularized flaps. A variety of donor sites have been used for this purpose, including the iliac crest, radius, scapula, and fibula.At this time, the iliac crest free flap represents a versatile reconstruction method after mandibular ablation. This article reports a clinical case using the iliac crest free flap for comprehensive reconstruction of discontinuity defects in the mandible after resections of an aggressive odontogenic tumor. The immediate implant positioning reduced the number of surgical procedures and the rehabilitation time.

Free microsurgical and pedicled flaps for oncological mandibular reconstruction: technical aspects and evaluation of patient comorbidities

Oncologic mandibular reconstruction has changed significantly over the years and continues to evolve with the introduction of newer technologies and techniques. Patient demographic, reconstructive, and complication data were obtained from a prospectively maintained clinical database of patients who underwent head and neck reconstruction at our institution. The free fibular flap is now considered the gold standard for mandibular reconstruction. However, in patients with multiple comorbidities, lengthy procedures may be less optimal and pedicled flaps, with specific modifications, can yield reasonable outcomes. Technical aspects and comorbidity profiles are examined in the oncological mandibular reconstruction cohort.