Flow-Through Flap for Salvage of Fibula Osseocutaneous Vascular Variations: A Surgical Approach and Proposed Modification of Its Classification

Use of Flow-through Free Flaps in Head and Neck Reconstruction

Background

Reconstructive obstacles in composite head and neck defects are compounded in reoperated, traumatized, irradiated, and vessel-depleted surgical fields. In cases that require multiple free flaps, recipient vessel accessibility and inset logistics become challenging. Strategic flow-through flap configurations mitigate these issues by supplying arterial inflow and venous outflow to a second flap in a contiguous fashion. This approach (1) permits the use of a singular native recipient vessel, (2) increases the reach of the vascular pedicle, avoiding the need for arteriovenous grafting, and (3) allows for a greater three-dimensional flexibility in configuring soft tissue and bony flap inset.

Methods

To demonstrate this technique, we conducted a retrospective review of all head and neck reconstruction patients presenting to us from March 2019 to April 2021.

Results

We present seven oncological and two traumatic patients (N = 9) who received flow-through free flaps for head and neck reconstruction. The most common flap used as the flow-through flap was the anterolateral thigh flap (N = 7), followed by the fibula flap (N = 2). Mean follow-up time was 507 days. No flap failures occurred.

Conclusion

In head and neck reconstruction, the use of the flow-through principle enables uninterrupted vascular flow for two distinct free flaps in single-stage reconstruction for patients with vessel-depleted, irradiated, and/or reoperated fields. We demonstrate that flow-through flaps in the head and neck may be used successfully for a variety of cases and flaps.

Fibular free flap with proximal perforator skin paddle due to aberrant anatomy - a case report

BACKGROUND

The fibular free flap is considered one of the most valuable options for mandible reconstruction. A perforator flap has gained widespread acceptance in oral and maxillofacial reconstruction. Typically, the fibula flap is obtained primarily with the distal perforator due to its reliable blood supply, with less attention given to the proximal perforators during the harvesting process. Normally, the distal perforator of the fibula exhibits stability and shows limited anatomical variations. However, there have been reported cases in which the distal perforator is absent. At times, these vascular abnormalities remain undetectable through Doppler examination or preoperative angiography evaluation. Therefore, this case details the experience of encountering the rare event of vascular abnormality in oral cancer surgery.

CASE PRESENTATION

This article reports the case of a patient who presented with a congenital absence of the distal perforator in the peroneal artery, attributed to a vascular abnormality. Additionally, we provide a review of the concept of utilizing the proximal perforator as an alternative approach in the flap harvesting process.

CONCLUSIONS

While the distal perforator of the peroneal artery is typically utilized for fibula free flap procedures, surgeons must remain cognizant of the potential for its absence due to aberrant anatomy. Recognizing an alternative approach in such cases can be pivotal for precise surgical planning and favorable outcomes in oral and maxillofacial reconstruction.

Chimeric Free Fibula Flap: An Encounter With Aberrant Anatomy

A 59-year-old male presented with recurrent mucoepidermoid carcinoma of the mandible. A resection with immediate free fibula flap reconstruction was done. The osteocutaneous free fibula flap relies on the peroneal artery and its distal perforators. Variant patterns necessitate consideration of the challenging to dissect proximal myocutaneous perforator raised on a single or double anastomosis, depending on origin. Even in cases of flap salvage, the fibula flap remains a reliable flap. This case describes a fibula flap with a sole proximal myocutaneous perforator identified during dissection despite a normal preoperative Doppler.

Flow-Through Free Fibula Osteocutaneous Flap in Reconstruction of Tibial Bone, Soft Tissue, and Main Artery Segmental Defects

OBJECTIVE

The aim of this report was to present the use of flow-through free fibula osteocutaneous flap for the repair of complex tibial bone, soft tissue, and main artery segmental defects.

PATIENTS AND METHODS

Five patients with bone, soft tissue, and segmental anterior tibial artery defects were included. The lengths of injured tibial bones ranged from 4 to 7 cm. The sizes of impaired soft tissues were between 9 × 4 and 15 × 6 cm. The lengths of defect of anterior tibial artery segments ranged from 6 to 10 cm. Two patients had distal limb perfusion problems. Flow-through free fibula osteocutaneous flap was performed for all 5 patients.

RESULTS

Patients were followed for 12 to 18 months. All wounds healed after 1-stage operation, and all flow-through flaps survived. The distal perfusion after vascular repair was normal in all patients. Superficial necrosis of flap edge was noted in 1 case. After the local debridement and partial thickness skin graft, the flap healed uneventfully, and the surgical operation did not increase injury to the donor site. Satisfactory bone union was achieved in all patients in 2 to 4 months postoperation. Enlargement of fibula graft was observed during follow-up from 12 to 18 months. The functions of adjacent joints were recovered, and all patients were able to walk normally.

CONCLUSIONS

Flow-through free fibula osteocutaneous flap was shown to be an effective and efficient technique for repairing composite tibial bone, soft tissue, and main artery segmental defects. This 1-stage operation should be useful in clinical practice for the treatment of complex bone, soft tissue, and vessel defects.

Designing a Fibular Flow-Through Flap with a Proximal Peroneal Perforator-Free Flap for Maxillary Reconstruction

Reconstruction of a composite maxillary defect is frequently performed with a fibular osteocutaneous free flap to address both the bony and mucosal defect. If during the harvest of the fibula a distal skin perforator is not present due to vascular variations, reconstruction can potentially be done using the soleus muscle for filling of the palatal mucosal defect. An additional challenge arises when the accompanying skin paddle that has been harvested is not perfused, but the fibula remains viable. This case report describes salvage following loss of the skin paddle in an osteocutaneous fibular free flap by designing a fibular flow-through flap using a proximal peroneal perforator free flap. The use of this second free flap allows a skin paddle to be positioned on the distal fibular segment, provides a surgical backup, and limits the donor sites to the same extremity.

Radial Artery Fascial Flow-Through Free Flap for Combined Revascularization in Moyamoya Disease

BACKGROUND

Free flaps are commonly used by other surgical subspecialties for soft tissue reconstruction and revascularization. Cranial applications of these flaps have been limited to only a single case report.

OBJECTIVE

To present a new technique for combined revascularization in moyamoya disease using a flow-through free flap.

METHODS

Data were obtained from an Institutional Review Board-approved, prospectively maintained database with informed consent from the patient.

RESULTS

A 28-yr-old patient presented with progressive stenosis of the proximal anterior cerebral artery resulting in ischemic infarcts. Direct revascularization of the anterior cerebral artery territory and indirect revascularization of the middle cerebral artery with a large vascularized fascial pedicle was performed.

CONCLUSION

Flow-through free flaps offer a unique combination of revascularization and a large vascularized pedicle. This technique highlights the application of these flaps for revascularization in moyamoya disease and the value of multidisciplinary collaboration. Revascularization will likely play an increasing role in the open surgical treatment of cerebrovascular disease. We believe that flow-through free flaps will be a contribution to the future of revascularization in neurosurgery.

Effects of preserving different veins on flow-through flap survival: An experimental study

Flow-through skin flap grafting is becoming widely used for the reconstruction of skin and soft tissue defects, particularly for patients with poor blood supply around the defect. However, the treatment of the veins remains controversial. In the present study, 5×2-cm skin flaps were created on the left inner thighs of rabbits in order to investigate the effects of various treatments of the veins on the survival of a flow-through skin flap. A femoral artery perforator running through the flap was preserved. Five groups were established in which no veins, one superficial vein (SV), one accompanying vein (AV), one SV plus one AV, or all trunk veins (control) were retained. The percentage of flap area survival was determined on day 10. On days 3, 5, 7 and 9, tissues were harvested from the skin flaps and immunohistochemical analysis was performed in order to count the number of microvessels. Western blot analysis was subsequently completed in order to determine the expression levels of vascular endothelial growth factor (VEGF). The flap areas in which no veins were retained demonstrated significantly reduced survival rates on day 10, as compared with those in the other four groups (P<0.01). Furthermore, flaps with the retention of a SV also demonstrated reduced survival rates, as compared with the AV, AV plus SV and all veins groups (P<0.01); however, there no significant differences were detected between the latter three groups (P>0.05). Immunohistochemical analysis on day 3 detected a greater number of microvessels in the flaps of the control group, as compared with the flaps of the other groups. Furthermore, the AV and AV plus SV groups demonstrated a greater number of microvessels, as compared with the SV and no vein groups, and he no vein group demonstrated the fewest microvessels. No significant differences were found between the AV, AV plus SV and control groups on day 5, 7 and 9. Western blot analysis on day 5 demonstrated that the expression levles of VEGF were significantly increased in the flaps of the AV, AV plus SV and control groups, as compared with those in the SV and no vein groups. No significant differences were detected between the former three groups, and increased VEGF expression levels were detected in the flaps of the SV group, as compared with the no vein group. The flow-through flap grafts with no retained veins barely survived. Anastomosing one AV was adequate for flap survival; however, further studies are required in order to investigate the survival of flow-through flaps in more detail.

Flow-through anastomosis using a T-shaped vascular pedicle for gracilis functioning free muscle transplantation in brachial plexus injury

OBJECTIVE

In gracilis functioning free muscle transplantation, the limited caliber of the dominant vascular pedicle increases the complexity of the anastomosis and the risk of vascular compromise. The purpose of this study was to characterize the results of using a T-shaped vascular pedicle for flow-through anastomosis in gracilis functioning free muscle transplantation for brachial plexus injury.

METHODS

The outcomes of patients with brachial plexus injury who received gracilis functioning free muscle transplantation with either conventional end-to-end anastomosis or flow-through anastomosis from 2005 to 2013 were retrospectively compared. In the flow-through group, the pedicle comprised a segment of the profunda femoris and the nutrient artery of the gracilis. The recipient artery was interposed by the T-shaped pedicle.

RESULTS

A total of 46 patients received flow-through anastomosis, and 25 patients received conventional end-to-end anastomosis. The surgical time was similar between the groups. The diameter of the arterial anastomosis in the flow-through group was significantly larger than that in the end-to-end group (3.87 mm vs. 2.06 mm, respectively, p<0.001), and there were significantly fewer cases of vascular compromise in the flow-through group (2 [4.35%] vs. 6 [24%], respectively, p=0.019). All flaps in the flow-through group survived, whereas 2 in the end-to-end group failed. Minimal donor-site morbidity was noted in both groups.

CONCLUSIONS

Flow-through anastomosis in gracilis functioning free muscle transplantation for brachial plexus injury can decrease the complexity of anastomosis, reduce the risk of flap loss, and allow for more variation in muscle placement.