T-Anastomosis in microsurgical free flap reconstruction: an overview of clinical applications

Anterolateral thigh flow-through flap: A versatile method for reconstruction of complex extremity defects

BACKGROUND

Flow-through flaps have been widely applied only for the reconstruction of complex defects in the extremities because they can be used for arterial reconstruction and soft tissue coverage simultaneously. This report attempts to fully demonstrate the role of the anterolateral thigh (ALT) flow-through flap as a versatile method for reconstructing complex defects in the extremities.

METHODS

From February 2011 to March 2017, we retrospectively analyzed the use of a reconstructive surgical technique based on the ALT flow-through flap to treat complex extremity defects in 87 patients (trauma, n = 79; diabetic ulcers, n = 5; squamous cell carcinoma, n = 3). Emergency surgery was performed in 12 patients to bridge a major artery gap and was followed by elective reconstruction in the remaining patients. Applications of the ALT flow-through flap included bridging major artery gaps, preserving recipient blood vessel integrity, reconstructing blood vessel continuity, protecting vascular anastomoses, avoiding difficult end-to-side anastomoses in the recipient area, and balancing blood flow, as well as combined application with an additional flap.

RESULTS

The flap size ranged from 6 × 3 cm to 17 × 9 cm. ALT flow-through flaps were used in combination with an additional flap (n = 4) and in vascular reconstruction (n = 83). Three patients required of the microvascular anastomostic reexploration for venous congestion, total necrosis occurred in two patients, and partial necrosis occurred in one patient. At the donor site, there were three cases of infection and two cases of wound dehiscence. At the recipient site, one case of infection and two cases of wound dehiscence were observed. One patient presented with deep infection secondary to renal failure and underwent amputation. During the follow-up period (range, 1-33 months), all other flaps (84 cases) survived uneventfully, with normal texture and color.

CONCLUSION

The ALT flow-through flap plays many roles as it is a versatile method for reconstructing complex defects of the extremities and serves various other clinical purposes.

Influence of VAC Therapy on Perfusion and Edema of Gracilis Flaps: Prospective Case-control Study

The gracilis muscle flap is a popular choice in reconstructive surgery to repair soft tissue defects or for functional restoration. Little is known on the influence of postoperative application of VAC (vacuum-assisted closure; Kinetic Concepts Inc., San Antonio, Tex.) therapy on perfusion and postoperative flap edema of free gracilis muscle flaps.

Methods

In total, 26 patients with soft tissue defects of lower extremity underwent gracilis muscle flap reconstruction. The study group (VAC, n = 13) was supplied with postoperative negative pressure therapy as a dressing; the control group (NVAC, n = 13) was supplied with conventional fat gauze dressing. Postoperative measurements of micro- and macroperfusion were performed intraoperatively, on postoperative day (POD) 3 and POD 5. Flap edema measurement was performed intraoperatively, on POD 5 and 2 weeks after operation.

Results

The VAC group showed significantly better macroflow during intraoperative VAC treatment, as well on POD 3 and POD 5. Venous outflow was also better with lower hemoglobin levels. Microflow was better in the NVAC group with higher measured oxygen levels. All gracilis muscle flaps of the VAC group showed significantly less flap edema compared with the control group.

Conclusions

VAC application on free gracilis muscle flaps leads to significantly less postoperative flap edema, improved arterial macroflow, and improved venous outflow. VAC therapy can be used without any danger for patient's safety, as flap survival is not endangered, and presents an easy to handle and pleasant dressing regimen for nursing staff and patients.

A Quantitative Evaluation of the Flow-Increasing Effect of Flow-Through Arterial Anastomosis in the Vascular Pedicle of Free Flaps: A Prospective Clinical Before-and-After Study

BACKGROUND

The clinical application of flow-through anastomosis has been reported in various studies; however, no studies have quantitatively evaluated and compared the actual hemodynamics in flow-through anastomosis and end-to-end anastomosis. This study quantitatively evaluated the blood inflow (volumetric flow rate) and vascular resistance (pulsatility index) of flow-through arterial anastomosis using an ultrasonic flowmeter, and compared these values with those of end-to-end anastomosis in actual clinical settings. In addition, factors affecting the outcomes have also been examined.

METHODS

Twenty-eight patients who underwent free flap reconstruction after tumor resection were subjected to flow-through arterial anastomosis and flow examination. First, in the end-to-end state, the proximal anastomotic site was measured. This was followed by the opening of the distal arterial clamp, and measurement was then continued (in the flow-through state).

RESULTS

In flow-through arterial anastomosis compared with end-to-end anastomosis, the volumetric flow rate was significantly increased (18.9 ± 14.1 ml/minute versus 6.0 ± 6.3 ml/minute) and the pulsatility index was significantly decreased (5.2 ± 3.7 versus 13.6 ± 10.2), when comparing paired data. Multiple regression analyses revealed that a perforator flap (versus a musculocutaneous flap) was independently associated with both reduced volumetric flow rate and increased pulsatility index in end-to-end anastomosis, and that hypertension was independently associated with an increased pulsatility index in end-to-end anastomosis. However, no factors in flow-through anastomosis were significantly associated with those values.

CONCLUSION

In terms of blood flow and vascular resistance, flow-through arterial anastomosis was considered to have promising quantitative effects and should be performed when the conditions of both the donor and recipient vessels meet the requirements.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Anterolateral thigh free flaps with T-shaped pedicles and multiple venous anastomosis for extremity reconstruction

The anterolateral thigh free flap is one of the most preferred options for reconstructing soft tissues of the extremities and vascular anastomosis is one of the most important factors for flaps survival. T-anastomosis and double venous anastomosis have been widely used for increasing flap survival. This report shows both application of T-shape pedicle and multiple venous anastomosis to each 43 cases for extremity reconstruction that have not been described so far in the literature and it showed the necessity of multiple anastomosis. The locations of the lesions were 8 upper extremities (4 hands, 3 forearms, and 1 upper arm) and 35 lower extremities (5 forefeet, 6 dorsal feet, 4 plantar feet, 11 ankles, and 9 lower legs). We applied T-shaped arterial pedicle to limited anatomical area that had 2 or more major arterial communication sites to overcome the obstruction by reverse flow from communication vessels when 1 of the 2 anastomosis was obstructed. We classified multiple venous anastomosis according to flow direction and the vascular connections between the superficial and deep veins. In result, 37 cases survived completely but 2 flaps developed severe necrosis (>50%) because of infection and hematoma and 4 flaps developed partial necrosis due to wound infection. In conclusion, T-shaped pedicle and multiple venous anastomosis is a method to improve free flap survival and useful in cases where sacrificing a dominant vessel is inevitable or those in which only 1 vessel remains.

Free flap transplantation combined with Ilizarov bone transport for the treatment of severe composite tibial and soft tissue defects

Objective

To evaluate the clinical efficacy of free flap transplantation combined with Ilizarov bone transport in the treatment of severe composite tibial and soft tissue defects.

Methods

We retrospectively analyzed the clinical data of 40 patients with severe composite tibial and soft tissue defects who underwent free flap transplantation combined with Ilizarov bone transport. The clinical efficacy was evaluated according to the following criteria: success rate of wound repair by free flap transplantation, incidence or recurrence rate of deep infection, healing rate of bone defects and external fixation index, incidence of complications, and functional score of affected extremities.

Results

All infections were generally well controlled by radical debridement and negative-pressure therapy, and all 40 patients’ wounds healed after repair and reconstruction of the tibia and soft tissues. Postoperative complications were alleviated by active treatment. The mean external fixation time was 12.83 ± 2.85 months, and the external fixation index was 1.55 m/cm. According to the Association for the Study and Application of Methods of Ilizarov (ASAMI) score, an excellent or good functional outcome was attained in 85% of patients.

Conclusion

Free flap transplantation combined with Ilizarov bone transport is an effective treatment for severe composite tibial and soft tissue defects.

Flow-Through Free Anterolateral Thigh Flap in Reconstruction of Severe Limb Injury

Supplemental digital content is available in the text.

This study aimed to present the use of flow-through free anterolateral thigh (ALT) flap for the reconstruction of severe limb injury.

Importance of Vascularity and Selecting the Recipient Vessels of Lower Extremity Reconstruction

BACKGROUND

 Successful lower extremity reconstruction using free flaps begins by identifying a good recipient vessel and understanding the surrounding environment of the defect.

METHODS

 One should consider multiple factors when selecting the recipient vessel such as the status of the axial arteries, trying to preserve flow as much as possible, extent and severity of the defect, and ultimately what type of anastomosis will be ideal.

RESULTS

 Multiple factors of importance are reviewed and show the relevance in decision making and provide an algorithm.

CONCLUSION

 In addition to the multiple factors to be considered, the ultimate decision should be made on the table during surgery when the actual artery or vein is exposed and shows signs of good pulsation and flow.

Popliteal fossa reconstruction with a medial sural artery perforator free flap using the medial sural vessel as the recipient

BACKGROUND

Reconstruction of the popliteal fossa using a free flap is challenging. Therefore, to facilitate easier free flap reconstruction of the popliteal fossa, we use a medial sural artery perforator (MSAP) free flap with a medial sural vessel as the recipient vessel, as it provides several advantages based on many reports.

METHODS

This report describes the authors' experience and outcomes with this technique. Between October 2010 and January 2015, 10 patients with medium-sized defects in their popliteal fossa underwent MSAP free flap reconstruction using the medial sural vessel as the recipient vessel. The flap size and thickness were evaluated, as well as the pedicle length, for each case.

RESULTS

The skin flap sizes ranged from 60-112 cm². The average flap thickness was 6 mm (range = 4-8 mm), and the average pedicle length was 7.5 cm (range = 6-9 cm). Full flap survival was observed in nine cases, and flap tip necrosis was observed in one case during a mean follow-up of 15 months (range = 3-36 months). MSAP free flap reconstruction was performed for moderate-sized defects in the popliteal fossa, using the medial sural vessel as the recipient vessel.

CONCLUSION

The obvious advantages of this technique included simple vascular anastomosis (minimal size discrepancy), no intraoperative position changes, and good aesthetic outcomes (replacing like with like).

Double free-flap for a bimalleolar defect of lower leg and ankle

Double free-flaps are necessary when tissue cover cannot be sufficed with a single flap. The other factors to be considered when using two free flaps for resurfacing of distal limb defects are the availability of more than one recipient vessel, the risk of distal limb ischaemia and the donor site morbidity of double flap harvest. If these factors are adequately addressed, double free-flaps can be safely executed for resurfacing distal limb defects with minimal morbidity. We report the simultaneous harvest and transfer of the anterolateral and anteromedial thigh flaps inset and vascularised as double free-flaps to resurface a large bimalleolar defect in a 14-year-old boy with no additional morbidity as compared to that of a single free tissue transfer.

Reconstruction of lateral forefoot using reversed medial plantar flap with free anterolateral thigh flap

Skin defects of the heel have frequently been reconstructed using the medial plantar flap; however, forefoot coverage has remained a challenge, because the alternatives for flap coverage have been very limited. We describe a case of malignant melanoma on the lateral forefoot that was radically removed and reconstructed successfully with a distally based medial plantar flap, together with a free anterolateral thigh flap. The advantages of this flap include that it does not reduce the vascular supply to the foot owing to reconstruction of the medial plantar vascular systems, reduces the risk of flap congestion, minimizes donor site morbidity, and enables the transport of structurally similar tissues to the plantar forefoot. We believe this technique is a reasonable reconstructive option for large lateral plantar forefoot defects.

Free flap transplantation combined with skin grafting and vacuum sealing drainage for repair of circumferential or sub-circumferential soft-tissue wounds of the lower leg

Background

This study is aimed at evaluating the operation techniques and clinical significance of free flap transplantation combined with skin grafting and vacuum sealing drainage (VSD) in repairing severe traumatic extensive circumferential or semi-circumferential soft-tissue defects of the lower leg.

Material/Methods

Thirty patients with severe lower leg injuries were treated by free flap transplantation combined with skin grafting and VSD from January 2008 to June 2011. The size of the wounds ranged from 23×8 cm to 44×28 cm and all affected more 70% of the low leg circumferential area. Wounds were complicated by exposure, necrosis, or infection of deep tissues. The wounds were first debrided and covered by VSD. When the condition of the wound had improved (5 to 7 days later), free flaps were harvested to reconstruct damaged tissue and skin grafts and VSD was used to cover granulation tissues around the transplanted flap.

Results

Granulation tissues developed and the area requiring flap cover decreased in all 30 patients after debridement and VSD. In 28 of 30 cases, the transplanted flaps grew well without complication. Peripheral necrosis was observed in only 2 cases, which required a second debridement and skin graft. Ten wound areas covered by grafts were left with scattered peripheral wounds, which healed with the help of 1 more skin graft or dressing change. Morphological appearance and functional recovery were satisfactory in all 30 cases.

Conclusions

Initial debridement and the temporary VSD cover followed after several days by free flap transplantation combined with skin grafting and VSD protection is a reliable treatment regimen for traumatic large circumferential or sub-circumferential soft tissue wounds of the lower leg with deep tissue exposure.