Optimizing the arterialized venous flap

Free peroneal artery perforator flap for reconstruction of traumatic limb soft tissue defects: A retrospective case series study

BACKGROUND

The free peroneal artery perforator (FPAP) flap is used for soft tissue defects after burns and trauma. However, the use of FPAP flaps to repair limb soft tissue defects for immediate reconstruction was rarely reported previously. Therefore, the purpose of this report is to evaluate free peroneal artery perforator flap to reconstruct traumatic limb soft tissue defects for immediate reconstruction.

PATIENTS AND METHODS

A total of 25 cases of limb soft tissue defects undergoing immediate reconstruction of FPAP flap transfer were retrospectively evaluated from January 2019 to June 2019 in our institute. The locations of defects included the palm (10 cases), finger (5 cases), foot (7 cases), ankle (2 cases) and wrist (1 case). The sizes of defect varied from 3 × 2 cm to 15 × 7 cm (54.1 cm2 in average). Flaps were harvested based on the peroneal perforator vessels, initially marked using hand-held Doppler.

RESULTS

Average size of harvested flap was 9.7 × 6.2 cm (ranging from 3.5 × 2 cm to 16 × 8 cm). All perforators were harvested from the peroneal artery and the arterial diameter ranged from 0.8 to 1.7 mm. The average pedicle length was 3.04 cm (range, 1.85-4.75 cm). Five vascular thrombosis were found including three cases of arterial thrombosis and two cases of venous thrombosis which were successfully salvaged by re-operation and vein graft. Satisfying functional outcome and acceptable appearance were achieved at 6 months or longer after surgery (range, 6-15 months, 12 months in average). All flaps survived at the end-point.

CONCLUSIONS

The FPAP flap is a reliable and thin fasciocutaneous flap, which can be used for repairing limb soft tissue defects. The FPAP flap can be used for covering defects with various appearances, locations, and sizes.

Multiple digit resurfacing with a lateral thoracic free flap: Two-stage mitten hand and division procedures

PURPOSE

The conventional abdominal and groin flaps for resurfacing the defect have several disadvantages, including the risk of flap failure due to accidental traction or detachment, immobilization of the arm before division, and aesthetic dissatisfaction because of the flap bulkiness. The aim of this study was to share our experiences with the free lateral thoracic flap and elucidate the optimal timing of division in complex hand reconstruction, which yielded favorable outcomes in terms of both functionality and aesthetics.

METHODS

This article is a retrospective review of multiple digit resurfacing using free tissue transfer from 2012 to 2022. Patients who underwent two-stage operation including mitten hand creation using superthin thoracodorsal artery perforator (TDAp) free flap and secondary division were included. A flap was elevated over the superficial fascia layer the midportion between the anterior border of the latissimus dorsi and pectoralis major muscles and once the pedicle was found, an outline that matched the defect was created. A process named "pushing with pressure and cutting" was carried out before pedicle ligation until all the superficial fat tissue had been removed except for around the perforator. Two cases (18%) involved defects of the entire fingers reconstructed by TDAp flap with anterolateral thigh flap. Six cases (55%) had a super-thin TDAp flap only. In two cases (18%), non-vascularized iliac bone grafting was required for finger lengthening. One case (9%) was resurfaced with a TDAp chimeric flap including a skin paddle with the serratus anterior muscle. The primary outcome was defined as the survival or failure of the flap, while the secondary outcomes associated complications such as infection and partial flap necrosis. A statistical analysis was not performed due to the size of the case series.

RESULTS

All 13 flaps survived completely without any complications. Flap dimension ranged from 12 cm × 7 cm to 30 cm × 15 cm. Mitten hand duration prior to division was 41.9 days on average which was essential for the optimal result. During the division procedures, there were nine cases of debulking (82%), six cases of split-thickness skin graft (STSG) (55%), and three cases of Z-plasty performed on the first web space (27%). The mean follow-up period was 20.2 months. Mean Disability of the Arm, Shoulder, and Hand (DASH) Questionnaire score was 10.76.

CONCLUSIONS

We resurfaced severe soft tissue defects of multiple fingers with thin to super-thin free flaps, mainly TDAp flaps. Surgeons can restore original hand shape using a two-stage reconstructive strategy of mitten hand creation and proper division timing to create a 3-dimensional hand structure, even in severely injured hands with multiple soft tissue defects of the digits.

Retrograde Free Venous Flaps for Extremity Reconstruction: A Roadmap

Background and Objectives: Retrograde free venous flaps represent a separate entity among free venous flaps: their physiology is still unclear, but they provide an immediate visible refill after reconnection, with a similar behaviour to conventional flaps. Therefore, the dimensions and the indications of these flaps can be extended beyond what was previously believed, and they can be easily customized, including with respect to tendons and nerves. Nevertheless, they are still debated and regarded as unsafe. Materials and Methods: From 2012 to 2019, we performed 31 retrograde free venous flaps on 31 patients to reconstruct hands, digits, and in one case the heel. All the flaps were arterialized in a retrograde manner; the donor site was the forearm in 28 cases, the foot in 2 cases, and the calf in 1 case. We recorded the size, vein architecture, donor site, donor artery, donor morbidity, function for composite and non-composite flaps, immediate complications, late complications, survival rate, and the number of revisions. We recorded the hand function when appropriate. A total of 10 flaps were also intraoperatively studied with indocyanine green to monitor their hemodynamical behaviour. Results: All the patients were followed for an average of 8 months (6−15). The flap dimensions ranged from 6 cm2 to 136 cm2. All the flaps, except two that had complete necrosis, survived. Two flaps had partial necrosis. There was no correlation between necrosis and the size of the flap, with one case of necrosis and one of partial necrosis in the small flaps (<10 cm2). None of the cases with partial necrosis needed a new flap. Two flaps developed a late arterio-venous shunt that was ligated. Conclusions: The retrograde free venous flaps proved to be a useful tool for complex reconstructions of the hand and extremities. They can provide a large island of pliable skin and composite tissue with tendons and nerves, but surgeons must be aware of some caveats.

The arterialised saphenous venous flow-through flap for managing the radial forearm free flap donor site

BACKGROUND

The radial forearm fasciocutaneous flap (RFFF) is a workhorse flap, however concerns with donor site morbidity include tendon exposure, delayed wound healing, impaired sensitivity, and poor cosmesis, have seen it fall out of favor. We present a method of using an arterialised saphenous flow through flap to reconstruct the RFFF donor site.

METHOD

A cohort study of six patients (five male, one female; mean age 59 [range 19-90]) who had their RFFF donor site reconstructed with an arterialised saphenous flow through flap is presented. The use of multiple peripheral efferent venous anastomoses, flap rotation 180 degrees prior to inset, and the ligation of intra-flap connecting veins were three modifications employed. Primary outcomes include complication rates. Secondary outcomes were patient reported outcome measures via the Michigan Hand Outcomes Questionnaire, and patency and flow through the flap.

RESULTS

In all six cases, there was flap survival. RFFF dimensions ranging from lengths of 6-15 cm (mean 11.5 cm) and widths of 4-6 cm (mean 5.3 cm), with an average flap area of 58 cm² (range 24-90). There were no total flap losses, one partial superficial flap loss and one minor donor site delayed healing, over a mean follow-up of 6 months (4-24 months). The average overall patient satisfaction was 91 on Michigan Hand Outcomes Questionnaire. Pain was well tolerated with a low average pain score of 15.

CONCLUSION

The modified arterialised saphenous flow through flap is a useful option for reconstructing the soft tissue defect and reconstituting the radial artery after RFFF harvest.

The use of indocyanine green angiography in arterialized-venous free flaps: case report and insight into flap vascular physiology

Arterialized venous flaps (AVFs) are an innovative option in hand reconstruction. Their exact vascular physiology and survival mechanisms remain unclear. We report on two hand reconstruction cases with AVFs. Indocyanine green laser angiography was used to assess vascular perfusion of the flaps. A notable change in flap perfusion was seen by 48 h post-operatively with normalization of shunting and progression to a diffuse perfusion pattern resembling traditional flaps. Flap survival was attributed to reversed shunting at the microvascular level occurring within the first 48 h post-operatively.

Effect of hirudin on arterialized venous flap survival in rabbits

Arterialized venous flap (AVF) is limited in clinical application because its survival remains inconsistent and its exact survival mechanism is still unclear. Hirudin is an effective thrombin specific inhibitor, which is isolated from the salivary gland secretions of the leech. Our study evaluated the impact of hirudin on the viability of AVFs in rabbits. Thirty-six rabbits were randomly divided into three groups: sham group (physiological perfusion), control group (AVF), and hirudin group (AVF + hirudin). In hirudin group, 20 antithrombin units (ATU) hirudin (2.5 ml) were injected into each flap. In sham group and control group, the same amount of normal saline was injected into each flap. Status of flap survival, water content, vascular perfusion, histopathology, expression of CD34, VEGF, eNOS and HIF-1α were analyzed in each group. Analysis of oxidative stress was performed by measuring the activity of superoxide dismutase (SOD) and malondialdehyde (MDA). Compared with flaps in sham group with physiological perfusion mode, results of survival rate, perfusion status, SOD activity, expression of CD34, VEGF, and eNOS of AVFs in control group were significantly lower, while water content, MDA level and expression of HIF-1α were higher. The flap condition of AVFs injected with hirudin in hirudin group was improved significantly, and the results were similar to sham group. Our findings revealed that hirudin can effectively improve survival of AVF.

Evaluation of Role of Arterialization of Venous Flaps in Abdomen in Rats

Introduction  Reconstruction forms the primary tenet in plastic surgery. Venous flaps are a known option but the survival is limited. Arterialization of venous flap can enhance its survival. While various techniques of arterialization of venous flaps are described, there are very few studies comparing them.

Material and methods  The current study was conducted among 34 rats weighing 160 to 200 grams. The rats were divided into four groups. Group I—islanded epigastric flap was raised with superficial caudal epigastric vessels as pedicle. Group II—arterialized flow through venous flap was raised with superficial caudal epigastric vein (SCEV) as afferent and lateral thoracic vein as drainage vein. Side-to-side anastomosis was done between femoral artery and vein, lateral to the origin of superficial caudal epigastric artery. Group III—after raising the flap, as in group II, femoral vein was ligated proximal to superficial caudal epigastric vessels. Group IV—an arterialized flow through venous flap was raised with superficial caudal epigastric vein as afferent and lateral thoracic vein as drainage vein. End-to-side anastomosis was done between femoral artery and superficial caudal epigastric vein. Animals that died before completion of the study were excluded. The color changes of flaps were noted. Flap survival was expressed as a percentage of the total flap surface area. The patency of anastomosis was seen on postoperative day 5.

Results  There was no total flap failure. On statical analysis, the flap survival area on day 5 between Group I and Group IV was not significant ( p value 0.431). The survival area in Group I (78.85 ± 10.54%) was comparable to Group IV (65.71 ± 20.70%). Group II and III had poor results as compared with Group I. In four rats, thrombosis of arteriovenous anastomosis was noted with flap survival area of 30 to 33%.

Conclusion  It was noted that epigastric venous flaps with end-to-side anastomosis between femoral artery and superficial caudal epigastric vein (group IV) have survival area comparable to islanded flaps.

Role of Arterial Perfusion in Early Survival of Arterialized Venous Flaps: A Mechanism Study and Clinical Application

BACKGROUND

The arterialized venous flap (AVF) is appropriate as a flap for hand and foot resurfacing meet the aesthetic demands in the same time. However, the inconsistency of survival rate limited its popularization in clinical settings. The purpose of this study was to investigate the role played by the caliber and location of the artery.

METHODS

Arterialized venous flaps were designed on the abdomen of New Zealand rabbits, and the animals were randomized into 3 groups and 2 groups in experiment 1 and 2, respectively. In experiment 1, the artery flow was restricted with vascular staplers of different calibers. In experiment 2, the artery was anastomosed with the afferent vein in the center or at the margin of the flap. Blood perfusion state, water content, epidermal metabolite levels, and flap survival status were observed in both experiments. Furthermore, outcomes of 12 patients received AVF to resurface soft tissue defects in the digits, hands, and feet between January 2016 and February 2018 were analyzed.

RESULTS

In experiment 1, compared with the control group, groups with restricted artery showed poor results regarding blood perfusion state, water content, epidermal metabolite levels, and flap survival status. In experiment 2, group with the afferent vein in the center of the flap showed better results mentioned previously. All the flaps survived uneventfully in this study. Two flaps partially failed (20% of the flap area) because of insufficient perfusion. Generally, larger caliber and center-located vein helped the survival of AVF.

CONCLUSIONS

Experimental findings suggested that increased arterial perfusion and center-located vein are beneficial for the survival of AVF. Clinical series proved the findings previously. The problem of inconsistency of AVF can be partially solved by increasing arterial perfusion and dissecting afferent vein into the center of flap, and still, further studies are needed to shed light on the mechanism behind.

The clinical result of arterialized venous free flaps for the treatment of soft tissue defect of the fingers

The purpose of this study is to report the clinical results of the arterialized venous free flaps in reconstructing soft tissue defects of the finger and to extend the indications for the use of the flaps based on clinical experiences of the authors.We retrospectively reviewed the records of 35 patients who underwent an arterialized venous free flaps for a finger reconstruction, between May 2007 and August 2015. The mean size of flap was 4.8 ± 1.23 × 3.1 ± 0.84 cm. The donor site was the ipsilateral volar aspect of the distal forearm in all cases. There were 17 (48.6%) cases of venous skin flaps, 9 (25.7%) cases of innervated venous flaps, 7 (20%) cases of tendocu taneous flaps, and 2 (5.7%) case of innervated tendocutaneous flap. The vascularity of recipient beds was good except 8 (22.9%) cases (partial devascularity in 3, more than 50% avascularity [bone cement] in 3, and chronic infected bed in 2).Of the 35 cases, 29 (82.9%) cases (including 3 cases who had more than 50% avascularity recipient bed) showed complete survival. 3 (8.6%) cases, which had partially devascularity of distal phalanx in recipient bed, showed partial necrosis (P = .015). The mean number of included veins was 2.4 ± 0.5 for a flap.A forearm arterialized venous free flap is a useful procedure for single-stage reconstructing of a soft tissue or combined defect of a finger, we consider that this technique could be applied to fingers despite an avascular or insufficient vascular recipient bed if the periphery of recipient bed vascularity was good and if the recipient beds were free from infection.

Unconventional Perfusion Flaps in the Experimental Setting: A Systematic Review and Meta-Analysis

Supplemental Digital Content is available in the text.

Background:

Unconventional perfusion flaps offer multiple potential advantages compared with traditional flaps. Although there are numerous experimental articles on unconventional perfusion flaps, the multiple animal species involved, the myriad vascular constructions used, and the frequently conflicting data reported make synthesis of this information challenging. The main aim of this study was to perform a systematic review and meta-analysis of the literature on the experimental use of unconventional perfusion flaps, to identify the best experimental models proposed and to estimate their global survival rate.

Methods:

The authors performed a systematic review and meta-analysis of all articles written in English, French, Italian, Spanish, and Portuguese on the experimental use of unconventional perfusion flaps and indexed to PubMed from 1981 until February 1, 2017.

Results:

A total of 68 studies were found, corresponding to 86 optimized experimental models and 1073 unconventional perfusion flaps. The overall unconventional perfusion flap survival rate was 90.8 percent (95 percent CI, 86.9 to 93.6 percent; p < 0.001). The estimated proportion of experimental unconventional perfusion flaps presenting complete survival or nearly complete survival was 74.4 percent (95 percent CI, 62.1 to 83.7 percent; p < 0.001). The most commonly reported animal species in the literature were the rabbit (57.1 percent), the rat (26.4 percent), and the dog (14.3 percent). No significant differences were found in survival rates among these species, or among the diverse vascular patterns used.

Conclusion:

These data do not differ significantly from those reported regarding the use of unconventional perfusion flaps in human medicine, suggesting that rabbit, rat, and canine experimental unconventional perfusion flap models may adequately mimic the clinical application of unconventional perfusion flaps.

Repair of soft tissue defects in finger, thumb and forearm: less invasive methods with similar outcomes

We review recent developments in using occlusive dressings, dermal templates, and venous flaps for less invasive approaches to treat soft tissue defects of the forearm and fingers. Occlusive dressings can be used for thumb tip or fingertip trauma with soft tissue defects of small or moderate sizes. They permit skin regeneration without use of skin graft or a flap transfer. This is currently a popular way to treat tip soft tissue defects in European countries. Extensive soft tissue defects in the thumb, fingers, hand and forearm require flap transfers traditionally, but in recent years, surgeons use dermal templates to cover the defect site to allow regeneration of subcutaneous tissues, over which a skin graft is used in lieu of a flap. Transfer of a venous flap is currently a reliable procedure and is less invasive compared with conventional flaps, which usually damage a named artery in the donor. We advocate that less invasive methods should be considered for soft tissue defects in the hand and forearm.

The experimental study of shunt-decompression arterialized vein flap

Background

Arterialized vein flap is a kind of unphysiological flap. Unphysiological reconstruction of blood circulation leads to higher load than that supported by physiological flap and is the culprit of flap swelling, blood stasis, skin blistering, and necrosis after flap grafting. To resolve the multiple disadvantages of traditional flap grafting, by introducing the principles of fluid mechanics, shunt-decompression surgery is prepared to decline the circulation preload and improve the prognosis of arterialized vein flap grafting.

Methods

By introducing the principles of fluid mechanics, we established the model of shunt-decompression arterialized vein flap, which satisfied the common properties of general fluid that the interface pressure between object and fluid is reduced when the velocity of fluid is increased and vice versa-the effect of Bernoulli. Under this rule, we anastomose the arterialized vein to the branch of main artery of recipient region or make end-to-side anastomosis, which can maintain the blood flow of main artery, decrease the perfusion of flap, and preserve the decompressive effect of main artery to branches. From March, 2016 to September, 2016, we performed animal experiments on ten male bama mini pigs with average weight of 28 ± 2.35 kg. Superior epigastric artery of pig was used for feeding artery to arterialize the superficial epigastric veins. The total area of flap is 8 cm × 6 cm. End-to-side anastomosis and end-to-end anastomosis were established in experimental group and control group, respectively. Doppler speckle perfusion imaging apparatus was used to monitor the alterations of flap perfusion, blood flow of flap, tissue swelling and survival of flaps.

Results

The average flap perfusion (PU) at 1 week after surgery is 83.62 ± 3.14 in experimental group and 98.14 ± 6.54 in control group, respectively (P < 0.05), indicating the significant reduction of flap blood perfusion in experimental group as compared with control group. As to the survival of flaps, 7 flaps completely survived, 3 showed partial necrosis, and no one was found as complete necrosis in experimental group, while only 3 flaps survived, and 4 flaps and 3 flaps showed partial necrosis and complete necrosis in control group, respectively (P < 0.05).

Conclusion

Based on the physiological features of arterialized vein flap and its problems in clinical application, we improved the anastomosis strategy of flap grafting and obtained excellent experimental outcomes, which provides an insight for the clinical application of arterialized vein flaps.

Palmaris longus tendocutaneous arterialized venous free flap to reconstruct the interphalangeal collateral ligament in composite defects

We present 12 cases in which palmaris longus tendocutaneous arterialized venous free flaps were used for the reconstruction of the collateral ligament in compound defects of digits. There were nine cases involving the interphalangeal joint of the fingers and three of the interphalangeal joints of the thumb. The venous flaps survived completely in 10 of the 12 cases. In 11 cases, there were excellent functional results for joint stability, pain, total active motion and pinch power. In all 12 cases, a pain-free joint with excellent stability was achieved after surgery. The palmaris longus tendocutaneous arterialized venous free flap is a good option for reconstruction of composite defects of the collateral ligament of the interphalangeal joint.

LEVEL OF EVIDENCE

IV.

Technical Points of 5 Free Vascularized Flaps for the Hand Repairs

In this article, we present the experiences from Chinese microsurgeons on 5 less commonly used free vascularized flaps in hand reconstruction. In many units in China, these flaps have become the mainstays of treatment; they are routinely used for fingertip and thumb reconstruction. Their combined experience has demonstrated the reliability and versatility of these flaps for hand reconstruction, as well as their cosmetic value.

The position of 'shunt restriction' along an arterialized vein affects venous congestion and flap perfusion of an arterialized venous flap

Restriction of arteriovenous (AV) shunting has been shown to enhance peripheral perfusion and also reduce venous congestion of an arterialized venous flap. Thus, this study is designed to investigate the effect of 'shunt-restriction' location on venous congestion and flap perfusion in a 'shunt-restricted' arterialized venous flap (AVF).

METHODS

Abdominal flaps based on the thoracoepigastric vessels of Sprague-Dawley rats were raised. The inferior epigastric vein was repaired to the femoral artery in order to create an AVF. The superior epigastric vein was preserved for drainage. Microcirculation and laser Doppler flowmetry results were compared between AVFs with 'shunt restriction' at a proximal third (SR-proximal) distance and 'shunt restriction' at a distal third (SR-distal) distance.

RESULTS

Bidirectional sluggish flow was detected at the proximal part of venous flaps in both groups. Unidirectional normal flow was observed in more capillaries of the distal flaps in the SR-proximal group. In the middle of the flaps, blood flow was sluggish and intermittent in the veins and was absent in most capillaries of the SR-distal group. The flow was prompt and unidirectional in more capillaries of the SR-proximal group. Using laser Doppler flowmetry, the average perfusion of the whole SR-proximal flaps was found to be higher than that of SR-distal flaps (p = 0.017). The average flux at the middle and distal portions of the SR-proximal group was significantly higher than those of the SR-distal group (p = 0.049).

CONCLUSION

'Shunt restriction' at the proximal third of the AV shunt resulted in enhanced perfusion and reduced venous congestion in an AVF.