Arterialized venous free flaps for soft-tissue reconstruction of digits: a 40-case series

The clinical application of arterialized venous flaps in repairing large area of soft tissue defects of extremities

BACKGROUND

The reconstruction of microsurgery emphasizes the low morbidity of donor sites. The arterialized venous flaps (AVFs) are tissue flaps harvested without conventional vascular pedicles. However, reports of high necrosis rates and poor understanding of physiology hindered the application of many surgeons in clinical practice. Recently, experimental and clinical studies have demonstrated the feasibility and relative reliability of various AVF techniques. This study aims to report the clinical results of the arterialized venous free flaps in reconstructing soft tissue defects of limbs and propose methods to improve flap perfusion, extending the indications for using the flaps based on the authors' clinical experiences.

METHODS

We retrospectively reviewed the records of 16 patients that underwent arterialized venous free flaps for limb wound reconstruction from January 2019 to June 2021. Following the venous network on the calf's tibial side, large venous flaps can be designed.

RESULTS

Of the 16 cases, 14 (87.50%) cases (including 8 cases significantly congested with tension blisters) showed complete survival, and 2 (12.5%) cases, which had only one vein performed anastomosis of the efferent vein according to the vascularity of the recipient bed, showed partial necrosis. In all cases, no infection or other specific complications occurred in the donor areas.

CONCLUSION

The rate of congestion and necrosis of arterialized venous flaps is still challenging, but it will be suitable for large soft tissue defects of limbs in the future.

A dorsalis pedis venous flap containing a U-shaped venous arch for the reconstruction of fingertip defects

In small-area soft tissue defects of the fingers, venous flaps have the advantages of easy design and harvesting, and also a thin and flexible texture. Although the artery-vein-vein (A-V-V) pattern is the safest pattern, the tiny veins in the finger pulp make anastomosis difficult. We have designed a modified blood flow pattern flap using the dorsum of the foot as the donor site and anastomosing the U-shaped blood vessels in the venous flap with the two digital arteries in an artery-vein-artery (A-V-A) pattern to reconstruct the digital arterial arch without the need for venous anastomosis. Our study included 22 patients with 23 fingertip defects. In the 23 fingers, 18 flaps survived completely and four had only partial marginal necrosis. The donor site healed well without significant scar hyperplasia.Level of evidence: IV.

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.

Venous Flap Reconstruction following Wide Local Excision for Primary Cutaneous Malignancies in Extremities

Cutaneous malignancies in the extremities are relatively common, and radical treatment such as ray amputation was performed for certain advanced skin cancer cases in the past. The concept of surgical treatment of primary cutaneous malignant tumor has gradually changed, and preservation of the extremity by performing the appropriate excision and reconstruction became possible. Various reconstructive methods after the resection of malignant tumors such as skin grafts, local flaps, and free flaps, including perforator flaps have been noted. Due to limitations and some disadvantages of these reconstructive materials for extremities, the arterialized venous flap arose as an alternative method. The arterialized venous flap, which has arterial inflow through an afferent vein perfusing the flap and venous outflow through the efferent veins, is considered to function as a great reconstructive material for distal extremities. Although efficacy of this flap has been noted in the past, usage of the flap considering the oncological aspects and application of the flap to the toes and feet have never been reported.

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.

Distal Brachial Artery Perforator flap: a new chimeric option for complex hand and digits defects

INTRODUCTION

Reconstruction of fingers pose unique challenges, as a thin and flexible flap is needed in order to guarantee a good functional outcome. For the first time, in this report, we present the DBAp (distal brachial artery perforator) flap, based on the distal perforator closer to the medial epicondyle. The DBAp flap was used to reconstruct complex digit defects as free flap, and to cover an elbow defect while raised as a propeller.

METHODS

Four patients underwent finger reconstruction (free flaps): two patients presented an unstable finger scar following previous surgery, whereas the other two patients presented a terminalized finger at the level of the middle phalanx. A further patient presented a post-traumatic loss of substance at the elbow and was reconstructed using a perforator propeller DBAP flap.

RESULTS

Loss of tissues included skin and subcutaneous tissue in all patients and in one patient it included a bone component. Flap dimensions ranged from 48 to 18 cm² (average: 32 cm²). Among complications, patient n.2 flap presented a marginal flap necrosis requiring a small skin graft after necrosis debridement.

CONCLUSION

The DBAp flap provides a slim, glabrous and pliable skin tissue with a well-hidden donor site scar and thanks to the anatomic location of the distal perforator can be designed to include a vascularized bone graft from the medial epicondyle. Despite the low number of cases, we believe that this flap should be considered as a dependable and effective source for complex reconstructions of both soft tissue and bone in fingers.

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.

Distal Arterialized Venous Supercharging Improves Perfusion and Survival in an Extended Dorsal Three-Perforasome Perforator Flap Rat Model

BACKGROUND

Perforator flaps are commonly applied for a variety of skin defects. Many strategies (e.g., hyperbaric oxygen and preconditioning) have been investigated to improve flap survival, but a postoperative 2.03 to 18.2 percent flap necrosis frequency remains a major complication. The authors hypothesized that a distal arterialized venous supercharged (DAVS) flap procedure might improve perfusion and survival in an extended three-perforasome perforator flap rat model and rescue flap ischemia intraoperatively.

METHODS

One hundred twenty male Sprague-Dawley rats (200 to 300 g) were divided into the thoracodorsal artery (TDA) flap group and the DAVS flap group (n = 60 per group). An approximately 11 × 2.5-cm2 flap based on the TDA perforasome was designed in the TDA flap. A DAVS flap was designed based on the TDA flap and supercharged by anastomosing the rat caudal artery with the deep circumflex iliac vein. At postoperative times 1, 3, 6, and 12 hours and 1, 3, 5, and 7 days, perfusion and angiography were compared. On day 7, flap viability and angiogenesis were assessed using histology and Western blotting.

RESULTS

The DAVS flap showed a higher survival rate compared with the TDA flap (100 percent versus 81.93 ± 5.38 percent; p < 0.001). All blood flow ratios of deep circumflex iliac artery to TDA perforasome and of choke zone II to choke zone I were higher in the DAVS flap (all p < 0.05). Angiography qualitatively revealed that choke vessels in choke zone II dilated earlier and extensively in the DAVS flap group. CD34+ vessels (68.66 ± 12.53/mm2 versus 36.82 ± 8.99/mm2; p < 0.001) and vascular endothelial growth factor protein level (0.22 ± 0.03 versus 0.11 ± 0.03; p < 0.001) were significantly increased in the DAVS flap group.

CONCLUSIONS

The DAVS procedure improves three-perforasome perforator flap survival and can be used for rescuing flap ischemia intraoperatively. Further study is needed before possible clinical adoption for reconstructive operations.

The Pediatric Arterialized Venous Flow-through Flap

Arterialized venous flow-through flaps are solely vascularized through the venous plexus. The flaps were first described 40 years ago; however, reports of venous congestion and ischemia discouraged surgeons from adopting them into their armamentarium. Nevertheless, recent studies have demonstrated a resurgence of venous flow-through flaps for reconstruction of small to medium defects of the hand and digits. Although current data report variable levels of success in adults, no case reports have been published in the pediatric population for this type of flap. In this study, an arterialized venous flow-through flap from the medial forearm was used to reconstruct a volar hand defect in a young child. Flap markings, surgical technique, and aftercare are described. The surgery was uncomplicated, and the postoperative outcomes were aesthetically and functionally excellent. Venous flow-through flaps restore full-thickness defects, are relatively easy to perform, allow an early return to daily activities, and have almost no morbidity. These flaps offer excellent options for pediatric hand and finger defects.

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.

Arterial or venous free flaps for volar tissue defects of the proximal interphalangeal joint: A comparison of surgical outcomes

Background

For volar soft tissue defects of the proximal interphalangeal (PIP) joint, free flaps are technically challenging, but have more esthetic and functional advantages than local or distant flaps. In this study, we compared the long-term surgical outcomes of arterial (hypothenar, thenar, or second toe plantar) and venous free flaps for volar defects of the PIP joint.

Methods

This was a single-center retrospective review of free flap coverage of volar defects between the distal interphalangeal and metacarpophalangeal joint from July 2010 to August 2019. Patients with severe crush injuries (degloving, tendon or bone defects, or comminuted/intra-articular fractures), thumb injuries, multiple-joint and finger injuries, dorsal soft tissue defects, and defects >6 cm in length were excluded from the study, as were those lost to follow-up within 6 months. Thirteen patients received arterial (hypothenar, thenar, or second toe plantar) free flaps and 12 received venous free flaps. Patients’ age, follow-up period, PIP joint active range of motion (ROM), extension lag, grip-strength ratio of the injured to the uninjured hand, and Quick Disabilities of Arm, Shoulder & Hand (QuickDASH) score were compared between the groups.

Results

Arterial free flaps showed significantly higher PIP joint active ROM (P=0.043) and lower extension lag (P=0.035) than venous free flaps. The differences in flexion, grip strength, and QuickDASH scores were not statistically significant.

Conclusions

The surgical outcomes of arterial free flaps were superior to those of venous free flaps for volar defects of the PIP joint.

Lateral Toe Pulp Flap Used in Reconstruction of Distal Dorsal Toe Defect: Case Report and Review of the Literature

BACKGROUND

When the distal dorsal part of the great toe is injured, especially with exposure of a tendon, bone, or joint, applying a free or local flap is difficult because of the lack of locally available tissue for reconstruction. Management of the distal dorsal part of a great toe soft tissue defect can be challenging for plastic surgeons.

PATIENT AND METHOD

An 18-year-old woman presented with an injury to the dorsal aspect of her right great toe caused by a cobra bite. After fasciotomy, the wound showed exposure of the extensor hallucis longus tendon. After demarcation and infection control, the wound was reconstructed using a lateral toe pulp flap of approximately 3.5 × 1.0 cm. The flap was transposed to the defect, and the donor site was closed primarily. Toe pulp flaps are mainly used to reconstruct finger pulp defects and are useful because they provide a glabrous skin flap suitable for resurfacing fingertip injuries. A lateral toe pulp flap uses a homodigital adjacent skin flap, which is transposed to cover the soft tissue defect. Using a quick and straightforward procedure, we designed this flap to reconstruct a distal dorsal defect of the great toe, with minimal morbidity at the donor site.

RESULTS

The flap initially showed mild congestion but survived completely.

CONCLUSIONS

Applying a lateral toe pulp flap is a quick, simple, and reliable 1-stage procedure. It may be an effective option in reconstructing distal dorsal defects of the great toe.

Flap Coverage of Dysvascular Digits Including Venous Flow-Through Flaps

A dysvascular digit is defined as a threatened circulatory condition of a digit caused owing to multiple reasons, such as medical illness or trauma. A dysvascular digit always needs surgical manipulation of the vessel in trauma cases. The revascularization of the digit is a priority in such conditions, after which reconstruction of the defect is performed. In this article, the authors present and discuss the venous free flap, thenar free flap, toe plantar free flap, free style perforator flap, hypothenar free flap, and anconeus muscle free flap.

Secondary Surgery Following Replantation and Revascularization

Secondary surgery following digital replantation and revascularization is common and is often performed to improve range of motion, tendon gliding, sensibility, and/or contour. In this article, the authors present the most common secondary procedures performed after digital replantation or revascularization and discuss current techniques. The importance of patient selection and postoperative compliance with ongoing hand therapy is paramount to achieving good outcomes.

Application of Concatenated Arterialized Venous Flaps in Finger Reconstruction

Venous flaps from the distal volar forearm are said to be suitable flaps for finger reconstruction. The pliability of the forearm venous flap makes it easy to follow the curvature of the finger contour. The thickness of the flap makes it appropriate as a flap for finger resurfacing. Following the venous network at the palmar forearm, diverse patterns of the venous flaps can be designed. This article describes the use of a 2-concatenated paddle, flow-through arterialized venous flap design for simultaneous resurfacing of 2 separate defects on a single digit. A technique that can be used to reduce postoperative venous congestion will be highlighted in this article.

Reverse Flow Shunt Restricted Arterialized Venous Free Flap

Several technical modifications have been described to avoid complications of venous flaps. The authors describe a technical variation of the venous flap to reduce the risk of venous congestion and the likelihood of shunting, thus increasing venous flap reliability.

Anatomy of medial plantar superficial branch artery perforators: Facilitation of medial plantar superficial branch artery perforator (MPAP) flap harvesting and design for finger pulp reconstruction

BACKGROUND

Medial plantar artery perforator (MPAP) flap was proposed as proper option for finger pulp reconstruction. To provide the previously unavailable vessel information required for this small flap design, this study aimed to gather all necessary anatomy of MPA, MPAP, and their territories of blood supply to apply in clinical MPAP flap reconstruction minimizing perforator injury.

METHODS

Dissection of 30 Thai cadaveric feet for visualizing superficial branch of MPA and its perforators (MPAP) using acrylic dye cannulation were performed. Diameter, length, number of branches, course, distributing areas of these vessels, and also their areas of blood supply were recorded in relation to specified landmarks, eg, C-MTH line; medial calcaneal tuberosity to plantar side of the first metatarsal head and S point; emerging point of superficial branch of MPA from deep fasciae into subcutaneous layer.

RESULTS

Average diameter of MPA at its origin and total length are 1.63 ± 0.3 and 52.8 ± 16.1 mm, respectively. It provides 1-3 perforators, with an average size and length of 0.36 ± 0.11 and 23.2 ± 5.47 mm, respectively. Its distribution is mostly in the posteromedial quadrant within 50 and 30 mm from the midpoint of C-MTH line and the S point, respectively. The estimated perforator flap area is 2.5 cm × 1.5 cm and 4.5 cm × 2.5 cm for single and double perforators, respectively.

CONCLUSIONS

MPAP flap was proved as another ideal option for finger pulp reconstruction. Its limitation is small size of perforators but this can be overcome by using MPA for microsurgical anastomosis instead.

Venous flaps for coverage of traumatic soft tissue defects of the hand: a systematic review

A PRISMA-guided systematic review was performed of all published cases that detail the use of venous flaps for soft tissue reconstruction of the hand following trauma. Outcome measures examined included flap survival rates, venous congestion, and return to theatre. Database searches were performed on Medline, Embase, AHMED, CINAHL. A total of 381 articles were identified. Data were extracted from 45 articles that met inclusion criteria. A total of 756 flaps were described and their data analysed. A total of 75% of flaps were arterialized and 25% were pure venous flaps. There was no difference in survival rate for arterialized or pure venous flaps. Unplanned return to theatre occurred in 5.3% due to flap compromise or necrosis. Early venous congestion was present in 60% of cases. Total early failure requiring re-operation occurred in 19 flaps (2.5%) of cases. Venous flaps offer a versatile and well-tolerated reconstructive option. Early venous congestion is common, but can be managed non-operatively.

LEVEL OF EVIDENCE

II.

USE of arterialized saphenous vein venous flow-through flaps as a temporizing measure for hand salvage in contaminated wounds presenting with limb ischemia: A case series

BACKGROUND

Vascular injuries resulting in limb ischemia are traditionally treated acutely with autologous or prosthetic bypass grafts. Traumatic contaminated injuries with soft tissue and vascular segmental loss are challenging as prosthetic bypasses are at risk of erosion, infection, and occlusion; and autologous bypasses are at risk of desiccation, blow-out, infection, and clotting. We propose a novel approach to these injuries by using arterialized saphenous vein venous flow-through free flaps (S-VFTF) as an autologous bypass, and present the results of its application in a series of cases.

METHODS

Spanning 2008 to 2015, four patients presenting with large contaminated crush/avulsion wounds with vascular injury underwent hand revascularization with S-VFTF, allowing the contaminated wounds to be serially debrided. Definitive soft tissue reconstruction was performed once the wound was considered clean. The S-VFTF skin paddle was de-epithelialized and the soft tissue defect covered with a free latissimus dorsi flap or a rectus abdominis myocutaneous flap.

RESULTS

All ischemic limbs were successfully reperfused and there were no take backs for perfusion issues. All S-VFTF remained patent at discharge and final follow-up. No partial or complete finger/hand amputations were required. All definitive coverage free flap survived with no complications.

CONCLUSION

The two-stage reconstruction presented may help reconstructive and vascular surgeons consider alternatives to traditional vascular reconstruction methods. This technique avoids an exposed vascular graft in an extensively contaminated open wound. It allows the surgeon to perform thorough and sufficient debridement of the wound, preventing definitive reconstruction in a not yet declared zone of injury.

Systematic Review and Meta-Analysis of Unconventional Perfusion Flaps in Clinical Practice

BACKGROUND

Although unconventional perfusion flaps have been in clinical use since 1975, many surgeons are still deterred from using them, because of some reports of high necrosis rates.

METHODS

The authors performed a systematic review and meta-analysis of all articles written in English, French, German, Spanish, and Portuguese on the clinical use of unconventional perfusion flaps and indexed to PubMed from 1975 until July 15, 2015.

RESULTS

A total of 134 studies and 1445 patients were analyzed. The estimated survival rate of unconventional perfusion flaps was 89.5 percent (95 percent CI, 87.3 to 91.3 percent; p < 0.001). Ninety-two percent of unconventional perfusion flaps (95 percent CI, 89.9 to 93.7 percent; p < 0.001) presented complete or nearly complete survival. Most defects mandating unconventional perfusion flap reconstruction were caused by trauma (63.6 percent), especially of the hand and fingers (75.1 percent). The main complication of all types of flaps was a variable degree of necrosis (7.5 percent of all unconventional perfusion flaps presented marginal necrosis; 9.2 percent and 5.5 percent had significant and complete necrosis, respectively). There was a positive correlation between the rate of postoperative infection and the need for a new flap (Pearson coefficient, 0.405; p = 0.001). Flaps used to reconstruct the upper limb showed better survival than those transferred to the head and neck or to the lower limb (p < 0.001).

CONCLUSION

Unconventional perfusion flaps show high survival rates and should probably be used more liberally, particularly in the realm of upper limb reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Skin Coverage Considerations in a Mutilating Hand Injury

The foremost goal of managing a mutilated hand is provision of adequate skin coverage. The most suitable method is free tissue transfer. The specific role of volar surface requires replacement tissue to have similar texture for aesthetically satisfactory and functionally acceptable outcomes. Hand surgeons must approach mutilating hand injuries with the recognition that no 2 injuries are ever the same. The injured hand must be evaluated on the individual demand and characteristics of hand use. Optimal function and aesthetic outcomes require appropriate selection of skin coverage. Lost tissues must be replaced like with like tissue.

Arterialized venous flow-through flaps in the reconstruction of digital defects: case series and review of the literature

BACKGROUND

Arterialized venous flow-through (AVFT) flaps are useful in reconstructing small soft tissue defects. Currently, no guidelines exist for the use of AVFT flaps for reconstructing soft tissue defects in the digits of the hand. We retrospectively reviewed our experience with AVFT flaps and developed a selection process for vascular anastomoses.

METHODS

We reviewed the use of AVFT flaps in a series of ten consecutive patients requiring reconstruction of small soft tissue defects of the fingers.

RESULTS

Between 2006 and 2012, ten consecutive digital reconstructions were performed using AVFT flaps. Flap sizes ranged from 5 to 13.5 cm(2). Initial congestion was seen in all flaps and resolved within 3-7 days. Leeches were utilized in two cases. All cases achieved good functional results. Three illustrative cases from our series of ten are presented, each demonstrating key decision-making factors in selecting recipient and flap vessels for anastomosis.

CONCLUSIONS

AVFT flaps appear congested post-operatively, resolving in days to weeks, and resulting in healthy coverage of digital soft tissue defects with good functionality. We suggest a selection process for the use of AVFT flaps in digital soft tissue reconstruction, based on dorsal vs. volar and proximal vs. distal defect location, and the flap's inherent venous architecture.

Retrograde arterialized free venous flaps for the reconstruction of the hand: review of 14 cases

PURPOSE

Although the literature is encouraging with regard to the survival rate of arterialized free venous flaps, previously reported difficulty in healing owing to early venous congestion and subsequent epidermolysis continues to prevent their widespread application. We report 14 arterialized free venous flaps for primary reconstruction of the hand, with inflow in the arterialized vein running against the valves.

METHODS

Between February 2010 and May 2012, we performed 14 arterialized free venous flaps, each of which included at least 2 veins running in parallel. The arterialized vein was anastomosed in a retrograde manner, with the inflow running against the valves. All flaps were customized with regard to dimension, shape, quality of skin, pedicle length, vessel size, inclusion of additional anatomical structures, and donor site. The flaps were used to cover small, medium, and large defects; 2 flaps were larger than 100 cm(2). Three flaps were injected with indocyanine green on the table after harvesting, to visualize the vascular tree of the flap. These 3 flaps were then monitored with systemic indocyanine green injection and an infrared camera for 3 days postoperatively.

RESULTS

All but 1 flap survived. Venous congestion and epidermolysis were observed in 2 small flaps. The flaps injected with indocyanine green displayed a ramified vascular tree with no arteriovenous flow-through phenomenon.

CONCLUSIONS

Arterialized free venous flaps with retrograde arterial flow offer thin and pliable coverage that fits easily around the contours of the hand. They are easy to harvest, with little donor site morbidity. Tendons or nerves can be incorporated for reconstruction of composite defects.

CLINICAL RELEVANCE

Our series suggests the possibility of routine use of a free venous flap with retrograde arterial flow for reconstruction of the hand.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Free arterialised flow-through venous flap with venous anastomosis as the outflow (A-A-V flap) for reconstruction after severe finger injuries

Abstract For reconstruction of volar defects, an arterialised flow-through venous flap (A-A flap) can be used to restore the soft tissues and the digital artery at the same time. However, there have been reports that the circulation of this flap is inadequate. This study used a venous flap with only one venous anastomosis for the outflow of an A-A flap (A-A-V flap) to solve this problem. Six patients with defects of the finger soft tissues and digital artery after severe finger injuries were performed. The venous flap with a Y-shaped vein was harvested. The digital artery was reconstructed, after which the other proximal vein of this flap was anastomosed to the dorsal subcutaneous vein. The flap survived in all patients and histological examination of flap tissue showed a nearly normal architecture. This study describes the good results obtained with an A-A-V flap, and discusses the utility of our flap in comparison with previously reported venous flaps.

Second toe plantar free flap for volar tissue defects of the fingers

Background

The reconstruction of volar surface defects is difficult because of the special histologic nature of the tissue involved. The plantar surface is the most homologous in shape and function and could be considered the most ideal of reconstructive options in select cases of volar surface defects. In this paper, we evaluate a single institutional case series of volar tissue defects managed with second toe plantar free flaps.

Methods

A single-institution retrospective review was performed on 12 cases of reconstruction using a second toe plantar free flap. The mean age was 33 years (range, 9 to 54 years) with a male-to-female ratio of 5-to-1. The predominant mechanism was crush injury (8 cases) followed by amputations (3 cases) and a single case of burn injury. Half of the indications (6 cases) were for soft-tissue defects with the other half for scar contracture.

Results

All of the flaps survived through the follow-up period. Sensory recovery was related to the time interval between injury and reconstruction-with delayed operations portending worse outcomes. There were no postoperative complications in this series.

Conclusions

Flexion contracture is the key functional deficit of volar tissue defects. The second toe plantar free flap is the singular flap whose histology most closely matches those of the original volar tissue. In our experience, this flap is the superior reconstructive option within the specific indications dictated by the defect size and location.

The physiology, microcirculation and clinical application of the shunt-restricted arterialized venous flaps for the reconstruction of digital defects

Reconstruction of digital defects using the venous flap offer several advantages but remained unpopular owing to levels of venous congestion rates. We performed animal studies to test the hypothesis that an arterio-venous shunt increases pressure for peripheral flap perfusion and decreases venous congestion. Using an abdominal adipofascial flap model in six male Sprague-Dawley rats, microcirculation was modified as follows: type I - arterial flap; type II - flow-through arterio-venous flap (AVF); and type III - shunt-restricted AVF. In type I flaps, blood flow was observed to be unidirectional in both arterioles and venules. In type I flaps, blood flow was observed to be unidirectional in both arterioles and venules. In type II flaps, blood flow oscillated without a dominant direction and came to a standstill. In type III flaps, blood flowed proximally in a reverse direction whereas distally, flow was similar to type I flaps. In a clinical series, 21 patients received a total of 22 shunt-restricted AVFs. All 22 clinical flaps survived; four flaps suffered epidermolysis but recovered without full thickness loss.

The reconstruction of the mutilated hand

The challenging reconstructive treatment of defects in the upper extremity requires a sound working knowledge of a variety of flaps. As the hand surgeon weighs the pros and cons of each possible flap to obtain definitive closure, he or she must also integrate the priorities of function, contour, and stability as well as the anticipation of further reconstructive surgery in choosing the flap of choice. This review describes the various flaps available for closure of soft tissue defects of the upper extremity. The principles of management of wounds of the upper extremity is described to guide hand surgeons in the early treatment of massive wounds that will eventually need free tissue coverage. Currently used flaps include fasciocutaneous, fascial, musculocutaneous, muscle, and osteocutaneous flaps. Flap selection is based on the characteristics of the defect including size, shape, and location, the availability of donor sites, and the goals of reconstruction. Improved techniques of microsurgery and an ever increasing repertoire of flaps provide the framework for hand surgeons to offer the most appropriate flap based on donor site, thickness, amount of tissue needed, and composition. A discussion of the selection of ideal flaps for any given defect should enable the reconstructive hand surgeon to provide the most appropriate coverage of wounds to the hand and upper extremity.

Clinical applications of venous flaps in the reconstruction of hands and fingers

In recent years, the venous flap has been highly regarded in microsurgical and reconstructive surgeries, especially in the reconstruction of hand and digit injuries. It is easily designed and harvested with good quality. It is thin and pliable, without the need of sacrificing a major artery at the donor site, and has no limitation on the donor site. It can be transferred not only as a pure skin flap, but also as a composite flap including tendons and nerves as well as vein grafts. All these advantages make it an optimal candidate for hand and digit reconstruction when conventional flaps are limited or unavailable. In this article, we review its classifications and the selection of donor sites, update its clinical applications, and summarize its indications for all types of venous flaps in hand and digit reconstruction.

Optimizing the arterialized venous flap

BACKGROUND

Outcome of arterialized venous flaps is quite varied. The authors' initial experiments showed that a good vascular bed contributes significantly to survival of the flap. In continuation of these experiments, this study aimed to understand the influence of architectural variations on flap outcome.

METHODS

Fasciocutaneous flaps were designed on the ears of New Zealand rabbits, and the animals were randomized into four groups having flaps that used the larger anterior marginal vein (1.3 mm) or the smaller central vein (0.6 mm) for arterial inflow, with or without isolation of the flap from its bed with a silicone sheet. Flaps were observed for area of flap survival and vasculature was assessed by microangiography.

RESULTS

Using the smaller central vein for arterial inflow (n = 15), arterialized venous flaps had an excellent outcome, with good flap survival in 100 percent of the animals (survival of >85 percent of flap area), and a mean flap survival area of 99.4 +/- 1.6 percent. Even when neovascularization was prevented by isolation of the flaps (n = 14), 92 percent of central vein flaps showed good survival, with a mean flap survival area of 93.3 +/- 7.3 percent, which was significantly better than that of anterior marginal vein flaps (n = 22), which showed good flap survival in only 27 percent of the animals (mean flap survival area, 76.4 +/- 12.1 percent).

CONCLUSIONS

Survival of arterialized venous flaps is optimized by using smaller-caliber veins for inflow and reserving larger-caliber veins for outflow. This regulates inflow and avoids high blood pressure, and arterialized venous flaps behave as physiologic flaps do, by not relying on neovascularization for survival.

Finger soft tissue reconstruction using arterialized venous free flaps having 2 parallel veins

PURPOSE

Arterialized venous free flaps with a single straight venous axis may require redirection of either the efferent or afferent vein for anastomosis to the digital vessels. To simplify these flaps, the authors propose use of an arterialized venous free flap having 2 parallel veins that does not require redirection of the veins.

METHODS

The authors performed 44 arterialized venous free flaps having 2 parallel veins for the reconstruction of digital soft tissue defects. The mean area of coverage was 6.5 cm(2). The donor sites included the volar aspect of the distal forearm in 35 cases, the thenar area in 8 cases, and the dorsal aspect of the foot in 1 case.

RESULTS

Thirty-nine of the 44 flaps survived. Complete flap necrosis occurred in 5 cases, and flap congestion was seen in 28 cases.

CONCLUSIONS

The authors had satisfactory results using arterialized venous free flaps having 2 parallel veins. By using these flaps, the authors were able to simplify the technique of arterialized venous flaps.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

A Retrospective Analysis of 154 Arterialized Venous Flaps for Hand Reconstruction: An 11-Year Experience

BACKGROUND

The purpose of this study was to present the authors' 11-year clinical experience involving 154 cases of arterialized venous flaps for hand reconstruction.

METHODS

The authors classified the venous flaps based on their size and composition. According to their size, flaps smaller than 10 cm were classified as small (n = 48), flaps larger than 25 cm were classified as large (n = 42), and those in between were classified as medium (n = 64). Classified according to their composition, there were 88 cases (57.1 percent) of venous skin flaps, 28 cases (18.2 percent) of innervated venous flaps, 15 cases (9.7 percent) of tendocutaneous venous flaps, and 17 cases (11 percent) of conduit venous flaps to repair arterial defects. There were six cases (3.9 percent) of composite venous flaps.

RESULTS

The success rate of the flap transfer was 98.1 percent. The incidence of partial flap necrosis was 5.2 percent. The mean number of included veins was 2.17 for a small flap, 2.60 for a medium-sized flap, and 4.07 for a large flap (p < 0.01). The mean area of flap necrosis was 45.0 percent, 31.67 percent, and 18.75 percent for small, medium, and large flaps, respectively (p = 0.807). In eight cases of innervated venous flaps, the average static two-point discrimination was 10 mm (range, 8 to 15 mm). In 12 cases of tendocutaneous venous flaps, active range of motion at the proximal interphalangeal, distal interphalangeal, and metacarpophalangeal joints was 60, 20, and 75 degrees, respectively.

CONCLUSIONS

The authors conclude that the arterialized venous flap is a valuable and effective tool for reconstructing complex hand injuries and may have a more comprehensive set of indications.

Arterialization of the Venous System of the Hand

BACKGROUND

The treatment of hand ischemia can be very challenging. In cases in which there are no reconstructible arterial lesions, treatment options are limited. Arterialization of the venous system of the hand is a straightforward surgical procedure that provides arterial blood to the distal soft tissues of an ischemic hand.

METHODS

The author conducted a retrospective review of the history, indications, technique, and results of this technique as applied to the treatment of five hands in three patients.

RESULTS

For each of these patients, the treatment included an anastomosis from the distal radial or ulnar artery to a dorsal hand vein. Blood flow was directed distally by ligating venous side branches. Valvulotomies were performed as needed to the base of the digits on the dorsum of the hand. This approach resulted in excellent pain relief in all treated hands and healing of digital wounds.

CONCLUSION

This relatively straightforward salvage procedure provides arterialized blood to ischemic digits, resulting in wound healing and significant reduction in pain.

Microvascular soft tissue reconstruction of the digits

INTRODUCTION

Composite tissue loss to digits following trauma may require flap coverage. Local reconstruction techniques are popular but can result in a functional limitation at the donor site. Small free flaps though complex, may provide a superior alternative.

METHOD

We retrospectively reviewed the case-notes of all patients who had a small free flap to a digit following trauma. The time period was 4 years (2000-2004). Sixteen patients with 18 digital free flaps were identified. These comprised of 10 venous flow-through flaps, one lateral arm flap, one great toe to thumb pulp transfer, three first web space flaps from the foot, one medial plantar flap and two free posterior interosseous flaps. All 16 patients were invited for clinical review at an out-patients clinic. Ten patients (11 flaps) attended follow-up. Standardised assessment of outcome in terms of scar quality at both the recipient and donor sites, sensibility, range of motion and function of the hand was completed.

RESULTS

Overall the average follow-up period was 14 months, with 16 out of 18 flaps surviving. Of the patients that attended for clinical review, the majority recovered excellent function of the hand (quick-DASH--av. 5.7) with satisfactory aesthetics, minimal pain or limitations in range of motion. The flaps were all soft and durable. Ten flaps recovered protective but not discriminative sensation (only one flap was innervated). The three patients whose donor site was the first-web space of the foot developed significant hypertrophic scarring.

CONCLUSION

Small free flaps provide an acceptable method of reconstructing digital defects. Venous flow-through flaps provided the best overall results in this series. The donor site for first-web space flaps is probably unacceptable.

Internal Arteriovenous Fistula Within a Radial Forearm Flap – A Novel Technique to Increase Femorodistal Bypass Graft Flow to the Diabetic Foot and Flap Covering Ischaemic Tissue Loss

BACKGROUND

The fascio-cutaneous radial forearm flap is especially suitable to rebuild the contour of the foot, but because of low natural low flow this flap lacks the beneficial effect of large muscle flaps on bypass graft flow. The aim of this study was to introduce a novel technique of flap coverage combined to vascular bypass: an internal av-fistula was created within a radial forearm flap.

METHODS

Nine critically ischaemic limbs were treated with a modified radial forearm flap in the Department of Plastic and Vascular Surgery, Helsinki University Central Hospital 1998-2003. All the patients were candidates for a major amputation unless this combined operation was attempted. A two-team approach was used: the vascular surgeon performed the distal bypass and the radial forearm flap was raised by the plastic surgeon. In eight cases a femorodistal bypass was performed and in the ninth the vein graft supplied the flap directly. The internal fistula within the flap was created between the distal end of the radial artery and either the cephalic vein or the concomitant vein of the radial artery. Flow was measured during surgery.

RESULTS

Vein graft flow increased significantly after the radial forearm flap anastomosis (76 vs 44 ml/min, p=0.016). The flow of both the bypass graft and the flap artery were higher with the av-fistula patent (p=0.016 and p=0.004). Graft patency was 89% at 2 years. Infection was a major cause of amputation, 1- and 2-year limb salvages being 67 and 53%.

CONCLUSION

In a group of diabetic patients increased flow in a vascular bypass graft was achieved by an internal av-fistula within a radial forearm flap. This method is useful in selected cases with poor run off and large ischaemic lesions.

Use of a sequential two-in-one free arterialised venous flap for the simultaneous reconstruction of two separate defects on the foot

A sequential free arterialised venous flap carrying two flaps nourished by a single venous pedicle was designed for the simultaneous reconstruction of two separate soft tissue defects on the dorso-medial aspect of the foot. These two defects were separated by approximately 3.5 cm, exposing the extensor hallucis longus tendon and first tarso-metatarsal joint. Superficial epidermolysis was noted postoperatively in the smaller flap. Nonetheless, flap survival was uneventful with no further surgery required, and the patient was discharged 7 days after surgery. Three months after the surgery, the patient was satisfied with the result and no morbidity was evident at the donor site. The sequential flap is not a new flap category, but we are unaware of any previous report of a free arterialised venous flap in the form of a sequential flap. We demonstrate the clinical value of this type of flap design for selected cases. The benefits and possible pitfalls of the sequential free arterialised venous flap are discussed.

Use of "spare parts" in mutilated upper extremity injuries

Management and treatment of complex mutilated upper extremity injuries often can be challenging and at times seemingly formidable. A reconstructive surgeon's ability to mobilize, transpose, and transfer tissues has allowed not only closure of complex wounds but also restoration of function and form. Use of "spare parts" from an otherwise unsalvageable limb represents the ultimate form of reconstruction that probes the creative mind and challenges the reconstructive knowledge of the surgeon. In this article, the authors review and discuss the use of various "spare parts" in the treatment of mutilating hand injuries.