Microsurgical Tissue Transfer Research Articles

Microsurgical Reconstruction of the Lower Extremity.

Reconstruction of bony and soft tissue defects of the lower extremity has been revolutionized by the advent of microsurgical tissue transfer. There are numerous options for reconstruction. Possibilities include transfer of soft tissue, composite (bone and soft tissue) tissue, and functional muscle. Many lower extremity reconstructions require staged procedures. Planning is of paramount importance especially in regard to vascular access when multiple free flaps are required. Soft tissue reconstruction of the lower extremity may be accomplished with muscle flaps such as the rectus femoris and latissimus dorsi covered with a skin graft. Fasciocutaneous flaps such as the anterolateral thigh flap may be more appropriate in a staged reconstruction which requires later elevation of the flap. Loss of a significant portion of bone, such as the tibia, can be difficult to manage. Any gap greater than 6 cm is considered a reasonable indication for vascularized bone transfer. The contralateral free fibula is the donor site of choice. Functional reconstruction of the anterior compartment of the leg may be performed with a gracilis muscle transfer, effectively eliminating foot drop and providing soft tissue coverage. Muscle tensioning is critical for effective excursion and dorsiflexion of the foot. Long-term results of microsurgical reconstruction of the lower extremity show good results and reasonable rates of limb salvage.

Reconstruction in pediatric orthopedic trauma: the role of primary cross leg flap cover.

Composite defects of the leg often involve microsurgical reconstruction. Microsurgery is technically demanding in post-trauma situations in very young children. There is renewed interest in cross leg flaps in this scenario. Children aged up to 5 years, who had open fractures or exposed bones in the leg, were followed up prospectively. Eight children, with a mean age of 4 years, underwent nine flaps for extensive tissue defects over the leg and foot. Six of these flaps were cross leg flaps. No flap failed and all wounds acquired early stable cover. The cross leg flap is a useful alternative in the pediatric population in lieu of microsurgical tissue transfer.

Improvement of ischemic or congested wound conditions by reconstruction with microsurgical flaps.

Intractable chronic wounds share the basic problem of the environment being unfavorable for wound healing and prone to infection, inflammation, and recurrences. Microsurgical flap provides a healthy, well-vascularized normal tissue to compromised intractable environment, and promotes wound healing. In this report, we present the results of microsurgical flaps used for the reconstruction of chronic intractable conditions including chronic ulcer with an ischemic environment and pathologic lesions with a congestive environment. From 1997 to 2015, 18 patients received microsurgical flaps for chronic intractable conditions. Among them, three patients had radiation ulcers with an ischemic environment and 15 had pathologic lesions with a congested environment, such as vascular malformations. Nine patients were male, and nine were female. The mean age was 31.9 years. All patients were treated using radical excision and reconstruction with microsurgical tissue transfer. All flaps survived completely. Among three patients with radiation ulcers, two had minor wound disruptions, which were managed conservatively. No further episodes of infections or breakdowns occurred. Among 15 patients who had pathologic lesions, one suffered facial palsy of the forehead. No complications in terms of infection, or recurrences were noted, and resolution of the residual surrounding lesions was observed on follow-ups. No donor related problems occurred in any patients. The mean follow-up period was 10.7 years. In this report, we present the results of reconstruction of chronic intractable conditions using microsurgical flaps. The reconstruction using microsurgical flaps was clinically successful, with long-term improvement of surrounding tissues and no recurrence.

Innervated Free Gracilis Muscle Transfer: An Experimental Model.

Although rodent models have been used extensively for surgical research, their use is limited in microsurgical tissue transfer due to their small size and the small size of their vessels and nerves. Also, fundamental anatomic differences may make rodent surgical models hard to extrapolate to humans. In this report, the authors present a rabbit model for studying free tissue transfer and nerve regeneration using the innervated free gracilis muscle flap. In providing this report, the authors are hopeful that this model could become a standard investigative method for future investigators to employ in other translational endeavors. The authors have completed 12 innervated gracilis muscle transfers with 2 surgical site infections requiring antibiotic treatment and postoperative wound care. There were no complications related to flap-viability in the study over an average follow-up of 9 months. The return of muscle function with nerve coaptation is seen initially around 12 weeks and complete return of function occurs by 20 weeks. Rabbits are comparatively small, easily available, easy to handle, and cost-effective experimental models. Use of the innervated gracilis muscle free flap in rabbits can provide an excellent and economic model for free tissue transfer and reinnervation studies.

Recent advances in microvascular autologous breast reconstruction after ablative tumor surgery.

Breast cancer is a ubiquitous disease and one of the leading causes of death in women in western societies. With overall increasing survival rates, the number of patients who need post-mastectomy reconstruction is on the rise. Especially since its psychological benefits have been broadly recognized, breast reconstruction has become a key component of breast cancer treatment. Evolving from the early beginnings of breast reconstruction with synthetic implants in the 1960s, microsurgical tissue transfer is on the way to become the gold standard for post oncology restoration of the breast. Particularly since the advent of perforator based free flap surgery, free tissue transfer has become as safe option for breast reconstruction with low morbidity. The lower abdominal skin and subcutaneous fat tissue typically offer enough volume to create an aesthetically satisfying breast mound. Nowadays, the most commonly used flap from this donor site is the deep inferior epigastric artery perforator flap. If the lower abdomen is not available as a donor site, the gluteal area and thigh provide a number of flaps suitable for breast reconstruction. If the required breast volume is small, and there is enough tissue available on the upper medial thigh, then a transverse upper gracilis flap may be a practicable method to reconstruct the breast. In case of a higher amount of required volume, a gluteal artery perforator flap is the best choice. However, what is crucial in addition to selecting the best flap option for the individual patient is the timing of the operation. In patients with confirmed post-mastectomy radiation therapy, it is advisable to perform microvascular breast reconstruction only in a delayed fashion.

What is the ideal interval between dressing changes during negative pressure wound therapy for open traumatic fractures?

Negative pressure wound therapy (NPWT) is effective in infection control during treatment of severe open fractures. However frequent dressing changes during NPWT are costly and cause patient discomfort. If the interval between dressing changes could be extended, these problems would be reduced. In this article we compare the outcomes of open IIIB fractures with 3-day versus 7-day intervals between dressing changes. Patients who sustained Gustilo IIIB open fractures were included. All underwent conventional orthopaedic fixation with delayed latissimus dorsi flap coverage. Group 1 had 3-day intervals between dressing changes and group 2 had 7-day intervals. The final outcomes in the two groups were analysed. There were 38 patients in group 1 and 34 patients in group 2. Although the period between admission and final operation was similar in the two groups, the mean number of NPWT changes was 4.54 in 3 day in group 1 and 1.95 in group 2 (p<0.001). This led to a difference in NPWT-related costs; $341.26 in group 1 and $237.49 in group 2 (p<0.001). There was no difference in the frequency of complications such as infection or non-union of fractures. NPWT is useful treatment option for open fractures, to bridge between initial debridement and final microsurgical tissue transfer. Considering patient comfort, the costs related to the NPWT, and the final flap results, a 7-day interval between changes of the NPWT is acceptable.

Refinements and restoring contour in head and neck reconstruction.

To date head and neck reconstructions of oncological defects have concentrated on primarily filling the defect to achieve primary wound healing, secondly restore function and lastly cosmesis. This paper describes a refinement of existing free tissue transfer techniques for improvement of contour, function and aesthetics. A retrospective review of 38 patients operated on by one surgeon at St Vincent's, Royal Melbourne and Western Hospitals over a 3-year period was conducted. Data were collected on patient demographics, tumour details, nature of the defect, type of reconstructive procedure, nature of additional tissue used, radiotherapy, complications and outcome. We present refinements in using de-epithelialized skin paddles, flexor hallucis longus, and rectus and vastus lateralis muscle in order to achieve optimal reconstruction. Free tissue transfer refinements are discussed in anterolateral thigh, fibula, rectus and anteromedial thigh free flaps. The average defect size and volume of neck dissection prior to reconstruction is presented. A variation of radical, modified radical and selective neck dissections were required for oncological staging and clearance. Rare and minor associated complications are discussed. Post-operative radiotherapy treatment was used in the majority of patients with preoperative adjuvant therapy required in some salvage cases. All patients achieved primary wound healing post-operatively with no salivary leaks, flap failures or exposure of neck vessels. Supplementary microsurgical tissue transfer of de-epithelialized skin, vastus lateralis, flexor hallucis longus and rectus muscles is a valuable option for restoring contour, aesthetics and vessel protection post-radiotherapy.

Perioperative factors that influence the outcome of microsurgical reconstructions in craniomaxillofacial surgery

Microsurgical tissue transfer is a well-established way of reconstructing the head and neck, but there are still many postoperative complications that require revision. The aim of this study was to clarify perioperative factors and characteristics of patients that influence the success of the flap and the need for revision. We retrospectively studied 368 patients who were treated with microsurgical free tissue transfer in the head and neck area at the Department of Oral and Maxillofacial Surgery at the University Medical Centre, Erlangen, between 2004 and 2009. Investigations concentrated on patients’ characteristics and operative factors. Free scapular or parascapular flaps (n=161, 44%) and radial forearm flaps (n=119, 32%) were predominantly used for the reconstruction of major defects in the mandible and the floor of the mouth. In 39 patients (11%) revision was required, which resulted in a success rate of 96%. There was a significant association between preoperative American Society of Anesthesiologists (ASA) grade and postoperative survival of the flap (p=0.04). Patients previously treated by irradiation required significantly more revisions than those not so treated (p=0.04). The use of vein grafts was also significantly associated with the need for revision (p=0.02). The ASA grade influenced the success rate but was not associated with the number of revisions. These factors must be taken into consideration when intervention is planned to reduce the number of postoperative complications and interventions further.

Assessment of free microvascular flap perfusion by intraoperative fluorescence angiography in craniomaxillofacial surgery

Microsurgical tissue transfer represents a standard technique for reconstruction in craniomaxillofacial surgery. The transferred tissue is anastomosed to vessels of varying diameters and different physiological conditions. The aim of this study was to evaluate the blood flow in free flaps at their origin and compare this with the flow after reperfusion.In 24 patients undergoing microsurgical procedures (13 radial forearm free flaps (RFFF) and 11 parascapular/scapular free flaps (PSFF)), blood flow was evaluated by intraoperative fluorescence angiography after flap raising and again after reperfusion in the neck area (Flow800, Carl Zeiss AG, Oberkochen, Germany). Flow is expressed by the blood flow index (BFI), maximum intensity (MaxInt) and half-time to MaxInt (t1/2) and was measured in the flap pedicle itself, as well as in the supplying vessels.Following anastomosis of the free flaps in the head and neck area, both the arterial and the venous BFI and MaxInt significantly increased, whereas t1/2 decreased significantly. There was no significant difference in the perfusion parameters between RFFF and PSFF.Intraoperative fluorescence angiography is a reliable method for assessing the perfusion of free microvascular flaps. In the head and neck area, free flaps undergo a significant increase in perfusion but show no differences between varying flap types.

Expression of transforming growth factor beta 1-related signaling proteins in irradiated vessels.

Microvascular free tissue transfer is a standard method in head and neck reconstructive surgery. However, previous radiotherapy of the operative region is associated with an increased incidence in postoperative flap-related complications and complete flap loss. As transforming growth factor beta (TGF-β) 1 and galectin-3 are well known markers in the context of fibrosis and lectin-like oxidized low-density lipoprotein 1 (LOX-1) supports vascular atherosclerosis, the aim of this study was to evaluate the expression of TGF-β1 and related markers as well as LOX-1 in irradiated vessels. To evaluate the expression of galectin-3, Smad 2/3, TGF-β1, and LOX-1, 20 irradiated and 20 nonirradiated arterial vessels were used for immunohistochemical staining. We semiquantitatively assessed the ratio of stained cells/total number of cells (labeling index). Expression of galectin-3, Smad 2/3, and TGF-β1 was significantly increased in previously irradiated vessels compared with nonirradiated controls. Furthermore, LOX-1 was expressed significantly higher in irradiated compared with nonirradiated vessels. Fibrosis-related proteins like galectin-3, Smad 2/3, and TGF-β1 are upregulated after radiotherapy and support histopathological changes leading to vasculopathy of the irradiated vessels. Furthermore, postoperative complications in irradiated patients can be explained by increased endothelial dysfunction caused by LOX-1 in previously irradiated patients. Consequently, not only TGF-β1 but also galectin-3 inhibitors may decrease complications after microsurgical tissue transfer.

Medial Sural Artery Perforator Free Flap: Legitimate Use as a Solution for the Ipsilateral Distal Lower Extremity Defect

The medial sural artery perforator (MSAP) flap captures the cutaneous territory of the medial calf, and can potentially be advantageous as a thin free flap, even in the most obese individual, for coverage of most foot and/or ankle defects where bulk is a liability. The anatomy is fairly constant, as usually at least one reasonably large perforator can always be found emanating from the medial head of the gastrocnemius muscle. As a microsurgical tissue transfer, a long vascular pedicle of large caliber is routinely possible which facilitates any requisite microanastomoses.Over the past decade from our free flap registry, 14 patients with distal lower extremity wounds were covered specifically with a perforator flap based on the ipsilateral medial sural artery; out of which only 2 (14%) were females.In this series using a MSAP free flap, there was only one failure requiring salvage by a different free flap. All but one case was a sequel of trauma, and these involved all zones of the foot and ankle. A skin graft of the donor site was necessary in 5/14 (36%) patients. In no cases did the flap subsequently impede the use of shoes nor hinder ambulation.The study concluded the major disadvantage of the MSAP flap is the nonaesthetic scar left at the donor site which can be quite conspicuous, especially if a skin graft had to be used. Yet even this detriment can be acceptable for ipsilateral distal lower extremity defects where reconstruction of the defect itself may be cosmetically unappealing. This may be the best indication for the MSAP flap to be considered first as the free flap of choice.

Reconstruction of complex oro-facial defects using the myocutaneous sub-mental artery flap

Oro-facial defects require reconstruction that provides suitable colour match and texture. Moreover inner and outer cheek lining and bulk are key considerations. In cases of severe oro-facial infections concomitant mandibular abnormality, for example trismus, can mandate the need for tissue to obturate mandibular defects. We assessed the use of the myocutaneous sub-mental artery flap (MSA) in non-oncological patients with such defects. Twenty two consecutive patients were included in this case series. All patients were survivors of Cancrum Oris (NOMA). Demographic details, nutritional status and co-morbidities were recorded. Defects were classified according to the tissues destroyed; cheek, mandible, oral cavity, lip(s), nose and eye(s). Simultaneous procedures carried out were recorded. The surgical anatomy of the MSA is described. All patients had composite defects of the cheek and oral cavity plus another local anatomical structure. Adjunct procedures such as trismus release were carried out in 18/22 patients. Four patients required a return to theatre. There was no trismus recurrence observed. No flap losses were incurred. The MSA is a robust flap with minimal incidence of major complications. The MSA negates the need for microsurgical tissue transfer. Furthermore the MSA provides adequate bulk to obturate these defects. Future applications of the MSA may include complex oro-facial oncological defects.

Fate of a Second Perforator Free Flap Used to Salvage Failure of the First Perforator Free Flap

Perforator flaps should no longer be considered an exotic or complicated option for microsurgical tissue transfer. However, despite a proper design and attention to detail, as with any free flap, failure can be anticipated sometimes to occur. If a free flap is then still indicated, the big question is what to do next? In our series of 314 perforator free flaps over the past decade, 21 (7%) total failures occurred. A second free flap was attempted for 17 (81%) of these cases. Overall these were successful for 16 (94%) patients, including 11 perforator free flaps that were 100% successful. The anterolateral thigh (ALT) free flap proved to be the "workhorse" alternative. It can be concluded that if failure of a free flap can best be rectified by a second free flap, failure of a perforator free flap can also be reliably salvaged by a second perforator free flap.

Angiogenese und Vaskularisation beim Tissue Engineering von Fettgewebe

The current standard for the reconstruction of large soft tissue defects with exposed bone, nerves or blood vessels, for example after extensive tumor resections, complex injuries, severe burns or infections, is the local or free microsurgical tissue transfer. Despite the development of new surgical techniques and many synthetic materials, there are still a large number of limitations and complications at the donor and recipient site. Thus, in a subset of patients either complete treatment is not possible or poses problems. Therefore, there is a great need for the development of new methods and materials allowing for a permanent replacement with body own soft tissue. A promising therapeutic approach is the soft tissue replacement with autologous adipose tissue. Innovative research on the reconstruction of soft tissue by adipose tissue, and clinical and experimental studies on the long-term survival and transplantation of autologous adipose tissue showed that the free fat tissue graft without direct vascular connection come along with disappointing results. Often a loss of volume or a complete resorption of the graft because of insufficient tissue quality by lack of cell differentiation was observed. This fact points to the special role of the maintenance and development of the graft's blood supply (angiogenesis and vascularization) crucial for maintaining a constant volume of the tissue. The rapidly growing interdisciplinary field of tissue engineering offers alternative solutions to the existing treatment options with the aim to produce autologous adipose tissue, stable in volume in vitro as well as in vivo, which can be transplanted as a permanent tissue replacement to corresponding parts of the body. Numerous studies have demonstrated the important and most critical factor of vascularisation for quality, volume and long-term survival of transplanted newly generated adipose tissue constructs. Although our understanding of the regulatory mechanisms of adipogenesis is still limited, there are clear indications that the complex sequences of cell interactions in the differentiation and proliferation of adipocytes is directly related to angiogenesis.

Platysma myocutaneous flap - its current role in reconstructive surgery of oral soft tissue defects

Reconstruction of oral soft-tissue defects following resection of oral carcinomas can be achieved using various techniques including microsurgical tissue transfer. However, there seems to be a role for regional or local flaps. Small to medium-size defects can be functionally reconstructed with the platysma myocutaneous flap as an excellent choice particularly in medically compromised patients not being eligible for free tissue transfer. The present paper reviews the indication, surgical technique, and complications following reconstruction of defects of the oral cavity with the platysma myocutaneous flap.

Recent advances in reconstructive surgery: head and neck reconstruction

Although advances in radiotherapy and chemotherapy for cancers of the head and neck have been remarkable, surgical resection followed by reconstructive surgery is still the mainstay of treatment. Of the reconstructive procedures, microsurgical tissue transfer has been considered the standard method for restoring postoperative functions and morphology. In this review article, we discuss the history of reconstructive surgery for treating cancers of the head and neck, current problems, and future challenges.

Sequential Bilateral Breast Reconstruction Using a Split Solitary Deep Inferior Epigastric Artery Perforator Flap

Autogenous tissue bilateral breast reconstruction often requires microsurgical tissue transfers. The reality is that sometimes revascularization cannot be accomplished, leading to a total flap failure. If one flap survives, another attempt using a second flap is necessary to achieve symmetry. Nonmicrosurgical options to achieve this are limited. If the successful flap is bulky enough, it can be bisected to create a local island flap based on the original flap pedicle to allow completion of the contralateral reconstruction. This concept is here presented using a split deep inferior epigastric artery perforator flap for sequential bilateral breast reconstruction.

The Keystone Island Flap: Use in Large Defects of the Trunk and Extremities in Soft-Tissue Reconstruction

Microsurgical perforator flaps are useful in an array of reconstructive scenarios, but their technical complexity, steep learning curves, and prolonged operative times may limit their widespread adoption. Alternatively, the keystone island flap combines perforator-based vascularity with relative simplicity of nonmicrosurgical tissue rearrangement. This article reviews the authors' reconstructive experience using the keystone flap to reconstruct large trunk and extremity defects. The authors performed a retrospective chart review of patients undergoing keystone flap reconstruction between 2002 and 2008. Patient demographic data, medical histories, comorbidities, surgical indications, defect characteristics and locations, hospitalization, complications, and follow-up care were evaluated and are presented in this article as an uncontrolled case series. Twenty-eight patients underwent keystone flap reconstruction. The average wound size measured 15.0 ± 11.7 × 13.0 ± 7.9 cm (250.5 ± 379.4 cm2). The average length of stay, including tumor resection, was 6.36 ± 6.68 days. A 35.7 percent overall complication rate was noted; partial and total flap loss was observed in only 7 percent of patients. One patient (3 percent) failed reconstruction and required alternative wound closure. The keystone flap can be applied to large defects of the trunk and extremities, obviating the need for either microsurgical techniques or extensive operative time while achieving primary wound healing. Despite minor complications, the 97 percent reconstructive success rate compares well to published rates of microsurgical tissue transfers but has several advantages: short operative times, high reproducibility, ease of use, and favorable aesthetic outcome. The authors conclude that the keystone flap is a reliable and effective reconstructive surgical technique for reconstruction of soft-tissue defects.

A Survey of U.K. Units and a Suggested Protocol for Free Flap Reconstruction of the Lower Limb: Follow-up and Management in the First Postoperative Week

A survey was performed of U.K. lower-limb reconstruction services and the protocol for management of free flaps to the lower limb in the first postoperative week. The postoperative period is of vital importance in these patients due to the complex nature of microsurgical tissue transfer. A range of answers were received in response to the questions regarding protocols, with no overall consensus on the postoperative plan for these patients. Patients are being managed differently in different units across the United Kingdom. A protocol that has been used successfully by the senior author is described, and we encourage others without a protocol to adopt this one.

Versatility of the pedicled peroneal artery perforator flaps for soft-tissue coverage of the lower leg and foot defects

Even a small defect in the lower leg and foot with exposure of bones or tendons can result in an intractable wound, which may require a microsurgical tissue transfer. With the concept of the perforator flap, a pedicled peroneal artery perforator flap can be used for coverage of this difficult region. Between August 2001 and August 2008, 18 pedicled peroneal artery perforator flaps were performed in 18 patients. The fasciocutaneous flaps were employed to cover defects in the pretibial area (n=6), Achilles' tendon and/or hindfoot (n=7) and lateral malleolar area (n=5). The pedicled peroneal artery perforator flaps are classified into five types: propeller flap (n=11), peninsular flap (n=4), advancement flap (n=2), proximally based island flap (n=1) and distally based island flap (n=0). The size of the flaps ranged from 7.5×3 cm(2) to 20×8 cm(2). The selected perforator depended on the defect location, ranging from 4.5 to 18 cm above the tip of the lateral malleolus. Postoperative venous congestion was encountered in four propeller flaps and one proximally based island flap. Venous congestion subsided within days without complications, except one which needed further reconstruction with skin grafts. In conclusion, the peroneal artery perforators are predictable and reliable for the design of a perforated-based flap. Elevation of the flap can be performed easily in the supine or prone position, depending on the defect location. Different designs of this perforator-based flap can repair a variety of leg and foot defects.