Microvascular Free Flap Transfer Research Articles

In Search of Optimal Practice: A Retrospective Comparative Study of Single- Versus Dual-Venous Anastomosis in Microvascular Flaps.

Background In the current era of reconstructive surgery, microvascular free flap transfers are the most popular reconstructive procedures performed. The main reason for the failure of the flap and re-exploration is venous thrombosis. Traditionally, most surgeons prefer performing two-vein anastomoses. There is insufficient literature to support that dual-venous anastomosis is better than single-venous anastomosis. In this study,we compared the success rate of single-venous anastomosis with dual-venous anastomosis of different free flap reconstructions. Methodology The retrospective cohort study was conducted with a total of 101 patients. Eighty-three were in the one-vein group, and the remaining 18 were in the two-vein group. Outcomes were compared between the two groups regarding re-exploration and flap failure. Results The overall success rate of free flap reconstruction was 96%.Among the 101 free flaps, 16 flaps had signs of venous compromise and were re-explored. Out of the 16 flaps, 11 flaps (13.2%) were in the one-vein group, and 5 flaps (27.7%) were in the two-vein group. In the two-vein group, 100% of the flaps were salvaged, and in the one-vein group, only 63% of the flaps were salvaged after re-exploration. There was no statistically significant difference between the one-vein group and the two-vein group concerning re-exploration. Conclusions The rate of re-exploration was lower in the one-vein group when compared to the two-vein group. However, this difference was not statistically significant. Hence, a single-vein anastomosis is sufficient for a successful microvascular free flap.However, the rate of flap salvage is better with two-vein anastomosis if there is venous congestion.

Modification of the pedicled osteomuscular dorsal scapula flap to include a skin paddle

This article describes a reliable surgical alternative for the repair of wide oromandibular defects that require bone and soft tissues, which was applied in two patient cases. While microvascular free flap transfer, especially the fibula flap, is the gold standard for mandibular reconstruction, this reconstruction is challenging in patients with a vessel-depleted neck and/or severe arteriosclerosis. The pedicled osteomuscular dorsal scapular (OMDS) flap is a surgical alternative to free flap transfer in this clinical setting. The technique described involves harvesting of the OMDS flap to include a skin paddle, which is often required to close wide oral mucosal defects.

Post-reconstruction Free Flap Complications After Oral Cancer Ablation.

Microvascular free flap transfer is considered a standard reconstruction after the ablation of oral cancer. Although the success rate is high, flap complications occasionally occur. This study investigated the reasons for and local factors involved in complications of free flap transfer and explored how to salvage the flaps. The cases of 53 patients who underwent a free flap transfer [radial forearm flaps (n = 36), abdominis musculocutaneous flaps (n = 6), scapular osteocutaneous flaps (n = 10), and fibular osteocutaneous flap (n = 1)] were analyzed: flap complications were observed in five of the cases. In the all five cases, a salvage operation was performed under general anesthesia. The flap complications occurred within 33h after anastomosis. In the salvage operation, thrombotic occlusion in veins of flap feeders was observed in three of the five cases. The possible reasons for flap complications were a twisting of the anastomosed vein where two veins were united, pressure to the feeder due to subcutaneous hematoma, and edema of adjacent tissue and/or drain tube; the reason was not clear in one case. The flaps were successfully salvaged in four cases by thrombectomy in veins, release of pressure at the veins, and/or interposition of the vein graft. Surgeons should pay close attention to the pressure and/or twisting in the feeder as well as the hemostasis in the surgical field, and a salvage operation should be carried out immediately when a flap complication is identified.

Postoperative care in ICU versus non-ICU after head and neck free-flap surgery: a systematic review and meta-analysis

ObjectiveAdmission to the intensive care unit (ICU) has long been considered as routine by most head and neck surgeons after microvascular free-flap transfer. This study aimed to answer the question...

What is the impact of infrapopliteal endovascular intervention on free flap survival in diabetic foot reconstruction?

BackgroundThe combination of endovascular intervention and microvascular free flap transfer has been effectively used for chronic ischemic wounds of lower limb. The aim of this study was to determine the influence of angioplasty on free flap survival in diabetic foot ulcer reconstruction.MethodsA retrospective research was conducted for 46 diabetic patients with chronic ulcer of the foot. All patients underwent free flap reconstruction because of their non-healing wound with tendon or bone exposure. Patient’s demography, clinical data related to vascular status, vascular intervention, and free flap transfer procedure were collected. Flap survival rate was compared between the group with severe arterial stenosis group and non-severe stenosis group. It was also compared among groups with different revascularization results.ResultsThe average age of patients was 56.2 ± 10.8 years. There were 14 (30.4%) men and 32 (69.6%) women. Of 46 patients, 23 (50%) had severe infrapopliteal arterial stenosis. All 23 patients underwent endovascular intervention. Their final results of the pedal arch were type 1 in 13 patients, type 2A in 7 patients, type 2B in 2 patients, and type 3 in 1 patient. Total flap necrosis was found in 5 (10.9%) cases, marginal necrosis in 4 (8.7%) cases, and wound dehiscence in 4 (8.7%) cases. There was no significant difference in flap loss between severe arterial stenosis patients and non-severe arterial stenosis patients. In the severe arterial stenosis group, after endovascular intervention, patients with type 1 of pedal arch had a significantly lower rate of total flap necrosis than others. There was no association between the use of revascularized recipient artery and flap survival.ConclusionsOur study revealed that the quality of pedal arch was crucial for free flap survival. Thus, PTA should aim to re-establish a complete pedal arch to increase wound healing rate and flap success.

Head and neck microsurgical reconstruction using the superficial temporal vein for antegrade and retrograde drainage: A clinical case series

In head and neck microsurgical reconstruction, previous surgery and past radiation exposure to the neck may adversely affect recipient vessel access in the neck. The superficial temporal vessels can be used to overcome these challenges. The purpose of this article is to demonstrate the viability of using the superficial temporal vein (STV) for a double venous anastomosis, for antegrade and retrograde drainage, in head and neck microvascular free flap transfers. An 11-year retrospective chart review was performed of clinical cases of head and neck reconstruction by free tissue transfer, in which the recipient vessels used were the superficial temporal artery (STA) and vein, with the latter providing for dual antegrade and retrograde drainage. The case series comprised of six patients who underwent free flap reconstruction of craniofacial defects following resection of malignant tumours in five, and due to noma in one. Compromising factors were scarring, radiotherapy, previous surgery and the recipient superficial temporal vein being less than 1 mm in diameter above the parotid. The recipient vessels used were the superficial temporal artery and veins in all cases. The use of the superficial temporal blood supply for a single arterial supply and a dual antegrade and retrograde venous drainage is a reliable technique for free flaps to the upper two thirds of the head. A double venous anastomosis adds to its dependability. Level of Evidence: Level IV, therapeutic study.

Pharmacological thrombolysis: the last choice for salvaging free flaps

Microvascular free flap transfer has become a prevailing surgery with a failure rate of <5%. However, pedicle thrombosis occurs more frequently than indicated by the failure rate. This difference is due to the successful salvage of failing flaps. During exploration, thrombi are often encountered at anastomotic sites, whereas these causes could not explain vascular compromise in other patients. Thus, we hypothesized that thrombogenic processes might occur at remote sites, specifically within microvessels of the transferred flap. This study retrospectively evaluated 323 patients who underwent microvascular free flap transfer between March 2012 and October 2016 at Korea University Guro Hospital. All patients requiring emergency exploration within 7 days after surgery were retrospectively reviewed. Of patients, 15 required explorative surgery for suspected circulatory compromise. Eight were diagnosed with thrombosis at the perianastomotic site and salvaged in accordance with our protocol. There was no detectable thrombosis at the anastomotic site in seven patients, including one patient in whom thrombosis resolved with topical papaverine application and heparinization. The remaining six patients were diagnosed with intra-flap microthrombosis without discernable thrombosis at the anastomotic site. All patients were treated following our urokinase administration protocol and salvaged without complications. Possible external causes should first be evaluated when salvaging free flaps; in the absence of such evidence, urokinase administration may be utilized as a last resort. This study is the first report describing the effectiveness of pharmacological thrombolysis in resolving intra-flap microthrombosis. Furthermore, a safe and efficient urokinase administration protocol is suggested for perianastomotic thrombosis and intra-flap microthrombosis.

Development of an Extracorporeal Perfusion Device for Small Animal Free Flaps.

BackgroundExtracorporeal perfusion (ECP) might prolong the vital storage capabilities of composite free flaps, potentially opening a wide range of clinical applications. Aim of the study was the development a validated low-cost extracorporeal perfusion model for further research in small animal free flaps.MethodsAfter establishing optimal perfusion settings, a specially designed extracorporeal perfusion system was evaluated during 8-hour perfusion of rat epigastric flaps followed by microvascular free flap transfer. Controls comprised sham-operation, ischemia and in vivo perfusion. Flaps and perfusate (diluted blood) were closely monitored by blood gas analysis, combined laser Doppler flowmetry and remission spectroscopy and Indocyanine-Green angiography. Evaluations were complemented by assessment of necrotic area and light microscopy at day 7.ResultsECP was established and maintained for 8 hours with constant potassium and pH levels. Subsequent flap transfer was successful. Notably, the rate of necrosis of extracorporeally perfused flaps (27%) was even lower than after in vivo perfusion (49%), although not statistically significant (P = 0,083). After sham-operation, only 6% of the total flap area became necrotic, while 8-hour ischemia led to total flap loss (98%). Angiographic and histological findings confirmed these observations.ConclusionsVital storage capabilities of microvascular flaps can be prolonged by temporary ECP. Our study provides important insights on the pathophysiological processes during extracorporeal tissue perfusion and provides a validated small animal perfusion model for further studies.

Effect of heparin on prevention of flap loss in microsurgical free flap transfer: a meta-analysis.

The effectiveness of heparin for thromboprophylaxis during microvascular free flap transfer is uncertain. The purpose of this meta-analysis was to determine the effect of heparin on the prevention of flap loss in microsurgical free flap transfer.A search of PubMed, Cochrane databases, and Google Scholar using combinations of the search terms heparin, free flap, flap loss, free tissue transfer was conducted on March 15, 2013. Inclusion criteria were: 1) Prospective randomized trials. 2) Retrospective, non-randomized studies. 3) Patients received free tissue transfer. Flap loss rate was used to evaluate treatment efficacy. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated and compared between therapies. Four studies meet the criteria for analysis and were included. Two studiescompared aspirin and heparin, and the ORs of the 2 studies were 1.688 and 2.087. The combined OR of 2.003 (95% CI 0.976–4.109, p = 0.058) did not indicate any significant difference between heparin and aspirin therapies. Two studiescompared high and low doses of dalteparin/heparin therapies, and the ORs of the 2 studies were 4.691 and 11.00. The combined OR of 7.810 (95% CI 1.859–32.808, p = 0.005) revealed a significant difference indicating that high dose dalteparin or heparin therapy is associated with a greater flap loss rate than low dose therapy. Heparin and aspirin prophylaxis are associated with similar flap loss rates after free flap transfer, and high dose dalteparin or heparin therapy is associated with a greater flap loss rate than low dose therapy.

Retrospective study of 100 microvascular free flap transfer

Background and objectives: Microvascular free flap transfer has a crucial role in head and neck reconstructive surgery. This is a complex region due to the complexity of the anatomy and the function that plays, which also frequently requires large areas must be removed. The objective of this study is to identify potential factors directly related with the complication rate and survival of the free flap.

Microvascular free-flap transfer for head and neck reconstruction in elderly patients

BackgroundWith the increase in life expectancy, the incidence of head and neck cancer has grown in the elderly population. Free tissue transfer has become the first choice, among all the reconstructive techniques, in these cases. The safety and success of micro vascular transfer have been well documented in the general population, but its positive results achieved in elderly patients have received less attention.MethodsWe retrospectively studied 28 patients over the age of 60 years. The aim of this paper was to study the success rate of free tissue transfer and investigate the complication incidence in this patient population.ResultsTwenty-eight free flaps were performed to reconstruct medium to large cervico-facial surgical defects in six years. No difference was noted between success and complication rates observed between general and elderly population.ConclusionThis study indicates that free-flap technique for head and neck reconstruction could be considered a safe option in elderly patients when a good pre-operative general status is present.

Opened end-to-side technique for end-to-side anastomosis and analyses by an elastic true-to-scale silicone rubber model

The end-to-side anastomosis is frequently used in microvascular free flap transfer, but detailed rheological analyses are not available. The purpose of this study was to introduce a new modified end-to-side (Opened End-to-Side, OES-) technique and compare the resulting flow pattern to a conventional technique. The new technique was based on a bi-triangulated preparation of the branching-vessel end, resulting in a "fish-mouthed" opening. We performed two different types of end-to-side anastomoses in forty pig coronary arteries and produced one elastic, true-to-scale silicone rubber model of each anastomosis. Then we installed the transparent models in a circulatory experimental setup that simulated the physiological human blood flow. Flow velocity was measured with the one-component Laser-Doppler-Anemometer system, recording flow axial and perpendicular to the model at four defined cross-sections for seven heart cycles in each model. Maximal and minimal axial velocities ranged in the conventional model between 0.269 and -0.122 m/s and in the experimental model between 0.313 and -0.153 m/s. A less disturbed flow velocity distribution was seen in the experimental model distal to the anastomosis. The OES-technique showed superior flow profiles distal to the anastomosis with minor tendencies of flow separation and represents a new alternative for end-to-side anastomosis.

Clinical Application of Human Adipose Tissue–Derived Mesenchymal Stem Cells in Progressive Hemifacial Atrophy (Parry-Romberg Disease) With Microfat Grafting Techniques Using 3-Dimensional Computed Tomography and 3-Dimensional Camera

Parry-Romberg disease is a rare condition that results in progressive hemifacial atrophy, involving the skin, dermis, subcutaneous fat, muscle, and, finally, cartilage and bone. Patients have been treated with dermofat or fat grafts or by microvascular free flap transfer. We hypothesized that adipose-derived stem cells (ASCs) may improve the results of microfat grafting through enhancing angiogenesis. We evaluated the utility of ASC in microfat grafting of patients with Parry-Romberg disease by measuring the change in the hemifacial volumes after injection of ASCs with microfat grafts or microfat grafts alone. In April 2008, this investigation was approved by the Korean Food and Drug Administration and the institutional review board of the Asan Medical Center (Seoul, Korea) that monitor investigator-initiated trials. Between May 2008 and January 2009, 10 volunteers with Parry-Romberg disease (5 men and 5 women; mean age, 28 y) were recruited; 5 received ASC and microfat grafts and 5 received microfat grafts only. The mean follow-up period was 15 months. Adipose-derived stem cells were obtained from abdominal fat by liposuction and were cultured for 2 weeks. On day 14, patients were injected with fat grafts alone or plus (in the test group) 1 × 10 ASCs. Patients were evaluated postoperatively using a 3-dimensional camera and 3-dimensional CT scans, and grafted fat volumes were objectively calculated. Successful outcomes were evident in all 5 patients receiving microfat grafts and ASCs, and the survival of grafted fat was better than in patients receiving microfat grafts alone. Before surgery, the mean difference between ipsilateral and contralateral hemiface volume in patients receiving microfat grafts and ASCs was 21.71 mL decreasing to 4.47 mL after surgery. Overall resorption in this ASC group was 20.59%. The mean preoperative difference in hemiface volume in those receiving microfat grafts alone was 8.32 mL decreasing to 3.89 mL after surgery. Overall resorption in this group was 46.81%. The preoperative and postoperative volume differences between the groups was statistically significant (P = 0.002; random-effects model [SAS 9.1]). Adipose-derived stem cells enhance the survival of fat grafted into the face. A microfat graft with simultaneous ASC injection may be used to treat Parry-Romberg disease without the need for microvascular free flap transfer.

Two-year quality of life after free flap reconstruction in tumor-site discrepancy among Taiwanese with moderately advanced oral squamous cell carcinoma

BackgroundThis study describes 2-year impact on quality of life (QOL) in relation to the anatomical discrepancy among T4a oral cancer patients after free flap reconstruction in Taiwan.MethodsThirty-two patients who underwent tumor ablation with simultaneous microvascular free flap transfer at 2-year follow-up were recruited. They were divided into six subgroups, according to the resected area, consisting of: (1) buccal/retromolar trigone; (2) cheek; (3) commissure; (4) lip; (5) mandible; and (6) tongue. Functional disturbances and daily activity were analyzed using the Version-1 UW QOL Questionnaire with one more specific category: ‘Drooling’. Kruskal-Wallis rank sums analysis was used to test differences in average QOL scores between these subgroups. Post-hoc analysis was applied to assess influence of dominant categories between subgroups.ResultsThe category ‘Pain’ revealed the highest average score and reached significant statistical difference (P = 0.019) among all the categories, however, the category ‘Employment’ averaged the lowest score. Regarding ‘Pain’, there existed a statistical significance (P = 0.0032) between the commissure- and cheek-involved groups, which described the former showed poorer pain quality of life.ConclusionsThe commissure-involved group had the lowest average score, which might imply the worst QOL in our study, especially for the categories ‘Pain’ and ‘Drooling’. This present study of T4a patients was the first carried out in Taiwan implementing the QOL questionnaire, and its results may serve for future reference.

Predictors and impact of microsurgical complications in patients with locally advanced oral squamous cell carcinoma

Microvascular free flap transfer for post-oncologic reconstructive surgery in oral cancer is considered to be a challenge due to the complexity of the anatomy and function of the region. We sought to identify possible factors associated with microsurgical complications and to assess the impact of these complications in relation to patient survival. Following the inclusion and exclusion protocol, 142 patients with stage III and IV oral squamous cell carcinoma (OSCC) who underwent immediate free flap reconstruction after tumor ablation were included in the study. Clinical and surgical procedural-related factors were retrieved from a database and analyzed retrospectively; survival data were evaluated using the Kaplan-Meier method. Major complications that required re-anastomosis of the flap vessels occurred in 23 patients (16.2%); total necrosis of the flaps, regardless of salvage treatment, occurred in seven cases, with 95.1% of full flap survival. The American Society of Anesthesiologists classification, types of neck dissection, and number of flaps were regarded as strong predictors for surgical complications. Patients with these complications appeared to have a shortened survival (5-year cancer-specific survival of approximately 60%, both in stage III and IV OSCC). However, the impact of surgical complications on survival was significant only in stage III OSCC (P = 0.037). Strategies to minimize surgical complications should be used to ensure better prognoses for these patients.

Scalp Defect Repair

Scalp defects often arise in multimorbid patients. This study aimed at establishing an algorithm of defect repair with particular focus on new regenerative options.All patients, who consulted to the Department of Oral and Maxillofacial Surgery/Plastic Surgery, University Jena between April 2005 and March 2010 were reviewed. Different reconstructive options were compared with regard to duration of hospital stay as well as rate of reoperations needed to achieve full closure.Sixty-eight patients were identified. Local flaps were more effective than skin grafts (P = 0.038) and microvascular free flaps (P = 0.037) in case of skin-galea-periosteal-defects. However, no differences were found between skin grafting in combination with wound bed preconditioning using a dermal regeneration template and microvascular free flap transfer. Scalp defects should be repaired based on careful evaluation of defect anatomy as well as patient's general health. Application of dermal regeneration templates allows for an increase of the indication spectrum of free skin grafts.

Factors Associated With Free Flap Complications After Head and Neck Reconstruction and the Molecular Basis of Fibrotic Tissue Rearrangement in Preirradiated Soft Tissue

Several factors are associated with free flap complications in head and neck reconstruction after radiotherapy. The present study aimed to identify the correlation between irradiation and the healing of wounds after microvascular free flap transfer and to clarify the molecular mechanisms for the differences in healing between irradiated and nonirradiated patients. A retrospective study of 81 cases of microvascular free flap transfer was conducted. Tissue samples were obtained from 3 different regions of the patients (nonirradiated oral mucosa, irradiated skin, and nonirradiated skin). Expression of transforming growth factor-beta(1) was monitored by immunohistochemistry and immunoblot analysis. The levels of matrix metalloproteinase-1 and tissue inhibitor of matrix metalloproteinase-1 were investigated qualitatively and quantitatively. Multivariate analysis revealed that only preoperative irradiation was a significant predictor of free flap complications (P = .006), with a 4 times greater risk (odds ratio 4.141). It was also shown that patients with an advanced tumor stage and those who had received chemotherapy after radiotherapy were twice as likely to develop free flap complications. Transforming growth factor-beta(1) was overexpressed in free flaps for as long as 6 months after radiotherapy. It was remarkably observed in the granulation tissue in the preirradiated skin. Moreover, extracellular matrix remodeling regulated by transforming growth factor-beta(1) was detected with decreased matrix metalloproteinase-1 and increased TIMP-1 expression in the irradiated skin. The healing of surgical wounds created by microvascular free flap transfer correlated negatively with preoperative radiotherapy. Extracellular matrix remodeling was also detectable in the free flap for up to 6 months after radiotherapy completion.

Complications and Outcome of Free Flap Transfers for Oral and Maxillofacial Reconstruction: Analysis of 213 Cases

Microvascular free flap transfers have become a preferred reconstructive technique; however, rare complications may still prove devastating. This study reviewed 213 consecutive freetissue transfers in order to assess the incidence and causes of complications in patients undergoing microvascular free flap reconstruction in the oral and maxillofacial region. In most cases, reconstruction was undertaken after resection of a malignant tumor. The flap donor sites were the radial forearm (n=111), rectus abdominis (n=88), scapula (n=13), and latissimus dorsi (n=1). The superior thyroid artery and the external jugular vein were commonly used as recipient vessels for anastomosis. The overall flap success rate was 99%. There were 7 cases of postoperative vascular thrombosis (6 venous and 1 arterial), constituting 3.3% of the entire series. Five flaps were salvaged, representing a 71.4% successful salvage rate in cases of vascular complications. Most of the successful salvage attempts were made within 24 hours of the end of the initial operation, and the successful salvage rate for re-exploration was 100%. Finally, the total flap loss rate was 0.9% and the partial flap loss rate was 2.3%. We conclude that early re-exploration should be the first choice for management of vascular compromised flaps. Complications at the donor site occurred in 17 cases (8.0%), the most common complication of which was partial skin graft loss after harvesting a radial forearm flap (n=10; 9.0%). Recipient and donor site morbidity was limited and considered acceptable.

Ateriovenous subclavia-shunt for head and neck reconstruction

Reconstruction of the facial hard- and soft tissues is of special concern for the rehabilitation of patients especially after ablative tumor surgery has been performed. Impaired soft and hard tissue conditions as a sequelae of extensive surgical resection and/or radiotherapy may impede common reconstruction methodes. Even free flaps may not be used without interposition of a vein graft as recipient vessels are not available as a consequence of radical neck dissection.We describe the reconstruction of the facial hard- and soft tissues with a free parasacpular flap in a patient who had received ablative tumor surgery and radical cervical lymphadenectomy as a treatment regimen for squamous cell carcinoma (SCC). To replace the missing cervical blood vessels an arteriovenous subclavia-shunt using a saphena magna graft was created. Microvascular free flap transfer was performed as a 2-stage procedure two weeks after the shunt operation. The microvascular reconstructive technique is described in detail.

Complete Recovery from Complications of Microvascular Free-flap Transfers after Oral Tumour Extirpation

Objective: In this retrospective study, all free-flap transfers done at the Kanagawa Dental College, Kanagawa, Japan, for reconstruction following ablation of head and neck tumours were analysed. The 5 patients who developed complications following reconstructive surgery and the course of recovery were examined.Patients and Methods: Thirty four microvascular free-flap transfer operations were performed, which included patients with cutaneous radial forearm (17; 50%), myocutaneous rectus abdominis (13; 38%), osteocutaneous scapula composite (2; 6%), osteocutaneous scapula composite with forearm chimera (1; 3%), and myocutaneous rectus abdominis with forearm chimera (1; 3%).Results: Complications were seen in the forearm (n = 2), osteocutaneous scapula composite (n = 2), and chimeric (scapula composite + forearm) [n = 1] microvascular free flaps. The facial artery showed the most complications when used as a recipient artery, presenting 2 complications in 4 inosculation cases; only 2 complications (7%) were observed for the superior thyroid artery (n = 28). The most frequently used recipient vein, the internal jugular vein (n = 27), showed 3 complications (11%). The presenting complications were first observed at 0.5, 4, 36, and 58 hours (mean ± standard deviation, 19.8 ± 26.1 hours) in the 5 patients with complication. Thrombosis was related to the cause of all complications, including bending of the anastomosis (n = 1), distorted pedicle (n = 1), oppression of the pedicle (n = 1), oppression due to coagulation in the surrounding scar (n = 1), and unknown factors (n = 1). Complete recovery was achieved in all patients.Conclusion: Early detection of complications, with diligent and meticulous postsurgical follow-up, is key to achieving complete recovery rates following free-flap transfer surgeries.