Free Flap Anastomosis Research Articles

Potential of the Thoracoepigastric Vein as a Drainage Vein in Breast Reconstruction With a Free Flap: An Anatomical Study Using Computed Tomography.

The recipient vessel choice is very important when performing free-flap breast reconstructions. Usually, the concomitant vein of the recipient artery is anastomosed, and mismatches in the diameter are occasionally observed. We consider the thoracoepigastric vein (TEV) as a potential useful recipient vein. The use of the TEV is not a novel technique. It has been used by surgeons for free-flap anastomoses in the axillary region, but usually as an anastomotic site for the second vein. However, anatomical findings such as TEV diameter, its deficiency rate, and influence on mastectomy are not clear. In this study, computed tomography (CT) was performed to evaluate the use of the TEV as a recipient vein for breast reconstruction. The medical records of patients who underwent breast reconstruction with free-flap transfer were retrospectively evaluated. In most cases, CT was performed using a tissue expander inserted after mastectomy. The TEV was considered suitable if its diameter on the mastectomy side was >1 mm and the vertical distance from the most distal slice level where the TEV could be seen at the third costal cartilage height of the parasternal region was <50 mm. Sixty-six sides of 33 patients were evaluated. The mean age of the patients was 49.3 ± 5.1 years. The TEV was used in five flaps. TEV diameters were not significantly different between the left and right sides (1.85 ± 0.53 vs. 1.82 ± 0.6, respectively, p = 0.836). On the mastectomy side, eight (25%) TEVs were injured, but only three (8.6%) were considered unavailable. On the healthy side, 96.4% TEVs were available. TEVs may be a good choice as vein anastomosis targets for breast reconstruction with a free flap because of their relatively large vessel diameter. UMIN-CTR: R000061573.

Intraoperative Blood Flow Analysis of Free Flaps with Arteriovenous Loops for Autologous Microsurgical Reconstruction

Background: Arteriovenous (AV) loops help to overcome absent or poor-quality recipient vessels in highly complex microvascular free flap reconstruction cases. There are no studies on blood flow and perfusion patterns. The purpose of this study was to evaluate and compare intraoperative hemodynamic characteristics of AV loops followed by free tissue transfer for thoracic wall and lower extremity reconstruction. Methods: this prospective clinical study combined Transit-Time Flowmetry and microvascular Indocyanine Green Angiography for the assessment of blood flow volume, arterial vascular resistance and intrinsic transit time at the time of AV loop construction and on the day of free flap transfer. Results: A total of 11 patients underwent AV loop creation, of whom five required chest wall reconstruction and six required reconstruction of the lower extremities. In seven of these cases, the latissimus dorsi flap and in four cases the vertical rectus abdominis myocutaneous (VRAM) flap was used as a free flap. At the time of loop construction, the blood flow volume of AV loops was 466 ± 180 mL/min, which increased to 698 ± 464 mL/min on the day of free tissue transfer (p &gt; 0.1). After free flap anastomosis, the blood flow volume significantly decreased to 18.5 ± 8.3 mL/min (p &lt; 0.001). There was no significant difference in blood flow volume or arterial vascular resistance between latissimus dorsi and VRAM flaps, nor between thoracic wall and lower extremity reconstruction. However, a significant correlation between the flap weight and the blood flow volume, as well as to the arterial vascular resistance, was found (p &lt; 0.05). Conclusion: This is the first study to perform intraoperative blood flow and hemodynamic measurements of AV loops followed by free tissue transfer. Our results show hemodynamic differences and contribute to deeper understanding of the properties of AV loops for free flap reconstruction.

The Subcalcaneal Fat Pad: An Innovative Space for Passage of the Pedicle in Free Flap Reconstruction of Lateral Heel Defects.

Soft-tissue defects of the lateral heel remain a challenge for reconstructive surgeons. Although a reliable vascular supply for free flap anastomosis is available anteriorly from the anterior tibial vessels and medially from the posterior tibial vessels, the vascular anatomy of the lateral side lacks suitable donor vessels for free flap anastomoses. Although the pedicle can be passed either ventrally beneath the skin or dorsally between the Achilles tendon and calcaneus, these passages are hardly applicable for lateral heel defects. We identified the space between the plantar surface of the calcaneus and the plantar aponeurosis as an innovative approach for reconstruction. Therefore, we propose the subcalcaneal fat pad as an alternative and reliable route for the passage of the flap pedicle to the posterior tibial vessels in free flap reconstruction of soft-tissue defects in the lateral calcaneal region. Consequently, the vascular pedicle can be safely anastomosed to the posterior tibial vessels. This approach provides a new option for recipient vessels in free flap reconstruction.

Lower Extremity Reconstruction with Anterolateral Thigh Free-Flap Anastomoses: A Computational Fluid Dynamic Analysis.

The anterolateral thigh free flap is an option for repairing soft tissue defects of the distal lower extremity. This flap uses the descending branch of the lateral circumflex femoral (LCF) artery as the flap vessel. The recipient vessel in these flaps is often the anterior tibial (AT), posterior tibial (PT), or peroneal (P) arteries. Computational fluid dynamic (CFD) evaluation of anastomoses between these vessels can optimize outcomes. Thirty-eight CFD models were created to model end-to-side (ETS) and end-to-end (ETE) anastomoses for lower extremity reconstruction. Seven out of thirty-eight models represented ETS anastomoses between the LCF and AT arteries with varying anastomotic angles. Nine out of thirty-eight models represented 45-degree ETS anastomoses between varying diameters of the LCF and AT, PT, and P arteries. Nine out of thirty-eight models represented stenosis on the flap vessel and recipient vessel, pre- and post-bifurcation. Nine out of thirty-eight models represented ETE anastomoses, rather than ETS, with varying vessel diameters. Four out of thirty-eight models represented ETE anastomoses with varying regions and levels of stenosis. Stasis of blood flow in ETS models increased as anastomotic angle increased in a logarithmic relationship (R 2 = 0.918). Flow was optimized overall as flap and recipient vessel diameters approached one another. In ETS models, flap vessel and postbifurcation recipient vessel stenosis were found to substantially increase stasis. Selection of flap and recipient vessels with similar diameters can optimize outcomes in microvascular anastomoses. In the context of lower extremity reconstruction with the ALT flap, the PT artery can be recommended as a first-line recipient vessel due to its similar vessel caliber to the LCF and relative ease of surgical access compared with the P artery. Avoidance of areas of stenosis is recommended to ensure laminar flow and reduce the operative difficulty associated with performing anastomoses on nonpliable arteries. Striving for increased acuity of anastomotic angles is recommended to optimize the flow in ETS microvascular anastomoses.

Efficacy of the microscopic parachute end-to-side technique for creating large-to-small venous anastomoses in free flaps in the extremities

The availability of reliable and suitably sized veins is limited for creating free flaps to treat severe trauma and infection, and it is important to manage vessel size discrepancy between the recipient and flap veins. We evaluated the clinical outcomes of free flaps with large-to-small venous end-to-side (ETS) anastomoses using the microscopic parachute end-to-side (MPETS) anastomosis in soft tissue defects in the extremities. This procedure comprises mainly a wide-slit venotomy and parachute procedure at the heel. We examined 24 free flaps in 23 patients given a large-to-small venous anastomosis using the MPETS technique. Patient demographics, details of vessel anastomoses, and flap outcomes and complications were obtained from medical records. Two veins were anastomosed in six flaps. Thirty anastomosed veins were assessed, and 24 deep veins, all of which accompanied main arteries, were chosen as recipient veins. The mean diameters were 1.5mm in the recipient veins and 2.7mm in the flap veins, and the mean vessel size discrepancy was 1.8-fold (range 1.3-3.3 fold). Because of the presence of venous valves at the anastomotic site, trimming of venous cusps was performed in six veins. All flaps survived, though one venous thrombosis occurred because of pedicle kinking in a case with a short pedicle. The MPETS technique is simple, reliable, and useful for performing various types of venous anastomoses regardless of a vessel size discrepancy and the presence of a venous valve. This may be a good option for large-to-small venous anastomosis in free flaps.

Results of contralateral anastomosis of microvascular free flaps in head and neck reconstruction.

Despite various solutions to the issue of ipsilateral vessel-depleted neck in microvascular head and neck reconstruction, concrete data on its safety and implementation are scarce. This paper focuses on the feasibility and success rates of contralateral anastomosis in free flap reconstruction in the head and neck region. This single-center retrospective study at a tertiary referral center includes all patients who underwent free flap reconstruction of the head and neck with contralateral anastomosis between January 1st, 2007 and February 28th, 2021. Primary objectives were frequency, success, and flap-associated complication rates. Secondary objectives were recipient vessels and flap type. Of 318 patients who underwent microvascular reconstruction, anastomosis was performed on the contralateral side of the neck in 32 patients (10.0%). Recipient vessels involved mainly the superior thyroid artery (74.2%; n = 23) and the facial vein (51.1%; n = 23). Thirty patients (93.8%) received a radial forearm free flap. Flap-associated complications occurred in 12.5% of included cases (n = 4): one partial flap necrosis (3.1%), one anastomotic insufficiency (3.1%), one venous thrombosis of the microvascular pedicle (3.1%), and one wound dehiscence (3.1%). All of these complications were resolved without complete flap loss. This study demonstrates that contralateral anastomosis is a successful and safe option in microvascular head and neck reconstruction, especially using a radial forearm free flap. Thus, anastomosing to the contralateral side of the neck can be advocated as a valuable option in the ipsilateral vessel-depleted neck.

PD31-09 USE OF THE DEEP INFERIOR EPIGASTRIC VESSELS FOR ARTERIOVENOUS ANASTOMOSIS IN FREE-FLAP PHALLO-URETHROPLASTY: TECHNIQUE, KEY POINTS, AND LESSONS LEARNED

You have accessJournal of UrologyTrauma/Reconstruction/Diversion: External Genitalia Reconstruction and Urotrauma (including transgender surgery) II (PD31)1 Sep 2021PD31-09 USE OF THE DEEP INFERIOR EPIGASTRIC VESSELS FOR ARTERIOVENOUS ANASTOMOSIS IN FREE-FLAP PHALLO-URETHROPLASTY: TECHNIQUE, KEY POINTS, AND LESSONS LEARNED Nance Yuan, Edward Ray, and Maurice Garcia Nance YuanNance Yuan More articles by this author , Edward RayEdward Ray More articles by this author , and Maurice GarciaMaurice Garcia More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002032.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Most descriptions of free-flap phalloplasty use the femoral artery and great saphenous vein as recipient vessels. This generally requires end-to-side arterial anastomosis and sometimes interposed vein grafts. Use of the deep inferior epigastric vessels (DIEA/V) as recipient vessels has been rarely reported. We present our technique and experience with using the DIEA/V as recipient vessels for free-flap phalloplasty. METHODS: We retrospectively reviewed consecutive patients who underwent free-flap phalloplasty and/or urethroplasty at a single institution from September 2017 to September 2020. In all cases, the DIEA/V were used as recipient vessels. The DIEA/V pedicle was dissected through skin and fascial incisions in the lower abdomen and externalized through a passageway dissected at the medial aspect of the external inguinal ring. Demographics, surgical details, and outcomes were recorded. RESULTS: 31 flaps were anastomosed to the DIEA/V. Mean age was 38 years; mean BMI was 26.9. Mean follow-up was 22.8 months. 29 patients underwent phalloplasty (22 radial-forearm free flap, 9 anterolateral-thigh free flap). 2 patients underwent radial-artery flap urethroplasty. No femoral vessels or interposition grafts were used. Most (90.3%) flaps had two veins anastomosed, using the DIEV. Microvascular outcomes were excellent. Of 31 cases, there was only one case of operative takeback for venous congestion and one case (3.2%) of total flap loss. We explore the lessons learned from this case. There were six (19.4%) cases of dehiscence, most of which were minor and easily repaired. CONCLUSIONS: Use of the DIEA/V as recipient vessels for free-flap phalloplasty has shown excellent outcomes and is our preferred technique. Advantages associated with use of the DIEA/V include a short, direct course to the recipient vessels, good donor-recipient vessel size-match allowing end-to-end anastomosis instead of end-to-side anastomosis, elimination of risks associated with arterialized interposed veins (including potential aneurysm or blow-out from high-pressure flow), reliable dissection anatomy, and a well-hidden scar. Potential pitfalls to avoid include any factors that could compress the pedicle. In cases where venous outflow may be at risk, we recommend a low threshold to use additional local veins for anastomosis, though we rarely need additional veins given the reliability of the DIEV. Source of Funding: none © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e542-e542 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nance Yuan More articles by this author Edward Ray More articles by this author Maurice Garcia More articles by this author Expand All Advertisement Loading ...

Intraluminal Monitoring of Micro Vessels. A Surgical Feasibility Study.

Objective: Monitoring of vessel perfusion is of high clinical importance in vascular anastomosis of free flaps. Current sensor systems are based on different principles and show limitations in validity and accuracy. Fiber optic pressure sensors exhibit high accuracy and are small in size. The aim of the present study was to evaluate the surgical feasibility of intraluminal pressure (ILP) measurements with a fiber optic pressure sensor in an animal model.Methods: In a microsurgical setting we sedated 10 Wistar rats with weight adapted phenobarbital, xylazine, and fentanyl. We performed a surgical approach to A. carotis communis and V. jugularis and introduced a 600 μm fiber optic pressure sensor into the vessels followed by measuring the ILP. The sensor was stabilized by the surrounding tissue, and the vessels were closed.Results: In all cases, surgical placement was uneventful. Measurement of intra-venous and intra-arterial pressure was possible and stable over the whole measurement period of an hour.Conclusion: Fiber optic pressure measurement in microvessels is possible and surgically feasible. An application to monitor the perfusion of free flaps seems possible.

Advantages and disadvantages of using the internal thoracic artery perforators as recipient vessels in autologous breast reconstruction—a narrative review

: The rates of breast reconstruction after mastectomy are rising each year. Autologous breast reconstruction using free tissue transfer is considered the gold standard reconstruction, especially with recent controversy surrounding breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). During free tissue transfer, the flap vessels must be anastomosed to recipient vessels on the chest wall. There are multiple options of recipient vessels during microvascular breast reconstruction. Most commonly, the thoracodorsal vessels or the internal thoracic vessels [also known as the internal mammary (IM) vessels] are used as the recipient vessels for microvascular anastomosis of the free tissue transfer. Other second-line options include the thoracoacromial axis and the lateral thoracic vessels. The use of perforators of the internal thoracic vessels for free flap anastomosis during autologous breast reconstruction has been in use for almost twenty years. They are generally favoured over use of thoracodorsal vessels as they result in medialisation of the flap. In recent years, the use of perforators of the internal thoracic vessels has become popular. Great debate surrounds whether or not they should be used as recipient vessels as opposed to the conventional main vessels. In this article, we discuss the advantages and disadvantages of both techniques to guide the choice of reconstructive microsurgeons.

Superficial versus deep system single venous anastomosis in the radial forearm free flap: a meta-analysis

The selection of the superficial or deep drainage system for use with the radial forearm free flap (RFFF) remains controversial. The aim of this study was to identify the optimal drainage system for single venous anastomosis. A systematic review and cumulative meta-analysis was performed to assess superficial and deep system single venous anastomosis for use with the RFFF in postoperative reconstruction of the head and neck. This study included 1073 flaps (495 superficial system-based flaps, 578 deep system-based flaps) reported in six studies. The outcomes assessed in the studies selected for this meta-analysis included venous compromise, flap failure, and the salvage success rate. Venous compromise was more common in the superficial system group (odds ratio (OR) 2.29, 95% confidence interval (CI) 1.36–3.86, P=0.002). The rate of successful salvage was higher with the superficial system (OR 8.19, 95% CI 1.75–38.3, P=0.008). The rate of flap failure was lower in the superficial system group (OR 0.30, 95% CI 0.04–2.48, P=0.27). Although the deep system showed a lower risk of venous compromise, the evidence provided by the meta-analysis was insufficient to determine which type of drainage system is more suitable for single venous anastomosis in RFFF. All included studies were cohort studies; therefore, findings must be interpreted with caution.

A multivariable miRNA signature delineates the systemic hemodynamic impact of arteriovenous shunt placement in a pilot study

Arteriovenous (AV) fistulas for hemodialysis can lead to cardiac volume loading and increased serum brain natriuretic peptide (BNP) levels. Whether short-term AV loop placement in patients undergoing microsurgery has an impact on cardiac biomarkers and circulating microRNAs (miRNAs), potentially indicating an increased hemodynamic risk, remains elusive. Fifteen patients underwent AV loop placement with delayed free flap anastomosis for microsurgical reconstructions of lower extremity soft-tissue defects. N-terminal pro-BNP (NT-proBNP), copeptin (CT-proAVP), and miRNA expression profiles were determined in the peripheral blood before and after AV loop placement. MiRNA expression in the blood was correlated with miRNA expression from AV loop vascular tissue. Serum NT-proBNP and copeptin levels exceeded the upper reference limit after AV loop placement, with an especially strong NT-proBNP increase in patients with preexistent cardiac diseases. A miRNA signature of 4 up-regulated (miR-3198, miR-3127-5p, miR-1305, miR-1288-3p) and 2 down-regulated miRNAs (miR30a-5p, miR-145-5p) which are related to cardiovascular physiology, showed a significant systemic deregulation in blood and venous tissue after AV loop placement. AV loop placement causes serum elevations of NT-proBNP, copeptin as well as specific circulating miRNAs, indicating a potentially increased hemodynamic risk for patients with cardiovascular comorbidities, if free flap anastomosis is delayed.

Laser-Assisted Microvascular Anastomosis of Free Flaps in Reconstruction of Orofacial Defects: A Comparative Study Among Conventional Methods and Diode Laser Anastomosis.

The key role played by anastomosis determines the outcome of any free flap surgery. Besides many methods, the application of LASERS for performing microvascular anastomosis gaining popularity in recent times. The ease of application, utilizing lesser time for performing anastomosis than the conventional methods and minimal injury to the vessel layers, are contributing factors to the success of free flap surgery. Laser-assisted vascular anastomosis (LAVA) fulfills the criteria of lesser vessel wall damage and faster anastomosis and thus resulting in reduced flap ischemic time and overall outcome of the surgery. A prospective randomized case-control trial comparing conventional suturing methods (group I) with Laser-assisted vascular anastomosis (group II) on free flaps were performed for the reconstruction of orofacial defects. The parameters assessed for evaluation were anastomotic time, ischemic time and vessel patency following anastomosis. Student's t test and Fisher's exact tests were implied for statistical analysis. The mean time taken for anastomosis was 19.75min in the conventional group and 3.86min in LAVA anastomosis. This difference was found to be extremely statistically significant (p < 0.00001). The mean ischemic time of the free flap harvested was 384.87min in group I and 138.7min in group II. This difference was also found to be extremely statistically significant (p < 0.00001). The average anastomosis time for LAVA group was considerably reduced and total ischemic time was considerably less with successful uptake of the flap. In LAVA group, the post-operative complication was less when compared to the conventional anastomosis technique.

Venous Coupler in Pediatric Free Tissue Transfer: Case Series and Literature Review

Background:Venous couplers have gained widespread acceptance as an effective, safe, and time-efficient alternative for hand-sewn anastomosis in microsurgical reconstruction. The literature on venous couplers use in pediatric free tissue transfer is scant. The purpose of this study is to present our experience with coupler-assisted venous anastomosis in young pediatric free flap reconstruction.Methods:This is a retrospective single-center review of all children younger than 10 years old who underwent free flap reconstruction over 36-month period. The primary objective was to assess flap survival rate at 30-day postoperative period. The rate of venous thrombosis, flap take back, flap salvage, and the mean coupling time were also assessed.Results:Four girls and 1 boy with a mean age of 7.3 ± 2.7 years (range 4–10 years) underwent 6 free flap transfers for head and neck, upper limb, and lower limb reconstructions. Microvascular anastomotic coupler system was used for 8 out of 9 performed venous anastomoses with a size ranging from 1.5 to 2.5 mm. Primary flap survival rate was 100%. None of the flaps in our series developed venous thrombosis or required flap take back for microvascular compromise (mean follow-up of 14.4 months). The mean coupling time was 7.1 minutes.Conclusions:In the current study, venous couplers were safe and reliable in free tissue transfer in children younger than 10 years old. Future studies with larger sample size are needed to further examine the safety and efficacy of venous couplers in pediatric microsurgical anastomosis.

Application of a 3D 4K exoscopic system to head and neck reconstruction: a feasibility study

Technological advancements in surgery provide convenience and new capabilities to surgical practice. A recently developed 3D 4K exoscopic system gives the surgeon a potential alternative to the operating microscope (OM). This paper focuses on the first experience on microsurgical free flap reconstructions performed with a 3D 4K system and evaluates the potentials and pitfalls of this new technology. Three consecutive cases of head and neck cancers requiring free flap reconstructions were included. Free flap harvesting and anastomosis in 2 and 3 patients, respectively, were performed using the 3D 4K exoscopic system. The 3D 4K exoscope provided a high quality of vision and perception of depth. The setting of the operating theater was ergonomically favorable. No case required a switch to traditional OM. This initial experience shows that harvesting free flaps and performing microanastomoses with the 3D 4K exoscopic system are feasible. Further studies on larger series are warranted to explore if the applicability of this technology to other fields of head and neck surgery can compensate for its costs. Level of Evidence: Level V, therapeutic study

The application of multiple end-to-side anastomosis in free anterolateral thigh perforator flap transplantation

Objective To explore the clinical application effect of multiple end-to-side anastomosis in free anterolateral thigh perforator flap transplantation. Methods From January, 2013 to October, 2017, 29 cases were applied the technology of multiple end-to-side anastomosis to the same recipient vessel in anterolateral thigh perforator flap transplantation for wound repair. Fifteen cases treated with multiple end-to-side anastomosis on flap arteries, and 2-3 arteries were anastomosed, with the average of 2.13. Nine cases were treated with venous multiple end-to-side anastomosis, and 2-4 veins were anastomosed, with the average of 3.11. Five cases treated with arterial and venous multiple end-to-side anastomosis, and 4-6 vessels were anastomosed, with the average of 5.20. Distribution of wounds: 10 cases with hands and wrists wounded, 15 cases with forearms and elbow joints wounded, and 4 cases with lower legs and feet wounded. The soft tissue defect size was 5 cm×13 cm-11 cm×27 cm, and the flap area was 6 cm×15 cm-12 cm×29 cm. Postoperative followed-up was performed every 3-6 months to review flap survival. Results All flaps of 29 cases survived. Venous congestion occurred in 2 flaps within 48 h after the operation, among which, 1 was overcomed after released the dressing and sutures, and the other underwent surgical exploration. The venous end-to-side anastomotic stomas were unobstructed, and hematoma was formed. After the hematoma compression was removed, circulation was recovered and the flap survived. With followed-up for 6 months to 2.5 years, both donor site and recipient site of the flaps healed well and the injured distal limbs had no hemodynamic disorder. Conclusion The application of multiple end-to-side anastomosis to the same recipient vessel for free transplantation of anterolateral thigh perforator flaps is safe and reliable. Key words: Anterolateral thigh perforator flaps; Vascular anastomosis; End-to-side anastomosis; Repair; Microsurgical technique

Venous bypass grafts versus arteriovenous loops as recipient vessels for microvascular anastomosis in lower extremity reconstructions: A matched‐pair analysis

Limb salvage in patients with peripheral vascular disease (PVD) and soft tissue defects often requires both a restoration of blood flow to the lower extremity and soft tissue coverage. Outcomes of free tissue transfer may be affected by vein grafts, which can be used for the placement of an autologous venous bypass or an arteriovenous (AV) loop leading to different hemodynamic situations. The purpose of this study was to investigate whether free flap anastomosis to a bypass or an AV loop can be performed with comparable results. We performed a matched-pair analysis of 22 patients with PVD undergoing free flap reconstructions of the lower extremity with end-to-side anastomosis to an autologous venous bypass (n = 11, 1 female and 10 male patients) or an AV loop (n = 11, 2 female and 9 male patients). Defects caused by trauma, infection, ulcer, or fasciotomy were reconstructed in each group with 5 muscle-based flaps, 3 parascapular flaps, 2 anterolateral thigh (ALT) flaps, and 1 conjoined latissimus dorsi and parascapular flap. Postoperative complications including thromboses, flap failures, wound complications, and hematomas were compared. Postoperative complication rates including 1 venous pedicle thrombosis (9%vs. 0%, P = 1.0), minor (18% vs. 9%, P = 1.0) and major wound complications (45% vs. 27%, P = .69) as well as hematomas (27% vs. 36%, P = 1.0) did not show relevant differences between the groups. Flap failures were absent in both groups. In patients with PVD, autologous venous bypass grafts may be used for end-to-side anastomoses of free flaps, with postoperative outcomes being comparable to AV loop reconstructions.

Safety of Single Vein Anastomosis versus Double Venous Anastomosis in ALT Perforator Flap in Foot and Leg Reconstruction

Introduction: Single or double venous anastomosis in free flap in general and ALT, in particular, is still a matter of debate between micro vascular surgeons. In this study, we will present our experience in single vein anastomosis versus double venous anastomosis in ALT perforator flap used in leg and foot reconstruction as regarding flap outcome, complications, operation time and the need for re-exploration. Patient and Methods: We retrospectively evaluate 60 patients with post traumatic foot and leg defects in the period between January 2014 and January 2018 where free ALT flap was done. The patients were divided into two groups, Group 1 where single vein anastomosis was done and Group 2 where double venous anastomosis was done; we utilize the deep venous system for the anastomosis in all cases. Results: Complete flap survival noticed in 56 cases (93.3%), defect size ranged from 70 to 200 cm (mean 126.35 ± 33.78). There was no difference between the 2 groups as regarding Flap survival, hospital stay, flap complications, donner site morbidity and vascular insufficiency. There is statistically significant difference between both groups as regarding Ischemia time, Operation time, and overall re-exploration rate. Conclusions: Our study suggests that the use of a single venous anastomosis in the venous drainage of anterolateral thigh free flaps is as safe and feasible as the two veins anastomoses.

Intraoral anastomosis of a vascularized iliac-crest flap in maxillofacial reconstruction

Intraoral anastomosis of free flaps was introduced to avoid extraoral scars. In addition, advances in vascularized iliac-crest flap have greatly facilitated jaw reconstruction. The primary aim of this study was to evaluate feasibility and outcomes of intraoral anastomosis of vascularized iliac-crest flaps used for jaw reconstruction.Methods: From December 2015 to June 2018, 10 (3 men and 7 women) patients aged 12-55 (median, 28) years were treated at the Peking University School and Stomatology Hospital, China. Six patients underwent maxillary reconstruction, and four patients underwent mandibular reconstruction with the intraoral anastomosis of vascularized iliac-crest flaps.Conclusion: In all cases, the facial artery was easily identified by intraoral Doppler ultrasound. The operative time for the preparation of facial vessels by the intraoral approach was 30-60 minutes. All DCIA flaps were successfully harvested. All intraoral anastomoses were successfully established and survived in 9 patients. However, one flap for maxillary reconstruction was lost because of arterial spasm. Nine patients with survived flaps had unrestricted mobilization and showed facial symmetry after surgery. No healing complications were reported in the transplant region in nine patients with survived flaps, and no serious donor site complications were observed during the follow-up period.

Micro-RNA-Regulated Proangiogenic Signaling in Arteriovenous Loops in Patients with Combined Vascular and Soft-Tissue Reconstructions: Revisiting the Nutrient Flap Concept.

The placement of arteriovenous loops can enable microvascular anastomoses of free flaps when recipient vessels are scarce. In animal models, elevated fluid shear stress in arteriovenous loops promotes neoangiogenesis. Anecdotal reports in patients indicate that vein grafts used in free flap reconstructions of ischemic lower extremities are able to induce capillary formation. However, flow-stimulated angiogenesis has never been systematically investigated in humans, and it is unclear whether shear stress alters proangiogenic signaling pathways within the vascular wall of human arteriovenous loops. Eight patients with lower extremity soft-tissue defects underwent two-stage reconstruction with arteriovenous loop placement, and free flap anastomoses to the loops 10 to 14 days later. Micro-RNA (miRNA) and gene expression profiles were determined in tissue samples harvested from vein grafts of arteriovenous loops by microarray analysis and quantitative real-time polymerase chain reaction. Samples from untreated veins served as controls. A strong deregulation of miRNA and gene expression was detected in arteriovenous loops, showing an overexpression of angiopoietic cytokines, oxygenation-associated genes, vascular growth factors, and connexin-43. The authors discovered inverse correlations along with validated and bioinformatically predicted interactions between angiogenesis-regulating genes and miRNAs in arteriovenous loops. The authors' findings demonstrate that elevated shear stress triggers proangiogenic signaling pathways in human venous tissue, indicating that arteriovenous loops may have the ability to induce neoangiogenesis in humans. The authors' data corroborate the nutrient flap hypothesis and provide a molecular background for arteriovenous loop-based tissue engineering with potential clinical applications for soft-tissue defect reconstruction.

The application of microvascular anastomotic coupler in vascular anastomosis of free tissue flap for reconstruction of defect after head and neck cancer resection

Objective: To investigate the application and operation skills in vein anastomosis by microvascular anastomotic coupler (MAC) in reconstruction of defects after head and neck cancer resection. Methods: From August 2015 to July 2016, in Department of Head and Neck Surgery, Sichuan Cancer Hosipital, 17 cases underwent the reconstruction of defects after head and neck cancer resection with free tissue flaps, including forearm flaps in 11 casess, anterolateral flaps in 4 casess and fibula flaps in 2 casess. Totally 17 MAC were used, including 14 MAC for end-to-end anastomosis and 3 MAC for end-to-side anastomosis. SPSS 22.0 software was used to analyze the data. Results: Venous anastomoses in 17 free tissue flaps were successfully completed, with no anastomotic errhysis. All flaps survived well. The time required for vascular anastomoses with MAC varied 2-9 min, with average time of (4.2±2.3) min, which was significantly shorter than that with manually anastomosis (17.4 ± 2.7) min (t=15.1, P<0.01). The followed-up time ranged from 6 to 18 months. The flaps in recipient area healed well. The shape and function of recipient area were satisfying. Conclusions: Microvascular anastomotic coupler can be used for vessel anastomosis in free tissue flap for reconstruction of defect after head and neck cancer resection, which requires for less operation time and shows good results.