Microvascular anastomotic arterial coupling: A systematic review

A clinical application for arterial coupling and histomorphometric comparison of internal mammary and thoracodorsal arteries for safe use

BACKGROUND

In breast reconstruction, arterial coupling has been reported to be more favorable in the thoracodorsal artery (TDA) than the internal mammary artery (IMA). This technique may help overcome anastomosis in a small, deep space. Understanding the arteries' mechanical properties is crucial for breast reconstruction's safety and success.

METHODS

Abdominal-based free flap breast reconstructions performed by a single surgeon between 2020 and 2022 were retrospectively analyzed. The patients were classified by microanastomosis technique (handsewn and coupler device) to compare the rate of vascular revision. Histomorphometric analysis of arterial coupling in TDA and IMA was performed in 10 fresh cadavers for comparing wall thickness and composition, including densities of elastic fiber, smooth muscle, and collagen.

RESULTS

A total of 309 patients (339 reconstructed breasts) were included. There were 29 patients in the TDA handsewn group (A), 38 patients in the TDA coupler group (B), and 242 patients in the IMA handsewn group (C). The rates of arterial revision in groups A, B, and C were 0.00% (95%CI: 0.00%-11.03%), 2.5% (95%CI: 0.44%-12.88%), and 1.49% (95%CI: 0.58%-3.77%), respectively, with no statistically significant differences (p-value = .694). Histologically, the thickness of the tunica media and adventitia between IMA and TDA showed no significant difference. The density of elastic fiber was significantly higher in IMA (16.70%) than in TDA (0.79%) (p-value <.001).

CONCLUSION

The histologic characteristics of TDA are more favorable for arterial coupling than those of IMA. Arterial coupling is a safe option in situations where TDA anastomosis must be performed through a narrow and deep incision.

Novel Osteomyocutaneous Flap Model for Vascularized Composite Allotransplantation

Background

Vascularized composite allotransplantation (VCA) has become a viable option for restoration of devastating injuries that are not amenable to conventional reconstructive techniques. However, the relative scarcity of procedures performed worldwide, as well as the potential for iatrogenic injury with biopsies, makes studying the immunopathogenesis of acute rejection challenging. Translational VCA research focuses on developing strategies to overcome these barriers with the use of animal models can be technically challenging and difficult to replicate without highly trained microsurgeons.

Methods

We describe a modified model of a femur-based composite tissue allograft using an adapted vascular cuff anastomotic technique with a tunneled skin flap in a rodent model.

Results

The use of a heterotopic osteomyocutaneous flap with a subcutaneously tunneled-skin paddle to the posterolateral aspect of the recipient rodent allows for ease of flap monitoring and reduces the risk of self-mutilation. A total of six transplantations were conducted with no signs of self-mutilation. Operative time decreased as our surgical technique improved, and long-term graft tolerance was possible under our immunosuppressive regimen. Additionally, we demonstrate cases of successful transplantation in both an allogeneic and syngeneic rodent model.

Conclusion

Animal models, although technically challenging, are a reliable and reproducible modality that has been used to investigate various aspects of VCA immunology. We describe the success of an osteomyocutaneous flap with a modified vascular cuff anastomosis that can be used by investigators with less experience in microsurgical techniques to further our understanding of VCA physiology. Furthermore, tunneling of the skin paddle reduces the risk of self-mutilation and other external factors affecting the graft.

Efficiency and safety of microvascular anastomotic coupler for wrist revascularization in traumatic injuries

Introduction

Effective vascular anastomosis is crucial for successful hand surgery, particularly in traumatic injuries where rapid restoration of blood flow is essential. The Synovis microvascular anastomotic coupler system presents a novel approach by potentially offering faster and more reliable outcomes than traditional suturing methods. This study was conducted to assess the effectiveness and safety of the Synovis coupler for microvascular anastomoses in the wrist, evaluating anastomosis time, patency rates, and complication rates.

Methods

This retrospective study examined 25 microvascular anastomoses (22 arteries and 3 veins) in 24 patients at a major trauma center. The primary outcomes measured were anastomosis time and vascular patency, which were assessed immediately post-operation and at subsequent follow-ups.

Results

The average time required for anastomosis using the coupler was 7.3 min. Immediate post-operative vascular patency was 100%, with a long-term patency rate of 88%. Complications included arterial narrowing at the coupler site in 3 arteries, and complete occlusion in 3 arteries, accounting for a 12% long-term complication rate.

Conclusion

Although the Synovis coupler demonstrated a significant reduction in anastomosis time and high patency rates, our data suggest that its effectiveness is more pronounced in venous anastomoses. The higher complication rates in arterial anastomoses warrant cautious use in these cases. Further research, including prospective randomized controlled trials, is needed to validate these findings and optimize patient selection criteria for using couplers in microvascular surgery.

Sutureless vascular anastomotic approaches and their potential impacts

Sutureless anastomotic devices present several advantages over traditional suture anastomosis, including expanded global access to microvascular surgery, shorter operation and ischemic times, and reduced costs. However, their adaptation for arterial use remains a challenge. This review aims to provide a comprehensive overview of sutureless anastomotic approaches that are either FDA-approved or under investigation. These approaches include extraluminal couplers, intraluminal devices, and methods assisted by lasers or vacuums, with a particular emphasis on tissue adhesives. We analyze these devices for artery compatibility, material composition, potential for intimal damage, risks of thrombosis and restenosis, and complications arising from their deployment and maintenance. Additionally, we discuss the challenges faced in the development and clinical application of sutureless anastomotic techniques. Ideally, a sutureless anastomotic device or technique should eliminate the need for vessel eversion, mitigate thrombosis through either biodegradation or the release of antithrombotic drugs, and be easily deployable for broad use. The transformative potential of sutureless anastomotic approaches in microvascular surgery highlights the necessity for ongoing innovation to expand their applications and maximize their benefits.

A Survey of Microvascular Technique Preferences Among American Head Neck Society Members

OBJECTIVE

To identify practices in microvascular techniques in routine and challenging scenarios.

STUDY DESIGN

Cross-sectional study.

METHODS

A national survey addressing practices related to microvascular free flap reconstruction was distributed to AHNS members between October and November 2021.

RESULTS

The respondents encompassed 95 microvascular surgeons. Median years of practice was 6 (interquartile range, 2-13) and median flaps per year was 35 (22-50). Common practices in arterial anastomosis included limited cleaning of artery (84.2%), use of a double approximating clamp (64.2%), and use of interrupted suture (88.4%). Common practices in venous anastomosis included limited cleaning (89.5%), downsizing the coupler (53.7%), and coupling to two independent venous systems (47.4%). In arterial anastomosis, respondents felt that kinking (50.5%) and tension (24.2%) were the riskiest challenges. Kinking was handled by loose sutures or native tissue/dissolvable biomaterial to orient pedicle. Excess tension was handled by additional dissection. With regards to associated practices, most surgeons perform anastomosis after partial inset (52.6%), give aspirin immediately postoperatively (66.3%), reserve transfusion for hemodynamic instability (69.5%), and utilize intraoperative pressors when needed (72.6%). More senior surgeons reported placing more suture to address leaks (p = 0.004) and perform end to side anastomosis on larger vein in case of venous mismatch (p = 0.012). In cases of tension, higher volume surgeons perform more extensive dissection (p = 0.035) and end to side coupling (p = 0.029).

CONCLUSIONS

This survey of AHNS members indicates patterns of microvascular techniques in routine and challenging scenarios. There exists a variation in approaches amongst surgeons based on volume and practice length.

LEVEL OF EVIDENCE

5 Laryngoscope, 134:1265-1277, 2024.

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

BACKGROUND

 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.

METHODS

 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.

RESULTS

 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.

CONCLUSION

 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.

Methodological Quality of Open Access Compared to Traditional Journal Publications in the Plastic Surgery Literature

BACKGROUND

The methodological quality of open access studies has long been questioned due to increasing popularity and accessibility. The objective of this study is to compare the methodological quality of open access versus traditional journal publications in the plastic surgery literature.

METHODS

Four traditional plastic surgery journals with their sister open access journals were chosen. For each of the eight journals, 10 articles were randomly selected for inclusion. Methodological quality was examined using validated instruments. Publication descriptors were compared to methodological quality values using ANOVA. Logistic regression was used to compare quality scores between open access and traditional journals.

RESULTS

There was a wide distribution of levels of evidence, with a quarter being level one. Regression of non-randomized studies indicated a significantly higher proportion of traditional journal articles were of high methodological quality (89.6%) when compared to open access journals (55.6%; p < 0.05). This difference persisted in three quarter of the sister journal groups. No publication descriptions were associated with methodological quality.

CONCLUSIONS

Methodological quality scores were higher among traditional access journals. Higher degrees of peer review may be necessary to ensure appropriate methodological quality in open access plastic surgery publications.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Evaluation of a novel anastomotic device in the animal model: A feasibility, safety, and efficacy study

BACKGROUND

A novel device was designed to assist with microvascular arterial anastomoses. This study compares the safety and efficacy of the anastomosis-assisting device with manual suturing in an ovine model.

METHODS

Arteries with a diameter ranging from 2 to 4 mm were transected and anastomosed at four locations. A comparison was done between manual anastomoses and anastomoses performed with a novel anastomotic device in seven sheep. All the device-assisted anastomoses were performed by a single surgeon. At day 45 ± 7, anastomotic sites were dissected to determine patency, and samples were obtained for pathology.

RESULTS

Thirteen of 13 (100%) samples from the Vesseal™ group demonstrated patency both on the day the anastomoses were performed and after the 45-day follow-up period. All four additional anastomoses performed using the Vesseal™ were found patent. In the hand-suturing group, six of six (100%) samples demonstrated patency on the day of the anastomoses and five of six (83%) were patent after the follow-up period. No thromboses or adverse events were observed in the anastomoses in either group. No difference in histopathology of the anastomoses was observed between the groups.

CONCLUSIONS

The anastomosis-assisting device is a safe and efficacious alternative to hand suturing. The patency rates of device-assisted anastomoses were greater than those of manual suturing and pose no additional risk, as demonstrated by clinical observation, histopathology, and macroscopic evaluation. The Vesseal™ anastomosis-assisting device may be a viable alternative to manual suturing, with an ergonomic and intuitive design, short learning curve, and consistent results.

[Increasing Safety in Microsurgical Breast Reconstruction - Technique and Technology]

Microsurgical reconstruction has established itself as a standard procedure in breast reconstruction as it permits creation of a natural and aesthetically appealing breast mound, even after modified radical mastectomy and radiation. In the past few decades numerous new free flap donor-sites have been described that permit an individualized approach to reconstruction, thus, resulting in a high level of patient satisfaction. Paralleling these technical innovations, the focus of microsurgical breast reconstruction has shifted from mere "flap success" to "aesthetic outcome", while also taking into account the respective donor-site morbidity. Here, the authors discuss contemporary developments in the field with a particular focus on surgical techniques and technologies that contribute to increasing the safety of microsurgical breast reconstruction.

Sutureless venous microanastomosis using thermosensitive poloxamer and cyanoacrylate: experimental study on a rat model

INTRODUCTION

Sutureless microvascular anastomoses could simplify the microvascular field, shortening operative time and improving the final outcome. The use of thermosensitive poloxamers (TP407) together with the application of cyanoacrylate as an alternative method for conventional sutures was well-documented for arteries, but not for veins. The purpose of our study was to prove the feasibility of this technique for venous anastomoses and compare it with the traditional hand-sewn technique on a rat model.

MATERIALS AND METHODS

Twenty male Sprague-Dawley rats that weighed between 265 and 310 g were used. In the sutureless group (SG), 20 left external jugular veins (LEJV) end-to-end anastomoses were performed using a T704 and cyanoacrylate glue. They were compared to 20 right external jugular veins (REJV) anastomoses sutured with conventional 10-0 stitches (control group - CG). Diameters of veins, anastomosis time, and patency rate at 15 days were reported. Foreign body reaction was assessed histologically.

RESULTS

The mean diameter of the LEJV was 0.94 ± 0.1 mm and 0.95 ± 0.09 mm for the REJV. The mean anastomosis time was 11.9 ± 1.37 min for the SG and 27.75 ± 3.31 min for the CG. In the latter group, the immediate patency rate was 95% and 90% at 15 days. For the SG group, 90% of the anastomoses were patent immediately and 85% at 15 days.

CONCLUSION

TP407 and cyanoacrylate could offer a fast and reliable technique for sutureless venous anastomoses. Before human application, effectiveness of this method remains to be confirmed in larger animals in a long-term follow-up.