The microvascular anastomotic coupler for venous anastomoses in free flap breast reconstruction improves outcomes

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.

The Microvascular Anastomotic Coupler for Venous Anastomosis in Head and Neck Reconstruction: An Institutional Experience

Background This study aimed to identify outcome predictors with the GEM microvascular coupler system (GEM Coupler) in a series of patients undergoing free flap reconstruction for head and neck defects. Methodology In this retrospective chart review of 218 consecutive microvascular procedures performed on 204 patients at an academic tertiary care center, demographics, comorbidities, surgical data, and outcomes were retrieved. The endpoints for the analysis were microvascular revision surgery and flap survival. Results The study included 142 (70.2%) males and 62 (29.8%) females, with a mean age of 56 years, primarily treated for malignancy (76%). The anterolateral thigh and fibula were the most commonly used flaps (40.4% and 27.1%, respectively). In 21 (9.6%) cases, a double venous anastomosis was performed. There were nine flap failures requiring microvascular revision surgery; the flap was salvaged in four of these cases yielding an overall success rate of 97.7%. Factors associated with total flap loss included a history of a thrombotic or embolic event (p = 0.017), deep circumflex iliac artery flap (p < 0.001), and absence of monitoring skin paddle (p < 0.001). Conclusions Prothrombotic conditions, buried flaps, and flap type are outcome predictors in patients undergoing microvascular reconstruction with GEM Coupler.

Comparing complications and perioperative teams in microsurgical breast reconstruction: retrospective cohort study

Background

Subspecialization with dedicated perioperative teams has become common practice in some surgical disciplines. While surgeon experience, the number of surgeons involved, and enhanced recovery after surgery (ERAS) pathways are known factors affecting the outcome after microsurgical breast reconstruction, the impact of the perioperative team has not been studied.

Methods

We conducted a retrospective cohort study consisting of a chart review of all patients who underwent microsurgical breast reconstruction from January 2019-April 2020. Surgery was performed by three microsurgeons at two institutions with different perioperative teams-one being a small clinic [private clinic (PC), 33 beds] and the other being a larger hospital [corporate hospital (CH), 335 beds]. Patients were grouped into two cohorts according to the institution where surgery was performed. The primary outcomes studied were frequency of revision surgery, flap loss and patient length-of-stay (LOS).

Results

One hundred and fifty microsurgical breast reconstructions were performed in 125 patients. Demographic data [age, body mass index (BMI), current tobacco use, donor site] was found statistically comparable between both cohorts. In the PC cohort with fewer perioperative care providers, lower rates of revision surgery and flap loss were observed (P value =0.009 and 0.04, respectively). LOS was not significantly different between the two cohorts (P value =0.44).

Conclusions

The outcome of microsurgical breast reconstruction depends on multiple factors. In this study, fewer flap complications occurred at the small clinic. One reason among others might be the lower number of perioperative care providers involved and hence higher likelihood of sharing microsurgical cases, which facilitates routine and ensures less variability in care. The value of perioperative team subspecialization in microsurgical breast reconstruction needs to be assessed in prospective studies.

[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.

Mechanical Anastomotic Coupling Device versus Hand-sewn Venous Anastomosis in Head and Neck Reconstruction-An Analysis of 1694 Venous Anastomoses

Background  There is a steep learning curve to attain a consistently good result in microvascular surgery. The venous anastomosis is a critical step in free-tissue transfer. The margin of error is less and the outcome depends on the surgeon’s skill and technique. Mechanical anastomotic coupling device (MACD) has been proven to be an effective alternative to hand-sewn (HS) technique for venous anastomosis, as it requires lesser skill. However, its feasibility of application in emerging economy countries is yet to be established.

Material and Method  We retrospectively analyzed the data of patients who underwent free-tissue transfer for head and neck reconstruction between July 2015 and October 2020. Based on the technique used for the venous anastomosis, the patients were divided into an HS technique and MACD group. Patient characteristics and outcomes were measured.

Result  A total of 1694 venous anastomoses were performed during the study period. There were 966 patients in the HS technique group and 719 in the MACD group. There was no statistically significant difference between the two groups in terms of age, sex, prior radiotherapy, prior surgery, and comorbidities. Venous thrombosis was noted in 62 (6.4%) patients in the HS technique group and 7 (0.97%) in the MACD group ( p = 0.000). The mean time taken for venous anastomosis in the HS group was 17 ± 4 minutes, and in the MACD group, it was 5 ± 2 minutes ( p = 0.0001). Twenty-five (2.56%) patients in the HS group and 4 (0.55%) patients in MACD group had flap loss ( p = 0.001).

Conclusion  MACD is an effective alternative for HS technique for venous anastomosis. There is a significant reduction in anastomosis time, flap loss, and return to operation theater due to venous thrombosis. MACD reduces the surgeon’s strain, especially in a high-volume center. Prospective randomized studies including economic analysis are required to prove the cost-effectiveness of coupler devices.

Mechanical strength and hydrostatic testing of VIVO adhesive in sutureless microsurgical anastomoses: an ex vivo study

Conventional anastomoses with interrupted sutures are challenging and inevitably associated with trauma to the vessel walls. The goal of this study was to evaluate a novel alternative adhesive-based suture-free anastomosis technique that uses an intraluminal stent. Overall, 120 porcine coronary vessels were analyzed in an ex vivo model and were examined for their mechanical (n = 20 per cohort) and hydrostatic strength (n = 20 per cohort). Anastomoses were made using the novel VIVO adhesive with an additional intraluminal nitinol stent and was compared to interrupted suture anastomosis and to native vessels. Sutureless anastomoses withstood pressures 299 ± 4.47 [mmHg] comparable to native vessels. They were performed significantly faster 553.8 ± 82.44 [sec] (p ≤ 0.001) and withstood significantly higher pressures (p ≤ 0.001) than sutured anastomoses. We demonstrate that the adhesive-based anastomosis can also resist unphysiologically high longitudinal tensile forces with a mean of 1.33 [N]. Within the limitations of an in vitro study adhesive-based suture-free anastomosis technique has the biomechanical potential to offer a seamless alternative to sutured anastomosis because of its stability, and faster handling. In vivo animal studies are needed to validate outcomes and confirm safety.

The Exoscope versus operating microscope in microvascular surgery: A simulation non-inferiority trial

Background

The Exoscope is a novel high-definition digital camera system. There is limited evidence signifying the use of exoscopic devices in microsurgery. This trial objectively assesses the effects of the use of the Exoscope as an alternative to the standard operating microscope (OM) on the performance of experts in a simulated microvascular anastomosis.

Methods

Modus V Exoscope and OM were used by expert microsurgeons to perform standardized tasks. Hand-motion analyzer measured the total pathlength (TP), total movements (TM), total time (TT), and quality of end-product anastomosis. A clinical margin of TT was performed to prove non-inferiority. An expert performed consecutive microvascular anastomoses to provide the exoscopic learning curve until reached plateau in TT.

Results

Ten micro sutures and 10 anastomoses were performed. Analysis demonstrated statistically significant differences in performing micro sutures for TP, TM, and TT. There was statistical significance in TM and TT, however, marginal non-significant difference in TP regarding microvascular anastomoses performance. The intimal suture line analysis demonstrated no statistically significant differences. Non-inferiority results based on clinical inferiority margin (Δ) of TT=10 minutes demonstrated an absolute difference of 0.07 minutes between OM and Exoscope cohorts. A 51%, 58%, and 46% improvement or reduction was achieved in TT, TM, TP, respectively, during the exoscopic microvascular anastomosis learning curve.

Conclusions

This study demonstrated that experts’ Exoscope anastomoses appear non-inferior to the OM anastomoses. Exoscopic microvascular anastomosis was more time consuming but end-product (patency) in not clinically inferior. Experts’ “warm-up” learning curve is steep but swift and may prove to reach clinical equality.

Interdisciplinary Treatment of Breast Cancer After Mastectomy With Autologous Breast Reconstruction Using Abdominal Free Flaps in a University Teaching Hospital-A Standardized and Safe Procedure

Background: Breast cancer is the most common malignancy in women. The interdisciplinary treatment is based on the histological tumor type, the TNM classification, and the patient's wishes. Following tumor resection and (neo-) adjuvant therapy strategies, breast reconstruction represents the final step in the individual interdisciplinary treatment plan. Although manifold flaps have been described, abdominal free flaps, such as the deep inferior epigastric artery perforator (DIEP) or the muscle-sparing transverse rectus abdominis myocutaneous (ms-TRAM) flap, are the current gold standard for autologous breast reconstruction. This retrospective study focuses on the safety of autologous breast reconstruction upon mastectomy using abdominal free flaps. Methods: From April 2012 until December 2018, 193 women received 217 abdominal free flaps for autologous breast reconstruction at the University Hospital of Erlangen. For perforator mapping, we performed computed tomography angiography (CTA). Venous anastomosis was standardized using a ring pin coupler system, and flap perfusion was assessed with fluorescence angiography. A retrospective analysis was performed based on medical records, the surgery report, and follow-up of outpatient course. Results: In most cases, autologous breast reconstruction was performed as a secondary reconstructive procedure after mastectomy and radiotherapy. In total, 132 ms1-TRAM, 23 ms2-TRAM, and 62 DIEP flaps were performed with 21 major complications (10%) during hospital stay including five free flap losses (2.3%). In all cases of free flap loss, we found an arterial thrombosis as the main cause. In 24 patients a bilateral breast reconstruction was performed without free flap loss. The majority of free flaps (96.7%) did not need additional supercharging or turbocharging to improve venous outflow. Median venous coupler size was 2.5 mm (range, 1.5-3.5 mm). Conclusion: Using CTA, intraoperative fluorescence angiography, titanized hernia meshes for rectus sheath reconstruction, and venous coupler systems, autologous breast reconstruction with DIEP or ms-TRAM free flaps is a safe and standardized procedure in high-volume microsurgery centers.

100 Steps of a DIEP Flap-A Prospective Comparative Cohort Series Demonstrating the Successful Implementation of Process Mapping in Microsurgery

Background

The demand to improve the efficiency of microsurgical breast reconstruction is driven by increasing number of breast cancer and risk reducing cases, and the concurrent requirement for hospitals to cut costs. Businesses have successfully used process mapping as a tool to improve efficiency; however, process mapping has been sparsely used in surgery. This prospective cohort study has used process mapping to break down the individual components of a deep inferior epigastric artery perforator (DIEP) flap operation into a template of 100 streamlined steps.

Methods

Through observation of the senior author's uniform technique, refined from experience of over 5,000 cases, the DIEP flap operation was broken down into 100 individual steps, all arranged in a logical sequence with which to maximize efficiency and outcome. This created a 100-step process-mapped template. Subsequently, 2 cohorts of 10 unilateral DIEP cases were prospectively timed. One cohort following this process mapped template and the other control group was blinded to the template.

Results

The process-mapped cohort was 56.1 minutes quicker than the control cohort, despite the addition of symmetrizing surgery being performed concurrently in 4 out of the 10 cases. Furthermore, there was no return to theater in the process-mapped cohort versus 1 return to theater in the control cohort with no flap loss in either group.

Conclusions

This study uniquely presents an approach to process map the DIEP flap operation and demonstrates its utility in improving operative efficiency, without compromising outcomes. It also illustrates the possibility of symmetrizing surgery being carried out through parallel operating processes, without affecting overall operative times.

The effect of CT angiography and venous couplers on surgery duration in microvascular breast reconstruction: a single operator's experience

Background

The use of CT angiography (CTA) or venous couplers (VCs) has led to shorter operative times in free flap breast reconstruction (FFBR). However, there are no reports on the effect of these two interventions relative to each other or combined.

Methods

Abdominal based FFBRs performed by a single surgeon before introduction of either intervention were compared to those with VC only, and those after the addition of CTA to VCs (CT-VC). Operative time was defined as from "knife-to-skin" to insertion of the last stitch.

Results

One hundred and twenty patients; 40 without intervention (WI), 40 with VC, and 40 with CT-VC. Introduction of VCs did not significantly reduce operative time compared to WI (P=0.73). However, patients in the CT-VC group had significantly shorter operations vs. WI (472 vs. 586 min, P<0.00001) and vs. VC alone (472 vs. 572 min, P=0.0006). Similarly, introduction of each intervention showed a stepwise decrease in ischaemia time (WI vs. VC: 100 vs. 89 min, P=0.0106; VC vs. CT-VC: 89 vs. 80 min, P=0.0307; WI vs. CT-VC: 100 vs. 80 min, P<0.00001).

Conclusions

Combination of CTA and VC significantly reduced operative and ischaemic times for FFBR; this was predominantly due to use of CTA. CTA mitigates the surgical learning curve as demonstrated by shorter operating times via providing a vascular anatomy roadmap, thus facilitating flap harvest.

Microsurgical refinements with the use of internal mammary (IM) perforators as recipient vessels in transverse upper gracilis (TUG) autologous breast reconstruction

BACKGROUND

The transverse upper gracilis (TUG) flap is the senior authors' second choice for autologous breast reconstruction when the DIEP flap is not available. It provides durable, pliable tissue with well hidden scars. The main criticism of this flap is the limited volume, donor site complications, short pedicle and vessel mismatch depending on which recipient vessels are used. We described methods of reducing vessel mismatch, complications of venous coupler and refinements to help give a more superior aesthetic outcome.

METHODS

We describe several maneuvers to help reduce vessel mismatch with the use of the internal mammary (IM) perforator vessels with a modification of the Harashina fish-mouth technique or the use of a vessel bifurcation to increase vessel diameter. We also describe the optimum method of perforator preparation and potential methods to prevent palpable venous couplers. The author's describe their case series of 14 TUG flaps to reconstruct 13 breasts in 12 patients.

RESULTS

Eight unilateral, 2 partial breast reconstruction, 1 bilateral and 1 bilateral TUG flap for a unilateral reconstruction was carried out. All flaps survived with one partial flap necrosis, one donor site seroma and two cases of palpable/tender venous couplers. The mean reconstructed breast was 320 grams.

CONCLUSIONS

The TUG flap is a reconstructive challenge, but with correct planning a good aesthetic outcome is possible. The IM perforator is our first choice recipient vessel in TUG breast reconstructions. With meticulous preparation and by overcoming vessel mismatch the use of this recipient vessel is a reliable option.

Assessment of Free Flap Breast Reconstructions

Free flap breast reconstruction may be offered as a treatment option at federal facilities with appropriate patient selection and planning.