Internal Thoracic Research Articles

A Single-Surgeon Experience Transitioning to Total Arterial Revascularization.

Background: Coronary artery bypass grafting remains the standard of care for advanced and multifocal coronary artery disease; however, for patients that are surgical candidates, total arterial revascularization (TAR) remains underutilized due to concerns such as sternal wound infections and the learning curve. We present the results of a large cohort of mid-career surgeons transitioning to TAR, focusing on short-term outcomes and the learning curve. Methods: The surgeons transitioned to using TAR as the preferred revascularization technique in August of 2017. The Society of Thoracic Surgeons database was reviewed to identify all patients who underwent isolated non-emergent CABG performed by a single surgeon from January 2014 through January 2022. Patients were divided into two groups-those who had TAR and those who had traditional CABG using one internal mammary artery and vein grafts (IMA-SVG). Results: Eight hundred ninety-eight patients meet inclusion criteria (458 IMA-SVG and 440 TAR). The TAR group had slightly longer cardiopulmonary bypass time, cross clamp times, and operative times (all p < 0.05); however, ICU stay was shorter and 30-day readmission rate was lower for TAR compared to IMA-SVG (all p < 0.05). The TAR group also required fewer postoperative transfusions (p = 0.005). There was no difference in prolonged intubation, stroke, length of stay, mortality, or sternal wound complications between groups (all p > 0.05). The average TAR was 30 min longer; however, learning curves, stratified by number of grafts placed, showed no significant learning curve associated with TAR. Conclusions: An experienced surgeon transitioning from IMA-SVG to TAR slightly increases operative time, but decreases ICU stay, readmissions, and postoperative transfusions with no significant difference in rates of immediate post-operative complications or 30-day mortality, with a minimal learning curve.

Indocyanine Green Angiography for Detecting Quantitative Perfusion Changes in Deep Inferior Epigastric Perforator Flap Breast Reconstruction With Second Venous Drainage.

This study aims to compare perfusion dynamics using indocyanine green videoangiography before and after the creation of a second venous anastomosis between the superficial inferior epigastric vein and the retrograde internal mammary vein (IMV) in deep inferior epigastric perforator (DIEP) flap breast reconstructions. Indocyanine green videoangiography performed during DIEP flap reconstructions was analyzed prospectively. The areas of interest were above the perforators with the highest intensity (complete perfusion), the most distal lateral edge of the flap (partial perfusion), and the next lowest intensity (ischemic). We compared the zone intensities before and after the second venous anastomosis, assessing venous drainage patency and functionality. Patient characteristics, operative details, and complications were collected. Seven patients (10 breasts) underwent DIEP reconstruction. Mean age was 54.5 ± 12.4 years. Mean operative duration was 575.5 ± 172.6 minutes. Donors included DIEV (n = 10, 100.0%), superficial inferior epigastric vein (n = 9, 90.0%), and superficial circumflex epigastric vein (n = 1, 10.0%). All DIEVs were anastomosed to the antegrade IMV (n = 10, 100.0%). Superficial inferior epigastric veins were anastomosed to the retrograde IMV (n = 10, 100.0%). Mean peak intensities of the complete perfusion zone before and after the second venous anastomosis were 160.7 ± 42.1 and 188 ± 42.1, respectively ( P = 0.163). Mean peak intensities of the partial perfusion zone were 100.8 ± 21.5 and 152 ± 31.5, respectively ( P < 0.001). Mean peak intensities of the ischemic zone were 90.4 ± 37.4 and 143.4 ± 45.3, respectively ( P = 0.012). These findings highlight the potential benefits of the super drainage technique in enhancing perfusion and reducing complications, emphasizing the need for further investigation and consideration of this technique in clinical practice.

Emergent use of a central venous catheter placed in the internal mammary vein

Emergent use of a central venous catheter placed in the internal mammary vein

Open-Y technique for the internal mammary vein in the free abdominal flap of unilateral breast reconstruction

BackgroundIn microvascular breast reconstruction, the internal mammary vein (IMV) has emerged as the most common recipient vein. The open-Y technique can increase the vessel diameter via the bifurcation site. This study aims to investigate the open-Y technique for IMV. MethodsThe characteristics and details of the operative procedure in patients who had undergone unilateral breast reconstruction with and without the open-Y approach for the free abdominal flap were compared. Differences in IMV anastomosis site (the bifurcation of the main duct or that of the perforator branch) were also compared in patients with the open-Y technique. The open-Y technique was performed on the IMV side. ResultsThe open-Y and conventional groups included 127 and 62 patients respectively. The main duct diameter of IMV was significantly smaller (median 2.5 vs. 3.0mm, P < 0.001), and the rate of right-sided anastomosis (47.2 vs. 82.3%, P < 0.001) was significantly lower in the open-Y group. When comparing the main duct and perforator groups, the branch diameter (1.8 vs. 1.0mm, P < 0.001) and the diameter after the open-Y technique (5.0 vs. 3.9mm, P < 0.001) were significantly higher, and the angle of bifurcation (45° vs. 60°, P = 0.007) was significantly lower in the main duct group. ConclusionsGiven a small venous diameter, the open-Y technique is superior, especially for left-sided breast reconstruction. Owing to the lower angle of bifurcation and large diameter, the open-Y technique at the main duct bifurcation of IMV causes less turbulence in the blood flow. Take home messageThe open-Y technique is especially effective for left-sided breast reconstruction. Considering the lower angle of bifurcation and large diameter, the open-Y technique at the main duct bifurcation of the internal mammary vein causes less turbulence in the blood flow.

Gross anatomy of vascular supply and drainage of mammary fat pads in mice models.

This work extensively studied the vasculature of mice mammary fat pads (BALB/c and C57BL/6) with special reference to haematogenous drainage routes. Mammary fat pads were five pairs (first cervical, second and third thoracic, fourth abdominal and fifth inguinal), bilaterally symmetrical, extending laterally and continuously with the subcutaneous fascia. The superficial cervical artery and vein primarily accomplished the blood vasculature of the first mammary fat pad, while the lateral thoracic and external thoracic arteries and veins supplied the second and third mammary fat pads. The superficial cervical vein (found parallel to the superficial cervical artery) drained into the external jugular vein. The lateral thoracic artery and external thoracic artery branched almost at the same level as the axillary artery (branch of subclavian artery), the latter being more medial in position. However, in some specimens, the branching of both arteries appeared to be at the same level, and their origins were indistinguishable. The lateral thoracic vein that was parallel to the lateral thoracic artery drained to the axillary vein close to the drainage of the external thoracic vein. The lateral thoracic, superficial caudal epigastric, iliolumbar and external thoracic arteries and veins vascularized the fourth mammary fat pad and displayed anastomosis among themselves. The iliolumbar vein (found parallel to the iliolumbar artery) drained into the inferior vena cava. The superficial caudal epigastric vein (found parallel to the superficial caudal epigastric artery (SCaEA)) drained into the femoral vein. Unlike humans, the internal thoracic artery and vein did not participate in the vasculature of mammary fat pads. The SCaEA and vein supplied blood and drained the fifth mammary fat pad. The anatomical continuity of the fourth and fifth mammary fat pads provided common drainage for both mammary fat pads. The BALB/c and C57BL/6 mice strains studied did not differ in topography and size of mammary fat pads. The vascular supply and drainage of the mammary fat pads also did not differ in the strains studied. Only minor variations could be noted in the small veins draining into the lateral thoracic vein. Lateral tributaries seen in the terminal end of the lateral thoracic vein were absent in the C57BL/6 mice.

Salvage free flap reconstruction of deep sternal wound infections post coronary artery bypass: a case series

The authors present cases of sternal reconstruction using the right internal mammary artery and vein as recipient vessels when the left IMA has been used for cardiac revascularisation.

Free Flap Reconstruction of Sternal Defects after Cardiac Surgery: An Algorithmic Approach for Dealing with Sparse Recipient Vessels.

Sparsity of recipient vessels poses a challenge for microsurgical free flap reconstruction of sternal defects following deep sternal wound infection after cardiac surgery. From January 2013, a standardized algorithm for dealing with sparse recipient vessels was strictly followed. In this retrospective study including 75 patients, we compared operative details, surgical complications, and reconstructive outcomes of patients treated according to this algorithm (group A: January 2013-May 2021; n = 46) with a historical control group (group B: January 2000-December 2012, n = 29). The left internal mammary artery had been harvested for arterial bypass grafting in 40 of 46 cases (87%) in group A and in all cases in group B. The right internal mammary artery (RIMA) and right internal mammary vein (RIMV) were the first choice as recipient vessels. In case of unsuitability of the RIMV, a right cephalic vein (CV) turndown was used for venous outflow. If both RIMA and RIMV proved insufficient, a single-stage arterio-venous loop (AVL) between the CV and subclavian artery (CV-SA AVL), CV and thoracoacromial artery (CV-TA AVL), or subclavian artery and subclavian vein (SA-SV AVL) was established. The algorithmic approach significantly reduced partial flap necrosis [group A: n = 3 (7%) versus group b: n = 7 (24%); P = 0.04], and overall operation time [group A: 360 ± 88 min versus group B: 415 ± 80 min; P = 0.01]. Standardized approaches improve clinical outcomes in microsurgical free flap sternal reconstruction after cardiac surgery.

Internal thoracic vein cannulation for venous port insertion

Internal thoracic vein cannulation for venous port insertion

Anatomical features of a crossing vein connecting left and right internal mammary veins: A preliminary study with computerized tomography or magnetic resonance imaging.

In breast reconstruction with free flaps, retrograde venous anastomosis into the internal mammary vein (IMV) is often unavoidable. Utility of a crossing vein between the right and left IMV, one of the anatomical foundations which make retrograde flow possible, has been reported but only with a few detailed features. This study evaluated the presence, actual location, and diameter of the crossing veins using preoperative imaging such as contrast-enhanced computed tomography (CECT), or contrast-enhanced magnetic resonance imaging (CEMRI). Moreover, this is a preliminary non-invasive study to clarify these processes on a larger scale. We included 29 cases of unilateral breast reconstruction performed between July 2018 and September 2023 at our institution using unipedicled or bipedicled free deep inferior epigastric artery perforator (DIEP) flaps with retrograde venous anastomosis to only one IMV at the level of anastomosis. No congestion or necrosis was observed. In the final 24 cases with sufficient imaging coverage of preoperative contrast-enhanced images (15 CECT and 9 CEMRI), the crossing veins of IMVs were detected and the number, localization, and diameter were measured. In 20 cases of 24 images, the crossing veins between IMVs were completely identified (83%). In 18 of the cases, only one crossing vein was established immediately ventral to the xiphoid process, averaging 19.3 ± 7.18 mm caudal to the fibrous junction between the sternal body and xiphoid process. The average diameter of the veins was 1.57 ± 0.42 mm. In two other cases, the second crossing vein originated on the dorsal surface of the sternum, but it was a very thin vein of about 0.4 mm. Three images indicated incomplete identification of the crossing vein at the xiphoid process, and in one case, no crossing vein was observed between bilateral IMVs. The contrast-enhanced imaging study revealed an anatomic feature that the crossing veins (about 1.5 mm in diameter) connecting the right and left IMVs are located just ventral to the xiphoid process. Furthermore, the crossing veins can be identified on contrast-enhanced images, and refinement of this method is expected to lead to future non-invasive anatomical investigations in an even larger number of cases.

Vascular access challenges in hemodialysis children.

Hemodialysis (HD) success is dependent mainly on vascular access (VA). The aim of this study is to share the experience of Pediatric Nephrology Unit (PNU), Cairo University Children's Hospital (CUCH), with VA-related obstacles in end stage kidney disease (ESKD) HD children. This is a retrospective analysis of VA related data of 187 ESKD children received regular HD over 3year duration (2019-2021). Kaplan-Meier curves were used to present arteriovenous fistula (AVF) and cuffed catheters survivals. Uncuffed central venous catheter (CVC) was the primary VA for HD in up to 97.3% with 2.7% of patients had AVF performed and attained maturation before initiation of regular HD. Fifty-six (29.9%) patients have inserted 120 tunneled CVCs. AVFs & AV grafts (AVF) were performed in 79 (42.2%) and 6 (3.2%) patients respectively. There were 112 uncuffed CVCs implanted beneath the screen in Rt internal jugular vein (IJV) (44%) Lt IJV (17%), right internal mammary vein (2.7%) while Trans hepatic (TH) technique was used to place 39 uncuffed CVCs (34%) in the inferior vena cava (IVC). Catheter-related bacteremia (CRB) was the most frequent complication in uncuffed and cuffed CVCs (2.58 / 100 catheters day and 10.1 /1000 catheter days respectively). AVFs achieved a high success rate (83%) after 757.71 ± 512.3 functioning days. Native AVF is the preferred VA for pediatric HD but its creation is limited by the small sized vessels where non-cuffed CVC could be a reasonable relatively long-term alternative. Challenging situations (occluded central veins) could benefit from TH technique of CVC insertion in IVC.

Focal hepatic hot spot sign: Clinical image

A 51‐year‐old women was hospitalized to start chemotherapy for small cell lung cancer diagnosed one months earlier. She underwent Computed Tomography (CT) of the chest and abdomen to re‐evaluate the progression of the lung tumour. Contrast-enhanced CT of the chest indicated an invasive anterior left lung tumour that caused an obstruction of the Superior Vena Cava (SVC) (Figure 1). Contrast-enhanced CT of the abdomen revealed an intense focal wedge-shaped homogeneous enhancement area in the quadrate lobe of the liver, which is known as the hot spot sign (Figure 2). Focal hepatic hot spot sign was first described by Ishikawa in 1983. The sign can be observed on technetium 99m (99mTc) Sulphur colloid scans or on contrast, material enhanced CT scans [1]. Hot spot sign is caused by portosystemic venous shunting between the superior vena cava and the left portal vein via the internal mammary and paraumbilical veins along the ligamentum teres, secondary to superior vena cava obstruction. The hot spot is created by areas of focally increased blood flow that result from this shunting [2]. Stanford and colleagues classified SVC syndrome into four types - type I and type II referred as supra-azygous partial and near complete obstruction of SVC with antegrade flow in azygous vein. Type III is defined as complete obstruction of SVC with reversal of azygous blood flow and type IV as complete obstruction of SVC and azygous system with development of chest wall collaterals [3]. This sign has been reported in Budd-Chiari syndrome, the causes of SVC syndrome (neoplasms of the thorax as lung carcinoma and lymphoma, Vasculo‐Behcet’s disease, fibrosing mediastinitis, and luetic aneurysm), and masses of the liver (abscess, haemangioma, focal nodular hyperplasia, and hepatocellular carcinoma) [4].

Very rare malposition of central venous catheter in cardiac surgery patients.

Malposition of a catheter is found in approximately 7% of cases after central venous catheterisation. This may result in haemorrhage, venous thrombosis and functional impairment, depending on the injury to the vessel wall. Uncomplicated catheterisation, easy aspiration of blood and monitoring of catheterisation do not guarantee correct placement of the catheter. In our rare case series, we share our experience of four cases of malposition into the left internal mammary vein (LIMV) that we experienced in a three-year period. The thinness and fragility of the vessel wall, particularly, increases the probability of complications in malposition into the LIMV. Administration of a catheter through the right jugular vein is associated with the lowest incidence of malposition. Performing the procedure under the guidance of ultrasonography (USG) and confirmation of the catheter position after puncture using one of the USG techniques will minimise the probability of malposition. In addition, a lung X-ray should immediately be taken, and venography and fluoroscopy should be considered in the presence of suspicion.

Acromiothoracic Venous Supercharge for Abdominal-Based Free Flaps in Breast and Chest Wall Reconstruction

Background Supercharging the venous drainage of free abdominal flaps in breast reconstruction has been well described in the literature, with diverse options used to augment venous drainage. In this study, we present our experience in using the acromiothoracic vein (ATV)/thoracoacromial vein (TAV) as a secondary recipient vein for the superficial inferior epigastric vein (SIEV) of free, muscle-sparing transverse rectus abdominis myocutaneous flaps in breast and chest wall reconstruction. Patients and Methods We retrospectively reviewed 523 free, muscle-sparing transverse rectus abdominis myocutaneous flaps the senior author (H.H.K.) performed between 2009 and 2022 for breast and chest wall reconstruction; 46 cases required venous super drainage. Seventeen patients had ipsilateral SIEV anastomosed into the second internal mammary vein, 5 had ipsilateral SIEV anastomosed into flap second deep inferior epigastric vein, and 24 required the use of the (ATV)/(TAV), which will be the focus of this study. Results The study included 24 female (20 breast and 4 chest wall reconstruction) patients ranging in ages between 39 and 72 years. They had a median follow-up of 26 months. Combined muscle splitting and cutting techniques were used to expose the ATV/TAV. Increase in operative time ranged between 10 and 20 minutes (median, 12 minutes). Vein coupler sizes were 1.5 to 3 mm. The mean weight of the flap was 740 g (range, 460–1300 g). There was 1 flap failure (salvage with latissimus dorsi flap performed), whereas 23 flaps wholly survived. Conclusions The ATV/TAV is a suitable recipient for venous supercharging free flaps used to reconstruct breast and chest wall defects.

Supercharging DIEP Flaps Using Contralateral Superficial Inferior Epigastric Vein Grafts

Introduction: Venous congestion, even with a patent deep venous anastomosis, can afflict some DIEP (Deep Inferior Epigastric Perforator) flaps and various techniques of superficial venous supercharging have been described, although the indications for its use are not consensual. The main goal of this study is to confirm that superficial venous supercharge of DIEP flaps, utilizing the contralateral Superficial Inferior Epigastric Vein (SIEV) as an interposition vein graft, is feasible and functional. Materials and Methods: We retrospectively reviewed all DIEP flap breast reconstruction patients treated at our institution between June 2016 and December 2017 and that met all the inclusion criteria: Unilateral breast reconstruction with a DIEP flap; flap weighing more than 750 gm; supercharging of the ipsilateral superficial venous system; contralateral SIEV interposition graft; implantable doppler probe in the superficial system for at least 5 days. In the technique described here, the contralateral SIEV graft was harvested and anastomosed to the ipsilateral SIEV, obtaining this way a long vein that easily reaches the recipient vein (distal end of the Internal Mammary Vein - IMV). A Doppler probe was implanted in the superficial system, for at least 5 postoperative days, to monitor the function of this supercharging. We also analyzed the patient’s history, flaps weight, number and perforator rows, recipient vessels, SIEV graft length and diameter and all perioperative complications. Results: Ten patients met all inclusion criteria. They were treated using this technique and analyzed. Two patients had some type of alteration of the Doppler signal and clinical signs of venous congestion. They were surgically revised with success and were analyzed in detail. No total or partial flap failures were found. Clinical fat necrosis was also absent. Conclusion: This technique seems to be feasible, functional and adds an extra length to ipsilateral SIEV to reach a recipient vein. This way, the flap inset is not compromised by a short SIEV. No further significant morbidity is added for SIEV harvest that is in the same operative field, unlike the saphenous or cephalic veins. In selected patients, it could be an alternative supercharging technique.

Bilateral versus single internal thoracic coronary artery bypass grafting: the ART RCT

Background There is debate whether the use of more arterial grafts during coronary artery bypass graft surgery provides advantages to the standard operation using the left internal thoracic artery plus vein grafts. We review data from the Arterial Revascularisation Trial to determine whether there is support for the multiple arterial graft hypothesis. Methods Patients undergoing coronary artery bypass graft for clinical reasons and who provided written informed consent were randomised to standard coronary artery bypass graft using the single internal thoracic artery or use of bilateral internal thoracic arteries. Additional vein grafts could be used. The primary outcome was all-cause mortality at 10 years and exploratory analyses were carried out to test the multiple arterial graft hypothesis. Results A total of 3102 patients were enrolled (1548 bilateral internal thoracic artery and 1554 single internal thoracic artery). Follow-up to 10 years for vital status was 98% complete. In the bilateral group, 14% of patients received a single internal thoracic artery only and use of radial artery grafts occurred in about 20% of patients in both groups. Aspirin was used in 81% of the patients, beta-blockers in 74%, statins in 90% and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in 73%. At 10 years, death rates were 20.3% and 21.2% in the bilateral internal thoracic artery and single internal thoracic artery groups, respectively (hazard ratio 0.96, 95% confidence intervals 0.82 to 1.12; p = 0.62) and composite of all-cause mortality, myocardial infarction or stroke 24.9% and 27.3%, respectively (hazard ratio 0.90, 95% confidence interval 0.79 to 1.03; p = 0.12). Exploratory analyses using the ‘as-treated’ approach indicate that outcomes were better in patients who received multiple arterial grafts (adding the right internal thoracic and/or radial arteries) compared with a single arterial graft. This effect appeared to be greater in patients with diabetes and those aged 70 years or less. Use of total arterial grafting without vein grafts may provide the best outcomes. Limitations The elevated cross-over rate between bilateral internal thoracic artery and single internal thoracic artery and the non-randomised use of radial artery grafts may have contributed to a loss of power to detect a difference in mortality between the two groups. Moreover, secondary analyses are prone to bias as they compare non-randomised groups. Conclusions The Arterial Revascularisation Trial is one of the largest long-term studies in cardiac surgery. The primary analysis did not show a mortality benefit for bilateral internal thoracic artery at 10 years, perhaps due to high crossover rates in the bilateral internal thoracic artery group and concomitant use of the radial artery. Secondary analyses suggest a mortality benefit for patients receiving multiple arterial grafts compared with single arterial graft with possible greater effects in patients with diabetes and separately in patients aged 70 years or above. The trial will follow patients to 15 years and the continuing Randomized Comparison of the Clinical Outcome of Single versus Multiple Arterial Grafts trial will further test the multiple arterial graft hypothesis. Trial registration This trial is registered as ISRCTN46552265. Funding This project was funded by the British Heart Foundation, the UK. Medical Research Council and the National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation programme and will be published in full in Efficacy and Mechanism Evaluation; Vol. 10, No. 7. See the NIHR Journals Library website for further project information.

Bivalirudin for cardiopulmonary bypass in a patient with heparin allergy

BackgroundHypersensitivity reactions to heparin are uncommon conditions but pose a serious clinical problem for patients requiring cardiopulmonary bypass. Bivalirudin is a reversible direct thrombin inhibitor that can be used instead of heparin.Case ReportA 49-year-old male patient was admitted to our hospital for coronary artery bypass graft operation with mitral insufficiency and tricuspid valve insufficiency. Heparin allergy was confirmed by skin biopsy and skin tests. Due to this allergy, we used bivalirudin (Bivacard VEM drug, Turkey) during the surgery. A loading dose of 1.0 mg/kg (100 mg) bivalirudin was administered through the central line and a continuous infusion of 2.5 mg/kg/h of the anticoagulant was initiated following the approved protocol. Serial ACTs were obtained at 15-minute intervals during the procedure and the measurements were 330s, 320s, 350s, 360s, and 340s consecutively. Additional boluses of 0.5 mg/kg (50 mg) were administered for each measurement. Left anterior descending, obtuse marginal arteries and the right coronary artery were grafted with the left internal mammary and saphenous veins. Also, mitral valve replacement with St Jude mechanical heart valve and tricuspid ring annuloplasty was performed with Medtronic Duran ring. After the surgery, the patient had an uneventful period in the postoperative intensive care unit with a total of 600ml and 300ml chest tube drainage for two days and was discharged on the 7th day.ConclusionAlternative anticoagulation strategies are needed for cardiopulmonary bypass in patients unable to use heparin. Bivalirudin may be recommended as a viable alternative anticoagulant in patients with heparin allergy during cardiopulmonary bypass. However, each patient should be evaluated individually and it should not be forgotten that more than recommended doses may be needed.

Catheter misplacement from an implantable central venous access port into the internal thoracic vein: a case description.

Catheter misplacement from an implantable central venous access port into the internal thoracic vein: a case description.

Structure and properties of fibrin/polyvinyl alcohol interpenetrating polymer network hydrogel as a modifying coating for small-diameter vascular grafts

Background: Interpenetrating polymer network (IPN) hybrid hydrogels enable regulating their properties by varying the composition and concentration of their components. Fibrin is an available natural polymer with ideal biological properties but low strength and tendency to retraction. Polyvinyl alcohol hydrogels are stable, comparable in strength to biological tissues but bioinert. Fibrin/polyvinyl alcohol (F/PVA) IPN can overcome the shortcomings of each component and create an improved material for tissue engineering.Objective: To assess the possibility of and conditions for obtaining a homogeneous IPN by subsequent fibrin polymerization and polyvinyl alcohol cryostructuring while preserving as much as possible mechanical and biological properties beneficial for tissue engineering.Methods: F/PVA IPN was obtained by subsequent fibrin polymerization (30 mg/mL) and polyvinyl alcohol cryostructuring (15, 30, and 60 mg/mL). We studied the structure using a scanning electron microscope, histology, infrared spectroscopy, and X-ray diffraction analysis. We tested mechanical properties and shrinkage of the samples. Biological features were assessed in vitro in terms of viability, cell count, proliferative and metabolic activity of EA.hy926 endothelial cell culture.Results: Our study found the maximum amount of fibrin on the surface of F30PVA15 IPN and its minimum amount on the surface of F30PVA60. These results were supported by the high biological appeal of F30PVA15 compared with F30PVA30 and F30PVA60. F30PVA60 hydrogels demonstrated shrinkage resistance compared to the template; F30PVA30 and F30PVA15 samples decreased by 1.4 and 2.5 times, respectively. Although the mechanical strength of all monocomponent hydrogels and IPN samples did not compare to that of the internal thoracic vein, F30PVA30 and F30PVA60 demonstrated better results than F30PVA15 and fibrin alone.Conclusion: Our method allows obtaining shrink-resistant IPN hydrogels with improved mechanical and tolerable biological properties at polyvinyl alcohol concentrations of &gt; 15 mg/mL and &lt; 60 mg/mL. However, the insufficient strength of this material limits its use in vascular engineering to a modifying coating. Received 25 January 2023. Revised 17 March 2023. Accepted 29 March 2023. Funding: This research was funded by the complex program of basic research under the Siberian Branch of the Russian Academy of Sciences within the basic research topic of Research Institute for Complex Issues of Cardiovascular Diseases No. 0419-2022-0001 “Molecular, cellular and biomechanical mechanisms of the pathogenesis of cardiovascular diseases in the development of new treatment methods based on personalized pharmacotherapy, minimally invasive medical devices, biomaterials and tissue-engineered implants”. Conflict of interest: The authors declare no conflict of interest. Contribution of the authorsConception and study design: V.G. Matveeva, M.A. RezvovaData collection and analysis: V.G. Matveeva, M.A. Rezvova, T.V. Glushkova, E.O. Krivkina, A.V. SergeevaStatistical analysis: V.G. Matveeva, M.A. Rezvova, T.V. Glushkova, A.V. SergeevaDrafting the article: V.G. MatveevaCritical revision of the article: V.G. Matveeva, M.A. Rezvova, L.V. Antonova, L.S. BarbarashFinal approval of the version to be published: V.G. Matveeva, M.A. Rezvova, T.V. Glushkova, A.V. Sergeeva, E.O. Krivkina, L.V. Antonova, L.S. Barbarash

Relationship between rib cartilage resection and postoperative chest recession deformity in breast reconstruction

The most versatile recipient vessels for breast reconstruction are the internal mammary artery and vein. For microvascular anastomosis, one or two costal cartilages are often dissected to increase the length of the vessel and the degree of freedom. In some cases, the resection of the rib cartilage causes long-term depression at the dissected site, compromising its cosmetic appearance. A total of 101 patients were examined, with 111 sides in which the internal mammary artery and vein were used as the recipient vessels. The patients were followed up for at least 6 months. A total of 37 of 38 patients with complete rib cartilage preservation had no depression, and 1 patient had a slight depression. In the case of partial resection of the rib cartilage, 37 of the 46 sides had no depression, 8 sides had mild depression, and 1 side had an obvious depression. When more than one rib cartilage was removed, 11 of the 27 sides had no depression, 11 had mild depression, and 5 had an obvious depression. The Spearman rank correlation coefficient was 0.4911936. This study reported the relationship between rib cartilage resection and postoperative concave deformity in breast reconstruction surgery using free flap transfer and the internal mammary artery and vein as the recipient vessels. A strong correlation was found between the extent of rib cartilage resected and the degree of depression. Minimizing rib cartilage resection when using the internal mammary artery and veins may minimize postoperative chest recession deformity and provide a well-dressed breast reconstruction.

Abstract P2-15-02: Omentum-Lipoaspirate Free-Flap Breast Reconstruction in Women with BMI &amp;lt;25

Abstract The Omental Fat-Augmented Free-flap (O-FAFF) is being offered at our institution as an alternative method of breast reconstruction. This novel free-flap construct is ideal for underweight and normal weight women who lack abdominal or other donor tissue, desire to avoid donor site morbidity and/or are averse to implant-based reconstruction. We analyze omentum, mastectomy and final construct weights in women with BMI &amp;lt; 25 kg/m2 who underwent nipple-sparing mastectomies and O-FAFF reconstruction. Methods Operative technical features of women undergoing nipple-sparing mastectomies with immediate O-FAFF breast reconstruction over a 34 month period are included. Steps of the operative procedure are as follows: laparascopic omentectomy, liposuction and unilateral or bilateral mastectomy is performed. An acellular dermal matrix (ADM) shell is fashioned around a tissue expander. This mold is filled with the omentum and then engrafted with lipoaspirate followed by microsurgical anastomoses of gastroepiploic artery and vein to internal mammary artery and vein. Weight of biological construct is compared to native breast weight. Results 26 women with average BMI 21.2 kg/m2 underwent unilateral (15) or bilateral (11) nipple-sparing mastectomies and O-FAFF reconstruction. Average omentum weight for 37 breasts was 149 gm (82- 262) and average mastectomy weighed 212.4 gm (85 – 396). The ratio of engrafted fat to omentum weight was 0.73 for unilateral versus 0.91 for bilateral cases. The ratio of omentum-fat graft construct to mastectomy weight was 1.24 for unilateral and 0.96 for bilateral cases. Conclusion O-FAFF is a novel procedure for autologous tissue breast reconstruction after nipple-sparing mastectomy in underweight and normal weight women. Comparable weight replacement for extirpated native breast is achieved. Citation Format: Irene L. Wapnir, Monica M. Dua, Yulia Zak, Dung Nguyen. Omentum-Lipoaspirate Free-Flap Breast Reconstruction in Women with BMI &amp;lt;25 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-15-02.