Hybrid Graft Research Articles

Commercial Hybrid Graft versus Traditional Arch Replacement with Frozen Elephant Trunk: A Multi-Institutional Comparison

Commercial Hybrid Graft versus Traditional Arch Replacement with Frozen Elephant Trunk: A Multi-Institutional Comparison

Evaluation of biocompatibility and osteoconductivity of a hybrid cell-tissue graft for bone regenerative medicine

Aim – to evaluate in vitro the biocompatibility and osteoconductivity of a hybrid graft based on a bioorganic matrix, human bone marrow mesenchymal stromal cells (BM-MSC) and osteogenic growth factors. Material and methods. Bioorganic matrices were studied for biocompatibility with human BM-MSC culture used in traumatology and orthopedics. For promoted osteogenic differentiation of BM-MSCs, allogeneic plasma enriched with soluble platelet factors was used. The osteogenic potential of BM-MSCs by the synthesis of mRNAs of early (transcription factor 2 (Run X2), alkaline phosphatase (ALP)) and late genes (osteopontin (OSP)) osteogenesis was analyzed. The properties of cell adhesion and proliferation of MSCs in the conditions of a three-dimensional hybrid graft by the MTT test and fluorescence microscopy were assessed. Results. The biocompatibility of the studied bioorganic matrices with human BM-MSCs was established. The collagen matrix promoted rapid cell adhesion and proliferation between the scaffold fibrils. It has also been established that allogeneic platelet-rich plasma affects the osteogenic differentiation of human BM-MSCs in vitro, increasing the expression of marker genes RunX2, ALP, OSP. When modeling a hybrid graft in vitro, the formation of a tight contact between the alloimplant and collagen biopolymer using MSCs was shown. Conclusion. The biological properties of the developed hybrid cell-tissue graft characterize its biocompatibility and osteoconductivity of its constituent components, which makes it promising for use in regenerative medicine, especially in reconstructive surgery of bone defects.

Muticomponent Melt‐Electrowritten Vascular Graft to Mimic and Guide Regeneration of Small Diameter Blood Vessels

AbstractCardiovascular disease is a leading cause of morbidity. Current treatments include vessel substitution using autologous/synthetic vascular grafts, but these commonly fail in small diameter applications, largely due to compliance mismatch and clot formation. In this study, a multicomponent vascular graft, that takes inspiration from native vessel architecture, is developed to overcome these limitations. Melt electrowriting (MEW) is used to produce tubular scaffolds with vascular‐mimetic fiber architecture and mechanics, which is combined with a lyophilized fibrinogen matrix with tailored degradation kinetics to generate a hybrid graft. The MEW framework not only contributes to graft mechanics, but also provides contact guidance to direct cell/neotissue orientation and mimic the native tunica media. This construct is further functionalized with heparin, which in combination with the smooth extracellular matrix (ECM) surface, reduced platelet adhesion and clot formation providing a substrate for endothelization, thereby mimicking the function of the intima. Lastly, an outer electrospun layer representing the adventitia is added to improve elasticity and reduce permeability. This graft satisfies ISO implantability requirements, matches the compliance of native vessels, and reestablishes physiological flow with minimal clot formation in a preclinical model. Therefore, this graft represents an innovative off‐the‐shelf alternative to address the unmet clinical need for small‐diameter vascular grafts.

A New Hybrid Graft for Thoracoabdominal Aortic Repair: From Bench to Bedside

A New Hybrid Graft for Thoracoabdominal Aortic Repair: From Bench to Bedside

Optimized design of an enthesis-mimicking suture anchor-tendon hybrid graft for mechanically robust bone-tendon repair

Repair of functionally graded biological interfaces requires joining dissimilar materials such as hard bone to soft tendon/ligament, with re-injuries/re-tears expected to be minimized by incorporating biomimicking, stress-reducing features within grafts. At bone-tendon interfaces (entheses), stress can be reduced via angled insertion, geometric flaring, mechanical gradation, and interdigitation of tissues. Here, we incorporated enthesis attributes into 3D in silico and physical models of a unique suture anchor-tendon hybrid graft (SATHG) and investigated their effects on stress reduction via finite element analyses (FEA) studies. Over 20 different simulations altering SATHG angulation, flaring, mechanical gradation, and interdigitation identified an optimal design, which included 90° angulation, 25° flaring, and a compliant (ascending then descending) mechanical gradient in SATHG's bone-to-tendon-like transitional region. This design reduced peak stress concentration factor (SCF) by 43.6 % relative to an ascending-only mechanical gradient typically used in hard-to-soft tissue engineering. To verify FEA results, SATHG models were fabricated using a photocrosslinkable bone-tendon-like polyurethane (QHM polymer) for ex vivo tensile assessment. Tensile testing showed that ultimate load (132.9 N), displacement-at-failure (1.78 mm), stiffness (135.4 N/mm), and total work-to-failure (422.1 × 10−3 J) were highest in the optimized design. Furthermore, to assess envisioned usage, SATHG pull-out testing and 6-week in vivo implantation into large, 0.5-cm segmental supraspinatus tendon defects was performed. SATHG pull-out testing showed secure bone attachment while histological assessment such as hematoxylin and eosin (H&E) together with Safranin-O staining showed biocompatibility including enthesis regeneration. This work demonstrates that engineering biomaterials with FEA-optimized, enthesis-like attributes shows potential for enhancing hard-to-soft tissue repair. Statement of significanceSuccessful repair of hard-to-soft tissue injuries is challenging due to high stress concentrations within bone-tendon/ligament grafts that mechanically compromise repair strength. While stress-reducing gradient biomaterials have been reported, little-to-no attention has focused on other bone-tendon/ligament interface (enthesis) features. To this end, a unique bone-tendon graft (SATHG) was developed by combining two common orthopaedic devices along with biomimetic incorporation of four enthesis-like features to reduce stress and encourage widespread clinician adoption. Notably, utilizing designs based on natural stress dissipation principles such as anchor insertion angle, geometric flaring, and mechanical gradation reduced stress by 43.6 % in silico, which was confirmed ex vivo, while in vivo studies showed SATHG's ability to support native enthesis regeneration. Thus, SATHG shows promise for hard-to-soft tissue repairs.

Implantation of Adipose-Derived Mesenchymal Stromal Cells (ADSCs)-Lining Prosthetic Graft Promotes Vascular Regeneration in Monkeys and Pigs

Background:Current replacement procedures for stenosis or occluded arteries using prosthetic grafts have serious limitations in clinical applications, particularly, endothelialization of the luminal surface is a long-standing unresolved problem.Method:We produced a cell-based hybrid vascular graft using a bioink engulfing adipose-derived mesenchymal stromal cells (ADSCs) and a 3D bioprinting process lining the ADSCs on the luminal surface of GORE-Tex grafts. The hybrid graft was implanted as an interposition conduit to replace a 3-cm-long segment of the infrarenal abdominal aorta in Rhesus monkeys.Results:Complete endothelium layer and smooth muscle layer were fully developed within 21 days post-implantation, along with normalized collagen deposition and crosslinking in the regenerated vasculature in all monkeys. The regenerated blood vessels showed normal functionality for the longest observation of more than 1650 days. The same procedure was also conducted in miniature pigs for the interposition replacement of a 10-cm-long right iliac artery and showed the same long-term effective and safe outcome.Conclusion:This cell-based vascular graft is ready to undergo clinical trials for human patients.

Frozen elephant trunk technique using hybrid grafts: 15-year outcomes from a single-centre experience.

The purpose of the study is to compare the short- and long-term outcomes of the frozen elephant trunk (FET) technique based on 2 different hybrid grafts implanted from January 2007 to July 2022. The study includes patients who underwent an elective or emergency FET procedure. Short-term, long-term mortality and freedom from thoracic endovascular aortic repair (TEVAR) were the primary end points. Analyses were carried out separately for the periods 2007-2012 and 2013-2022. Of the 367 enrolled, 49.3% received E-Vita Open implantation and 50.7% received Thoraflex Hybrid implants. Overall mean age was 61 years [standard deviation (SD) = 11] and 80.7% were male. The average annual volume of FET procedures was 22.7 cases/year. Compared to E-Vita Open, patients implanted with Thoraflex Hybrid grafts were more likely to receive distal anastomosis in zone 2 (68.3% vs 11.6%, P < 0.001) with a shorter stent portion, mean = 103mm (SD = 11.3) vs mean = 149 mm (SD = 12.7; P < 0.001) and they underwent a reduced visceral ischaemia time, mean = 42.5 (SD = 14.2) vs mean= 61.0 (SD = 20.2) min, P < 0.001. In the period 2013-2022, overall survival at 1, 2 and 5 years was 74.8%, 72.5% and 63.2% for Thoraflex and 73.2%, 70.7% and 64.1% for E-Vita, without significant differences between groups (log-rank test = 0.01, P = 0.907). Overall freedom from TEVAR at 1, 2 and 5 years was 66.7%, 57.6% and 39.3% for Thoraflex and 79%, 69.7% and 66% for E-Vita, with significant differences between groups (log-rank test = 5.28, P = 0.029). In a competing risk analysis adjusted for chronic/residual aortic syndromes and stent diameter, the Thoraflex group was more likely to receive TEVAR during follow-up (subdistribution hazard ratio SHR = 2.12, 95% confidence interval 1.06-4.22). The FET technique addresses acute and chronic arch disease with acceptable morbidity and mortality. Downstream endovascular reinterventions are very common during follow-up.

The Frozen Elephant Trunk Procedure Using New Russian Hybrid Prosthesis "Soft Elephant Trunk": the Early Experience.

Aim To present the first experience of performing the Frozen Elephant Trunk (FET) surgery in patients with thoracic aorta disease using a new Russian hybrid stent graft "Soft Elephant Trunk".Material and methods Between 2014 and 2021, 170 patients with thoracic aortic disease underwent complete aortic arch replacement using the FET technique. In 70 of these cases (since June 2019), a hybrid graft "Soft Elephant Trunk" was used. A specific feature of this graft is the conical reduction of the radial force of nitinol crowns and the soft distal end without radial force. The study endpoints were early postoperative results, as well as the absence of reoperations on the aorta, absence of stent-graft-associated complications, including distal stent-graft-induced fenestration, and survival at a mid-term follow-up of up to 2.5 years.Results Interventions were performed in patients with A type aortic dissection (n=51; 72.9 %), type B aortic dissection (n=13; 18.6 %), and thoracoabdominal aortic aneurysm (TAAA) (n=6; 8.5 %). In 14 (20 %) of these cases, interventions were performed after a primary intervention on the proximal aorta. Acute aortic dissection was diagnosed in 17 (24.3 %) cases. Aortic root replacement was performed in 21 (30 %) cases, David procedure in 5 (7.2 %) cases, Bentall-DeBono procedure in 11 (15.7 %) cases, and supracoronary graft placement in 33 (47.1 %) cases. There were no cases of paraplegia or paraparesis. Respiratory insufficiency was observed in 8 (11.4%) cases. In one (1.4%) case, acute renal failure developed, which required renal replacement therapy. In-hospital mortality was 4.3 % (3 patients died). Mean follow-up duration was 9 [4.25; 16] months. Three-year survival was 94 % (95 % confidence interval, CI: 88-99.9) and absence of reoperation was 96.6 % (95 % CI: 90.1-100). There were no cases of distal stent-graft-induced fenestration in this group.Conclusion The new hybrid graft, due to its specific structure, provides prevention of distal stent-graft-induced fenestration and, thereby, a stable long-term result. Using this stent-graft is effective in patients with thoracic aorta pathology undergoing the FET surgery. However, further studies are needed to determine potential advantages and disadvantages of this new hybrid graft, to obtain long-term results and accumulate experience.

Total aortic arch replacement without deep hypothermic circulatory arrest in type A aortic dissection: Left axillar artery for arterial cannulation

ObjectiveTotal aortic arch replacement (TAR) necessitates hypothermic circulatory arrest (CA). The frozen elephant trunk technique (FET) additionally requires commercial hybrid grafts. Herein we describe a novel modified FET technique without CA using standard grafts thanks to left axillary artery (LAxA) cannulation in patients with acute type A aortic dissection. MethodsLAxA anastomosis is made first using a homemade debranching graft, and cardiopulmonary bypass is initiated, followed by anastomoses of left common carotid and innominate arteries. The rest of the operation is performed with complete cerebral perfusion. Following replacement of ascending aorta/root, cardiac reperfusion is started using a root cannula which continues throughout the procedure. Distal arch anastomosis is performed clamp-on, allowing lower body perfusion via left subclavian artery. Lower body perfusion is interrupted for 5 to 8 minutes to deploy an endograft to complete a modified FET. Following cannulation of distal arch graft, perfusion of distal aorta is restarted, and all three grafts are incorporated to construct a neo-ascending aorta and arch. ResultsBetween December 2018 and May 2022, 38 patients underwent TAR without operative mortality. Hospital mortality was %15.7, and spinal cord ischemia and stroke were not encountered in surviving patients. The mean lower body CA time was 7.2 ± 2.8 minutes. ConclusionsTAR using standard endografts without CA is possible with LAxA cannulation. To perform a FET, only a short interruption of lower body circulation is sufficient to deploy an endograft, also improving hemostasis of distal anastomosis. Further studies are required with a higher number of patients to evaluate the efficiency of this novel technique.

Five-Year Outcomes of Hybrid Arch Frozen Elephant Trunk Repair With Novel Multibranched Hybrid Graft

BackgroundThe objective of this study was to report the 5-year outcomes of hybrid arch frozen elephant trunk (FET) procedures with a multibranched hybrid graft. MethodsBetween 2014 and 2020, 50 consecutive patients (63 ± 15 years old; 34% women) underwent hybrid arch FET with Thoraflex hybrid graft (Terumo Aortic) at a single center. Indications included aortic aneurysm (n = 48 [96%]), acute aortic dissection (n = 10 [20%]), and chronic dissection (n = 20 [40%]). Follow-up was complete, and mean follow-up was 1455 ± 664 days. ResultsAll 50 patients experienced successful device implantation. The 30-day/in-hospital mortality was 2% (n = 1). Stroke and transient neurologic deficits occurred in 1 patient (2%) and 3 patients (6%). Two patients (4%) and 1 patient (2%) experienced transient and permanent spinal cord ischemia. FET thromboembolic complication was observed in 1 patient (2%). In follow-up, 6 patients died of aortic events, and there were 13 reinterventions in the downstream aorta, of which 46% (6/13) were planned second-stage operations. Survival rate at 1 year, 2 years, and 5 years was 96%, 92%, and 85%, and freedom from unplanned distal reintervention at 1 year, 2 years, and 5 years was 98%, 92%, and 81%. Computed tomography follow-up demonstrated positive distal aortic remodeling with aneurysmal regression and stabilized aortic dimensions in patients with aortic dissection. ConclusionsThe hybrid arch FET procedure with a novel hybrid graft is associated with good early and midterm outcomes. Longer term outcomes merit further investigation.

Autograft-Only and Allograft-Augmented Hamstring Autograft Have Similar Failure Rates After Anterior Cruciate Ligament Reconstruction

PurposeTo compare failure rates and clinical outcomes after hamstring autograft anterior cruciate ligament (ACL) reconstruction with and without allograft augmentation by a single surgeon otherwise using the same surgical technique.MethodsThis was a retrospective analysis with prospectively collected patient-reported outcomes of primary hamstring autograft ACL reconstruction with and without allograft augmentation performed in a military population by a single surgeon. The primary outcome measure was graft failure, defined as graft rupture confirmed by use of magnetic resonance imaging scans and/or revision ACL reconstruction. The secondary outcome measure was the postoperative Knee Injury and Osteoarthritis Outcome Score.ResultsThis study included 112 patients with a mean follow-up period of 65.3 months. In patients with a graft diameter of 8 mm or greater, there was no difference in failure rates (9.4% for autograft only vs 6.3% for hybrid, P = .59). There was a higher failure rate in patients in the autograft-only group with a graft diameter of less than 8 mm (29.4%) when compared with the hybrid graft group (6.3%, P = .008). There were no hybrid grafts less than 8 mm in diameter. There were no differences in the Knee Injury and Osteoarthritis Outcome Score between groups as long as the graft diameter was 8 mm or greater.ConclusionsIn patients undergoing hamstring ACL reconstruction, there was no significant difference in graft failure rates or outcome scores between autograft only and autograft with allograft augmentation as long as grafts were 8 mm or greater. High failure rates were seen when the graft diameter was less than 8 mm.Level of EvidenceLevel III, retrospective cohort study. To compare failure rates and clinical outcomes after hamstring autograft anterior cruciate ligament (ACL) reconstruction with and without allograft augmentation by a single surgeon otherwise using the same surgical technique. This was a retrospective analysis with prospectively collected patient-reported outcomes of primary hamstring autograft ACL reconstruction with and without allograft augmentation performed in a military population by a single surgeon. The primary outcome measure was graft failure, defined as graft rupture confirmed by use of magnetic resonance imaging scans and/or revision ACL reconstruction. The secondary outcome measure was the postoperative Knee Injury and Osteoarthritis Outcome Score. This study included 112 patients with a mean follow-up period of 65.3 months. In patients with a graft diameter of 8 mm or greater, there was no difference in failure rates (9.4% for autograft only vs 6.3% for hybrid, P = .59). There was a higher failure rate in patients in the autograft-only group with a graft diameter of less than 8 mm (29.4%) when compared with the hybrid graft group (6.3%, P = .008). There were no hybrid grafts less than 8 mm in diameter. There were no differences in the Knee Injury and Osteoarthritis Outcome Score between groups as long as the graft diameter was 8 mm or greater. In patients undergoing hamstring ACL reconstruction, there was no significant difference in graft failure rates or outcome scores between autograft only and autograft with allograft augmentation as long as grafts were 8 mm or greater. High failure rates were seen when the graft diameter was less than 8 mm.

C40 SYSTEMATIC TOTAL ARCH REPLACEMENT WITH THORAFLEX HYBRID GRAFT IN ACUTE TYPE A AORTIC DISSECTION: A SINGLE CENTRE EXPERIENCE

Abstract Introduction The traditional surgical management for acute Type A aortic dissection focuses on handling emergencies in the aortic root and ascending aorta. The remaining untreated distal portion of the aorta has a potential risk of rupture or causing malperfusion syndrome. Therefore, an aggressive repair approach using total aortic arch replacement combined with the frozen elephant trunk (FET) implantation has been advocated. We describe the early and midterm clinical outcomes of the Thoraflex Hybrid graft for the treatment of emergency type A aortic dissection. Methods Between December 2017 and January 2022, 69 consecutive patients were admitted with acute type A aortic dissection; of those, 66 patients (62.9 ± 10.2 years of age, 81.8% men) underwent emergency hybrid aortic arch and frozen elephant trunk repair with the multibranched Thoraflex hybrid graft and were enrolled in the study. Primary end point were 30 days– and in–hospital mortality. To better clarify the impact of age on surgical outcomes, we have divided the study population into two groups: group A for patients &amp;lt; 70 years of age (47 patients), group B for patients ≥ 70 years (19 patients). Results All 66 device implants were technically successful. Mean follow–up was 19.7 ±17.4 months. 30–days– and in–hospital mortality were 10.6 and 13.6%, respectively. Stroke occurred in 3 (4.5%) patients. Two (3.0%) patients experienced spinal cord ischemia. Renal failure requiring CVVH and respiratory failure requiring tracheostomy were 30.3% and 28.8%, respectively. Overall survival for the entire cohort at 3 months, 6 months, 12 months and 24 months was 85%, 80.3%, 76.5%, 74.4% respectively. We did not find any statistically significant difference among the two groups in terms of main post–operative outcomes. The multivariable Cox proportional hazard model showed left ventricular ejection fraction (HR: 0.83, 95% CI: 0.79–0.92, p &amp;lt;0.01), peripheral vascular disease (HR: 15.8, 95% CI: 3.9–62.9, p &amp;lt; 0.01), coronary malperfusion (HR: 0.10, 95% CI: 0.01–0.77, p =0.03), lower limbs malperfusion (HR: 5.1, 95% CI: 1.10–23.4, p = 0.04) and cardiopulmonary bypass time (HR: 1.02, 95% CI: 1 – 1.04, p = 0.01) as independent predictors of long term mortality. Conclusions Hybrid aortic arch and frozen elephant trunk repair with the Thoraflex Hybrid graft to treat emergency type A aortic dissection appears to be associated with good early and mid–term clinical outcomes even in the elderly.

No difference in revision risk between autologous hamstring graft less than 8mm versus hybrid graft 8mm or larger in anterior cruciate ligament reconstruction.

Hamstring autograft (HA) is commonly used for primary anterior cruciate ligament reconstruction (ACLR). However, if the harvested HA is inadequate in diameter, it is often augmented with an allograft tendon, forming a hybrid graft (HY). This study sought to evaluate aseptic revision risk following HA versus HY ACLR. A retrospective cohort study was performed using data obtained from our healthcare system's ACLR registry. Patients ≤ 25years of age who underwent primary isolated ACLR were identified (2005-2020). Graft type and diameter size was the primary exposure of interest: < 8mm HA and ≥ 8mm HY. A secondary analysis was performed to examine 7mm HA and 7.5mm HA vs ≥ 8mm HY. Propensity score-weighted Cox proportional hazard regression was used to evaluate the risk of aseptic revision. The study sample included 1,945 ACLR: 548 ≥ 8mm HY, 651 7mm HA, and 672 7.5mm HA. The crude cumulative aseptic revision probability at 8-years for ≥ 8mm HY was 9.1%, 11.1% for 7mm HA, and 11.2% for 7.5mm HA. In adjusted analysis, no difference in revision risk was observed for < 8mm HA (hazard ratio [HR] 1.15, 95% confidence interval [CI] 0.72-1.82), 7mm HA (HR 1.23, 95% CI 0.71-2.11), or 7.5mm HA (HR 1.16, 95% CI 0.74-1.82) compared to ≥ 8mm HY. In a US-based cohort of ACLR patients aged ≤ 25years, we failed to observe any differences in aseptic revision risk for HA < 8mm compared to HY ≥ 8mm. Augmentation of a HA as small as 7mm is not necessary to prevent a revision surgery. Level III.

Biomimetic in situ tracheal microvascularization for segmental tracheal reconstruction in one-step.

Formation of functional and perfusable vascular network is critical to ensure the long-term survival and functionality of the engineered tissue tracheae after transplantation. However, the greatest challenge in tracheal-replacement therapy is the promotion of tissue regeneration by rapid graft vascularization. Traditional prevascularization methods for tracheal grafts typically utilize omentum or muscle flap wrapping, which requires a second operation; vascularized segment tracheal orthotopic transplantation in one step remains difficult. This study proposes a method to construct a tissue-engineered tracheal graft, which directly forms the microvascular network after orthotopic transplantation in vivo. The focus of this study was the preparation of a hybrid tracheal graft that is non-immunogenic, has good biomechanical properties, supports cell proliferation, and quickly vascularizes. The results showed that vacuum-assisted decellularized trachea-polycaprolactone hybrid scaffold could match most of the above requirements as closely as possible. Furthermore, endothelial progenitor cells (EPCs) were extracted and used as vascularized seed cells and seeded on the surfaces of hybrid grafts before and during the tracheal orthotopic transplantation. The results showed that the microvascularized tracheal grafts formed maintained the survival of the recipient, showing a satisfactory therapeutic outcome. This is the first study to utilize EPCs for microvascular construction of long-segment trachea in one-step; the approach represents a promising method for microvascular tracheal reconstruction.

Frozen Elephant Trunk for Aortic Dissection Using Different Hybrid Grafts: Preliminary Results from a Prospective Study.

The frozen elephant trunk technique has become popular and led to an expansion of indications for surgery. Various hybrid grafts for the frozen elephant trunk are used, sometimes with significantly different features. The objective of this study was to compare early- and mid-term outcomes after the frozen elephant trunk for aortic dissection using different hybrid grafts. The prospective study included 45 patients with acute/chronic aortic dissections. The patients were randomized into two groups. Group 1 patients (n = 19) were implanted with a hybrid graft E-vita open plus (E-vita OP). Group 2 (n = 26) included patients who received a MedEng graft. The inclusion criteria were type A and type B acute and chronic aortic dissection. The exclusion criteria were as follows: hyperacute aortic dissection (less than 24 h), organ malperfusion, oncology, severe heart failure, stroke, and acute myocardial infarction. The primary endpoint was early- and mid-term mortality. The secondary endpoints were postoperative complications (stroke and spinal cord ischemia, myocardial infarction, respiratory failure, acute renal injury, and re-operation for bleeding). The rate of stroke and spinal cord ischemia in the E-vita OP vs. MedEng groups was 11% vs. 4% (p = 0.565) and 11% vs. 0% (p = 0.173), respectively. The respiratory failure rate was comparable in both groups (p > 0.999). Acute kidney injury requiring hemodialysis and the need for re-sternotomy in the MedEng group vs. E-vita OP group was 31% vs. 16% (p = 0.309) and 15% vs. none (p = 0.126), respectively. Early mortality in the MedEng and E-vita OP groups did not differ (8% vs. 0, p = 0.501). The mid-term survival in the analyzed groups was 79% vs. 61%, (p = 0.079), respectively. No statistically significant differences were observed between patients receiving frozen elephant trunk with the hybrid MedEng and E-vita OP grafts in regard to early mortality and morbidity. Mid-term survival was also non-significant between analyzed groups with a trend toward more favorable mortality in the MedEng group.

Analysing debranching techniques in Frozen Elephant Trunk procedures: a narrative literature review.

Since 2003, the Frozen Elephant Trunk (FET) technique has attained rising popularity for treating extensive aortic arch pathologies such as acute and chronic aortic dissection, as well as thoracic aortic aneurysm. Conventionally, the FET procedure included a complete resection of the aortic arch and, subsequently, a distal aortic anastomosis of the prosthetic part of the hybrid graft in arch zone 3. Simultaneous to the introduction of the FET technique, the traditional Elephant Trunk technique was simplified by adding debranching techniques which allows for proximalization of the distal aortic anastomosis. Nowadays, modern concepts of aortic arch surgery combine the FET technique with proximalization of the distal anastomosis in arch zone 2 or further proximal, achieved by using different debranching techniques. This review describes different debranching techniques to facilitate arch reconstruction, and aims to critically assess the outcomes and potential clinical advantages of proximalization using debranching in FET surgery. We conducted a search using the PubMed and Google Scholar electronic databases to evaluate published outcomes of different debranching techniques. An overview of the data synthesis of 21 included studies is reported. Most studies report numeric, but not statistically significant improved outcomes after debranching in FET surgery for mortality, neurological complications, spinal cord injury, kidney failure, bowel ischemia and recurrent nerve palsy. Some studies report statistically significant improved results in isolated endpoints such as neurological, bowel ischemia, and recurrent nerve palsy. Most studies report debranching to be technically easier, but this is difficult to objectively assess and measure. There is an improved numeric outcome of different debranching techniques with proximalization of the distal anastomosis, but without reaching statistical significance. This review shows marked heterogeneity across included studies and highlights the scarce use of existing guidelines in clinical research of open aortic arch surgery as proposed by the International Aortic Arch Surgery Study Group. Furthermore, this review demonstrates the urgent need for multicenter registries or studies to be able to compare the outcome of different surgical techniques for various aortic arch pathologies.

Advanced Graft Development Approaches for ACL Reconstruction or Regeneration.

The Anterior Cruciate Ligament (ACL) is one of the major knee ligaments, one which is greatly exposed to injuries. According to the British National Health Society, ACL tears represent around 40% of all knee injuries. The number of ACL injuries has increased rapidly over the past ten years, especially in people from 26-30 years of age. We present a brief background in currently used ACL treatment strategies with a description of surgical reconstruction techniques. According to the well-established method, the PubMed database was then analyzed to scaffold preparation methods and materials. The number of publications and clinical trials over the last almost 30 years were analyzed to determine trends in ACL graft development. Finally, we described selected ACL scaffold development publications of engineering, medical, and business interest. The systematic PubMed database analysis indicated a high interest in collagen for the purpose of ACL graft development, an increased interest in hybrid grafts, a numerical balance in the development of biodegradable and nonbiodegradable grafts, and a low number of clinical trials. The investigation of selected publications indicated that only a few suggest a real possibility of creating healthy tissue. At the same time, many of them focus on specific details and fundamental science. Grafts exhibit a wide range of mechanical properties, mostly because of polymer types and graft morphology. Moreover, most of the research ends at the in vitro stage, using non-certificated polymers, thus requiring a long time before the medical device can be placed on the market. In addition to scientific concerns, official regulations limit the immediate introduction of artificial grafts onto the market.

Superior capsular reconstruction using hybrid graft for irreparable massive rotator cuff tear.

To evaluate the clinical and radiological outcomes of arthroscopic superior capsular reconstruction (SCR) using hybrid grafts composed of tensor fascia lata autografts and human dermal allografts. This study included 30 patients with chronic irreparable posterosuperior rotator cuff tears (RCTs) who underwent arthroscopic SCR using a hybrid graft composed of tensor fascia lata autograft and human dermal allograft. Clinical outcomes were evaluated using the pain visual analogue scale score, shoulder range of motion, American Shoulder and Elbow Surgeons score, constant score, University of California-Los Angeles score, and simple shoulder test score preoperatively and at least 2years after surgery. Radiographic analysis included the Hamada classification grade, acromiohumeral distance (AHD), and graft integrity at 2years after surgery. All patients exhibited significant clinical improvement in all functional outcome measurements, except external rotation (all P < 0.05). The number of patients who exhibited pseudoparalysis decreased from 7 (23.3%) to 2 (6.7%) postoperatively. Complications were not observed. Radiologically, the mean postoperative AHD increased significantly from 6.9 ± 1.6cm to 8.8 ± 2.1cm at 2years postoperatively (P < 0.001). Twenty five out of the 30 (83.3%) patients showed successful graft healing, and all healing failures occurred on the humeral side. The differences between the healed-graft and failed-graft groups were significantly lower graft thickness (P = 0.001) and smaller AHD (P < 0.001) in the failed-graft group. Every functional outcome scores were not statistically different between healed-graft and failed-graft groups. An arthroscopic SCR technique using a hybrid graft consisting of a tensor fascia lata autograft and human dermal allograft showed satisfactory clinical outcomes in patients with irreparable RCTs. IV.

Retracted: Anterior Cruciate Ligament Reconstruction with Hybrid Graft versus Autograft: A Systematic Review and Meta‐Analysis

Retracted: Anterior Cruciate Ligament Reconstruction with Hybrid Graft versus Autograft: A Systematic Review and Meta‐Analysis

First in Human Implantation of the Thoracoflo Graft: A New Hybrid Device for Thoraco-Abdominal Aortic Repair

Despite a high rate of success when performed in specialised centres, current techniques for thoraco-abdominal aortic repair are associated with serious complications. The problem of spinal cord ischaemia remains unsolved. The new hybrid graft for thoraco-abdominal aortic repair was developed based on the frozen elephant trunk principle. The device consists of a proximal stent graft for transabdominal retrograde delivery to the descending thoracic aorta, combined with a distal six branched abdominal device for open aortic repair. An additional seventh branch is provided for possible lumbar artery re-implantation. Because the stent graft is implanted via a transabdominal approach, it avoids the need for thoracotomy and extracorporeal circulation. A 56 year old patient with Loeys-Dietz syndrome was placed in a supine position. The aorto-iliac axis was exposed via a midline transperitoneal approach. Following an end to side anastomosis of the iliac branch to the left common iliac artery, the stent graft portion was inserted into the thoracic aorta via the coeliac trunk ostium. After stent implantation and graft de-airing by needle puncture, retrograde blood flow to the abdominal aortic segment, and the lumbar and visceral arteries was established via the end to side iliac anastomosis creating an extra-anatomic bypass. Subsequently, the visceral and renal arteries were anastomosed to the branches. Finally, the aorta was opened and surgical graft attached via the collar. The reconstruction ended with end to end anastomoses of both common iliac arteries to the graft branches. The first and successful implantation of the new Thoracoflo hybrid device via a novel surgical technique is reported, eliminating the need for thoracotomy and extracorporeal circulation for thoraco-abdominal aortic repair.