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Patients with long‐segment tracheal defects, deemed technically inoperable, constitute a population in critical need of airway replacement. Regardless of the underlying cause—be it benign or malignant processes—this patient category requires either a tracheal transplant or admission to a palliative care facility. Despite over 50 years of exploration in thoracic surgery and regenerative medicine, airway transplantation remains a significant challenge. Various tracheobronchial substitutes, such as synthetic prostheses, bioprostheses, allografts, autografts, and bioengineered conduits, have been experimentally tested, yet none have provided a standardized method for airway replacement. Aortic grafts were suggested by Aortic grafts have been suggested as a biological matrix for extensive airway reconstruction as a biological matrix for extensive airway reconstruction. Cryopreserved aortic allografts, because of their availability in tissue banks and the lack of need for immunosuppressive therapy, were first used in clinical applications. The TRITON‐01 study (NCT04263129) focuses on patients who received airway replacement to determine the routine applicability of this novel approach. The primary objective of this review is to provide information on advancements in the use of aortic allografts as tracheal replacements. [ABSTRACT FROM AUTHOR]

Tracheal reconstruction following extensive resection for malignant or benign lesions remains a major challenge in thoracic surgery. Numerous studies have attempted to identify the optimal tracheal replacement with different biological or prosthetic materials, such as various homologous and autologous tissues, with no encouraging outcomes. Recently, a few clinical studies reported attaining favorable outcomes using in vitro or stem cell-based airway engineering and also with tracheal allograft implantation following heterotopic revascularization. However, none of the relevant studies offered a standardized technology for airway replacement. In 1997, a novel approach to airway reconstruction was proposed, which involved using aortic grafts as the biological matrix. Studies on animal models reported achieving in-vivo cartilage and epithelial regeneration using this approach. These encouraging results inspired the subsequent application of cryopreserved aortic allografts in humans for the first time. Cryopreserved aortic allografts offered further advantages, such as easy availability in tissue banks and no requirement for immunosuppressive treatments. Currently, stented aortic matrix-based airway replacement has emerged as a standard approach, and its effectiveness was also verified in the recently reported TRITON-01 study. In this context, the present review aims to summarize the current status of the application of aortic grafts in tracheal replacement, including the latest advancements in experimental and clinical practice.

Histoplasma vascular graft infection (VGI) is rarely reported, with only a handful of instances documented in the existing literature. Reporting Histoplasma VGI cases is important as they demonstrate previous treatment strategies and their outcomes. In this paper, we report a case of disseminated histoplasmosis with ascending aortic graft infection. Conservative therapy was attempted initially but failed, and our patient eventually required surgical graft explantation. Our case demonstrates the challenges in diagnosing and managing VGI caused by Histoplasma capsulatum.

This case report follows a 47-year-old man who had multiple grafts undergoing FDG PET/CT (positron emission tomography/computed tomography) scan to evaluate for graft infection. Initial CT showed enhancing soft tissue and fluid collection around the graft, and the subsequent FDG PET/CT showed findings concerning for graft infection. This case exemplifies that FDG PET/CT is a synergistic tool in diagnosing aortic graft infections, a rare and often fatal complication of aortic grafts.

Decellularized porcine aortas are proposed as scaffolds for revolutionary active aortic grafts. A change in the static and dynamic mechanical properties, associated with the microstructure of elastin and collagen fibers, corresponds to alteration in the cyclic expansion and perfusion, in addition to possible graft damage. Therefore, the present study thoroughly investigates the mechanical response of the decellularized scaffolds of human and porcine origin to static and dynamic mechanical loads. The responses of the native human and porcine aortas are also compared; this is unavailable in the literature. Because the aorta is subjected to pulsatile blood pressure, dynamical responses to cyclic loads and their associated viscoelastic properties are particularly relevant for advanced graft design. In parallel, this study examines the microstructure of the decellularized aorta. The resulting data are compared to the analogous data obtained for the native human and porcine tissues. The results indicate that by using an optimized decellularization protocol – based on sodium dodecyl sulfate (SDS) and DNase – that minimizes mechanical and structural changes of the tissue, layered scaffolds with static and dynamic properties very similar to natural human aortas are obtained. In particular, a decellularized porcine aorta is non-inferior to a decellularized human aorta. About 55,000 patients undergo abdominal aortic aneurysm repair annually in the USA. The currently implanted grafts present a large mechanical mismatch with the native tissue. This increases the pulsatile nature of the blood flow with negative consequences to the organ perfusion. For this reason, biomimetic and mechanically compatible grafts for aortic repair are urgently needed and they can be obtained through tissue engineering. In this study, scaffolds from porcine and human aortas are obtained from an optimized decellularization protocol. They are accurately compared to the native tissue and present the ideal static and dynamic mechanical properties for developing innovative aortic grafts. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Background Fungal prosthetic graft infections are associated with high mortality, typically requiring aggressive surgical debridement. We present an alternative, minimally invasive approach to address these challenging clinical cases. Case presentation A 76-year-old Caucasian male with prior aortic root and arch replacement presented with localized chest wall tenderness after being hit by a car door. Computed tomography angiogram incidentally identified fluid in the anterior mediastinum, surrounding his ascending aortic graft. Rather than undertaking a high-risk reoperative sternotomy and redo complex aortic reconstruction, we elected to proceed with a robotic-assisted, minimally invasive debridement of the aortic graft, coupled with an omental wrap, entirely within the closed chest. Microbiology was positive for Aspergillus species. The patient made an uncomplicated recovery and was discharged home on antifungal therapy, likely to continue indefinitely. Conclusions Infected prosthetic aortic grafts can be successfully managed with debridement and pedicled omental flap coverage via a minimally invasive approach within the closed chest, obviating the morbidity of a complex reoperative open procedure.

Background: Fungal prosthetic graft infections are associated with high mortality, typically requiring aggressive surgical debridement. We present an alternative, minimally invasive approach to address these challenging clinical cases.Case Presentation: A 76-year-old Caucasian male with prior aortic root and arch replacement presented with localized chest wall tenderness after being hit by a car door. Computed tomography angiogram incidentally identified fluid in the anterior mediastinum, surrounding his ascending aortic graft. Rather than undertaking a high-risk reoperative sternotomy and redo complex aortic reconstruction, we elected to proceed with a robotic-assisted, minimally invasive debridement of the aortic graft, coupled with an omental wrap, entirely within the closed chest. Microbiology was positive for Aspergillus species. The patient made an uncomplicated recovery and was discharged home on antifungal therapy, likely to continue indefinitely.Conclusions: Infected prosthetic aortic grafts can be successfully managed with debridement and pedicled omental flap coverage via a minimally invasive approach within the closed chest, obviating the morbidity of a complex reoperative open procedure. [ABSTRACT FROM AUTHOR]

Aortic diseases located in the ascending aorta, aortic arch or proximal descending aorta often require more than one surgical intervention depending on the type of pathology and its extent as well as future anticipated aortic problems. These obstacles were tackled in 1983 by Hans Borst with the introduction of the classic elephant trunk (cET). This was an outstanding and straightforward procedure. Since then, the cET was very often the first surgical approach for patients with extensive aortic pathology of the ascending aorta and arch extending into the downstream aorta. Thirteen years later, Suto and Kato introduced the frozen elephant trunk (fET) which was later on perfectionized by industry and applied in various ways by many surgical groups worldwide. Comparing the cET with the fET raises a lot of difficulties. The lack of randomization and the presence of procedural and complication-related limitations for each technique do not allow for definitive conclusions about the ideal procedure to treat complex aortic pathology. It would be very short-sighted to close all future discussions about the subject with this statement of the Hannover group made in 2011. Since both techniques and its results cannot be compared statistically due to the heterogeneity of patient groups, the lack of randomization, the difference in type and extent of pathology, the differences in surgical techniques, the learning curve in gaining experience in both techniques, and the lack of reporting standards, no scientific conclusion can be drawn as to which technique is most successful. Comparisons may even be considered futile. It is the purpose of this paper merely to make a descriptive observation of both techniques, to discuss some important elements of interest and to give some constructive and useful criticism. [ABSTRACT FROM AUTHOR]

Histoplasma vascular graft infection (VGI) is rarely reported, with only a handful of instances documented in the existing literature. Reporting Histoplasma VGI cases is important as they demonstrate previous treatment strategies and their outcomes. In this paper, we report a case of disseminated histoplasmosis with ascending aortic graft infection. Conservative therapy was attempted initially but failed, and our patient eventually required surgical graft explantation. Our case demonstrates the challenges in diagnosing and managing VGI caused by Histoplasma capsulatum ., (© 2024 The Authors.)

Abstract Woven Dacron grafts are currently used for the surgical treatment of aortic aneurysm and acute dissection, two otherwise fatal pathologies when aortic wall rupture occurs. While Dacron is chosen for aortic grafts because of characteristics such as biocompatibility and durability, few data are available about the dynamic response of Dacron prosthetic devices and about their side effects on the cardiovascular system. In this study, a Dacron graft was subjected to physiological flow conditions in a specifically-developed mock circulatory loop. Experiments were conducted at different physiological pulsation-per-minute rates. Results show that, in comparison to an aortic segment of the same length, the prosthesis is extremely stiffer circumferentially, thus limiting the dynamical radial expansion responsible for the Windkessel effect in human arteries. The prosthesis is instead excessively compliant in the axial direction and develops preferentially bending oscillations. This very different dynamic behaviour with respect to the human aorta can alter cardiovascular pressure and flow dynamics resulting in long-term implant complications. [ABSTRACT FROM AUTHOR]

Abstract Complete aortic transection is typically fatal and extremely rare in pediatric patients. High clinical suspicion, even in hemodynamically stable patients, is essential for timely recognition and intervention. There is scant literature on the management of complete aortic transection in pediatric patients. Retrospective chart review of an adolescent who survived a large complete thoracic aortic rupture along with systematic pediatric literature review. A 16-year old female presented with a complete thoracic aortic transection with a 5–6 cm gap after an auto-pedestrian collision. Mediastinal vascular injury was suspected based on presentation, confirmed by chest radiograph, and further delineated by computed tomography. CT angiography was critical in determining the anatomy of injury and planning repair. Repair was achieved by left heart bypass and Dacron interposition grafting. The patient survived without vascular-related complications and remains well at 3-year follow up. Literature review revealed scant data on the diagnosis and management of complete aortic transection in children. The role of selective imaging for diagnosis is warranted. The applicability of endovascular stent-grafting in pediatric patients remains uncertain. Highlights • Complete aortic transection is extremely rare but typically fatal in children. • High clinical suspicion and a systematic approach are essential for survival. • Good outcomes are possible if prompt diagnosis and intervention are achieved. • The role of selective imaging for diagnosis is warranted. • The applicability of endovascular stent-grafting in pediatrics remains uncertain. [ABSTRACT FROM AUTHOR]

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Tracheal reconstruction following extensive resection for malignant or benign lesions remains a major challenge in thoracic surgery. Numerous studies have attempted to identify the optimal tracheal replacement with different biological or prosthetic materials, such as various homologous and autologous tissues, with no encouraging outcomes. Recently, a few clinical studies reported attaining favorable outcomes using in vitro or stem cell-based airway engineering and also with tracheal allograft implantation following heterotopic revascularization. However, none of the relevant studies offered a standardized technology for airway replacement. In 1997, a novel approach to airway reconstruction was proposed, which involved using aortic grafts as the biological matrix. Studies on animal models reported achieving in-vivo cartilage and epithelial regeneration using this approach. These encouraging results inspired the subsequent application of cryopreserved aortic allografts in humans for the first time. Cryopreserved aortic allografts offered further advantages, such as easy availability in tissue banks and no requirement for immunosuppressive treatments. Currently, stented aortic matrix-based airway replacement has emerged as a standard approach, and its effectiveness was also verified in the recently reported TRITON-01 study. In this context, the present review aims to summarize the current status of the application of aortic grafts in tracheal replacement, including the latest advancements in experimental and clinical practice., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Shixiong Wei reports financial support was provided by Natural Science Foundation of Jilin Province. Shixiong Wei reports financial support was provided by Education Department of Jilin Province, China. Shixiong Wei reports financial support was provided by Youth Development Fund of the First Hospital of Jilin University., (© 2023 The Japanese Society for Regenerative Medicine. Production and hosting by Elsevier B.V.)

Hemolytic anemia after thoracic aortic surgery is rare. A 69-year-old female patient, who underwent ascending aorta replacement for acute type A aortic dissection 7 years ago, was transferred from another hospital due to hemolytic anemia necessitating regular blood transfusions. After engaging in interdisciplinary discussions, we ruled out alternative medical diagnoses and treatments, ultimately identifying the kinked aortic graft as the primary cause of hemolysis. Due to the patient's comorbidity, it was deemed high-risk to perform a redo thoracic aorta surgery for the replacement of the kinked aortic graft. Therefore, we decided to insert a patient-specific bare-metal stent into the kinked aortic graft to alleviate the kinking and promote improvement in hemolysis. We decided to perform the stent procedure under local anesthesia. The bare-metal stent was designed to be approximately 15% larger than the size of the pre-existing kinked aortic graft. A stent measuring 32 mm × 80 mm was successfully inserted and ballooned within the patient's ascending aortic graft. As a result, the patient's hemolytic condition showed gradual improvement over time. In this way, we aim to share our experience of inserting a patient-specific bare-metal stent under local anesthesia in patients who exhibit mechanical hemolysis due to a kinked aortic graft, especially when redo surgery is considered high-risk., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-23-688/coif). The authors have no conflicts of interest to declare., (2023 Journal of Thoracic Disease. All rights reserved.)