Aberrant subclavian artery (ASA) is one of the most common congenital vascular anomalies of the aortic arch. The incidences of aberrant right subclavian artery (ARSA) and aberrant left subclavian artery (ALSA) are 0.4% to 2.3% and 0.05%, respectively. Approximately 60% of ARSA patients will have a Kommerell's diverticulum at the origin of the ASA. Symptomatic or aneurysmal ASAs need to be treated. Historically, open operation was the favored method to reconstruct ASA anatomy; however, novel endovascular techniques are now available. Following a brief discussion of embryonic development, symptoms, and treatment history of the ASA and Kommerell's diverticulum, the results of a literature review to collect the worldwide experience of endovascular/hybrid treatment of ASA is presented.

Purpose: To summarize a single-center experience using the single/double chimney technique in association with thoracic endovascular aortic repairs (TEVAR) for aortic arch pathologies. Methods: From November 2007 to March 2016, 122 patients (mean age 50.4±12.7 years, range 29-80; 92 men) with aortic arch pathologies underwent TEVAR combined with single (n=101) or double (n=21) chimney grafts to reconstruct the supra-aortic branches: 21 innominate arteries, 114 left common carotid arteries, and 8 left subclavian arteries (LSA). Pathologies included type B aortic dissection (n=47), aortic arch dissection (n=49), retrograde type A aortic dissection (n=8), thoracic aortic aneurysm (n=7), penetrating aortic arch ulcer (n=9), and post-TEVAR type I endoleak (n=2). Follow-up examinations included computed tomography at 0.5, 3, 6, and 12 months and yearly thereafter. Results: The aortic stent-grafts were deployed in zone 0 (n=21), zone 1 (n=93), and zone 2 (n=8). One (0.8%) of the 122 patients died at 4 days due to a perforated peptic ulcer. Type Ia endoleaks were found intraoperatively in 13 (10.7%) patients, including 3 with the double chimney technique. Type II endoleaks occurred in 6 (4.9%) patients; 3 were treated with duct occluders in the LSA. Postoperative chimney graft migration occurred in 1 (0.8%) patient with double chimneys; additional stent-grafts were deployed in both chimneys. Median follow-up was 32.3 months, during which 1 (0.8%) patient died after a stroke at 3 months. Chimney stent-graft patency was observed in the remaining 120 patients. Two (1.7%) secondary TEVARs were performed for distal aortic dissection. Nine asymptomatic type Ia endoleaks and 1 type II endoleak persisted in follow-up; a type II endoleak in 1 patient with Marfan syndrome sealed in 52 months. Conclusion: TEVAR with the chimney technique provides a safe, minimally invasive alternative with good chimney graft patency and low postoperative mortality during midterm follow-up. The double chimney technique should be used judiciously owing to its potential complications.

Neointimal hyperplasia (NIH) in bypass conduits such as veins and prosthetic grafts is an important clinical entity that limits the long-term success of vascular interventions. Although the development of NIH in the conduits shares many of the same features of NIH that develops in native arteries after injury, vascular grafts are exposed to unique circumstances that predispose them to NIH, including surgical trauma related to vein handling, hemodynamic changes creating areas of low flow, and differences in biocompatibility between the conduit and the host environment. Multiple different approaches, including novel surgical techniques and targeted gene therapies, have been developed to target and prevent the causes of NIH. Recently, the PREVENT trials, the first molecular biology trials in vascular surgery aimed at preventing NIH, have failed to produce improved clinical outcomes, highlighting the incomplete knowledge of the pathways leading to NIH in vascular grafts. In this review, we aim to summarize the pathophysiologic pathways that underlie the formation of NIH in both vein and synthetic grafts and discuss current and potential mechanical and molecular approaches under investigation that may limit NIH in vascular grafts.

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Background: Revascularization of the supra-aortic major branches in thoracic endovascular aortic repair (TEVAR) is challenging owing to the complex anatomic configuration of aortic arch pathologies. This study aims to evaluate the feasibility, effectiveness, and safety of three major techniques-chimney, fenestrated, and in-situ fenestration-for patients with aortic arch pathologies. Methods: A retrospective analysis was performed involving 234 patients with aortic arch lesions, who underwent TEVAR with adaptations in technique (chimney, fenestrated, or in-situ fenestration) between January 2016 and December 2017. Results: One hundred and twenty-six patients underwent the chimney technique (98 single chimneys, 24 double chimneys, and four triple chimneys); one hundred and two patients (102/234) were treated with on-the-table fenestration technique (92 single fenestrations, nine double fenestrations, and one double fenestration plus innominate artery chimney); and the remaining six patients underwent in-situ needle fenestration technique. Overall, indications included aortic dissections (99/234), aortic arch aneurysms (60/234), penetrating aortic ulcers (72/234), and re-interventions (3/234). The technical success rates were 99.6%. There were five cases of early all-cause mortality. The patency rates of overall branches were 99.6%.There were 15 cases with type Ia endoleak-14 in the chimney group (11.1%) and one in the on-the-table fenestration group (1%). Five patients underwent re-interventions. The median follow-up time for all patients was 28 (range, 16-41) months. Conclusions: Our experience suggests that chimney, on-the-table fenestration, and in-situ needle fenestration techniques are feasible, effective, and safe treatment options for aortic arch pathologies with encouraging mid-term results. Long-term durability concerns require further evaluation.

ObjectivePericardial patches are commonly used in vascular surgery to close arteriotomies. The mechanism of early healing after patch implantation is still not well defined. We used a rat aortic patch model to assess pericardial patch healing and examined Ephrin-B2, a marker of arterial identity, expression within the post-implantation patch. We also determined whether endothelial progenitor cells (EPC) are associated with early patch healing in the arterial environment.MethodsWistar rats (200–250 grams) underwent infrarenal aortic arteriotomy and then closure via bovine or porcine pericardial patch angioplasty. Control groups included subcutaneously implanted patches. Patches were harvested at 0–30 days and analyzed by histology, immunohistochemistry, immunofluorescence and Western blot as well as quantitative PCR.ResultsPrior to implantation, pericardial patches are largely composed of collagen and are acellular. Following arterial implantation, increasing numbers of CD68-positive cells as well as Ephrin-B2 and CD34 dual-positive cells are found within both bovine and porcine pericardial patches, whereas the infiltrating cells are negative for vWF and α-actin. Porcine patches have a luminal monolayer of cells at day 7, compared to bovine patches that have fewer luminal cells. Subcutaneously implanted patches do not attract Ephrin-B2/CD34-positive cells. By day 30, both bovine and porcine pericardial patches develop a neointima that contains Ephrin-B2, CD34, and VEGFR2-positive cells.ConclusionBoth CD68-positive and Ephrin-B2 and CD34 dual-positive cells infiltrate the pericardial patch early after implantation. Arteriotomy closure via pericardial patch angioplasty shows patch adaptation to the arterial environment that may involve a foreign body response as well as localization of EPC. Arterial remodeling of pericardial patches support endothelialization and may represent a paradigm of healing of scaffolds used for tissue engineering.

To investigate microcracks as a potential index of bone biomechanical quality in rats, 98 Sprague-Dawley (SD) rats, 10 months old, were used. Eight rats were killed at the beginning of the study, to serve as baseline controls. The remaining 90 rats were ovariectomized (OVX), and treated with 17 Beta-estradiol (EST) at 10 microg/kg per day, or sham-operated (sham). These 90 rats were killed at 3, 15, and 12 weeks post-surgery. Bone mineral density (BMD) of the total body, the lumbar spine L1-L4, and the tibiae was measured, using dual-energy X-ray absorptiometry (DXA). Bone histomorphometry of the right proximal tibial metaphysis was performed. Compressive testing was performed on the L5 vertebral body. Microcrack density (CrDn) and microcrack surface density (CrSDn) of L4 vertebral bodies that were fatigue-damaged in vitro were determined from bone sections. BMD at various sites, and CrDn and CrSDn were higher at weeks 15 and 21 than at week 3 post-operation. Trabecular separation (TbSp) increased, while trabecular number (TbN) decreased, and the maximum loading (ML) and elastic modulus (EM) of the vertebrae reached their peak values at week 15. At week 3 post-surgery, OVX rats displayed greater TbSp, CrDn, and CrSDn but less trabecular bone volume (BV) than both sham and EST rats. At week 15, BMD and ML were decreased in OVX rats compared with sham rats. At week 21, BMD, TbN, and TbAr were decreased in OVX compared with EST and sham rats. The OVX rats showed greater TbSp, bone formation rate, mineral apposition rate, percent labeled perimeter (%Pm), CrDn, and CrSDn, and lower ML and EM values than both EST and sham rats. Thus, microcrack parameters represent bone biomechanical quality changes associated with ovariectomy in rats, and they indicate the efficacy of estrogen replacement therapy.

The dosage of 0.15 mg/kg NYL prevented bone loss, decreased bone turnover rate and increased the maximal loading of bone without obvious side effects in RA-induced osteoporotic rats. The addition of 0.015-0.15 mg/kg of LNG (L2-L4) reduced uterine weights and serum ALP levels. Overall results showed that 0.15 mg/kg of NYL in combination with 0.015 mg/kg of LNG produced beneficial effects on bone metabolism in RA-induced osteoporotic rats.