Keiwa Kin

Tissue- and Plasma-Specific MicroRNA Signatures for Atherosclerotic Abdominal Aortic Aneurysm

Background Atherosclerotic abdominal aortic aneurysm (AAA) is a progressive, gradual aortic rupture that results in death in the absence of surgical intervention. Key factors that regulate initiation and progression of AAA are unknown, making targeted interventions difficult. MicroRNAs play a fundamental role in atherosclerosis, and atherosclerotic coronary artery disease is characterized by tissue- and plasma-specific microRNA signatures. However, little is known about microRNAs involved in AAA pathology. This study examined tissue and plasma microRNAs specifically associated with AAA. Methods and Results AAA and normal wall tissues were sampled from patients undergoing AAA repair (n=13; mean age, 68±6 years) and aortic valve replacement surgery (n=7; mean age, 66±4 years), respectively. MicroRNA expression was assessed by high-throughput microRNA arrays and validated by real-time polymerase chain reaction for individual microRNAs that showed significant expression differences in the initial screening. MicroRNAs related to fibrosis (miR-29b), inflammation (miR-124a, miR-146a, miR-155, and miR-223), and endothelium (miR-126, let-7 family members, and miR-21) were significantly upregulated in AAA tissue. Significant negative correlations were seen in expression levels of monocyte chemoattractant protein-1 and miR-124a, -146a, and -223; tumor necrosis factor-α and miR-126 and -223; and transforming growth factor-β and miR-146a. Expression of microRNAs, such as miR-29b, miR-124a, miR-155, and miR-223, that were upregulated in AAA tissue was significantly reduced in plasma of patients with AAA (n=23; mean age, 72±9 years) compared to healthy controls (n=12; mean age, 51±11 years) and patients with coronary artery disease (n=17; mean age, 71±9 years). Conclusions The expression of some microRNAs was specifically upregulated in AAA tissue, warranting further studies on the microRNA function in AAA pathogenesis and on the possibility of using a microRNA biomarker for AAA diagnosis.

Laparoscopic resection of intra-abdominal esophageal duplication cyst.

&NA; Esophageal duplication cysts are frequently encountered in the mediastinum and rarely in the abdomen. A case of laparoscopic resection of an intra‐abdominal esophageal duplication cyst is reported. An incidental 4.5 × 4.0 × 3.5‐cm, wellcircumscribed, homogenous mass anterior to the intra‐abdominal esophagus was detected on staging CT examinations for breast cancer in a 51‐year‐old woman. Laparoscopic resection of the lesion was performed after completion of breast‐conserving surgery and whole breast irradiation. The defect of the muscular layer of the esophagus caused by the complete removal of the lesion required repair with muscular sutures. It was helpful to inspect the integrity of the esophageal wall repair by examining the exterior wall of the esophagus laparoscopically while insufflating air into the esophageal lumen through a fiberoptic esophagoscope. A laparoscopic approach utilizing intraoperative esophagoscopy is easy and safe for removal of intra‐abdominal esophageal duplication cysts.

Tissue-engineered stent-graft integrates with aortic wall by recruiting host tissue into graft scaffold

OBJECTIVE To prevent postoperative migration and endoleaks after endovascular aneurysm repair, we developed a tissue-engineered vascular graft that integrates with the aortic wall by recruiting the host tissue into the graft scaffold. In the present study, we assessed the mechanical properties of the new graft and evaluated the integration between the graft and aortic wall histologically and mechanically in canine models. METHODS The tissue-engineered vascular graft was woven to be partially degradable with a double-layered fiber (core; polyethylene terephthalate [PET], and sheath; polyglycolic acid [PGA]). The mechanical properties of the graft were assessed compared with a thin-walled woven polyester graft (control; 12 mm in diameter, 30 mm long). The stent-grafts, composed of a stainless Z stent (20 mm in diameter, 25 mm long) and a PET/PGA or control graft (n=5 in each group), were implanted in the descending thoracic aorta of mongrel dogs for 2 months. We assessed the histologic findings of the explants and the degree of adhesion between the graft and aortic wall. RESULTS The PET/PGA graft achieved nearly the same mechanical properties as those of the control graft in tensile strength and flexibility, with slightly greater water permeability. At 2 months after implantation, in the PET/PGA group, the PGA component had degraded and been replaced by host tissue that contained a mixture of α-smooth muscle actin-positive cells and other host cells. The graft was a unified structure with the aorta. The adhesion strength between the graft and aortic wall was significantly enhanced in the PET/PGA group. CONCLUSIONS The PET/PGA stent-graft demonstrated histologic and mechanical integration with the native aorta. This next-generation stent-graft might reduce the risk of migration and endoleaks, leading to preferable long-term results of endovascular aneurysm repair.

Endovascular aortic repair for spontaneous rupture of a non-aneurysmal infrarenal aorta

We report the case of a patient who underwent an endovascular aortic repair for spontaneous rupture of a non-aneurysmal infrarenal aorta. A 67-year-old male with a diagnosis of infrarenal aortic rupture was referred to our hospital. Preoperative computed tomography showed focal ulcers adjacent to the site of rupture, with no evidence of aneurysm formation, suggesting that this aortic rupture was likely to be associated with perforation of penetrating atheromatous ulceration. Open surgical repair might have carried a high-risk because of the patients history of laparotomy and respiratory impairment, so endovascular aortic repair was planned. We deployed a Powerlink proximal infrarenal cuff 25-25-75L at the rupture site through the femoral artery, with the additional placement of two extra large Palmaz stents at the proximal and distal sites of the Powerlink stent-graft. Completion angiography showed total exclusion with no endoleaks. The patient was successfully extubated on the third postoperative day and recovered well until he contracted aspiration pneumonia two weeks after surgery. Unfortunately, he eventually died of a non-aortic cause three months after the operation. Endovascular aortic repair may be an alternative to conventional surgical repair for high-risk patients with spontaneous infrarenal aortic rupture.

Type 1a endoleak following Zone 1 and Zone 2 thoracic endovascular aortic repair: effect of bird-beak configuration†

OBJECTIVES Type 1a endoleak is one of the most severe complications after thoracic endovascular aortic repair (TEVAR), because it carries the risk of aortic rupture. The association between bird‐beak configuration and Type 1a endoleak remains unclear. The purpose of this study was to analyse the predictors of Type 1a endoleak following Zone 1 and Zone 2 TEVAR, with a particular focus on the effect of bird‐beak configuration. METHODS From April 2008 to July 2015, 105 patients (mean age 68.6 years) who underwent Zone 1 and 2 landing TEVAR were enrolled, with a mean follow‐up period of 4.3 years. The patients were categorized into 2 groups, according to the presence (Group B, n = 32) or the absence (Group N, n = 73) of bird‐beak configuration on the first postoperative multidetector computed tomography. RESULTS The Kaplan‐Meier event‐free rate curve showed that Type 1a endoleak and bird‐beak progression occurred less frequently in Group N than in Group B. Five‐year freedom from Type 1a endoleak rates were 79.7% and 100% for Groups B and N, respectively (P = 0.007). Multivariable logistic regression analysis showed that dissecting aortic aneurysm (odds ratio 3.72, 95% confidence interval 1.30‐11.0; P = 0.014) and shorter radius of inner curvature (odds ratio 1.09, 95% confidence interval 0.85‐0.99; P = 0.025) were significant risk factors for bird‐beak configuration. Multivariable Cox proportional hazard regression showed that Z‐type stent graft (hazard ratio 2.69, 95% confidence interval 1.11‐6.51; P = 0.030) was a significant risk factor for bird‐beak progression. CONCLUSIONS Appropriate stent grafts need to be chosen carefully to prevent Type 1a endoleak and bird‐beak configuration after landing Zone 1 and 2 TEVAR. Patients with bird‐beak configuration on early postoperative multidetector computed tomography require closer follow‐up to screen for Type 1a endoleak.

Hybrid Repair of an Abdominal Aortic Aneurysm: Debranching with Endovascular Aneurysm Repair in a Patient with Horseshoe Kidney

Abdominal aortic aneurysm (AAA) with associated horseshoe kidney (HSK) poses a technical challenge when performing conventional open surgical repair because of possible complications including renal infarction, neuralgia, and collecting system disruption. Endovascular aortic repair (EVAR) is considered the first-line treatment for this pathology, allowing for aneurysm repair without isthmus bisection. However, whether to sacrifice commonly presenting aberrant renal arteries during EVAR is a point of controversy. We report a case in which hybrid repair was performed for AAA to preserve aberrant renal vasculature in a patient with HSK.

Scallop Technique of Urgent Endovascular Repair for Symptomatic Throacoabdominal Aortic Aneurysm With a Ready-Made Device

A 72-year-old woman had a large thoracoabdominal aortic aneurysm (TAAA) with abdominal pain. This aneurysm involved the celiac artery and the superior mesenteric artery (SMA). The risk of open surgery was very high due to severe comorbidity, and there was no appropriate distal attachment for thoracic endovascular repair (TEVAR) with ready-made devices. Therefore, TEVAR with the scallop technique was performed in this urgent setting. A scallop was created in a Talent thoracic stent graft. The aneurysm was successfully excluded, and perfusion in the SMA was preserved using this scalloped endograft. The scallop technique with a ready-made device may be one of the treatment options for urgent TAAA.