Endothelial cells differentially sense laminar and disturbed flows by altering the lipid order of their plasma and mitochondrial membranes.

Endothelial cells (ECs) experience two different blood flow patterns: laminar and disturbed flow. Their responses to laminar flow contribute to vascular homeostasis, whereas their responses to disturbed flow result in EC dysfunction and vascular diseases. However, it remains unclear how ECs differentially sense laminar and disturbed flow and trigger signaling that elicits different responses. Here, we showed that ECs differentially sense laminar and disturbed flows by altering the lipid order of their plasma and mitochondrial membranes in opposite directions. This results in distinct changes in mitochondrial function, namely, increased adenosine triphosphate (ATP) production for laminar flow and increased hydrogen peroxide (H2O2) release for disturbed flow, leading to ATP- and H2O2-mediated signaling, respectively. When cultured human aortic ECs were subjected to laminar or disturbed flow in flow-loading devices, the lipid order of their plasma membranes immediately decreased in response to laminar flow and increased in response to disturbed flow. Laminar flow also decreased the lipid order of mitochondrial membranes and increased mitochondrial ATP production. In contrast, disturbed flow increased the lipid order of mitochondrial membranes and increased the release of H2O2 from the mitochondria. The addition of cholesterol to the cells increased the lipid order of both membranes and abrogated laminar flow-induced ATP production, while treatment of the cells with a cholesterol-depleting reagent, methyl-ß cyclodextrin, decreased the lipid order of both membranes and abolished disturbed flow-induced H2O2 release, indicating that changes in the membrane lipid order and/or cholesterol content are closely linked to flow-induced changes in mitochondrial functions.NEW & NOTEWORTHY How vascular endothelial cells (ECs) differentially sense laminar and disturbed flows and trigger intracellular signaling remains unclear. Here, we show that EC plasma membranes act as mechanosensors to discriminate between laminar and disturbed flows by undergoing opposite changes in their lipid order. Similar lipid order changes occur simultaneously in the mitochondrial membranes, which are linked to changes in mitochondrial function, that is, increased ATP production for laminar flow and increased H2O2 release for disturbed flow.

Area reduction of perforation with a small-size sheath technique for iatrogenic femoral artery pseudoaneurysm with a large perforation.

Open surgery for femoral artery pseudoaneurysms is invasive, and complications can be detrimental. Several cases of treatment of iatrogenic femoral artery pseudoaneurysms using percutaneous suture-mediated closure devices have been reported. However, it is difficult to properly deploy the foot of the device to the arterial wall when the perforation area is large. We developed a technique using a double guidewire to partially occupy the perforation with a small-size sheath, which reduces the area of the perforation. This AREPAS (area reduction of perforation with a small-sized sheath) technique might allow for minimally invasive closure of perforations even in patients with large perforation areas.

Popliteal artery aneurysm in a 14-year-old boy with tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is rarely associated with aneurysms. We have described a patient with a popliteal artery aneurysm that was associated with TSC and occlusion of the right posterior tibial artery. The patient underwent aneurysm resection and vein graft replacement, with an uneventful postoperative course and no recurrence at 11 months of follow-up. Patients with TSC could have aneurysms in areas that will not be recognized on abdominal imaging. Physical examination of the lower extremities should be performed owing to the possibility of a popliteal artery aneurysm, and imaging studies should be performed if an aneurysm is suspected.

Volumetric computed tomography analysis for gastroduodenal and pancreaticoduodenal artery aneurysm formation: A retrospective single-center study.

ABSTRACT: Gastroduodenal artery aneurysms (GDAA) and pancreaticoduodenal artery aneurysms (PDAA) are rare, have high rupture risks, and are located in the arcade between the celiac artery and the superior mesenteric artery. Pancreaticoduodenal artery aneurysms are associated with celiac artery stenosis, and it is hypothesized that these celiac lesions might contribute to the formation of aneurysms. In contrast, a few studies have reported an association between a gastroduodenal artery aneurysm and celiac lesions. This study aimed to investigate the potential differences between patients with gastroduodenal and pancreaticoduodenal artery aneurysms and better understand their pathogenesis.We selected patients with GDAA and PDAA who were admitted to our department between January 2010 and December 2020. Aortic wall volume, aortic wall calcification, and pancreaticoduodenal arcade volume of computed tomography images were calculated semi-manually using Horos 3.3.5.Eight GDAAs and 11 PDAAs were analyzed. Celiac lesions were found in all PDAA patients, with none in GDAA cases. Volumetry demonstrated that aortic wall volume and calcification were more prominent in the GDAA group than in the PDAA group (P = .026 and P = .049, respectively). The pancreaticoduodenal arcade volume was larger in the PDAA group (P = .002).In our study, celiac artery lesions were strongly correlated with PDAA. The volume of the pancreaticoduodenal arcade was larger in the PDAA group, and aortic wall volume and calcification were larger in the GDAA group.

Laparoscopic treatment of a vesicointestinal fistula due to a Meckel's diverticulum: a case report and review of the literature.

While there have been numerous reports about colovesical fistulas and ruptured intestinal diverticula, there have been far fewer reports about vesicointestinal fistulas caused by Meckel's diverticula. Most Meckel's diverticula are asymptomatic. Furthermore, they seldom cause vesicointestinal fistulas, and the associated complications are non-specific. Thus, their preoperative diagnosis is difficult. We experienced a case in which a vesicointestinal fistula was caused by a Meckel's diverticulum and was treated with laparoscopic surgery. A 46-year-old male was referred to our hospital after exhibiting hematuria. Cystoscopy revealed a fistula between the small intestine and bladder. Contrast-enhanced computed tomography and magnetic resonance imaging showed a diverticulum in the ileum and a fistula between the ileum and bladder, which passed through the diverticulum. A Meckel's diverticulum was suspected. We conducted a laparoscopic operation. We dissected the Meckel's diverticulum with an automatic suturing device and removed it together with part of the ileum. The patient's postoperative course was good. We experienced a case in which a vesicointestinal fistula was caused by a Meckel's diverticulum and was successfully treated with laparoscopic surgery. In selected cases of Meckel's diverticulum, the dissection of the diverticulum with an automatic suturing device is appropriate.

Primary hepatic schwannoma: A case report.

INTRODUCTION: A hepatic schwannoma is extremely rare and difficult to diagnose preoperatively. PRESENTATION OF CASE: We report the case of a 47-year-old male patient who was referred to our hospital for the close investigation of a hepatic tumor which had not been detected two years earlier. An enhanced computed tomography revealed a well-circumscribed and encapsulated tumor with a size of 50mm which was adjacent to the inferior vena cava (IVC) and the right hepatic vein. The tumor was heterogeneously enhanced until the equilibrium phase. A magnetic resonance image showed a hypointense area on a T1-weighted image and a hyperintense area on a T2-weighted image. These findings differed from those of common malignant hepatic tumors, such as hepatocellular carcinoma and colorectal liver metastases. The tumor was most likely a mucus-producing tumor or a liquefactive degenerated adenocarcinoma. Although we could not confirm an exact diagnosis of the tumor, we performed a surgical resection in view of the possibility of malignancy. The patient underwent a limited liver resection with resection of the IVC. Histologically, the tumor was diagnosed as a benign schwannoma comprised of Antoni A and B areas. The nuclear palisading formation of the tumor showed Verocay bodies. DISCUSSION: 15 cases of hepatic schwannoma are reviewed to clarify the typical radiological features. The radiological findings of the present case were consistent with those of the hepatic schwannoma when considering retrospectively. CONCLUSION: A precise preoperative diagnosis of hepatic schwannoma is difficult, and liver resection is recommended when a hepatic schwannoma is suspected.