Naoki Toya

Reconstituted High-Density Lipoprotein Stimulates Differentiation of Endothelial Progenitor Cells and Enhances Ischemia-Induced Angiogenesis

Background—Plasma high-density lipoprotein (HDL) levels have an inverse correlation with incidence of ischemic heart disease as well as other atherosclerosis-related ischemic conditions. However, the molecular mechanism by which HDL prevents ischemic disease is not fully understood. Here, we investigated the effect of HDL on differentiation of endothelial progenitor cells and angiogenesis in murine ischemic hindlimb model. Methods and Results—Intravenous injection of reconstituted HDL (rHDL) significantly augmented blood flow recovery and increased capillary density in the ischemic leg. rHDL increased the number of bone marrow–derived cells incorporated into the newly formed capillaries in ischemic muscle. rHDL induced phosphorylation of Akt in human peripheral mononuclear cells. rHDL (50 to 100 &mgr;g apolipoprotein A-I/mL) promoted differentiation of peripheral mononuclear cells to endothelial progenitor cells in a dose-dependent manner. The effect of rHDL on endothelial progenitor cells differentiation was abrogated by coadministration of LY294002, an inhibitor of phosphatidylinositol 3-kinase. rHDL failed to promote angiogenesis in endothelial NO–deficient mice. Conclusions—rHDL directly stimulates endothelial progenitor cell differentiation via phosphatidylinositol 3-kinase/Akt pathway and enhances ischemia-induced angiogenesis. rHDL may be useful in the treatment of patients with ischemic cardiovascular diseases.

Endotension following endovascular aneurysm repair.

Abstract Endovascular aneurysm repair (EVAR) is a new and minimally invasive alternative to open repair for patients with abdominal aortic aneurysm (AAA). Soon after its introduction in 1990, it was recognized that EVAR had potential and distinct advantages in the elective and emergency settings. However, long-term follow-up has shown enlargement of the AAA in a substantial percentage of patients who underwent EVAR with the original-permeability Excluder. Of interest is that sac expansion frequently occurs in the absence of endoleak, often referred to as endotension. The pathophysiology of endoleak is beginning to be elucidated and its management is ready to be established, while controversy still exists about the etiology and clinical consequences of endotension. Fortunately, the incidence of endotension is decreasing and it appears that AAA expansion after EVAR with the original Excluder can be arrested by endovascular relining with a low-permeability Excluder endoprosthesis. The aim of this brief review is to provide historical perspective and a good understanding of the etiology, diagnosis, and management of endotension.

Push-up exercise induced thrombosis of the subclavian vein in a young woman: report of a case.

Deep venous thrombosis (DVT) is common, but only 2%–4% of DVTs involve the upper extremities (Roos in Am J Surg 154:568–73, 1987). Upper extremity DVT has a primary or secondary cause, and primary thrombosis is much rarer than secondary thrombosis. Primary upper extremity DVT comprises effort venous thrombosis and idiopathic thrombosis. Effort subclavian venous thrombosis, also called Paget–Schroetter syndrome, is an uncommon entity, which usually develops after strenuous effort of the upper extremities. Effort thrombosis of the upper extremity has been described in athletes involved in a wide variety of sports, including ball games, combatant sport and heavy athletics, games with rackets or clubs, and aquatic sports (Zell et al. in Angiology 52:337–42, 2001). Push-up exercise is a strengthening exercise for building up strength and endurance in the muscles of the upper arm and shoulders. It is also considered to be a core exercise in shoulder rehabilitation programs to activate the serratus anterior muscle in people with shoulder dysfunction (Ludewig et al. in J Sports Med 32:484–93, 2004). We report what to our knowledge is the first case of effort DVT of an upper extremity caused by push-up exercise.

Secondary interventions following endovascular repair of abdominal aortic aneurysm.

Endovascular aneurysm repair (EVAR) of the abdominal aortic aneurysms is an attractive alternative to open surgery with significantly improved perioperative outcomes. However, EVAR is accompanied by a higher rate of graft-related complications and secondary interventions. Therefore, life-long surveillance and management of secondary treatment is essential for successful EVAR. Endoleaks are one of the most crucial problems after EVAR. Persistent endoleaks are classified into five types and its management depends on the type and severity. Most persistent endoleaks are detectable by contrast-enhanced computed tomography; however, in some cases, two different endoleak types may coexist. Determining whether an endoleak requires any treatment or not is an important consideration. Most if not all type I and III endoleaks require prompt and definitive secondary treatment. While type II endoleaks are most commonly encountered during follow-up, not all type II endoleaks require invasive treatment. When secondary treatment is required, it can be treated endovascularly in most cases, even if there is no endoleak. Following EVAR, due to the decompression of the sac, the integrity of the aneurysmal wall strength reduces. Therefore, sudden sac expansion/rupture may occur when an endoleak is encountered following a period of complete aneurysmal exclusion. If diagnosed promptly most late complications can be treated in a less invasive manner, but it could lead to catastrophic event if it is missed. Therefore, adequate and life-long radiographic follow-up is as important as the appropriate patient and device selection as well as the EVAR procedure itself.

Periodic duplex ultrasonography screening together with elective percutaneous transluminal angioplasty in the management of graft arteriovenous fistulas for hemodialysis.

PurposeTo evaluate the effectiveness of regular duplex ultrasonography in the management of graft arteriovenous fistulas for hemodialysis.MethodsBetween March 1997 and December 2004, we prospectively studied consecutive patients who underwent polytetrafluoroethylene graft arteriovenous (AV) fistulae in the upper extremity with a subsequent regular duplex ultrasound examination for the identification of stenosis. The main ultrasound-guided indication for percutaneous transluminal angioplasty (PTA) was the identification of 50% or more venous stenosis. The assisted primary and secondary patency rates of vascular access were calculated in these 36 patients and were then compared with those in 19 patients who had undergone graft AV fistula before the start of regular ultrasonographic screening.ResultsThe mean follow-up lasted 25 months. PTA procedures were performed in 24 patients, of which 13 patients received multiple PTAs. The half survival time (secondary patency) of the graft was 49 ± 3.8 months in patients who had undergone ultrasound screening followed by elective PTA, which was significantly (P < 0.01) longer than the 22 ± 7.1 months observed in patients who had not undergone regular duplex ultrasound screening.ConclusionThe prospective monitoring of AV fistula with ultrasound is a simple and reliable technique for detecting graft AV outflow stenosis. Elective PTA is therefore considered to be an effective therapy for the maintenance of hemodialysis access.

Aneurysm of an Anomalous Systemic Arterial Supply to the Basal Segments of the Left Lung

An anomalous systemic artery originating from the descending thoracic aorta and supplying the normal basal segments of the lower lobe of the left lung without sequestration is a rare congenital anomaly, and an aneurysm of this aberrant artery is even rarer. An abnormal shadow was detected on an annual chest roentgenogram in a 38-year-old man, who complained of persistent sputum production for 2 months. No history of chest trauma, pneumonia, or hemoptysis was reported. Chest computed tomography revealed a

Aortic arch aneurysm repair using the Najuta stent graft in a challenging compromised seal zone

We report the case of a 67-year-old patient with an anatomically complex aneurysm of the aortic arch treated by fenestrated thoracic endovascular aortic repair with subclavian-carotid extrathoracic bypass. We used the Najuta thoracic stent graft, which was approved for use in January 2013 in Japan and successfully excluded the aneurysm. Our case shows that the Najuta stent graft procedure is a feasible treatment if open repair is unsuitable for cases of aortic arch aneurysm with a challenging compromised seal zone.

Fenestrated endovascular repair of aortic arch aneurysm in patients with bovine arch using the Najuta stent graft

We describe the case of a 74-year-old man with a thoracic aortic aneurysm with a bovine arch who underwent fenestrated endovascular repair of aortic arch aneurysm using the Najuta stent graft (Kawasumi Laboratories, Inc, Tokyo, Japan). He has had a previous endovascular aneurysm repair and femoropopliteal bypass for abdominal aortic aneurysm combined with peripheral arterial disease. The Najuta stent graft was inserted and deployed at zone 0 with delicate positional adjustment of the fenestration of the stent graft to the brachiocephalic trunk. There was no endoleak or complication. His postoperative course was uneventful. At 7-month follow-up, complete exclusion of the aneurysm was noted. The Najuta stent graft repair of aortic arch aneurysms is a safe and effective treatment option for patients with a bovine arch.

Better Clinical Practice Could Overcome Patient-Related Risk Factors of Vascular Surgical Site Infections

Purpose: To clarify the current status of surgical site infection (SSI) during endovascular aortic repair and to define risk factors for SSI among the patients who underwent thoracic or abdominal stent-graft repair through a groin incision. Methods: Between 2006 and 2013, data were collected from 1604 patients (mean age 75.2±9.5 years; 1282 men) with 2799 groin incisions for transfemoral access during aortic stent-graft procedures. SSIs were classified as superficial or deep (both occurring within 30 days) or organ/space infections (occurring within 1 year after surgery) according to the Centers for Disease Control and Prevention guidelines. Strategies in place for minimizing SSIs were (1) employing oblique groin incisions, (2) covering the incision with saline-soaked gauze, (3) irrigating the incision thoroughly with saline per layer, and (4) using absorbable sutures. Results: Overall incidence of SSI was 0.4% (6 patients). The majority of SSIs were late-onset prosthetic graft infections (5, 0.3%). Five of the 6 were successfully treated with conservative therapy; one patient died of sepsis. Univariate analysis showed additional therapy (eg, coil embolization) with a stent-graft procedure was a risk factor for SSI. Conclusion: Appropriate antibiotic administration, oblique groin incision, meticulous operative technique, protection against airborne infection during the operation, and closed dressings may avert vascular wound SSIs.

Surgical Treatment of a Giant Right Hepatic Artery Aneurysm with an Aberrant Left Hepatic Artery: Report of a Case

Hepatic artery aneurysms are rare. We describe a case of a successful surgical treatment of a giant hepatic aneurysm without revascularization. A 63-year-old female was admitted to our department complaining of abdominal pain. Computed tomography showed a thrombosed hepatic artery aneurysm measuring 5.5 cm in diameter. A celiac angiography revealed an aberrant left hepatic artery and a right hepatic aneurysm. Liver blood flow and the right hepatic aneurysm were visualized via collateral pathway from the aberrant left hepatic artery. We performed an aneurysmorrhaphy without revascularization. Postoperative course was uneventful and the patient is doing well 3 months after surgery.