Toshiyuki Namba

Anastomotic aneurysms after surgical treatment of Takayasu's arteritis: A 40-year experience☆☆☆★

PURPOSE To evaluate the clinical characteristics of anastomotic aneurysms that develop in surgically treated patients with Takayasus arteritis. METHODS Among 103 patients with Takayasus arteritis treated surgically over 40 years, 91 patients with 259 anastomoses (allowing for exclusion of 12 operative deaths) participated in follow-up study from 1 month to 37.3 years with a mean value +/- SEM of 17.3 +/- 1.1 years with a follow-up completion rate of 93% at 30 years. The clinical characteristics of anastomotic aneurysms were clarified, and the influences of several factors (sites of anastomoses, occlusive or aneurysmal disease, suture material, preoperative systemic inflammation, and administration of corticosteroids) on formation of anastomotic aneurysms were analyzed by means of life-table method and Cox regression analysis. RESULTS Twenty-two uninfected anastomotic aneurysms were found among 14 patients (22 of 259 anastomoses, 8.5%). The interval between the previous operation and diagnosis varied from 1.6 to 30 years with a mean value +/- SEM of 9.8 +/- 1.8 years. The cumulative incidence of anastomotic aneurysm at 20 years was 12.0%. Systemic inflammation or steroid administration had little influence on formation of anastomotic aneurysm. Instead, anastomotic aneurysm tended to occur after operations for aneurysmal lesions. CONCLUSIONS Anastomotic aneurysm can occur anytime after operations for Takayasus arteritis. The development of anastomotic aneurysm is not influenced by any factor specific to this disease except the presence of an aneurysmal lesion.

Targeting endogenous platelet-derived growth factor B-chain by adenovirus-mediated gene transfer potently inhibits in vivo smooth muscle proliferation after arterial injury

Platelet-derived growth factor (PDGF), especially its B chain, has been implicated in the pathogenesis of vascular proliferative disorders such as atherosclerosis and restenosis after angioplasty. We constructed a replication-deficient recombinant adenovirus containing the gene encoding the extracellular region of PDGF β-receptor (PDGFXR) that binds PDGF-B chain and acts as its antagonist. The administration into balloon-injured rat carotid arteries of an adenovirus containing the Escherichia coli lacZ gene as a marker gene at 5 days after injury markedly facilitated efficacy of gene transfer, as compared with its administration immediately after injury. Adenovirus-mediated gene transfer of PDGFXR into injured arteries performed at 5 days resulted in a more than 50% reduction in the neointimal area of injured arteries at 14 days. In con- trast, the administration of control adenoviruses containing lacZ gene or containing no foreign gene was without suppressive effects on neointima formation. The inhibition of neointima formation by the expression of PDGFXR was accompanied by a reduction in bromodeoxyuridine-labeled cells and nearly complete inhibition of tyrosine phosphorylation of both α- and β-receptors for PDGF, but not of epidermal growth factor receptor, in injured arteries. This is the first report to indicate the usefulness of targeting a growth factor by expressing an extracellular binding region of a receptor using an adenovirus for the treatment of vascular proliferative disorders, and provide direct evidence that PDGF-B chain plays an essential role in neointimal formation.

Utilization of the Lateral Circumflex Femoral Artery as a Midway Outflow for Aorto-popliteal Grafting : Report of a Case

We describe herein the case of a patient who presented with total occlusion of all the major arteries in the unilateral iliofemoral region, including the distal deep femoral artery, on whom an aortolateral circumflex femoral-popliteal artery sequential bypass was successfully performed. This case report serves to demonstrate that the lateral circumflex femoral artery can provide a suitable midway outflow for aortopopliteal bypass in patients with extensive thrombosis of the iliofemoral arteries.

Adenovirus-mediated transfer of tissuetype plasminogen activator gene to human endothelial cells☆

Abstract Background. Seeding of vascular grafts with genetically engineered human endothelial cells (hECs) secreting antithrombogenic or fibrinolytic agents has considerable clinical potential. Methods. An adenoviral vector was used to transfer the human tissue-type plasminogen activator (htPA) gene to hECs, and the ability of the transduced hECs to secrete htPA was examined. Cultured hECs on plates were incubated with various concentrations of recombinant adenoviruses containing the htPA or LacZ gene for various times to determine the optimal transfer conditions. Transduced hECs were seeded onto fibronectin-coated expanded polytetrafluoroethylene grafts (4 mm in diameter), some of which were exposed to pulsatile flow in vitro. Results. Effective transduction of the htPA gene into hECs (htPAhECs) was achieved with viral soup at a multiplicity of infection of 30 after incubation for 1 day, which yielded 4.8 ± 0.20 × 10 3 ng/10 6 cells/6 hr htPA antigen on plates (n = 3), 2.2 ± 2.0 × 10 3 ng/10 6 cells/6 hr on grafts (n = 6), and 6.8 ± 1.7 × 10 2 ng/10 6 cells/6 hr on perfused grafts (n = 6). The retention of htPAhECs by perfused grafts was 84.0% ±3.0%, comparable with the noninfected (82.1% ± 8.0%) and mock-infected (94.2% ±0.4%) hEC values. Conclusions. By adenoviral vector-mediated gene transfer, 10 2–3 -fold enhancement of htPA secretion was demonstrated, which did not affect cell retention by grafts.

Intraoperative evaluation of small-calibre arterial reconstructions

A new hammerhead-shaped, small probe for intraoperative duplex ultrasound was devised to evaluate small-calibre arterial reconstructions. This probe was used in two patients; one with terminal liver cirrhosis who had a left hepatic lobe that had been transplanted from her mother, and a second patient with limb-threatening ischaemia who had undergone arterial reconstructions. The technique was diagnostically useful and contributed to successful clinical outcomes.

Aortoesophageal Fistula: Report of an Unusual Case

We report herein the case of a patient with an aortoesophageal fistula (AEF) who was managed successfully by surgery. A 5-mm oval, well circumscribed aortic perforation just above the orifice of the celiac axis and a 4-mm defect in the esophagus were primarily closed, and an omental flap was placed between the aorta and the esophagus. No definite etiology could be determined. Our experience of this case suggests that primary closure for defects in both the aorta and the esophagus is the best option when the defects are small, and that the possibility of an AEF must be considered in patients with midthoracic pain or hematemesis, even if there is no history of thoracic aortic aneurysm, foreign body ingestion, trauma, or esophageal disease.

Surgery for Descending Thoracic Aortic Anastomotic Aneurysms with a Temporary External Bypass Method

The surgical treatment of descending thoracic aortic anastomotic aneurysms is technically challenging. The purpose of this study was to evaluate the use of a temporary external bypass method as an intraoperative measure in the surgical treatment of anastomotic aneurysms of the descending thoracic aorta. An analysis of five consecutive patients who had undergone surgery for a collective seven descending thoracic aortic anastomotic aneurysms in our university hospital over a period of 14 years was conducted. A temporary bypass technique was used as an intraoperative measure in all the operations, four of which were performed with a right axillary to left external iliac artery bypass, while other sites were used in the remaining three. Systemic heparinization was able to be avoided in six operations and was markedly reduced in the remaining one. Although the major postoperative complication was coagulated hemothorax after six procedures, all patients recovered well and are still alive after a mean follow-up period of 8.2±1.5 (SEM) years. The results of this analysis led us to conclude that our temporary bypass method for treating descending thoracic aortic anastomotic aneurysm prevented the risks of anticoagulant administration for circulatory support, which contributed to the success of the operation. This method can be used as adjunct treatment for anastomotic aneurysms in the descending thoracic aorta.