Clinical application of a curved nitinol stent-graft for thoracic aortic aneurysms.

PURPOSE: To evaluate the clinical efficacy of a curved nitinol stent-graft for repair of thoracic aortic aneurysms. METHODS: The Matsui-Kitamura stent-graft (MKSG), composed of a self-expanding nitinol stent and polyester fabric, was shaped to match the aortic curvature of 11 patients (6 men; mean age 72.6 years, range 33-90) with 6 true and 5 false aneurysms of the distal arch or proximal descending aorta. The delivery system was an 18 or 20-F J-shaped sheath combined with a preloader-type introducer. The original mean proximal neck length was 16.4 mm, but 4 patients received an axilloaxillary bypass to lengthen the neck. Although the mean corrected proximal neck length was 21.9 mm (overall), 5 cases still had proximal necks <15 mm long. RESULTS: All curved MKSGs were successfully deployed in the correct position and fitted to the curvature of the aortic arch, achieving complete aneurysm exclusion in 8 (73%) cases. The other 3 repairs displayed early endoleaks; 1 received an additional MKSG, but the other 2 are being observed. Thirty-day mortality was 0%. One patient developed transient renal failure requiring hemodialysis; no neurological complications were observed. CONCLUSIONS: Endovascular repair of thoracic aortic aneurysms using curved MKSGs appears to be feasible and clinically effective. A tighter fit of the device to the curvature of the aortic arch may exclude distal arch aneurysms despite a short proximal neck.

Stent-graft repair of a mycotic left subclavian artery pseudoaneurysm.

PURPOSE: To report successful stent-graft treatment of a mycotic pseudoaneurysm of the left subclavian artery in an immunosuppressed patient. CASE REPORT: A 17-year-old immunosuppressed woman undergoing treatment for recurrent leukemia developed persistent fever and 2 episodes of hemoptysis. A contrast-enhanced computed tomographic (CT) scan demonstrated a saccular aneurysm of the left subclavian artery, which was considered to be a mycotic aneurysm caused by erosive fungal infection from the lung. The pseudoaneurysm was treated with a homemade stent-graft consisting of a nitinol stent and a polyester fabric. A type II endoleak present at the end of the procedure appeared to have sealed spontaneously on the CT scan at 3 days. No neurological deficit or ischemic symptoms of the left arm were noted during the follow-up, which lasted until the patient died 11 months later after rejecting a second bone marrow transplant. CONCLUSIONS: Endovascular repair may be an alternative to open surgery for the management of mycotic aneurysms of the subclavian artery.

Doxycycline treatment in a model of early abdominal aortic aneurysm.

PURPOSE: To evaluate the effects doxycycline (Dox) in animal models of early abdominal aortic aneurysm. METHODS: Of 43 male Wistar rats, 33 underwent intraluminal perfusion of the abdominal aorta with thioglycolate plus plasmin to reproduce early aortic aneurysm. These rats then were treated for 7 days with subcutaneous injections of Dox or saline. The 10 remaining rats underwent intra-aortic perfusion with saline and were injected subcutaneously with saline. On day 7, the rats were killed after abdominal aortic diameters were measured. Some aortic specimens were examined microscopically after elastica van Gieson (EVG) and hematoxylin-eosin (H&E) staining. In other specimens, the matrix metalloproteinase (MMP) activity in tissue extracts was evaluated by gelatin zymography. RESULTS: Among the thioglycolate plus plasmin-perfused rats, the degree of aortic dilation was less in Dox-treated than in saline-treated rats. EVG staining indicated that Dox maintained a nearly normal pattern of elastic lamellae and normal medial elastin thickness. The aortic inflammatory response was not suppressed by Dox in H&E staining. In gelatin zymography, Dox reduced the MMP-9 activity, but did not significantly change either MMP-2 or the percentage of activated MMP-2. CONCLUSIONS: Dox inhibited experimental aneurysmal dilation by preserving medial elastin. This effect involved the suppression of MMP-9 but not of the MMP-2 activity.

Matrix metalloproteinase-9 and urokinase-type plasminogen activator in varicose veins.

The purpose of this study was to evaluate the roles of matrix metalloproteinases (MMPs) and urokinase-type plasminogen activator (uPA) with regard to varicose veins (VVs). Immunohistochemical staining and ELISA were performed on samples from 73 patients with the following leg VVs: 82 greater saphenous veins (GSV) from the groin (GSV groin), 28 GSV from the ankle (GSV ankle), 85 VVs, and 13 normal GSV groin (control [CR]) obtained during coronary artery bypass surgery. Immunohistochemically, MMP-9 was localized in the smooth muscle cells (SMCs) in the tunica media. The ratio of immunopositive cells of MMP-9 in the GSV groin, VVs, and GSV ankle were significantly higher than that of CR. The ratios of immunopositive cells of uPA and uPA receptor (uPAR) were not significantly different among the groups. uPA and uPAR were found to be positive in a different set of SMCs of the MMP-9-positive cells. An ELISA showed that the amount of uPA in the culture of the GSV groin was significantly higher than that in CR. For the remodeling process, MMP-9 may be produced in the VV wall and degrade elastic lamellae and other extracellular components of the venous wall. uPA may be produced by groin tissue of the GSV and flow downward because of valvular incompetence, activating MMP-9 at VV tissues.

Use of three-dimensional computed tomographic angiography of pulmonary vessels for lung resections.

BACKGROUND: Identification and appropriate treatment of the pulmonary artery (PA) is a key to successful anatomic resection of the lung. Preoperative identification of branching pattern of the PA seems to make pulmonary resection easier and safer especially when there is severe adhesion or incomplete fissure between the lobes. With the development of the multidetector row spiral computed tomography (MDCT), three-dimensional (3D) CT angiography can be obtained easily and can provide very useful information about various organs. We studied the usefulness of 3D-CT pulmonary angiography (3D-CTPA) in evaluating the PA branching pattern before anatomic pulmonary resection. METHODS: Fourteen patients with primary lung cancer undergoing anatomic pulmonary resections were the subjects of this study. The 3D-CTPA images were obtained using MDCT. The obtained images of the PA branching pattern were compared with intraoperative findings in each case at the time of thoracotomy. RESULTS: MDCT scanning required approximately 15 seconds per patient during a single respiratory pause and the 3D images were processed within 10 minutes after scannning. According to intraoperative findings, 98% (84 of 86) of PA branches were revealed to be successfully identified on preoperative 3D-CTPA. Two missed branches on 3D-CTPA were small vessels, which were less than 1.5 mm in actual diameter. Pulmonary vessels were clearly identified even when contrast medium was not administered intravenously. CONCLUSIONS: Obtaining 3D-CTPA using MDCT is noninvasive yet it provides precise preoperative information regarding pulmonary vessels. This technique is a far less invasive and an easier investigation than conventional pulmonary angiography. The 3D-CTPA navigation may have the potential to increase the safety of surgical procedure and to reduce surgical morbidity in anatomic lung resection.

Results of wedge resection for focal bronchioloalveolar carcinoma showing pure ground-glass attenuation on computed tomography.

BACKGROUND: Focal bronchioloalveolar carcinoma (BAC) showing pure ground-glass attenuation (GGA) on thin-section computed tomography (CT), which is considered to be an early-stage adenocarcinoma, has been diagnosed with increasing frequency due to the development and spread of the helical CT scanner. We discussed the appropriateness of limited resection for this type of lesion. METHODS: Between July 1996 and June 2001, 17 patients with localized BAC showing "pure GGA" (GGA without central scar formation) on thin-section CT underwent limited pulmonary resections. The mean patient age was 57.2 +/- 10.5 years old. Among these patients, four tumors were detected in a CT mass-screening program and the others were incidentally detected on CT during follow-up for other diseases. Fourteen patients underwent thoracoscopic wedge resection, and 3 underwent segmentectomy because of tumor location. RESULTS: The mean tumor diameter was 7.9 +/- 1.9 mm. On pathological examination, all tumors showed a pure bronchioloalveolar growth pattern and no evidence of stromal, vascular, or pleural invasion. The median follow-up time was 32.0 months, with no cancer death or relapse to date. CONCLUSIONS: Focal BAC showing pure GGA on thin-section CT is peripheral in situ adenocarcinoma. Wedge resection by VATS is considered to be an appropriate treatment for this type of lung cancer. It can be a minimally invasive complete resection for this type of early cancer, and offer the best chance for long-term survival and good quality of life.