Risk Assessment for a Learning Curve in Endovascular Abdominal Aortic Aneurysm Repair with the Zenith Stent-Graft: The First Year in Japan / 日本心臓血管外科学会雑誌

In Japan, doctors inexperienced stent-graft new devices are required to secure agreement on criteria and choice of the device size in endovascular aneurysm repair (EVAR) from experienced doctors. It was hoped that strict patient selection might reduce the learning curve for initial successes in given procedures. In a leading center in Japan, a number of cases which were scheduled for operation at other institutes were evaluated anatomically. We surveyed the initial success of Zenith AAA system implantation in the remaining cases by inexperienced doctors and evaluated the results. This study aimed to verify the validity of strict patient selection in improving the success rate of inexperienced doctors. We enrolled 112 consecutive patients from 19 institutes, who were scheduled for repair between January and October in 2007. All patients were evaluated on the basis of a less-than-3mm reconstructed CT image. Mean patient age was 76±5.7 years. All cases satisfied the Zenith's anatomic prerequisites. Fifteen cases were excluded for various reasons, the major reason being insufficiency of the proximal landing zone (LZ) length, angle and contour. The second reason was difficulty to approach via the iliac artery. Ninety seven cases were included, of which 17 cases were low-risk candidates for EVAR. Medium-risk seventy two cases requiring some advice to avoid problems with device size, technique of implantation and choice of main-body side. Eight cases were high-risk, requiring the presence of an experienced surgeon. Excluded cases had significantly shorter proximal LZ, larger aortic diameters 15mm below the renal artery and tortuous access routes on preliminary measurement by inexperienced doctor. Perioperative mortality was 0%, while the major complications were injury to the iliac artery in one high-risk case and thromboembolism of the superficial femoral artery in another. Perioperative proximal type I endoleak occurred in 5 cases. In 3 of these cases, the endoleak was eliminated by implantation of a Palmatz stent. In the other 2 cases, it disappeared within a month without additional procedures. These cases had a significantly greater angle between the proximal LZ and the suprarenal aorta and significant amount of mural thromboses in the proximal LZ. Perioperative type III endoleak occurred in 3 cases. In all cases the endoleak was eliminated by additional procedure. Perioperative type II endoleak occurred 8 cases. In 3 of these cases, the endoleak disappeared within a month. In the 5 other cases, the endoleak did not disappear. Mid-term results showed iliac leg thromboembolism in one case and new type II endoleaks in 3 cases. Type II endoleak occurred in cases which had significantly greater angles between the proximal LZ and the aneurysm. The results which were evaluated in our center had excellent perioperative and mid-term outcomes. We think this evaluation system is effective for risk assessment and reduces the learning curve in EVAR. In anatomically marginal cases, it is possible for proximal type I endoleak and injury of the iliac artery to occur. It is impossible to exclude these marginal cases if treatment need for EVAR is a priority. In these cases, lessexperienced operators should be trained in troubleshooting techniques in advance.

Successful Two-Staged Surgical Treatment for a Thoracoabdominal Aortic Aneurysm Combined with an Aberrant Right Subclavian Artery, Kommerell's Diverticulum, and Angina Pectoris / 日本心臓血管外科学会雑誌

A 72-year-old man with a thoracoabdominal aortic aneurysm combined with an aberrant right subclavian artery, Kommerell's diverticulum, and angina pectoris during follow-up for peripheral arterial disease was successfully treated surgically by two-staged operation. First, we performed total arch replacement using cardiopulmonary bypass, systemic hypothermia, selective cerebral perfusion, and coronary artery bypass grafting. Secondly, we performed replacement of the thoracoabdominal aortic aneurysm using a partial cardiopulmonary bypass. The postoperative course was uneventful. This is apparently the first case of repair for the thoracoabdominal aortic aneurysm combined with an aberrant right subclavian artery and Kommerell's diverticulum.

Oral Beraprost Sodium as a Prostaglandin I<SUB>2</SUB> Analogue for Vascular Events in Patients with Peripheral Arterial Disease : Meta-Analysis of Two Placebo-Controlled Randomized Trials / 薬剤疫学

Objective : To evaluate the effect of beraprost sodium (beraprost) on the vascular events occurring in patients with peripheral arterial disease (PAD) in a meta-analysis of placebo-controlled, randomized trials.<BR>Design : Meta-analysis<BR>Methods : Among the clinical trials of beraprost in patients with intermittent claudication associated with PAD, placebo-controlled, randomized trials with vascular events as outcome measures were selected. Two trials met the criteria, each of which was a comparative trial of beraprost (40 μg t.i.d.) and placebo (t.i.d.), with a six-month follow-up period.<BR>Results : With both trials combined, the analysis included 594 patients in the beraprost group and 590 in the placebo group. The risk ratio was 0.608 (95%CI : 0.41 to 0.90, p =0.012), demonstrating the efficacy of beraprost on all vascular events. The risk ratio for lower limb deterioration was 0.598 (95% CI : 0.34 to 1.06, p =0.079), which was similar to that for all vascular events. A statistically insignificant but similar result was also obtained for cardio/cerebrovascular events with a risk ratio of 0.619 (95%CI : 0.36 to 1.07, p = 0.085). Heterogeneity between the two studies was not found for any of the events.<BR>Conclusion : The results demonstrated the efficacy of beraprost on the vascular events in patients with PAD. The potential benefit of beraprost on vascular events will require evaluation in a larger prospective investigation.

An 84-year-old Case of Abdominal Aortic Aneurysm with Three-vessel Coronary Artery Disease / 日本心臓血管外科学会雑誌

An 80-year-old male patient had complained of left abdominal pain since 1990, and an abdominal aortic aneurysm (AAA) 5.3cm in diameter was diagnosed by computed tomography (CT). The patient was NYHA class III with complaints of chest pain during exercise. Coronary arteriography showed that he had three-vessel disease. At that time, aneurysmectomy was not anticipated due to his age and because the AAA showed no tendency to enlarge. However, in October 1993, CT showed that the AAA rapidly enlarged to 6.8cm in diameter. Due to the greater risk of rupture of the AAA, aneurysmectomy was considered necessary. The operative mortality associated with aneurysmectomy in patients with coronary artery disease (CAD) is higher than that in patients without CAD. Therefore, coronary artery bypass grafting (CABG) was indicated prior to aneurysmectomy. The patient underwent CABG (two vessels) in December 1993, and aneurysmectomy was successfully performed in February 1994. He was discharged uneventfully 17 days after the operation.