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.

Pleural Effusion after Endovascular Grafting for Aortic Dissection / 日本心臓血管外科学会雑誌

We studied the appearance of pleural effusion and inflammatory reactions after endovascular grafting in cases of aortic dissection. From December 1995 to January 2000, 16 patients with chronic double-barrel type aortic dissection (DeBakey type III b) were treated by endovascular grafting. In all cases, enhanced computed tomography (CT) of the chest was examined before operation and at about the 7th postoperative day (POD). Patients were divided into 3 groups. Group P: patients who had pleural effusion before the operation. Group E: patients who had new pleural effusion after the operation. Group N: patients who did not have any pleural effusion. In each group, onset of dissection, patient's age, maximum diameter of dissecting aorta, period of postoperative fever (above 37.0°C), and WBC counts and CRP value at POD 1, 3, 7 and 14 were compared. Four patients were in group P, 4 patients were in group F, and 8 patients were in group N. Period between onset and operation was 41.6±34.6 months in group P, 18.2±27.3 months in group E and 7.3±11.6 months in group N. There was no relation between the effusion and the period after onset. Postoperative fever continued for 5.0±2.0 days in group P, 13.5±2.6 days in group E and 2.5±0.3 days in group N. The period of fever of group E was significantly longer than in group N and P (p<0.01). WBC showed a peak on the first POD in each group. CRP showed a peak value on POD 3 in group P and N. There was no significance among the 3 groups about WBC and CRP, but group E showed slightly high CRP values on POD 7 and 14. No patient had complications regarding respiratory function. After endovascular grafting for aortic dissection, postoperative pleural effusion appeared in 25% of patients. They had prolonged postoperative fever, but there was no respiratory function complication. Endovascular grafting is a minimally invasive procedure with regard to respiratory function.

A Case Report of Impending Ruptured Suprarenal Abdominal Aortic Aneurysm Associated with a Penetrating Atherosclerotic Ulcer / 日本心臓血管外科学会雑誌

A 71-year-old woman was admitted with sudden onset of abdominal pain. CT scan image and symptoms showed an impending ruptured suprarenal abdominal aortic aneurysm therefore we performed an emergency operation. The abdominal aorta was replaced with a trunk prosthetic graft with four branches for visceral and lumbar arteries. The post-operative course was uneventful. Pathological examination showed that the aorta had severe atherosclerotic changes. The fibrous tissues increased in the aneurysmal wall which was not consistent with the normal aorta. Intima and media of the aorta everted into the aneurysm. These findings suggested that aneurysm was caused by a penetrating atherosclerotic ulcer.

A Case of Complete Thrombotic Occlusion by Endovascular Stent Grafting for Anastomosis Leakage after Aortic Arch Replacement of Stanford Type A Dissecting Aortic Aneurysm / 日本心臓血管外科学会雑誌

A 60-year-old woman with acute Stanford type A dissecting aneurysm underwent Dacron graft replacement of the total aortic arch combined with the modified elephant trunk technique. Follow-up CT and angiogram demonstrated blood flow into the false lumen from the distal anastomosis. In order to interrupt the blood flow, endovascular stent grafting was undertaken. She recovered uneventfully, and was discharged on the 14th postoperative day. Follow-up CT taken in the third postoperative month demonstrated exclusion of the blood flow into the false lumen of descending thoracic aorta. Aortic arch replacement followed by endovascular stent grafting of the descending thoracic component is a potential therapeutic option in patients with dissecting aneurysm.

Endovascular Stent-Graft Repair for Abdominal Aortic Aneurysms in Comparison with Open Surgery / 日本心臓血管外科学会雑誌

This report describes the results of endovascular stent graft repair for abdominal aortic aneurysms in comparison with conventional open surgery. Endovascular repair of abdominal aortic aneurysm was performed in 21 patients (SG group) and 69 patients were treated with conventional open surgery (OS group). The SG group had a higher preoperative risk than the OS group. The complete exclusion of the aneurysm at 2 weeks after the stent graft treatment was obtained in 16 out of 21 SG cases (76%). On the other hand, in the OS group, 68 of 69 cases underwent successful surgery (99%). The average amount of bleeding during the endovascular stent graft repair was 427ml and the average operation time was 242 minutes. Both blood loss and operation time were significantly lower compared to the OS group. The endovascular stent graft repair was less invasive in comparison with conventional open surgery. However, judging from the initial success rate, open surgery is more reliable than the endovascular stent graft repair. Our data suggested that the endovascular stent graft repair should be performed only in selected cases.