Mikio Ishikawa

Preliminary report on prediction of spinal cord ischemia in endovascular stent graft repair of thoracic aortic aneurysm by retrievable stent graft

OBJECTIVE To predict spinal cord ischemia after endovascular stent graft repair of descending thoracic aortic aneurysms, temporary interruption of the intercostal arteries (including the aneurysm) was performed by placement of a novel retrievable stent graft (Retriever) in the aorta under evoked spinal cord potential monitoring. METHODS From February 1995 to October 1997, endovascular stent graft repair of descending thoracic aortic aneurysms was performed in 49 patients after informed consent was obtained. In 16 patients with aneurysms located in the middle and distal segment of the descending aorta, the Retriever was placed temporarily before stent graft deployment. The Retriever consisted of two units of self-expanding zigzag stents connected in tandem with stainless steel struts. Each strut was collected in a bundle fixed to a pushing rod, and the stent framework was lined with an expanded polytetrafluoroethylene sheet. The Retriever was delivered beyond the aneurysm through a sheath and was retracted into the sheath 20 minutes later. A stent graft for permanent use was deployed in patients whose predeployment test results with the Retriever were favorable. Evoked spinal cord potential was monitored throughout placement of the Retriever and stent grafting until the next day. RESULTS The Retriever was placed in 17 aneurysms in 16 patients. There were no changes in amplitude or latency of evoked spinal cord potential records obtained before or during Retriever placement. After withdrawal of the Retriever, all aneurysms were excluded from circulation immediately after permanent stent grafting. There were no changes in evoked spinal cord potential, nor were neurologic deficits seen after stent graft deployment in any patient. CONCLUSIONS These results suggest that predeployment testing with the Retriever under evoked spinal cord potential monitoring is promising as a predictor of spinal cord ischemia in candidates for stent graft repair of thoracic aortic aneurysms.

Clinical results of endovascular stent graft repair for fifty cases of thoracic aortic aneurysms

Between February 1995 and December 1997, 50 cases (55 lesions) of thoracic aortic aneurysms including 20 cases of aortic dissections were treated with an endovascular technique using the stent grafts. All patients were treated in the operating room under general anesthesia and the stent grafts were implanted through 18 Fr. or 20 Fr. sheaths via femoral arteries under fluoroscopic guidance. The stent graft was composed of several units of self-expanding stainless-steel Z stents covered with an ultra-thin polyester fabric. Stent graft deployment was technically successful in 53 of 55 lesions (delivery success rate: 96.4%). Exclusion of the aneurysms and entry closing without endoleak were achieved within two weeks after the operation in 43 of 53 lesions (initial success rate: 81.1%). Endoleak was found in 10 lesions (minor endoleak: 8 and major endoleak: 2 lesions). Two patients died in the periopertive period of delivery failures as injury to external iliac artery and damage to the delivery sheath caused by tortuous and narrow access routes. Endovascular stent graft repair of thoracic aortic aneurysms is minimally invasive operation in comparison with conventional surgical graft replacement with extracorporeal circulation. These early results suggest that the stent graft repair is possibly safe and useful treatment for the patients of thoracic aortic aneurysms especially in high risk patients. However, careful long-term follow-up is necessary to prove the value and the effects of this endovascular treatment and improvement of the stent graft system and technical training of endovascular surgery for operators are required to reduce the delivery failure and to determine the stent graft repair is reliable treatment.

The surgical treatment of aortic dissection in a patient with Turner's syndrome: Report of a case

We report herein the successful surgical management of a 42-year-old patient with Turners syndrome (TS) complicated by Stanford type B aortic dissection. The patient had a single entry in the proximal descending aorta with dissection extending from the entry point to the abdominal aorto-left iliac bifurcation. A patch plasty using felt reinforcement was performed through a left 4th intercostal space thoracotomy. Her postoperative course was uneventful and she has been well during the 3 years since her operation. There have been only nine reports of patients with TS complicated by aortic dissection for whom operations were performed; however, the details of surgical treatment have not been well documented. This paper reports the course of aortic dissection and the surgical methods employed in the treatment of our patient.

Prediction of spinal cord ischemia with a retrievable stent graft on endovascular treatment for a case of thoracic aortic aneurysm

Multiple aortic aneurysms in Behçets disease were repaired with transluminaly placed endovascular stent grafts. Before deploying the stent graft device for permanent implantation for the saccular aneurysm located in the descending thoracic aorta, from which feeding arteries for the spinal cord possibly branched, a retrievable stent graft was inserted and evoked spinal cord potential (ESP) were monitored in order to predict spinal cord ischemia. The original retrievable stent graft, constructed of a self-expandable Z-shaped stainless steel stent covered with e-PTFE, can be easily withdrawn into a 18 Fr. sheath after deployment. Blood flow into intercostal arteries branching from that part of the descending aorta where the permanent stent graft is planned to be implanted, is intercepted by the retrievable stent graft. A change of ESP during the temporary implantation of the device indicates that spinal cord ischemia would be caused by permanent implantation of the stent graft. In this case, no change of ESP was observed and the patient showed no postoperative paraplegia. The retrievable stent graft was useful for prediction of spinal cord ischemia before endoluminal stent graft repair of the descending aortic aneurysm. However, the device is not flexible enough to fit a severely tortuous aorta, therefore we are obliged to select patients to some extent. Further improvement of the device is required to make prediction of spinal cord ischemia with the retrievable stent graft possible in all cases.

Six year experience with wrinkled ePTFE vascular prostheses for arteriosclerosis obliterans

From November 1986 to January 1993, 97 wrinkled ePTFE prosthetic vascular grafts were implanted in 90 peripheral arterial reconstructions for 87 patients with arteriosclerosis obliterans (ASO) (79 men and 8 women). Grafts used in this series were 54 Vitagraft and 33 Technograft. Initial results for a period of as long as 6 years are summarized here. Forty-four (45.3%) grafts were implanted anatomically, and the remaining were extra-anatomically routed. The mean age of patients in the anatomic bypass group was 64.7 years, and that of patients in the other group was 71.4 years. Twenty-three (43.3%) grafts in the extra-anatomic group were anastomosed sequentially. Mean follow-up periods for each group were 32.4 months and 30.9 months, respectively. None of nine late deaths during the follow-up period was graft related. There was one primary obstruction in the anatomic group; in the extra-anatomic groups, primary graft occlusion occurred in four grafts. In addition, one perigraft seroma and one pseudoaneurysm requiring surgical repair were seen. Cumulative event free ratio for this group was 80.8% at 72 months. These results reveal that the wrinkled ePTFE graft is clinically applicable to arterial reconstruction for ASO with satisfactory long-term patency, even in extra anatomic sequential bypasses.

Clinical results of acute closing aortic dissection

The therapeutic outcomes of 43 patients with acute closing aortic dissection treated during the past 10 years were evaluated. The patients consisted of 30 men and 13 women with a mean age of 65 +/- 9 years. Ten were classified as Stanford type A, and the remaining 33 as type B. During follow-up (6 to 120 months; average 55 months), recanalization and an enlarged ulcer-like projection (ULP) were observed in 5 and 2 type a patients. Although recanalization was not observed in type B patients, enlarged ULP was observed in 10 of them, in 6 of whom developed aneurysm. During the follow-up period, ULP was observed at 30 sites in 26 patients. Monitoring the change in ULP over time showed that the ascending and the proximal descending aorta frequently tended to be enlarged and progressed to aorta frequently tended to be enlarged and progressed to aneurysm. Surgery was performed in 3 patients with recanalization, 5 with enlarged ULP, and 3 with atheroscloerotic aortic aneurysm. Although one patient died of cerebral complications, the other 10 patients showed favorable postsurgical courses. Among 8 patients who died, the actuarial survival rate was favorable, being 96, 91 and 83% at 1, 3 and 5 years. However, the survival rate free from complications related to aortic dissection, defined as rupture, ercanalization, enlarged ULP and aneurysmal change, was 78, 58 and 54% at 1, 3 and 5 years, indicating that aortic dissection-related complications are likely to develop within 3 years. This being the case, conservative therapy may be selected for closing aortic dissection when there are no serious complications in the acute phase. However, closely following patients with diagnostic imaging techniques is essential as there may be complications such as recanalization or enlarged ULP. Such complications should be surgically treated because they may affect long-term prognosis.

Endovascular Grafting for Various Conditions of the Descending Thoracic Aorta

Since 1995 a total of 129 patients with aneurysm, dissection, or other conditions of the descending thoracic aorta were treated by a homemade stent-graft system. The basic framework of our system consisted of Gianturco Z stents connected at each section by two longitudinal struts and covered with a thin-walled woven polyester fabric. Under fluoroscopy, the stent-graft was deployed in the aorta through a sheath introduced by the brachial-femoral traction guidewire technique called “tug of wire.” The flexible stent device enabled successful stent-graft deployment, particularly in the proximal descending aorta. A predeployment test using a novel retrievable stent-graft helps predict the possibility of spinal cord ischemia in patients with the target region located in the critical distal descending aorta. The fate of the dissected false lumen treated by endovascular primary entry closure depends not only on size and the location of reentry but on the period after onset. Balloon fenestration efficiently prevented visceral malperfusion following entry closure. Although anastomotic pseudoaneurysms can be successfully repaired, hemoptysis does not disappear if the lung was damaged by aneurysm formation. Traumatic and inflammatory aneurysms are good candidates for endovascular grafting, although long-term follow-up results must be investigated.

A Case of Complete Thrombotic Occlusion by Endovascular Stent Grafting for Anastomosis Leakage after Aortic Arch Replacement of Stanford Type A Dissecting Aortic Aneurysm.

症例は60歳女性. 突然の胸背部痛で発症した早期閉塞型 Stanford A型大動脈解離と診断され, 保存的治療を行っていた. 発症後約2カ月で再び胸背部痛が出現し, 解離腔の再開通と診断され, elephant trunk を併用した弓部全置換術を行った. 術後のDSAにて, 人工血管末梢吻合部より解離腔へ造影剤の漏出を認め, 1カ月後にステントグラフト内挿術を施行した. 解離腔は血栓化し早期離床が可能であった.

MRSA Infection after Grafting for Thoraco-abdominal Aneurysm: A Case Successfully Treated by Omentopexy.

症例は69歳, 男性. Crawford III型の胸腹部大動脈瘤に対して人工血管置換術を行った. 術後8日目より炎症所見が著しくなり, 創部皮下膿瘍を形成した. 排膿および胸腔ドレーン排液よりMRSAが検出され創部から胸腔内への感染と診断し, 再開胸術を施行した. 感染組織を掻爬した後, 人工血管除去による再建術を選択せず大網充填術を行い, 術後3日間は1%イソジン液による持続胸腔内洗浄を行った. 炎症は鎮静化し, 軽快退院した. 近年, MRSAによる人工血管感染は増加し治癒例も散見されるが, 本例のごとく胸腹部における人工血管を温存しえた例は稀であることから, 文献的考察を加えて報告した.