Nobusato Koizumi

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 The Retriever was delivered beyond the aneurysm through a sheath and was retracted into the sheath 20 minutes later.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.

Prevalence of Coronary Heart Disease in Patients With Aortic Aneurysm and/or Peripheral Artery Disease

Although the presence of coronary heart disease (CHD) was the major determinant of perioperative mortality and long-term prognosis in patients with aortic aneurysm (AA) and peripheral artery disease (PAD), the prevalence and severity of CHD in patients with individual vascular diseases was unknown. Adenosine triphosphate-loading myocardial single-photon emission computed tomography therefore was performed in 788 patients with vascular diseases of the aorta and peripheral arteries, with AA in 500, PAD localized in the lower-limb arteries in 183, and combined AA and PAD in 105. Patients with known CHD, such as those with previous myocardial infarction or revascularization procedures, were excluded. Myocardial single-photon emission computed tomography was analyzed using a 20-segment model, and summed stress scores and summed difference scores were calculated. Stress-induced myocardial ischemia was defined as a summed difference score >or=2. The presence of myocardial ischemia was highest in patients with combined PAD and AA (73%), followed by PAD (55%; p = 0.005), and the lowest in patients with AA (37%; p <0.0001). Summed stress score was also the highest in patients with combined PAD and AA (11.6 +/- 9.9), followed by PAD (7.8 +/- 8.8; p <0.0001), and the lowest in patients with AA (4.0 +/- 6.2; p <0.0001 for both). Similarly, summed difference score was the highest in patients with combined PAD and AA (6.4 +/- 6.1), followed by PAD (4.4 +/- 5.7; p = 0.001) and AA (2.3 +/- 4.0; p <0.0001 for both). In conclusion, the prevalence of CHD in patients with PAD was >50%, and although myocardial ischemia was observed in only (1/3) of patients with AA, its prevalence not only doubled, but also indicated extensive myocardial ischemia when combined with PAD. Thus, cardiac evaluation was particularly important in patients with combined AA and PAD.

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.

Thoracic endovascular aortic repair with aortic arch vessel revascularization

BACKGROUND Revascularization of aortic arch vessels was performed with thoracic endovascular aortic repair (TEVAR) to preserve the endoprosthesis landing zone in 19 high-risk patients. METHODS The operative procedure used was a bypass or transposition involving the common carotid and subclavian arteries. Homemade fenestrated stent-grafts, deployed in landing zone 0, were used for TEVAR. RESULTS All lesions resolved without endoleaks. No perioperative deaths occurred; seven patients had postoperative complications. One patient with acute respiratory distress syndrome required reoperation to change the bypass route and permit tracheostomy. One patient died of pneumonia 2 months after treatment, after an anastomotic pseudoaneurysm and cerebral infarction developed and an operation was performed to obtain hemostasis. The procedure-related mortality was 5.3%. CONCLUSION Aortic arch vessel revascularization before TEVAR may permit less invasive surgery, although careful patient selection is essential.

Ruptured coronary artery aneurysm with pulmonary artery fistulae

Fistulae to the pulmonary artery (PA) in adults are usually associated with aortic pathology. Coronary artery aneurysms may be located in close proximity to the left main trunk or communicate with other coronary vessels. It is rare to find a coronary artery aneurysm communicate with the PA. An 84-year-old female developed acute shortness of breath. In the emergency room, shewas noted to be hypotensive, and a transthoracic echocardiogram revealed a circumferential effusion resulting in cardiac tamponade (Figure 1A). A coronary angiogram demonstrated a small, proximal right coronary artery (RCA) aneurysm (Figure 1B), and a larger left anterior descending (LAD) artery aneurysm with flow into the PA (Figure 1C). The patient underwent emergency surgery with cardiopulmonary bypass via a median sternotomy, at which time the hole in the LAD aneurysm was detected (Figure 2). Following

Hybrid procedures combining conventional and thoracic endovascular aortic repair for thoracic aortic aneurysms

PurposeTo minimize surgical invasiveness for extensive aortic aneurysms and expand the indications for thoracic endovascular aortic repair (TEVAR), we evaluated outcomes of hybrid procedures combining conventional surgical aortic repair and TEVAR for thoracic aortic aneurysms.MethodsThe following hybrid procedures were performed: second-stage TEVAR after total aortic arch replacement using the elephant trunk as the landing zone in 17 patients; and for multiple aortic aneurysms, vascular graft replacement and TEVAR in 13 patients, vascular graft replacement and TEVAR with bypass in 2 patients, and TEVAR with bypass in 23 patients.ResultsThere were three (5.3%) hospital deaths, from serious complications including stroke, paraplegia, paraparesis, and aspiration pneumonia; and eight late deaths. There was only one aneurysm-related death, of a patient who underwent emergency surgery for an esophageal fistula resulting from enlargement of a residual false lumen of a thoracoabdominal aorta after second-stage TEVAR.ConclusionHybrid procedures minimize surgical invasiveness in thoracic aortic aneurysm repair, but further evaluation of a larger number of patients is necessary.

Long-term results of second-stage thoracic endovascular aortic repair following total aortic arch replacement

PurposeWe investigated the surgical results of secondary thoracic endovascular aneurysm repair (TEVAR) using the elephant trunk graft after total aortic arch replacement (TAR) for extensive thoracic aortic lesions.MethodsThe subjects comprised 16 patients who underwent TEVAR as a staged procedure following TAR at our institution between 1997 and 2007. Long-term results were retrospectively surveyed (mean observation period 68.4 months). We performed TEVAR with the elephant trunk graft as a proximal landing zone for the descending thoracic repair, the mean duration between TAR and TEVAR was 4.7 weeks for the staged operations and 18.3 months for the nonstaged operations.ResultsEarly results were good in all cases, with no deaths and no noteworthy complications. For the seven patients without dissection, long-term results were also good. Among the nine patients with dissection, the false lumen in the thoracoabdominal area enlarged in three during follow-up. We performed thoracoabdominal repair in two, but one died of an aneurysm-esophageal fistula. There was only one long-term aneurysm-related death.ConclusionSecond-stage TEVAR using the elephant trunk graft after TAR allows less invasive surgery for extensive aortic lesions and achieves good long-term results. However, enlargement of the false lumen was a long-term concern in patients with aortic dissection, and careful follow-up is essential.

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.

Skin perfusion pressure measurement to assess improvement in peripheral circulation after arterial reconstruction for critical limb ischemia.

AIM To assess the utility of skin perfusion pressure (SPP) measurement in evaluating the outcome of vascular constructions for critical limb ischemia (CLI) patients. METHODS We retrospectively studied 19 lower limbs in 18 patients who underwent arterial reconstruction for CLI from whom SPP measurements had been obtained pre- and postoperatively between 2008 and 2010. Six limbs whose ulcers had healed postoperatively were classified into group H, 7 limbs whose ulcers had not healed into group U, and 6 limbs without ulcers into group N. SPP values were compared among these groups. RESULTS The preoperative SPP values in all groups were <30 mmHg, without significant differences among the groups. The SPP values in groups H and N significantly improved after operation, and those in group U were significantly lower than those in the other groups. CONCLUSIONS SPP measurement before and after arterial reconstruction is useful to assess improvement in tissue circulation and to predict the likelihood of wound healing. An SPP value ≥30 mmHg was considered necessary for wound healing, supporting the findings of the few reports in the literature on the usefulness of SPP for assessing vascular reconstruction effects on ulcer wound healing.

Surgical repair for aortic dissection accompanying a right-sided aortic arch

Aortic anomaly in which a right-sided aortic arch associated with Kommerells diverticulum and aberrant left subclavian artery is rare. The present report describes a patient with type-B aortic dissection accompanying aortic anomalies consisting of right-sided aortic arch and the left common carotid and left subclavian artery arising from Kommerells diverticulum. As dissecting aortic aneurysm diameter increased rapidly, Single-stage surgical repair of extensive thoracic aorta was performed through median sternotomy and right posterolateral fifth intercostal thoracotomy, yielding favorable results. Our surgical procedures are discussed.