Nationwide study of surgery for primary infected abdominal aortic and common iliac artery aneurysms.

BACKGROUND: Primary infected aneurysms of the abdominal aorta and iliac arteries are potentially life-threatening. However, because of the rarity of the disease, its pathogenesis and optimal treatment strategy remain poorly defined. METHODS: A nationwide retrospective cohort study investigated patients who underwent surgical treatment for a primary infected abdominal aortic and/or common iliac artery (CIA) aneurysm between 2011 and 2017 using a Japanese clinical registry. The study evaluated the relationships between preoperative factors and postoperative outcomes including 90-day and 3-year mortality, and persistent or recurrent aneurysm-related infection. Propensity score matching was used to compare survival between patients who underwent in situ prosthetic grafting and those who had endovascular aneurysm repair (EVAR). RESULTS: Some 862 patients were included in the analysis. Preceding infection was identified in 30.2 per cent of the patients. The median duration of postoperative follow-up was 639 days. Cumulative overall survival rates at 30 days, 90 days, 1 year, 3 years and 5 years were 94.0, 89.7, 82.6, 74.9 and 68.5 per cent respectively. Age, preoperative shock and hypoalbuminaemia were independently associated with short-term and late mortality. Compared with open repair, EVAR was more closely associated with persistent or recurrent aneurysm-related infection (odds ratio 2.76, 95 per cent c.i. 1.67 to 4.58; P < 0.001). Propensity score-matched analyses demonstrated no significant differences between EVAR and in situ graft replacement in terms of 3-year all-cause and aorta-related mortality rates (P = 0.093 and P =0.472 respectively). CONCLUSION: In patients undergoing surgical intervention for primary infected abdominal aortic and CIA aneursyms, postoperative survival rates were encouraging. Eradication of infection following EVAR appeared less likely than with open repair, but survival rates were similar in matched patients between EVAR and in situ graft replacement.

Growth rates of abdominal aortic aneurysms in Japanese patients observed in one institute.

AIM: The aim of this paper was to investigate the growth rate of abdominal aortic aneurysms (AAA) in Japanese patients. METHODS: We retrospectively studied patients conservatively followed with infrarenal AAA in terms of AAA diameter measured using computed tomography (CT) in our hospital between 1999 and 2009. The AAA surgery criterion in our institute was a diameter ≥ 5.0 cm or a growth rate ≥5 mm/year. We estimated operation-free ratios by initial AAA diameter and changes in AAA growth rates. Patients with an initial AAA diameter < 5.0 cm were divided into 2 groups. Patients with AAA that met the criteria for surgery were classified into the expansion group, and those remaining into the non-expansion group. Their AAA growth rates were compared. RESULTS: The group consisted of 124 patients (average age, 73.7±8.6 years (range 54-92)) who had at least 2 recorded AAA measurements. The average follow-up period was 3.0±2.2 years (range 0.3-10.2). There were no cases of rupture during follow-up. Twenty-six patients (21.0%) underwent surgery (open replacement [N.=20]; endovascular abdominal aneurysm repair [N.=6]). The growth rate determined from the initially measured diameter was significantly faster in AAAs measuring 5.0-5.4 cm than in AAAs measuring 4.5-4.9 cm (P=0.01). More than 90% of patients with an initial AAA diameter <5.0 cm were observed conservatively for 2 years or more. However, more than half of the patients with an initial AAA diameter ≥4.0 cm needed surgery within 5 years. The growth rates of AAAs for each size during growth were significantly faster when the AAA diameter was 4.5-4.9 cm than when it was 4.0-4.4 cm (P=0.006), and when the AAA diameter was 5.0-5.4 cm than when it was 4.5-4.9 cm (P = 0.009). The expansion and non-expansion groups consisted of 38 (34.2%) and 73 (75.8%) patients, respectively. The AAA growth rate in the expansion group was significantly faster than that in the non-expansion group (3.4±2.2 mm/year vs. 1.4±1.3 mm/year, P=0.0001). CONCLUSION: It may be considered that the appropriate indication for AAA repair is defined by a diameter of 5.0 cm for Japanese patients. Patients with AAA that is growing continuously by ≥3 mm/year and who have low operative risk may undergo surgery even if their AAA is <5.0 cm.

Transfection of human HGF plasmid DNA improves limb salvage in Buerger's disease patients with critical limb ischemia.

AIM: Hepatocyte growth factor is a potent angiogenic agent. This study investigated the efficacy and safety of intramuscular injection of naked plasmid DNA encoding the human hepatocyte growth factor gene in Japanese patients with Buerger's disease and critical limb ischemia. METHODS: An open-label clinical study was performed at eight hospitals in Japan from May 2004 to April 2008. Ten patients were enrolled. They had Buerger's disease with ischemic ulcers, were not candidates for revascularization, and were unresponsive to conventional drug therapy. Treatment consisted of 8 injections (total dose: 4 mg) of hepatocyte growth factor plasmid, which were administered into the calf muscles and/or distal thigh muscles of the ischemic limbs under ultrasound guidance. Administration was done twice at an interval of 4 weeks. If there was no improvement after 2 doses, a 3rd dose could be administered. The response to treatment was evaluated from the reduction of ischemic ulcer size. RESULTS: The size of ischemic ulcers showed a decrease in 6/9 (66.7%) patients and the ulcers healed completely in 5/9 (55.6%) patients after gene therapy. Major amputation was not required. There were no deaths and no major safety concerns. CONCLUSION: Hepatocyte growth factor gene therapy is safe and effective for critical limb ischemia in patients with Buerger's disease.

Three-year cardiovascular events and disease progress in patients with peripheral arterial disease: results from the Japan Medication Therapy for Peripheral Arterial Disease (J-METHOD).

AIM: To investigate the current status of peripheral arterial disease (PAD) drug treatment in Japan, and the effects of drug treatment, risk factors, and complications on disease progress and onset of cardiovascular events in PAD patients. METHODS: In this prospective observational cohort study, 557 PAD patients were followed up for 3 years, and the current status of PAD treatment, risk factors, and cardiovascular events were monitored. RESULTS: Three drugs, i.e., beraprost sodium, cilostazol, and aspirin, were most frequently used. The patients who had undergone vascular reconstruction of the lower limbs before enrollment showed significant improvement in ABI. Among the patients who had not undergone vascular reconstruction before enrollment, there was a significant improvement in ABI after treatment with beraprost. During the observation period, cardiovascular deaths occurred in 35 patients (6.3%), heart diseases in 63 (11.3%), brain diseases in 39 (7.0%), and events in the lower limbs in 94 (16.9%). The factors affecting the increase of the cardiovascular events were explored by multivariate analysis (Cox regression analysis). As a result, age (75 years or older), ischemic heart disease and increase in severity on the Fontaine classification were identified as significant factors for cardiovascular deaths, whereas kidney disorders and increase in severity on the Fontaine classification were identified for heart diseases, the number of oral drugs for treating PAD was identified for brain diseases, and age (younger than 75 years), dialysis, ABI (less than 0.7) and aspirin were identified for the events in the lower limbs. CONCLUSION: As a result of the three-year follow-up on the Japanese PAD cohort, the current status of PAD treatment, risk factors, and cardiovascular events could be identified.

The education system to master endovascular aortic repair in Japan - the Japanese Committee for Stentgraft Management.

OBJECTIVE: The Japanese Committee for Stentgraft Management (JACSM) was established with the aim of ensuring the safe and proper reach of commercial stent grafts following their regulatory approval. This study examines the validity of the practice standards developed by JACSM. METHODS: JACSM comprises 10 associations related to endovascular treatment. Based on the practice standards developed by JACSM, the status of practising institutions, practising surgeons, supervising surgeons and the results of follow-up surveys were analysed. RESULTS: In the 2.5 years following the establishment of JACSM, 298 institutions have fulfilled the practice standards. The number of practising surgeons reached 493, and the number of supervising surgeons reached 177. There were 3089 registered cases up to June 2009. The present study analysed 1570 cases registered in the 2 years from July 2006 to June 2008. The hospital mortality rate was low (0.4%) in the follow-up surveys. CONCLUSIONS: Early results following the introduction of stent grafts were generally good. The procedure spread safely without the learning curve seen in the initial stages following introduction of new medical materials, indicating that the practice standards were appropriate.

Clinical comparison of two different types of bifurcated graft for postoperative baPWV and ABI.

AIM: A newly-designed bifurcated graft with the distal end larger than the conventional type has been developed. The purpose of this study was to evaluate the early results of graft replacement using this new graft, and to compare whether the new graft is more advantageous than the conventional graft in terms of peripheral blood flow and arterial stiffness. METHODS: Records of 36 patients who underwent bifurcated graft replacement for infrarenal abdominal aortic aneurysm (AAA), from May 2003 to September 2006 were reviewed after excluding peripheral arterial disease (ABI > 0.9). Subjects were divided into two groups: group C (N.=20), with implantation of the conventional type and group N (N.=16), with implantation of the new type. We investigated changes in brachial-ankle pulse wave velocity (baPWV) and ankle-brachial pressure index (ABI), measurements being performed preoperatively and postoperatively. RESULTS: baPWV in the postoperative group as a whole was significantly higher than in the preoperative group (P<0.05), while ABI in the postoperative group was lower than in the preoperative group (P<0.05). In group C, baPWV increased (P<0.05) and ABI decreased (P<0.05) after bifurcated graft replacement, whereas in group N, there were no significant differences in changes of baPWV and ABI. CONCLUSIONS: This study shows that the new graft reduces the development of arterial stiffness postoperatively compared with the conventional type. These results may predict the new type graft decrease in the risk of morbidity and mortality caused by atherosclerotic disease.

[Adequate size of elephant trunk in the procedure of total arch replacement for acute aortic dissection].

Total aortic arch replacement using the 'elephant trunk (ET)' procedure has commonly been applied to acute aortic dissection, but enlargement of a residual false lumen of the descending thoracic aorta sometimes occurs. We performed endovascular stent-grafting to close the entry as the second operation and obtained successful outcomes. From April 1997 to January 2004, we performed the modified ET procedure for acute aortic dissection in 29 patients and evaluated postoperative changes of the false lumen. In many cases of the residual false lumen, kinks and wrinkles were observed at the site of the ET grafts in the descending aorta. An adequate length of ET would be about 8 cm long to prevent kinking, and a diameter about 20 mm to prevent wrinkles.

[Evaluation of spinal cord ischemia in endovascular stent graft repair and surgical operation of descending thoracic or thoracoabdominal aortic aneurysms].

Between October 1996 and June 2003, endovascular stent graft repair was performed in 87 patients with descending thoracic aortic aneurysms, graft replacement was performed in 24 patients with thoracoabdominal aortic aneurysms, and endovascular stent graft repair with concomitant surgical bypass of abdominal visceral arteries was performed in 3 patients with thoracoabdominal aortic aneurysms. The retrievable stent graft was inserted and evoked spinal cord potential were monitored in order to predict spinal cord ischemia for stent graft repair. There was no paraplegia or hospital death, although 3 patients had paraparesis in stent graft repair. Two of the 3 patients with paraparesis made a full neurologic recovery. There were no cases of paraplegia or paraparesis in surgical operations with thoracoabdominal aortic aneurysm. The concomitant surgical procedure was a good technique for patients in whom cardiopulmonary bypass could not be used. Our results of stent graft repair and surgical operation for descending thoracic or thoracoabdominal aortic aneurysms were acceptable. The retrievable stent graft was useful for prediction of spinal cord ischemia before endovascular stent graft repair of descending thoracic or thoracoabdominal aortic aneurysm.

[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.

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

Multiple aortic aneurysms in Behçet's 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.

[Postoperative changes in the coagulation and fibrinolytic systems in endoluminal stent-graft treatment of thoracic aortic aneurysms].

We studied changes in blood coagulation and fibrinolytic system in 18 cases of thoracic aortic aneurysm and 5 cases of aortic dissection treated with stent grafts. The mean operation time was 259 +/- 67 minutes and the amount of blood loss during operation was 472 +/- 456 ml. Although blood transfusion of 220 +/- 360 ml was performed in 7 cases, 16 of 23 cases (70%) received no homologous blood transfusion. Consequently, the endoluminal stent graft treatment was minimally invasive compared with the conventional surgical procedure. On the 1st postoperative day, platelet counts and AT-III decreased and TAT increased. The promotion of blood coagulability was found in these patients on the 1st day after the operation. Changes in the fibrinolytic system were less marked than that in coagulation. These results suggest that the thrombosed aneurysm was excluded from systemic blood flow by the stent graft. There was no consumption coagulopathy in any case with aneurysm excluded by stent graft deployment. Stent-graft treatment for thoracic aortic aneurysm can be successfully performed without consumption coagulopathy when the aneurysm is completely excluded.

[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.

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.

[Stent graft treatment for two cases of DeBakey IIIb dissecting aortic aneurysm].

Two patients with DeBakey IIIb dissecting aortic aneurysms were treated with transluminally placed endovascular stent grafts. Surgery was required for both patients because the false lumens were not thrombosed for several months. Stent graft devices composed of several units of self-expandable Z stents covered with ultra-thin woven Dacron were inserted through 18 Fr sheathes via femoral arteries. The stent grafts were deployed successfully and blood flow into the false lumens was reduced immediately and finally thrombosed without blood leakage from the entries. The endoluminal stent graft treatment is minimally invasive operation in comparison with former surgical operations, and is useful for aortic aneurysms especially in high risk patients. However, improvement of the stent graft devices, including the delivery systems such as the dilator, sheath and pushing rod, which are incomplete, and developing better devices, is required to reduce delivery failure and to make the stent graft treatment more reliable.

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.

[A new method for closure of median sternotomy: applications of a stapler system].

Power driven staples were used in 20 patients for median sternotomy closure, and the staples were evaluated for clinical fixation. In each case four to six staples and two wires were used to secure closure. Clinically, in one patient prolonged sternal flail was observed, but this disappeared after six weeks. In the remaining 19 patients, good sternal fixation was secured. No cases required surgical procedures such as refixation of the sternum or removal of the staples. As a means of assessing the status of "backing out", which is a major cause of poor fixation, the backing out part of the staple leg was measured from lateral sternal radiographies. The ratio of the backing out portion to the staple leg, the backing out ratio (BOR), was calculated. The average BOR was found to be 32.7 +/- 21.4% (n = 102). The BOR was 70% or less in 91.2% of all staples, and 70% or more in 8.8%. The fragility of the sternum, poor sternal connection and inadequate technique to drive were suspected as factors accountable for backing out. In conclusion, the stapler system seems to be useful for sternal fixation and will become even more after improvement of the staple size and technical modifications to assure better connection at the driven site.

[A case report of Bentall procedure for annulo-aortic ectasia associated with right coronary artery dissection].

A 30-year-old man who had annuloaortic ectasia associated with aortic insufficiency owing to marked annular dilatation was treated by replacement of the ascending aorta and aortic valve with a composite graft. It was necessary to transpose the origin of the coronary artery because of the development of dissection to right coronary ostia. We have applied the Bentall procedure with aorta coronary bypass between the right coronary artery and the aortic prosthesis with the use of saphenous vein graft. His post operative course is uneventful and engaging full work 18 month after operation. This technique is useful for the case of annuloaortic ectasia associated with difficulty coronary anastomosis such as coronary artery dissection, obstruction or dislocation.