Evaluation of a portable assembly catheter simulator using a 3D-printed heart model for percutaneous transvenous mitral commissurotomy in developing countries: Catheter simulator for PTMC.

AIMS: We developed a catheter simulator for percutaneous transvenous mitral commissurotomy (PTMC) based on the data from a patient with mitral valve stenosis. The simulator has the following characteristics: 1) the simulator is portable and easy to assemble and disassemble, 2) the cardiac portion is created using a 3D-printer, based on patient computed tomography data, 3) the simulator uses a foot-operated water pump to create pulsatile flow, and 4) the fossa ovalis in the atrial septum of the heart model is made of a thin polyurethane membrane and is interchangeable. We aimed to assess the effectiveness of this novel simulator for training in PTMC using the Inoue balloon in developing countries. METHODS AND RESULTS: We used this simulator for training in the National Institute of Cardiovascular Diseases in Bangladesh (13 physicians), and in Kenyatta National Hospital in Kenya (11 physicians). The effectiveness of training was evaluated by questionnaire and the procedure time in simulation. The questionnaire obtained from the trainees showed that the model scored 4.7±0.5 for realism, utility of pulsatile flow scored 4.7±0.5, simulator utility scored 4.9±0.3, and the effect of training on PTMC performance scored 4.9±0.5. The procedure time in simulation was shortened from 30.0±12.6 min (first time), to 23.4±11.9 min (second time) and to 20.4 ± 11.1 min (third time) (p<0.01). CONCLUSIONS: The novel portable assembly catheter simulator using a 3D-printed heart model for PTMC received positive comments and improved the skills of trainees.

A novel guidewire-integrated embolic protection filter device with a handy-folding system: In vitro and in vivo performance assessment.

OBJECTIVES: We developed a novel guidewire-integrated filter device with a handy-folding system (IFD: Inoue filter device). In vitro and in vivo studies were conducted to evaluate the feasibilityof the IFD. BACKGROUND: Although distal atheromatous and thrombotic embolizations remain unresolved critical issues during catheter interventions, distal protection devices are infrequently used partly because of reduced lower maneuverability. METHODS: In the in vitro experiment, we created an experimental circulation model composed of silicone latex tubes, a reservoir, and a roller pump. After the filter device was deployed in the tube, polystyrene fluorescent microspheres were injected and the capture rate was calculated. Ten trials were performed using the IFD and Spider FX. In the in vivo study, five independent operators deployed, and they retrieved the IFD in swine common iliac and internal carotid arteries. The procedural success rate as well as the delivery and retrieval time was evaluated. RESULTS: In the in vitro study, the mean capture rate was 94% and 35% in the IFD and Spider groups, respectively. In the in vivo study, all procedures were successful, with no complications. The mean delivery time was 281 ± 87 s and 194 ± 67 s and the mean retrieval time was 24 ± 9 and 13 ±1 s in the left internal carotid and the left common iliac arteries, respectively. CONCLUSION: Although further studies and improvements are required, the study results indicate that the IFD is feasible.

Thoracic endovascular aortic repair with branched Inoue Stent Graft for arch aortic aneurysms.

BACKGROUND: Thoracic endovascular aortic repair (TEVAR) for thoracic aortic aneurysms (TAAs) is in rapid expansion due to its minimal invasiveness. However, TEVAR for an arch aneurysm with a straight stent graft needs surgical reconstruction for supra-aortic vessels. A branched stent graft pioneered by Inoue (branched Inoue Stent Graft [ISG]) has been expected to resolve this problem, but its utility remains to be established in the real clinical setting. This study evaluated the long-term clinical outcome of branched ISGs for TAAs. METHODS: Among 217 consecutive patients who underwent TEVAR with ISGs between March 2003 and September 2013, 89 patients with TAAs were treated with implantation of the branched ISG (single branch: n = 64; double branch: n = 18; triple branch: n = 7). The primary end point was freedom from aneurysm-related death. Secondary end points included periprocedural adverse events, freedom from all-cause death and major adverse events (composite of aneurysm-related death, surgical conversion, aneurysm rapture, persistent type I or III endoleak, graft infection, graft occlusion, graft migration, and aneurysm expansion), changes of aneurysm diameter, stroke, and any endovascular reintervention during follow-up. RESULTS: All deployments of branched ISGs were successful. The 30-day mortality was 4.5% (single branch, 3.1%; double branch, 0%; triple branch, 29%), and periprocedural stroke was 16% (single branch, 7.8%; double branch, 33%; triple branch, 42%). At 1 and 5 years, freedom from aneurysm-related death was 93% and 93%, respectively, and freedom from all-cause death was 85% and 59%, respectively. Survival free of major adverse events was 76% at 5 years. The cumulative incidence of stroke was 11% at 5 years. Three patients underwent surgical conversion because of persistent type I endoleak. One branch graft occlusion was observed at the left subclavian artery in a patient who received a double-branched graft. CONCLUSIONS: Periprocedural outcome of the single-branched ISG was acceptable, and long-term safety and efficacy were demonstrated. However, the procedural complications of the multibranched ISG leave room for improvement.

Comparison of endovascular repair with branched stent graft and open repair for aortic arch aneurysm.

OBJECTIVES: Although conventional open repair is our preference for patients with aortic arch aneurysms, we have often chosen thoracic endovascular aneurysm repair (TEVAR) with a handmade branched stent graft (bTEVAR) in high-risk patients. The aim of this study was to compare the midterm clinical outcomes of our bTEVAR technique to those of the open repair. METHODS: Between January 2007 and December 2014, we treated 129 patients with aortic arch aneurysm by means of either conventional open repair (OPEN, n = 61) or bTEVAR (n = 68) at our institution. RESULTS: The mean ages were 70.5 ± 12.7 years in the OPEN group and 72.7 ± 12.5 years in the bTEVAR group (P = 0.32). The aetiologies included true aneurysm in 101 patients (78.3%) and chronic dissection in 26 (20.1%). There were 2 (3.3%) in-hospital deaths in the OPEN group and 3 (4.4%) in the bTEVAR group. The mean follow-up duration was 3.0 ± 2.1 years (2.4 ± 1.9 years in the OPEN group and 3.6 ± 2.3 years in the bTEVAR group). There was no difference in 5-year aneurysm-related mortality between groups (10.7% in OPEN vs 12.8% in bTEVAR, P = 0.50). In terms of late additional procedures, however, none were required in the OPEN group, whereas 10 (15.4%) additional endovascular repairs and 4 (6.2%) open repairs were required in the bTEVAR group. CONCLUSIONS: Our bTEVAR could be performed with low early mortality, and it yielded similar midterm aneurysm-related mortality to that of conventional open repair. However, these patients undergoing this technique required more late additional procedures than those undergoing conventional open repair.

Antegrade transcatheter aortic valve implantation using the looped Inoue balloon technique: A pilot study in a swine model.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is an established therapy for patients who are inoperable or at high risk for open heart surgery. The retrograde transfemoral approach is the most widely used and is the first choice in TAVI. However, existence of peripheral vascular disease or a small iliofemoral artery often limits the application of the transfemoral approach. Transvenous antegrade transseptal TAVI is an attractive option, but has already been abandoned due to its technical complexities. METHODS AND RESULTS: We have previously described a novel technique to simplify antegrade transseptal balloon aortic valvuloplasty, which utilizes a custom-made Inoue balloon catheter with two stylets. The technique is named as the looped Inoue balloon technique, and its feasibility and efficacy were proven in an animal model and a clinical case. We applied this technique to TAVI. The present study aimed to assess the feasibility of the looped Inoue balloon technique for TAVI in two healthy pigs. The valve implantation was successful in both pigs, although the pigs died soon after the implantation (2 and 24h). The causes of death were access site bleeding (Case 1) and migration of the prosthetic valve (Case 2). CONCLUSIONS: Although several improvements and further studies are required, the study results indicate that antegrade TAVI using the looped Inoue balloon technique is feasible.

First clinical experience of the looped Inoue balloon technique for antegrade percutaneous balloon aortic valvuloplasty.

Balloon aortic valvuloplasty (BAV) has played a limited role in the management of patients with severe aortic stenosis. However, BAV is being performed more frequently these days with the emergence of transcatheter aortic valve implantation (TAVI). We previously described a technique named "looped Inoue balloon technique" to simplify the antegrade transvenous BAV by making a loop in the left atrium using two stylets. We present a case in which the looped Inoue balloon technique was successfully applied. The patient was an 83-year-old woman with progressive dyspnea due to severe aortic stenosis. The aortic valve area was 0.39 cm(2) with a mean transvalvular gradient of 46 mmHg. The patient was deemed high risk for surgical aortic valve replacement or TAVI in view of the multiple comorbidities and frailty. Antegrade BAV using the looped Inoue balloon technique was performed. The procedure was successful without any complications. The post procedural aortic valve area increased to 1.15 cm(2) with a mean pressure gradient of 23 mmHg. This is the first report of clinical use of the looped Inoue balloon technique for antegrade BAV.

A novel device for antegrade percutaneous balloon aortic valvuloplasty: feasibility of the looped Inoue balloon technique in swine model.

OBJECTIVES: The study aimed to assess the feasibility of a novel device and technique for antegrade percutaneous balloon aortic valvuloplasty (BAV) in a swine model. BACKGROUND: BAV is currently being applied more frequently compared to the past with the advent of transcatheter aortic valve replacement. Although the antegrade BAV approach offers several advantages over the retrograde approach, the antegrade approach is technically more complicated and demanding. METHODS: We developed a novel balloon catheter and a technique to simplify the antegrade BAV. The balloon catheter was designed to make a loop in left atrium by inserting two different sized stylets. The balloon catheter was easily dropped into the left ventricle via the mitral valve while maintaining the loop. The balloon catheter was advanced to the ascending aorta by holding the two stylets. Then, the balloon was inflated. We named the technique as the looped Inoue balloon technique. The feasibility of the looped Inoue balloon technique was assessed in a healthy swine with a body weight of 40 kg by four independent operators. Every operator conducted the procedure twice. RESULTS: The procedural success rate was 100% in all operators. The average procedure time was 170 ± 35 sec. No procedure related complications were noted. CONCLUSIONS: The study results indicate that the antegrade BAV using the looped Inoue balloon technique is feasible and may simplify the antegrade approach.

Percutaneous balloon valvuloplasty for bioprosthetic mitral valve stenosis.

Percutaneous transcatheter mitral valvuloplasty is the indicated treatment of choice for symptomatic native mitral valve stenosis, but there have been limited reports of successful procedures of balloon valvuloplasty for bioprosthetic mitral valve stenosis. We present the case of a 62-year-old woman suffering from progressive dyspnea due to bioprosthetic mitral valve stenosis. The measured mean pressure gradient across the mitral valve was 30 mmHg and the mitral valve area was 0.73 cm(2). Redoing mitral replacement was considered high risk and was refused by the patient. Percutaneous balloon valvuloplasty was performed with an Inoue balloon catheter inflated to 20 mm. The patient's symptoms immediately improved after the procedure, with no procedure-related complications. The mean pressure gradient across the valve decreased to 19 mmHg, and the mitral valve area increased to 1.21 cm(2) in postprocedural echocardiography. We conducted a literature search and identified 26 cases of balloon valvuloplasty for degenerated bioprosthetic valves. Of these, 14 cases were bioprosthetic mitral valves, and the results were favorable. However, more case reports are required to establish an evidence base for future expert recommendation of balloon valvuloplasty of prosthetic mitral valve. Meanwhile, balloon valvuloplasty will serve a niche role in highly selected patients with prosthetic mitral valve stenosis.

A novel detachable filter to prevent thromboembolism during endovascular surgery.

OBJECTIVE: Thromboembolism remains a serious complication during endovascular surgery. Commercially available filter devices, which are unified with the stenting systems, provide short-time performance owing to the adhesion of thrombus to the filters themselves. We have, therefore, developed a new detachable filter that can be used in all major aortic branches and shows greater longevity. The present study assessed the efficacy of the new detachable filter and examined the feasibility of deploying and retrieving the filters. METHODS: We first performed in vitro studies. Our experimental flow model used silicon tubing to simulate the aortic branches. Polystyrene-divinylbenzene microspheres (100 and 200 µm in diameter), which simulated embolic particles, were injected into the tubing after the detachable filter was deployed. The capture efficacy (number of microspheres trapped in the detachable filter/total injected microspheres) was calculated. In the in vivo studies, the detachable filters were implanted into the carotid, visceral, and renal arteries of 5 mongrel dogs. Angiography was performed every 30 minutes. At 5 hours after implantation, each detachable filter was retrieved by a gooseneck snare catheter. RESULTS: In the in vitro studies, our detachable filters showed high capture efficacy, capturing 99.2% of the 100-µm microspheres and 99.4% of the 200-µm microspheres. In the in vivo studies, all detachable filters were successfully deployed into the major branches. Each angiographic study revealed smooth flow without any embolic obstruction of the filter. At 5 hours after deployment, all devices were completely retrieved by the snare catheter without aortic injury. CONCLUSIONS: The new detachable filter showed high efficacy in capturing the particles. All detachable filters were successfully deployed for 5 hours, and the filters were retrieved from the aortic branches without any complications. This novel detachable filter can help prevent serious distal thromboembolism during endovascular surgery.

[Feasibility and possibility of Inoue stent graft for thoracic aortic aneurysms].

Open surgical repair is a traditional treatment for patients with thoracic aortic aneurysms. Despite recent advances in surgical techniques and anesthetic management, the surgical repair of thoracic aortic aneurysms is still associated with significant mortality and morbidity. Endovascular aneurysm repair of thoracic aortic aneurysms is emerging as an alternative method for repair in selected patients. Although endovascular stent grafting is less invasive than open surgical repair, involvement of branch vessels and precipitous curvature of the aortic arch limits the application of stent grafting. Inoue stent graft system consists of soft nitinol ring-type stent which enables very flexible stent graft, and it can well comply with the precipitous curvature of the aortic arch. The system also provides a stent graft with a side branch to manage the left subclavian artery. This system does not require the surgical revascularization of the left subclavian artery. In this report, we show the feasibility and possibility of Inoue stent graft system to manage the aortic arch aneurysm.

A novel approach to prevent spinal cord ischemia: Inoue stent graft with a side branch of small caliber for the reconstruction of the artery of Adamkiewicz.

OBJECTIVES: Paraplegia remains a serious complication after endovascular repair of thoracic aortic aneurysms, and it has been reported that paraplegia might be due to ischemia of the artery of Adamkiewicz. This study investigates the feasibility of an Inoue stent graft with a side branch of a small caliber for the reconstruction of the intercostal artery branching the artery of Adamkiewicz. METHODS: Branched Inoue stent grafts were implanted into the thoracic aorta and 11th intercostal artery of 5 mongrel dogs. The side branch measured 3 x 5 mm and contained a bare-metal coronary stent for fixing to the intercostal arterial wall. Aortography and selective angiography of the 11th intercostal artery were performed before and immediately after implantation and after 1, 4, 8, and 12 weeks. The luminal diameter of the intercostal artery before implantation was 2.4 +/- 0.3 mm. RESULTS: All stent grafts were successfully deployed. The main body of the graft did not develop endoleak or migrate, and the side branch remained patent for 12 weeks. Angiography performed 1 week postoperatively revealed smooth flow with slight stenosis (4.2% +/- 1.7%) along the side branches and the intercostal arteries in all dogs. Four weeks postoperatively, however, mild concentric stenosis (38% +/- 16%) along the side branch was observed in 4 of the 5 dogs. The percent stenosis at 8 and 12 weeks was 38% +/- 15% and 33% +/- 11%, respectively; these values were not significantly different from the value at 4 postoperative weeks. CONCLUSIONS: A novel Inoue stent graft with a side branch of small caliber was successfully deployed into the canine thoracic aorta and intercostal artery; the side branch remained patent for 12 weeks. This novel technique may enable endovascular reconstruction of the Adamkiewicz artery.

Successful repair of thoracoabdominal aortic aneurysm secondary to chronic dissection by hybrid therapy comprising surgical visceral reconstruction and dual Inoue stent graft implantation.

Crawford type II thoracoabdominal aortic aneurysm (TAAA) secondary to chronic dissection was successfully treated with hybrid therapy comprising surgical visceral reconstruction and dual Inoue stent graft implantation. The proximal single-branched Inoue stent graft effectively sealed the entry located near the left subclavian artery and simultaneously excluded the TAAA, while the distal tubular Inoue stent graft sealed the reentry; thus, the artery of Adamkiewicz was left unexcluded and intact between the two Inoue stent grafts. The visceral arteries were reconstructed using a quadrifurcated retrograde bypass with posterior aortic tunneling and end-to-end distal anastomosis to all four vessels to achieve a curved and smooth configuration.

Repeated transluminal endovascular Inoue stent graft placement for progressive dilatation of prosthetic graft that had been repaired with Inoue stent graft placement for dilatation 23 years after extraanatomical bypass.

A 76-year-old man had undergone aneurysm exclusion and ascending abdominal aortic extraanatomical bypass for a thoracoabdominal aortic aneurysm in 1978. In 1983 hemoptysis occurred, and resection and closure of the central stump of the aorta and a left lower lobectomy were performed. Dilatation (phi50 mm) of a prosthetic graft (Cooley Graft phi18 mm) used for extraanatomical bypass was noted in 2001 and was repaired by placement of an Inoue stent graft. However, the aneurysm diameter increased further (phi70 mm), although no endoleak was noted: Placement of an Inoue stent graft covering the whole length of the prosthetic graft was repeated in 2006. The postoperative course was smooth, no endoleak occurred, and the patient was discharged 2 weeks after surgery.

Endovascular repair of a thoracoabdominal aortic aneurysm involving the celiac artery and the superior mesenteric artery.

We present a successful endovascular repair of a thoracoabdominal aortic aneurysm (TAAA) involving the celiac artery and the superior mesenteric artery. After the intentional occlusion of the celiac artery, an Inoue stent graft with a side arm to the superior mesenteric artery was implanted. Management of the visceral arteries in the endovascular repair of TAAA was highlighted.

Feasibility of the Inoue single-branched stent-graft implantation for thoracic aortic aneurysm or dissection involving the left subclavian artery: short- to medium-term results in 17 patients.

OBJECTIVE: This study assessed the short- to medium-term clinical results of the Inoue single-branched stent graft for repair of thoracic aortic aneurysms or dissections involving the left subclavian artery. METHODS: A retrospective review of experiences at two institutions was performed. We analyzed the data of consecutive 17 patients with thoracic aortic aneurysms or dissections who underwent endovascular repairs with the Inoue single-branched stent graft between July 1999 and April 2004. Complete baseline and follow-up data were available on all patients. The mean age was 71 +/- 9 years, and 13 of the patients (76%) were men. Eight patients (47%) were considered unfit for open surgery because of advanced age or the presence of comorbid diseases. RESULTS: The stent grafts were successfully delivered and deployed in all 17 patients. Periprocedural major complications, defined as those that caused any persistent disorder, occurred in one patient who developed spinal ischemia. A postoperative computed tomographic scan revealed three attachment site endoleaks; two endoleaks were from the proximal attachment sites and one endoleak was from the distal attachment site. The mean follow-up period was 26 months (range, 7 to 65 months). Two deaths occurred in the follow-up period from cerebral bleeding and pneumonia, both considered unrelated to the stent grafting. Two patients with attachment site endoleaks needed secondary stent-grafting; one patient required the implantation of a straight stent-graft in the distal attachment site and the other, the implantation of a double-branched stent-graft. Another patient with attachment site endoleak was considered very high-risk for open surgery or secondary stent grafting and did not undergo secondary intervention. The aneurysmal sac size of the patient has been stable for 28 months. The branched section of the stent graft was patent in all patients in the follow-up period. CONCLUSION: The results demonstrate the feasibility of the Inoue single-branched stent graft for thoracic aortic aneurysms or dissections involving the left subclavian artery.

Successful endovascular repair of an aneurysm of the ductus diverticulum with a branched stent graft: case report and review of literature.

Aneurysm of the ductus diverticulum rarely has been reported in adults, and the reported aneurysms were treated with conventional open surgery or were diagnosed at autopsy. We report a successful endovascular repair of an aneurysm of the ductus diverticulum with the Inoue branched stent graft. In a 78-year-old woman, an abnormal shadow was noted at the aortopulmonary window on a chest x-ray film. A computed tomography scan demonstrated a 3.8-cm saccular aneurysm, which protruded inferiorly from the distal end of the aortic arch. The aneurysm was considered an aneurysm of the ductus diverticulum, and surgery was required. However, the patient was considered at high risk for respiratory dysfunction with conventional open surgery. Endovascular repair with an Inoue single-branched stent graft was performed with the patient under local anesthesia, successfully and without complication or endoleak. To our knowledge, this is the first report of endovascular treatment of an aneurysm of the ductus diverticulum.