Nobuoki Tabayashi

Aortic stent-grafting with transrenal fixation : use of newly designed spiral Z-stent endograft

PURPOSE To evaluate the feasibility and efficacy of a newly designed stent-graft placed across the renal arteries for exclusion of abdominal aortic aneurysms (AAAs) with short or tortuous proximal necks. METHODS Among a group of AAA patients treated with endovascular grafting, 5 had tortuous proximal necks and 13 had necks <20 mm (mean 13 mm). In these 18 cases, a 2- to 3-cm uncovered segment of the stent-graft was placed transrenally using a catheter inserted into the renal artery as a guide for graft margin positioning. A newly designed stent-graft was constructed from a custom-made spiral Z-stent covered with a thin-walled Dacron material; the endografts were deployed through 16-F (aortoaortic model) or 18-F sheaths (bifurcated devices). Renal function was assessed by preoperative and postoperative measurement of urea nitrogen and creatinine. Aneurysm exclusion and renal artery patency were evaluated during follow-up using spiral computed tomography and angiography. RESULTS The stent-grafts were correctly placed at the intended site in all 18 patients. Renal function was not affected except transiently in 1 patient who developed bilateral renal artery stenoses 24 hours after the procedure; Palmaz stents were deployed in each renal artery to reestablish satisfactory blood flow. Of the 33 renal arteries crossed by the bare stent-graft segment, all were patent over a mean 14-month follow-up (range 7-24), including the patient with Palmaz stents implanted for postprocedural renal stenosis. Complete aneurysm exclusion was maintained in 15 (83%) of 18 patients; proximal leaks persisted in 3 patients, including 2 with severely angled proximal necks. CONCLUSIONS Transrenal placement of the uncovered leading edge of custom-made spiral Z-stent-based endografts appears feasible and clinically effective in the treatment of AAAs with short or tortuous proximal necks.

Assessment of intraoperative motor evoked potentials for predicting postoperative paraplegia in thoracic and thoracoabdominal aortic aneurysm repair

PurposeMonitoring motor evoked potentials (MEPs) has been recognized as a highly reliable method to detect intraoperative spinal cord ischemia (SCI) in aortic repair. However, the data regarding the sensitivity and specificity of MEPs for predicting postoperative paraplegia are limited. We retrospectively assessed the value of intraoperative MEP amplitudes for predicting postoperative paraplegia.MethodsThe medical records of 44 patients were reviewed. A train-of-five stimulation was delivered to C3–C4, and MEPs were recorded from the abductor pollicis brevis and the tibialis anterior muscles. The cutoff point for detecting SCI was set at 75% decrease of the baseline MEP. Receiver operating characteristic curves were applied at various cutoff points.ResultsThree patients (6.8%) had postoperative paraplegia. The minimum MEP during surgery had 100% sensitivity and 64.9% specificity in predicting paraplegia, and the MEP at the end of surgery had 66.7% sensitivity and 78.0% specificity in predicting paraplegia: only 1 patient, who had borderline paraplegia (right monoparesis), showed a false-negative result. Receiver operating characteristic curves indicated that adequate cutoff points for the minimum MEP during surgery and for the MEP amplitude at the end of surgery were a 75–90% decrease and a 64–75% decrease of the baseline MEP, respectively.ConclusionMonitoring MEPs had relatively high sensitivity and acceptable specificity, with the cutoff point set at 75% decrease of the baseline MEP, for predicting paraplegia and paraparesis. Because of the small sample in our study, further investigations would be necessary to investigate an adequate cutoff point that could predict postoperative paraplegia.

Aortic valve replacement in a patient with a patent internal thoracic artery graft

Myocardial protection in patients requiring a second open-heart surgical procedure after coronary artery bypass grafting, especially when there is a patent left internal thoracic artery graft to the left anterior descending coronary artery, remains controversial. We present the case of a patient in whom aortic valve replacement was undertaken 18 months after coronary artery revascularization. Unusual features included beating-heart aortic valve replacement with continuous retrograde coronary sinus perfusion and avoidance of dissection of the patent grafts, including the left internal thoracic artery and a saphenous vein graft.

Clinical outcomes of thoracic endovascular aneurysm repair using commercially available fenestrated stent graft (Najuta endograft)

OBJECTIVE Thoracic endovascular aneurysm repair (TEVAR) for the aortic arch aneurysm is challenging because of its curved anatomic configuration and the presence of the supra-aortic branches. The Najuta fenestrated endograft (Kawasumi Laboratories, Inc, Tokyo, Japan) was developed to treat aortic arch diseases, offering maximal proximal landing length while preserving the blood flow to the supra-aortic branches. We evaluated the perioperative and midterm outcomes of this fenestrated endograft. METHODS Between July 2007 and July 2013, 32 patients were treated with the Najuta endograft at three vascular centers. The mean age of the patients was 74.5 ± 9.8 years (23 patients were men). Technical success, complication, overall survival rate, freedom from aneurysm-related death, secondary intervention, aneurysm enlargement, device migration, and patency of supra-aortic branches were investigated retrospectively. RESULTS The median follow-up period was 2.5 years (range, 0.2-6.2 years). Seventy-one supra-aortic vessels (30 brachiocephalic arteries, 31 left common carotid arteries, 10 left subclavian arteries) were planned to be preserved with fenestrations. Technical success rate was 91% (29 of 32; three type I endoleaks were seen), and five perioperative complications (two Stanford A dissections, one cerebral infarction, one celiac artery obstruction, one spinal cord ischemia) were recognized. Perioperative death was not observed. Overall survival rate and rate of freedom from aneurysm-related death at 3 years were 67% and 97%, respectively. The rate of freedom from secondary intervention and the rate of freedom from aneurysm enlargement at 3 years were 84% and 85%, respectively. Device migration was not observed. There were two branch (left carotid artery and left subclavian artery) occlusions at 2 weeks after TEVAR due to the endografts infolding. No other branch occlusion was seen in this follow-up period. As a result, the patency rate of the supra-aortic branch was 97% at 3 years. CONCLUSIONS The perioperative and 3-year outcomes of TEVAR using the Najuta precurved, fenestrated endograft demonstrated high freedom from aneurysm enlargement and patency rates of the supra-aortic branches.

Deteriorating Consumptive Coagulopathy with Type III Endoleak following Endovascular Repair for Abdominal Aortic Aneurysm Associated with Liver Cirrhosis

Purpose: To report a case of deteriorating consumptive coagulopathy with type III endoleak following endovascular aneurysm repair (EVAR) of the abdominal aorta associated with liver cirrhosis. Case Report: A 72-year-old man with liver cirrhosis developed type III endoleak following EVAR. Spontaneous intramuscular hematoma developed due to deteriorating consumptive coagulopathy induced by type III endoleak and liver dysfunction. Although additional EVAR was performed at 52 months after primary EVAR, the patient died due to multiorgan failure and multifocal hematoma of the muscles and subserosa. Conclusion: EVAR for patients with liver dysfunction and coagulopathy should be considered with great caution. We suggest that prompt and adequate treatment using an endovascular technique or surgical repair should be performed for patients with liver dysfunction, coagulopathy, and turbulent endoleak, even if the coagulopathies are worse compared to before EVAR.

Minimally Invasive Direct Coronary Artery Bypass Combined With Abdominal Aortic Aneurysm Repair

BACKGROUND For simultaneously combined coronary artery bypass surgery with infrarenal abdominal aortic aneurysm (AAA) repair, a relatively high operative mortality and morbidity have been reported. METHODS From February 1998 to December 1998, simultaneous minimally invasive direct coronary artery bypass combined with the AAA repair was performed for 4 patients (3 males, 1 female; mean age, 74+/-7 years). Three were high-risk patients: 2 were over 75 years of age, 2 had respiratory insufficiency, and 1 had severe renal impairment. RESULTS There were no mortalities. The endotracheal tube was removed within approximately 12 hours, and the postoperative courses were uneventful. During 4+/-4 months of follow-up, there was neither angina recurrence nor other morbidity. CONCLUSIONS Minimally invasive direct coronary artery bypass combined with AAA repair was safe even for high-risk patients.

Midterm outcomes of endovascular repair with the zenith endovascular graft: does the ipsilateral limb level of the main body of the graft affect outcome?

PURPOSE To clarify whether the ipsilateral limb level of the main body of the graft above or below the aortic bifurcation affects midterm outcomes of endovascular abdominal aortic aneurysm repair (EVAR) with the Zenith abdominal aortic aneurysm endovascular graft. MATERIALS AND METHODS The authors analyzed 70 consecutive patients treated with the Zenith endograft between 1999 and 2006 with a retrospective review of prospectively collected clinical and imaging data. Patients were divided into two groups--those in whom the ipsilateral limb of the main body was placed above the aortic bifurcation (group A, n = 34) and those in whom the ipsilateral limb of the main body was placed below the aortic bifurcation (group B, n = 36). The frequency of sac enlargement, late type I or III endoleak, and secondary intervention and freedom from major adverse events associated with an aneurysm were compared. RESULTS The median follow-up was 38 months (range, 1-84 months). The frequency of sac enlargement was 12% (four of 34 patients) in group A and 8% (three of 36 patients, P = .94) in group B. The frequency of late type I or III endoleak was 9% (three of 34 patients) in group A and 6% (two of 36 patients, P = .95) in group B. The frequency of secondary intervention was 15% (five of 34 patients) in group A and 6% (two of 36 patients, P = .38) in group B. Rate of freedom from major adverse events at 60-month follow-up was 62% in group A and 80% in group B (P = .54). CONCLUSIONS Placement of the ipsilateral limb of the main body above the aortic bifurcation should be considered as one option in patients with an inadequate iliac anatomy at this time. Further follow-up and accumulation of patients will help clarify outcomes with regard to differences in ipsilateral limb level.

Initial experience of branched endovascular graft for abdominal aortic aneurysm with complex anatomy of proximal neck: planning and technical considerations

The purpose of this report was to demonstrate initial Japanese cases of abdominal aortic aneurysm (AAA) with complex anatomy of proximal neck treated using a Zenith fenestrated endograft with branched endovascular technique and to describe the device’s design and technical considerations. Planning and sizing of endografts were performed using high-resolution computed tomography on a three-dimensional workstation. Branched endograft technique combined with reinforced fenestrated device and balloon-expandable stent graft was used in two patients because of challenging morphology for the fenestrated device with a bare stent. Successful exclusion of the aneurysm sac was achieved in both patients with antegrade perfusion in incorporated visceral vessels. Endovascular repair using a fenestrated device with graft material incorporating the visceral arteries is feasible. The combination of the reinforced fenestration and the balloon-expandable stent graft can provide an adequate sealing effect for the compromised anatomy. Initial and midterm results are reported with further follow-up and patient accrual.

A Decade of Outcomes and Predictors of Sac Enlargement after Endovascular Abdominal Aortic Aneurysm Repair Using Zenith Endografts in a Japanese Population

PURPOSE To present 10-year outcomes and risk factors for sac enlargement after endovascular aneurysm repair (EVAR) using the Zenith AAA Endovascular Graft (Cook, Inc, Bloomington, Indiana) in a Japanese population. MATERIAL AND METHODS During the period 1999-2011, 127 patients underwent elective EVAR using Zenith endografts at a single institution. A retrospective investigation looked at initial rates of technical success and complications, 10-year rate of freedom from all-cause and aneurysm-related mortality, freedom from secondary intervention and sac enlargement, and risk factors for second intervention and sac enlargement. RESULTS The median age of the patients was 78 years, and the median follow-up time was 43 months. The initial technical success rate was 98.4% (125 of 127 patients). Major adverse events occurred in 7 of 127 (5.5%) patients. Rates of freedom from all-cause and aneurysm-related mortality at 1, 3, 5, and 10 years were 95%, 87%, 77%, and 39% (all-cause mortality) and 100%, 100%, 99%, and 93% (aneurysm-related mortality). Rates of freedom from secondary intervention at 1, 3, 5, and 10 years were 97%, 91%, 88%, and 70%. Rates of primary freedom from sac enlargement at 1, 3, 5, and 10 years were 99%, 87%, 75%, and 67%. Multivariate analysis revealed aneurysm sac diameter as an independent risk factor for a secondary intervention. Preoperative sac diameter combined with an angulated short (AS) proximal neck was a risk factor for sac enlargement. CONCLUSIONS The 10-year results of EVAR using Zenith endografts in a Japanese population were comparable to results from Western countries. Larger aneurysms and AS neck were predictors of sac enlargement after EVAR.

Ocular Blood Flow Measured Using Laser Speckle Flowgraphy During Aortic Arch Surgery With Antegrade Selective Cerebral Perfusion

OBJECTIVE The objective of this study was to evaluate the validity of ocular blood flow measured using laser speckle flowgraphy (LSFG) for the assessment of cerebral perfusion during aortic arch surgery. DESIGN A prospective study. SETTING A single university hospital. PARTICIPANTS The study included 17 patients undergoing aortic arch surgery with cardiopulmonary bypass (CPB) using antegrade selective cerebral perfusion (ASCP). INTERVENTIONS Measurement of ocular blood flow using LSFG. MEASUREMENTS AND MAIN RESULTS Measurement of ocular perfusion that is supplied mainly from the ophthalmic artery might be useful as an indicator of cerebral blood flow because the ophthalmic artery is the first branch of the internal carotid artery. Recently, LSFG has been developed for noncontact estimation of ocular perfusion using the laser speckle phenomenon. In this study, the LSFG system was used to measure blood flow in the optic nerve head during aortic arch surgery with CPB using ASCP. The blood flow in the optic nerve head during ASCP was statistically significantly reduced by 40.6% compared with the baseline value after anesthetic induction. CONCLUSIONS Ocular blood flow measured using LSFG showed favorable validity for assessment of cerebral perfusion during aortic arch surgery with ASCP.