Wataru Higashiura

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.

Prevalence, factors, and clinical impact of self-expanding stent fractures following iliac artery stenting

PURPOSE To evaluate the prevalence, factors, and clinical impact of self-expanding stent fracture following iliac artery stenting. MATERIALS AND METHODS A review of the endovascular registry database for our department showed 353 patients with occlusive diseases of the iliac artery who underwent stenting between 1997 and 2007. While clinical data and images were retrospectively reviewed for all patients, 165 patients who underwent self-expanding stenting and plain radiograph with >or=6-months follow-up were analyzed. Mean follow-up was 43 months for 305 stents (elgiloy, n = 83; nitinol, n = 222) implanted in 216 iliac arteries. The mean duration until the last imaging study was 38 months. Items concerning prevalence of stent fracture, factors associated with fracture, and outcomes for patients with stent fracture were analyzed. RESULTS Stent fracture was detected in 11 of 216 iliac arteries (5.1%). In stent-based analysis, 11 of 305 stents (3.6%) showed stent fracture, classified as type I in 2 stents, type II in 3 stents, type III in 4 stents, type IV in 1 stent, and type V in 1 stent. Stent fracture was detected in 11 of 222 nitinol stents (5.0%), but no Elgiloy stents. Cox proportional hazards regression model indicated stenting for chronic occlusion as a risk factor associated with nitinol stent fracture (hazard ratio [HR] = 6.09, P = 0.008, 95% confidence interval [CI] 1.59-23.3). Cumulative primary patency rates in iliac arteries with and without fractured stents were 90% and 91% at 8 years (P = .80), respectively. CONCLUSION Fracture of self-expanding stents is rare in iliac arteries, but stenting for chronic occlusion represents a risk factor for fracture. Fractures of stents placed in iliac arteries rarely affect patency.

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.

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.

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.

Fracture and Collapse of Balloon-Expandable Stents in the Bilateral Common Iliac Arteries Due to Shiatsu Massage

We report a case of stent fracture and collapse of balloon-expandable stents caused by shiatsu massage. A 76-year-old man presented with complaints of intermittent claudication of the right lower extremity. Stenoses of the bilateral common iliac arteries (CIAs) were detected. Balloon-expandable stents were deployed in both CIAs, resulting in resolution of symptoms. Five months later, pelvis x-ray showed collapse of both stents. Despite the stent collapse, the patient was asymptomatic, and his ankle brachial index values were within the normal range. Further history showed that the patient underwent daily shiatsu therapy in the umbilical region, which may have triggered collapse of the stent. Physicians should advise patients to avoid compression of the abdominal wall after implantation of a stent in the iliac artery.

Stent-Graft Treatment of Dissecting Aneurysm in Association with Aortic Intramural Hematoma: When Should the Procedure Be Performed?

Purpose: To report 2 cases of stent-graft implantation for localized dissecting aneurysm during the conservative treatment of aortic intramural hematoma. Case Reports: One patient underwent stent-graft implantation for 2 localized dissecting aneurysms about 23 months after symptom onset. Computed tomography (CT) 1 year after the procedure demonstrated aneurysm shrinkage. In the other patient, a localized dissecting aneurysm was treated about 3 months after symptom onset, even though the intramural hematoma had not resolved. CT scanning 3 months after the procedure demonstrated aneurysm shrinkage, but also revealed poor attachment of the distal stent-graft to the aortic wall due to subsequent resolution of the hematoma. Conclusions: Endograft implantation for treatment of localized dissecting aneurysm associated with aortic intramural hematoma should probably not be performed before the hematoma has completely resolved.

Recurrent brain abscess induced by pulmonary arteriovenous fistula

Brain abscess associated with an arteriovenous fistula (AVF) is sometimes difficult to diagnose and tends to recur. We report a case of recurrent brain abscess due to a pulmonary AVF (PAVF). A 69-year-old woman with a mass in the left cerebral peduncle had taken a progressively worse and shown decorticate rigidity. After an intravenous antibiotic for fever of unknown origin was changed, her condition gradually improved. She was discharged with the help of a cane. Thirty-one months later, she suffered left hemiparesis. Magnetic resonance imaging revealed a cystic mass in the right lateral frontal lobe. At surgery, we confirmed pus in the cyst. A PAVF was detected and was treated with coil embolization. The left hemiparesis improved and the postoperative course was uneventful. Exhaustive study is absolutely necessary to detect the etiology of recurrent brain abscess and to achieve a cure.

Intravascular Ultrasound Assessment of Acute Expansion of the Balloon-expandable Stent in Heavy Calcified Iliac Artery Lesions or in Lesions Resistant to Dilation by a Self-expanding Stent

BACKGROUND To evaluate the acute stent expansion of a balloon-expandable stent (BES) by intravascular ultrasound (IVUS) in lesions with heavy calcification or in lesions resistant to dilation by a self-expanding stent (SES). METHODS Primary stent placement using the Express LD was performed for 72 limbs in 56 patients. The BES was deployed both for ostial lesions of the common iliac artery (CIA) in 63 limbs and for additional dilation of an SES using a stent-in-stent maneuver in 9 limbs. Of the CIA ostial lesions, 71% (45 of 63) had heavy calcification. The primary endpoint was an acute stent expansion as assessed by IVUS. The ratio of the IVUS-measured minimal stent diameter (MSD) to the diameter predicted by the manufacturers compliance chart was used as a measure of the acute stent expansion. The ratio was compared between noncalcified and calcified CIA lesions and between before and after additional placement of the BES in the case of insufficient expansion of an SES. RESULTS The BES achieved 81 ± 10% of the predicted MSD in noncalcified CIA lesions and 78 ± 12% of the predicted MSD in heavy calcified CIA lesions (P = 0.346). In the 9 limbs with insufficient expansion of an SES, deployment of the BES resulted in an improvement in MSD from 39 ± 16% to 77 ± 8% of the predicted MSD (P < 0.001). CONCLUSIONS Sufficient acute expansion of the BES was demonstrated in heavy calcified lesions or in lesions with insufficient expansion of an SES.

Catheter-Based Bailout Techniques for an Interrupted Deployment of the Excluder Endograft Due to Broken Deployment String

In this report we describe catheter-based bailout techniques for when the distal end of the ipsilateral leg of an Excluder endograft has remained undeployed due to a broken deployment string. We attempted to advance a percutaneous transluminal angioplasty (PTA) balloon into an undeployed leg via the brachial artery, but were unable to do so. The delivery catheter was then pulled out through the undeployed leg while the main body was supported by a dilated touch-up balloon to prevent stent graft migration, which subsequently enabled insertion of the balloon via the ipsilateral femoral artery. Complete deployment was accomplished by balloon dilation. Although this is situation is extremely rare, it should be recognized and catheter-based strategies should be known for dealing with this complication.