Aneurysm Expansion after Stent-Graft Placement in the Absence of Endoleak (2023)

Citation Excerpt :

However, no significant differences were found in taper ratios between patients in the SINE and non-SINE groups. Kato et al.12 suggested a more fibrotic and seemingly stable membrane for endovascular repair in the chronic phase. Our previous work13 demonstrated that endograft area oversized more than 4 times significantly increased SINE occurrence after hybrid arch elephant trunk repair using stainless steel-based devices in aortic dissection.

This study evaluated sequential aortic morphologic remodeling and influencing factors between distal stent graft-induced new entry (SINE) in chronic residual type A dissecting aortic aneurysm after extensive hybrid arch repair.

We retrospectively analyzed operative and follow-up data of 30 consecutive patients with chronic residual type A aortic dissection aneurysm treated by hybrid type III arch repair (ascending aortic and arch replacement combined with elephant trunk technique before stent-graft deployment) between November 2006 and October2011.

In 3 years, follow-up of 24 patients with successful 1-stage hybrid arch repair and stent grafting. The ratio of true lumen area increased at pulmonary artery level, but minimal change was seen in the thoracic segment distal to stent graft and abdominal aorta. Late distal SINE occurred in 14 patients (SINE group). Cross-sectional area showed significant differences in distal end of pre–stenting graft oversizing ratio (SINE group 4.32 vs. non-SINE group 2.23, P=0.021^∗). The thoracic segment thrombosis rate was 90% in SINE and 57% in non-SINE (P=0.089) groups.

In homogenous population of chronic residual type A dissection, noticeable false lumen thrombosis with true lumen progressive dilatation was only found at the proximal descending aortic segment extending to the middle of stent grafts in both groups. A smaller size selection of the distal stent graft by area measurement would be accompanied with poor aortic remodeling but might be beneficial for SINE prevention. On the other hand, a larger size selection of the distal stent graft area might be favorable for aortic remodeling but could potentially induce SINE.

Previous studies have demonstrated that women tend to have adverse aortic neck morphology leading to exclusion of some women from undergoing endovascular aneurysm repair (EVAR). The objective of this study is to investigate differences in aortic neck morphology in men versus women, changes in the neck morphology and sac behavior after EVAR, and investigate how these features may influence outcomes.

We conducted a retrospective review of elective EVARs (2004–2013). We excluded patients who underwent elective EVAR with no postoperative imaging available and those patients with fenestrated repairs. Using TeraRecon and volumetric analysis, several features were investigated. These included percent thrombus, shape, length, angulation of the neck, and changes in neck and abdominal aortic aneurysm diameter.

A total of 146 patients were found to meet inclusion criteria (115 men and 31 women) with similar baseline characteristics. Neck angulation was greater in women (23.9° vs. 13.5°; P<0.028). The percent thrombus in women was higher than men (35.4% vs. 31%; P<0.02). Abdominal aneurysm's were smaller in women at 1year (4.2cm vs. 5.1cm; P<0.002), and secondary interventions were higher in men (11.3% vs. 0%; P<0.05). Other features such as neck shape, changes in neck diameter, neck length, and percent oversizing of graft where not statistically different between genders.

Gender differences in neck characteristics and changes in neck morphology do not appear to adversely affect EVAR outcomes. Longer follow-up is necessary to further assess whether these findings are clinically durable.

Citation Excerpt :

The treatment methods for endoleaks depend on the location of the leak and its type. Various methods have been reported such as glue,12 coils,15 and ligation of branches; however, these methods have shown residual endoleak.14 Surgical conversion to standard repair is the last resort for refractory endoleaks associated with expansion of the sac.

Persistent endoleak and endotension, complications after endovascular aortic repair, may be caused by an unorganized thrombus inside the aneurysm. The experimental study was designed to evaluate the effectiveness of stent grafts (S/Gs) with slow release of basic fibroblast growth factor (bFGF) for the organization.

The S/Gs were constructed of self-expanding Z stent covered with expanded polytetra fluoroethylene graft, and coated with elastin to be able to bind and slowly release bFGF. Five elastin-coated S/Gs with bFGF (bFGF-S/Gs) and without bFGF (C-S/Gs) were placed in the normal canine aorta respectively. The thoracic aortic aneurysm models were surgically created with a jugular vein patch in 12 beagles. S/Gs with six holes, for creating endoleaks, were used in the experiment of aneurysmal repair. The bFGF-S/Gs (n = 6) and C-S/Gs (n = 6) were implanted. The beagles were sacrificed at two weeks after the endovascular procedure and examined histologically.

The bFGF-S/Gs induced six times the intimal proliferation of the C-S/Gs in normal aorta. Twelve animals had successfully created aneurysms, and had endoleaks just after the endovascular procedure. At two weeks after the endovascular procedure, the percentage of fibrous area in the aneurysmal cavity treated with bFGF-S/G (35.7 ± 4.3%) was significantly greater than C-S/G (13.6 ± 2.2%) (P < .01).

bFGF-S/Gs are effective for accelerating organization of the aneurysm cavity and developing neointima. Further research on bFGF-S/Gs would clarify the association of endoleaks.

Citation Excerpt :

This concept is supported by some operative findings where endografts have been explanted owing to endotension. In some cases, gel-like semi-liquid thrombus has been documented at proximal, distal, and junctional seal zones,12 and in others, back-bleeding has been found from lumbar vessels upon removal of this thrombus.14 It has also been noted, however, that some patients with endotension have no obvious thrombus in the intra-aneurysmal sac, but instead a clear straw-colored liquid is found.14,15

There are two graft materials for endovascular repair of aortic diseases, i.e., polyester and expanded polytetrafluoroethylene (ePTFE). The latest reports have suggested that there is graft-specific difference in outcomes. The purpose of this article was to evaluate the difference in terms of aneurysm shrinkage.

Eighty-six patients who underwent endovascular repair of aortic diseases were included. Forty patients had true aortic aneurysms, 8 had aortic pseudoaneurysms, and 38 had aortic dissections. Eighteen patients with true aortic aneurysms were treated with stent grafts fabricated with polyester, while the other 68 patients, including 22 patients with true aneurysms, 8 patients with pseudoaneurysms, and 38 patients with aortic dissections, were treated with stent grafts fabricated with ePTFE. All patients were followed-up by computed tomography (CT) for more than 1 year. The mean follow-up term was 28 months. Computed tomography confirmed that there were sufficiently long necks, and the aneurysm or the entry tear was completely excluded without any endoleak in all patients. The diameter of the preoperative lesion was compared with that measured on follow-up CT at 1 year and at the end of the follow-up term. Increase or decrease in the diameter by more than 5 mm was defined as a significant diameter change.

Aneurysm shrinkage was observed in 40% of patients with true aneurysms, 88% of patients with pseudoaneurysms, and 55% of patients with aortic dissections at 1 year. There was no significant increase in patients with aneurysm shrinkage at the end of follow-up in any groups. In the case of true aortic aneurysms, shrinkage of aneurysms was observed more frequently with polyester-fabricated stent grafts (67%, 13/18) than with ePTFE-fabricated ones (18%, 4/22) at 1 year (P<.01). In contrast, expansion of aneurysms was observed only in patients treated with ePTFE (14%, 3/22). Shrinkage of the descending aorta was observed in 55% of patients with acute aortic dissections and 36% of patients with chronic aortic dissections. There was no case with aortic enlargement in either group. There was no significant difference between acute and chronic dissection in terms of shrinkage of the descending aorta.

Expanded polytetrafluoroethylene appears to be effective for the treatment of pseudoaneurysms and aortic dissections. However, polyester seems to be more effective than ePTFE when true aneurysms are to be treated.

To investigate a virtual reality imaging system in terms of visualization accuracy and appropriate orientation when displaying cardiac anatomy, we used an exvivo model enabling direct comparison between reconstructed 3-dimensional visualization of intracardiac structures and real-time visual images.

We established a systole-diastole platform using a swine heart activated by an external mechanical pump and reservoir, allowing simultaneous acquisition of endoscopic visual and computed tomography images of the aortic valve. Virtual images were processed from computed tomography data using 3-dimensional software (the Vesalius 3D suite; PS Medtech, Amsterdam, Netherlands) and compared with visual images seen through a fiberoptic scope.

An endoscope gave a fine view of the aortic valve, whereas the virtual images elucidated the valve structures. Superimposition of the images from the 2 different modalities showed the virtual reality images precisely matching the visual images in both systole and diastole, confirming the validity of this virtual reality application.

In view of this demonstrated fidelity of virtual imaging, this technology may be of sufficiently high quality to be considered a gold standard for cardiac anatomy.

There is at present no accurate figure for the long-term patency rate of the skeletonized gastroepiploic artery (GEA).

From January 2002 to July 2012, 956 consecutive patients underwent isolated off-pump coronary artery bypass graft (OPCABG) surgery at our institution. Of these, the 424 who underwent GEA grafting and postoperative GEA graft evaluation were the subjects of the present study. Of these 424 subjects, 155 (36.6%) underwent long-term outpatient evaluation using multidetector computed tomography angiography.

No patient was converted from off pump to on pump surgery. Overall 30-day mortality was 0.5% (2 of 424). The overall early (4 to 21 days after surgery) patency rate of the skeletonized GEA was 98.2% (599 of 610 anastomoses). A total of 215 GEA anastomoses, including 55 sequential bypasses, were followed for long-term evaluation, of which 12, including three sequential bypasses, were found to be occluded. The overall patency rate in skeletonized GEA grafting over a mean follow-up period of 73 months was 94.4% (203 of 215). The cumulative patency rate of the skeletonized GEA was 97.8% at 30 days, 96.7% at 1 year, 96.0% at 3 years, 94.7% at 5 years, and 90.2% at 8 years after surgery. Multivariate Cox proportional hazard regression analysis showed that target vessel stenosis (p= 0.008, hazard ratio 0.086, 95% confidence interval: 0.014 to 0.53) was the only independent predictor of late graft occlusion.

We demonstrated an accurate long-term patency rate for the skeletonized GEA superior to that for pedicled GEA or saphenous vein graft. A low-grade degree of target vessel stenosis was the only risk factor for late GEA occlusion.

Stabilization of microcatheters during coiling after their optimal shaping are key factors for successful endovascular coil embolization of cerebral aneurysms. However, stabilization and optimal shaping of microcatheters are sometimes difficult. Our aim was to introduce “tailor-made” microcatheter shapes for coil embolization using three-dimensional (3D) printed vessel models.

Since August 2014, we have been investigating the use of 3D printed models of intracranial arterial aneurysms to produce optimally shaped microcatheters for endovascular coil embolization. Using Digital Imaging and Communication in Medicine data obtained from preoperative cerebral angiography, a vessel model was produced with a 3D printer using acrylic resin. Preoperative planning of microcatheter navigation and shaping were performed using the 3D vessel models. Before the procedure, microcatheter mandrels were bent manually to the intended angle, referring to the vessel model, and then sterilized. The 3D vessel models were also sterilized with plasma and used during the procedure.

Twenty-six patients (27 aneurysms) were treated using a total of 48 microcatheters shaped while referring to the 3D printed vessel model. Of the 48 catheters, only 9 (19%) required modification of the initial shape due to inappropriate positioning of the catheter. Only 29% of the catheter placements required repositioning due to catheter kick back. There were no procedure-related complications, including aneurysm rupture. The responses from assistants to a questionnaire administered after the embolizations on the usefulness of the technique were favorable.

Tailor-made shaping of microcatheters may facilitate easier and safer procedures in coil embolization of intracranial aneurysm.

It is impossible to resolve all the problems of the entire diseased aorta with just one operation for acute type A aortic dissection, which requires additional surgical treatment in the long-term.

From April 2004 to March 2017, 310 patients underwent surgical repair for acute type A aortic dissection at our institution. Of these, 32 (10.3%) died in the hospital. Of the 278 hospital survivors, 38 underwent late reoperation associated with aortic dissection during the follow-up period. We compared the 240 nonreoperation patients and the 38 reoperation patients to analyze risk factors for late reoperation after operations for acute type A dissection.

The mean duration from the initial operation to reoperation was 3.54 ± 3.0 years. The rates of actuarial freedom from reoperation were 96.9%, 83.2%, and 64.2% at 1, 5, and 10 years, respectively. The multivariate Cox proportional hazard regression analysis revealed the following as independent predictors of late reoperation: younger age, Marfan syndrome, nonprescription of β-blockers, greater diameter of the descending aorta, ratio of false lumen to true lumen of more than 1, limb malperfusion, and primary entry in the ascending aorta. Log-rank analysis revealed no difference in long-term survival between the two groups.

We found several risk factors for both late reoperation and death. Specifically, aortic diameter in the early phase after the initial operation and nonuse of β-blockers were strong predictors. The ratio of the false lumen to the true lumen may also be a new and useful indicator for late reoperation.

The present study aims to examine the medium-term results of butterfly resection.

Of 587 consecutive patients who underwent surgery for mitral regurgitation between January 2002 and August 2012, 162 patients underwent valve reconstruction of a prolapsed posterior leaflet. Quadrangular resection (n=50, Quadrangular group) was primarily used before November 2006 (when we innovated the concept of butterfly resection). After that, we mainly used butterfly resection (n=76, Butterfly group).

Although there was no sign of systolic anterior motion in the Butterfly group, it occurred in 2 patients in the Quadrangular group. One patient in the Quadrangular group died of stroke at postoperative day 17. The mean follow-up period was 2.2 ± 1.6 years for the Butterfly group and 6.1 ± 2.5 years for the Quadrangular group. During those periods, 2 patients died of noncardiac causes in the Butterfly group and 1 patient died of an unknown cause in the Quadrangular group. One patient in the Quadrangular group required a reoperation for recurrent mitral regurgitation arising from a new lesion of the anterior leaflet. One patient in the Butterfly group required a reoperation for partial dehiscence of suture at the posterior leaflet. The 3-year estimated survivals free from overall death and reoperation for recurrent mitral regurgitation in the Butterfly group and the Quadrangular group were 97% ± 2% versus 96% ± 3% (P=.89) and 95% ± 3% versus 96% ± 3% (P=.75), respectively.

Butterfly resection provides acceptable early and medium-term results.

We were interested in how favorable an influence total arterial reconstruction has on the clinical outcome of patients undergoing off-pump coronary artery bypass graft surgery.

From January 2002 to December 2013, a total of 1,064 patients underwent isolated off-pump coronary artery bypass graft surgery at our institution. Of these 1,064 patients, 763 underwent total arterial revascularization (AR) and 301 underwent a combination of artery and vein revascularization (AVR). We compared the clinical results between the two groups using the propensity score matching technique.

In all, 260 cases from the AVR group and 520 from the AR group were successfully matched. All procedures were performed using the off-pump technique without conversion to on-pump. Eight patients in the AVR group (3.1%) and 5 in the AR group (1.0%) died in hospital. Multivariate analysis revealed that chronic kidney disease (odds ratio 6.9, p < 0.001), urgency (odds ratio 7.3, p < 0.001), and body mass index (odds ratio 1.3, p= 0.02) were independent risk factors for hospital death. Follow-up was complete for 97.6% of the patients to a maximum of 13 years. According to the Kaplan-Meier method, the rate of 12-year freedom from all causes of death was 69.7% for the AVR group and 72.6% for the AR group (p= 0.002), and the corresponding rates for major adverse cardiac events were 83.9% and 87.7% (p= 0.009). By multivariate Cox regression analysis, total arterial reconstruction was identified as a preventive factor for late cardiac events.

Total arterial revascularization has some degree of favorable effect on the long-term clinical outcome of patients undergoing off-pump coronary artery bypass graft surgery.