Long-Term Outcomes of a Japanese Prospective Multicenter Registry Using a Heparin-Bonded Expanded Polytetrafluoroethylene Graft for Above-the-Knee Femoropopliteal Bypasses

BACKGROUND

Despite the widespread use of PROPATEN®, a bioactive heparin-bonded expanded polytetrafluoroethylene graft, in bypass surgery, there are only a few reports of long-term results. We evaluated the long-term results of PROPATEN®use for above-knee femoropopliteal bypass (AKFPB).Methods and Results: After PROPATEN®-based AKFPB, patients were prospectively registered at 20 Japanese institutions between July 2014 and October 2017 to evaluate long-term results. During the median follow-up of 76 months (interquartile range 36-88 months) for 120 limbs (in 113 patients; mean [±SD] age 72.7±8.1 years; 66.7% male; ankle-brachial index [ABI] 0.45±0.27; lesion length 26.2±5.7 cm; chronic limb-threatening ischemia in 45 limbs), there were 8 major amputations; however, clinical improvement was sustained (mean [±SD] ABI 0.87±0.23) and the Rutherford classification grade improved in 105 (87.5%) limbs at the latest follow-up. At 8 years, the primary patency, freedom from target-lesion revascularization, secondary patency, survival, and amputation-free survival, as estimated by the Kaplan-Meier method, were 66.3±4.8%, 71.5±4.4%, 86.5±3.4%, 53.1±5.0%, and 47.4±5.3%, respectively.

CONCLUSIONS

This multicenter prospective registry-based analysis showed sustained excellent clinical improvement and secondary patency for up to 8 years following PROPATEN®-based AKFPB. PROPATEN®constitutes a durable and good revascularization option for complex superficial femoral artery lesions, especially when endovascular treatment is inappropriate or an adequate venous conduit is unavailable.

Impact of wound management strategies after revascularization for chronic limb-threatening ischemia

OBJECTIVE

There is no established consensus or guidelines for wound management after revascularization for patients with chronic limb-threatening ischemia (CLTI) without severe infection. This study is designed to evaluate the clinical effect of the wound management strategy on toe wounds after revascularization for CLTI.

METHODS

This retrospective cohort study was performed at eight institutions affiliated with Keio University School of Medicine in Japan and included 261 patients who underwent revascularization for CLTI between April 2019 and July 2021. We identified 132 patients with toe wounds from the database who had restored in-line blood flow to the foot. Patients were divided into two groups by the timing of toe resection after revascularization, which dictated the wound management policy. Group A (62 patients) underwent early toe amputation for suspected osteomyelitis, whereas group B (70 patients) underwent watchful waiting. The primary outcome was wound healing after revascularization; the secondary outcome was major amputation. We compared outcomes between groups A and B after propensity score matching.

RESULTS

Using propensity score matching, each patient in group A (33 patients) was matched with a patient in group B (33 patients). Wound healing in matched group A was significantly better than that in matched group B (respectively: 1-year wound healing rate: 90.0% vs 68.2%, P < .001; median wound healing time: 65 days vs 258 days, P < .01). Although five major amputations were necessary in matched group B, none were required in matched group A (P = .05). The high rate of major amputations in group B was attributed to the sudden exacerbation of infection. Limb salvage rate in matched group A exceeded matched group B (100.0% vs 90.5%: 1-year limb salvage rate, P = .02).

CONCLUSIONS

Early toe amputation for highly suspected osteomyelitis in patients with CLTI with toe wounds may expedite wound healing compared with watchful waiting, potentially avoiding unnecessary major amputation. Considering the wound management strategy is crucial when evaluating wound healing outcomes in patients with CLTI with revascularization.

Prediction of need for bowel resection in acute superior mesenteric artery occlusion: A retrospective study of 48 Japanese patients

Aim

This study aimed to predict cases of acute superior mesenteric artery (SMA) occlusion requiring bowel resection using occlusion site and time from symptom onset to diagnosis at five Japanese institutions. Advances in imaging, endovascular treatment, and perioperative management have improved the clinical outcomes of patients with acute SMA occlusion; however, in clinical practice it remains difficult to effectively determine patients requiring bowel resection.

Methods

We retrospectively analyzed the data of 48 patients (mean age: 82.5 y; male: 37.5%) diagnosed with acute SMA occlusion between June 2009 and August 2018. Background data of patients who required and did not require bowel resection were compared. A multivariable predictive model was developed using the time from symptom onset to diagnosis and whether SMA occlusion was proximal, including the origin of the middle colic artery.

Results

Fifteen patients (31.3%) died during the hospital stay. Atrial fibrillation (83.3%) was the most common comorbidity. The median time from symptom onset to diagnosis was 13.0 (interquartile range, 4.75-24.0) h. Laparotomy, bowel resection, and thrombus embolectomy were performed in 41 (85.4%), 26 (54.2%), and 21 (43.8%) patients, respectively. A logistic regression model achieved 78.6% sensitivity in predicting cases not requiring bowel resection. Proximal occlusion was significantly associated with the requirement for bowel resection (P = .039).

Conclusion

The time from symptom onset to diagnosis and occlusion site contributed to high sensitivity in determining the need for bowel resection in patients with acute SMA occlusion. Further prospective studies are warranted to investigate the clinical impact of this model.

Long-term Outcomes of the Endurant and Excluder Stent Grafts for Endovascular Aneurysm Repair in a Japanese Cohort

PURPOSE

To compare the long-term outcomes of the most widely used third-generation stent grafts, the Endurant and Excluder stent grafts, in Japanese patients using a multicenter registry.

MATERIALS AND METHODS

A retrospective analysis of endovascular aneurysm repairs for abdominal aortic and iliac artery aneurysms using either the Endurant or the Excluder stent grafts from January 2012 to July 2019 at 10 Japanese hospitals was performed.

RESULTS

A total of 332 and 378 repairs using the Endurant and Excluder stent grafts, respectively, were analyzed. Although the patients' characteristics were generally similar in the two groups, the Endurant group exhibited significantly shorter (Endurant: 31.5±18.6 mm, Excluder: 37.4±21.0 mm; p<0.001), larger (Endurant: 22.4±4.2 mm, Excluder: 21.7±3.8 mm; p=0.029), and more reversed tapered (Endurant: 12.1%, Excluder: 5.8%; p=0.003) proximal necks. The incidence of instructions for use (IFU) violations was similar between the two groups (Endurant: 59.0%, Excluder: 54.5%; p=0.223). However, the Endurant group had significantly more proximal neck-related IFU violations (54.1% and 46.3%, respectively; p=0.039), more access-related IFU violations (8.1% and 4.0%, respectively; p=0.019), and fewer bilateral hypogastric artery embolizations (5.1% and 9.3%, respectively; p=0.035) compared with the Excluder group. The incidence of intraoperative (Endurant: 3.6%, Excluder: 3.7%; p=0.950) and perioperative complications (Endurant: 3.6%, Excluder: 3.4%, p=0.899) was equivalent in the two groups. However, there was a significantly higher incidence of postoperative type II endoleaks in the Excluder group (Endurant: 28%, Excluder: 46.0%, p<0.001). Aneurysm sac regression was more frequent in the Endurant group (Endurant: 40.7%, Excluder: 31.7%, p=0.013). The Endurant group also had significantly higher rates of sac increase (Endurant: 13.0%, Excluder: 7.7%, p=0.020). Kaplan-Meier curve and log-rank analyses revealed no statistical differences in late complications (p=0.868) and overall survival (p=0.926).

CONCLUSIONS

There were no statistically significant differences between the Endurant and the Excluder stent grafts in terms of intraoperative, perioperative, and late complication rates; however, the anatomical characteristics of the patients were significantly different.

Midterm Results of a Japanese Prospective Multicenter Registry of Heparin-Bonded Expanded Polytetrafluoroethylene Grafts for Above-the-Knee Femoropopliteal Bypass

BACKGROUND

This study prospectively analyzed the midterm results of above-the-knee femoropopliteal bypass (AKb) using bioactive heparin-bonded expanded polytetrafluoroethylene (HB-ePTFE) graft in patients with femoropopliteal occlusive disease.Methods and Results:This prospective, multicenter, non-randomized study reviewed limbs undergoing AKb with HB-ePTFE graft for femoropopliteal lesion in 20 Japanese institutions between July 2014 and October 2017. Primary efficacy endpoints were primary, primary assisted, and secondary graft patency. Safety endpoints included any major adverse limb event and perioperative mortality. During the study period, 120 limbs of 113 patients (mean age, 72.7 years) underwent AKb with HB-ePTFE grafts. A total of 45 patients (37.5%) had critical limb ischemia and 17 (15.0%) were on hemodialysis (HD). Median duration of follow-up was 16 months (range, 1-36 months). Estimated 1- and 2-year primary, primary assisted, and secondary graft patency rates were 89.4% and 82.7%, 89.4% and 87.2%, and 94.7% and 92.5%, respectively. On univariate analysis of 2-year primary graft patency, having 3 run-off vessels, cuffed distal anastomoses, no coronary artery disease, and no chronic kidney disease requiring HD were significantly associated with favorable patency.

CONCLUSIONS

AKb using HB-ePTFE grafts achieved favorable 2-year graft patency. AKb using HB-ePTFE grafts may therefore be an acceptable, highly effective treatment option for femoropopliteal artery lesions.

Impact of Stent Graft Design on External Iliac Artery Limb Occlusion Rates After Endovascular Aneurysm Repair: Post-hoc Analysis of a Japanese Multicentre Database

OBJECTIVE/BACKGROUND

It was hypothesised that a helical stent with expanded polytetrafluoroethylene (ePTFE) grafts could provide a preventive effect for external iliac artery (EIA) limb occlusion following endovascular aortic aneurysm repair (EVAR). Therefore, a post-hoc analysis of a Japanese multicentre database was conducted to assess the impact of the stent graft design on EIA limb occlusion rates.

METHODS

Patients who underwent EVAR with EIA limb deployment between 2008 and 2016 were evaluated. The stent graft limbs were divided into two groups: group A comprised stent graft limbs made of a helical stent with ePTFE grafts (Excluder; n = 255), and group B comprised stent graft limbs made of a Z stent with polyester grafts (Zenith, Flex and Endurant; n = 173). The main outcome was the incidence of limb occlusion and severe limb stenosis (EIA related limb complications). The risk factors for EIA related limb complications were analysed and the midterm results between groups A and B compared. Fine-Gray generalisation of the proportional hazards model was used after propensity score matching to calculate the hazard ratio (HR).

RESULTS

One complication occurred in group A and 10 complications occurred in group B. The risk factors for EIA related limb complications for the entire group were a stent graft limb size ≤10 mm (HR 5.41; p = .01) and inclusion in group B (HR 14.9; p = .009). After propensity matching, group A (n = 159) was matched with group B (n = 159). The cumulative incidence function of EIA related limb complications at five years was 0.66% in group A and 7.8% in group B (HR 8.67; p = .039).

CONCLUSION

Stent graft design can affect limb patency in EIA limb deployment. When EIA limb deployment is necessary for patients with a small EIA, such as Japanese patients, stent graft limbs made of a helical stent with ePTFE should be used to reduce the risk of limb occlusion.

Characteristics and Risk Factors for Type 2 Endoleak in an East Asian Population From a Japanese Multicenter Database

BACKGROUND

Clinically distinct differences exist between East Asian and Caucasian subjects, but data for type 2 endoleak (T2EL) are limited in the East Asian population. The aim of this study was to analyze the characteristics of East Asian T2EL using a Japanese multicenter database.

METHODS AND RESULTS

Retrospective analysis of 832 endovascular aneurysm repairs performed from 2008 to 2014 were conducted. T2EL was observed in 234 cases (28.1%), and in 32 cases (3.8%) it led to sac expansion >5 mm caused by isolated T2EL (median follow-up, 35.6 months). On univariate and multivariate analysis, non-smoker status (odds ratio [OR], 2.216; P<0.001), Excluder stent graft (OR, 2.027; P<0.001), and T2EL at final angiogram (OR, 2.080; P<0.001) were risk factors for T2EL. On multivariate analysis for isolated T2EL with sac expansion, only non-smoker status remained (OR, 2.671; P<0.001). Other than T1EL, isolated T2EL was the most significant risk factor for sac expansion (OR, 18.486; P<0.001). Furthermore, out of 11 transarterial embolization procedures initiated, 4 led to rupture during follow-up.

CONCLUSIONS

East Asian T2EL had a strong relationship with non-smoker status. Also, T2EL was a significant risk factor for sac expansion, which sometimes led to rupture even after intervention. Along with the high prevalence of T2EL observed, East Asian T2EL may not always be benign.

Effect of sarpogrelate hydrochloride, a 5-hydroxytryptamine2 receptor antagonist, on allograft arteriosclerosis after aortic transplantation in rats

BACKGROUND

Sarpogrelate hydrochloride, a 5-hydroxytryptamine2 receptor antagonist, is known to prevent serotonin-induced neointimal hyperplasia. We examined the effect of this agent on allograft arteriosclerosis in a rat model of aortic transplantation.

METHODS

Rats were given an aortic isograft or allograft and oral administration of either saline vehicle alone or 20mg/kg daily of sarpogrelate for 8 weeks. The grafts were then harvested, and the lumen diameter and the thickness of the intima and media were measured. Comparisons were made between measurement results in isografts and allografts from rats treated and not treated with sarpogrelate. Immunohistochemistry assessments were used to detect expression of serotonin in graft specimens.

RESULTS

For both allografts and isografts, significantly less intimal thickening was observed in specimens from rats given sarpogrelate compared with rats given saline. Sarpogrelate had no effect on medial thickening in either graft type. Serotonin was detected in allografts from rats given saline alone but not in allografts from rats given sarpogrelate or in isografts.

CONCLUSIONS

Sarpogrelate hydrochloride may mitigate arteriosclerosis in allografts. Platelet aggregation and serotonin may be correlated with intimal thickening associated with chronic rejection.

Resolvin D2 restores neutrophil directionality and improves survival after burns

Following severe burns and trauma injuries, the changes of neutrophil migratory phenotype are a double-edged sword. Activated neutrophils migrate into injured tissues and help contain microbial infections, but they can also enter normal tissues and damage vital organs. Depleting the neutrophils from circulation protects vital organs against neutrophil-induced damage but leaves the body exposed to infectious complications. Here we show that restoring normal neutrophil migratory phenotype in rats with burn injuries correlates with improved survival in a classical double-injury model of sequential burn and septic insults. We uncovered that the directionality of neutrophils from burned rats can be restored both in vitro by 1 nM resolvin D2 (RvD2) and in vivo by RvD2 for 7 d, 25 ng/kg body mass (8-10 ng/rat). Restoring neutrophil directionality dramatically increases survival after a second septic insult at d 9 postburn. Survival of RvD2-treated animals increases from 0 to 100% after lipopolysaccharide injection and is extended by 1 wk after cecal ligation. Survival does not significantly increase when the restoration of neutrophil directionality is incomplete, following shorter regimens of RvD2. We conclude that restoring neutrophil directionality using RvD2 could have prophylactic value and delay lethal complications after burn injuries.

Estrogen deficiency attenuates neovascularization in a murine model of hindlimb ischemia

BACKGROUND

The possible relation between menopause and the development of peripheral arterial disease, especially lower extremity disease, has not been fully studied. To explore this issue, we investigated whether estrogen deficiency affected neovascularization in a murine model of hindlimb ischemia.

METHODS

Ischemia was surgically induced in one hindlimb of oophorectomized and control female BALB/c mice. Neovascularization in the ischemic hindlimbs was evaluated using laser Doppler blood flow analysis and capillary density analysis of the adductor muscle. The expression of endothelial nitric oxide synthase protein in the adductor muscle of the ischemic hindlimbs was assessed.

RESULTS

The plasma 17-β estradiol levels were significantly lower in the oophorectomized mice than in the control mice. The oophorectomized mice also had a significantly reduced blood perfusion index and capillary density on day 21 after the induction of hindlimb ischemia and significant suppression of endothelial nitric oxide synthase protein expression on day 3 after ischemia induction.

CONCLUSIONS

Estrogen deficiency attenuated neovascularization in a murine model of hindlimb ischemia. Impaired neovascularization in oophorectomized mice might correlate with a reduction in endothelial nitric oxide synthase expression caused by estrogen deficiency.

Multiple aneurysms of the splenic artery caused by fibromuscular dysplasia

Splenic artery aneurysms (SAAs) are relatively rare. Moreover, there has been only one previous report of fibromuscular dysplasia (FMD) affecting the splenic artery alone. We describe a 64-year-old man with long, segmental, large, and multiple SAAs in whom the splenic artery branched from the aorta. The patient underwent endoaneurysmorrhaphy and splenectomy, with ligation in the proximal segment of the splenic artery. Histopathological analyses of resected specimens showed characteristics compatible with FMD. To our knowledge, long, segmental, large, and multiple SAAs caused by FMD have not previously been reported.

Surgical and Endovascular Procedures for Treating Isolated Iliac Artery Aneurysms: Ten-year Experience

Characteristics of atherosclerotic isolated iliac artery aneurysms (IAAs) and various strategies for their treatment were assessed retrospectively. The computerized medical records of 18 patients who underwent surgical or endovascular treatment of an IAA during the 10 years from April 1993 to March 2003 at our university hospital were reviewed to obtain information on patient demographics, risk factors, type of IAA treatment, and outcome. Additional data were obtained by mail and telephone. Patients with an IAA were compared with 168 patients treated for an abdominal aortic aneurysm (AAA) also at our institution. Early in the series of isolated IAA repairs, patients underwent prosthetic graft interposition ( n = 7) or thromboexclusion ( n = 4). Subsequently, patients had either endovascular thromboembolization ( n = 4) or endovascular thromboembolization with femorofemoral crossover bypass ( n = 3). No perioperative deaths occurred in the series. Deep venous thrombosis developed postoperatively in one patient; there were no other serious complications. The cumulative patency rate for the implanted interposition grafts during the mean observation time of 5.5 years was 100%. No endoleakage was observed after the endovascular procedures. In the long-term, five patients died of causes unrelated to the IAA treatment. A statistical analysis revealed no significant differences between the IAA group and the AAA group with respect to atherosclerotic risk factors. In conclusion, open surgical procedures to repair isolated IAAs generally have a good outcome, although the risk of injury to adjacent iliac veins remains. Endovascular treatments appear to have some advantages, but studies including long-term follow-up are needed to assess the efficacy and durability of prosthetic grafts used for these procedures.