Successful treatment of aortic endograft thrombosis with rheolytic thrombectomy

Rotational Mechanical Thrombectomy to Treat Iliac Limb Occlusion after Endovascular Aortic Aneurysm Repair: The Rotational Mechanical Thrombectomy Italian Study

PURPOSE

To assess the safety and effectiveness of a rotational mechanical atherothrombectomy device in patients with symptomatic iliac limb occlusion after abdominal endovascular aneurysm repair (EVAR).

MATERIALS AND METHODS

A retrospective analysis was conducted on patients who underwent rotational mechanical thrombectomy using the Rotarex S device for symptomatic acute, subacute, or chronic graft limb thrombosis at 5 vascular centers between 2017 and 2021. This study comprised 23 male patients with a mean age of 74.5 years (SD ± 7.2) at the time of the procedure. The clinical presentation of the patients varied, with 1 patient experiencing acute limb ischemia and 11 patients (47.8%) experiencing disabling intermittent claudication. The remaining patients developed chronic limb-threatening ischemia after iliac limb occlusion. Early outcomes included technical success, postprocedural complications, and periprocedural mortality. Follow-up evaluations encompassed primary patency, patient survival, freedom from reintervention, and the need for surgical conversion.

RESULTS

Technical success was achieved in all cases, with no occurrences of distal embolization during or after the procedure, and no periprocedural deaths were reported. Endograft relining was performed in 82.6% of patients to establish a new, nonthrombogenic surface within the graft. Over a median follow-up period of 8 months (interquartile range, 3-16 months), 2 patients experienced iliac limb reocclusion. No deaths or other reinterventions occurred during the observational follow-up period.

CONCLUSIONS

Rotational mechanical thrombectomy for iliac limb occlusion after EVAR appears to be both safe and effective. This technique may uncover intraluminal defects contributing to graft occlusion and enable their resolution within the same procedure.

Comparison of Outcomes in Elective Endovascular Aortic Repair vs Open Surgical Repair of Abdominal Aortic Aneurysms

IMPORTANCE

Knowledge regarding the long-term outcomes of elective treatment of abdominal aortic aneurysm (AAA) using endovascular aortic repair (EVAR) is increasing. However, data with greater than 10 years' follow-up remain sparse and are lacking from population-based studies.

OBJECTIVE

To determine the long-term outcomes of EVAR compared with open surgical repair (OSR) for elective treatment of AAA.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, population-based cohort study used linked administrative health data from Ontario, Canada, to identify all patients 40 years and older who underwent elective EVAR or OSR for AAA repair from April 1, 2003, to March 31, 2016, with follow-up terminating on March 31, 2017. A total of 17 683 patients were identified using validated procedure and billing codes and were propensity score matched. Analysis was conducted from June 26, 2018, to January 16, 2019.

EXPOSURES

Elective EVAR or OSR for AAA.

MAIN OUTCOMES AND MEASURES

The primary outcome was overall survival. Secondary outcomes were major adverse cardiovascular event-free survival, defined as being free of death, myocardial infarction, or stroke; reintervention; and secondary rupture.

RESULTS

Among 17 683 patients who received elective AAA repairs (mean [SD] age, 72.6 [7.8] years; 14 286 [80.8%] men), 6100 (34.5%) underwent EVAR and 11 583 (65.5%) underwent OSR. From these patients, 4010 well-balanced propensity score-matched pairs of patients were defined, with a mean (SD) age of 73.0 (7.6) years and 6583 (82.1%) men. In the matched cohort, the mean (SD) follow-up was 4.4 (2.7) years, and maximum follow-up was 13.8 years. The overall median survival was 8.9 years. Compared with OSR, EVAR was associated with a higher survival rate up to 1 year after repair (91.0% [95% CI, 90.1%-91.9%] vs 94.0% [95% CI, 93.3%-94.7%]) and a higher major adverse cardiovascular event-free survival rate up to 4 years after repair (69.9% [95% CI, 68.3%-71.3%] vs 72.9% [95% CI, 71.4%-74.4%]). Cumulative incidence of reintervention was higher among patients who underwent EVAR compared with those who underwent OSR at the 7-year follow-up (45.9% [95% CI, 44.1%-47.8%] vs 42.2% [95% CI, 40.4%-44.0%]). Survival analyses demonstrated no statistically significant differences in long-term survival, reintervention, and secondary rupture for patients who underwent EVAR compared with those who underwent OSR. Kaplan-Meier analysis suggested superior long-term major adverse cardiovascular event-free survival among patients who underwent EVAR compared with those who underwent OSR (32.6% [95% CI, 26.9%-38.4%] vs 14.1% [95% CI, 4.0%-30.4%]; stratified log-rank P < .001) during a maximum follow-up of 13.8 years.

CONCLUSIONS AND RELEVANCE

Endovascular aortic repair was not associated with a difference in long-term survival during more than 13 years' maximum follow-up. The reasons for these findings will require studies to consider specific graft makes and models, adherence to instructions for use, and types and reasons for reintervention.

The impact of randomized trial results on abdominal aortic aneurysm repair rates from 2003 to 2016: A population-based time-series analysis

Objectives

The uptake of endovascular aortic repair for elective and ruptured abdominal aortic aneurysm repair is not well studied. We aimed to examine the trends in open surgical repair and endovascular aortic repair of eAAA and rAAA and to examine the effects of randomized trial publications on elective open surgical repair and endovascular aortic repair rates.

Methods

We conducted a population-based time-series analysis of eAAA and rAAA repairs in Ontario, Canada from 2003 to 2016. We examined changes in overall and approach-specific rates of eAAA and rAAA repair using exponential smoothing models. Interventional autoregressive integrated moving average models were fit to the eAAA rates to examine the impact of randomized trial results on these rates.

Results

We identified 19,489 eAAA (12,232 open (63%) and 7257 endovascular (37%)) and 2732 rAAA (2466 open (90%) and 266 endovascular (10%)) repairs from 2003 to 2016. The rate of eAAA repair declined from 6.39/100,000 in 2003 to 5.59/100,000 in 2016 (13% decrease, p = 0.17). The rate of elective open surgical repair decreased nearly three-fold from 6.07/100,000 to 2.12/100,000 ( p < 0.0001), while elective endovascular aortic repair increased approximately 10-fold (0.32/100,000 to 3.47/100,000, p < 0.0001). The rate of ruptured open surgical repair decreased from 1.62/100,000 to 0.37/100,000 ( p < 0.44), while ruptured endovascular aortic repair uptake increased (0.00/100,000 to 0.12/100,000, p < 0.25). The mid-term results of the DREAM and EVAR-1 trials were associated with a decrease in the rate of elective open surgical repair decline after 2010 ( p = 0.01).

Conclusions

While elective open surgical repair use has significantly decreased from 2003 to 2016, elective endovascular aortic repair use has significantly increased. The DREAM and EVAR-1 results significantly impacted the observed rates of elective open surgical repair only. The reasons for these trends require further characterization.

Heparin-Induced Thrombocytopenia and Graft Thrombosis following Endovascular Aneurysm Repair

Purpose:

To report a case of heparin-induced thrombocytopenia (HIT) complicated by stent-graft thrombosis.

Case Report:

An 82-year-old woman underwent endovascular aortic aneurysm repair using a Zenith stent-graft. She returned 2 weeks later with an occluded graft limb, large quantities of thrombus lining the remainder of the stent-graft, thrombocytopenia, and antiplatelet antibodies. There were no signs of kinking or compression of the graft, nor was there any thrombosis of the native arteries downstream from the occluded graft limb. Thrombolysis restored graft patency. Anticoagulation was induced using hirudin and warfarin. The graft remains patent at 6-month follow-up.

Conclusion:

HIT is a rare cause of postoperative endograft thrombosis. In this case, the presumed source of the inciting heparin dosage was the stent-graft itself, which had been soaked in a concentrated heparin solution prior to insertion.

Limb Graft Occlusion Following EVAR: Clinical Pattern, Outcomes and Predictive Factors of Occurrence

INTRODUCTION

We reviewed our experience with limb occlusion after EVAR in order (1) to assess the clinical pattern and treatment options (2) to assess outcomes and (3) to identify predictive factors of occurrence.

MATERIALS AND METHOD

Between 1995 and 2005, 460 AAA patients were electively treated with a variety of commercially available stent grafts. There were 369 bifurcated and 91 aortouniiliac grafts (829 limbs). Follow-up included physical examination, plain X-ray, Duplex ultrasonography, and spiral computed tomographic scans at 1, 6, 12 months and annually thereafter. All pertinent data were collected prospectively and analysed retrospectively. The follow-up period ranged from Day 0 to 104 months, with a median follow-up of 23.4 months.

RESULTS

36 limbs in 33 patients (7.2%) occluded between Day 0 and 71 months (average: 9.5 months) after EVAR. Presentation was acute ischemia in 11 cases, rest pain in 9, claudication in ten. Four occlusions remained asymptomatic and two occurred intraoperatively. Treatment was femoro-femoral cross-over graft in 19 cases, axillo-femoral bypass in three, thrombectomy and stent in three, thrombolysis and stent in nine, and conservative in two. One patient (3%) died of multiple organ failure after thrombolysis. There was no amputation. Reocclusions occurred in two patients (6.1%). Multivariate logistic regression showed that kinking (odds ratio [OR] 11.9; confidence interval [CI] 3.39-42.1; p=0.0001), first graft generation (OR 2.87; CI 1.25-6.62; p=0.017) and younger age (OR 1.05; CI 1.00-1.09; p=0.034) were independently related to the occurrence of graft limb occlusion.

CONCLUSION

Acute graft limb occlusion is not rare after EVAR. The frequency of limb occlusion has declined with current stent grafts generation. Although surgery and endovascular treatments are efficient and safe, development of a graft limb kink should lead to aggressive pre-emptive treatment to prevent occlusion.

Evaluation of thrombogenicity by indium-111 platelet scintigraphy in endografting for abdominal aortic aneurysms

Obstruction of the endograft limb by thrombosis has often been reported and may cause fatal complications such as leg necrosis or myonephropathic metabolic syndrome. The purpose of this study was to evaluate endograft antithrombogenicity by indium-111 platelet scintigraphy. Seventeen patients with abdominal aortic aneurysms were treated by endografting. Thirteen patients were treated with conventional open surgery using an artificial graft. The endograft was constructed from a self-expanding Z-shaped stent and woven polyester fabric. Autologous platelets labeled with indium-111 were injected at 2 weeks postoperatively. At 24 hours and 72 hours postinjection, the ratio of scintillation count of the endograft or graft to that of the native artery was calculated to assess platelet deposition. The normalization ratio was calculated as follows: (scintillation count per pixel of endograft or graft/circumference)/(scintillation count per pixel of the native femoral artery). Platelet factor 4 and beta-thromboglobulin were measured to evaluate the systemic platelets activity at 2 weeks postoperatively. There was no significant difference in platelet counts or labeling efficiency between the groups. The ratio was significantly higher in the endografting group than in the open surgery group at 72 hours postinjection (2.5-0.7 vs 3.9-1.1, P<.001). There was no significant difference in platelet factor 4 and beta-thromboglobulin between the groups. Although there was no difference in systemic platelet activity, endografting was associated with lower antithrombogenicity. It remains unclear whether lower antithrombogenicity causes thromboembolism as a complication of the procedure. The authors recommend the administration of antiplatelet drugs to prevent endograft obstruction in patients with very narrow iliac arteries.

Adjunctive primary stenting of Zenith endograft limbs during endovascular abdominal aortic aneurysm repair: Implications for limb patency

OBJECTIVE

Endograft limb occlusion is an infrequent but serious complication of endovascular abdominal aortic aneurysm (AAA) repair. The insertion of additional stents within the endograft limb may prevent future occlusion. This study evaluates limb patency with and without adjunctive stenting of endograft limbs at the time of endovascular AAA repair.

METHODS

We performed a retrospective review of 248 patients who underwent endovascular abdominal aortic aneurysm repair with the Zenith AAA endovascular graft between 1999 and 2004. Among these patients, two groups were identified: 64 patients with adjunctive stents placed in 85 limbs and 184 patients without additional bare stent placement in endograft limbs at the time of endovascular AAA repair.

RESULTS

Women comprised 23% of stented and 11% of unstented patients (P = .02). The mean length of follow-up in the stented and unstented groups was 2.0 years. There were 13 instances of limb thrombosis in 13 patients (5.2% of patients, 2.7% of limbs), all in the unstented group. No limb occlusions occurred in the presence of adjunctive bare metal stents. Seventy-three percent of the occlusions occurred < or = 6 months of endovascular AAA repair. Two patients (15%) had no symptoms of lower-extremity ischemia despite graft limb occlusion and did not undergo intervention. The others underwent thrombectomy (n = 2), thrombectomy with bare stent placement (n = 3), femoral-femoral bypass (n = 4), thrombolysis (n = 1), and thrombolysis with bare stent placement (n = 1). Of the seven who underwent thrombectomy or thrombolysis, three had no additional stents placed at the secondary procedure, and two of these three went on to rethrombose. By life-table analysis, primary patency at 3 years in the stented and nonstented limbs was 100% +/- 0% and 94% +/- 3%, respectively (P = .05).

CONCLUSIONS

The intraoperative insertion of additional bare metal stents appeared to eliminate the risk of thrombosis and was without complication. Of the 85 stented limbs in this series, not one occluded. The overall rate of limb thrombosis was low, with most limb occlusions occurring < or = 6 months of stent-graft insertion, and would probably have been even lower had we been able to identify all high-risk cases for prophylactic adjunctive stenting. Limb occlusion denotes an underlying problem with the graft, which if left untreated after thrombectomy or thrombolysis will lead to rethrombosis. Postoperative imaging was of little value in detecting impending limb occlusion. Based on these findings, we believe one should identify and stent any limbs that appear to be at risk for thrombosis, but this study lacks the data to predict which limbs need stenting.

Secondary interventions after endovascular abdominal aortic aneurysm repair

BACKGROUND

One adverse outcome of endovascular abdominal aortic aneurysm (AAA) repair (EVAR) is a significantly increased incidence of secondary interventions (SIs) required compared with traditional open aortic repair. We present a consecutive series of EVARs using a single endograft to identify the incidence and types of SIs performed.

METHODS

From February 1, 2000, to January 31, 2005, we repaired 136 AAAs with the Zenith (Cook, Bloomington, Indiana) endograft. All patients met the same strict anatomic inclusion and exclusion criteria. Follow-up lasted from 1.5 to 61 months (median 36). The indications for SI group A were procedural and technical errors, for group B were aortic morphology, and for group C were device failures.

RESULTS

Twenty-one SIs were required in 17 of 136 patients (12.5%). Three patients required multiple interventions. Nine patients were in group A, four were in group B, and six were in group C. All but 4 patients required SIs for late (>30 days) complications.

CONCLUSIONS

Although it is a viable alternative to open aortic repair, EVAR is associated with a significantly higher rate of SIs. To maintain the efficacy of EVAR, patients must be followed-up in a vigilant graft surveillance protocol for life.

Thrombus originating from frayed distal edge of an aortic stent-graft

An 87-year-old woman who had undergone a stent-graft repair of a descending aortic aneurysm had additional stent-graft implantation for endoleak. The postoperative course was eventful reflecting her preexisting multiple organ disorder, and despite intensive treatment over a span of 2 months, she died of disseminated intravascular coagulation due to intestinal ischemia. Autopsy revealed a thrombus originating from the frayed distal edge of the graft. Although the relation between intestinal ischemia and the thrombus remains to be proven, this is considered a vital finding.