Clinical efficacy of a stent-in-stent procedure for stent fracture in a narrowing anastomosis of femoral-popliteal bypass represented repetitive acute limb ischemia

Abstract

A 72-year-old male with sudden onset pain and coldness in his left lower limb was referred to our hospital. An emergency angiography of the lower limbs demonstrated the cause of acute limb ischemia as a subsequent acute thromboembolism at the site of a narrowing anastomosis of femoral-popliteal bypass (FPB). In particular, the site of the narrowing anastomosis had already been fixed using a nitinol stent 4 years previously. We confirmed that the severe stent fracture resulted from misalignment. After local lysis therapy, we decided to deploy another nitinol stent to in-stent restenosis (ISR) lesion of the stent fracture. Final angiography confirmed full patency in FPB without flow delay. Additionally, to maintain the patency of arterial flow, we prescribed aspirin and warfarin. After 2 years of operation, his follow-up ankle-brachial pressure index on the left side remained 0.86 and no ischemic leg pain was observed to date. Stent-in-stent procedure using another nitinol stent for ISR treatment for the narrowing anastomosis in FPB indicated feasible and effective results.

<Learning objective: Endovascular intervention for acute limb ischemia (ALI) is one of the most challenging cases. Physicians often come up against a problem as no-flow phenomenon after revascularization. Local lysis therapy has established its own position in ALI treatment. However, the effectiveness of various interventional treatments for ALI has not been clarified. This report highlights the potential of a combination of local lysis and intervention in achieving good outcomes in represented repetitive ALI.>

Introduction

Acute limb ischemia (ALI) is a severe condition that needs the release of ischemia and reperfusion as soon as possible because a significant reduction in arterial perfusion can result in severe manifestations, such as injury to the limbs, possibly necessitating amputation, and life-threatening complications. The therapeutic management of ALI has established two major procedures: local lysis and vascular intervention, including Fogarty maneuver, mechanical thrombectomy, endovascular intervention, and endarterectomy. Therapeutic recommendations, such as local lysis, based on large randomized studies have been reported [1]. However, the effectiveness of various interventional treatments for ALI has not been clarified. Additionally, the efficacy of stent-in-stent procedure for stent fracture remains unknown. To the best of our knowledge, there is no report about treating stent fracture in a narrowing anastomosis of femoral-popliteal bypass (FPB) using stent-in-stent technique. Here, we report a rare case with ALI which resulted from repetitive occlusion of the anastomosis site in FPB that was treated with a combination therapy, including local lysis and endovascular intervention.

Case report

A 72-year-old male with a sudden onset pain and coldness in his left lower limb was transferred to our hospital 1 week after the onset of these symptoms in 2015. The patient presented a clinical medical history of coronary artery bypass graft in 2002, and bilateral FPB in 2003. Moreover, in 2005, he had a history of exacerbation of claudication in his right lower limb and at that time, his right FPB was already confirmed with occlusion. Previous cardiovascular surgeons performed profundaplasty for his right deep femoral artery and endarterectomy for his right common femoral artery to relieve the symptom of claudication. Subsequently, in 2011, he experienced ALI in his left leg while resting. He was transferred to the previous hospital and was diagnosed with acute thromboembolism of left FPB. Accordingly, a combination therapy of surgical embolectomy using a Fogarty catheter and endovascular intervention was administered. The details of the endovascular intervention were as follows: an 8 × 100 mm Smart stent (Cordis Corp., Miami Lakes, FL, USA) deployed in his left common iliac artery (CIA), an 8 × 30 mm Smart stent in the left external iliac artery (EIA), a 6 × 30 mm Smart stent at the site of a narrowing anastomosis of FPB to distal superficial femoral artery (SFA), an 8 × 60 mm Smart stent in right CIA; an 8 × 40 mm Smart stent in right EIA. After this treatment, his legs were symptom-free and he suddenly stopped visiting the hospital. Consequently, he discontinued the anticoagulant agent (warfarin) and dual antiplatelet therapy (DAPT). To make matters worse, he had untreated diabetes mellitus [HbA1c level was 7.4% (NGSP); reference value (RV) 4.6–6.2%] and was unable to quit smoking. Other laboratory studies revealed increased white blood cell count [9390/μL; RV 4000–8500/μL], lactate dehydrogenase (227 IU/L; RV 106–211 IU/L), and creatine phosphokinase (308 IU/L; RV 14–170 IU/L) levels. Physical examination on admission to our hospital revealed a well-palpable pulse in only the right brachial artery, and an impalpable pulse in the left brachial artery, both radial and femoral arteries. Ankle-brachial pressure index (ABI) was 0.62 on the right side and 0.35 on the left side. Further, he had coexisting congestive heart failure (CHF) that needed respiratory support. Severe rest ischemic pain in his foot indicated worsening CHF; therefore, we administered intubation and considered the necessity to release the ischemic symptoms. Therefore, 17 h after hospitalization, angiographic examination was performed under the intubation condition, and the angiogram showed complete occlusion from abdominal aorta bifurcation to the distal left FPB (Fig. 1A). Surgical thrombectomy was not considered because the previously deployed stent for the treatment of the narrowing distal anastomosis in FPB was completely destroyed (Fig. 1B). Using a 6-Fr/90 cm long sheath via right brachial artery, a 0.035″ hydrophilic guidewire through a 5-Fr Judkins right curve 4 (JR4) catheter was advanced into the site of aortoiliac bifurcation aiming at left side of CIA. The 0.035″ hydrophilic guidewire could be crossed through a lot of thrombi forming a knuckle-shape, but we could not cross the site of the stent fracture in distal FPB anastomosis. Guidewire size was changed to 0.018″, which enabled us to cross the narrowing lesion. The following procedures were performed:

• 1.Balloon angioplasty of the occluded left CIA, EIA, and FPB was performed using a 5 × 100 mm balloon with long inflation. The blood flow in FPB recovered to the first grade in Thrombolysis In Myocardial Infarction classification.
• 2.Local lysis of the occluded left CIA, EIA, and FPB using 48,000 IU urokinase via the 5-Fr JR4 catheter. Although thrombus aspiration was subsequently performed using the JR4 catheter, no clot was captured.
• 3.The cause of thromboembolism was confirmed as a distal stent fracture from the angiography after thrombolysis and long balloon inflation.
• 4.Endovascular intervention for in-stent restenosis (ISR) due to the distal stent fracture using a 6 × 40 mm Smart stent. The stent was expanded using a 5 × 100 mm balloon (Fig. 2).

Fig. 1.

(A) The initial angiogram showed complete occlusion from the abdominal aortic bifurcation to the distal end of left FPB without any collateral flows. (B) The stent previously deployed in the distal site of the narrowing anastomosis of left FPB was broken repeatedly. The type of stent fracture was classified as type 5, as advocated by Rocha-Singh et al. [5].

FPB, femoral-popliteal bypass.

Fig. 2.

Endovascular intervention for distal stent fracture site using a 6 × 40 mm Smart stent (Cordis Corp., Miami Lakes, FL, USA). The method is called stent-in-stent. Afterward, the stent was expanded using a 5 × 100 mm balloon.

The final angiography revealed full patency from the aortoiliac bifurcation to the distal below-the-knee arteries without flow delay (Fig. 3). After 7 days postoperatively, he was extubated and reported resolution of pain at rest and coldness in left leg. ABI on the left side reached 0.99. Further, we introduced angiotensin-converting enzyme inhibitor and beta blocker in order to stabilize CHF and prescribed 100 mg of aspirin, 75 mg of clopidogrel, and 3.5 mg of warfarin (adjusted international normalized ratio: 2.5 ± 0.5). One month after the intervention, we allowed him to stop taking clopidogrel and suggested to continue taking orally aspirin and warfarin. After 2 years of our procedure, his follow-up ABI of the left side remained at 0.86 and no ischemic leg pain has been observed to date.

Fig. 3.

Full patency was confirmed from the aortoiliac bifurcation to the distal below-the-knee arteries through femoral-popliteal bypass without flow delay in the final angiogram.

Discussion

ALI caused by acute FPB occlusion is always challenging. Albayrak et al. [2] reported the effective use of Fogarty catheter in acute FPB occlusions. Lichtenberg et al. [3] showed that “rotation thrombectomy” could be an alternative in the treatment of acute and subacute FPB occlusions in comparison to established therapies such as vascular surgery and local lysis. However, unfortunately, the Rotarex thrombectomy system (Straub Medical, Wangs, Switzerland) is not available in Japan. de Donato et al. [4] reported the improvement in outcomes in patients with ALI and effectiveness of combination therapy including surgical embolectomy and endovascular techniques. Supporting their enforcement, our case was completely treated by combination therapy of thrombolysis using urokinase and endovascular intervention technique. Furthermore, our case was rare because the occlusive site showed that the disorders associated with the FPB anastomosis had been previously treated with a nitinol stent that resulted in repetitive acute thromboembolism due to stent fracture. Morphology of the stent fracture was classified into five types based on a report by Rocha-Singh et al. [5]. In short, a single-tine fracture is defined as type 1, multiple-tine fractures as type 2, stent fracture(s) with preserved alignment of the components as type 3, stent fracture(s) with mal-alignment of the components as type 4, and stent fractures in a trans-axial spiral configuration as type 5. Some authors insisted that there was little correlation between stent fractures and re-obstruction [6], [7]. In contrast, Scheinert et al. [8] found that stent fractures were associated with stent restenosis or re-occlusions in approximately two-thirds of their cases. Our patient’s stent fracture indicated type 5. We support the opinion that multiple, severe misalignment stent fractures are associated with restenosis or re-occlusions at the stented site. As for interventional cardiologists who sometimes encounter a narrowed coronary anastomosis of the internal mammary artery, one of the best solutions is to perform the angioplasty using a stent at the site [9]. Our patient previously underwent treatment for the site of a narrowed distal SFA anastomosis of FPB using a nitinol stent. We chose the stent-in-stent strategy for ISR of a repetitive narrowing distal SFA anastomosis of FPB. Zeller et al. [10] revealed the favorable outcomes on the treatment of femoral-popliteal ISR with paclitaxel-eluting stents. However, in their study, stent fractures classified as types 4 and 5 occurred in 8.4% of cases. Here we needed to apply a firmer radial force to the occlusive lesion due to the narrowed distal SFA anastomosis of FPB. Therefore, we chose a Smart stent, which has been known to have a strong radial force according to cardiologists. Two years after this procedure, the patient has no complaints regarding leg symptoms, although ABI decreased from 0.99 to 0.86. Finally, most interventional cardiologists do not have a clear idea regarding the duration for which patients should be administered an anticoagulant agent and/or DAPT after intervention for narrowing of the anastomosis of FPB. Moreover, if such patients suffer claudication in the near future, what procedures should be taken toward repetitive ISR? Further case reports are warranted to confirm our findings in this report.

Conclusions

Through experiencing this case, we were able to comprehend the effectiveness and safety of a combination therapy including local lysis and endovascular intervention techniques. Stent thrombosis following stent fracture is one of the most difficult problems for cardiologists. In our case, stent fracture was caused by narrowing of the anastomosis of FPB, which presented a tough and critical situation. The method of using stent-in-stent for ISR indicated feasible and effective results.

Conflict of interest

The authors declare that there is no conflict of interest.

Funding

The present case has not been supported by any grant or funders.