Peripheral Atherectomy: A Critical Review

Overexpression of Hepatocyte Growth Factor mRNA Induced by Gene Transfer Attenuates Neointimal Hyperplasia After Balloon Injury

Hepatic growth factor (HGF) has been widely used in studies on arterial remodeling after injury, and results turn out to be inconsistent. The changes of endogenous HGF expression after injury also remain controversial. This study clarified the role of exogenous human HGF (hHGF) gene transfer in neointimal hyperplasia and investigated the associated alterations of endogenous HGF and c-Met expressions under endothelial denudation with or without hHGF gene transfer using a balloon-injured rabbit aorta model. Sixty-one rabbits were randomly divided into normal controls, endothelial injury, endothelial injury with hHGF, or the control vector gene transfer groups. On weeks 1, 2, 4, and 8 after injury, neointimal hyperplasia and endothelialization were evaluated by the ratio of neointimal area to medial area (N/M ratio), CD31-positive staining, α-smooth muscle actin, and endothelial nitric oxide synthase expressions using histological analysis, immunohistochemistry staining, or real-time quantitative reverse transcriptase polymerase chain reaction. Endogenous rabbit HGF (rHGF) and c-Met expressions were detected with immunohistochemistry staining and quantitative reverse transcriptase polymerase chain reaction. It was found that expressions of endogeneous rHGF and c-Met in endothelial injury upregulated with peak levels on week 2 or week 4 after injury (p < 0.01). On week 1 after hHGF transfer, neointimal hyperplasia was significantly inhibited (p < 0.001), with decreased α-smooth muscle actin expression (p < 0.05) and improved endothelial cells regeneration and function (p < 0.01). More remarkable overexpression of endogenous rHGF and c-Met mRNAs were detected, and lowered positive staining of rHGF and c-Met was shown in the neointima (p < 0.05). These results demonstrated hHGF gene transfer induced further overexpression of endogenous rHGF and c-Met mRNAs but lowered immunoreactivities of rHGF and c-Met in the neointima, thus leading to significant attenuation of neointimal hyperplasia.

Application of rotational atherectomy for a calcified superficial femoral artery lesion

A 78-year-old man on dialysis with a history of femoro-popliteal bypass grafting of his right superficial femoral artery was presented with a recurrence of intermittent claudication. Angiography revealed new heavily calcified stenosis located distal to the anastomosis of the graft. A guide wire was crossed the lesion, however, a balloon catheter could not pass. Rotational atherectomy with Rotablator enabled the balloon to cross the lesion with full dilatation. Due to residual stenosis and dissection, a stent was implanted. Final angiogram showed no residual stenosis with TIMI 3 flow. The patient remained free of symptoms during the 1-year follow-up.

Three-year results after directional atherectomy of calcified stenotic lesions of the superficial femoral artery

OBJECTIVE

To investigate the 3-year outcome of patients with peripheral arterial disease (PAD) and heavily calcified stenotic lesions of the superficial femoral artery after directional atherectomy.

MATERIALS AND METHODS

Fifty-three patients (mean age 67 ± 10 years; 18 females, 35 males, TASC B and C, mean lesion length 7.9 ± 3.5 cm) with PAD (Rutherford 2-6) were enrolled into this prospective monocentric study. In total, 59 calcified lesions of the superficial femoral artery were treated with the Silverhawk atherectomy device (Covidien, Plymouth, MN, USA). Patients were followed-up for 36 months with a 6-month interval to perform clinical re-evaluation, including measurement of maximum walking distance and ankle-brachial index (ABI) as well as duplex-sonography.

RESULTS

The primary success rate of the procedure was 92 %. In five cases (8 %), additional balloon-PTA and/or stent-PTA was necessary. Procedure-related embolization occurred in seven cases (12 %), which were all successfully treated by aspiration. The primary patency rate after 3 years was 55 %. Median Rutherford score decreased significantly from 5 to 0 after 36 months (p < 0.001). At the same time, the ABI increased from 0.65 to 1.12 (not significant). The limb-salvage rate after 3 years was 87 %.

CONCLUSION

In this subgroup of patients with POD and calcified stenotic lesions, atherectomy was successfully applied to decrease the plaque burden. Results after 3 years showed a significant decrease of Rutherford score with persistent improvement of ABI and reasonable patency rate.

Using the modern Silverhawk™ atherectomy catheter to characterize biliary structures that appear malignant: review of initial experience

BACKGROUND

Diagnosis of a biliary stricture often hinges on cytological interpretation. In the absence of accompanying stroma, these results can often be equivocal. In theory, advanced shave biopsy techniques would allow for the preservation of tissue architecture and a more accurate definition of biliary pathology.

OBJECTIVES

We sought to determine the initial diagnostic utility of the modern Silverhawk™ atherectomy (SA) catheter in the evaluation of biliary strictures that appear to be malignant.

METHODS

A total of 141 patients with biliary pathology were identified during a retrospective review of medical records for the years 2006-2011. The SA catheter was employed 12 times in seven patients for whom a tissue diagnosis was otherwise lacking.

RESULTS

Neoplasia was definitively excluded in seven specimens from four patients. These four individuals were followed for 1-5 years to exclude the development of cholangiocarcinoma (CC). Samples were positive for CC in three patients, one of whom became eligible for neoadjuvant therapy and orthotopic liver transplantation.

CONCLUSIONS

The SA catheter appears to be a useful adjunct in diagnosing patients with biliary pathology. The existence of this technique, predicated on tissue architecture, may impact therapy, allow more timely diagnosis, and exclude cases of equivocal cytology. Although the initial results of SA use are promising, more experience is required to effectively determine its clinical accuracy.

Arteriovenous fistula complicating directional atherectomy of the popliteal artery

We describe a case of a 70-year-old man with a critical popliteal artery stenosis treated by directional atherectomy and complicated by a huge arteriovenous fistula. A 70-year-old man, previously treated by bilateral femoropopliteal bypass, was admitted to our hospital because of right leg intermittens claudication. A critical infrapopliteal stenosis was documented; this lesion was treated by directional atherectomy, which was complicated by a huge arteriovenous fistula. Due to the failure of any conservative approach, surgical repair was necessary. Following surgery, the patient was discharged without any deficit. Although rare, huge arteriovenous fistula may be a serious complication of peripheral directional atherectomy.

Which diabetics are at risk for lower-extremity problems and what preventive measures can be taken?

Diabetes mellitus is a well-known risk factor for development and progression of peripheral arterial disease. Prospective cardiovascular clinical trials have also clearly demonstrated that diabetics fare worse than their nondiabetic counterparts. Diabetics also differ from nondiabetics in that multiple revascularization procedures may be required in order for the clinical outcome to be equivalent to that of a nondiabetic patient. However, by advocating an aggressive approach to peripheral arterial disease, good results in survival and limb salvage can be achieved in diabetic patients despite the presence of increased medical comorbidities. Key to the management of such patients will be identifying which diabetic patients will be at most risk so that preventive measures can be undertaken.