Use of intraluminal stents in the treatment of carotid, renal, and peripheral arterial disease. Am J Med Sci. 2000;319:111-117. [PMID: 10698096 DOI: 10.1097/00000441-200002000-00008]

Choice of wound care in diabetic foot ulcer: A practical approach

Diabetic foot ulcers are the consequence of multiple factors including peripheral neuropathy, decreased blood supply, high plantar pressures, etc., and pose a significant risk for morbidity, limb loss and mortality. The critical aspects of the wound healing mechanism and host physiological status in patients with diabetes necessitate the selection of an appropriate treatment strategy based on the complexity and type of wound. In addition to systemic antibiotics and surgical intervention, wound care is considered to be an important component of diabetic foot ulcer management. This article will focus on the use of different wound care materials in diabetic foot. From a clinical perspective, it is important to decide on the wound care material depending on the type and grade of the ulcer. This article will also provide clinicians with a simple approach to the choice of wound care materials in diabetic foot ulcer.

The Nitinol SMART Stent vs Wallstent for Suboptimal Iliac Artery Angioplasty: CRISP-US Trial Results

PURPOSE

The Cordis Randomized Iliac Stent Project-US (CRISP-US) trial evaluated, with an equivalence design, the performance of the shape memory alloy recoverable technology (SMART) nitinol self-expanding stent and the stainless steel Wallstent for treating iliac artery disease after suboptimal percutaneous transluminal angioplasty (PTA).

MATERIALS AND METHODS

This multicenter, prospective, randomized trial comprised 203 patients with chronic limb ischemia who received either the SMART stent (n = 102) or the Wallstent (n = 101) after suboptimal PTA. The primary equivalence end point was a composite of 9-month restenosis, 30-day death, and 9-month target vessel revascularization. Functional, clinical, and hemodynamic assessments were made at hospital discharge and at 1, 6, 9, and 12 months.

RESULTS

The 9-month composite end point rate was equivalent for the SMART stent and Wallstent (6.9% vs 5.9%), with low rates of restenosis (3.5% vs 2.7%), death (2.0% vs 0.0%), and revascularization (2.0% vs 4.0%) in the two groups. Primary patency at 12 months was 94.7% and 91.1% with the SMART stent and Wallstent, respectively. Functional and hemodynamic improvement was also comparable between the groups. The acute procedural success rate was higher in the SMART stent group (98.2% vs 87.5%; P =.002). The frequency of major adverse events was similar at 1 year (4.9% vs 5.9%).

CONCLUSIONS

The performance of the SMART stent was equivalent to that of the Wallstent for treating iliac artery stenosis. The design characteristics of the SMART stent may contribute to greater procedural success and more accurate stent deployment.

Surgical removal of self-expanding stents from the carotid artery: does the type of stent make a difference?

PURPOSE

To evaluate the degree of difficulty in surgically removing 2 different stent models placed in the canine carotid artery.

METHODS

In 5 dogs, each carotid artery was stented with a braided Elgiloy self-expanding stent (BESES) on one side and a surface-spanning micro stent (SSMS) on the other. After 4 weeks, an arteriogram was obtained, and the stents were removed via direct surgical exposure. The minimum lengths of the skin incisions and arteriotomies, the ease of stent removal, and the presence of a distal intimal flap were recorded.

RESULTS

Stent deployment and removal were successful in each animal, but there was a substantial difference in the ease of removal. The BESES could be removed in a strand-by-strand fashion via a more proximal, smaller arteriotomy compared to the SSMS (8.8+/-1.3 versus 37.2+/-4.7 mm, p<0.01). Furthermore, a smaller skin incision (3.85+/-0.9 versus 9.75+/-0.5 cm, p<0.01) was required for the BESES. There was no distal flap formation following BESES removal, whereas SSMS removal produced a large distal flap in each artery (p<0.01).

CONCLUSIONS

Although rare, restenosis after stenting occurs, and surgical repair may become necessary in some patients. Each stent has inherent advantages and disadvantages, but the braided Elgiloy self-expanding stent lends itself to easier surgical removal, which may have important clinical implications, especially when used in the carotid artery.

Dosimetry of a 188rhenium-labeled self-expanding stent for endovascular brachytherapy in peripheral arteries

PURPOSE

Radioactive stents have been proposed as endovascular irradiation device to prevent in-stent restenosis by inhibiting neointimal proliferation. 32P-stents have been used in several studies so far, but require large-scale labeling procedures and endovascular barotrauma for stent expansion supporting the development of edge restenosis. Purpose of this study was to establish dosimetry of a self-expanding nitinol stent for peripheral vascular disease, which was radiolabeled with 188rhenium (188Re) by a dip coating technique.

METHODS AND MATERIALS

The surface of nitinol Memotherm FLEXX stents was polymer-coated providing functional NH(2) groups for diethylenetriaminepentaacetic acid (DTPA) binding, providing the ligand for the complexation of 188Re onto the stent surface. Stability of radiolabeling was tested over 48 h using an in vitro blood circulation (Chandler Loop). Radial and longitudinal dose distributions of a radiolabeled stent were obtained with a plastic scintillator dosimetry system.

RESULTS

Stents with a length of 30 mm and a diameter of 8 mm were labeled with up to 33 MBq 188Re. A total of 69+/-4% of the labeled 188Re remained stable on the stent surface after 48 h. Ninety-five percent of the infinitely accumulated dose was supplied to the target tissue within 72 h. Including correction for radioactivity washout from the stent, the infinitely accumulated dose at 1 mm radial distance from the stent surface was 1.85+/-0.19 Gy/MBq 188Re/cm stent length.

CONCLUSIONS

We developed a technique for radiolabeling of self-expanding nitinol stents with 188Re by dip coating and formation of 188Re chelate complexes. We provide dosimetry data useful for application of this beta-emitting stent for endovascular brachytherapy in peripheral vascular occlusive disease.

Cerebrovascular angioplasty and stenting for the prevention of stroke

Until recently, stroke preventive strategies have focused on either medical regimens aimed at antagonizing or reversing atherosclerosis, or surgical intervention for revascularization of the cerebrovascular system. However, with the advent of rapidly emerging microcatheterization techniques and technology, endovascular surgical revascularization of the brain is rapidly emerging as a powerful therapeutic modality. In particular, significant advances already have been made in revascularization of the extracranial carotid artery and many common anatomic sites of intracranial athero-occlusive disease, using special adaptations of conventional percutaneous angioplasty and stenting techniques. This paper reviews the cumulative experience with these emerging techniques, with a particular emphasis on clinical outcomes and future directions. It also reports the substantial cumulative institutional experience of the authors over the past 18 months with both extracranial carotid and intracranial artery stent-assisted carotid angioplasty.