Primary stent placement for recanalization of iliac artery occlusions: using a self-expanding spiral stent

Postnatal dilatation of umbilical cord vessels and its impact on wall integrity: Prerequisite for the artificial placenta

INTRODUCTION

A lung assist device, which acts as an artificial placenta, can provide additional gas exchange for preterm and term newborns with respiratory failure. The concept of the lung assist device requires a large bore access via umbilical vessels to allow pumpless extracorporeal blood flow rates up to 30 mL/kg/min. After birth, constricted umbilical vessels need to be reopened for vascular access. The objective is to study the impact of umbilical vessel expansion on vessel integrity for achieving large bore access.

METHODS

Umbilical cords from healthy term deliveries were cannulated and dilatated with percutaneous transluminal angioplasty catheters in 1 mm increments from 4 to 8 mm for umbilical artery and from 4 to 15 mm for umbilical vein, n = 6 per expansion diameter. Paraffin-embedded transverse sections of dilated and control samples were HE & Van Gieson stained. Effects of dilatation, shown by splitting, were measured.

RESULTS

Umbilical vessel expansion led to concentric splitting, shown by areas devoid of extracellular matrix and nuclei in the tunica intima and media. No radial splitting was observed. Results suggest an expansion threshold of umbilical artery at 6 mm and umbilical vein at 7 mm, while maximal splitting was observed above this threshold (3.6 ± 0.8%, p = 0.043 for umbilical artery 7 mm and 6.3 ± 1.8%, p = 0.048 for umbilical vein 8 mm). Endothelial cell sloughing was present in all dilated samples but not in the control samples.

CONCLUSION

The suggested thresholds for safe expansions are similar to in utero umbilical vessel diameters and demonstrate a proof of concept for attaining large bore access for the lung assist device.

Percutaneous laser-assisted recanalization of long chronic iliac artery occlusions: primary and mid-term results

We report the primary and mid-term outcome of patients with long chronic iliac artery occlusions after percutaneous excimer-laser-assisted interventional recanalization. Between 2000 and 2001, 43 patients with 46 chronic occlusions of either the common iliac artery (n=27), the external iliac artery ( n=13) or both (n=3) underwent laser-assisted percutaneous transluminal angioplasty and implantation of stents. The average length of the occlusion was 57.1+/-26 mm. After laser-assisted angioplasty and implantation of a total of 60 stents, the patients were followed up for up to 4 years. Patency rates were analyzed by ankle-brachial index (ABI) measurement and duplex ultrasound. The primary technical success rate was 95.3%, with a major complication rate of 6.9%. Clinical improvement as categorized by the Rutherford guidelines could be observed in 97.6% of cases. The ABI of all patients improved from an average of 0.46+/-0.08 before intervention to 0.97+/-0.13 at the end of the follow-up period. The overall primary patency rate was 86.1%. Four reinterventions were successful (secondary patency rate 95.4%). The mid-term results of the percutaneous recanalization of iliac artery occlusions with primary and secondary patency rates of 86.1 and 95.4% are similar to those of the treatment of short stenoses.

Percutaneous interventional reconstruction of the iliac arteries: primary and long-term success rate in selected TASC C and D lesions

We report the primary and long-term outcome of patients with selected TransAtlantic Inter-Society Consensus (TASC) C or D lesions of the iliac arteries after percutaneous interventional reconstruction. Between 1999 and 2001, 89 patients with peripheral arterial disease categorized as TASC C (n=37) and D (n=52) underwent percutaneous interventional reconstruction and stent implantation. Patients were followed for 1-62 months (mean 36 months). Patency rates were assessed by Duplex ultrasound and ankle-brachial index (ABI) measurement. The primary technical success rate was 96.9% with an overall complication rate of 5.6%. The ABI improved from an average of 0.51+/-0.15 before intervention to 0.79+/-0.16 on the day following intervention and to 0.81+/-0.17 within 3 years after intervention. Clinical improvement was observed in 97.3% of the patients in the TASC C group and in 88.5% in the TASC D group. Eighty of 89 patients (89.9%) remained patent at 3-year follow-up. In five patients the reintervention was successful. The secondary patency rate was 95.5%. The patency rates were similar in our selected TASC C and D patients to those so far published for TASC A and B, with low complication rates. Therefore, percutaneous intervention can be recommended for these patients.

Long-term results of stenting for chronic iliac artery occlusion

PURPOSE

To evaluate the long-term results of stent placement for chronic occlusions of the iliac arteries.

METHODS

Between October 1992 and December 1997, 73 patients (40 men; median age 64 years, range 42-89) with 76 occluded iliac arteries (33 common, 34 external, and 9 both vessels) were treated with percutaneous recanalization and stenting using a variety of self-expanding and balloon-expandable devices. Median occlusion length was 7 cm (range 1-14). Follow-up consisted of clinical assessment, ankle-brachial index measurement, and arteriography or duplex ultrasound when indicated.

RESULTS

Anatomical success was achieved in 74 (97%) limbs. Seven (10%) patients experienced major complications: 2 distal embolizations, 2 arterial ruptures, 1 myocardial infarction, 1 groin hematoma requiring surgery, and 1 contrast-induced nephropathy. There was no 30-day mortality. Over a median follow-up of 27 months (range 1-75), there was 1 early occlusion (< or = 30 days) and 16 late recurrent lesions (11 occlusions and 5 stenoses) at a median 6.2 months (range 1.4-30). The recurrent lesions were treated with endovascular techniques in 8 limbs and surgery in 7 limbs (5 after failed endovascular procedures); 1 patient died before retreatment, and 1 patient refrained from further intervention. Primary and secondary patencies were 79% and 87% at 1 year and 69% and 81% at 3 years, respectively.

CONCLUSIONS

Stenting of chronic iliac occlusions is a safe and durable alternative to surgical treatment.