Stephen Cox

Effect of Renal Artery Stenting on Renal Function and Size in Patients with Atherosclerotic Renovascular Disease

BackgroundRenal artery stenting is widely performed, but little is known about its effectiveness in preserving renal function and size in patients with renovascular disease and chronic renal insufficiency. We studied the effect of renal artery stenting on renal function and size in patients with obstructive renovascular disease and chronic renal insufficiency. Methods and ResultsStent deployment was performed in patients with chronic renal insufficiency (creatinine >1.5 mg · dL−1) and global renovascular obstruction (bilateral renal artery stenosis or unilateral stenosis in the presence of a solitary or single functional kidney). The effect of renal artery stenting on renal function was assessed by comparing the slopes of the regression lines derived from the reciprocal of serum creatinine versus time plotted before and after stent deployment. Renal size was assessed by serial ultrasound of pole-to-pole kidney length. Stenting was successful in all 61 vessels in 33 patients. Twenty-five patients had complete follow-up (mean 20±11 months). Before stent deployment, all patients exhibited a negative slope, indicating progressive renal insufficiency. After stent deployment, the slopes were positive in 18 and less negative in 7 patients. Thus, the mean slope increased from −0.0079 to 0.0043 dL · mg−1 · mo−1 (P <0.001). Ultrasonography on 41 kidneys revealed preservation of size, with the kidney length measuring 10.4±1.4 cm at baseline and 10.4±1.1 cm at last follow-up (P =NS). Patient survival at 20±11 months was 90%. ConclusionsIn patients with chronic renal insufficiency and global obstructive atherosclerotic renovascular disease, renal artery stenting improves or stabilizes renal function and preserves kidney size.

Percutaneous revascularization of atherosclerotic obstruction of aortic arch vessels

OBJECTIVES To compare stenting of aortic arch vessel obstruction with surgical therapy and to establish recommendations for treatment. BACKGROUND Though surgery has been considered to be the procedure of choice for subclavian and brachiocephalic obstruction, little work has been done to compare it with stenting. METHODS Eighteen patients with symptomatic aortic arch vessel stenosis or occlusion were treated with stenting, followed by periodic clinical follow-up and noninvasive arterial Doppler studies. Data were compared with the results as shown in a systematic review of a published series of surgery and stenting procedures which included comparison of technical success, complications, mortality and patency. RESULTS Primary success in our series was 100% with improvement in mean stenosis from 84+/-11% to 1+/-5% and mean arm systolic blood pressure difference from 44+/-16 mm Hg to 3+/-3 mm Hg. There were no major complications (death, stroke, TIA, stent thrombosis or myocardial infarction). At follow-up (mean 17 months), all patients were asymptomatic with 100% primary patency. Literature review demonstrates equivalent patency and complications in the other published series of stenting. In contrast, there was a similar patency but overall incidence of stroke of 3+/-4% and death of 2+/-2% in the published surgical series. CONCLUSIONS Subclavian or brachiocephalic artery obstruction can be effectively treated by primary stenting or surgery. Comparison of stenting and the surgical experience demonstrates equal effectiveness but fewer complications and suggests that stenting should be considered as first line therapy for subclavian or brachiocephalic obstruction.

Increased platelet-derived microparticles in the coronary circulation of percutaneous transluminal coronary angioplasty patients

Platelet-derived microparticles that are produced during platelet activation are capable of adhesion and aggregation. Endothelial trauma that occurs during percutaneous transluminal coronary angioplasty (PTCA) may support platelet-derived microparticle adhesion and contribute to development of restenosis. We have previously reported an increase in platelet-derived microparticles in peripheral arterial blood with angioplasty. This finding raised concerns regarding the role of platelet-derived microparticles in restenosis, and therefore the aim of this study was to monitor levels in the coronary circulation. The study population consisted of 19 angioplasty patients. Paired coronary artery and sinus samples were obtained following heparinization, following contrast administration, and subsequent to all vessel manipulation. Platelet-derived microparticles were identified with an anti-CD61 (glycoprotein IIIa) fluorescence-conjugated antibody using flow cytometry. There was a significant decrease in arterial platelet-derived microparticles from heparinization to contrast administration (P = 0.001), followed by a significant increase to the end of angioplasty (P = 0.004). However, there was no significant change throughout the venous samples. These results indicate that the higher level of platelet-derived microparticles after angioplasty in arterial blood remained in the coronary circulation. Interestingly, levels of thrombin–antithrombin complexes did not rise during PTCA. This may have implications for the development of coronary restenosis post-PTCA, although this remains to be determined.

Transcatheter aortic valve replacement is associated with comparable clinical outcomes to open aortic valve surgery but with a reduced length of in-patient hospital stay: a systematic review and meta-analysis of randomised trials

BACKGROUND Aortic valve replacement is indicated in patients with severe symptomatic aortic stenosis (AS). Transcatheter aortic valve replacement (TAVR) has evolved as a potential strategy in a growing proportion of patients in preference to surgical aortic valve replacement (SAVR). This meta-analysis aims to assess the differential outcomes of TAVR and SAVR in patients enrolled in published randomised controlled trials (RCTs). METHODS A systematic literature search of Cochrane Library, EMBASE, OVID, and PubMed MEDLINE was performed. Randomised controlled trials of patients with severe AS undergoing TAVR compared with SAVR were included. Clinical outcomes and procedural complications were assessed. RESULTS Five RCTs with a total of 3,828 patients (1,928 TAVR and 1,900 SAVR) were analysed. There was no statistically significant difference in combined rates of all-cause mortality and stroke at 30-days for TAVR vs SAVR (6.3% vs 7.5%; OR 0.83; 95% CI: 0.64-1.08; P=0.17) or at 12 months (17.2% vs 19.2%; OR 0.87; 95% CI: 0.73-1.03; P=0.29). No statistically significant difference was seen for death or stroke separately at any time point although a numerical trend in favour of TAVR for both was recorded. Length of in-patient stay was significantly less with TAVR vs SAVR (9.6 +/- 7.7 days vs 12.2 +/- 8.8 days; OR -2.94; 95% CI: -4.64 to -1.24; P=0.0007). Major vascular complications were more frequent in patients undergoing TAVR vs SAVR (8.2% vs. 4.0%; OR 2.15; 95% CI: 1.62-2.86; P <0.00001) but major bleeding was more common among SAVR patients (20.5% vs 44.2%; OR 0.34; 95% CI: 0.22-0.52; P=<0.00001). CONCLUSIONS Transcatheter aortic valve replacement and SAVR are associated with overall similar rates of death and stroke among patients in intermediate to high-risk cohorts but with reduced length of in-patient hospital stay.

Percutaneous closure of an aortic prosthetic paravalvar leak: an Australian first.

Percutaneous intervention is becoming an increasingly recognised modality for the management of prosthetic paravalvar leaks (PVLs) with particular utility in severely symptomatic non-surgical candidates. To date, application of this intervention has predominantly involved closure of mitral valve PVLs. Consequently, current literature on its application to aortic PVLs is limited. This article describes what we believe to be the first percutaneous closure of an aortic prosthetic PVL in Australia.

Left Ventricular Aneurysm Perforating into the Right Ventricle: A Rare Complication of a Small Side Branch Occlusion after Elective Percutaneous Coronary Intervention

Graphical abstract