Comparison of surgical bypass and percutaneous balloon dilatation with primary stent placement in the treatment of central venous obstruction in the dialysis patient: one-year follow-up.

Central venous stenosis and occlusion are complications that are being observed with increasing frequency as a result of the use of long-term central venous catheters. These complications are especially problematic in patients with end-stage renal disease and functioning ipsilateral arteriovenous (AV) grafts or fistulas (AV grafts). We have previously demonstrated that the 1-year patency rate for simple balloon angioplasty in these patients is less than 10%. To compare the results of surgical treatment vs. percutaneous dilatation with stent placement, we undertook this retrospective study. All patients underwent multiple central venous catheter placements and had functioning ipsilateral AV grafts. Twenty-six patients were divided into two groups. The surgical treatment group included 13 patients: 10 with subclavian vein thrombosis and three with innominate vein thrombosis. All patients in the surgical group had arm swelling and edema. Surgical bypass procedures were performed in these patients using either polytetrafluoroethylene or saphenous vein. The stent group also included 13 patients; all of them had a diagnosis of subclavian or innominate vein obstruction and were treated with percutaneous transluminal angioplasty and placement of either a self-expanding rigid stent (n = 6) or a balloon-expandable flexible stent (n = 7). Two patients required multiple stent placements. No significant complications occurred in either group. The 1-year mortality rate in both groups was 31%. The percentages of patients who were symptom free at 6 and 12 months were also similar in the two groups. We conclude that surgical bypass and percutaneous transluminal angioplasty with stent placement are both efficacious in the treatment of central venous obstruction.

Alterations in heart rate variability and its circadian rhythm in hypertensive patients with left ventricular hypertrophy free of coronary artery disease.

Heart rate variability (HRV) and its circadian rhythm were evaluated in 22 patients with treated hypertension and left ventricular hypertrophy in whom coronary artery disease was excluded by stress thallium or angiography. By using 24-hour Holter monitoring, HRV and its spectral components were measured. Findings were compared with 11 age-matched normal controls. The difference between mean R-R intervals during sleep (11 PM to 7 AM) and while awake (9 AM to 9 PM) (73 +/- 33 vs 263 +/- 63 msec, p < 0.0001) and the mean 24-hour SD of the R-R intervals (55 +/- 6.3 vs 93 +/- 11, p < 0.0001) were lower among the hypertensive patients compared with controls. The percentage of difference between successive R-R intervals that exceeded 50 msec, a measure of parasympathetic tone, was also lower among the hypertensive patients (6.8 +/- 7.1 vs 13.6 +/- 8.9, p < 0.002); it increased at night and decreased during the day among the controls, and this circadian rhythm was blunted among the patients. Spectral analysis showed that power in the high-frequency range (0.15 to 0.40 Hz) was lower among the hypertensive patients during 21 of 24 hours but that the difference was statistically significant only during 9 hours (p ranging from < 0.05 to 0.009). Power in the low-frequency range (0.04 to 015 Hz) was lower at night, increased in the morning, and higher during the day among controls; this circadian rhythm was absent among hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)