Renal artery stent placement for the management of ischemic nephropathy

PURPOSE

To evaluate the angiographic and clinical results of percutaneously implanted renal artery endoprostheses (stents) for the treatment of patients with ischemic nephropathy.

MATERIALS AND METHODS

During a 52-month period, 45 patients with azotemia (serum creatinine > or = 1.5 mg/dL) and atheromatous renal artery stenosis untreatable by, or recurrent after, balloon angioplasty were treated by percutaneous placement of Palmaz stents. Stent implantation was unilateral in 32 cases and bilateral in 11 cases. Clinical results were determined by measurements of serum creatinine and follow-up angiography. Clinical benefit was defined as stabilization or improvement in serum creatinine level. Angiographic patency was defined as less than 50% diameter recurrent arterial stenosis.

RESULTS

Stent placement was technically successful in 51 of 54 (94%) renal arteries. Technical failures were stent misdeployment requiring percutaneous stent retrieval (n = 2) and inadvertent placement distal to the desired position (n = 1). Complications included acute stent thrombosis (n = 1) and early initiation of hemodialysis (within 30 days; n = 1). There were two periprocedural deaths. With use of life-table analysis, clinical benefit was seen in 78% of patients at 6 months (n = 36), 72% at 1 year (n = 24), 62% at 2 years (n = 12), and 54% at 3 years (n = 3). In patients with clinical benefit, average creatinine level was reduced from 2.21 mg/dL +/- 0.91 before treatment to 2.05 mg/dL +/- 1.05 after treatment (P = .018). Lower initial serum creatinine level was associated with a better chance of clinical benefit (P = .05). No other variables affected outcome, including patient age, sex, diabetes, implanted stent diameter, unilateral versus bilateral stent placement, or ostial versus nonostial stent positioning. Conventional catheter angiography or spiral computed tomographic (CT) angiography performed in 19 patients (28 stents) at a mean interval of 12.5 months demonstrated primary patency in 75%. Maintained stent patency appeared to correlate with renal functional benefit.

CONCLUSIONS

Percutaneous renal artery stent placement for angioplasty failures or restenoses provides clinical benefit in most patients with ischemic nephropathy.

On tests for group variation with a small to moderate number of groups

This paper considers a family of penalized likelihood score tests for group variation. The tests can be indexed by a measure of degrees of freedom. At one extreme, with degrees of freedom one less than the number of groups, is the usual score test for a fixed effects alternative using indicator variables for the groups, while at the other extreme, in the limit as the degrees of freedom-->0, is a test closely related to a score test based on a random effects alternative. Asymptotic power comparisons are made for the tests in the family. As would be expected, different members of the family are more efficient for different alternatives. Generally the tests with smaller degrees of freedom appear to have better power than the standard test for alternatives focusing on differences among the larger groups, and lower power for alternatives focusing on differences among the smaller groups. Simulations indicate the asymptotic approximation to the distribution performs better for the tests with small degrees of freedom.

Effect of recombinant human erythropoietin on transfusion risk in coronary bypass patients

BACKGROUND

Patients having a cardiac operation frequently require allogeneic blood transfusions despite surgical blood-conservation techniques. Recombinant human erythropoietin (Epoetin alfa) may augment this conservation by stimulating erythropoiesis. The safety and efficacy of perioperative use of Epoetin alfa to reduce the need of allogeneic transfusion was studied.

METHODS

A multicenter double-blind, placebo-controlled, parallel-group study involved 182 patients having coronary artery bypass grafting and randomized to receive Epoetin alfa (300 or 150 IU/kg) or placebo subcutaneously for 5 days before, on the day of, and for 2 days after operation.

RESULTS

Perioperative Epoetin alfa resulted in greater increases in baseline to preoperative hemoglobin levels and hematocrit (300 IU/kg) and in presurgery to postsurgical day 1 reticulocyte counts versus placebo (p < or = 0.05). However, there was no significant difference in transfusion requirements. Incidences of adverse events were similar in all study groups.

CONCLUSIONS

Lower incidences of allogeneic blood exposure were observed in both Epoetin alfa-treated groups; however, the differences between all treatment groups were not significant. This was probably due to the relatively short 5-day preoperative course of Epoetin alfa therapy. There were no significant differences between the three groups relative to safety. Epoetin alfa was well tolerated in this population.

The pattern of splint usage in the management of two common temporomandibular disorders. Part III: Long-term follow-up in an assessment of splint therapy in the management of disc displacement with reduction and pain dysfunction syndrome

OBJECTIVE

To assess the long-term follow-up of patients successfully treated for disc displacement with anterior repositioning splint therapy and patients successfully treated for pain dysfunction syndrome with stabilisation therapy.

DESIGN

Retrospective analysis.

SETTING

Dental school clinic unit.

METHODS

Maintenance of improvement was assessed by a postal questionnaire or by direct telephone contact 3 years after cessation of splint treatment.

RESULTS

90% of patients successfully treated for disc displacement with reduction and 88% of patients successfully treated for pain dysfunction reported maintenance of improvement after 3 years. In both groups the reported improvement was independent of the pattern of splint usage.

CONCLUSIONS

The short-term use of an appropriate occlusal splint for a specific temporomandibular disorder leads to a long-term resolution of the problem.

The pattern of splint usage in the management of two common temporomandibular disorders. Part II: The stabilisation splint in the treatment of pain dysfunction syndrome

OBJECTIVE

To examine whether the stabilisation splint is a suitable treatment for pain dysfunction syndrome and to determine the most appropriate pattern of usage.

DESIGN

Prospective random control clinical trial.

SETTING

Dental school clinic unit.

SUBJECTS

70 patients diagnosed with pain dysfunction syndrome were treated with a stabilisation splint for 3 months. Group 1 (23 patients) wore the splint 24 hours/day. Group 2 (19 patients) wore the splint only during the day. Group 3 (28 patients) wore the splint only at night.

RESULTS

There was no statistically significant advantage to any pattern of splint usage; all groups showed a marked improvement by subjective and objective assessment.

CONCLUSIONS

Patients being treated for pain dysfunction syndrome by a stabilisation splint need wear the splint only at night.

The pattern of splint usage in the management of two common temporomandibular disorders. Part I: The anterior repositioning splint in the treatment of disc displacement with reduction

OBJECTIVE

To examine whether the anterior repositioning splint is suitable treatment for temporomandibular joint disc displacement with reduction and to determine the most appropriate pattern of usage.

DESIGN

Prospective random control clinical trial.

SETTING

Dental school clinic unit.

SUBJECTS

Three groups of patients were treated, wearing the splint either during the day or at night or all the time.

RESULTS

69% of patients could be classed as improvers, by subjective and objective assessments, at final review (3 months after treatment with an anterior repositioning splint). 88% of patients who wore the splint for 24 hours per day improved over the 3-month period; this improvement was statistically significant when compared with the other two groups.

CONCLUSIONS

An anterior repositioning splint is an appropriate method of treatment for disc displacement with reduction. Patients should wear the splint 24 hours a day.

The incidence of temporomandibular disorder signs in patients wearing complete dentures compared to patients with a natural dentition

The aim of this study was to determine the incidence of signs of a temporomandibular disorder in patients wearing complete upper and lower dentures and to compare this to the incidence of signs in dental out-patients with a natural dentition. One hundred and sixty patients were assessed using a questionnaire and clinical examination. The results showed statistically significant differences between the two groups regarding the presence of temporomandibular disorder signs, the dentate group having a higher incidence (P < .04).

Emergency treatment of acute temporomandibular disorders: Part II

In this, the second part of a presentation on the emergency treatment of an acute temporomandibular disorder, we will address the problems of joint sounds, open and closed locking and psychological considerations. The management of pain and muscle spasm was considered in the previous paper.

Emergency treatment of acute temporomandibular disorders: Part 1

The purpose of this short series of articles is to provide guidance in the management of patients who present with an acute temporomandibular disorder. This article is the first of two, highlighting the role of the general dental practitioner in the primary care of acute temporomandibular disorders.

Administration of PRN medication by mental health nurses

The administration of PRN medication by mental health nurses is an important, yet poorly explored aspect of psychiatric inpatient care. An examination of nurses' reasons for administering PRN medication is essential in ensuring its appropriate and effective use. Data were gathered from the drug charts of 44 inpatients on two acute psychiatric wards. Most PRN medication was given orally and the most frequently administered drugs were procyclidine, lorazepam, ibuprofen, diazepam and droperidol. The main reason for administering PRN medication was because patients had 'requested' it. Results were broadly consistent with previous research. It is recommended that nurses should give clear and specific reasons for administering PRN medication based on a valid assessment. Implications for clinical practice and further research are also discussed.

Adverse 5-year outcome after coronary artery bypass surgery in blacks

BACKGROUND

Coronary heart disease is the leading cause of death among blacks, but little is known about the late results of coronary artery bypass surgery in this population. It is not known whether differences in preoperative medical characteristics or medical health insurance affect outcome. We studied the effects of medical risk factors on survival outcome after coronary artery bypass surgery in a population of medically insured black and white patients.

METHODS

Racial status and outcomes from surgery were determined in 3728 consecutive patients who had coronary artery bypass surgery at the authors' institution from January 1, 1984, to June 30, 1992. Coronary artery bypass surgery (excluding valve replacement) was performed in 115 black and 3113 white patients.

RESULTS

Late survival probability was worse for blacks than whites at 1 year (84% vs 92%) and at 5 years (64% vs 82%, P=.001, Wilcoxon test). Most deaths were due to cardiac events in both groups (68% in blacks vs 67% in whites). Blacks had more hypertension (84% vs 54%), diabetes mellitus (36% vs 23%), and more were current smokers (21% vs 14%) (all P<.05, Fisher's exact test). Medical insurance coverage for blacks and whites was as follows: Medicare (60% vs 57%), private (38% vs 42%), and Medi-Cal (2% vs 2%). Operative mortality (30 days) was similar (5.2% for blacks vs 4.1% for whites; P=.48, Fisher's exact test). In a Cox regression model, race predicted long-term survival and persisted as an important risk factor after adjusting for preoperative factors related to patient survival (adjusted hazard ratio, 2.10; 95% confidence interval, 1.43 to 3.07).

CONCLUSIONS

In this group of predominantly medically insured patients undergoing coronary artery bypass surgery, the risk of death in blacks at 5 years was twice that of whites.

Multilocus genetic determinants of LDL particle size in coronary artery disease families

Recent interest in atherosclerosis has focused on the genetic determinants of low-density lipoprotein (LDL) particle size, because of (i) the association of small dense LDL particles with a three-fold increased risk for coronary artery disease (CAD) and (ii) the recent report of linkage of the trait to the LDL receptor (chromosome 19). By utilizing nonparametric quantitative sib-pair and relative-pair analysis methods in CAD families, we tested for linkage of a gene or genes controlling LDL particle sizes with the genetic loci for the major apolipoproteins and enzymes participating in lipoprotein metabolism. We confirmed evidence for linkage to the LDL receptor locus (P=.008). For six candidate gene loci, including apolipoprotein(apo)B, apoAII, apo(a), apoE-CI-CII, lipoprotein lipase, and high-density lipoprotein-binding protein, no evidence for linkage was observed by sib-pair linkage analyses (P values ranged from .24 to .81). However, in addition, we did find tentative evidence for linkage with the apoAI-CIII-AIV locus (chromosome 11) (P=.06) and significant evidence for linkage of the cholesteryl ester transfer protein locus (chromosome 16) (P=.01) and the manganese superoxide dismutase locus (chromosome 6) (P=.001), thus indicating multilocus determination of this atherogenic trait.

Use of Wallstents for hemodialysis access-related venous stenoses and occlusions untreatable with balloon angioplasty

PURPOSE

To determine whether the Wallstent endoluminal prosthesis can be used to maintain patency of venous stenoses and occlusions related to hemodialysis access.

MATERIALS AND METHODS

Wallstents were placed in 52 patients with 56 lesions. Thirty-two lesions were in central veins and 24 were in peripheral veins. Stents were placed immediately after failed angioplasty in 39 patients, because of early restenosis after angioplasty in four, and for treatment of a lesion unsuitable for angioplasty in eight. The remaining five lesions were treated at the operator's discretion after predilation.

RESULTS

The procedural success rate was 96%. The cumulative primary patency rate was 46% at 6 months and 20% at 12 months; however, with repeat treatment, the cumulative assisted patency rate was 76% at 6 months and 33% at 12 months. Known causes of recurrence included intimal hyperplasia in or near the stent, stent slippage, and remote stenoses. Complications included two stent migrations due to central line placement and one stent-related pseudoaneurysm.

CONCLUSION

Wallstents are safe to deploy for dialysis access. Wallstents are useful for treating lesions that fail angioplasty and catheter-related central venous occlusions.

Treatment of anastomotic bypass graft stenosis with directional atherectomy: short-term and intermediate-term results

PURPOSE

Areas of anastomotic stenosis in lower-extremity bypass grafts (BPGs) were treated by means of directional atherectomy (DA) in hopes of achieving better patency rates than have been reported with percutaneous transluminal angioplasty (PTA).

MATERIALS AND METHODS

During a 4-year period, 17 patients (11 men and six women) with 23 areas of anastomotic stenosis in 18 lower-extremity BPGs were selected for treatment with DA. Urokinase thrombolysis was initially performed in eight BPGs that were thrombosed at the time of presentation. Adjunctive preatherectomy PTA was performed in six lesions, and postatherectomy PTA was performed in three lesions.

RESULTS

The technical success rate for DA was 92% (23 of 25 sites). There was less than 50% restenosis at 74% of the areas of stenosis (14 of 19 sites), with a mean follow-up time for the sites of 13 months. The graft patency rate was 88% (14 of 16 grafts), with a mean follow-up time for the grafts of 14 months. Areas of stenosis treated with DA alone had the same patency rates as those treated with DA and PTA.

CONCLUSIONS

DA is an effective treatment method for anastomotic peripheral arterial BPG stenosis. The intermediate-term patency rates following DA are superior to those reported for PTA and similar to those reported for surgical revision.

Ergonomic vascular access needle with blood-containment capability: clinical evaluation during arterial access procedures

PURPOSE

To evaluate the performance of the ergonomic vascular access needle (EVAN), which is designed to contain blood while allowing for observation of pulsations before passage of a guide wire, in arterial catheterization.

MATERIALS AND METHODS

EVANs were used for initial puncture in 118 arterial access procedures. Visualization of pulsatile blood motion and containment of blood were prospectively evaluated. Results from 82 separate procedures performed with standard access needles were used as a control. Success or failure of guide-wire passage through the needle, number of attempts, guide-wire type, findings on the access vessel arteriogram, and complications were recorded for both groups.

RESULTS

In the EVAN group, 92% of procedures were successfully completed, usually within two attempts (82%). Success was independent of guide-wire type (P = .4) and was not significantly different from that of the control group (96%) (P = .37). In 89% of the EVAN procedures, contained pulsatile blood motion was observed before attempted guide-wire passage. Uncontrolled spraying of pulsatile blood did not occur unless the hemostasis valve was removed. In 16%, slow oozing of blood occurred through the needle hub, mainly during guide-wire passage. Oozing was common with floppy-tipped guide wires (46%) but was uncommon with stiffer-tipped wires (6%). There were no needle-related complications.

CONCLUSION

The EVAN provides protection from blood spray while allowing for successful guide-wire passage into the arterial system as often as standard access needles. However, slow periwire leakage occurs frequently with floppy-tipped guide wires.

Percutaneous hepatic venous reanastomosis in a patient with Budd-Chiari syndrome

A 33-year-old woman with Budd-Chiari syndrome for 9 years presented with worsening right upper quadrant pain and progressive liver dysfunction. Hepatic venography demonstrated hepatic vein occlusions, without significant IVC obstruction. Attempts at stenting a stenotic middle hepatic vein were unsuccessful. Transjugular access, however, allowed puncture from the stump of the right hepatic vein into the engorged right intrahepatic vein that had been demonstrated by retrograde hepatic venography. Two Palmaz stents were used to form the veno-venous reanastomosis. Initial success was documented angiographically and by pressure measurements before and after shunting. Followup at 7 and 16 months confirmed patency of the anastomosis without intimal hyperplasia. The patient noted near-complete resolution of her pain, and her liver function stabilized.

Genetic variation in lipoprotein (a) levels in families enriched for coronary artery disease is determined almost entirely by the apolipoprotein (a) gene locus

Lipoprotein (a) (Lp[a]) is a cholesterol-rich lipoprotein resembling LDL but also containing a large polypeptide designated apolipoprotein (a) (apo[a]). Its levels are highly variable among individuals and, in a number of studies, are strongly correlated with the risk of coronary artery disease (CAD). In an effort to determine which genes control Lp(a) levels, we have studied 25 multiplex families (comprising 298 members) enriched for CAD. The apo(a) gene was genotyped among the families, using a highly informative pulse-field gel electrophoresis procedure. In addition, polymorphisms of the gene for the other major protein of Lp(a), apolipoprotein B (apoB), were examined. Quantitative sib-pair linkage analysis indicates that apo(a) is the major gene controlling Lp(a) levels in this CAD population (P = .001; 99 sib pairs), whereas the apoB gene demonstrated no significant quantitative linkage effect. We estimate that the apo(a) locus accounts for < or = 98% of variance of Lp(a) serum levels. Approximately 43% of this variation is explained by size polymorphisms within the apo(a) gene. These results indicate that the apo(a) gene is the major determinant of Lp(a) serum levels not only in the general population but also in a high-risk CAD population.