Percutaneous intervention for symptomatic vertebral artery stenosis using coronary stents

BACKGROUND

There is very limited experience with percutaneous treatment of symptomatic vertebral artery disease. Angioplasty and stenting for vertebral artery stenosis are still evolving and have generally been performed for asymptomatic disease. We performed vertebral artery stenting in 12 patients with vertebrobasilar transient ischemic attacks and present our short- and intermediate-term results.

METHODS

A total of 12 lesions affecting the vertebral artery were treated by coronary stent placement. The mean age was 72 +/- 8 years and 83% were males (10 males, 2 females). Baseline characteristics included hypertension (11/12); hypercholesterolemia (8/12); coronary artery disease (8/12); and diabetes (5/12). Mean lesion length was 8.6 +/- 2.7 mm, mean calipered stenosis was 78 +/- 8%, and mean arterial diameter was 4.1 +/- 0.3 mm. All patients were symptomatic, fulfilling our criteria for vertebral artery angioplasty. All patients were followed for at least 6 months after treatment.

RESULTS

All 12 lesions were successfully stented, with a mean residual stenosis of 11 +/- 6%. Clinical follow-up showed resolution or improvement of symptoms in all patients. One patient had symptomatic restenosis seven months after the initial procedure requiring repeat angioplasty.

CONCLUSIONS

Stent placement for symptomatic stenosis involving the vertebral artery is safe and effective for alleviating symptoms of vertebrobasilar ischemia. Coronary stents appear to be well suited to treat atherosclerotic lesions of the vertebral artery.

Effectiveness of training on infant feeding practices among community influencers in a rural area of west Bengal

Total 34 Influencers were trained in a subcentre area of South 24-parganas district of West Bengal. Knowledge was imparted to community influencers on infant feeding practices through lecture, group discussion, question-answer session and hand-on-training by trained health workers. Pre-assessment was done before initiation of training. Repeat training was conducted at frequent intervals within a period of 3 months. Mean score of knowledge of influencers during pre-training assessment was 13.3 and improved thereafter-following training to 20.8 (1st assessment), 20.6 (2nd assessment), 23.7 (3rd assessment) and 25.2 (final-assessment). Repeat training had also desired impact.

Clinical application of procedural platelet monitoring during percutaneous coronary intervention among patients at increased bleeding risk

The goal of platelet function testing in the catheterization laboratory is to provide information about the platelet contributions to the risk of thrombotic or hemorrhagic events and optimization of anti-platelet therapy for percutaneous interventions. We present several illustrative cases in which platelet monitoring with the Rapid Platelet Function Assay (RPFA, Accumetrics) was used to guide dosing of a glycoprotein (GP) IIb/IIIa inhibitor for coronary and peripheral intervention among patients at increased bleeding risk.

Extra-anatomic arterial reconstruction with ligation of common iliac arteries and embolization of the aneurysm for the treatment of abdominal aortic aneurysms in high-risk patients

PURPOSE

The mortality of an unrepaired abdominal aortic aneurysm (AAA) generally exceeds the mortality associated with surgical repair. However, as our longevity increases, more frequently we see patients whose risk of surgical repair approximates the risk of rupture. We present an extra-anatomic bypass graft with complete aneurysm exclusion by iliac ligation and coil embolization of the aneurysm as an alternative for these high-risk patients.

METHODS

An extra-anatomic bypass graft, followed by bilateral iliac artery ligation (retroperitoneal approach) and complete coil embolization of the AAA, was performed in eight patients (mean age, 77 years) found to be at prohibitive operative risk because of multiple comorbidities (American Society of Anesthesiologists class IV). Most patients (5 of 8) were symptomatic on presentation with a mean AAA diameter of 7 cm (range, 6.7-9.5 cm). We repair approximately 30 infrarenal aneurysms per year electively at our institution.

RESULTS

All patients tolerated the surgical procedures. The average hospital stay was 8 days. All but two aneurysms demonstrated complete thrombosis by 48 hours. After 48 months there was no incidence of graft thrombosis, peripheral ischemia, visceral ischemia or thrombus infection. There was one perioperative death from aspiration pneumonia. Seventy-five percent (6 of 8) of patients have survived at least 1 year without surgical complications. No patient has had a ruptured aneurysm.

CONCLUSION

Combining an extra-anatomic bypass graft and complete exclusion of the AAA by ligation of the common iliac arteries and a coil embolization is an effective, less invasive treatment option for patients with AAA and prohibitive operative risk. We emphasize the need for complete embolization documented by decreased aneurysm size.

Hearing aids versus ventilation tubes in persistent otitis media with effusion: a survey of clinical practice

A postal survey was carried out to determine the current clinical practice amongst consultant otolaryngologists in the UK, regarding re-insertion of ventilation tubes or recommendation of hearing aids in cases of recurrence of otitis media with effusion (OME) after ventilation tube extrusion. Amongst the 319 respondents, 15 (4.70 per cent) routinely, 146 (45.77 per cent) sometimes, and 158 (49.53 per cent) either never, or very rarely, recommend hearing aids. Hearing aids and ventilation tubes were both suggested to be equally good options by some consultants but they preferred surgery for a number of reasons. There were inconsistencies in practice and some of the reasons for re-inserting ventilation tubes are not evidence-based. A hearing aid is a non-invasive option and this survey shows a need for a randomized control trial of hearing aids and ventilation tubes in the management of persistent and recurrent OME.

Hepatopulmonary syndrome: prevalence and clinical profile

BACKGROUND

The hepatopulmonary syndrome (HPS) is defined as a triad of liver dysfunction, intrapulmonary vascular dilatations (IPVD) and arterial hypoxemia. There is paucity of Indian studies regarding the prevalence of IPVD and arterial hypoxemia particularly amongst patients with non-cirrhotic portal fibrosis (NCPF) and extrahepatic portal vein obstruction (EHPVO), where liver dysfunction is not a feature.

METHODS

All patients with portal hypertension and esophageal varices seen at a tertiary care hospital during 1995-98 were studied. Ultrasonography of abdomen, contrast-enhanced echocardiography (CEE), arterial blood gas analysis and assessment of alveolar-arterial oxygen gradient were done.

RESULTS

Of 138 patients with portal hypertension seen during the study period, 88 fulfilled the inclusion and exclusion criteria. These included 63 with cirrhosis, 15 with NCPF and 10 with EHPVO. CEE showed IPVD in 17 (27%) patients with cirrhosis, of which 11 (17.5%) fulfilled the criteria for HPS. IPVD were also noted in 4 (26.6%) cases of NCPF and 3 (30%) of EHPVO, though only 2 (13.3%) and 1 (10%) respectively had elevated alveolar-arterial gradient and liver dysfunction in addition. Age and sex distribution and duration of symptoms were not different in patients with HPS. Patients with HPS had higher incidence of dyspnea, platypnea, clubbing and spider nevi.

CONCLUSIONS

Hepatopulmonary syndrome is present in 17.5% of cirrhotics, 13.3% of patients with NCPF and 10% with EHPVO. Patients with HPS had significantly higher incidence of dyspnea, platypnea, clubbing and spider nevi.

Monitoring antiplatelet therapy: What is the best method?

Platelet function tests measure different aspects of platelet function, which include adherence, activation, aggregation and secretion. Clinically, the goal of platelet function testing is to provide information about the platelet contribution to the risk of thrombotic or haemorrhagic events and the optimisation of antiplatelet therapy. The important clinical questions are whether an antiplatelet agent is having the desired effect on platelet inhibition (effectiveness) and whether the patient has sufficient residual platelet function to avoid bleeding (safety). The role of aspirin (acetylsalicylic acid) and thienopyridines is well established in the management of patients with coronary artery disease and in the setting of coronary interventions. The last several years have demonstrated the unequivocal effectiveness of intravenously administered platelet glycoprotein (GP) IIb/IIIa antagonists in the management of acute coronary syndromes and in the setting of percutaneous coronary interventions. With the increasing use of these GPIIb/IIIa antagonists, it is becoming more important clinically to measure platelet inhibition with these agents. This paper reviews major techniques and instrumentation for platelet monitoring and discusses the goals of the best method.

Stimulation of pregnenolone metabolism and aromatase activity by luteinizing hormone in mouse uterus

In vitro metabolism of pregnenolone (P5) as well as production of 17beta-estradiol (E2) were studied in uteri of untreated and luteinizing hormone (LH)-treated mice that had been ovariectomized (OVX) at late-diestrus stage. In the uteri of untreated mice, [H]pregnenolone was shown to be metabolized to Delta-components such as 17alpha-hydroxypregnenolone (17alpha-P5) and dehydroepiandrosterone (DHEA), whereas LH treatment resulted in significant increases in the formation of progesterone (P4), 17alpha-hydroxyprogesterone (17alpha-P4), androstenedione (AD) and testosterone (T). This was assessed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The content and release of P4 was shown to be stimulated by LH. Trilostane, an inhibitor of 3beta-hydroxysteroid dehydrogenase (3beta-HSD), inhibited LH-induced P4 synthesis and its release in a dose-dependent manner. A considerable increase in [H]estradiol formation from [H]testosterone was recorded in LH-stimulated uterine tissue as compared with the control, indicating the stimulatory effect of LH on aromatase activity. LH-stimulation in the synthesis of P4 and E2 in OVX mouse uteri was mimicked by dbcAMP (cell-permeable cAMP). Incubation with LH was shown to augment the conversion of P4 to various delta-3-oxosteroids. In vitro effects of LH on the synthesis and metabolism of P4, as well as on the stimulation of aromatase activity, were more pronounced in the uterine tissue of LH-primed OVX mice. Thus the results of the present study indicate that, under specific conditions, the uterus of the mouse behaves like steroidogenic tissue. Its prompt response to LH reveals the probable physiological relevance of the existence of LH receptors of high binding affinity in the uterine tissue of the mouse, as reported earlier.

Applications of monitoring platelet glycoprotein IIb/IIIa antagonism and low molecular weight heparins in cardiovascular medicine

With the addition of more potent antiplatelet and antithrombin therapies to the armamentarium of the treatment of acute coronary syndromes and percutaneous coronary interventions, monitoring these therapies has become an important interest. Current and evolving technologies to monitor the extent of inhibition of platelet aggregation and activity of factor Xa caused by IIb/IIIa antagonists and low-molecular-weight heparin, respectively, will be covered in this overview. An underlying question to be considered is whether the results generated from monitoring will effect a change that will improve the efficacy (prevent thrombotic events) or reduce adverse events (bleeding) from these potent therapies.

Carotid and cerebrovascular disease

Stroke remains a major public health problem, and carotid artery atherosclerotic disease causes a significant proportion of all strokes. Because the U.S. population is aging, the incidence of cerebrovascular disease is increasing, and cardiologists often are involved in the care of these patients because many of them have either occult or symptomatic coronary artery disease. We review the current status of carotid and cerebrovascular diseases and therapeutic options.

Unexpected mortality reduction with abciximab for in-stent restenosis

Treatment of in-stent restenosis is generally considered low risk, and it is not clear if adjunctive use of abciximab is beneficial in this low-risk population. We determined the effect of adjunctive abciximab during percutaneous coronary intervention (PCI) for treatment of in-stent restenosis. Two hundred and ninety-three patients with in-stent restenosis underwent PCI at the Cleveland Clinic between January 1996 and December 1998. Patients undergoing directional atherectomy, laser treatment and brachytherapy were excluded (9 patients). Of the remaining 284, seventy-nine patients received abciximab during PCI and 205 were treated without abciximab. The groups were similar with respect to age, gender, left ventricular function, number of vessels involved, history of prior coronary artery bypass grafting and unstable symptoms at presentation. There were more diabetics, hypertensives, and patients with elevated cholesterol in the abciximab-treated group. At 1-year follow-up, there was a significantly lower incidence of myocardial infarction (2.5% versus 5.3%; p < 0.05) and lower mortality (1.2% versus 5.8%; p < 0.01) in the abciximab-treated group. There was no difference in the incidence of revascularization. The findings of a lowered mortality and myocardial infarction rate with abciximab warrants further prospective study in patients with in-stent restenosis.

Bypass graft to the contralateral internal jugular vein for venous outflow obstruction of a functioning hemodialysis access fistula

As survival among patients with renal failure improves, vascular access becomes more difficult, and preservation of functioning access increases in importance. Subclavian vein thrombosis associated with a distal arteriovenous fistula can result in massive and debilitating swelling of the affected extremity. We describe a novel crossover bypass grafting procedure to the contralateral internal jugular vein in a patient with a thrombosed internal jugular and subclavian vein. This procedure resulted in preservation of the functioning arteriovenous fistula and resolution of the symptoms. Unlike previously described crossover procedures to the contralateral basilic or axillary veins, this bypass graft has the added benefit of not obviating future fistula creation in that extremity.

Identification of maturation-inducing steroid in a freshwater perch Anabas testudineus and differential responses of intact follicles and denuded oocytes to cyclic AMP in oocyte maturation

Postvitellogenic follicles of freshwater perch Anabas testudineus incubated with [(3)H]pregnenolone as exogenous precursor produced several metabolites, including 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (DHP) and 5 beta-pregnane-3 alpha, 17 alpha,20 beta-triol (5 beta-3 alpha,17 alpha,20 beta-P). These were identified by chromatography, microchemical reactions, and crystallization to constant specific activity. Following stimulation with fish (perch) pituitary extract (FPE) there was significant high production of DHP and 5 beta-3 alpha,17 alpha,20 beta-P, concomitant with a high percentage of germinal vesicle breakdown (GVBD). Inhibitor of steroidogenesis (trilostane) and inhibitors of protein synthesis (cycloheximide and actinomycin-D) completely blocked FPE-induced pregnenolone metabolism and oocyte maturation. The effectiveness of various C(21) steroids in inducing GVBD was examined. Results indicate that DHP was the most potent inducer of GVBD than other structurally related C(21) steroids. In intact follicles, FPE-stimulated production of DHP was shown to be mediated through the adenylate cyclase-cAMP pathway. Addition of IBMX or forskolin, which increases the endogenous cAMP level, as well as directly supplementing dbcAMP to the incubation medium, had no inhibitory effect on DHP-induced GVBD in the intact follicles. But all these agents were shown to inhibit GVBD in fully denuded oocytes. This study provides evidence that DHP, produced by postvitellogenic follicles through the adenylate cyclase-cAMP pathway, is the maturation-inducing steroid in freshwater perch and that the role played by cAMP in the induction of GVBD in intact follicles is different from that in the denuded oocytes. J. Exp. Zool. 287:294-303, 2000.

Influence of insecticides on microbial transformation of nitrogen and phosphorus in Typic Orchragualf soil

Four insecticides, viz., BHC, phorate, carbofuran, and fenvalerate, were applied at the rate of 7.5, 1.5, 1.0, and 0.35 kg a.i. ha(-)(1), respectively, to investigate their effects on the growth and activities of N(2)-fixing and phosphate-solubilizing microorganisms in relation to the availability of N and P in laterite (Typic Orchragualf) soil. Insecticides in general, and BHC and phorate in particular, stimulated the proliferation of aerobic nonsymbiotic N(2)-fixing bacteria and phosphate-solubilizing microorganisms and also their biochemical activities, such as nonsymbiotic N(2)-fixing and phosphate-solubilizing capacities, which resulted in greater release of available N (NH(4)(+) and NO(3)(-)) and P in soil. All the insecticides were persistent in soil for a short period of time, and the rate of dissipation was highest for fenvalerate followed by phorate, carbofuran, and BHC, depicting the half-lives (T(1/2)) 8.8, 9.7, 16.9, and 20.6 days, respectively. The insecticides followed first-order reaction kinetics during their dissipation in soil.

New options for untreatable coronary artery disease: angiogenesis and laser revascularization

Some patients with severe symptomatic coronary artery disease despite maximal medical therapy are not eligible for bypass surgery or percutaneous coronary intervention, but may be eligible for two newer therapies: therapeutic angiogenesis with growth factors and transmyocardial laser revascularization.

Improvement in right ventricular systolic function after surgical correction of isolated tricuspid regurgitation

Chronic tricuspid regurgitation (TR) may lead to impairment in right ventricular (RV) function. Whether surgical correction results in restoration of normal RV geometry and function is unknown. The purpose of this study was to determine whether surgical correction of TR results in improved RV geometry and function. Measurements of RV areas were made from digitized 4-chamber echocardiographic views. Right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), and ejection fraction (EF) were calculated with the single-plane subtraction method. There was a significant decrease in RVEDV (109.06 +/- 12.45 versus 71.63 +/- 6. 83; P =.005) and RVESV (76.2 +/- 9.83 versus 44.5 +/- 5.58; P =.002) and a significant increase in RVEF (0.30 +/- 0.05 versus 0.38 +/- 0. 05; P =.01) at a mean follow-up of 130 +/- 63 days after surgery. These results demonstrate significant remodeling of the right ventricle with reduction in size and improved EF after tricuspid valve surgery.

'Rescue' angioplasty for failed thrombolysis

Early restoration of patency of the infarct-related artery is a universally accepted goal in the treatment of acute myocardial infarction. However, even with the most successful fibrinolytic regimen only approximately 50% of patients achieve restoration of normal flow at 90 minutes. "Rescue" angioplasty, the mechanical reopening of an infarct-related artery after unsuccessful fibrinolytic therapy, appears to be beneficial.

Ten-fold augmentation of endothelial uptake of vascular endothelial growth factor with ultrasound after systemic administration

OBJECTIVES

In this study, the feasibility of delivering and enhancing the uptake of vascular endothelial growth factor (VEGF) into the intact endothelium by using ultrasound (US) facilitation was determined.

BACKGROUND

A limitation of tissue-targeted drug delivery is the need for direct arterial cannulation. We postulate a mechanism by which agents injected intravenously may be targeted to a tissue using US and ultrasonic contrast agents.

METHODS

We used a rat model to test the ability of US and an ultrasonic contrast agent perflurocarbon exposed sonicated dextrose albumin (PESDA) to increase uptake of VEGF in the myocardium. Continuous wave Doppler US (0.6 W/cm2 at 1 MHz for 15 min) was applied to the chest wall overlying the myocardium during intravenous injection with either VEGF (100 microg/kg) alone or a combination of VEGF and PESDA (0.1%). Control rats had VEGF infused without US or PESDA. The VEGF uptake was measured quantitatively in the heart, lung, liver and kidneys by enzyme-linked immunosorbent assay (ng/g of tissue) and morphologically by fluorescence microscopy.

RESULTS

There was an eight-fold increase in VEGF uptake in the heart by US alone (16.86 +/- 1.56 vs. 2.11 +/- 0.953 ng/g of tissue, p < 0.0001) and a 13-fold increase with US + PESDA (26.78 +/- 2.88 vs. 2.11 +/- 0.953 ng/g of tissue, p < 0.0001) compared with control rats. Fluorescence microscopy revealed deposition of VEGF in the endothelium of small intramyocardial arterioles.

CONCLUSIONS

These results show a marked increase in endothelial VEGF uptake with US and US + PESDA. Thus, US may be used to augment endothelial VEGF uptake 10-fold to 13-fold.

Achieving tissue-level perfusion in the setting of acute myocardial infarction

Treatment for ST-elevation myocardial infarction (MI) has advanced rapidly in the last few years with improvements in early fibrinolytic therapy, primary percutaneous revascularization, and use of potent platelet glycoprotein IIb/IIIa inhibitors. It is now obvious that establishing epicardial patency after myocardial infarction is not synonymous with tissue-level perfusion. Techniques and therapies are now available that measure true tissue-level perfusion and that may improve tissue-level perfusion after myocardial infarction.

Mitral valve surgery in patients with severe left ventricular dysfunction

OBJECTIVES

The objectives of this study were to determine (1) survival, (2) functional status and freedom from readmission for heart failure and (3) change in postoperative left ventricular (LV) dimensions and function following mitral valve repair or replacement in patients with severe LV dysfunction and mitral regurgitation.

PATIENTS AND METHODS

Between 1990 and 1998, 44 patients with mitral regurgitation and a LV ejection fraction <35% (mean+/-SD, 28+/-6%) underwent isolated mitral repair (n=35) or replacement (n=9). The etiology of regurgitation was valvular in 18 (40%) patients, ischemic in 13 (30%) patients and dilated idiopathic cardiomyopathy in 13 (30%) patients. Every patient had been hospitalized one to six times for symptoms of heart failure (mean+/-SD, 2.3+/-1.5). All patients were receiving maximal drug therapy with 15 (34%) in New York Heart Association (NYHA) class III and 12 (27%) in class IV. Seven (16%) patients were initially referred for consideration of transplantation. The mean+/-SD duration of follow-up was 40+/-21 months.

RESULTS

One (2.3%) patient died 9 days postoperatively of acute bronchopneumonia. The mean+/-SD duration of ICU and hospital stay was 41+/-34 h and 9+/-3 days, respectively. The 1-, 2- and 5-year survival rates were 89, 86 and 67%, respectively. Heart failure and sudden death accounted for 62% of the late deaths. The NYHA class improved for survivors from 2.8+/-0.8 preoperatively to 1. 2+/-0.5 at follow-up (P<0.0001). Freedom from readmission for heart failure was 88, 82 and 72% at 1, 2 and 5 years, respectively. No patient has been listed for transplantation.

CONCLUSIONS

Mitral valve surgery offers symptomatic improvement and survival benefit in patients with severe LV dysfunction and mitral regurgitation. More liberal use of this surgery for cardiomyopathy patients is warranted.