Color Doppler ultrasound evaluation of arteriovenous grafts for hemodialysis

Although arteriovenous fistula (AVF) continues to be the vascular access of choice for the hemodialysis, arteriovenous graft (AVG) can be the best choice in certain categories of patients and could have several advantages over AVF in a "patient centered approach" to vascular access. In the clinical management of prosthetic fistulas, color Doppler ultrasound (CDU) is the imaging method of choice for identifying stenosis and other AVG complications. In this review, besides highlighting the pivotal role of CDU in the diagnosis of AVG complications, we will underline the key role that ultrasound can play in identifying those stenosis most likely to cause AVG thrombosis. Furthermore, we will emphasize the support that CDU can play in distinguishing the different types of grafts and prosthetic devices such as stent-grafts, in identifying AVG with lower survival, CDU utilities and limitations in the evaluation of freshly-implanted grafts, the different sites available for AVG volume flow measurement and their use based on the configuration of the prosthesis, the time interval elapsed from the surgical intervention and the integrity of the prosthetic walls.

Report on an Italian survey of 72 stuck hemodialysis catheters

BACKGROUND

Reports of stuck hemodialysis catheters have been on the rise in recent years. Aim of this work is to report how this complication has been managed and the relative outcomes in a multicente Italian survey.

METHODS

Since 2012, the Italian Society of Nephrology (SIN) Project Group of Vascular Access has collected data among nephrologists on this complication. Data regarding 72 cases of stuck tunnelled central venous catheter (tCVC) in 72 patients were retrieved thanks to this survey.

RESULTS

In 11 patients (15%) the stuck catheter was directly buried or left in place. Sixty-one cases were managed through advanced removal techniques. Among these, 47 (77%) stuck tunnelled central venous catheters were successfully removed, while 14 (23%) failed to be withdrawn. Considering removed tCVCs, the use of endoluminal balloon dilatation alone or in combination with other tools showed a percentage of success of 88%. The removal procedure involved numerous specialists. Some complications occurred, such as breakage of the line or bleeding, and two cases of haemopericardium during an advanced procedure.

CONCLUSION

The survey shows how the stuck catheter complication was managed in different ways, with conflicting results. When utilized, endoluminal balloon dilatation proved to be the most effective and most often utilized technique, while some cases had suboptimal management or failure. This underlines how delicate the procedure is, and the need for both precise knowledge of this complication and timely organization of removal attempts.

Central Venous Occlusion Caused by a Collapsed Stent: Endovascular Treatment in an Emergency

Stenosis and central venous obstruction are very serious and frequent complications in hemodialysis patients. The incidence of these complications is 30% and is due to an increase in the flow and venous flow that generates inflammation and proliferation of the endothelium. Causes of acute venous occlusion have rarely been described. We report the clinical case of a acute occlusion of a covered stent in a right anonymous vein treated through a Bard Covera Plus recanalization and stent delivery procedure.  

[The Montecorvino Rovella Project: prevalence of coronary disease risk factors in an area of Campania]

BACKGROUND

The "Montecorvino-Rovella Project" is a clinical epidemiological study, whose aim is to ascertain the distribution of the coronary risk factors and to treat the high risk people in a southern Italian community (21,328 inhabitants) with a reference area.

METHODS

The project consists of three phases: 1) identification and classification of high risk subjects among people aged 25-74 years at Montecorvino Rovella and Bellizzi (intervention area) and in a significant sample at Battipaglia (reference area); 2) treatment of high risk people at Montecorvino Rovella and Bellizzi; 3) periodic rescreening (after 5 and 10 years) of the enrolled cohorts and monitoring of morbidity and fatal cardiovascular events. In the first phase (1988-1990) 569 females and 522 males were examined. The participation response was high: 72.7% (75.9% females and 69.6% males).

RESULTS

In this paper were described the main risk factors prevalence. The mean values (age-standardized) of total serum cholesterol (tc), triglycerides (tg) and fasting blood sugar (gl), for all males were of 204.8 mg/dl (tc), 159.4 mg/dl (tg), and 93.5 mg/dl (gl). In the females the mean values were lower: 202.9 mg/dl (tc), 134.2 mg/dl (tg), and 87.8 mg/dl (gl). The prevalences of this risk factors are the following hypercholesterolemia (serum cholesterol = > 240 mg/dl): males 20.7%, females 19.8%; hypertriglyceridemia (serum triglycerides = > 170 mg/dl): males 38.3%, females 23.1%; hyperglycemia (blood glucose = > 120 mg/dl: males 8.8%, females 6.6%. The mean levels of systolic blood pressure were: males 130.3 mm Hg and females 129.2 mm Hg; diastolic blood pressure: males 80.5 mm Hg and females 78.6 mm Hg. The male subjects with hypertension (B.P. = > 160/95 mm Hg) were 16.3% while female subjects were 26.1%. Hypertension control level in the examined sample was quite low. The prevalence of smokers was: 46% males and 17.3% females. Smokers were more frequently observed in young people (men > 50%), than in the oldest groups.

[Evaluation of the function of heart valve prostheses by Doppler echocardiography. Primary findings]

The authors have executed an investigation on the functional evaluation of the valvular prosthesis, availing themselves of the use of the Echocardiography complete of Doppler effect and executing echocardiography tracings not according to the standard position, but putting the sound in correspondence with the cardiac apex. This method has been considered valid to obtain olways images of the movable element for all the types of the prosthesis and for amy situation of theirs. Furthermore the classic position of the sound can't be respected either for the eventual cardiomegaly, either for the manipulations that the heart undergoes inevitable during the operation, either for the pleurapericardic adhesions, alla factors that induce a change of the anatomic focuses.

[The index of left ventricle dilatation estimated with echocardiography in infarct patients]

The Authors have introduced, for functional valuation of the left ventricle in infarcted patients, an echocardiographic new parameter: the index of dilatation (ID). This index constantly show oneself increased in all infarcted patients that clinically show marks of the cardiac decompensation, also when the Vcf and Fe show modest alterations. According to the Authors, the ID have in report with the PTDVS and constitute and important evidence of the left ventricular working controllable in the time.

[Echocardiographic study with the Doppler effect, of floating of the interventricular septum as a determining factor in the genesis of innocent murmurs]

The present study offers the possibility of individuating the genesis of innocent murmurs. 30 patients between 5 and 20 years, showing at the phonocardiogram a train of oscillations in a proto-mesosistolic or mesosistolic phase with characteristics that testify an innocent murmur, have been examined. The routine examinations and cardiac cateterism to exclude congenital or acquired heart diseases have been done to all the patients. The echocardiographic examination has shown a characteristic floating of the interventricular septum, that, producing a variable mutability of the dimensions of the right ventricular cavities, determines, particularly in the tract of the right ventriculae efflux, a hematic turbolent flow well visible with the Doppler effect. The genesis of the innocent murmurs must be referred to such a turbolence, secondary to the floating of the septum, and this accords with Feruglio, who asserts he has always found, with the endocavitary phonocardiography, innocent murmurs only in the infundibulum of the pulmonary.

[Cardiac muscle malacia as the factor inhibiting myocardiac electric stimulation, as seen in echocardiographic examination]

In this present research work the Authors think that a preliminary echocardiography study may be useful to evoluate the type of answer of the cardiac muscle to the artificial stimulus; they deem, forthmore, thot, among the ecocardiografic obtainable parameters the principle importance must be attributed to the velocity of contraction of the circumference fibres (Vef) and to the velocity of the motion of the back wall in a sistolic phase the cases like the one mentioned in the text, with marked reduction of the motion and with Vef of 0.25 circ./sec, according to the Authors can't be stimulated through the employment of a stimulating endocavitle catheter, but they require, for a sure stimulation, the application of the epicardic electrodes.

[Non-invasive method of control of myocardial function in post-infarction patients treated with digitalis glycosides. Polygraphic and echocardiographic methods]

Following the guide of the publications written by Weissler, Thomas, Ahmed, Perry, Buyukoztur, Rahimotola, the Authors have executed on 25 patients with results of the myocardic infarction a polygraphic examination, comparing the variations of the intervals of the systolic time (STI) with the modifications of the fraction of the ejection (Fe) and of the velocity of the circular fibres (Vcf), calculated with echocardiographic method. From the results obtained the Authors have concluded that there is a perfect correspondence among the alterated values of the isovolumetric contraction time (TCIV), preejection period (PEP), LVET/PEP, and the variations of the Fe and Vcf, and furthermore the amelioration obtained with the digitalis therapy are controlled justly with both the methods. In conclusion both the polygraphic examination and the echocardiographic examination consent a perfect control of the patients with results of the miocardic infarction if they are subject to a digitalis treatment or not, and furthermore they permit a functional valutation of the patient.

[The cholecysto-coronary syndrome observed with polygraphic and echocardiographic examinations]

The cholecysto-coronary syndrome already many times observed by various Authors at the standard electrocardiogram and after effort with not much significative results, has been studied by our group with a polygraphic and echocardiographic method. 55 subjects aged between 30 and 55 years have been examined, to each of them besides a standard electrocardiogram and after effort a polygraphic examination including a tracing of electrocardiogram, a phonocardiogram, and a carotid pulse has been made, after the STEM, TEVS, TC, TCIV, PPE and the TEVS/PPE have been calculated. The parameters obtained have been compared with the ideal values of the subject in examination, calculated according to the formula of Diamond and Killip. Moreover an echocardiographic examination has been performed in 10 of the 55 patients, both to exclude valvular anomalies and ventricle enlargements, and to calculate the velocity of the contraction of the circumferential fibres (Vcf). The examination performed pointed out an increase of the TCIV and PPE with decrease of the ratio TEVS-PPE at the polygraphic examination and moreover a decrease of the Vcf at the echocardiogram. From the whole of the results obtained we can conclude that the cholecysto-coronary reflex determines a decrease of the contribution of the O2 to the myocardium, of a limited entity, so much that it doesn't give clear signs in the standard ECG, but sufficient to establish a suffering of the sarcomer that manifests itself with an alteration of its contraction velocity.