A Randomised Trial Comparing Drug Coated Balloons and Conventional Balloons for the Treatment of Stent Graft Stenosis in Dialysis Vascular Access

OBJECTIVE

Previous studies on arteriovenous fistulas have demonstrated the potential benefit of drug coated balloons (DCBs) in maintaining the patency of dialysis access. However, stenoses involving stent grafts were excluded from these studies. Therefore, the aim was to evaluate the effectiveness of DCBs in treating stent graft stenosis.

METHODS

This was a prospective, single blinded, randomised controlled study. From March 2017 to April 2021, 40 patients with dysfunctional vascular access owing to stent graft stenosis were randomised to treatment with a DCB or conventional balloon. Clinical follow up was scheduled at one, three, and six months, and angiographic follow up was performed six months after the intervention. The primary outcome was angiographic late luminal loss at six months, and secondary outcomes included target lesion and access circuit primary patency at six months.

RESULTS

Thirty-six participants completed follow up angiography. The DCB group had a superior mean late luminal loss at six months compared with the control group (1.82 mm ± 1.83 mm vs. 3.63 mm ± 1.08 mm, respectively, p = .001). All 40 patients completed clinical follow up. The DCB group had a superior six month target lesion primary patency compared with the control group [hazard ratio (HR) 0.23, 95% confidence interval (CI) 0.07 - 0.71; p = .005). Additionally, the DCB group had a numerically higher six month access circuit primary patency rate than the control group, although the difference was not statistically significant (HR 0.54, 95% CI 0.26 - 1.11, p = .095).

CONCLUSION

Conventional balloon angioplasty is not durable in stent graft stenosis treatment. Treatment with DCBs provides less angiographic late luminal loss and potentially superior primary patency of the target lesion than treatment with conventional balloons. [ClinicalTrials ID: NCT03360279.].

Neuropsychological investigation into the carcinoid syndrome

RATIONALE

In patients suffering from metastatic carcinoid tumors, chronic disturbances of serotonergic metabolism are frequently present. Serotonin is supposed to influence a range of cognitive functions.

OBJECTIVES

The present study evaluated the cognitive performance of carcinoid patients.

METHODS

In 14 patients with proven carcinoid syndrome, neuropsychological functioning was studied. Visual search, sustained attention, set shifting ability and spatial working memory were assessed using tests from the CANTAB neuropsychological battery. This was compared with the performance of matched healthy controls.

RESULTS

Plasma tryptophan levels were lower than controls. Patients showed an enhanced ability to learn new stimulus-response associations. Sustained visual attention, however, was impaired.

CONCLUSION

Cognitive patterns were different from those found in depressive patients and partly mimicked those found in tryptophan depletion experiments. Further investigation has to point out the role of serotonergic changes in the accomplishment of affective states.

The influence of biographical information on event memory: when it's not what you know but whom you know

In this study, we investigated the effects on memory or the provision of contextual information concerning the central character depicted in a brief video film. The findings of the study, which involved 82 male and 103 female student subjects, suggest that at test a week later, recognition judgments for foil sequences were biased in context-specific ways. However, the influence of the contextual information on memory was observed only when the information was made available to subjects before or immediately after seeing the film. When the character information was provided only after a week's retention interval, no significant contextual influences were found. The results are discussed in terms of their implications for memory theory and eyewitness reliability.

Sodium nitroprusside-induced hypotension in dogs. Drug sensitivity and resistance experimentally provoked by circulating blood volume alterations

The effects of small circulating blood volume alterations on the SNP dosage required to maintain the mean arterial pressure at 70 mm Hg were studied in 6 anesthetized dogs; (A) normovolemia, (B) hypovolemia by arterial bleeding 7 ml/kg, and (C) hypervolemia by infusing 7 ml/kg whole blood. The animals became extremely SNP sensitive during hypovolemia and resistant during hypervolemia (SNP dosage A: 25.8, B: 14.7, C: 70.0 microgram/kg/min); these changes were accompanied by significant changes in cardiac output (A: 193, B: 142, C: 249 ml/kg/min). The intravenous administration of SNP with the aim of inducing hypotension generally causes a balanced pre- and afterload reduction. This balance is rather delicate and easily disturbed by small intravascular fluid changes leading to cardiac output and thus to SNP sensitivity changes. Slowly developing tachyphylaxis can be explained on the basis of such intercompartimental fluid shifts and a case of SNP tachyphylaxis reported in literature is discussed on the basis of overinfusion. SNP tachyphylaxis or resistance might be treated by preload reducing measures like phlebotomy or the administration of nitroglycerin.

Sodium nitroprusside induced hypotension and isovolemic hemodilution in dogs

Hypotension at 70 mm Hg was induced with sodium nitroprusside in 6 hemodiluted and 6 control dogs. In contrast to the control dogs, the reduction in mean arterial pressure was not primarily due to the peripheral resistance reduction, but the result of a hazardous fall in cardiac output.

Intravascular persistence of hydroxyethyl starch in man

In two groups, each consisting of five healthy volunteers, 7 ml blood/kg body weight were exchanged with equal amount of hydroxyethyl starch (HES) and dextran 60 solutions, respectively. Dextran 60 plasma levels, determined by the anthrone method, were undetectable after 4 weeks. The elimination of HES from the blood, determined by an immunological technique and by the anthrone method, had a very protracted course. Two weeks after infusion the HES plasma concentrations were 9% of the initial value and after 17 weeks they were still above the 1% level. The prolonged intravascular persistence of HES in its commercially available preparation, and the possibility of tissue accumulation after repeated HES infusions were considered undesirable. The hypothesis that HES infusion causes and augmentation of serum alpha-amylase concentrations in man was confirmed. This effect should be borne in mind when HES solutions are given to patients in whom the diagnosis of acute pancreatitis might be considered.