Percutaneous Peritoneal Dialysis Catheter Placement in Patients with Complex Abdomen.

Peritoneal dialysis (PD) is an effective treatment for end-stage renal disease. There are several techniques of percutaneous PD catheter placement including trocar or Seldinger techniques. Placement can be performed with fluoroscopy and/or sonography or as a blind percutaneous procedure. Historically, percutaneous PD catheters have been placed in patients even if they had prior abdominal surgeries. The outcomes of percutaneous PD catheter placement in patients with complex abdomen (patients with two or more abdominal surgeries or known adhesions) are unknown. This study was carried out to determine the outcomes of percutaneous PD catheter placements using Seldinger technique with sonography and fluoroscopy in patients with complex abdomen. Preprocedure sonography was also used to identify site of adhesions and blood vessels. The goal was to see if ultrasound and fluoroscopy would support placement of PD catheters in patients with complex abdomens. There were total of 10 catheter placements in 10 patients with complex abdomen. The initial success rate was 100%. The patients had an average of 2.8 abdominal surgeries. The mean BMI was 28.4. There were no incidences of perforation or failed placements. One catheter was replaced due to outflow failure and one patient discontinued PD due to peri-catheter leak. One year catheter survival was 80%. Our study demonstrates benefits of using ultrasonography and fluoroscopy during percutaneous PD catheter placement by the Seldinger technique in patients with complex abdomen.

Mild Renal Artery Stenosis Can Induce Renovascular Hypertension and is Associated with Elevated Renal Vein Renin Secretion.

Renovascular hypertension is a syndrome which encompasses the physiological response of the kidney to changes in renal blood flow and renal perfusion pressure. Such physiological changes can occur with renal artery occlusion irrespective of the severity of the lesion. We have analyzed hypertensive patients with mild renal artery stenosis and compared them to patients with no stenosis. Renal vein renin sampling from catheterization of the renal vein was performed in all these patients. Patients with mild stenosis had higher renal vein renin ratio (3.01 ± 1.5) than the patients with no stenosis (1.10 ± 0.29; p = 0.002). Patients with mild stenosis were also found to have higher diastolic blood pressure and renal artery resistive indices when compared to patients with no stenosis. We therefore conclude that mild stenosis can precipitate renin-mediated hypertension in renovascular stenosis and also emphasis that parameters pertinent to renal physiology need to be evaluated before considering treatment options in patients with renal artery stenosis and medical management with RAAS blockade is the preferred modality of therapy for patients with renin-mediated hypertension.

Persistent Median Artery As A Cause Of Nonmaturing AV Fistula.

A 68-year-old right handed male with End-Stage Renal Disease with a left radiocephalic fistula created 8 months ago was referred for the evaluation of a nonmaturing access. Patient had an arterial anastomosis lesion that underwent successful angioplasty. Diagnostic arteriogram of the AV access extremity revealed the presence of a short radial artery and dominant common interosseous artery manifesting as a persistent median artery in the distal forearm and was anastomosed to the fistula and then continues as the median-ulnar superficial arch in the palm. Balloon angioplasty of the common interosseous artery led to a complication when the distal 30 cm of the 0.018 guide wire fractured and had to be retrieved using a snare device. In addition to anticipating and treating the common complications of vascular access procedures, it is also important to be aware of the anomalies of the distal forearm arterial anatomy and perform a detailed arterial evaluation prior to creating the arterio-venous anastomosis.

Obstructive sleep apnea: a cardiopulmonary perspective and medical therapeutics.

The clinical importance of obstructive sleep apnea (OSA) is gradually rising to the extent that many clinicians now consider OSA as an underlying etiology or precipitating factor for many cardiovascular and pulmonary events. Although the incidence and pathophysiology underlying these cardiopulmonary structural and functional abnormalities are not well defined, various mechanisms are hypothesized. These include but are not limited to sympathetic activation, oxidative stress, inflammation, and endothelial dysfunction. Given the rising awareness of OSA, it is timely to review the effects of OSA on cardiovascular complications like arrhythmias and ventricular remodeling. In the later part of the review, we focused on the role of therapeutics in the management of patients with OSA. Although the role of medical therapeutics is not well defined, we reviewed the available literature focusing on the available options, supporting evidence and their role in specific subgroup of patients with OSA.

Renin angiotensin system blockade and cardiovascular outcomes in patients with chronic kidney disease and proteinuria: a meta-analysis.

OBJECTIVE: The role of renin angiotensin system (RAS) blockade in controlling hypertension and the positive impact on cardiovascular (CV) outcomes is well known. However, the role of RAS blockade in improving CV outcomes in patients with chronic kidney disease (CKD) is still unclear. METHODS: Randomized controlled trials that analyzed CV outcomes in patients with CKD/proteinuria treated with RAS blockade (angiotensin-converting enzyme inhibitors/angiotensin receptor blockers) were included in our study. The relative risk across all study groups was computed using Mantel-Hanszel random effects model. Results were calculated with 95% CI and was considered statistically significant if 2-sided alpha error was <.05. Renin angiotensin system blockade-based therapy was compared with placebo and control (beta-blocker, calcium-channel blockers and other antihypertensive-based therapy) therapy in the study. RESULTS: Twenty-five trials (N = 45758) were used for analysis. Renin angiotensin system blockade decreased the risk for heart failure in patients with diabetic nephropathy when compared with placebo 0.78 (95% CI 0.66-0.92, P = .003) and control therapy (0.63, 95% CI 0.47-0.86, P = .003). The risk for CV outcomes was decreased with RAS blockade (0.56, 95% CI 0.47-0.67, P < .001) in nondiabetic nephropathy patients with CKD when compared with control therapy. There was also a significant reduction of CV outcomes (0.84, 95% CI 0.78-0.91, P < .0001), myocardial infarction (0.78, 95% CI 0.65-0.97, P = .03), and heart failure (0.74, 95% CI 0.58-0.95, P = .02) when we pooled all the patients with CKD and compared RAS blockade to placebo. CONCLUSIONS: A pooled analysis of all causes of CKD revealed a reduction in the risk for myocardial infarction, heart failure, and total CV outcomes when RAS blockade was compared with placebo. RAS blockade decreases the risk for CV outcomes and heart failure when compared with control therapy in patients with proteinuria. There were also benefits with RAS blockade in reducing the risk of CV outcomes and heart failure in patients with diabetic nephropathy when compared with placebo.

Evaluation and management of hyponatremia: an emerging role for vasopressin receptor antagonists.

Vasopressin-2 receptor antagonists, collectively known as the 'vaptans', provide a new approach to the treatment of hyponatremia; therefore, an updated Review of the pathophysiology of hyponatremia is particularly timely. After briefly defining hyponatremia and introducing its clinical aspects and complications, we present an approach to the diagnosis and evaluation of hyponatremia that is based primarily on the often-underused concept of free water clearance and, more specifically, the electrolyte-free water clearance. Then we review the use of vasopressin receptor antagonists in the management of hyponatremia from the standpoint of their pharmacology, their mechanism of action, and available efficacy data from clinical trials.

Clinical predictors of recurrent stenosis and need for re-intervention in the cephalic arch in patients with brachiocephalic AV fistulas.

INTRODUCTION: Cephalic arch stenosis is one of the most common reasons for repeated endovascular intervention and eventual abandonment of access in hemodialysis patients. There is no prediction model to identify risk factors for recurrent cephalic arch stenosis. We have developed a mathematical model to predict the need for reintervention in brachiocephalic (BC) fistulas with recurrent cephalic arch stenosis. METHODS: Single-center retrospective analysis of 143 patients with a BC fistula referred to the vascular clinic for access dysfunction who underwent cephalic arch angioplasty were included for the analysis. Twelve-month post-index angioplasty data were analyzed using parametric, non-parametric and multiple regression models using SPSS software. RESULTS: The mean need for re-intervention in 1 year since first index visit was 2.46 ± 1.404. Statistically significant correlation (p≤0.001) for re-intervention was observed with the severity of stenosis at index visit, access flow, vessel wall diameter proximal to the stenosis, average venous pressure >50% of the delivered blood flow rate and prolonged bleeding for >30 minutes as a reason for referral. Three equations have been derived for calculating the need for re-intervention based on the diameter of the vessel wall proximal to the stenosis. CONCLUSIONS: Risk stratification of BC fistulas utilizing the above parameters could enable clinicians to identify accesses that are at risk for multiple re-interventions. Early identification of accesses that are at high risk for re-interventions at the cephalic arch might prolong access survival and reduce the cost for intervention by utilizing alternate strategies.

Flow reduction in high-flow arteriovenous fistulas improve cardiovascular parameters and decreases need for hospitalization.

High output heart failure (HF) and pulmonary hypertension have been demonstrated in patients with prevalent arteriovenous (AV) fistulas. Fistulas with flow >2000 mL/minutes are more likely to induce changes in cardiac geometry and pulmonary artery pressure. The effects of reducing flow in AV access and its implications on HF decompensation and hospitalizations have not been studied. Retrospective analysis of 12 patients who needed hospitalization for acute Congestive Heart Failure (CHF) decompensation with AV access flow of 2 L/minutes (as defined by Kidney Disease Outcomes Quality Initiative (KDOQI)) or more were included in the study. All the patients underwent banding of their inflow at the anastomosis with perioperative access flow measurement. Follow-up period was 6 months. 2D echo was done at 6 months postbanding in addition to access flow and clinical evaluation. Complete data was available for all the 12 patients. Study data was collected on all the 12 patients. Mean age was 64.7 years. The mean access flow pre and postbanding were 3784 mL/minutes and 1178 mL/minutes, respectively (P < 0.001). Eighty percent of the patients had diabetes and 41% had coronary artery disease. There was a statistically significant decrease in cardiac output (pre = 7.06 L/minutes, post = 6.47 L/minutes P = 0.03), pulmonary systolic pressure (pre = 54 mmHg, post = 44 mmHg P = 0.02), left ventricular mass index (LVMI) (pre = 130 g/m(2) , post = 125 g/m(2) P = 0.006) and need for rehospitalization for CHF decompensation. The New York Heart Association (NYHA) staging improved by 1 stage postbanding (P = 0.002). The hospitalization rate was 3.75 ± 1.2 in the 6 months before banding and was decreased to 1.08 ± 1.2 (P = 0.002) postbanding. The hemoglobin level, predialysis systolic blood pressure, calcium phosphorous product and the use of Renin Angiotensin Aldosterone System (RAAS) blockade agents and calcium channel blockers were comparable before and after inflow banding. Flow reduction in high flow fistulas are associated with decreased LVMI and pulmonary artery pressures. There is also a significant reduction in the risk for hospitalization due to acute HF and an improvement in NYHA heart failure stage.

Self-centering split-tip catheter versus conventional split-tip catheter in prevalent hemodialysis patients.

PURPOSE: This study compared the patency of a split-tip self-centering catheter with a predesigned curve (CentrosFLO; Merit, Salt Lake City, Utah) and a standard split-tip catheter with straight distal limbs (Medcomp, Harleysville, Pennsylvania) catheter in patients requiring exchange of a dysfunctional tunneled dialysis catheter (TDC). MATERIALS AND METHODS: A single-center retrospective chart review was performed between January 2013 and July 2014. Patients had an existing dysfunctional TDC that was exchanged over a wire using the same access site for either a split-tip self-centering catheter with a predesigned curve or a standard split-tip catheter with straight distal limbs catheter. The primary endpoint was catheter patency analyzed at 1, 3, and 6 months after initial exchange. RESULTS: A total of 73 patients met inclusion criteria (46 in the self-centering catheter group and 27 in the standard split-tipped group). Mean durations of the exchanged catheters were similar between groups. The mean 1-, 3-, and 6-month patency rates for the self-centering and split-tip catheters were 89%, 67.4%, and 23.9% and 81.5%, 40.7%, and 14.8%, respectively. Mean blood flow rates (BFRs) were similar between groups at 1 and 3 months; however, at 6 months, mean rates were 388 mL/min versus 352 mL/min for the self-centering group and split-tipped group, respectively (p<0.01). CONCLUSIONS: These results demonstrate improved patency with the CentrosFLO self-centering catheter versus the split-tip catheter. This may be due to the unique design of the self-centering catheter, allowing for preserved BFRs and patency. These results should be further explored in prospective, randomized multicenter studies.

Acute renal dysfunction in patients with alcoholic hepatitis.

Acute renal dysfunction is common in patients with alcoholic hepatitis (AH). Its presence leads to higher mortality in these patients. Despite advances in medical care, the outcome has changed little over the past decades. Studies using Pentoxifylline and molecular adsorbent recirculation system have shown encouraging data in small studies. Further larger well designed studies are needed to assess these modalities of treatment for the treatment of AH.