Arterial Stent Placement in Arteriovenous Dialysis Access by Interventional Nephrologists

Arterial stenoses in patients with arteriovenous dialysis access can create a variety of problems including access dysfunction, thrombosis, and hand ischemia. While percutaneous balloon angioplasty is largely successful in the management of arterial stenoses, elastic recoil can present a real predicament to this treatment. In this report, we present two cases of arterial stenosis that demonstrated elastic recoil after angioplasty and required endovascular stent insertion. Both cases were treated successfully without any complications on an outpatient basis. This report describes arterial stent placement in patients with arteriovenous access and discusses anticoagulation considerations in such cases.     

Outcomes of Cephalic Arch Stenosis With and Without Stent Placement after Percutaneous Balloon Angioplasty in Hemodialysis Patients

Cephalic arch stenosis is a common complication in maintenance hemodialysis (MHD) patients with brachial artery‐cephalic vein fistulas and frequently leads to loss of the functioning brachial artery‐cephalic vein fistula. There is paucity of conclusive data to guide appropriate management. We examined the risk of recurrence of cephalic arch stenosis after angioplasty compared to angioplasty after stent placement determined by angiography of the involved upper extremity over time in a contemporary cohort of MHD patients treated in two interventional nephrology practices from March 2008 through May 2011. We retrospectively identified 45 MHD patients with evidence of cephalic arch stenosis (age 60 ± 30 years, 45% men) on elective angiograms. The median number of days until another angioplasty was required decreased, starting with a median of 91.5 days after the first, 70.5 days after the second, 85 days after the third, and 56 days after the fourth. Angioplasty is associated with a faster rate of recurrence of cephalic arch stenosis. The placement of intravascular stent seems to prolong the patency compared to angioplasty alone. Clinical trials with a larger sample size will better elucidate the value and timing of angioplasty versus stent placement in cephalic arch stenosis.     

Meta‐analysis and trial sequential analysis of local vs. general anaesthesia for carotid endarterectomy

Controversy exists regarding the best choice of anaesthesia for carotid endarterectomy. We aimed to evaluate the peri‐operative outcomes of local vs. general anaesthesia for carotid endarterectomy. We conducted a systematic search of electronic information sources and applied a combination of free text and controlled vocabulary searches adapted to thesaurus headings, search operators and limits in each of the electronic databases. We defined peri‐operative stroke, transient ischaemic attack, mortality and myocardial infarction as the primary outcome measures. We identified 12 randomised controlled trials and 21 observational studies reporting a total of 58,212 patients undergoing carotid endarterectomy under local or general anaesthesia. Analysis of observational studies demonstrated that local anaesthesia was associated with a significantly lower incidence of stroke (odds ratio (OR (95% CI) 0.66 (0.55–0.80), p < 0.0001), transient ischaemic attack (0.52 (0.38–0.70), p < 0.0001), myocardial infarction (0.55 (0.41–0.75), p = 0.0002) and mortality (0.72 (0.56–0.94), p = 0.01) compared with general anaesthesia. Analysis of randomised controlled trials did not find a significant difference in the risk of stroke (0.92 (0.67–1.28), p = 0.63), transient ischaemic attack (2.20 (0.48–10.03), p = 0.31), myocardial infarction (1.25 (0.57–2.72), p = 0.58) or mortality (0.61 (0.35–1.05), p = 0.07) between local and general anaesthesia. On trial sequential analysis of the randomised trials, the Z‐curve did not cross the α‐spending boundaries or futility boundaries for stroke, mortality and transient ischaemic attack, suggesting that more trials are needed to reach conclusive results. Our meta‐analysis of observational studies suggests that local anaesthesia for carotid endarterectomy may be associated with lower peri‐operative morbidity and mortality compared with general anaesthesia. Although randomised studies have not confirmed any advantage for local anaesthesia, this may be due to a lack of pooled statistical power in these trials.     

Pre‐operative Assessment for Arteriovenous Fistula Placement for Dialysis

Native AV fistulas are considered to be the best VA for most dialysis patients. A careful preoperative process of care is essential to maximize the proportion of fistulas that achieve adequacy for dialysis. An individualized and timely evaluation of patients starts early with the identification of risk factors, followed by a physical examination which should be complemented by ultrasound vascular mapping in most cases. Vascular mapping includes any technique that leads to information on patient′s inflow and outflow anatomy (± hemodynamics) as they relate to arteriovenous access creation and may predict maturation. There is increasing evidence favoring the utilization of preoperative Doppler ultrasound which is recommended in all patients by NFK‐KDOQI Guidelines. It allows noninvasive evaluation of both structural and functional aspects of vessels that play an important role in access maturation. Its major limitation is the relative inability to assess central vein patency. Although conventional venography is still the gold standard to evaluate central veins, it provides otherwise limited information and can incur serious adverse effects related to its invasive nature and contrast use. Alternatives to these two imaging techniques are rarely used, especially because of their higher costs and low availability.     

Hand Ischemia Associated With Dialysis Vascular Access: An Individualized Access Flow‐based Approach to Therapy

With the rise in the median age of hemodialysis patients, the increasing numbers of patients with multiple risk factors for vascular disease, and the efforts being made to increase the creation of autogenous arteriovenous fistulas (AVFs), dialysis access‐related steal syndrome (DASS) has become a growing problem. This syndrome, caused by arterial insufficiency distal to the arteriovenous access due to diversion of blood into the access, is a potentially devastating complication. It is crucial that physicians who manage hemodialysis patients and perform vascular access procedures have a comprehensive understanding of the pathophysiology, symptoms, diagnostic maneuvers, and treatment options for DASS. The goals of management must be twofold—relieve the ischemia and preserve the access. The choice of any intervention, if such is necessary, should be based upon the clinical features presented by that individual patient; the clinical condition and prognosis of the patient, stage of the disease, location of the arterial anastomosis, and the level of blood flow within the access. This review presents information that supports an individualized, physiologic approach to this condition.     

Long-term Results of Primary Stent Placement to Treat Infrarenal Aortic Stenosis

OBJECTIVE: To determine the safety and the long-term results of primary stent placement for localized distal aortic occlusive disease. DESIGN: Retrospective observational study. PATIENTS AND METHODS: From July 1998 to July 2005 17 patients (14 female and 3 men, mean age 57 years (39-80)) were treated for intermittent claudication. Five of these patients underwent additional endovascular treatment of focal iliac lesions. RESULTS: Technical success defined as residual stenosis of less than 50% or a trans-stenotic systolic pressure gradient <10% was achieved in 14 of 17 (82%) patients. Major complications included dissection at the puncture site in one patient and thrombosis of additional iliac stents in another patient. Both of these complications were successfully treated. During a mean follow-up of 27 months (range 1-86), four patients had recurrence of symptoms due to in-stent restenoses (n=2), femoral (n=1) or iliac occlusion (n=1), respectively. By Kaplan-Meier analysis, primary aortic hemodynamic patency was 83% at 3 years. Secondary aortic hemodynamic patency was 100%. The primary clinical patency was 68% at 3 years. CONCLUSION: Primary stent placement for distal aortic stenoses is an alternative to surgical treatment because of its high patency and relatively low complication rates.     

Meta‐analysis of the colon J‐Pouch vs transverse coloplasty pouch after anterior resection for rectal cancer

Purpose To evaluate the outcome of colonic J‐pouches (CJP) and transverse colonic pouches (TCPs) after anterior resection for rectal cancer. Method Trials were located through Medline, Embase, the Cochrane Central Register of Controlled Trials, VIP and CNKI. Main end‐points included functional outcomes, postoperative complications and anorectal physiological outcomes. Results Of 120 articles, 34 compared CJP and TCP. Of these only six were randomized controlled trials (RCT), which fulfilled the inclusion criteria. These six included 648 patients, including 326 in the CJP group and 322 in the TCP group. There were no differences in the incidences of anastomotic leak [odds ratio 0.50, 95% confidence interval (CI) 0.21–1.18], chest infection (0.43, 0.09–2.00), wound infection (0.87, 0.33–2.30), anastomotic stricture (1.30, 0.44–3.84), fistula (0.64, 0.18–2.31).There were no difference in functional outcomes such as stool frequency [weighted mean difference (WMD) of −0.01, −0.30–0.27 at 6 months].There was no difference for anorectal physiology but heterogeneity existed: resting pressure (0.39, −1.76 to 2.55; 3.09, −0.04 to 6.23; 4.15, 2.21–6.094, at preoperation, 6 and 12 months,); squeeze pressure (−15.02, −46.14 to 16.10; −15.04, −37.04 to 6.97;0.83, −7.70 to 9.37 at preoperation, 6 and 12 months);(Neo)rectal threshold volume(8.49, 5.18–11.81; 27.13, −5.08 to 59.35, at preoperation and 6 months); Maximal (neo) rectal volume (−14.05, −36.60 to 8.50; 23.37, 2.65–44.09; −0.54, −0.91 to −0.18, at preoperation, 6 and at 12 months). Conclusions Transverse colonic pouch has similar results as CJP. As it is a safe, feasible, simple, technically easy and time‐saving surgical procedure, TCP is a good candidate for wider clinical application.     

Autografts vs Synthetics for Cruciate Ligament Reconstruction: A Systematic Review and Meta‐Analysis

To describe the outcomes of autografts and synthetics in anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction with respect to instrumented laxity measurements, patient‐reported outcome scores, complications, and graft failure risk. We searched PubMed, Cochrane Library, and EMBASE for published randomized controlled trials (RCT) and case controlled trials (CCTs) to compare the outcomes of the autografts versus synthetics after cruciate ligament reconstruction. Data analyses were performed using Cochrane Collaboration RevMan 5.0. Nine studies were identified from the literature review. Of these studies, three studies compared the results of bone–patellar tendon–bone (BPTB) and ligament augmentation and reconstruction system (LARS), while six studies compared the results of four‐strand hamstring tendon graft (4SHG) and LARS. The comparative study showed no difference in Lysholm score and failure risk between autografts and synthetics. The combined results of the meta‐analysis indicated that there was a significantly lower rate of side‐to‐side difference > 3 mm (Odds Ratio [OR] 2.46, 95% confidence intervals [CI] 1.44–4.22, P = 0.001), overall IKDC (OR 0.40, 95% CI 0.19–0.83, P = 0.01), complications (OR 2.54, 95% CI 1.26–5.14, P = 0.009), and Tegner score (OR ?0.31, 95% CI ?0.52–0.10, P = 0.004) in the synthetics group than in the autografts group. This systematic review comparing long‐term outcomes after cruciate ligament reconstruction with either autograft or synthetics suggests no significant differences in failure risk. Autografts were inferior to synthetics with respect to restoring knee joint stability and patient‐reported outcome scores, and were also associated with more postoperative complications.     

Portal Vein Stent Placement in Anastomotic Stenosis After Deceased Donor Liver Transplantation: A Case Report

Vascular complications (VCs) after liver transplantation (LT) frequently result in graft and patient loss. The smaller vessels and the insufficient length for reconstruction in living donor LT and pediatric transplantation predispose patients to a higher incidence of VCs. Herein we present a case of portal vein stenosis (PVS) in an adult deceased donor LT recipient with portal vein thrombosis requiring extended thrombectomy at the time of LT. He presented with ascites 4 months after LT, was diagnosed with PVS, and was successfully treated with percutaneous transhepatic venoplasty and placement of a portal stent. This case highlights the importance of Doppler ultrasound as a screening modality for detection of VCs after LT and the pivotal role of endovascular repair as a first-line treatment for PVS.     

Meta‐analysis of the success of block following combined spinal‐epidural vs epidural analgesia during labour

Observational studies suggest that combined spinal‐epidural analgesia (CSE) is associated with more reliable positioning, lower epidural catheter replacement rates, and a lower incidence of unilateral block compared with epidural analgesia. However, evidence from high‐quality trials still needs to be assessed systematically. We performed a systematic review that included 10 randomised controlled trials comparing CSE and epidural analgesia in 1722 labouring women in labour. The relative risk of unilateral block was significantly reduced after CSE vs epidural analgesia (0.48, 95% CI 0.24–0.97), but significant between‐study heterogeneity was present (I² = 69%, p = 0.01). No differences were found for rates of epidural catheter replacement, epidural top‐up, and epidural vein cannulation. On the basis of current best evidence, a consistent benefit of CSE over epidural analgesia cannot be demonstrated for the outcomes assessed in our review. A large randomised controlled trial with adequate power is required.     

Implementation of the Dialysis Outcomes Quality Initiative Vascular Access Guidelines

To better care for patients with chronic renal failure and end-stage renal disease, the National Kidney Foundation has published a set of Clinical Guidelines, the Dialysis Outcomes Quality Initiative, based on current available evidence and, where such evidence is lacking, the expert opinions of current leaders in vascular access research. These Guidelines were developed to standardize the care of chronic renal failure and end-stage renal disease patients. This report describes some of the more important aspects of these recommendations and the authors' implementation strategies.