Results of a Peripheral Cutting Balloon Prospective Multicenter European Registry in Hemodialysis Vascular Access

Anesthetic effect of ultrasound-guided block of the musculocutaneous nerve during endovascular treatment of dysfunctional radiocephalic arteriovenous fistulas

BACKGROUND

Delivering requisite and minimal anesthesia for endovascular treatment (EVT) of dysfunctional arteriovenous fistulas (AVFs) under the target nerve block can achieve reasonable analgesia. We evaluated the anesthetic efficacy of ultrasound (US)-guided selective block of the musculocutaneous nerve (MCN) during the EVT of runoff venous strictures in the forearm through the radiocephalic (RC)-AVF at the wrist or the anatomical snuff box and analyzed the factors inhibiting the analgesia achieved under the MCN block.

METHODS

We enrolled 30 adult patients undergoing hemodialysis who had received 78 EVT sessions in an outpatient clinic mainly for long and/or multiple outflow-venous strictures in the forearm under US-guided blocks of the MCN, which provides sensory innervation to the anterolateral forearm where the cephalic vein courses. We assessed patients' pain during balloon dilations using the Wong-Baker FACES® Pain Rating Scale (WBFRS) and evaluated the factors increasing the pain (WBFRS score ⩾4), including patient characteristics, dilated strictures, additional nerve blocks, and types of balloon catheters.

RESULTS

In 25 EVT sessions (32.1%) out of 78 sessions, patients complained of stronger pain (WBFRS score ⩾4), while in the other 53 sessions (67.9%), presented with no pain and slight pain (WBFRS score = 0 or 2). Univariate analysis clarified that dilation of the AVF anastomosis, presence of dilated stenosis >4 cm, and a single block of the MCN or its sensory terminal significantly triggered more pain (p < 0.05). Consequently, multivariate analysis of all the factors with p < 0.1 in the univariate analysis, including multiple dilated stenosis sites, demonstrated that dilation of the AVF anastomosis significantly caused severe pain despite the anesthesia of the MCN block (p < 0.05).

CONCLUSION

US-guided selective block of the MCN could be a leading anesthetic option for EVT for multiple long stenoses of the cephalic vein draining through the RC-AVF in the wrist or anatomical snuff box.

Cubital vein transposition for a distal radiocephalic fistula complicated by outflow obstruction

Introduction:

Outflow stenosis is a frequent complication of vascular access for hemodialysis. It may cause increased pressure within the angioaccess along with reduced blood flow. Elective treatment is percutaneous transluminal angioplasty; however, when a long occlusion (>2 cm) occurs, success and mid-term patency of endovascular treatment are uncertain. We describe a case series of patients with long occlusion of elbow outflow complicating an otherwise excellent forearm arteriovenous fistula, treated by a bypass across the elbow through cubital vein transposition.

Patients and methods:

Six consecutive patients have been treated between 2015 and 2017; all were referred because of either low flow, increased venous pressure, excessive bleeding time, or recirculation and were examined by duplex ultrasound. A total of 83% of patients showed associated thrombosis within the access. All procedures were performed under loco-regional anesthesia and preventive hemostasis. Surgical thrombectomy was also performed when needed.

Results:

Immediate success was obtained in all but two patients converted in veno-venous polytetrafluoroethylene bypass. Post-operative blood flow increased from 316 to 878 mL/min. All patients were dialyzed through the forearm access immediately the day after surgery, without the need for central vein catheter. Overall, 75% of patients needed a percutaneous transluminal angioplasty of the veno-venous anastomosis within 6 months. Primary and secondary patency at 12 and 24 months were 25%–0% and 100%–100%, respectively.

Conclusion:

Outflow reconstruction through the elbow bypass by cubital vein transposition is a valuable resource to rescue radiocephalic arteriovenous fistula complicated by outflow obstruction, avoiding the use of an interim central vein catheter. Endovascular treatment is vital to maintain functional patency in the mid- and long term.

Clinical Evaluation of the Cook Advance Enforcer 35 Focal-Force PTA Balloon Catheter for Treatment of Hemodialysis Fistula Stenoses: A Feasibility Study

PURPOSE

A prospective, single-center, single-arm feasibility study evaluated procedural and short-term performance of the Advance Enforcer 35 focal-force percutaneous transluminal angioplasty (PTA) balloon catheter in treating stenoses of mature native arteriovenous (AV) hemodialysis access circuits.

MATERIALS AND METHODS

Twenty-eight patients undergoing treatment for stenosis of a mature native AV hemodialysis access circuit were enrolled at a single institution. Angiographic assessments of the study lesion were required at baseline and after the procedure. Adjunctive procedures for significant residual stenosis were permitted, and patients had clinical and imaging follow-up for as long as 6 months.

RESULTS

Treatment with the study balloon was effective in reducing the average percent diameter stenosis of the treated lesion from 66.3% (range, 43.8%-93.3%) before the procedure to 23.7% (range, -6.7% to 51.4%) after the procedure. The average inflation pressure required was 12.3 atm. Only 1 patient required an adjunctive procedure, and all patients could resume normal dialysis following the study procedure. At 3 months, 62.0% of study lesions remained patent, and the 6-month patency rate was 25.1%. Two adverse events associated with the study procedure were reported: access-site hematoma and forearm pain (3.6% each).

CONCLUSIONS

The results demonstrate safety of the study balloon in treating AV access stenosis. Nominal-diameter angioplasty was achieved at relatively low pressure in most study patients without the use of adjunctive procedures, and resumption of normal dialysis was achieved for all patients.

Combined cutting balloon and conventional balloon angioplasty in a dog with supravalvular pulmonary stenosis

A 7-year-old Miniature Schnauzer presented with exercise intolerance and easy fatigability. Echocardiography revealed the presence of supravalvular pulmonary stenosis. The peak velocity through the stenosis was 6.4 m/sec, and the interventricular septum was flattened. Cutting balloon angioplasty was designed for the treatment of coronary artery stenosis, which was resistant to conventional balloon angioplasty. Accordingly, the dog underwent cutting balloon angioplasty and conventional balloon dilation. One month after treatment, it showed neither exercise intolerance nor easy fatigability. The ventricular septum flattening disappeared. Five months later, the dog showed an increase in activity. Two years later, the peak velocity through the stenosis decreased to 4.4 m/sec. Neither clinical symptoms nor restenosis was observed. Thus, supravalvular pulmonary stenosis was successfully treated using this combination method. The present case showed that combined cutting balloon and conventional balloon angioplasty is a useful and minimally invasive treatment for supravalvular pulmonary stenosis.

Cephalic Arch Stenosis in Autogenous Brachiocephalic Hemodialysis Fistulas: Results of Cutting Balloon Angioplasty

Purpose

Cephalic arch stenosis is a known cause of hemodialysis access failure in patients with brachiocephalic fistulas (BCFs). Outcomes of endovascular treatment are affected by resistance of the stenosis to balloon dilation, a high vein rupture rate and the development of early restenosis. The purpose of this retrospective study was to report outcomes after cutting balloon angioplasty (CBA) of cephalic arch stenosis.

Methods

In our vascular access database we identified 74 dysfunctional BcFs of which 30 (41%) were caused by cephalic arch stenosis. Seventeen fistulas in 17 patients (13 males and four females; median age 62 yrs; range 52–86) were treated with CBA (June 2005 to January 2008). Twenty-five procedures were performed. In 15 procedures, a cutting balloon was used alone and in 10 procedures CBA was followed by standard or high-pressure balloon angioplasty. Restenosis rates were calculated and patency rates were estimated with the Kaplan-Meier method.

Results

Primary patency rates (±SEE) at 3, 6, 12 and 15 months were 94% (±6%), 81% (±10%), 38% (±14%) and 22% (±15%), respectively. Assisted primary patency rates (±SEE) at the same intervals were 100% (±0%), 94% (±6%), 77% (±12%) and 63% (±13%), respectively. The mean interval between radiological interventions was 13 months (SD=8) and the mean number of interventions required per patient-year of dialysis was 0.9.

Conclusion

Treatment of cephalic arch stenosis with CBA did not improve patency compared to published results of conventional PTA, but our results indicate that CBA may lower the frequency of required re-interventions.

Future research directions to improve fistula maturation and reduce access failure

With the increasing prevalence of end-stage renal disease, there is a growing need for hemodialysis. Arteriovenous fistulae (AVF) are the preferred type of vascular access for hemodialysis, but maturation and failure continue to present significant barriers to successful fistula use. AVF maturation integrates outward remodeling with vessel wall thickening in response to drastic hemodynamic changes in the setting of uremia, systemic inflammation, oxidative stress, and pre-existent vascular pathology. AVF can fail due to both failure to mature adequately to support hemodialysis and development of neointimal hyperplasia that narrows the AVF lumen, typically near the fistula anastomosis. Failure due to neointimal hyperplasia involves vascular cell activation and migration and extracellular matrix remodeling with complex interactions of growth factors, adhesion molecules, inflammatory mediators, and chemokines, all of which result in maladaptive remodeling. Different strategies have been proposed to prevent and treat AVF failure based on current understanding of the modes and pathology of access failure; these approaches range from appropriate patient selection and use of alternative surgical strategies for fistula creation, to the use of novel interventional techniques or drugs to treat failing fistulae. Effective treatments to prevent or treat AVF failure require a multidisciplinary approach involving nephrologists, vascular surgeons, and interventional radiologists, careful patient selection, and the use of tailored systemic or localized interventions to improve patient-specific outcomes. This review provides contemporary information on the underlying mechanisms of AVF maturation and failure and discusses the broad spectrum of options that can be tailored for specific therapy.

Restoration of failed renal graft function after successful angioplasty of pressure-resistant renal artery stenosis using a cutting balloon: a case report

This study is the report of a 37-year-old male with a transplanted kidney from a 3.5-year-old donor: the graft had two arteries transplanted with an aortic patch to an external iliac artery. Four months after transplantation, the graft function deteriorated, together with the development of hypertension. Stenosis of both graft arteries was detected and the patient was referred for angioplasty. The angiographic result was suboptimal, nevertheless, the graft function improved and was more or less stable (serum creatinine, 160-200 micromol/l) for 4 years, along with persistently difficult-to-control hypertension. Five years after transplantation, the graft function deteriorated again and severe graft artery restenosis was detected. The restenosis did not respond to dilatation, graft function failed, hypertension decompensated, and left ventricular failure developed. The patient required dialysis. A cutting balloon angioplasty opened the artery, and kidney function was restored after a few days: the serum creatinine level dropped to 140-160 micromol/l, and the glomerular filtration rate (creatinine clearance) to 0.65 ml/min/1.73 m(2). The graft function has now been stable for more than 2 years, however, the hypertension is still difficult to control.

How I do it: directional atherectomy for in-stent restenosis of a PTFE arteriovenous graft

We describe the use of directional atherectomy (DA) to restore patency of a thrombosed polytetrafluoroethylene arteriovenous graft with an in-stent restenosis at the venous anastomosis. Technically, the procedure described is not an atherectomy per se, but rather the removal of fibrosis and intimal hyperplasia with sharp endoluminal dissection. Certainly, the operator must be cautious when performing DA directly adjacent to a previously deployed stent. Nevertheless, our report suggests that there may be a role for DA in the treatment of severe, resistant in-stent stenosis. Further investigation is necessary to evaluate the safety and efficacy of the described technique.