Primary Intraoperative Transluminal Angioplasty: A New Approach to Reduce the Early Failure of Distal Arteriovenous Fistulas

Endovascular tools for vascular access stenosis: Flow-chart proposal

Stenosis represents the most relevant arteriovenous fistula (AVF) pathology and can affects the entire conduit forming the fistula, from afferent artery to central venous vessels. Correction of vascular access stenosis significantly affects the survival and quality of life for end stage renal disease patients (ESRD) dependent on hemodialysis. Guidelines consider the procedure of percutaneous transluminal angioplasty (PTA) relevant for the primary treatment of these lesions with excellent results in restoring AVF immediately at the end of the procedure. From first AVF angioplasty in 1981 to now, wide scientific innovation has led to development of new devices, composed by different materials and technologies, specific for the site and the type of stenosis to be treated, able to manage resistant stenotic lesion and to reduce stenosis recurrences. International guidelines do not clearly specify all treatment possibilities in the individual case. In this review the authors want to provide specific information on most used devices for stenosis treatment based on literature evidence, showing when and where to use the various tools available with flow-chart treatment proposal.

Zero upper arm hemodialysis fistulas: utopian or realistic goal?

BACKGROUND

Although distal native fistula is the best first-line vascular access (VA), upper arm fistula (UAF) prevalence is increasing worldwide, except in Japan. Our previous survey on 50% of hemodialysis patients (HP) revealed a prevalence of UAF of less than 5%, which is lower than the findings published by the DOPPS 5 study in our country. We analyzed the VA prevalence on 100% of HPs from our department.

METHODS

In December 2021, we investigated the prevalence of vascular access of 1295 hemodialysis patients from 17 dialysis factories. VAs were classified according to location into distal forearm fistula (DFF), middle-proximal forearm fistula (MPFF), and UAF. The department manages VA using a Hub and Spoke model. The hub performs simple and complex VA including Graft placement, the Percutaneous Transluminal Angioplasty (PTA) of fistulas and central stenosis, and the surgical and endovascular rescue of thrombosed or stenotic fistulas. The spokes perform mainly simple DFFs.

RESULTS

The mean age of 1295 HP (35% females and 21% diabetics) was 69 ± 12.4 years; 506 (39%) were over 75 years old. The prevalence of DFF, MPFF, UAF, GRAFT, and CVC was 63.5%, 10.1%, 3%, 0.7%, and 22.5%, respectively. Data comparison between our two surveys revealed a lower MPFF, UAF, and GRAFT prevalence and increased CVC prevalence. Patients aged 75 years or older, women, and diabetics showed a higher frequency of CVC and a lower prevalence of DFF.

CONCLUSIONS

The findings confirm the low prevalence of UAF found in our prior survey, demonstrating that UAFs can be reduced to 5% or less, as seen in Japanese experience.

Percutaneous ecoguided endovascular lithotripsy to recruit failed-to-mature arteriovenous fistula due to completely calcified radial artery

The first-choice vascular access for starting dialysis is autogenous distal forearm arteriovenous-fistula (AVF); the increasing demand to create more fistulas may lead to their creation in borderline vessels and, in this setting, the early failure (EF) and failure of maturation (FTM) remain the main issues. The size of vessels or preexisting stenotic lesions of artery or vein are no longer considered absolute exclusion criteria for the creation of distal AVF, but huge arterial calcification still represents an indication to create upper arm AVF. A novel approach to treat arterial calcifications is represented by intravascular lithotripsy (IVL). This technique could represent a valid option to save failed to mature AVF due to extended calcified artery. We describe a case of a male patient, 43 years old with middle forearm AVF failed to mature with a completely calcified radial artery, low brachial flow (Qa) and small efferent vein. We treated the patient AVF with less invasive, percutaneous, endovascular, eco-guided IVL on the entire radial artery. After the procedure was observed a rapid increase of Qa, with reduction of calcification in the arterial wall, increase of arterial caliper and flow. This procedure could represent a valid alternative to surgical upper-arm AVF creation in patient with functioning but failed to mature fistula due to spread artery calcification, with a rapid, less invasive procedure.

Distal AVF creation with marginal calcified radial artery: Multicentric experience of intraoperative intravascular lithotripsy

INTRODUCTION

The first-choice vascular access to starting dialysis in patients with End Stage Renal Disease (ESRD) is autogenous distal arteriovenous-fistula (AVF) to spare vascular district avoiding proximal fistula complications. One of most significant exclusion criteria to create distal AVF is still now the presence of huge calcification of the feeding artery due to large numbers of early failure (EF) and failure in maturation (FTM). In recent years the possibility to use new devices able to deliver intravascular lithotripsy (IVL) to treat high calcified stenosis could be a possibility to recruit these marginal arteries to create distal AVF.

METHODS

ESRD patients with totally calcified radial artery wall were enrolled to participate to this prospective, single arm, multicentric study. The selected patients were treated with intraoperative IVL at surgical time, during anastomosis creation to soften calcified radial artery. Patients were followed 1 month after surgery with eco-doppler, for flow and vessels maturation assessment. At 3 month was investigated how many patients have started dialysis treatment with two needle cannulation and good efficiency.

RESULTS

Nineteen distal forearm radio-cephalic fistula were built in 19 patients. One-month doppler assessment showed mean AVF flow of 743 ml/min and efferent vein caliper of 6.46 mm. At 3 months 14 patient have started stable 2 needles dialysis (other three patients were not yet dialysis dependent CKD). Were observed one immediate failure, one failure in maturation, and two late failures at 4 and 16 months respectively. Sixteen months primary and secondary patency was 78.9% and 89.5% respectively.

CONCLUSION

These results showed how intraoperative IVL could help to recruit huge calcified marginal artery to create autogenous distal forearm AVF, avoiding proximal AVF, risking distal ischemia syndrome, and sparing vascular district to eventually rebuilt more proximal AVF in future.

The intraoperative intravascular lithotripsy to recruit a calcified radial artery for creating a distal radio-cephalic fistula

Guidelines for vascular access recommend that the distal autogenous arteriovenous fistula (AVF) should be the first choice-access procedure for patients starting dialysis. Arteriosclerosis of radial artery may cause early failure, as well as failure of maturation of distal arteriovenous fistulas. To increase the incidence of distal AVFs, our team, specialized in vascular access surgery from 2004 onwards, has introduced Intraoperative Transluminal Angioplasty (ITA) under ultrasound (UG) or fluoroscopic guidance, to recruit inadequate arterials for creating distal fistulas. Intravascular lithotripsy (IL) is a novel approach to treat luminal and medial calcifications in patients with peripheral arterial disease and coronary disease. We believe that intraoperative IL may be an opportunity to recruit calcified radial arteries for creating distal radio-cephalic fistulas. Purpose of this study is to describe the intraoperative IL technical applied in our clinical experience. A 37-year-old diabetic patient with distal radio-cephalic fistula was recruited for the first IL experience. One year ago, a wrist radio-cephalic fistula was created in the right upper limb, with intraoperative UG radial artery angioplasty for extensive calcifications. The fistula was functioning but showed a delay in maturation. An angioplasty was unsuccessfully attempted to facilitate the maturation. Subsequently, a surgical revision of the fistula was performed, creating a new anastomosis immediately upstream of the previous one by performing an intraoperative IL UG of the radial artery. The fistula was immediately well functioning, and was cannulated with two needles after 1 month. It is currently being used with intradialytic adequate blood flow. The positive outcome of the case described in this paper, even if only anecdotal, could act as a trigger for further experiences with IL.

Ultrasound guided interventional procedures on arteriovenous fistulae

Autogenous (AVF) and prosthetic (AVG) arteriovenous fistulas are the vascular accesses (VA) of choice for hemodialysis thanks to their improved patency, reduced costs, and lower rate of infections relative to catheters.

In an effort to maximize the number of primary AVF and AVG, shorten maturation times for AVF, and reduce the number of indwelling catheters, several new techniques have been developed within the context of an overall program designed to optimize access care.

This approach includes: (a) Primary Intraoperative Balloon Angioplasty on the vessels selected for AV creation whether small-sized or altered by pre-existing lesions; (b) Percutaneous Transluminal Angioplasty (PTA) on AVF and AVG stenosis, performed under ultrasonographic (UG) or fluoroscopic guide (FG).

We report the experience of two Center in performing the above mentioned procedures on even complex VA. The wise adoption of these techniques may avail to meet the stringent demands for reliable VA placement as defined by KDOQI and, thereby, expand the duration and quality of life for hemodialysis patients.

The Pre-dilatation of vessels: A simple method to recruit small caliber veins for creating distal fistulas

Maturation failure remains a major clinical problem of distal arteriovenous fistula (AVF). Early failure (EF) is associated with the small size of the veins. For about 10 years we have used in more than 1000 fistulas, the Vessels Pre-Dilatation (VPD) to increase the recruitment of small veins for creating distal AVFs. The purpose of this study is to highlight if the VPD can reduce the incidence of EF or failure to mature (FTM) in AVFs created with small veins. Data of all the consecutive patients directly admitted to our Department for their first distal AVF from January to December 2019 were collected. The patients were divided in two groups, one with a vein diameter after the tourniquet ⩽2.0 mm (G1) and one >2 mm (G2). Both in G1 then in G2 the vessels had undergone VPD. Immediate failure (IF), EF, FTM, delayed or arrested maturation rate (DAM), unassisted AVFs and matured AFVs were evaluated. The patients recruited totalled 104, 37 in G1, and 67 in G2. The two groups were homogeneous in age, incidence of diabetes, obesity, heart disease, peripheral vasculopathy, and race. Female were more numerous in G1 (51% vs 12%, p < 0.001). In G1 and G2 occurred respectively 3 IF versus zero ( p < 0.05), 10 EF (29%) versus 6 (9%) ( p < 0.05), 6 DAM (16%) versus 6 (9%), 21 unassisted AVFs (57%) versus 57 (85%) ( p < 0.01). Dividing the patients into groups of unassisted and assisted AVFs, female and low vein diameter are more represented in the assisted group. There were 32 matured AVFs (86%) in G1 and 65 (97%) in G2. In order to increase the incidence of the distal AVF, the PDV allows to include small veins. However, more patients require further interventions to achieve maturation of the fistula.