AV Fistulae by Nephrologists.... Challenges and Opportunities Dr

AV Fistulae by Nephrologists .... Challenges and Opportunities

Dr

Overview

Introduction History AV fistula creation

Nephrologists or surgeons? Results from nephrologists Information from active centres Dr Konner’s Suggestions Postoperative care

Intervention nephrology Conclusions

Introduction

Vascular access has been considered to be the Achilles’ heel of hemodialysis

therapy

An Achilles’ heel is a deadly weakness in spite of overall strength, that can actually or potentially lead to downfall

Advances in Chronic Kidney Disease 2009; 16(5):321-8.

History

Faced with daunting challenges in achieving adequate dialysis therapy because of inadequate vascular access, In 1966, four physicians from the Bronx

Veterans Administration Hospital described the creation of the radial-

cephalic fistula, which was created using a side-to-side anastomosis between the distal radial artery and cephalic vein


History


History

The publication by physicians in 1966 is Sentinel article

with regard to chronic hemodialysis vascular access


History

Despite numerous advances in dialysis technology since that time, this basic configuration remains a Gold standard for hemodialysis vascular

access A more recently developed

technique is End-to-side anastomosis

The end of the vein is sutured to the side wall of the artery


History


History

Even though much of the developmental work for AV fistula to dialysis access was credited to nephrologists, The actual creation of the accesses

reported in was in fact performed by a surgeon…


Nephrologists or Surgeons?

AV fistula creation Nephrologists or Surgeons?

Few American nephrologists have engaged in access creation

Outside of the US, it is not uncommon for autologous AV fistula creation and vascular access surgery to remain within the domain of the

Nephrologist


Nephrologists or Surgeons?

Reports from most active European centers indicate that the Likelihood of the successful creation of

a vascular access in the hands of a nephrologist is excellent


Results from Nephrologists

In 2002, Konner and colleuges published outcomes of fistula creation in 748 consecutive patients with ESRD from 1993 to 1998 Of these patients, 24% were diabetic, and 42% were

> 65 years of age; yet, None of these patients required synthetic graft

material for placement of their arteriovenous access Results

No statistical difference in primary access survival at 1 and 2 years when comparing patients > 65 years (77% and 68%) and younger patients (77% and 65%), and

No significant difference in secondary access survival at 1 and 2 years for younger patients (95% and 90%) and patients older than 65 years (93% and 90%)

Kidney Int 2002;62:329-38.


Nephrologists from India and the United States have reported results of their autologous fistula creations in abstract form at the 2008 American Society of Nephrology

Renal Week



Gopesh Modi from Bhopal, India, created 179 fistulae from 2002 to 2007 The mean age was 50.6 years, and 56% of the

patients were diabetics; 89.9% of the fistulas were functional at 2

weeks A total of 112 or 62.6% of the total created

were used for dialysis Of those used for dialysis,

109 or 97% were deemed to have adequate blood flow of > 250 mL/min

Interventional nephrology and vascular accessmanagement—AVfistulae creation by the nephrologist.Poster presented at AmericanSocietyofNephrologyRenalWeek2008. November 4-9, 2008, Philadelphia, PA

Opportunities for Nephrologists

Findings indicate that the direct involvement of nephrologists in autologous access surgery can be Effective in increasing the use and

durability of a native AV fistula for HD access


Challenges for Nephrologists

How, then, do these nephrologists approach the placement of a vascular access in a patient who is in need of a dialysis access?


Guidelines

KDOQI guideline 2.1.1 further prioritizes the selection and placement of the hemodialysis access

It advises that a structured approach to the type and location of long-term HD accesses should help optimize access survival and minimize complications Ideally, the access should be placed distally

and in the upper extremities whenever possible


Guidelines

Options for fistula placement should be considered first, followed by Prosthetic grafts if fistula placement is not

possible The order of preference

for the placement of fistulae in patients with kidney failure who choose HD as their initial mode of renal replacement therapy should be

(in descending order of preference)(1) a wrist (radiocephalic) primary fistula, (2) an elbow (brachiocephalic) primary fistula, and (3) finally a transposed brachial basilic vein

fistula


Guidelines

Guideline 2.1.4 advises that patients should be considered for the

construction of a primary fistula after failure of every dialysis AV access

KDOQI does not provide detailed guidance as to the operative

setting or type of anesthesia that is appropriate for use in AVF creation


Information by active centres

Italy Usually cases were performed using local

anesthesia in a procedure room located within the nephrology ward

Neither cardiopulmonary monitoring nor nursing assistance was routinely used during the procedures

Otherwise, usual operative equipment and sterile fields were used with the exception of electrocautery

Microscopic glasses were not consistently used except by one of the nephrologists

Semin Dial 2005;18:542-9.


Slovenia The utility of duplex sonography for preoperative

evaluation was studied and reported by Malovrh from a center in Slovenia

Investigator used sonography to interrogate arteries and veins before AVF construction in 116 consecutive patients

He studied numerous parameters preoperatively that included the

internal diameter of the feeding artery (IDA), resistance index (RI), blood flow before and after reactive hyperemia

(RH), and internal diameter of the vein before and after proximal vein compression (PVC)

Am J Kidney Dis 2002;39:1218-25.


Slovenia Successful construction of a fistula (primary

patency) was accomplished in 80.2% of the patients

In this group, the mean values for IDA were 0.264 cm (RI at RH 0.50)

In the group with failed fistulas (19.8%), the mean IDA was 0.162 cm (RI at RH 0.70)

This study showed that duplex sonography may provide useful data

on preoperative morphologic and functional characteristics of vessels used for AV fistula construction

Am J Kidney Dis 2002;39:1218-25.


Germany Dr Konner also has performed most of

his fistula creations in an outpatient procedure room near the dialysis unit

Nursing assistance has been somewhat limited, and, therefore, the procedures were performed using local anesthesia

J Am Soc Neph 2003;14:669-1680.


Germany Preoperative evaluation emphasized

preserving all forearm veins in both arms by permitting phlebotomy only using the veins on the dorsum of the hands

Duplex sonography has proved valuable for preoperative assessment in this center

These authors advocated Assessing the vasodilatory capacity of the

palmar arch by calculating the resistive index from postischemic diastolic blood flow after fist clenching

J Am Soc Neph 2003;14:669-1680.

Dr Konner’s Suggestions









Although his list is somewhat lengthy, Dr Konner makes Excellent suggestions based on years of

experience and thousands of vascular access procedures….



US Anecdotal experience at the Phoenix center seems

to indicate that local anesthesia with or without conscious sedation

may offer a benefit in terms of reduced injury Because the patient is able to converse during a

procedure performed under conscious sedation and/or local anesthesia,

early warning can be given by the patient if a nerve is being encroached upon because he/she will be able to report the pain or paresthesias encountered

These warning signs are usually not present with regional anesthesia or general anesthesia.


Postoperative Care

Robin et al found that ultrasound measurements of fistulas at

2 to 4 months in patients undergoing dialysis were

Highly predictive of fistula maturation and adequacy for dialysis

The same study also concluded that experienced dialysis nurses’ accuracy in predicting eventual fistula maturity was 80%


Postoperative Care

Postoperative evaluation at the Phoenix center is based on the physical examination and consists of 3

scheduled visits A physical examination with emphasis on

wound status and fistula function is performed 2 weeks after the access is created

A physical examination and ultrasound surveillance then occur at 6- and 12-week intervals after creation

Catheter and/or surgically based interventions are scheduled if problems develop in any time with the access


Postoperative Care

Author’s experience has been that endovascular interventions in patients with CKD and a failing fistula are safe and effective After 3 months, if the fistula is suitable

for but not in use for dialysis because of the patient’s continued CKD status, further ultrasound surveillance is prescribed by the operating physician.


Intervention nephrology

Skill set and knowledge base that are developed by an experienced interventional nephrologist seem to be

Well aligned with those needed to perform fistula creation and tools such as a

thorough physical examination and Doppler ultrasound surveillance are readily available



Another potential advantage of fistula creation in the interventional nephrology setting is that Many CKD and dialysis patients may become

acquainted with the facilities and physicians and staff through previous appointments and procedures.

This familiarity may obviate the need for obtaining a consultation

with a new physician at a new center and perhaps facilitate scheduling a fistula creation in a timely manner



It is on this foundation of continuity of patient care that Nephrologists will likely continue to

expand their roles in the care dialysis patients by engaging in AV fistula creation…..

Conclusions

AV fistula creation is an opportunity as well as challenge for a nephrologist

Based on skill and sound knowledge, nephrologists are set to enter in the field of intervention nephrology

Conclusions

AV fistula creation by nephrologist would have many potential advantages Providing continuity and familiarity in

patient care

Documents

AV Fistulae by Nephrologists.... Challenges and Opportunities Dr