AV Fistulae by Nephrologists .... Challenges and Opportunities

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

History

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

History

 The publication by physicians in 1966 is  Sentinel article with regard to chronic hemodialysis vascular access Advances in Chronic Kidney Disease 2009; 16(5):321-8.

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

History

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

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

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

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

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.

Results from Nephrologists

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

Results from Nephrologists

 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 access management—AVfistulae creation by the nephrologist.

Poster presented at AmericanSocietyofNephrologyRenalWeek 2008. 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 Advances in Chronic Kidney Disease 2009; 16(5):321-8.

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?

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

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

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

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

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.

Information by active centres

 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.

Information by active centres

 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.

Information by active centres

 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.

Information by active centres

 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

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

Dr Konner’s Suggestions

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

Dr Konner’s Suggestions

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

Dr Konner’s Suggestions

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

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….

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

Information by active centres

 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.

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

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

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

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.

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

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

Intervention nephrology

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

Intervention nephrology

 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