Why Can't I Cannulate This Fistula? Fistula Immaturity: The Simple But Critical Steps for a Functioning (Mature) AVF

Transcription

1 Why Can t I Cannulate This Access? Steven J. Bander M.D. Adjunct Professor of Nephrology St. Louis University Director, Vascular Access Center, St. Luke s Hospital Saint Louis, MO Why Can't I Cannulate This Fistula? Fistula Immaturity: Magnitude of the Problem and Possible Solutions The Simple But Critical Steps for a Functioning (Mature) AVF Nephrology Care Surgical Placement AVF Maturation Successful Cannulation 1

2 Vascular Access Snap Shot USRDS % of prevalent patients using an AV fistula (2014) AV fistula use at initiation of hemodialysis has risen from 12% (2005) to 17.1% (2014) 80.2% of hemodialysis patients use a catheter at initiation in no change since 2005 * > 40 % have no access plan when starting dialysis The percentage of patients using an AV fistula exclusively at the end of 1 year was 65% (up from 17%) 35.9% of fistulas placed failed to be use following placement Mean days from placement to first use 133 Younger patients have higher fistula maturation rates Trends in Vascular Access for Prevalent Patients Is it Fistula First? Or Fistula Worst? It should be Catheters Last 2

3 Mission Statement To increase the likelihood that every suitable patient will receive the optimal form of vascular access which, in most patients, will be a native arteriovenous fistula Once a fistula, graft or catheter is placed, the die is cast - complications and failures will ensue. Stenosis, thrombosis and / or infection are inevitable. Fistula are not as good as you ve been told, and grafts are not as bad. 3

4 Functional longevity Reported Advantages of - PTFE graft : 2 3 years - Fistula : 3 5 years Arteriovenous Fistulae Durability - fewer reparative procedures Lower costs Fistula First The data used to support the Fistula First Initiative used poor scientific methods Previous reports touting the advantages of fistula have failed to account for failure of fistula maturation Complications During First Year of Hemodialysis of Mature Vascular Access 2005 USRDS: combined data from 1999 and Sepsis Declot A-plasty Fistula Graft 4

5 Vascular Access Patency Hodges J Vasc Surg 1997;26: Pt # 1 yr 1 yr Graft % 59% Fistula 87 43% 46% Catheter 112 9% 9% Peritoneal % 68% 215 of 236 grafts (91%) required 2 procedure Vascular Access Survival USRDS Dialysis Morbidity and Mortality Study 1 Type 1 year 2 years Fistula 56% 40% Grafts 38% 25% Venous transposition 43% 28% 1 Gibson et al. J Vasc Surg 2001; 34: Access Dysfunction The Problem Fistula Failure to develop (30-63%) Thrombosis Stenosis Aneurysms High Output Cardiac Failure Prosthetic bridge graft Stenosis Thrombosis Pseudoaneuryms Infection 5

6 The Simple But Critical Steps for a Functioning (Mature) AVF Nephrology Care Surgical Placement AVF Maturation Successful Cannulation Reasons for Late Access Referral PCP Providers: knowledge deficits, perception, preferences Availability of nephrologists: perceptions and preferences Healthcare Systems: lack of integration of information systems and financial incentives; patient co-pays Patients: lack of insurance; knowledge deficits; adherence; negative attitudes and misconceptions of dialysis Payors: no payment for counseling and education Strategic Plan for Prevention, Identification and Management of the Non maturing AVF Timely referral to nephrologist (>12 months before anticipated use) Timely referral to surgeon (7 months before anticipated use) Vessel mapping / Central Vein Evaluation Post op 4-5 wks.: for maturation progress, if uncertain reassess in 1 week If inadequate 4-6 wks.: diagnostic study and intervention as indicated If it cannot be used by days, consider the AVF failed and intervene 6

7 Surgeon Selection Think AVF Only Artery Size (> 2mm); minimal calcium deposits; Type of Anastomosis Interrupted not running sutures; non penetrating clips or U- clip Prevention of Swing Segment Stenosis Angle of anastomosis - causing turbulent flow leading to hyperplasia Low elasticity in artery; close proximity to vein Vein Size (>2 mm) and Depth (<10mm) Central Vein Evaluation KDOQI Guideline 9 Access Maturation A primary AV Fistula is mature and suitable for use when the vein diameter is sufficient to allow successful cannulation. Fistula Maturation 11-63% or more never mature or used as long term access No standardize definition or objective criteria Subjective assessment widely variable Lack of accountability 7

8 Fistula Maturation Increased blood flow Increased vein diameter Increased vein thickness Increased visibility brachiocephalic fistula Ultrasound evaluation of fistulas Rule of 6 s Blood flow 600ml/min Vein diameter 6mm Depth of vein 6mm If a fistula fails to mature by 6 weeks a fistulogram should be performed to determine the cause of the problem. Ultrasound can be used to improve initial cannulation of new fistulas Mark fistula to assist hemodialysis nurses Measure depth of fistula 8

9 Use of ultrasound to map fistula Extensive roadmap of brachiocephalic fistula Cannulation of Immature Fistulas hematoma ecchymosis 9

10 Non-Maturing Fistula Etiology Poor arterial inflow Anastomotic stenosis Small vein Venous stenosis Branching vein Vein too deep Incidence of Maturation Failure NIH DAC (2007) 63 % USRDS (2016) 36 % Author Failure to Mature Miller ( 99) 53% Hodges ( 97) 31% Huber ( 02) 29% Robbin ( 02) 22% Ascher ( 00) 15% Kalman ( 99) 11% Cumulative Survival of AVF and AVG (Allon, Seminars in Dialysis, 2017) Reference # of Patients Primary Failure Median Excluding Median Including access primary access primary survival failures survival failures (months) (months) AVF AVG AVF AVG AVF AVG AVF AVG Schild 2008 Maya 2009 Lok 2013 Allem ang (2014) % 15% 42* 20* < % 19% 62* 24* <

11 AV Fistula Patency Interventions to Promote Fistula Maturation surgical creation angioplasty Maturation (2-6 months) Hemodialysis Primary Patency angioplasty angioplasty Very short primary patency rates AV Graft Patency Interventions to Maintain Graft Patency angioplasty angioplasty Maturation (<3 weeks) Hemodialysis angioplasty Etiology of Non-Mature Fistulae Author Art. Inflow Art. Anast Swing Point Outflow Vein Central Vein Acc. Vein Multiple Beathard 4% 38% 43% 36% 9% 46% 40% 2003 Nassar 5% 47% 64% 59% 8% 29% 71% 2006 Clark 6% 4% 38% 49% 3% 4% 42% 2006 Falk 8% 6% 25% 33% 2% 19% 29%

12 Endovascular Management of Non-Maturing Fistulae Angioplasty Embolization Ligation Failure to Mature : Arterial Stenoses juxta-anastomotic stenosis cephalic vein radial artery stenosis Right radiocephalic fistula Failure to Mature : Arterial Stenoses cephalic vein brachial artery arterial stenosis brachiocephalic fistula 12

13 Failure to Mature : Venous Stenoses juxta-anastomotic native outflow vein Failure to Mature : Venous Stenoses venous stenoses Non-maturing brachiocephalic fistula Failure to Mature : Venous Stenoses axillary vein arterial anastomosis long stenosis of basilic vein Left upper arm brachiobasilic fistula which has never been used for hemodialysis 13

14 Failure to Mature : Prominent Side Branches Distal venous stenosis obstructs blood flow Blood preferentially flows through side branches venous stenosis Diverts blood flow from primary outflow vein Thereby inhibits maturation of fistula Failure to Mature : Prominent Side Branches side branch venous stenosis Prominent side branches are often due to a distal stenosis Failure to Mature : Prominent Side Branches left shoulder left elbow venous segment too short plethora of outflow veins brachiocephalic fistula 14

15 venous side branch cephalic vein fistula basilic vein A Failure to Mature : Embolization of Side Branches Initial Post-embolization Final : Post angioplasty Access Maturation Although there are no definitive data on the subject, any intervention that increases blood flow to the extremity may improve the chances of successful fistula development. 15

16 Salvage Rate for Non-Maturing Fistulae Author # Fistulae Fistula Age (months) Salvage Rate Faiyez % Shin % Falk % Nassar % Asif % Clark % Maintenance and Salvage of Arteriovenous Fistulas Falk J Vasc Intervent Radiol 2006; 17: fistulas (42%) underwent 113 procedures to promote maturation procedures per fistula 63 fistulas required 209 procedures to maintain patency 3.3 procedures per fistula Maintenance and Salvage of Arteriovenous Fistulas Falk J Vasc Intervent Radiol 2006; 17: Cumulative Patency 3 months 73% 6 months 72% 12 months 68% Mean follow-up period for 154 fistulas = 317 days 16

17 No Fistula Left Behind.. If the autogenous fistula is the preferred form of vascular access for hemodialysis Evaluate, Refer, Intervene Early evaluation and treatment of the non-maturing fistula is advantageous Consequences of Non Maturing Fistula Prolonged use of a Hemodialysis Catheter Suboptimal treatment Increased risk of catheter related infection, stenosis, and thrombosis Wasted time before creation of a functional vascular access Potential loss of future access sites Cost of Care for Dialysis Access (J. Am. Coll Surg 2015 A) Month TDC $$ AVF $$ AVG $$ EC AVG $$

18 Points to be Made The patency and longevity of fistula are not much better than grafts when primary failures are included Fistula require more procedures and more cost then previously thought. Increased fistulae use has contributed to increased / prolonged catheter use. New technology and techniques have improved the patency and longevity of grafts Tunneled catheters have the highest associated cost, morbidity and mortality Autogenous Fistula Prosthetic Graft Type of Vascular Access Recommended Order of Preference 1. Fore arm fistula 2. Fore arm prosthetic loop graft 3. Brachiocephalic (Upper arm) fistula 4. Transposed Brachiobasilic Fistula 5. Prosthetic graft in upper arm 6. Prosthetic graft in lower extremity Use of Tunneled Central venous catheter should be discouraged 18

19 Cannulation of the Access Physical examination Preparation Needle selection Trouble shooting Physical Examination of the Vascular Access Visual Examination Palpation Auscultation 19

20 Examine Fistula or Graft Redness Drainage Abscess Cannulation sites Aneurysms Examine Hands/Feet Cold Painful Discolored Numb Examine Entire Arm / Leg Skin color Edema /Swelling Hematoma Bruising Identify Sites for Needle Insertion Arm position is important -Extend the 90 degrees angle in patients (surgical construction position). Stabilize access by placing a cushion or pillow placed under access arm: upper arm - the axilla to elbow; fore arm - elbow to wrist Look for straight areas of at least 1 for each cannulation site Avoid aneurysms and flat or thinned-out areas Stay 1.5 away from the arterial anastomosis Keep the needles at least 1.5 apart A tourniquet is required for all fistula cannulation procedures Use of a tourniquet provides uniform dilatation and stabilization of the vein during needle insertion 20

21 Always cannulate the venous needle with the direction of the blood flow Venous needle directed back toward the heart Arterial needle directed toward the arterial anastomosis arterial anastomosis Venous needle directed back toward the heart Arterial needle can be inserted in either direction Arterial needle directed toward the heart arterial anastomosis 21

22 Rope ladder technique of cannulation Proper needle site rotation with rotation of both the venous and arterial needle sites General Guideline: angles for fistula 45 for grafts Reality: Needle Angulation Some fistulae are very shallow and a shallow angle should be used. You will need to carefully assess the depth of the access and adjust the angle of cannulation 22

23 Needle Removal Apply gauze dressing without pressure Remove needle at insertion angle Apply pressure with 2 fingers Do not use excessive pressure Hold for minutes, no peeking Check for bruit or thrill after applying dressing to stick site Clamps vs. Holding Sites Patients should be taught to hold sites properly; otherwise, staff should hold sites Clamps should not be used routinely However, if clamps must be used: Be sure they are adjustable Check for thrill above the clamp to ensure vessel is not occluded Clamps should never be left on longer than 20 minutes (bleeding longer than 20 min needs to be investigated) 23

24 Questions? Physical Exam What do you think? dialysis graft 24

25 Arm edema due to central venous stenosis Cannulation site hematoma 25

26 Inflammation of forearm graft Superficial infection Cannulation site infection 26

27 Friable eschar is worrisome for acute rupture Large hematoma around upper arm graft Cannulation of Immature Fistulas Massive hematoma in left upper arm due to premature cannulation of a brachiocephalic fistula 27

28 Cannulation of Immature Fistulas hematoma ecchymosis venous aneurysms arterial anastomosis Left brachiocephalic fistula Determine Direction of Blood Flow Locate anastomosis Palpate Arterial inflow pulses with flow Venous outflow = diminished or no pulse Auscultate Arterial inflow = pulsatile sound Venous outflow = minimal or no sound 28

29 venous needle arterial needle arterial anastomosis 29

30 Do not flip or rotate the bevel of the needle 180 Flipping can lead to stretching of the needleinsertion site and cause oozing during the dialysis treatment 30

31 Needle Gauge vs. Blood Flow Rate Needle Gauge 17-gauge 16-gauge 15-gauge 14-gauge Maximum BFR < 300 ml/min ml/min ml/min > 450 ml/min 31

32 Cannulation of Immature Fistulas Massive hematoma in left upper arm due to premature cannulation of a brachiocephalic fistula Ultrasound evaluation of fistulas Rule of 6 s Blood flow 600ml/min Vein diameter 6mm Depth of vein 6mm If a fistula fails to mature by 6 weeks a fistulogram should be performed to determine the cause of the problem. Ultrasound can be used to improve initial cannulation of new fistulas Mark fistula to assist hemodialysis nurses Measure depth of fistula 32

33 Use of ultrasound to map fistula Extensive roadmap of brachiocephalic fistula Type of Vascular Access Recommended Order of Preference 1. Fore arm fistula 2. Fore arm prosthetic graft 3. Brachiocephalic (Upper arm) fistula 4. Transposed Brachiobasilic Fistula 5. Prosthetic graft in upper arm 6. Prosthetic graft in lower extremity Use of Tunneled Central venous catheter should be discouraged 33

34 Non-Maturing Fistula Etiology Poor arterial inflow Anastomotic stenosis Small vein Venous stenosis Branching vein Vein too deep Management of Non Maturing Fistulae Surgical Ligation Angioplasty Embolization Interventions done to promote fistula maturation prior to use as access = very short primary patency rates Maintenance and Salvage of Arteriovenous Fistulas Falk J Vasc Intervent Radiol 2006; 17: fistulas (42%) underwent 113 procedures to promote maturation procedures per fistula 66 venous angioplasty 21 ligation of venous side branches 16 arterial angioplasty 5 thrombectomy 3 banding 2 other 34

35 Maintenance and Salvage of Arteriovenous Fistulas Falk J Vasc Intervent Radiol 2006; 17: fistulas required 209 procedures to maintain patency procedures per fistula 174 venous angioplasty 18 arterial angioplasty 14 thrombectomy 3 ligation of side branches 2 stents Failure to Mature : Arterial Stenoses radiocephalic fistula blood flow arterial stenosis brachial artery Maintenance and Salvage of Arteriovenous Fistulas Falk J Vasc Intervent Radiol 2006; 17: Retrospective review of 154 fistulas created in 146 patients 112 fistulas (73%) were successfully used for hemodialysis 35

36 Endovascular Salvage of Non Maturing or Dysfunctional Fistula Article Salvage 2 patency Radiology 2008; 246: Radiology 2007; 242: J Vasc Interv Rad 2008; 19: Nephrol Dial Trans % 88% 75% at 12 months 87% 50% at 3 years 97% 96% at 12 months 91% at 48 months Fistula Maturation Increased blood flow Increased vein diameter Increased vein thickness Increased visibility brachiocephalic fistula 36