Guidelines for Arteriovenous Access Intervention, Management and Abandonment, and for Removal of Pre- Study Dialysis Catheter

Transcription

1 Guidelines for Arteriovenous Access Intervention, Management and Abandonment, and for Removal of Pre- Study Dialysis Catheter The guidelines for arteriovenous access intervention, management and abandonment, and for removal of pre-study dialysis catheter have been developed by the clinical events committee (CEC) for the phase 3 AV access study sponsored by Humacyte. This study will evaluate the clinical outcomes of the Humacyte HAV vs. AVF in a head-to-head non-blinded clinical study in the setting of dialysis access. The CEC will play an essential role in evaluating and adjudicating clinical events related to the conduct and execution of the study., these guidelines are intended to establish acceptable standards for, assessment of infection, adjudication of infection and study access site abandonment following surgical revision, and althouth AV access interventions will not be adjudicated by the CEC in this study, acceptable standards for AV access intervention. 1. Guidelines for Considering Arteriovenous Access Intervention on the Study Access 1.1. Routine angiography and intervention (without cause) on the Study Access (SA) should not be done 1.2. Reasons for angiography or possible intervention: Clinical Exam Absent thrill over the index access site (access site thrombosis) Abnormal auscultation (presence of a high-pitched, systolic bruit) over the index access site Pulsatile flow by palpation over the index access site Persistent generalized or focal swelling in the extremity of the index access site Persistent localized swelling over the access site (suggestive of a seroma) within the first 30 days following access placement Aneurysmal expansion (> than 9 mm for either true or false aneurysm) of the index access conduit Prolonged local bleeding after decannulation of the index access site Spontaneous bleeding from or presence of compromised skin overlying the index access site Atypical or persistent arm or hand pain on the side of index site access Distal limb ischemia in the extremity of the index access 1 Trerotola SO, Ponce P, Stavropoulos SW, Clark TW, Tuite CM, Mondschein JI, et al. Physical examination versus normalized pressure ratio for predicting outcomes of hemodialysis access interventions. J Vasc Interv Radiol 2003;14: Schuman E, Ronfeld A, Barclay C, Heinl P. Comparison of clinical assessment with ultrasound flow for hemodialysis access surveillance Arch Surg 2007;142: Asif A, Leon C, Orozco-Vargas LC, Krishnamurthy G, Choi KL, Mercado C, et al. Accuracy of physical examination in the detection of arteriovenous fistula stenosis. Clin J Am Soc Nephrol 2007;2: Humacyte CLN-PRO-V007: CEC Guidelines Page 1 of 6 21Jul2017

2 Dialysis Data/Access Blood Flow Measurement Recurrent episodes of needle infiltration following cannulation from the index access site Recurrent episodes of thrombus aspiration from the index access site Difficult cannulation of the index access site by expert cannulator Excessive negative pre-pump arterial pressures (below -200 mm Hg with 15 gauge needles and blood flow of 400 ml/min) during dialysis treatment of the index access site Inability to consistently achieve the prescribed blood pump speed Unexplained decrease in delivered dialysis dose: Kt/V below 1.2 or urea reduction rate (URR) < 60% Intra-access blood flow rate < 600 ml/min within the index access site A > 25% decline in intra-access blood flow within the index access site 2. Guidelines for Arteriovenous Access Intervention and Management 2.1. Access Interventions: Prior to access site intervention, a contrast study should be performed and documented. This study should include the entire access circuit including the arterial inflow, the actual access site (and cannulation zone), the venous anastomosis (for HAV), the outflow vein, and central vein runoff extending all the way to the right atrium. If a clinically significant stenosis (> 60%) is detected, balloon angioplasty or other appropriate surgical or endovascular procedures can be performed at the same sitting. In the event that no clinically significant lesion is identified, a physiologic etiology causing low access flow/thrombosis should be investigated such as severe hypotension, thrombophilia or inappropriate access compression following needle decannulation Access site thrombosis: The resolution of access thrombosis for either HAV or AVF involves three principle steps; removal of intragraft clot burden, identification of pathologic lesion(s) (stenosis) causing access site thrombosis, and management of these lesion(s). Clot removal alone is usually not sufficient for long-term patency unless the inciting factor is transient, such as access compression or profound post-dialysis hypotension. Management of the clotted access can be done by either surgical or endovascular techniques. With either method, the clot or thrombus needs to be removed: surgically using a mechanical/balloon catheter or by endovascular means using thrombolysis, mechanical thrombectomy devices, or a combination thereof Open surgical management: Open surgical thrombectomy typically involves a small cut down incision over a segment of the access AVF/HAV. Using this small incision in the access, thrombectomy catheters or balloons are inserted and clot burden of the access is removed by direct mechanical means. If the stenotic segment of the access is amenable to surgical exposure, the access can be managed by open surgical techniques. 5 Moist LM, Churchill DN, House AA, Millward SF, Elliott JE, Kribs SW, et al. Regular monitoring of access flow compared with monitoring of venous pressure fails to improve graft survival. JAmSoc Nephrol 2003;14: Schwab SJ, Oliver MJ, Suhocki P, McCann R. Hemodialysis arteriovenous access: Detection of stenosis and response to treatment by vascular access blood flow. Kidney Int 2001;59: Humacyte CLN-PRO-V007: CEC Guidelines Page 2 of 6 21Jul2017

3 If the lesion is short, a patch angioplasty can be performed using either autogenous venous or prosthetic material of the surgeon s choice. When the lesion is long or multiple sequential lesions are found, a vein segment or piece of prosthetic graft can be used to bypass the diseased segment. This bypass can be performed either to replace the diseased segment or to bypass it to a proximal healthy vein. This should be planned in a way to keep, if possible, an incorporated segment of AVF or HAV free to be continuously used for dialysis, thus obviating the need for catheter placement while the new replacement segment incorporates or matures Endovascular techniques: Endovascular thrombectomy typically involves access to the AVF/ HAV via percutaneous techniques (with or without ultrasound guidance). One or two small (5-7 French) vascular sheaths are placed directly in the access. Clot burden can be managed by a variety of endovascular techniques with or without biochemical thrombolysis. After successful clot removal, angiography of the entire access circuit is recommended. Pathologic/stenotic lesions may be identified anywhere in the access circuit; including the arterial anastomosis, in the AVF/HAV material, at the venous outflow anastomosis (for HAV), immediate outflow veins, or in a more central vein segment. Stenotic lesions can be managed using balloon angioplasty and/or stenting techniques. Balloon angioplasty of the intra-graft portion of the HAV must be limited to (no larger than) a 6 mm non-compliant balloon. If an intragraft stenosis becomes refractory to treatment with a 6mm balloon, it is permissible to use a 7mm balloon to treat residual stenosis in that area only. However, balloon length should remain as short as possible to avoid over dilating areas outside of the stenosis. Balloons > 6mm in diameter may be used at the anastomoses as long as the body of the balloon remains outside of the HAV. Placement of a stent (stent-graft or bare metal) within the cannulation zone of an AVF or HAV for treatment of pseudoaneurysm or stenosis is not recommended due to increased risk of complication and infection. 7 Stent-graft placement within the SA for treatment of acute hemorrhage is acceptable, but eventual revision via surgical reconstruction would be recommended. Following any angioplasty or stenting procedure, post-intervention images (completion) should be obtained. Mechanical, suction, or rotational thrombectomy devices (i.e. Angiojet, Trerotola, Amplatz, Trellis, EKOS, etc.) have not been extensively tested for safety or efficacy within the HAV. We do not recommend use of these devices for thrombectomy procedures until adequate safety testing has been performed Hybrid/combination techniques: Open balloon catheter thrombectomy through a small transverse incision remote from both the arterial and venous anastomosis (for HAV) of the access may be performed. Clot burden can be managed by a variety of endovascular or open techniques with or without biochemical thrombolysis. After successful clot removal, angiography of the entire access circuit is recommended. Pathologic/stenotic lesions may be identified anywhere in the access circuit; including the arterial anastomosis, within the AVF/HAV material, at the venous outflow 7 Kim CY, Guevara CJ, Engstrom, BI, et al. Analysis of Infection Risk following Covered Stent Exclusion of Pseudoaneurysms in Prosthetic Arteriovenous Hemodialysis Access Grafts. J Vasc Interv Radiol 2012;23: Humacyte CLN-PRO-V007: CEC Guidelines Page 3 of 6 21Jul2017

4 anastomosis (for HAV), immediate outflow vein, or in a more central vein segment. Stenotic lesions can be managed using balloon angioplasty, stenting or surgical techniques as deemed appropriate by the interventionalist/surgeon. Balloon angioplasty of the intra-graft portion of the HAV must be limited to (no larger than) a 6 mm non-compliant balloon. If an intragraft stenosis becomes refractory to treatment with a 6mm balloon, it is permissible to use a 7mm balloon to treat residual stenosis in that area only. However, balloon length should remain as short as possible to avoid over dilating areas outside of the stenosis. Balloons > 6mm in diameter may be used at the anastomoses as long as the body of the balloon remains outside of the HAV. Open surgical revision, with or without balloon angioplasty or stent placement within the access circuit are all acceptable if deemed to be appropriate from imaging studies. Placement of a stent (stent-graft or bare metal) within the cannulation zone of an AVF or HAV for treatment of pseudoaneurysm or stenosis is not recommended due to increased risk of complication and infection. (Kim 2012) Stent-graft placement within the SA for treatment of acute hemorrhage is acceptable, but eventual revision via surgical reconstruction would be recommended.following any significant revision of the access circuit post intervention, images (completion) should be obtained. 3. Guidelines for Adjudication of Arteriovenous Access Infection 3.1. CDC Definitions of true and suspected arteriovenous access site infection Access related bloodstream infection (ARB): A positive blood culture with the suspected source reported as either the vascular access or uncertain Bloodstream Infection (BSI): Any positive blood culture Local access site infection (LASI): Purulance, or greater than expected redness, or greater than expected swelling of a vascular access site in the absence of access-related bloodstream infection Vascular access infection (VAI): Either local access site infection or access-related bloodstream infection SA related infection: A bloodstream infection or access site infection with the suspected source reported as the SA All access site infections and associated infections in AVF/HAV subjects will be adjudicated with special attention as to the most likely source of the infection. Infections will be classified in one of three ways: Blood stream infection, not associated with SA infection Local site access cannulation infection, not associated with true SA infection which is managed by conservative measures and antibiotics True SA infection requiring explant of material and any of the following; bacterial contamination of the access, presence of a biofilm, and/or significant surgical revision of the access or abandonment. 8 CDC. Dialysis Event Surveillance Manual. In: Network NHS, ed.: CDC; Nassar GM, Ayus JC. Infectious complications of the hemodialysis access. Kidney Int 2001;60:1-13. Humacyte CLN-PRO-V007: CEC Guidelines Page 4 of 6 21Jul2017

5 4. Guidelines for Considering Study Access Abandonment Access abandonment is defined as an access that can no longer be used for 2 needle, prescribed dialysis as it may be unable to provide adequate flows and/or is deemed unsafe for the subject, and the associated problem cannot be corrected by rest, or any intervention, including medical, surgical or radiological interventions. All access abandonment will be evaluated as to the reason and appropriateness of terminal loss of access function. All access abandonment will be evaluated as to the reason and appropriateness of terminal loss of access function. The CEC will ensure that one SA type verses the other is not inappropriately being abandoned as to affect the outcome of the study Access should be considered appropriately abandoned for one or more of the following reasons: The SA does not have a thrill or bruit anywhere along the access and one or more of the appropriate interventions for access salvage had been attempted The SA has flow, but does not have adequate diameter to promote cannulation, is too deep to allow for cannulation, or has inadequate flow to promote adequate HD Endovascular intervention (angioplasty, thrombolysis, stenting, embolization or other) does not salvage the SA to make it useable A surgical revision of the SA does not salvage the access to make it useable. (Revision is considered a revision of the current access and not a surgical procedure that creates a new access) The SA is viable but there are complications that require the abandonment of the access (e.g. high cardiac output, refractory hypotension) Severe arterial steal which jeopardizes the permanent function of the hand or digits, where the operative surgeon feels that appropriate surgical maneuvers (DRIL, flow reduction, distalization of the inflow, or proximalization of the inflow) have either failed or are considered surgically unsafe Severe SA infection where local excision and/or antibiotic therapy are unsafe or have failed and where the entire SA segment must be explanted Terminal loss of functional cannulation zone of the access segment due to acute or chronic cannulation injury which cannot be salvaged by surgical revision Interventional futility where an access has undergone more than 3 consecutive interventions/thrombectomies over a 3-month period and enduring functional patency cannot be restored Eroded or exposed access material that places the patient in significant risk of bleeding or infection and in which the SA cannot be repaired with a simple surgical revision Severe wound complications in the access placement sites where simple conservative wound care attempts have failed and the patient is at risk for anastomotic disruption Severe or disabling arm edema or pain on the side of the functioning access in which appropriate surgical or endovascular therapies to resolve access outflow obstruction have been attempted, and by clinical or functional exam have failed. Humacyte CLN-PRO-V007: CEC Guidelines Page 5 of 6 21Jul2017

6 4.2. Adjudication of access abandonment following surgical revision. Following major surgical replacement of the access conduit, it is possible that the access will continue to run in the same location but the majority of the original SA has been replaced. Thus following every major surgical revision of the SA, operative reports from the procedure will be reviewed by the CEC and the following guidelines will be followed If no portion of the original SA remains in the access circuit (i.e. area being cannulated by at least 1 needle) following surgical revision, the access will be considered abandoned. For example, if a substantial portion of the original SA is excised and replaced with new material as an interposition graft, while leaving the original SA intact at the arterial and venous anastomosis, but the original SA is not access by at least 1 needle, the access wil be considered abandoned If any portion of the original SA remains in the access circuit (i.e. area being cannulated by at least 1 needle) following surgical revision, the access will be considered notabandoned. 5. Guidelines for Removal of a Pre-Study Dialysis Catheter 5.1. As the diagnoses of ESRD and renal replacement therapy via central venous dialysis catheter are requirements for enrollment into this study, we propose a set of guidelines to standardize the expectations for safe and timely catheter removal SA cannulation is allowed after day 28, and as such, we encourage investigators to plan for timely use of the SA as close to day 28 as possible, if deemed safe and reasonable If a period of short-term stable SA use can be achieved, and there are no other concerns over the access function, expeditious (e.g. within 2 weeks) catheter removal is recommended Definition of Short-term Stable SA Use Successful, 2 needle dialysis session with machine blood pump speed 300 ml/min on 3 consecutive treatments. Humacyte CLN-PRO-V007: CEC Guidelines Page 6 of 6 21Jul2017