Lysis-Assisted Balloon (LAB) Thrombectomy Panagiotis M. Kitrou MD, MSc, PhD, EBIR Consultant Interventional Radiologist Interventional Radiology Dpt. Patras University Hospital Greece
Facts & Figures Thrombosis: Most important Vascular Access- Related Complication Stenosis: Most common cause of Thrombosis But also: hypotension, dehydration, infection, compression, etc.
Facts & Figures Endovascular > Surgical NKF-K/DOQI 2006update vascular access. Guideline 2: selection and placement of hemodialysis access. Am J Kidney Dis 2006; 48(1 Suppl 1):s192 s200
Why? Facts & Figures Perform both declotting and angioplasty in the same setting. Venous preservation Rapid return to dialysis NKF-K/DOQI 2006update vascular access. Guideline 2: selection and placement of hemodialysis access. Am J Kidney Dis 2006; 48(1 Suppl 1):s192 s200
Options Thrombolysis Lysis: something that is solved, disintegrates (not a problem anymore) Thrombectomy Ectomy: Ablation, taking something away (not burning!)
Thrombectomy - Thrombolysis
Technique
AA VA
Technique Arterial Access: Micro-puncture Kit 5mg of rtpa for 6min Venous Access: 6Fr Sheath 7 X Long (HPB): Multiple short-term inflations Thrombus Maceration Stenosis Evaluation Access Sites: min 4cm apart
Venous Access: Technique 5.000 IU of Heparin through the balloon catheter distal to the thrombus Slow velocity hand injection of diluted contrast (5ml, 70% saline, 30% contrast) residual thrombus estimation
Technique Arterial Access: Upsize to 6Fr Sheath 4Fr catheter to inflow artery to perform DSA for thrombus estimation Fogarty like technique with a 6X40mm low pressure balloon at 3-4atm
Technique Residual Stenosis: Very High Pressure Balloon Stent Graft (Vein-Graft anastomosis or distally)
Study Single-Center, Retrospective analysis investigating the results of a hybrid thrombolysis-thrombectomy method for the treatment of thrombosed dialysis arteriovenous grafts (AVG) Kitrou et al., Lysis-Assisted Balloon (LAB) Thrombectomy. A Declotting Technique for the Treatment of Thrombosed Arteriovenous Dialysis Grafts. 5-Year Experience of 241 Endovascular Procedures. CVIR, 2018
Baseline Variables Period: 5 years (January 2012-Decmber 2016) De-clotting procedures: 291 for AVGs and AVFs Data available for 129 patients (75 men, 58.1%) with an AVG undergoing 241 procedures [1.87procedures/patient (1-10)]. Kitrou et al., Lysis-Assisted Balloon (LAB) Thrombectomy. A Declotting Technique for the Treatment of Thrombosed Arteriovenous Dialysis Grafts. 5-Year Experience of 241 Endovascular Procedures. CVIR, 2018
Baseline Variables 61 patients had 2 declotting procedures. Stent Graft Insertion: 80 cases (80/241; 33.2%) for thrombus apposition or treatment of persistent stenosis. Kitrou et al., Lysis-Assisted Balloon (LAB) Thrombectomy. A Declotting Technique for the Treatment of Thrombosed Arteriovenous Dialysis Grafts. 5-Year Experience of 241 Endovascular Procedures. CVIR, 2018
Outcome Measures Primary outcome measure: Circuit Survival. Secondary outcome measures included procedural complications and investigation of independent factors that could influence survival. Kitrou et al., Lysis-Assisted Balloon (LAB) Thrombectomy. A Declotting Technique for the Treatment of Thrombosed Arteriovenous Dialysis Grafts. 5-Year Experience of 241 Endovascular Procedures. CVIR, 2018
Results
Circuit Survival Median Survival: 434 days 54.27% @ 1-year Kitrou et al., Lysis-Assisted Balloon (LAB) Thrombectomy. A Declotting Technique for the Treatment of Thrombosed Arteriovenous Dialysis Grafts. 5-Year Experience of 241 Endovascular Procedures. CVIR, 2018
Complications In 6 cases (6/241, 2.49%) declotting failed and a catheter was placed. There were 16 minor (16/241, 6.64%) and no major complications. Kitrou et al., Lysis-Assisted Balloon (LAB) Thrombectomy. A Declotting Technique for the Treatment of Thrombosed Arteriovenous Dialysis Grafts. 5-Year Experience of 241 Endovascular Procedures. CVIR, 2018
S.G. Vs. No S.G. Median Survival: No SG 406 days vs. SG 349 days; p=0.24 Kitrou et al., Lysis-Assisted Balloon (LAB) Thrombectomy. A Declotting Technique for the Treatment of Thrombosed Arteriovenous Dialysis Grafts. 5-Year Experience of 241 Endovascular Procedures. CVIR, 2018
1 st Vs. 2 nd Declotting Median Survival in 61 patients with 2 procedures 1 st : 162 days vs. 2 nd : 447 days; p<0.0001 Kitrou et al., Lysis-Assisted Balloon (LAB) Thrombectomy. A Declotting Technique for the Treatment of Thrombosed Arteriovenous Dialysis Grafts. 5-Year Experience of 241 Endovascular Procedures. CVIR, 2018
Limitations Single-Center Single-Arm Retrospective Failed to report the time between the event of thrombosis and the time of the procedure Not all interim angioplasty procedures were available and therefore primary patency is not mentioned Kitrou et al., Lysis-Assisted Balloon (LAB) Thrombectomy. A Declotting Technique for the Treatment of Thrombosed Arteriovenous Dialysis Grafts. 5-Year Experience of 241 Endovascular Procedures. CVIR, 2018
Conclusion This hybrid de-clotting method performed in our department has high survival rates with increased technical success and minimum complications without the use of thrombectomy devices. Kitrou et al., Lysis-Assisted Balloon (LAB) Thrombectomy. A Declotting Technique for the Treatment of Thrombosed Arteriovenous Dialysis Grafts. 5-Year Experience of 241 Endovascular Procedures. CVIR, 2018
Analysis Characteristics Review Period: 2001 2017 17 studies 8 prospective, 8 retrospective, 1 partly pro-retro 1,807 patients 3,000 declotting procedures AVGs: 1067 (1067/2009; 53.1%) AVFs: 942 (942/2009; 46.89%)
Statistical Method Study-specific outcomes (and their respective variances) were extracted from the main text and published Kaplan Meier curves at different time points. Quoted survival outcomes and numbers at risk and digitized Kaplan Meier were used to generate individual time-to-event patient data with the methods of Guyot et al. A parametric meta-analysis of the study-specific survival outcomes of the primary endpoint was performed with a multivariate random effects methodology within the R environment (MetaSurv package version 0.4). Guyot P et al. Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves. BMC medical research methodology. 2012 Feb 01;12:9. doi: 10.1186/1471-2288-12-9. Package MetaSurv version 0.4 June 30, 2014. Meta-analysis of a single survival curve using the multivariate methodology of DerSimonian and Laird.
Author (Year) Study Type NoPat NoPro Access Type Procedure Type Special Device CS (%) PR (%) Complications (m/m) Kitrou (2017) Retrospective 129 241 AVG (129) LAB Thrombectomy Balloon Maceration + 5mg rtpa 96.26 52.7 @ 12m 16/0 Bermudez (2017) Retrospective 68 129 AVG (68) M Thrombectomy Angiojet 86 57 @ 12m 6/1 Regus (2017) Retrospective 84 152 AVF (90) Thrombolysis rtpa 2.7 ± 1.2mg 89.5 82 @ 12m N/A/5 Monsky (2016) Prospective 18 18 AVG (15) AVF (3) M Thrombectomy XCOIL (NexGen Medical Systems) 77 N/A 0/0 Dyer (2016) Retrospective 19 27 AVG (14) AVF (13) M Thrombectomy Aspirex (Straub) 81.5 32.77 @ 16m N/A/0 Nassar (2014) Retrospective Partly - Pros 465 520 AVF (465) Thromboaspiration Python (Applied Medical Resources) 91.9 1.88 years 4/3 Simoni (2013) Prospective 72 72 AVG (44) AVF (28) M Thrombectomy Angiojet (Boston Scientific) 92 64.4 @ 3m 2/1 Yang (2012) Retrospective 109 134 AVF (134) M Thrombectomy Angiojet (Boston Scientific) 76 74 @ 12m 0/1 106 141 AVF (106) M Thrombectomy Arrow-Trerotola (Teleflex) 91 87 @ 12m 0/2 Choi (2012) Retrospective 82 279 AVG (82) PM Thrombolysis Urokinase (200,000 IU) 90.25 96 @ 12m 29/0 Vashchenko (2010) Retrospective 157 427 Thrombolysis L&W Urokinase (250,000 IU) N/A 9.6m PP 18/0 AVG (157) 136 M Thrombectomy Arrow-Trerotola (Teleflex) N/A 10.7m PP 4/0 Littler (2009) Prospective 48 64 AVG (20) AVF (44) M Thrombectomy Angiojet (Boston Scientific) 91 62 @ 12m 6/0 Kakkos (2008) Prospective 187 285 AVG (261) AVF (24) M Thrombectomy Angiojet (Boston Scientific) 95.1 30.3 @ 12m 2/0 Uflacker (2004) Prospective 109 140 AVG (109) M Throbectomy Amplatz MTD (Microvena) 79.2 75.2 @ 3m 31/0 Cooper (2003) Prospective 17 17 AVG PS Thrombolysis tpa (2mg) 94 47 @ 3m PP 0/0 Sofocleous (2002) Smits (2002) Prospective Prospective 30 41 PS Thrombolysis tpa (2-10mg) 95 AVG (50) 19 27 Thrombolysis Lyse & Wait tpa(2-10mg) 92.6 63 6/1 13 13 AVG (13) Cragg Thrombolytic Brush 62 44 @ 3m PP 4/1 14 18 AVG (18) M Thrombectomy Hydrolyser (Cordis) 67 33 @ 3m PP 10/1 28 37 AVG (37) Arrow Trerotola (Arrow) 86 40 @ 3m PP 16/0 Falk (2001) Prospective 33 42 AVG (33) Thrombolysis tpa (2mg) 88 50 @ 6m PP 6/2
Outcome Measures Primary outcome measures: Postintervention Assisted Primary Patency (PAPP): defined as the interval of patency after an endovascular intervention until dialysis circuit thrombosis or a surgical intervention of the access circuit Clinical success (CS): defined as the resumption of normal hemodialysis for a minimum of at least 1 session following percutaneous intervention Secondary outcome measures included: Subgroup analysis of independent factors that could influence PAPP Minor and major complications
Results
PAPP 6 months: 54.8% (CI: 44.8-67%) 12 months: 41.6% (CI: 30.4-56.9%) 24 months: 26% (CI: 17-39.7%) Mean PAPP: 10.9 months (CI: 8.5-13.6)
Clinical Success 88% (CI = 85-91%)
Complications Minor: 4.6% (140/3,000) Major: 0.6% (18/3,000)
AVFs Vs. AVGs AVFs: 18.54months (CI: 13.7-21.1) AVGs: 8.09months (CI: 5.6-11.2) p<0.05
Thrombectomy - Thrombolysis Thrombolysis-dependent 9.64months (3.5-18.8) Thrombectomy- dependent 11.6months (9.2-14) p=0.128
Old vs. New studies Old studies 6 m (CI: 4.6-7.5) New studies 7.82 m (6.2-9.4) p=0.098
Conclusion Declotting procedures have significantly better results in AVFs compared to AVGs. Thrombectomy procedures using dedicated devices failed to significantly improve PAPP.
Lysis-Assisted Balloon (LAB) Thrombectomy Panagiotis M. Kitrou MD, MSc, PhD, EBIR Consultant Interventional Radiologist Interventional Radiology Dpt. Patras University Hospital Greece