Initial Clinical Experience: Symmetric-Tip Dialysis Catheter with Helical Flow Characteristics Improves Patient Outcomes.

PURPOSE: To report preliminary clinical experience with a new symmetric-tip dialysis catheter compared with a conventional split-tip catheter. MATERIALS AND METHODS: Over a 5-month period, patients requiring a tunneled catheter for hemodialysis or undergoing exchange of a dysfunctional dialysis catheter at a tertiary academic medical center were retrospectively analyzed. Patients underwent placement of a VectorFlow or Ash Split Cath catheter at the discretion of the inserting interventional radiologist. Patient demographics, catheter patency, mean blood flow rate, and arterial and venous pressures were compared according to catheter type. Catheter failure was analyzed based on clinical and anatomic variables by using a multivariate Cox proportional-hazards model. RESULTS: A total of 33 VectorFlow and 46 Ash Split Cath catheters were placed. Patients in the VectorFlow group had significantly higher body mass index (P = .013) and Charlson Comorbidity Index (P = .049), as well as more non-internal jugular vein placements. At 120 days, 89% of VectorFlow catheters remained functional, compared with 45% of Ash Split Cath catheters (P = .046). The VectorFlow catheter was associated with 16% lower arterial pressures during dialysis (P = .009); mean blood flow rate was equivalent. On multivariate analysis, the risk of catheter failure was 13.3 times higher in the Ash Split Cath group compared with the VectorFlow group (P = .004). Left-sided catheters were also predictive of catheter failure (relative risk = 5.5; P = .02). CONCLUSIONS: The VectorFlow catheter was associated with a significant increase in intervention-free catheter patency compared with the Ash Split Cath catheter, with equivalent flow at lower arterial pressures during dialysis.

Outcomes of percutaneous interventions in transposed hemodialysis fistulas compared with nontransposed fistulas and grafts.

PURPOSE: To compare postpercutaneous intervention outcomes of autogenous venous-transposition arteriovenous fistulas (AVFs) versus those of autogenous nontransposed AVFs (nAVFs) and prosthetic arteriovenous grafts (AVGs). MATERIALS AND METHODS: A total of 591 hemodialysis accesses (195 transposed AVFs [tAVFs], 205 nAVFs, 191 AVGs) in 522 patients (278 male; mean age, 57 y; range, 15­91 y) underwent percutaneous transluminal angioplasty (PTA) and/or mechanical thrombectomy (ie, declotting). Access characteristics, surgical history, percutaneous interventions, postinterventional primary and secondary access patency, and follow-up data were collected. Cox proportional-hazards regression analyses, Fisher exact tests, and χ2 tests were performed. RESULTS: Mean follow-up period was 32 months. Mean access ages at initial percutaneous intervention were 260 days (tAVF), 206 days (nAVF), and 176 days (AVG; P < .01). One-year postinterventional primary patency (PIPP) rates were 25% (tAVF), 24% (nAVF), and 14% (AVG). One-year postinterventional secondary patency (PISP) rates were 77% (tAVF), 61% (nAVF), and 63% (AVG). Median PIPP durations were 138 days (tAVF), 121 days (nAVF), and 79 days (AVG; P = .0001). Median PISP durations were 1,076 days (tAVF), 783 days (nAVF), and 750 days (AVG; P = .019). Total interventions needed to maintain PISP were 2.4 (tAVF), 1.3 (nAVF), and 3.2 (AVG) per patient-year (P < .001), which included 1.9, 1.2, and 1.4 PTAs (P < .01) and 0.45, 0.15, and 1.8 declotting procedures, respectively (P < .001). CONCLUSIONS: Based on the number of percutaneous interventions needed to maintain PISP, these results confirm the current Dialysis Outcomes Quality Initiative access preference of nAVFs before tAVFs before AVGs. tAVFs offered superior postinterventional outcomes than AVGs. With additional interventions, tAVFs could even outperform nAVFs in terms of PISP.

Outcomes of thrombectomy procedures performed in hemodialysis grafts with early failure.

PURPOSE: Percutaneous declotting is usually not offered for hemodialysis access grafts clotting < 30 days after placement because of concerns regarding safety of percutaneous transluminal angioplasty in fresh anastomoses, potential need for surgical correction of the underlying cause, and poor outcomes. The authors sought to determine acute and long-term outcomes of declotting of grafts with early failure. MATERIALS AND METHODS: Of 860 percutaneous mechanical thrombectomies performed between July 2001 and June 2007, 23 were performed in grafts < 30 days after initial placement. In addition, 16 percutaneous thrombectomies performed in grafts 31-60 days after placement were identified. Data collected included medical history, graft characteristics, immediate technical and clinical success, complications, and subsequent graft patency and survival. Kaplan-Meier analysis compared outcomes in grafts < 30 days (U30) versus those 31-60 days (U60) old. RESULTS: There was no difference between the U30 and U60 groups in primary patency (13 vs 19 days, respectively, P = 0.17) or in postintervention access patency (38 vs 189 days, respectively, P = 0.63). A strong trend toward shorter secondary patency in U30 grafts was observed (17 vs 73 days, P = 0.06). Underlying lesions not amenable to percutaneous treatment were found in 62% of U30 grafts and 33% of U60 grafts (P = 0.18). Neither group achieved the K/DOQI Guidelines' recommended 85% technical success or 40% 90-day primary patency; in the U30 group it was 0% and in the U60 group 17%. CONCLUSIONS: Percutaneous declotting of grafts yields poor outcomes, well below the K/DOQI threshold not only within 30 days but also within 60 days of placement.