Use of the Viabahn stent graft for the treatment of recurrent cephalic arch stenosis in hemodialysis accesses.

OBJECTIVE: Cephalic arch stenosis (CAS) is a frequent and challenging failure mode of brachiocephalic fistulas. Natural tortuosity of the cephalic arch requires special consideration in selecting a treatment modality. Typical percutaneous angioplasty and bare-metal stent (BMS) treatments provide a short-term treatment solution for CAS without a durable effect. This study assessed Viabahn (W. L. Gore & Associates, Flagstaff, Ariz) stent grafts (SGs) as a first-line percutaneous option to provide a durable treatment for CAS. METHODS: SG data were collected at a free-standing physician office between July 10, 2009, and January 26, 2011. A single-arm, prospective, observational study was conducted of 50 consecutive CAS patients treated with angioplasty followed by deployment of Viabahn SGs. Outcomes included target lesion primary patency and reintervention rates as well as secondary access patency. Results were compared with historic cohorts of percutaneous balloon angioplasty (N = 50) and angioplasty followed by BMS deployment (N = 50). The cohorts were treated between May 5, 2005, and May 20, 2010, and assessed in chronologic order. RESULTS: The SG cohort target lesion primary patency reported at 3, 6, and 12 months was 90% ± 7%, 74% ± 12%, and 60% ± 14% (±95% confidence interval), respectively. Compared with historic cohorts, the SG cohort demonstrated statistically superior target lesion primary patency (P < .001), with a reduced reintervention rate per access-year (P < .001). Secondary access patency was statistically superior compared with the percutaneous balloon angioplasty cohort (P = .034) but not statistically different from the BMS cohort when assessed during a 2.5-year period. The secondary access patency for the SG cohort at 5 years was 80% ± 15%. CONCLUSIONS: In treatment of a CAS, the Viabahn SG study group demonstrated superior target lesion primary patency and required fewer subsequent interventions compared with historic cohorts treated with angioplasty or angioplasty followed by BMS placement. Given the significant improvement in target lesion primary patency, future studies should challenge Viabahn SGs as a primary percutaneous treatment modality vs durable surgical alternatives.

Sharp needle recanalization for salvaging hemodialysis accesses with chronically occluded peripheral outflow.

PURPOSE: To assess the effectiveness of sharp needle recanalization (SNR) for treatment of chronically occluded venous outflow in hemodialysis access. METHODS: A retrospective analysis of patient records from January 2006 to March 2010 was conducted. Forty-four hemodialysis patients (31 fistulas, 13 grafts) were referred for arm swelling (18%), excessive bleeding after dialysis (29%), and thrombosis (53%). All patients had chronic occlusion of the outflow vein which failed conventional recanalization techniques. A new outflow pathway was established by advancing a 21g needle and dilating the subcutaneous tract to bridge the fistula body to a juxtaposed patent vein. If necessary, uncovered or covered stents were utilized to maintain patency of the newly formed subcutaneous tract. RESULTS: Forty-four patients underwent 45 SNR procedures, with restoration of normal function and complete relief of symptoms in 40 (91%) patients. The average tract length was 15 mm (range, 1 to 32) and the average dilatation diameter was 8 mm. During the initial SNR procedure, bare metal (n=21) or covered (n=5) stents were inserted in 26 patients. The average follow-up was 18.4 months (range, 0.2 to 48 months). No major complications were observed with the procedure. At 12 months, the primary access, primary tract, and secondary access patencies were 10%, 51%, and 92%, respectively. Percutaneous thrombectomy procedures were performed at a rate of 1.16 per access-year and the number of interventions within the tract was 0.94 per access-year. CONCLUSIONS: Sharp needle recanalization is an effective percutaneous treatment for restoring function to hemodialysis accesses with chronically occluded venous outflow pathways.

Percutaneous salvage of thrombosed immature arteriovenous fistulas.

Thrombosed immature fistulas have historically been considered unsalvageable. However, advances in procedure and balloon catheter technologies have expanded the scope of endovascular treatments. This study investigates the efficacy, functionality, and cost associated with the use of percutaneous techniques for the salvage of thrombosed immature fistulas. Over a 2-year period and from a population of 18,000 patients on hemodialysis, 140 consecutive patients with thrombosed immature fistulas underwent attempts at salvage via thrombectomy procedures. All fistulas had thrombosed following access creation and had never been used for hemodialysis. Multiple approaches were utilized to gain access to the fistula, including trans-fistula cannulation, distal arterial puncture, and proximal retrograde venous access. Thrombectomy was performed via balloon maceration and aspiration. Accelerated maturation was achieved through sequential angioplasty of diffusely stenotic veins and elimination of competing branch vessels. Primary access, primary assisted, and secondary access patencies were calculated at 3, 6, 12, and 24 months. A cost analysis was performed based on procedure statistics and the 2009 Medicare reimbursement schedule and compared with data from the 2009 United States Renal Data Survey. Thrombectomy was successful in 119 (85%) immature clotted fistulas, and hemodialysis adequacy was achieved in 111 (79%) fistulas. The average maturation time from thrombectomy to cannulation for dialysis was 46.4 days, with an average of 2.64 interventions per patient. There were 5 (3.5%) cases of angioplasty-induced rupture, all of which were treated with stent placement. Clinically significant pseudoaneurysm formation occurred in 4 (2.8%) patients. At 12 months, secondary access patency of salvaged accesses was 90%. Based on 2009 Medicare outpatient billing rates per patient per initial access-year and the maturation times observed in the New York area, percutaneous salvage of thrombosed immature fistulas costs $4881 to $14,998 less than access abandonment and new access creation. Endovascular techniques can be used for the salvage of thrombosed nonmaturing fistulas. When analyzed within the initial access-year, this approach yields significant cost savings over access abandonment.

Access flow reduction and recurrent symptomatic cephalic arch stenosis in brachiocephalic hemodialysis arteriovenous fistulas.

BACKGROUND: Recurrent cephalic arch stenosis (CAS) has been linked to high flow and has a high rate of recurrence following angioplasty. This study investigates the effectiveness of access flow reduction in decreasing rapidly recurrent symptomatic CAS. METHODS: A retrospective study of patient records from February 2005 to April 2009 was conducted. Patients with brachiocephalic fistulas who had undergone two or more instances of cephalic arch angioplasty within 3 months, and thereafter underwent flow reduction via banding of the access inflow (n=33) were included. A before-and-after analysis was conducted: the rates of cephalic arch angioplasty were calculated for each patient before and after the banding procedure, and compared via a paired t-test. RESULTS: At 3, 6, and 12 months, the cephalic arch primary lesion patency was 91%, 76%, and 57%. The cephalic arch intervention rate was reduced from 3.34 to 0.9 per access-year (t=7.74, p<.001). The average follow-up time was 14.5 months (range, 4.8-32). CONCLUSION: Flow reduction of a brachiocephalic arteriovenous hemodialysis fistula may effectively diminish the incidence of symptomatic CAS.

Long thoracic vein embolization for the treatment of breast edema associated with central venous occlusion and venous hypertension.

PURPOSE: Breast edema is a rare complication in hemodialysis patients with central venous occlusions. The present study sought to determine whether coil embolization of the long thoracic vein is an effective long-term treatment for this pathology. METHODS: The study patients were 6 female hemodialysis patients whose primary clinical manifestation of central vein occlusion was breast edema. When conservative treatment (allowing collaterals to dilate over time), as well as recanalization of occlusions through angioplasty with or without stent placement, failed to alleviate symptoms, patients underwent coil embolization of the long (lateral) thoracic vein. RESULTS: In 4 of the 6 cases, the breast edema was completely resolved without recurrence, while the other 2 patients experienced durable symptomatic improvement with only mild residual swelling. Average follow-up was 22 months. There were no adverse sequelae and none of the patients experienced increased swelling elsewhere following the coil embolization procedure. CONCLUSIONS: Coil embolization of the long thoracic vein effectively alleviates breast edema in hemodialysis patients with elevated venous hydrostatic pressure due to central venous occlusions.

The MILLER banding procedure is an effective method for treating dialysis-associated steal syndrome.

We evaluated the efficacy of the Minimally Invasive Limited Ligation Endoluminal-Assisted Revision (MILLER) banding procedure in treating dialysis-associated steal syndrome or high-flow access problems. A retrospective analysis was conducted, evaluating banding of 183 patients of which 114 presented with hand ischemia (Steal) and 69 with clinical manifestations of pathologic high access flow such as congestive heart failure. Patients were assessed for technical success and symptomatic improvement, primary and secondary access patency, and primary band patency. Overall, 183 patients underwent a combined 229 bandings with technical success achieved in 225. Complete symptomatic relief (clinical success) was attained in 109 Steal patients and in all high-flow patients. The average follow-up time was 11 months with a 6-month primary band patency of 75 and 85% for Steal and high-flow patients, respectively. At 24 months the secondary access patency was 90% and the thrombotic event rates for upper-arm fistulas, forearm fistulas, and grafts were 0.21, 0.10, and 0.92 per access-year, respectively. Hence, the minimally invasive MILLER procedure appears to be an effective and durable option for treating dialysis access-related steal syndrome and high-flow-associated symptoms.

Aggressive approach to salvage non-maturing arteriovenous fistulae: a retrospective study with follow-up.

PURPOSE: To establish a standardized approach for the maturation of non-maturing arteriovenous fistulae. METHODS: Consecutive patients (n=122) with non-maturing fistulae presented to our outpatient vascular access center for percutaneous interventions to assist in maturation. The techniques used included flow rerouting, competing branch vein elimination, staged balloon angioplasty, and limited controlled extravasation. RESULTS: Successful fistula maturations were achieved in 118/122 patients. Fistulae were divided into two classes according to initial vessel size: class 1 (6.0-8.0 mm diameter, >6 mm deep) and class 2 (2.0-5.0 mm diameter) fistulae were evaluated for differences in technical procedures and clinically successful fistula maturation. Class 1 and class 2 fistulae were evaluated for mean number of procedures to maturation (1.6 and 2.6, respectively), and time to maturation (5 and 7 weeks, respectively). Follow-up for 109 of the initial 118 patients was achieved (mean=24 months, range=0.25-60 months). Class 1 and class 2 fistulae had primary patencies of 17 and 39% at 6 months; and secondary patencies of 72 and 77% at 12 months, 53 and 61% at 24 months, and 42 and 32% at 36 months, respectively. Primary and secondary patencies (Mann-Whitney test, p=0.44 and p=0.38, respectively) of class 1 and class 2 fistulae did not differ significantly, and secondary patencies were comparable to other fistula salvage studies. CONCLUSION: Fistula salvage attempts should not be limited by factors such as a diffusely small diameter or an inaccessibly deep position.

Critical care of the obese and bariatric surgical patient.

Obesity is associated with a chronic inflammatory state that predisposes to atherogenesis, thrombogenesis, and carcinogenesis and may increase susceptibility to infections. Critically ill, obese patients have higher mortality. MOF is the best predictor of ICU mortality for obese patients. Pulmonary hypertension and higher BMI are associated with higher surgical risk. Progress in surgical technique and anesthesia has substantially improved the safety of performing operations in severely obese patients.