First-in-human feasibility study of the aXess graft (aXess-FIH): 6-Month results.

OBJECTIVE: The creation of an arteriovenous fistula (AVF) is considered the most effective hemodialysis (HD) vascular access. For patients who are not suitable for AVF, arteriovenous grafts (AVGs) are the best access option for chronic HD. However, conventional AVGs are prone to intimal hyperplasia, stenosis, thrombosis, and infection. Xeltis has developed an AVG as a potential alternative to currently available AVGs based on the concept of endogenous tissue restoration. The results of the first 6-month follow-up are presented here. METHODS: The aXess first-in-human (FIH) study [NCT04898153] is a prospective, single-arm, multicenter feasibility study that evaluates the early safety and performance of the aXess Hemodialysis Graft. A total of 20 patients with end-stage renal disease were enrolled across six European investigational sites. RESULTS: At 6-months follow-up, all grafts were patent with primary and secondary patency rates were 80% and 100%, respectively. Three patients required a re-intervention to maintain graft patency, while one re-intervention was required to restore patency. One graft thrombosis and zero infections were reported. CONCLUSION: The expected advantages of the novel aXess Hemodialysis Graft over conventional AVGs would be evaluated by the analysis on long-term safety and effectiveness during the 5-year follow-up of the currently ongoing trial.

Study protocol of a prospective single-arm multicenter clinical study to assess the safety and performance of the aXess hemodialysis graft: The pivotal study.

BACKGROUND: Arteriovenous grafts (AVGs) are used for patients deemed unsuitable for the creation of an autogenous arteriovenous fistula (AVF) or unable to await maturation of the AVF before starting hemodialysis. However, AVGs are prone to infection and thrombosis resulting in low long-term patency rates. The novel aXess Hemodialysis Graft consists of porous polymeric biomaterial allowing the infiltration by cells and the growth of neotissue, while the graft itself is gradually absorbed, ultimately resulting in a fully functional natural blood vessel. The Pivotal Study will examine the long-term effectiveness and safety of the aXess Hemodialysis Graft. METHODS: The Pivotal Study is a prospective, single-arm, multicenter study that will be conducted in 110 subjects with end-stage renal disease who are not deemed suitable for the creation of an autogenous vascular access. The primary efficacy endpoint will be the primary patency rate at 6 months. The primary safety endpoint will be the freedom from device-related serious adverse events at 6 months. The secondary endpoints will include the procedural success rate, time to first cannulation, patency rates, the rate of access-related interventions to maintain patency, the freedom from device-related serious adverse events and the rate of access site infections. Patients will be followed for 60 months. An exploratory Health Economic and Outcomes Research sub-study will determine potential additional benefits of the aXess graft to patients, health care institutions, and reimbursement programs. DISCUSSION: The Pivotal study will examine the long-term performance and safety of the aXess Hemodialysis Graft and compare the outcome measures with historical data obtained with other graft types and autogenous AVFs. Potential advantages may include superior long-term patency rates and lower infection rates versus currently available AVGs and a shorter time to first cannulation compared to an autologous AVF. As such, the aXess Hemodialysis Graft may fulfill an unmet clinical need in the field of hemodialysis access.

Spontaneous Isolated Bilateral Iliac Artery Dissection in a Patient with Relapsing Polychondritis.

INTRODUCTION: Isolated iliac artery dissection (IAD) is a rare form of arterial dissection. The most commonly known causes of non-traumatic isolated iliac dissection are connective tissue diseases. Relapsing polychondritis (RP) is a rare inflammatory and multisystemic disease, typically affecting cartilage and connective tissue. Cardiovascular complications occur in approximately 25% of patients with RP. CASE DESCRIPTION: The first case of spontaneous isolated bilateral iliac artery dissection in a patient with RP is reported. A 48-year-old woman presented with a two year history of severe right leg intermittent claudication (Rutherford category 3). The complaints were initially attributed to joint pathology associated with RP. However, clinical examination and computed tomography angiography led to a diagnosis of bilateral IAD. A dissection in the left common iliac artery (CIA) began at its origin and ended at the origin of the internal iliac artery, with the true and false lumen both comprising half of the entire lumen. The right CIA was completely occluded from its origin to the origin of the right internal iliac artery. The patient was treated endovascularly by bilateral CIA stent placement with covered stent grafts (Bentley BeGraft), 8 × 57 mm on the right side and 8 × 37 mm on the left. The patient recovered pedal pulses, the stent remained patent, and the patient was asymptomatic at the one month follow-up. DISCUSSION: Early identification of intermittent claudication is necessary to prevent the progression of complications in patients with RP. Vascular surgeons should be aware of IAD as the potential first presentation of underlying systemic disease. Internists should also keep vascular complications in mind in patients with systemic diseases like RP suffering from unexplained complaints in the lower limbs, undertake a basic vascular examination, and make a vascular referral where appropriate.

Hemodialysis catheter design and catheter performance: a randomized controlled trial.

BACKGROUND: A complication of long-term use of tunneled cuffed catheters for hemodialysis is the high rate of infection and thrombus-related dysfunction. Specific mechanical features of tunneled cuffed catheters may improve hemodynamic performance and decrease thrombosis and infection rates. However, there currently is no proven advantage of one design over another. STUDY DESIGN: Single-center randomized clinical trial. SETTING & PARTICIPANTS: 302 hemodialysis patients who required a tunneled cuffed catheter as temporary or definite vascular access. INTERVENTION: Palindrome Symmetric Tip Dialysis Catheter or HemoStar Long-Term Hemodialysis Catheter. OUTCOMES & MEASUREMENTS: The primary end point was primary assisted patency. Secondary end points were incidence of catheter-related bloodstream infections (CRBSIs), thrombosis, and 2 indicators of rheologic function: mean effective blood flow rate and urokinase use. RESULTS: Mean primary assisted patency was 135.9 days for Palindrome and 136.5 days for HemoStar (P=0.8). Definite CRBSI occurred in 0.24 and 0.10/1,000 catheter-days for Palindrome and HemoStar, respectively (P=0.3). Removal rates for thrombosis that could not be resolved with thrombolysis were 0.53 and 0.43/1,000 catheter-days for Palindrome and HemoStar, respectively (P=0.7). Urokinase use was lower for Palindrome than for HemoStar, as evidenced by a lower number of urokinase infusions/1,000 catheter-days (17 and 35; P<0.001) and higher number of catheters that never required thrombolysis (58% and 45%; P=0.03). Mean effective blood flow rate was higher for Palindrome than for HemoStar (333 and 304mL/min; P<0.001). LIMITATIONS: Single-center nonblinded trial. CONCLUSIONS: Primary assisted patency and incidence of infection and thrombosis were similar for both catheter types. The Palindrome catheter required less thrombolysis and achieved higher blood flow rates than the HemoStar catheter. These findings suggest that mechanical catheter design may improve catheter rheology, but does not affect risks for thrombosis and infection and hence catheter survival.

Endograft treatment of ruptured abdominal aortic aneurysms using the Talent aortouniiliac system: an international multicenter study.

OBJECTIVE: To understand the potential of endovascular aneurysm repair (EVAR) in patients presenting with a ruptured abdominal aortic aneurysm (rAAA), the proportion in whom this procedure was applicable was assessed. Mortality and morbidity was also determined in patients treated with emergency EVAR (eEVAR) when anatomic and hemodynamic conditions allowed (ie, in the entire cohort with patients receiving endovascular and open repair combined). In addition, a comparison was made between the treatment group with eEVAR and open repair. METHODS: Between February 2003 and September 2004, 10 participating institutions enrolled a representative sample of 100 consecutive patients in whom eEVAR was considered. Patients in the New Endograft treatment in Ruptured abdominal aortic Aneurysm (ERA) trial were offered eEVAR or open repair in accordance with their clinical condition or anatomic configuration. Written informed consent was obtained from all patients or their legal representatives. The study included patients who were treated by stent-graft technique or by open surgery in the case of adverse anatomy for endoluminal stent-grafting or severe hemodynamic instability, or both. Data were collated in a centralized database for analysis. The study was sponsored and supported by Medtronic, and eEVAR was uniquely performed with a Talent aortouniiliac (AUI) system in all patients. Crude and adjusted 30-day or in-hospital and 3-month mortality rates were assessed for the entire group as a whole and the EVAR and open repair category separately. Complication rates were also assessed. RESULTS: Stent-graft repair was performed in 49 patients and open surgery in 51. No significant differences were observed between these treatment groups with regard to comorbidity at presentation, hemodynamic instability, and the proportion of patients who could be assessed by preoperative computed tomography scanning. Patients with eEVAR more frequently demonstrated a suitable infrarenal neck for endovascular repair, a longer infrarenal neck, and suitable iliac arteries for access than patients with open repair. The primary reason to perform open aneurysm repair was an unfavorable configuration of the neck in 80% of the patients. In patients undergoing eEVAR, operative blood loss was less, intensive care admission time was shorter, and the duration of mechanical ventilation was shorter (P < or = .02, all comparisons). The 30-day or in-hospital mortality was 35% in the eEVAR category, 39% in patients with open repair, and 37% overall. There was no statistically significant difference between the treatment groups with regard to crude mortality rates or rates adjusted for age, gender, hemodynamic shock, and pre-existent pulmonary disease. The cumulative 3-month all-cause mortality was 40% in the eEVAR group and 42% in the open repair group (no significant differences at crude and adjusted comparisons). The 3-month primary complication rate in the two treatment groups was similar at 59%. CONCLUSIONS: In approximately half the rAAA patients, eEVAR appeared viable. An unsuitable infrarenal neck was the most frequent cause to select open repair. In dedicated centers using a Talent AUI system, eEVAR appeared to be a feasible method for treatment of a rAAA. The overall first-month mortality did not differ across treatment groups (patients with endovascular and open repair combined), yet was somewhat lower than observed in a recent meta-analysis reporting on open repair.

Prediction of aortoiliac stent graft length: comparison of a semiautomated computed tomography angiography method and calibrated aortography.

OBJECTIVE: The aim of this study is to compare multislice computed tomography (MSCT) in combination with a newly developed semiautomated software program with calibrated aortography in patients who are scheduled for endovascular aortic stent graft placement. METHODS: From November 2000 until December 2001, seven patients with an abdominal aortic aneurysm (AAA) underwent both calibrated aortography and MSCT for preoperative endovascular stent graft planning. Both studies were performed within 14 days. Further, length measurements were performed with a semiautomated computerized tomographic angiography (CTA) calibration method and a conventional calibrated aortography technique using three differently configured tubes with variable tortuosity. The AAA length measurements of the semiautomated CTA calibration method and the calibrated aortography were compared. RESULTS: Statistical analysis included linear regression analysis and revealed a probability value of 0.000381 and an r2 value of 0.93. Using phantoms, it is proven by the authors that the accuracy of the semiautomated CTA calibration method increases with increasing tortuosity when compared with the conventional calibrated aortography technique. CONCLUSIONS: Our preliminary results show that the semiautomated CTA calibration method has a potentially advantageous role in preoperative stent graft planning regarding the aortic length measurements and seems to be more accurate than calibrated aortography, especially in extremely tortuous vessels. Further studies have to be performed, however.