The value of intravascular ultrasound in the treatment of central venous obstructions in hemodialysis patients.

INTRODUCTION: Digital subtraction angiography (DSA) is the gold standard in diagnosis and treatment of central venous obstructions (CVOs) in hemodialysis access. However, growing data suggest that DSA might underestimate the degree and morphology of venous outflow stenosis. This could lead to inappropriate CVO management. Intravascular ultrasound (IVUS) has been shown to identify lesion characteristics remaining obscure with angiography. With the current study we suggest IVUS as an eminent imaging modality in CVO management. METHODS: Twelve patients (8 male, mean age 62.4 ± 9 years) were analyzed for suspicion of symptomatic CVO. Both angiography and IVUS evaluation were performed to determine the degree of obstruction before and after PTA. Stent placement was indicated when significant residual stenosis (>50% lumen reduction) was suspected. RESULTS: Conventional plain angiography determined 8 out of 12 central venous lesions significant. Secondary signs of obstruction, i.e., collateral filling, was present in all 12 cases. After PTA, persistent significant stenosis was observed in 3 out of 12 patients. IVUS showed significant lumen reduction in all 12 cases. Additionally, IVUS showed a median cross-sectional area of 24 ± 12 mm2 before PTA and 37 ± 23 mm2 after PTA (NS). Furthermore, IVUS showed signs of intraluminal fibrotic trabeculations in 9 patients. Stenting was performed in 10 patients with >50% lumen reduction on IVUS after PTA. CONCLUSIONS: Conventional angiography seems unreliable to identify all significant aspects of a central venous outflow obstruction. Additional use of IVUS might aid in the decision-making process and select the optimal treatment strategy.

Peritoneal dialysis in centenarian patients: no age limitation?

BACKGROUND: The majority of dialysis patients are elderly, and the trend towards even more elderly people with end-stage renal disease (ESRD) will further determine the dialysis field in the future. METHOD: If these elderly ESRD patients do not opt for conservative ESRD care, they may still qualify for peritoneal dialysis (PD), which may be assisted or unassisted. RESULTS: Although they may be more frail and have a greater co-morbidity burden compared to their younger counterparts, elderly patients with ESRD may still be able to maintain a good functionality level with adequate quality of life by performing PD, which may be assisted (treatment performed or supported e.g. by partner or nurse) or unassisted (without support). PD may indeed further contribute to maintaining autonomy, and enhance quality of life compared to in-center conventional hemodialysis. In order to illustrate this strategy, we hereby describe a centenarian patient with ESRD who received assisted PD successfully. CONCLUSIONS: With appropriate management and infrastructure, (very) high age is not a contra-indication for PD.

Diagnostic algorithms and treatment strategies in primary aortic and aortic graft infections.

Aortic infections and aortic graft infections are one of the most dreadful clinical entities that a vascular surgeon can face. Clinical presentation of the patient can vary greatly and diagnosis can be difficult to make. In this manuscript, diagnostic modalities are reviewed and a diagnostic algorithm suggested. Further, results of present treatment options are evaluated and treatment strategies for different clinical scenarios suggested.

Hemodialysis vascular access management in the Netherlands.

PURPOSE: In the Netherlands, 86% of patients start renal replacement therapy with chronic intermittent hemodialysis (HD). Guidelines do indicate predialysis care and maintenance of a well-functioning vascular access (VA) as critical issues in the management of the renal failure patient. Referral to the surgeon and time to VA creation are important determinants of the type and success of the VA and HD treatment. METHODS AND RESULTS: Data from a national questionnaire showed that time from referral to the surgeon and actual access creation is <4 weeks in 43%, 4 to 8 weeks in 30% and >8 weeks in 27% of the centers. Preoperative ultrasonography and postoperative access flowmetry are the diagnostic methods in the majority of centers (98%). Most facilities perform rope-ladder cannulation with occasionally the buttonhole technique for selected patients in 87% of the dialysis units. Endovascular intervention for thrombosis is practiced by 13%, surgical thrombectomy by 21% and either endovascular or surgery by 66% of the centers. Weekly multidisciplinary meetings are organized in 57% of the units. Central vein catheters are inserted by radiologists (36%), nephrologists and surgeons (32%). CONCLUSIONS: We conclude that guidelines implementation has been successful in particular regarding issues as preoperative patient assessment for VA creation and postoperative surveillance in combination with (preemptive) endovascular intervention, leading to very acceptable VA thrombosis rates.

Surgical or endovascular repair of thrombosed dialysis vascular access: is there any evidence?

INTRODUCTION: Endovascular and surgical strategies have been used to manage patients with thrombosed vascular access for hemodialysis. We analyzed the evidence to see whether endovascular or surgical treatment has the best outcome in terms of primary success rate and long-term patency. METHODS: We performed a systematic literature search of endovascular and surgical repair of thrombosed hemodialysis vascular access. The analysis included meta-analysis, randomized, and population-based studies of thrombosed arteriovenous fistulae and grafts. RESULTS: One meta-analysis and eight randomized studies on the treatment of arteriovenous graft thrombosis were identified. Studies conducted before 2002 demonstrated a significantly better primary success rate and primary and secondary patencies of surgical thrombectomy vs endovascular intervention. After 2002, similar results of both techniques have been reported. Only population-based studies on the treatment of thrombosed autogenous arteriovenous fistulae have been published, showing similar outcome of surgical and endovascular intervention in terms of primary success. The long-term primary and secondary patencies are slightly better for surgical treatment, but this concerns only forearm fistulae. CONCLUSIONS: The outcome of endovascular and surgical intervention for thrombosed vascular access is comparable, in particular for thrombosed prosthetic grafts. Surgical treatment of autogenous arteriovenous fistulae is likely to have benefit compared with endovascular means. Definitive randomized trials are needed to provide the level 1 evidence to resolve this latter issue.

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.

Emergency endovascular treatment for ruptured abdominal aortic aneurysm and the risk of spinal cord ischemia.

BACKGROUND: Spinal cord ischemia is a rare complication after open surgical repair for ruptured abdominal aortic aneurysms (rAAA). The use of emergency endovascular aortic aneurysm repair (eEVAR) is increasing, and paraplegia has been observed in a few patients. The objective of this study was to assess the incidence and pathogenesis of spinal cord ischemia after eEVAR in greater detail. METHODS: This was a retrospective analysis of patients who had eEVAR for rAAA in three hospitals in The Netherlands and Belgium during a 3-year study period that ended in February 2004. The use of aortouniiliac devices combined with a femorofemoral crossover bypass was the preferred technique. Patients with postoperative symptoms of spinal cord ischemia were identified and the influence of potential risk factors was assessed. These factors included the presence of common iliac artery aneurysms necessitating device limb extension to the external iliac artery with associated overlapping the hypogastric artery, the prolonged interruption of bilateral hypogastric artery arterial inflow during the procedure (defined "functional aortic occlusion time" >30 minutes), and the occurrence of preoperative hemodynamic shock. RESULTS: Thirty-five patients were treated by EVAR and they constituted the study group. The first-month mortality in the study group with EVAR was 23%. Four patients (11.5%) with EVAR developed paraplegia postoperatively; the unilateral or bilateral hypogastric artery in all four patients became occluded during the procedure. In the other 31 patients who did not have paraplegia, the unilateral or bilateral hypogastric arteries became occluded in 14 patients (45%). This constituted a significant difference in the prevalence of hypogastric artery occlusion in patients with or without paraplegia (P = .04). The functional aortic occlusion time was prolonged in all four patients with paraplegia and in five without spinal cord ischemia (P = .0003). All four patients with spinal cord ischemia presented with hemodynamic shock. This factor did not reach a significant difference from nonparaplegic patients. CONCLUSION: Emergency EVAR continues to be a promising approach to reduce the high mortality of rAAA, but the incidence of spinal cord ischemia after endovascular treatment of rAAA was worrisome. Although the pathogenesis is most likely multifactorial, interruption of the hypogastric artery inflow appeared to have significant influence. In patients with aneurysmatic common iliac arteries, any effort should be made to minimize hypogastric occlusion time during the procedure and to maintain hypogastric artery inflow afterwards, either by the use of a bell-bottom iliac extension or by electing open repair.

Diameter of abdominal aortic aneurysm and outcome of endovascular aneurysm repair: does size matter? A report from EUROSTAR.

OBJECTIVES: This study was undertaken to determine the effect of the preoperative diameter of abdominal aortic aneurysms on the midterm outcome after endovascular abdominal aneurysm repair (EVAR). METHOD: The data for 4392 patients who had undergone EVAR were analyzed. Patients were enrolled over 6 years to June 2002 in the EUROSTAR database. Outcomes were compared between three groups defined by the preoperative diameter of the aneurysm: group A (n = 1962), 4.0 to 5.4 cm; group B (n = 1528), 5.5 to 6.4 cm; and group C (n = 902), 6.5 cm or larger. Patient characteristics, details of aortoiliac anatomy, operative procedures, old or current device generation, and postoperative complications in the three patient groups were compared. Outcome events included aneurysm-related death, unrelated death, conversion, and post-EVAR rupture of the aneurysm. Life table analysis and log-rank tests were used to compare outcome in the three study groups. Multivariate Cox models were used to determine whether baseline and follow-up variables were independently associated with adverse outcome events. RESULTS: Patients in group C were significantly older than patients in groups A and B (73 years vs 70 and 72 years, respectively; P =.003 - P <.0001 for different group comparisons), and more frequently were at higher operative risk (American Society of Anesthesiologists classification >or=3; 63% vs 48% and 54%; P =.0002-P <.0001). Device-related (type I) endoleaks were more frequently observed at early postoperative arteriography in group C compared with groups A and B (9.9% vs 3.7% and 6.8%; P =.01-P <.0001). Postoperatively systemic complications were more frequently present in group C (17.4% vs 12.0% in group A and 12.6% in group B; P <.0001 and.001). The first-month mortality was approximately twice as high in group C compared with the other groups combined (4.1% vs 2.1%; P <.0001). Late rupture was most frequent in group C. Follow-up results at midterm were less favorable in groups C and B compared with group A (freedom from rupture, 90%, 98%, and 98% at 4 years in groups C, B, and A, respectively; P <.0001 for group C vs groups A and B). Aneurysm-related death was highest in group C (88% freedom at 4 years, compared with 95% in group B and 97% in A; P =.001 and P <.0001, respectively; group B vs A, P =.004). The annual rate of aneurysm-related death in group C was 1% in the first 3 years, but accelerated to 8.0% in the fourth year. Incidence of unrelated death also was higher in groups C and B than in group A (76% and 82% freedom at 4 years vs 87%; P <.0001 for both comparisons). Ratio of aneurysm-related to unrelated death was 23%, 21%, and 50% in groups A, B, and C, respectively. Cox models demonstrated that the correlation between large aneurysms (group C) and all assessed outcome events was independent and highly significant. Older generation devices had an independent association with aneurysm-related and unrelated deaths (P =.02 and P =.04, respectively). However, this correlation was less strong than large aneurysm diameter (P =.0001 and P =.0009, respectively). CONCLUSIONS: The midterm outcome of large aneurysms after EVAR was associated with increased rates of aneurysm-related death, unrelated death, and rupture. Reports of EVAR should stratify their outcomes according to the diameter of the aneurysm. Large aneurysms need a more rigorous post-EVAR surveillance schedule than do smaller aneurysms. In small aneurysms EVAR was associated with excellent outcome. This finding may justify reappraisal of currently accepted management strategies.

Emergency treatment of symptomatic or ruptured abdominal aortic aneurysms: the role of endovascular repair.

PURPOSE: To report the initial experience with endovascular aortic repair (EVAR) in patients with ruptured or symptomatic abdominal aortic aneurysms (AAA) and to compare the results with conventional open surgery. METHODS: Between May 1999 and December 2001, 24 patients (21 men; mean age 75 years, range 56-89) with ruptured or symptomatic AAA underwent EVAR using a specially designed aortomonoiliac endograft. Six patients were selected based on device and operator availability; the subsequent 18 patients were treated under a modified management protocol that offered stent-graft repair to all symptomatic AAA patients. The results of this new treatment protocol were analyzed on an intention-to-treat basis for the last 8 months of the study. The 30-day outcomes in all patients treated with emergency EVAR were compared with 40 consecutive, contemporaneous patients undergoing open surgery for symptomatic or ruptured AAA. RESULTS: No early conversions to open surgery were performed. Significantly decreased operative blood loss and intensive care stay (p<0.05 for both) were observed in EVAR patients. The mortality rate for EVAR patients was 17% compared to 32% in conventionally treated patients (NS). Among patients with ruptured AAA, the 30-day mortality rates were 24% (4/17) and 41% (12/29) for EVAR and open surgery, respectively (NS). Of 26 unselected patients who were treated prospectively under the modified protocol, the majority (81%, 21/26) had anatomy suitable for endovascular repair; however, only 18 (69%) underwent EVAR owing to a short infrarenal neck (n=2) or device/operator unavailability (n=6). CONCLUSIONS: EVAR is a feasible treatment in the majority of patients with ruptured or symptomatic AAA. The 30-day mortality appears to be similar between conventionally treated patients and those undergoing endovascular repair.