Good outcomes for arteriovenous fistula with buttonhole cannulation for chronic hemodialysis in children and adolescents.

BACKGROUND: Arteriovenous fistula (AVF) is the preferred access for chronic hemodialysis (HD) in children and adolescents, but central venous catheter use is still high. METHODS: Retrospective chart review of children and adolescents with AVF created between January 2003 and December 2015 was performed to assess primary failure (PF), maturation time, functional primary and functional cumulative patency, and potential risk factors for AVF dysfunction. RESULTS: Ninety-nine AVF were created in 79 patients (54% male; 7-24 years; 16-147 kg) by experienced surgeons. Duplex ultrasonography vein mapping was used to assist with site selection. PF occurred in 17 AVF (17%) in 14 patients. Patient age, gender, ethnicity, underlying disease, time on dialysis, and AVF site were not associated with PF or patency. Coagulation abnormality was positively associated with PF (p = 0.03). Function was achieved in 82 AVF (83%) in 77 patients (97%). Median maturation time was 83 days (range 32-271). AVF were accessed via buttonholes. Functional primary patency was 95%, 84%, and 53% at 1, 2, and 5 years. Overall 1- and 2-year functional cumulative patency was 95%, but lower for small patients 16-30 kg (88%) and those greater than 80 kg (91%). The 5-year patency rate was 80%, but significantly lower for 16-30 kg (59%) and greater than 80 kg (55%). Risk analysis showed significantly better patency for 31-45 kg and 46-80 kg groups (p < 0.01), non-obese BMI (p = 0.01), and buttonhole self-cannulation (p = 0.03). CONCLUSIONS: This study provides more information about successful AVF with buttonhole cannulation in pediatric hemodialysis patients lending additional support for AVF use in pediatrics. A higher resolution version of the Graphical abstract is available as Supplementary information.

Diseases of the thoracic aorta in women.

Women have now equaled or surpassed men in the number of cardiovascular deaths per year in published statistics. In 2006, according to the National Center for Health Statistics and the Center for Disease Control, cardiovascular disease was the cause of death in 428,906 women (35% of all deaths in women) and in 394,840 men (33% of all deaths in men). Of those numbers, it was estimated that 5506 women (0.4% of all deaths in women) and 7732 men (0.6%) died because of aortic aneurysm or dissection. Currently, aortic disease ranks as the 19th leading cause of death with reported increases in incidence. Historically, aortic disease is thought to affect men more frequently than women with a varying reported gender ratio. Gender bias has long been implicated as an important factor, but often overlooked, in the analysis and interpretation of cardiovascular diseases outcome, in part, because of the under-representation of women in clinical trials and studies. In this section, we provide an up-to-date review of the epidemiology and management of common diseases of the thoracic aorta, focusing on the differences and similarities in women and men.

Imaging work-up and endovascular treatment options for aorto-enteric fistula.

Aorto-enteric fistula (AEF) is a rare life-threatening condition. Early recognition and diagnosis are of paramount importance to improve outcome. In this article four cases of AEF with relevant pre- and post-procedural images are presented to demonstrate the utility of cross-sectional imaging in the work-up of AEF. The literature is reviewed to describe the typical presentation of AEF, the diagnostic work-up of AEF, and the different methods used to treat AEF. Endovascular repair of AEF is gaining increasing attention due to its decreased short-term mortality compared to open surgical techniques.

Multilevel somatosensory evoked potentials and cerebrospinal proteins: indicators of spinal cord injury in thoracoabdominal aortic aneurysm surgery.

OBJECTIVE: Multilevel somatosensory evoked potentials (SSEP) and the release of biochemical markers in cerebrospinal fluid (CSF) were investigated to identify patients with spinal cord ischemia during thoracoabdominal aortic repair and/or a vulnerable spinal cord during the postoperative period. METHODS: Thirty-nine consecutive patients undergoing elective aneurysm repair using distal aortic perfusion and cerebrospinal fluid drainage were studied. Continuous SSEP were monitored using nerve stimulation of the right and left posterior tibial nerves with signal recording at the level of both common peroneal nerves, the cervical cord and at the cortical level. CSF concentrations of the markers glial fibrillary acidic protein (GFAp), the light subunit of neurofilament triplet protein (NFL), and S100B were determined at different time points from before surgery until 3 days postoperatively. RESULTS: SSEP indicated spinal cord ischemia in two patients leading to additional intercostal artery reattachments. In one of them the signal loss was permanent and the patient woke up with paraplegia. In the other the signal returned but the patient later developed delayed paraplegia. Three patients without SSEP indications of spinal cord ischemia during surgery later developed delayed paraplegia. The patients with spinal cord symptoms had significant increases, during the postoperative period of CSF biomarkers GFAp (571-fold), NFL (14-fold) and S100B (18-fold) compared to asymptomatic patients. GFAp increased before or in parallel to onset of symptoms in the patients with delayed paraplegia. CONCLUSIONS: Peroperative multilevel SSEP has a high specificity in detecting spinal cord ischemia but does not identify all patients with a postoperative vulnerable spinal cord. Biochemical markers in CSF increase too late for intraoperative monitoring but GFAp is promising for identifying patients at risk for postoperative delayed paraplegia.

Nonmaturing Fistulae: Epidemiology, Possible Interventions, and Outcomes.

Autogenous arteriovenous fistulae are the best method for prolonged, successful dialysis access. However, a substantial limitation of dialysis fistulae is their high primary failure rate, estimated to be as high as 70% for radiocephalic fistulae. Fistula maturation is influenced by demographic risk factors as well as anatomical barriers, the latter of which can be readily identified by noninvasive ultrasound imaging and physical examination. These barriers can be categorized as inflow problems (native arterial disease, arteriovenous anastomotic stenosis, and juxta-anastomotic stenosis) or outflow problems (proximal venous stenosis or collateral veins). Venous stenoses represent the most commonly observed barrier to fistula maturation. By treating these barriers with a systematic approach, interventionalists can significantly improve the likelihood of a fistula's usability for dialysis.

Cerebral monitoring with transcranial Doppler ultrasonography improves neurologic outcome during repairs of acute type A aortic dissection.

OBJECTIVE: Neurologic complications after repair of acute type A aortic dissection remain significant. The use of power M-mode transcranial Doppler monitoring to verify cerebral blood flow during these repairs might decrease cerebral ischemia by correcting malperfusion. The purpose of this study was to analyze the use of power M-mode transcranial Doppler monitoring during repairs of acute type A dissection with regard to neurologic outcome. METHODS: We performed a prospective study of patients undergoing repairs of acute type A aortic dissection. Repairs included profound hypothermic circulatory arrest and retrograde cerebral perfusion. Patients in whom transcranial Doppler monitoring was used to monitor cerebral blood flow and modify operative technique during repair (study group) were compared with those without monitoring and modification (control group). RESULTS: Between September 2001 and October 2003, we repaired 56 cases of acute type A dissection. Power M-mode transcranial Doppler monitoring was used in 50% (28/56) of cases. Power M-mode transcranial Doppler monitoring altered operative cannulation and guided retrograde cerebral perfusion flow in 28.5% (8/28) and 78.6% (22/28) of cases, respectively. Two patients presented with preoperative stroke, one in each group. One operative death occurred in each group. In-hospital mortality and the occurrence of new stroke were not significantly different between the 2 groups. Temporary neurologic dysfunction occurred less often in the study group (14.8% [4/27] vs 51.8% [14/27], P = .008). CONCLUSIONS: Identification of cerebral malperfusion requires cerebral monitoring. By ensuring cerebral blood flow by using power M-mode transcranial Doppler monitoring and correcting cerebral malperfusion by modifying operative technique, neurologic outcome was improved during repairs of acute type A aortic dissection.

Surgical repair of extensive aortic aneurysms.

We present our 14-year experience in the management of extensive aortic aneurysms. Significant progress has been made in reducing the morbidity and mortality associated with these procedures. Our strategies for organ protection, operative techniques, including the elephant trunk technique, and surgical results are discussed.

Preoperative and operative predictors of delayed neurologic deficit following repair of thoracoabdominal aortic aneurysm.

PURPOSE: Delayed neurologic deficit has been recognized in recent years as a source of morbidity following thoracic and thoracoabdominal aortic repair. We wanted to find risk factors specifically significant for delayed neurologic deficit. In this initial study we looked at preoperative and operative risk factors. METHODS: We performed 854 thoracoabdominal aortic repairs between February 1991 and May 2001. For this study we excluded 26 patients who died before postoperative neurologic status could be evaluated and 38 who had immediate neurologic deficit on initial postoperative evaluation, leaving 790 consecutive patients. We evaluated a wide range of demographic, preoperative physiological and intraoperative data, using univariate and multivariable statistical analyses. RESULTS: Twenty-one of 790 (2.7%) patients had delayed neurologic deficit. Significant univariate predictors included preoperative renal dysfunction (odds ratio 5.9; P <.006), acute dissection (odds ratio 3.9; P <.05), extent II thoracoabdominal aorta (odds ratio 3.0; P <.03), and use of adjuncts (cerebrospinal fluid drainage and distal aortic perfusion; odds ratio 7.7; P <.03). The use of the adjuncts dropped from the multivariable model but all other factors remained. No other significant risk factors were identified. Twelve of 21 (57%) patients recovered neurologic function with optimization of blood pressure and cerebrospinal fluid drainage. CONCLUSION: Preoperative renal dysfunction, acute dissection, and extent II thoracoabdominal aorta are significant predictors of delayed neurologic deficit. Previous studies have demonstrated that the use of adjuncts protects against immediate neurologic deficit. The findings of this study are consistent with the hypothesis that adjuncts reduce ischemic insult enough to prevent immediate neurologic deficit but that a period of increased spinal cord vulnerability persists several days postoperatively.

Replacement of the ascending and transverse aortic arch: determinants of long-term survival.

BACKGROUND: Although little has been published on the natural history of aneurysms of the ascending aorta and aortic arch, long-term prognosis of untreated aneurysms is generally poor. We reviewed our 10-year experience in the repair of the ascending aorta and aortic arch to evaluate long-term outcome. METHODS: Between January 1991 and May 2001, we repaired 423 aneurysms of the ascending aorta or aortic arch using profound hypothermic circulatory arrest. Median age was 65 years. Retrograde cerebral perfusion (RCP) was used in 357 cases. Mean pump and RCP times were 139 and 33.9 minutes, respectively. Survival was ascertained by direct patient contact or by searching the social security death index. Survival was analyzed by Kaplan-Meier stratified analysis and by multivariate Cox regression. RESULTS: Overall actuarial survival was 72% at 5 years and 71% at 10 years after surgery. Univariate analysis identified increasing age (p < 0.0001), chronic obstructive pulmonary disease (p < 0.014), concurrent unoperated aneurysm (p < 0.005), arch involvement (p < 0.042), pump time (p < 0.0004), concurrent aortic valve replacement (p < 0.009), and postoperative renal failure (p < 0.0002) as factors that negatively influenced survival. Multivariate analysis identified increasing age (p < 0.0001) and pump time (p < 0.0001). RCP did not have a significant independent effect on the long-term survival. CONCLUSIONS: Our experience indicates that repair of the ascending aorta and aortic arch can be accomplished with good long-term survival.

Staged repair of extensive aortic aneurysms.

BACKGROUND: We adopted a two-stage approach (elephant trunk procedure) in the repair of extensive aortic aneurysms in 1991, performing 241 procedures in 155 patients. METHODS: Reversed elephant trunk (graft replacement of the descending thoracic aorta followed by ascending/arch replacement) was performed in 18 patients. All other patients underwent conventional staged repair. The first stage was performed in 137 patients, with 86 patients returning for the second stage. RESULTS: First stage 30-day mortality was 9.5% (13 of 137). There was no second stage immediate neurologic deficit. Second stage mortality was 7.0% (6 of 86). During the interval of 31 days to 6 weeks after stage one, mortality was 10 of 124 (8%). Seven of the 10 interval deaths (70%) were due to rupture of the untreated aortic segment. The mortality rate was 32.1% (18 of 56) in the group of patients who did not return for the second stage repair. CONCLUSIONS: Extensive aortic aneurysms can be repaired with acceptable morbidity and mortality using the elephant trunk technique. After stage one, prompt treatment of the remaining aneurysm is crucial to success.

Determination of cerebral blood flow dynamics during retrograde cerebral perfusion using power M-mode transcranial Doppler.

BACKGROUND: Retrograde cerebral perfusion (RCP) during profound hypothermic circulatory arrest has been used as an adjunct for cerebral protection for repairs of the ascending and transverse aortic arch. Transcranial Doppler ultrasound has been used to monitor cerebral blood flow during RCP with varying success. The purpose of this study was to characterize cerebral blood flow dynamics during RCP using a new mode of monitoring known as transcranial power motion-mode (M-mode) Doppler ultrasound. METHODS: Data on pump-flow characteristics and patient outcomes were collected prospectively for patients undergoing ascending and transverse aortic arch repair. Retrograde cerebral perfusion during profound hypothermic circulatory arrest was used for all operations. Intraoperative cerebral blood flow dynamics were monitored and recorded using transcranial power M-mode Doppler ultrasound. RESULTS: Between August 2001 and March 2002, we used transcranial power M-mode Doppler ultrasound monitoring for 40 ascending and transverse aortic arch repairs during RCP. Mean RCP time was 32.2 +/- 13.8 minutes. Mean RCP pump flow and RCP peak pressure for identification of cerebral blood flow were 0.66 +/- 0.11 L/min and 31.8 +/- 9.7 mm Hg, respectively. Retrograde cerebral blood flow during RCP was detected in 97.5% of cases (39 of 40 patients) with a mean transcranial power M-mode Doppler ultrasound flow velocity of 15.5 +/- 12.3 cm/s. In the study group, 30-day mortality was 10.0% (4 of 40 patients). The incidence of stroke was 7.6% (3 of 40 patients); the incidence of temporary neurologic deficit was 35.0% (14 of 40 patients). CONCLUSIONS: Transcranial power M-mode Doppler ultrasound consistently demonstrated retrograde middle cerebral artery blood flow during RCP. Transcranial power M-mode Doppler ultrasound can provide optimal RCP with individualized settings of pump flow.

Is acute type A aortic dissection a true surgical emergency?

Untreated acute aortic dissection involving the ascending aorta (type A) is associated with a high early mortality owing to rupture. Despite advancements in surgical technique and critical care, early mortality remains high. Operative mortality may be related to the technical challenges associated with intervening on the acutely dissected aorta as well as the multiorgan insult it induces. In this article, we review our approach to acute type A aortic dissection with regard to diagnosis, initial medical management, surgical repair, and timing of repair.

The effect of aortic dissection on outcome in descending thoracic and thoracoabdominal aortic aneurysm repair.

It is estimated that 20% to 40% of the patients who survive the acute phase of aortic dissection will develop significant aneurysmal dilatation of the descending thoracic or thoracoabdominal aorta. Aortic dissection has long been considered a risk factor for mortality and neurologic deficit following surgical repair of the descending thoracic and/or thoracoabdominal aorta. In this article we review the surgical approach to patients with aortic dissection and thoracoabdominal aortic aneurysms and discuss the impact of adjuncts on survival and neurologic outcome.

Cardiac function predicts mortality following thoracoabdominal and descending thoracic aortic aneurysm repair.

OBJECTIVE: Previous studies have identified age, renal failure and aneurysm extent as predictors of mortality following thoracoabdominal and descending thoracic aortic aneurysm (TAA) repair. We studied the impact of coronary artery disease (CAD) and cardiac function on 30-day mortality following TAA repair. METHODS: Between February 1991 and May 2001, we performed 854 TAA repairs. Two hundred ninety-one patients (34%) had a history of coronary artery disease. One hundred forty-one/291 (49%) had undergone coronary artery bypass surgery (CAB) prior to TAA repair. We conducted multivariable analyses of known risk factors along with the left ventricular ejection fraction (EF) and prior CAB to determine the adjusted effect of CAD on outcome. RESULTS: Mortality in patients with CAD was 54/291 (18%) compared to 75/563 (13%) without CAD (P<0.05). In patients who had prior CAB, mortality was 31/141 (22%) compared to 98/713 (14%) patients without prior CAB, (P<0.02). In multivariable analysis, the effects of CAD and CAB on mortality were eliminated by consideration of a low EF (defined as less than 50%). CONCLUSION: Impaired left ventricular function appears to be the strongest cardiac predictor of mortality for TAA repair, independent of the presence of coronary artery disease or coronary artery bypass revascularization.

Analysis of short-term multivariate competing risks data following thoracic and thoracoabdominal aortic repair.

OBJECTIVE: Estimating the overall successfulness of a treatment can be difficult when success is defined by freedom from multiple endpoints that are each subject to competing risks. We describe a method for modeling short-term competing outcomes. METHODS: We used polytomous categorical variable modeling to describe the 30-day onset of renal failure, neurologic deficit, stroke or death (events) following repair of 841 thoracoabdominal aortic aneurysms. This was to determine whether common risk factors had a multivariate association with these outcomes, and whether predictor variables might be positively associated with some outcomes and negatively associated with others. The goal was to determine whether a single aggregate-endpoint logistic model could accurately predict the probability of good outcome 30 days following surgery. RESULTS: When more than one event occurred in a single patient, the first (or most severe simultaneous) event was used for censoring. Five hundred and ninety-three out of 841 (70.5%) patients had no postoperative events. The most common event was renal failure. We detected five predictors that were significant for at least one of the four outcomes. These were age, poor preoperative renal function (RENAL), acute dissection, extent II aneurysm, and use of cerebrospinal fluid drainage and distal aortic perfusion (ADJUNCT). Only RENAL was significant for all outcomes. ADJUNCT was highly significant only for neurologic deficit in the polytomous analysis and dropped out of the aggregate-endpoint multiple logistic model. CONCLUSION: Polytomous-outcome multivariate categorical modeling can detect effects missed by aggregate models, and is a valuable and statistically powerful method for evaluating risk factor effects on multiple competing endpoints.

Limb salvage in women.

The prevalence of peripheral arterial occlusive disease (PAD) in women and men is equal. Studies to date present conflicting data of gender effects on the risk factors, clinical presentation, and treatment outcomes. Clinical trials have often failed to analyze results by gender or to recruit sufficient women to enable such an analysis. This review summarizes the management and outcome of limb salvage therapy with a particular focus in women.

Hybrid interventions in limb salvage.

Hybrid interventions have become an integral part of our strategy for limb salvage in patients with multilevel arterial occlusive disease. In this article, we describe the commonly used hybrid interventions and review their indications and outcomes. Iliac stenting and femoral endarterectomy are the two most frequently performed procedures in hybrid cases. Short- and long-term outcomes of hybrid interventions are at least comparable to conventional endovascular and surgical revascularization procedures. Hybrid revascularization offers the efficiency and convenience of a single-stage revascularization.