Significance of Blunted Venous Waveforms Seen on Upper Extremity Ultrasound.

BACKGROUND: Current guidelines recommend vascular mapping ultrasound (US) prior to arteriovenous fistula creation. Blunted venous waveforms (BVWs) suggest central venous stenosis; however, this relationship and one between BVWs and the presence of a central venous catheter (CVC) remain unclear. METHODS: All patients who received upper extremity vascular mapping US between January 2013 and October 2014 at a single institution were retrospectively reviewed. Patient demographics, comorbidities, US results, pacemaker history, and CVC status were collected. Waveforms were assessed at the proximal subclavian vein/distal axillary vein and interpreted by radiologists. Patients were determined to have central venous stenosis (CVS) if detected by venography within 6 months of US. RESULTS: There were 342 patients, of which 165 (48%) had a current CVC and 29 (8.5%) had BVW of at least 1 arm. Right-sided BVW were associated with a history of a prior ipsilateral CVC (odds ratio [OR] = 4.5, 95% confidence interval [CI] = 1.6-12.6, P = 0.009). Of the 342 patients, 69 (20%) had a venogram within 6 months. Seventeen (25%) of the 69 patients had CVS, with 7 involving the left subclavian vein, 8 the right subclavian vein, and 3 the superior vena cava (one patient had tandem stenoses). A BVW on the left side was not associated with any CVS. A BVW on the right side was associated with an ipsilateral CVS (OR = 5.8, 95% CI = 1.2-27.4, P = 0.04). This association persisted in the setting of a prior CVC (relative risk = 1.3, 95% CI = 0.9-2, P = 0.01). CONCLUSIONS: There are associations between right-sided BVW and an ipsilateral subclavian vein stenosis. We recommend that hemodialysis access planning includes venography to rule out central vein stenosis in patients with BVW, especially if right-sided and in the setting of a prior CVC.

A comparison of brachial artery-brachial vein arteriovenous fistulas with arteriovenous grafts in patients with poor superficial venous anatomy.

OBJECTIVE: The autogenous arteriovenous fistula (AVF) has been shown to be superior to the arteriovenous graft (AVG) with respect to cost, complications, and primary patency. Therefore, the National Kidney Foundation Disease Outcomes Quality Initiative guidelines recommend reserving AVGs for patients who do not have adequate superficial venous anatomy to support AVF placement. The brachial artery-brachial vein arteriovenous fistula (BVAVF) has emerged as an autologous last-effort alternative. However, there are limited data comparing BVAVFs and AVGs in patients who are otherwise not candidates for a traditional AVF. METHODS: Patients who received a BVAVF from July 2009 to July 2014 were compared with those who received an AVG during the same period. At our institution, BVAVF and AVG are only performed in patients with poor superficial venous anatomy. Patient demographic data, operative details, and subsequent follow-up were collected. BVAVFs were performed with a two-stage approach, with initial arteriovenous anastomosis, followed by delayed superficialization or transposition. Our primary outcome measure was primary functional assisted patency at 1 year. Patients lost to follow-up were excluded. A subgroup analysis was also performed for patients in whom the BVAVF or the AVG was their first hemodialysis access surgery. RESULTS: During the study period, 29 patients underwent BVAVF and 32 underwent AVG. There were no differences in age, gender, or presence of diabetes between the two groups. The median days to cannulation from the initial operation were 141 (interquartile range, 94-214) in the BVAVF group and 29 (interquartile range, 14-33) in the AVG group (P < .001). Fewer patients required interventions to maintain or re-establish patency in the BVAVF group than in the AVG group (10% v. 44%; P < .01). The 1-year primary patency was greater for BVAVF (62% vs 25%; P < .01); however, there was no difference in the functional assisted primary patency rates at 1 year (45% vs 25%; P = .1). Subgroup analysis demonstrated greater 1-year primary functional assisted primary patency (52% vs 19%; P < .05) in patients without prior access surgery. CONCLUSIONS: The BVAVF is a viable alternative to the AVG in patients with inadequate superficial venous anatomy, especially in access-naïve patients. The decision to perform BVAVF must be weighed against the delay in functional maturation expected compared with AVG.

Factors predictive of complicated appendicitis in children.

BACKGROUND: The ability to predict whether a child has complicated appendicitis at initial presentation may influence clinical management. However, whether complicated appendicitis is associated with prehospital or inhospital factors is not clear. We also investigate whether hyponatremia may be a novel prehospital factor associated with complicated appendicitis. MATERIALS AND METHODS: A retrospective review of all pediatric patients (≤12 y) with appendicitis treated with appendectomy from 2000 to 2013 was performed. The main outcome measure was intraoperative confirmation of gangrenous or perforated appendicitis. A multivariable analysis was performed, and the main predictors of interest were age <5 y, symptom duration >24 h, leukocytosis (white blood cell count >12 × 103/mL), hyponatremia (sodium ≤135 mEq/L), and time from admission to appendectomy. RESULTS: Of 392 patients, 179 (46%) had complicated appendicitis at the time of operation. Univariate analysis demonstrated that patients with complicated appendicitis were younger, had a longer duration of symptoms, higher white blood cell count, and lower sodium levels than patients with noncomplicated appendicitis. Multivariable analysis confirmed that symptom duration >24 h (odds ratio [OR] = 5.5, 95% confidence interval [CI] = 3.5-8.9, P < 0.01), hyponatremia (OR = 3.1, 95% CI = 2.0-4.9, P < 0.01), age <5 y (OR = 2.3, 95% CI = 1.3-4.0, P < 0.01), and leukocytosis (OR = 1.9, 95% CI = 1.0-3.5, P = 0.04) were independent predictors of complicated appendicitis. Increased time from admission to appendectomy was not a predictor of complicated appendicitis (OR = 0.8, 95% CI = 0.5-1.2, P = 0.2). CONCLUSIONS: Prehospital factors can predict complicated appendicitis in children with suspected appendicitis. Hyponatremia is a novel marker associated with complicated appendicitis. Delaying appendectomy does not increase the risk of complicated appendicitis once intravenous antibiotics are administered. This information may help guide resource/personnel allocation, timing of appendectomy, and decision for nonoperative management of appendicitis in children.

Routine intraoperative cholangiography is unnecessary in patients with mild gallstone pancreatitis and normalizing bilirubin levels.

BACKGROUND: The benefit of intraoperative cholangiography (IOC) is controversial in patients with gallstone pancreatitis whose bilirubin levels are normalizing. IOC with subsequent endoscopic retrograde cholangiopancreatography may lengthen duration of surgery and length of stay, whereas failure to clear the common bile duct may result in recurrent pancreatitis. METHODS: We performed a 6-year retrospective cohort analysis of consecutive adult patients with mild gallstone pancreatitis undergoing same-admission cholecystectomy at 2 university-affiliated medical centers. Institution A routinely performed IOC, whereas institution B did not. The primary outcome was readmission within 30 days for recurrent pancreatitis. RESULTS: Of 520 patients evaluated, 246 (47%) were managed at institution A (routine IOC) and 274 (53%) were managed at institution B (restricted IOC). Patients at institution B had a shorter duration of surgery (1.0 vs 1.6 hours, P < .001), shorter length of stay (4 vs 5 days, P < .001), and fewer postoperative endoscopic retrograde cholangiopancreatographies performed (1.8% vs 21%, P < .001), without a difference in readmissions (1.5% vs 0%, P = .12). CONCLUSIONS: Routine IOC is not necessary in the setting of mild gallstone pancreatitis with normalizing bilirubin values.

Association of Admission Laboratory Values and the Timing of Endoscopic Retrograde Cholangiopancreatography With Clinical Outcomes in Acute Cholangitis.

Importance: Acute cholangitis (AC), particularly severe AC, has historically required urgent endoscopic decompression, although the timing of decompression is controversial. We previously identified 2 admission risk factors for adverse outcomes in AC: total bilirubin level greater than 10 mg/dL and white blood cell count greater than 20 000 cells/µL. Objectives: To validate previously identified prognostic factors in AC, evaluate the effect of timing of endoscopic retrograde cholangiopancreatography on clinical outcomes, and compare recent experience with AC vs an historical cohort. Design, Setting, and Participants: A retrospective analysis (2008-2015) of patients with AC (validation cohort, n = 196) was conducted at 2 academic medical centers to validate predictors of adverse outcome. Timing of endoscopic retrograde cholangiopancreatography and outcome were stratified by severity using the Tokyo Guidelines for acute cholangitis diagnosis. Outcomes for the validation cohort were compared with the derivation cohort (1995-2005; n = 114). Data analysis was conducted from July 1, 2015, to September 9, 2015. Main Outcomes and Measures: Death and a composite outcome of death or organ failure. Results: The median age of patients in the derivation cohort was 54 years (interquartile range, 40-65 years) and in the validation cohort was 59 years (45-67 years). Multivariate logistic regression analysis of the validation cohort confirmed white blood cell count of more than 20 000 cells/µL (odds ratio, 3.4; 95% CI, 1.2-9.5; P = .02) and total bilirubin level of more than 10 mg/dL (odds ratio, 5.4; 95% CI, 1.8-16.4; P = .003) as independent risk factors for poor outcomes. In the validation cohort, timing of endoscopic retrograde cholangiopancreatography was not significantly different between those with and without an adverse outcome, even when stratified by AC severity (moderate: median, 0.6 hours [interquartile range (IQR), 0.5-0.9] vs 1.7 hours [IQR, 0.7-18.0] and severe: median, 10.6 hours [IQR, 1.2-35.1] vs 25.5 hours [IQR, 15.5-58.5] for those with and without adverse events, respectively). Patients in the validation cohort had a shorter hospital length of stay (median, 7 days [IQR, 4-10 days] vs 9 days [IQR, 5-16 days]) and lower rate of intensive care unit admission (26% vs 82%), despite a higher rate of severe cholangitis (n = 131 [67%] vs n = 29 [25%]). There were no significant differences in the composite outcome between the validation and derivation cohorts (22 [18.6%] vs 44 [22.4%]; P = .47). Adjusted analysis demonstrated decreased mortality in the validation cohort (odds ratio, 0.3; 95% CI, 0.1-0.7; P = .01). Conclusions and Relevance: White blood cell count greater than 20 000 cells/µL and total bilirubin level greater than 10 mg/dL are independent prognostic factors for adverse outcomes in AC. Consideration should be given to include these criteria in the Tokyo Guidelines severity assessment. Timing of endoscopic retrograde cholangiopancreatography does not appear to affect clinical outcomes in these patients. Management of AC has improved with time, with an overall shorter hospital length of stay, lower rate of intensive care unit admission, and a decreased adjusted mortality, demonstrating improvements in care efficiency and delivery.