Early duplex predicts restenosis after renal artery angioplasty and stenting.

OBJECTIVE: To examine the relationship between early renal duplex sonography (RDS) and restenosis after primary renal artery percutaneous angioplasty and stenting (RA-PTAS). METHODS: Consecutive patients undergoing RA-PTAS for hemodynamically significant atherosclerotic renal artery stenosis with hypertension and/or ischemic nephropathy between September 2003 and July 2010 were identified from a prospective registry. Patients had renal RDS pre-RA-PTAS, within 1 week of RA-PTAS and follow-up RDS examinations after the first postoperative week for surveillance of restenosis. Restenosis was defined as a renal artery peak systolic velocity (PSV) ≥ 180 cm/s on follow-up RDS. Associations between RDS and restenosis were examined using proportional hazards regression. RESULTS: Eighty-three patients (59% female; 12% nonwhite; mean age, 70 ± 10 years; mean pre-RA-PTAS PSV, 276 ± 107 cm/s) undergoing 91 RA-PTAS procedures comprised the sample for this study. All procedures included a completion arteriogram demonstrating no significant residual stenosis. Mean follow-up time was 14.9 ± 10.8 months. Thirty-four renal arteries (RAs) demonstrated restenosis on follow-up with a median time to restenosis of 8.7 months. There was no significant difference in the mean PSV pre-RA-PTAS in those with and without restenosis (287 ± 96 cm/s vs 269 ± 113 cm/s; P = .455), and PSV pre-RA-PTAS was not predictive of restenosis. Within 1 week of RA-PTAS, mean renal artery PSV differed significantly for renal arteries with and without restenosis (112 ± 27 cm/s vs 91 ± 34 cm/s; P = .003). Proportional hazards regression analysis demonstrated increased PSV on first post-RA-PTAS RDS was significantly and independently associated with subsequent restenosis during follow-up (hazard ratio for 30 cm/s increase, 1.81; 95% confidence interval, 1.32-2.49; P = .0003). There was no difference in pre- minus postprocedural PSV in those with and without restenosis on follow-up (175 ± 104 cm/s vs 179 ± 124 cm/s; P = .88), nor was this associated with time to restenosis. Best subsets model selection identified first postprocedural RDS as the only factor predictive of follow-up restenosis. A receiver-operating characteristic curve was examined to assess the first week PSV post-RA-PTAS most predictive of restenosis during follow-up. The ideal cut point for RA-PSV was 87 cm/s or greater. This value was associated with a sensitivity of 82.4%, specificity of 52.6%, and area under the receiver-operating characteristic curve of 69.3%. Increased first postprocedural RA-PSV was predictive of lower estimated glomerular filtration rate in the first 2 years after the procedure (-1.6 ± 0.7 mL/min/1.73 m(2) lower estimated glomerular filtration rate per 10 cm/s increase in RA-PSV; P = .010). CONCLUSIONS: Early renal artery PSV within 1 week after RA-PTAS predicted renal artery restenosis and lower postprocedure renal function. Recurrent stenosis demonstrated no association with absolute elevation in PSV prior to RA-PTAS nor with the change in PSV after RA-PTAS. These data suggest that detectable differences exist in renal artery flow parameters following RA-PTAS that are predictive of restenosis during follow-up but are not apparent on completion arteriography or detectable by intra-arterial pressure measurements. Further study is warranted.

Results of endovascular aortic aneurysm repair with general, regional, and local/monitored anesthesia care in the American College of Surgeons National Surgical Quality Improvement Program database.

BACKGROUND: This study examined outcomes of endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) using general, spinal, epidural, and local/monitored anesthesia care (MAC) in a multicenter North American hospital database reflecting contemporary anesthesia and surgical practices. METHODS: Elective EVAR cases performed between 2005 and 2008 were identified from the American College of Surgeons National Surgical Quality Improvement Program database using Current Procedural Terminology codes. Excluded were emergency cases and patients with concomitant procedures requiring general anesthesia. Patient-level comorbidities, characteristics, and intraoperative and postoperative details were examined. Complications were analyzed individually and in aggregate categories, including wound, pulmonary, renal, venous thromboembolic, cardiovascular, operative, and septic. Length of stay (LOS) and 30-day mortality were examined. Characteristics and outcomes were described using mean ± standard deviation or count (%), and comparisons were evaluated for statistical significance using χ(2), Fisher exact test, and univariate linear regression. LOS was analyzed with linear regression techniques using a log transformation. Associations between anesthesia type and outcomes were examined using univariable and multivariable regression techniques. RESULTS: We identified 6009 elective EVAR procedures for analysis. General anesthesia was used in 4868 cases, spinal anesthesia in 419, epidural anesthesia in 331, and local/MAC in 391. Defined morbidity occurred in 11% of patients. Median LOS was 2 (interquartile range, 1-3) days, and mean LOS was 2.8 ± 4.3 days. The 30-day mortality rate was 1.1%. Significant multivariate associations were observed between anesthesia type, pulmonary morbidity, and log-LOS. General anesthesia was associated with an increase in pulmonary morbidity vs spinal (odds ratio [OR], 4.0; 95% confidence interval [CI], 1.3-12.5; P = .020) and local/MAC anesthesia (OR, 2.6; 95% CI, 1.0-6.4; P = .041). Use of general anesthesia was associated with a 10% increase in LOS for general vs spinal anesthesia (95% CI, 4.8%-15.5%; P = .001) and a 20% increase for general vs local/MAC anesthesia (95% CI, 14.1%-26.2%; P < .001). Trends toward increased pulmonary morbidity and LOS were not observed for general vs epidural anesthesia. No significant association between anesthesia type and mortality was observed. CONCLUSIONS: In contemporary North American anesthetic and surgical practice, general anesthesia for EVAR was associated with increased postoperative LOS and pulmonary morbidity compared with spinal and local/MAC anesthesia. These data suggest that increasing the use of less-invasive anesthetic techniques may limit postoperative complications and decrease the overall costs of EVAR.

A vascular disease educational program in the preclinical years of medical school increases student interest in vascular disease.

BACKGROUND: New training paradigms in vascular surgery necessitate medical student interest in vascular disease. We examined the effects of incorporation of a vascular disease educational program during the second year of the medical school curriculum on student acquisition of knowledge and interest in the treatment of vascular disease. METHODS: We developed and administered a new educational program on vascular disease and delivered the program to all second-year medical students. The new program encompassed 9 didactic hours, including 7 traditional lecture hours and 2 hours of problem-based learning. After completing the program, students were surveyed regarding vascular disease-specific knowledge, interest in treating vascular disease, and career choices. Third-year students who were not exposed to the program were surveyed as a control group. We recorded the voluntary student enrollment in the vascular and endovascular surgery rotation during the following academic year. Voluntary enrollment of the students exposed to the vascular disease education program was compared with enrollment for the previous 8 years. RESULTS: Before the introduction of the new educational program, 946 total lecture hours were delivered to first- and second-year medical students, comprising 490 hours (52%) given by nonsurgeon physicians, 445 (47%) by nonphysicians, and 11 (1%) by surgeons. Survey response rate was 93% (112 of 121) for second-year students and 95% (39 of 41) for third-year students. After the vascular disease program, second-year students answered 7.1 +/- 1.4 of 9 vascular disease questions correctly, whereas unexposed third-year students answered 7.2 +/- 1.7 questions correctly (P = .96). Most second-year medical students described a "somewhat" or "much greater" interest in the medical (63%), procedural (59%), and overall (63%) management of vascular disease after exposure to the program. Most also had a "somewhat" or "much greater" interest in a vascular medicine (64%) or vascular and endovascular surgery (60%) rotation. Enrollment in the vascular surgery third-year clerkship increased significantly to a mean of 3.0 students/month from 1.16 students/month in the prior year (P = .0032, postintervention year vs 8 prior years). CONCLUSION: A vascular disease educational program administered to second-year medical students increases interest in vascular disease and interest in further training. The increased interest translates to greater student enrollment in the vascular surgery clerkship in the subsequent academic year.

Accuracy of duplex sonography scans after renal artery stenting.

PURPOSE: Reports of duplex sonography scan criteria for recurrent renal arterial (RA) stenosis after endoluminal stenting have suggested that criteria for native arteries may overestimate recurrent disease. This retrospective report examines the utility of renal duplex sonography (RDS) scans to define the presence of significant (ie, ≥ 60%) renovascular disease (RVD) after percutaneous angioplasty and endoluminal stenting (PTAS). METHODS: Demographic, duplex, and angiographic data were reviewed and compared. RDS was obtained. Peak systolic velocities (PSV) were obtained after PTAS from multiple sites along the main RA from both anterior and flank approaches. Comparable images from digital subtraction angiography were independently examined for restenosis. Percent diameter stenosis was determined from the site of maximal stenosis compared with the normal RA distal to the stent. Sensitivity and specificity were estimated and 95% confidence intervals (CIs) were computed after adjusting for within patient "clustering" of observations applying native RA RDS criteria using angiography as the gold standard. Receiver operating characteristic (ROC) curves were used to estimate the optimal RDS values for recurrent stenosis. RESULTS: From October 2003 to June 2009, 49 patients had angiographic imaging after PTAS. There were 30 patients (18 women, 12 men; mean age, 71 ± 9 years) provided technically adequate paired angiographic and RDS assessment after PTAS for 66 RAs. Paired analysis was performed for 23 RAs after primary PTAS and 43 RAs after secondary treatment. The prevalence of significant restenosis was 35% (23 of 66 RAs). RAs with greater than 60% diameter restenosis had higher peak systolic velocity (PSV) compared to those without (2.48 ± 1.15 millisecond vs 1.44 ± 0.58 millisecond; P < .001). Compared to angiography, RA-PSV ≥ 1.8 millisecond with distal RA turbulence demonstrated a sensitivity of 73% (95% CI, 54%, 91%), specificity of 80% (95% CI, 67%, 93%), and an overall accuracy of 77% (95% CI, 67%, 88%) with a positive predictive value of 64% (95% CI, 46%, 82%). Optimal RDS value estimated by ROC curve resulted in RA-PSV of 2.5 millisecond which was associated with a sensitivity of 59% (95% CI, 36%, 82%), specificity of 95% (95% CI, 89%, 100%), an accuracy of 83% (95% CI, 74%, 92%), and a positive predictive value of 87% (95% CI, 68%, 100%). CONCLUSION: Renal duplex sonography has utility to detect significant restenosis after PTAS. RDS criteria for significant native RA stenosis compare favorably with optimal RDS criteria for restenosis estimated by ROC curves.

Late erosion of a prophylactic Celect IVC filter into the aorta, right renal artery, and duodenal wall.

We present the case of a patient with retrievable inferior vena cava (IVC) filter-related pseudoaneurysms of the infrarenal aorta and right renal artery, with associated erosion into the duodenal wall. The patient was seen 10 months following multiorgan trauma and placement of a prophylactic retrievable IVC filter (R-IVCF). Management required autogenous aortic reconstruction, caval repair, and subsequent right nephrectomy. This case demonstrates that R-IVCFs may be associated with significant risks, which is concerning, as a majority of prophylactic R-IVCFs placed after multisystem trauma are not removed.

Trends in vena caval interruption.

OBJECTIVE: This study examined the national use of vena cava filters (VCFs) from 1998 to 2005. METHODS: Methods for complex surveys were used to examine hospital discharge data from the Nationwide Inpatient Sample (NIS) to determine the use of VCFs for the years 1998 to 2005. VCF placement in the absence of deep venous thrombosis (DVT) or pulmonary embolus (PE) was categorized as prophylactic. RESULTS: During the study period, the estimated rate of hospitalizations per year with a diagnosis of DVT (odds ratio [OR], 1.025; 95% confidence interval [CI], 1.019-1.032; P < .01) or PE (OR, 1.076; 95% CI, 1.069-1.083; P < .01) rose significantly. The estimated weighted frequency of VCF placement increased from 52,860 procedures in 1998 to 104,114 procedures in 2005 (0.15% and 0.27% of all discharges, respectively), representing an 80% increase. VCF placement significantly increased during hospitalizations with any diagnosis of DVT or PE, or both, and no DVT or PE (P < .01 for each). Logistic regression models revealed that the rate of prophylactic VCF placement increased at a significantly higher rate than VCF placement associated with DVT or PE (157% vs 42%; P < .01), after adjusting for age, gender, and hospital characteristics. Prophylactic VCF placement in the setting of morbid obesity (P < .01) and head injury (P = .03) rose significantly over time. CONCLUSIONS: From 1998 to 2005, the estimated rates of prophylactic VCF placement increased at a significantly higher rate than VCF placement in the setting of DVT or PE. Significant increases in the use of prophylactic VCFs were seen in the setting of morbid obesity and head injury.

Atherosclerotic renovascular disease among hypertensive adults.

PURPOSE: This report describes the change in atherosclerotic renovascular disease (AS-RVD) among hypertensive adults referred for renal duplex sonography (RDS) scan. METHODS: From Oct 1993 through July 2008, 20,994 patients had RDS at our center. A total of 434 hypertensive patients with two or more RDS exams without intervention comprised the study cohort. Patient demographics (blood pressures, medications, serum creatinine levels, and data from RDS) were collected. Analyses of longitudinal changes in Doppler scan parameters, blood pressures, and renal function were performed by fitting linear growth-curve models. After confirming the linearity of change in Doppler scan parameters among patients with variable number of studies, estimates of mean slopes were calculated using maximum likelihood techniques. For changes in renal function, quadratic growth curves were required to describe longitudinal change. RESULTS: A total of 434 subjects (212 men [49%] and 222 women [51%]; mean age, 64.6 +/- 12.2 years) provided 1351 studies (mean, 3.2 +/- 2.4; range, 2 to 18) for 863 kidneys over a mean follow-up of 34.4 +/- 25.1 months. At baseline, 20.6% of kidneys demonstrated hemodynamically significant stenosis. On follow-up, 72 kidneys (9.1%) demonstrated anatomic progression of disease. A total of 54 kidneys (6.9%) progressed to significant stenosis and 18 (2.3%) progressed to occlusion. Controlling for progression of disease, baseline renal artery status demonstrated a strong association with baseline kidney length (P = .0006). Significant annualized change in renal length was observed (cm change/year +/- standard error of the mean [SEM]: 0.042 +/- 0.011; P = .0002) among both kidneys with and without critical disease at baseline, however, decline in length was significantly greater among kidneys exhibiting progression of renovascular disease (-0.152 +/- 0.028 cm/year; comparison of slopes between groups P = .0005). In the absence of progression, the presence or absence of critical renal artery stenosis at baseline did not affect the rate of decline in renal length. Fitted models for the natural log transform of serum creatinine demonstrated a significant increase during follow-up (P < .0001). No association was observed between change in serum creatinine and baseline renovascular disease status, or its progression. CONCLUSION: A total of 32% of hypertensive adults referred for RDS demonstrated hemodynamically significant renal artery stenosis. Regardless of the presence or absence of baseline disease, a small percentage of patients demonstrated anatomic progression of AS-RVD. A total of 9.1% demonstrated anatomic progression and 2.3% progressed to occlusion. Although anatomic progression of AS-RVD was associated with an increased rate of decline in renal length, progression did not predict a decline in excretory renal function. Intervention for AS-RVD should be selective and reserved for strict indications.

Effect of challenging neck anatomy on mid-term migration rates in AneuRx endografts.

OBJECTIVE: To establish the effect of challenging neck anatomy on the mid- and long-term incidence of migration with the AneuRx bifurcated device in patients treated after Food and Drug Administration approval and to identify the predictive factors for device migration. METHODS: Prospectively maintained databases at the University of North Carolina (UNC) and Washington University (WU) were used to identify 595 patients (UNC, n = 230; WU, n = 365) who underwent endovascular repair of an infrarenal abdominal aortic aneurysm with the AneuRx bifurcated stent graft. Those patients with at least 30 months of follow-up were identified and underwent further assessment of migration (UNC, n = 25; WU, n = 59) by use of multiplanar reconstructed computed tomographic scans. RESULTS: Eighty-four patients with a mean follow-up time of 40.3 months (range, 30-55 months) were studied. Seventy percent of the patients (n = 59) met all inclusion criteria for neck anatomy (length, angle, diameter, and quality) as defined by the revised instructions for use guidelines and are referred to as those with favorable neck anatomy (FNA). The remaining 25 patients retrospectively fell outside of the revised instructions for use guidelines and are referred to as those with unfavorable neck anatomy (UFNA). Life-table analysis for FNA patients at 2 and 4 years revealed a migration rate of 0% and 6.1%, respectively. For UFNA patients, it was 24.0% and 42.1% at 2 and 4 years, respectively (P < .0001). The overall (FNA and UFNA) migration rate was 7.1% and 17.1% at 2 and 4 years, respectively. Overall, late graft-related complications occurred in 38% of patients (FNA, 27%; UFNA, 64%; P = .003; relative risk, 1.7). There was no incidence of late rupture or open conversion. The relative risk of migration for UFNA patients was 2.5 compared with FNA patients (P = .0003). A larger neck angle and a longer initial graft to renal artery distance were predictors of migration, whereas shorter neck length approached but did not reach statistical significance. CONCLUSIONS: Patients who have unfavorable aneurysm neck anatomy experience significantly higher migration, device-related complication, and secondary intervention rates. However, there was no incidence of open conversion, rupture, or abdominal aortic aneurysm-related death, thereby supporting the AneuRx device as a feasible alternative to open repair even in patients with challenging neck characteristics. Enhanced surveillance should be used in these high-risk patients.

Computed tomographic angiography allows accurate planning of the setting and technique of open and percutaneous vascular interventions.

BACKGROUND: Vascular surgeons can offer patients with arterial and venous disorders a multitude of endovascular and surgical options. Computed tomographic angiography (CTA) has the potential to allow the development of an effective interventional strategy without subjecting patients to invasive diagnostic testing. METHODS: A prospectively maintained database was reviewed comprising 6 consecutive months of arterial and venous procedures performed using an algorithm emphasizing CTA supplemented with other noninvasive imaging. RESULTS: Eighty-five patients underwent 90 arterial or venous procedures, the majority of which were based on CTA. Preprocedure plans matched a successful intervention in 35 of 40 (88%) procedures performed in the interventional suite, and 48 of 49 (98%) procedures performed in the surgical suite. Two of 40 patients treated initially in the interventional suite eventually required a surgical vascular procedure. The majority of procedures were therapeutic (86%) rather than diagnostic (14%). CONCLUSIONS: An algorithm using CTA and supplemented with other noninvasive imaging allows safe and effective planning for open surgical and endovascular procedures.

Aortic neck attachment failure and the AneuRx graft: incidence, treatment options, and early results.

Some investigators have reported that proximal attachment failure is a long-term complication of endovascular abdominal aortic aneurysm repair (EVAR) with the AneuRx (Medtronic, Santa Rosa, CA) device. We evaluated the need for an intervention in patients with suboptimal proximal fixation as well as the feasibility and early success of a variety of treatment strategies. From October 1999 to October 2003, we performed 365 EVARs using the AneuRx graft. At a mean follow-up of 23.7 +/- 14.8 months, 20 patients (5.5%) with suboptimal outcomes (14 with a type I endoleak, one with a type III endoleak, and 5 with an inadequate seal zone <1 cm) were considered for treatment. Characteristics of each patient''s aortic neck anatomy that could be associated with proximal attachment failure were evaluated. Eighteen patients (90%) underwent successful treatment (9 AneuRx cuffs, 6 Talent cuffs, 5 aortic stents, one redo endograft, and two surgical conversions) without major perioperative complications, one patient had a persistent type I endoleak despite endovascular treatment, and one patient refused treatment, ultimately leading to aneurysm rupture. There have been no further endoleaks or graft migrations noted since the secondary intervention at a mean follow-up of 13.9 +/- 11.8 months. In our experience, proximal attachment failure associated with the AneuRx graft is relatively uncommon and usually associated with unfavorable neck anatomy. Despite this, most cases are treatable by endovascular means. Long-term follow-up is needed to assess the ultimate frequency of these combined device reconstructions.

Natural killer cells participate in bacterial clearance during septic peritonitis through interactions with macrophages.

Natural killer (NK) cells have a well-established role in host defense against viral infections and malignancies. However, their function in bacterial infection and sepsis is poorly defined. We hypothesized that NK cells, as a major producer of interferon-gamma during sepsis, would be important in host defense against bacterial infections. Cecal ligation and puncture (CLP) was performed on Swiss Webster mice depleted of NK cells by pretreatment with anti-asialo GM1 and control mice given immunoglobulin G (IgG) antibody. NK cell-depleted mice had significantly higher anaerobic bacterial counts in the liver and peritoneal lavage fluid, as well as higher aerobic counts in the liver and blood 4 h after CLP. Macrophage phagocytosis, nitric oxide production, and interleukin (IL)-6 levels at 4 h were also decreased in mice depleted of NK cells compared with controls. Greater neutrophil influx into the peritoneum, indicated by higher myeloperoxidase levels, was also seen in NK cell-depleted mice. At 8 and 18 h after CLP, bacterial counts were similar between groups, and overall survival rates were not significantly different. Peritoneal IL-12 levels significantly increased by 18 h in normal mice, but not in NK cell-depleted animals. Our data suggest that NK cells participate in the early local and systemic eradication of bacteria and regulation of IL-12 during polymicrobial sepsis. These effects are likely due to their interactions with macrophages.

Treatment of Helicobacter pylori infection in patients with peptic ulcer disease.

Helicobacter pylori is an organism that is thought to be important in the pathophysiology of peptic ulcer disease and gastritis. Eradication of the organism is useful in clinical cure of infected patients. Efficacious regimens generally include an antisecretory agent combined with two to three antimicrobials. The main determinant of overall cost of treatment is the rate of eradication of the organism. Impediments to patient compliance include intensive dosage schedules and drug side effects. Resistance can occur to the commonly used antibiotics but can usually be overcome with an altered regimen.

Genetic background determines susceptibility during murine septic peritonitis.

BACKGROUND: The tolerance of mouse strains to cecal ligation and puncture (CLP), a clinically relevant model of sepsis, can vary greatly. We compared the immune response and bacterial eradication during CLP in two mouse strains with different susceptibilities to the lethal effects in an effort to understand alterations in tolerance. MATERIALS AND METHODS: CLP of increasing severity was performed on Swiss Webster mice. Interleukin (IL)-12 levels, bacterial counts, and myeloperoxidase were determined. We then compared the same parameters in Swiss Webster and in BALB/c mice and determined survival for both mouse strains after CLP. RESULTS: Bacterial counts locally and systemically as well as serum IL-12 correlated with the severity of CLP in Swiss Webster mice. Lung myeloperoxidase increased with increasing severity CLP, while peritoneal myeloperoxidase decreased. Following CLP, one-half of the Swiss Webster mice survived versus none of the BALB/c mice. Despite worsened survival, BALB/c mice had lower bacterial counts and similar IL-12 levels compared to Swiss Webster mice. Myeloperoxidase and IL-6 levels were similar between experimental groups. CONCLUSIONS: Swiss Webster and BALB/c mice have significantly different susceptibilities to the lethal effects of CLP, and this difference may be related to IL-12 responsiveness.