Imaging Signs of May-Thurner Syndrome in Asymptomatic Patients: Computed Tomography Angiography Analysis of Kidney Donors.

BACKGROUND: The current study aimed to evaluate the distance between the right common iliac artery (RCIA) and lumbar vertebra in asymptomatic patients in order to determine whether such distance was statistically correlated with the left common iliac vein (LCIV) diameter (LCIVD) and to investigate if both measures were related to demographic characteristics and anthropometric data, such as sex, age, height, and body mass index (BMI). METHODS: In this descriptive and uncontrolled anatomic study, data from high-definition computed tomography (CT) angiography images of living kidney donors without a medical history of chronic venous insufficiency or past deep vein thrombosis (DVT) were analyzed. The RCIA crossed over the LCIV in 311 individuals, who were then included in this study. CT scans were reviewed to measure (1) the narrowest space between the RCIA and fifth lumbar vertebral body and (2) the LCIVD. Measures were subjected to normality tests and were divided according to the sex of the study population. Correlations of measures with age, BMI, and height were calculated. RESULTS: Of the 311 patients analyzed, 66.6% (n = 207) were female. The mean lumbar vertebral body-iliac artery distance (LVBIAD) was 7.2 mm, whereas the mean LCIVD was 8.5 mm; both were higher in men (P < 0.001). The statistical analysis of LVBIAD and LCIVD distributions revealed no normality pattern (P < 0.05). The analysis of the correlation between them showed a weak statistically significant relationship with age. A linear regression model considering the normality percentile interval indicated a strong positive correlation between LVBIAD and LCIVD (R2 = 0.884). CONCLUSIONS: The LVBIAD was <5 mm and <3 mm in 25% and 5% of asymptomatic individuals, respectively. The LCIVD correlated with the space between the RCIA and lumbar vertebra. The distance between the RCIA and lumbar vertebra and the LCIVD were higher in male subjects and older patients, but did not correlate with BMI and height.

Normal Costoclavicular Distance as a Standard in the Radiological Evaluation of Thoracic Outlet Syndrome in the Costoclavicular Space.

BACKGROUND: The costoclavicular space is a common site of thoracic outlet syndrome. When there is no anatomical alteration, the diagnosis of thoracic outlet syndrome is difficult. Several authors relate costoclavicular distance to symptoms of thoracic outlet syndrome; however, there is no standardized site for measurement of the costoclavicular distance. This study aimed to determine the standard costoclavicular distance at neurovascular bundle crossing points (near the subclavian vein [Measure V] and the subclavian artery/brachial plexus branches [Measure NA]) using high-resolution chest computed tomography (CT) scans and evaluate its variations with respect to age, sex, height, and body mass index. METHODS: This prospective cross-sectional observational study analyzed 150 of 156 CT scans from consecutive adult patients (72 females and 78 males). Costoclavicular distance was measured at the subclavian vein and brachial plexus/subclavian artery sites, where narrowing of the costoclavicular distance could lead to symptoms of thoracic outlet syndrome. Costoclavicular distance was analyzed with respect to sex, laterality, age group (<50 and ≥50 years) and body mass index group (body mass index <25 and ≥25 kg/m2). RESULTS: Measures of V and NA were normally distributed. The measured costoclavicular distances were 1.23 cm (±0.40) and 1.24 cm (±0.47), respectively. Age (≥50 years) and body mass index (≥25 kg/m2) increased the costoclavicular distance. Measurements V and NA below the fifth percentile indicated a narrowed costoclavicular distance and a greater chance of developing thoracic outlet syndrome. For young (<50 years) and eutrophic patients (body mass index <25 kg/m2), these measurements were 0.46 and 0.44 cm, respectively; for young people and body mass index ≥25 kg/m2, they were 0.54 and 0.24 cm, respectively; for the elderly (≥50 years) and eutrophic, they were 0.57 and 0.48 cm, respectively; and for the elderly and body mass index ≥ 25 kg/m2, they were 0.83 and 0.73 cm, respectively. There was no significant difference between measurements V and NA regarding patient laterality, gender, and height. CONCLUSIONS: Standardization of costoclavicular distance measurements at neurovascular bundle crossing points (subclavian vein and brachial plexus/subclavian artery) is possible. It may aid the diagnosis and help direct the therapeutic indications for symptomatic patients with thoracic outlet syndrome.

Prevalence of left renal vein compression (nutcracker phenomenon) signs on computed tomography angiography of healthy individuals.

OBJECTIVE: We evaluated the frequency of significant left renal vein (LRV) compression, also called the nutcracker phenomenon (NCP), in a normal asymptomatic population. METHODS: The present retrospective descriptive anatomic study analyzed the data from high-definition renal computed tomography (CT) angiography of living kidney donors. A total of 324 CT examinations were evaluated for signs of LRV compression, including the beak sign, aortomesenteric angle <41°, LRV diameter ratio ≥4.9, and beak angle ≥32°. The presence of pelvic varicose veins and the left gonadal vein in the proximal and mid-portion (considered dilated if >0.5 cm) were also evaluated. Anthropometric and laboratory (urine erythrocyte count) data were collected from the medical records. Statistical inference was calculated using Fisher's exact test and Student's t test. RESULTS: The mean aortomesenteric angle was 53.1° in women and 58.7° in men (P = .044). The beak sign and beak angle were present in 15.3% and 9.8%, respectively, and both had a greater prevalence in the women (P = .01). An aortomesenteric angle <41° was identified in 30.5%, with a greater prevalence in women (P < .01). The diameter ratio was positive in 0.7% of the cases, with no difference between the sexes. A left gonadal vein >0.5 cm was more prevalent in women in both the proximal and the mid-portions (P < .01). Although analysis stratified by positive criteria (3 or 4) showed no difference between the sexes, a positive correlation was found with younger age (P < .01). The limitations included the absence of a nutcracker syndrome (NCS) population; the lack of a renocaval pressure gradient, because of the need for intervention; the absence of other types of imaging studies, such as duplex ultrasound scan; and the absence of female parity data. CONCLUSIONS: The NCP and NCS CT criteria were present with a high frequency in healthy individuals. Women and younger individuals showed a greater prevalence of compression findings in the aortomesenteric axis. Revision of the current NCP and NCS criteria with a distinct categorization between sex, age, and body mass index is recommended to better evaluate LRV compressive events.

Role of Lock Therapy for Long-Term Catheter-Related Infections by Multidrug-Resistant Bacteria.

The management of long-term central venous catheter (LTCVC) infections by multidrug-resistant (MDR) bacteria in cancer patient is a challenge. The objectives of this study were to analyze outcomes in cancer patients with LTCVC-associated infection, identify risks for unfavorable outcomes, and determine the impact of MDR bacteria and antibiotic lock therapy (ALT) in managing such infections. We evaluated all LTCVC-associated infections treated between January 2009 and December 2016. Infections were reported in accordance with international guidelines for catheter-related infections. The outcome measures were 30-day mortality and treatment failure. We analyzed risk factors by Cox forward-stepwise regression. We identified 296 LTCVC-associated infections; 212 (71.6%) were classified as bloodstream infections (BSIs). The most common agent was Staphylococcus aureus Forty-six (21.7%) infections were due to MDR Gram-negative bacteria. ALT was used in 62 (29.2%) patients, with a 75.9% success rate. Risk factors identified for failure of the initial treatment were having a high sequential organ failure assessment (SOFA) score at diagnosis of infection and being in palliative care; introduction of ALT at the start of treatment was identified as a protective factor. Risk factors identified for 30-day mortality after LTCVC-associated infection were a high SOFA score at diagnosis, infection with MDR bacteria, and palliative care; introduction of ALT at the start of treatment, hematological malignancies, and adherence to an institutional protocol for the management of LTCVC-associated infection were identified as protective factors. Despite the high incidence of infection with MDR bacteria, ALT improves the outcome of LTCVC-associated infection in cancer patients.

Calf Muscle Oxygen Saturation during 6-Minute Walk Test and Its Relationship with Walking Impairment in Symptomatic Peripheral Artery Disease.

BACKGROUND: Impaired microcirculation is associated with poor walking capacity in symptomatic peripheral artery disease (PAD) patients during treadmill test; however, this test does not simulate the efforts of daily walking of these patients. Thus, the aim of the study was to describe the microcirculation responses during a 6-minute walk test (6MWT) and to analyze the relationship between microcirculation indicators and walking impairment in symptomatic PAD patients. METHODS: Thirty-four patients were included (mean age = 67.6 ± 11.2 years). Their clinical characteristics were collected, and they performed a 6MWT, in which the initial claudication distance (ICD) and total walking distance (TWD) were recorded. During and after the 6MWT, calf muscle oxygen saturation (StO2) parameters were monitored continuously to measure microcirculation behavior. The association between calf muscle StO2 parameters and walking impairment were analyzed by Pearson or Spearman correlations. RESULTS: Walking impairment was not associated with any StO2 parameters during exercise. In contrast, after 6MWT, recovery time of StO2 (r = -0.472, P = 0.008) and recovery time to maximal StO2 (r = -0.402, P = 0.019) were negatively correlated with ICD. Furthermore, the distance walked under claudication symptoms (ΔTWD-ICD) was positively correlated with recovery time to maximal StO2 (r = 0.347, P = 0.048). CONCLUSIONS: In symptomatic PAD patients, shorter ICD values during a 6MWT are associated with a delayed recovery in calf muscle StO2 after exercise. Calf muscle StO2 parameters decrease subtly during 6MWT, suggesting that the degree of ischemia in the calf muscle during ground walking, simulating efforts of the daily walking, is relatively low.

Infection related to implantable central venous access devices in cancer patients: epidemiology and risk factors.

OBJECTIVE: To describe the epidemiology of infections related to the use of implantable central venous access devices (CVADs) in cancer patients and to evaluate measures aimed at reducing the rates of such infections. DESIGN: Prospective cohort study. SETTING: Referral hospital for cancer in São Paulo, Brazil. PATIENTS: We prospectively evaluated all implantable CVADs employed between January 2009 and December 2011. Inpatients and outpatients were followed until catheter removal, transfer to another facility, or death. METHODS: Outcome measures were bloodstream infection and pocket infection. We also evaluated the effects that the creation of a multidisciplinary team for CVAD care, avoiding in-hospital implantation of CVADs, and limiting CVAD insertion in neutropenic patients have on the rates of such infections. RESULTS: During the study period, 966 CVADs (mostly venous ports) were implanted in 933 patients, for a combined total of 243,792 catheter-days. We identified 184 episodes of infection: 154 (84%) were bloodstream infections, 21 (11%) were pocket infections, and 9 (5%) were surgical site infections. During the study period, the rate of CVAD-related infection dropped from 2.2 to 0.24 per 1,000 catheter-days ([Formula: see text]). Multivariate analysis revealed that relevant risk factors for such infection include surgical reintervention, implantation in a neutropenic patient, in-hospital implantation, use of a cuffed catheter, and nonchemotherapy indication for catheter use. CONCLUSIONS: Establishing a multidisciplinary team specifically focused on CVAD care, together with systematic reporting of infections, appears to reduce the rates of infection related to the use of these devices.

Impact of endovascular technique in vascular surgery training at a large university hospital in Brazil.

OBJECTIVES: The aim of this study was to determine the impact of endovascular surgery versus open vascular technique training in a Brazilian teaching service. DESIGN: Cross-sectional study. SETTING: Hospital das Clinicas-Faculty of Medicine-University of Sao Paulo, a tertiary institutional hospital-Brazil. PARTICIPANTS: We reviewed 1,040 arterial operations performed during 2 distinct time periods: January 1995 to December 1996, and January 2006 to December 2007. Based on the disease treated, the procedures were classified into the following 5 groups: abdominal aortic aneurysms (AAA), aorto-iliac obstructive disease (AI), obstructive disease of the femoropopliteal-tibial segment (FP), carotid disease (C), and others (O). The operations were also divided into an endovascular surgery (ES) group and an open surgery (OS) group. We compared the number of open and endovascular procedures for each arterial disease group during both periods. RESULTS: During the 2006-2007 period, 654 patients were treated surgically, whereas over the 1995-1996 period, 386 arterial operations were performed. A significant increase in endovascular procedures (p < 0.001) was found from the 1995-1996 period to the 2006-2007 period (35 vs 351, respectively) in all groups, whereas open surgery showed a slight increase in the number of procedures in the AAA and O groups only. In the 1995-1996 period, OS was the primary surgical method for all groups, but in the 2006-2007 time frame, OS was performed more frequently than ES only in the AAA and O groups. Considering all vascular disease groups, OS was the technique used in 90.9% (351 of 386) of the operations during 1995-1996, whereas in 2006-2007, OS was performed in only 46.3% (303 of 654) of the procedures. CONCLUSIONS: The increase in the number of ES observed over the past decade has had little impact on OS procedures performed at our medical center, not bringing harm to open surgical training.