Comparison of autograft and allograft aortic valve replacement in children

OBJECTIVE: This study was undertaken to compare the clinical and hemodynamic results following aortic valve replacement with a pulmonary valve autograft (Ross procedure) or an allograft valve in children. METHODS: The records of 107 pediatric aortic valve replacements from 1994 through 2001 were reviewed, including 78 autografts and 25 allografts. Four mechanical aortic valve replacements performed during this period were excluded from analysis. RESULTS: There were 3 perioperative deaths and 1 late death. Reoperations were required in 5 autograft recipients (with autograft preservation in 4) and in 3 allograft recipients (all requiring valve re-replacement). Seven-year survival (96% in both groups) and reoperation-free survival (88% in the autograft group; 73% in the allograft group, P =.5) were not significantly different. Serial echocardiographic studies showed that in the autograft group, left ventricular outflow tract maximal velocity (2.0-1.8 m/s, P =.02) and left ventricular thickness (10.1-8.4 mm, P <.0001) fell significantly. In the allograft group, maximal velocity (2.3-3.0 m/s, P =.03) increased significantly and left ventricular thickness (9.5-9.0 mm, P =.2) showed minimal change. Analysis according to preoperative physiology (aortic stenosis versus insufficiency), congenital cardiac anatomy, number or type of previous operations, age of patient, and use of balloon valvotomy did not predict outcomes. CONCLUSIONS: Aortic valve replacement with either the autograft or allograft provides excellent clinical results in children during an intermediate duration of observation. The Ross procedure achieves a superior hemodynamic result, which may be clinically important with longer follow-up.     

Phase II study of abarelix depot for androgen independent prostate cancer progression during gonadotropin-releasing hormone agonist therapy

PURPOSE: We determine the clinical efficacy of the gonadotropin-releasing hormone (Gn-RH) antagonist abarelix in patients with androgen independent prostate cancer, and measure its effect on serum follicle-stimulating hormone (FSH) and testosterone. MATERIALS AND METHODS: A total of 20 patients with prostate cancer progression during Gn-RH agonist therapy received 100 mg. abarelix depot by intramuscular injection on days 1, 15 and 29, and then every 28 days for up to 24 weeks. Gn-RH agonist therapy was not continued. Patients who met criteria for prostate specific antigen (PSA) response after 24 weeks of therapy could receive treatment for up to 52 weeks. PSA response was the primary end point and was defined as a 50% decrease confirmed 4 weeks later. Secondary end points of this study were the effect of therapy on serum FSH and testosterone. RESULTS: No patient met the criteria for PSA response. At the end of the 6 cycles of therapy 2 patients remained stable without PSA progression or other signs of disease progression. Median time to progression was 8 weeks (95% CI 5.7-10.3). Mean serum FSH decreased by more than 50% from a baseline of 5.7 IU/l. (95% CI 4.2-7.1) and remained suppressed throughout the observation period. Mean serum testosterone did not change after 4 and 8 weeks of therapy and remained in the anorchid range. Treatment was well tolerated with no grade 3 or higher toxicity. CONCLUSIONS: Treatment of androgen independent prostate cancer with abarelix decreases circulating FSH and maintains anorchid testosterone but does not result in clinical responses.     

咪达唑仑复合氯胺酮应用于小儿基础麻醉的临床探讨

 目的 探讨应用咪达唑仑复合氯胺酮不同给药方法在小儿基础麻醉中的优化方案.方法 200例1～6岁,ASAⅠ～Ⅱ级患儿随机分成以下五组:A组为口服咪达唑仑0.7 mg/kg;B组为口服氯胺酮8 mg/kg;C组为肌注氯胺酮5mg/kg;D组为口服咪达唑仑0.5 mg/kg和氯胺酮4 mg/kg;E组为先口服咪达唑仑0.5 mg/kg,再肌注氯胺酮4 mg/kg.观察各组诱导结果及呼吸循环变化、不良反应.结果 ①A组与B组比较,A组起效更快(P<0.01),合作更好,不良反应较少;②A组、B组均比C组更合作,但不如C组起效更快;③D组和E组相比,患儿更合作,不良反应更少,但起效更慢,两组诱导效果无显著差异(P>0.05).结论 咪达唑仑复合氯胺酮优于单独给药,对循环呼吸影响小;口服给药可行性更佳.     

Breast tomosynthesis and digital mammography: a comparison of breast cancer visibility and BIRADS classification in a population of cancers with subtle mammographic findings

The main purpose was to compare breast cancer visibility in one-view breast tomosynthesis (BT) to cancer visibility in one- or two-view digital mammography (DM). Thirty-six patients were selected on the basis of subtle signs of breast cancer on DM. One-view BT was performed with the same compression angle as the DM image in which the finding was least/not visible. On BT, 25 projections images were acquired over an angular range of 50 degrees, with double the dose of one-view DM. Two expert breast imagers classified one- and two-view DM, and BT findings for cancer visibility and BIRADS cancer probability in a non-blinded consensus study. Forty breast cancers were found in 37 breasts. The cancers were rated more visible on BT compared to one-view and two-view DM in 22 and 11 cases, respectively, (p < 0.01 for both comparisons). Comparing one-view DM to one-view BT, 21 patients were upgraded on BIRADS classification (p < 0.01). Comparing two-view DM to one-view BT, 12 patients were upgraded on BIRADS classification (p < 0.01). The results indicate that the cancer visibility on BT is superior to DM, which suggests that BT may have a higher sensitivity for breast cancer detection.     

Stroke volume measurements with first-pass dynamic positron emission tomography: Comparison with cardiovascular magnetic resonance

Background  The assessment of forward stroke volume (SV) using dynamic, first-pass cardiac positron emission tomography (PET) was shown to be feasible in a limited number of studies with small numbers of subjects. The aim of this study was to compare first-pass derived SV with cardiovascular magnetic resonance imaging (CMR)-obtained values in a larger population of subjects. Methods and Results  Fifty-nine subjects with varying degrees of cardiac function were studied. Stroke volume was assessed using oxygen-15-labeled water (H₂ ¹⁵O) dynamic first-pass PET for both the right ventricle (RV) and left ventricle (LV), and compared with the findings of aorta velocity-encoded phase-contrast CMR. The PET-estimated SV was higher for the RV than for the LV (133±34 vs 116±31 mL, P<.01, ±SD), and both were higher compared with values obtained by CMR (81±20 mL, both P<.01,±SD). Although significant, the correlations between PET and CMR were moderate for both the RV (r=0.37, P<.01) and the LV (r=0.40, P<.01,±SD). Bland-Altman analysis revealed a progressive overestimation with increasing SV measured in either ventricle. Conclusions  First-pass dynamic H₂ ¹⁵O PET for the assessment of forward SV is feasible, although values are progressively overestimated with increasing SV, particularly when the RV is used, and correlations with aorta velocity-encoded phase-contrast CMR are moderate. These findings are probably protocol-dependent and warrant further study before the use of first-pass dynamic H₂ ¹⁵O PET in clinical or research settings can be advocated.     

More than just stones: a pictorial review of common and less common gallbladder pathologies

Although stone disease is by far the most commonly encountered pathology of the gallbladder, there are several other important disease processes affecting it. These include adenomyomatosis, cholesterolosis, polyps, porcelain gallbladder, acalculous cholecystitis, xanthogranulomatous cholecystitis, emphysematous cholecystitis, gallbladder cancer, and gallbladder hemorrhage. The purpose of this article was to review the different gallbladder pathologies encountered in everyday radiological practice and to describe their features in the standard imaging modalities.     

Venous thromboembolism in trauma: a local manifestation of systemic hypercoagulability?

BACKGROUND: The purpose of this study was to evaluate the relative importance of systemic hypercoagulability, preexisting and acquired risk factors, and specific injury patterns in the development of venous thromboembolism (VTE) after injury. METHODS: Injured patients with an Injury Severity Score > or = 15 were followed with lower extremity venous duplex ultrasonography, prothrombin fragment 1 + 2, and quantitative D-dimer levels at 1 and 3 days and then weekly until discharge. RESULTS: Among 101 patients with a mean Injury Severity Score of 27.3 +/- 10.5 followed for 12.4 +/- 8.7 days, 28 (27.7%) developed a lower extremity thrombosis, 2 (1.9%) sustained a pulmonary embolism, and 1 (0.9%) had a symptomatic upper extremity thrombosis. Although admission fragment 1 + 2 and D-dimer levels were elevated in 81.4% and 100% of patients, respectively, mean levels were not significantly different in those with or without VTE. VTE was more common (p < 0.05) among those with obesity, age > 40 years, immobilization for > 3 days, spine fractures, and lower extremity fractures. However, only obesity (p = 0.004) and immobilization > 3 days (p = 0.05) were independent predictors of VTE in a multivariate analysis. CONCLUSION: Although elevated in seriously injured patients, neither markers of activated coagulation nor specific injury patterns are predictive of VTE. Associations with immobilization and obesity suggest that VTE after injury is a systemic hypercoagulable disorder with local manifestations of thrombosis related to lower extremity stasis.     

Positron Emission Tomography Affects Surgical Management in Recurrent Colorectal Cancer Patients

Background: We determined the effect of positron emission tomography (PET) on surgical decision-making in patients with metastatic or recurrent colorectal cancer.Methods: A total of 114 patients with advanced colorectal cancer were imaged with computed tomography (CT) and PET scans. The PET and CT scans were independently interpreted before surgery and recorded.Results: Forty-two of the 114 patients had resectable disease on the basis of CT. PET altered therapy in 17 (40%) of these 42 patients on the basis of the following results: extrahepatic disease (n = 9), bilobar involvement (n = 3), thoracic involvement (n = 5), retroperitoneal lymphadenopathy (n = 2), bone involvement (n = 1), and supraclavicular disease (n = 1). In 25 patients with liver metastases only, PET found additional disease in 18 (72%), extrahepatic disease in 11, chest disease in 13, retroperitoneal lymphadenopathy in 4, and bone disease in 3. In five patients, both scans underestimated small-volume peritoneal metastases discovered at laparotomy.Conclusions: PET altered therapy in 40% of patients. In patients with isolated liver involvement, 72% had more extensive disease that precluded surgical resection. PET scans should be used in the management of patients with recurrent colorectal cancer who are being considered for potentially curative surgery.     

Congenital high airway obstruction syndrome: natural history and management

Background

Congenital high airway obstruction syndrome (CHAOS) is a life-threatening condition with a poorly understood natural history.

Methods

A retrospective review of five patients with CHAOS between 1997 and 2002 was performed.

Results

All fetuses had large echogenic lungs, dilated airways, inverted diaphragms, and massive ascites. One fetus with a laryngeal cyst was terminated at 22 weeks. A twin fetus with findings suggestive of a tracheal web had progressive hydrops, which led to fetal demise. The remaining 3 patients delivered via the ex utero intrapartum treatment (EXIT) procedure survived. The first patient tolerated progressive hydrops for 12 weeks in utero. He had tracheal atresia but underwent laryngotracheoplasty successfully. He is the first long-term CHAOS survivor and is speaking at 5 years of age. The 2 patients with relatively stable lung volumes prenatally have laryngeal atresia with a pinpoint posterior laryngeal fistula. Their postnatal clinical courses were much more benign than the first survivor.

Conclusions

The prenatal natural history and postnatal course of CHAOS depends on whether the airway obstruction is complete. The EXIT procedure offers the potential for salvage of this otherwise lethal condition. Hydrops may be well tolerated prenatally for weeks with potential resolution if airway fistulization is present.     

Biomechanical analysis of five fixation techniques used in glenohumeral arthrodesis

Background: The purpose of the present study is to compare five fixation techniques in shoulder fusion. The most common complications resulting from shoulder fusion, non‐union and unacceptable arm position, might reflect a failure to achieve rigid fixation during the surgical procedure. Methods: Twenty‐five shoulder fusions were carried out on human cadaveric specimens using the following techniques: screw fixation, external fixation, external fixation supplemented with screw fixation, single plate fixation and double plate fixation. Each specimen was tested on a servohydraulic machine to determine stiffness. Results: There was a statistically significant difference in bending and torsional stiffness between all five fixation techniques. Normalized bending (B) and torsional stiffness (T), in descending order, were: double plate (B = 1.00, T = 1.00), single plate (B = 0.77, T = 0.89), external fixation with screws (B = 0.68, T = 0.74), external fixation alone (B = 0.40, T = 0.53), and screws alone (B = 0.13, T = 0.26). Conclusion: The risk of the most common complications resulting from shoulder fusion might be minimized if these biomechanical findings are applied to surgical decision making.