Accuracy of Right and Left Ventricular Functional Assessment by Short-Axis vs Axial Cine Steady-State Free-Precession Magnetic Resonance Imaging: Intrapatient Correlation With Main Pulmonary Artery and Ascending Aorta Phase-Contrast Flow Measurements

Objective

The left ventricle (LV) is routinely assessed with cardiac magnetic resonance imaging (MRI) by using short-axis orientation; it remains unclear whether the right ventricle (RV) can also be adequately assessed in this orientation or whether dedicated axial orientation is required. We used phase-contrast (PC) flow measurements in the main pulmonary artery (MPA) and the ascending aorta (Aorta) as nonvolumetric standard of reference and compared RV and LV volumes in short-axis and axial orientations.

Methods

A retrospective analysis identified 30 patients with cardiac MRI data sets. Patients underwent MRI (1.5 T or 3 T), with retrospectively gated cine steady-state free-precession in axial and short-axis orientations. PC flow analyses of MPA and Aorta were used as the reference measure of RV and LV output.

Results

There was a high linear correlation between MPA-PC flow and RV–stroke volume (SV) short axis (r = 0.9) and RV-SV axial (r = 0.9). Bland-Altman analysis revealed a mean offset of 1.4 mL for RV axial and –2.3 mL for RV–short-axis vs MPA-PC flow. There was a high linear correlation between Aorta-PC flow and LV-SV short-axis (r = 0.9) and LV-SV axial (r = 0.9). Bland-Altman analysis revealed a mean offset of 4.8 m for LV short axis and 7.0 mL for LV axial vs Aorta-PC flow. There was no significant difference (P = .6) between short-axis–LV SV and short-axis–RV SV.

Conclusion

No significant impact of the slice acquisition orientation for determination of RV and LV stroke volumes was found. Therefore, cardiac magnetic resonance workflow does not need to be extended by an axial data set for patients without complex cardiac disease for assessment of biventricular function and volumes.     

Klippel-Feil syndrome: patterns of bony fusion and wasp-waist sign

Cervical spine radiographs of 33 patients with Klippel-Feil syndrome were studied for patterns of bony fusion and presence of wasp-waist sign. Five patients were found to have the classic features of massive cervical fusion. Two patients with two adjacent levels of bony fusion showed a wasp-waist sign. Fusion at one level of the cervical spine accounted for 26 remaining cases. The wasp-waist sign was observed in 14 of the cases in which there was complete vertebral interbody fusion, making this finding a valuable radiologic sign. Partial anterior or posterior vertebral interbody fusion, or isolated fusion of the neural arch, however, may or may not be associated with the wasp-waist sign. Klippel-Feil syndrome, easy to recognize when presenting with classic features or when associated with the wasp-waist sign, may be confused with a variety of other entities.     

Gastrointestinal duplications

Background/Purpose: The aim of this study was to review the presentations of gastrointestinal duplication (GID) and to assess the influence of prenatal diagnosis on treatment. Methods: Retrospective review of all GID at 2 pediatric hospitals from 1980-2002 was conducted. Results: Seventy-three patients (M43:F30) were identified: 21 neonates, 28 infants (1 to 24 months), 15 children (1 to 10 years), 9 adolescents ([ge ]11 years). GID location by frequency was ileum (31.5%), ileocaecal valve (30.2%), duodenum (9.6%), stomach (8.2%), jejunum (8.2%), colon (6.8%), and rectum (5.5%). In neonates and infants, vomiting and distension were the most common presentations. Volvulus, caused by a duplication, occurred in 23.8% of neonates and caused the death of one neonate. Intussusception was identified in 10.9% of patients. In older children and adolescents, pain and vomiting were the most common associations. Six of these patients were being treated for Crohn[apos ]s disease, with the diagnosis of duplication made at laparotomy. Eighteen patients had a prenatal diagnosis by ultrasound scan, with 77.2% of these asymptomatic after birth. Most prenatal diagnoses occurred after 1991 (77.8%). When comparing an earlier period (1980 to 1991; 29 patients) with the current (1992 to 2002; 44 patients), a greater proportion of the latter patients were asymptomatic (36.4 v 13.8%) and had a lower incidence of complications (volvulus/intussusception). Conclusions: GID can lead to life-threatening complications. Prenatal diagnosis should lead to expeditious postnatal investigation and treatment before the onset of symptoms or complications. GID in older children can mimic Crohn[apos ]s disease. Laparoscopy/laparotomy should be considered in patients with atypical Crohn[apos ]s disease or when the diagnosis of an intraabdominal mass is unclear. J Pediatr Surg 38:740-744. [copy ] 2003 Elsevier Inc. All rights reserved.     

AOPP-induced activation of human neutrophil and monocyte oxidative metabolism: a potential target for N-acetylcysteine treatment in dialysis patients

AOPP-induced activation of human neutrophil and monocyte oxidative metabolism: A potential target forN-acetylcysteine treatment in dialysis patients. BACKGROUND: Oxidative stress largely contributes to hemodialysis-associated lethal complications, thus explaining the urgent need of antioxidant-based therapeutic strategies in hemodialysis patients. We previously identified advanced oxidation protein products (AOPP) in the uremic plasma as exquisite markers of oxidative stress and potent mediators of monocyte activation. The present study was aimed at searching whether (1) AOPP can also trigger activation of polymorphonuclear neutrophils (PMN), and (2) whether AOPP-induced activation could be inhibited by N-acetylcysteine (NAC), a widely used compound which has been shown to prevent oxidative injury to kidney. METHODS: Both human serum albumin (HAS) AOPP (i.e., HOCl-modified HSA in vitro preparations and AOPP extracted from plasma of hemodialysis patients) were tested for their capacity to trigger phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and myeloperoxidase (MPO)-dependent activities as measured by lucigenin- and luminol-amplified chemiluminescence (CL), respectively, as compared to receptor-dependent [opsonized zymosan or receptor-independent phorbol myristate acetate (PMA)]. The effect of PMN priming by platelet-activating factor (PAF), and the effect of NAC on normal monocyte and on normal or hemodialysis patient's (N = 16) PMN oxidative responses were compared. RESULTS: HSA-AOPP triggered in a HOCl dose-dependent manner both NADPH-oxidase- and MPO-dependent CL of PMN. This latter was further enhanced by PAF priming. Plasma-derived AOPP obtained from hemodialysis patients also triggered PMN respiratory burst. NAC significantly reduced HSA-AOPP-mediated responses of normal monocyte and of normal and uremic PMN but had no significant effect on opsonized zymosan- or PMA-induced CL responses. CONCLUSION: This dual potential of NAC to inhibit phagocyte oxidative responses induced by HSA-AOPP without affecting those mediated by compounds mimicking pathogens supports the proposal of a therapeutic trial with NAC aimed at reducing oxidative stress-related inflammation in hemodialysis patients.     

Free-breathing 3D steady-state free precession coronary magnetic resonance angiography: comparison of diaphragm and cardiac fat navigators

PURPOSE: To compare the performance of the conventional diaphragm navigator (DNAV) and the recently developed cardiac fat navigator (FatNAV) in suppressing respiration-induced cardiac motion in free-breathing 3D balanced steady-state free precession coronary MRA (SSFP CMRA). MATERIALS AND METHODS: In 16 healthy volunteers the right coronary artery (RCA) was imaged at 1.5T using a navigator-gated 3D SSFP CMRA sequence. DNAV and FatNAV gating were performed in random order. Image quality difference was scored by three experienced readers blinded to the gating technique. Blood signal-to-noise ratio (SNR), blood-to-myocardium contrast-to-noise ratio (CNR), and navigator efficiency were calculated. RESULTS: Diagnostically interpretable CMRA was obtained successfully in all 16 subjects with FatNAV gating (0% failure rate) and only 14 subjects with DNAV gating (12% failure rate). Compared to DNAV gating, FatNAV gating provided similar SNR and CNR, better image quality (P < 0.01), and 28% improvement in navigator efficiency (P = 0.002). CONCLUSION: FatNAV gating provides more effective motion suppression and better image quality than DNAV gating for free-breathing 3D SSFP CMRA of the RCA in healthy subjects.     

Small bowel transit and gastric emptying after biliodigestive anastomosis using the uncut jejunal loop

BACKGROUND: The Roux-en-Y loop is an effective procedure for biliodigestive drainage. However, up to 15% of patients suffer from postoperative cholangitis or blind loop syndrome. A new technique to prevent motility abnormalities has been developed. METHODS: Male Lewis rats were used to compare gastric emptying and transit in the small bowel after either a standard Roux-en-Y anastomosis or a new biliodigestive anastomosis technique which involves creating an "uncut" jejunal loop with luminal occlusion. Unoperated rats served as controls. (99)Technetium HIDA and (111)Indium-tagged amberlite were respectively used to investigate small bowel transit and gastric emptying. RESULTS: Histopathology showed distinctive abnormalities only in the liver of conventional Roux-en-Y animals. No recanalization of the obliterated gut lumen occurred in uncut Roux animals. Distribution of (99)Tc-HIDA and (111)In showed were similar in both groups. Gastric emptying is slowed in both groups. CONCLUSIONS: The uncut proximal jejunum loop is a good alternative to the conventional Roux-en-Y loop and showed preserved small bowel motility and adequate jejunal transit. Gastric emptying is slowed in both groups.     

Biomarkers for the early detection of acute kidney injury

Acute kidney injury (AKI), previously referred to as acute renal failure (ARF), represents a persistent problem in clinical medicine. Despite significant improvements in therapeutics, the mortality and morbidity associated with AKI remain high. A major reason for this is the lack of early markers for AKI, akin to troponins in acute myocardial disease, and hence an unacceptable delay in initiating therapy. Fortunately, the application of innovative technologies such as functional genomics and proteomics to human and animal models of AKI has uncovered several novel genes and gene products that are emerging as biomarkers. The most promising of these are chronicled in this article. These include a plasma panel [neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C] and a urine panel [NGAL, interleukin 18 (IL-18), and kidney injury molecule 1 (KIM)-1]. As they represent sequentially expressed biomarkers, it is likely that the AKI panels will be useful for timing the initial insult and assessing the duration of AKI. Based on the differential expression of the biomarkers, it is also likely that the AKI panels will distinguish between the various types and etiologies of AKI. It will be important in future studies to validate the sensitivity and specificity of these biomarker panels in clinical samples from large cohorts and from multiple clinical situations.     

Soft Tissue Coverage at the Resource-challenged Facility

Covering soft tissue defects remains challenging for orthopaedic surgeons, especially those in resource-challenged facilities. Covering tissue defects follow a plan from simple to complex: primary closure, local flap, area flap, pedicle flap, and free flap. I will limit my discussion to the role of latter two. At the district-level hospital in Vietnam, pedicle flaps are generally more useful, so I will discuss free flaps only briefly. The choices of pedicle flaps include: kite flap, posterior interosseous flap, radial flap (Chinese flap), neurocutaneous flap, anterolateral thigh fasciocutaneous flap, gastrocnemius flap, sural flap, posterior leg flaps; we typically use a free flap with the latissimus dorsi. Soft tissue coverage with pedicle flaps has many advantages: reliability, relatively easy harvest, and good blood supply. Free flaps with microanastomosis have an important place in covering difficult medium- or large-sized soft tissue defects but also require more instruments and more highly trained surgeons. The author certifies that he/she has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. The author certifies that his/her institution does not require approval for the human protocol for this investigation and that the investigation was conducted in conformity with ethical principles of research.     

Remission of diabetes after laparoscopic gastric bypass

Diabetes is a well-recognized and treatable risk factor for cardiac disease, and one of many comorbidities associated with obesity. The aim of this study was to evaluate the clinical outcome of a cohort of morbidly obese patients with documented diabetes who underwent laparoscopic Roux-en-Y gastric bypass. Fifty-nine patients with sufficient follow-up were included in the study. Mean preoperative duration of diabetes was 68 months. At 1 month postoperatively, mean excess body weight loss was 17 per cent with 29 patients (49%) showing improvement and 21 patients (36%) having remission of their disease. Mean excess body weight loss was 67 per cent at 12 months postoperatively with 25 patients (42%) showing improvement and 34 patients (58%) having remission of diabetes. Mean preoperative fasting blood glucose level decreased from 152 g/dL preoperatively to 100 g/dL at 12 months (P = 0.02), whereas glycosylated hemoglobin decreased from 7.9 per cent to 5.7 per cent, respectively (P < 0.01). Patients with remission of diabetes had a shorter length of condition compared with patients with only improvement (43 vs 103 months, P < 0.01). Weight loss associated with laparoscopic gastric bypass significantly improves diabetes control and results in discontinuation or marked reduction of antidiabetic medications in the majority of patients. Improvement in glucose control occurs as early as 1 month postoperatively.