Natural history of brain lesions in extremely preterm infants studied with serial magnetic resonance imaging from birth and neurodevelopmental assessment

OBJECTIVES

The aim was to survey the range of cerebral injury and abnormalities of cerebral development in infants born between 23 and 30 weeks' gestation using serial MRI scans of the brain from birth, and to correlate those findings with neurodevelopmental outcome after 18 months corrected age.

METHODS

Between January 1997 and November 2000, consecutive infants born at < 30 weeks' gestational age underwent serial MRI brain scans from birth until term-equivalent age. Infants were monitored after 18 months of age, corrected for prematurity, with the Griffiths Mental Development Scales and neurologic assessment.

RESULTS

A total of 327 MRI scans were obtained from 119 surviving infants born at 23 to 30 weeks of gestation. Four infants had major destructive brain lesions, and tissue loss was seen at term for the 2 survivors. Fifty-one infants had early hemorrhage; 50% of infants with term scans after intraventricular hemorrhage had ventricular dilation. Twenty-six infants had punctate white matter lesions on early scans; these persisted for 33% of infants assessed at term. Early scans showed cerebellar hemorrhagic lesions for 8 infants and basal ganglia abnormalities for 17. At term, 53% of infants without previous hemorrhage had ventricular dilation and 80% of infants had diffuse excessive high signal intensity within the white matter on T2-weighted scans. Complete follow-up data were available for 66% of infants. Adverse outcomes were associated with major destructive lesions, diffuse excessive high signal intensity within the white matter, cerebellar hemorrhage, and ventricular dilation after intraventricular hemorrhage but not with punctate white matter lesions, hemorrhage, or ventricular dilation without intraventricular hemorrhage.

CONCLUSIONS

Diffuse white matter abnormalities and post-hemorrhagic ventricular dilation are common at term and seem to correlate with reduced developmental quotients. Early lesions, except for cerebellar hemorrhage and major destructive lesions, do not show clear relationships with outcomes.

Aortic root dilatation in young men with normally functioning bicuspid aortic valves

OBJECTIVE

To evaluate the dimensions of the aortic root in a selected population of young males with isolated normally functioning bicuspid aortic valve.

DESIGN AND SETTING

Echocardiographic and Doppler evaluation of conscripts with bicuspid aortic valve at the time of military pre-enrolment screening in two military hospitals.

SUBJECTS AND METHODS

66 consecutive young men with a normally functioning bicuspid aortic valve were studied to assess aortic size at four aortic levels: annulus, sinuses of Valsalva, supra-aortic ridge, and proximal ascending aorta; 70 consecutive normal young subjects, matched for age and body surface area, were used as controls.

RESULTS

In men with a bicuspid aortic valve, the diameter of the aortic root was significantly larger than in controls at the sinuses (3.16 (0.37) v 2.87 (0.31) cm, p < 0.001), at the supra-aortic ridge (2.64 (0.46) v 2.47 (0.28) cm, p = 0.01), and at the level of the proximal ascending aorta (3.12 (0.48) v 2.69 (0.28) cm, p < 0.001). The prevalence of aortic root dilatation was 7.5% at the annulus (5/66), 19.6% at the sinuses (13/66), 15% at the supra-aortic ridge (10/66), and 43.9% at the ascending aorta (29/66); 32 subjects (48%) had aortic root dimensions comparable with controls, while 34 (52%) had definitely abnormal aortic root dimensions.

CONCLUSIONS

Aortic root enlargement in people with a bicuspid aortic valve occurs independently of haemodynamic abnormalities, age, and body size. However, there appear to be different subgroups of young adults with bicuspid aortic valves, one of which is characterised by aortic dilatation, possibly caused by a congenital abnormality of the aortic wall.

Increased risk of biochemical and local failure in patients with distended rectum on the planning CT for prostate cancer radiotherapy

PURPOSE

To retrospectively test the hypothesis that rectal distension on the planning computed tomography (CT) scan is associated with an increased risk of biochemical and local failure among patients irradiated for prostate carcinoma when a daily repositioning technique based on direct prostate-organ localization is not used.

METHODS AND MATERIALS

This study included 127 patients who received definitive three-dimensional conformal radiotherapy for prostate cancer to a total dose of 78 Gy at The University of Texas M. D. Anderson Cancer Center. Rectal distension was assessed by calculation of the average cross-sectional rectal area (CSA; defined as the rectal volume divided by length) and measuring three rectal diameters on the planning CT. The impact of rectal distension on biochemical control, 2-year prostate biopsy results, and incidence of Grade 2 or greater late rectal bleeding was assessed.

RESULTS

The incidence of biochemical failure was significantly higher among patients with distended rectums (CSA >11.2 cm(2)) on the planning CT scan (p = 0.0009, log-rank test). Multivariate analysis indicates that rectal distension and high-risk disease are independent risk factors for biochemical failure, with hazard ratios of 3.89 (95% C.I. 1.58 to 9.56, p = 0.003) and 2.45 (95% C.I. 1.18 to 5.08, p = 0.016), respectively. The probability of residual tumor without evidence of radiation treatment (as scored by the pathologist) increased significantly with rectal distension (p = 0.010, logistic analysis), and a lower incidence of Grade 2 or greater late rectal bleeding within 2 years was simultaneously observed with higher CSA values (p = 0.031, logistic analysis).

CONCLUSIONS

We found strong evidence that rectal distension on the treatment-planning CT scan decreased the probability of biochemical control, local control, and rectal toxicity in patients who were treated without daily image-guided prostate localization, presumably because of geographic misses. Therefore, an empty rectum is warranted at the time of simulation. These results also emphasize the need for image-guided radiotherapy to improve local control in irradiating prostate cancer.

Alterations in atrial electrophysiology and tissue structure in a canine model of chronic atrial dilatation due to mitral regurgitation

BACKGROUND

Clinically, chronic atrial dilatation is associated with an increased incidence of atrial fibrillation (AF), but the underlying mechanism is not clear. We have investigated atrial electrophysiology and tissue structure in a canine model of chronic atrial dilatation due to mitral regurgitation (MR).

METHODS AND RESULTS

Thirteen control and 19 MR dogs (1 month after partial mitral valve avulsion) were studied. Dogs in the MR group were monitored using echocardiography and Holter recording. In open-chest follow-up experiments, electrode arrays were placed on the atria to investigate conduction patterns, effective refractory periods, and inducibility of AF. Alterations in tissue structure and ultrastructure were assessed in atrial tissue samples. At follow-up, left atrial length in MR dogs was 4.09+/-0.45 cm, compared with 3.25+/-0.28 at baseline (P<0.01), corresponding to a volume of 205+/-61% of baseline. At follow-up, no differences in atrial conduction pattern and conduction velocities were noted between control and MR dogs. Effective refractory periods were increased homogeneously throughout the left and right atrium. Sustained AF (>1 hour) was inducible in 10 of 19 MR dogs and none of 13 control dogs (P<0.01). In the dilated MR left atrium, areas of increased interstitial fibrosis and chronic inflammation were accompanied by increased glycogen ultrastructurally.

CONCLUSIONS

Chronic atrial dilatation in the absence of overt heart failure leads to an increased vulnerability to AF that is not based on a decrease in wavelength.

Exaggerated left ventricular dilation and reduced collagen deposition after myocardial infarction in mice lacking osteopontin

Osteopontin (OPN), an extracellular matrix protein, is expressed in the myocardium with hypertrophy and failure. We tested the hypothesis that OPN plays a role in left ventricular (LV) remodeling after myocardial infarction (MI). Accordingly, OPN expression and LV structural and functional remodeling were determined in wild-type (WT) and OPN knockout (KO) mice 4 weeks after MI. Northern analysis showed increased OPN expression in the infarcted region, peaking 3 days after MI and gradually decreasing over the next 28 days. In the remote LV, OPN expression was biphasic, with peaks at 3 and 28 days. In situ hybridization and immunohistochemical analyses showed increased OPN mRNA and protein primarily in the interstitium. Infarct size, heart weight, and survival were similar in KO and WT mice after MI (P=NS), whereas the lung wet weight/dry weight ratio was increased in the KO mice (P<0.005 versus sham-operated mice). Peak LV developed pressure was reduced to a similar degree after MI in the KO and WT mice. The number of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive myocytes was similar in KO and WT mice after MI. In contrast, post-MI LV chamber dilation was approximately twice as great in KO versus WT mice (P<0.001). Myocyte length increased after MI in WT mice (P<0.001) but not in KO mice. Electron microscopy showed increased collagen content in WT mice after MI but not in KO mice after MI. Type I collagen content was increased approximately 3-fold and approximately 7-fold in remote and infarcted regions, respectively, of WT hearts after MI but not in KO hearts (P<0.01 versus WT hearts). Likewise, Northern analyses showed increased collagen I(alpha(1)) mRNA after MI in remote regions of WT hearts but not in KO hearts. Thus, increased OPN expression plays an important role in regulating post-MI LV remodeling, at least in part, by promoting collagen synthesis and accumulation.

Posthaemorrhagic ventricular dilatation in the premature infant: natural history and predictors of outcome

OBJECTIVE

To investigate the natural history and predictors of outcome of posthaemorrhagic ventriculomegaly in the very low birthweight (VLBW) infant.

METHODS

All VLBW infants admitted between September 1994 and September 1997 to the neonatal intensive care units of Brigham and Women's Hospital (Boston), Children's Hospital (Boston), and Christchurch Women's Hospital (New Zealand) with germinal matrix intraventricular haemorrhage (IVH) were identified. All charts and ultrasound scans were reviewed to define the natural history and perinatal and/or postnatal factors of value in prediction of the course of posthaemorrhagic ventriculomegaly. Progressive ventricular dilatation (PVD) was defined from the results of serial cranial ultrasound scans.

RESULTS

A total of 248 VLBW infants had evidence of IVH (22% of all VLBW infants, mean (SD) gestational age 26.8 (2.6) weeks). A quarter of the infants exhibited PVD. Spontaneous arrest of PVD occurred without treatment in 38% of infants with PVD. Of the remaining 62% with persistent PVD, 48% received non-surgical treatment only (pharmacological and/or drainage of cerebrospinal fluid by serial lumbar punctures), 34% received surgical treatment with insertion of a ventriculoperitoneal reservoir and/or shunt, and 18% died. The development of PVD after IVH and adverse short term outcome, such as the requirement for surgery, were predicted most strongly by the severity of IVH.

CONCLUSIONS

These data reflect the natural history of PVD in the 1990s and show that, despite a slight reduction in its overall incidence, there appears to be a more aggressive course, with appreciable mortality and morbidity in the extremely premature infant. The major predictor of adverse short term outcome, defined as death or need for surgical intervention, was the severity of IVH. These findings may be valuable for the management of very small premature infants.

Arterial remodeling and coronary artery disease: the concept of "dilated" versus "obstructive" coronary atherosclerosis

Traditionally, the development of coronary artery disease (CAD) was described as a gradual growth of plaques within the intima of the vessel. The outer boundaries of the intima, the media and the external elastic membrane (EEM), were thought to be fixed in size. In this model plaque growth would always lead to luminal narrowing and the number and severity of angiographic stenoses would reflect the extent of coronary disease. However, histologic studies demonstrated that certain plaques do not reduce luminal size, presumably because of expansion of the media and EEM during atheroma development. This phenomenon of "arterial remodeling" was confirmed in necropsy specimens of human coronary arteries. More recently, the development of contemporary imaging technology, particularly intravascular ultrasound, has allowed the study of arterial remodeling in vivo. These new imaging modalities have confirmed that plaque progression and regression are not closely related to luminal size. In this review, we will analyze the role of remodeling in the progression and regression of native CAD, as well as its impact on restenosis after coronary intervention.

Surgical pathology of pure aortic insufficiency: a study of 225 cases

The gross surgical pathologic features of the aortic valve were reviewed in 225 patients who had had clinically pure aortic insufficiency and aortic valve replacement at our institution during the years 1965, 1970, 1975, and 1980. The four most common causes of aortic regurgitation were postinflammatory disease (46%), aortic root dilatation (21%), incomplete closure of a congenitally bicuspid aortic valve (20%), and infective endocarditis (9%). Other causes of aortic incompetence in our study included ventricular septal defects (2%) and quadricuspid aortic valves (1%); the cause was indeterminate in 1%. The mean age of patients at valve replacement was approximately 50 years for all etiologic factors except a ventricular septal defect. All forms of aortic insufficiency were much more common in male than in female patients, except the postinflammatory and indeterminate types, which occurred approximately equally in both sexes. Moreover, the incidences of postinflammatory disease and aortic root dilatation changed appreciably with time. Before 1980, their incidences were 51% and 17%, respectively, but during 1980, they were 29% and 37%, respectively. Accordingly, aortic root dilatation is now the most common cause of pure aortic regurgitation in our surgical population. The decrease in the incidence of postinflammatory disease may be a result of the decreasing incidence of acute rheumatic fever reported in western countries.

Corpus callosum size and very preterm birth: relationship to neuropsychological outcome

Thinning of the corpus callosum (CC) is often observed in individuals who were born very preterm. Damage to the CC during neurodevelopment may be associated with poor neuropsychological performance. This study aimed to explore any evidence of CC pathology in adolescents aged 14-15 years who were born very preterm, and to investigate the relationship between CC areas and verbal skills. Seventy-two individuals born before 33 weeks of gestation and 51 age- and sex-matched full-term controls received structural MRI and neuropsychological assessment. Total CC area in very preterm adolescents was 7.5% smaller than in controls, after adjusting for total white matter volume (P = 0.015). The absolute size of callosal subregions differed between preterm and full-term adolescents: preterm individuals had a 14.7% decrease in posterior (P < 0.0001) and an 11.6% decrease in mid-posterior CC quarters (P = 0.029). Preterm individuals who had experienced periventricular haemorrhage and ventricular dilatation in the neonatal period showed the greatest decrease in CC area. In very preterm boys only, verbal IQ and verbal fluency scores were positively associated with total mid-sagittal CC size and mid-posterior surface area. These results suggest that very preterm birth adversely affects the development of the CC, particularly its posterior quarter, and this impairs verbal skills in boys.

Iatrogenic keratectasia after laser in situ keratomileusis for less than -4.0 to -7.0 diopters of myopia

PURPOSE

To study 13 eyes with less than -4.0 to -7.0 diopters of myopia that developed central or inferior keratectasia after laser in situ keratomileusis (LASIK).

METHODS

The progress of the ectasia was determined by a series of pre- and post-LASIK topographies and the case histories.

RESULTS

Progressive ectasia developed from 1 week to 27 months after LASIK. This necessitated the wearing of hard contact lenses or penetrating keratoplasty. One eye improved for some months after photorefractive keratectomy retreatment. Two eyes in 1 patient and 1 eye in a second patient had latent keratoconus before surgery.

CONCLUSION

Laser in situ keratomileusis can cause permanent weakening and ectasia of the cornea even in eyes with low myopia.

Pathogenesis of the glomerulopathy associated with renal infarction in rats

The present studies were designed to characterize the extent and pathogenesis of the glomerular lesions which occur in the viable portion of the kidney following partial renal infarction in rats. Control rats with two normal kidneys had a mean blood pressure of 112 mm Hg, minimal proteinuria and no glomerular pathology on light (LM), electron (EM) or immunofluorescence microscopy (IFM). Rats with two-thirds infarction of one kidney (stage II) became hypertensive, although less than 4% of the glomeruli from either kidney were abnormal. Rats with two-thirds infarction of one kidney and contralateral nephrectomy (stage III) developed proteinuria and hypertension whether fed a normal, low or high Na+ diet. By light microscopy 37% of glomeruli were abnormal 28 days after partial infarction and contralateral nephrectomy and thereafter the percent of abnormal glomeruli increased. Detectable amounts of immunoglobulin and complement (C3) were present in kidneys of stage II or III rats but were always accompanied by more extensive albumin and fibrin deposits. Basement membrane deposits characteristic of immune complexes were not seen on EM. Administration of antihypertensive medication to stage III rats significantly lowered blood pressure and reduced the number of abnormal glomeruli on LM; however, IFM abnormalities remained prominent. Platelet thrombi seen by EM and abundant glomerular fibrin deposits seen on IFM suggested that coagulation mechanisms may be prominent in the pathogenesis of the renal lesion. Heparin-treated stage III rats had significantly lower blood urea nitrogen concentrations, blood pressures and proportion of abnormal glomeruli although glomerular deposition of serum proteins was still present on IFM. These observations suggest that this glomerulopathy is initiated by an unknown agent(s) which increased capillary permeability. This lesion progresses via thrombotic mechanisms which are prevented by heparin administration.

Time course of left ventricular dilation after myocardial infarction: influence of infarct-related artery and success of coronary thrombolysis

Dilation of the left ventricle after myocardial infarction is common, occurs rapidly (within 2 weeks of infarction) and may be self-limited. To evaluate the time course of postinfarction left ventricular dilation and to assess the impact of successful coronary thrombolysis, serial radionuclide left ventricular volume analyses were performed in 36 patients undergoing attempted thrombolysis for acute transmural myocardial infarction. All patients underwent cardiac catheterization, coronary angiography and attempted thrombolysis within 7 h of the onset of symptoms. The site of coronary occlusion was the left anterior descending coronary artery in 17 patients, the right coronary artery in 18 and, in 1 patient, occluded bypass grafts to the right and left circumflex coronary arteries. Attempted reperfusion using a thrombolytic agent was successful in 22 individuals, occurring 5 +/- 1 h after the onset of symptoms. Gated radionuclide ventriculography was performed early (mean time 1 day after admission, n = 36), subacutely (mean time 11 days postinfarction, n = 36) and late after infarction (mean time 10.5 months, n = 25), and a geometric technique was used to measure serial left ventricular end-diastolic volume. Left ventricular end-diastolic volume for the entire group increased significantly (p less than 0.01) from 153 +/- 30 ml at baseline to 172 +/- 45 ml (at 11 days) to 220 +/- 63 ml (at 10.5 months). Twenty of 36 patients showed greater than 20% increase in left ventricular end-diastolic volume (dilation) with time. This appeared early in seven patients, occurred remote from infarction in seven others and showed a progressive pattern in six.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebrovascular abnormalities in a population of children with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is associated with vasculopathy, which may result in a variety of cerebrovascular complications. The purpose of this study was to evaluate the spectrum of cerebrovascular disease in a pediatric population with NF1. Of 316 patients with NF1 who underwent brain MRI, 8 (2.5%) children were reported to have an abnormality of the cerebrovascular system, including narrowed or ectatic vessels, vascular stenoses, aneurysm, and moyamoya.

Delayed onset keratectasia following laser in situ keratomileusis

We present a case of unilateral iatrogenic keratectasia developing 10 months after bilateral laser in situ keratomileusis (LASIK) involving enhancement surgery using a broad-beam excimer laser (Summit Apex) to treat 6.6 diopters (D) of myopia. The ectasia progressed rapidly over the subsequent 12 months. The surgeon did not measure preoperative pachymetry, but preoperative topography and corneal measurements did not reveal underlying keratoconus or forme fruste keratoconus. Corneal transplantation was required for final visual rehabilitation. Light microscopy of the button revealed no underlying inflammation, which suggests biomechanical corneal weakening as the cause of the ectasia. Scanning electron microscopy showed the dramatic thinning seen clinically. latrogenic keratectasia appears to be a possible complication of LASIK.

Progressive aortic root dilatation in adults late after repair of tetralogy of Fallot

BACKGROUND

Aortic valve or aortic root (AoRo) replacement is occasionally required because of AoRo dilatation and aortic regurgitation (AR) in repaired tetralogy of Fallot (TOF). We evaluated AoRo size and possible factors associated with its dynamic nature in adults with repaired TOF.

METHODS AND RESULTS

Of 216 patients with TOF repair who underwent echocardiography in 1997, we identified 32 patients (mean age, 36+/-8.0 years) with AoRo dilatation, defined as ratio of observed to expected AoRo size by standard nomogram >1.5 (group A), and 54 TOF controls, matched for age with AoRo ratio <1.5 (group B), who underwent at least 1 previous echocardiogram in the preceding 10 years. Mean indexed AoRo size (cm/m2) in 1997 was 2.5+/-0.5 in group A and 1.7+/-0.2 in group B (P<0.0001). AoRo rate of change (mm/year) from the first to 1997 study (mean interval, 5.2+/-3.8 years) was 1.7+/-3.8 in group A and 0.03+/-1.6 in group B (P=0.001). Patients from group A had a longer shunt-to-repair interval (P=0.048) with a higher prevalence of pulmonary atresia (P<0.0001), right aortic arch (P=0.03), moderate to severe AR (P=0.002), aortic valve replacement (P=0.02), larger cardiothoracic ratio (P=0.02), and increased left ventricular end-diastolic dimensions (P=0.002).

CONCLUSIONS

A subset of adult TOF exhibits ongoing dilatation of AoRo late after repair. This dilatation relates to previous long-standing volume overload of AoRo and possibly to intrinsic properties of AoRo and may lead to AR. Meticulous follow-up of AoRo after TOF repair is recommended.

Virchow-Robin spaces on magnetic resonance images: normative data, their dilatation, and a review of the literature

INTRODUCTION

Virchow-Robin spaces (VRS) are perivascular spaces in the brain and can be visualized on magnetic resonance images (MRI). We attempt to provide a better understanding of the significance of VRS for pathological and physiological processes by reviewing the literature, presenting normative data for the first time, and proposing a definition for the dilatation of the VRS on MRI that is based on shape rather than size.

METHODS

We evaluated the VRS in 125 healthy subjects (age range 1-30 years) using high-resolution 3D images, and in 36 patients (age range 2-16 years) with normal MRI, using routine clinical sequences.

RESULTS

VRS were visible in all high-resolution images of the 125 healthy subjects. Two of them revealed dilated VRS, giving a prevalence of 1.6%. VRS could be visualized in 29 (80%) of the 36 paediatric clinical scans; none was dilated. It was demonstrated that the visibility of VRS on MRI is sequence-dependent.

CONCLUSION

From the results of this study and the literature on the nature and pathology of VRS, we conclude that VRS on MR images of healthy individuals are normal findings, even if they are dilated. A judgement on whether dilated VRS in an individual patient is a normal variant or part of a disease process can be made by taking into account the appearance of the adjacent tissue on MRI and the clinical context.

The diameter of the common femoral artery in healthy human: influence of sex, age, and body size

PURPOSE

To determine the relevance of dilatations of the common femoral artery (CFA), knowledge of the normal CFA diameter is essential. The diameter of the CFA in healthy male and female subjects of different ages was investigated.

METHODS

The diameter of the CFA was measured in 122 healthy volunteers (59 male, 63 female; 8 to 81 years of age) with echo-tracking B-mode ultrasound scan. The influence of age, sex, height, weight, body surface area (BSA), and systolic blood pressure was analyzed by means of a multiple regression model.

RESULTS

The CFA increased steadily in diameter throughout life. From 25 years onwards, the diameter was larger in men than in women. Significant correlations were found between the CFA diameter and weight (r = 0.58 and r = 0.57 in male and female subjects, respectively; P <.0001), height (r = 0.49 and r = 0.54 in male and female subjects, respectively; P <.0001), and BSA (r = 0.60 and r = 0.62 in male and female subjects, respectively; P <.0001). Age and BSA were used to create a model for prediction of the CFA diameter (r = 0.71 and r = 0.77 in male and female subjects, respectively; P <.0001).

CONCLUSION

The diameter of the CFA increases with age, initially during growth but also in adults. This is related to age, body size, and sex male subjects have larger arteries than female subjects. It is now possible to predict the normal CFA diameter, and nomograms that may be used in the study of aneurysmal disease are presented.

Pulmonary autograft in children: realized growth potential

Pulmonary autograft replacement of the aortic valve has the potential to remain viable and grow in proportion to the somatic growth of the child. Changes in aortic annulus and sinotubular dimensions were compared early and late postoperatively, and related to normal. Eighty-six children, 0.9 to 21 years, were operated on between 1986 and 1993: 42 had a root replacement, 24 an inclusion cylinder, and 20 a scalloped subcoronary implant. Actuarial survival at 7 years was 96.5% +/- 2.0%. Freedom from reoperation for the pulmonary autograft or the homograft reconstruction of the right ventricular outflow tract was 92% +/- 4%. Freedom from reoperation on the autograft in root replacements was 96% +/- 4%, in the inclusion cylinder was 100%, and in the scalloped subcoronary was 90% +/- 7% (not significant). Aortic annulus and sinotubular junction diameters were compared with normal values predicted by body surface area. In 22 intraaortic implants, early and late postoperative annulus diameter mean Z values are in the normal range. In the 23 root replacements, early annulus diameter was within the normal range, but late Z values were larger than normal (p < 0.02). Intraaortic implant annulus diameter increased proportionally to somatic growth, but the sinotubular junction, which was small, remained small but increased toward normal. In the root replacements, the annulus increased in diameter and became dilated. The sinotubular junction, which was small early, increased and was within the normal range late. Lower operative risk and valve durability without failure suggest improved results with inclusion cylinder technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Nature of the bleeding vessel in recurrently bleeding gastric ulcers

An unselected consecutive series of 826 patients admitted for acute upper gastrointestinal bleeding underwent urgent endoscopy. Peptic ulcers were found in 402 (49%). Of the 329 ulcer craters that could be fully examined, visible vessels were identified in 156 (47%), other stigmata of recent hemorrhage in 66, and no stigmata of recent hemorrhage in 107. One hundred twenty-nine patients with stigmata of recent hemorrhage (93 of whom had visible vessels) randomly allocated to no endoscopic treatment were observed for evidence of further bleeding. Fifty-four of the 93 patients (58%) with visible vessels rebled, compared with 2 of 36 (6%) with other stigmata of recent hemorrhage. No patient without stigmata of recent hemorrhage rebled. Twenty-seven patients in whom a visible vessel in a gastric ulcer was identified at endoscopy underwent urgent partial gastrectomy because of recurrent bleeding. The vessel identified at endoscopy was found in 26 of 27 resection specimens (96%). The arterial vessel wall protruded above the surface of the ulcer crater in 10 specimens, and clot in continuity with a breach in the vessel wall protruded in a further 10 specimens. Postoperative angiography, when technically possible, showed that the breached artery ran across the base of the ulcer in all of these specimens. Pathological changes were common in the bleeding artery and included arteritis in 24 of 29 (83%) eroded arteries found in these specimens, with aneurysmal dilatation in 14 of 27 (52%) bleeding points that could be fully examined. The ulcer had penetrated to serosa in 13 specimens (45%). The bleeding artery had a mean external diameter of 0.7 mm with a range of 0.1-1.8 mm. This study provides new information about the nature of the bleeding vessel in gastric ulcers, and some of this information is relevant in planning studies of endoscopic therapy for bleeding peptic ulcers. It validates the endoscopic identification of a visible vessel, and confirms that such identification has a high predictive value for the development of recurrent hemorrhage.

Posterior corneal surface topographic changes after laser in situ keratomileusis are related to residual corneal bed thickness

OBJECTIVE

To determine whether ectasia after laser in situ keratomileusis (LASIK) is related to residual corneal bed thickness.

DESIGN

Retrospective noncomparative case series.

PARTICIPANTS

Thirty-two eyes of 16 patients with refractive errors of -4.00 to -18.00 diopters were examined.

INTERVENTION

LASIK was performed. The topography of the posterior corneal surface was examined with the Orbscan slit scanning corneal topography/pachymetry system.

MAIN OUTCOME MEASURES

The difference in the elevation of posterior corneal surface regarding the best-fit sphere was measured.

RESULTS

After surgery, mean bulge of 17.2 +/- 7.2 microns was found in eyes with residual corneal bed of 250 microns or greater, whereas 41.0 +/- 22.1 microns was seen in eyes with bed thickness less than 250 microns (t = 4.29; P = 0.000).

CONCLUSION

Posterior corneal bulge is correlated with the residual corneal bed thickness. The risk of ectasia may be increased if the residual corneal bed is thinner than 250 microns.

Aortopathy is prevalent in relatives of bicuspid aortic valve patients

OBJECTIVES

This study aimed to determine the prevalence of dilation and abnormal elastic properties of aortic root in first-degree relatives (FDRs) of bicuspid aortic valve (BAV) patients.

BACKGROUND

Evidence indicates that BAV is a genetic disorder. Although FDRs of affected individuals have an increased prevalence of BAV, their risk of aortic root abnormalities is unknown.

METHODS

We studied dimensions as well as the elastic properties of the ascending aorta in 48 FDRs with morphologically normal tricuspid aortic valves, 54 BAV patients, and 45 control subjects using 2-dimensional echocardiography.

RESULTS

The prevalence of aortic root dilation was 32% in FDRs and 53% in BAV patients, whereas all control subjects showed normal aortic dimensions (p < 0.001). The FDRs and BAVs had significantly lower aortic distensibility (1.7 +/- 1.4 x 10(-3) mm Hg and 1.4 +/- 2.0 x 10(-3) mm Hg vs. 2.5 +/- 1.6 x 10(-3) mm Hg, p < 0.001) and greater aortic stiffness index (26.7 +/- 25.8 and 55.9 +/- 76.8 vs. 18.7 +/- 40.1, p = 0.001) compared with control subjects. This difference remained significant in subjects without aortic root dilation or hypertension (p = 0.002 and p = 0.004, respectively).

CONCLUSIONS

The aortic root is functionally abnormal and dilation is common (32%) in first-degree relatives of patients with BAV. Screening of FDRs by transthoracic 2-dimensional echocardiography should be considered for detection of aortic valve malformation and dilated ascending aorta.

Prognostic significance of the pattern of aortic root dilation in the Marfan syndrome

OBJECTIVES

The present study examines the incidence of aortic complications (dissection, marked dilation requiring surgery or progressive moderate to severe aortic regurgitation) and their relation to clinical features and aortic root morphology in patients with the Marfan syndrome.

BACKGROUND

Considerable phenotypic variability exists in the Marfan syndrome, and the prospective prediction of the risk for aortic complications in individual patients remains elusive.

METHODS

One hundred thirteen patients with the Marfan syndrome underwent anthropometric and echocardiographic evaluation and were followed-up for 49 +/- 24 (mean +/- SD) months. Aortic root dilation was defined as localized when confined to the sinuses of Valsalva (based on two-dimensional echocardiographic confidence limits utilizing age and body size) and generalized if dilation additionally involved the supraaortic ridge and proximal ascending aorta.

RESULTS

Aortic root dilation was present in 80% of patients and was localized in 28% and generalized in 51%. Aortic complications occurred during follow-up in none of 23 patients with normal initial aortic size, in 2 (6%) of 32 patients with initially localized dilation and in 19 (33%) of 58 patients with generalized dilation (p < 0.0005). Complications were associated with larger initial aortic size (p < 0.00005), higher systolic blood pressure (p < 0.005), height (p < 0.05), aortic growth rate (p < 0.05) and older age (p < 0.01). The only independent predictor of aortic complications was initial aortic root size (p < 0.005). However, when aortic size, one of the indications for surgical referral, was excluded from analyses, the only independent predictor of aortic complications was generalized aortic dilation (p < 0.005).

CONCLUSIONS

The present study indicates that generalized aortic root dilation is a potent marker of an increased risk for subsequent aortic complications in Marfan syndrome.

Cardiotomy suction: a major source of brain lipid emboli during cardiopulmonary bypass

BACKGROUND

Brain injury remains a significant problem in patients undergoing cardiac surgery assisted by cardiopulmonary bypass (CPB). Autopsy brain specimens of patients after cardiac operations with CPB reveal numerous acellular lipid deposits (10 to 70 microm) in the microvasculature. We hypothesize that these small capillary and arterial dilatations result from a diffuse inflammatory response to CPB or from emboli delivered by the bypass circuit. This study was undertaken to determine which aspect of CPB is most clearly associated with these dilatations.

METHODS

Thirteen dogs were studied in four groups: group I (n = 3), right-heart CPB; group II (n = 2), lower-extremity CPB; group III (n = 3), hypothermic CPB; and group IV (n = 5), hypothermic CPB with cardiotomy suction. All dogs in all groups were maintained on CPB for 60 minutes and then euthanized. Brain specimens were harvested, fixed in ethanol, embedded in celloidin, and stained with the alkaline phosphate histochemical technique so that dilatations could be counted.

RESULTS

All dogs completed the protocol. The mean density of dilatations per square centimeter for each group was as follows: group I, 1.77 +/- 0.77; group II, 4.17 +/- 1.65; group III, 4.54 +/- 1.69; and group IV, 46.5 +/- 14.5. In group IV (cardiotomy suction), dilatation density was significantly higher than in group III (hypothermic cardiopulmonary bypass) (p = 0.04) and all other groups (p = 0.04).

CONCLUSIONS

Blood aspirated from the surgical field and subsequently reinfused into dogs undergoing CPB produces a greater density of small capillary and arterial dilatations than CPB without cardiotomy suction, presumably because of lipid microembolization.

Mucin-producing pancreatic tumors: comparison of MR cholangiopancreatography with endoscopic retrograde cholangiopancreatography

PURPOSE

To compare magnetic resonance cholangiopancreatography (MRCP) with endoscopic retrograde cholangiopancreatography (ERCP) in the detection of mucin-producing pancreatic tumors.

MATERIALS AND METHODS

The authors retrospectively reviewed MRCP and ERCP images obtained in 28 patients with mucin-producing pancreatic tumors. Detectability of the pancreatic duct and its branches, intraductal cystic lesions, and intracystic nodules or septa was assessed.

RESULTS

MRCP depicted cystic dilated ductal branches significantly better than did ERCP (P < .001). The difference in the number of nodules or septa detected with MRCP compared with ERCP was not significant. MRCP, however, simultaneously showed not only the main pancreatic duct but also the cystic lesions; this was not always possible with ERCP.

CONCLUSION

MRCP appears to be more effective and less invasive than ERCP to evaluate changes in the size and extent of tumors and to determine if new lesions appear, as well as to follow up mucin-producing pancreatic tumors.

Post-laser in-situ keratomileusis ectasia: current understanding and future directions

PURPOSE OF REVIEW

The aim of this article is to review the causes, risk factors, management, and future research directions for corneal ectasia after laser in situ keratomileusis.

RECENT FINDINGS

Complex corneal biomechanical processes influence the integrity of the normal and postoperative cornea, and developing an understanding of these processes facilitates recognition of risk factors for ectasia after laser in-situ keratomileusis. Currently identified risk factors include keratoconus, high myopia, low residual stromal bed thickness from excessive ablation or thick flap creation, and defined topographic abnormalities such as forme fruste keratoconus and pellucid marginal corneal degeneration. Ectasia can also rarely occur in patients without currently identifiable risk factors, and future identification of at-risk patients may be facilitated by corneal interferometry and corneal hysteresis measurements. Utilization of intraoperative pachymetry measurements at the time of surgery and confocal microscopy prior to enhancement to measure residual stromal bed thickness should avoid unanticipated low residual stromal bed thickness. Management options for ectasia after laser in situ keratomileusis include intraocular pressure reduction, rigid gas permeable contact lenses, and intracorneal ring segments, in addition to corneal transplantation. In the future, collagen cross-linking may reduce corneal steepening and improve refractive error.

SUMMARY

When ectasia develops, early recognition and proper management are essential to prevent progression, to promote visual rehabilitation, and to reduce the need for corneal transplantation for these patients.