A multi-centre randomized controlled trial of open vs closed management of the rectal defect after transanal endoscopic microsurgery.

AIM: Transanal endoscopic microsurgery (TEM) is a technically challenging strategy that allows expanded indications for local excision of rectal lesions. Transluminal suturing is difficult, so open management of the resultant defect is appealing. Expert opinion suggests there is more pain when the defect is left open. The aim of this study was to determine if closure of the defect created during full thickness excision of rectal lesions with TEM leads to less postoperative pain compared to leaving the defect open. METHOD: At the time of surgery, patients undergoing a full thickness TEM were randomized to sutured (TEM-S) or open (TEM-O) management of the rectal defect. At five Canadian academic colorectal surgery centres, experienced TEM surgeons enrolled patients ≥ 18 years treated by full thickness TEM. The primary outcome was postoperative pain measured by the visual analogue scale. Secondary outcomes included postoperative pain medication use and 30-day postoperative complications, including bleeding, infection and hospital readmission. RESULTS: Between March 2012 and October 2013, 50 patients were enrolled and randomized to sutured (TEM-S, n = 28) or open (TEM-O, n = 22) management of the rectal defect. There was no difference between the two study groups in postoperative pain on postoperative day 1 (2.8 vs 2.6, P = 0.76), day 3 (2.8 vs 2.1, P = 0.23) and day 7 (2.8 vs 1.7, P = 0.10). CONCLUSION: In this multicentre randomized controlled trial, there was no difference in postoperative pain between sutured or open defect management in patients having a full thickness excision with TEM.

Unmeasured costs of haemophilia: the economic burden on families with children with haemophilia.

INTRODUCTION AND OBJECTIVES: Although economic evaluations of haemophilia-related care have highlighted both the health care payer and societal perspectives, the costs to families with children with haemophilia have not been examined. This study determined the costs incurred by families of children with haemophilia, attending a haemophilia treatment centre (HTC), servicing a large geographical area in Eastern Canada. METHODS: Families recorded all direct and indirect costs associated with haemophilia-related care for a year. Costs incurred to receive care at the HTC and local health care centres were compared. The relationship between distance to the HTC and costs was modelled using linear regression. RESULTS: Participants included 31/45 children (68%) from 27 families attending the HTC. Median age was 12 years (range: 0.5-17 years); 24/31 (77%) had severe haemophilia. The median distance to the HTC and local health care facility was 230 km (range: 7-600 km) and 33.5 km (range: 2-400 km) respectively. Due to this difference in distance, 23/31 (74%) children do not attend the HTC for management of acute haemorrhage. The median annual total cost per family to attend the HTC is $775.93 (range: $200.00-$5741.00). The total cost to attend the HTC increases by $2.16 (95% CI 1.24-3.9) per kilometer from the HTC. The median total annual cost of haemophilia-related care per family is $1222.50 (range: $396.00-$8037.00). CONCLUSION: Families incur high costs related to haemophilia care. The distance to the HTC is a barrier to care. Improving access to HTCs is paramount in improving haemophilia-related outcomes.

The clinical results of the Turnbull-Cutait delayed coloanal anastomosis: a systematic review.

Turnbull and Cutait described abdominoperineal pull-through followed by delayed coloanal anastomosis (DCA) in 1961. DCA could reduce anastomotic leaks, pelvic morbidity and use of stomas. Strong evidence about its clinical benefits is still lacking. This systematic review examined the clinical outcomes of DCA for the treatment of malignant or benign colorectal conditions. A systematic search of electronic medical databases was conducted. Two independent reviewers selected studies, extracted data and assessed risk of bias. The primary outcome was pelvic morbidity (anastomotic leak, pelvic abscess or sepsis, use of stoma). Fecal continence and survival data were also analyzed. From 1,251 citations, we included seven observational studies including 1,124 patients. All included studies were considered at high risk of bias. Two studies comparing DCA with immediate anastomosis reported a significant decrease in anastomotic leak, and pelvic abscess or sepsis. Low rates of pelvic morbidity were reported in the other five studies: anastomotic leak 0-7 %, pelvic abscess 0-11.8 % and pelvic sepsis 6.8-10 %. Rates of permanent stoma after DCA were low in six studies (1-6 %), with one study reporting an incidence of 25 %. Fecal continence was reported as satisfying in all studies. No differences were observed in a comparative setting. Survival data were reported in four studies. Clinical heterogeneity and methodological issues precluded meta-analysis. Based on retrospective evidence, DCA offers a low rate of anastomotic leak, pelvic morbidity and use of stoma, with reasonable fecal continence. Results are encouraging, but prospective studies are needed for comparison with standard of care.

Generation of human TRIM5alpha mutants with high HIV-1 restriction activity.

Rhesus macaque tripartite motif (TRIM)5alpha potently inhibits early stages of human immunodeficiency virus (HIV)-1 replication, while the human orthologue has little effect on this virus. We used PCR-based random mutagenesis to construct a large library of human TRIM5alpha variants containing mutations in the PRYSPRY domain. We then applied a functional screen to isolate human cells made resistant to HIV-1 infection by the expression of a mutated TRIM5alpha. This protocol led to the characterization of a human TRIM5alpha variant containing a mutation at arginine 335 as conferring resistance to HIV-1 infection. The level of protection stemming from expression of this mutant was comparable to that of previously described mutations at position 332. R332/R335 double mutants decreased permissiveness to HIV-1 and to other lentiviruses by 20- to 50-fold in TE671 fibroblasts and in the T-cell line SUP-T1, and prevented HIV-1 spreading infection as efficiently as the rhesus macaque TRIM5alpha orthologue did. The finding that only two substitutions in human TRIM5alpha can confer resistance to HIV-1 at levels as high as one of the most potent natural orthologues of TRIM5alpha removes a roadblock toward the use of this restriction factor in human gene therapy applications.

Architectural strategies of Cornus sericea, a native but invasive shrub of Southern Quebec, Canada, under an open or a closed canopy.

BACKGROUND AND AIMS: Qualitative and quantitative studies of the pattern of invasive plant development is considered a key aspect in understanding invasiveness. An architectural analysis was therefore performed in order to understand the relationship between shoot architecture and invasiveness in red-osier dogwood, Cornus sericea (Cornaceae). METHODS: The structural and ontogenic characteristics of individuals in invading and non-invading populations in the native range of the species were compared to test the implication of developmental plasticity on invasiveness. KEY RESULTS AND CONCLUSIONS: The results show that the shrub has a modular architecture governed by strong developmental rules. Cornus sericea is made up of two levels of organization, each with its own intrinsic sequence of differentiation. These intrinsic mechanisms were used as a framework for comparison and it was found that, in response to the light environment, developmental plasticity was elevated, resulting in two architectural strategies. This developmental plasticity concerns the growth direction and the size of the modules, the speed of their time-course changes, their branching and flowering. Under an open canopy, C. sericea rapidly develops large vertical structures and abundant flowering. This strategy leads the plant to be invasive by excluding competitors and disseminating in the landscape. In the understorey, C. sericea slowly develops long horizontal structures which creep across the soil surface, while assimilating structures are poorly developed. This strategy does not lead to invasiveness but may allow the plant to survive in the understorey and reach sunny patches.

Coloseminal vesicle fistula after low anterior resection: Report of a case and review of the literature.

INTRODUCTION: A rectoseminal vesicle fistula after a low anterior resection for rectal cancer is a rare complication despite their anatomic proximity. From a Medline search from 1966 to date, a total of twenty-one previous cases of coloseminal vesicle fistula have been reported. From these cases, eleven were a complication of laparoscopic low anterior resection for rectal cancer. DESCRIPTION OF THE CASE: This report presents the case of a 63-year-old patient who was readmitted to the hospital on the fifteenth postoperative day after his surgical intervention for fever, abdominal pain, dysuria and pneumaturia. A sinography with water-soluble contrast revealed a tract between the rectum and the seminal vesicle. The condition was treated conservatively with antibiotics, urinary catheter and a transanastomotic Malecot probe for abscess drainage. The fistula had completely recovered on postoperative day 71 and the patient is still symptoms free, six months after the complication developed. DISCUSSION: This case reinforces the presumed link between anastomotic leakage and rectoseminal vesicle fistula in cases of low anterior resection while reviewing and summarizing similar previously reported cases on the course of the disease, diagnostic procedures and treatment options. CONCLUSION: Seminal vesicle are susceptible to fistula in oncological resection of rectum. Both CT scan with water-soluble contrast or sinography are effective diagnostic examinations. Depending on the characteristics of the fistula, conservative approach may be adequate and benefits much less morbidities than the surgical options.

Subacromial temperature profile during bipolar radiofrequency use in shoulder arthroscopy. Comparison of Coblation® vs. VAPR®.

BACKGROUND: The use of bipolar electrodes for arthroscopic procedures carries a theoretical ex vivo risk of inducing burn injuries. Few studies have measured the in vivo temperatures produced by bipolar electrodes during arthroscopy, and their results are conflicting. The objective of this study was to evaluate the temperature profile within the subacromial space during shoulder arthroscopy with two different electrode systems. HYPOTHESIS: The primary hypothesis was that the two electrode systems produced similar temperature variations and peak temperatures. The secondary hypothesis was that neither electrode system produced irrigation-fluid temperatures above the tissue-damage threshold. MATERIAL AND METHODS: A comparative, prospective, single-centre, single-surgeon, single-blind study was conducted to compare the Coblation® system (Smith&Nephew, Andover, MA, USA) and the VAPR® system (DePuy Synthes Mitek Sports Medicine, Raynham, MA, USA) in 13 patients undergoing shoulder arthroscopy. A temperature probe inserted into the subacromial space was used to record temperatures at 10-second intervals for 60seconds during continuous radiofrequency application. RESULTS: Mean baseline temperature was 21.4±0.7°C with VAPR® and 23.0±2.2°C with Coblation®. No significant between-group differences were found during the first 40seconds. The mean peak temperature reached after 60seconds was 25.0±1.9°C with VAPR® and 27.9±2.8°C with Coblation® (P<0.05). DISCUSSION: Few studies have compared the in vivo temperatures produced during arthroscopy by different electrode systems. In vivo studies have established that temperature increases can cause tissue damage, particularly to chondrocytes, and that the irrigation flow rate plays a key role in lowering the in vivo temperatures. Our study showed a significant difference between the two electrode systems after 50seconds of use, with lower temperatures with the VAPR®. Nevertheless, neither system increased the irrigation-fluid temperatures above the tissue-damage threshold. Both systems can be used safely, provided the manufacturer instructions are followed and the irrigation system is effective. LEVEL OF EVIDENCE: II (prospective randomized trial).

Notch1 antiapoptotic activity is abrogated by caspase cleavage in dying T lymphocytes.

Excessive signaling via the Notch1 receptor inhibits apoptosis in T lymphocytes. Since several antiapoptotic proteins are cleaved by caspases during cell death, we investigated whether Notch1 was a caspase substrate. Results demonstrate that the intracellular domain of Notch1 (NICD) is cleaved into six fragments during apoptosis in Jurkat cells or peripheral T lymphocytes. Notch1 cleavage is prevented by the caspase inhibitors DEVD-fmk and VEID-fmk or by Bcl-2 expression. Caspase-3 and caspase-6 cleave the NICD into six fragments using sites located within the NF-kappaB binding domain, the ankyrin repeats and the transactivation domain. Notch1 cleavage correlates with the loss of HES-1 expression in apoptotic T cells. Notch1 fragments cannot inhibit activation-induced cell death in a T-cell hybridoma, confirming the abrogation of Notch1 antiapoptotic activity by caspases. The ability of the NICD but not the fragments to antagonize Nur77 activity supports a role for this factor in Notch1 antiapoptotic function.

Spontaneous remission is a frequent outcome of variant angina.

To assess the prevalence of spontaneous remission in variant angina, 100 patients with this diagnosis who had undergone coronary arteriography in the hospital and a follow-up of at least 1 year were studied. Patients with coronary bypass surgery or myocardial infarction were excluded. Remission was diagnosed in 45 of the 100 patients who had been angina-free and had had no treatment for more than 3 months (mean 18.3). The other 55 patients were receiving medical treatment; 37 had been angina-free for at least 6 months (mean 22.5) and angina persisted in 18. The persistent angina group had a lower prevalence of organic coronary stenoses 70% or greater: 4 of 18 versus 22 of 45 and 22 of 37 for the other two groups (p less than 0.05), and a longer history of rest angina before admission. The remission group contained more patients (17 of 45 versus 4 of 55 [p less than 0.001]) whose attacks had been documented only by provocative testing. Rest angina recurred when calcium antagonist drugs were discontinued in 15 of 51 instances, within 1 month in 11 patients and later in 4 patients. Remission was eventually attained in 35 of the 38 patients in whom these drugs were stopped. These results indicate that remission is a frequent outcome of variant angina. This fact should be considered in the evaluation of the long-term results of treatment and in the planning of care for an individual patient.

Comparison of clinical variables and variables derived from a limited predischarge exercise test as predictors of early and late mortality after myocardial infarction.

An exercise test limited to 5 METS or 70% of age-predicted maximal heart rate was performed 1 day before hospital discharge by 225 survivors of acute myocardial infarction, all of whom were subsequently followed up for at least 5 years. The mortality rate was 11.1% during the first year, but averaged only 2.9% per year from the second to fifth year. Over the entire follow-up period, the five variables that predicted mortality by multivariate analysis were QRS score, an exercise-induced ST segment shift, previous infarction, failure to achieve target heart rate or work load and ventricular arrhythmia during the exercise test. Because mortality differed markedly before and after 1 year, Cox regression analyses were performed separately for both of these periods. The factors that were predictive of mortality during the first year were an exercise-induced ST shift (p less than 0.0001, relative risk 7.8), failure to increase systolic blood pressure by 10 mm Hg or more during exercise (p = 0.0039, relative risk 4.3) and angina in hospital 48 hours or longer after admission (p = 0.0046, relative risk 3.4). None of these three variables was predictive of mortality after 1 year. Previous infarction (p = 0.0007), QRS score (p = 0.0042) and ventricular arrhythmia during the exercise test (p = 0.016) were predictive of mortality after the first year. Thus, clinical and exercise test variables are complementary predictors of mortality after myocardial infarction. An abnormal ST segment response during an early limited exercise test and angina in the hospital are common strong predictors of mortality to 1 year, but not thereafter. Late mortality correlates with markers of poor left ventricular function.

Measurement of left ventricular stroke volume using continuous wave Doppler echocardiography of the ascending aorta and M-mode echocardiography of the aortic valve.

A number of reports have described different Doppler echocardiographic methods to calculate left ventricular stroke volume and cardiac output, but the clinical application of the noninvasive measurements of cardiac function remains in the early stages of development. This slow dissemination may be partly explained by the varying success of these ultrasound methods in determining accurate left ventricular stroke volume. The purpose of this study was to improve the simplicity and accuracy of Doppler stroke volume determination so that it could be more easily applied to patient management. Stroke volume was measured using the product of the integral of aortic velocity obtained by continuous wave Doppler technique and the M-mode tracing of the aortic valve, validating the data against cardiac output obtained by thermodilution technique in 41 patients (r = 0.95, SEE = 7 cc). Intra- and interobserver variability was between 9 and 11%. The results of different sampling sites and the temporal relation between Doppler and thermodilution measurements were also studied. Analysis of 21 patients who had M-mode and two-dimensional echocardiographic studies of the aortic root revealed that the method using M-mode measurement of aortic valve area was most accurate in determining left ventricular stroke volume (r = 0.94, SEE = 10 cc), stroke volume being overestimated when area measurements of the ascending aorta were used. In conclusion, maximal ascending aortic velocity determined by continuous wave Doppler echocardiography with M-mode measurement of aortic valve area can be used to calculate left ventricular stroke volume and cardiac output. The simplicity and practicality of this method should enhance the clinical application of Doppler echocardiography as a noninvasive monitoring technique.

The value of cine nuclear magnetic resonance imaging for assessing regional ventricular function.

Previous nuclear magnetic resonance (NMR) imaging studies to assess left ventricular function have used multiple axial planes, which are compromised by partial volume effects and are time consuming to acquire and analyze. Accordingly, an imaging approach using cine NMR and planes aligned with the true cardiac axes of the left ventricle was developed in views comparable with left ventricular cineangiography. Cine NMR imaging was used to assess regional wall motion and was validated by comparison with biplane left ventricular cineangiography. Fifty-nine patients underwent cineangiographic and NMR studies within 72 h. A poor quality NMR study precluded analysis in 4. leaving a study group of 55 patients (mean age 58 +/- 12: 17 women). Cine NMR movie loops were acquired in two long-axis planes: 1) right anterior oblique plane, parallel to the septum, and 2) four chamber orthogonal plane, perpendicular to the septum (this view is comparable to the angiographic left anterior oblique view). To assess regional wall motion, the left ventricle in both cine NMR and cineangiographic images was divided into five segments and graded on a five point grading scale from 3 for normal through 0 for akinesia and -1 for dyskinesia. Regional wall thickening was used qualitatively to aid in the analysis of wall motion. For the 275 segments compared in the right anterior oblique view, agreement was within one grade in 263 (95.6%) of 275 segments, whereas absolute agreement was observed in 171 (62%) of 275 segments. In the left anterior oblique view, of 200 segments evaluated, agreement within one grade was achieved in 184 segments (92%) and agreement was complete in 132 (66%).(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular mass and volume/mass ratio determined by two-dimensional echocardiography in normal adults.

This study prospectively defined the range of left ventricular mass and volume/mass ratio determined by two-dimensional echocardiography in 84 normal adults. A modified Simpson's rule algorithm was used to calculate ventricular volumes from orthogonal two and four chamber apical views. An algorithm based on a model of the left ventricle as a truncated ellipsoid was used to calculate ventricular mass. Like left ventricular volumes, left ventricular mass values were larger in normal men than in women (mean 148 versus 108 g, p less than 0.001) and remained larger after correction for body surface area. Volume/mass ratios, however, were constant at end-diastole (0.80) and end-systole (0.26). The influence of age and heart rate on all variables in this normal group was minimal, and no correction for these variables was necessary. The definition of normal mass, volume and volume/mass ratios by two-dimensional echocardiography will facilitate the noninvasive, quantitative diagnosis of left ventricular hypertrophy and help clarify the relation between hypertrophy and systolic wall stress.

Cardiac consequences of renal transplantation: changes in left ventricular morphology and function.

To characterize changes in left ventricular morphology and function associated with renal transplantation, noninvasive cardiac evaluations were performed in 41 adults at the time of surgery and at follow-up. At the time of transplantation, 36 patients had undergone hemodialysis through a fistula for 2.3 +/- 2.5 years (mean +/- SD); their hematocrit level was 26 +/- 6% and systolic blood pressure was 151 +/- 19 mm Hg. Perioperatively, left ventricular hypertrophy was present in 93% of patients by echocardiography, but in only 37% by electrocardiography. Abnormal left ventricular diastolic function was present in 67% of patients and indicated a high risk for perioperative pulmonary edema. At follow-up (1.5 +/- 1.4 years), mean hematocrit level increased to 39 +/- 7%, systolic blood pressure decreased to 132 +/- 14 mm Hg and spontaneous closure of the fistula occurred in 13 patients. Left ventricular mass by echocardiography decreased from 237 +/- 66 to 182 +/- 47 g (p less than 0.001), a decrease of 23%. Left ventricular volumes and cardiac index also decreased significantly, reflecting the rapid resolution of a pretransplant high output state. Despite proportionate regression of left ventricular hypertrophy within months of transplantation, diastolic function did not improve. The significant regression of left ventricular hypertrophy that occurs after renal transplantation may help explain the improved cardiovascular survival of patients with a renal transplant over that of patients on long-term dialysis.

Noninvasive assessment of cardiomyopathy in normotensive diabetic patients between 20 and 50 years old.

PURPOSE: To further the understanding of diabetic heart disease, we tested the hypothesis that an asymptomatic group of normotensive diabetic patients between 20 and 50 years old had a restrictive cardiomyopathy independent of clinically significant coronary artery disease. PATIENTS AND METHODS: Quantitative two-dimensional echocardiography and stress myocardial perfusion scintigraphy were performed to detect and characterize the cardiac abnormalities in this study group comprising 88 patients with rigorously classified diabetes and 65 volunteer control subjects. RESULTS: Diabetic patients were shown to have a mildly reduced left ventricular end-diastolic volume index: 50.1 +/- 8.2 and 52.1 +/- 14.7 mL/m2 for patients with type I and type II diabetes, respectively, versus 58.9 +/- 11.7 mL/m2 for control subjects. The left ventricular diastolic filling was also impaired in diabetic patients as reflected by a lower atrial emptying index: 0.73 +/- 0.24 and 0.76 +/- 0.3 for type I and type II diabetics, respectively, compared with 1.14 +/- 0.24 for control subjects. Exercise tolerance was normal in subjects with type I diabetes and slightly reduced in subjects with type II diabetes. Only one patient developed regional ischemia on thallium exercise testing. CONCLUSION: Using a comprehensive, noninvasive approach, we have shown that asymptomatic normotensive patients with type I or type II diabetes who were between 20 and 50 years old had a restrictive cardiomyopathy characterized by mildly reduced left ventricular end-diastolic volume and altered left ventricular compliance independent of critical coronary artery disease.

Magnetic resonance imaging in pulmonary arterial hypertension.

Magnetic resonance imaging (MRI) was used to examine the right ventricle and pulmonary arteries in 17 patients with pulmonary artery (PA) hypertension documented by cardiac catheterization. The study population consisted of 7 patients with primary pulmonary hypertension, 7 with Eisenmenger's syndrome and 3 with pulmonary hypertension secondary to lung disease. The MRI studies of patients were compared with those of 10 normal volunteers. Multislice gated transaxial images encompassed the right ventricle and central pulmonary arteries, showing the severity of right ventricular (RV) hypertrophy in proportion to the elevation of PA pressure and reversal of septal curvature when PA pressure approximated systemic pressure. End-diastolic RV wall thickness and mean pulmonary pressure correlated well (r = 0.79). MRI showed enlargement of PAs in all patients with PA hypertension. A magnetic resonance signal was present in the PAs throughout the cardiac cycle in patients with severe PA hypertension (more than 90 mm Hg) and was absent during systole in normal subjects. A signal within the PAs in systole is consistent with decreased flow velocity in patients with severe PA hypertension. MRI was useful in detecting each of the congenital anatomic defects in patients with Eisenmenger's syndrome. This study indicates the potential of MRI for evaluating the severity of PA hypertension by providing direct measurements of RV wall thickness and PA diameter and by detecting abnormal intraluminal signal intensity during the cardiac cycle.

Circadian variation in variant angina.

Thirteen hospitalized patients with variant angina were studied to assess circadian variation in disease activity. Over 48 hours, all angina attacks were noted, a continuous Holter electrocardiogram was recorded and 2 ergonovine tests were performed 12 hours apart, 1 at 4 AM and the other at 4 PM. Only 2 patients gave a clearcut history of more frequent nocturnal or early morning attacks. During the study period, 1.8 +/- 1.6 AM and 0.62 +/- 1.2 PM angina episodes per patient were reported (p less than 0.02), but a circadian pattern was apparent in only 4 patients. However, Holter analysis revealed 5.3 +/- 13.8 AM and 2.6 +/- 8.5 PM episodes of ST elevation per patient (p less than 0.05) and 8.1 +/- 13.9 AM and 3.2 +/- 8.5 PM episodes of ST elevation, ST depression or T-wave pseudonormalization (p less than 0.01). Ten of 11 patients with Holter abnormalities had more frequent AM than PM attacks (p less than 0.01). ST elevation developed during all 13 of the 4-AM and 12 of 13 of the 4-PM ergonovine tests. In 10 cases the ergonovine threshold at which the attack occurred was lower in the morning, in no case was it lower in the afternoon, and in 3 patients the morning and afternoon doses were identical (p less than 0.01). Thus, circadian variation in disease activity both for spontaneous and provoked attacks is present in most patients with variant angina, even though it is often not clinically apparent.

Upper extremity deep venous thrombosis. Underdiagnosed and potentially lethal.

The significance of upper extremity deep venous thrombosis (DVT) has been minimized in comparison to iliofemoral thrombosis, likely due to the erroneous belief that subsequent pulmonary thromboembolism is rare. The possibility of pulmonary thromboembolism originating in the upper extremity veins must now be seriously considered with catheters and medical instrumentation being performed more commonly in accessing the central venous system. It has been incorrectly assumed that the risk of pulmonary embolism was low due to the abundant collateral flow, and thus lack of stasis around an upper extremity even with venous occlusion. However, several studies, including a recent prospective trial, concluded that pulmonary embolism is not a rare complication in upper extremity DVT. Significantly, when comparing all sources of secondary upper extremity DVT, catheter-related upper extremity DVT is at greatest risk of subsequent pulmonary thromboembolism. We present an illustrative case documenting extensive pulmonary embolization that occurred following insertion of a central venous catheter and subsequent thrombosis of the right subclavian and innominate veins. With absolute contraindications to thrombolytic and anticoagulation therapy, prevention of further embolization was achieved by percutaneous insertion of a superior vena cava filter.

Cigarette smoking and peripheral arterial occlusive disease.

BACKGROUND: The importance of cigarette smoking in the etiology of peripheral arterial occlusive disease is well known, but there have been few studies that have quantified this relationship. METHODS: A case-control study design was used in which the case subjects were men with a history of claudication for at least 1 year and abnormal findings on noninvasive blood flow studies or on arteriography; control subjects were men attending the same hospital for conditions other than cancer, with no history of cancer or vascular disease and with a normal ankle-brachial index. Case and control subjects were interviewed by a trained nurse interviewer using a pilot-tested questionnaire. Current smoking status was confirmed by serum cotinine level estimation. Univariate odds ratios for smoking and other potential risk factors were calculated, and their significance was tested by comparison with the chi-squared distribution. Logistic regression analysis was used to adjust the effect of smoking for confounding variables, and the regression equation was used to estimate the proportion of disease attributable to smoking. RESULTS: Of the patients approached, 94% of the eligible case subjects and 93% of the eligible control subjects agreed to participate. Recruitment ended with 102 cases of peripheral arterial occlusive disease and 99 controls. Most of the control subjects were attending clinics for other surgical specialties. Compared with men who had never smoked the relative risk was 7 for exsmokers and 16 for current smokers (p < 0.001). The relative risk increased directly with the lifetime number of cigarettes smoked, the chi-squared test for trend being highly significant (p < 0.001). Age, lipoprotein concentration, body mass index, and history of hypertension or heart disease were also significant risk factors. CONCLUSIONS: After adjustment for confounding variables the estimate of the fraction of disease attributable to smoking was 76%.

Doppler echocardiographic evaluation of mitral regurgitation.

Evaluation of the severity and hemodynamic significance of mitral regurgitation remains an important and difficult problem. Cardiac ultrasound has emerged as the procedure of choice for the initial evaluation of mitral incompetence, as a result of its ability to confirm the diagnosis and provide a semiquantitative estimate of the severity of incompetence, determine its etiology, and assess the hemodynamic impact of the incompetence on ventricular function. This article reviews established as well as investigational methods of evaluating mitral incompetence by echocardiography and explores established and potential clinical applications of this evolving technology.