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Biomedical subjects

Y Shapira

Publications and source records attributed to Y Shapira.

At least 37 records · Page 2Linked to original sources
PubMed2001

Laryngotracheal anastomosis: primary and revised procedures.

OBJECTIVES: Acquired upper airway stenosis is usually associated with a complex of pathological conditions at the high tracheal and the subglottic levels. Reported reconstructive techniques include widening by incorporation of grafts, segmental resection, and anastomosis or combined procedures. The management of recurrent stenosis after reconstructive surgery is a major challenge and has rarely been discussed in the literature. The purposes of the present study are to compare the clinical course of primary versus revised reconstructive procedures and to analyze the effect of age, diabetes, chronic lung disease, grading of stenosis, extent of resection, and revised procedures on the operative rate of success. STUDY DESIGN: A cohort study in a tertiary referral medical center. METHODS: The clinical course of 23 consecutive patients undergoing laryngotracheal anastomosis was studied comparing a group of 13 primary with 10 revision procedures. Seventeen patients underwent cricotracheal and six patients thyrotracheal anastomoses. All patients but one were tracheotomized before the definitive reconstructive procedure. Suprahyoid release was routinely performed except for two cases, and only one patient required sternotomy. The Wilcoxon test was used to examine the relationship between preoperative clinical parameters and the postoperative success (i.e., airway patency). RESULTS: Twenty-two of 23 patients (95.6%) had successful decannulation. Four patients required a revision procedure because of repeat stenosis at the site of the anastomosis (2) or distal tracheal malacia (2). Residual airway stenosis of less than 50% was noted in six patients, although only three complained of dyspnea during daily-activity exertion. There was no associated mortality. Complications included subcutaneous emphysema (4), granulation tissue formation (3), pneumonia (2), cardiac arrhythmia (2), and one each of pneumomediastinum, neck hematoma, and urosepsis. Protracted aspirations were noted in one patient who had revision surgery. Age was the only parameter that correlated with postoperative airway patency (P <.07), whereas the presence of chronic obstructive lung disease and diabetes, grade of stenosis, type of surgery, and revision surgery were found to be insignificant. CONCLUSIONS: The clinical course of laryngotracheal anastomosis in primary and revised procedures was similar in our group of patients. The operation can be performed safely, with an expected high rate of success and acceptable morbidity.

Anastomosis, Surgical↗
PubMed2001

Idiopathic trigeminal sensory neuropathy in childhood.

Harris first reported transient idiopathic trigeminal sensory neuropathy in 1935, although it later appeared that, in some of his patients, this condition evolved to typical chronic and painful trigeminal neuralgia. The patients who were later described by Hill and Hughes suffered a combined motor-sensory Vth cranial nerve dysfunction, and most cases reported by Spillane and Wells developed sustained permanent trigeminal neuropathy. The largest reported series of pure trigeminal sensory neuropathy includes 10 adults with varying degrees of sensory disturbance confined to all three nerve divisions. These patients experienced no facial pain or motor deficit, and 5 (50%) recovered completely within a few months. It is estimated that typical trigeminal neuralgia occurs in about 1 in 25,000 of the population and is uncommon prior to the third decade, with 1% of the cases occurring before the age of 20 years. To our knowledge, we present the first clinical report of idiopathic trigeminal sensory neuropathy occurring in childhood.

Administration, Topical↗
PubMed2001

Anticoagulant management of patients with mechanical prosthetic valves undergoing non-cardiac surgery: indications and unresolved issues.

A wide array of recommendations is available for the management of anticoagulation in patients with a prosthetic heart valve scheduled for non-cardiac surgery, ranging from avoidance of replacement anticoagulant therapy in all cases (excluding those with a recent thromboembolic event), to replacement anticoagulant therapy in all, without risk stratification. These guidelines are derived from only a few small- to medium-sized, non-randomized and often methodologically flawed studies conducted during the late 1970s, and applies mainly to caged-ball and caged-disc valves. Furthermore, extrapolation of the thromboembolic risk from data on patients not receiving oral anticoagulants at all is based on assumptions that are not necessarily valid. In this review, the direct and indirect evidence on which these guidelines are based is examined critically. Their applicability to the newer, less thrombogenic valve models is questionable. The need for further prospective, randomized studies is emphasized by the failure of existing studies to adjust properly for the main known or presumed thromboembolic risk factors, and their low statistical power to detect significant differences between protocols in an intention-to-treat manner. The evaluation of obstructive and non-obstructive thrombosis should serve as a secondary outcome measure in the assessment of anticoagulation management before non-cardiac surgery.

Administration, Oral↗
PubMed2001

Erythropoietin can obviate the need for repeated heart valve replacement in high-risk patients with severe mechanical hemolytic anemia: case reports and literature review.

BACKGROUND AND AIM OF THE STUDY: Brisk hemolysis due to perivalvular leak is usually an indication for valve re-replacement. Repeated surgery after multiple previous valve operations is associated with high mortality, morbidity and failure rates. The present study evaluated the role of erythropoietin (EPO) administration in deferring or obviating the need for repeated surgery. METHODS: Three patients (two men, one woman; age range 62-76 years) with two mechanical valves each and two to four previous heart valve operations, who suffered from severe mechanical hemolytic anemia, were given subcutaneous EPO for 15-17 months. RESULTS: A marked reduction in red blood cell consumption was achieved with a weekly EPO dose of 18,000 U in two patients, both of whom also had mild or moderate kidney malfunction. A third patient with normal renal function and extreme hemolysis showed a transient, partial response to 30,000 U of EPO per week, and eventually needed a fifth operation. CONCLUSION: EPO may defer or even obviate the need for repeated valve surgery in patients with severe hemolysis due to perivalvular leak, especially those with inadequate EPO response, such as those with renal malfunction.

Aged↗
PubMed2001

Impact of atrial fibrillation on clinical status, atrial size and hemodynamics in patients after mitral valve replacement.

BACKGROUND AND AIM OF THE STUDY: The association between mitral valve disease and atrial fibrillation (AF) is well known, but few data exist regarding the impact of AF after mitral valve replacement (MVR) on NYHA functional class, atrial size and hemodynamic parameters. The present study was conducted to evaluate these issues. METHODS: Eighty-six patients (26 men, 60 women) who underwent MVR were evaluated by transthoracic echocardiography. Fifty-nine patients had chronic AF (AF group), and 27 were in sinus rhythm (sinus group). Variables analyzed included end-systolic left atrial and right atrial areas, tricuspid regurgitation, and presence and duration of AF. Peak and mean transprosthetic mitral valve gradients and pulmonary pressure were estimated by Doppler echocardiography. RESULTS: Groups were matched for age, sex and time from MVR (mean 6.6 years). Sixty-four patients (77%) had rheumatic heart disease, 18 (21%) had mitral valve disease, and two (2%) had mitral valve prolapse. Mean duration of AF was 11+/-12 years (range: 8-50 years). Preoperatively, AF patients had a worse NYHA class than sinus patients (2.8+/-0.8 versus 1.1+/-0.7, p = 0.001), but both had similar fractional shortening of the left ventricle and preserved prosthetic mitral valve function. Multivariate analysis identified AF as a single predictor of NYHA class after MVR. Although left and right atrial areas were larger in AF patients (47+/-25 versus 27+/-7 cm2, p = 0.0001 and 30+/-12 versus 17+/-5 cm2, p = 0.0001, respectively), the left:right atrial size ratio was not significantly different between groups. Multivariate analysis identified mean transmitral gradient and duration of AF as independent predictors of left atrial size after MVR (p = 0.01 and p = 0.0001, respectively). Tricuspid regurgitation and duration of AF were independent predictors of right atrial size (p = 0.003 and p = 0.0001, respectively). CONCLUSION: The presence of AF after MVR is associated with a worse NYHA functional class, increased transmitral gradients, and larger areas of both atria, when compared with sinus rhythm. Hence, a special effort should be made to correct arrhythmia during surgery, and in case of paroxysmal arrhythmia, earlier surgery should be considered before the condition becomes chronic.

Aged↗
PubMed2000

Detection and sorting of neural spikes using wavelet packets.

We propose a novel method for the detection and sorting of recorded neural spikes using wavelet packets. We employ the best basis via the Shannon's information cost function and local discriminant basis using mutual information. We demonstrate the efficiency of the method on data recorded in vitro from 2D neural networks. We show that our method is superior both in separation from noise and in identifying superimposed spikes.

Action Potentials↗
PubMed2000

Nonobstructive aortic valve calcium as a window to atherosclerosis of the aorta.

Aortic valve calcium without stenosis and mitral annulus calcium (MAC) are known to correlate with atherosclerotic risk factors. Recently, it has been reported that MAC is associated with atherosclerosis of the cardiovascular system, suggesting MAC as an atherosclerotic process by itself. Hence, the aim of the present study was to determine whether a similar association between aortic valve calcium and aortic atheroma exists. Ninety-six patients (54 men and 42 women, mean age 72 +/- 12 years) with aortic valve calcium who underwent transesophageal echocardiography (TEE) formed the study group. They were compared with 92 sex- and age-matched patients without aortic valve calcium who underwent TEE for the same indications during the same period. The presence and echocardiographic features of aortic atheromas were evaluated by TEE. No differences were found between the groups in risk factors for atherosclerosis or in indications for referral for TEE. Significantly higher rates were found in the aortic valve calcium group for prevalence of aortic atheroma (86% vs 30%, p = 0.001). This significant trend was also consistent with the dimension and complexity of the atheromas. On multivariate analysis aortic valve calcium, and MAC were the only independent predictors of aortic atheroma (p = 0.0001, 0.006 respectively). We conclude that there is a significant association between the presence of aortic valve calcium and the presence and severity of aortic atheroma. Thus, aortic valve calcium may serve as a window to atherosclerosis of the aorta.

Aged↗
PubMed2000

Activation of mitogen-activated protein kinases in human heart during cardiopulmonary bypass.

Mitogen-activated protein kinases (MAPKs) have been shown to be activated in both in vitro and in vivo models of cardiac tissue in response to ischemia/reperfusion injury. We investigated whether MAPKs are activated in human heart during coronary artery bypass grafting (CABG) surgery. During elective CABG surgery of 8 patients, 3 right atrial appendage biopsies were obtained at baseline, at the end of cross-clamping, and after coronary reperfusion. The expression of the p38-MAPK, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinases (ERK1/2) MAPKs was not altered during CABG. The phosphorylation and activation of both ERK1/2 and p38-MAPK were increased approximately 2-fold by ischemia and even more (8- and 4-fold, respectively) by reperfusion. Although the ischemic period did not result in a significant activation of JNK, an approximately 6-fold increase in JNK activity could be observed after reperfusion. In conclusion, distinct activation patterns of ERK1/2, p38, and JNK MAPKs can be observed in human heart during CABG.

Aged↗
PubMed2000

Association between mitral annulus calcification and aortic atheroma: a prospective transesophageal echocardiographic study.

BACKGROUND AND PURPOSE: Although mitral annulus calcification (MAC) has been reported to be a significant independent predictor of stroke, no causative relationship was proven. It is also known that aortic atheroma (AA), especially those >/=5 mm thick and/or protruding and/or mobile are associated with stroke. This study was designed to determine whether an association exists between MAC and AA. METHODS: We prospectively evaluated the records of 279 consecutive patients who underwent transesophageal echocardiography (TEE) for various indications to measure the presence and characteristics of AA. The 105 patients in whom a diagnosis of MAC was made on transthoracic echocardiography (TTE) immediately preceding the TEE, were compared with 174 age-matched patients without MAC. MAC was defined as a dense, localized, highly reflective area at the base of the posterior mitral leaflet. We measured MAC thickness with two-dimensional-TTE in four-chamber view and AA thickness, protrusion and mobility with TEE. AA was defined as localized intimal thickening of >/=3 mm. A lesion was considered complex if there was plaque extending >/=5 mm into the aortic lumen and/or if it was protruding, mobile or ulcerated. RESULTS: No differences were found between the groups in risk factors for atherosclerosis or in indications for referral for TEE. Significantly higher rates were found in the MAC group for prevalence of AA (91 vs. 44%, P<0.001), atheromas >/=5 mm thick (68 vs. 19%, P<0.001), protruding atheromas (44 vs. 15%, P<0.001), ulcerated atheromas (10 vs. 1%, P<0.001) and complex atheroma (74 vs. 22%, P<0.001). Sixty patients had MAC thickness >/=6 mm and 45<6 mm. AA thickness was significantly greater in the patients with a MAC thickness of >/=6 mm (6.1+/-2.8 vs. 5.0+/-2.6 mm, P=0.03). On multivariate analysis MAC, hypertension and age were the only independent predictors of AA (P=0.0001, 0.005 and 0.007, respectively). CONCLUSIONS: There is a significant association between the presence and severity of MAC and AA. MAC may be an important marker for atherosclerosis of the aorta. This association may explain in part the high prevalence of systemic emboli and stroke in patients with MAC.

Adult↗
PubMed2000

Thrombolysis is an effective and safe therapy in stuck bileaflet mitral valves in the absence of high-risk thrombi.

OBJECTIVES: We sought to evaluate the effectiveness and safety of thrombolytic therapy in stuck mitral bileaflet heart valves in the absence of high-risk thrombi. BACKGROUND: Current recommendations for the thrombolytic treatment of stuck prosthetic mitral valves are partially based on older valve models and inclusion of patients in whom high-risk thrombi were either ignored or not sought for. The feasibility and safety of thrombolysis in bileaflet models may be affected by the predilection of thrombi to catch the leaflet hinge. METHODS: We studied 12 consecutive patients (men/women = 5/7, age 58.8 +/- 14.9 years) who experienced one or more episodes of stuck bileaflet mitral valve over a 33-month period and received thrombolytic therapy with streptokinase, urokinase or tissue-type plasminogen activator. Transesophageal echocardiography was performed in all patients. Patients with mobile or large (>5 mm) thrombi were excluded. Functional class at initial episode was I-II in 4 patients (33.3%) and III-IV in 8 patients (66.6%). RESULTS: Patients receiving thrombolytic therapy achieved an overall 83.3% freedom from a repeat operation or major complications (95% confidence interval 51.6-97.9%). Minor bleeding occurred in three patients (25%) and allergic reaction in one (8.3%). Transient vague neurologic complaints, without subjective findings, occurred in four patients (33.3%). Three patients had one or more relapses within 5.2 +/- 3.1 months from the previous episode, and readministration of thrombolytics was successful. CONCLUSIONS: In clinically stable patients with stuck bileaflet mitral valves and no high-risk thrombi, thrombolysis is highly successful and safe, both in the primary episode and in recurrence. The best thrombolytic regimen is yet to be established.

Adult↗
PubMed2000

Raised interleukin-6 levels in obese patients.

OBJECTIVE: Obese patients demonstrate a variety of biochemical, metabolic, and pulmonary abnormalities. Inflammatory mediators such as tumor necrosis factor-alpha and interleukin-6 (IL-6) may have a direct effect on glucose and lipid metabolism. Hypoxemia in itself induces release of IL-6. The aim of this study was to examine the relationship between IL-6 levels in healthy volunteers (control group) and three different groups of obese patients: patients without obstructive sleep apnea syndrome (OSAS), patients with OSAS, and patients with obesity hypoventilation syndrome (OHS) (daytime baseline oxygen saturation of <93%). RESEARCH METHODS AND PROCEDURES: We measured serum IL-6 levels in 25 obese patients (body mass index of >35 kg/m2) and 12 healthy women. RESULTS: The results demonstrate statistically significant differences in serum IL-6 levels between the control group (1.28 +/- 0.85 pg/mL) and obese patients without OSAS (7.69 +/- 5.06 pg/mL, p < 0.05) and with OSAS (5.58 +/- 0.37 pg/mL, p < 0.0005). In the patients with OHS, IL-6 concentrations were highest (43.13 +/- 24.27 pg/mL). DISCUSSION: We conclude that serum IL-6 is increased in obese patients. The highest IL-6 levels were found in the patients with OHS.

Adult↗
PubMed2000

Hypodontia in children with various types of clefts.

The prevalence of hypodontia in children with clefts, both inside and outside the cleft region, and the possible association between the side of the cleft and the side of the missing teeth were studied using radiographs of 278 patients with cleft lip, cleft palate, or both (158 boys and 120 girls), age 5 to 18 years (mean age 10.4 years). A hypodontia prevalence of 77% (excluding third molars) was found for the total cleft sample. This was significantly higher, both statistically and clinically, than the incidence of hypodontia reported for noncleft populations, and considerably higher than the prevalence reported in other studies of children with clefts. The maxillary permanent lateral incisors were the teeth most frequently missing on the cleft side (259 teeth) followed by the maxillary (47 teeth) and mandibular (23 teeth) second premolars, in both boys and girls. The teeth that were most often missing on the noncleft side were the maxillary second premolars (12 teeth), followed by the maxillary lateral incisors (10 teeth) and mandibular second premolars (6 teeth). Hypodontia of both the maxillary lateral incisors and second premolars was found more frequently on the left side, which also has a higher frequency of clefting.

Adolescent↗
PubMed2000

The effect of aortic valve replacement on left ventricular mass assessed by echocardiography.

AIMS: The aim of the study was to investigate whether aortic valve replacement (AVR) has different effects on the left ventricular mass (LVM) in patients with different types of aortic valve disease, i.e. aortic stenosis (AS), aortic regurgitation (AR), or combined disease. METHODS AND RESULTS: We studied 100 patients with AS; (n=57), AR; (n=22), and combined disease; (n=21). Each patient was evaluated before and up to 8.7 years (mean follow-up period 1.42 +/- 1.65 years) after operation by transthoracic echocardiography. LVM was calculated based on echocardiographic parameters. Following AVR, the LVM for the entire group decreased from 373 +/- 145 g to 280 +/- 102 g (P=0.0001). The AS subgroup lost 13.7 +/- 30.7% from the preoperative LVM, compared to 28.8 +/- 24.8% in the AR subgroup (P<0.05) and 23.1 +/- 33.1% in the combined subgroup. The preoperative LVM was higher among patients with AR vs. AS patients (501 +/- 173 g vs. 319 +/- 100 g respectively, P<0.05). The decrease in LVM was significantly higher in patients with preoperative AR compared to AS patients (165 +/- 150 g vs. 58 +/- 96 g, respectively, P<0.05). However, the postoperative LVM remained higher among the former. The only preoperative parameter (of the LVM formula) that was different between AR and AS patients was the left ventricular end diastolic diameter (68 +/- 11 mm vs. 51 +/- 7 mm, respectively, P<0.05). No significant differences were found in wall thickness among the groups studied. Univariate analysis showed that gender (male), type of aortic valve disease (AR vs. AS), and larger prosthetic valve diameter correlated significantly with greater decrease in postoperative LVM. In multivariate analysis comparing the above variables between AS and AR subgroups, only the patient's gender (i.e. male) was identified as an independent predictor of LVM regression. CONCLUSION: Patients with AR have a greater decline in LVM compared with patients with AS following AVR. The postoperative decline in LVM is higher among males and those with larger prosthetic valve diameter.

Aged↗