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Cascio S, Tien A, Chee W, Tan HL. Laparoscopic Dismembered Pyeloplasty in Children Younger Than 2 Years. J Urol 2007; 177:335-8. [PMID: 17162086 DOI: 10.1016/j.juro.2006.08.145] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE Since the first laparoscopic pyeloplasty was described in a child in 1995, there have been several reports of pyeloplasty in older children. However, to date there have been few reports of laparoscopic pyeloplasty in infants and toddlers. The aim of this study was to evaluate the results of laparoscopic pyeloplasty in children younger than 2 years. MATERIALS AND METHODS All laparoscopic Anderson-Hynes pyeloplasties performed in children younger than 2 years were retrospectively reviewed. The diagnosis of ureteropelvic junction obstruction was confirmed on renal sonography and diuretic renogram. Laparoscopic pyeloplasties were performed via a transperitoneal route as originally described, with key modifications. All children were investigated with postoperative diuretic renogram and renal ultrasonography. RESULTS A total of 38 children with ureteropelvic junction obstruction underwent laparoscopic Anderson-Hynes pyeloplasty between January 2001 and December 2005. Of these patients 11 (7 males and 4 females) were younger than 2 years at surgery (median 1.4, range 2 to 22 months) and 1 had bilateral ureteropelvic junction obstruction, for a total of 12 primary repairs. However, 2 patients (17%) required redo laparoscopic pyeloplasty, for a total of 14 laparoscopic dismembered pyeloplasties in this age group. Operative time ranged from 70 to 140 minutes (mean 100) and median hospital stay was 2 days. Followup studies showed normal drainage in all patients except 1, who after redo pyeloplasty exhibited significantly improved but still prolonged drainage. CONCLUSIONS This study suggests that laparoscopic pyeloplasty can now be performed in young children with good results.
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Tan HL, Tantoco JG, Ee MZ. The role of diagnostic laparoscopy in micropremmies with suspected necrotizing enterocolitis. Surg Endosc 2006; 21:485-7. [PMID: 17103277 DOI: 10.1007/s00464-006-9030-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Revised: 04/04/2006] [Accepted: 04/27/2006] [Indexed: 11/28/2022]
Abstract
BACKGROUND The timely diagnosis of perforations or dead gut can be extremely difficult in micropremmies with necrotizing enterocolitis. A negative laparotomy is just as detrimental as failure to recognize early perforation in this group of patients. We have been exploring the role of microlaparoscopy using a needlescope to determine if this modality is feasible and useful in the surgical management of these patients. We report our technique and initial experience with needlescopic diagnosis. METHODS Four patients (weight >500 to <1000 g) with abdominal distension and clinical sepsis not responsive to aggressive medical treatment were included in this study. None had radiologic evidence of pneumatosis or perforation. There was no absolute surgical indication for laparotomy except for strong suspicion of a surgical cause. Needlescopic diagnosis was performed in all these patients. RESULTS There was no evidence of perforation or bile in the abdominal cavity in one patient. This patient improved on medical management, avoiding a laparotomy. The rest had bile or fibrin in the abdominal fluid with a localized perforation, and in each case we performed a microlaparotomy directly over the site of perforation to create a stoma. CONCLUSIONS Needlescopic diagnosis is feasible and appears to be safe, even in critically ill micropremmies less than 1000 g. The technique can provide useful information for surgical decision-making and allows for precise placement of a microlaparotomy incision over the site of perforation, thus minimizing the trauma from open surgery in this special group of patients. We are currently expanding its role in patients with overt perforations to determine if we can limit the extent of surgical exploration without compromising the adequacy of surgical management.
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MESH Headings
- Abdominal Cavity/pathology
- Abdominal Cavity/surgery
- Enterocolitis, Necrotizing/diagnosis
- Enterocolitis, Necrotizing/pathology
- Enterocolitis, Necrotizing/surgery
- Humans
- Infant, Extremely Low Birth Weight
- Infant, Newborn
- Infant, Premature, Diseases/diagnosis
- Infant, Premature, Diseases/pathology
- Infant, Premature, Diseases/surgery
- Laparoscopy/methods
- Treatment Outcome
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Verkerk AO, Wilders R, de Geringel W, Tan HL. Cellular basis of sex disparities in human cardiac electrophysiology. Acta Physiol (Oxf) 2006; 187:459-77. [PMID: 16866777 DOI: 10.1111/j.1748-1716.2006.01586.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIM Sex disparities in electrocardiogram variables and dysrhythmia susceptibility exist, notably in long QT syndrome (LQTS) and Brugada syndrome, but the underlying mechanisms in man are unknown. We studied the cellular basis of sex distinctions in human cardiac electrophysiology and dysrhythmia susceptibility using mathematical models of human ventricular myocytes. METHODS We implemented sex differences in the Priebe-Beuckelmann and ten Tusscher-Noble-Noble-Panfilov human ventricular cell models by modifying densities of the L-type Ca(2+) current (I(Ca,L)), transient outward K(+) current (I(to)), and rapid delayed rectifier K(+) current (I(Kr)), according to experimental data from male and female hearts of various species. Sex disparities in transmural repolarization were studied in transmural strands of cells with ion current densities based on canine experimental data. RESULTS Female cells have longer action potential duration (APD), steeper APD-heart rate relationship, larger transmural APD heterogeneity, and a greater susceptibility to pro-dysrhythmogenic early afterdepolarizations (EADs) than male cells. Conversely, male cells have more prominent phase-1 repolarization and are more susceptible to all-or-none repolarization. CONCLUSION Sex differences in I(Ca,L), I(to) and I(Kr) densities may explain sex disparities in human cardiac electrophysiology. Female cells exhibit a limited 'repolarization reserve' as demonstrated by their larger susceptibility to EADs, which, combined with their larger transmural electrical heterogeneity, renders them more vulnerable to tachydysrhythmias in LQTS. Conversely, male cells have a limited 'depolarization reserve', as shown by their larger susceptibility to all-or-none repolarization, which facilitates tachydysrhythmias in Brugada syndrome. These general principles may also apply to dysrhythmia susceptibility in common disease.
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Amin AS, Verkerk AO, Bhuiyan ZA, Wilde AAM, Tan HL. Novel Brugada syndrome-causing mutation in ion-conducting pore of cardiac Na+ channel does not affect ion selectivity properties. ACTA ACUST UNITED AC 2006; 185:291-301. [PMID: 16266370 DOI: 10.1111/j.1365-201x.2005.01496.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIM Brugada syndrome is an inherited cardiac disease with an increased risk of sudden cardiac death. Thus far Brugada syndrome has been linked only to mutations in SCN5A, the gene encoding the alpha-subunit of cardiac Na+ channel. In this study, a novel SCN5A gene mutation (D1714G) is reported, which has been found in a 57-year-old male patient. Since the mutation is located in a segment of the ion-conducting pore of the cardiac Na+ channel, which putatively determines ion selectivity, it may affect ion selectivity properties. METHODS HEK-293 cells were transfected with wild-type (WT) or D1714G alpha-subunit and beta-subunit cDNA. Whole-cell configuration of the patch-clamp technique was used to study biophysical properties at room temperature (21 degrees C) and physiological temperature (36 degrees C). This study represents the first measurements of human Na+ channel kinetics at 36 degrees C. Ion selectivity, current density, and gating properties of WT and D1714G channel were studied. RESULTS D1714G channel yielded nearly 80% reduction of Na+ current density at 21 and 36 degrees C. At both temperatures, no significant changes were observed in V(1/2) values and slope factors for voltage-dependent activation and inactivation. At 36 degrees C, but not at 21 degrees C, D1714G channel exhibited more slow inactivation compared with WT channel. Ion selectivity properties were not affected by the mutation at both temperatures, as assessed by either current or permeability ratio. CONCLUSION This study shows no changes in ion selectivity properties of D1714G channel. However, the profoundly decreased current density associated with the D1714G mutation may explain the Brugada syndrome phenotype in our patient.
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McHoney MC, Corizia L, Eaton S, Wade A, Spitz L, Drake DP, Kiely EM, Tan HL, Pierro A. Laparoscopic surgery in children is associated with an intraoperative hypermetabolic response. Surg Endosc 2006; 20:452-7. [PMID: 16432658 DOI: 10.1007/s00464-004-2274-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Accepted: 06/10/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Laparoscopic surgery is thought to be associated with a reduced metabolic response compared to open surgery. Oxygen consumption (VO2) and energy metabolism during laparoscopic surgery have not been characterized in children. METHODS We measured respiratory gas exchange intraoperatively in children undergoing 19 open and 20 laparoscopic procedures. Premature infants and patients with metabolic, renal, and cardiac abnormalities were excluded. Anesthesia was standardized. Unheated carbon dioxide was used for insufflation. VO2 was measured by indirect calorimetry. Core temperature was measured using an esophageal temperature probe. RESULTS We found a steady increase in VO2 during laparoscopy. The increase in VO2 was more marked in younger children and was associated with a significant rise in core temperature. Open surgery was not associated with significant changes in core temperature or VO2. CONCLUSIONS Laparoscopy in children is associated with an intraoperative hypermetabolic response characterized by increased oxygen consumption and core temperature. These changes are more marked in younger children.
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Wilde AAM, Tan HL. Should I be worried? Neth Heart J 2006; 14:33-39. [PMID: 25696555 PMCID: PMC2557218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
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van Langen IM, Birnie E, Schuurman E, Tan HL, Hofman N, Bonsel GJ, Wilde AAM. Preferences of cardiologists and clinical geneticists for the future organization of genetic care in hypertrophic cardiomyopathy: a survey. Clin Genet 2005; 68:360-8. [PMID: 16143023 DOI: 10.1111/j.1399-0004.2005.00502.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In view of the increasing demands for genetic counselling and DNA diagnostics in cardiogenetics, the roles of cardiologists and clinical geneticists in the delivery of care need to be redefined. We investigated the preferences of both groups of professionals with regard to the future allocation of six cardiogenetic responsibilities in counselling and testing, using hypertrophic cardiomyopathy (HCM) as a prevalent model disease. In this cross-sectional survey, the participants were Dutch cardiologists (n = 643) and clinical geneticists (n = 60), all members of professional societies. Response rates were 33 and 82%, respectively. In both groups, the majority preferred to perform most of the tasks described above in collaboration. Informing HCM patients about the genetics of HCM and requesting DNA testing in symptomatic patients was viewed by 43 and 35% of cardiologists, respectively, as their sole responsibility, however, and 39 and 59% of clinical geneticists did not object to these views. Both groups felt that the task of discussing the consequences of HCM for offspring and that of discussing the results of DNA diagnostics should be shared or performed by clinical geneticists. Both groups considered co-ordination of family screening the sole responsibility of clinical geneticists. Opinions on who should request DNA diagnostics in asymptomatic relatives were divided: 86% of clinical geneticists considered it their exclusive responsibility, 10% of cardiologists believed that this task could be performed individually by either group and 30% preferred to collaborate. Most professionals said that they would appreciate education programmes and clinical guidelines. Both cardiologists and clinical geneticists prefer to share rather than divide most cardiogenetic responsibilities in caring for HCM patients. Consequently, capacity problems in both groups are to be expected. To safeguard current professional standards in genetic counselling and testing, deployment of non-medical personnel might be essential.
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Ong KH, Tan HL, Lai HC, Kuperan P. Accuracy of various iron parameters in the prediction of iron deficiency in an acute care hospital. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2005; 34:437-40. [PMID: 16123817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
INTRODUCTION Iron parameters like serum ferritin and iron saturation are routinely used in diagnosing iron deficiency. However, these tests are influenced by many factors. We aimed to review the accuracy of iron parameters among inpatients in an acute care hospital. MATERIALS AND METHODS From October 1997 to April 2002, bone marrow aspirate samples from patients on whom concurrent iron studies had been done were analysed. Accuracy of the various iron parameters was analysed using receiver operating characteristic curves. RESULTS Among 92 bone marrow aspirate samples, 58, 86 and 83 had a concurrent serum ferritin, serum iron and percentage iron saturation done respectively. Serum ferritin is the best marker for predicting the presence of iron deficiency. This is followed by percentage iron saturation and lastly by serum iron. At the most optimal, a serum ferritin of <60 ng/mL has a positive likelihood ratio of 24.35, sensitivity of 69.6%, specificity of 97.1% and positive predictive value of 94.1%. An iron saturation of <7% has a positive likelihood ratio of 21.62, sensitivity of 44.1%, specificity of 98.0% and positive predictive value of 93.8%. Seven out of 50 samples, which had concurrent measurements of iron saturation and serum ferritin, were discordant in indicating the presence of iron deficiency. In 6 cases, the iron saturation was the spurious result. CONCLUSION A serum ferritin of <60 ng/mL or a percentage iron saturation of <7% is highly predictive of iron deficiency among inpatients in an acute care hospital.
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Tan HL, Pinder M, Parsons R, Roberts B, van Heerden PV. Clinical evaluation of USCOM ultrasonic cardiac output monitor in cardiac surgical patients in intensive care unit. Br J Anaesth 2005; 94:287-91. [PMID: 15653709 DOI: 10.1093/bja/aei054] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The USCOM ultrasonic cardiac output monitor (USCOM Pty Ltd, Coffs Harbour, NSW, Australia) is a non-invasive device that determines cardiac output by continuous-wave Doppler ultrasound. The aim of this study was to evaluate the accuracy of the USCOM device compared with the thermodilution technique in intensive care patients who had just undergone cardiac surgery. METHODS We conducted a prospective study in the 18-bed intensive care unit of a 600-bed tertiary referral hospital. Twenty-four mechanically ventilated patients were studied immediately following cardiac surgery. We evaluated the USCOM monitor by comparing its output with paired measurements obtained by the standard thermodilution technique using a pulmonary artery catheter. RESULTS Forty paired measurements were obtained in 22 patients. We were unable to obtain an acceptable signal in the remaining two patients. Comparison of the two techniques showed a bias of 0.18 and limits of agreement of -1.43 to 1.78. The agreement may not be as good between techniques at higher cardiac output values. CONCLUSIONS The USCOM monitor has a place in intensive care monitoring. It is accurate, rapid, safe, well-tolerated, non-invasive and cost-effective. The learning curve for skill acquisition is very short. However, during the learning phase the USCOM monitor measurements are rather 'operator dependent'. Its suitability for use in high and low cardiac output states requires further validation.
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Abstract
Several surgical options are available for managing varicoceles. Although conventional surgery offers good surgical results, the most common long-term complication of surgery is the development of hydroceles, thought to be due to interruption in the lymphatic outflow from the subservient testis. The authors describe a new technique of in vivo methylene blue mapping of testicular lymphatic vessels at laparoscopy, allowing these vessels to be spared during laparoscopic varicocelectomy. This novel method of in vivo staining of lymphatic vessels should prevent damage to the lymphatic system and avoid the late development of hydroceles. A prospective multicenter trial is currently underway to evaluate the medium- and long-term results.
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Ong KH, Tan HL, Lai HC, Kuperan P. Serum transferrin receptor levels in the normal population and subjects with iron deficiency and thalassaemia trait. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2004; 33:S43-4. [PMID: 15651202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
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Verkerk AO, Tan HL, Ravesloot JH. Ca2+-activated Cl- current reduces transmural electrical heterogeneity within the rabbit left ventricle. ACTA ACUST UNITED AC 2004; 180:239-47. [PMID: 14962005 DOI: 10.1111/j.0001-6772.2003.01252.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Various cationic membrane channels contribute to the heterogeneity of action potential configuration between the transmural layers of the left ventricle. The role of anionic membrane channels is less intensively studied. We investigated the role of the Ca2+-activated Cl- current, ICl(Ca), in transmural electrical heterogeneity. METHODS AND RESULTS We determined the density of ICl(Ca) and its physiological role in subepicardial and subendocardial ventricular myocytes of rabbit using the patch-clamp technique. ICl(Ca) was measured as the 4,4'diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) sensitive current. The current-voltage relationships and the densities of ICl(Ca) were similar in subepicardial and subendocardial myocytes. However, the functional role of ICl(Ca) exhibited striking differences. In subendocardial myocytes, blockade of ICl(Ca) by DIDS increased action potential duration (APD) significantly at all measured stimulus frequencies (3.33-0.2 Hz). In subepicardial myocytes, ICl(Ca) blockade increased APD only at 3.33 Hz, but not at the lower stimulus frequencies. At 1 Hz, ICl(Ca) blockade in subepicardial myocytes only caused an APD increase when the transient outward K+ current, Ito1, was blocked. CONCLUSIONS The densities and gating properties of ICl(Ca) are similar in subepicardial and subendocardial myocytes. ICl(Ca) contributes to APD shortening in subendocardial, but not in subepicardial myocytes except at 3.33 Hz. These differences in functional expression of ICl(Ca) reduce the electrical heterogeneity in rabbit left ventricle.
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Wilde AAM, Tan HL. A fainting lady with some extrasystoles. Neth Heart J 2004; 12:73-89. [PMID: 25696300 PMCID: PMC2497063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
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Verkerk AO, Tan HL, Kirkels JH, Ravesloot JH. Role of Ca2+-activated Cl- current during proarrhythmic early afterdepolarizations in sheep and human ventricular myocytes. ACTA ACUST UNITED AC 2004; 179:143-8. [PMID: 14510777 DOI: 10.1046/j.1365-201x.2003.01190.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES The proarrhythmic early afterdepolarizations (EADs) during phase-2 of the cardiac action potential (phase-2 EADs) are associated with secondary Ca2+-release of the sarcoplasmic reticulum. This makes it probable that the Ca2+-activated Cl- current [ICl(Ca)] is present during phase-2 EADs. Activation of ICl(Ca) during phase-2 of the action potential will result in an outwardly directed, repolarizing current and may thus be expected to prevent excessive depolarization of phase-2 EADs. The present study was designed to test this hypothesis. METHODS AND RESULTS The contribution of ICl(Ca) during phase-2 EADs was studied in enzymatically isolated sheep and human ventricular myocytes using the patch-clamp methodology. EADs were induced by a combination of a low stimulus frequency (0.5 Hz) and exposure to 1 microm noradrenaline. In sheep myocytes, the ICl(Ca) blocker 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS, 0.5 mm) abolished phase-1 repolarization of the action potential in all myocytes tested. This indicates that ICl(Ca) is present in all sheep myocytes. However, DIDS had no effect on phase-2 EAD characteristics. In human myocytes, DIDS neither affected phase-1 repolarization nor phase-2 EAD characteristics. CONCLUSION In sheep ventricular myocytes, but not in human ventricular myocytes, ICl(Ca) contributes to phase-1 repolarization of the action potential. In both sheep and human myocytes, ICl(Ca) plays a limited role during phase-2 EADs.
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van Langen IM, Hofman N, Tan HL, Wilde AAM. Family and population strategies for screening and counselling of inherited cardiac arrhythmias. Ann Med 2004; 36 Suppl 1:116-24. [PMID: 15176433 DOI: 10.1080/17431380410032526] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Family screening in inherited cardiac arrhythmias has been performed in The Netherlands since 1996, when diagnostic DNA testing in long QT syndrome (LQTS) and hypertrophic cardiomyopathy (HCM) became technically possible. In multidisciplinary outpatient academic clinics, an adjusted protocol for genetic counselling, originally derived from predictive testing in Huntington's disease, is being used. 1110 individuals, including 842 relatives of index patients, were informed about their risks, and most were tested molecularly and/or clinically for carriership of the disease present in their family. Of 345 relatives who were referred for cardiologic follow-up, 189 are being treated, because of an increased risk of life-threatening arrhythmias. Evaluation of the psychological and social consequences of family screening for inherited arrhythmias can be performed by using the adapted criteria of Wilson and Jüngner, i.e., from a point of view of public health. Preliminary results of psychological research show that parents of children at risk for LQTS show high levels of distress. Many other aspects have to be evaluated yet, making final conclusions about the feasibility of family screening difficult, particularly in HCM. Clinical guidelines are urgently needed. Population screening by molecular testing, for instance in athletic preparticipation screening, will become possible in the future and has its own prerequisites for success.
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MESH Headings
- Arrhythmias, Cardiac/diagnosis
- Arrhythmias, Cardiac/genetics
- Arrhythmias, Cardiac/prevention & control
- Cardiomyopathy, Hypertrophic, Familial/diagnosis
- Cardiomyopathy, Hypertrophic, Familial/genetics
- Cardiomyopathy, Hypertrophic, Familial/prevention & control
- Death, Sudden, Cardiac/prevention & control
- Family
- Follow-Up Studies
- Genetic Carrier Screening/methods
- Genetic Counseling/methods
- Genetic Testing/methods
- Humans
- Long QT Syndrome/diagnosis
- Long QT Syndrome/genetics
- Long QT Syndrome/prevention & control
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Tan HL, Lopez PJ, Shankar KR, Boucaut HAP. Silicon headrests are ideal lithotomy restraints for neonatal and infant cystoscopy. BJU Int 2003; 93:177-8. [PMID: 14678393 DOI: 10.1111/j.1464-410x.2004.04579.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Tan HL, Shankar KR, Ford WDA. Laparoscopic resection of type I choledochal cyst. Surg Endosc 2003; 17:1495. [PMID: 12811656 DOI: 10.1007/s00464-003-4502-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2003] [Accepted: 03/05/2003] [Indexed: 02/07/2023]
Abstract
Type I choledochal cyst is a rare saccular or fusiform congenital dilatation of the extrahepatic biliary tract. It is usually treated by laparotomy at which the cyst is completely excised and a Roux-en-Y hepaticojejunostomy is performed to establish biliary enteric drainage. We report the laparoscopic excision and hepaticoduodenostomy of type I choledochal cyst in two girls aged 1 and 3 years. The entire procedure was performed laparoscopically using needlescopic instruments. A 7-mm telescope port was inserted at the umbilicus, a 3-mm port in the right upper quadrant, and a 6-mm port in left upper quadrant. An additional 3-mm fan-shaped liver retractor was passed through the abdominal wall without a trocar. The gallbladder and choledochal cyst was dissected and removed en bloc. The lower end of the common bile duct was closed with 5-0 polydioxanone. The duodenum was anastomosed to the common hepatic duct below the confluence of the right and left hepatic ducts. There were no intraoperative complications, and the children were asymptomatic with no episodes of cholangitis at 6 months follow-up. Pediatric surgeons trained in advanced laparoscopic techniques including intracorporeal suturing can perform laparoscopic repair of choledochal cyst safely.
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Tan HL, Sithasanan N, Foley P, Davidson GP. The successful medical management of severe duodenal strictures secondary to eosinophilic gastroenteritis in an infant. Pediatr Surg Int 2003; 19:562-3. [PMID: 12905002 DOI: 10.1007/s00383-003-0995-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/23/2002] [Indexed: 10/26/2022]
Abstract
Eosinophilic gastroenteritis is an uncommon condition of unknown etiology that has only been relatively recently reported. Its clinical manifestations range from a mild disease to more severe forms resembling Crohn's disease. Enteric strictures are a rare but recognized complication of this condition. We report a case of eosinophilic gastroenteritis in an infant presenting with severe duodenal strictures that was successfully managed with oral prednisolone. We believe that this is the first reported case of duodenal strictures secondary to eosinophilic gastroenteritis.
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Tan HL, Shankar KR, Ade-Ajayi N, Guelfand M, Kiely EM, Drake DP, De Bruyn R, McHugh K, Smith AJ, Morris L, Gent R. Reduction in visceral slide is a good sign of underlying postoperative viscero-parietal adhesions in children. J Pediatr Surg 2003; 38:714-6. [PMID: 12720177 DOI: 10.1016/jpsu.2003.50190] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND/PURPOSE Viscera stuck to the anterior abdominal wall from previous surgery risk injury during laparoscopic surgery. A prospective study was conducted to determine if these adhesions are detectable on ultrasound scan by showing a reduction in the normal visceral slide. METHODS Patients undergoing laparoscopic procedure after a previous laparotomy underwent preoperative real-time ultrasound scan to observe if viscera slides freely under the abdominal wall. A reduction in slide was considered a positive sign of underlying adhesions. These findings were correlated with the operative findings. RESULTS Anterior abdominal wall scans were performed on 17 children. Reduced visceral slide was seen in 10. Viscero-parietal adhesions were found in 9 of 10 patients. Visceral slide was reduced in a very localized area in 6 patients, and, in these, a loop of bowel (n = 3), liver and bowel (n = 2), or liver (n = 1) was adherent. In 4, reduced visceral slide was seen over a wide area. Extensive adhesions were found in 3 of 4. One renal transplant patient with peritonitis had a false-positive ultrasound scan. At laparotomy there were no adhesions. The peritonitis is thought to have prevented an adequate examination. Seven patients had normal visceral slide. Of these, 4 had no adhesions, but 3 children had flimsy omental adhesions. The sensitivity and specificity of visceral slide in predicting adhesions were 75% and 80%, respectively. CONCLUSIONS Reduction in visceral slide is a good sign of underlying postoperative viscero-parietal adhesions. Ultrasonographic mapping of the abdominal wall may be useful in selecting an adhesion-free site for trocar insertion in children with previous operations requiring laparoscopic procedures.
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Verkerk AO, Tan HL, Baartscheer T, Ravesloot JH. Limited role of Ca 2+-activated Cl - current in early afterdepolarisations. Neth Heart J 2002; 10:506-511. [PMID: 25696055 PMCID: PMC2499824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
Abstract
OBJECTIVES The proarrhythmic, early afterdepolarisations during phase two of the action potential (phase-2 EADs) are associated with secondary Ca2+ release from the sarcoplasmic reticulum. This makes it probable that the Ca2+-activated Cl- current (ICl(Ca)) may contribute to phase-2 EADs. Activation of ICl(Ca) during phase two of the action potential will result in a repolarising current and may thus be expected to prevent excessive depolarisation of phase-2 EADs. The present study was designed to test this hypothesis. METHODS The contribution of ICl(Ca) during phase-2 EADs was studied in enzymatically isolated sheep ventricular myocytes using the patch-clamp methodology. EADs were induced at a stimulus frequency of 0.5 Hz by exposure of the myocytes to 1 μM noradrenaline. RESULTS The ICl(Ca) blocker 4,4'-diisothiocyanostilbene-2,2'-disulphonic acid (DIDS, 0.5 mM) abolished phase-1 repolarisation of the action potential in all myocytes tested. This indicates that ICl(Ca) is present in all myocytes. However, DIDS had no effect on phase-2 EAD characteristics. CONCLUSION In sheep ventricular myocytes, ICl(Ca) contributes to phase-1 repolarisation of the action potential, but plays a limited role in phase-2 EADs.
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Wilde AAM, Tan HL, Bezzina CR. Familial primary arrhythmia syndromes: Nice to know or need to know. Neth Heart J 2002; 10:225-228. [PMID: 25696097 PMCID: PMC2499719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
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Tan HL, Liew QY, Loo S, Hawkins R. Severe hyperphosphataemia and associated electrolyte and metabolic derangement following the administration of sodium phosphate for bowel preparation. Anaesthesia 2002; 57:478-83. [PMID: 11966559 DOI: 10.1046/j.0003-2409.2001.02519.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Sodium phosphate is widely used as an effective bowel preparation agent. It is used in smaller volumes, leading to improved patient tolerance. Although it is generally safe, cases of severe hyperphosphataemia following sodium phosphate administration have been reported in the literature. The common risk factors identified are advanced age, impaired renal function, impaired colonic motility and multiple doses. However, many doctors remain unaware of the dangers associated with this agent. We report six cases of severe electrolyte and metabolic derangement due to sodium phosphate bowel preparation: two patients had delayed awakening from general anaesthesia, and four patients suffered life-threatening consequences.
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Tan HL. Laparoscopic repair of inguinal hernias in children. J Pediatr Surg 2001; 36:833. [PMID: 11329600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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Abstract
While adenosine effectively terminates most supraventricular tachycardias (SVT), rare case reports have demonstrated its proarrhythmic potential, including induction of ventricular tachycardia (VT). The aim of this study was to define the proarrhythmic effects of adenosine in a large, unselected population. During a 5-year period, adenosine was used (average dose 9.7 mg) in the emergency room to manage 187 episodes of tachycardia in 127 patients. In two thirds of the cases, adenosine induced ventricular ectopy following successful termination of SVT, including premature ventricular complexes (PVC) and nonsustained VT. The adenosine induced PVCs and VT were transient and self-terminating. More than half had a right bundle branch block morphology with a superior axis that suggested an origin in the inferior left ventricular septum. In conclusion, although adenosine is commonly used in clinical practice to treat SVTs, we found that it induced PVCs and VT in two thirds of the patients. The high incidence of ventricular arrhythmias following adenosine infusion was surprising but did not require further intervention. These arrhythmias appeared to frequently originate from the inferior left ventricular septum, suggesting that this area may be particularly susceptible to the proarrhythmic effects of adenosine.
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