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Biomedical subjects

E K Sim

Publications and source records attributed to E K Sim.

At least 37 records · Page 2Linked to original sources
PubMed1998

Thoracoscopic thymectomy for myasthenia gravis: a case report.

Total thymectomy combined with medical therapy is currently the most effective therapeutic strategy for patients with myasthenia gravis. The standard approach for total thymectomy is that of a median sternotomy. Other approaches include the cervical approach and partial sternotomy. We report a patient who underwent video-assisted thoracoscopic thymectomy at our institution. There was no postoperative complications and the patient was discharged on the fifth postoperative day. Video-assisted thoracoscopic thymectomy has proved to be an effective surgical therapy for the treatment of myasthenia gravis. The long-term outcome awaits close follow-up of the patients operated using this technique.

Adult↗
PubMed1997

Isolated right ventricular diverticulum with chest pain.

A 26-year-old man presented with severe chest pain. Subsequent investigations revealed a right ventricular diverticulum communicating with the right atrium. Surgery was performed, following which the chest pain disappeared completely.

Adult↗
PubMed1997

Early closure of coronary cameral fistula in a 3.9 kg infant.

Congenital communications between the coronary artery and cardiac chambers are rare. The majority of cases present in adulthood. We report a patient with a coronary cameral fistula in which surgical closure of the fistula was performed at 10 weeks of age at a weight of 3.9 kg. We recommend early closure of coronary cameral fistula in symptomatic patients. Low weight or young age at presentation should not be a limiting factor.

Arteriovenous Fistula↗
PubMed1996

Blood cyst of the tricuspid valve.

Blood-filled cysts of the heart valves are commonly reported at postmortem examination of infants but are rarely seen in older children and adults. These cysts appear to be benign lesions and should be removed only if they cause problems. We present the case of a patient with a tricuspid valve blood cyst that was surgically removed and then discuss the differential diagnosis and management of these cysts. When a cardiac mass has features suggestive of a blood cyst, radical resection should not be performed unless histologic confirmation of tumor is obtained.

Child, Preschool↗
PubMed1996

Lecompte operation with preservation of the pulmonary valve for anomalies of ventriculoarterial connection with ventricular septal defect and subpulmonary stenosis.

A modification of the Lecompte operation is reported in which the pulmonary valve is preserved. This technique is applicable in certain anomalies of ventriculoarterial connection with ventricular septal defect and subpulmonary stenosis. The main advantage of this modification, besides preservation of growth potential of the translocated pulmonary artery, consists of preservation of pulmonary valve function, which may have a beneficial effect on the long-term preservation of right ventricular compliance.

Heart Defects, Congenital↗
PubMed1995

Morphometric features of ruptured congenital sinus of Valsalva aneurysm: implication for surgical treatment.

Five hearts with ruptured congenital sinus of Valsalva aneurysm were studied. In 3 hearts of Caucasian patients, the sinus of Valsalva aneurysms were located in the immediate vicinity of the commissure between the noncoronary and right aortic cusps with rupture from the noncoronary sinus to the right atrium (n = 2) and from the right sinus to the right ventricle (n = 1). In 2 hearts of indigenous North Americans, the defects were sited in the immediate vicinity of the commissure between right and left aortic cusps with rupture into the right ventricle; both patients had an associated conal septal hypoplasia ventricular septal defect and aortic insufficiency. The diameters of the rupture holes at the base of the sinus of Valsalva aneurysms in the five hearts ranged from 0.4 to 1.1 cm (mean 0.7 cm). Histologic examination of longitudinal sections through the ruptured sinus of Valsalva showed 0.8 to 1.7 cm (mean 1.1 cm) wide areas in which there was lack of continuity between the aortic media and the aortic annulus. Conclusions. This study shows that the site of congenital weakness in sinus of Valsalva aneurysm in indigenous North American patients may be similar to that in Oriental patients, whereas the site tends to be different in Occidental patients. It also emphasizes the importance of patch closure rather than suture closure of ruptured sinus of Valsalva aneurysms.

Adolescent↗
PubMed1994

Coronary artery anatomy in complete transposition of the great arteries.

Knowledge of the variations in coronary artery pattern is important in the arterial switch operation for complete transposition of the great arteries (TGA). As autopsy specimens provide the most definitive means of identifying the coronary anatomy, 255 hearts with complete TGA were reviewed by a single pathologist. The age of the patients ranged from 1 day to 34 years (mean, 2.9 years). The origin of the coronary arteries was defined as seen by an observer looking from the pulmonary artery toward the aorta. The usual pattern with the right coronary artery originating from the right hand sinus and the left coronary artery from the left hand sinus (184 cases) and the circumflex coronary artery arising from the right coronary artery (46 cases) accounted for 90% of the cases. Eleven other patterns were identified. The usual coronary artery pattern was more prevalent in TGA with the aorta in a right anterior or anterior position (74.8%) than in TGA with a side-by-side relationship of the great arteries (38.9%). In only 2 cases (0.8%) was an aortic intramural course of the left coronary artery identified. The latter 2 cases confirm our belief that an aortic intramural course of the left coronary artery or the left anterior descending coronary artery must be assumed when the vessel has an aberrant origin from the right sinus or when it is in intimate relationship with the commissure between the right and left sinuses and courses between the great arteries. In the vast majority of specimens a favorable coronary artery pattern with regard to feasibility of the arterial switch operation was encountered.

Abnormalities, Multiple↗
PubMed1994

Imaging strategies for vascular rings.

Thirty-nine patients have undergone operation for relief of tracheoesophageal compression resulting from vascular rings and related entities at the Mayo Clinic. Nineteen patients had a double aortic arch, 11 patients had a right aortic arch with an aberrant left subclavian artery, 5 patients had a left aortic arch with an aberrant right subclavian artery, 2 patients had a pulmonary artery sling, 1 patient had a right aortic arch with mirror-image branching and a left ligamentum arteriosum, and 1 patient had a left aortic arch, a right descending aorta, and a right ductus arteriosus. Diagnostic examinations included chest radiography, barium esophagography, angiography, and, more recently, transthoracic echocardiography, computed tomography, and magnetic resonance imaging. A comparison among the various diagnostic techniques used in 12 patients during the last 12 years showed that angiography (n = 7), magnetic resonance imaging (n = 5), and computed tomography (n = 3) were the most reliable, as they always accurately delineated the anatomy. However, in the 6 patients who underwent transthoracic echocardiography, 1 of whom was an older child and 2 of whom were adults, the vascular abnormality was described correctly only once; in the other 5 patients, the results were false-negative or the technique failed to visualize the relevant vascular structures sufficiently. Currently, magnetic resonance imaging is our imaging technique of choice for the delineation of the vascular and tracheal anatomy in patients suspected of having a vascular ring.

Adolescent↗
PubMed1994

Aortic intramural course of the left coronary artery in dextro-transposition of the great arteries.

Three patients with dextro-transposition of the great arteries and an aortic intramural left coronary artery are described. A review of our patients with dextro-transposition of the great arteries and those reported in the literature suggests that an aortic intramural course of the left coronary artery or left anterior descending coronary artery must be assumed when the artery arises from the right (posterior) sinus of Valsalva, distal to the right sinotubular junction, or at the commissure between the right and left (anterior) sinuses and courses between the great arteries.

Aorta, Thoracic↗
PubMed1994

Preoperative diagnosis of coronary artery anatomy in dextrotransposition of the great arteries.

BACKGROUND: Preoperative diagnosis of the coronary artery pattern in dextrotransposition of the great arteries is important because deviation from the usual pattern may influence the surgical strategy. METHODS: For assessment of the value of angiography and echocardiography in this setting, we analyzed the preoperative echocardiographic and angiographic findings in 74 patients with dextrotransposition of the great arteries in whom an arterial switch operation was performed. RESULTS: Two-dimensional echocardiography established a diagnosis of the coronary artery pattern in 40 of the 74 patients; that diagnosis was correct in 38-30 of 32 (94%) with the usual coronary artery pattern and 8 (100%) with an atypical pattern. Angiography established a diagnosis of the coronary artery pattern in 52 patients; that diagnosis was correct in 50-41 of 42 (98%) with the usual coronary artery pattern and 9 of 10 (90%) with an atypical pattern. The accuracy of echocardiography in diagnosing the coronary artery pattern in dextrotransposition of the great arteries in this series was 95% and that of angiography was 96%. CONCLUSION: Both echocardiography and angiography can establish the diagnosis of the coronary artery anatomy in most patients. Echocardiography is routinely performed in infants with dextrotransposition of the great arteries and is proving to be increasingly sensitive for diagnosing the coronary artery anatomy; the role of angiography may evolve to be supplementary, especially in cases in which the coronary artery anatomy is not clearly demonstrated by echocardiography.

Child, Preschool↗
PubMed1994

Influence of prosthesis size on change in left ventricular mass following aortic valve replacement.

Current surgical practice regarding valve replacement has as its primary concern the appropriateness of tissue versus mechanical prostheses and perhaps lesser emphasis has been placed on the size of the device. Despite technical advances, which provide maximal valve orifice area in valve substitutes, small device implantation may be accomplished in the aortic root but not effectively relieve the obstructive nature of the original disease. We reviewed 39 patients who had undergone aortic valve replacement (AVR) for aortic stenosis (AS) and had preoperative and postoperative (6 months-3 years) echo measurements which permitted calculation of the left ventricular mass (LVM) and mass index (LVMI). The mean age for the 32 women and 7 men was 67.4 years (22-83). There were four groups as determined by prosthetic size and aortic root enlargement (ARE) or not. The majority of the prostheses were heterografts (26), and the others were tilting discs or bileaflet. There was no difference (P = ns) in preoperative NYHA class, cardiopulmonary bypass (CPB) time, cross-clamp time, associated procedures or complications among the four groups. Although all groups demonstrated a reduction in LVM and LVMI, there was a greater and equal mass and mass index reduction in patients receiving a 21 mm prosthesis or larger. Despite the refinements in artificial valve designs, the 19 mm size valves may not provide comparable reduction in LVM and LVMI following AVR for AS, and the aortic root enlargement permits a larger prosthetic implantation and greater potential for reduction in LVM and LVMI without an increase in the operative time or postoperative complications.

Adult↗
PubMed1993

Diagnostic laparoscopy: reducing the number of normal appendectomies.

A prospective, controlled study was conducted to determine whether a selective policy of diagnostic laparoscopy could reduce the number of unnecessary normal appendectomies in patients with acute right iliac fossa pain. The cohort consisted of patients admitted with acute right iliac fossa pain by the emergency department. Of 102 patients in the study group, 28 subsequently required a diagnostic laparoscopy when a definite diagnosis could not be reached after 8 to 12 hours of observation. Of these, only 18 had inflamed appendices, which were removed. In the rest of the patients (10), the appendices were normal and unnecessary laparotomies were avoided. In the control group, wherein equivocal cases were laparotomized after a similar period of observation, there was a normal appendectomy rate of 15.7 percent (P < 0.05). There was no significant difference in the incidence of perforation between the control and study groups. Diagnostic laparoscopy in equivocal cases could thus significantly reduce the number of unnecessary appendectomies without compromising on the rate of perforation.

Adolescent↗
PubMed1993

Surgical treatment of vascular rings: the Mayo Clinic experience.

From 1947 through 1992, 37 Mayo Clinic patients underwent operation for the relief of tracheoesophageal obstruction that resulted from vascular rings and related entities. Of the 37 patients, 18 had a double aortic arch, 11 had a right aortic arch with an aberrant left subclavian artery, 4 had a left aortic arch with an aberrant right subclavian artery, 2 had a pulmonary artery sling, 1 had a right aortic arch with mirror-image branching and a left ligamentum arteriosum, and 1 had a left aortic arch, a right descending aorta, and a right ductus arteriosus. Symptoms consisted of stridor, recurrent respiratory infections, and dysphagia. The anomaly was approached through a left thoracotomy in 31 patients, through a right thoracotomy in 4, and through a median sternotomy in 2. Only one early postoperative death (3%) and no late deaths occurred. At long-term follow-up (maximal duration, 45 years), three patients had residual symptomatic tracheomalacia, one of whom required right middle and lower lobectomy for recurrent pneumonia. Magnetic resonance imaging is the imaging technique of choice for accurate delineation of the vascular and tracheal anatomy. When patients are symptomatic, vascular ring should be repaired. The surgical risk is minimal, and the long-term results are excellent.

Adolescent↗
PubMed1993

Deep vein thrombosis complicating colorectal surgery in the Chinese in Singapore.

It has been reported that the risk of thromboembolism after general surgery in Chinese is negligible, thus, prophylaxis has not been used. This study examined the incidence in the high risk subgroup of patients undergoing colorectal operations. In a two-year retrospective review, 35 rectum resections for cancer, 72 colon resections for cancer, and 22 colon resections for benign disease were analysed. The clinical incidence of deep vein thrombosis (DVT) in patients with malignancy was 4.7% (5/107). None of the patients with benign disease had DVT. Three of the five patients with DVT had pulmonary embolism, of which one died. Rectal surgery incurred a higher risk (11.4%) compared to colonic resection (1.4%) (p = 0.038). Postoperative wound infection was an important predisposing factor (p = 0.027). In view of these findings, a prospective trial has been planned to further evaluate the need for prophylaxis in selected high risk patients.

Adult↗