Self-Assembled Silica Nanostructures: Simultaneous Discrimination of Handedness, Pitch and Diameter of Helical Silica Nanotubes

The left- and right-handed helical silica nanostructures were obtained with the aid of organic templates, the formation of the nanostructures might follow a co-operation self-assembly mechanism. The chirality of the organogel self-assemblies was successfully transcribed in to the silica. The helical pitch and pore size of the silica nanotubes sensitively depended on the optical purity of the neutral gelator in the reaction mixtures.

Off-pump coronary artery bypass grafting is a safe and effective treatment modality for Asian patients requiring coronary revascularisation

INTRODUCTION

Off-pump coronary artery bypass grafting (OPCABG) is gaining widespread acceptance as the preferred choice for myocardial revascularisation. However, no definite data exist as to whether it is better than conventional CABG. We aimed to study the efficacy of the procedure in our patients, which constituted of a predominantly Asian population.

METHODS

Between January 2000 and December 2002, 1062 patients underwent isolated coronary artery bypass in our institution. 184 patients (17.3 percent) underwent OPCABG. Patients were preoperatively prospectively risk stratified under the EuroSCORE risk assessment model under high, medium and low risk classes thereby making them comparable. Post-operative complications, intensive care unit stay, hospital stay, types of grafts done were then analysed in these different risk classes.

RESULTS

The incidence of off-pump procedures showed a gradual increase over the last three years in this institution. A reduction in the number of post-operative complications, hospital stay, intensive care unit stay and mortality in the off-pump group was observed. Certain differences were found to be statistically significant.

CONCLUSION

Off-pump CABG is a safe and viable alternative to conventional CABG as a treatment modality for surgical coronary revascularisation.

Needlescopic thoracic sympathectomy: treatment for palmar hyperhidrosis

BACKGROUND

Open thoracic sympathectomy has been the established option for patients with essential hyperhidrosis. Recently, video-assisted endoscopic sympathectomy has provided a simple, safe, reliable, and cost-effective alternative to the earlier technique. With advances in instrumentation, performing the procedure through 2-mm and 3-mm needlescopic ports is now possible. The authors evaluate the effectiveness of so-called needlescopic thoracic sympathectomy for the treatment of primary hyperhidrosis.

METHODS

Thirty five consecutive patients with a mean age of 24 years, including 23 men and 12 women, underwent bilateral needlescopic thoracic sympathectomies at the National University Hospital of Singapore.

RESULTS

The mean operative duration was 56 minutes, and the mean hospital stay was 1.2 days. In no patient did Horner's syndrome or significant pneumothorax develop. The rate of success, defined as completely dry hands, was 97%. Two patients had unilateral recurrences that responded well to repeat needlescopic sympathectomies. We performed a total of 72 sympathectomies.

CONCLUSIONS

Our study demonstrates that the use of miniature port access sites produces excellent medical and cosmetic results and is associated with a short hospital stay and low risk of complications.

A case report on the perinatal management of a 30-week preterm baby with congenital complete heart block

INTRODUCTION

Congenital complete heart block is an uncommon condition in the newborn, but is known to occur with maternal systemic lupus erythematosus.

CLINICAL PICTURE

This paper presents one such baby with complete heart block who was born premature (after a gestation of 30 weeks) and weighing 759 g.

TREATMENT

Continuous isoprnaline infusion was initially used to support the baby while her other neonatal problems were treated. A Medtronics VV1 pacemaker was subsequently inserted to maintain a heart rate that would be more physiologically acceptable for the patient.

OUTCOME

This baby is currently thriving well, having been followed up for one year.

CONCLUSIONS

The management issues, encompassing maternal and neonatal problems, and a review of current literature on this condition are discussed.

Computational modelling of blood flow through curved stenosed arteries

A computational model of three-dimensional blood flow in curved arteries with elliptic stenosis was developed. Two groups of models, (a) different angles of curvature and (b) degrees of stenosis, have been studied under typical conditions for stenosed coronary artery. Useful information on the haemodynamics has been obtained. Results of pressure drop show that the presence of the curvature augments the increased flow resistance due to stenotic lesions. The study also demonstrates the significant presence of secondary flow in a curved artery. In addition, the results have shown that the secondary flow in a curved artery brings about elevated shear stress on the vessel wall. These results indicated that both curvature and stenosis should be considered together by cardiologists to assess or quantify the severity of the stenosis. This study employed a powerful computer-aided design (CAD) package to construct the model and a commercial computational fluid dynamics (CFD) code for the analysis of blood flow in stenosed arteries. The long-term application of this form of research promises to be an effective tool for gaining insights into the pathology of arterial diseases.

Hybrid cardiac revascularisation surgery

Currently, 3 methods of myocardial revascularisation are available for the treatment of coronary artery disease: i) coronary artery bypass grafting (CABG); ii) percutaneous transluminal coronary angiography (PTCA), and iii) transmyocardial laser revascularisation (TMR). Until recently, these procedures were performed exclusive to one another. We report 2 cases of minimally invasive direct coronary artery bypass grafting with subsequent PTCA, and 1 case of staged PTCA followed by TMR performed at our institution. We discuss the role of hybrid procedures in the current era of treatment of ischaemic heart disease.

Influence of surgery on aortic valve prolapse and aortic regurgitation in doubly committed subarterial ventricular septal defect

Doubly committed subarterial ventricular septal defects should be closed surgically once aortic valve deformity is present before the onset of aortic regurgitation.

Enzymatic dissolution of post-operative haemothorax by purified streptokinase

Enzymatic dissolution of haemothorax is highly effective in the evacuation of proteinaceous material from the pleural space. Its use in postcardiotomy haemothorax has not been described. We report the case of a 4-year-old girl with Fallot's Tetralogy diagnosed at birth. She underwent a total correction of Fallot's Tetralogy at 4 years of age. Chest X-ray taken post-operatively showed a large pleural collection in her right haemithorax. Repeated intraplueral infusion of purified streptokinase into the right upper pleural chest tube greatly reduced the extent of the right haemothorax. Enzymatic dissolution of haemothorax by purified streptokinase has proven to be a rapid and successful method of therapy. It has provided an alternative which is less invasive and has a low morbidity.

Treatment of delayed partial bronchial rupture with expandable metallic stent

Traumatic bronchial rupture is a rare entity. The severity of the trauma often causes lethal injury to other thoracic organs. The incidence in patients with blunt chest trauma admitted to the hospital ranges from 1.5% to 3%. As a rule, early diagnosis and surgical treatment are important to facilitate successful repair of the disruption. We describe an unusual case of bronchial rupture which was diagnosed 15 days after blunt chest trauma and was treated by bronchial stenting. The success of this case involving the left main bronchial rupture provides a feasible alternative to the repair of partial airway disruption and greatly reduces the morbidity.

Minimally invasive surgical closure of atrial septal defects via a right anterior thoracotomy

BACKGROUND

Surgical closure of the atrial septal defect (ASD) is a low-risk operation with little post-operative morbidity involved. The standard approach to ASD closure is via a median sternotomy. However the post-operative midline scar is cosmetically undesirable.

PATIENTS

We report our experience with four female patients who have undergone closure of ASD through a right anterior thoracotomy and a left groin incision for femoral cannulation.

RESULTS

Post-operative recovery was uneventful. The cosmetic results of their operations were good.

CONCLUSION

Closure of ASD via a right anterior approach is a safe method and should preferably be used in young female patients, as better cosmetic results are expected.

Outcome of surgical closure of doubly committed subarterial ventricular septal defect

BACKGROUND

From 1986 to March 1997, 128 patients diagnosed to have doubly committed subarterial ventricular septal defects (VSD) were reviewed. Patients with aortic regurgitation (AR), and aortic valve (AV) deformity or a large left-to-right shunt across the VSD were offered operation. Forty-five patients (27 men, 18 women) agreed to surgical closure of their VSDs.

METHODS

Thirty-eight patients had VSD closure alone, and 7 had an additional AV repair. Other associated defects corrected at operation were closure of atrial septal defects, closure of other ventricular septal defects, ligation of patent ductus arteriosus, and repair of ruptured sinus Valsalva aneurysm.

RESULTS

There was no mortality nor major morbidity associated with operation. In the 26 patients with AR and AV deformity preoperatively, valve repair was performed in 6 patients. The condition of AR improved in 4, and remained unchanged in 22 patients. In the 10 patients with a deformity of the AV and no AR preoperatively, the condition remained unchanged in 5 patients, from whom 1 had valve operation, but progressed in 5 patients postoperatively at a mean follow-up of 6.4 years. In 9 patients with no deformity of the AV and no AR preoperatively, there was no postoperative AR and no progress of valve deformity.

CONCLUSIONS

Excellent results were obtained with VSD closure and AV repair. Surgical closure of VSD, if performed before the onset of AV deformity, may prevent progressive AR. If AV repair is performed after the onset of AV deformity, progressive AR may not always be prevented.

Bidirectional cavopulmonary anastomosis

The Fontan operation has been used to palliate patients with a functional single ventricle. In many such patients the operative risk for a Fontan procedure is high. The bidirectional cavopulmonary anastomosis (BCPA) is a useful intermediate palliative procedure before Fontan correction. It may reduce the deleterious sequelae of chronic hypoxaemia and long-term ventricular overload, thus yielding a more suitable Fontan candidate. We reviewed our experience of 9 patients with univentricular hearts who were at the time of the BCPA not considered suitable candidates for conventional Fontan operation. Two patients had double inlet right ventricle (DIRV) with pulmonary stenosis (PS) and ventricular septal defect (VSD), 2 had univentricular heart, 4 had tricuspid atresia (TA) and hypoplastic right ventricle (RV), 1 patient had atrioventricular septal defect (AVSD) with double outlet right ventricle (DORV) with hypoplastic RV. Two of the 9 patients had bilateral superior vena cavae. All except one had undergone prior palliative operations. The mean age at BCPA was 4.7 years (range 1.5 years to 6 years) and the mean weight at surgery was 15 kg (range 7 to 22 kg). There were no operative deaths. The mean hospitalization stay was 8.5 days (range 5 to 13 days) with a mean follow up of 14 months. Median oxygen saturation improved from 78.7 +/- 6.3% to 85.9 +/- 3.9%. The BCPA is a useful palliative procedure to stage Fontan type reconstruction in selected patients with univentricular hearts.

Minimally invasive direct coronary artery bypass

BACKGROUND

Minimally invasive cardiac surgery is a new and promising approach to the treatment of coronary artery disease allowing surgery to be performed through smaller incisions with lesser morbidity.

METHODOLOGY

From November 1995 to February 1997, ten minimally invasive direct coronary artery bypass (MIDCAB) grafts were performed. The left internal mammary artery was used to bypass the left anterior descending coronary artery (LAD) through a limited left anterior thoracotomy.

PATIENTS

There were seven males and three females and their ages ranged from 42 to 72 years (mean = 60 years). Two patients had prior interventional procedures. Cardiopulmonary bypass was used in the first two patients. Two patients were converted to conventional surgery early in the series.

RESULTS

There was no mortality nor major morbidity. Mean post-operative hospital stay was seven days. To date, three patients have had post-operative angiography confirming the patency of the left internal mammary artery to LAD anastomosis.

CONCLUSION

Early results of the MIDCAB procedure are encouraging. However, the definitive place of such procedures awaits longer term follow-up.

Co-existing left atrial thrombus and myxoma in mitral stenosis--a diagnostic challenge

We report an unusual case of an adult who underwent a mitral valve replacement with concomitant excision of the left atrial myxoma and thrombus. Echocardiography showed the presence of a large "thrombus" within the left atrial appendage, body and atrial septum. There was difficulty in trying to distinguish between the atrial thrombus and myxoma due to their morphological similarities. At time of surgery, frozen section confirmed the atrial septal component of the thrombus to be an atrial myxoma and the atrial septum was excised to obtain a clear margin.

Accurate length adjustment of aortocoronary saphenous vein bypass grafts

We describe a simple method for tailoring the length of aortocoronary saphenous vein grafts. The objective is to prevent any kinking of the these grafts, which may compromise blood flow in them and lead to their early occlusion.

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.

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.

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.

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.

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.

Surgical repair of complete atrioventricular septal canal defects with absent posterior leaflet

We report 2 cases of absence of the posterior (left mural) leaflet in complete atrioventricular septal defect. Closure of the atrioventricular septal defect was successfully accomplished in both cases. We describe the technique of left atrioventricular valve repair that led to a competent reconstructed valve.

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.

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.

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.

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.

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.

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.

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.

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.

Prevalence of peripheral artery disease in patients with coronary artery disease

The incidence of coronary artery disease in Singapore has shown a rapid rise in recent years, however, there is a subjective impression that the prevalence of atherosclerotic peripheral artery diseases, although sharing common aetiological factors with coronary artery disease, has not shown a similar rise. We set out to determine the incidence of occlusive peripheral artery diseases of the lower limb in a selected population of Asian patients using a non-invasive test and we analysed the risk factors. The overall prevalence of peripheral artery disease of the subjects as determined by an abnormal ankle brachial index less than 0.9 in at least one limb was 19.1%. Increasing age, hypercholesterolemia and smoking were risk factors. In patients with proven coronary artery disease, abnormal ankle brachial indices were present in 21.3% of patients with angiographic evidence of coronary artery disease but in only 13.0% of those without. In this study, the incidence of peripheral artery disease in this selected Asian population was high. With the increasing availability of vascular laboratories and awareness of the diseases, we can expect to see increasing numbers of patients presenting with these problems.

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.

The surgical treatment of multiple small bowel strictures in Crohn's disease by combined resection and stricturoplasty

Crohn's disease is extremely rare among Asians. Resection of strictures causing obstruction has traditionally been the accepted choice in surgical therapy. This may lead to problems such as iatrogenic short bowel syndrome and its sequelae. Stricturoplasty is an acceptable and safe alternative. We report a case where combined stricturoplasty and resection was performed safely and advocate its use.

Ectopic thymoma: a case for median sternotomy for complete thymectomy

Thymomas are normally found in the superior mediastinum or the upper part of the anterior mediastinum. We report a case of thymoma arising in the inferior aspect of the anterior mediastinum. This case illustrates that thymic tissue may be found low in the anterior mediastinum and supports the practice of a median sternotomy approach for thorough mediastinal exploration in all cases of thymectomy.

Coronary artery bypass surgery in young patients

Coronary atherosclerosis is being increasingly observed in young patients. However results of surgery in such patients have so far been disappointing both in terms of operative mortality, symptomatic relief and long-term survival. Reasons given for this include the increased prevalence of risk factors in young patients and a higher incidence of graft occlusion. In the treatment of Asian patients, a further negative factor is the belief that coronary artery disease is more often diffuse and the vessels smaller. Between January 1987 and May 1991, a total of 66 patients under the age of 45 years at the time of surgery had coronary artery bypass grafting performed. The demographic, clinical, angiographic and operative data were analysed. Eighty-nine per cent of the patients were male and their racial distribution was 63% Chinese, 8% Malays, 26% Indians and 3% Others. Their mean age was 40.8 years. The presence of risk factors was high: 45.6% had hypertension; 34.8% were smokers; 21.2% had diabetes mellitus; and 12.1% had hyperlipidaemia. The main indication in these patients was either angina or a previous myocardial infarction (53%). There were no patients with perioperative infarction diagnosed by the presence of new Q wave. There was no hospital death. The stay of the patients ranged from 6 to 28 days with a mean of 10 days. Follow-up ranged from 3 to 54 months. There were no late deaths. It was concluded that there is a high incidence of risk factors among young patients with coronary artery disease, which follows the pattern of many other studies. The operative risk in these patients is low and morbidity is minimal.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary artery bypass grafting in patients with left main coronary artery stenosis. Improved survival in a predominantly Oriental population

Over the last 10 years, there has been a reduction of surgical mortality in coronary bypass grafting for left main coronary artery disease. Most of the available literature reports are of Caucasian populations. We report our experience of the surgical treatment of this disease in a predominantly Oriental population. From 1 January 1987 to 30 June 1991, 86 consecutive patients had coronary artery bypass surgery for left main stenosis. There were 65 men and 21 women with an age range of 34 to 80 years (mean age: 58 years SD +/- 8.63). There were no operative deaths and 1 hospital death (1.2%) from a non-cardiac cause. The perioperative myocardial infarction rate was 3.5% (3/86). These results are better than some earlier series in which hospital mortality was reported as high as 12.6% and the preoperative myocardial infarction rate 11.8%. In this series where the patients are predominantly Oriental, the results are comparable if not better than in series reported in centres where the population is predominantly Caucasian.

Early experiences of intra-operative trans-oesophageal echocardiography (TEE) in mitral valve repair

Whenever possible Mitral valve repair should be performed instead of Mitral valve replacement. It is important to assess the adequacy of the repair during the operation so that any corrective steps may be taken immediately. We present three cases of Mitral valve repair in which the intraoperative TEE was used to assess the adequacy of the repair. There was good correlation of the immediate post bypass TEE findings and early post operative transthoracic echocardiographic findings. Intraoperative TEE is a useful tool in the early assessment of Mitral Valve Repair.

Mitral valve repair in patients on chronic hemodialysis

Two cases of successful mitral valve repair in patients on chronic hemodialysis are presented. We stress that valve repair is preferable to valve replacement whenever feasible because of improved left ventricular function, reduced complication rate, and freedom from anticoagulation. This especially applies to patients on chronic hemodialysis as they have impaired immunological function, are subjected to repeated fistula punctures with possible bacteremia, and are more susceptible to early calcification and degeneration of tissue valves.

Intravascular hemolysis after mitral valve repair: a word of caution

The case of a young patient who presented with severe hemolysis after mitral valve repair is presented. Valve repair included chordal shortening, transposition of chordae tendinae, and annular remodelling using a Duran flexible ring. Reoperation and valve replacement were required to control hemolytic anemia. The possible mechanisms leading to such an uncommon complication after plastic repair of the mitral valve are commented on. The scanty literature concerned is reviewed.

Safe and rapid palliation of dysphagia for carcinoma of the esophagus

Patients with carcinoma of the esophagus continue to present late when their tumors are inoperable. This makes palliation of their dysphagia the main therapeutic aim. The Nd-YAG laser has been used in our department to treat dysphagia resulting from cancer of the esophagus since 1986. Our rapid, one-stage cannulation technique using the Nd-YAG laser in both contact and noncontact modes was applied to 35 cases of carcinoma of the esophagus with the aim of achieving rapid and safe palliation of dysphagia. During the treatment we aimed not to coagulate the tumor and await sloughing, but to vaporize the tumor and ablate as much as possible in a single session. In this way there was less need for repeat sessions to create an adequate lumen. In a small number of patients (9) who had tight strictures with no visible lumen, a pre-laser dilation was required to allow visualization of the lumen and tumor vaporization. For nondilated patients (26) we achieved a 15-mm lumen in an average of 1.6 sessions, and in the dilated patients (9) this was achieved in one session in all patients. Functional improvement occurred in 28 patients (80%). There were four minor complications and no mortality associated with the procedure.