Biomedical subjects

M K Teoh

Publications and source records attributed to M K Teoh.

11 recordsLinked to original sources

PubMed2002

Surgical management and outcome of carotid body tumours.

INTRODUCTION: Carotid body tumours are rare but are interesting in their manner of presentation and challenging with respect to surgical extirpation. They may present as a neck mass from which a bloody aspirate is obtained on fine needle aspiration. They are occasionally diagnosed only at the time of surgery, when one encounters the vascular tumour mass. METHODS: We reviewed the results of 8 cases operated in our department over a 10-year period from 1989 to 1999. We evaluated in-hospital mortality and morbidity, as well as the long-term outcome especially with regards to functional disability. RESULTS: Preoperative evaluation included angiography, computed tomography (CT) or magnetic resonance angiography. Operative technique involves good exposure, vascular control, identification and preservation of neurovascular structures and subadventitial tumour dissection. In all cases the vagus nerve was preserved, except in 1 case who had a malignant tumour and resection of the vagus nerve together with the accessory nerve and sympathetic chain. Two patients had unexpected hoarseness of voice postoperatively, 1 was due to permanent vagus nerve palsy and the other to transient vagus nerve palsy. One of them needed vocal cord medialisation and long-term tube feeding. One patient had bilateral tumours and developed a stroke after an operation on the second tumour. No patients exhibited local or metastatic disease during follow-up. There was no mortality in all cases. CONCLUSION: Although resection of the carotid body tumour is safe in experienced hands, long-term morbidity is still a significant problem and can be debilitating to the patient.

Adult↗

PubMed2000

Use of a peripherally implanted subcutaneous permanent central venous access device for chemotherapy--the Singapore General Hospital experience.

BACKGROUND: Venous access for chemotherapy patients at the Singapore General Hospital has conventionally been via an externalised (Hickman) catheter. A peripherally implanted permanent subcutaneous central venous access device (P.A.S.Port) was introduced in 1996. AIMS: We review its use, complications and cost competitiveness with other chemotherapy delivery systems. METHODS: A retrospective study of clinical records was conducted with follow up interviews of patients and nursing staff. RESULTS: Twelve patients had the P.A.S.Port inserted for administration of chemotherapy as an outpatient procedure. Immediate complications were pain (8%) and bruising (8%). One port-related infection (8%) one week following insertion was reported and one patient complained of interference with elbow movement as a late complication. Cost analysis was favourable for P.A.S.Port over an externalised Hickman catheter or chest-placed port at one year. Patient and nursing staff acceptance was high. CONCLUSION: P.A.S.Port insertion is a safe outpatient procedure and is an alternative for permanent venous access.

Catheterization, Central Venous↗

PubMed1999

Randomized, controlled trial of low molecular weight heparin vs. no deep vein thrombosis prophylaxis for major colon and rectal surgery in Asian patients.

PURPOSE: Routine deep venous thrombosis prophylaxis is controversial in Asian patients, because deep venous thrombosis incidence was considered negligible. Because of recent reports of significantly higher incidences, a randomized, controlled trial was conducted to assess the effectiveness and complications of enoxaparin prophylaxis (low molecular weight heparins) in major colorectal surgery. METHODS: Three hundred twenty consecutive patients were randomly assigned to control or low molecular weight heparins groups. Patients in the low molecular weight heparins group were given perioperative enoxaparin starting 12 hours before surgery. The surgeon (blinded) assessed for difficulties related to possible enoxaparin administration. Independent blinded observers performed daily clinical assessments and Doppler studies (at the 3rd and 5th postoperative day). Deep venous thrombosis was confirmed by duplex ultrasound, and pulmonary embolism was confirmed by lung scans or postmortem examinations. RESULTS: Deep venous thrombosis developed in 5 of 169 (3 percent) controls and 0 of 134 low molecular weight heparins patients (P = 0.045). Three of the deep venous thrombosis patients had pulmonary embolism, which was fatal in one patient. The surgeons were unable to perceive any increased surgical difficulties in the low molecular weight heparins group. The bleeding-related complications were significantly higher in the low molecular weight heparins patients (controls, n = 3 (1.8 percent); low molecular weight heparins, n = 9 (6.7 percent)). However, apart from one subdural hematoma and two abdominal hemorrhages needing re-exploration, which also occurred in one of the controls, these complications were minor bruises at the wounds, drains, or injection sites. CONCLUSION: Deep venous thrombosis prophylaxis is needed in Asian patients undergoing major colorectal surgery.

Aged↗

PubMed1999

Takayasu's arteritis with renovascular hypertension: results of surgical treatment.

Renal artery stenosis caused by Takayasu's arteritis is an important cause of hypertension in young patients in the Far East. The role of surgery in Takayasu's arteritis is not as well-defined as in atherosclerosis or fibromuscular dysplasia. In this retrospective review, the author reports the results of 19 renal artery reconstructions in 12 young patients (median age 23.5 years, range 10-46 years) presenting with renovascular hypertension and Takayasu's arteritis, and discusses the different surgical options. The procedures performed included aortorenal bypass using vein (five), aortorenal bypass using polytetrafluoroethylene (PTFE) (eight), iliorenal bypass using vein (four), reimplantation of renal artery (one) and aortic replacement graft-renal bypass (one). Postoperatively, all 12 patients had a successful outcome with improved hypertension. There was no perioperative mortality, and complications included two early graft thrombosis and one late graft occlusion. These results support the view that surgical treatment for renovascular hypertension in Takaysu's disease is safe and effective.

Adult↗

PubMed1999

Chronic haemodialysis with PTFE arterio-venous grafts.

BACKGROUND/AIM OF STUDY: End-stage renal failure (ESRF) patients requiring long-term haemodialysis need a durable vascular access. The arterio-venous fistula (AVF) with its long patency rate and low complication profile is usually the first choice procedure for vascular access creation. However when superficial veins are not suitable for AVF creation or have all been exhausted as a result of repeated AVF procedures, arterio-venous grafts (AVG) using polytetraflouroethylene (PTFE) to bridge arteries and veins is an alternative for provision of continued vascular access for haemodialysis. This study is a review of our experience in using PTFE AVGs for vascular access in patients requiring chronic haemodialysis. METHODS AND MATERIALS: A retrospective review was done on 92 grafts in 77 patients placed by 3 vascular access surgeons at the Singapore General Hospital from January 1989 to December 1994. RESULTS: There were 58 female and 19 male patients with a median age of 43 years (range 15-76 years). Twelve patients (16%) were diabetic and 6 patients (8%) had systemic lupus erythematosis requiring long-term steroids. Seventy-three percent of patients had up to 2 previous AVF creations before placement of AVG over the forearm (64%), upper arm (23%) or thigh (6.5%). Complications include graft infection (19), pseudoaneurysm formation (10), graft thrombosis (24), steal syndrome (1), venous congestion (1) and venous end stenosis (1). Diabetic status and long-term steroid therapy did not significantly increase the incidence of graft infection. The patency rates at 24 months and 36 months were 77% and 58% respectively. However serviceability rates were 61% at 2 years and 38% at 3 years mainly due to infective complications. CONCLUSION: PTFE AVGs offer reasonable patency and serviceability rates as a vascular access modality but in view of their complication profile, the native vein arteriovenous fistula should continue to be the first choice procedure for vascular access in patients requiring chronic haemodialysis.

Adolescent↗

PubMed1998

Surgical reconstruction for mesenteric angina in a patient with infra-renal aortic occlusive disease--a case report and review.

Mesenteric angina is an uncommon condition which is underdiagnosed, or diagnosed too late when the patient has a mesenteric infarct. The preferred treatment is by surgical reconstruction. A case presented here illustrates the condition and the modifications necessary to reconstruct a completely occluded lower abdominal aorta in treating both mesenteric angina and claudication.

Aorta, Abdominal↗

PubMed1998

Graft rescue for haemodialysis arterio-venous grafts: is it worth doing and which factors predict a good outcome?

Arterio-venous grafts in patients with end-stage renal failure are used when the patients have inadequate native veins or where there is an urgent need for permanent vascular access. Complications include thrombosis, bleeding, infection and pseudoaneurysm formation. The factors causing thrombosis can be divided into patient-related and graft-related factors. In this study 47 graft rescues in 24 patients were analysed. Polytetrafluoroethylene (PTFE) and polyurethane grafts were used. A successful graft rescue was defined as one in which a thrill was felt after surgical thrombectomy and the graft was subsequently used for haemodialysis. Eighteen grafts were PTFE and 10 were polyurethane; there were 15 women and nine men. There were 20 successful and 27 unsuccessful rescues, the overall success rate being 42.6% (20/47 rescues). Evidence of underlying stenoses was found in 14 graft rescues: 11 were at the venous end, two at the arterial end and one at the apex. A vein patch was used in these patients. In successful graft rescues an identifiable structural cause was found in only seven (25.9%) of the failed graft rescues. In spite of the common belief that graft rescue is unproductive, this study has shown that graft rescue was successful in 42.6% of cases. This was especially so when there was a surgically correctable underlying graft stenosis.

Adult↗

PubMed1998

Early experience of limb salvage in critical leg ischaemia.

BACKGROUND: We report the retrospective review of 82 leg bypass grafts done in 79 patients who had critical leg ischaemia between May 1993 and November 1996. The mean age of the patients was 68 years (range 50 to 82). PATIENTS: There were 49 male and 35 female patients. Fifty-nine percent of the study population presented with gangrene, 33% had ischaemic ulceration and 58% had rest pain. Seventy-five percent of them were diabetics. Thirty-eight femoro-popliteal, 28 femoro-distal, 6 popliteal-distal, 5 pedal, 1 aorto-bifemoral, 3 axillo-bifemoral and 1 cross-over bypass grafts were done. RESULTS: The peri-operative mortality rate was 11.3% and 71% of patients were discharged with salvaged feet. Ninety percent of these legs were still viable 12 months after the operation.

Aged↗

PubMed1994

Protection by tocotrienols against hypercholesterolaemia and atheroma.

Antioxidants such as tocotrienols may protect against atherosclerosis since tissue injury from free radicals is a final common pathway of damage in arterial disease. In this study, the effects of tocotrienols on serum cholesterol, lipid peroxides, and aorta atheroma were assessed in rabbits fed an atherogenic diet for 12 weeks. Tocotrienols were more effective than tocopherols in preventing increases in serum LDL (p = 0.03) and total cholesterol (p = 0.008) levels in the cholesterol-fed rabbits. Elevation of serum lipid peroxides was effectively suppressed by tocotrienols (p = 0.01). Both tocopherols and tocotrienols offered significant protection against atheroma in the rabbit aorta, but tocotrienols had a stronger hypolipidaemic effect.

Animals↗

PubMed1990

Perforated appendicitis--the Malaysian experience.

Perforated appendicitis, with its increased complication rate, today still poses a formidable problem in the Kuala Lumpur General Hospital. Out of 1694 emergency operations performed by our unit in 1987, there were 927 appendicectomies. A retrospective study of these cases showed 126 cases of perforated appendicitis, which were then subjected to detailed analysis. We have a diagnostic accuracy of 81% and perforation rate of 18%. In addition, it is interesting to note the racial differences in the relationship of diagnostic accuracy to perforation rate. Perforation is associated with an increased wound infection rate. Transperitoneal drainage in perforated appendicitis did not lead to a lower incidence of wound infection or improve postoperative performance. Distinguishing between perforated and non-perforated appendicitis may be difficult. Perforation could occur while awaiting operation. We recommend the early administration of systemic antibiotics should appendicectomy be delayed and the cautious use of drains in cases of perforated appendicitis.

Adolescent↗

PubMed1987

Removal of skin staples in an emergency.

We have highlighted this problem as there are situations where skin staples have to be removed rapidly, for example where bleeding and subsequent respiratory distress develop following neck surgery. A survey of junior hospital staff showed that many doctors had never removed skin staples nor were aware how best to remove them in the event of an emergency. Using skin simulation we compared the time to remove sutures and staples, and found it takes 55% longer to remove skin staples. Where the standard staple remover is not immediately available, an artery forceps, correctly applied, is just as quick.

Dermatologic Surgical Procedures↗