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Biomedical subjects

M K Li

Publications and source records attributed to M K Li.

At least 73 records · Page 4Linked to original sources

Laparoscopic cholecystectomy: results of first 300 cases in Hong Kong.

Prospective analysis of the first three hundred patients who underwent laparoscopic cholecystectomy was carried out in three surgical centres of Hong Kong. Over a 20-month period, 300 consecutive patients were recruited, including elective and emergency cases. The indications for laparoscopic cholecystectomy were symptomatic gallstones (78%), cholangitis (6%), pancreatitis (5%) and cholecystitis (11%). Patients with common duct stones (12) had preoperative endoscopic sphincterotomy and stone extraction prior to cholecystectomy. Laparoscopic cholecystectomy was accomplished successfully in 287 patients. Thirteen patients (4.3%) required conversion to open cholecystectomy. The reasons for conversion were: inability to identify cystic duct and common bile duct clearly (6); bleeding (5); Mirizzi syndrome (1); and slippage of cystic duct clip (1). The median operation time was 80 min with a range of 28-270 min. The median hospital stay was 3 days. Seventy-five per cent of patients required only a single dose of pethidine injection. None of the patients required blood transfusion. The overall complication rate was 7%. These included mild cellulitis of the subumbilical wound (3%) and postoperative chest infection (3%). One patient developed subphrenic abscess which resolved on percutaneous drainage under ultrasound guidance. Iatrogenic injury to the common bile duct was seen in one patient who had an impacted stone at Hartmann's pouch. With adequate training laparoscopic cholecystectomy can be performed safely. The advantages over open cholecystectomy are less wound pain, better cosmesis and shorter convalescence.

Cholecystectomy↗

A case of localised ureteric amyloidosis.

We describe a case of localised amyloidosis of the distal ureter in a 66-year-old lady who presented with intermittent haematuria. Ureteric transitional cell carcinoma was strongly suspected from the clinical and radiological features, and subsequent nephroureterectomy was performed. Histology revealed nodular eosinophilic deposits in the ureteric wall, with the staining characteristics of amyloid. The literature is reviewed, and conservative surgery is advocated, based on a greater awareness together with improved intraoperative diagnosis of this rare lesion.

Aged↗

Long-term results of antral gastrocystoplasty.

Long-term results of gastrocystoplasty had not been reported in the literature. The results of 10 patients (7 augmentation and 3 replacement) during 15 years were reviewed. All patients voided spontaneously and achieved daytime continence. Enuresis occurred in 3 patients. Median peak flow rate and post-void residual urine were 16.0 ml. per second and 10 ml., respectively. Average cystometric capacity was 554 ml. and median pressure at full capacity was 46 cm. water. Phasic contractions resulted in pressures higher than 50 cm. water in 4 patients. Small capacity, absence of bladder sensation and high pressure were identified as risk factors for a poor result. Routine urine culture was positive in 20.5%. Urine mucus content remained low. Electrolyte disturbance, histopathological abnormalities and ulcer syndrome related to hypergastrinemia were absent. The data showed that antral gastrocystoplasty is superior because of the low infective complication rate, ability to empty and absence of metabolic disturbance.

Adult↗

Lost stone during laparoscopic cholecystectomy: retrieval using a condom.

Laparoscopic cholecystectomy is becoming increasingly popular for the treatment of gall stone disease. In this technique, the gall bladder is dissected free under laparoscopic vision and then extracted. We report an interesting complication that occurred during extraction of a gall bladder containing a large stone and a novel method of overcoming the problem.

Abdomen↗

Extracorporeal shockwave lithotripsy using Storz Modulith SL20--the Singapore General Hospital experience.

The Storz Modulith SL20 is a third-generation lithotripter which was installed in our hospital in March 1991. The aim of this paper is to evaluate our results in the management of renal calculi using this machine. We report our experience in the treatment of the first 215 renal units (118 renal and 83 ureteric) in 190 patients with a minimum follow-up period of three months. Success for renal stones was defined as stone-free or with insignificant residual fragments of less than 4 mm in size post therapy. Success for ureteric stones was defined as stone-free after therapy. The success rate for renal calculi was 88% and for ureteric calculi 71%. The mean number of sessions to achieve these results for renal calculi was 1.6 and for ureteric calculi 1.4. Of the failures, only 1.9% required open surgery whilst the remainder were dealt with using minimally invasive procedures like intracorporeal laser lithotripsy. There was no mortality in our series. Complications occurred in four patients, who required hospitalisation for renal colic (n = 1), urinary tract infection (n = 1) and obstructive uropathy (n = 2).

Aged↗

The dual effect of urinary macromolecules on the crystallization of calcium oxalate endogenous in urine.

The nucleation-promoting and growth-inhibiting activities of urinary macromolecules on the crystallization of calcium oxalate endogenous in urine of stoneformers and normal controls were studied by freezing the ultrafiltrate and retenate fractions of concentrated whole urine (pH 5.3, 1,250 mosmol/kg). Among the normal controls, macromolecules nominally of 10-20 kDa showed nucleation-promoting and growth-inhibiting activities; the 5-10 kDa population was incapable of such effects but did cooperate with molecules greater than 10 kDa in enhancing the effect. In the case of stone-formers, molecules in the nominal ranges of 5-10 kDa and 10-20 kDa when considered separately were not active in the aspects studied but collectively could cooperate to produce pronounced effects. Application of the test to urine ultrafiltrate reconstituted with polyanionic macromolecules recovered from urine indicated that molecules from stoneformers were more powerful than those from normal controls in bringing about promotion of nucleation and inhibition of growth of crystals from urinary calcium oxalate.

Adult↗

Laparoscopy-guided percutaneous cholecystolithotomy: an evolving technique.

Gall-bladder conservation therapy has been evolving during the past decade. Popular techniques of conservative therapy are extracorporeal shock wave lithotripsy (ESWL) and medical dissolution therapy. The limitations of these procedures have prompted a search for alternative techniques, particularly in relation to percutaneous stone extraction. The cases of four patients with symptomatic gallstones who underwent percutaneous cholecystolithotomy under laparoscopic guidance are reported. The gall-bladder was punctured with a long needle and the tract dilated so that a nephroscope could be introduced. Three cases required stone fragmentation by an ultrasonic lithotripter before removal. Postoperative recovery was uneventful in all cases.

Adult↗

Tracheal rupture from incorrect positioning of endotracheal tube.

Significant ischaemic tracheal damage from endotracheal intubation is uncommon when the lateral wall pressure exerted by the cuff does not exceed the mean capillary perfusion pressure of the mucosa. This is facilitated by the modern endotracheal tubes with high-volume-low-pressure cuffs. We report a case of tracheal rupture due to an incorrectly positioned softcuffed tube. The need to review tube position radiologically and to make immediate adjustment cannot be overemphasised.

Aged↗

Preliminary experience in ileal neobladder reconstruction.

In the treatment of transitional cell carcinoma of the bladder, the recent trend is towards radiation or chemotherapy which can be either regional or systemic. There have also been good results with giving Mitomycin or Bacillus Calmette Guerin instillation into the bladder for superficial tumours. There are occasions where patients present with large bulky tumours which cannot be controlled by endoscopic measures, invasion involving multiple sites and carcinoma in-situ which progresses to invasion. In these occasions, we have to resort to surgical clearance of the tumour. If it is possible, all patients would not like to wear a urinary bag for the rest of their lives. A bladder replacement if ever possible is always welcomed because the patient can pass urine from the natural passage. Due to the magnitude of a radical cystectomy and status of the urethra, it is not always technically possible to reconstruct the bladder. With improvement of operative techniques and suture materials, there has been a recent development of a method of bladder reconstruction that uses an ileal pouch. We report our early experience with this operation.

Aged↗

Low anterior resection of the rectum using a double stapling technique.

Using a double stapling technique in 30 patients, anterior resection of the rectum was attempted for low rectal carcinoma (n = 28), giant rectal adenoma (n = 1) and radiation-induced rectal stricture (n = 1). There were three emergency operations. The rectum was stapled transversely more than 3 cm below the tumour using the adjustable-angle linear stapler (Roticulator). Colorectal or coloanal anastomoses were constructed using the EEA circular stapler introduced per anum through the anorectal stump staple line. Ten coloanal and 19 low rectal anastomoses were achieved. A protecting transverse loop colostomy was fashioned in one patient with coloanal anastomosis who developed a vaginal tear during the procedure. In one patient technical failure necessitated conversion to abdominoperineal excision of the rectum. All staple rings and resection margins were intact and free from tumour. There were two clinical anastomotic leaks, both treated successfully with a defunctioning transverse loop colostomy. One patient developed a small infective pelvic haematoma 2 weeks after surgery which required drainage. Hospital stay ranged from 6 to 15 days (mean 8 days). Continence was normal in all patients at 8 weeks. One soft coloanal anastomotic stricture required dilatation. No recurrences have been detected during a follow-up of between 10 and 22 months.

Adult↗

Urinary tract infections in post-renal transplant patients.

The overall incidence of urinary tract infections (UTIs) in our renal transplant population was 30.9%, i.e. 0.15 episode per patient-year. UTIs occurred more often within the first 3 months (60%) of transplantation. Fifty per cent of UTIs were asymptomatic. Recurrences were common. Acute tubular necrosis and cellular rejections were important associations. UTIs had little effect on graft function and survival up to 3 years post-transplant.

Adolescent↗

Haematological changes after renal transplantation: differences between cyclosporin-A and azathioprine therapy.

Haematological changes after renal transplantation in 76 patients were reviewed and the differences observed between patients treated with cyclosporin-A and prednisolone and those treated with azathioprine and prednisolone were compared. Erythrocytosis defined as haemoglobin concentration equal to or exceeding 17 g/dl occurred in 25% of patients treated with cyclosporin-A and in 11.4% of patients treated with azathioprine. Only one patient, who received cyclosporin-A, had clinical evidence of thrombosis. Eight patients treated with cyclosporin-A and five treated with azathioprine had therapeutic venesections. There was no difference in the incidence of putative risk factors for post-transplant erythrocytosis between the two groups.

Adolescent↗

Demonstration of Lipiodol in paraffin sections using a modified silver impregnation technique.

To demonstrate postangiographic Lipiodol (LIP) in hepatocellular carcinoma (HCC) in paraffin sections, direct impregnation of formalin-fixed tissue blocks with silver nitrate (AgNO3) was followed by routine processing. LIP appeared as black globules in the sinusoids. Ninety-four tissue blocks from 13 postangiographic LIP HCCs and 69 from 8 non-LIP HCCs and 4 fatty livers were studied. Seventy-two of 73 negative controls and all positive blocks as seen on soft tissue radiographs (STRs) were correctly coded (specificity 98.6%, sensitivity 100%). Twenty-six of the 44 LIP-negative areas on STRs from LIP cases contained scanty globules of less than 10 microns in diameter. Fatty change gave no positive readings. Thus, modified AgNO3 impregnation is a simple, accurate means of detecting LIP in high-quality paraffin sections suitable for tumor diagnosis and, if applied to postangiographic LIP, ultrasonographically guided liver biopsy, can verify that a biopsy has reached a suspected tumor focus.

Biopsy↗

Newcastle bone disease in Hong Kong: a study of aluminum associated osteomalacia.

We measured serum aluminum concentrations in 104 haemodialysis patients from 3 centres in Hong Kong. We found that the 52 patients dialyzed in unit A had much higher mean aluminium levels (100 micrograms/L) than those from the other two units (61 and 39 micrograms/L respectively). In unit A, where water treatment by reverse osmosis had been introduced only recently, 30.8% of patients had fractures/looser zones, 46.2% had rugger-jersey spine and 28.8% had skeletal erosions. When these patients were divided into two groups according to whether their serum aluminium concentration was below or above 100 micrograms/l, the latter patients had significantly lower alkaline phosphatase, serum phosphate, and higher total prescribed dose of aluminium hydroxide. It was concluded that both dialysate aluminium and oral aluminium intake seemed to have contributed to the high incidence of osteomalacic fractures among Unit A patients. In eight of these patients serum aluminium increased by more than 150 micrograms/L after four weeks of receiving 1.5 g desferrioxamine twice weekly. Serial X-rays showed that the mean time after dialysis for the appearance of fractures/Looser zones was 72 months. Three patients developed fractures/Looser zones after successful renal transplantation; and it was postulated that the prompt excretion of aluminium permitted increased osteoclastic activity, resulting in fractures in these patients.

Adult↗

Upper urinary tract tumours in Hong Kong (1972-1987).

A retrospective analysis of all primary upper urinary tract tumours (300) filed in the pathology department of a regional hospital in Hong Kong during 1972-87 showed that renal cell carcinoma (143) was the commonest malignant tumour. Transitional cell carcinoma of the renal pelvis (62) was the next most frequent. Fibromas, which occurred as frequently as angiomyolipomas (28) and outnumbered tumours such as squamous cell carcinoma (13) and nephroblastoma (12), were of little clinical significance since they were invariably incidental findings. Nephrectomies were seldom performed for kidneys involved in secondary malignancies. Rare tumours encountered were adenocarcinoma of the renal pelvis, leiomyosarcoma, malignant fibrous histiocytoma, adenoma, oncocytoma, mesoblastic nephroma and multilocular cystic nephroma. Angiomyolipomas were responsible for most cases of surgical emergency.

Adolescent↗

Hepatitis B infection and renal transplantation: the absence of anti-delta antibodies and the possible beneficial effect of silymarin during acute episodes of hepatic dysfunction.

The incidence of hepatitis B infection among renal transplant recipients was reviewed. Among 90 patients, 13 were HBsAg positive prior to renal transplantation. Episodes of hepatic dysfunction were seen in eight and one died of fulminating hepatitis and disseminated tuberculosis. Silymarin, a herbal extract, appears to confer some benefits in ameliorating hepatic dysfunction. Antibodies to the delta agent were not detected during any of these episodes. One patient contracted hepatitis B after transplantation and rapid reduction in steroid dose was associated with deterioration of liver function. He developed antibodies and cleared the virus. Four HBsAg-negative patients received kidneys from HBsAg positive donors without becoming HBsAg positive.

Adult↗