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Biomedical subjects

M K Li

Publications and source records attributed to M K Li.

At least 19 recordsLinked to original sources
PubMed2001

Laparoscopic-assisted total mesorectal excision and colonic J pouch reconstruction in the treatment of rectal cancer.

BACKGROUND: Total mesorectal excision (TME) and colonic J pouch reconstruction has been widely practiced for mid- or low-rectal cancer. However, the laparoscopic version of TME has never been described. METHODS: Five patients suffering from newly diagnosed mid- to low-rectal cancer were seen between March and July 1999. These five patients were selected for laparoscopic TME and colonic J pouch reconstruction because preoperative investigations revealed resectable tumor without extrarectal disease. RESULTS: There were three men and two women with a mean age of 61 years. The average body weight was 69 kg (range, 57-80). None of the patients had had previous abdominal operations. In all five patients, the tumor was located within 9 cm from anal verge. The average size of the main incision was 5 cm. All patients had a covering ileostomy at the end of the procedure. The mean operating time was 208 min; average blood loss was 158 ml; and mean hospital stay was 10.6 days. Three patients had Dukes' B disease and two had Dukes' C disease. The resection margins (proximal, circumferential, and distal) were all clear. There were no deaths or major complications. Two patients suffered from transient urinary retention. After ileostomy closure, the median frequency of bowel motion was twice per day at 6-month follow-up. Neither incontinence nor nocturnal soiling was reported. CONCLUSION: To the best of our knowledge, this is the first published series of such an operation. With good patient selection, laparoscopic-assisted TME and colonic J pouch-anal anastomosis is safe and feasible.

Aged↗
PubMed2001

Outpatient laparoscopic cholecystectomy in Hong Kong: patient acceptance.

The authors performed a prospective evaluation of 60 Hong Kong Chinese patients with symptomatic gallstones and gallbladder polyps undergoing outpatient laparoscopic cholecystectomy in a regional hospital in Hong Kong from March 1996 to May 1998 to determine the feasibility, satisfaction, and acceptance of this procedure among Chinese patients. Patients with American Society of Anesthesiologists grade I and II gallstones or polyps were selected. Exclusion criteria included 1) history of upper abdominal operations, attacks of acute cholecystitis, cholangitis, or pancreatitis; 2) abnormal liver function; and 3) ultrasonographic evidence of contracted gallbladder, thickened gallbladder wall, dilated common bile duct, or common bile duct stones. Patients discharged at 5:00 PM on the day of cholecystectomy were defined as having undergone outpatient procedure. Patients were asked about procedure acceptance, rated on a scale of 1 to 10 (best), using a standardized questionnaire 4 weeks after operation. The study included 21 men and 39 women with mean age of 40.5 years (range, 27-59). There were no conversions to open procedures in the series. There were 6 (10%) unanticipated postoperative hospital admissions; all patients were discharged on the first postoperative day. Another patient was readmitted 3 days after operation because of a common bile duct stone. Overall patient acceptance of outpatient laparoscopic cholecystectomy was good, with a mean score of 8.6 of 10. Thirteen patients (22%) expressed dissatisfaction with being discharged earlier than they had expected, and 9 (15%) would have preferred inpatient care. Forty-eight patients (80%) resumed full daily activities by the first postoperative day; the remaining 12 did so by the end of the first week. Among the 44 working patients, only 4 (9%) resumed full duty within the first postoperative week; 29 (66%) did so by the second week and the remaining 11 (25%) returned to work after the third week. By selecting appropriate subjects, outpatient laparoscopic cholecystectomy is feasible and highly accepted among Hong Kong Chinese patients. Approximately one quarter of the patients preferred a longer postoperative stay or inpatient care.

Adult↗
PubMed2000

Retroperitoneoscopic nephrectomy (RN): using the gravity technique to facilitate specimen entrapment.

BACKGROUND: Kidney entrapment is generally considered to be a difficult step in retroperitoneoscopic nephrectomy (RN). Normally, a large device is needed to accommodate the specimen, which may measure </=14 x 10 cm. There is just too little space to maneuver either the entrapment device or the specimen. Herein we describe a technique that can overcome this difficulty and even turn the space limitation to advantage. METHODS: After the nephrectomy, the specimen is pushed caudally. A 15-mm Endocatch is inserted via the posterior cranial port. It is positioned strategically underneath the specimen so that when the entrapment bag is released, the specimen will have no room to move (because of the limited space) and will simply fall into the bag (because of gravity). RESULTS: We have used this technique for our last four cases of retroperitoneoscopic nephrectomy and found that it remarkably shortened the operative time for this step. CONCLUSION: One of the criticisms leveled against retroperitoneoscopic surgery concerns the problems posed by the space limitation. This technique turns the space limitation into an advantage and guarantees successful specimen entrapment.

Gravitation↗
PubMed2000

Surgical management of angiomyolipoma: nephron-sparing surgery for symptomatic tumour.

Angiomyolipoma (AML) is a benign renal tumour that occasionally requires intervention. We evaluated the surgical management of symptomatic angiomyolipoma, with special attention to the feasibility of nephron-sparing surgery. A retrospective study was conducted enlisting 23 patients (including 3 patients with tuberous sclerosis) who had their AML treated surgically from 1991 to 1998. The study included 7 males and 16 females, with a mean age of 49 years (range 24-75). The mean tumour size was 12.3 cm (range 1.5-30.0) including 7 lesions < or = 4 cm and 16 lesions > 4 cm. The presenting features included abdominal/loin pain (9 patients), spontaneous rupture (5 patients), non-specific symptoms (7 patients) and incidental findings (2 patients). AML was diagnosed by computed tomography in 16 patients and malignancy was suspected in 7 patients. The latter group included 5 patients with lesions smaller than 4 cm, one of them having coexisting AML and renal cell carcinoma. All patients underwent elective surgery, with the exception of one, who required a semi-emergency operation. Nephron-sparing surgery using frozen section in 5 patients (all diagnostic) was carried out on 16 patients, including all 5 patients with previous haemorrhage and 2 patients with suspected lesions from preoperative studies. Total nephrectomy was performed in 7 patients, including the other 5 patients with lesions suspected to be malignant. There was no operative mortality. Two complications were encountered in the entire group. We conclude that elective nephron-sparing surgery is feasible, even for massive angiomyolipoma or after previous rupture, especially when the diagnosis is made by preoperative imaging and/or intraoperative frozen section.

Adult↗
PubMed2000

Laparoscopic telesurgery between the United States and Singapore.

INTRODUCTION: Telemedicine is the use of electronic digital signals to transfer information from one site to another. With the advent of a telepresence operative system and development of remote robotic arms to hold and manoeuvre the laparoscope, telemedicine is finding its role in surgery, especially laparoscopic surgery. CLINICAL FEATURES AND TREATMENT: We report two successful cases of laparoscopic surgery--radical nephrectomy and varicocelectomy for a 3-cm renal tumour and for bilateral varicoceles causing pain, where a less experienced laparoscopic surgeon in Singapore was telementored by an experienced laparoscopic surgeon located remotely in the United States. Both patients recovered uneventfully and returned home on postoperative day 4 and on the day of surgery, respectively. OUTCOME: This study demonstrates that telementored laparoscopic systems are feasible and safe, between countries halfway across the world. CONCLUSIONS: As the Internet expands in utility and the cost of higher bandwidth telecommunication lines decreases, even to remote countries, telementoring systems will become more affordable and may potentially pave the way for advanced surgical and laparoscopic applications and training for the future.

Humans↗
PubMed2000

Transurethral alprostadil for the treatment of erectile dysfunction: results of a multicentre trial.

INTRODUCTION: The incidence of erectile dysfunction (ED) has been shown to increase significantly in Singaporean male population. Thus, this prospective study (no controls) assessed the clinical efficacy and safety of a medicated urethral system for erection (MUSE) in Singaporean male patients with a known history of ED. SUBJECTS AND METHOD: Eighty-six men with a mean age of 55.7 years with differential causes of ED were administered with MUSE in the clinic with a titration adjustment of 4 possible dose regimes (125, 250, 500 and 1000 mcg) till efficacy is achieved. Subsequently, patients were subjected to home treatment for a duration of 3 months. RESULTS: Sixty per cent of inclinic patients exhibited good responses and were given MUSE for home treatment. The efficacy rate for home treatment was 86%. Overall, the patients (n = 86) had a 51.2% success rate in achieving satisfactory sexual intercourse. Diabetic and psychogenic patients were noted to respond well to MUSE. No severe adverse events were found in this study. CONCLUSION: MUSE showed to be a safe, less invasive, well-tolerated and efficient alternative treatment for ED in Singaporean men.

Adult↗
PubMed1999

Partial nephrectomy for renal tumours: the Singapore General Hospital experience.

From January 1991 to August 1998, 220 radical nephrectomies were performed for renal cell carcinoma (RCC). During the same period, 27 patients underwent partial nephrectomy for their renal tumours. These included 19 male and 8 female (mean age, 54; range, 35-75). Their clinical presentation, diagnostic modalities and surgical outcome were evaluated. The lesions included 18 RCCs, 7 angiomyolipomas (AMLs), 1 oncocytoma and 1 dysoncogenetic renal tumour. Only 8 patients had specific urological symptoms. Computerised tomography (CT) scan was diagnostic in 78% of cases. Tumour size ranged from 15-50 mm for RCC and 30-190 mm for AML, respectively. Operative time averaged 92 minutes (range: 35-145). The hospital stay ranged from 3 to 25 days (mean 11). Complications occurred in four cases (14.8%); there was one death (3.7%). No tumour recurrence was detected during a mean follow up of 20 months. None of the patients developed significant renal impairment. Partial nephrectomy is feasible in small RCC and some large AML, and can be offered in selected patients.

Adult↗
PubMed1999

Clinics in diagnostic imaging (36). Benign renal oncocytoma.

A 50-year-old Indian man presented with non-specific right-sided abdominal pain. Ultrasound of the abdomen demonstrated a small right renal tumour. Computed tomography showed features suggestive of a benign renal oncocytoma. This was confirmed by frozen section during surgical exploration. A partial nephrectomy was carried out. The role and limitations of imaging in the management of solid renal masses is discussed.

Adenoma, Oxyphilic↗
PubMed1999

Clinics in diagnostic imaging (38). Post-ESWL perinephric haematoma.

A 57-year-old man presented with urosepsis related to urinary calculi. He underwent multiple sessions of ESWL and developed a perinephric haematoma that was treated conservatively and monitored by serial imaging. However, the haematoma became infected, necessitating percutaneous drainage 2 months after the initial ESWL. The risk factors and sequelae of post-ESWL perinephric haematoma, as well as its diagnosis and imaging, are discussed.

Abscess↗
PubMed1999

Preliminary results of heart-beating and non-heart-beating donor kidney transplants--the Singapore experience.

Renal transplantation is the ideal renal replacement therapy for treatment of end stage kidney failure but its limitation is the constant shortage of cadaveric donors. While the traditional source of cadaveric kidneys is procurement from heart-beating donors, organ procurement from non-heart-beating donors (NHBD) would help in coping with the rising demand for organs. However various important legal, logistic and technical constraints have limited the implementation of such a procurement programme. Nevertheless, prolonged warm ischaemic times in procuring kidneys from NHB donors may affect the viability of these organs and adversely affect overall outcome after transplant. Fifty-three consecutive patients who underwent renal allotransplantation (Tx) between January and December 1994 at the Singapore General Hospital were retrospectively reviewed. Outcomes after renal transplantation among 25 heart-beating donor (HBD) and 28 NHBD were compared. Despite significant differences in donor age (23.7 +/- 11.0 and 34.1 +/- 7.9, P = 0.001), first warm (0 and 22.2 +/- 9.0 minutes) and cold ischaemic times (12.8 +/- 6.7 and 5.2 +/- 5.0 hours, P = 0.001) between the HBD and NHBD groups, the two-year patient and graft survivals were very similar in both groups (100% versus 98% and 98% versus 96%). The incidence of delayed graft function (DF) was also comparable between the HBD (41%) and the NHBD (50%) Tx. These results suggest that NHBD is a viable source for kidney transplants and comparable patient and graft survivals can be achieved if the first warm and cold ischaemic times are kept to the minimum.

Adolescent↗
PubMed1999

Inferior vena cava thrombectomy for renal cell carcinoma with thrombus.

Up to 10% of patients with renal cell carcinoma have intracaval neoplastic extension. The results of nephrectomy and caval cavotomy to remove the renal tumour and caval thrombus were reviewed. From September 1991 to October 1997, 16 consecutive patients (13 males, 3 females) with a mean age of 59 years (range 45 to 75 years) underwent radical nephrectomy together with cavotomy and thrombectomy (15) or caval resection (1). The tumour thrombi extended to the infrahepatic vena cava in 9 patients, intrahepatic cava in 5 and suprahepatic cava in 2. The surgical approaches included abdominal (8), right thoraco-abdominal (5) and abdominal with median sternotomy (3), respectively; cardiac bypass was not required. The mean cava clamp time was 15 minutes and the average operative time was 127 minutes (range 70 to 190 minutes). There was no operative mortality but the complication rate was 31%. The mean hospital stay was 12 days (range 7 to 23 days). Ten patients had Robson's stage IIIa disease, 4 had stage IIIc disease and 2 had stage IV disease. During a mean follow up of 20 months (range 1 to 54 months), 6 patients were alive with no recurrence and 10 patients had died of the disease. The survival of stage IIIa patients was significantly better than stage IIIc and IV patients. In summary, caval thrombectomy is associated with acceptable operative morbidity and mortality; however, advanced staged disease dictates a short survival.

Aged↗
PubMed1999

Renal cell carcinoma in patients with chronic renal failure.

It has been found that patients suffering from chronic renal failure (CRF) are prone to develop acquired cystic kidney disease, which may subsequently lead to the development of renal cell carcinoma (RCC). We reviewed 250 consecutive cases of RCC diagnosed between January 1990 and June 1998 in our department and found 19 had associated CRF (7.6%). Their clinical presentation, mode and duration of dialysis, diagnostic evaluations, pathological stage and surgical outcome were reviewed. Sixteen had CRF with chronic glomerulonephritis and 3 with adult polycystic kidney disease. Three patients were on continuous ambulatory peritoneal dialysis (CAPD), 5 were on haemodialysis (HD) and 3 had renal transplant (2 on HD, 1 on CAPD previously). The remaining 8 patients were not on renal replacement therapy at the time of diagnosis. Ten patients were asymptomatic with incidental radiological findings while 9 had specific urological symptoms, most commonly haematuria. Ultrasonography (USG) and computed tomography (CT) scan were the main modalities of imaging employed. Nine out of the 10 asymptomatic patients had suspicious lesions detected incidentally by USG. All had subsequent preoperative CT scans confirming the presence of these lesions. All patients had single focus RCC except for 1 with multi-focal disease involving both kidneys. Sixteen patients had early stage (T1 or T2) and low grade (G1 or G2) RCC. The remaining 3 patients had advanced stage (T3a or T3b) and high grade (G3) tumours. Since half of the patients were asymptomatic, USG may be a useful tool in the outpatient review of patients with CRF and allow early diagnosis and surgical treatment of early stage, low-grade tumours and therefore may have better survival.

Carcinoma, Renal Cell↗
PubMed1998

Potassium channels participate in gastric mucosal protection in rats with partial portal vein ligation.

Glybenclamide, an adenosine triphosphate-dependent potassium (K+(ATP)) channel blocker, lowered portal pressure and attenuated the hyperdynamic splanchnic circulation in rats with partial portal vein ligation (PPVL). The purpose of this report was to confirm these observations and to test the hypothesis that glybenclamide could reduce acidified ethanol-induced gastric mucosal injury in rats with PPVL. Gastric mucosal blood flow (hydrogen gas clearance), systemic blood pressure, and portal pressure were monitored in rats with PPVL or sham operation (SO). Intravenous glybenclamide (20 mg/kg) or vehicle was administered, followed by intragastric acidified ethanol (0.15 N HCl and 15% ethanol). The area of gastric mucosal lesions was assessed by image analysis. In contrast to published findings, there was no significant elevation of portal pressure after glybenclamide administration in rats with PPVL. Glybenclamide did not alter the gastric mucosal hyperemia in these rats. Glybenclamide significantly increased mucosal injury. The data are consistent with the hypothesis that K+(ATP) channels play a role in protecting the gastric mucosa in rats with PPVL.

Animals↗