Biomedical subjects
Publications and source records attributed to W K Cheah.
We present three patients with bleeding duodenal tumors who were managed by laparoscopic excision. This represents the largest study of such an experience. The literature is reviewed, and the various technical approaches are discussed.
BACKGROUND: There is an increased incidence of postoperative nausea and vomiting (PONV) after laparoscopic cholecystectomy. The aim of the study was to evaluate the efficacy of intravenous ondansetron, a 5-HT anatagonist, for prevention from PONV after laparoscopic cholecystectomy. METHODS: Sixty-eight patients were entered into the study. Thirty-six patients were randomized to receive a single intravenous dose of 4 mg of ondansetron before extubation. Thirty-two patients received no prophylaxis. There were no differences in terms of sex ratio, age, ASA status, and duration of operation between the two study groups. Patients were interviewed by an independent observer to assess the postoperative pain and nausea using visual analog score. Patients' satisfaction scores to the procedure were measured. RESULTS: There was no complication in the series. Pain scores at 2 and 24 h after operation and analgesics consumption were not different between the two groups. For the patients who received ondansetron, the mean (SD) nausea score at 2 and 24 h was 1.5 (1.2) and 1.4 (1.4), respectively. The score for the control group was 1.4 (1.0) and 1.2 (0.5), respectively. There was also no difference in episodes of vomiting and usage of antiemetics between the two groups. Both groups were equally satisfied with the procedures. CONCLUSION: Routine use of ondansetron does not reduce the incidence of postoperative nausea and vomiting after laparoscopic cholecystectomy.
BACKGROUND: Head-mounted display (HM) units are used in various industries, but they have been tried only recently in surgery. In this study, we evaluated whether a commercially available HMD would improve or impede a laparoscopic task-in this case, suturing. METHODS: Six participants performed a total of 120 laparoscopic suture knots in an experimental model. The Olympus FMD011 model with a two-dimensional image was used. The order of each task with or without the head display unit was random. The time to complete each knot was recorded, and the results were analyzed. RESULTS: The display unit prolonged the suturing times of the subjects by 10% (p < 0.04). CONCLUSIONS: In this experimental model, the HMD we utilized did not appear to improve laparoscopic suturing. More developments, such as improved depth perception and better resolution, may increase its usefulness for laparoscopic tasks.
HYPOTHESIS: Since the advent of laparoscopic surgery in 1987 and the introduction of robotics into medicine in 1991, medical technology has advanced to robotic applications in performing surgery. In our study, we investigated the feasibility of performing simple laparoscopic maneuvers and laparoscopic cholecystectomy using a robotic surgical system. DESIGN: The study used a ZEUS robotic system (Computer Motion Inc, Goleta, Calif), consisting of 3 interactive robotic arms fixed at the operating table and remotely controlled by the surgeon. After initial training, using a bench model and 3 isolated porcine livers to perform cholecystectomy, 7 female pigs underwent robotically assisted laparoscopic cholecystectomy. The surgeon, seated at the console, manipulated the 3-mm laparoscopic instruments and performed the surgery. RESULTS: Robotically assisted laparoscopic cholecystectomy was accomplished in all 7 pigs, with a mean operative time of 46 minutes (range, 30-62 minutes). There were no complications. The mean time to setup of the robotic system decreased from 30 minutes to 14 minutes. All the robotic maneuvers were performed without any particular difficulties, and the movements were stable, accurate, and reliable, with good control. CONCLUSIONS: Our preliminary experimental study showed that robotically reproduced laparoscopic maneuvers, such as tying, suturing, dissection, clipping, and cautery, seemed to be as accurate and as fast as maneuvers made without robotics. We conclude that our initial experimental and animal study confirmed the feasibility of robotically assisted laparoscopic cholecystectomy. Further reports are needed to show that robotics can be used for clinical applications in surgery.
BACKGROUND: Several studies have reported the feasibility of using 'needlescopic' instruments with a diameter less than 3 mm in minimally invasive surgery. This study reports a comparison of needlescopic cholecystectomy and laparoscopic cholecystectomy. METHODS: Seventy-five patients with symptomatic chronic cholelithiasis were randomized to needlescopic (n = 37) or laparoscopic (n = 38) cholecystectomy. RESULTS: The duration of surgery in the two groups was similar. Patients in the needlescopic group had less pain (mean visual analogue score 2.2 versus 3.6; P < 0.003) and had smaller scars (median length 17.0 versus 25.0 mm; P < 0.001). In addition, patients in the needlescopic group tended to require fewer intramuscular pethidine injections (P = 0.05). However, oral analgesic requirements in the two groups were similar. There were no complications in either group. CONCLUSION: Needlescopic cholecystectomy resulted in less postoperative pain and a smaller surgical scar than laparoscopic cholecystectomy in patients with chronic cholecystitis.
BACKGROUND: There is considerable controversy today concerning the most appropriate surgical approach for patients with primary hyperparathyroidism. The conventional surgical operation involves a bilateral neck exploration through a collar incision with identification of all parathyroid tissue and removal of abnormal parathyroid glands while the patient is under general anesthesia. The success rate of this operation is about 95% or greater in the hands of an experienced endocrine surgeon. Preoperative localization techniques are generally considered to be unnecessary before initial parathyroid operations. The purpose of this investigation was (1) to evaluate the individual and combined accuracy of ultrasonography and technetium 99m sestamibi scans in localizing abnormal parathyroid glands and (2) to determine whether such scans could be used to direct a focused operation. METHODS: We retrospectively studied 338 patients with sporadic primary hyperparathyroidism who had preoperative neck localization studies, ultrasonography and/or technetium 99m sestamibi scans, and parathyroid exploration (238 patients or, reexploration, 60 patients) from January 1996 to April 2000 at the University of California San Francisco/Mount Zion Medical Center. The preoperative localization studies were recorded as true-positive, false-positive, and false-negative and compared with the surgical and pathologic findings and with the outcome of the operation. RESULTS: All of the abnormal parathyroid glands were correctly identified by ultrasonography in 184 of 303 patients (60.7%) and by technetium 99m sestamibi scanning in 183 of 237 patients (77.2%). The sensitivities of ultrasonography and sestamibi were 65% and 80%, respectively. Among the 202 patients who received both ultrasonography and sestamibi scans, a parathyroid tumor was identified at the same site in 105 (52%) of them. When both techniques identified a parathyroid tumor at the same site, the tests were correct in 101 of 105 patients and the sensitivity increased to 96%. CONCLUSIONS: When both the ultrasonography and sestamibi scans identified the same, solitary parathyroid tumor in patients with sporadic primary hyperparathyroidism, this was the only abnormal parathyroid gland in 96% of the patients. A focused parathyroidectomy could therefore be performed in such patients with an acceptable ( approximately 95%) success rate.
Use of the laparoscopic approach for the management of gastric cancer is still in the developmental phase. The authors present their experience with laparoscopic radical gastrectomy for advanced gastric cancer. Between September 1997 and August 1999, four laparoscopic gastrectomies for gastric carcinoma were performed on two male and two female patients (mean age, 61.5 years). One D2 total radical gastrectomy and three D2 subtotal distal gastrectomies were performed, using a totally laparoscopic approach. Mean operative time was 210 minutes. There were no intraoperative complications. All four patients recovered uneventfully from surgery and began oral feeding on the third postoperative day. Median postoperative stay was 7 days (range, 6-9). All patients were alive 8 months to 3 years after the operation, with no cancer recurrences. This series shows that laparoscopic radical gastrectomy for moderately advanced cancers can produce good results in terms of safety and oncologic adequacy.
Telesurgery is a form of operative videoconferencing in which a remotely located surgeon observes a procedure through a camera and provides visual and auditory feedback to the operative site. With the use of more robotic devices in laparoscopic surgery, various forms of telesurgery have been tried. We describe the first two international telesurgical, telementored, robot-assisted laparoscopic cholecystectomies performed in the world, between the Johns Hopkins Institute, Baltimore, Maryland, USA, and the National University Hospital, Singapore.
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.
BACKGROUND: Emergency gastric resection for complicated peptic ulcer and gastric cancer is a major challenge for general surgeons. This study aimed to evaluate the results of emergency gastrectomy and to examine the factors that predict the operative outcome. METHODS: A total of 82 consecutive patients who underwent emergency gastrectomy were studied. The following variables were assessed: pathology, mortality rate, morbidity, reasons for reoperation and factors related to the outcome. RESULTS: There were 64 men and 18 women with a median age of 62 (range 30-90) years. The indications were bleeding and perforated gastric or duodenal ulcers in 45 and 20 patients respectively, and bleeding and perforated gastric tumours in seven and ten patients respectively. The overall mortality rate was 17 per cent (n = 14). The complication rate was 63 per cent and 11 patients (13 per cent) required reoperation. By multivariate analysis, age greater than 65 years and blood haemoglobin level less than 10 g/dl on admission were predictive of complications after emergency gastrectomy. Postoperative pulmonary and cardiac complications and hypotension on admission were independent risk factors associated with operative death. CONCLUSION: Age more than 65 years, haemoglobin level less than 10 g/dl and hypotension on admission were associated with a poor outcome after emergency gastrectomy. The operative result was not affected by the underlying gastric pathology.
OBJECTIVE: To describe a new transoral technique of cervical oesophagogastric and oesophagojejunal anastomoses using the EEA stapler. DESIGN: Prospective clinical study. SETTING: University Hospital, Bratislava, Slovakia. SUBJECTS: Two patients with squamous cell carcinoma of the middle and distal third of the oesophagus. INTERVENTIONS: Transhiatal subtotal oesophagectomy without thoracotomy, and cervical oesophageal anastomosis by transoral EEA stapling. MAIN OUTCOME MEASURES: Morbidity and mortality. RESULTS: Transoral stapling was successful in both patients with no anastomotic leaks. The patients were discharged on the 14th and 21st postoperative days, respectively. CONCLUSIONS: Transoral stapling of the cervical anastomosis gave good results in two patients. More development and evaluation are needed.
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Needlescopic or minisite cholecystectomy is laparoscopic cholecystectomy done through tiny ports from 1.4 mm to 3 mm in size. This refinement of conventional laparoscopic cholecystectomy reduces further the invasiveness of the operation and gives an improved cosmetic effect. This series describes the result of 36 needlescopic cholecystectomies done between February 1996 and April 1997. Patients with acute cholecystitis were excluded. There were two conversions to conventional laparoscopic surgery and no conversions to open surgery. Thirty-four patients were successfully treated by this technique. Analgesic consumption and cosmetic result was superior compared to a previous published series of conventionally done cases in the same department.
A patient swallowed a fish bone that perforated the stomach wall and embedded in the head of the pancreas. This was confirmed by computed tomographic imaging. We describe a case of successful fish bone removal using a laparoscopic technique, thus avoiding a laparotomy. The patient recovered well and was discharged from the hospital the next day. This is the first description of such a case.
Needlescopic surgery is a refinement of laparoscopic surgery wherein instruments smaller than 3 mm are used. The advantage is the minute wounds that heal imperceptibly. Initial reports of needlescopic cholecystectomy were confined to uninflamed gallbladders where the antegrade technique was invariably used. This case demonstrates a needlescopic cholecystectomy by the retrograde approach for an inflamed gallbladder.
A retrospective review was performed of the records of 93 children with urinary tract calculi treated during a 10-year period (1983 to 1992). Two distinct groups of patients were identified. One group comprised 63 Aboriginal children, mainly from the northern region of Western Australia, who presented at a young age (average, 2.8 years) with urinary tract infections and failure to thrive. The other group comprised of 30 non-Aboriginal children, mainly from the metropolitan region, who presented at an older age (average, 6.7 years) with abdominal and flank pain. Calculi were located in the upper urinary tract in 85 children (91.4%) and in the bladder in eight (8.6%). Most patients underwent open surgical procedures for removal of their calculi, and the overall success rate was 86%. In recent years, percutaneous nephrolithotomy has been used successfully in selected patients with renal pelvic calculi. This method seems to be the trend for the future.
BACKGROUND/AIMS: Benign duodenal tumors are rare and less common than malignant tumors. They comprise a wide variety of pathologies. Treatment is by endoscopic excision or surgical resection. In this report, we aim to review the management of benign tumors located in the proximal duodenum. METHODOLOGY: A retrospective review of 11 patients with benign duodenal tumors treated in a single institution was performed over 10 years. Malignant tumors and periampullary tumors were excluded from the study. RESULTS: The most common presentations were abdominal pain and upper gastrointestinal bleeding. Diagnosis was established by gastroduodenoscopy with biopsy. Seven tumors were located in the first part of the duodenum. The mean size of the tumors was 2.8 cm. Three patients with bleeding tumors were treated with endoscopic hemostasis and underwent surgery because the tumors were larger than 2 cm. Four patients had endoscopic polypectomies and 5 patients had surgical excision. The histological types included 6 adenomas, 3 Brunner's gland adenomas or harmatoma, 1 schwannoma and 1 leiomyoma. The results were good with only 1 case of recurrence. CONCLUSIONS: The presentation of benign duodenal tumors is non-specific. They are diagnosed by gastroduodenoscopy and the tumors can be removed if small and pedunculated. Endoscopic ultrasound is useful in detecting submucosal involvement of sessile tumors. In such cases and large tumors (> 2 cm), surgical excision by laparotomy or laparoscopy should be undertaken.