Biomedical subjects

Wai-Meng Ho

Publications and source records attributed to Wai-Meng Ho.

14 recordsLinked to original sources

PubMed2006

Perioperative parenteral tranexamic acid in liver tumor resection: a prospective randomized trial toward a "blood transfusion"-free hepatectomy.

OBJECTIVE: To examine the feasibility of a real "blood transfusion"-free hepatectomy in a large group of patients with liver tumors. SUMMARY BACKGROUND DATA: Bleeding control and blood transfusion remains problematic in liver resection. A real "blood transfusion"-free hepatectomy in a large group of patients has rarely been reported. The impact of tranexamic acid (TA), an antifibrinolytic agent, on blood transfusion in liver resection is unknown. METHODS: A prospective double-blind randomized trial was performed on elective liver tumor resections. In group A, TA 500 mg was intravenously administered just before operation followed by 250 mg, every 6 hours, for 3 days. In group B, only placebo was given. The patients' background, blood transfusion rates, and early postoperative results in the 2 groups were compared. Factors that influenced blood requirement were analyzed. RESULTS: There were 108 hepatectomies in group A and 106 hepatectomies in group B. The patients' backgrounds, operative procedures, and hepatectomy extent did not significantly differ between the 2 groups. Although the differences of the operative morbidity and postoperative stay were not significant, a significantly lower amount of operative blood loss, lower blood transfusion rate, shorter operative time, and lower hospital costs were found in group A patients. No patient in group A received blood transfusion. No hospital mortality occurred in either group. Tumor size and use of TA were independent factors that influenced blood transfusion. CONCLUSIONS: Perioperative parenteral use of TA reduced the amount of operative blood loss and the need for blood transfusion in elective liver tumor resection. A real "blood transfusion"-free hepatectomy may be feasible with the assistance of parenteral TA.

Aged↗

PubMed2006

Management of catheter-induced pulmonary artery perforation during weaning from cardiopulmonary bypass--a case report.

We report a case of pulmonary artery perforation induced by Swan-Ganz catheter. Brisk massive airway hemorrhage occurred after withdrawl of the Swan-Ganz catheter post cardiopulmonary bypass. Early recognition, immediate re-establishment of cardiopulmonary bypass, lobectomy of the sanguineous lobe subsequent to rupture of the involved pulmonary artery, and thorough bronchial toilet were the major determinants contributing to successfully rescuing the patient's life. She was discharged uneventfully in spite of high mortality rate of the catheter-induced pulmonary artery perforation.

Aged↗

PubMed2004

Appraisal of concomitant splenectomy in liver resection for hepatocellular carcinoma in cirrhotic patients with hypersplenic thrombocytopenia.

BACKGROUND: Liver resection usually is not recommended for hepatocellular carcinoma (HCC) in cirrhotic patients with portal hypertension. The role of concomitant splenectomy in liver resection for HCC in cirrhotic patients with hypersplenic thrombocytopenia (HT) resulting from portal hypertension remains undefined. METHODS: Among 526 cirrhotic patients who underwent liver resection for HCC, 41 underwent a concomitant splenectomy (Sp group) because of HT (platelet count </=80 x 10(3)/mm(3)). The patients' backgrounds, pathologic characteristics of HCC, and short- and long-term results after liver resection of Sp group were compared with those of the other 485 cirrhotic patients who did not undergo splenectomy (non-Sp group). RESULTS: Compared to the non-Sp group, the liver function was worse, the tumor size was smaller, the liver resection extent was narrower, and tumor stages were earlier in the Sp group. The postoperative morbidity, mortality, hospital stay, and hospital costs were not significantly different between the groups. The disease-free survival rate of the Sp group was better than that of non-Sp group, but the actuarial survival rates of both groups were similar. After stratification with UICC-TNM stages, there were no significant differences regarding the disease-free and actuarial survival rates in each stage. CONCLUSIONS: Concomitant splenectomy extends the indication of liver resection for HCC in cirrhotic patients with portal hypertension. It is justified in selected cirrhotic patients with HCC and HT.

Aged↗

PubMed2004

Cardiac catheterization-induced type-A aortic dissection detected by intra-operative transesophageal echocardiography--a case report.

Cardiac catheterization is not only a diagnostic tool but also a means of treatment of coronary artery disease. Coronary artery dissection is one of the complications of cardiac catheterization. Emergency coronary artery bypass graft (CABG) surgery is indicated when coronary artery dissection is associated with unstable perfusion or residual severe stenosis. We present a case of progressive type-A aortic dissection as a continuity of catheterization-induced dissection of right coronary artery (RCA) with occlusion, disclosed by transesophageal echocardiography (TEE) during the emergent CABG surgery for the iatrogenic injury. Once the aortic dissection has been diagnosed by TEE, the surgical procedure and cannulation site for cardiopulmonary bypass were altered from those used in regular CABG surgery. Therefore, TEE is able and valuable in such situation to detect this rare but severe complication due to catheterization, especially when retrograde coronary artery dissection has been noted preoperatively.

Aged↗

PubMed2003

Bacterial translocation after cirrhotic liver resection: a clinical investigation of 181 patients.

BACKGROUND: Cirrhotic patients are usually associated with a high susceptibility to infection. Although bacterial translocation from gut mucosa to mesenteric lymph node (MLN) and systemic circulation is a well-known phenomenon after hepatectomy, its role in cirrhotic patients remains unclear. MATERIALS AND METHODS: MLN was harvested for bacterial culture before and after liver resection in 181 cirrhotic patients. The characteristics and postoperative courses of patients with positive and negative bacterial culture for MLN after hepatectomy were compared. Postoperative systemic antibiotics were administered if infectious complications occurred. RESULTS: No bacteria were cultured in MLN before hepatectomy. Bacterial translocation (BT) to MLN after hepatectomy occurred in 36 patients (BT group). After multivariate analysis, intraoperative blood transfusion was the only independent factor that influenced bacterial translocation rates after cirrhotic liver resection. BT group patients also had higher infectious and overall complication rates, with a longer postoperative hospital stay. Among the cultured bacteriae from infected sites in BT group patients with infectious complications, only 2 patients (12.5%) had totally different bacterial species to those cultured from MLNs. CONCLUSIONS: Bacterial translocation more often occurred after liver resection in cirrhotic patients who received intraoperative blood transfusion. Such patients had higher postoperative infectious and overall complication rates. Thus, avoidance of intraoperative blood transfusion is mandatory for cirrhotic liver resection.

Bacterial Infections↗

PubMed2003

Accidental subdural catheterization due to complication of epidural anesthesia--a case report.

Although accidental subdural injection is a well-recognized complication of epidural block, only a mere handful cases have been substantially proven by radiological evidence. Here we report a case of subdural catheterization during the attempt of epidural anesthesia for a gynecological procedure. Its clinical course and radiological findings are compared with those of the cases previously reported in literature. Whenever there is the occurrence of widespread of sensory block together with respiratory distress and hemodynamic unstability following epidural injection of local anesthetic, a subdural injection should be considered in spite of a negative confirmation. Repeated subdural injection of a local anesthetic at the same site may predispose patients to serious morbidity. Therefore, we recommend that when a subdural injection is evident or suspected, reinsertion of the catheter in the epidural space via another entry or contemplation of a switch to another anesthetic technique is mandatory.

Anesthesia, Epidural↗

PubMed2003

Complications of fluid overloading with different distention media in hysteroscopy--a report of two cases.

Complications arising from hysteroscopy are relatively rare events. They occur more frequently with operative hysteroscopy than with diagnostic hysteroscopy. Hysteroscopic procedures, which are alternatives to hysterectomy for surgical treatment of menorrhagia and uterine fibroids, place women to run the risk of intravasation of uterine distention fluid. Excessive intravasation can entail fluid overload, pulmonary edema, congestive heart failure, and electrolyte imbalances. The prerequisite for treatment of hysteroscopic fluid overload is knowing the nature of the intravasation fluid and it should be promptly treated to prevent neurological sequelae. Almost all serious complications of operative hysteroscopy can be avoided if proper precautions are taken and close communication is maintained between the gynecologic surgeon, the anesthesiologist, and nursing staff. Here, we present two cases of fluid overload with acute pulmonary edema and electrolyte imbalance from hysteroscopy with different distention media.

Female↗

PubMed2002

A convenient one-step extraction of cellular ATP using boiling water for the luciferin-luciferase assay of ATP.

Cellular ATP is commonly determined as production of bioluminescence using a luciferin-luciferase reaction system. Before the measurement of bioluminescence, cellular ATP must first be extracted. Two commonly used extraction methods are: () Tris-borate buffer (pH 9.2) coupled with a heating process (to inactivate ATPase) and () perchloric acid followed by neutralization. However, we found that both Tris-borate buffer and perchloric acid interfered with the luciferin-luciferase system. Here, we report a convenient single-step boiling deionized water (DW) method for extracting cellular ATP to replace perchloric acid and Tris-borate buffer. We showed that the boiling DW method did not interfere with the bioluminescence and was effective in inhibiting ATPase. This improved method required no neutralization and dilution and thus was more convenient than the perchloric acid method. Unlike the Tris-borate/heating procedure, our method did not require a separate heating step because boiling DW effectively inhibited ATPase and thus accomplished the two missions in one step for both suspended and attached cells. The improved method was precise for both suspended cells and attached cells, when cell numbers were between 10(3) and 10(6). The method also was more sensitive than other methods because it required much fewer cells (10(4) to 10(5)) than other methods for ATP determination. Thus, this one-step method is suitable for routine assay of cellular ATP for both suspended and attached cells.

Adenosine Triphosphate↗

PubMed2002

ATP depletion is an important factor in DHEA-induced growth inhibition and apoptosis in BV-2 cells.

Dehydroepiandrosterone (DHEA), a major steroid secreted by the adrenal gland, is known to have antiproliferative effects but the mechanism is unclear. We recently reported that DHEA induces growth inhibition and apoptosis in BV-2 cells and these effects are inversely associated with glucose concentrations in the medium. Here, we further showed that incubation of BV-2 cells with DHEA under glucose deprivation (G0) led to dose- and time-dependent decrease in cellular ATP levels. The decrease in ATP preceded growth inhibition and apoptosis induced by DHEA and all these effects of DHEA (i.e., loss of ATP, antiproliferation and apoptosis) were prevented by glucose added at 4.5 mg/ml (G4.5) during incubation. In addition, two ATP-depleting agents, iodoacetic acid (IAA) and 2,4-dinitrophenylhydrazine (2,4-DNP), potentiated the antiproliferative and apoptotic effects of DHEA. We also determined whether decrease in nucleic acid synthesis (due to glucose-6-phosphate dehydrogenase inhibition by DHEA) contributes to DHEA-induced antiproliferation and apoptosis. Using a mixture of deoxyribonucleotides (DN) and ribonucleotides (RN), we showed that DNRN had little or no effect on DHEA-induced growth inhibition and apoptosis. We also showed that mevalonic acid (MVA) did not affect DHEA-induced antiproliferation and apoptotic effects, indicating that protein isoprenylation and membrane association are not affected by DHEA in BV-2 cells. Taken together, the present results demonstrate that depletion of ATP by DHEA plays an important role in DHEA-induced antiproliferation and apoptosis of BV-2 cells.

2,4-Dinitrophenol↗

PubMed2002

Occlusion of hepatic blood inflow for complex central liver resections in cirrhotic patients: a randomized comparison of hemihepatic and total hepatic occlusion techniques.

BACKGROUND: Intermittent occlusion of hepatic blood inflow by means of a hemihepatic or total hepatic occlusion technique is essential for reducing operative blood loss. Central liver resection to preserve more functioning liver parenchyma is mandatory for centrally located liver tumors in patients with cirrhosis, but it requires a longer overall hepatic ischemic time because of a wide transection plane. No controlled comparison has been performed for the 2 techniques in these operations. HYPOTHESIS: Hemihepatic inflow occlusion may be beneficial in cirrhotic patients who undergo complex central hepatectomy with a wide liver transection plane. DESIGN: A prospective, randomized study. SETTING: University hospital and tertiary referral center. PATIENTS: During liver parenchymal transection, 58 cirrhotic patients who underwent complex central liver resections with a wide transection plane were prospectively randomized into 2 groups. In the group undergoing total hepatic inflow clamping (group T; n = 28), occlusion of hepatic blood inflow was performed for 15 minutes with declamping for 5 minutes. In the group undergoing selective clamping of ipsilateral blood inflow (group H; n = 30), clamping was performed for 30 minutes with declamping for 5 minutes. INTERVENTION: Comparison of patient backgrounds, operative procedures, and early postoperative results. MAIN OUTCOME MEASURES: Operative blood loss, need for blood transfusion, and postoperative morbidity. RESULTS: The patients' backgrounds, operative procedures, and area of liver transection plane were not significantly different between the 2 groups. In all patients, the liver transection areas were greater than 60 cm(2) and overall liver ischemic times were greater than 60 minutes. The amount of operative blood loss and incidence of blood transfusion were significantly greater in group T because of greater blood loss during declamping. Overall liver ischemic and total operative times, postoperative morbidity, and postoperative changes in liver enzyme levels were not significantly different between groups. No in-hospital deaths occurred in either group. CONCLUSIONS: Intermittent hemihepatic and total occlusion of hepatic blood inflow are safe in cirrhotic patients with an overall ischemic time of greater than 60 minutes. However, for complex liver resections with an estimated liver transection plane of greater than 60 cm(2), hemihepatic occlusion of blood inflow, if feasible, may be recommended in cirrhotic patients to reduce operative blood loss and the incidence of blood transfusion under our defined occlusion time.

Adult↗

PubMed2002

Intraoperative aortic dissection--a case report.

Intraoperative aortic dissection is a rare but potentially fatal complication of cardiac surgery. Prompt recognition and repair are necessary to limit the extent of dissection to minimize morbidity and mortality. Here, we present a case of acute type A dissection of ascending aortic artery occurring after removal of aortic cannula at the end of cardiopulmonary bypass. The surgeon immediately recannulated him at the femoral artery and repaired the dissection under deep hypothermia. Ascending aorta was replaced with Hemashield graft and venous graft was reimplanted. Unfortunately, the patient expired the following day due to cardiac tamponade resulting from uncontrolled bleeding. Long-standing severe hypertension, severe atherosclerotic change of the aortic wall, thin and dilating ascending aorta and cystic medial necrosis or collagen vascular disease were thought to predispose him to this complication. Gentle manipulation and surgical discreetness to forestall aoratic injury could minimize the risk of intraoperative aortic dissection. Once aortic dissection has been suspected, prompt application of transesophageal echocardiography to confirm the diagnosis, and rapid as well as appropriate surgical management are necessary to grasp a better outcome.

Aged↗

PubMed2002

Contralateral neurologic deficits following microvascular decompression surgery--a case report.

Microvascular decompression (MVD) surgery for trigeminal neuralgia (Jannetta operation) is common in our institution, and postoperative complications are uncommon. However, a 46 year-old obese female who underwent MVD surgery for right trigeminal neuralgia suffered from postoperative neurologic deficits consisting of left facial palsy, left total deafness, weakness and numbness of the left arm, and unsteady gait. Here, we bring forth the patient's postoperative events, such as delayed emergence, postoperative convulsions, pneumocephalus, and probable causes of the neurologic deficits for discussion.

Deafness↗

PubMed2002

Metastatic hepatocellular carcinoma of the right atrium causing right ventricular outflow tract obstruction during induction of anesthesia--a case report.

Metastatic hepatocellular carcinoma (HCC) to the right atrium occurs rarely and may lead to lethal perioperative complications. A 61-year-old female who was about to undergo operation for resection of a right intraatrial tumor thought possibly to be metastatic hepatocellular carcinoma met with sudden protrusion of the tumor from the right atrial wall that sank into the right ventricle during induction of anesthesia. Right ventricular outflow tract obstruction developed and was quickly diagnosed by transesophageal echocardiography. Emergent cardiopulmonary bypass was rushed on the spot and the surgery was completed smoothly. Here we discuss the possible causes of the event and we recommend that special attention should be paid to the anesthetic techniques and proper precaution should be taken in the face of such a risky surgery.

Anesthesia↗

PubMed2002

Endotracheal tube fire induced by electrocautery during tracheostomy--a case report.

Airway fire resulting from ignition of the endotracheal tube (ETT) caused by electrocautery during tracheostomy is a severe and possibly fatal event, and should be avoided. An 88-year-old male because of respiratory failure received elective tracheostomy for ventilatory support on which prolonged dependence was anticipated. Unfortunately, flame was noted to jet out from the trachea incision just after a single burst of electrocautery to coagulate a bleeder in the trachea tissue nearby the incision. After primary management, including extinguishing the flame and evaluation of the tracheal injury by bronchoscope, a tracheostomy tube was inserted smoothly without causing hypoxemia or hemodynamic instability. The patient stood this ordeal of fire well without related sequelae and was returned from the intensive care unit (ICU) to the general ward two weeks later. From this accident, we recommend that, besides emphasis on lowering of the inspired oxygen concentration (FiO2) and careful use of electrocautery during the tracheostomy procedure, special attention should be paid to the integrality of ETT cuff. It serves as a barrier to prevent oxygen leaking out from the trachea to be exposed to the sparks of electrocautery while the surgical procedure is under way, and thus it plays a significant role in the avoidance of airway fire induced by electrocautery.

Aged↗