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Biomedical subjects

B C Cheng

Publications and source records attributed to B C Cheng.

16 recordsLinked to original sources
PubMed2006

Successful outpatient treatment of renal vein thrombosis by low-molecular weight heparins in 3 patients with nephrotic syndrome.

Renal vein thrombosis (RV Thromb) is a serious complication ofnephrotic syndrome. Anticoagulation is usually recommended as the treatment of choice. This study reports 3 nephrotic patients diagnosed to have RVThromb combined with thromboembolic events. Low-molecular weight heparin (LMWHep) was given subcutaneously every 12 hours following the diagnosis of RVTromb, which continued at the outpatient clinic after an average of 11 in-hospital days. The patients visited the nephrology outpatient clinic every other week and underwent magnetic resonance image (MRI) studies at 6-week intervals for follow-up of patency of the involved renal vein. LMWHep was discontinued when MRI showed this patency. The average outpatient treatment period was 74 days. There was no recurrent RVThromb in the follow-up course of 6 months after discontinuation of LMWHep. Kidney function was preserved, as indicated by image studies and serial renal function tests. LMWHep produced a more predictable anti-coagulant effect, a superior bioavailability, a longer half-life and a dose-independent effect than unfractionated heparin and coumadin. These benefits made the outpatient treatment of RVThromb possible. Our report recommends outpatient treatment of RVThromb by LMWHep because it is feasible, effective and safe.

Adult↗
PubMed2005

Surgical treatment for upper or middle esophageal carcinoma occurring after gastrectomy: a study of 52 cases.

Fifty-two patients presenting with upper or middle esophageal carcinoma after gastrectomy between 1980 and 2003 were analyzed retrospectively. Among them, there were five cases of total gastrectomy, six cases of proximal partial gastrectomy and 41 cases of distal subtotal gastrectomy. The interval between gastrectomy and the diagnosis of esophageal carcinoma ranged from 2 to 22 years. Surgical procedures included resection of the esophageal lesion with esophageal replacement using non-reversed or reversed gastric tubes (2 and 3 cases respectively), and short or long segment colon (5 and 40 cases respectively); two cases underwent a palliative procedure (jejunostomy). Complications included cervical anastomotic leaks (3 cases), pulmonary infection (3 cases), atelectasis (2 cases) and cordis arrhythmia (5 cases), all of which responded to treatment. In our group, resection of the esophageal lesions and reconstruction of the esophagus was performed in 45 cases (86.5%), exclusion and bypass procedure of esophageal carcinoma and following radiotherapy and chemotherapy in four (7.7%), eternal jejunostomy for intestinal nutrition in two (3.9%) and death occurred in one case (1.9%) due to multiple organ dysfunction syndrome (MODS). Esophageal resection combined with lymph node dissection is indicated for the treatment of upper or middle esophageal carcinoma following gastrectomy. While esophageal substitutes can include non-reversed or reversed gastric tubes as well as short or long segment colon interpositions, we usually recommend the use of colon interposition. The 1-, 3- and 5-year survival rate of cases with resection of the esophageal lesions and reconstruction of the esophagus was 84.6%, 57.7% and 26.7% respectively.

Aged↗
PubMed2004

Data management using the personal digital assistant in an acute pain service.

Handheld personal digital assistants (PDA) are increasingly being used by physicians for a variety of information and data management purposes. We evaluated a PDA-based data management system for our acute pain service. A structured questionnaire survey was conducted to assess staff experience and attitude towards the paper system before the introduction of the PDA, and three months after introduction of the PDA system. We compared the time taken to conduct the acute pain round before and after the implementation of the PDA. The time saved in data management and the amount of paper saved were estimated. Data from 177 patients with a total of 635 acute pain follow-up visits were entered over a three-month period. User satisfaction, ease of access to drug reference and clinical guidelines were similar between the two systems. The respondents found that the PDA was easy to use but less so than the paper system (P = 0.007), in particular, when accessing a patient's cumulative data (P = 0.007). There was no missed follow-up or data entry with the use of PDA. The time taken to attend follow-up visits was similar for the two systems (Paper: 8.8 +/- 3.2 compared to PDA: 7.0 +/- 2.0 minutes, P = 0.151). The estimated annual amount of paper and time saved in data management was 650 sheets and 130 man-hours respectively. Our experience with the use of the PDA in APS was satisfactory. The PDA system can potentially reduce time and paper use and missed data entry and patient follow-up.

Acute Disease↗
PubMed2001

Biomechanical comparison of posterior cervical fixation.

STUDY DESIGN: Biomechanical stability using four different posterior cervical fixation techniques was evaluated in human cadaveric spine. OBJECTIVES: To introduce an alternative interspinous fixation technique using wavy-shaped rods, and to compare its in vitro biomechanical stability with that of other posterior cervical fixation techniques. SUMMARY OF BACKGROUND DATA: Fixation of the posterior cervical spine with interspinous wiring is well known as Rogers' or Bohlman's technique. Recently, several plate fixation techniques have been used for posterior cervical stabilization. Since 1983, the authors have developed the wavy-shaped rod system as an alternative to the interspinous fixation technique. This unique technique has been proven clinically useful in Japan. However, the authors are not aware of any prior biomechanical studies. METHODS: Seven fresh frozen cervical human spines were tested at the C5-C6 motion segment. Nondestructive static biomechanical testing was performed with flexion-extension, lateral bending, and axial rotation for the following stabilization techniques: intact spine, creation of a Stage 3 distractive-flexion injury followed by fixation with the wavy-shaped rods bounded by three multistrand cables, interspinous wiring with a multistrand cable, triple wiring technique using multistrand cables with a pair of unicortical grafts from the ilium, and lateral mass plate fixation with Magerl's screw technique. Testing was performed on a material testing machine (MTS 858 Bionix test system, MTS, Minneapolis, MN), and load displacement curves were obtained using four linear extensometers and one rotatory extensometer across the C5-C6 motion segment. RESULTS: In axial compression loading, the reconstructed specimens showed significant differences in range of motion measured at the anterior and posterior positions, and statistical analysis was performed using one-way analysis of variance. In a comparison of the four fixation techniques, the construct with the wavy-shaped rod indicated significantly less motion both anteriorly and posteriorly than with the other fixation techniques. Also in flexion-extension loading, all the techniques significantly limited the intervertebral motion below the level of the intact motion segment. Particularly, the construct with the wavy-shaped rod showed the smallest mobility, 49.9% anteriorly and 9.3% posteriorly, compared with that of the intact spine. In lateral bending, the lateral mass plate provided the greatest stability, which was superior to the intact segment, but the difference was not statistically significant. In axial rotation, all the reconstruction techniques limited the angular motion below the intact level (wavy rod, 68.0%; Rogers' wiring, 75.2%; Bohlman's triple wiring, 59.8%; lateral mass plate, 71.7%), but no significant differences were observed using one-way analysis of variance, as compared with the intact segment. CONCLUSIONS: All four reconstruction techniques restored the stability of the cervical motion segment to at least the level of the intact motion segment before destabilization. An alternative cervical posterior fixation technique, the Wavy Rod system, was considered the most effective technique in stabilizing a cervical motion segment, particularly in axial compression and flexion extension loading.

Biomechanical Phenomena↗
PubMed1998

Biomechanical evaluation of translaminar facet joint fixation. A comparative study of poly-L-lactide pins, screws, and pedicle fixation.

STUDY DESIGN: Nine sheep cadaveric spines were used in this acute postoperative model. OBJECTIVES: To compare the biomechanical performance of translaminar facet joint fixation techique with that of cortical screws and bioabsorbable poly-L-lactide pins and with that of rigid pedicle screw fixation in the lumbar spine. SUMMARY OF BACKGROUND DATA: Among numerous posterior spine fixation techniques, pedicle screw fixation has been reported to be the most rigid construct and to provide high fusion rate. Translaminar facet joint screw fixation is an alternative to pedicle screw fixation and is the lowest profile construct that achieves stabilization. The authors have developed a new concept involving application of bioabsorbable poly-L-lactide pins to translaminar facet joint fixation. Degradation in the stiffness of the implants with time may be advantageous for fusion mass remodeling. METHODS: A total of nine sheep L2-L6 cadaveric spines were used. Each intact spine was nondestructively tested in flexion-extension bending (+/- 5-Nm peak bending moment with 100-N axial compression) on a modified testing machine. Loads were applied for 10-second periods using sinusoid waveforms. After testing the intact spine, bilateral fenestration was performed between L4 and L5 and the medial aspect of the facet capsule was resected. The L4-L5 functional spinal unit was than stabilized by five methods: translaminar facet joint fixation with smooth poly-L-lactide pins; translaminar facet joint fixation with cortical screws; pedicle screw fixation with the Texas Scottish Rite Hospital system; and without instrumentation, in that order. Linear displacement of L4 inferior and L5 superior articular processes in the sagittal plain (delta facet) and L4-L5 intervertebral rotation in the sagittal plain (theta sagittal) were measured by the extensometers mounted to the spine. Ranges of motion (delta facet and theta sagittal), neutral zones, linear elastic zone stiffness, and the total energy absorption during the load-unload cycle (hysteresis) were calculated. RESULTS: By resecting the facet joint capsules and ligamentum flavum, delta facet and theta sagittal were not increased significantly, whereas the increase of neutral zones and hysteresis were statistically significant. Compared with the intact spine, delta facet was significantly reduced to 41% of normal with translaminar facet joint fixation with poly-L-lactide pins, to 9% with translaminar facet joint fixation with screws, and to 11% with the Texas Scottish Rite Hospital system. Neutral zones of delta facet showed a similar pattern, and these differences were significant. Regarding linear elastic zone stiffness, translaminar facet joint fixation with screws provided a stiffer construct than did pedicle screw fixation in the flexion loading mode, whereas pedicle screw fixation yielded higher values for stiffness in extension loading. Translaminar facet joint fixation with poly-L-lactide pins increased linear elastic zone stiffness in extension loading, but the increase was less than was achieved with the other constructs. CONCLUSIONS: The facet joint is the only true articulation in the lumbosacral spine. It is logical to fix this part directly to achieve spine fixation. Translaminar facet joint fixation with screws show similar biomechanical performance to pedicle screw fixation. Translaminar facet joint fixation with poly-L-lactide pins is significantly less stiff than either type of screw fixation, but it also restricts the facet joint and intervertebral motions significantly when compared with the intact spine.

Analysis of Variance↗
PubMed1998

Multilaminate resorbable biomedical device under biaxial loading.

The design and test of a multilaminate sheet developed for a hernia repair application is presented. As biomaterial applications become more complex, characterization of uniaxial properties becomes insufficient and biaxial testing becomes necessary. A measure of the in-plane biaxial strength of the device is inferred from a ball burst test. The results of this test for different thicknesses of the device are correlated with the uniaxial strength of the material. A biaxial test such as the ball burst test is more indicative of the properties of a planar material than would be a uniaxial test. The interactions in the biaxial mode of failure are of value and can be related back to a classical uniaxial tensile test from the ball burst test. The material used in this study to fabricate the device was a resorbable biomaterial called small intestinal submucosa (SIS). The effects of rehydration on the stiffness and associated ball burst properties of the SIS device were also measured. It is shown that at a rehydration time of 5 min from a reference dry state, steady-state mechanical properties are reached.

Biocompatible Materials↗
PubMed1997

[Observation of therapeutic effect by combined administration of Salvia miltiorrhiza, ligustrazine and Panax notoginseng on late hemorrhagic shock of rabbits].

OBJECTIVE: To explore the therapeutic mechanism of Salvia miltiorrhize, ligustrazine and Panax notoginseng in treating late hemorrhagic shock in rabbit. METHODS: Rabbit hemorrhagic shock models (MPA 5.3 kPa) were set up according to Wiggers' method and administrated Salvia miltiorrhiza, ligustrazine, Panax notoginseng. The values of blood RBC superoxide dismutase (SOD) and blood lactate (BL), plasma malondialdehyde (MDA) and magnesium (Mg++) were continuously monitored before shock, 120 minutes after shock, 60 and 120 minutes after hydraulic dilatation. RESULTS: (1) In 120 minutes after shock, the level of SOD decreased and the concentrations of MDA, BL, Mg++ were markedly increased, which indicated that the cell membrane damage caused by oxygen free radicals in rabbit hemorrhagic shock. (2) Salvia miltiorrhiza, Ligustrazine or Panax notoginseng could alleviate lipidperoxidation injury to tissue. Compared with the single drug administration groups, the effects of oxygen free radicals scavangers by combined administration with half dose of 2 drugs were better than the single drug with full dose alone and the side effects such as depression of blood pressure and heart rates would be alleviated. CONCLUSION: Combined administration of Salvia miltiorrhiza, ligustrazine and Panax notoginseng would half the dosage, the blood pressure depression and heart rate reduction alleviated and better result obtained.

Animals↗
PubMed1995

Animal study of phoenix total artificial heart implantation.

BACKGROUND: It is well accepted that a total artificial heart (TAH) can be used as a bridge to heart transplantation during the waiting period for organ donation. A series of combined studies, conducted by the Kaohsiung Veterans General Hospital, National Yang-Ming Medical College and Municipal Tainan Hospital, has been performed to improve the Phoenix artificial heart developed by Dr. Kevin Kuo-Tsai Cheng. METHODS: In growing calves (weighed about 80 kg), standard procedures were used to remove the hearts and replace them with the TAHs. Records were made of hemodynamic data, physiological responses, blood biochemistry data and physical activities after operation and until the death of the calves. Finally, autopsies were used to determine the causes of death. RESULTS: A total of 23 calves were studied. Twenty-two of them survived 1 to 12 days, or an average 4.95 days. One survived more than 30 days. All the calves could breathe, stand, eat and void by themselves two hours after operation. Respiratory failure was the major cause of death. CONCLUSIONS: No thrombus within the TAH was noted in the last five cases, meaning that turbulent flow or dead space of the TAH was improved. Better intensive care and prevention of infection will be the next challenge for long-term use of TAH.

Animals↗
PubMed1994

Colon replacement from esophagus. Clinical experience from 240 cases.

The clinical experience in the colon replacement of the esophagus in 240 cases is reported. The overall operative morbidity was 17.5%; the incidence of the anastomotic leaks was 10.4%; and the mortality was 2.80%. The points in surgical technique were: 1) utilizing the left colic artery as the supporting vessel if possible, based on the anatomy of the colon vessel; 2) using the colon segment in an isoperistaltic position, which has been proved much physiological; 3) single-layer anastomosis which is simple and reliable, with minimal inflammation and quick healing; and 4) choosing the channel of the colon transplant according to the disease condition, the age, and the function of the heart and the lung of the patients.

Adolescent↗
PubMed1993

Right gastroepiploic artery: an alternative arterial conduit for coronary artery bypass.

From September 1990 to February 1991, 15 cases of myocardial revascularization with the right gastroepiploic artery (RGEA) combined with arterial or venous grafts were performed at VGH-Taipei. All were males, ranging in age from 49 to 64 years (mean age 61.2 +/- 4.6 years). The mean number of distal anastmoses including vein grafts was 3.6 +/- 0.7 and the mean number of graft was 3.1 +/- 0.3 per patient. The mean aortic clamp time was 123.6 +/- 24.0 minutes and the mean cardiopulmonary bypass time was 176 +/- 35 minutes. There was one mortality (6.7%). The other 14 patients are alive without angina. Studied within 3 postoperative months, graft early patency was 100% (6/6) in GEA graft. GEA graft should be a third available arterial conduit for coronary artery bypass.

Aged↗
PubMed1992

[Early pericardiectomy of acute purulent pericarditis].

The results of early pericardiectomy in 15 cases of acute purulent pericarditis were reported. 13 cases were followed up from 2 to 8 years, none of them developed chronic constrictive pericarditis. The operation is simple and can shorten the time of hospitalization following thorough debridement of the infected foci.

Acute Disease↗
PubMed1992

[Emergency lung resection in patients with massive hemoptysis].

Emergency lung resection was done in 32 patients with massive hemoptysis. The morbidity and mortality rates were 18.75% and 6.25% respectively. Problems about how to find the focus of hemoptysis, when to perform the operation, how to select anaesthesia, operative techniques and limits of lung resection were discussed.

Adolescent↗
PubMed1992

A new autoperfusion technique for aortic reconstruction of suprarenal aortic aneurysm.

Visceral ischemia is a serious factor in the postoperative morbidity and mortality of suprarenal aortic reconstruction. We reported two patients of suprarenal aortic aneurysm involving visceral arteries, who received successful Dacron graft replacement by using Pruitt-Inahara balloon catheters as an autoperfusion for preservation of the visceral organs. No visceral organ ischemia occurred postoperatively except in patient 2 who had preoperative chronic renal failure and persistent renal failure after the operation. The renal function recovered gradually during the follow-up period. Both patients are doing well at the present time. The new autoperfusion technique can directly deliver normothermic blood from the arterial cannula at proximal aorta to the individual visceral arteries by using the balloon perfusion catheters. It is simple, safe, easily instituted and the used products are readily obtainable. It allows the surgeon to provide an effective protection of visceral organs for the suprarenal aortic reconstruction.

Aged↗
PubMed1990

Experimental study and clinical application of a single-row suturing esophagogastrostomy.

A single-row suturing anastomosis (SRA) for an esophagogastrostomy was experimentally investigated in dogs. SRA not only shortened operating time, but also led to better pathological results when compared with double-row suturing anastomosis. Wide-brim suturing and equal distance between the sutures, providing increased and well-distributed blood circulation, are the key points for success of SRA. Its simplicity and safety are advantages of SRA as has been shown in 90 cases in clinical application.

Anastomosis, Surgical↗
PubMed1989

[Clinical study of colic vessels with respect to their significance in the replacement of the esophagus by the colon].

In 162 cases of esophageal replacement by colon we observed the configuration, distribution and pulsation of the middle, left, right and marginal colic arteries. Observation showed that the middle colic artery had only one major stem in 120 cases, 2-4 branches in 37 cases, and was absent in 5 cases. The middle colic artery originated from the superior mesenteric artery in 126 cases, had one stem originating from the superior mesenteric artery and another from the right colic artery in 10 cases. The middle and the right colic arteries forming one stem and originating from the superior mesenteric artery were seen in 21 cases. The distributive patterns of the middle colic arteries showing "T" type was seen in 37 cases, "V" type in 28 cases, and multiple paralleled branches in 9 cases. Vascular anastomoses between the ascending branch of the left colic artery and the middle colic artery were available in 157 cases (97%), 12 cases with the arc of Riolan. The nearest distance between the marginal artery and the colic wall was at the splenic flexure. The origin of the right colic artery varied greatly and its distributive area was small. We advocated the use of the ascending branch of the left colic artery for blood supply and the transverse colon for replacement of the esophagus in an isoperistaltic fashion (131/162 cases) to be the procedure of choice.

Adolescent↗