Biomedical subjects

S W Ueng

Publications and source records attributed to S W Ueng.

35 records · Page 2Linked to original sources

PubMed1998

Limb-threatening necrotizing alternariosis salvaged by adjunctive hyperbaric oxygen therapy.

We describe, to our knowledge, the first case of limb-threatening necrotizing alternariosis whose limbs were successfully salvaged by adjunctive hyperbaric oxygen therapy (HBO2). This 58-y-old patient was immunocompromised with both diabetes and Cushing's syndrome. She suffered from necrotizing soft tissue infection of both legs caused by Alternaria. It was impossible to halt the progression of the invasive infection with standard anti-fungal treatment and aggressive surgical debridement. After the use of HBO2, the wound was stabilized and eventually healed. Adjunctive HBO2 in this case has demonstrated its role in the treatment of complicating necrotizing soft tissue infection caused by invasive fungal infection. The possible mechanisms may be the potentiation of immune responses and the enhancement of fibroblast proliferation.

Alternaria↗

PubMed1998

Bone healing of tibial lengthening is enhanced by hyperbaric oxygen therapy: a study of bone mineral density and torsional strength on rabbits.

We investigated the effect of intermittent hyperbaric oxygen (HBO) therapy on the bone healing of tibial lengthening in rabbits. Twelve male rabbits were divided into two groups of six animals each. The first group went through 2.5 atmospheres absolute of hyperbaric oxygenation for 2 hours daily, and the second group did not go through hyperbaric oxygenation. Each animal's right tibia was lengthened 5 mm using an uniplanar lengthening device. Bone mineral density (BMD) study was performed for all of the animals at 1 day before operation and at 3, 4, 5, and 6 weeks after operation. All of the animals were killed at 6 weeks postoperatively for biomechanical testing. Using the preoperative BMD as an internal control, we found that the BMD of the HBO group was increased significantly compared with the non HBO group. The mean %BMD at 3, 4, 5, and 6 weeks were 69.5%, 80.1%, 87.8%, and 96.9%, respectively, in HBO group, whereas the mean %BMD were 51.6%, 67.7%, 70.5%, and 79.2%, respectively, in non-HBO group (two tailed t test, p < 0.01, p < 0.01, p < 0.01, and p < 0.01 at 3, 4, 5, and 6 weeks, respectively). Using the contralateral nonoperated tibia as an internal control, we found that torsional strength of lengthened tibia of the HBO group was increased significantly compared with the non-HBO group. The mean percent of maximal torque was 88.6% in HBO group at 6 weeks, whereas the mean percent of maximal torque was 76.0% in non-HBO group (two-tailed t test, p < 0.01). The results of this study suggest that the bone healing of tibial lengthening is enhanced by intermittent hyperbaric oxygen therapy.

Absorptiometry, Photon↗

PubMed1998

Augmentative plate fixation for the management of femoral nonunion with broken interlocking nail.

Five patients with femoral nonunion and a broken interlocking nail were treated with the augmentative plating procedure. This group included two male and three female patients whose average age was 25 years (range, 21-35 years). All of the injuries resulted from traffic accidents and were closed fractures. Four of the injuries were initially managed with a Grosse-Kempf interlocking nailing system, and one case was managed with an AO interlocking nailing system. The broken interlocking nail was left in place in situ, and an augmentative plate fixation was applied to the fracture site to provide a rigid fixation. Simultaneous bone grafting was performed in three of the patients to repair the bony defect. All of these patients walked bearing full weight on the extremity without aching at the fracture site within 3 months, and all of these five fractures obtained a bony union within an average of 5.4 months after this treatment. From our experience, we have found this method to be a useful treatment for the nonunion of femoral shaft fracture with a broken interlocking nail.

Adult↗

PubMed1998

Management of small infected tibial defects with antibiotic-impregnated autogenic cancellous bone grafting.

Between January of 1991 and December of 1993, 36 patients who had tibia fractures complicated by small infected tibia defects were treated at the authors' service. The group included 30 men and 6 women whose average age was 36.5 years (range, 18-72 years). The average follow-up period was 3.7 years. By using the Cierney-Mader staging classification of chronic osteomyelitis, 26 of 36 patients (72%) were stage 4A and 10 of 36 patients (28%) were stage 4B. Ten patients required muscle transfer. All patients were treated with a two-stage protocol. In the first stage, antibiotic-impregnated polymethylmethacrylate bead chains were used to obliterate the debrided osseous defect. In the second stage, the beads were removed, and the defects were reconstructed with antibiotic-impregnated autogenic cancellous bone graft. The time between the first and second stage was 2 to 8 weeks for patients without muscle transfer and 8 to 12 weeks for the patients with muscle transfer. The bone defects ranged from 2 to 4 cm. Wound healing and bony union were achieved in all patients. Only two patients had recurrent infections. The infection arrest rate was 94.4%. Minor pin tract infection of the external skeletal fixation was seen in two patients. Two patients developed skin rashes secondary to antibiotic therapy. Radiographs at an average follow-up of 3.7 years showed good consolidation and hypertrophy of grafted bones in all patients. After 3 to 5 years of follow-up, our results suggest that the use of impregnating antibiotics have no adverse effects on autogenic cancellous bone graft incorporation and may help to eliminate infection. This treatment protocol provided rapid recovery from osteomyelitis. The use of antibiotic-impregnated autogenic bone graft seems to be an effective and safe method for the management of small infected tibial defects.

Adolescent↗

PubMed1998

Closed management and percutaneous fixation of unstable proximal humerus fractures.

BACKGROUND: In dealing with displaced proximal humerus fractures, there is still much controversy in treatment modalities. The latest investigations emphasize the concept of minimal exposure and rigid fixation. METHODS: The technique of closed reduction and percutaneous fixation with cannulated screws and k-pins was performed on 19 patients with two- and three-part proximal humerus fractures. The outcomes were evaluated with a mean follow-up of 21 months. RESULTS: All except one case had a solid union of the fracture. Sixteen of 19 patients (84%) acquired good or excellent results according to Neer's classification. No further collapse or avascular necrosis was found. CONCLUSION: The method of closed reduction and percutaneous fixation, although technically demanding, yields satisfactory results in displaced proximal humerus fracture. Cannulated screws provided rigid fixation that was the underlying tenet for early functional retrieval.

Adolescent↗

PubMed1998

Hyperbaric oxygen pretreatment attenuates hepatic reperfusion injury.

Microcirculatory derangement, energy depletion and lipid peroxidation have been related to development of ischemia-reperfusion injury in the liver. This study investigates the effects of hyperbaric oxygen (HBO) on hepatic ischemia-reperfusion injury. Adult, male Sprague-Dawley rats were used. Three groups were evaluated: 1) sham-operated control (laparotomy only, no ischemia, no HBO), n=8; 2) ischemia control (1-h ischemia, 2-h reperfusion, no HBO), n=8; and 3) HBO pretreatment (100%, oxygen, 2.5 atm absolute, 90 min) plus ischemia (1-h ischemia, 2-h reperfusion), n=8. An in vivo microscope was used to investigate hepatic microcirculation. Tissue malondialdehyde (MDA) and adenosine triphosphate (ATP) were determined. In comparison with the ischemia control group, HBO significantly improved harmful insults following ischemia-reperfusion. HBO lessened adherent leukocyte count (6.00+/-1.31 cells/200 microm vs 11.38+/-2.88 cells/200 microm), and improved flow velocity (1.72+/-0.26 mm/s vs 0.83+/-0.19 mm/s) in post-sinusoidal venules. HBO also reduced MDA (1.04+/-0.24 nmol/mg protein vs 2.24+/-0.49 micromol/g protein), and increased ATP (2.03+/-0.17 micromol/g wet wt vs 0.73+/-0.11 micromol/g wet wt) levels. This study demonstrates that HBO before ischemia may ameliorate the ischemia-reperfusion injury of the liver in the rat model.

Adenosine Triphosphate↗

PubMed1998

Tuberculosis of the ankle: report of four cases.

Tuberculosis of the ankle joint is relatively uncommon, and the treatment usually includes chemotherapy, immobilization and non-weight bearing protection. It is easily confused with pyogenic arthritis, which often leads to delayed diagnosis. We reviewed the records of 4 patients with ankle tuberculosis with advanced articular lesions without evidence of pulmonary tuberculosis. They took antituberculous agents for 5 to 6 months. Two of them had positive bacterial cultures, and all four had initially received surgical management under the impression of pyogenic osteomyelitis. Two patients underwent arthrodesis and the other two synovectomy with debridement. The clinical and radiologic results were better in the patients who underwent arthrodesis. We consider surgery with open biopsy of a painful swelling ankle to be helpful in the differential diagnosis of tuberculous and pyogenic arthritis. Arthrodesis in patients with severe osteoarticular destruction of the ankle provides a better prognosis and more stable joint than other treatment methods.

Adult↗

PubMed1998

Hyperbaric oxygen therapy attenuates pancreatic microcirculatory derangement and lung edema in an acute experimental pancreatitis model in rats.

This study was designed to investigate hyperbaric oxygen (HBO) therapy as a treatment for managing animals with induced acute pancreatitis. Forty-five anesthetized male Sprague-Dawley rats were studied. A severe acute pancreatitis model was established by combining an intravenous infusion of cerulein (15 microg/kg/h) and an intraductal injection of 0.1 ml of glycodeoxycholic acid (5 mM). Pathology, serum amylase level, pancreatic malondiadehyde levels and water content of the lungs and the pancreas were used to evaluate the severity of disease. Moreover, an in vivo microscopic technique was used to investigate microcirculatory derangement in the pancreas, i.e., flow velocity and leukocytes sticking in postcapillary venules. HBO was delivered in three regimens, i.e., 100% oxygen at 2.5 absolute atmospheric pressure (AAP), 40% oxygen at 2.5 AAP, and 100% oxygen at 1 AAP, 6 h after the initiation of induction of acute pancreatitis. All animals survived until the end of the experiments. HBO significantly improved the pathologic conditions and pancreatic malondiadehyde levels. Concomitantly, it also significantly lessened the severity of lung edema and improved the microcirculatory environment in the pancreas. Our results support the findings that HBO therapy has a beneficial effect on pancreatic microcirculation and lung edema during acute pancreatitis in rats.

3,4-Methylenedioxyamphetamine↗

PubMed1998

Chronic refractory tibia osteomyelitis treated with adjuvent hyperbaric oxygen: a preliminary report.

BACKGROUND: Refractory osteomyelitis is a serious disease that fails to respond to aggressive medical and surgical treatment. A plethora of alternative therapies have evolved. Hyperbaric oxygen has been proven to enhance bone and soft tissue healing in many in vitro and in vivo studies. This article presents the preliminary results of adjunctive hyperbaric oxygen therapy in patients with refractory osteomyelitis. MATERIALS AND METHODS: Fifteen patients who were diagnosed with refractory tibia osteomyelitis were treated prospectively with adjunctive hyperbaric oxygen therapy, aggressive surgical debridement, and parenteral antibiotic treatment. The effectiveness was evaluated with an average follow-up of 17.2 months. RESULTS: The hyperbaric oxygen therapy averaged 26 daily sessions. Successful treatment was achieved in 13 patients (86%). The mean length of treatment was 45 days. The preliminary results are comparable with other series. CONCLUSION: Hyperbaric oxygen is effective as an adjunct to aggressive medical and surgical management in refractory osteomyelitis. A precise clinical staging system for patient selection and treatment organization is imperative to successful outcome.

Adolescent↗

PubMed1997

Effect of intermittent cigarette smoke inhalation on tibial lengthening: experimental study on rabbits.

We investigated the effect of intermittent cigarette smoke inhalation on the bone healing of tibial lengthening in rabbits. Thirty-eight male rabbits were divided into two groups of 19 animals each. The first group went through intermittent cigarette smoke inhalation, and the second group did not go through intermittent cigarette smoke inhalation. Each animal's right tibia was lengthened 5 mm using an uniplanar lengthening device. Five animals of each group were killed at 4, 6, and 8 weeks postoperatively for biomechanical testing, and one animal of each group was killed at 2, 4, 6, and 8 weeks postoperatively for histologic study. Using the contralateral nonoperated tibia as an internal control, we found that torsional strength of the lengthened tibia of the smoke inhalation group was decreased significantly compared with the non-smoke inhalation group. The mean percent of maximal torque at 4, 6, and 8 weeks were 22.0, 66.3, and 78.6%, respectively, in the smoke inhalation group, whereas the mean percent of maximal torque were 48.0, 84.1, and 90.8% %, respectively, in non-smoke inhalation group (one-tailed t test, p < 0.01, p < 0.01, and p < 0.05 at 4, 6, and 8 weeks, respectively). Our histologic observations revealed that the granulation tissue resorption, bone formation, and remodeling were delayed in smoke inhalation group. The results of this study suggest that intermittent inhalation of cigarette smoke delays, but does not prevent, the bone healing in tibial lengthening.

Animals↗

PubMed1997

Management of large infected tibial defects with antibiotic beads local therapy and staged fibular osteoseptocutaneous free transfer.

Fifteen patients with tibial fractures complicated by large infected tibial defects were treated with a two-stage protocol. In the first stage, antibiotic-impregnated polymethylmethacrylate bead chains were used to obliterate the debrided osseous defect, and a meshed porcine skin was used for temporary wound coverage. In the second stage, the bead chains were removed, and the defects were reconstructed with a microvascularized fibular osteoseptocutaneous free transfer. The time between the first and second stages of treatment was 2 to 6 weeks. The bone defects ranged from 6 to 16 cm, and the skin defect areas ranged from 10 to 82 cm2. Wound healing and bony union were achieved in all 15 cases. An additional muscle flap or skin graft was required for only three patients with a large skin defect. Minor pin tract infections were seen in two patients. Stress fractures in three cases were successfully managed with bracing, external skeletal fixation or plating, and cancellous bone grafting. All of the most recent roentgenograms showed good consolidation and hypertrophy of grafted fibular bones. No recurrence of osteomyelitis was observed during an average follow-up period of 50 months (range, 36-86 months). We therefore conclude that this treatment protocol provides rapid recovery from osteomyelitis. The fibular osteoseptocutaneous graft is a useful method for the reconstruction of a large tibial defect, and it also offers the unique advantage of simultaneously reconstructing a moderate skin defect.

Adult↗

PubMed1997

Augmentative plate fixation for the management of femoral nonunion after intramedullary nailing.

Seventeen femoral nonunions after intramedullary nail internal fixation were treated with augmentative plate internal fixation. Six of them were initially managed with a Küntscher nail internal fixation; the other 11 fractures were managed with a locked nail internal fixation. All the femoral nonunions were caused by insecure fixation of the intramedullary nailing, in which a rotational instability of the fracture site was verified in all cases during operation. Leaving the intramedullary nail in situ, an augmentative plate fixation was applied to the fracture site to counter the rotational instability. A simultaneous bone grafting was performed in seven of them to repair the bony defect. All these patients walked bearing full weight on the extremity without aching at the fracture site within 3 months and all these 17 fractures obtained a bony union within an average of 7 months after this treatment. From our experience, we have found this method is a useful treatment for the nonunion of the femoral shaft fracture after an intramedullary nail internal fixation. The technique is simple and does not require any special instrument. It facilitates an early weight bearing and gives a quick recovery from nonunion.

Adolescent↗

PubMed1997

Staged management of infected humeral nonunion.

Fourteen patients with infected humeral nonunion complicated by sinus discharge were treated with a staged protocol consisting of (1) radical debridement with local antibiotic beads implantation, and (2) external skeletal fixation with autologous bone grafting. In the first stage, a thorough debridement and sequestrectomy were done. Antibiotic beads were used to obliterate the bone defect, and the wound was then directly closed. In the second stage, the bead chains were replaced with autogenous cancellous bone graft. Unilateral Hoffman external skeletal fixators were applied simultaneously. The mean follow-up period was 73.6 months (range, 29 months to 9 years). The length of time to achieve bony union ranged from 3.5 to 8 months (average, 4.3 months). Hoffman pin complication was found in two cases, which were then shifted to plate internal fixation. All the infections were eradicated, and the wounds healed without further skin graft or flap coverage. All the fractures achieved bony union except for one in a patient who died. Most patients acquired satisfactory function of elbow motion after removal of external fixation and physical therapy. The method of two-stage management was effective for infected humeral nonunion. Not only was the infection eradicated and osseous union achieved, but also the limb function and joint motion were preserved.

Adult↗

PubMed1997

Hyperbaric oxygen in the treatment of diabetic foot infection.

BACKGROUND: Although hyperbaric oxygen therapy to treat diabetic foot lesions has been approved for insurance reimbursement in Taiwan, its clinical application has not yet been well accepted. This study evaluated multiple healing predictive factors in patients with diabetic foot infections to determine the usefulness of adjunctive hyperbaric oxygen in the treatment of such patients. METHODS: From March 1995 to May 1996, we treated 31 diabetic patients presenting with infected foot lesions with a regimen of adequate metabolic control, frequent wound debridement and hyperbaric oxygen therapy. Age, gender, leukocyte count, total lymphocyte count, hemoglobin, erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), glycosylated hemoglobin Alc (HbAlc), albumin, ankle-brachial index, types of bacterial cultures and number of debridements were compared between successful and failed treatments. Independent t-test and Fisher's exact test were used to identify the prognostic factors associated with outcome of treatment. RESULTS: The mean age of the patients was 63.0 +/- 9.7 years (range 43 to 81). The mean number of hyperbaric oxygen therapies was 35.3 +/- 21.8 treatments (range 5 to 83). Of the 31 patients, 6 received below knee amputation, and 25 had their foot preserved or achieved a lower level of amputation. Elevated leukocyte count and low ankle-brachial index were significantly related to poor outcome. CONCLUSIONS: In the treatment of diabetic foot infection, adjunctive hyperbaric oxygen therapy seems to be a useful tool to enhance wound healing provided that there are preserved circulation and controlled infection.

Adult↗

PubMed1996

Vastus lateralis flaps for chronic recalcitrant hip infection.

Between January 1991 and May 1994, 11 patients with chronic recalcitrant infection of the hip joint were successfully treated by transposition of a vastus lateralis flap. The average duration of the infection was 7.9 months. The patients had undergone an average of 2.8 procedures in an attempt to eradicate the infection before transposition of the flap. Three patients had recurrence of drainage after the procedure and were successfully treated with antibiotics and local debridement. Delayed exchange total hip arthroplasty was performed in 2 patients. All the patients achieved wound healing and infection resolution. This flap has several advantages. The donor site has not usually been scarred from previous operations; the flap has a consistent vascular pedicle which permits a wide arc of rotation; knee extension is unaffected; the transposed portion of the vastus lateralis can act as a cushion between the acetabulum and the proximal femur; it may also act as a tether to prevent extreme proximal migration of the femur. In the management of chronic recalcitrant infection of the hip, use of a transposition flap can be combined with a Girdlestone arthroplasty. It can also be an interim procedure before a further total joint arthroplasty.

Adult↗

PubMed1996

Management of large infected tibial defects with radical debridement and staged double-rib composite free transfer.

Seven patients with tibial fractures complicated by large infected tibial defects were treated with a two-stage protocol. In the first stage, antibiotic-impregnated polymethylmethacrylate (PMMA) bead chains were used to obliterate the debrided osseous defect, and a meshed porcine skin was used for temporary wound coverage. In the second stage, the bead chains were removed, and the defects were reconstructed with a microvascularized double-rib and serratus anterior muscle composite free transfer. The interval between the first and second operations was 2 to 4 weeks. The bone defects ranged from 6 to 9 cm, and the skin defect areas ranged from 20 to 40 cm2. Wound healing and bony union was achieved in all seven cases. Minor pin track infection was seen in one patient. Stress fractures in two cases were successfully managed with patellar tendon short-leg bracing for 6 months in one case and a plate internal fixation in the other case. Within 2 years, all seven patients returned to light work without any external support, and all of their most recent radiographs showed good consolidation and hypertrophy of grafted rib bones. No occurrence of osteomyelitis was observed during an average follow-up of 37 months (out of a range of 24 to 50 months). We conclude that this treatment protocol provides rapid recovery from osteomyelitis and the double-rib graft is a useful, durable alternative for large tibial defect management.

Adult↗

PubMed1996

Staphylococcal pyomyositis.

Pyomyositis, a suppurative infection of the skeletal muscle, is uncommon and frequently misdiagnosed. Staphylococcus aureus has been reported as the most common causative organism in the tropics. The purposes of this study were to examine the clinical courses including presentations, treatments, and final outcomes of Staphylococcal pymyositis in Chang Gung Memorial Hospital and to suggest a treatment modality for this disorder. From July 1985 to June 1994, 12 patients were treated in this hospital for Staphylococcal pyomyositis. There were 9 males and 3 females, whose mean age was 22.1 years. The involved patients were either in the first two or in the fifth to seventh decades of life. Fever was found in all of them. The average time lag in diagnosis was 11.8 days from the onset of minor symptoms. The Gallium-67 scan was very sensitive and valuable in localization of the disease. Debridement or surgical drainage of the abscess was done in 11 patients. All the patients recovered after between 4 and 6 weeks of adequate antibiotic treatment without major abnormalities and complications. In summary, Staphylococcal pyomyositis is a rather benign disease. However, diagnosis is often delayed due to its vague presentation and lack of clinical suspicion. Unfamiliarity with this disease may be an obstacle to appropriate management.

Adolescent↗