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Biomedical subjects

P J Lin

Publications and source records attributed to P J Lin.

At least 55 records · Page 3Linked to original sources
PubMed1998

Totally minimally invasive cardiac surgery for coronary artery disease.

OBJECTIVE: We report our experience using minimally invasive techniques both to perform coronary artery bypass and harvesting of saphenous vein grafts in 25 patients with left main or triple vessels disease. METHODS: From March 1997 to June 1997, 25 patients received elective coronary artery bypass grafting using minimally invasive surgical techniques for left main or triple vessels disease. Saphenous vein grafts were harvested using minimally invasive techniques under direct vision. The coronary artery bypass grafting was performed through a limited left anterior parasternal minithoracotomy under femoro-femoral or aorto-atrial cardiopulmonary bypass. The myocardium was protected by antegrade infusion of cold blood cardioplegic solution while the aorta was cross-clamped. RESULTS: Three to four distal anastomoses were performed with the saphenous vein graft and the left internal thoracic arterial graft. The aortic cross-clamp time was 60-135 min. The duration of cardiopulmonary bypass was 89-172 min. The postoperative course was uneventful for all patients. All patients were found to be in New York Heart Association functional class I or II on follow-up from 3-7 months after surgery. CONCLUSIONS: Minimally invasive coronary artery surgery is technically feasible and can be performed in left main or triple vessel disease safely and effectively for complete revascularization.

Cardiopulmonary Bypass↗
PubMed1998

Minimally invasive cardiac surgery for intracardiac congenital lesions.

OBJECTIVE: Minimally invasive cardiac surgery has recently been applied to the correction of intracardiac lesions. This report reviews our experience of minimally invasive cardiac surgery in 119 patients with intracardiac congenital lesions. METHODS: From October 1995 to April 1997, 119 patients (48 male and 71 female, aged 0.9-65 years old, 18.5+/-17.8) received elective minimally invasive cardiac surgery at Chang Gung Memorial Hospital, Taipei, Taiwan for repair of atrial septal defect (96 patients) or ventricular septal defect (23 patients). The operations were performed through right submammary incision (ASD) or left parasternal minithoracotomy (VSD), under femoro-femoral or femoro-atrial cardiopulmonary bypass with fibrillatory arrest. RESULTS: All of the defects were repaired successfully. The bypass time was 25-125 min (46+/-18). The operation time was 1.5-5.2 h (2.8+/-0.8). The postoperative course was uneventful in all patients. Follow-up (1.0-18.2 months, mean 7.3) was complete, with no late deaths or residual shunt. All patients were found to be in NYHA functional class I or II. CONCLUSION: Our experience demonstrate that minimally invasive cardiac surgery is a technically feasible, safe, and effective procedure in surgical correction of selective simple intracardiac congenital lesions, yielding good short-term results.

Adolescent↗
PubMed1998

Video-assisted cardiac surgery for intracardiac tumors.

OBJECTIVE: To present our experience in surgical excision of intracardiac tumors in three patients using video-assisted cardiac surgical techniques. METHODS: Three patients received emergency video-assisted cardiac surgery for excision of right atrial or left atrial tumors. These surgeries were performed through right anterior submammary minithoracotomies and guided by video-assisted endoscopic techniques by projected images on a video monitor while under femoro-femoral cardiopulmonary bypass. The myocardium was protected by continuous coronary perfusion with fibrillatory arrest. Conventional instruments were used. RESULTS: All but one of the tumors were excised completely. The bypass time was 88-148 min. The operation time was 3.5-4.4 h. There were no operative deaths. Pathological examination of the tumors showed left atrial myxoma, metastatic left atrial choriocarcinoma, and right atrial lymphoma. One patient died from non-cardiac origin 5 weeks after discharge. Follow-up was completed with the two survivors. Transthoracic echocardiographic examination showed good ventricular function without any residual tumors. They were both in New York Heart Association functional class I or II. They were satisfied with the cosmetic healing of their incisions. CONCLUSION: Video-assisted cardiac surgery is technically feasible and can be performed in surgical excision of intracardiac tumors.

Adult↗
PubMed1998

Myosin light chain kinase: functional domains and structural motifs.

Conventional myosin light chain kinase found in differentiated smooth and non-muscle cells is a dedicated Ca2+/calmodulin-dependent protein kinase which phosphorylates the regulatory light chain of myosin II. This phosphorylation increases the actin-activated myosin ATPase activity and is thought to play major roles in a number of biological processes, including smooth muscle contraction. The catalytic domain contains residues on its surface that bind a regulatory segment resulting in autoinhibition through an intrasteric mechanism. When Ca2+/calmodulin binds, there is a marked displacement of the regulatory segment from the catalytic cleft allowing phosphorylation of myosin regulatory light chain. Kinase activity depends upon Ca2+/calmodulin binding not only to the canonical calmodulin-binding sequence but also to additional interactions between Ca2+/calmodulin and the catalytic core. Previous biochemical evidence shows myosin light chain kinase binds tightly to actomyosin containing filaments. The kinase has low-affinity myosin and actin binding sites in Ig-like motifs at the N- and C-terminus, respectively. Recent results show the N-terminus of myosin light chain kinase is responsible for filament binding in vivo. However, the apparent binding affinity is greater for smooth muscle myofilaments, purified thin filaments, or actin-containing filaments in permeable cells than for purified smooth muscle F-actin or actomyosin filaments from skeletal muscle. These results suggest a protein on actin thin filaments that may facilitate kinase binding. Myosin light chain kinase does not dissociate from filaments in the presence of Ca2+/calmodulin raising the interesting question as to how the kinase phosphorylates myosin in thick filaments if it is bound to actin-containing thin filaments.

Animals↗
PubMed1998

Video-assisted cardiac surgery: preliminary results in Chang Gung Memorial Hospital.

OBJECTIVE: To summarize the experience of utilization of video-assisted endoscopy in 91 patients operated on at Chang Gung Memorial Hospital, Taipei, China. METHODS: From October 1995, through August 1996, 91 patients (44 male and 47 female) received video-assisted cardiac surgery (VACS). Their ages ranged from 1 year to 79.5 years (25.7 +/- 21.7). Indications for surgery were atrial septal defect (59 patients), ventricular septal defect (15), coronary artery disease (4), severe mitral regurgitation (4), severe tricuspid regurgitation (3), thrombosis of mitral mechanical prosthesis (3), left atrial tumor (2), and left ventricular thrombus with dilated cardiomyopathy (1). The VACS was performed through right or left anterior minithoracotomy and guided by video-assisted endoscopic techniques by means of projected images on the video monitor under extracorporeal circulation. The aorta was not cross-clamped and the myocardium was protected by continuous coronary perfusion with hypothermic fibrillatory arrest (rectal temperature 22.6 +/- 4.0 degrees C). Conventional instruments were used. RESULTS: All lesions were corrected successfully. The bypass time was 27 to 335 minutes (72.8 +/- 52.7). The operative time was 1.3 to 8.5 hours (3.0 +/- 1.7). There were no operative deaths and 3 late deaths. Follow-up was complete in all survivors (6 to 16 months, mean 8.7). Most of them were found to be in NYHA functional I or II. CONCLUSION: Our preliminary experiences demonstrate that VACS is simple and effective in surgical correction of selected cardiac lesions. Short-term results show good outcomes.

Adolescent↗
PubMed1998

Minimally invasive coronary surgery in women.

OBJECTIVE: To evaluate the minimally invasive surgery in coronary artery bypass grafting and the feasibility for revascularization of triple vessel coronary artery disease. METHODS: Nine female patients, aged 49.1 to 81.6 years (mean 64.3), were operated on for triple vessel disease through minimally invasive surgical techniques. The surgeries were performed through limited left parasternal incision under femorofemoral extracorporeal circulation. The myocardium was protected by antegrade infusion of cold blood cardioplegic solution while the aorta was cross-clamped. Under direct vision, the left saphenous vein grafts were connected sequentially to the diagonal branch, obtuse marginal branch and posterior descending branch, and the left internal thoracic arterial graft was anastomosed to the left anterior descending artery in each patient. RESULTS: The number of distal anastomoses was 3 to 4 with a mean of 3.7. The aortic crossclamp time was 52 to 130 minutes (82 +/- 25 minutes). The duration of extracorporeal circulation was 78 to 151 minutes (115 +/- 29 minutes). The postoperative course was uneventful in all patients. The postoperative length of stay was 4 to 12 days (7.2 +/- 2.0 days). Follow-up (4.2 to 8.7 months, mean 6.4) was complete in all patients and there were no late deaths or angina. Coronary angiography of 2 patients showed patent grafts. All patients were satisfied with the good cosmetic healing of the incision. CONCLUSION: Our experience demonstrates that minimally invasive surgery in coronary artery bypass grafting is technically feasible and may be an alternative approach in surgical revascularization of triple vessel coronary artery disease, especially in female patients.

Aged↗
PubMed1998

Endothelium-dependent relaxation of canine pulmonary artery endothelium after prolonged preservation.

OBJECTIVE: Experiments were designed to investigate the effect of Euro-Collins (EC) solution and University of Wisconsin (UW) solution on function of pulmonary arterial endothelium. METHODS: Third order canine pulmonary artery segments were preserved in cold (4 degrees C) UW (group 1, n = 8) or EC (group 2, n = 9) solutions for 16 hours. The preserved (group 1 and 2) and control (group 3, n = 7) pulmonary arterial segments with and without endothelium were studied in vitro in organ chambers to measure isometric tension. RESULTS: The endothelium-dependent relaxation to acetylcholine and adenosine diphosphate of group 1 and 3 were significantly better than those of group 2. CONCLUSIONS: We concluded that endothelium-dependent relaxation of canine pulmonary arterial endothelium to receptor-dependent acetylcholine and adenosine diphosphate were impaired after preservation with Euro-Collins solution. However, endothelium-dependent relaxation of pulmonary segments were well maintained after preservation with University of Wisconsin solution.

Animals↗
PubMed1997

Minimally invasive approach for coronary artery bypass surgery.

Forty-two patients, 33 male and 9 female, aged 35.7 to 81.6 years old (mean 62.7), were operated on for left main and/or triple vessel coronary artery disease by using minimally invasive cardiac surgical techniques. A myocardial infarction had occurred in 26 patients (61.9%). The left ventricular ejection fraction ranged from 17 to 83% (52+/-22). The surgeries were performed through left parasternal minithoracotomy (8 to 12 cm in length) under femoro-femoral or aorto-atrial cardiopulmonary bypass. The myocardium was protected by blood cardioplegic solution with the aorta crossclamped. Under direct vision, average 3.8 distal anastomoses were performed in each patient, with the saphenous vein grafts and the left internal thoracic arterial graft. The aortic crossclamp time was 62 to 137 min (80+/-15). The duration of cardiopulmonary bypass was 88 to 168 min (115+/-24). The postoperative course was uneventful in all patients. Follow-up (1.0 to 5.6 months, mean 2.9) was complete in all patients and there were no late deaths or angina. Coronary angiography of ten patients showed patent grafts. Our experience demonstrates that minimally invasive cardiac surgery during cardioplegic arrest is technically feasible and can be performed in coronary artery disease safely and effectively for complete revascularization.

Adult↗
PubMed1997

Impaired endothelium-dependent relaxation after cardiac global ischemia and reperfusion: role of warm blood cardioplegia.

OBJECTIVES: Experiments were designed to determine whether coronary endothelial dysfunction after cardiac global ischemia and reperfusion could be prevented by warm blood cardioplegic solution. BACKGROUND: The coronary endothelium produces endothelium-derived relaxing factor (EDRF) to prevent vasospasm and thrombosis. After ischemia and reperfusion, endothelium-dependent relaxation (EDR) is diminished as a result of G-protein dysfunction. METHODS: Dogs were exposed to extracorporeal circulation in 37 degrees C (group 1) or 28 degrees C (groups 2 and 3). The heart was ischemic for 120 min while continuous warm blood cardioplegic solution (group 1) or intermittent cold (4 degrees C) crystalloid cardioplegic solution was not used in group 3 animals. The heart was then allowed to function for 60 min of reperfusion. RESULTS: Endothelium-derived relaxation in response to acetylcholine, adenosine diphosphate and sodium fluoride of the coronary rings of group 1 was significantly different from that of groups 2 and 3 but was not significantly different from that of group 4. In contrast, EDR in response to the receptor-independent calcium ionophore agonist A23187 was not significantly different between the four groups. Scanning electron microscopic studies showed that platelet adhesion and aggregation, area of microthrombi, disruption of endothelial cells and separation of the intercellular junction could be found in coronary segments of groups 2 and 3 but not in vessels of groups 1 and 4. CONCLUSIONS: These experiments suggest that cardiac global ischemia and reperfusion impair receptor-mediated release of EDRF from the coronary endothelium with G-protein dysfunction. This type of coronary endothelial dysfunction can be prevented by continuous anterograde infusion of warm blood cardioplegic solution during global ischemia.

Animals↗
PubMed1997

Impaired endothelium-dependent relaxation of human hepatic arteries after preservation with the University of Wisconsin solution.

OBJECTIVE: To evaluate the effect of University of Wisconsin solution on endothelium-dependent relaxation and contraction of human hepatic arteries in vitro. DESIGN: Human hepatic arteries were harvested from 24 patients with hepatocellular carcinoma who had undergone hepatectomy. SETTING: A tertiary care center. INTERVENTIONS: Human hepatic arteries (n = 6 in each group) were harvested during resection for hepatocellular carcinoma. The arteries in group 1 (i.e., the control group) were immediately studied without preservation. The arteries in group 2 were preserved in cold (4 degrees C) physiological solution for 1 hour, while the arteries in groups 3 and 4 were preserved in University of Wisconsin solution for 1 and 16 hours, respectively. Segments of control and preserved hepatic arteries with or without endothelium were then suspended in organ chambers to measure the isometric force. RESULTS: The relaxation of segments of the hepatic arteries with endothelium in response to acetylcholine and adenosine diphosphate was significantly (P < .05) greater than that of segments without endothelium. The maximal relaxation of hepatic arterial segments with endothelium in groups 3 and 4 in response to acetylcholine was notably different from that of segments in groups 1 and 2. The maximal relaxation of hepatic arterial segments with endothelium in groups 3 and 4 in response to adenosine diphosphate was notably different from that of segments in groups 1 and 2. Perfusate hypoxia (mean +/- SD PO2, 30 +/- 5 mm Hg) caused the endothelium-dependent contraction of the arteries (the median initial tension in groups 1, 2, 3, and 4 was 251%, 233%, 276%, and 260%, respectively; P > .05). CONCLUSIONS: The endothelium-dependent relaxation of human hepatic arteries in response to acetylcholine and adenosine diphosphate was notably attenuated by University of Wisconsin solution. The impaired endothelium-dependent relaxation by University of Wisconsin solution and the prominent endothelium-dependent contraction of human hepatic arteries would favor vasospasm and thrombosis after hepatic transplantation.

Adenosine↗
PubMed1997

Video-assisted thoracoscopic operation for interruption of patent ductus arteriosus in adults.

BACKGROUND: Patent ductus arteriosus (PDA) is a frequent congenital heart disease encountered in premature neonates, infants, and children. Video-assisted endoscopic techniques have been used in PDA interruption since 1993. Almost all the experiences are in pediatric patients. Applications in adults with PDA have been limited. METHODS: We report our experience of video-assisted thoracoscopic surgical ligation of PDA in adults. From August 1995 to January 1996, 60 patients with PDA were operated on with a video-assisted thoracoscopic technique. Twelve adults were identified with mean age of 30 years (range, 20 to 57 years). With the patient under general anesthesia and double-lumen endotracheal intubation, two 5-mm holes were made in the left lateral chest wall. Another 4-cm incision was made in the left third intercostal space for manipulation, dissection, and ligation. Conventional surgical instruments were used except an endoscopic grasper and an endoscopic tube that connected to a video camera. The surgical procedure was viewed on a video screen. Transesophageal echocardiography was used for monitoring during PDA ligation. RESULTS: All patients had successful ligation of the PDA. There was no surgical mortality, but there was one morbidity; transient recurrent nerve injury, which recovered 3 months later. Ten patients were extubated in operative room and 2 patients were extubated 2 hours after the operation. Tube thoracostomy was performed in the first 2 cases; it was omitted thereafter. No patients needed narcotic to control chest pain. Postoperative follow-up by echocardiography showed faint ductal flow in 1 patient without any murmur. All patients were discharged within 3 days after the operation. CONCLUSIONS: Our experience suggests that with refinement of instruments and surgical technique, video-assisted thoracoscopic surgical ligation can be safely applied not only in pediatric patients, but also in adults with PDA.

Adult↗
PubMed1997

Video-assisted coronary artery bypass grafting during hypothermic fibrillatory arrest.

BACKGROUND: Hypothermic fibrillatory arrest without aortic cross-clamping is a technique for quieting the heart during coronary artery bypass grafting. This report reviews the preliminary results with this technique in 4 patients having video-assisted coronary artery bypass grafting. METHODS: Four male patients 28.5 to 64.5 years old (mean age, 45.4 years) underwent operation for unstable angina. With video-assisted techniques, coronary artery bypass grafting was performed through a left anterior minithoracotomy with femoral-femoral cardiopulmonary bypass without cross-clamping the aorta. The myocardium was protected by continuous coronary perfusion during hypothermic fibrillatory arrest. RESULTS: A left internal thoracic artery graft was anastomosed to the left anterior descending coronary artery in each patient. The posterior descending branch of the right coronary artery was grafted with a pedicled right gastroepiploic artery in 1 patient. The duration of cardiopulmonary bypass was 72 to 127 minutes (mean duration, 92 +/- 21 minutes). The postoperative course of each patient was uneventful. Follow-up (range, 3.9 to 5.8 months; mean follow-up, 4.9 months) was complete for all patients. There were no late deaths. Coronary angiography showed patent grafts. All patients were in New York Heart Association functional class I or II (mean class, 1.25). CONCLUSIONS: Hypothermic fibrillatory arrest is a simple and effective method of quieting the heart, thereby providing a motionless operative field for video-assisted coronary artery bypass grafting.

Adult↗
PubMed1997

Continuous antegrade warm blood cardioplegia attenuates augmented coronary endothelium-dependent contraction after cardiac global ischemia and reperfusion.

BACKGROUND: Experiments were designed to evaluate the effect of warm blood cardioplegia on endothelium-dependent contraction of the coronary endothelium after cardiac global ischemia and reperfusion. METHOD: Dogs (n = 12 in each group) were exposed to extracorporeal circulation with the body temperature at 37 degrees C (group 1) or 28 degrees C (groups 2 and 3). The ascending aorta was crossclamped for 120 minutes while continuous infusion of warm blood cardioplegec solution (group 1) or intermittent infusion of cold (4 degrees C) crystalloid cardioplegic solution (group 2) was performed via the coronary arteries through the aortic root. Cardioplegic solution was not used in group 3 animals. The heart was then allowed to function for 60 minutes of reperfusion. Reperfused (groups 1, 2, and 3) and control (group 4) coronary arteries were then harvested for study. RESULTS: Perfusate hypoxia caused endothelium-dependent contraction in the arteries of all four groups that could be attenuated by NG-monomethyl-L-arginine (L-NMMA) or L-NMMA plus D-arginine, but not by L-NMMA plus L-arginine or endothelin receptor A and B antagonist PD 145065. The endothelium-dependent contraction results in groups 2 and 3 (75% +/- 4% and 80% +/- 5%, respectively) were significantly greater than those in groups 1 and 4 (15% +/- 3% and 18% +/- 5%, respectively). Scanning electron microscope studies showed that platelet adhesion and aggregation, areas of microthrombi, disruption of endothelial cells, and separation of the intercellular junction could be found in coronary segments from groups 2 and 3, but not in vessels from groups 1 and 4. CONCLUSION: These experiments suggest that global ischemia and reperfusion enhances hypoxia-mediated endothelium-dependent contraction of the coronary endothelium and damages the ultrastructure. These kinds of changes can be prevented by continuous antegrade infusion of warm blood cardioplegic solution during global ischemia.

Animals↗
PubMed1997

Thoracoscopic loop ligation of parenchymal blebs and bullae: is it effective and safe?

Surgeons who have gained experience and confidence with video-assisted thoracic surgery are now routinely applying the minimally invasive approach to treat patients with spontaneous pneumothorax. Although the endoscopic stapling device may be a preferred method for resection of parenchymal blebs or bullae, the stapling device is not inexpensive. In an effort to contain costs since we started performing the video-assisted thoracoscopic procedure in chest surgical diseases, we have used a self-made endoscopic loop as an alternative method. It has assisted us in performing bulla ablation in a cost-effective manner. Over a 4-year period (1992 to 1996), we assessed the efficacy of ligating parenchymal blebs and bullae with a self-made endoscopic loop by video-assisted techniques. A total of 263 ligations were performed in 250 patients. Surgical indications included recurrence (n = 146), bilaterality of the disease (n = 13), hemopneumothorax (n = 7), radiologically demonstrated large bulla (n = 9), persistent air leak (n = 52), and nonexpansion of the lung (n = 23). There were no operative deaths. Early postoperative complications included a dislodged endoscopic loop necessitating reexploration in one patient and postoperative minor wound infections in 13. The average postoperative hospitalization was 4.5 days. Two hundred seventeen patients (86.8% of all patients) were followed up for a median of 28 months (1 to 46 months) after the operation. There have been no recurrences to date. Our results showed that thoracoscopic loop ligation is safe and effective in managing blebs and parenchymal bullae, with a lower cost, fewer complications, and a lower recurrence rate than provided by standard surgical techniques. On the basis of our results, we advocate the use of the self-made endoscopic loop for ligation of parenchymal blebs and bulla in patients with spontaneous pneumothorax to achieve a truly cost-effective and minimally invasive thoracoscopic procedure.

Adolescent↗
PubMed1997

Isolated common iliac artery occlusion secondary to atherosclerotic plaque rupture from blunt abdominal trauma: case report and review of the literature.

Traumatic isolated common iliac artery occlusion is unusual. Only rare cases of common iliac arterial injuries resulting from blunt abdominal trauma have been reported, and most of them were attributed to the seat-belt syndrome and associated with visceral organ perforation or pelvic fracture. We reported an unusual isolated common iliac artery occlusion secondary to atherosclerotic plaque rupture from blunt abdominal compressive trauma without other visceral injury. This case presented with acute limb ischemia and paralysis that was successfully treated by thromboendarterectomy. The symptoms and signs, surgical modalities, and associated injuries were reported and the literature was also reviewed.

Arterial Occlusive Diseases↗
PubMed1997

Video-assisted thoracic surgery in treatment of chest trauma.

Although the indications for video-assisted thoracic surgery (VATS) have expanded rapidly, especially in the areas of therapeutic and operative procedures, its role in the definite surgical treatment of chest trauma is not clear. From July 1994 to December 1995, 56 patients with hemothorax or posthemothorax complications resulting from chest trauma received thoracic surgery. Their ages ranged from 17 to 71 years. Mechanisms of injury included penetrating (n = 23) and blunt injury (n = 33). VATS was successfully applied in 50 patients; six patients with cardiovascular injuries (n = 4) or minor chest wall lacerations (n = 2) did not receive VATS. All patients who received VATS survived, with no morbidity. Twelve of the 50 patients treated with VATS would have otherwise had to undergo thoracotomy. Our results indicate that VATS can be safely used in hemodynamically stable patients with no cardiovascular or great vessel injury, sparing many patients the pain and morbidity associated with thoracotomy. Additionally, use of VATS may reduce the likelihood of posthemothorax complications by allowing early direct inspection of the chest wall, because VATS has a lower associated risk and can be performed with a lower index of suspicion than can standard thoracotomy.

Adolescent↗