Search PubMed⌕ Search

Biomedical subjects

P J Lin

Publications and source records attributed to P J Lin.

At least 91 records · Page 5Linked to original sources
PubMed1995

Application of thoracoscopy for lung metastases.

Lung nodules in patients with a history of malignancy usually require tissue diagnosis that will provide prognostic information and dictate further therapy. Patients with a favorable tumor histologic condition and limited tumor burden were often considered for resection. This is usually accomplished by wedge resection through open thoracotomy when the lesions were peripheral. However, complications related to open thoracotomy often exclude poor-risk patients, especially those with impaired pulmonary function. Currently, technique of thoracoscopic resection is opening up new vistas and unimagined options for the thoracic surgeon in the management of pulmonary diseases. With the application of thoracoscopy and small incisions, it is now possible for the thoracic cavity and its contained organs to be thoroughly explored. Our recent experience with the thoracoscopic resection as a primary treatment for lung metastases is the focus of this report. Forty-seven patients with a history of malignancy and new lung metastases underwent this type of resection. Postoperatively, there is less pain, quick functional recovery, and excellent cosmetic healing. It is a safe and promising approach.

Female↗
PubMed1995

Thoracoscopic surgery as a routine procedure for spontaneous pneumothorax. Results from 82 patients.

A total of 82 consecutive patients with recurrent or persistent spontaneous pneumothorax were considered for thoracoscopic blebectomy or bullectomy and pleurodesis. The median age was 47 years, and 70% were men. All the patients were successfully treated using a video-assisted thoracoscopic technique. There were no deaths attributable to the procedure. Complications occurred in 6 patients (7.3%). Three patients (4%) with diffuse bullous lung disease had prolonged intubation (9, 11, and 12 days, respectively). Persistent air leaks lasting from 10 to 14 days occurred in 2 patients (3%). One patient had an endoloop slip from the lung parenchyma after a forceful sneeze 2 days after the operation. Air leak subsided after the second operation using a conventional suturing technique. Blebs or bullae were present in 69 patients (83%). These were ablated by endoscopic stapling (37 patients) and through thoracoscopic ligation using an endoloop technique (32 patients). In this group of patients, the median postoperative hospital stay was 5 days. Thirteen patients with air leaks and diffuse bullous lung disease received only talc insufflation thoracoscopically. All of them showed good lung expansion after the operation. There are no recurrences, with a mean follow-up of 22 months. These results suggest that thoracoscopic ablation of blebs or bullae and pleurodesis may be applicable to patients with spontaneous pneumothorax who require surgical intervention.

Adolescent↗
PubMed1995

Thoracoscopic-assisted lobectomy. Preliminary experience and results.

A preliminary report is made on the use of videothoracoscopy to achieve pulmonary lobectomy in 16 patients, including 12 with centrally located pulmonary metastases and 4 with benign lesions (3 bronchiectases and 1 endobronchial hamartoma). Videothoracoscopy was performed on eight right-lower lobes, one middle lobe, two right-upper lobes, four left-lower lobes, and one left-upper lobe with a thoracoscope and conventional thoracic instruments. All patients received standard pulmonary lobe resection with lymph node clearance similar to that achieved with open thoracotomy. The mean operative time was 3 h (range, 2.5 to 4 h). Average blood loss was 100 mL and mean length of hospital stay was 6 days (range, 4 to 8 days). A combination of videothoracoscopy with use of conventional instruments resulted in similar performance but less chest wall interruption than in conventional pulmonary lobectomy. Videothoracoscopy showed safer and faster lung resection, which subsequently minimized the perioperative morbidity. Pain intensity was lessened, functional recovery was quicker, and hospital stays were shorter in the patients we reviewed.

Adult↗
PubMed1995

Aortic dissection in Taiwan.

We retrospectively reviewed all patients with a final diagnosis of spontaneous thoracic aortic dissection treated at Linkou Chang Gung Memorial Hospital between January 1989 and December 1994. There were a total of 109 patients with a mean age of 55 +/- 11 years ranging from 19 to 88 years. The male-to-female ratio was 2 to 1 (73 to 36). There was a predilection to present during the colder months, with 69% seen between September 1 and February 28 and only 31% during the warmer half of the year. In most patients, hypertension (85%) was the major predisposing factor with another 7% having Marfan syndrome. The remaining 8% had no obvious underlying disease except for one patient who had an atrial septum defect. Presenting chief complaints in order of frequency included: anterior chest pain 58.7% (64/109), back pain 19.2% (21/109), abdominal pain 10.1% (11/109), consciousness change 3.7% (4/109), neck pain 2.7% (3/109), paraparesis 2.7% (3/109), dyspnea 1.8% (2/109), and hemoptysis 0.9% (1/109). The diagnostic breakdown revealed 46% to be type A (50/109) and 54% type B (59/109). A total of 26 (24%) patients died in hospital (16% were type A and 8% were type B). (Type A included all proximal dissections and those distal dissections that extend retrograde to involve the arch and ascending aorta; Type B refers to the other distal dissections without proximal extension; proposed by Daily et al.) Thoracic aortic dissection remains an important concern in patients with a history of hypertension. Patients seem particularly susceptible during cold weather months. The average age of our patients was only 55 years and 24% of them died during hospitalization. Earlier identification and more aggressive antihypertensive treatment is required.

Adult↗
PubMed1994

Enhancement of endothelium-dependent contraction of the canine coronary artery by UW solution.

University of Wisconsin (UW) solution has been used almost routinely in the preservation of the hepatic, pancreatic, renal, and cardiac allografts. However, its effect on vascular endothelium is unknown. Experiments were designed to evaluate its effect on canine coronary endothelium. Canine coronary arteries (n = 8 in each group) were preserved in cold (4 degrees C) UW solution (group 1) and physiological solution (group 2) for 6 hr immediately after harvesting. Segments of preserved and control (group 3) coronary arteries with or without endothelium were then suspended in organ chambers to measure isometric force. Perfusate hypoxia (pO2 30 +/- 5 mmHg) caused endothelium-dependent contraction in the arteries of all 3 groups. However, vascular segments with endothelium of group 1 exhibited hypoxic contractions (107 +/- 26% of the initial tension contracted by prostaglandin F2 alpha 2 x 10(-6) mol/L, P < 0.05) that were significantly greater than those of the group 2 and group 3 segments with endothelium (25 +/- 5% and 20 +/- 4%). The hypoxic contraction in arteries of group 1 could be attenuated by NG-monomethyl-L-arginine (L-NMMA), the blocker of endothelial cell synthesis of the nitric oxide from L-arginine. The action of L-NMMA could be reversed by L-arginine but not D-arginine. Endothelium-dependent relaxation of coronary endothelium to acetylcholine and adenosine diphosphate and endothelium-independent relaxation and contraction of coronary smooth muscle were not altered by the UW solution. After preservation with the UW solution, endothelium-dependent contraction of the canine coronary arteries, occurs by L-arginine-dependent pathway, is enhanced. This augmentation by the UW solution would favor vasospasm after transplantation.

Acetylcholine↗
PubMed1994

Treatment of acute type A aortic dissection with intraluminal sutureless prosthesis.

Sutureless intraluminal aortic graft has been used for substitution of aorta, with the advantages of decreasing the aortic cross-clamp time and decreased blood loss. From January 1991 to December 1992, 10 consecutive patients underwent emergency operations to repair acute type A aortic dissection in which sutureless intraluminal grafts were used for replacement of ascending aorta. There were 5 men and 5 women, with ages that ranged from 40 to 74 years (mean, 51 years). The inclusion method was used in all patients. Modified Cabrol shunts were created in 7 patients. Dacron graft (Meadox Medicals, Inc, Oakland, NJ) was used to wrap the ascending aorta in 7 patients. The circulatory arrest time was 33 +/- 13 (mean +/- standard deviation) minutes, and the cardiac ischemic time was 64 +/- 17 minutes. Retrograde superior vena cava cerebral perfusion during circulatory arrest was performed on 4 patients. All patients survived. One patient had a minor stroke and pneumonia with complete recovery. There was no evidence of pseudoaneurysm formation, graft erosion, graft migration, or aortic bleeding in the postoperative period. No patients had permanent renal deficit. Follow-up (1 to 22 months; mean, 9.6 months) of all patients revealed satisfactory graft function, with no device-related deaths and no known complications attributable to the prosthesis, such as thrombosis, erosion, pseudoaneurysm formation, or hemorrhage. Our experience suggests that grafting of the ascending aorta is less hazardous with the sutureless grafts than with the conventional sutured anastomosis technique. We are now using this method whenever possible in all substitutions of the aorta.

Acute Disease↗
PubMed1994

Long-term results of polytetrafluoroethylene mitral annuloplasty.

Prosthetic rings are customarily used for mitral annuloplasty to plicate and reinforce the annulus and keep the annulus from further dilating. From July 1984 to March 1992, mitral annular plication using polytetrafluoroethylene (PTFE) graft material was performed on 73 patients (age range, 15 to 69 years; mean, 35.7 years) with mitral regurgitation. The cause of the mitral regurgitation was rheumatic in 50.7% and degenerative in 36.9% of the patients. After other repair procedures on the mitral valve apparatus had been performed, a PTFE graft (3 mm) was tailored to the length of the free edge of the anterior leaflet and then inserted at the posterior part of the mitral annulus between the commissures. The operative mortality was 2.7%. Follow-up ranged from 0.7 to 8.5 years (mean, 5.6 years). Postoperative echocardiography confirmed that 94.2% of the survivors had either no or only mild mitral regurgitation with a large mitral valve area (2.7 +/- 0.3 cm2) and almost no pressure gradient across the mitral valve or left ventricular outflow tract. Two patients successfully underwent redo PTFE mitral annuloplasty. Two patients died, one 15 and the other 20 months later, due to myocardial failure, with no mitral regurgitation. The event-free survival rate was 90% +/- 4% at 8 years. We conclude that PTFE mitral annuloplasty is an effective procedure that yields good long-term results.

Adolescent↗
PubMed1994

Acute endothelial reperfusion injury after coronary artery bypass grafting.

Coronary artery endothelium exhibits functional impairment after ischemia and reperfusion. Canine left anterior descending coronary arteries were exposed to ischemia (60 minutes) followed by reperfusion (60 minutes) through a left internal mammary artery graft. In organ chamber experiments, control (left circumflex coronary artery) and reperfused (left anterior descending coronary artery) arterial segments were contracted with prostaglandin F2 alpha and exposed to hypoxia (oxygen tension = 35 +/- 5 mm Hg). Reperfused coronary rings with endothelium exhibited contractions to hypoxia that were significantly greater than contractions in control rings with endothelium (+78% +/- 8% and +14% +/- 5%, respectively; p < 0.05). This phenomenon could be blocked by NG-monomethyl-L-arginine. Electron microscopic studies showed platelet adhesion and aggregation, denudation of the endothelium and disruption of the intercellular junctions, edematous subendothelial matrix, and vesiculation of the smooth muscle cells in reperfused LAD. Swelling, vacuole formation, and loss of neurofilament occurred in the nerve fibers accompanying the vessels. These phenomena were not observed in control vessels. This study demonstrates that early after coronary artery bypass grafting, hypoxia can induce coronary vasospasm mediated by an L-arginine-dependent metabolic pathway in the endothelium. The ultrastructural changes in the coronary endothelium include platelet adhesion, aggregation, and platelet-induced contraction of coronary smooth muscle. The endothelium-dependent hypoxic coronary vasospasm and ultrastructural changes in the coronary endothelium may play an important role in the pathogenesis of myocardial ischemia and infarction after coronary artery bypass grafting.

Acute Disease↗
PubMed1994

Thoracoscopic management of effusive pericardial disease: indications and technique.

Video-assisted thoracoscopic technique was evaluated in 28 patients who underwent operation for massive pericardial effusion. Excellent results were obtained using this newly developed approach for inspection of all pericardial surfaces as well as pleural and pulmonary disorders. No perioperative or postoperative complications ensued. Videothoracoscopy revealed positive lung malignancies in 11 patients, and these would not have been promptly diagnosed without thoracoscopy. Thoracoscopy also confirmed metastatic deposits on the pleura and diaphragm in 4 other patients. The visible nodules were proved to be metastatic adenocarcinoma. In 13 patients, thoracoscopy did not reveal malignancy, although 2 of these patients had a clinically suspected malignant lung tumor. Other indications for thoracoscopic drainage included 2 patients with impending pericardial tamponade after heart procedures and 6 patients with recurrent/loculated pericardial effusion. All of the patients showed promising and favorable postoperative courses after thoracoscopy. From our experience, video-assisted thoracoscopy was a safe and effective procedure, especially for those patients with combined pericardial effusion and abnormal pulmonary or pleural pathology in whom subxiphoid pericardial window was not clearly diagnostic at the time of operation. It was effective also in the situation with recurrent or loculated pericardial effusion which allowed localization and drainage of it. We believe that the use of videothoracoscopy to visualize the whole pericardial and pleural cavity will continue to be of great benefit to patients with combined pericardial and pleural/lung diseases.

Adenocarcinoma↗
PubMed1994

University of Wisconsin solution extends lung preservation after prostaglandin E1 infusion.

University of Wisconsin (UW) solution has been demonstrated to enhance and extend the preservation of the hepatic, pancreatic, renal, and cardiac allografts. Prostaglandin E1 (PGE1), which has been used to produce pulmonary vasodilatation, has improved preservation in lung transplantation. Experiments were designed to evaluate their potential role in 24-h preservation of the allografts in lung transplantation. Thirty-six dogs underwent left lung transplantation. The donor lungs (n = 6 in each group) were flushed with UW solution (group 1 and 2) or modified Euro-Collins (EC) solution (group 3) after PGE1 infusion (500 micrograms). In group 1, donor lungs were transplanted immediately. Lung allografts of group 2 and 3 were cold stored (4 degrees C) in the same preservation solution for 24 h in the inflated state and then transplanted. The right pulmonary artery and right main bronchus were ligated 1 h after completion of the transplantation, forcing the recipient dogs to survive with the transplanted left lung. The recipients were ventilated with an inspired oxygen fraction of 0.4 and end-expiratory pressure 10 cm H2O. Two dogs died prematurely in group 3, whereas all dogs in group 1 and 2 survived the experimental period. The arterial oxygen tension and saturation and dynamic lung compliance were significantly higher in dogs of group 1 and 2. Transplanted lungs of group 1 and 2 had significantly lower pulmonary vascular resistance, alveolar-arterial oxygen difference, and wet/dry lung weight ratio. Histologically, pulmonary edema, congestion, sloughing of bronchial mucosa, and peribronchial and peripulmonary arterial hemorrhage were shown in lungs of group 3, but not in those of group 1 and 2. Airway mucosa and pulmonary vascular structure were well preserved in lungs of group 1 and 2. There was no significant difference between group 1 and 2 in lung functions, hemodynamics, or morphologic features. We concluded that PGE1 and UW solution could effectively extend lung preservation up to 24 h in this in vivo canine lung allotransplantation model.

Adenosine↗
PubMed1994

Reversal of refractory hypotension in septic shock by inhibitor of nitric oxide synthase.

Septic shock is a life-threatening condition that results from exposure to bacterial endotoxin. It is mediated by the release of cytokines. Some of these cytokines cause the release of vasoactive substances. We report the case of a 62-year-old male patient who received redo operation for replacement of the degenerative porcine aortic and mitral prostheses. High cardiac output shock developed on the seventh postoperative day with severe metabolic acidosis and oliguria. Systemic vascular resistance and mean arterial pressure elevated within 5 min and stabilized 60 min after the start of a single dose of intravenous administration of NG-monomethyl-L-arginine (50 mg), a potent and selective inhibitor of nitric oxide synthesis. These findings indicate that nitric oxide overproduction is an important contributor to refractory hypotension in high cardiac output septic shock. Our findings suggested the utilization of nitric oxide synthase inhibitor in the treatment of septic shock in humans.

Amino Acid Oxidoreductases↗
PubMed1994

Expression of multiple oncogenes in human esophageal carcinomas.

To study the oncogenesis of human esophageal carcinoma, the expression of a variety of oncogenes was studied in 10 esophageal carcinoma cell lines and 16 pairs of tumor and nontumor tissues removed from patients with esophageal carcinoma. Northern blot analyses using 11 different oncogene probes revealed that 5 oncogenes, i.e. c-myc, c-H-ras, c-sis, c-raf, and c-fos, were expressed. Among them, a variant c-sis mRNA transcript of 2.7 kilobase (kb) was expressed in 7 of 10 cell lines and in 9 of 16 tumor tissues. Furthermore, an overexpression and an amplification of c-myc gene was observed in some cell lines. These results suggest that multiple oncogene expression may be required for the induction, maintenance, and progression of esophageal carcinoma. The expression of a 2.7-kb transcript, of c-sis and overexpression of c-myc gene may play some role in the carcinogenesis of esophageal carcinoma.

Carcinoma, Squamous Cell↗
PubMed1994

Surgical treatment of acute type A aortic dissection with an intraluminal sutureless graft.

The surgical treatment of acute type A aortic dissection remains a great challenge to all cardiac surgeons. From January 1991 to June 1993, 21 consecutive patients (13 men and eight women, aged 34 to 74 years) underwent emergency operations to repair acute type A aortic dissection, with the aid of hypothermic circulatory arrest. The intima tear was located in the ascending aorta in 13 patients, in the aortic arch in five patients, and in the descending aorta in three patients. The dissected ascending aorta was replaced with sutureless, intraluminal vascular grafts in all 21 patients. The intima tears in the aortic arch of five patients were primarily repaired. Modified Cabrol's shunts were created in seven patients for hemostasis, and Dacron grafts were used to wrap the ascending aorta in 18 patients. Retrograde cerebral perfusion during circulatory arrest was performed on 15 patients. The circulatory arrest time was 37 +/- 10 minutes (mean +/- SD). All patients survived the operation and regained consciousness in the early postoperative period without neurologic deficit. Post-treatment follow-ups (mean, 18.2 months) were completed in all patients except one, who died 12 months after the operation as a result of a traffic accident. All of the surviving patients are doing well without any further aortic operations. Our experience suggests that surgical repair of the acute type A aortic dissection can be a simple and safe procedure if sutureless intraluminal grafts are used and hypothermic circulatory arrest and retrograde cerebral perfusion are utilized.

Acute Disease↗
PubMed1994

Endothelium dysfunction in cardiovascular diseases.

During the past 10 years, it has become obvious that endothelium regulates vasomotion, modulates hemostasis, influences vascular permeability, and controls blood vessel growth. The role of endothelium in modulating vasomotor tone is mediated by the releasing of a number of potent vasoactive compounds, including endothelium-derived relaxing factors (one of which is either nitric oxide or a compound that releases nitric oxide), vasoactive prostaglandins, endothelium-derived hyperpolarizing factor, and a number of constricting factors (such as thromboxane A2, endothelin, superoxide anion, L-arginine-dependent products etc.). This role of the endothelium is dramatically changed by several disease processes, including diabetes mellitus, cerebrovascular disease, and so on. Abnormalities of endothelial regulation of vascular tone may contribute to a number of clinical syndromes, including atherosclerosis, hypertension, septic shock syndrome, and many others. Endothelium dysfunction, characterized by altered synthesis or release of these relaxing factors along with maintained or facilitated synthesis or release of contracting factors, can lead to various pathological conditions such as thrombosis, vasospasm, and hypertension. Better understanding of the exact nature of endothelial dysfunction, including the role played by endothelium-derived vasoactive factors, may provide a basis for novel therapies in these vasculopathies.

Cardiovascular Diseases↗
PubMed1994

Video-assisted thoracic surgery. The Chang Gung experience.

Thoracoscopy has assumed a major role in the management of a variety of surgical diseases of the chest. This technique, which was primarily devised for diagnostic purposes, has subsequently come to be used for therapeutic applications in most centers today. In this report we review 300 cases of therapeutic thoracic procedures in which a video-assisted technique was used. We describe mainly our own experience and the basic approach strategies we found helpful in the video-assisted procedures. No complications or deaths were attributable to these procedures. Our conclusions were as follows: (1) Video-assisted thoracic surgery can be as effective therapeutically as many formal thoracotomy. (2) Excellent exposure can be obtained by the use of double-lumen endotracheal tubes. (3) Video-assisted thoracic surgery is an excellent alternative treatment for pneumothorax, blebs, and bullous disease. (4) Video-assisted thoracic surgery allows safe, complete, visually guided wedge resection of lung lesions, lobectomy, pericardiectomy, removal of mediastinal tumor, esophagectomy, and reconstruction of the thoracic esophagus. (5) Video-assisted thoracic surgery also allows management of a broad scope of other general thoracic diseases such as empyema, pleural effusion, and chest trauma (hemothorax), as well as cancer staging. (6) Video-assisted thoracic surgery will not compromise the primary diagnostic and therapeutic goals set forth for the patient. (7) Because conventional instruments and extended manipulation incisions can be used, video-assisted thoracic surgery offers the promise of expediency, safety, minimal discomfort, less postoperative pain, quick functional recuperation, excellent cosmetic healing, shortened stays in the hospital, and therefore savings in cost. Accordingly, we are now using video-assisted thoracic surgery to treat the majority of patients with surgical diseases of the chest.

Adolescent↗
PubMed1994

Protection of the brain by retrograde cerebral perfusion during circulatory arrest.

Hypothermic circulatory arrest is commonly used to facilitate repair of complex congenital heart defects and aortic lesions and for complex neurosurgical procedures. However, extended periods of circulatory arrest may impair cerebral metabolism and cause ischemic injury. Retrograde cerebral perfusion has been applied recently in aortic surgery to protect the brain. From January 1991 to December 1993, 29 patients underwent emergency operations to repair acute type A aortic dissection with the aid of hypothermic circulatory arrest. Six patients received hypothermic circulatory arrest without retrograde cerebral perfusion with a rectal temperature of 16.4 degrees +/- 0.9 degrees C (mean +/- standard error of the mean, group 1). Retrograde cerebral perfusion during hypothermic circulatory arrest was performed in 15 patients with a rectal temperature of 15.9 degrees +/- 0.5 degrees C (group 2) and in eight patients with a rectal temperature of 21.7 degrees +/- 0.8 degrees C (group 3). The hypothermic circulatory arrest times were 25 +/- 4, 42 +/- 4, and 63 +/- 6 minutes, respectively (p < 0.05). The cardiopulmonary bypass times were 173 +/- 5, 184 +/- 7, and 143 +/- 6 minutes, respectively (p < 0.05). All patients survived the operation and regained consciousness with no neurologic defects. Follow-up (mean 23.2, 14.5, and 5.1 months, respectively) was complete in all patients except one. This patient, from group 2, was killed in a road traffic accident 12 months after the operation. Our experience suggests that retrograde cerebral perfusion can effectively protect the brain from ischemic injury and extend the safe period of hypothermic circulatory arrest. With the aid of retrograde cerebral perfusion, prolonged circulatory arrest can probably be performed safely with moderate hypothermia.

Adult↗