Biomedical subjects
Publications and source records attributed to J LoCicero.
Removal of a normal appearing thymus gland may be necessary, particularly in patients with myasthenia gravis. Complete removal is a basic tenet of this type of operation. A combined cervical and upper sternotomy incision is described. This is appropriate for thymectomy in such patients because of the minimal morbidity and excellent exposure for the thoracic portion of the thymus gland.
BACKGROUND: This study was designed to evaluate the clinical accuracy of multiplanar reconstructions and three-dimensional shaded surface displays compared with conventional transaxial computed tomography, bronchoscopy, and surgical pathologic findings. METHODS: Transaxial computed tomographic images, two-dimensional nonstandard multiplanar reconstruction images, and three-dimensional images obtained from patients with tracheobronchial disease were prospectively evaluated for the relationship to adjacent structures, lesion characterization, and surgical anatomic correlation before invasive procedures. RESULTS: Compared with conventional transaxial computed tomographic images, multiplanar reconstructions and three-dimensional shaded surface displays provided a correlative map of bronchoscopic and surgical anatomy in patients with benign and malignant tracheobronchial pathology. The longitudinal extent of abnormalities are better demonstrated on the multiplanar reconstruction and three-dimensional images, whereas the transverse extent of disease and relationships to adjacent structures were better shown on axial computed tomographic sections. CONCLUSIONS: Three-dimensional and multiplanar two-dimensional images are additive to transaxial computed tomography for evaluation of diseases involving the central airways. They are beneficial for planning invasive procedures. More importantly, they provide consistent, highly accurate measurements for routine follow-up and for future clinical trials.
BACKGROUND: We examined the effects of in vivo administration of a potent inhibitor of iron-dependent lipid peroxidation, lazaroid U74389G, on lung preservation. METHODS: Lungs isolated from Sprague-Dawley rats (n = 23) were either immediately reperfused after removal (control, n = 8) for 2 hours by means of an isolated, pulsatile blood perfusion system or reperfused after cold storage (4 degrees C) for 24 hours in the University of Wisconsin solution with (n = 7) or without (n = 8) lazaroid. The lazaroid group had in vivo infusion of lazaroid U74389G (6 mg/kg) before lung harvest plus addition to the perfusate (50 mu mol/L) at the onset of reperfusion. Routine aerodynamics, hemodynamics, and blood gases were assessed during the perfusion period. Lipid peroxidation in the lung tissue was assayed with the thiobarbituric acid-reactive product, malondialdehyde. Histologic evaluation was performed with light microscopic and transmission electron microscopic analyses. RESULTS: All lungs in the University of Wisconsin solution group (24-hour storage without lazaroid) failed within 1 hour of reperfusion. Lungs in control and University of Wisconsin solution + lazaroid group survived the 2-hour perfusion period. University of Wisconsin solution + lazaroid group showed significantly better arterial oxygen tension values relative to those in the University of Wisconsin solution group (control, 85.2 +/- 1.9; University of Wisconsin solution, 53.9 +/- 3.2 [p < 0.05 versus control group and University of Wisconsin solution + lazaroid]; University of Wisconsin solution + lazaroid, 74.8 +/- 1.4; arterial oxygen tension (mm Hg) at 30 minutes). Lipid peroxide in University of Wisconsin solution + lazaroid group was significantly lower than that of the University of Wisconsin solution group (65.0 +/- 5.0 versus 495 +/- 105 nmol malondialdehyde/gm wet lung tissue; p < 0.01). Transmission electron microscopic analysis showed that University of Wisconsin solution + lazaroid group significantly attenuated lung damage when compared with University of Wisconsin solution group. CONCLUSION: Administration of lazaroids in vivo before organ harvest and in situ at the onset of the reperfusion enhances lung preservation in this model.
Pulmonary actinomycosis is a rare disease. Of 2,247 patients presenting with a radiological pulmonary opacity, 13 (0.6%) were identified with pulmonary actinomycosis in a 13 year period. Twelve of the 13 patients underwent thoracotomy and one had clinical diagnosis and subsequent medical treatment alone. Neither mortality nor major complications were observed. One patient had recurrent disease after surgery. The other surgical patients are well and free from disease at a minimum 6 month follow-up. Diagnosis of actinomycosis is frequently difficult because it often infects pre-existing cavitary disease in the lung. As a consequence, the infection may progress to stages which will not respond to medical treatment alone. Surgery then provides the best method to achieve diagnosis and ultimate treatment.
Vasoactive intestinal peptide (VIP) is a known pulmonary and bronchial vasodilator as well as an oxygen free radical scavenger. Since its effect as an additive to University of Wisconsin (UW) solution for lung preservation has been shown previously, the aim of this study was to determine the ability of VIP to improve lung preservation followed by reperfusion. Four groups of excised Sprague-Dawley rat lungs (n = 24) were studied using an isolated blood perfused working lung model. The first 3 groups of lungs were flushed and stored in UW solution at 4 degrees C for: (1) 4 hr, (2) 18 hr, and (3) 24 hr. Group 4 lungs were flushed with UW solution + VIP (1 microgram/ml) and stored in UW solution + VIP (0.5 microgram/ml) for 24 hr. After preservation, the lungs were reperfused to evaluate their functions for 2 hr or until lung failure occurred (arterial oxygen saturation less than 90% and/or appearance of bronchial fluid in the bronchial cannula). In the lungs stored in UW solution for 24 hr, failure occurred after 10 min of reperfusion and all functions were significantly altered. The addition of VIP to UW solution maintained the functional capacity of the lungs, recorded by lung resistance, lung compliance, elastic work, flow resistive work, shunt fraction, and blood oxygen tension. No statistical difference in these parameters other than shunt fraction was found when the VIP group was compared with the group preserved for 4 hr in UW solution. We conclude that lung preservation can be extended to 24 hr with the maintenance of lung functional capacity if VIP is added to UW solution.
BACKGROUND: Discrepancy between clinical and research works in lung transplantation could be due to differences between compromised clinical donor lungs and intact research lungs. The purpose of this laboratory study was to produce compromised lungs to compare with normal ones. METHODS: Sprague-Dawley rats were continuously infused with lipopolysaccharide (5 mg/kg) for 24 hours before organ harvest. Lungs were stored in University of Wisconsin solution at 4 degrees C for the following period: group 1: intact lungs, no storage (n = 12); group 2: septic lungs, no storage (n = 6); group 3: septic lungs for 6 hours (n = 5); and group 4: septic lungs for 12 hours (n = 5). All lungs were reperfused for 2 hours with venous blood using an isolated, pulsatile perfused lung system. RESULTS: Experimental variables were comparable between groups 1, 2, and 3. All septic lungs stored for 12 hours (group 4) failed within 1 hour of perfusion. CONCLUSIONS: These results indicate that compromised lungs with septic injury functioned at near control levels after 6 hours of preservation. Six hours may be a safe limit for human donor lungs, all of which are compromised in some way by the time of harvest.
The effects of initial lung flushing with intracellular and extracellular fluid type solutions were studied in lungs stored with the University of Wisconsin solution. Excised Sprague-Dawley rat lungs (n = 39) were flushed first with one of the following solutions: (1) the University of Wisconsin solution (K+ = 140 mmol/L), (2) modified (low potassium) University of Wisconsin solution (K+ = 20 mmol/L), (3) phosphate buffered saline solution (K+ = 3.9 mmol/L), (4) modified low-potassium phosphate-buffered saline solution (K+ = 20 mmol/L), (5) modified high-potassium phosphate-buffered saline solution (K+ = 40 mmol/L), and (6) Euro-Collins solution (K+ = 115 mmol/L) followed by secondary flush with storage solution and cold (4 degrees C) storage in University of Wisconsin solution for 24 hours. The lungs were then reperfused in the isolated, pulsatile, blood-perfused working lung system for 2 hours or until lung failure. Blood gas analysis and shunt fraction, aerodynamic parameters (airway resistance, lung compliance, elastic work, and flow resistive work), and total pulmonary vascular resistance were measured throughout the perfusion period. The mean oxygen tensions (in millimeters of mercury) at 30 minutes after the onset of reperfusion for University of Wisconsin solution, modified University of Wisconsin solution, phosphate-buffered saline solution, modified phosphate-buffered saline solutions (20 and 40 mmol/L), and Euro-Collins solution were 56.1 +/- 4.2, 72.7 +/- 9.1, 87.7 +/- 6.9 (p < 0.01 versus University of Wisconsin solution; p < 0.01 versus Euro-Collins solution), 86.0 +/- 9.6 (p < 0.01 versus University of Wisconsin solution; p < 0.01 versus Euro-Collins solution), 87.9 +/- 7.7 (p < 0.01 versus University of Wisconsin solution; p < 0.01 versus Euro-Collins solution), and 53.5 +/- 6.0, respectively. All aerodynamic parameters in the lungs flushed with extracellular fluid type solutions were superior to those flushed with intracellular fluid type solutions. We conclude that the efficacy of initial flushing was essential for successful lung preservation and that extracellular fluid type solutions were superior to intracellular fluid type solutions, at least for flushing the lung before storage with University of Wisconsin solution. Potassium concentration in flushing solution should be 20 mmol/L or less to obtain appropriate flushing and subsequent adequate distribution of the storage solution.
Explore the source record for details and available documents.
Previous reports have indicated that the senescent myocardium is less tolerant to surgically induced ischemia and that diminished functional recovery is associated with alterations in cytosolic calcium ([Ca2+]i) accumulation. Recently, increased [Ca2+]i has been suggested to alter nuclear calcium ([Ca2+]n) accumulation. To investigate the relation between [Ca2+]i and [Ca2+]n, we subjected mature and aged rabbit hearts to normothermic global ischemia, either without treatment or after treatment with potassium cardioplegia, magnesium cardioplegia, or a combination of potassium and magnesium cardioplegia. The relation between altered [Ca2+]n and DNA fragmentation was also investigated. Our results indicate that [Ca2+]i was increased during 30 minutes of normothermic global ischemia without treatment in both the mature and aged hearts (p < 0.05). Accumulation of [Ca2+]i during global ischemia was reduced with the use of potassium, magnesium, and a combination of potassium and magnesium cardioplegia (p < 0.05 versus untreated ischemia) in both the mature and aged hearts. Levels of [Ca2+]n were unaffected by global ischemia or cardioplegia in the mature myocardium; however, in the aged myocardium, [Ca2+]n was increased during global ischemia and with potassium cardioplegia and was associated with increased nuclear DNA fragmentation (p < 0.05). The use of magnesium and a combination of potassium and magnesium cardioplegia attenuated [Ca2+]n accumulation and nuclear DNA fragmentation (p < 0.05). Control of [Ca2+]i and [Ca2+]n was associated with enhanced functional recovery during reperfusion. These results indicate that during normothermic ischemia, there is increased [Ca2+]i and [Ca2+]n in the aged myocardium, and increased [Ca2+]n is associated with increased nuclear DNA fragmentation.(ABSTRACT TRUNCATED AT 250 WORDS)
STUDY OBJECTIVE: Define the negative predictive factors for survival in patients who undergo open-lung biopsy. DESIGN: Retrospective analysis from July 1988 through January 1992 (prior to widespread use of video-assisted techniques). Factors included in analysis were: oxygen therapy, requirement for intubation, and HIV status. Also analyzed were the accuracy of the preoperative presumptive diagnosis and the outcome of therapy. SETTING: University hospital in an urban area with active medical and surgical critical care services. PATIENTS: All patients who underwent open-lung biopsy during the study design period. Patients excluded were those with lung transplants and one patient who had a thoracoscopic biopsy. Forty-eight lung biopsies were performed and 31 patients without AIDS and 15 with AIDS. Twenty-four (16 without AIDS, 8 with AIDS) were receiving oxygen therapy, met intubation criteria, or were intubated and ventilated at the time of biopsy. The indications were undiagnosed nodular or interstitial lung disease. INTERVENTIONS: Presurgical evaluation included a preoperative diagnostic algorithm of transthoracic needle biopsy and nodular disease (9 patients) and at least one bronchoscopy with bronchoalveolar lavage and transbronchial biopsy in interstitial disease (22 patients). Seven patients with nodular disease and nine with infiltrate had no preoperative procedures. MEASUREMENTS AND RESULTS: Lung biopsy obtained at definitive diagnosis in 98 percent of patients. Biopsy significantly altered therapy in 79 percent (81 percent without AIDS, 73 percent with AIDS). Postoperatively, in-hospital mortality was 8 (17 percent): 5 (16 percent) without AIDS and 3 (20 percent) with AIDS p > 0.1. Mortality rates showed patients without respiratory compromise, 4.2 percent (7 percent without AIDS, 0 percent with AIDS); patients receiving oxygen therapy, 6 percent (10 percent without AIDS; 0 percent with AIDS); patients who met intubation criteria, 60 percent (33 percent without AIDS, 100 percent with AIDS); patients who were ventilated, 75 percent (66 percent without AIDS [p < 0.05], 100 percent with AIDS [p < 0.05]. CONCLUSION: We recommend that the decision for lung biopsy be individualized based on respiratory status.
The diagnosis and management of pleural effusions have been well recognized over the years as indications for thoracoscopy. New technology has enhanced its appeal. Video-assisted thoracic surgery is a well-tolerated procedure that affords excellent visualization of the entire pleural surface. Directed biopsies of suspicious areas lead to a high diagnostic yield, particularly when compared with percutaneous biopsies. New algorithms reflect this fact. Video-assisted thoracic surgery now follows diagnostic thoracentesis as the next step in the evaluation of effusion suspicious for malignancy. Video-assisted thoracic surgery can also aid the lysis of adhesions, which might limit the effectiveness of surgical procedures to produce pleurodesis, and is an ideal tool for therapeutic management. It may be performed with general anesthesia or local anesthesia and sedation. All of the pleural fluid can be removed and this facilitates the procedure. With minimal instrumentation, pleurodesis may be performed by pleurectomy, mechanical abrasion, or talc sclerosis. Visually directed placement of chest tubes ensures adequate reexpansion of the lung.
Both patients and the medical profession are quick to embrace new technology, particularly when it may replace an existing surgical procedure. Unfortunately, the rapidity of acceptance is rarely associated with careful evaluation. Laparoscopy is a recent example of such widely embraced technology. Studies of laparoscopy that yielded good comparative data to more traditional methods were slow to accrue. This led to the exposure of its shortcomings through governmental reports and the lay press. To prevent this from happening in thoracoscopy, two types of studies are required so that valid conclusions about the new technology can be drawn. The first is an accounting of the new technology as procedures evolve around it. The data collected in such a study should contain basic information, including the indications for the procedure, how it was performed, procedure length, associated complications, and patient outcome. Such information provides a broad profile of the technology, emphasizing from the outset its potential strengths and weaknesses. The second type of study involves a more detailed concurrent comparison of the specific procedures utilizing this technology to the established traditional methods. Such randomized studies help to firmly establish through scientific process the place of the new technology. The Video-Assisted Thoracic Surgery Study Group was organized in early 1992 to address these concerns. From an initial four surgeons the group has grown to include more than 41 institutions. Currently the group is collecting data in a registry and has established three clinical trials to evaluate video-assisted thoracic surgery.(ABSTRACT TRUNCATED AT 250 WORDS)
With the resurgence of thoracoscopy, there is renewed interest in less invasive methods of pleurodesis. We wished to compare in an animal model a variety of methods suggested in reports. The purpose of the study was to rank the effectiveness of each procedure against the standard mechanical pleurodesis. Twenty-five mongrel dogs (weight, 25 to 35 kg) underwent bilateral thoracotomy. Each animal was randomly assigned to receive two of the following methods of pleurodesis: tetracycline, talc, mechanical abrasion, neodymium: yttrium-aluminum garnet (Nd:YAG) laser (Hereus Inc, E. Rutherford, NJ) photocoagulation, and argon beam coagulator (ABC) (Beacon Lab, Bloomfield, CO) electrocoagulation of the parietal pleura. At evaluation at 30 +/- 2 days, the efficacy of pleurodesis was graded on a scale of 0 to 4, with 0 representing a complete absence of pleural symphysis and 4 the adhesion of more than one lobe to both the chest wall and mediastinum. Mean grade and standard deviation of each method were: talc, 3.0 +/- 0.67; mechanical, 3.0 +/- 0.82; tetracycline, 2.3 +/- 1.4; ABC, 1.5 +/- 0.97; and Nd:YAG laser, 0.7 +/- 0.95. Both the talc and mechanical methods were superior to either the Nd:YAG laser or the ABC (p < 0.01). In this study, neither the Nd:YAG laser nor the ABC proved efficacious in producing pleurodesis. Talc poudrage is the only method of pleural symphysis comparable with mechanical abrasion.
The Video Assisted Thoracic Surgery Study Group was formed to collect data on thoracoscopic procedures in an effort to define the role for this new technique. With more than 40 participating institutions, 1,820 cases have been collected through December 1992. Lung nodules and pleural effusions represent the most frequent indications, and wedge resection and operation in the pleural space were the most common procedures performed. Four hundred thirty-nine procedures (24%) were converted to a thoracotomy because of the need for more extensive resection (219), inability to find the pathology (65), too large a lesion or difficult location (62), adhesions (58), equipment failure (25), or bleeding (10). Prolonged air leak (> 5 days) was the most frequent complication. Patients undergoing video-assisted thoracic surgery and wedge resection had a mean hospital stay of 5.1 days; video-assisted thoracic surgical lobectomy was performed in 38 patients, who had a mean stay of 6.3 days. Air leaks were more prevalent in patients with poor pulmonary function (forced expiratory volume in 1 second < 1 L) and the elderly (> or = 75 years) after video-assisted thoracic surgical wedge resection. Video-assisted thoracic surgery appears safe and may be advantageous for some procedures. Further studies will be required to define its precise role in thoracic surgery.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
OBJECTIVES: To characterize the course of open-heart surgery patients who require prolonged (greater than 72 hrs) mechanical ventilation and to define the role and timing of tracheostomy. DESIGN: Retrospective review. SETTING: Cardiac surgery ICU and surgery wards at a university hospital. PATIENTS: All open-heart surgery patients during an 18-month period from January 1988 to July 1989 (n = 581). From this group, 58 patients (9.9%) required prolonged mechanical ventilation. INTERVENTIONS: Study patients (n = 58) were followed through the course of intubation and/or tracheostomy until they were extubated, left the hospital on ventilation, or died. MEASUREMENTS AND MAIN RESULTS: End-points for mortality and complications were determined. Overall mortality rate was 43% in the patients who required prolonged mechanical ventilation. Twenty-eight percent of the 58 patients died within the first 14 days. Of those patients who survived, 55% required an endotracheal tube only and were extubated in less than 14 days; 45% of the patients required tracheostomy. Of those patients who required tracheostomy, five (26%) were eventually extubated, seven (37%) remained mechanically ventilated, and seven (37%) died. The complication rate for endotracheal tubes was 65%; the complication rate for tracheostomy was 37%. CONCLUSIONS: Open-heart surgery patients requiring prolonged mechanical ventilation are a desperately ill subset of cardiac surgery patients. Those patients who survive are either extubated in less than 14 days or require prolonged mechanical ventilation beyond that point. In our opinion, patients should be given 1 wk to recover and one trial of weaning from the ventilator. If this approach fails, then they should undergo elective tracheostomy.
Maximum preservation times of 4-6 hr continue to plague lung transplantation. The high-potassium colloid University of Wisconsin solution (UWS) has proved superior to the crystalloid modified Eurocollins' solution (ECS) for preservation of the liver, kidney, and pancreas. The purpose of this study was to compare UWS and ECS for extended lung preservation using a technique of combined pulmonary and bronchial artery perfusion. Simultaneous pulmonary artery and bronchial artery (via a closed aortic segment) perfusion was employed to harvest the lungs of ten mongrel dogs (wt 25-35 kg) using either UWS (n = 5) or ECS (n = 5) preservation solutions. Following 17 hr of cold (4 degrees C) pulmoplegic storage, the lungs were placed in an isolated perfused working lung (IPWL) apparatus. Seven freshly harvested lungs served as a control group (CON). Lung aerodynamics and gas exchange were evaluated at standard intervals until failure of the lung on the IPWL apparatus. Time until failure (mean +/- SEM) for each group was: CON = 209 +/- 14 min; UWS = 227 +/- 26 min; and ECS = 123 +/- 29 min. Only one of the ECS lungs lasted longer than 90 min. UWS-preserved lungs displayed a gas exchange efficiency equal to the CON group and better than that in the ECS-preserved lungs (lower A-aDO2, lower intrapulmonary shunt), suggesting better protection of the alveolar capillary membrane. Although the UWS lungs were initially less compliant than the ECS lungs, at no time was there a significant difference in the total work of respiration between the two groups. We conclude that UWS provides superior protection of the alveolar capillary membrane. The aerodynamic disadvantages of UWS preservation did not effect lung survival or total work of respiration.