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Biomedical subjects

L R Kaiser

Publications and source records attributed to L R Kaiser.

At least 145 records · Page 8Linked to original sources
PubMed1991

Single-lung transplantation for pulmonary hypertension. Three-month hemodynamic follow-up.

BACKGROUND: Shorter waiting times, relative technical simplicity, and satisfactory application to a broad spectrum of patients has made single-lung transplantation an attractive option in the treatment of patients with end-stage pulmonary hypertension. METHODS AND RESULTS: Seven patients with pulmonary hypertension underwent single-lung transplantation. Simultaneous closure of associated atrial septal defects was accomplished in two patients. Despite severely compromised pretransplant right ventricular function in all patients, there was no early or late mortality. Right ventricular functional recovery as characterized by hemodynamic assessment before and at a mean of 13 weeks posttransplant was nearly uniform and characterized by a drop in 1) pulmonary arterial systolic pressure from 92 +/- 7 mm Hg to 29 +/- 6 mm Hg (p = 0.001), 2) central venous pressure from 10 +/- 6 mm Hg to 1 +/- 2 mm Hg (p = 0.02), and 3) pulmonary vascular resistance index from 1,924 +/- 663 to 232 +/- 73 dyne.sec.cm-9 (p = 0.001). Radionuclide ventriculography before and at a mean of 17 weeks posttransplant documented a significant (p = 0.006) increase in right ventricular ejection fraction from 22 +/- 15% to 51 +/- 11%. Quantitative pulmonary perfusion scintigraphy at a mean of 17 weeks posttransplant demonstrated a significant (p = 0.001) increase in perfusion to the transplanted lung from 56 +/- 6% to 89 +/- 7%. There was a concomitant, slight but significant (p = 0.004) decrease in ventilation to the transplanted side from 56 +/- 6% to 49 +/- 8%. After transplantation, all patients returned to New York Heart Association functional class I or II from their preoperative levels of class III or IV. CONCLUSIONS: These early follow-up data cautiously support the option of single-lung transplantation in patients with pulmonary hypertension, although long-term durability of these hemodynamic changes deserves documentation before widespread application.

Follow-Up Studies↗
PubMed1991

The evolution of single lung transplantation for emphysema. The Washington University Lung Transplant Group.

Classic transplantation dogma mandated bilateral lung replacement for lung transplant candidates with end-stage emphysema to avoid air trapping in the native lung and subsequent crowding of the newly transplanted lung. During a recent 12-month period 11 patients with emphysema received a single lung transplant. There was no hospital mortality and only one patient had any notable degree of air trapping in the native lung. Substantial improvement in pulmonary function was seen as early as 2 weeks after transplantation, with significant functional improvement seen by 6 weeks, despite some residual ventilation-perfusion mismatch. We have demonstrated the utility and safety of single lung transplantation for patients with end-stage emphysema, and it is our operation of choice in recipients more than 50 years of age.

Exercise Test↗
PubMed1991

Role of health-care workers in the future delivery of health care.

There is no logical, linear way to approach a future in which knowledge and technology explode and new opportunities go hand-in-hand with rapid obsolescence. Teams and task groups will replace the vertical command structures of the past, making teamwork, flexibility, and imagination more important that absolute knowledge. Maximum downward task delegation and decentralization will empower workers at all levels while challenging the assumptions of licensure. As the health-care organization grows more ephemeral, management will become an increasingly subtle art. Visionary skills are essential in a dynamic, rapidly changing society where the past is no longer a guide for the future.

Career Mobility↗
PubMed1990

Primary sarcoma of the superior pulmonary vein.

A case of a primary sarcoma of the right superior pulmonary vein is described. To the best of the authors' knowledge, this is the first report of successful surgical management of this unusual tumor. The tumor was confined to the superior pulmonary vein and the presentation was that of a hilar mass, assumed to be a bronchogenic carcinoma. Unlike previously reported cases, there was no clinical evidence of left atrial obstruction. The management of the case is discussed, and a review of the pertinent literature is presented.

Brain Neoplasms↗
PubMed1990

Improved technique for bilateral lung transplantation: rationale and initial clinical experience.

We previously described a technique for en bloc double-lung transplantation that was initially applied to select patients with cystic fibrosis and emphysema. This procedure is quite complex and associated with several limitations, including a substantial incidence of airway ischemia, postoperative myocardial depression, and cardiac denervation. To address these problems we have developed a simpler procedure for replacing both lungs. The operation is done through a transverse thoracosternotomy and involves sequential replacement of the two lungs. Positive features include separate bronchial anastomoses to reduce ischemic airway complications, elimination of the need for total cardiopulmonary bypass and a period of ischemic cardiac arrest, improved exposure to reduce intraoperative and postoperative hemorrhage, and maintenance of cardiac innervation. Additionally, the technique can be more easily mastered and widely applied. Details of the procedure and its initial clinical application in 3 patients having emphysema, cystic fibrosis, and bronchiolitis obliterans following previous double-lung transplantation, respectively, are described. All 3 patients recovered without complication. Postoperative function was excellent in spite of lung ischemic times ranging up to 91/2 hours.

Adult↗
PubMed1989

Significance of extramucosal residual tumor at the bronchial resection margin.

Extramucosal microscopic residual disease (MRD) at the bronchial resection margin was identified in 45 (1.6%) of 2,890 patients who underwent resection of primary non-small cell lung cancer between 1975 and 1985. In 9 of these patients, residual tumor was confined to submucosal lymphatics, whereas in the other 36, MRD was found in peribronchial soft tissue. All patients underwent complete mediastinal lymphadenectomy. Three patients had stage I disease, 3 had stage II, 33 had stage IIIa, 4 had stage IIIb, and 2 had stage IV. Recurrent disease developed in 34 (81%) of the evaluable patients; the recurrence was local in 11 (32%). Median time from operation to diagnosis of local recurrence was 8 months. Sixty percent of the recurrences in the N0 group were local, and only 23% of those in the N2 group were local. Extramucosal MRD is most frequently associated with advanced-stage disease. Postoperative therapy had no effect on the development of recurrent disease. We found no difference in survival between patients whose initial site of recurrence was local as opposed to distant. Median survival after the identification of either local or distant recurrence was 5 months. The finding of extramucosal MRD identifies a subset of patients with a poorer prognosis compared with those with clear resection margins.

Adult↗
PubMed1989

Lung transplantation.

The supply of donor organs remains extremely limited, and improved methods of maintaining the lungs of potential donors to allow for transplantation must be developed. Currently the upper limit of donor lung ischemic even with our "best" preservation techniques is approximately 4 to 6 hours. Improved methods for preservation will increase the supply of suitable lungs and will considerably simplify the logistics of transplantation just as has occurred with liver transplantation. Efficient use of donor organs remains of paramount importance. We recently performed two single-lung transplants utilizing lungs from one donor. Likewise, there is no reason why a lung could not be sent to another center for transplantation if the harvesting group uses only one lung. Sufficient progress has been achieved to date to warrant continued application of lung transplantation for end-stage pulmonary disease. With increasing experience, one can anticipate refinement of techniques and broader application of these procedures. Single lung transplantation, initially restricted to patients with end-stage pulmonary fibrosis, has now been successfully applied to patients with emphysema, pulmonary hypertension, and other conditions. Although transplantation currently can offer real benefit only to a limited number of persons, it serves to create hope for many others. An additional benefit may prove to be the interest and attention that transplantation focuses on patients with end-stage lung disease and on the pathophysiology of chronic respiratory failure. Knowledge gained may ultimately result in the prevention of many of the disorders for which lung transplantation currently offers the only hope.

Graft Rejection↗
PubMed1989

Indeterminate mediastinal invasion in bronchogenic carcinoma: CT evaluation.

The computed tomographic (CT) scans of 80 patients with bronchogenic carcinoma classified as indeterminate for direct mediastinal invasion were retrospectively reviewed after the patients had undergone thoracotomy. Forty-eight (60%) of the masses were resectable, without invasion of the mediastinum, 18 (22%) focally invaded the mediastinum but were technically resectable, and 14 (18%) invaded the mediastinum and were not technically resectable. Although in most circumstances in this relatively small subset of patients CT was not helpful in differentiating masses with and without mediastinal invasion, CT was able to separate a large group of masses that were likely to be technically resectable. Thirty-six (97%) of 37 masses with one or more of these CT findings were considered technically resectable: contact of 3 cm or less with mediastinum, less than 90 degrees of contact with aorta, and mediastinal fat between mass and mediastinal structures. Of these 36 masses, 28 were resectable without mediastinal invasion, and eight were resectable with focal limited mediastinal invasion.

Adult↗
PubMed1989

Single lung transplantation for severe chronic obstructive pulmonary disease. Washington University Lung Transplant Group.

Single lung transplantation (SLT) has been considered physiologically inappropriate for patients with chronic obstructive pulmonary disease (COPD). It has been postulated that the high static compliance and elevated pulmonary vascular resistance of the native lung functioning in parallel with the more normal allografted lung could cause unacceptable ventilation-perfusion mismatching and/or overinflation of the native lung with encroachment on the expansion of the transplanted lung. While some degree of ventilation-perfusion imbalance may be physiologically obligatory after SLT for COPD, a significant disruption in gas exchange may not occur unless a complication, such as rejection or infection, arises in the transplanted lung. A 60-year-old man with COPD who underwent successful SLT is presented and discussed. In spite of scintigraphic evidence of ventilation-perfusion mismatching between the native lung and the allograft during the first six postoperative weeks, the recipient had normal resting gas exchange on room air after the second postoperative week. Fourteen weeks after transplantation, his maximum oxygen uptake was 37.3 percent of the predicted maximal value, and no evidence of ventilatory limitation was detected. His functional status and lifestyle have been markedly improved by SLT. The role of SLT for COPD should be reconsidered. It may be a reasonable transplantation alternative for selected patients with COPD who are not candidates for double lung transplantation (DLT).

Exercise↗
PubMed1988

Blood transfusion and lung cancer recurrence.

Recent reports have suggested that perioperative blood transfusions may adversely affect prognosis after resection of non-small cell lung cancer (NSCLC). To determine the impact of perioperative transfusion on the recurrence-free interval, the status of 352 patients who underwent pulmonary resection for pathologic Stages I and II NSCLC was investigated. Transfused patients were significantly older than untransfused patients (P = 0.0009) but were not significantly different in sex distribution (P = 0.12) or tumor stage (P = 0.09). Recurrence was not significantly different in transfused patients when compared with patients who received no blood (P = 0.23) even when stratified for stage (Stage I, P = 0.58; Stage II, P = 0.14). Furthermore, the number of units transfused was not associated with time to tumor recurrence (P = 0.58). Contrary to other reports, these results do not support the contention that perioperative blood transfusion is significantly associated with decreased recurrence-free survival.

Aged↗
PubMed1988

Bilobectomy for bronchogenic carcinoma.

During a 12-year period, bilobectomy was performed on 166 patients for the treatment of primary lung carcinoma: 108 patients (65%) underwent right upper and middle lobectomy, while 58 patients (35%) underwent right middle and lower lobectomy. Indications for bilobectomy were tumor extending across a fissure (45%), absent fissure (21%), endobronchial tumor (14%), extrinsic tumor or nodal invasion of bronchus intermedius (10%), and vascular invasion (5%). Thirty-one patients (19%) suffered 41 perioperative complications, and 7 patients (4.2%) died. Upper and middle lobectomies were not associated with a significantly different morbidity (p greater than 0.10) or mortality (p greater than 0.10) when compared with middle and lower lobectomy. The postoperative chest roentgenograms of all patients demonstrated ipsilateral volume loss, and 31 patients were found to have asymptomatic hydropneumothoraces, which cleared during the follow-up period. Late complications occurred in 4 patients (2%) and included two empyemas, one bronchopleural fistula, and one superficial wound infection. These results indicate that bilobectomy is associated with morbidity and mortality that lie between those currently reported for lobectomy and pneumonectomy.

Adenocarcinoma↗
PubMed1988

The effects of preoperative chemotherapy on the resectability of non-small cell lung carcinoma with mediastinal lymph node metastases (N2 M0).

We have defined "clinical N2" disease in non-small cell lung cancer to mean the presence of enlarged metastatic mediastinal nodes evident on plain chest roentgenograms or widening of the carina at bronchoscopy. Forty-one patients with non-small cell carcinoma of the lung and clinical N2 M0 disease presumed operable received 2 to 3 cycles of high-dose cisplatin with vindesine (or vinblastine sulfate) with or without mitomycin-C. Following chemotherapy, 30 patients (73%) had a major radiographic response. Of these patients, 28 had thoracotomy, and 21 (75%) of them had complete resection of the disease, 8 of whom had total sterilization of the tumor proven histologically. An additional 4 patients had limited microscopic foci of residual tumor either in lung or lymph nodes. Survival at 3 years from diagnosis was 34% for all patients, 40% for those who completed the combined treatment (chemotherapy and surgery), and 54% for those who had complete resection with a median follow-up of 44 months and a median survival not yet attained.

Adult↗
PubMed1988

Surgical considerations in the management of the immunocompromised patient.

We have attempted to give a broad overview of issues of importance to the surgeon that may arise in the management of the immunocompromised patient. These include airway obstruction, diffuse and focal pulmonary lesions, vascular access problems, gastrointestinal bleeding, perforation, obstruction, and soft tissue infections. Principles of perioperative management in this patient group are discussed in detail. Often they will require broad metabolic and hemodynamic support. The spectrum of pathology ranges from common problems found in the general patient population that present with only subtle clinical findings, making diagnosis difficult, to conditions unique to the patient with a deficient immune system. The importance of early consultation with the surgeon for the indications that have been described cannot be overemphasized. One should attempt to identify certain surgeons who have a particular interest in dealing with these complex problems. It is of the utmost importance for the surgeon to have the guidance of the primary physician with regard to aggressiveness of therapy. This decision must take into account the basic underlying disorder as well as the wishes of the patient and family. Many of these patients can be salvaged despite the seemingly endless problems that may arise along the way.

Acquired Immunodeficiency Syndrome↗