Calculation of lung flow differential after single-lung transplantation: a transesophageal echocardiographic study.

Single-lung transplantation (SLT) is a viable option for patients with end-stage pulmonary disease. After successful SLT, pulmonary blood flow is preferentially shifted to the transplanted lung, creating a flow differential. Lack of flow differential may be indicative of potential vascular complications such as anastomotic stenosis or thrombosis. To assess the ability of transesophageal echocardiography (TEE) in estimating lung flow differential in patients undergoing SLT, biplane TEE was prospectively performed in 18 consecutive patients undergoing SLT early (24 to 72 hours), and in 10 of them late (3 to 6 months) after surgery. Right and left pulmonary vein flow were calculated as Qnu=A. VTI, where A, the pulmonary vein area, was derived as pi.(D/2)(2) and VTI is the velocity time integral of the pulmonary vein spectral display. Lung flow differential was calculated as the ratio of right (RQnu) or left (LQnu) pulmonary vein flow to total pulmonary venous flow (RQnu + LQnu). Lung perfusion imaging scintigraphy (technetium-99m) was used for comparison. Pulmonary vein velocity time integral of transplanted lung was significantly greater than that of native lung (34 +/- 9 vs 18 +/- 8 cm, p <0.001). Percent differential lung flow derived by perfusion imaging scintigraphy and by TEE showed a good correlation (r = 0.67, p <0.001). Pulmonary artery anastomoses were seen in all 12 right-lung recipients, and in 4 of the 6 left-lung recipients; no significant stenosis was noted in the arteries visualized. The pulmonary venous anastomoses were imaged in all patients. Small, nonocclusive pulmonary vein thrombi were seen in 1 patient. In conclusion, TEE is a useful method for calculating lung flow differential in patients undergoing SLT. In addition, TEE provides superb direct visualization of the venous and arterial anastomoses in most patients. Contrary to previous reports, the overall incidence of anastomotic complications is relatively low.

Investigation and control of aspergillosis and other filamentous fungal infections in solid organ transplant recipients.

Filamentous fungal infections are associated with high morbidity and mortality in solid organ transplant patients, and prevention is warranted whenever possible. An increase in invasive aspergillosis was detected among solid organ transplant recipients in our institution during 1991-92. Rates of Aspergillus infection (18.2%) and infection or colonization (42%) were particularly high among lung transplant recipients. Epidemiologic investigation revealed cases to be both nosocomial and community-acquired, and preventative efforts were directed at both sources. Environmental controls were implemented in the hospital, and itraconazole prophylaxis was given in the early period after lung transplantation. The rate of Aspergillus infection in solid organ transplant recipients decreased from 9.4% to 1.5%, and mortality associated with this disease decreased from 8.2% to 1.8%. The rate of Aspergillus infection or colonization among lung transplant recipients decreased from 42% to 22.5%; nosocomial Aspergillus infection decreased from 9% to 3.2%. Cases of aspergillosis in lung transplant recipients were more likely to be early infections in the pre-intervention period. Early mortality in lung transplant recipients decreased from 15% to 3.2%. Two cases of dematiaceous fungal infection were detected, and no further cases occurred after environmental controls. The use of environmental measures that resulted in a decrease in airborne fungal spores, as well as antifungal prophylaxis, was associated with a decrease in aspergillosis and associated mortality in these patients. Ongoing surveillance and continuing intervention is needed for prevention of infection in high-risk solid organ transplant patients.

Pathophysiology of chest trauma.

Recent information indicates that there is a complex cellular and molecular generic response to injury that can lead to multi-organ failure. For many years, basic physiology and biochemistry were considered to be the systemic mechanisms to injury, but now it is known that subcellular and molecular events are the keys to unlocking the secrets of the body's response to trauma. The interaction of the endothelial cell with neutrophils and platelets to produce cytokines, free radicals, and upregulating adhesion molecules is especially significant.

Penetrating intrapericardial wounds: clinical experience with a surgical protocol.

BACKGROUND: From 1972 to 1977, a treatment protocol was developed at our institution for patients with suspected penetrating intrapericardial wounds. It consists of immediate transport to the operating room, pericardial decompression by subxiphoid pericardial window under local or light general anesthesia in patients in stable condition, and median sternotomy and operative repair with limited use of cardiopulmonary bypass. METHODS: The records of 79 consecutive patients with acute penetrating intrapericardial injury who underwent operation from March 1978 to July 1991 were reviewed. There were 59 patients (75%) with stab wounds and 20 (25%) with gunshot wounds. Wound location was as follows: right ventricle, 33 (42%); left ventricle, 28 (35%); multiple sites, 8 (10%); atrium, 5 (6%); and great vessels, 5 (6%). RESULTS: Subxiphoid pericardial window was performed under local or light general anesthesia in 53 patients (67%). Cardiopulmonary bypass was required in only 4 patients. Overall mortality was 6%. CONCLUSION: Approach to a trauma victim must be systematic. We believe one treatment protocol for patients with suspected penetrating intrapericardial wounds is effective.

Homograft patch repair for hemorrhagic mediastinitis.

Hemorrhage from the heart and great vessels is a potentially lethal complication of post-sternotomy mediastinitis. We report 2 cases in which a cryopreserved descending thoracic aortic homograft was used successfully to repair defects of the ascending aorta and right ventricle in the setting of active mediastinal infection. An overview of mediastinitis and management strategies for life-threatening mediastinal bleeding is included.

Echocardiographic assessment of right and left ventricular function after single-lung transplantation.

To evaluate the impact of single-lung transplantation on right and left ventricular performance and to identify potential preoperative characteristics that could predict postoperative outcome, a large group of patients were retrospectively evaluated by means of serial Doppler echocardiography. Twenty-six of 57 consecutive single-lung transplant patients had satisfactory Doppler echocardiographic studies before and after surgery. A significant reduction in right ventricular diastolic and systolic areas and an increase in right ventricular fractional area were noted after transplantation. The left ventricular contractility remained unchanged. In addition, significant reduction in right atrial area, right ventricular free wall thickness, and tricuspid regurgitation were also seen. Paradoxical septal motion present in eight patients before the procedure resolved in all of them after single-lung transplantation. Transthoracic echocardiography is a useful technique to document improvement in right ventricular function in 63% of patients following single-lung transplantation. Preoperative paradoxical septal motion identifies single-lung transplant recipients who have the largest postoperative right ventricular area reduction and fractional area increase. Alternative imaging modalities should be sought for single-lung transplant candidates in whom conventional transthoracic echocardiography is suboptimal.

Graft position and pulmonary function after single lung transplantation for obstructive lung disease.

Single lung transplantation (SLT) has become a therapeutic option for the treatment of end-stage obstructive lung disease. Between January 1989 and June 1990, there were 14 patients with end-stage obstructive lung disease who underwent SLT. Eleven of these patients were surviving at 1 year following transplantation. Three of the patients had received left-sided SLT, and eight had received right-sided SLT. In the patients receiving left-sided SLT, the native right lung radiographically appeared to compress the left lung graft. In the patients receiving right-sided SLT, the native left lung did not appear to compress the right lung graft. We hypothesized that right SLT may provide a functional advantage over left SLT for patients with obstructive lung disease. We compared pulmonary function test results before and after transplantation (approximately 3 and 12 months) and compared quantitative ventilation-perfusion lung scan results between the patients with left SLT and those with right SLT. Additionally, we compared graded-exercise test results at 3 and 12 months after transplant between the two groups. Our data revealed no statistical difference in pulmonary function test results or graded-exercise test results between the two groups, although patients undergoing right SLT showed greater increases in FEV1 and forced vital capacity than those undergoing left SLT. Quantitative ventilation and perfusion were greater to the graft in patients receiving right-sided SLT than in patients receiving left-sided SLT, most likely due to the larger size of the right lung. We conclude that there is no functional difference between patients undergoing left or right SLT for end-stage obstructive lung disease.

Exercise performance after lung transplantation.

Heart-lung, double lung, and single lung transplantation have been shown to be effective in the treatment of patients with advanced cardiopulmonary disorders. An overlap in indications occurs for the different procedures, and in many situations the factors that are important in selecting the best operation for a given patient have not been clearly elucidated. To determine whether the anticipated exercise capacity should be an important consideration in the selection of the optimal procedure for a given patient, we compared exercise performance in patients who had undergone the different lung transplantation procedures in the preceding year and were otherwise well. Eleven heart-lung, six double lung, and 16 single lung recipients and 28 control subjects underwent maximal symptom-limited incremental exercise tests using a cycle ergometer. At peak exercise, transplant recipients reached maximum oxygen uptakes in the range of 40% to 60% of predicted values; no significant differences existed between the means of the different transplant groups. Ventilatory factors did not appear to limit exercise in any group. The exercise responses in the transplant subjects were characterized by reduced aerobic capacity and diminished oxygen pulse, factors indicating abnormal cardiovascular performance. Our data indicate that moderate levels of exercise can be anticipated early after heart-lung, double lung, and single lung transplantation. In the absence of substantial differences in exercise capacity, other considerations would appear to be more important in guiding the selection of the optimal lung replacement procedure for an individual patient.

Lung transplantation in a patient with a prior bone marrow transplant.

A 25-year-old woman with acute lymphoblastic leukemia underwent two bone marrow transplants. She subsequently developed severe restrictive lung disease which was successfully treated with a single lung transplant.

Chest trauma. Approach and management.

A synopsis of both blunt and penetrating thoracic trauma, this article outlines an approach to management for injuries to the lung, heart, esophagus, tracheobronchial tree, diaphragm, and major thoracic vessels. Also outlined are the management of rib fractures, scapula fractures, sternal fractures, and, in particular, flail chest with associated pulmonary contusion.

Ventilation-perfusion inequalities during graft rejection in patients undergoing single lung transplantation for primary pulmonary hypertension.

We report herein data on single lung transplant (SLT) recipients with primary pulmonary hypertension (PPH). One patient did well following surgery but died on the 30th postoperative day due to cytomegalovirus pneumonia. The remaining two patients initially did well with unlimited exercise tolerance following transplantation, but then developed marked dyspnea on exertion and hypoxemia on postoperative days 144 and 120, respectively. Pulmonary function testing showed marked deterioration of function and transbronchial lung biopsy specimens revealed acute graft rejection in one patient and evidence of chronic graft rejection in the second patient. Quantitative ventilation-perfusion lung scanning demonstrated a marked decrease in ventilation to the transplanted lung in both cases associated with only a mild decrease in perfusion. This V/Q mismatch resulted in markedly decreased arterial oxygen saturations, widened alveolar-arterial oxygen gradients, and clinically debilitating dyspnea. We conclude that rejection may result in significant V/Q mismatch and hypoxemia in PPH patients undergoing SLT, which may limit the use of this specific type of surgery for PPH.

Single lung transplantation. Factors in postoperative cytomegalovirus infection.

Thirty-one single lung transplantations were performed between March 17, 1988, and November 1, 1990. Postoperative infection, especially with cytomegalovirus, has been the major cause of morbidity and mortality. Eighteen of the 31 patients were receiving prednisone before transplantation. Every patient was prepared preoperatively with oral cyclosporine 5 mg/kg and azathioprine (Imuran) 2 mg/kg. Every patient received methylprednisolone for 3 days postoperatively, followed by prednisone 1.0 mg/kg/day, oral cyclosporine, and azathioprine. Ten patients additionally had cytolytic therapy with OKT3 and 12 with antilymphocyte globulin. Nine patients had no cytolytic therapy. Cytolytic therapy was chronologic, not randomized. Postoperative infection occurred in 20 patients, 13 of whom had cytomegalovirus infection. Preoperative use of prednisone did not correlate with postoperative infection, cytomegalovirus, or death. Postoperative infection occurred in 17 of 22 patients with cytolytic therapy compared with three of nine without cytolytic therapy (p = 0.035). Cytomegalovirus infection occurred in 13 of 22 with cytolytic therapy and in none of the nine without cytolytic agents (p = 0.003). Therefore preoperative prednisone does not appear to be a contraindication to single lung transplantation. Cytolytic therapy with either OKT3 or antilymphocyte globulin increases the prevalence of postoperative infection with cytomegalovirus and should not be used in patients undergoing lung transplantation.

Glutathione decreases the pulmonary reimplantation response in canine lung autotransplants.

The pulmonary reimplantation response (PRR) is a form of membrane permeability pulmonary edema occurring in lung transplants. The severity of the PRR reflects the quality and duration of lung graft preservation. Free radicals formed during ischemia with reperfusion in the autotransplanted dog lung may play a role in producing PRR. We hypothesized that the addition of reduced glutathione (GSH) to the preservative solution could decrease PRR if hydroperoxides are being formed. Six dogs underwent left lung autotransplantation after the lung was flushed with Euro-Collins solution (EC). These dogs demonstrated radiographic and histopathologic evidence of bilateral pulmonary edema, greatest in the transplanted left lung. They also had increases in lung wet to dry weight (W/D) ratios in both lungs (left, 12.0 +/- 0.9; right, 10.1 +/- 0.8) as compared with a group of five unmanipulated control animals (left, 6.0 +/- 0.5; right, 7.0 +/- 0.4). Malondialdehyde (MDA) concentrations were significantly increased in the transplanted left lungs (14 +/- 4) from this group as compared with the controls (5 +/- 7). Five additional dogs underwent left lung autotransplantation with GSH added to the EC cryopreservation fluid. These animals did not develop histologic or radiographic evidence of pulmonary edema, and W/D ratios as well as MDA concentrations were not different from those in controls. To evaluate the effect of ischemia alone on changes in lung GSH concentrations, ten additional dogs underwent left pneumonectomy. Left lungs were cryopreserved in EC + GSH. In five of the animals, the right lung was removed and preserved in EC alone. In the other five animals, the right lung remained in vivo for 3 h and was then removed. Lung GSH concentrations were doubled after 3 h of ischemia when incubated in EC + GSH compared to in vivo controls and to EC-treated lungs. These data suggest that GSH added to the preservation fluid prevents PRR following transplantation and that lung GSH concentrations actually increase during preservation prior to reimplantation and reperfusion if the lung graft is exposed to GSH in the preservation fluid.

Cardiopulmonary exercise responses after single lung transplantation for severe obstructive lung disease.

The purpose of this study was to characterize cardiovascular and ventilatory responses to exercise in single lung transplantation (SLT) recipients with nonseptic, severe obstructive lung disease (SLT-OB). We also investigated whether the hyperinflated native lung in SLT-OB recipients could limit normal increases in tidal volume by mechanically constraining the transplanted lung, resulting in ventilation-perfusion imbalance in the lung graft. Data from six SLT-OB recipients (five women, one man) and six age-matched SLT recipients (two women, four men) with severe interstitial lung disease (SLT-IN) were compared. Resting arterial O2 and CO2 tensions were normal and comparable between the SLT groups. Spirometry results were reduced but comparable between SLT groups. Total lung capacity was significantly larger in patients with SLT-OB than in patients with SLT-IN. Diffusion capacity was not different between SLT groups when differences in alveolar volume were accounted for. Quantitative perfusion to the lung graft was comparable between the SLT groups, but quantitative ventilation was greater in patients with SLT-OB than in patients with SLT-IN. Maximum exercise capacity following SLT-OB was decreased, but was comparable to that of SLT-IN recipients. None of the SLT-OB recipients reached predicted maximum minute ventilation and only one experienced mild arterial O2 desaturation, suggesting peripheral muscle abnormalities from corticosteroid use and deconditioning as limiting factors rather than a ventilatory limitation. Tidal volumes at end exercise in the SLT-OB recipients were normal. Our quantitative lung scan and exercise testing data suggest that ventilation-perfusion imbalance and resulting gas exchange abnormalities from lung graft constraint and compression do not occur at rest or with exercise after SLT for obstructive lung disease.

Single lung transplantation. Alternative indications and technique.

Twenty-two patients have undergone 23 single lung transplants between March 1980 and April 1990 at the University of Texas Health Science Center at San Antonio. The actuarial survival rate is 77.27% at 12 months and 72.73% at 24 months. There have been no instances of bronchial dehiscence or stenosis, even though 13 of the patients were on a program of preoperative prednisone, every patient had high-dose perioperative methylprednisolone, and omental wraps were not used on any bronchial anastomosis. Of particular interest is the fact that three patients had primary pulmonary hypertension, three had secondary pulmonary hypertension, and 10 patients had chronic obstructive pulmonary disease, due in five cases to an alpha 1-antitrypsin deficiency. Each of these entities was previously thought to contraindicate single lung transplantation. Donor selection was based on an oxygen tension/inspired oxygen concentration ratio greater than 300, donor/recipient chest circumference within 3 inches, clear chest x-ray film, negative sputum Gram stain, and less than 6-hour estimated ischemic time. Harvest technique included donor prostaglandin E1 500 micrograms, topical slush, and pulmonoplegia with cold Euro-Collins solution. The heart and lung were separated in situ rather than the heart lung block being removed. A telescoping bronchial anastomosis was performed with 4-0 Prolene (not absorbable) sutures. We conclude that single lung transplantation has evolved into a simple operation, necessitating meticulous preoperative and postoperative care, which can be performed on a wide spectrum of critically ill patients with an acceptable mortality rate.

Apparent cytomegalovirus epithelial keratitis in a cardiac transplant recipient.

A 44-year-old immunosuppressed man developed initial symptoms of intermittent irritation of the left eye three months after cardiac transplantation. Symptoms increased, with decreased vision, photophobia, and lacrimation. Slit lamp examination showed slightly raised, swollen, grayish epithelium in a broad multibranching dendritic pattern associated with fine and medium punctate epithelial erosions that stained slightly with fluorescein. Histopathologic study of the corneal epithelial scraping demonstrated swollen epithelial cells with intranuclear and intracytoplasmic viral inclusions. Viral cultures manifested a cytopathic pattern characteristic of cytomegalovirus 14 days after inoculation on human embryonic lung cells (MRC-5). Pretransplantation cytomegalovirus IgM and IgG serologic titers were negative (less than 1:16 for IgG, no IgM noted) until the onset of symptoms. Subsequently, IgM titers rose against cytomegalovirus consistent with concurrent infection.

Single lung transplantation for primary pulmonary hypertension.

Single lung transplantation has become a therapeutic option for end-stage interstitial lung disease and obstructive lung disease. Our group recently extended this treatment to three patients with primary pulmonary hypertension. All patients had marked decreases in pulmonary artery pressures and pulmonary vascular resistance and increases in cardiac output following single lung transplantation. Spirometry, lung volumes, and diffusion capacity were not different in comparison to preoperative studies. Quantitative ventilation-perfusion scans revealed the majority of perfusion distributed to the transplanted lung, with ventilation approximately equally divided between the native and the transplanted lung. Despite ventilation-perfusion imbalance, there was no resting hypoxemia and there was no arterial oxygen desaturation with exercise. One patient expired on the 30th postoperative day due to cytomegalovirus infection of the lungs. In the remaining two patients, maximum exercise capacity following transplantation was near normal in one recipient and reduced in the second recipient. Of note, there was no evidence of ventilatory limitation or impaired oxygenation during exercise in these two recipients. Although an exaggerated exercise ventilatory response was present, this did not limit exercise performance. This report supports the use of single lung transplantation for the treatment of primary pulmonary hypertension.