Adaptation over a wide range of donor graft lung size discrepancies in living-donor lobar lung transplantation.

Living-donor lobar lung transplantation (LDLLT), unlike deceased donor lung transplantation, often involves a wide range of size discrepancies between donors and recipients. The aim of this study was to evaluate the function of donor lung grafts in the recipient thorax in 14 cases of bilateral LDLLT involving 28 successfully transplanted lower-lobe grafts. Pulmonary function tests and three-dimensional computed tomography (3D-CT) volumetry were performed perioperatively. According to 3D-CT size matching, donor graft volumes ranged from 40% to 161% of the hemilateral thoracic volumes of the recipients. Graft forced vital capacity (FVC) values increased over time, reaching 102 ± 39% of preoperatively estimated values at 12 months postoperatively. Graft volumes also increased over time, reaching 120 ± 38% of the original values at 12 months postoperatively. Undersized donor grafts expanded more after LDLLT than oversized donor grafts, producing greater FVC values than those estimated preoperatively, whereas oversized donor grafts became inflated to their original size and maintained FVC values that approached the preoperative estimates. Thus, donor grafts were found to overinflate or underinflate to the extent that they could preserve their native function in the new recipient's environment.

Transesophageal and contact ultrasound echographic assessments of pulmonary vessels in bilateral lung transplantation.

BACKGROUND: Intraoperative transesophageal echocardiographic visualization of the vascular anastomosis of lung grafts can be difficult. The goal of this prospective study was to compare intraoperative transesophageal echocardiography and contact ultrasound. METHODS: Vessel imaging and Doppler analysis obtained before chest closure by both techniques were compared in 18 bilateral lung transplant recipients. RESULTS: Twenty-four arteries in 36 and 45 pulmonary veins in 72 were recorded using transesophageal echocardiography versus 34 and 60 by contact ultrasound (p = 0.05). Views of the left pulmonary artery (p = 0.04) and of the left superior and inferior pulmonary veins (p = 0.04 and p = 0.02, respectively) were more often obtained with contact ultrasound. Measurements of vessel diameters were similar by both methods except for the left superior vein, which was smaller by the transesophageal approach (p = 0.002). In 1 patient, inferior venous diameters could not be obtained by either method. Nine arterial and 47 venous velocities were recorded by transesophageal echocardiography versus 21 and 33 by contact ultrasound (p = 0.001). Contact ultrasound produced better left pulmonary artery recordings (p = 0.02), whereas transesophageal echocardiography was more effective on venous velocities. Left inferior vein velocity was twofold higher using transesophageal echocardiography (p < 0.001). CONCLUSIONS: These results suggest clinicians should exercise caution when making treatment decisions when using transesophageal echocardiography alone.

Periostitis secondary to prolonged voriconazole therapy in a lung transplant recipient.

This article reports a case of perostitis deformans in a lung transplantation patient taking the fluoride-containing medication voriconazole, a relatively new and potent anti-fungal. The patient had a normal range of motion in all joints and a normal gait. On radiographs at presentation, multifocal areas of periostitis were visualized involving the left-hand first, second, and third proximal phalanx shafts. Similar periostitis was present on the left-hand third, fourth, and fifth middle phalanx shafts. Plain radiographs of the right hand also demonstrated multifocal periostitis of the third and fourth proximal and middle phalanges. Aggressive periostitis at the level of the right fourth proximal and middle phalanges was also present. Given her long-term treatment with voriconazole and a presentation consistent with periostitis deformans, voriconazole was presumed to be the offending agent and was replaced with itraconazole. The patient's symptoms resolved shortly after withdrawal of voriconazole.Voriconazole-associated periostitis has only recently been reported in the literature. Food and Drug Administration-approved in 2002, voriconazole is efficacious in treating serious, invasive fungal infections that are generally seen in immunocompromised patients. Due to the novel nature of voriconazole and the uncommon indications for its long-term use, the periostitis deformans described in this article may be unfamiliar to the orthopedic surgeon. Consequently, a patient presenting with bone pain and periosteal involvement on plain radiographs may provoke a broad, expensive, and ultimately unnecessary diagnostic evaluation. The clinical case and imaging findings presented here can help to promote understanding of this benign condition and its simple cure: voriconazole discontinuation.

Preoperative graft volume assessment with 3D-CT volumetry in living-donor lobar lung transplantations.

To determine the effectiveness of living-donor lobar lung transplantation (LDLLT), it is necessary to predict the recipient's postoperative lung function. Traditionally, Date's formula, also called the segmental ratio, has used the number of lung segments to estimate the forced vital capacity (FVC) of grafts in LDLLT. To provide a more precise estimate of graft FVC, we calculated the volumes of the lower lobe and total lung using three-dimensional computed tomography (3D-CT) and the volume ratio between them. We calculated the volume ratio in 52 donors and tested the difference between the segmental volume ratios with a one-tailed t-test. We also calculated the predicted graft FVC in 21 LDLLTs using the segmental ratio pFVC(c) and the volume ratio pFVC(v), and then found the Pearson's correlation coefficients for both pFVC(c) and pFVC(v) with the recipients' actual FVC (rFVC) measured spirometrically 6 months after surgery. Significant differences were found between the segmental ratio and the average volume ratio for both sides (right, p＝0.03;left, p＝0.0003). Both pFVC(c) and pFVC(v) correlated significantly with rFVC at 6 months after surgery (p＝0.007 and 0.006). Both the conventional and the volumetric methods provided FVC predictions that correlated significantly with measured postoperative FVC.

Thin-section computed tomography findings before and after azithromycin treatment of neutrophilic reversible lung allograft dysfunction.

OBJECTIVES: Recently a novel subgroup of bronchiolitis obliterans syndrome (BOS) has been described in patients after lung transplantation with high neutrophil counts in broncho-alveolar lavage and recovery of lung functional decline with azithromycin treatment. We aimed to describe the thin-section computed tomography (CT) findings of these neutrophilic reversible allograft dysfunction (NRAD) patients before and after azithromycin. METHODS: A cohort of 100 lung transplant recipients with BOS were treated with azithromycin and underwent lung function testing, broncho-alveolar lavage and CT before azithromycin treatment and during follow-up. The 200 CT data sets were scored for bronchial dilatation, mucus plugging, centrilobular abnormalities, airway wall thickening, consolidation, ground glass and end-expiratory air trapping. RESULTS: NRAD was characterized by more centrilobular abnormalities on CT (p = 0.03 for prevalence and p = 0.06 for severity) compared to non-responders. At follow-up NRAD patients showed improvement in all CT abnormalities including air trapping, but the degree of improvement in all CT abnormalities was significantly different between responders and non-responders (who showed progression of bronchus dilatation, consolidation and air trapping). CONCLUSIONS: Within BOS patients those with NRAD differ from azithromycin non-responders by more centrilobular abnormalities on CT before azithromycin and improvement in bronchus dilatation, consolidation and air trapping during treatment.

Medication-induced periostitis in lung transplant patients: periostitis deformans revisited.

We report five cases of diffuse periostitis resembling hypertrophic osteoarthropathy and perostitis deformans in lung transplantation patients on chronic voriconazole, a fluoride-containing compound. Although drug-related periostitis has long been known, the association of lung transplant medication with periostitis was only recently introduced in the literature. To our knowledge, imaging findings have not been fully characterized in the radiology literature. Imaging features along with clinical history help to distinguish this benign condition from other disease entities. In this article, we review the current literature and illustrate the variety of imaging characteristics of this entity so that interpreting radiologists can make accurate diagnoses and avoid unnecessary work up.

Bronchoscopic lung volume reduction in a single-lung transplant recipient with natal lung hyperinflation: a case report.

After single lung transplantation for emphysema native lung hyperinflation is a common complication that may cause respiratory failure. Herein we have reported satisfactory bronchoscopic lung volume reduction in a left single-lung transplant recipient with native lung hyperinflation, who suffered from Medical Research Council (MRC) class 3 dyspnea and chest pain. Three endobronchial valves (Zephyr; Emphasys Medical, Redwood, Calif, United States) were placed into the segmental bronchi of the right upper lobe, using videobronchoscopy under general anesthesia. Postoperative chest computed tomography revealed subsegmental atelectasis in that lobe. The clinical benefit was an improved MRC dyspnea class from 3 to 2, which was still present at 4 months after the procedure, although there were no remarkable changes in spirometric parameters.

Radiopharmaceutical considerations for using Tc-99m MAA in lung transplant patients.

OBJECTIVES: To elucidate radiopharmaceutical considerations for using technetium Tc-99m albumin aggregated (Tc-99m MAA) in lung transplant patients and to establish an appropriate routine dose and preparation procedure. SETTING: Tertiary care academic hospital during May 2007 to May 2009. PRACTICE DESCRIPTION: Nuclear pharmacist working in nuclear medicine department. PRACTICE INNOVATION: Radiopharmaceutical considerations deemed important for the use of Tc-99m MAA in lung transplant patients included radioactivity dose, particulate dose, rate of the radiolabeling reaction (preparation time), and final radiochemical purity. Evaluation of our initial 12-month experience, published literature, and professional practice guidelines provided the basis for establishing an appropriate dose and preparation procedure of Tc-99m MAA for use in lung transplant patients. MAIN OUTCOME MEASURES: Radiochemical purity at typical incubation times and image quality in subsequent lung transplant patients imaged during the next 12 months. RESULTS: Based on considerations of radioactivity dose, particulate dose, rate of the radiolabeling reaction (preparation time), and final radiochemical purity, a routine dose consisting of 3 mCi (111 MBq) and 100,000 particles of Tc-99m MAA for planar perfusion lung imaging of adult lung transplant patients was established as reasonable and appropriate. MAA kits were prepared with a more reasonable amount of Tc-99m and yielded high radiochemical purity values in typical incubation times. Images have continued to be of high diagnostic quality. CONCLUSION: Tc-99m MAA used for lung transplant imaging can be readily prepared with high radiochemical purity to provide a dose of 3 mCi (111 GBq)/100,000 particles, which provides images of high diagnostic quality.

Progression of native lung fibrosis in lung transplant recipients with idiopathic pulmonary fibrosis.

BACKGROUND: Single lung transplant recipients with idiopathic pulmonary fibrosis provide an opportunity to study fibrosis in the native lung over time in the setting of pronounced immunosuppression. Lung transplant patients are treated with a regimen of steroids, an antiproliferative agent and a calcineurin inhibitor. This represents a much greater immunosuppression regime than the typical treatment for IPF. To determine whether this regimen of high dose immunosuppression would arrest the progression of fibrosis, the high-resolution chest CT scans (HRCTs) of these patients were reviewed. METHODS: HRCTs of 21 patients who underwent single lung transplant for IPF between 1/96 and 1/06 were reviewed. Scans were evaluated by two readers at 6 months intervals, beginning within 1-2 months after transplant. Two calculations were made on the native lung: total volume and percentage of lung affected by fibrosis. Baseline pulmonary function test data was correlated with the immediate post-transplant CT. Patients were followed for an average of 35 months after transplant. RESULTS: The mean total volume of the native lung just after transplant was 1120cc. This decreased to 875cc by 2 years and 691cc by 4 years after transplant, representing an average decline of 10.8%/year. Initially, 52% of the native lung was affected by fibrosis compared to 92% at 4 years. Excluding scans with 100% of the lung affected by fibrosis, percentage fibrosis increased 11% per year. CONCLUSION: Fibrotic disease within the native lung progresses rapidly in single lung transplant recipients with IPF despite prolonged high dose immunosuppression.

Pseudallescheria boydii (Scedosporium species) in 3 lung transplant recipients: computed tomography findings and literature review.

OBJECTIVE: The objective of our study was to evaluate chest computed tomography (CT) findings in 3 lung transplant recipients infected with Pseudallescheria boydii complex or its asexual anamorph, Scedosporium apiospermum, 2 after double-lung transplant and 1 after single-lung transplantation. Awareness and early diagnosis of this rare but potentially lethal infection are important, as it is largely refractory to treatment with the antifungal agents of choice used for the more common Aspergillus species. Computed tomography investigation focused on the location, quality, and appearance of the various pulmonary lesions as well as the presence of cavitation, mediastinal lymphadenopathy, and pleural effusions. A literature review of previous lung and other solid organ transplant recipients infected with pulmonary Pseudallescheria boydii was also conducted and compared with our findings. CONCLUSION: While the high-resolution CT findings of pulmonary P. boydii infection are nonspecific and markedly similar to the manifestations of the more common Aspergillus species, awareness of this rare opportunist is important, given the high mortality associated with disseminated infection and the relative success possible with timely and appropriate treatment. The most common CT abnormalities present in our 3 patients included hilar and paratracheal adenopathy, noncavitary tree-in-bud nodules surrounded by ground-glass opacities, and airway thickening.

Computed tomography findings of postoperative complications in lung transplantation.

Due to the increasing number and improved survival of lung transplant recipients, radiologists should be aware of the imaging features of the postoperative complications that can occur in such patients. The early treatment of complications is important for the long-term survival of lung transplant recipients. Frequently, HRCT plays a central role in the investigation of such complications. Early recognition of the signs of complications allows treatment to be initiated earlier, which improves survival. The aim of this pictorial review was to demonstrate the CT scan appearance of pulmonary complications such as reperfusion edema, acute rejection, infection, pulmonary thromboembolism, chronic rejection, bronchiolitis obliterans syndrome, cryptogenic organizing pneumonia, post-transplant lymphoproliferative disorder, bronchial dehiscence and bronchial stenosis.

Monitoring of experimental rat lung transplants by high-resolution flat-panel volumetric computer tomography (fpVCT).

OBJECTIVE: Noninvasive assessment of experimental lung transplants with high resolution would be favorable to exclude technical failure and to follow up graft outcome in the living animal. Here we describe a flat-panel Volumetric Computed Tomography (fpVCT) technique using a prototype scanner. METHODS: Lung transplantation was performed in allogeneic as well as in corresponding syngeneic rat strain combinations. At different time points post-transplantation, fpVCT was performed. RESULTS: Lung transplants can be visualized in the living rat with high-spatial resolution. FpVCT allows a detailed analysis of the lung and the bronchi. Infiltrates developing during rejection episodes can be diagnosed and follow-up studies can easily be performed. CONCLUSIONS: With fpVCT it is possible to control the technical success of the surgical procedure. Graft rejection can be visualized individually in the living animal noninvasively, which is highly advantageous for studying the pathogenesis of chronic rejection or to monitor new therapies.

Imaging of lung transplantation: review.

OBJECTIVE Lung transplantation is an established treatment for end-stage pulmonary disease. Complications of lung transplantation include airway stenosis and dehiscence, reimplantation response, acute rejection, infection, posttransplantation lymphoproliferative disorder, and bronchiolitis obliterans syndrome. The incidence of graft rejection and airway anastomosis experienced in the early years of lung transplantation have been significantly reduced by advances in immunosuppression and surgical techniques. Infection is currently the most common cause of mortality during the first 6 months after transplantation, whereas chronic rejection or obliterative bronchiolitis is the most common cause of mortality thereafter. This article reviews the radiologic findings of different surgical techniques as well as the common early and late complications of lung transplantation. CONCLUSION Radiology plays a pivotal role in the diagnosis and management of complications of lung transplantation. Advancements in surgical technique and medical therapy influence the spectrum of expected radiologic findings. Familiarity with the radiologic appearances of common surgical techniques and complications of lung transplantation is important.

Assessment of mean transit time in the engrafted lung with 133Xe lung ventilation scintigraphy improves diagnosis of bronchiolitis obliterans syndrome in living-donor lobar lung transplant recipients.

OBJECTIVE: Staging of bronchiolitis obliterans syndrome (BOS) following lung transplantation is based on declines in forced expiratory volume in 1 s (FEV(1)). The aim of this study was to evaluate the usefulness of (133)Xe ventilation scintigraphy in the early detection of BOS following living-donor lobar lung transplantation (LDLLT), to compare (133)Xe washout imaging with computed tomography (CT) findings for early detection of BOS following LDLLT, and to evaluate (133)Xe washout imaging by quantitative analyses. METHODS: Subjects comprised 30 double-lung recipients and 1 single-lung recipient, who had undergone LDLLT at our institution and survived more than 1 year. Clinically diagnosed BOS developed in six recipients. Declines in graft function were evaluated using a combination of three methods, namely, dynamic spirometry, high-resolution CT (HRCT), and (133)Xe ventilation scintigraphy. Findings for all transplanted lungs were compared between CT and (133)Xe washout imaging. (133)Xe washout imaging was assessed using mean transit time (MTT) of bi-and unilateral lungs. Correlations between MTT of bilateral lungs and FEV(1)% were evaluated. Differences in MTT between BOS and non-BOS lungs, and between non-BOS and donor lungs were also evaluated on unilateral lungs. Appropriate cut-off values of MTT of unilateral lungs were set for the diagnosis of BOS. RESULTS: In all six BOS cases, prolonged-washout images of engrafted lungs revealed early-phase BOS with declines from baseline FEV(1), whereas only one BOS case could be detected using early CT findings of BO (bronchodilatation, decrease in number and size of pulmonary vessels, thickening of septal lines, and volume reduction). A significant correlation was identified between MTT and FEV(1)% (r = -0.346, P < 0.0001). MTT of unilateral lungs was significantly longer in BOS lungs than in non-BOS lungs (P < 0.0001). The cut-off MTT of unilateral lungs for the diagnosis of BOS was set at 64.77 s. CONCLUSIONS: Our data show that (133)Xe washout imaging offers excellent potential for early detection of BOS compared with early CT findings. Using (133)Xe washout imaging and MTT with radioactive tracer offers a noninvasive indication of selective ventilatory function in engrafted lungs following LDLLT. MTT appears useful for identifying BOS following LDLLT and allows quantitative evaluation of graft function in unilateral lungs.

Postoperative complications of lung transplantation: radiologic findings along a time continuum.

In the past decade, lung transplantation has become established as an accepted therapy for end-stage pulmonary disease. Complications of lung transplantation that may occur in the immediate or longer postoperative term include mechanical problems due to a size mismatch between the donor lung and the recipient thoracic cage; malposition of monitoring tubes and lines; injuries from ischemia and reperfusion; acute pleural events; hyperacute, acute, and chronic rejection; pulmonary infections; bronchial anastomotic complications; pulmonary thromboembolism; upper-lobe fibrosis; primary disease recurrence; posttransplantation lymphoproliferative disorder; and native lung complications such as hyperinflation, malignancy, and infection. Radiologic imaging--particularly chest radiography, computed tomography (CT), and high-resolution CT--is critical for the early detection, evaluation, and diagnosis of complications after lung transplantation. To enable the selection of an effective and relevant course of therapy and, ultimately, to decrease morbidity and mortality among lung transplant recipients, radiologists at all levels of experience must be able to recognize and understand the imaging manifestations of posttransplantation complications.

Quantitative lung perfusion following single lung transplantation.

BACKGROUND: Following successful lung transplantation, most of the lung perfusion, as well as ventilation, is shifted towards the transplanted lung. We investigated the changes in perfusion during exercise in lung transplant recipients. PATIENTS AND METHODS: Twelve patients were included in the study. Six patients had emphysema and 6 patients had idiopathic pulmonary fibrosis (IPF). Patients underwent two upright lung perfusion scans: the first at rest and the second during a maximal cardiopulmonary exercise test. Lung perfusion was assessed in each lung and regionally. RESULTS: At rest, patients with emphysema had 83.3 +/- 8 % of total perfusion to the transplanted side and 16.7 +/- 8 % to the native lung, while in the IPF patients, it was 68.7 +/- 12 and 32.7 +/- 10 %, respectively ( P = 0.028). At peak exercise, perfusion shifted from the transplanted lung to the native lung ( P = 0.0095) both in emphysema and IPF patients. CONCLUSIONS: Following successful lung transplantation, most of the perfusion is directed towards the transplanted lung. During exercise, there was a small but significant shift towards the native lung. These findings highlighted the important role of the native lung during maximal exercise.