Magnetic resonance imaging of breast implants: Optimizing tissue contrast

INTRODUCTION

Patients with breast implants need to undergo regular screening MRI procedures. One of the key requirements of this screening scan is the ability to suppress one or more tissues (water, fat, or silicone) simultaneously. However, the presence of "foreign" implants within the breast biological space affects the MRI scanner's normal operating mode. Often, this requires operator's supervision to make sure the correct image contrast is achieved.

METHODS

We built a phantom that represents the commonly encountered tissues (water, fat, and silicone) in breast implant imaging. The phantom was used to optimise imaging parameters and highlight common challenges encountered while imaging breast implants. We scanned the phantom on seven different MRI scanners (including 1.5T and 3T) and produced vendor-specific cheat-sheets on how to image breast implants. Ethical approval was not required for this article type.

CONCLUSION

Performing a breast MRI procedure with implants in-situ can be challenging. Employing a purpose-built phantom, we provide easy-to-use cheat sheets, with examples, outlining steps that can be taken to ensure appropriate tissue suppression and image contrast in breast implant MRI. We hope these cheat-sheets will help MRI practitioners to confidently and efficiently achieve accurate image contrasts across a number of implant scenarios which will aid in improving diagnostic accuracy, treatment plans, and thus prognosis for the patient.

Test-retest reliability and sample size estimates after MRI scanner relocation

OBJECTIVE

Many factors can contribute to the reliability and robustness of MRI-derived metrics. In this study, we assessed the reliability and reproducibility of three MRI modalities after an MRI scanner was relocated to a new hospital facility.

METHODS

Twenty healthy volunteers (12 females, mean age (standard deviation) ​= ​41 (11) years, age range [25-66]) completed three MRI sessions. The first session (S1) was one week prior to the 3T GE HDxt scanner relocation. The second (S2) occurred nine weeks after S1 and at the new location; a third session (S3) was acquired 4 weeks after S2. At each session, we acquired structural T1-weighted, pseudo-continuous arterial spin labelled, and diffusion tensor imaging sequences. We used longitudinal processing streams to create 12 summary MRI metrics, including total gray matter (GM), cortical GM, subcortical GM, white matter (WM), and lateral ventricle volume; mean cortical thickness; total surface area; average gray matter perfusion, and average diffusion tensor metrics along principal white matter pathways. We compared mean MRI values and variance at the old scanner location to multiple sessions at the new location using Bayesian multi-level regression models. K-fold cross validation allowed identification of important predictors. Whole-brain analyses were used to investigate any regional differences. Furthermore, we calculated within-subject coefficient of variation (wsCV), intraclass correlation coefficient (ICC), and dice similarity index (SI) of cortical segmentations across scanner relocation and within-site. Additionally, we estimated sample sizes required to robustly detect a 4% difference between two groups across MRI metrics.

RESULTS

All global MRI metrics exhibited little mean difference and small variability (bar cortical gray matter perfusion) both across scanner relocation and within-site repeat. T1- and DTI-derived tissue metrics showed ​< ​|0.3|% mean difference and <1.2% variance across scanner location and <|0.4|% mean difference and <0.8% variance within the new location, with between-site intraclass correlation coefficient (ICC) ​> ​0.80 and within-subject coefficient of variation (wsCV) ​< ​1.4%. Mean cortical gray matter perfusion had the highest between-session variability (6.7% [0.3, 16.7], estimate [95% uncertainty interval]), and hence the smallest ICC (0.71 [0.44,0.92]) and largest wsCV (13.4% [5.4, 18.1]). No global metric exhibited evidence of a meaningful mean difference between scanner locations. However, surface area showed evidence of a mean difference within-site repeat (between S2 and S3). Whole-brain analyses revealed no significant areas of difference between scanner relocation or within-site. For all metrics, we found no support for a systematic difference in variance across relocation sites compared to within-site test-retest reliability. Necessary sample sizes to detect a 4% difference between two independent groups varied from a maximum of n ​= ​362 per group (cortical gray matter perfusion), to total gray matter volume (n ​= ​114), average fractional anisotropy (n ​= ​23), total gray matter volume normalized by intracranial volume (n ​= ​19), and axial diffusivity (n ​= ​3 per group).

CONCLUSION

Cortical gray matter perfusion was the most variable metric investigated (necessitating large sample sizes to identify group differences), with other metrics showing substantially less variability. Scanner relocation appeared to have a negligible effect on variability of the global MRI metrics tested. This manuscript reports within-site test-retest variability to act as a tool for calculating sample size in future investigations. Our results suggest that when all other parameters are held constant (e.g., sequence parameters and MRI processing), the effect of scanner relocation is indistinguishable from within-site variability, but may need to be considered depending on the question being investigated.

Beta Amyloid Deposition Is Not Associated With Cognitive Impairment in Parkinson's Disease

The extent to which Alzheimer neuropathology, particularly the accumulation of misfolded beta-amyloid, contributes to cognitive decline and dementia in Parkinson's disease (PD) is unresolved. Here, we used Florbetaben PET imaging to test for any association between cerebral amyloid deposition and cognitive impairment in PD, in a sample enriched for cases with mild cognitive impairment. This cross-sectional study used Movement Disorders Society level II criteria to classify 115 participants with PD as having normal cognition (PDN, n = 23), mild cognitive impairment (PD-MCI, n = 76), or dementia (PDD, n = 16). We acquired 18F-Florbetaben (FBB) amyloid PET and structural MRI. Amyloid deposition was assessed between the three cognitive groups, and also across the whole sample using continuous measures of both global cognitive status and average performance in memory domain tests. Outcomes were cortical FBB uptake, expressed in centiloids and as standardized uptake value ratios (SUVR) using the Centiloid Project whole cerebellum region as a reference, and regional SUVR measurements. FBB binding was higher in PDD, but this difference did not survive adjustment for the older age of the PDD group. We established a suitable centiloid cut-off for amyloid positivity in Parkinson's disease (31.3), but there was no association of FBB binding with global cognitive or memory scores. The failure to find an association between PET amyloid deposition and cognitive impairment in a moderately large sample, particularly given that it was enriched with PD-MCI patients at risk of dementia, suggests that amyloid pathology is not the primary driver of cognitive impairment and dementia in most patients with PD.

Practical implications of motion correction with motion insensitive radial k-space acquisitions in MRI

OBJECTIVE

To highlight specific instances when radial k-space acquisitions in MRI result in image artifacts and how to ameliorate such artifacts.

METHODS

We acquired axial T₂ weighted MR images on (1) the American College of Radiology (ACR) phantom and (2) a sedated sheep with rectilinear and multiblade radial k-space filling acquisitions. Images were acquired on four (2 × 1.5T and 2 × 3T) different MRI scanners. For the radial k-space acquisitions, we acquired images with and without motion correction. All images were visually inspected for the presence of artifact.

RESULTS

Images collected via the conventional rectilinear method were of diagnostic quality and free of artifact. Both ACR and sheep images acquired with radial k-space acquisitions and motion correction suffered significant artifact at different slice locations, scan sessions and across all the four scanners. Severity of the artifact was associated with echo train length. However, the artifact was eliminated when motion correction was not employed.

CONCLUSION

When little to no motion is present, the use of motion correction with radial k-space acquisitions can compromise image quality. However, image quality is quickly improved, and the artifact eliminated, by repeating the scan without motion correction or by using a conventional rectilinear alternative. Advances in Knowledge: By improving awareness and understanding of this artifact, MRI users will be able to adjust MRI protocols, resulting in more successful scanning sessions, better image quality, fewer call backs and increased diagnostic confidence.

Tracking Parkinson's Disease over One Year with Multimodal Magnetic Resonance Imaging in a Group of Older Patients with Moderate Disease

Background & Objectives

Cross-sectional magnetic resonance imaging (MRI) suggests that Parkinson’s disease (PD) is associated with changes in cerebral tissue volume, diffusion tensor imaging metrics, and perfusion values. Here, we performed a longitudinal multimodal MRI study—including structural, diffusion tensor imaging (DTI), and perfusion MRI—to investigate progressive brain changes over one year in a group of older PD patients at a moderate stage of disease.

Methods

Twenty-three non-demented PD (mean age (SD) = 69.5 (6.4) years, disease duration (SD) = 5.6 (4.3) years) and 23 matched control participants (mean age: 70.6 (6.8)) completed extensive neuropsychological and clinical assessment, and multimodal 3T MRI scanning at baseline and one year later. We used a voxel-based approach to assess change over time and group-by-time interactions for cerebral structural and perfusion metrics.

Results

Compared to controls, in PD participants there was localized grey matter atrophy over time in bilateral inferior and right middle temporal, and left orbito-frontal cortices. Using a voxel-based approach that focused on the centers of principal white matter tracts, the PD and control cohorts exhibited similar levels of change in DTI metrics. There was no significant change in perfusion, cognitive, or motor severity measures.

Conclusions

In a cohort of older, non-demented PD participants, macrostructural MRI detected atrophy in the PD group compared with the control group in temporal and orbito-frontal cortices. Changes in diffusion MRI along principal white matter tracts over one year were found, but this was not differentially affected by PD.

Comparing cerebral perfusion in Alzheimer's disease and Parkinson's disease dementia: an ASL-MRI study

Emerging evidence suggests that Alzheimer's disease (AD) and Parkinson's disease dementia (PDD) share neurodegenerative mechanisms. We sought to directly compare cerebral perfusion in these two conditions using arterial spin labeling magnetic resonance imaging (ASL-MRI). In total, 17 AD, 20 PDD, and 37 matched healthy controls completed ASL and structural MRI, and comprehensive neuropsychological testing. Alzheimer's disease and PDD perfusion was analyzed by whole-brain voxel-based analysis (to assess absolute blood flow), a priori specified region of interest analysis, and principal component analysis (to generate a network differentiating the two groups). Corrections were made for cerebral atrophy, age, sex, education, and MRI scanner software version. Analysis of absolute blood flow showed no significant differences between AD and PDD. Comparing each group with controls revealed an overlapping, posterior pattern of hypoperfusion, including posterior cingulate gyrus, precuneus, and occipital regions. The perfusion network that differentiated AD and PDD groups identified relative differences in medial temporal lobes (AD Collapse

Key Words

• alzheimer's disease
• arterial spin labeling
• dementia
• mri
• parkinson's disease

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MESH Headings

• Aged
• Aged, 80 and over
• Alzheimer Disease/diagnostic imaging
• Alzheimer Disease/physiopathology
• Blood Flow Velocity
• Cerebrovascular Circulation
• Female
• Humans
• Limbic System/blood supply
• Limbic System/diagnostic imaging
• Limbic System/physiopathology
• Magnetic Resonance Angiography
• Male
• Parkinson Disease/diagnostic imaging
• Parkinson Disease/physiopathology
• Radiography

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Affiliation(s)

Campbell J Le Heron New Zealand Brain Research Institute, Christchurch, New Zealand
Sarah L Wright New Zealand Brain Research Institute, Christchurch, New Zealand
Tracy R Melzer New Zealand Brain Research Institute, Christchurch, New Zealand Department of Medicine, University of Otago, Christchurch, New Zealand
Daniel J Myall New Zealand Brain Research Institute, Christchurch, New Zealand
Michael R MacAskill New Zealand Brain Research Institute, Christchurch, New Zealand Department of Medicine, University of Otago, Christchurch, New Zealand
Leslie Livingston New Zealand Brain Research Institute, Christchurch, New Zealand Department of Medicine, University of Otago, Christchurch, New Zealand
Ross J Keenan New Zealand Brain Research Institute, Christchurch, New Zealand Christchurch Radiology Group, Christchurch, New Zealand
Richard Watts College of Medicine, University of Vermont, Burlington, Vermont, USA
John C Dalrymple-Alford New Zealand Brain Research Institute, Christchurch, New Zealand Department of Medicine, University of Otago, Christchurch, New Zealand Department of Psychology, University of Canterbury, Christchurch, New Zealand
Tim J Anderson New Zealand Brain Research Institute, Christchurch, New Zealand Department of Medicine, University of Otago, Christchurch, New Zealand Department of Neurology, Christchurch Hospital, Christchurch, New Zealand

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White matter microstructure deteriorates across cognitive stages in Parkinson disease

OBJECTIVES

To characterize different stages of Parkinson disease (PD)-related cognitive decline using diffusion tensor imaging (DTI) and investigate potential relationships between cognition and microstructural integrity of primary white matter tracts.

METHODS

Movement Disorder Society criteria were used to classify 109 patients with PD as having normal cognition (PD-N, n = 63), mild cognitive impairment (PD-MCI, n = 28), or dementia (PD-D, n = 18), and were compared with 32 matched controls. DTI indices were assessed across groups using tract-based spatial statistics, and multiple regression was used to assess association with cognitive and clinical measures.

RESULTS

Relative to controls, PD-N showed some increased mean diffusivity (MD) in corpus callosum, but no significantly decreased fractional anisotropy (FA). Decreased FA and increased MD were identified in PD-MCI and PD-D relative to controls. Only small areas of difference were observed in PD-MCI and PD-D compared with PD-N, while DTI metrics did not differ significantly between PD-MCI and PD-D. Executive function, attention, memory, and a composite measure of global cognition were associated with MD, primarily in anterior white matter tracts; only attention was associated with FA. These differences were independent of white matter hyperintensity load, which was also associated with cognition in PD.

CONCLUSIONS

PD is associated with spatially restricted loss of microstructural white matter integrity in patients with relatively normal cognition, and these alterations increase with cognitive dysfunction. Functional impairment in executive function, attention, and learning and memory appears associated with microstructural changes, suggesting that tract-based spatial statistics provides an early marker for clinically relevant cognitive impairment in PD.

Reduced striatal volumes in Parkinson's disease: a magnetic resonance imaging study

Background

The presence and extent of structural changes in the brain as a consequence of Parkinson’s disease (PD) is still poorly understood.

Methods

High-resolution 3-tesla T1-weighted structural magnetic resonance images in sixty-five PD and 27 age-matched healthy control participants were examined. Putamen, caudate, and intracranial volumes were manually traced in the axial plane of 3D reconstructed images. Striatal nuclei volumes were normalized to intracranial volume for statistical comparison. Disease status was assessed using the Unified Parkinson’s Disease Rating Scale and Hoehn and Yahr scale. Cognitive status was assessed using global status tests and detailed neuropsychological testing.

Results

Both caudate and putamen volumes were smaller in PD brains compared to controls after adjusting for age and gender. Caudate volumes were reduced by 11% (p = 0.001) and putamen volumes by 8.1% (p = 0.025). PD striatal volumes were not found to be significantly correlated with cognitive or motor decline.

Conclusion

Small, but significant reductions in the volume of both the caudate and putamen occur in PD brains. These reductions are independent of the effects of age and gender, however the relation of these reductions to the functional loss of dopamine, which is characteristic of PD, remains unclear.

Grey matter atrophy in cognitively impaired Parkinson's disease

OBJECTIVE

Mild cognitive impairment and dementia are common non-motor features of Parkinson's disease (PD). The aim of this study was to characterise grey matter changes associated with clearly defined stages of cognitive impairment in PD using structural MRI.

METHODS

96 PD subjects were classified using detailed cognitive testing as PD with normal cognition (PD-N, n=57), PD with mild cognitive impairment (PD-MCI, n=23) or PD with dementia (PD-D, n=16); 34 controls matched for mean age and sex ratio also participated. Grey matter volume differences were evaluated using voxel based morphometry of grey matter segments derived from T1 weighted 3 T MRI, and multiple linear regression assessed the relationship between cognitive and motor impairments and grey matter concentration.

RESULTS

Compared with controls, no grey matter differences were found in PD-N. PD-MCI showed limited grey matter atrophy in the temporal, parietal and frontal cortex as well as the bilateral caudal hippocampus, amygdala and right putamen. PD-D subjects exhibited far more extensive atrophy in regions involved in PD-MCI but also had reduced grey matter volume in other large areas of the temporal lobe (including the parahippocampi), the intracalcarine and lingual gyri, posterior cingulate gyrus, frontal regions and bilateral caudate. Grey matter loss in PD correlated with global cognitive score but not motor impairment in most of these regions.

INTERPRETATION

Marked grey matter atrophy occurs in PD with dementia but far less extensive changes are evident in PD-MCI. Some grey matter atrophy precedes the development of dementia but may be accelerated once frank dementia begins.

Bronchoscopic palliation of primary lung cancer: Single or multimodality therapy?

BACKGROUND

An obstructing primary lung cancer is a challenging disease frequently requiring endobronchial interventional therapy. A variety of interventional modalities, including Nd:YAG laser, stenting, photodynamic therapy (PDT), and endoluminal brachytherapy, are utilized to relieve airway obstruction and bleeding. The aim of this study is to compare the effect on patient survival of bronchoscopic palliation for lung cancer utilizing one interventional modality compared to the use of combination of modalities to relieve the airway problem. METHODS. We reviewed our longitudinal experience with interventional bronchoscopy in 75 patients who underwent 176 procedures for the management of endobronchial lung cancer between 1994 and 2002. Indication for intervention was hemoptysis in 24 patients (32%) and airway obstruction in the remaining. Six patients died within 30 days from the first intervention and were excluded. Forty of the surviving 69 patients (58%) were treated with a single interventional modality (group A). In 29 patients (42%) a multimodality endoscopic treatment was utilized (group B). Single-modality treatment in group A included Nd-YAG laser in 60%, stent in 17%, brachytherapy in 20%, and PDT in 3%. A variety of combinations of the aforementioned modalities were used in group B to enhance airway patency. Patient data were compared with the Student's t-test and chi-square test. Survival analysis and the log rank test were used to compare difference in survival between the two groups. A p-value of 0.05 was considered significant.

RESULTS

There were 46 males and 23 females, with a mean age of 67 years. The tumor was located in the trachea 9%, in the carina in 7%, and primary bronchial in 84%. Two patients had complications due to stent malposition. There was no significant difference between the two groups in relation to age, gender, tumor location, histology, and type of previous cancer therapy. There was a significant improvement in survival for the multimodality group (p = 0.04). The 1- and 3-year cumulative survival rate for groups A and B was 51.3% versus 50% and 2.3% versus 22%, respectively.

CONCLUSIONS

Improvement in survival can be seen with diligent airway surveillance after interventional bronchoscopy and liberal use of a variety of endobronchial treatment modalities for airway obstruction or bleeding. Physicians involved in the management of this difficult problem should be versed in the use of all available treatment modalities to enhance therapeutic outcome.

Laparoscopic repair of large paraesophageal hernia is associated with a low incidence of recurrence and reoperation

BACKGROUND

Laparoscopic repair of paraesophageal hernia (LRPEH) is a feasible and effective technique. There have been some recent concerns regarding possible high recurrence rates following laparoscopic repair.

METHODS

We reviewed our experience with LRPEH from 5/1996 to 8/2002. Large paraesophageal hernia (PEH) was defined by the presence of more than one-third of the stomach in the thoracic cavity. Principles of repair included reduction of the hernia, excision of the sac, approximation of the crura, and fundoplication. Pre- and postoperative symptoms were evaluated utilizing visual analogue scores (VAS) on a scale ranging from 0 to 10. Patients were followed with VAS and barium esophagram studies. Statistical analysis was performed using two-tailed Student's t-test.

RESULTS

A total of 166 patients with a mean age of 68 years underwent LRPEH. PEH were type II ( n = 43), type III ( n = 104), and type IV ( n = 19). Mean operative time was 160 min. Fundoplications were Nissen (127), Toupet (23), Dor (1), and Nissen-Collis (1). Fourteen patients underwent a gastropexy. One patient required early reoperation to repair an esophageal leak. Mean hospital stay was 3.9 days. At 24 months postoperatively there was statistically significant improvement in the mean symptom scores: heartburn from 6.8 to 0.5, regurgitation from 5.9 to 0.3, dysphagia from 4.0 to 0.5, chest pain from 3.7 to 0.3. Radiographic surveillance was obtained in 120 patients (72%) at a mean of 15 months postoperatively. Six patients (5%) had radiographic evidence of a recurrent paraesophageal hernia (two required surgery), 24 patients (20%) had a sliding hernia (two required surgery), and four patients (3.3%) had wrap failure (all four required surgery). Reoperation was required in 10 patients (6%); two for symptomatic recurrent PEH (1.2%), four for recurrent reflux symptoms (2.4%), and four for dysphagia (2.4%). Patients with abnormal postoperative barium esophagram studies who did not require reoperation have remained asymptomatic at a mean follow up of 14 months.

CONCLUSION

LPEHR is a safe and effective treatment for PEH. Postoperative radiographic abnormalities, such as a small sliding hernia, are often seen. The clinical importance of these findings is questionable, since only a small percentage of patients require reoperation. True PEH recurrences are uncommon and frequently asymptomatic.

The presence of colorectal hepatic metastases does not preclude pulmonary metastasectomy

Hepatic metastases due to colorectal carcinoma have often been felt to preclude pulmonary metastasectomy. With the recent advances in surgical options, should patients with both liver and lung metastases be considered for surgical resection? The current study reviews the impact of such aggressive management on disease-free and overall survival (OS). The clinical course of 63 patients presenting with colorectal metastasis to the lung alone (group 1, n = 45) or combined hepatic and lung metastases (group 2, n = 18) were reviewed. All patients underwent complete resection of their lung metastases. Surgical control of hepatic tumor burden was achieved by tumor ablation, intra-arterial therapy, and/or resection. All patients in group 1 and group 2 were available for a mean follow-up of 27 and 24 months, respectively. The presence of hepatic metastases, the resectability of hepatic tumor burden, and the disease-free interval after pulmonary metastasectomy did not significantly influence survival. These findings demonstrate that aggressive surgical management of pulmonary metastases in the presence of liver metastases offers a similar benefit as compared to patients with pulmonary metastases alone. Therefore, hepatic metastatic disease does not preclude an attempt at pulmonary metastasectomy if hepatic metastases can be resected or remains responsive to therapy. Such an approach achieves comparable OS and mean survival when compared to pulmonary metastasectomy alone.

Effectiveness of laparoscopic fundoplication in relieving the symptoms of gastroesophageal reflux disease (GERD) and eliminating antireflux medical therapy

BACKGROUND

Recent reports have suggested that antireflux surgery should not be advised with the expectation of elimination of medical treatment. We reviewed our results with laparoscopic fundoplication as a means of eliminating the symptoms of gastroesophageal reflux disease (GERD), improving quality of life, and freeing patients from chronic medical treatment for GERD.

METHODS

A total of 297 patients who underwent laparoscopic fundoplication (Nissen, n = 252; Toupet, n = 45) were followed for an average of 31.4 months. Preoperative evaluation included endoscopy, barium esophagram, esophageal manometry, and 24-h pH analysis. A preoperative and postoperative visual analogue scoring scale (0-10 severity) was used to evaluate symptoms of heartburn, regurgitation, and dysphagia. A GERD score (2-32) as described by Jamieson was also utilized. The need for GERD medications before and after surgery was assessed.

RESULTS

At 2-year follow-up, the average symptom scores decreased significantly in comparison to the preoperative values: heartburn from 8.4 to 1.7, regurgitation from 7.2 to 0.7, and dysphagia from 3.7 to 1.0. The Jamieson GERD score also decreased from 25.7 preoperatively to 4.1 postoperatively. Only 10% of patients were on proton pump inhibitors (PPI) at 2 years after surgery for typical GERD symptoms. A similar percentage of patients (8.7%) were on PPI treatment for questionable reasons, such as Barrett's esophagus, "sensitive" stomach, and irritable bowel syndrome. Seventeen patients (5.7%) required repeat fundoplication for heartburn ( n = 9), dysphagia ( n = 5), and gas/bloating ( n = 3).

CONCLUSIONS

Laparoscopic fundoplication can successfully eliminate GERD symptoms and improve quality of life. Significant reduction in the need for chronic GERD medical treatment 2 years after antireflux surgery can be anticipated.

Selection of patients for lung volume reduction surgery using a power law analysis of the computed tomographic scan

BACKGROUND

A study was undertaken to test the hypothesis that patients respond better to lung volume reduction surgery (LVRS) if their emphysema is confluent and predominantly located in the upper lobes.

METHODS

A density mask analysis was used to identify voxels inflated beyond 10.2 ml gas/g tissue (-910 HU) on preoperative and postoperative CT scans from patients receiving LVRS. These hyperinflated regions were considered to represent emphysematous lesions. A power law analysis was used to determine the relationship between the number (K) and size (A) of the emphysematous lesions in the whole lung and two anatomical regions using the power law equation Y=KA(-D).

RESULTS

The analysis showed a positive correlation between the change in the power law exponent (D) and the change in exercise (Watts) after surgery (r=0.47, p=0.03). There was also a negative correlation between the power law exponent D in the upper region of the lung preoperatively and the change in exercise following surgery (r=-0.60, p<0.05).

CONCLUSIONS

These results confirm that patients with large upper lobe lesions respond better to LVRS than patients with small uniformly distributed disease. Power law analysis of lung CT scans provides a quantitative method for determining the extent and location of emphysema within the lungs of patients with COPD.

Prediction of postoperative gas bloating after laparoscopic antireflux procedures based on 24-h pH acid reflux pattern

BACKGROUND

Postoperative gas/bloating (G/B) is a common sequelae after laparoscopic fundoplication. Patients with "upright" reflux are thought to have more aerophagic tendencies contributing to their GERD symptoms than patients with significant "supine" patterns of reflux. The risk of postoperative G/B developing was analyzed in relation to patient preoperative patterns of upright, mixed, or supine 24-h pH scores.

METHODS

In this study, 339 patients undergoing fundoplication (278 Nissen and 61 Toupet) were evaluated for preoperative G/B symptoms using a 0 to 10 severity visual analogue scale. Reflux patterns were classified as upright, supine, or mixed according to 24-h pH studies.

RESULTS

As compared with preoperative values, 46% of the patients with a preoperative G/B score less than 3 and an upright or mixed reflux pattern had a significant increase in their average G/B score at 2 years (upright, from 0.9 to 4.2; mixed, from 1.1 to 4.1). However, the patients with a supine reflux pattern did not have a statistically significant change (from 2.0 to 2.2; p > 0.05). The patients with established aerophagic tendencies preoperatively (G/B score > 3) showed significant improvement in these symptoms at 2 years across all three reflux patterns (average G/B score, from 7.7 preoperatively to 4.8 at 2 years). There was no gender predisposition, nor was there any difference in the incidence of G/B between complete and partial fundoplication.

CONCLUSIONS

The pattern of 24-h acid reflux can be predictive of G/B after antireflux surgery. Patients with mild preoperative G/B symptoms (score <3) and upright or mixed patterns of 24-h acid reflux appear to have an increased postoperative risk for chronic G/B as compared with patients who have supine reflux and mild preoperative G/B. Patients with moderate to severe preoperative G/B symptoms (score, 3-10) appear to have a general improvement in G/B symptoms at 2 years after fundoplication.

Outcome analysis of laparoscopic Roux-en-Y gastric bypass for morbid obesity. The first 116 cases

BACKGROUND

Morbid obesity has been described as a continuing epidemic affecting a growing portion of our population. We report an outcome analysis of our early experience with laparoscopic Roux-en-Y gastric bypass (LRYGB) in the treatment of morbid obesity.

METHODS

Two surgeons performed 116 consecutive LRYGBs at a single institution, creating a 25-ml pouch and a 90- to 150-cm Roux limb. The prospectively collected data included patient demographics, comorbidities, postoperative weight loss, and complications.

RESULTS

All eight conversions to an open procedure occurred early during the experience of the surgeons. The mean operating room time for the first 50 cases was 272 min, which decreased to 198 min with experience. The mean length of hospital stay was 3 days. There were 34 complications in 27 patients (23.3%), 14 of which (12%) required reoperation. At 18 months postoperatively, the patients had lost 77% of their excess weight, and their body mass index had decreased from a mean of 49.3 to 32.6 kg/m2. As a result of LRYGB, 25% of the patients were rendered completely free of any pharmacologic treatment for their preexisting comorbidities.

CONCLUSIONS

Although technically challenging, LRYGB can be performed safely with excellent long-term results. The mean operating room time and conversion rate improved with experience. As this study showed, LRYGB achieves an excellent rate of weight loss and improvement in preoperative comorbidities with a minimal length of hospital stay and an acceptable complication rate.

The signal recognition particle

The signal recognition particle (SRP) and its membrane-associated receptor (SR) catalyze targeting of nascent secretory and membrane proteins to the protein translocation apparatus of the cell. Components of the SRP pathway and salient features of the molecular mechanism of SRP-dependent protein targeting are conserved in all three kingdoms of life. Recent advances in the structure determination of a number of key components in the eukaryotic and prokaryotic SRP pathway provide new insight into the molecular basis of SRP function, and they set the stage for future work toward an integrated picture that takes into account the dynamic and contextual properties of this remarkable cellular machine.

Core to rind distribution of severe emphysema predicts outcome of lung volume reduction surgery

Computed tomography (CT) has shown that emphysema is more extensive in the inner (core) region than in the outer (rind) region of the lung. It has been suggested that the concentration of emphysematous lesions in the outer rind leads to a better outcome following lung volume reduction surgery (LVRS) because these regions tend to be more surgically accessible. The present study used a recently described, computer-based CT scan analysis to quantify severe emphysema (lung inflation > 10.2 ml gas/g tissue), mild/moderate emphysema (lung inflation = 10.2 to 6.0 ml gas/g tissue), and normal lung tissue (lung inflation < 6.0 ml gas/g tissue) present in the core and rind of the lung in 21 LVRS patients. The results show that the quantification of severe emphysema independently predicts change in maximal exercise response and FEV(1). We conclude that a greater extent of severe emphysema in the rind of the upper lung predicts greater benefit from LVRS because it identifies the lesions most accessible to removal by LVRS.

Outcomes after minimally invasive esophagomyotomy

BACKGROUND

Thoracic surgeons traditionally performed thoracotomy and myotomy for achalasia. Recently minimally invasive approaches have been reported with good success. This report summarizes our single-institution experience using video-assisted thoracoscopy (VATS) or laparoscopy (LAP) for the treatment of achalasia.

METHODS

A review of 62 patients undergoing minimally invasive myotomy for achalasia was performed. There were 27 male and 35 female patients. Mean age was 53 years (range 14 to 86). Thirty-seven (59.7%) had failed prior treatments (balloon dilation, botulinim toxin injection, or prior surgery). Outcomes studied were dysphagia score (1 = none, 5 = severe), Short-Form 36 quality of life (SF36 QOL) score, and heartburn-related QOL index (HRQOL).

RESULTS

Surgery included myotomy and partial fundoplication (5 VATS and 57 LAP). Mortality was zero, and complications occurred in 9 (14.5%) patients. There were 6 perforations (4 repaired by LAP and 2 open). Median length of stay was 2 days, time to oral intake was 1 day. At a mean of 19 months follow-up, 92.5% of patients were satisfied with outcome. Dysphagia scores improved from 3.6 to 1.5 (p < 0.01) but 3 patients ultimately required esophagectomy for recurrent dysphagia. HRQOL scores for heartburn and SF-36 QOL scores were comparable with control populations.

CONCLUSIONS

Minimally invasive myotomy and partial fundoplication for achalasia improved dysphagia in 92.5% of patients with heartburn and QOL scores were comparable with normal values at 19-month follow-up. The laparoscopic approach offers excellent results and was the preferred approach by our thoracic group for treating achalasia. Thoracic residency training should strive to include laparoscopic esophageal experience.

Paraplegia secondary to Burkholderia pseudomallei myelitis: a case report

Bacterial infection is an uncommon cause of acute paraplegia. A 42-year-old Aboriginal man presented to a remote health clinic in northern Australia with myelitis associated with Burkholderia pseudomallei. He was treated with analgesia and intravenous flucloxacillin, ceftriaxone, and gentamicin and transferred to our hospital, where an urgent T12-L1 laminectomy and decompression was performed. Urine culture confirmed B. pseudomallei infection (melioidosis). Abdominopelvic computed tomography revealed left prostatic lobe and right periprostatic abscesses, which were managed conservatively. The patient was given intravenous ceftazidime (8g/d) for 2 months, followed by oral sulfamethoxazole (1600mg) and trimethoprim (320mg) twice daily for 8 weeks. Magnetic resonance imaging 3 weeks after his admission confirmed transverse myelitis. His rehabilitation was complicated by his difficulty in adjusting to disability, by urinary retention and fecal incontinence, by communication barriers, and his isolation from a culture familiar to him. He returned to his community after 15 weeks, free of infection, with T10-11 paraplegia and an indwelling catheter.

Neutrophils, unopposed neutrophil elastase, and alpha1-antiprotease defenses following human lung transplantation

Neutrophils are sequestered in the newly transplanted lung after reperfusion or with infection, rejection, and chronic graft dysfunction. Because unopposed (free) neutrophil elastase (NE) released into bronchoalveolar secretions may injure the lung allograft and impair bacterial clearance, we assessed total neutrophil numbers, myeloperoxidase activity as an index of neutrophil influx and degranulation, alpha1-antiprotease (alpha1-AP) concentrations, and unopposed NE activity in bronchoalveolar secretions from lung transplant recipients. Unopposed NE activity was present in bronchoalveolar lavage fluid (BALF) from recipients transplanted for emphysema associated with alpha1-AP deficiency as well as recipients without such deficiency (171 of 2,137 BALF; 8%). Ten of 17 (59%) recipients with alpha1-AP deficiency who were followed for at least 1 yr after transplant with multiple surveillance and diagnostic bronchoscopies had at least one BALF containing unopposed NE, usually associated with the presence of > or = 10(5) colony forming units/ml BALF of aerobic bacteria. In contrast, 19 of 58 (33%) with emphysema not associated with alpha1-AP deficiency, 8 of 32 (25%) recipients with cystic fibrosis (CF), 6 of 16 (38%) with idiopathic pulmonary fibrosis (IPF), and 11 of 36 (31%) with other indications for transplant had unopposed NE in BALF. alpha1-AP levels were significantly elevated in the early posttransplant time period and could be augmented considerably in alpha1-AP-deficient recipients with episodes of infection or rejection. Our findings indicate that unopposed NE activity can be found in both alpha1-AP-deficient and alpha1-AP-sufficient recipients after transplantation, usually in association with endobronchial bacterial infection.

Therapeutic video-assisted thoracoscopic surgical resection of colorectal pulmonary metastases

OBJECTIVE

Careful patient selection is vital when video-assisted thoracoscopic surgical (VATS) therapeutic pulmonary metastasectomy of colorectal carcinoma is considered. Complete resection of all metastatic disease remains a vital concept. We reviewed our VATS experience for therapeutic metastasectomy of peripheral colorectal pulmonary metastases.

METHODS

Over 90 months, therapeutic VATS metastasectomy was accomplished upon 80 patients with colorectal metastases. Thin cut computed tomography (CT) was central in identifying lesions. The mean interval from primary carcinoma to VATS resection was 41 months (1-156 months; median, 33). A solitary lesion was resected in 60 patients and multiple (2-7) lesions resected in 20 patients. Statistics were obtained using the Student's t-test.

RESULTS

No operative mortality or major postoperative complications occurred. The hospital stay was 4.5+/-2. 2 days (range, 1-13). All lesions were resected by VATS, with four conversions to thoracotomy to improve the margins. The mean survival of patients with one lesion was 34.8 months compared with 26.5 months for patients with multiple lesions (P=0.37). The mean survival was 20.5 months when metastases occurred <3 years vs. 28.1 months for >3 years from primary carcinoma resection (P=0.20). Twenty-five (31%) patients are disease free; with a mean interval of 38.7 (3-84; median, 35) months. Sixty-nine percent (55/80) of patients developed a recurrence: 6/80 (8%) local; 19/80 (24%) regional (same hemithorax away from resection); and 30/80 (38%) distant. The overall survival at 1 year was 81.2%, 48.4% at 3 years and 30.8% at 5 years.

CONCLUSIONS

Therapeutic VATS resection of colorectal metastases appears efficacious. Preoperative CT can identify peripheral colorectal metastases amenable to VATS. Conversion to thoracotomy is indicated when none of the lesions identified by CT are found or when clear surgical margins are jeopardized.

Preoperative severity of emphysema predictive of improvement after lung volume reduction surgery: use of CT morphometry

STUDY OBJECTIVE

To determine how the volume and severity of emphysema measured by CT morphometry (CTM) before and after lung volume reduction surgery (LVRS) relates to the functional status of patients after LVRS.

DESIGN

A histologically validated CT algorithm was used to quantify the volume and severity of emphysema in 35 patients before and after LVRS: total lung volume (TLV), normal lung volume (< 6.0 mL gas per gram of tissue), volume of mild/moderate emphysema (ME; 6.0 to 10.2 mL gas per gram of tissue), volume of severe emphysema (> 10.2 mL gas per gram of tissue), surface area/volume (SA/V; meters squared per milliliter), and surface area (SA; meters squared). Outcome parameters included maximal cardiopulmonary exercise (CPX) performance in 21 patients and routine pulmonary function in all patients. We hypothesized that baseline CTM parameters predict response to LVRS and that the change in these parameters may offer insight into mechanisms of improvement.

PATIENTS AND INTERVENTION

Thirty-five patients with severe emphysema who had successful LVRS.

RESULTS

The significant decrease in TLV following LVRS was entirely accounted for by a decrease in severe emphysema. The SA/V and the SA both increased significantly following LVRS. The change in maximal CPX in watts following surgery correlated significantly with baseline values of severe emphysema (r = 0.60), which was collinear with TLV, and SA/V. The change in diffusing capacity of the lung for carbon monoxide revealed a significant positive linear relationship with preoperative severe emphysema (r = 0.37) and a negative relationship with ME (r = -0.37). Change in watts revealed a strong relationship with changes in severe emphysema (r = -0.75) and weaker but significant relationships with change in TLV, ME, SA/V, and SA. Other measures of pulmonary function revealed significant albeit less dominant relationships with baseline CTM and change in these indexes.

CONCLUSION

Using CTM, we have identified a close relationship between baseline severe emphysema, or change in severe emphysema, and the improvement in CPX after LVRS. These observations support a potential role of CTM in future clinical trials for predicting responders to LVRS and identifying mechanisms of improvement.

Laparoscopic repair of giant paraesophageal hernia: 100 consecutive cases

OBJECTIVE

To summarize the authors' laparoscopic experience for paraesophageal hernia (PEH).

SUMMARY BACKGROUND DATA

Laparoscopic antireflux surgery and repair of small hiatal hernias are now routinely performed. Repair of a giant PEH is more complex and requires conventional surgery in most centers. Giant PEH accounts for approximately 5% of all hiatal hernias. Medical management may be associated with a 50% progression of symptoms and a significant death rate. Conventional open surgery has a low death rate, but complications are significant and return to routine activities is delayed in this frequently elderly population. Recently, short-term outcome studies have reported that minimally invasive approaches to PEH may be associated with a lower complication rate, a shorter hospital stay, and faster recovery.

METHODS

From July 1995 to February 2000, 100 patients (median age 68) underwent laparoscopic repair of a giant PEH. Follow-up included heartburn scores and quality of life measurements using the SF-12 physical component and mental component summary scores.

RESULTS

There were 8 type II hernias, 85 type III, and 7 type IV. Sac removal, crural repair, and antireflux procedures were performed (72 Nissen, 27 Collis-Nissen). The 30-day death rate was zero; there was one surgery-related death at 5 months from a perioperative stroke. Intraoperative complications included pneumothorax, esophageal perforation, and gastric perforation. There were three conversions to open surgery. Major postoperative complications included stroke, myocardial infarction, pulmonary emboli, adult respiratory distress syndrome, and repeat operations (two for abscess and one each for hematoma, repair leak, and recurrent hernia). Median length of stay was 2 days. Median follow-up at 12 months revealed resumption of proton pump inhibitors in 10 patients and one repeat operation for recurrence. The mean heartburn score was 2.3 (0, best; 45, worst); the satisfaction score was 91%; physical and mental component summary scores were 49 and 54, respectively (normal, 50).

CONCLUSION

This report represents the largest series to date of laparoscopic repair of giant PEH. In the authors' center with extensive experience in minimally invasive surgery, laparoscopic repair of giant PEH was successfully performed in 97% of patients, with a minimal complication rate, a 2-day length of stay, and good intermediate results.

Minimally invasive esophagectomy

BACKGROUND

Open esophagectomy can be associated with significant morbidity and delay return to routine activities. Minimally invasive surgery may lower the morbidity of esophagectomy but only a few small series have been published.

METHODS

From August 1996 to September 1999, 77 patients underwent minimally invasive esophagectomy. Initially, esophagectomy was approached totally laparoscopically or with mini-thoracotomy; thoracoscopy subsequently replaced thoracotomy.

RESULTS

Indications included esophageal carcinoma (n = 54), Barrett's high-grade dysplasia or carcinoma in situ (n = 17), and benign miscellaneous (n = 6). There were 50 men and 27 women with an average age of 66 years (range 30 to 94 years). Median operative time was 7.5 hours (4.5 hours with > 20 case experience). Median intensive care unit stay was 1 day (range 0 to 60 days); median length of stay was 7 days (range 4 to 73 days) with no operative or hospital mortalities. There were four nonemergent conversions to open esophagectomy; major and minor complication rates were 27% and 55%, respectively.

CONCLUSIONS

Minimally invasive esophagectomy is technically feasible and safe in our center, which has extensive minimally invasive and open esophageal experience. Open surgery should remain the standard until future studies conclusively demonstrate advantages of minimally invasive approaches.

Total Videothoracoscopic Lobectomy Versus Open Thoracotomy for Early-Stage Non–Small-Cell Lung Cancer

Lobectomy remains the standard procedure for early-stage non small-cell lung cancer (NSCLC). Advances in minimally invasive surgery allow lobectomy to be performed by videothoracoscopy (VATSLOBE). The objective of this study was to compare open thoracotomy (OPENLOBE) to VATSLOBE in the treatment of early-stage NSCLC. A retrospective review over a 6-year period at a single tertiary care center identified 31 patients treated by VATSLOBE. A comparison was made with 31 patients undergoing OPENLOBE during the same time period. The cases were matched for age, pulmonary function testing, tumor size, and comorbidities. The VATSLOBE technique was carried out using four 1 cm thoracoports, one of which was enlarged to a 4-6 cm access incision for lobe retrieval. OPENLOBE was performed by standard posterolateral thoracotomy. The VATSLOBE group had a longer operative time (214.03 min) compared to OPENLOBE (140.67 min). There was no difference in the extent of lymph node dissection or in morbidity between the two groups. VATSLOBE patients had their chest tubes removed earlier (4.77 vs. 8.16 days) and stayed in the hospital for a shorter time (7.07 vs. 11.94 days) compared to OPENLOBE patients. In this retrospective review, lobectomy performed by the videothoracoscopic approach was comparable to OPENLOBE in terms of lymph node dissection, morbidity, and long-term survival. VATSLOBE had the advantages of a shorter hospital stay and fewer days with a chest tube. Minimally invasive surgery for early-stage lung cancer should be further investigated in multi-institutional controlled trials.

Minimally invasive surgical staging for esophageal cancer

BACKGROUND

The incidence of esophageal adenocarcinoma is increasing in the United States, and the 5-year survival rate is dismal. Preliminary data suggest that conventional imaging is inaccurate in staging esophageal cancer and could limit accurate assessment of new treatments. The objective of this study was to compare minimally invasive surgical staging (MIS) with conventional imaging for staging esophageal cancer.

METHODS

Patients with potentially resectable esophageal cancer were eligible. Staging by conventional methods used computed tomography (CT) scan of the chest and abdomen, and endoscopic ultrasound (EUS), whereas MIS used laparoscopy and videothoracoscopy. Conventional staging results were compared to those from MIS.

RESULTS

In 53 patients, the following stages were assigned by CT scan and EUS: carcinoma in situ (CIS; n = 1), I (n = 1), II (n = 23), III (n = 20), IV (n = 8). In 17 patients (32.1%), MIS demonstrated inaccuracies in the conventional imaging, reassigning a lower stage in 10 patients and a more advanced stage in 7 patients.

CONCLUSIONS

In 32.1% of patients with esophageal cancer, MIS changed the stage originally assigned by CT scan and EUS. Therefore, MIS should be applied to evaluate the accuracy of new noninvasive imaging methods and to assess new therapies for esophageal cancer.

Endoscopic photodynamic therapy for obstructing esophageal cancer: 77 cases over a 2-year period

BACKGROUND

Photodynamic therapy (PDT) is an alternative treatment option for the palliation of obstructive esophageal cancer. We report our experience with PDT for patients presenting with inoperable, obstructing, or bleeding esophageal cancer.

METHODS

Seventy-seven patients with inoperable, obstructing esophageal cancer were treated with PDT from November 1996 to July 1998. Photofrin (1.5-2.0 mg/kg) was administered, followed by endoscopic light treatment (630 nm red dye laser) at 48 h. Dysphagia score (1 for no dysphagia to 5 for complete obstruction), dysphagia-free interval, and patient survival were assessed.

RESULTS

Seventy-seven patients underwent 125 PDT courses. The mean dysphagia score at 4 weeks after PDT in 90.8% of the patients improved from 3.2 +/- 0.7 to 1.9 +/- 0.8 (p < 0.05). PDT adequately controlled bleeding in all six patients who had bleeding. The most common complications after the 125 PDT courses were esophageal stricture (4.8%), Candida esophagitis (3.2%), symptomatic pleural effusion (3.2%), and sunburn (10.0%). Twenty-nine patients (38%) required more than one PDT course, and seven patients required placement of an expandable metal stent for recurrent dysphagia. The mean dysphagia-free interval was 80.3 +/- 58.2 days. The median survival was 5.9 months.

CONCLUSIONS

Photodynamic therapy is a safe and effective treatment for the palliation of obstructing and bleeding esophagus cancer.

Laparoscopic repair of giant paraesophageal hernia

Giant paraesophageal hernias (PEHs) account for less than 5% of all hiatal hernias. In contrast to the small type I hiatal hernia, nonsurgical management of giant PEHs may be associated with progression of symptoms and life-threatening complications including hemorrhage, strangulation, and death. Most giant PEHs are associated with a current or previous history of gastroesophageal reflux disease and represent progression of the typical type I hernia to a type III hernia. Conventional open repair is associated with good results and low mortality but also with a significant morbidity and a delay in return to routine activities in this frequently elderly population. Recently, short-term outcome studies have reported that minimally invasive approaches to PEH may be associated with less morbidity, shorter hospital stay, faster recovery, and excellent clinical results.

Airway complications following pediatric lung and heart-lung transplantation

Obstruction at the airway anastomosis is a recognized complication of adult heart-lung transplantation (HLT) and lung transplantation (LT). Data for pediatric transplantation have been scarce. We reviewed our experience in pediatric HLT and LT to determine the frequency of airway complications and to document the therapeutic modalities used for their treatment. Fifty-three patients (median age: 13.8 yr; range: 1.3 to 28.2 yr) underwent HLT (n = 25), SLT (n = 3), DLT (n = 25), or repeat DLT (n = 3) and survived for more than 72 h. Major anastomotic airway complications requiring intervention affected one of the 25 HLT (4%) and seven of the 28 LT (SLT + DLT) patients (25%) (p = 0.05). Four patients with granulation tissue occluding the airway were treated with forceps resection, laser ablation, or balloon dilatation. Three patients with fibrotic strictures received silicone stents, laser ablation, or balloon dilatation. Two patients with bronchomalacia or diffuse stricture below the anastomosis underwent metal stent placement. Five of seven patients who were treated for anastomotic complications had satisfactory relief of airway obstruction. As compared with previously studied adults, pediatric heart-lung transplant recipients had the same or a lower frequency, and pediatric lung transplant recipients had a higher frequency of major anastomotic airway complications. A variety of treatment modalities were necessary to achieve adequate relief of airway obstruction.

Risk analysis for thoracoscopic lung volume reduction: a multi-institutional experience

OBJECTIVE

Most reports of thoracoscopic lung volume reduction (TLVR) are relatively small and early experiences from a single institution, factors which limit both the statistical validity and the applicability to the population at large. In order to address these shortcomings we undertook an analysis of the TLVR experience at five separate institutions to assess operative morbidity and identify predictors of mortality.

METHODS

Questionnaires were sent to four groups of surgical investigators at five institutions actively performing TLVR. Data was requested regarding preoperative, operative and postoperative parameters. Twenty-five potential predictors of mortality were analyzed and seven proved to be at least marginally significant (P<0.10). These parameters were entered into a stepwise logistic regression analysis to identify independent predictors.

RESULTS

The 682 patients (415 males, 267 females, mean age 64.0 years) underwent unilateral (410) or bilateral (272) TLVRs. Overall, operative mortality was 6% with half of the deaths resulting from respiratory causes. The remaining patients were discharged to home (88%), a rehabilitation facility (4%) or a ventilator facility (2%). There were 25 perioperative factors chosen representing clinically important indices such as spirometry, oxygenation, functional status, clinical and demographic variables. Univariate analysis identified seven variables as predictors of mortality (P<0.10) and these were entered into a stepwise logistic regression analysis. Only age, 6-min walk, gender (male 8%, female 3% mortality) and the procedure performed (unilateral 4.6%, bilateral 8%) were independent predictors while preoperative steroid therapy, preoperative oxygen administration, and time since smoking cessation dropped out of the model. The specific institution, learning curve (early vs. late experience), type of lung disease, spirometric indices and predicted maximum VO(2) were not significant predictors.

CONCLUSION

This experience suggests that unilateral and bilateral lung volume reduction procedure can be performed with acceptable morbidity and mortality. Although age, gender, exercise capacity and the procedure performed are all independent predictors of mortality, the risk of operative death did not appear excessive in this fragile patient subset.

Comparison of clinical results for unilateral and bilateral thoracoscopic lung volume reduction

BACKGROUND

It is widely believed that bilateral thoracoscopic lung volume reduction (BTLVR) yields superior results when compared with unilateral thoracoscopic lung volume reduction (UTLVR) with regard to spirometry, functional capacity, oxygenation and quality of life results.

METHODS

To address these issues, we compared the results of patients undergoing UTLVR (N = 338 patients) and BTLVR (N = 344 patients) from 1993 to 1998 at five institutions. Follow-up data were available on 671 patients (98.4%) between 6 and 12 months after surgery, and a patient self-assessment was obtained at a mean of 24 months.

RESULTS

It was found that BTLVR provides superior improvement in measured postoperative percent change in FEV1 (L) (UTLVR 23.3% +/- 55.3 vs BTLVR 33% +/- 41, p = 0.04), FVC(L) (10.5% +/- 31.6 vs 20.3% +/- 34.3, p = 0.002) and RV(L) (-13% +/- -22 vs -22% +/- 17.9, p = 0.015). BTLVR also provides a slight improvement over UTLVR in patient's perception regarding improved quality of life (UTLVR 79% vs BTLVR 88%, p = 0.03) and dyspnea relief (71% vs 61%, p = 0.03). There was no difference in mean changes in PO2 (mm Hg) (UTLV 4.5 +/- 12.3 vs BTLVR 4.9 +/- 13.3, p = NS), 6-minute walk (UTLVR 26% +/- 66.1 vs BTLVR 31% +/- 59.6, p = NS) or decreased oxygen utilization (UTLVR 78% vs BTLVR 74%, p = NS).

CONCLUSIONS

These data suggest that both UTLVR and BTLVR yield significant improvement, but the results of BTLVR seem to be superior with regard to spirometry, lung volumes, and quality of life.

Effects of donor bone marrow infusion in clinical lung transplantation

BACKGROUND

We have demonstrated that donor cell chimerism is associated with a lower incidence of obliterative bronchiolitis (OB) in lung recipients, and that donor chimerism is augmented by the infusion of donor bone marrow (BM). We herein report the intermediate results of a trial combining the infusion of donor BM and lung transplantation.

METHODS

Clinical and in vitro data of 26 lung recipients receiving concurrent infusion of donor bone marrow (3.0 to 6.0 x 10(8) cells/kg) were compared with those of 13 patients receiving lung transplant alone.

RESULTS

Patient survival and freedom from acute rejection were similar between groups. Of the patients whose graft survived greater than 4 months, 5% (1 of 22) of BM and 33% (4 of 12) of control patients, developed histologic evidence of OB (p = 0.04). A higher proportion (but not statistically significant) of BM recipients (7 of 10, 70%) exhibited donor-specific hyporeactivity by mixed lymphocyte reaction assays as compared with the controls (2 of 7, 28%).

CONCLUSIONS

Infusion of donor BM at the time of lung transplantation is safe, and is associated with recipients' immune modulation and a lower rate of obliterative bronchiolitis.

Balloon dilation and endobronchial stent placement for bronchial strictures after lung transplantation

PURPOSE

To evaluate the effect of balloon dilation and endobronchial stent placement for bronchial fibrous stenoses and bronchomalacia after lung transplantation.

MATERIALS AND METHODS

Bronchial dilation and/or stent placement was performed on 25 lung transplant recipients. Indications included severe dyspnea with postobstructive pneumonia (n = 24) and respiratory failure (n = 1). All patients underwent pulmonary function testing (PFT) before and after bronchial dilation, the results of which were evaluated for changes. A total of 63 procedures were performed between February 1996 and December 1998. Thirty-five lesions were treated (18 were due to bronchomalacia, 17 were due to fibrosis). Areas treated included the left mainstem bronchus (n = 11), bronchus intermedius (n = 10), right mainstem bronchus (n = 7), left upper lobe bronchus (n = 4), right lower lobe bronchus (n = 2), and right middle lobe bronchus (n = 1). Bronchoscopic and/or bronchographic follow-up ranged from 1 to 34 months (mean, 15 months).

RESULTS

Six-month primary patency of stents placed for bronchomalacia was 71% (10 of 14), with three of the four occlusions caused by mechanical failure of Palmaz stents in the mainstem bronchi. Six-month primary patency for treatment of fibrous strictures was 29%. Secondary patency at 1 year was 100% for both bronchomalacia and fibrous strictures. After treatment, there was a significant improvement in mean PFT results (P = .01-.0001). There was one acute complication, obstruction of the left lower lobe bronchus by a Wallstent treated by dilating a hole in the side of the stent.

CONCLUSIONS

Balloon dilation and stent placement are safe and effective for bronchial strictures and bronchomalacia after lung transplantation, resulting in significant improvement in PFT results. However, there is almost universal restenosis in patients treated for fibrous strictures necessitating reintervention for prolonged patency.

Long-term survival after thoracoscopic lung volume reduction: a multiinstitutional review

BACKGROUND

It has been suggested that bilateral thoracoscopic lung volume reduction (BTLVR) yields significantly better long-term survival than unilateral thoracoscopic lung volume reduction (UTLVR).

METHODS

All perioperative data were collected at the time of the procedure. Follow-up data were obtained during office visits or by telephone.

RESULTS

A total of 673 patients underwent thoracoscopic LVR: 343 had either simultaneous or staged BTLVR and 330, UTLVR. As of July 1998, follow-up was available on 667 (99%) of the 673 patients with a mean follow-up of 24.3 months. The patients in the BTLVR group were significantly younger (62.6+/-8.0 years versus 65.4+/-8.1 years; p < 0.0001), had a higher preoperative arterial oxygen tension (69.7+/-12 mm Hg versus 65.3+/-11 mm Hg; p < 0.0001), and had a superior preoperative 6-minute walk performance (279.9+/-93.6 m [933+/-312 feet] versus 244.5+/-101.4 m [815+/-338 feet] p < 0.0001). There was no difference in the operative mortality rate between the two groups (UTLVR, 5.1%, and BTLVR, 7%). Actuarial survival rates for the UTLVR group at 1 year, 2 years, and 3 years were 86%, 75%, and 69%, respectively versus 90%, 81%, and 74%, respectively, for the BTLVR group (p = not significant).

CONCLUSIONS

Contrary to previous reports, survival after BTLVR was not superior to that after UTLVR even though the former group appeared to have a lower risk preoperatively because of younger age, higher arterial oxygen tension, more advantageous anatomy, and better functional status. Despite thoracoscopic LVR, the actuarial mortality rate approached 30% at 3 years, and this calls into question whether this procedure offers any survival advantage to patients with end-stage emphysema.

Effect of ischemic time on survival in clinical lung transplantation

BACKGROUND

While there is convincing evidence that prolonged ischemic times correlate with reduced long-term survival in heart transplantation, the effect of ischemic time on outcome in clinical lung transplantation remains controversial. To assess the effect of ischemic time on outcomes in lung transplantation, we reviewed our experience.

METHODS

The study was performed by retrospective chart review.

RESULTS

First-time lung transplantation was performed on 392 patients between 1988 and 1998. All grafts were flushed with cold crystalloid preservation solution and stored on ice. Ischemic time data were available for 352 of 392 (90%) patients. Ischemic times were grouped as follows: 0 to 4 hours (n = 91), 4 to 6 hours (n = 201), more than 6 hours (n = 60). Ischemic time did not correlate with survival: 3-year actuarial survival = 56% (0 to 4 hours), 58% (4 to 6 hours), 68% (> 6 hours), p = 0.58. There was no significant difference in the incidence of biopsy-proven diffuse alveolar damage in the first 30 days after transplantation (31%, 32%, 38%), episodes of acute rejection in the first 100 days after transplantation (1.9, 1.8, 1.7), duration of intubation (median 3, 4, 3 days), or incidence of obliterative bronchiolitis (23%, 28%, 26%) between the three groups (0 to 4 hours, 4 to 6 hours, > 6 hours, respectively). A diagnosis of diffuse alveolar damage was associated with a significantly worse outcome (1-year survival = 82% versus 54%, p < 0.0001).

CONCLUSIONS

In contrast to heart transplantation, pulmonary allograft ischemic time up to 9 hours does not appear to have a significant impact on early graft function or survival. The presence of diffuse alveolar damage on biopsy early after transplantation does not correlate with prolonged ischemic time, but is associated with substantially reduced posttransplantation survival.

Optimism and coping styles: A comparison of candidates for liver transplantation with candidates for lung transplantation

BACKGROUND

Dispositional optimism and adaptive coping styles have been shown to correlate with each other and with physical and psychological well-being in a number of studies with medical patients. Few studies in the transplant literature evaluate psychological characteristics of patients across medical diagnoses. A comparison of optimism and coping styles among candidates for liver and lung transplantation is presented.

METHOD

Subjects were 73 candidates for lung transplantation at the University of Pittsburgh Medical Center and 76 candidates for liver transplantation at the Pittsburgh VA Healthcare System. All candidates were classified according to medical diagnosis and history of substance abuse (alcohol/drugs or smoking). There were no significant between- or within-group differences on optimism.

RESULTS

There was a significant difference within both groups, according to history of substance abuse on the coping style 'acceptance'. There were also significant between-group differences on a number of coping styles.

CONCLUSIONS

This preliminary study is intended to suggest direction for future research; studying psychological variables known to impact on health apart from medical diagnosis may provide data pertinent to selection criteria and the design of interventions to more effectively maximize the benefit of transplantation for all concerned.

Structure of the phylogenetically most conserved domain of SRP RNA

The signal recognition particle (SRP) is a phylogenetically conserved ribonucleoprotein required for cotranslational targeting of proteins to the membrane of the endoplasmic reticulum of the bacterial plasma membrane. Domain IV of SRP RNA consists of a short stem-loop structure with two internal loops that contain the most conserved nucleotides of the molecule. All known essential interactions of SRP occur in that moiety containing domain IV. The solution structure of a 43-nt RNA comprising the complete Escherichia coli domain IV was determined by multidimensional NMR and restrained molecular dynamics refinement. Our data confirm the previously determined rigid structure of a smaller subfragment containing the most conserved, symmetric internal loop A (Schmitz et al., Nat Struct Biol, 1999, 6:634-638), where all conserved nucleotides are involved in nucleotide-specific structural interactions. Asymmetric internal loop B provides a hinge in the RNA molecule; it is partially flexible, yet also uniquely structured. The longer strand of internal loop B extends the major groove by creating a ledge-like arrangement; for loop B however, there is no obvious structural role for the conserved nucleotides. The structure of domain IV suggests that loop A is the initial site for the RNA/protein interaction creating specificity, whereas loop B provides a secondary interaction site.

Psychological symptom levels and their correlates in lung and heart-lung transplant recipients

This study examined depression, anxiety, and anger-hostility symptom levels, as well as overall quality of life, in a cohort of 50 lung and heart-lung transplant recipients. Only the subjects' mean anxiety symptoms were substantially elevated over normative levels. However, nearly half of the sample showed clinically significant distress in one or more of the three symptom areas. Pretransplant psychiatric history, educational level, posttransplant caregiver support, and health concerns were the most important independent correlates of the recipients' psychological outcome. Low sense of mastery and poorer physical functional status also showed some evidence of association with mental health.

Diagnostic and therapeutic video-assisted thoracic surgery resection of pulmonary metastases

BACKGROUND

Appropriateness of video-assisted thoracic surgery (VATS) pulmonary metastasectomy for curative intent has been a controversial topic. We reviewed our experience with VATS wedge resection for peripheral lung metastases to determine the efficacy and potential adverse consequences of this approach for pulmonary metastasectomy.

METHODS

One hundred seventy-seven patients underwent VATS resection of pulmonary metastases. Diagnostic resection (VATS-dx) was performed for 78 patients when percutaneous biopsy was unsuccessful or not feasible. Potentially curative resections (VATS-rx) were performed for 99 patients. The histologic findings in this group included colorectal (68), renal (7), sarcoma (6), breast (4), melanoma (3), head/neck (3), lymphoma (2), uterine (1), and "other" (5). The average number of lesions resected was 1.4 (range, 1-7).

RESULTS

VATS resection was successfully performed for all VATS-dx and VATS-rx patients. There were no perioperative deaths. Longitudinal follow-up demonstrated a mean survival of 18 months in the VATS-dx group and 28 months in the VATS-rx group. In the VATS-rx group, 37 (37%) of 99 were free of disease, at a mean follow-up interval of 37 months. Of the 57 recurrences, 5% were local, 26% were regional, and 69% were distant.

CONCLUSIONS

Results with VATS resection of peripheral pulmonary metastases for diagnostic and potentially curative intentions appear comparable with historical results by "open" thoracotomy. Careful patient selection based on high-resolution helical CT scanning is important to avoid compromise of therapeutic intent. Conversion to thoracotomy is indicated when lesions identified preoperatively are not found or when technical problems encountered may compromise surgical margins when resecting lung metastases for potential cure.

Evaluation of distant metastases in esophageal cancer: 100 consecutive positron emission tomography scans

BACKGROUND

Pilot studies suggest positron emission tomography (PET) scanning may be superior to conventional imaging in staging esophageal cancer, especially in the detection of radiographically occult distant metastases. This report summarizes our experience with PET in staging esophageal cancer.

METHODS

One hundred consecutive PET scans in 91 patients with esophageal cancer referred for surgery were prospectively collected (1995 to 1998) and compared with computerized tomography (CT) and bone scan. PET images were acquired after injection of 18F-fluorodeoxyglucose and evaluated for abnormal uptake. Minimally invasive surgical staging (MIS) and/or clinical correlation were used to confirm or refute imaging results.

RESULTS

MIS or clinical correlation confirmed 70 distant metastases in 39 cases. PET detected 51 metastases in 27 of 39 cases (69% sensitivity, 93.4% specificity, 84% accuracy) compared with CT, which detected 26 metastases in 18 of 39 cases (46.1% sensitivity, 73.8% specificity, 63% accuracy) (p < 0.01).

CONCLUSIONS

PET was more accurate than CT in detecting distant metastases, but was only 69% sensitive compared with minimally invasive staging.

Diagnostic and therapeutic video-assisted thoracic surgery resection of pulmonary metastases

BACKGROUND

Appropriateness of video-assisted thoracic surgery (VATS) pulmonary metastasectomy for curative intent has been a controversial topic. We reviewed our experience with VATS wedge resection for peripheral lung metastases to determine the efficacy and potential adverse consequences of this approach for pulmonary metastasectomy.

METHODS

One hundred seventy-seven patients underwent VATS resection of pulmonary metastases. Diagnostic resection (VATS-dx) was performed for 78 patients when percutaneous biopsy was unsuccessful or not feasible. Potentially curative resections (VATS-rx) were performed for 99 patients. The histologic findings in this group included colorectal (68), renal (7), sarcoma (6), breast (4), melanoma (3), head/neck (3), lymphoma (2), uterine (1), and "other" (5). The average number of lesions resected was 1.4 (range, 1-7).

RESULTS

VATS resection was successfully performed for all VATS-dx and VATS-rx patients. There were no perioperative deaths. Longitudinal follow-up demonstrated a mean survival of 18 months in the VATS-dx group and 28 months in the VATS-rx group. In the VATS-rx group, 37 (37%) of 99 were free of disease, at a mean follow-up interval of 37 months. Of the 57 recurrences, 5% were local, 26% were regional, and 69% were distant.

CONCLUSIONS

Results with VATS resection of peripheral pulmonary metastases for diagnostic and potentially curative intentions appear comparable with historical results by "open" thoracotomy. Careful patient selection based on high-resolution helical CT scanning is important to avoid compromise of therapeutic intent. Conversion to thoracotomy is indicated when lesions identified preoperatively are not found or when technical problems encountered may compromise surgical margins when resecting lung metastases for potential cure.

Functional changes in the structure of the SRP GTPase on binding GDP and Mg2+GDP

Ffh is a component of a bacterial ribonucleoprotein complex homologous to the signal recognition particle (SRP) of eukaryotes. It comprises three domains that mediate both binding to the hydrophobic signal sequence of the nascent polypeptide and the GTP-dependent interaction of Ffh with a structurally homologous GTPase of the SRP receptor. The X-ray structures of the two-domain 'NG' GTPase of Ffh in complex with Mg2+GDP and GDP have been determined at 2.0 A resolution. The structures explain the low nucleotide affinity of Ffh and locate two regions of structural mobility at opposite sides of the nucleotide-binding site. One of these regions includes highly conserved sequence motifs that presumably contribute to the structural trigger signaling the GTP-bound state. The other includes the highly conserved interface between the N and G domains, and supports the hypothesis that the N domain regulates or signals the nucleotide occupancy of the G domain.

Photodynamic therapy for treatment of malignant dysphagia

Photodynamic therapy (PDT) was recently approved by the Food and Drug Administration for palliating obstructing esophageal cancer. This report reviews our initial experience using PDT to treat malignant dysphagia. Patients with inoperable, obstructing esophageal cancer were considered for PDT. Photofrin was injected 48 hours before endoscopic laser activation. Dysphagia score was assessed. Thirty patients underwent 53 PDT courses. Improvement in dysphagia occurred in 83%. Mean dysphagia score decreased from 2.8 to 1.8 (p < 0.05). Complications included esophageal stricture (9.4%), candida esophagitis (5.7%), symptomatic pleural effusion (5.7%), contained esophageal perforation (1.9%), aspiration pneumonia (1.9%), and sunburn (13.2%). Seventeen patients (57%) required more than one PDT treatment, and in 10 an expandable metal stent was used as an adjunct. The 30-day mortality rate was 7%. PDT is effective in palliating patients with malignant dysphagia. The ideal patient for PDT has an obstructing, primarily endoluminal esophageal tumor with minimal extrinsic compression.

Empyema complicating successful lung transplantation

OBJECTIVE

To assess the prevalence and etiology of empyema complicating successful lung transplantation.

DESIGN

Retrospective review.

SETTING

University medical center transplant service.

PATIENTS

All recipients (n = 392) of single-lung, double-lung, and heart-lung transplantation between May 1984 and April 1997.

RESULTS

Of the 392 transplant recipients, empyema was documented in 14 patients (3.6%) at a mean time (+/- SD) of 46 days after transplantation (range, 14 to 167 days). Of these 14 recipients with empyema, 4 recipients (28.6%) died of infectious complications related to empyema. Empyema was seen secondary to Gram-positive, Gram-negative, and saprophytic organisms; however, there was no predominance of a particular organism recovered from the empyemic fluid (chi2 = 0.53; p = 0.75). The development of empyema was not related to whether the transplant was performed secondary to a septic or nonseptic lung disorder (chi2 = 1.06; p = 0.67), nor was it related to the type of transplant procedure performed (ie, single-lung, double-lung, or heart-lung allografts; chi2 = 4.39; p = 0.30).

CONCLUSION

Empyema, a relatively uncommon complication of lung transplantation, is not related to the type of allograft received or to whether the recipient had a septic or a nonseptic lung disorder. If empyema does occur, the mortality associated with this infection is substantial.

Computed tomography-guided wire localization of pulmonary lesions before thoracoscopic resection: results in 101 cases

The authors determine the success rate, safety, and potential complications of computed tomography-guided preoperative hookwire localization of small peripheral pulmonary nodules. One hundred one consecutive wire localizations with addition of methylene blue injection were performed in 94 patients immediately before thoracoscopic resection of small lung lesions. Sixty-two patients had a known primary malignancy, whereas 32 had an asymptomatic nodule. Eighty-eight patients underwent single lesion localization, five underwent double localization, and one underwent triple wire placement. Five patients had previously undergone percutaneous biopsy that was nondiagnostic. The nodule was within the first wedge biopsy of lung tissue in 95 of 97 specimens (98%). A second wedge and an open lobectomy were required in one patient each. Three additional biopsies were intraoperatively deferred after the histologic diagnosis was established after removal of another nodule. The procedure was terminated before wire placement in one patient who was unable to successfully hold his breath. The wire dislodged with the tip in the pleural space rather than in the lung parenchyma in 22 cases; however, methylene blue tattoo allowed localization in 13 of these (59%). In the other nine cases, extra portals, digital palpation, or expanded wedge resection was required. Complications included pneumothorax in 48 cases, moderate pleuritic pain in five cases, seven small intercostal hematomas, and a 7-mm wire fragment retained in one patient's lung along the suture line. No patient required a preoperative drain for treatment of pneumothorax. Wire dislodgement occurred in 6 of 52 (12%) cases without an initial pneumothorax and in 16 of 48 (33%) cases if a pneumothorax occurred. Wires dislodged less frequently if placed either directly into or through the nodule in 11 of 64 (17%) cases than if placed adjacent to the nodule in 11 of 36 (31%) cases. Average wire tip depth from the visceral pleura was significantly less when the wire dislodged (11 mm) than when the wire remained in place (25 mm). Wire localization of small peripheral pulmonary nodules is a safe and effective procedure to assist thoracoscopic sublobectomy resection.

Lung transplantation for end-stage pulmonary sarcoidosis

BACKGROUND

Sarcoidosis is a multi-system granulomatous disease which can cause significant pulmonary morbidity and occasionally be fatal. The long term benefit of lung transplantation for this disorder are unknown.

METHODS

A retrospective review was made of nine single lung transplant procedures performed at the University of Pittsburgh between March 1991 and March 1995 in patients with end-stage lung disease secondary to sarcoidosis. Two contemporaneous groups of recipients receiving transplants for COPD (n = 30) and inflammatory lung disease (n = 13) served as control groups. Surviving recipients underwent sequential surveillance bronchoscopy with transbronchial biopsy.

RESULTS

All recipients survived beyond post-operative day (POD) 30, with 5 recipients currently alive. One year survival for this group was 6/9 (67%). Eight of the 9 sarcoidosis recipients had sequential lung biopsy procedures. Five of these 8 recipients (62.5%) had recurrence of granulomata in the lung allograft with the mean time to diagnosis of recurrent sarcoidosis being POD 224.2 +/- 291.3 (range POD 21-719). None of these 5 recipients had radiographic evidence or clinical symptoms related to granulomatous inflammation in the allograft. Pre-operative and post-operative spirometric values were available on 8 recipients. Vital capacity significantly improved in all recipients from 1.54 +/- 0.43 litres to 2.55 +/- 0.63 litres by POD 180 and was maintained through the fourth postoperative year (p < 0.05 Wilcoxon Signed Rank). Spirometric values were also compared before and after transplantation in the 5 recipients with granulomata in the allograft. Vital capacity significantly improved in these 5 recipients from 1.53 +/- 0.48 litres to 2.71 +/- 0.71 litres by POD 180 and was maintained throughout the first postoperative year (p < 0.05, Wilcoxon Signed Rank). The prevalence of high grade acute cellular rejection [ACR (histologic grades III and IV)] did not differ from that seen in a contemporaneous group of 30 single lung recipients who received allografts for COPD (p < 0.05 Mann-Whitney U), nor when compared to a group of 13 single lung recipients who received allografts for immunologically mediated lung disease (p < 0.05 Mann-Whitney U). The prevalence of chronic rejection (histologic obliterative bronchiolitis [OB]) in the sarcoidosis recipients was 4/8 (50%). In the controls with COPD recipients the prevalence of OB was 10/30 (33.3%), and in the 13 controls with immunologic disease it was 6/13 (46.2%). There was no significant difference in the prevalence of OB between the sarcoidosis recipients and controls. When analyzed to the fifth year after transplantation, freedom from the development of OB also failed to differ between these 3 groups (p = 0.25, Logrank, Mantel-Cox).

CONCLUSIONS

Although granulomatous inflammation in the lung allograft is common following transplantation for sarcoidosis, it is not clinically or radiographically relevant. In addition, the prevalence of high grade ACR and histologic OB is no different when compared to other single lung recipients. For these reasons lung transplantation is a viable alternative for end-stage lung disease secondary to sarcoidosis.

Ablation of persistent air leaks after thoracic procedures with fibrin sealant

Prolonged air leak after thoracic procedures was successfully treated in 11 of 12 patients under local anesthesia using video thoracoscopic instillation of fibrin sealant over the site of the leak. No related complications occurred. This method should be considered an effective option for the treatment of persistent pulmonary air leaks.