Dynamic four-dimensional computed tomography for preoperative assessment of lung cancer invasion into adjacent structures†.

OBJECTIVES: The 320-slice computed tomography (CT) provides three-dimensional and dynamic imaging resulting in the ability to assess motion analysis between two adjacent structures (the fourth dimension). Differential movements between two adjacent structures would indicate that there is no fixation between the two structures. METHODS: Eight patients with non-small-cell lung cancers located adjacent to vital structures (e.g. the great vessels) (n = 4), mediastinum (n = 1) or chest wall (n = 3) where conventional CT was unable to exclude local invasion underwent dynamic four-dimensional (4D) CT assessment. In 3 patients, the lung tumour was abutting the chest wall and 1 patient had tumour abutting the mediastinum. The remaining patients included a patient with a large 14-cm left lower lobe cancer abutting the descending thoracic aorta who had previous pleurodesis; a patient with an apical right upper lobe 6-cm cancer with static imaging appearances suggestive of tumour invasion into the apex, the mediastinal surface and superior vena cava (SVC); a patient with a 3.5-cm cancer which had a broad 2.5-cm base abutting the distal aortic arch and a patient with a 14-cm left upper lobe cancer abutting the aortic arch, descending thoracic aorta and chest wall. Differential movements between the tumour and adjacent structure on 4D CT were considered indicative of the absence of frank invasion. RESULTS: Dynamic 4D imaging revealed differential movements between the tumour and the adjacent structures in 7 cases, suggesting the absence of overt malignant invasion. Intraoperative assessments confirmed the findings. In 1 case, a small area of fixation seen on dynamic CT corresponded intraoperatively to superficial invasion of the adventitia of the SVC. CONCLUSIONS: Dynamic 4D 320-slice CT is useful in the preoperative assessment of the direct invasion of lung cancer into adjacent structures and hence its resectability.

Anatomy and pathophysiology of the pleura and pleural space.

Pleural effusions are most often secondary to an underlying condition and may be the first sign of the underlying pathologic condition. The balance between the hydrostatic and oncotic forces dictates pleural fluid homeostasis. The parietal pleura has a more significant role in pleural fluid homeostasis. Its vessels are closer to the pleural space compared with its visceral counterpart; it contains lymphatic stomata, absent on visceral pleura, which are responsible for a bulk clearance of fluid. The diagnosis and successful treatment of pleural effusions requires a mixture of imaging techniques and pleural fluid analysis.

Decision making and algorithm for the management of pleural effusions.

Pleural effusions can be catagorised in to transudative effusions or exudative effusions. Causes include cardiovascular disease, infection and neoplasm. Diagnosis is the key to determining what management is required. History and examination can elicit the cause of the effusion and radiological investigations can be a useful adjunct. Thoracocentesis and laboratory testing of the pleural fluid is usually diagnostic and can direct further investigations or treatment. Management of the pleural effusion ultimately varies according to the diagnosis but can be either directed towards reversing the cause of the effusion or treating the symptoms that arise as a result of the effusion.

Acute pulmonary embolectomy.

Acute pulmonary embolism (PE) is a common condition frequently associated with a high mortality worldwide. It can be classified into non-massive, sub-massive and massive, based on the degree of haemodynamic compromise. Surgical pulmonary embolectomy, despite having been in existence for over 100 years, is generally regarded as an option of last resort, with expectedly high mortality rates. Recent advances in diagnosis and recognition of key qualitative predictors of mortality, such as right ventricular stress on echocardiography, have enabled the re-exploration of surgical pulmonary embolectomy for use in patients prior to the development of significant circulatory collapse, with promising results. We aim to review the literature and discuss the indications, perioperative workup and outcomes of surgical pulmonary embolectomy in the management of acute PE.

Survival after surgical repair of ischemic ventricular septal rupture.

OBJECTIVES: We reviewed our results and experience over a 14-year period to identify predictors of outcome following surgical repair of postinfarction ventricular septal rupture. METHODS: A retrospective review was carried over a 14-year period. All patients had surgical repair of a postinfarction ventricular septal rupture. Patient demographics, perioperative variables, and survival data were collected. Logistic regression identified independent predictors of 30-day mortality. Multivariate analysis determined the effects of independent risk factors on survival. RESULTS: Surgery for postinfarction ventricular septal rupture was carried out on 59 patients. The median age was 69 years, and 69% were male. In 54% of patients, the ventricular septal rupture was anterior, and 75% had concomitant coronary artery bypass grafting. Mortality was 39% at 30 days. Age was the most important predictor of 30-day and long-term outcome. Logistic regression analysis identified age, preoperative ventilation, and female sex as significant predictors of 30-day mortality. Cardiogenic shock, preoperative ventilation, and advanced age were associated with reduced medium-term survival. Surprisingly, anterior ventricular septal rupture was associated with reduced long-term survival. Concomitant coronary artery bypass grafting did not influence 30-day or long-term outcome. CONCLUSIONS: Despite advances, the surgical mortality from ventricular septal rupture remains high. Age remains the most important predictor of outcome, and concomitant coronary artery bypass grafting does not appear to have a demonstrable benefit. Interestingly, anterior ventricular septal rupture had poorer long-term outcome than inferior ventricular septal rupture.

Prolonged stay in intensive care unit is a powerful predictor of adverse outcomes after cardiac operations.

BACKGROUND: The aim of this study was to examine the impact of prolonged intensive care unit (ICU) stay on in-hospital mortality and long-term survival. METHODS: Prospectively collected data from 6,101 consecutive patients who underwent surgery between 2003 and 2007 were analyzed. Prolonged ICU stay was defined as a total duration of ICU stay of 3 days or more postoperatively, including readmissions; patients with an ICU stay less than 3 days were identified as controls. Univariate and multiple variable analyses were performed to identify risk factors associated with prolonged ICU stay. RESULTS: Of 6,101 patients, 1,139 (18.7%) patients had a prolonged ICU stay. These patients had a higher ICU mortality (10%) compared with controls (0.6%; p < 0.001). On discharge from the ICU, their hospital mortality was still 6-fold higher (1.2%) compared with controls (0.2%; p < 0.001). Finally, the patients who had prolonged ICU stays had lower survival after discharge from the ICU-89.2% and 81.2% at 1 year and 3 years, respectively, compared with 97.8% and 93.6%, respectively, for controls (p < 0.001). Multiple variable analysis revealed prolonged ICU stay to be an independent predictor of prolonged hospital stay, higher hospital mortality, and poorer long-term survival (all p < 0.001). CONCLUSIONS: Prolonged ICU stay is an important predictor of adverse immediate, short-term, and long-term outcomes after cardiac operations.

The value of post mortems in cardiac surgery: learning from the dead.

BACKGROUND: Little information is available regarding the role of post-mortem in cardiac surgery. The cause of death by clinical presumption can be misleading. The aim is evaluate the role of post-mortem following cardiac surgery by comparing clinically attributed causes of death versus post-mortem findings. METHODS: A total of 10,099 cardiac operations were performed over a seven-year period in a single institution in the United Kingdom. There were 363 (3.6%) deaths. The mean age at death was 71 with 66.7% male. Of these, 348 (95.9%) patients underwent a post-mortem examination. RESULTS: There was a significant disparity between presumed and actual causes of death in 78 (22.4%) patients. The commonest unrecognised cause of death was cardiac causes (21 patients, 6.0%). The most overestimated cause of death was multi-organ failure, which was incorrectly diagnosed as the cause of death in 28 patients (8.0%). CONCLUSIONS: Post-mortem can determine unsuspected diagnoses in a significant proportion of patients undergoing cardiac surgery. It plays an important role in cardiac surgery and remains essential for quality assessment in perioperative treatment.

Prospective European multicenter randomized trial of PleuraSeal for control of air leaks after elective pulmonary resection.

OBJECTIVES: We sought to evaluate the efficacy and safety of a synthetic bioresorbable pleural sealant (PleuraSeal; Covidien, Bedford, Mass) to treat air leaks after pulmonary resection. METHODS: Patients with air leaks after lung resection were randomized to treatment with pleural sealant on air leak sites after standard methods of lung closure or standard lung closure only. The primary outcome variable was the percentage of patients remaining air leak free until discharge. The secondary outcome variables were the proportion of patients with successful intraoperative air leak sealing, time to last air leak, and durations of chest tube drainage and hospitalization. RESULTS: The sealant group comprised 62 subjects, and the control group comprised 59 subjects. Most patients (98.3%) underwent open lobectomy for bronchogenic carcinoma. The overall success rates for intraoperative air leak sealing were as follows: sealant group, 71.0%; control group, 23.7% (P < .001). For grade 2 and 3 air leaks (n = 77), the intraoperative sealing rates were as follows: sealant group, 71.7%; control group, 9.1% (P < .001). More patients with grade 2 and 3 air leaks had their leaks remain sealed in the sealant group (43.5% vs 15.2%, P = .013). The median time from skin closure to last observable air leak was 6 hours (sealant group) versus 42 hours (control group, P = .718). No treatment-related complications were reported. No differences in drainage or hospitalization were observed. CONCLUSIONS: In this multicenter study the pleural sealant was safe and effective treatment for intraoperative air leaks after lung resection. Significantly fewer patients with surgically relevant intraoperative air leaks had postoperative air leaks when the pleural sealant was applied.

Emphysema quantification in inflation-fixed lungs using low-dose computed tomography and 3He magnetic resonance imaging.

OBJECTIVE: To evaluate the use of inflation-fixed lung tissue for emphysema quantification with computed tomography (CT) and He magnetic resonance (MR) diffusion imaging. METHODS: Fourteen subjects representing a range of chronic obstructive pulmonary disease severity who underwent complete or lobar lung resection were studied. Computed tomographic measurements of lung attenuation and MR measurements of the hyperpolarized 3He apparent diffusion coefficient (ADC) in resected specimens fixed in inflation with heated formalin vapor were compared with measurements obtained before fixation. RESULTS: The mean (SD) CT emphysema indices were 56% (17%) before and 58% (19%) after fixation (P = 0.77; R = 0.76). Index differences correlated with differences in lung volume (R = 0.47). The mean (SD) 3He ADCs were 0.40 (0.15) cm/s before and 0.39 (0.14) cm/s after fixation (P = 0.03, R = 0.98). The CT emphysema index and the 3He ADC were correlated before (R = 0.89) and after fixation (R = 0.79). CONCLUSIONS: Concordance of CT and 3He MR imaging measurements in unfixed and inflation-fixed lungs supports the use of inflation-fixed lungs for quantitative imaging studies in emphysema.

Effects of CT section thickness and reconstruction kernel on emphysema quantification relationship to the magnitude of the CT emphysema index.

RATIONALE AND OBJECTIVES: Computed tomography (CT) section thickness and reconstruction kernel each influence CT measurements of emphysema. This study was performed to assess whether their effects are related to the magnitude of the measurement. MATERIALS AND METHODS: Low-radiation-dose multidetector CT was performed in 21 subjects representing a wide range of emphysema severity. Images were reconstructed using 20 different combinations of section thickness and reconstruction kernel. Emphysema index values were determined as the percentage of lung pixels having attenuation lower than multiple thresholds ranging from -960 HU to -890 HU. The index values obtained from the different thickness-kernel combinations were compared by repeated measures analysis of variance and Bland-Altman plots of mean versus difference in all subjects, and correlated with quantitative histology (mean linear intercept, Lm) in a subset of resected lung specimens. RESULTS: The effects of section thickness and reconstruction kernel on the emphysema index were significant (P < .001) and diminished as the index attenuation threshold was raised. The changes in index values from changing the thickness-kernel combination were largest for subjects with intermediate index values (10%-30%), and became progressively smaller for those with lower and higher index values. This pattern was consistent regardless of the thickness-kernel combinations compared and the HU threshold used. Correlations between the emphysema index values obtained with each thickness-kernel combination and Lm ranged from r = 0.55-0.68 (P = .007-.03). CONCLUSION: The effects of CT section thickness and kernel on emphysema index values varied systematically with the magnitude of the emphysema index. All reconstruction techniques provided significant correlations with quantitative histology.

Transannular pulmonary enlargement and bioprostheses for carcinoid disease.

A diminutive pulmonary artery and right ventricular outflow tract in a 46-year-old woman with a 10-year history of carcinoid syndrome required transannular pulmonary patch enlargement to allow replacement of the pulmonary and tricuspid valves with bioprostheses. The avoidance of anticoagulation permitted further hepatic arterial embolization without an increased risk of bleeding.

Effects of diffusion time on short-range hyperpolarized (3)He diffusivity measurements in emphysema.

PURPOSE: To characterize the effect of diffusion time on short-range hyperpolarized (3)He magnetic resonance imaging (MRI) diffusion measurements across a wide range of emphysema severity. MATERIALS AND METHODS: (3)He diffusion MRI was performed on 19 lungs or lobes resected from 18 subjects with varying degrees of emphysema using three diffusion times (1.6 msec, 5 msec, and 10 msec) at constant b value. Emphysema severity was quantified as the mean apparent diffusion coefficient (ADC) and as the percentage of pixels with ADC higher than multiple thresholds from 0.30-0.55 cm(2)/sec (ADC index). Quantitative histology (mean linear intercept) was obtained in 10 of the lung specimens from 10 of the subjects. RESULTS: The mean ADCs with diffusion times of 1.6, 5.0, and 10.0 msec were 0.46, 0.40, and 0.37 cm(2)/sec, respectively (P < 0.0001, analysis of variance [ANOVA]). There was no relationship between the ADC magnitude and the effect of diffusion time on ADC values. The mean linear intercept correlated with ADC (r = 0.91-0.94, P < 0.001) and ADC index (r = 0.78-0.92, P < 0.01) at all diffusion times. CONCLUSION: Decreases in ADC with longer diffusion time were unrelated to emphysema severity. The strong correlations between the ADC at all diffusion times tested and quantitative histology demonstrate that ADC is a robust measure of emphysema.

Concomitant lung cancer resection and lung volume reduction surgery.

Patients who are offered concomitant surgery are highly selected and must satisfy the strict criteria set out for both LVRS and cancer surgery. Several evaluative processes have been reported for the selection of suitable patients. These various evaluative processes, together with the physical condition of the patient and the surgeon's experience, help to best select patients suitable for combined surgical resection. Several intraoperative strategies are available for dealing with a patient who has concomitant lung cancer and severe emphysema. The choice of technique depends on the location and size of the tumor, the severity and distribution of the emphysema, and the surgeon's experience and preference. Lung volume reduction surgery in well-selected patients who have severe emphysema results in postoperative improvement of symptoms and measured pulmonary function. The combination of lung cancer resection with LVRS offers selected patients who have concomitant early lung cancer and severe emphysema the opportunity to undergo resection of their cancer with improvement rather than further reduction in their pulmonary function. By traditional criteria these patients would otherwise be considered unsuitable surgical candidates because of the limited pulmonary function.

Combined cardiac and lung volume reduction surgery.

Coronary artery disease is prevalent in patients who have severe emphysema and who are being considered for lung volume reduction surgery (LVRS). Significant valvular heart diseases may also coexist in these patients. Few thoracic surgeons have performed LVRS in patients who have severe cardiac diseases. Conversely, few cardiac surgeons have been willing to undertake major cardiac surgery in patients who have severe emphysema. This report reviews the evidence regarding combined cardiac surgery and LVRS to determine the optimal management strategy for patients who have severe emphysema and who are suitable for LVRS, but who also have coexisting significant cardiac diseases that are operable.

Airway bypass treatment of severe homogeneous emphysema: taking advantage of collateral ventilation.

Airway bypass is being investigated as a new form of minimally invasive therapy for the treatment of homogeneous emphysema. It is a bronchoscopic catheter-based procedure that creates transbronchial extra-anatomic passages at the bronchial segmental level. The passages are expanded, supported with the expectation that the patency is maintained by paclitaxel drug-eluting airway bypass stents. The concept of airway bypass has been demonstrated in two separate experimental studies. These studies have shown that airway bypass takes advantage of collateral ventilation present in homogeneous emphysema to allow trapped gas to escape and reduce hyperinflation. It improves lung mechanics, expiratory flow, and volume. Airway bypass stent placements have been shown to be feasible and safe in both animal and human studies. Paclitaxel-eluting airway bypass stents were found to prolong stent patency and were adopted for clinical studies. A study evaluating the early results of the clinical application of airway bypass with paclitaxel-eluting stents found that airway bypass procedures reduced hyperinflation and improved pulmonary function and dyspnea in selected subjects who have severe emphysema. The duration of benefit appeared to correlate with the degree of pretreatment hyperinflation. These preliminary clinical results supported further evaluation of the procedure and led to the EASE Trial. The EASE Trial is a prospective, multicenter, randomized, double-blind, sham-controlled study. The trial aims to evaluate the safety and effectiveness of the airway bypass to improve pulmonary function and reduce dyspnea in homogeneous emphysema subjects who have severe hyperinflation. The trial is presently ongoing worldwide, though enrollment was completed.

Severe triple vessel coronary artery disease and aneurysms in a young white man: disease progression of childhood Kawasaki disease.

Kawasaki disease usually affects younger age groups, but cardiac sequelae of 'missed' (incomplete) childhood Kawasaki disease may first present in adult life. We report a case of a 28-year-old white man presenting with ST elevation myocardial infarction and later found to have triple vessel coronary artery aneurysmal disease, probably secondary to childhood Kawasaki disease for which he underwent cardiac bypass surgery. The patient has remained well and asymptomatic at 1-year follow-up. This case is highlighted as the incidence of Kawasaki disease is relatively low among the white population, and yet there are increasing reports of adult patients presenting with coronary artery aneurysmal disease secondary to childhood Kawasaki disease. There has been a relative paucity of reports of surgical revascularization for adult survivors of childhood Kawasaki disease. This report also emphasizes the importance of early recognition and aggressive treatment of the often missed, incomplete, form of Kawasaki disease, which may reduce the risk of late development of coronary artery aneurysms. There should be a high index of suspicion of Kawasaki disease in young adults presenting with aneurysmal coronary artery disease with no significant coronary risk factors and in the absence of generalized atherosclerosis.