Amaze: a randomized controlled trial of adjunct surgery for atrial fibrillation.

OBJECTIVES: Atrial fibrillation (AF) reduces survival and quality of life (QoL). It can be treated at the time of major cardiac surgery using ablation procedures ranging from simple pulmonary vein isolation to a full maze procedure. The aim of this study is to evaluate the impact of adjunct AF surgery as currently performed on sinus rhythm (SR) restoration, survival, QoL and cost-effectiveness. METHODS: In a multicentre, Phase III, pragmatic, double-blinded, parallel-armed randomized controlled trial, 352 cardiac surgery patients with >3 months of documented AF were randomized to surgery with or without adjunct maze or similar AF ablation between 2009 and 2014. Primary outcomes were SR restoration at 1 year and quality-adjusted life years at 2 years. Secondary outcomes included SR at 2 years, overall and stroke-free survival, medication, QoL, cost-effectiveness and safety. RESULTS: More ablation patients were in SR at 1 year [odds ratio (OR) 2.06, 95% confidence interval (CI) 1.20-3.54; P = 0.009]. At 2 years, the OR increased to 3.24 (95% CI 1.76-5.96). Quality-adjusted life years were similar at 2 years (ablation - control -0.025, P = 0.6319). Significantly fewer ablation patients were anticoagulated from 6 months postoperatively. Stroke rates were 5.7% (ablation) and 9.1% (control) (P = 0.3083). There was no significant difference in stroke-free survival [hazard ratio (HR) = 0.99, 95% CI 0.64-1.53; P = 0.949] nor in serious adverse events, operative or overall survival, cardioversion, pacemaker implantation, New York Heart Association, EQ-5D-3L and SF-36. The mean additional ablation cost per patient was £3533 (95% CI £1321-£5746). Cost-effectiveness was not demonstrated at 2 years. CONCLUSIONS: Adjunct AF surgery is safe and increases SR restoration and costs but not survival or QoL up to 2 years. A continued follow-up will provide information on these outcomes in the longer term. Study registration: ISRCTN82731440 (project number 07/01/34).

Atrial function as a guide to timing of intervention in mitral valve prolapse with mitral regurgitation.

OBJECTIVES: The purpose of this study was to determine the clinical utility of left atrial (LA) functional indexes in patients with mitral valve prolapse (MVP) and mitral regurgitation (MR). BACKGROUND: Timing of surgery for MVP remains challenging. We hypothesized that assessment of LA function may provide diagnostic utility in these patients. METHODS: We studied 192 consecutive patients in sinus rhythm with MVP, classified into 3 groups: moderate or less MR (MOD group, n = 54); severe MR without surgical indication (SEV group, n = 52); and severe MR with ≥1 surgical indication (SURG group, n = 86). Comparison was made with 50 control patients. Using 2D speckle imaging, average peak contractile, conduit, and reservoir atrial strain was recorded. Using Simpson's method we recorded maximal left atrial volume (LAVmax) and minimal left atrial volume (LAVmin), from which the total left atrial emptying fraction (TLAEF) was derived: (LAVmax-LAVmin)/LAVmax × 100%. RESULTS: TLAEF was similar in the MOD and control groups (61% vs. 57%; p = NS), was reduced in the SEV group (55%; p < 0.001 vs. control group), and markedly lower in the SURG group (40%; p < 0.001 vs. other groups). Reservoir strain demonstrated a similar pattern. Contractile strain was similarly reduced in the MOD and SEV groups (MOD 15%; SEV 14%; p = NS; both p < 0.05 vs. control group 20%) and further reduced in the SURG group (8%; p < 0.001 vs. other groups). By multivariate analysis, TLAEF (odds ratio [OR]: 0.78; p < 0.001), reservoir strain (OR: 0.91; p = 0.028), and contractile strain (OR: 0.86; p = 0.021) were independent predictors of severe MR requiring surgery. Using receiver-operating characteristic analysis, TLAEF <50% demonstrated 91% sensitivity and 92% specificity for predicting MVP with surgical indication (area under the curve: 0.96; p < 0.001). CONCLUSIONS: We report the changes in left atrial function in humans with MVP and the relationship of LA dysfunction to clinical indications for mitral valve surgery. We propose that the findings support the utility of quantitative assessment of atrial function by echocardiography as an additional tool to guide the optimum timing of surgery for MVP.

Mechanisms of atrial mitral regurgitation: insights using 3D transoesophageal echo.

AIMS: Functional mitral regurgitation (FMR) is a consequence of mitral annular enlargement, leaflet tethering and reduced co-aptation. The importance of the left atrium (LA) as a cause of mitral regurgitation (MR) is less clear. We applied a co-aptation index using three-dimensional (3D) transoesophageal echocardiography to FMR and MR secondary to LA dilatation (atrial mitral regurgitation, AMR). METHODS AND RESULTS: Seventy-two patients underwent comprehensive 3D echo studies: FMR (n = 19); AMR (n = 33); and 20 controls. We recorded: LV size and function; LA dimensions; mitral annular area (MVA); and leaflet area in early and late systole. MVA fractional change was defined: (MVA late systole - MVA early systole)/MVA late systole × 100%; the co-aptation index was defined: (leaflet area early systole - leaflet area late systole)/leaflet area early systole × 100%. Despite normal LV size and function in AMR, MVA was increased similarly to FMR (AMR 12.86 cm(2) vs. FMR 12.33 cm(2), P = ns; both P < 0.01 vs. controls 8.83 cm(2)), and MVA fractional change similarly reduced (AMR 5.1% vs. FMR 6.3%; P = ns; both P < 0.001 vs. controls 14.6%). The co-aptation index was reduced in both MR groups (FMR 6.6% vs. AMR 7.0%, P = ns; both P < 0.001 vs. controls 19.6%). After multivariate analysis, the co-aptation index (χ(2) = 41.2) and MVA fractional change (χ(2) = 22.1) remained the strongest predictors of MR (both P < 0.001 for the model). A co-aptation index of ≤13% was 96% sensitive and 90% specific for the presence of MR. CONCLUSION: LA dilatation leads to MVA enlargement, reduced leaflet co-aptation and MR even without LV dilatation. A co-aptation index describes this in vivo. This work provides insights into the mechanism of AMR.

The prevalence and impact of deep clefts in the mitral leaflets in mitral valve prolapse.

AIMS: Deep clefts are a cause of early failure of mitral valve repair, but it is not known whether clefts represent normal morphology, or whether they occur more frequently in mitral valve prolapse (MVP). METHODS AND RESULTS: Deep clefts were defined as indentations extending ≥ 50% of the depth of the mitral valve leaflet. Using trans-oesophageal echo (TOE), 3D zoom images were acquired of the mitral valve in 176 patients: 76 patients with MVP, 43 patients with alternative causes of mitral regurgitation (MR), and 57 controls. Three-dimensional TOE results were corroborated with findings made at surgery for a subset of patients who subsequently underwent mitral valve surgery. An assessment of the proportion of the valve that was prolapsing was documented, and correlated to the number of clefts. The relationship of clefts to the region of prolapse or flail was recorded. Three-dimensional TOE was 93% sensitive and 92% specific for detecting clefts. Clefts were documented in 84% of patients with MVP, but significantly less frequently in patients with alternative MR (16%; P < 0.001) and controls (12%, P < 0.001). Clefts always appear in prolapsing regions or framing them, and the number of clefts increased in patients with more extensive prolapse. CONCLUSION: Clefts are frequently seen in MVP, but are uncommon in patients without this diagnosis. They occur in greater numbers as a larger proportion of the valve prolapses. They may play an important role in the development of MVP.

Stage migration: results of lymph node dissection in the era of modern imaging and invasive staging for lung cancer.

OBJECTIVES: Lung cancer staging has improved in recent years. Assuming that contemporary detailed preoperative staging may yield a lower rate of stage change after surgery, we were interested to determine the impact of our lymph node dissections performed at the time of surgical resection. METHODS: We retrospectively analysed a database in our surgical unit that prospectively captured information on all patients assessed and treated for lung cancer. We reviewed the data on patients who underwent lung cancer surgery with curative intent between January 2006 and August 2010 so as to reflect contemporary practice. Prior to potentially curative treatment, patients systematically underwent staging computerized tomography (CT), integrated positron emission tomography (PET) with CT and brain imaging. Enlarged and/or PET-positive nodes were subject to invasive evaluation to establish the nodal status in line with the current guidelines. This was performed by needle aspiration or biopsy usually with ultrasound guidance, endobronchial or endo-oesophageal ultrasound with needle biopsy; mediastinoscopy; mediastinotomy; video-assisted or open surgery. RESULTS: Three hundred and twelve lung cancer resections were performed (a mean age of 68 years [range 42-86] and a male-to-female ratio of 1.14:1). Despite thorough preoperative evaluations, 25.3% of patients had a change in nodal status after lung resection and lymph node dissection; of which 20.8% of patients had a nodal status upstaging. Occult N2 disease was identified in 31 (9.9%) of 312 patients. Patients with cT1 tumours showed a nodal upstaging of 12.3% compared with 25.3% in cT2 tumours. There was no difference in the rate of N2 disease for different tumour histological types. CONCLUSIONS: Despite systematic preoperative staging, there continues to be a high rate of nodal status change following surgical resection and lymph node dissection. If considering non-surgical treatments for the early stage lung cancer, the impact of this discrepancy should be considered. If not, errors in prognosis and in determining correct adjuvant treatment may arise.

Intermediate outcome and dynamic computerised tomography after chest wall reconstruction with the STRATOS titanium rib bridge system: video demonstration of preserved bucket-handle rib motion.

We report the intermediate clinical outcome following resection of a chest wall sarcoma and layered reconstruction with a deep expanded polytetrafluroethylene patch, four STRATOS titanium rib bridges and an overlying muscle flap. After 21 months there is no evidence of recurrence. The reconstruction remains intact despite trauma sufficient to fracture the ipsilateral scapula and elbow. Exercise capacity, pain control and quality of life are good. We developed a functional computed tomography (CT) algorithm which allowed dynamic imaging. Video images for the first time demonstrate preserved physiological type bucket-handle movement of the ribs in continuity with the rib bridges.

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.

A novel titanium rib bridge system for chest wall reconstruction.

Chest wall resection for liposarcoma was performed. To reconstruct the chest wall we used a novel titanium rib bridge system and preserved anatomically equivalent layers.

Transthoracic real-time three-dimensional echocardiography offers additional value in the assessment of mitral valve morphology and area following mitral valve repair.

AIMS: The accurate postoperative assessment of mitral valve repair is important not only to document operative outcome, but also to confirm the functional morphology of the repaired valve. METHODS AND RESULTS: We assessed 25 consecutive patients following mitral valve repair with transthoracic real-time 3-dimensional echocardiography (RT3DE) and 2-dimensional echocardiography (2DE). We compared the adequacy of the visualization of the mitral valve Carpentier segments, the site of the repair, and the accuracy of planimetry by RT3DE and 2DE in estimating the postoperative mitral valve area (MVA), compared to the Doppler-derived pressure half-time (PHT) value. Inter-observer variability and feasibility were also assessed for RT3DE. Adequate visualization of the mitral valve segments was more frequently obtained by 3DE imaging (163/170 by 3DE vs. 121/170 by 2DE, P < 0.001). In particular, the mitral valve commissures were more clearly identified with 3DE. 3DE also was significantly better at correctly identifying the site of the repaired segment (26/30 by 3DE vs. 19/30 by 2DE, P < 0.05). The difference in MVA (mean difference +/- SD) determined by 3DE planimetry, when compared to PHT was -0.21 +/- 0.46 cm(2) and -0.44 +/- 0.95 cm(2) for 2DE (P = 0.014). Planimetry by 3DE more closely correlated with the MVA calculated by PHT than 2DE planimetry (r = 0.89 for 3DE vs. r = 0.6 for 2DE). Imaging with RT3DE was both feasible, with a mean acquisition time of 4.02 +/- 1.68 min, and data analysis time of 15.82 +/- 3.9 min, and reproducible, with good inter-observer variability for segment scoring with 3DE (kappa = 0.79) and mean inter-observer difference in assessing MVA by 3DE planimetry of 0.18 +/- 0.12 cm(2) (P = NS). CONCLUSION: This study suggests that RT3DE offers additional morphological postoperative data of repaired mitral valves, and increases the accuracy of MVA estimation by planimetry. It is both feasible in a busy echocardiography department and reproducible.

Predicting survival in potentially curable lung cancer patients.

Lung cancer is the most common cause of cancer death with unchanged mortality for 50 years. Only localized nonsmall-cell lung cancer (NSCLC) is curable. In these patients it is essential to accurately predict survival to help identify those that will benefit from treatment and those at risk of relapse. Despite needing this clinical information, prospective data are lacking. We therefore prospectively identified prognostic factors in patients with potentially curable lung cancer. Over 2 years, 110 consecutive patients with confirmed localized NSCLC (stages 1-3A) were recruited from a single tertiary center. Prognostic factors investigated included age, gender, body mass index (BMI), performance status, comorbidity, disease stage, quality of life, and respiratory physiology. Patients were followed up for 3-5 years and mortality recorded. The data were analyzed using survival analysis methods. Twenty-eight patients died within 1 year, 15 patients died within 2 years, and 11 patients died within 3 years postsurgery. Kaplan-Meier survival estimates show a survival rate of 51% at 3 years. Factors significantly (p < 0.05) associated with poor overall survival were age at assessment, diabetes, serum albumin, peak VO(2) max, shuttle walk distance, and predicted postoperative transfer factor. In multiple-variable survival models, the strongest predictors of survival overall were diabetes and shuttle walk distance. The results show that potentially curable lung cancer patients should not be discriminated against with respect to weight and smoking history. Careful attention is required when managing patients with diabetes. Respiratory physiologic measurements were of limited value in predicting long-term survival after lung cancer surgery.

A surgeon's case volume of oesophagectomy for cancer strongly influences the operative mortality rate.

OBJECTIVE: To assess if individual case volume of oesophagectomy for cancer influences the risk of mortality and long-term survival. METHODS: Between January 1994 and December 2005, 195 resections for oesophageal cancer were performed by nine surgeons in a single institution. Operative mortality, defined as in hospital death, was compared between the high-volume and low-volume surgeons. Multivariate logistic regression was used to analyze the risk factors for death between the two groups, also in the presence of covariates. RESULTS: There were 140 males and 55 females with mean age of 63.4 (32-84). Two high-volume surgeons performed 61% (118) of the operations with a mean of 11 per year compared to 4 per year in the low-volume group. The patients in the two groups were matched for age (63 years vs 64; p=0.53), sex (67 vs 79% male; p=0.07). Ivor Lewis resections were performed more frequently by high-volume surgeons (95 vs 73%; p<0.001). The operative mortality rate was much lower when high case volume surgeons performed the procedure (4 vs 17%; p=0.001). The relative risk of death when low-volume surgeons performed the procedure was 4.59 (95% CI 1.57-13.46; p<0.001). In-hospital mortality was significantly associated with low-volume surgeon when controlling separately for age (OR 4.60; 95% CI 1.55, 13.60, p=0.006), tumor stage (OR 3.76; 95% CI 1.24, 11.45, p=0.02) and tumor type (OR 3.87; 95% CI 1.29, 11.60, p=0.016). Kaplan-Meier curves comparing the survival of high- and low-volume surgeons showed no statistical differences (Log rank p=0.48). CONCLUSIONS: Operative mortality rate for oesophagectomy for cancer is strongly influenced by case volume and was 4.6-fold higher when performed by surgeons with low case volume. Patients with oesophageal cancer in need of an oesophagectomy may benefit from referral to a high-volume thoracic surgeon.

The effect of lung resection on pulmonary function and exercise capacity in lung cancer patients.

OBJECTIVE: Prospectively to evaluate the effects of lung resection on lung function (as measured via spirometry) and exercise capacity (as measured via shuttle-walk test) in lung cancer patients. METHODS: We conducted pulmonary function tests and the shuttle-walk test with 110 consecutive patients, before and 1 month, 3 months, and 6 months after lobectomy (n = 73) or pneumonectomy (n = 37). All the patients underwent a standard posterolateral thoracotomy. Eighty-eight patients completed all 3 postoperative assessments. RESULTS: At 6 months after resection, the lobectomy patients had lost 15% of their preoperative forced expiratory volume in the first second (FEV1) (p < 0.001) and 16% of their exercise capacity (p < 0.001), and the pneumonectomy patients had lost 35% of their preoperative FEV(1) (p < 0.001) and 23% of their exercise capacity (p < 0.001). CONCLUSIONS: Lobectomy patients suffered significant reduction of functional reserve, with almost equal deterioration between lung function and exercise capacity. Pneumonectomy patients had a more substantial loss of functional reserve, and a disproportionate loss of pulmonary function relative to exercise capacity. Therefore, pulmonary function test values considered in isolation may exaggerate the loss of functional exercise capacity in pneumonectomy patients, which is important because many lung cancer patients who require resection for cure are prepared to accept the risks of immediate surgical complications and mortality, but are unwilling to risk long-term poor exercise capacity.

The incidence and impact of low body mass index on patients with operable lung cancer.

BACKGROUND & AIMS: To prospectively assess the nutritional status of patients referred for lung cancer surgery, as well as to assess the prognostic value of nutritional status in determining the surgical outcome. METHODS: One hundred and forty-six patients with potentially operable lung cancer were recruited. Loss of appetite and weight loss were recorded. All patients had serum albumin levels and body mass index (BMI) measured. Surgical outcome were noted. RESULTS: Mean age was 69 (range 42-85) years; 29/146 were not referred for surgery. Eight patients underwent failed thoracotomy. In the remaining 109 patients, mean BMI was 26. Seven patients had BMI of 19 or less. Forty-four patients had ideal body weight. The majority of patients (n=58) were overweight. Mean serum albumin was 37g/l and lower than 30g/l in 5 cases. There were 4% postoperative deaths and 32% with poor surgical outcome. There was no statistical difference in mean BMI, serum albumin, loss of appetite or weight loss between the two outcome groups. CONCLUSION: BMI is usually well preserved in patients with operable lung cancer. There was no association between low BMI, low serum albumin, loss of appetite or weight loss, and postoperative death or poor surgical outcome in this study.

Ventilation-perfusion scintigraphy to predict postoperative pulmonary function in lung cancer patients undergoing pneumonectomy.

OBJECTIVE: The American College of Chest Physicians (ACCP) recommends using quantitative perfusion scintigraphy to predict postoperative lung function in lung cancer patients with borderline pulmonary function tests who will undergo pneumonectomy. However, previous scintigraphic data were gathered on small cohorts more than a decade ago, when surgical populations were significantly different with respect to age and sex compared with typical lung cancer patients undergoing pneumonectomy in 2005. We therefore revisited the use of V/Q scintigraphy in pneumonectomy patients in predicting postoperative pulmonary function and the appropriateness of current clinical guidelines. CONCLUSION: Contrary to ACCP guidelines, we found that ventilation scintigraphy alone provided the best correlation between the predicted and actual postoperative values and recommend its use to predict postoperative lung function. However, scintigraphic techniques may underestimate postoperative lung function, so caution is required before unnecessarily preventing a patient from undergoing surgery that offers a potential cure.

Cardiopulmonary exercise tests and lung cancer surgical outcome.

STUDY OBJECTIVES: Surgical resection remains the treatment of choice for anatomically resectable non-small cell lung cancer. However, the presence of associated comorbid conditions increases the risk of death and surgical complications. Several studies have evaluated the usefulness of preoperative exercise testing for predicting postoperative morbidity and mortality. The aim of this study was to establish whether exercise testing could predict poor surgical outcome in lung cancer surgery and whether the absolute value or percentage of predicted value is the better predictor of the surgical outcome. DESIGN: The study was designed as a prospective study. PATIENTS AND SETTING: One hundred thirty patients with potentially operable lung cancer at Papworth Hospital over 2 years were recruited; of these, 101 underwent curative surgery. INTERVENTIONS: Spirometry and cardiopulmonary exercise tests were performed for every patient (n = 99), except for two patients with back problems. We also recorded the outcome of surgery, in particular, complications and mortality. MEASUREMENTS AND RESULTS: Mean maximum oxygen transport at peak exercise (Vo(2)peak) was 18.3 mL/kg/min (SD, 4.7 mL/kg/min), and mean percentage of predicted Vo(2)peak value was 84.4% (SD, 30%). Poor surgical outcome was significantly related to Vo(2)peak percentage of predicted (p < 0.01) but not to the actual oxygen uptake value. CONCLUSIONS: The use of the percentage of predicted Vo(2)peak value would be a better indicator of surgical outcome, since it predicts the surgical outcome better, and corrects for normal physiologic ranges. The threshold of Vo(2)peak for surgical intervention could be set between 50% and 60% of predicted without excess surgical mortality.

Relationship of shuttle walk test and lung cancer surgical outcome.

OBJECTIVE: Surgery remains the treatment of choice in patients with potentially resectable lung carcinoma. Both the British Thoracic Society and American Chest Physician guidelines for the selection of patients with lung cancer surgery suggest the use of a shuttle walk test to predict outcome in patients with borderline lung function. The guidelines suggest that if the patient is unable to walk 250 m during a shuttle walk test, they are high risk for surgery. However, there is no published evidence to support this recommendation. Therefore, we undertook a prospective study to examine the relationship between shuttle walk test and surgical outcome in 139 patients undergoing assessment for possible lung cancer surgery. METHODS: The shuttle walk test was performed in 139 potentially resectable patients, recruited over a 2 year period, prior to surgery. One hundred and eleven patients underwent surgery. Outcome of surgery, including duration of hospital stay, complication and mortality rates was recorded. Student's t-test was used to compare the shuttle walk distance in patients with good and poor outcome from surgery. RESULTS: Mean age of patients undergoing surgery was 69 years (42-85). Mean shuttle walk distance was 395 m (145-780), with a mean oxygen desaturation of 4% (0-14) during the test. Sixty nine patients had a good surgical outcome and 34 had a poor outcome. The shuttle walk distance was not statistically different in the two outcome groups. CONCLUSION: Shuttle walk distance should not be used to predict poor surgical outcome in lung cancer patients, contrary to current recommendations. It is therefore advisable to perform a formal cardiopulmonary exercise test if at all possible. The usefulness of a shuttle walk test might be improved. It could be compared to a predicted value, as for a formal cardiopulmonary exercise test.

Use of quantitative lung scintigraphy to predict postoperative pulmonary function in lung cancer patients undergoing lobectomy.

BACKGROUND: In patients with non-small cell lung cancer, the only realistic chance of cure is surgical resection. However, in some of these patients there is such poor respiratory reserve that surgery can result in an unacceptable quality of life. In order to identify these patients, various pulmonary function tests and scintigraphic techniques have been used. The current American College of Physicians and British Thoracic Society guidelines do not recommend the use of quantitative ventilation-perfusion scintigraphy to predict postoperative function in lung cancer patients undergoing lobectomy. These guidelines may have been influenced by previous scintigraphic studies performed over a decade ago. Since then there have been advances in both surgical techniques and scintigraphic techniques, and the surgical population has become older and more female represented. METHODS: We prospectively performed spirometry and quantitative ventilation-perfusion scintigraphy on 61 consecutive patients undergoing lobectomy for lung cancer. Spirometry was repeated one-month postsurgery. Both a simple segment counting technique alone and scintigraphy were used to predict the postoperative lung function. RESULTS: There was statistically significant correlation (p < 0.01) between the predicted postoperative lung function using both the simple segment counting technique and the scintigraphic techniques. However, the correlation using simple segment counting was of negligible difference compared to scintigraphy. CONCLUSIONS: In keeping with current American Chest Physician and British Thoracic Society guidelines, our results suggest that quantitative ventilation-perfusion scintigraphy is not necessary in the preoperative assessment of lung cancer patients undergoing lobectomy. The simple segmenting technique can be used to predict postoperative lung function in lobectomy patients.