Objective To clarify the perioperative and oncologic outcome of pulmonary resection for a metachronous second primary lung cancer (MSPLC) following resection of an initial non–small cell lung cancer ...(NSCLC). Methods Retrospective chart review identified 161 patients (88 men and 73 women) with a median age of 70 years (range, 34-88 years) who underwent pulmonary resection for MSPLC between January 2000 and December 2009. Operative morbidity, mortality, and relevant factors were analyzed with χ2 test or Fisher exact test and Mann-Whitney U test. Survival was analyzed with Kaplan-Meier and Cox proportional hazard method. Results The median interval between the initial and subsequent resection for MSPLC was 42.7 months (range, 7-205 months). There was no operative mortality and postoperative complication rate was 29%. In multivariate analysis, ipsilateral operation ( P = .0002) and a lower predicted preoperative percent forced expiratory volume in the first second ( P = .0035) were significant risk factors for postoperative complications. Five-year overall survival rates after resection of the initial and second metachronous NSCLC were 87.4% and 60.8%, respectively. Significant negative long-term prognostic factors for survival following resection of a MSPLC in multivariate analysis were tumor size >2 cm ( P = .003) and number of pack years of smoking ( P = .005). Metastatic nodal disease ( P = .19) or a sublobar resection ( P = .17) were not associated with worse survival. Conclusions Surgical treatment of a MSPLC can be undertaken with 5-year survival rate of 60%. Expected operative morbidity and mortality are comparable to primary surgery. Tumors 2 cm or smaller are associated with improved survival and freedom from recurrence. Close long-term follow-up of patients who have undergone resection of NSCLC is recommended.
Background The aim of this study was to clarify the clinical outcome and significance of mediastinal lymph node dissection (LND) during pulmonary resection of metastases from colorectal ...adenocarcinoma. Methods A retrospective chart review was performed. Between April 1985 and December 2009, 518 patients underwent 720 pulmonary metastasectomies for metastatic colorectal adenocarcinoma. Relevant factors were analyzed with the χ2 or Fisher exact test and the Mann-Whitney test. Survival and lymph node (LN) recurrence-free period after pulmonary metastasectomy were analyzed with Kaplan-Meier and Cox proportional hazards methods. Results The overall 5-year and 10-year survival rate after pulmonary metastasectomy were 47.1% and 27.7%, respectively. The only significant prognostic factor for survival after pulmonary metastasectomy was mediastinal LN metastasis ( p = 0.047 in univariate and 0.0028 in multivariate analysis); 199 patients did not undergo LND, 279 patients underwent LND that were negative, and 40 patients underwent LND that contained 1 or more positive mediastinal LN for metastases. The sensitivity of positron emission tomographic scan for detecting mediastinal LN metastases was only 35%. Although long-term survivors were present, systematic LND was not a significant factor for prolonged survival ( p = 0.26) in the positive LND group. Conclusions Mediastinal LN metastases are a significant negative prognostic factor for survival after pulmonary metastasectomy for metastatic colorectal cancer. Computed tomography and positron emission tomography based imaging, as well as preoperative carcinoembryonic antigen levels have poor sensitivity for detecting malignant mediastinal LN in this setting. Systematic mediastinal LND should be performed for prognostic purposes during pulmonary metastasectomy for colorectal metastases.
Abstract Complete surgical resection is the most effective curative treatment for lung cancer. However, many patients with lung cancer also have severe COPD which increases their risk of ...postoperative complications and their likelihood of being considered “inoperable.” Preoperative pulmonary rehabilitation (PR) has been proposed as an intervention to decrease surgical morbidity but there is no established protocol and no randomized study has been published to date. We tested two preoperative PR interventions in patients undergoing lung cancer resection and with moderate-severe COPD in a randomized single blinded design. Outcomes were length of hospital stay and postoperative complications. The first study tested 4 weeks of guideline-based PR vs. usual care: that study proved to be very difficult to recruit as patients and providers were reluctant to delay surgery. Nine patients were randomized and no differences were found between arms. The second study tested ten preoperative PR sessions using a customized protocol with nonstandard components (exercise prescription based on self efficacy, inspiratory muscle training, and the practice of slow breathing) ( n = 10) vs. usual care ( n = 9). The PR arm had shorter length of hospital stay by 3 days ( p = 0.058), fewer prolonged chest tubes (11% vs. 63%, p = 0.03) and fewer days needing a chest tube (8.8 vs. 4.3 days p = 0.04) compared to the controlled arm. A ten-session preoperative PR intervention may improve post operative lung reexpansion evidenced by shorter chest tube times and decrease the length of hospital stay, a crude estimator of post operative morbidity and costs. Our results suggest the potential for short term preoperative pulmonary rehabilitation interventions in patients with moderate-severe COPD undergoing curative lung resection. 4 weeks of conventional preoperative PR seems non feasible.
The classic Jaccard and Sørensen indices of compositional similarity (and other indices that depend upon the same variables) are notoriously sensitive to sample size, especially for assemblages with ...numerous rare species. Further, because these indices are based solely on presence–absence data, accurate estimators for them are unattainable. We provide a probabilistic derivation for the classic, incidence‐based forms of these indices and extend this approach to formulate new Jaccard‐type or Sørensen‐type indices based on species abundance data. We then propose estimators for these indices that include the effect of unseen shared species, based on either (replicated) incidence‐ or abundance‐based sample data. In sampling simulations, these new estimators prove to be considerably less biased than classic indices when a substantial proportion of species are missing from samples. Based on species‐rich empirical datasets, we show how incorporating the effect of unseen shared species not only increases accuracy but also can change the interpretation of results.
Background Little consensus exists and varying outcomes are reported when the 4 most common esophagogastric anastomotic techniques are compared: circular stapled (CS), hand sewn (HS), linear stapled ...(LS) (longitudinally stapled anastomosis), and modified Collard (MC) (combined linear and transverse stapled anastomosis). This report analyzes outcomes of these anastomotic techniques. Methods From July 2004 through December 2008, all intrathoracic and cervical esophagogastric anastomoses at our institution were reviewed. Results There were 432 patients (358 men, 74 women) who underwent primary esophagogastric operations. Median age was 64 years (range, 23–90 years). The approach was an Ivor Lewis esophagectomy in 254 patients (59%), transhiatal esophagectomy in 115 patients (27%), McKeown (3-hole) esophagectomy in 49 (11%) patients, minimally invasive esophagectomy in 9 (2.1%) patients, and thoracoabdominal esophagectomy in 6 (1.4%) patients. There were 268 intrathoracic (62%) and 164 cervical (38%) anastomoses. Anastomotic techniques included LS in 260 (60%) patients MC in 67 (16%) patients, HS in 57 (13%) patients, and CS in 48 (11%) patients. Operative mortality was 3.7%. Anastomotic leak occurred in 50 patients (11%). Grade III or IV leaks occurred in 21 patients (4.9%), including 13 in the chest (4.8%) and 8 in the neck (4.9%). Grade III or IV leaks occurred in 12 patients (4.6%) with LS anastomoses, in 4 (7.0%) patients with HS anastomoses, in 3 (6.2%) patients with CS anastomoses, and in 2 (3.0%) patients with MC anastomoses. HS anastomoses had the highest odds of leakage ( p = 0.01) and LS anastomoses had the lowest risk of stricture ( p = 0.006). Conclusions When performing an esophagogastric anastomosis, clinically significant leaks occur with similar frequency in both cervical and intrathoracic locations. The HS technique has the highest leak rate and the LS technique had the lowest rate of stricture formation.
Mechanical stimuli can modify the energy landscape of chemical reactions and enable reaction pathways, offering a synthetic strategy that complements conventional chemistry. These mechanochemical ...mechanisms have been studied extensively in one-dimensional polymers under tensile stress using ring-opening and reorganization, polymer unzipping and disulfide reduction as model reactions. In these systems, the pulling force stretches chemical bonds, initiating the reaction. Additionally, it has been shown that forces orthogonal to the chemical bonds can alter the rate of bond dissociation. However, these bond activation mechanisms have not been possible under isotropic, compressive stress (that is, hydrostatic pressure). Here we show that mechanochemistry through isotropic compression is possible by molecularly engineering structures that can translate macroscopic isotropic stress into molecular-level anisotropic strain. We engineer molecules with mechanically heterogeneous components-a compressible ('soft') mechanophore and incompressible ('hard') ligands. In these 'molecular anvils', isotropic stress leads to relative motions of the rigid ligands, anisotropically deforming the compressible mechanophore and activating bonds. Conversely, rigid ligands in steric contact impede relative motion, blocking reactivity. We combine experiments and computations to demonstrate hydrostatic-pressure-driven redox reactions in metal-organic chalcogenides that incorporate molecular elements that have heterogeneous compressibility, in which bending of bond angles or shearing of adjacent chains activates the metal-chalcogen bonds, leading to the formation of the elemental metal. These results reveal an unexplored reaction mechanism and suggest possible strategies for high-specificity mechanosynthesis.
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