'Six sigma approach' - an objective strategy in digital assessment of postoperative air leaks: a prospective randomised study.

OBJECTIVE: Until now, only way to report air leaks (ALs) has been with an analogue score in an inherently subjective manner. The Six Sigma quality improvement methodology is a data-driven approach applicable to evaluate the quality of the quantification method of repetitive procedures. We applied the Six Sigma concept to improve the process of AL evaluation. METHODS: A digital device for AL measurement (Drentech PALM, Redax S.r.l., Mirandola (MO), Italy) was applied to 49 consecutive patients, who underwent pulmonary intervention, compared with a similar population with classical chest drainage. Data recorded were postoperative AL, chest-tube removal days, number of chest roentgenograms, hospital length of stay; device setup time, average time rating AL and patient satisfaction. Bivariable comparisons were made using the Mann-Whitney test, the χ² test and Fisher's exact test. Analysis of quality was conducted using the Six Sigma methodology. RESULTS: There were no significant differences regarding AL (p=0.075), although not statistically significant; there was a reduction of postoperative chest X-rays (four vs five) and of hospital length of stay (6.5 vs 7.1 days); and a marginally significant difference was found between chest-tube removal days (p=0.056). There were significant differences regarding device setup time (p=0.001), average time rating AL (p=0.001), inter-observer variability (p=0.001) and patient satisfaction (p=0.002). Six Sigma analyses revealed accurate assessment of AL. CONCLUSIONS: Continuous digital measurement of AL reduces degree of variability of AL score, gives more assurance for tube removal, and reports AL without the apprehension of observer error. Efficiency and effectiveness improved with the use of a digital device. We have noted that the AL curves depict actually sealing of AL. The clinical importance of AL curves requires further study.

Laminin alpha2 chain-positive vessels and epidermal growth factor in lung neuroendocrine carcinoma: a model of a novel cooperative role of laminin-2 and epidermal growth factor in vessel neoplastic invasion and metastasis.

Capillaries expressing the laminin alpha2 chain in basement membranes may be considered early developing vessels in normal and neoplastic human tissues. Therefore, we investigated whether up-regulation of this extracellular matrix protein favors transendothelial migration of neoplastic cells and then metastasis. In lung small and large cell neuroendocrine carcinomas, which exhibit a stronger metastatic tendency among carcinomas, laminin alpha2 chain-positive vessels were more numerous than in carcinoid tumors and supraglottis, breast, and lung non-small cell carcinomas, suggesting a direct relationship between these vessels and metastasis. In vitro studies showed that epidermal growth factor (EGF) induced a more efficient migration of the AE-2 lung neuroendocrine carcinoma cell line through the purified laminin alpha2 chain rather than through the laminin beta1 chain and fibronectin. AE-2 cells constitutively expressed all EGF receptors and the alpha6beta1 integrin, which is one of the laminin alpha2 chain receptors. EGF up-regulated alpha6beta1 expression in several tumors. In this regard, we show that EGF increased the chemo-kinetic migration of AE-2 cells through EAHY endothelial monolayers, which was inhibited by the anti-alpha6 integrin chain monoclonal antibody. These data indicate that laminin alpha2 chain and alpha6beta1 may be mutually involved in EGF-dependent migration of AE-2 cells and that laminin alpha2 chain-positive vessels may favor metastasis of EGF-dependent tumors.

Bullectomy is comparable to lung volume reduction in patients with end-stage emphysema.

OBJECTIVES: Emphysema is one of the most prevalent disabling diseases, not modified by current medical treatment and physical rehabilitation. Lung transplantation is an effective clinical option in end-stage emphysema but it is available only for a limited number of patients. Bullectomy and lung volume reduction represent other surgical options to improve symptoms and exercise tolerance in selected patients. Both procedures allow the removal of the area of emphysematous lung resulting in improvement in chest wall mechanics, ventilation/perfusion ratio and re-expansion and better function of the residual lung. There is some evidence that in patients with end-stage emphysema bullectomy and lung volume reduction work in the same manner and yield similar functional results. METHODS: We compared and analyzed retrospectively two groups of patients with end-stage emphysema who underwent bullectomy or lung volume reduction. Over the last 5 years 20 patients with end-stage emphysema presenting with bullae underwent thoracoscopic bullectomy (Group I). During the same period of time 18 patients with end-stage non-bullous emphysema underwent thoracoscopic unilateral lung volume reduction. Pre-operative baseline respiratory function data, peri-operative data, and functional results recorded at 6 and 12 months were compared and analyzed. RESULTS: Both groups were homogeneous in terms of age, degree of respiratory derangement and severity of emphysema. Complication rate and peri-operative data were similar in the two groups. Improvement in symptoms, respiratory function and exercise tolerance was comparable. CONCLUSIONS: Our experience supports the hypothesis that the physiopathological basis of respiratory improvement after bullectomy and lung volume reduction surgery in patients with end-stage emphysema is the same, although the exact mechanism remains incompletely understood.