Lean processes for optimizing OR capacity utilization: prospective analysis before and after implementation of value stream mapping (VSM).

BACKGROUND: The decision to optimize the processes in the operating tract was based on two factors: competition among clinics and a desire to optimize the use of available resources. The aim of the project was to improve operating room (OR) capacity utilization by reduction of change and throughput time per patient. SETTING: The study was conducted at Centre Hospitalier Emil Mayrisch Clinic for specialized care (n = 618 beds) Luxembourg (South). METHOD: A prospective analysis was performed before and after the implementation of optimized processes. Value stream analysis and design (value stream mapping, VSM) were used as tools. VSM depicts patient throughput and the corresponding information flows. Furthermore it is used to identify process waste (e.g. time, human resources, materials, etc.). For this purpose, change times per patient (extubation of patient 1 until intubation of patient 2) and throughput times (inward transfer until outward transfer) were measured. VSM, change and throughput times for 48 patient flows (VSM A(1), actual state = initial situation) served as the starting point. Interdisciplinary development of an optimized VSM (VSM-O) was evaluated. Prospective analysis of 42 patients (VSM-A(2)) without and 75 patients (VSM-O) with an optimized process in place were conducted. RESULTS: The prospective analysis resulted in a mean change time of (mean ± SEM) VSM-A(2) 1,507 ± 100 s versus VSM-O 933 ± 66 s (p < 0.001). The mean throughput time VSM-A(2) (mean ± SEM) was 151 min (±8) versus VSM-O 120 min (±10) (p < 0.05). This corresponds to a 23% decrease in waiting time per patient in total. CONCLUSION: Efficient OR capacity utilization and the optimized use of human resources allowed an additional 1820 interventions to be carried out per year without any increase in human resources. In addition, perioperative patient monitoring was increased up to 100%.

Complete loss of PTEN expression as a possible early prognostic marker for prostate cancer metastasis.

The EGF/IGF growth factors are potent mitogens that regulate cell proliferation and cell survival and are involved in prostate cancer development. Using laser microdissection technology and real-time PCR, together with immunohistochemistry, we have explored the growth factor and integrin dependent PI3-kinase/PTEN/Akt signalling pathway in prostate cell lines and tumour samples by analysing EGF-R, IGF1-R, ILK, beta3 integrin, PTEN and p-Akt protein expression. We provide evidence that loss of PTEN expression rather than upregulated EGF/IGF1 receptor expression was responsible for increased p-Akt in neoplastic prostate cells. We therefore compared PTEN expression in patient biopsies at first time diagnosis recruited prospectively (Study I, 112 patients) and patients with confirmed metastasis recruited retrospectively from the Luxembourg cancer registry (Study II, 42 patients). In Study I, loss of PTEN expression at first time diagnosis was found in 26 of 112 patients (23%). In Study II, 25 of the 42 patients (59%) with lymph node metastasis had complete loss of PTEN expression in both the neoplastic glands of the prostate and the invasive prostate cancer cells in the lymph node, and of these 13 (52%) exhibited already loss of PTEN expression at first diagnosis. These findings demonstrate that loss of PTEN expression is an important factor in progression towards metastatic disease and could potentially serve as an early prognostic marker for prostate cancer metastasis.

Involvement of the RNAse L gene in prostate cancer.

Prostate cancer is one of the most common cancers among men and has long been recognized to occur in familial clusters. Identification of genetic susceptibility loci for prostate cancer has however been extremely difficult, and only in 1996 was the first prostate cancer susceptibility locus HPC1 mapped to chromosome 1q24-25. Since, several additional putative loci have been identified by genetic linkage analysis on chromosome 1, 17, 20 and X (reviewed in). For three of these loci, family-based studies have identified three genes associated with inherited prostate cancer: the 3' processing endoribonuclease ELAC2/HPC2 gene, the macrophage scavenger receptor 1 gene (MSR1), and the endoribonuclease RNase L gene (RNAse L/HPC1). Here we will focus our review on the RNAse L gene and its involvement in prostate cancer and other diseases.

ILK as a potential marker gene to ascertain specific adenocarcinoma cell mRNA isolation from frozen prostate biopsy tissue sections.

A major technical challenge related to gene expression profiling of tissue samples is the difficulty of procuring selected cell populations from tissues that by nature are heterogeneous, such as prostate tissue. In this study we have examined the expression of integrin-linked kinase (ILK) mRNA in prostate adenocarcinoma cells versus normal prostate epithelial cells in order to determine whether ILK could be used as a reference marker gene for prostate adenocarcinoma cell mRNA isolation. Using laser microdissection (LMD) technology and real-time PCR, together with immunohistochemistry, we have analyzed ILK mRNA expression in epithelial cells isolated from frozen prostate biopsy specimens as well as 4 prostate cell lines (RWPE-1, LNCaP, PC-3 and DU 145) and correlated ILK mRNA expression with ILK protein expression. We demonstrate that quantitative upregulation of ILK mRNA expression in prostate epithelial cells derived from prostate tissue correlated with ILK protein expression and with the histopathology diagnosis of prostate adenocarcinoma. We further show that the level of ILK overexpression was directly influenced by the method used to isolate prostate adenocarcinoma cells (bulk tissue versus LMD dissected cells). These data provide evidence that ILK mRNA is quantitatively upregulated in prostate adenocarcinoma cells versus normal epithelial cells and is therefore a useful internal reference gene marker to evaluate the quality of prostate adenocarcinoma cell derived mRNA used for large scale prostate cancer cDNA gene profiling.