Tomas Skalicky

Workflow Optimization with FlowOpt: On Modelling, Optimizing, Visualizing, and Analysing Production Workflows

Workflow optimization is an important aspect of many problems including project management and manufacturing. In this paper we describe an innovative general tool supporting a complete workflow optimization process in small and medium manufacturing enterprises. The tool supports interactive modeling of workflows with nested structure and additional logical and synchronization constraints. Then the tool automatically schedules workflows to available resources while optimizing on-time-in-full performance (just in time scheduling). Obtained schedules are visualized in the form of Gantt charts where the user can arbitrarily modify the schedule. Finally, the schedules can be analyzed and the tool suggests how to modify the enterprise, for example by buying new resources, to obtain better quality schedules. By supporting workflows with alternative processes the tool realizes integrated planning and scheduling.

Prognostic importance of some clinical and therapeutic factors for the effect of portal vein embolization in patients with primarily inoperable colorectal liver metastases

Introduction Portal vein embolization (PVE) may increase the resectability of liver metastases. However, the problem of PVE is insufficient growth of the liver or tumor progression in some patients. The aim of this study was to evaluate the significance of commonly available clinical factors for the result of PVE. Material and methods Portal vein embolization was performed in 38 patients with colorectal liver metastases. Effects of age, gender, time between PVE and liver resection, oncological therapy after PVE, indocyanine green retention rate test, synchronous, metachronous and extrahepatic metastases, liver volume before and after PVE, increase of liver volume after PVE and the quality of liver parenchyma before PVE on the result of PVE were evaluated. Results Liver resection was performed in 23 (62.2%) patients within 1.3 ±0.4 months after PVE. Tumor progression occurred in 9 (23.7%) patients and 6 (15.8%) patients had insufficient liver hypertrophy. Significant clinical factors of PVE failure were number of liver metastases (cut-off – 4; odds ratio – 4.7; p < 0.03), liver volume after PVE (cut-off 1000 cm3; odds ratio – 5.1; p < 0.02), growth of liver volume after PVE (cut-off 150 cm3; odds ratio – 18.7; p < 0.002), oncological therapy administered concomitantly with PVE (p < 0.003). Conclusions Negative clinical factors of resectability of colorectal cancer liver metastases after PVE included more than four liver metastases, liver volume after PVE < 1000 cm3, growth of the contralateral lobe by less than 150 cm3 and concurrent oncological therapy.

Portal Vein Embolization (PVE) Versus PVE with Haematopoietic Stem Cell Application in Patients with Primarily Non-resectable Colorectal Liver Metastases

Background: Portal vein embolization (PVE) and PVE with autologous mesenchymal stem cell application (PVE–MSC) increases future liver remnant volume (FLRV). The aim of this study was to compare both methods from the aspect of FLRV growth, progression of colorectal liver metastases (CLM), CLM resectability and long-term results. Patients and Methods: Fifty-five patients with CLM and insufficient FLRV were included in the study. FLVR growth and CLM volume were evaluated using computed tomography. Liver resection was performed in patients with FLVR >30% of total liver volume. Results: In the PVE (N=27) group, FLRV growth was observed in 23 patients (85.2%) and in 100% of patients in the PVE–MSC (N=28) group (p<0.05). The rapidity of FLRV and CLM growth did not differ between groups. R0 resection was performed in 14 (51.8%) and 24 (85.7%) patients from the PVE and PVE–MSC (p<0.02) groups, respectively. The 3-year overall and progression-free survival rates were 85.75% and 9.3% in the PVE group and 68.7% and 17.1% in the PVE–MSC group, respectively (p<0.67 and p<0.84, respectively). Conclusion: PVE–MSC allows for more effective growth of FLRV and resectability of CLM compared to PVE. The two methods do not differ in their long-term results.

Liver Parenchyma Regeneration in Connection with Extended Surgical Procedure - Experiment on Large Animal

Liver surgery underwent enormous evolution after development and introduction of new technical skills in surgical praxis. Nevertheless many patients with primary or secondary liver malignancies are not indicated to radical surgical therapy that could reach complete remission of malignant disease because the frontiers of liver surgery are limited today by the functional reserves of remnant parenchyma. The main argument to non surgical treatment is increased risk of acute liver failure after extended liver resection, where retained liver parenchyma is to small to sustain the liver functions (Abdalla, 2001). Portal vein embolization (PVE) can multiply the future liver remnant volume (FLRV) in spite of affection of only one of liver lobes by malignant diseases (Makuuchi, 1984, Makuuchi, 1990, Harada, 1997). This procedure was performed firstly in 1984 by Makuuchi (Abdalla, 2001, Makuuchi, 1984, Makuuchi, 1990). PVE of portal branch of with malignancy afflicted liver lobe initiates compensatory hypertrophy of contralateral non-occluded lobe. The occluded lobe underlies atrophy. The compensatory hypertrophy is supposed to be stimulated by increased flow of portal blood, that contains hepatotrophic substances (Kusaka, 2004, Azoulay, 2000). Liver resection after PVE is performed only in 63-96% of patients (Kokudo, 200, Stefano, 2005, Lagasse, 2000). The main reason for this resolution is unsuccessful hypertrophy of FLRV or progression of malignancy. Liver resection after PVE is performed only in 63-96% of patients (Azoulay, 200, Kokudo, 2001, Stefano, 2005). The main reason for this resolution are unsuccessful hypertrophy of FLRV or progression of malignancy.

A complex oncosurgical approach to increasing the resectability of colorectal cancer metastases - a case report

AIM In this case report, the authors aim to demonstrate the success of recent methods in the radical treatment of a patient with primary inoperable liver and subsequent colorectal cancer pulmonary metastases. METHODS A 75 year old patient with inoperable bulky metastasis in the right hepatic lobe and insufficient future remnant liver volume was indicated for a stage procedure in the liver parenchyma. Embolization of the right branch of the portal vein was first performed with subsequent administration of stem cells into the contralateral liver lobe. Following compensatory growth of the left liver lobe, right-sided hepatectomy was performed with subsequent adjuvant oncological treatment. Six months after the surgery, a metastasis developed in the right pulmonary lobe which was solved by metastasectomy. RESULTS The patient, one year after the diagnosis of inoperable liver metastasis, is completely healthy and free of signs of disease recurrence. CONCLUSION A comprehensive oncosurgical approach using up-to-date diagnostic and treatment options may offer patients with metastatic colorectal cancer, radical treatment with the hope of long-term quality survival.

P2-15-06: Breast Cancer Liver Metastases – Possibilities and Limits of Surgical Treatment.

Background Breast cancer liver metastases (BCLM) are often considered as a sign of a systemic disease with little hope of therapeutic success. The aim of study was to assess the possibilities and determine the limits of the surgical treatment of BCLM. Method : 646 patients were operated for malignant and benign lesions of the liver between 1999 and 2010. Liver surgery for BCLM was performed in 21 women of the average age of 48.5 years (33-71). The average time from the primary surgery for breast cancer till BCLM diagnosis was 4.7 years (2 months - 9 years). BCLM were solitary in 17 and in four cases multiple. Patient selection for liver surgery was based on sufficient future remnant liver volume, the absence of systemic non-resectable tumor dissemination and response to chemotherapy. The authors performed six right-sided hepatectomy, four segmentectomies, three left lobectomies, one metastasectomy, six radiofrequency ablations (RFA), one combined procedure -liver resection and RFA. Histological examination revealed ductal carcinoma in fourteen and lobular carcinoma in seven cases. All patients were treated with the curative adjuvant chemotherapy after surgery. The data were statistically evaluated by statistical software Statistica 9.0. Results : 30 - days mortality rate was 0%. One patient had a complicated hepatectomy with iatrogenic bile duct injury. According to statistical analysis the probability of patients survival twelve, resp. thirty months after surgery was 100, resp. 66.7% and the probability of the tumor relapse anywhere in the body was at the same time intervals 0, resp. 71. 5%. Conclusion : Liver surgery combined with the adjuvant chemotherapy are a therapeutic methods of choice for highly selected patients with metastases limited to the liver and objective response to neoadjuvant chemotherapy. The study was supported by the research projects IGA MZ NS 9727 and IGA MZ NS 102 40. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-15-06.