Treatment of Complex Two-Vessel Coronary Heart Disease with Single Left Internal Mammary Artery as T-Graft with Itself-A Retrospective Double Center Analysis of Short-Term Outcomes.

Background and Objectives: The strategy of revascularization may be constrained in patients with insufficient bypass grafts and with increased risk of wound healing disorders. Among those with complex left-sided double-vessel disease in whom a percutaneous coronary intervention (PCI), as well as the surgical procedure of minimally invasive coronary artery bypass grafting via left minithoracotomy (MICS CABG), is not a treatment option, CABG using the left internal mammary artery as a T-graft with itself may be an effective treatment strategy. Materials and Methods: We reviewed the data from patients treated in Cologne and Tuebingen from 2019 to 2022. We included 40 patients who received left internal mammary artery (LIMA) grafting, and additional T-graft with the LIMA itself. The objective was focused on intraoperative and short-term outcomes. Results: A total of 40 patients were treated with the LIMA-LIMA T-graft procedure with a Fowler score calculated at 20.1 ± 3.0. A total of 37.5% of all patients had lacking venous graft material due to prior vein stripping, and 21 patients presented severe vein varicosis. An overall of 2.6 ± 0.5 distal anastomoses (target vessels were left anterior descending, diagonal, intermediate branch, and/or left marginal ramus) were performed, partly sequentially. Mean flow of LIMA-Left anterior descending (LAD) anastomosis was 59.31 ± 11.04 mL/min with a mean PI of 1.21 ± 0.18. Mean flow of subsequent T-Graft accounted for 51.31 ± 3.81 mL/min with a mean PI of 1.39 ± 0.47. Median hospital stay was 6.2 (5.0; 7.5) days. No incidence of postoperative wound healing disorders was observed, and all patients were discharged. There was one 30-day readmission with a diagnosis of pericardial effusion (2.5%). There was no 30-day mortality within the cohort. Conclusions: Patients requiring surgical myocardial revascularization due to complex two-vessel coronary artery disease (CAD) can be easily managed with LIMA alone, despite an elevated Fowler score and a promising outcome. A prospective study needs to be conducted, as well as longer term surveillance, to substantiate and benchmark the long-term results, as well as the patency rates.

Thoracoscopic mesh implantation as a definitive treatment approach for peritoneal dialysis-associated hydrothorax.

Pleuroperitoneal leakage with the formation of hydrothorax is a rare complication of peritoneal dialysis, usually necessitating termination of peritoneal dialysis. We hypothesized that implantation of a polypropylene mesh on the diaphragm using video-assisted thoracoscopic surgery might induce permanent closure of pleuroperitoneal leakage. We report a case series of n = 12 peritoneal dialysis patients with pleuroperitoneal leakage and right-sided hydrothorax who underwent video-assisted thoracoscopy with mesh implantation from 2011 to 2020. Pleuroperitoneal leakage had been confirmed before surgery by intraperitoneal administration of toluidine blue, contrast-enhanced computer tomography or glucose determination from the pleural effusion. Median time from the start of peritoneal dialysis to manifestation of pleuroperitoneal leakage was 52 days. Video-assisted thoracoscopic surgery revealed multiple penetration points in the tendinous part of the diaphragm in all patients, which appeared as blebs. These were closed by covering the whole diaphragm with a polypropylene mesh. In all patients, peritoneal dialysis was paused for three months and bridged by hemodialysis. After restarting peritoneal dialysis and a median follow-up time of 1.9 years, none of the patients experienced a recurrence of pleuroperitoneal leakage. This case series demonstrates that pleuroperitoneal leakage in peritoneal dialysis patients can be permanently closed using thoracoscopic mesh implantation and allows peritoneal dialysis to be continued as renal replacement therapy.

Surgical Management of Sporadic Peripheral Nerve Schwannomas in Adults: Indications and Outcome in a Single Center Cohort.

Most sporadic peripheral nerve sheath tumors in adults are schwannomas. These tumors usually present with significant pain but can also cause neurological deficits. Symptomatology is diverse, and successful surgical interventions demand interdisciplinarity. We retrospectively reviewed 414 patients treated between 2006 and 2017 for peripheral nerve sheath tumors. We analyzed clinical signs, symptoms, histology, and neurological function in the cohort of adult patients with schwannomas without a neurocutaneous syndrome. In 144 patients, 147 surgical interventions were performed. Mean follow-up was 3.1 years. The indication for surgery was pain (66.0%), neurological deficits (23.8%), significant tumor growth (8.8%), and suspected malignancy (1.4%). Complete tumor resection was achieved on 136/147 occasions (92.5%). The most common location of the tumors was intraspinal (49.0%), within the cervical neurovascular bundles (19.7%), and lower extremities (10.9%). Pain and neurological deficits improved significantly (p ≤ 0.003) after 131/147 interventions (89.1%). One patient had a persistent decrease in motor function after surgery. Complete resection was possible in 67% of recurrent tumors, compared to 94% of primary tumors. There was a significantly lower chance of complete resection for schwannomas of the cervical neurovascular bundle as compared to other locations. The surgical outcome of sporadic schwannoma surgery within the peripheral nervous system is very favorable in experienced peripheral nerve surgery centers. Surgery is safe and effective and needs a multidisciplinary setting. Early surgical resection in adult patients with peripheral nerve sheath tumors with significant growth, pain, neurological deficit, or suspected malignancy is thus recommended.

Video assisted thoracoscopic sympathectomy for intractable recurrent VT after minimal-invasive LVAD implantation.

BACKGROUND: Recurrent ventricular tachycardia (VT) can occur after left ventricular assist device (LVAD) implantation. In this case, medical treatment might be insufficient. We report a case of a left-sided thoracoscopic sympathectomy as a feasible treatment escalation in intractable VT. CASE REPORT: A 72-year-old patient underwent an internal cardioverter defibrillator (ICD) implantation as primary prophylaxis for VTs in the setting of staged heart failure therapy. Afterwards, due to a progressive dilative cardiomyopathy he underwent a minimal-invasive LVAD implantation (HeartWare, Medtronic). After an uneventful minimal-invasive LVAD-implantation the patient was discharged to a rehabilitation program. However, after 7 weeks he developed recurrent VTs which were successfully terminated by ICD shocks deliveries leading to severe discomfort and frequent hospitalizations. Eventually, the patient was admitted with an electrical VT storm. Successful endocardial catheter ablation of all inducible VTs were performed combined with multiple rearrangements of his oral antiarrhythmic medication. However, all these treatments could not suppress further occurrence of VTs. After an interdisciplinary discussion the patient agreed to a left-sided video-assisted thoracoscopic sympathectomy. After a follow up of 150 days the patient was free from VTs apart from one short event. CONCLUSION: We believe video-assisted thoracoscopic sympathectomy might be a surgical treatment option in patients with intractable recurrent VTs after catheter ablation of VT reentrant substrate even after minimal-invasive LVAD implantation.

Endoscopic negative pressure therapy with open-pore film drainage and open-pore polyurethane sponge drainage for iatrogenic perforation of the esophagus.

BACKGROUND: Management of iatrogenic esophageal perforation (IEP) is challenging. Endoscopic negative pressure therapy (ENPT) is an emerging and effective tool for the treatment of gastrointestinal and anastomotic leaks. We have used ENPT as first-line therapy for IEP since 2017. The aim of this study was to present our results with this strategy in patients with IEP. METHODS: Nine patients were treated with ENPT for IEP between August 2017 and August 2019. Their treatment characteristics, including duration of therapy, strategy used, and outcomes, were analyzed. Treatment included ENPT with open-pore film drainage (OFD) and open-pore polyurethane foam drainage (OPD). RESULTS: Early diagnosis (< 24 hours) of IEP occurred in four patients. After a mean (standard deviation) of 19.0 (13.5) days of ENPT, 6.4 (3.4) endoscopies, and 38.1 (40.3) days of hospitalization, endoscopic treatment was effective and successful in all of the patients. Additional video-assisted thoracic surgery (VATS) was done in four patients. CONCLUSIONS: ENPT is an effective new method for the management of IEP. ENPT with OFD and OPD can be combined with minimally invasive operative methods for sepsis control in IEP.

Cryobiopsy increases the EGFR detection rate in non-small cell lung cancer.

OBJECTIVES: Detection of activating epidermal growth factor receptor (EGFR) mutation is crucial for individualized treatment of advanced non-small-cell lung cancer (NSCLC). However little is known about how biopsy technique affects the detection rate of EGFR mutations. This retrospective, single center study evaluated the detection rate of EGFR mutations in tissue obtained by bronchoscopic cryobiopsy and compared this to other standard tissue sampling techniques. MATERIALS AND METHODS: We retrospectively analyzed 414 patients with histologically confirmed NSCLC and known EGFR mutation status between 3/2008-7/2014. Tumor specimens obtained by tissue preserving bronchoscopic cryobiopsy were compared to those obtained by other techniques. RESULTS AND CONCLUSION: Analysis of bronchoscopic cryobiopsy tissue detected 29 activating EGFR mutations in 27 (21.6 %) out of 125 patients, while analysis of tissue obtained by non-cryobiopsy techniques (bronchoscopic forceps biopsies, fine needle aspiration, imaging guided transthoracical and surgical procedures) detected 42 EGFR mutations in 40 (13.8 %) out of 298 patients (p < 0.05). Cryobiopsy increased detection rate of EGFR mutations in central tumors compared with forceps biopsy (19.6 % versus 6.5 %, p < 0.05), while an insignificant trend was detected also for peripheral tumors (33.3 % versus 26.9 %). Bronchosopic cryobiopsy increases the detection rate of activating EGFR mutations in NSCLC in comparison to other tissue sampling techniques. This will help to optimize individualized treatment of patients with advanced tumors. Because of the retrospective nature of this analysis, a prospective trial is mandatory for final assessment.

New method in treatment of post-operative air leakage with fresh frozen plasma.

BACKGROUND: No consensus regarding the best post-operative treatment option for air leak has been established. In this study, we evaluate the use of intra-pleural fresh frozen plasma (FFP) as a promising treatment method. METHODS: Treatment for a sustained air leak (3 days) was warranted in approximately 12% of the lung surgeries at our institution. Fifty-two patients were treated with FFP by application of 250 mL daily. The patients were divided into two cohorts: cohort 1 consisted of 35 patients undergoing anatomical lung resections and cohort 2 consisted of 17 patients after miscellaneous types of lung surgery. Successfulness of the procedure as well as the potential influential factors was evaluated statistically and validated by a bootstrapping. Area under receiver operating characteristic curve was used to establish a cut-off value of the predictor. RESULTS: In the first cohort, air leakage was successfully treated in 28 (80%), while in seven (20%) it was still present after third treatment with FFP. The success rate in cohort 2 was 76.5%. The only covariate which appeared to remain significant in both cohorts was flow as displayed on the digital suction device prior to application of FFP. Flow ≤375 mL/min was indicative of successful aerostasis. CONCLUSION: Intra-pleural instillation of FFP seems to be a feasible method for the treatment of post-operative air leakage. Although the optimum strategy regarding its application as well as its limitations is yet to be established, an absence of complications or undesirable events makes this (off label) method a safe and promising alternative to existing options.

TuThor: an innovative new training model for video-assisted thoracic surgery.

OBJECTIVES: Video-assisted thoracic surgery (VATS) is a complex technique requiring dedicated surgical training. Platforms for such training are scarce and often rely on the use of live animals, which raises ethical concerns. The objective of this study was to develop a box trainer that is dedicated for VATS training and able to reproduce bleeding scenarios. METHODS: The developed Tuebingen Thorax Trainer comprises 5 components that are mounted on a human anatomy-like thoracic cavity containing a porcine organ complex. Any standard thoracoscopic instrument can be used. The organ complex is attached to a perfusion module. We assessed the applicability of the system in four 1-day VATS training courses at the Tuebingen Surgical Training Center. Assessment was performed using a questionnaire handed out to all participants. RESULTS: Forty participants have been trained with the Tuebingen Thorax Trainer at our institution since November 2016. Thirty-five (87.5%) participants stated that the Tuebingen Thorax Trainer is an adequate model for VATS training. The ex vivo organ complex was reported to be realistic with regards to the level of detail and scale (76%). A large proportion of participants (27.5%) were experienced with VATS and reported having performed >50 procedures before taking the training course. CONCLUSIONS: This new training device allows realistic training for VATS procedures. 'Stagnant hydrostatic perfusion' permits simulation of reproducible bleeding scenarios. The device is low in production costs and offers a strong resemblance to the clinical scenario. It reduces the use of animal models and contributes to the efforts in making surgical skills training for VATS more accessible.

Cardiac surgery in the presence of chronic internal carotid artery occlusion.

The aim was to evaluate the incidence of stroke in the setting of cardiac surgery with or without hemodynamically relevant asymptomatic carotid stenosis contralateral to the occlusion. We designed a historical cohorts study, focused on patients with unilateral totally occluded internal carotid arteries who were referred for any cardiac surgery at our center. Isolated unilateral occlusions were assigned to group 1 (n = 60), and those with a contralateral stenosis grade ≥ 60% were included in group 2 (n = 51). A total of 111 patients operated in our center from 1997 to 2016 were included. Patients in group 2 had an asymptomatic contralateral internal carotid artery stenosis with a mean stenosis grade of 71 ± 20%. Simultaneous carotid endarterectomy (CEA) was performed in 22 patients from group 2. The overall mortality was 8/111 (7.2%). Carotid-associated mortality was not observed, whereas an overall stroke incidence of 8/111 (7.2%) was detected. The group-related outcome showed comparable results for mortality (group 1: 4/60 (6.7%) vs. group 2: 4/51 (7.8%); p = 1.0). Regarding stroke incidence, group 2 had a higher incidence of overall strokes (2/60 (3.3%) vs. 6/51 (11.8%); p = 0.14) with more contralateral (0/60 (0%) vs. 2/51 (3.9%); p = 0.209) and ipsilateral strokes (2/60 (3.3%) vs. 4/51 (7.8%); p = 0.411). Stroke rate peaked in patients with simultaneous carotid and cardiac surgery (n = 22; 18.2%; p = 0.048). Performing simultaneous CEA during cardiac surgery in the presence of a contralateral occlusion may promote stroke. Asymptomatic contralateral carotid stenosis is a risk factor for stroke in patients with carotid occlusion prior to cardiac surgery.

Inflammatory potential of cotton-based surgically invasive devices: Implications for cardiac surgery.

Cotton-based surgical invasive devices with their desired hemostyptic properties have been used for decades in the surgical field. However, in cardiac surgery using the heart-lung machine with direct retransfusion of suction blood, activated blood may re-enter the circulation without filtration and may trigger a cascade reaction leading to systemic inflammation and thrombosis. We therefore set out to evaluate the inflammatory potential of untreated and pyrogen-impregnated cotton-based surgical invasive medical devices. After incubation of the swabs with whole blood or PBMC, the cell-free supernatant was investigated for IL1ß and IL6. While the reaction of human whole blood toward cotton swabs could not be influenced by any sterilization technique, dry heat and gamma-irradiation were able to diminish the inflammatory reaction of PBMC toward the material and the used pyrogens. In conclusion, using PBMC in direct contact to cotton we are the first to establish a suitable test method for quantification of the pyrogenic/inflammatory activity of this material. The unaltered reaction of whole blood, however, suggests a crosstalk of cells and plasma proteins in the inflammation activation that is not prevented by sterilization of the swabs. This new in vitro testing methodology may help to better display the clinical situation during development of new materials. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1877-1888, 2019.

Impact of surgery in patients with metastatic soft tissue sarcoma: A monocentric retrospective analysis.

BACKGROUND AND OBJECTIVES: The role of local surgical procedures in patients with metastatic soft tissue sarcoma is still undefined. Few retrospective studies have reported survival benefits for patients with pulmonary metastases after complete surgical resection. Treatment decisions are therefore mainly based on personal experiences rather than on reproducible knowledge. METHOD: A total of 237 patients with metastatic sarcoma, treated between 1982 and 2015 at the University Hospital Tuebingen, Germany, were eligible for inclusion. Out of the 237 screened patients, 102 patients underwent at least one metastasectomy. Overall survival was defined as the primary endpoint in this study. For association of non-linear relationship to the endpoint, significant prognostic factors were included into a recursive partitioning model. A subgroup analysis for long-term survivors was also performed. RESULTS: The median overall survival was 64 months. The 3-, 5-, 10-, and 20-years overall survival rates were 70.7%, 50.3%, 24.7%, and 14.8%, respectively. The number of resections and the progression-free intervals were independent prognostic factors in three statistical models. CONCLUSION: Repeated resections of metastases from different localizations are a strong predictor for prolonged survival. We suggest that the progression-free interval after metastasectomy should be considered as a predictive factor for benefit from further surgery.

Recurrence of Spontaneous Pneumothorax Is Not Associated with Allegedly Risk-Prone Lifestyle Conduct.

PURPOSE: Spontaneous pneumothorax (PNTX) is a common disease frequently operated at specialized thoracic surgery units. Videothoracoscopic surgery (VATS) has become the standard for treatment and recurrence prevention. While there is broad consensus regarding indications and techniques of PNTX surgery, postoperative risks and consecutive patient behavioral advice have not been sufficiently elucidated. METHODS: Single-center cohort analysis of 641 patients operated for primary PNTX by VATS over 10 years. Putatively recurrence-prone lifestyle activities (smoking status, flying habits, and scuba diving) and actual occurrence of recurrences were correlated. RESULTS: Follow-up rate was 46% (279/607 patients). Mean time interval between primary operation and follow-up was 61 (range: 5-177) months. In 10 patients (3.6%), a PNTX recurrence was observed. Regarding postoperative risk behavior reported at follow-up, 28% of patients were active smokers (15 ± 7 cigarettes/day), 59% traveled by plane repeatedly, and only two patients did scuba diving (0.7%). Low body-mass-index was associated with an increase in PNTX recurrence, whereas smoking, flying, and scuba diving could not be identified as risk factors. CONCLUSION: In our study, none of the supposed "classic" lifestyle-associated risk factors for PNTX recurrence after VATS proved to be a significant threat. Postoperative patient behavior might not be constrained by overcautious medical advice.

A new strategy in the treatment of chemoresistant lung adenocarcinoma via specific siRNA transfection of SRF, E2F1, Survivin, HIF and STAT3.

OBJECTIVES: According to the actual treatment strategies of lung cancer, the current therapeutic regimen is an individualized, multidisciplinary concept. The development of chemoresistance in the last decade represents the most important obstacle to an effective treatment. In our study, we examined a new therapeutic alternative in the treatment of multiresistant lung adenocarcinoma via siRNA-specific transfection of six crucial molecules involved in lung carcinogenesis [serum response factor(SFR), E2F1, Survivin, hypoxia inducible factor1 (HIF1), HIF2 and signal transducer and activator of transcription (STAT3)]. METHODS: Three chemoresistant A549 adenocarcinoma cells were cultured under standard conditions at 37°C and 5% CO2. The chemoresistance against Vinflunine, Vinorelbine and Methotrexate was induced artificially. The A549 cells were transfected for 2 h at 37°C with specific siRNA targeting SRF, E2F1, Survivin, HIF1, HIF2 and STAT3 in a non-viral manner. The efficiency of siRNA silencing was evaluated via quantitative real-time polymerase chain reaction, whereas the surviving cells after siRNA transfection as predictor factor for tumoural growth were analysed with a CASY cell counter 3 days after transfection. RESULTS: The response of the chemotherapeutic resistant adenocarcinoma cells after siRNA transfection was concentration-dependent at both 25 and 100 nM. The CASY analysis showed a very effective suppression of adenocarcinoma cells in Vinorelbine, Vinflunine and Methotrexate groups, with significantly better results in comparison with the control group. CONCLUSIONS: In our study, we emphasized that siRNA interference might represent a productive platform for further research in order to investigate whether a new regimen in the treatment of multiresistant non-small-cell lung cancer could be established in vivo in the context of a multimodal cancer therapy.

Application of intravascular dissection devices for closed chest coronary sinus lead extraction: an interdisciplinary approach.

BACKGROUND: Increasing application of cardiac resynchronization therapy is accompanied by an increase in patients requiring removal of coronary sinus (CS) leads. The aim of this study was to determine outcomes of closed chest CS lead extraction using intravascular dissection devices. METHODS: Between 2000 and 2011, 41 patients (80.5% men; aged 64.2±13.8 years) underwent transvenous CS lead extraction procedures. Reasons for lead extraction were infection in 9, CS lead dislodgement in 15, lead malfunction, including manufacturer-initiated product recall in 6, phrenic nerve stimulation in 5, combinations of causes in 5, and elective extraction concomitant with generator replacement for battery depletion in 1. RESULTS: In addition to 24 isolated CS lead extractions, we performed 17 multiple lead extractions (2 to 4 leads) after a mean of 30.6±32.5 months. The time elapsed from implantation was 4.6±9.1 months for isolated CS and 42.6±32.4 months for multiple lead extractions. Extraction by direct manual traction was feasible in 13 patients by locking stylets in 6. Escalation to mechanical sheaths was required in 17 patients and to electrosurgical sheaths in 5. More aggressive methods were associated with longer implantation times and positive infection status. No deaths or major periprocedural complications occurred. Six minor postprocedural complications, of which three were surgically related, occurred in 5 patients. CONCLUSIONS: Closed chest CS lead extraction can be safely performed with excellent results. We recommend an escalating approach from isolated manual traction over locking stylets to mechanical sheaths and, eventually, electrosurgical dissection devices. The application in mainly high-risk patients demands an interdisciplinary approach to enhance safety and limit morbidity and death.

Safety and Efficacy of the Prostar XL Vascular Closing Device for Percutaneous Closure of Large Arterial Access Sites.

Purpose. The purpose of this study is to retrospectively evaluate the efficacy and safety of the Prostar XL device for percutaneous large access site closure in an unselected patient and operator collective. Materials and Methods. All patients (n = 50) who had received percutaneous vascular closing with the Prostar XL device in our institution with follow-up data of at least 6 months were retrospectively included. Primary (freedom from surgical conversion) and continued (freedom from groin surgery in further course) technical success and major (deviations from expected outcome requiring surgery) and minor (other deviations from expected outcome) complications were assessed. Success and complications rates were correlated with delivery system size (Mann-Whitney Rank Sum Tests) and operator experience (paired samples t-test). Results. Rates of primary and continued technical success as well as major and minor complications were 93.6%, 89.7%, 10.3%, and 10.3% (groin based) and 90.0%, 84.0%, 16.0%, and 16.0% (patient based), respectively. No correlation of success and complications rate was found with delivery system sizes and operator experience. Conclusions. Application of the Prostar XL device for percutaneous closure of large arterial access sites is safe with a relatively high rate of technical success and low rate of major complications. Sizes of the delivery systems and the experience of the operator did not influence the results.

Rapidly progressive paraplegia and pleural empyema: how does that correlate?

A 74-year-old man presented with progressive dyspnea after a 10-days latency following a thoracic trauma. CT imaging showed multiple rib fracture and an empyema that was primarily treated by a chest tube. In the course of the hospital stay, a rapidly progressive paraplegia developed and the MR imaging revealed a peridural abscess caused by a pleural empyema. Due to trauma-related barrier damage and the initial delay of the operative therapy a usually less invasive pathogen (streptococcus intermedius) could affect the peridural space. The successful therapy consisted of urgent laminectomy and a subsequent video-assisted thoracoscopy supported by systemic antibiotic therapy.

Does dose matter? Effect of two different neoadjuvant protocols in advanced NSCLC.

BACKGROUND: For stage III, NSCLC neoadjuvant protocols have been intensified up to full dose protocols but up till now the effect of more intensive protocols in a trimodal setting could not be compared directly because of different selection criteria or experience of involved facilities in different studies or multicenter studies. We analyzed our experience with two different neoadjuvant protocols, consistent selection criteria, and surgical teams over 17-year time period. METHOD: Single-center retrospective study in 159 patients concerning survival, recurrence, and downstaging effect. RESULTS: Overall median survival was 32 months, with 26 months for protocol 1, and 35 months for protocol 2, respectively. Hospital mortality was 5%. Log-rank test showed significant difference between the protocols for UICC-downstaging-effect, ypT-stage, ypN-stage, and ypUICC-stage, respectively, but only ypN-stage and ypUICC-stage were significant risk factors for survival using Cox regression. CONCLUSION: The median survival benefit of 9 months is evident but (probably still) not significant. The more aggressive protocol 2 shows a significant better downstaging effect concerning N- and UICC-stage if R0-resection can be achieved. Insofar dose does matter!

Small interfering RNA-mediated suppression of serum response factor, E2-promotor binding factor and survivin in non-small cell lung cancer cell lines by non-viral transfection.

OBJECTIVES: Serum response factor (SRF), E2F1 and survivin are well-known factors involved in a multitude of cancer-related regulation processes. However, to date, no suitable means has been found to apply their potential in the therapy of non-small cell lung cancer (NSCLC). This study deals with questions of small interfering ribonucleic acid (siRNA) transfection efficiency by a non-viral transfection of NSCLC cell-lines and the power of siRNA to transiently influence cell division by specific silencing. METHODS: Different NSCLC cell lines were cultured under standard conditions and transfected, with specific siRNA targeting SRF, E2F1 and survivin in a non-viral manner. Cells treated with non-specific siRNA (SCR-siRNA) served as controls. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed for messenger RNA (mRNA) expression levels. Additionally, transfection efficiency was evaluated by flow cytometry. The analysis of cell proliferation was determined with a CASY cell counter 3 days after transfection with SRF or SCR-siRNA. RESULTS: Transfection of the NSCLC cell lines with specific siRNAs against SRF, E2F1 and survivin resulted in a very considerable reduction of the intracellular mRNA concentration. CASY confirmation of cell viability demonstrated an excellent survival of the cell lines treated with non-specific siRNA, in contrast to with application of specific siRNA. CONCLUSIONS: This study reports a reliable transfectability of NSCLC-cell lines by siRNA, initially in a non-viral manner, and a reproducible knockdown of the focussed targets, consequently leading to the death of the tumour cells. This constitutes a strong candidate for a new assessment strategy in the therapy of non-small cell lung cancer.