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Biomedical subjects

P Kienle

Publications and source records attributed to P Kienle.

At least 19 recordsLinked to original sources

Development and evaluation of a training module for the clinical introduction of the da Vinci robotic system in visceral and vascular surgery.

BACKGROUND: With the increasing use of the surgical robotic system in the clinical arena, appropriate training programs and assessment systems need to be established for mastery of this new technology. The authors aimed to design and evaluate a clinic-like training program for the clinical introduction of the da Vinci robotic system in visceral and vascular surgery. METHODS: Four trainees with different surgical levels of experience participated in this study using the da Vinci telemanipulator. Each participant started with an initial evaluation stage composed of standardized visceral and vascular operations (cholecystectomy, gastrotomy, anastomosis of the small intestine, and anastomosis of the aorta) in a porcine model. Then the participants went on to the training stage with the rat model, performing standardized visceral and vascular operations (gastrotomy, anastomosis of the large and small intestines, and anastomosis of the aorta) four times in four rats. The final evaluation stage was again identical to the initial stage. The operative times, the number of complications, and the performance quality of the participants were compared between the two evaluation stages to assess the impact of the training stage on the results. RESULTS: The operative times in the final evaluation stage were considerably shorter than in the initial evaluation stage and, except for cholecystectomies, all the differences reached statistical significance. Also, significantly fewer complications and improved quality for each operation in the final evaluation stage were documented, as compared with their counterparts in the initial evaluation stage. These improvements were recorded at each level of experience. CONCLUSIONS: The presented experimental small and large animal model is a standardized and reproducible training method for robotic surgery that allows evaluation of the surgical performance while shortening and optimizing the learning-curve.

Animals↗

Comparison of Venae Sectio vs. modified Seldinger Technique for totally implantable access ports; Portas-trial [ISRCTN:52368201].

BACKGROUND: The insertion of a Totally Implantable Access Port (TIAP) is a routinely employed technique in patients who need a safe and permanent venous access. The number of TIAP implantations is increasing constantly mainly due to advanced treatment options for malignant diseases. Therefore it is important to identify the implantation technique which has the optimal benefit/risk ratio for the patient. STUDY DESIGN: A single-centre, randomized, controlled superiority trial to compare two different TIAP implantation techniques. SAMPLE SIZE: 160 patients will be included and randomized intra-operatively. ELIGIBILITY CRITERIA: Age equal or older than 18 years, patients scheduled for primary elective implantation of a TIAP in local anaesthesia and a signed informed consent. Primary endpoint: Primary success rate of the randomized technique. INTERVENTION: Venae Sectio in combination with the Seldinger Technique (guide wire and a peel away sheath) will be used to place a TIAP. Reference treatment: Conventional Venae Sectio will be used with a direct insertion of the TIAP without guide wire or peel away sheath. Duration of study: Approximately 20 months. ORGANISATION/RESPONSIBILITY: The trial will be conducted in compliance with the protocol and in accordance with the moral, ethical, and scientific principles governing clinical research as set out in the Declaration of Helsinki (1989) and Good Clinical Practice (GCP). The trial will also be carried out in keeping with local and regulatory requirements. The Klinisches Studienzentrum Chirurgie (KSC)--Centre of Clinical Trials in Surgery at the Department of Surgery, University Hospital Heidelberg is responsible for planning and conduction of the trial. Documentation of patient's data will be accomplished via electronical Case Report Files (eCRF) with MACRO-Software by the KSC. Randomization, data management, monitoring and biometry are provided by the independent Koordinierungszentrum für Klinische Studien (KKS)--Coordination Centre for Clinical Trails at the University of Heidelberg.

Journal Article↗

[Importance of anesthesia in multimodal oncologic therapeutical concepts].

Patients with malignant diseases are increasingly being treated with multimodal therapeutical concepts based on the three major modalities surgery, radiotherapy and chemotherapy. The perioperative period is crucial within this multimodal concept as the prognosis of patients may be directly influenced by perioperative measures. In addition, it is of major importance to avoid complications in the perioperative phase, as these might worsen the prognosis of the patient and in order to prevent a delay in the beginning of planned adjuvant therapies. These aspects demonstrate the important role of anesthesia in the treatment of patients with cancer. Further studies defining the relevance of anesthesiologic measures in oncologic patients are needed.

Aged↗

[Project selection and protocol design in the Study Centre of the German Surgical Society].

BACKGROUND: The Study Centre of the German Surgical Society (SDGC) designs, conducts, and analyses multicentre randomised controlled surgical trials. The aim of this paper is to present the decision-making process and responsibilities of the SDGC from submission of a study idea to full protocol development in order to achieve transparency in trial selection. METHODS: The process is divided into four steps. Study ideas can be submitted electronically by members of the German Surgical Society using a form via the homepage of the institution. Firstly, ideas are screened by staff members within 4 weeks for methodological and clinical relevance. Feasible and novel ideas are then converted to trial outlines in cooperation with the submitting surgeon. As a third step, the Steering Committee of the SDGC decides whether to accept the project using a list of defined criteria. Finally, the SDGC draws up a full protocol together with the submitting surgeon. All ideas and decisions are accessible via the SDGC homepage. CONCLUSIONS: The process described should help in the selection of relevant projects, acquisition of grants, and maintenance of transparency in trial selection and the protocol development process.

Decision Making↗

Laparoscopic surgery for colorectal cancer.

Traditionally open surgical resection has been recommended for colorectal tumours, but recently, laparoscopic surgery has gained popularity. This review summarizes the published data on laparoscopic colorectal cancer surgery with emphasis on recently published trials. For colon cancer laparoscopic resection appears to be associated with the same outcome as open surgery. However, whilst short-term outcome was better in the laparoscopic group in most of the randomized trials, when comparing laparoscopic with fast-track open surgery, no differences could be demonstrated in a randomized control trial. For rectal cancer the data are less clear. It seems that it may be feasible to resect at least small rectal cancers laparoscopically. Clearly the role of the laparoscopic technique needs to be better defined in rectal cancer. It has been well documented that short- and long-term outcome of colorectal cancer surgery depends on the quality and experience of the team treating the patient. Therefore, the major future challenge in laparoscopic colorectal cancer surgery will be to provide and structure adequate training and introduce quality control measures.

Colectomy↗

Simultaneous measurement of beta- decay to bound and continuum electron states.

We report the first measurement of a ratio lambda(beta(b))/lambda(beta(c)) of bound-state ((lambda(beta(b))) and continuum-state (lambda(beta(c))) beta(-)-decay rates for the case of bare 207Tl81+ ions. These ions were produced at the GSI fragment separator FRS by projectile fragmentation of a 208Pb beam. After in-flight separation with the Brho-deltaE-Brho method, they were injected into the experimental storage-ring ESR at an energy of 400.5A MeV, stored, and electron cooled. The number of both the 207Tl81+ ions and their bound-state beta(-)-decay daughters, hydrogen-like 207Pb81+ ions, were measured as a function of storage time by recording their Schottky-noise intensities. The experimental result, lambda(beta(b))/lambda(beta(c)) = 0.188(18), is in very good agreement with the value of 0.171(1) obtained from theory employing spectra of allowed transitions.

Journal Article↗

Measurement of the kaonic hydrogen x-ray spectrum.

The DEAR (DAPhiNE exotic atom research) experiment measured the energy of x rays emitted in the transitions to the ground state of kaonic hydrogen. The measured values for the shift epsilon and the width Gamma of the 1s state due to the K(-)p strong interaction are epsilon(1s)=-193 +/- 37 (stat) +/- 6 (syst) eV and Gamma(1s)=249 +/- 111 (stat) +/- 30 (syst) eV, the most precise values yet obtained. The pattern of the kaonic hydrogen K-series lines, K(alpha), K(beta), and K(gamma), was disentangled for the first time.

Journal Article↗

Microsatellite instability in colorectal cancer is associated with local lymphocyte infiltration and low frequency of distant metastases.

Colorectal carcinomas (CRCs) with high microsatellite instability (MSI-H) share clinicopathological features distinctly different from their microsatellite stable (MSS) counterparts. Unlike MSS cancers, MSI-H CRCs occur predominantly in the right-sided colon and are often characterised by a strong lymphocyte infiltration. A poor differentiation pattern is found in most MSI-H CRCs, even though patients with MSI-H carcinomas seem to have a significantly longer survival after surgical resection. To clarify which factors contribute to the obvious paradoxon of a more favourable prognosis of MSI tumours, several clinical and histopathological features as well as the microsatellite status were evaluated in 120 colorectal cancer cases fulfilling clinical criteria (Bethesda) indicative for familial colorectal cancer. Microsatellite instability status and lymphocyte infiltration were related to tumour stage and patients' follow-up. Statistical analysis confirmed well-known relations, such as enhanced lymphocyte infiltration accompanied by Crohn's like reaction (CLR) in MSI-H cancers (CLR+ in 27 out of 47 MSI-H vs 14 out of 71 MSS CRCs, P<0.001). However, after stratification for depth of local invasion and penetration of the primary tumour, T3 tumours displaying MSI had a significantly lower rate of distant metastases (M1 in four out of 35 MSI-H vs 20 out of 41 MSS CRCs, P<0.001). A similar tendency was observed for CLR-positive CRCs (M1 in six out of 29 CLR+ vs 17 out of 45 CLR- CRCs, P=0.13). In a logistic regression model, the MSI-H phenotype and the presence of CLR were independent predictors of a low UICC stage (P=0.006 and 0.04, respectively). These data, together with the recent definition of highly immunogenic neo-antigens expressed in MSI-H tumour cells, suggest that MSI-H CRCs elicit a protective host response that may prevent metastasis formation.

Adult↗

Laparoscopic restorative proctocolectomy.

BACKGROUND: Restorative proctocolectomy is increasingly being performed using minimally invasive surgery. In published series laparoscopically assisted techniques have usually included a suprapubic incision to enable major parts of the operation to be done openly. METHODS: Fifty consecutive patients with familial adenomatous polyposis or ulcerative colitis underwent laparoscopic restorative proctocolectomy using only a small perumbilical incision of 4 cm or less for vascular dissection and pouch formation; all other steps were performed entirely laparoscopically. Logistic regression was used for statistical analysis. RESULTS: In four patients (8 per cent) the operation was converted to an open procedure. The diagnosis of ulcerative colitis was associated with a higher overall rate of complications (P = 0.011), and an increased body mass index (BMI) with a higher rate of major complications (P = 0.050). The occurrence of wound infection was related to the diagnosis of ulcerative colitis (P = 0.049). Conversion resulted in greater blood loss (P = 0.004), but not in a higher complication rate. No patient required a blood transfusion. Patients with an increased BMI and those taking immunosuppressive therapy had a longer hospital stay (P = 0.043). CONCLUSION: Laparoscopic restorative proctocolectomy is technically feasible. Patients with ulcerative colitis and increased BMI have a higher risk of complications. This minimally invasive technique may reduce the need for perioperative blood transfusion.

Adenomatous Polyposis Coli↗

[Surgical strategies for the prevention of gastrointestinal tumours].

Over many decades the surgical treatment of gastrointestinal tumours was limited to cases of manifest malignancy and was performed with curative or palliative intent. Molecular diagnostics have now led to an optimised characterisation of different sporadic and hereditary tumour entities. Furthermore, a number of diseases which are an obligatory precancerosis or which carry a very high risk of cancer in their long courses have now been identified. Parallel to these developments, a dramatic reduction of morbidity has been achieved in major abdominal surgery due to more subtle and blood-sparing surgical techniques and mortality has been reduced to a minimum even in the most major procedures. This combination nowadays safely allows preventive or preventive extended surgical measures in cases where interventional therapy cannot be adequately employed.

Adenomatous Polyposis Coli↗

Precision spectroscopy of pionic 1s states of Sn nuclei and evidence for partial restoration of chiral symmetry in the nuclear medium.

Deeply bound 1s states of pi(-) in (115,119,123)Sn were preferentially observed using the Sn(d,3He) pion-transfer reaction under the recoil-free condition. The 1s binding energies and widths were precisely determined and were used to deduce the isovector parameter of the s-wave pion-nucleus potential to be b1=-(0.115+/-0.007)m(-1)(pi). The observed enhancement of |b(1)| over the free piN value (b(free)1/b1=0.78+/-0.05) indicates a reduction of the chiral order parameter, f*pi(rho)2/f2pi approximately 0.64, at the normal nuclear density, rho=rho(0).

Journal Article↗

Hematogenous tumor cell dissemination during colonoscopy for colorectal cancer.

BACKGROUND: It has long been suspected that mechanical influences may enhance the release of viable colorectal cancer cells into the circulation. The objective of this study was to determine the extent of hematogenous tumor cell spread in colorectal cancer patients during colonoscopy. METHODS: Peripheral venous blood samples were taken before and after colonoscopy from 44 patients with colorectal cancer. Blood samples were examined using a reverse-transcriptase polymerase chain reaction assay to amplify cytokeratin 20 transcripts. RESULTS: Eleven patients with colorectal cancer displayed circulating tumor cells before and after colonoscopy (25%), whereas tumor cells were detected in six of 44 patients (14%) only after the procedure (p = 0.03, McNemar's test: tumor cell detection before after colonoscopy). All control samples consistently tested negative. CONCLUSIONS: Mechanical forces may result in enhanced release of viable colorectal cancer cells into the circulation; however, the clinical significance of these results needs to be clarified.

Adenocarcinoma↗

Detection of disseminated tumour cells as a potential surrogate-marker for monitoring palliative chemotherapy in colorectal cancer patients.

In a pilot study the effect of palliative chemotherapy on the detection rates of circulating tumour cells in peripheral venous blood of stage IV colorectal cancer patients was investigated. The results indicate a recruitment of tumour cells during chemotherapy and suggest a poorer survival for tumour cell positive patients. Circulating tumour cells have been shown to be a potential prognostic factor in patients who undergo curative resection for colorectal cancer. The effect of chemotherapy on the detection rates of disseminated tumour cells in blood has not yet been adequately investigated. Objective of this pilot-study was to analyze circulating tumour cells in peripheral venous blood of colorectal cancer patients undergoing chemotherapy in order to evaluate its potential value as a surrogate-marker for predicting clinical outcome after chemotherapy. Our hypothesis was that chemotherapy results in a reduction of the detection rates of circulating tumour cells in colorectal cancer patients. Forty-two Stage IV patients were examined at three different time points before and during palliative chemotherapy for the presence of disseminated tumour cells, using a previously described RT-PCR-assay for cytokeratin 20. 80.1% of the patients showed disseminated tumour cells at least once. Before chemotherapy, patients with multi-organ metastases were positive in 62.5%, patients with locally limited disease in only 14.3%. After the first chemotherapy, the detection rates in the latter group increased to 62.5%, for all patients in the same time from 46.3% to 57.5%. Clinical therapy responders showed an increase in the detection rates from 28.5% before to 71.4% after chemotherapy. In contrast, chemotherapy had no effect on tumour cell detection rates of patients with progressive disease (57% before vs. 60% after therapy). Patients with detected circulating tumour cells showed a shorter overall survival than patients without circulating tumour cells (83 vs. 53 weeks). Clinical therapy responders on average lived only 3 weeks longer than non-responders. In contrast to the original hypothesis, our data suggest a recruiting of circulating tumour cells during chemotherapy in advanced colorectal cancer. Further investigations are needed to clarify the potential role of circulating tumour cells for monitoring chemotherapy in these patients.

Antineoplastic Agents↗

Accuracy of diagnostic laparoscopy for early diagnosis of abdominal complications after cardiac surgery.

BACKGROUND: In the early postoperative period after major cardiac surgery using extracorporal circulation, abdominal complications can have serious consequences with a mortality rate of up to 70%. Early diagnosis and the timely institution of therapy are the most important factors to improve the outcome; however, clinical evaluation of the abdomen is difficult in these patients. Diagnostic laparoscopy is a minimally invasive procedure with low procedure-associated morbidity, even in critically ill patients. The aims of our study were to investigate the safety of laparoscopy in critically ill patients suspected to have intraabdominal pathology following cardiac surgery and to evaluate the accuracy of diagnostic laparoscopy compared to laparotomy in this setting. METHODS: A total of 17 patients were included (13 male, four female, age 52-80 years) in the early (3-30 days) postoperative period after cardiac surgery using extracorporal circulation (10 ACVB, four valve replacement, one aorto-coronary-venous-bypass (ACVB)+ valve replacement, two cardiac transplantation). Clinical and laboratory findings included distended abdomen (17 of 17), elevated white blood cells (12 of 17), elevated C-reactive protein (CRP) (13 of 17), and elevated lactate levels (11 of 17). The decision to perform laparotomy was taken in all patients on the basis of their clinical condition. Diagnostic laparoscopy was always performed immediately before laparotomy. The laparoscopic findings were then compared to the laparotomy findings. RESULTS: In one patient, laparoscopy showed no abnormal findings, this was confirmed on laparotomy. Five patients were found to have massive distension of the large bowel without ischemia on both laparoscopy and laparotomy. Colonic ischemia of the right hemicolon was found laparoscopically in six patients, which was confirmed in all cases by open resection and histological workup. Three patients suffered from acute cholecystitis, which was correctly diagnosed by laparoscopy in all cases. In one patient, laparoscopy revealed fibrinous peritonitis without other findings. Open exploration failed to identify the cause of the peritonitis in this patient. Laparoscopy showed no pathological findings in one patient, but laparotomy then revealed necrotizing pancreatitis confined to the lesser sac. There was one laparoscopy-associated intraoperative complication (6%) in this series. CONCLUSIONS: Diagnostic laparoscopy is a minimally invasive procedure that can be performed at low intraoperative risk in critically ill patients and has a high sensitivity (94%) for the correct diagnosis of intraabdominal complications after major cardiac surgery. These results suggest that bedside laparoscopy should be considered for all patients with equivocal abdominal symptoms in this setting.

Aged↗

Laparoscopically assisted colectomy and ileoanal pouch procedure with and without protective ileostomy.

BACKGROUND: Apart from an obviously better cosmetic situation, there is controversy on the actual benefit of laparoscopic and laparoscopically assisted techniques in restorative proctocolectomy. The need for a protective ileostomy remains unclear. METHODS: Fifty-nine consecutive patients with ulcerative colitis and familial polyposis were included in this prospective cohort study. The colon was mobilized laparoscopically with a four-trocar technique, facilitating vascular dissection, rectal resection, and ileoanal pouch construction to be done through a Pfannenstiel incision. A protective ileostomy was constructed only in patients where the operation was difficult or where the anastomosis was under tension. Intra- and postoperative data were recorded; statistical analyses were performed by exact logistic regression. RESULTS: Laparoscopic mobilisation was successful in 54 patients (91.2%). Two patients had to be primarily converted because of exceeding the set time limit; 3 other patients had to have an additional median laparotomy. These 5 patients all had an increased body mass index (BMI), which was a statistically significant risk factor for failure of the laparoscopic technique. 18.6% of patients developed major complications (n = 11). Nine patients required secondary ileostomies; all of them either were under high dose immunosuppressants (n = 5) or had an increased BMI (average 28.42 kg/m2). Failure of the laparoscopic technique was associated with major complications. CONCLUSION: Laparoscopically assisted restorative proctocolectomy is technically feasible; an increased BMI is a relevant risk factor for failure. The minimally invasive approach probably does not reduce the need for a protective ileostomy in selected patients. The selection criteria for the addition or omission of a protective ileostomy in minimally invasive restorative proctocolectomy remain to be clearly defined.

Adenomatous Polyposis Coli↗

Comparison of laparoscopic versus conventional technique in colonic and liver resection in a tumor-bearing small animal model.

BACKGROUND: Laparoscopic procedures in oncological surgery are either done in curative or palliative intent. We present two experiments comparing laparoscopic to conventional surgery in the curative and palliative setting regarding short-term (stress and immune alteration) and long-term aspects (survival time and recurrence rate). METHODS: We established two syngenic tumor-bearing small animal models for curative liver resection (Morris hepatoma 3924A, ACI rats) and palliative colon resection (BSp73 ASML, BOX rats). Male rats were operated on, performing laparoscopic and conventional liver resection as well as laparoscopic and conventional colon resection; control groups (anesthesia) were included. The following parameters of the stress and immune system were measured: corticosterone, neopterine, Il-1-b, Il-6, and body weight as a parameter of postoperative recovery. Analyzed long-term parameters were survival time, tumor weight, and recurrence rate (histology). RESULTS: After colon resection, analysis of variance showed significant differences in all short-term parameters, including body weight after laparoscopic versus conventional colon resection (p <0.05). In the case of laparoscopic versus conventional liver resection, only Il-6 showed globally statistically significant differences for the short-term parameters (p = 0.05). Long-term parameters were not significantly different between the laparoscopic and conventional groups, regardless of the type of resection (colon or liver) or the operative setting (curative or palliative). However, there were differences after curative liver resection compared to the control group (anesthesia alone). CONCLUSION: These results suggest that the type of intraabdominal operation (colon or liver) may influence the degree of trauma of an operation more than the type of technique (laparoscopic or open). The perioperative alteration of stress and immune function has no implications on the long-term results, such as survival time or recurrence, neither in the curative nor in the palliative setting. The thesis that laparoscopic surgery results in less pain, which in turn means less stress and less alteration of the immune system and therefore results in a lower rate of postoperative metastasis is only valid for laparoscopic colonic resection in our model. The part of the thesis that states that fewer metastases should occur after laparoscopic oncological surgery cannot be confirmed in our study.

Adenocarcinoma↗

Deeply bound 1s and 2p pionic states in 205Pb and determination of the s-wave part of the pion-nucleus interaction.

We observed well-separated 1s and 2p pi(-) states in 205Pb in the 206Pb(d,3He) reaction at T(d) = 604.3 MeV. The binding energies and the widths determined are B(1s) = 6.762+/-0.061 MeV, Gamma(1s) = 0.764(+0.154)(-0.171) MeV, B(2p) = 5.110+/-0.045 MeV, and Gamma(2p) = 0.321(-0.062)(+0.060) MeV. They are used to deduce the real and imaginary strengths of the s-wave part of the pion-nucleus interaction, which translates into a positive mass shift of pi(-) in 205Pb.

Journal Article↗