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排序方式: 共有2420条查询结果,搜索用时 15 毫秒
21.
Retroperitoneoskopische Nierenchirurgie   总被引:1,自引:0,他引:1  
Retroperitoneoscopy enables quick, simple, and direct access to the retroperitoneal cavity. We describe our operative technique and discuss the advantages and disadvantages of retroperitoneoscopy. We report on our experience with this operative technique after 360 procedures: nephrectomy, partial nephrectomy, living donor nephrectomy, cryotherapy of renal tumors, pyeloplasty, adrenalectomy, and further operations. In addition, we discuss indications that are suitable for beginners to retroperitoneoscopy and some topics that require special attention.  相似文献   
22.
Background The value of re-exploration for pancreatic ductal adenocarcinoma after the initial diagnosis of unresectability is unclear. Methods In this study, we analyzed 33 patients who were re-explored after an initial diagnosis of unresectability. Results At the time of reoperation, a resectable tumor was found in 18 patients: therefore, 15 pancreaticoduodenectomies, two total pancreatectomies and one left resection were performed with three vascular resections. Morbidity and mortality rates for the cohort were 6/33 and 1/33, without significant differences between resectable and nonresectable patients. Length of stay, duration of operation, and blood loss were significantly increased in the resection group. Kaplan–Meier survival analysis demonstrated increased median survival for resected patients (1078 days after the initial operation versus 547 days in the group of unresectable patients; p = 0.018). Analysis of the reasons against initial resection showed that, if the patients had been sent to a tertiary referral center for pancreatic surgery, a different decision in favor of resection would probably have been made in 14 out of 33 patients. A review of 10 published reports on reoperation for pancreatic cancer revealed results comparable to our study in terms of low morbidity and mortality as well as a survival benefit. Conclusions Reoperation for pancreatic ductal adenocarcinoma that is initially deemed unresectable can be safely performed in a selected group of patients by experienced surgeons, supporting the concept of patient centralization in pancreatic surgery. Resection at the second operation may confer a survival benefit even when the initial findings preclude a potentially curative approach.  相似文献   
23.
Streak line flow visualization and laser Doppler velocimetry (LDV) were conducted in the regurgitant leakage flow region of 3 mechanical heart valve types: CarboMedics, Medtronic Hall, and St. Jude Medical. Streak line flow visualization identified regions of high regurgitant flow, and LDV measurements were focused on those locations. Maximum regurgitant flow velocities after valve closure ranged from 0.7 to 2.6 m/s, and maximum Reynolds shear stress after valve closure ranged from 450 to 3,600 dyne/cm2. These data indicate that leakage flows can generate turbulent jets with elevated Reynolds stresses even in bileaflet valves.  相似文献   
24.
Background contextPsychological factors are believed to influence the development of chronic low back pain. To date, it is not known how fear-avoidance beliefs (FABs) influence the treatment efficacy in low back pain.PurposeTo summarize the evidence examining the influence of FABs measured with the Fear-Avoidance Belief Questionnaire or the Tampa Scale of Kinesiophobia on treatment outcomes in patients with low back pain.Study design/settingThis is a systematic review.Patient samplePatients with low back pain.Outcome measuresWork-related outcomes and perceived measures including return to work, pain, and disability.MethodsIn January 2013, the following databases were searched: BIOSIS, CINAHL, Cochrane Library, Embase, OTSeeker, PeDRO, PsycInfo, PubMed/Medline, Scopus, and Web of Science. A hand search of the six most often retrieved journals and a bibliography search completed the search. Study eligibility criteria, participants, and interventions: research studies that included patients with low back pain who participated in randomized controlled trials (RCTs) investigating nonoperative treatment efficacy. Out of 646 records, 78 articles were assessed in full text and 17 RCTs were included. Study quality was high in five studies and moderate in 12 studies.ResultsIn patients with low back pain of up to 6 months duration, high FABs were associated with more pain and/or disability (4 RCTs) and less return to work (3 RCTs) (GRADE high-quality evidence, 831 patients vs. 322 in nonpredictive studies). A decrease in FAB values during treatment was associated with less pain and disability at follow-up (GRADE moderate evidence, 2 RCTs with moderate quality, 242 patients). Interventions that addressed FABs were more effective than control groups based on biomedical concepts (GRADE moderate evidence, 1,051 vs. 227 patients in studies without moderating effects). In chronic patients with LBP, the findings were less consistent. Two studies found baseline FABs to be associated with more pain and disability and less return to work (339 patients), whereas 3 others (832 patients) found none (GRADE low evidence). Heterogeneity of the studies impeded a pooling of the results.ConclusionsEvidence suggests that FABs are associated with poor treatment outcome in patients with LBP of less than 6 months, and thus early treatment, including interventions to reduce FABs, may avoid delayed recovery and chronicity. Patients with high FABs are more likely to improve when FABs are addressed in treatments than when these beliefs are ignored, and treatment strategies should be modified if FABs are present.  相似文献   
25.

Background

While convergent placement of pedicle screws in the axial plane is known to be more advantageous biomechanically, surgeons intuitively aim toward a parallel placement of screws in the sagittal plane. It is however not clear whether parallel placement of screws in the sagittal plane is biomechanically superior to a non-parallel construct. The hypothesis of this study is that sagittal non-parallel pedicle screws do not have an inferior initial pull-out strength compared to parallel placed screws.

Methods

The established lumbar calf spine model was used for determination of pull-out strength in parallel and non-parallel intersegmental pedicle screw constructs. Each of six lumbar calf spines (L1-L6) was divided into three levels: L1/L2, L3/L4 and L5/L6. Each segment was randomly instrumented with pedicle screws (6/45 mm) with either the standard technique of sagittal parallel or non-parallel screw placement, respectively, under fluoroscopic control. CT was used to verify the intrapedicular positioning of all screws. The maximum pull-out forces and type of failure were registered and compared between the groups.

Results

The pull-out forces were 5,394 N (range 4,221 N to 8,342 N) for the sagittal non-parallel screws and 5,263 N (range 3,589 N to 7,554 N) for the sagittal-parallel screws (p?=?0.838). Interlevel comparisons also showed no statistically significant differences between the groups with no relevant difference in failure mode.

Conclusion

Non-parallel pedicle screws in the sagittal plane have at least equal initial fixation strength compared to parallel pedicle screws in the setting of the here performed cadaveric calf spine experiments.  相似文献   
26.

Context

Laser treatment of benign prostatic obstruction (BPO) has become more prevalent in recent years. Although multiple surgical approaches exist, there is confusion about laser-tissue interaction, especially in terms of physical aspects and with respect to the optimal treatment modality.

Objective

To compare available laser systems with respect to physical fundamentals and to discuss the similarities and differences among introduced laser devices.

Evidence acquisition

The paper is based on the second expert meeting on the laser treatment of BPO organised by the European Association of Urology Section of Uro-Technology. A systematic literature search was also carried out to cover the topic of laser treatment of BPO extensively.

Evidence synthesis

The principles of generation of laser radiation, laser fibre construction, the types of energy emission, and laser-tissue interaction are discussed in detail for the laser systems used in the treatment of BPO. The most relevant laser systems are compared and their physical properties discussed in depth.

Conclusions

Laser treatment of BPO is gaining widespread acceptance. Detailed knowledge of the physical principles allows the surgeon to discriminate between available laser systems and their possible pitfalls to guarantee high safety levels for the patient.  相似文献   
27.
Image quality on dual-source computed-tomographic coronary angiography   总被引:1,自引:1,他引:1  
Multi-detector CT reliably permits visualization of coronary arteries, but due to the occurrence of motion artefacts at heart rates >65 bpm caused by a temporal resolution of 165 ms, its utilisation has so far been limited to patients with a preferably low heart rate. We investigated the assessment of image quality on computed tomography of coronary arteries in a large series of patients without additional heart rate control using dual-source computed tomography (DSCT). DSCT (Siemens Somatom Definition, 83-ms temporal resolution) was performed in 165 consecutive patients (mean age 64 +/- 11.4 years) after injection of 60-80 ml of contrast. Data sets were reconstructed in 5% intervals of the cardiac cycle and evaluated by two readers in consensus concerning evaluability of the coronary arteries and presence of motion and beam-hardening artefacts using the AHA 16-segment coronary model. Mean heart rate during CT was 65 +/- 10.5 bpm; visualisation without artefacts was possible in 98.7% of 2,541 coronary segments. Only two segments were considered unevaluable due to cardiac motion; 30 segments were unassessable due to poor signal-to-noise ratio or coronary calcifications (both n = 15). Data reconstruction at 65-70% of the cardiac cycle provided for the best image quality. For heart rates >85 bpm, a systolic reconstruction at 45% revealed satisfactory results. Compared with earlier CT generations, DSCT provides for non-invasive coronary angiography with diagnostic image quality even at heart rates >65 bpm and thus may broaden the spectrum of patients that can be investigated non-invasively.  相似文献   
28.
Epidemiological outbreak investigations were conducted in highly pathogenic avian influenza virus of the subtype H5N8 (HPAIV H5N8)‐affected poultry holdings and a zoo to identify potential routes of entry of the pathogen via water, feedstuffs, animals, people, bedding material, other fomites (equipment, vehicles etc.) and the presence of wild birds near affected holdings. Indirect introduction of HPAIV H5N8 via material contaminated by infected wild bird seems the most reasonable explanation for the observed outbreak series in three commercial holdings in Mecklenburg‐Western Pomerania and Lower Saxony, while direct contact to infected wild birds may have led to outbreaks in a zoo in Rostock and in two small free‐range holdings in Anklam, Mecklenburg‐Western Pomerania.  相似文献   
29.
Background: Pain after laparoscopic cholecystectomy (LCC) is multifactorial. Effective post-operative pain control is necessary in LCC performed as day-case surgery. We studied the efficacy of paracetamol or valdecoxib with or without dexamethasone after LCC.
Methods: One hundred sixty patients were randomized to four groups of 40 patients. Groups 1 and 3 received parecoxib 40 mg intravenously (IV) during surgery and valdecoxib 40 mg × 1 per os (PO) for 7 post-operative days. Groups 2 and 4 received paracetamol 1 g × 4 IV during surgery and 1 g × 4 PO for 7 days. In addition, Groups 3 and 4 were given dexamethasone 10 mg IV intra-operatively. Propofol and remifentanil were used during surgery. The patients were given oxycodone 0.05 mg/kg IV in phase 1 post-anaesthesia care unit (PACU 1) or 0.15 mg/kg PO in phase 2 post-anaesthesia care unit (PACU 2) as needed to keep visual analogue scale <3/10. The patients were supplied with the study drugs for 7 post-operative days.
Results: Pain intensity, nausea and the need of oxycodone in phase 1 PACU were similar in all groups. Dexamethasone reduced the need of oral oxycodone in phase 2 PACU (7.0 ± 1.0 mg vs. 9.1 ± 1.0 mg, P <0.05). Pain intensity was similar in all groups at home. More patients in the parecoxib/valdecoxib groups needed rescue medication on the 1st post-operative day ( P <0.001) than paracetamol-treated patients.
Conclusion: Paracetamol was as effective as parecoxib/valdecoxib for pain after LCC. Dexamethasone decreased the need of oxycodone in phase 2 PACU. The effect of dexamethasone was similar in paracetamol and parecoxib/valdecoxib patients.  相似文献   
30.
Previous studies have shown frequent mutations in the BRAF (V-raf murine sarcoma viral oncogene homolog B1) or NRAS (neuroblastoma RAS viral [V-ras] oncogene homolog) genes in cutaneous melanoma, but the relationship between these alterations and tumor cell proliferation has not been examined in human melanoma. In our study of 51 primary nodular melanomas and 18 paired metastases, we found mutations in BRAF (codon 600, previously denoted 599) in 15 primary tumors (29%) and eight metastases (44%). The figures for NRAS mutations were 27% and 22%, respectively. Mutations in BRAF and NRAS genes were mutually exclusive in all but one case, and were maintained from primary tumors through their metastases. Mutations, however, were not associated with tumor cell proliferation by Ki-67 expression, tumor thickness, microvessel density, or vascular invasion, and there were no differences in patient survival. Although BRAF and NRAS mutations are likely to be important for the initiation and maintenance of some melanomas, other factors might be more significant for proliferation and prognosis in subgroups of aggressive melanoma.  相似文献   
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