TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: The aim of this study was the analysis of total, early and late complications following venous access port implantation between 1998 and 2008 at the Department of Surgery of the University of Rostock, Germany. A comparison between different implantation techniques addressing success rate, complication rate and duration of operation was performed. These results were further analysed in regard to the level of training of the participating surgeons.', 'A retrospective analysis of 1423 venous access port implantations between 1998 and 2008 was performed.', "The rate of total complications was 13.8%. Among 4.7% early complications pneumothorax was the most common. The rate of late complications was 9.1%. Most common were infection (4.9%) followed by dysfunction of the catheter (3.5%). 1322 venous access port implantations were performed using puncture of the subclavian vein and Seldinger's technique. 101 operations were performed by direct access through dissection of the cephalic vein and open introduction of the catheter. Operation time in the open group was significantly longer than in the puncture group (46.5min vs. 38.7min, p=0.005). There were significantly more late complications (9.6% vs. 2%, p=0.01) and total complications (14.5% vs. 4%, p=0.005) in the puncture group vs. the open access group. Primary success rates of open access vs. puncture were 100% and 96.8%, respectively. The rate of complications was independent of the experience status of the surgeon. However, the rate of total and late complications significantly decreases with number of performed operations.\Question: Is [ Venous Access Port Implantation an Ideal Teaching Operation - An Analysis of 1423 Cases ]?

SOLUTION: Venous port implantation is a relatively simple procedure despite its possible complications. An open access technique is safer than puncture. The rate of complications significantly decreases with increasing number of performed operations. Therefore venous port implantation and especially the open access method is an ideal teaching operation in a structured surgical training programme.

PROBLEM: Context: Monitoring renal function is crucial in children undergoing chemotherapy. To date, a combination of routine serum creatinine (SCR) monitoring with occasional determination of creatinine clearance ratio (CCR) is widely used as clinical standard for this purpose. Both methods have their limitations regarding diagnostic value (SCR) or practicability (CCR), especially in young children. Diagnostic alternatives, such as glomerular filtration rate (GFR) estimation formulas have not been proved to be superior. The aim of the study was to evaluate whether serum cystatin C (CysC) may have a diagnostic impact on pediatric patients.', 'CysC, SCR, several GFR estimation formulas (Counahan-Barratt, Ghazali-Barratt, Schwartz, Shull, Traub), and CCR were studied in 80 pediatric cancer patients (age range: 0.17-17.9 years) during their chemotherapy. Special attention was given to children under the age of 3 in whom accurate urine collection for CCR is difficult.', 'All parameters correlated similarly well with CCR. Total accuracy was 66% and 67% for CysC and SCR, respectively. In very young children (<3 years), correlation with CCR was for CysC r = -0.74 with an area under the curve (AUC) of 0.646, and for SCR r = -0.27 with AUC = 0.594. Total accuracy was 60% for CysC, 50% for SCR.\Question: Is serum cystatin C a suitable marker for routine monitoring of renal function in pediatric cancer patients , especially of very young age?

SOLUTION: CysC represents a suitable marker for monitoring renal function in pediatric cancer patients. In young children (<3 years), CysC may have a better diagnostic value than SCR. Future studies should show if CysC can improve renal monitoring by replacing SCR, especially in very young children.

PROBLEM: Context: There is a lot of evidence that angina during the 24-48 h before a reperfused myocardial infarction improves the evolution of the patients. However, there are studies that failed to demonstrate this protective effect of preinfarction angina in an interventional reperfusion setting.', 'To compare the effect of preinfarction angina (PIA) on inhospital evolution of thrombolysis vs. interventionally reperfused acute myocardial infarction (AMI).', 'There were prospectively studied 133 consecutive AMI patients, eligible for reperfusion (thrombolysis or interventional). History of PIA under 48 hours was obtained. Evolution of AMI was evaluated considering the following end-points: the ratio between the number of ECG leads with final pathologic Q wave and the number of leads with initial ST elevation, CK-MB values, separate and composite incidence of death, heart failure, shock and incidence of serious arrhythmia (sustained VT or ventricular fibrillation).', 'ECG ratio was lower in patients with PIA (0.511 +/- 0.281 vs. 0.646 +/- 0.274, p=0.02) in thrombolysed patients, but it was higher in interventionally reperfused patients (0.740 +/- 0.418 vs. 0.554 +/- 0.295 p=0.11). CK-MB values were lowered by PIA in thrombolysed AMI (122 +/- 74 vs. 190 +/- 89, p=0.0003), but they were not in the interventional group. Clinical end-points were slightly less frequent in patients with PIA, in both reperfusion groups, but not statistically significant. Major arrhythmia occurred less frequently in interventionally reperfused patients with PIA (9.5% vs. 31.6%, p=0.12).\Question: Does prodromal angina reduce infarcted mass less in interventionally reperfused than in thrombolysed myocardial infarction?

SOLUTION:
Preinfarction angina under 48 hours significantly reduces infarcted mass (measured by ECG and enzymes) in thrombolysed patients, but not in the interventional group. However, PIA reduced arrhythmic end-point in interventional setting.