[Digital documentation of complications in visceral surgery: possibilities and evaluation of an instrument for quality management]

Against the background of the growing economization of clinical medicine, in the last decades the topics of risk and complication management have also become more important in surgical disciplines. The standardization and reproducible documentation of outcome and complication data play a key role for valid quality control. In this article a digital system implemented at the surgical clinic of the Charité University Medicine in Berlin is analyzed with respect to its practicability for perioperative and postoperative monitoring of complications within the framework of quality assurance.

Challenging the in-vivo assessment of biomechanical properties of the uterine cervix: A critical analysis of ultrasound based quasi-static procedures

Measuring the stiffness of the uterine cervix might be useful in the prediction of preterm delivery, a still unsolved health issue of global dimensions. Recently, a number of clinical studies have addressed this topic, proposing quantitative methods for the assessment of the mechanical properties of the cervix. Quasi-static elastography, maximum compressibility using ultrasound and aspiration tests have been applied for this purpose. The results obtained with the different methods seem to provide contradictory information about the physiologic development of cervical stiffness during pregnancy. Simulations and experiments were performed in order to rationalize the findings obtained with ultrasound based, quasi-static procedures. The experimental and computational results clearly illustrate that standardization of quasi-static elastography leads to repeatable strain values, but for different loading forces. Since force cannot be controlled, this current approach does not allow the distinction between a globally soft and stiff cervix. It is further shown that introducing a reference elastomer into the elastography measurement might overcome the problem of force standardization, but a careful mechanical analysis is required to obtain reliable stiffness values for cervical tissue. In contrast, the maximum compressibility procedure leads to a repeatable, semi-quantitative assessment of cervical consistency, due to the nonlinear nature of the mechanical behavior of cervical tissue. The evolution of cervical stiffness in pregnancy obtained with this procedure is in line with data from aspiration tests.

Abstract P4-15-03: Proteomic modulation in breast tumors after metformin use: Results from a “window of opportunity” trial

Background: Laboratory and population studies demonstrate that metformin offers a beneficial breast cancer (BC) effect through reduction of serum insulin levels and changes in cellular protein synthesis and growth, such as AMPK pathway signaling. In a pre-surgical metformin trial of overweight/obese, multi-ethnic BC patients, we reported no difference in tumor proliferation, as measured by ki-67. However, reductions in other biomarkers were observed, including reduction in body mass index (BMI), serum cholesterol, serum insulin, and leptin. Reverse Phase Protein Array (RPPA) is a high-throughput antibody-based technique to assess cellular protein activity in signaling networks. The goal of this study was to assess changes in functional proteomics through RPPA in patients treated in a pre-surgical metformin trial.

Methods: Metformin 1500mg PO daily (500mg am/1000 mg pm) was administered for 2-4 weeks prior to resection in 35 patients with stage 0-III operable BC, BMI ≥ 25 kg/m2, and no history of diabetes. Protein was extracted from pre- and post-metformin paraffin-embedded tumor tissue, denatured by sodium dodecyl sulfate, and printed on nitrocellulose-coated slides. Samples were probed with 160 antibodies. Evaluated antibodies associated with various cellular activities, including PI3K/AKT signaling, HSP90 clients, Src/STAT activity, and apoptosis. We analyzed changes in RPPA parameters in tumor tissue of study patients with those of untreated historical controls, matched by age, BMI, and tumor characteristics. Paired t-test was used to calculate within-group changes in RPPA, and two-sample t-tests were used to compare between-group changes in cases and controls (significance: p ≤ 0.05). Multiple comparisons were adjusted for by fixing the false discovery rate (FDR) at 25%.

Results: Of the 35 metformin-treated patients, 32 were evaluable. The majority were Hispanic (80%). Metformin was administered for a median of 23 days (range: 8-64). Of the invasive BCs (n = 21/35), 80% of patients had HR+/HER2- BC. The 33 historical controls were well-matched. For RPPA, the mean total formalin-fixed paraffin embedded protein concentration was 38.9 ug (SD: 3.3). Of the 160 antibodies, 67 antibodies significantly changed after metformin use in the treated group, including reduction in pAKTS473, pAKTT308, and MTOR (unadjusted). Nineteen antibodies were identified as having between group differences in change from baseline: increase in BadpS112, C-RAF, Claudin-7, Cyclin B1, Cyclin D1, EGFR, HER3 pY1298, Lck, PKC-alphapS657, RAD50, Raptor, Syk, and TRFC; reduction in 14-3-3 epsilon, FOXO3a, JNKpT183, MAPKpT202, MEK1pS217, and SrcpY416. Adjusting for multiple comparisons, the following remain statistically significantly different between cases vs. controls: increase in BadpS112, C-RAF, Cyclin D1, and Raptor; and reduction in JNKpT183. Further assessment of RPPA modulation is ongoing, including changes grouped by signaling pathway and activity, as well as validation by immunohistochemistry.

Conclusions: Compared to controls, metformin use associates with changes in apoptosis, cell signaling, C-RAF, and Raptor. These results should be further validated in larger metformin intervention trials to better define populations who may benefit from this therapy.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-15-03.

The influence of the wider use of surfactant therapy on neonatal mortality among blacks and whites

BACKGROUND

Surfactant therapy reduces morbidity and mortality among premature infants with the respiratory distress syndrome (RDS). Fetal pulmonary surfactant matures more slowly in white than in black fetuses, and therefore RDS is more prevalent among whites than among blacks. We reasoned that the increased use of surfactant after its approval by the Food and Drug Administration (FDA) in 1990 might have reduced neonatal mortality more among whites than among blacks.

METHODS

We merged vital-statistics information for all 1563 infants with very low birth weights (500 to 1500 g) born from 1987 through 1989 or in 1991 and 1992 to residents of St. Louis with clinical data from the four neonatal intensive care units in the St. Louis area; we then compared neonatal mortality during two periods, one before and one after the FDA's approval of surfactant for clinical use (1987 through 1989 and 1991 through 1992).

RESULTS

The use of surfactant increased by a factor of 10 between 1987 through 1989 and 1991 through 1992. The neonatal mortality rate among all very-low-birth-weight infants decreased 17 percent, from 220.3 deaths per 1000 very-low-birth-weight babies born alive (in 1987 through 1989) to 183.9 per 1000 (in 1991 through 1992; P = 0.07). This decrease was due to a 41 percent reduction in the mortality rate among white newborns with very low birth weights (from 261.5 per 1000 to 155.5 per 1000; P = 0.003). In contrast, among black infants, the mortality rate for very-low-birth-weight infants did not change significantly (195.6 per 1000 and 196.8 per 1000). The relative risk of death among black newborns with very low birth weights as compared with white newborns with similar weights was 0.7 from 1987 through 1989 and 1.3 from 1991 through 1992 (P = 0.02). The differences in mortality were not explained by differences in access to surfactant therapy, by differences in mortality between black and white infants who received surfactant, or by differences in the use of antenatal corticosteroid therapy.

CONCLUSIONS

After surfactant therapy for RDS became generally available, neonatal mortality improved more for white than for black infants with very low birth weights.

Cesarean section versus vaginal delivery for the breech fetus weighing less than 1,500 grams

Although previous studies have suggested that the breech infant weighing less than 1,500 gm benefits from cesarean section, the published results have not demonstrated statistically significant differences. We have evaluated pediatric outcome data for 240 breech infants and 525 vertex infants who weighed less than 1,500 gm, to determine whether route of delivery affects infant morbidity and mortality. Twenty-nine percent of these very small breech infants who were delivered by cesarean section died, as compared to 58% of breech infants of similar weight who were delivered vaginally (p less than 0.001). Comparable significant differences were found for the infants delivered at a university hospital as well as for those delivered at a group of nonuniversity hospitals. Apgar scores and the incidence and severity of intraventricular hemorrhage were not different for the cesarean section and vaginally delivered breech infants. Furthermore, the survival rate of the breech infants delivered by cesarean section equaled that of the vertex infants delivered either by cesarean section or vaginally.

Surgical mortality and morbidity in extremely low-birth-weight infants

Twenty extremely premature infants (birth weight, less than 1,100 g) underwent 49 surgical procedures for acquired conditions, including necrotizing enterocolitis, other forms of gastrointestinal perforation, gastroesophageal reflux, patent ductus arteriosus, and hydrocephalus. Few congenital anomalies requiring operation were encountered in this group. The overall survival rate was 58%. Using a computerized data base to compare surgical patients with a weight-matched group of nonsurgical patients, it was shown that survival was similar and that adverse prenatal and perinatal influences were equally distributed between both groups. Surgery per se did not adversely influence survival in extreme low-birth-weight infants, and surgical patients are not a preselected group of stronger infants.