Gynaecologic surgery from uncertainty to science: evolution of randomized control trials. Prospective trial of supranormal values of survivors as therapeutic goals in high-risk surgical patients. Surgeon and hospital characteristics as predictors of major adverse outcomes following colon cancer surgery: understanding the volume-outcome relationship. Reducing the risk of major elective surgery: randomised controlled trial of preoperative optimisation of oxygen delivery.
It is now accepted that both medical and surgical practice should be based on reliable and sound clinical evidence. However, randomized control trials comparing surgical interventions have been associated with many problems. The aim of this review is to assess if there has been progress made in establishing the evidence base for surgical interventions in gynaecology.
                Relevant reviews were identified from Cochrane Database of Systematic Reviews (Issue , 2006) and data from individual randomized control trials extracted. Chi-squared test was used to compare quality pre- and post-Consolidated Standards of Reporting Trials (CONSORT) statement. Meta-regression analyses were performed to test the hypothesis that effect size decreased over time. Further multiple linear regression analyses were used to test the hypothesis that precision increased over time and finally a logistic regression model was used to estimate whether treatment effects differed between trials with and without allocation concealment.
                Twenty-three relevant reviews were identified, including 94 trials. The proportion of studies reporting allocation concealment significantly increased after the introduction of the CONSORT statement (P = 0.002). There was a trend towards improvement in precision over time. Similarly, there was a reduction in size of treatment effect over time (log of the ratio of odds ratios per year 0.96; 95% confidence interval 0.93-0.99, P = 0.04).
                Gynaecologic surgical practice appears to be benefiting from improvement in its research base in a subject where practitioners do not participate readily in randomized evaluation. Survivors of high-risk surgical operations were previously observed to have significantly higher mean CI, DO2, and VO2 than nonsurvivors. The hypothesis was proposed that increased CI and DO2 are circulatory compensations for increased postoperative metabolism. We tested this hypothesis in two series. In series 1, prospectively allocated by services, mortality and morbidity of the control group were significantly greater than those of the protocol group. In series 2, patients who fulfilled previously defined high-risk criteria were preoperatively randomized to one of three monitoring/treatment groups: CVP-control group, PA-control group and PA-protocol group. Postoperative mortalities in the CVP-control and PA-control groups were not statistically significantly different, but PA-protocol group mortality was significantly reduced compared with its control group. The PA-protocol group had reduced complications, duration of hospitalization, duration in ICU, and mechanical ventilation, and reduced costs when the PA catheter was placed preoperatively and used to augment circulatory responses. Although numerous studies have demonstrated an association between surgical volume and improved outcome in cancer surgery, the specific structures and mechanisms of care that are associated with volume and lead to improved outcomes remain poorly defined. We hypothesize that there are modifiable surgeon and hospital characteristics that explain observed volume-outcome relationships.
                Retrospective cohort study.
                Surveillance, Epidemiology, and End Results cancer registry areas.
                Patients aged 66 years and older, diagnosed and surgically treated for stage I, II, or III colon cancer between 1992 and 1996 (n = 22 672).
                Thirty-day postoperative mortality and 30-day postoperative procedural interventions, including reoperation and image-guided percutaneous procedures.
                Surgeon volume, but not hospital volume, is a significant predictor of postoperative procedural intervention (adjusted odds ratio for very high-volume surgeons vs low-volume surgeons, 0.79; 95% confidence interval, 0.64-0.98). In the unadjusted analyses, high hospital volume (odds ratio, 0.67; 95% confidence interval, 0.56-0.81) and very high hospital volume (odds ratio, 0.65; 95% confidence interval, 0.54-0.79) is associated with lower postoperative mortality. Postoperative procedural intervention is not a significant mediator of the relationship between hospital volume and mortality. A single variable-the presence of sophisticated clinical services-was the most important explanatory variable underlying the relationship between hospital volume and mortality.
                Very high surgeon volume is associated with a reduction in surgical complications. However, the association between increasing hospital volume and postoperative mortality appears to derive mainly from a full spectrum of clinical services that may facilitate the prompt recognition and treatment of complications. To determine whether preoperative optimisation of oxygen delivery improves outcome after major elective surgery, and to determine whether the inotropes, adrenaline and dopexamine, used to enhance oxygen delivery influence outcome.
                Randomised controlled trial with double blinding between inotrope groups. Setting: York District Hospital, England.
                138 patients undergoing major elective surgery who were at risk of developing postoperative complications either because of the surgery or the presence of coexistent medical conditions. Interventions: Patients were randomised into three groups. Two groups received invasive haemodynamic monitoring, fluid, and either adrenaline or dopexamine to increase oxygen delivery. Inotropic support was continued during surgery and for at least 12 hours afterwards. The third group (control) received routine perioperative care.
                Hospital mortality and morbidity.
                Overall, 3/92 (3%) preoptimised patients died compared with 8/46 controls (17%) (P=0.007). There were no differences in mortality between the treatment groups, but 14/46 (30%) patients in the dopexamine group developed complications compared with 24/46 (52%) patients in the adrenaline group (difference 22%, 95% confidence interval 2% to 41%) and 28 patients (61%) in the control group (31%, 11% to 50%). The use of dopexamine was associated with a decreased length of stay in hospital.
                Routine preoperative optimisation of patients undergoing major elective surgery would be a significant and cost effective improvement in perioperative care.
There is no evidence of relevant differences in mortality, morbidity and survival between the two operations. Given obvious clinical and methodological heterogeneity, future research must be undertaken to perform high-quality randomised controlled trials of complex surgical interventions on the basis of well-defined outcome parameters.