Pelvic lymph node dissection during radical cystectomy for muscle-invasive bladder cancer.

Radical cystectomy is the gold-standard treatment option for muscle-invasive and metastatic bladder cancer. At the time of cystectomy, up to 25% of patients harbour metastatic lymph node deposits. These deposits most frequently occur in the obturator fossa, but can be as proximal as the interaortocaval region. Thus, the use of concurrent pelvic lymph node dissection (PLND) with cystectomy has been increasingly reported. Data from studies including many patients suggest substantial oncological benefit in PLND cohorts versus non-PLND cohorts, irrespective of pathological nodal status. Additionally, PLND provides useful prognostic information, including disease burden, lymph node density, and extracapsular extension of metastatic lymph nodes. Accordingly, the National Comprehensive Cancer Network guidelines advocate the use of PLND during radical cystectomy for muscle-invasive bladder cancer. Despite this recommendation, a lack of consensus exists regarding the optimal PLND template. Comparative series suggest that extended PLND provides improved recurrence-free survival and cancer-specific survival compared with more limited PLND templates. More extensive templates (such as super-extended PLND) provide no additional survival benefit at the potential cost of increased operative time and patient morbidity. In addition to extended PLND templates, increased nodal harvest confers an oncological benefit in patients with node-positive disease or in patients with node-negative disease. Accordingly, recommendations for a minimum nodal yield have been proposed. Despite the growing body of evidence, formal recommendations by oncological and urological authoritative bodies have been limited owing to the lack of randomized data and level I evidence.

Using Hematology Data from Malaria Vaccine Research Trials in Humans and Rhesus Macaques (Macaca mulatta) To Guide Volume Limits for Blood Withdrawal.

Guidelines on safe volume limits for blood collection from research participants in both humans and laboratory animals vary widely between institutions. The main adverse event that may be encountered in large blood volume withdrawal is iron-deficiency anemia. Monitoring various parameters in a standard blood panel may help to prevent this outcome. To this end, we analyzed the Hgb and MCV values from 43 humans and 46 macaques in malaria vaccine research trials. Although the percentage of blood volume removed was greater for macaques than humans, macaques demonstrated an overall increase of MCV over time, indicating the ability to respond appropriately to frequent volume withdrawals. In contrast, humans showed a consistent declining trend in MCV. These declines in human MCV and Hgb were significant from the beginning to end of the study despite withdrawals that were smaller than recommended volume limits. Limiting the volume withdrawn to no more than 12.5% seemed to be sufficient for macaques, and at 14% or more individual animals tended to fail to respond appropriately to large-volume blood loss, as demonstrated by a decrease in MCV. The overall positive erythropoietic response seen in macaques was likely due to the controlled, iron-fortified diet they received. The lack of erythropoietic response in the human subjects may warrant iron supplementation or reconsideration of current blood volume withdrawal guidelines.