Preoperative Calcium and Parathyroid Hormone Values Are Poor Predictors of Gland Volume and Multigland Disease in Primary Hyperparathyroidism: A Review of 2000 Consecutive Patients.

OBJECTIVE: Calcium and parathyroid hormone (PTH) values are believed to have a linear relationship in patients with primary hyperparathyroidism and correlate with parathyroid gland size, with higher values predicting single-gland disease. In this modern series, these preoperative values were correlated with operative findings to determine their utility in predicting the gland involvement at parathyroid exploration. METHODS: Two thousand consecutive patients who underwent initial surgery for sporadic primary hyperparathyroidism from 2000 to 2014 were reviewed. All patients underwent a 4-gland exploration. Relationships between preoperative calcium and PTH values with the total gland volume of each patient were examined and stratified using the number of involved glands: single adenoma (SA), double adenoma (DA), and hyperplasia (H). RESULTS: There were 1274 (64%) SA, 359 (18%) DA, and 367 (18%) H cases. There was a poor correlation between preoperative calcium and PTH values (R = 0.37) and both poorly correlated with the total gland volume (R < 0.40). Similarly, subgroup analysis using the number of involved glands showed poor correlation. The mean total gland volume was similar among all subgroups (SA = 1.28 cm3, DA = 1.43 cm3, and H = 1.27 cm3; P = .52), implying that individual glands were smaller in multigland disease. SA was found in 271 (53%) of patients with calcium levels of ≤10.5 mg/dL and 122 (78%) with levels of ≥12 mg/dL (P < .001). CONCLUSION: This is the largest series correlating preoperative calcium and PTH values with operative findings of gland size and number of diseased glands. Although a lower calcium value predicts somewhat more multigland disease, the overall poor correlation should make the parathyroid surgeon aware that gland size and multigland disease cannot be predicted by preoperative laboratory testing.

Local Plants, Not Soils, Are the Primary Source of Foliar Fungal Community Assembly in a C4 Grass.

Microbial communities, like their macro-organismal counterparts, assemble from multiple source populations and by processes acting at multiple spatial scales. However, the relative importance of different sources to the plant microbiome and the spatial scale at which assembly occurs remains debated. In this study, we analyzed how source contributions to the foliar fungal microbiome of a C4 grass differed between locally abundant plants and soils across an abiotic gradient at different spatial scales. Specifically, we used source-sink analysis to assess the likelihood that fungi in leaves from Panicum hallii came from three putative sources: two plant functional groups (C4 grasses and dicots) and soil. We expected that physiologically similar C4 grasses would be more important sources to P. hallii than dicots. We tested this at ten sites in central Texas spanning a steep precipitation gradient. We also examined source contributions at three spatial scales: individual sites (local), local plus adjacent sites (regional), or all sites (gradient-wide). We found that plants were substantially more important sources than soils, but contributions from the two plant functional groups were similar. Plant contributions overall declined and unexplained variation increased as mean annual precipitation increased. This source-sink analysis, combined with partitioning of beta-diversity into nestedness and turnover components, indicated high dispersal limitation and/or strong environmental filtering. Overall, our results suggest that the source-sink dynamics of foliar fungi are primarily local, that foliar fungi spread from plant-to-plant, and that the abiotic environment may affect fungal community sourcing both directly and via changes to host plant communities.

Open, Laparoscopic, and Robotic Inguinal Hernia Repair: Outcomes and Predictors of Complications.

BACKGROUND: The robotic approach to an inguinal hernia has not been compared head to head with the open and laparoscopic techniques in randomized controlled trials. Furthermore, long-term outcomes for robotic inguinal hernia repair (RHR) are lacking. In this study, we compared laparoscopic inguinal hernia repair (LHR) and RHR with open inguinal hernia repair (OHR) in veteran patients performed by surgeons most familiar with each approach. METHODS: A retrospective single-institution analysis of 1299 inguinal hernia repairs performed at the VA North Texas Health Care System between 2005 and 2017 was undertaken. Three surgeons performed the operations, each an expert in one approach, and there was no crossover in techniques. A total of 1100 OHRs, 128 LHRs, and 71 RHRs were performed. Univariable analysis was undertaken to determine associations between techniques and outcomes (OHR versus LHR; OHR versus RHR; LHR versus RHR). Setting complications as a dependent variable, multivariable analyses were undertaken to determine an association with complications as well as independent predictors of complications. RESULTS: Patient demographics were similar among groups except for age that was higher in the OHR cohort. The average follow-up was 5.2 ± 3.4 y. In the present report, recurrence was associated with a higher rate in the RHR versus OHR (5.6% versus 1.7%; P < 0.02), but not in the LHR versus OHR (3.9% versus 1.9%; P = 0.09). Inguinodynia was more likely to occur in both the LHR and RHR compared with the OHR (9.4% and 14.1 versus 1.5%; both P's < 0.001). Urinary retention was also more common in the LHR and RHR than in the OHR (5.5% and 5.6% versus 1.8%, both P's < 0.05) as was the rate of overall complications (34.4% and 38.0% versus 11.2%, both P's < 0.001). Multivariable regression analysis showed femoral hernias, ASA, serum albumin, operative room time, a recurrent hernia, and the minimally invasive approaches were independent predictors of overall complications. CONCLUSIONS: Outcomes in the OHR cohort were, in general, superior compared with both the LHR and RHR. However, these strategies should be viewed as complementary. The best approach to an inguinal hernia repair rests on the specific expertise of the surgeon.

Clinical and molecular diagnosis of pathologic complete response in rectal cancer: an update.

INTRODUCTION: The standard of care for locally advanced rectal cancer includes neoadjuvant chemoradiation with subsequent total mesorectal excision. This approach has shown various degrees of response to neoadjuvant chemoradiation (ranging from complete response to further tumor growth), which have substantial prognostic and therapeutic implications. A total regression of the tumor is a predictor of superior oncologic outcomes compared with partial responders and non-responders. Further, this concept has opened the possibility of nonoperative strategies for complete responders and explains the widespread research interest in finding clinical, radiographic, pathologic, and biochemical parameters that allow for identification of these patients. Areas covered: The present review evaluates the most recent efforts in the literature to identify predictors of patients likely to achieve a complete response following neoadjuvant treatment for the management of rectal cancer. This includes clinical predictors of pathologic complete response such as tumor location, size, and stage, molecular predictors such as tumor biology and microRNA, serum biomarkers such as carcinoembryogenic antigen and nomograms. Expert commentary: There has been significant progress in our ability to predict pathological complete response. However, more high-quality research is still needed to use this concept to confidently dictate clinical management.