Guilherme Namur

Experimental study of the action of COX-2 selective nonsteroidal anti-inflammatory drugs and traditional anti-inflammatory drugs in bone regeneration

OBJECTIVE The aim of this study is to compare the effects of traditional nonsteroidal anti-inflammatory drugs with nonsteroidal anti-inflammatory drugs that are selective cyclooxygenase-2 (COX-2) inhibitors in the process of bone regeneration in a rat model. MATERIALS AND METHODS Forty-four Wistar strain rats were subjected to osteotomy of the right femur and randomly divided into 3 groups according to the drug to be given (diclofenac, rofecoxib, or placebo). Each group was divided into 2 subgroups according to the time to euthanasia after the surgery. The animals of Subgroup 1 were submitted to euthanasia 2 weeks after surgery, and those of Subgroup 2, underwent euthanasia 4 weeks after surgery. Radiographic examinations and bone callus histomorphometry were analyzed. RESULTS No intergroup statistical difference was found in the bone callus area or in bone formation area 2 and 4 weeks after surgery. Intra-group analysis concerning the bone neoformation area inside the callus showed a significant difference within the diclofenac group, which presented less tissue. CONCLUSIONS Fracture consolidation in Wistar rats occurs within less than 2 weeks, and the use of nonsteroidal anti-inflammatory drugs does not significantly influence this process.

MINIMALLY INVASIVE SURGERY FOR PSEUDOPAPILLARY NEOPLASM OF THE PANCREAS

ABSTRACT Background: Solid pseudopapillary pancreatic neoplasia is usually a large well-circumscribed pancreatic mass, with cystic and solid areas more frequently found in young women. It is a benign pancreatic neoplasia in most cases, therefore minimally invasive surgery could be an interesting approach. Aim: Evaluate the results of minimally invasive surgery for this neoplasia. Methods: Patients with this tumor who underwent minimally invasive pancreatectomies between 2009 and 2015 in a single institution, were analyzed regarding demographic, clinical-pathological futures, post-operative morbidity and disease-free survival. Results: All were women, and their median age was 39 (18-54) years. Two patients with tumor in the head of the pancreas underwent laparoscopic pancreaticoduodenectomy, and another one underwent laparoscopic enucleation. Two patients with tumor in the neck underwent central pancreatectomy. Distal pancreatectomies were performed in the other five, one with splenic preservation. None required blood transfusion or conversion to open surgery. Two (20%) developed clinical relevant pancreatic fistulas, requiring readmission. Median length of postoperative hospital stay was five days (2-8). All resection margins were negative. Patients were followed for a median of 38 months (14-71), and there was no recurrence. Conclusions: Minimally invasive surgery for solid pseudopapillary pancreatic neoplasia is feasible for tumors in different locations in the pancreas. It was associated with acceptable morbidity and respected the oncologic principles for treatment.

Evaluation of microvessel density and p53 expression in pancreatic adenocarcinoma

OBJECTIVE: To evaluate the prognostic significance of microvessel density and p53 expression in pancreatic cancer. METHODS: Between 2008 and 2012, 49 patients with pancreatic adenocarcinoma underwent resection with curative intention. The resected specimens were immunohistochemically stained with anti-p53 and anti-CD34 antibodies. Microvessel density was assessed by counting vessels within ten areas of each tumoral section a highpower microscope. RESULTS: The microvessel density ranged from 21.2 to 54.2 vessels/mm2. Positive nuclear staining for p53 was found in 20 patients (40.6%). The overall median survival rate after resection was 24.1 months and there were no differences in survival rates related to microvessel density or p53 positivity. Microvessel density was associated with tumor diameter greater than 3.0 cm and with R0 resection failure. CONCLUSIONS: Microvessel density was associated with R1 resection and with larger tumors. p53 expression was not correlated with intratumoral microvessel density in pancreatic adenocarcinoma.

Advanced age does not increase morbidity in pancreaticoduodenectomy

Background Due to rising life expectancy of population, very complex surgical procedures such as pancreaticoduodenectomy (PD), are more commonly being performed in elderly patients. The objective of this study was to evaluate the safety of PD in patients older than 75 years old and the risk factors associated with severe complications. Methods Patients who underwent PD for periampullary tumors were retrospectively reviewed and divided into two groups, A (<75 years) and B (>75 years). The primary endpoint was severe postoperative complications (Clavien 3 or greater). Secondary endpoints were mortality and any complications. Results Ninety consecutive patients underwent PD for periampullary tumors in the studied period, 70 in group A and 20 in group B. Clinical and pathological characteristics of both groups were equivalents except for age. There were no difference regarding the incidence of severe complications (17% vs. 10%, P=0.72) or all complications (50% vs. 50%, P>0.999). Although mortality was greater in group A (8.6% vs. 0%), it was not statistically significant (P=0.333). On multivariate analyses, only male sex, obesity and American Society of Anesthesiology Score of 3 or 4 were associated with severe postoperative complications. Conclusions Poor clinical status, obesity and male gender are associated with severe complications in PD, but not age greater than 75 years, therefore PD can be considered safe in elderly patients and age itself should not be a contraindication for PD.