Reginaldo Ceneviva

Evaluation of the biocompatibility of a new biomembrane

Biocompatibility has been considered one of the most important items to validate a biomaterial for its application in human organisms. The present work evaluates the biocompatibility of a new biomembrane using in vivo assay in different animal species. The experiments to evaluate the cellular reaction were carried out through the implantation of the material into the subcutaneous tissue of animals and the results showed a good reaction of the host tissue without any signal of fibrosis or rejection. The cell adhesion experiments were done by means of the measure of the DNA content on the material surface after its implantation into the subcutaneous tissue of animals and the results showed a growing number of DNA that was proportional to the time of implantation. The healing process was evaluated using a dermal ulcer model and the results showed a good tissue repair resembling a physiologic process. The overall results presented here lead to the conclusion that this new biomembrane is a biocompatible material but more research must be done, as it is a new material desired for medical use.

Anemia and iron deficiency before and after bariatric surgery

BACKGROUND Iron deficiency and anemia are changes often associated with obesity. Bariatric surgery is responsible for increasing the iron loss and reducing its absorption. The objective of this study was to evaluate anemia and iron deficiency before and after bariatric surgery and to relate them to possible predisposing factors. METHODS A retrospective study was conducted on obese patients submitted to open Roux-en-Y gastric bypass, in which clinical and laboratory data were obtained up to 48 months postoperatively. Patients were divided into groups according to the presence or absence of anemia and to the presence or absence of iron deficiency (even without anemia), and all data were compared between these groups. RESULTS Preoperatively, 21.5% of patients had anemia and 20% had iron deficiency. The number of patients with anemia did not vary through the 4 years of the study, but ferritin levels significantly decreased with time (P<.01). Younger patients and patients with greater weight loss had a higher incidence of anemia. Female gender was a variable associated with a greater incidence of iron deficiency. CONCLUSIONS Anemia and iron deficiency are frequent in obese patients and must be treated before surgery. Medical and nutritional surveillance is important in the postoperative period of bariatric surgery. Management of each condition must be directed at correcting the 2 major sources of iron deficiency and anemia: food intolerance (mostly meat intolerance) and losses (frequently due to menstruation). These are the factors more related to iron deficient anemia.

As bases experimentais da lesão por isquemia e reperfusão do fígado: revisão

Hepatic transplantation has become the main treatment for patients with terminal hepatic disease. Whatever the success of such surgery, the hepatic dysfunction associated with liver transplantation is an important cause of morbidity and mortality. Paradoxically, on restoring the blood supply, the liver is subjected to a further insult, aggravating the injury already caused by ischemia. This complex phenomenon is termed ischemia-reperfusion injury and involves endothelial cell dysfunction, leukocyte entrapment, platelet aggregation, oxidant stress and hepatic microcirculatory perfusion failure. This review discusses the physiopathlogicals mechanisms of liver ischemia-reperfusion injury.

Interfaces between bariatric surgery and oral health: a longitudinal survey.

PURPOSE To evaluate oral changes, such as dental caries, periodontal disease, dental wear and salivary flow in bariatric patients. Fifty four obese patients who underwent bariatric surgery were studied before (n=54), up after 3 months (n=24) and 6 months (n=16). METHODS Indices for evaluating oral conditions were: DMFT, CPI, DWI and salivary flow. OIDP questionnaire was used to assess the impact of oral health on quality of life. ANOVA and Spearman correlation were used (p<0.05). RESULTS DMFT was 17.6 ± 5.7, 18.4 ± 4.1 and 18.3 ± 5.5 (P>0.05), presence of periodontal pockets in 50%, 58% and 50% of patients (p>0.05), tooth wear in dentin present in 81.5%, 87.5% and 87.5% before, 3 and 6 months after surgical treatment respectively. There were differences between the three periods for prevalence and severity of dental wear (p = 0.012). Salivary flow was 0.8 ± 0.5 ml/min before surgery, 0.9 ± 0.5 ml/min for 3 months and 1.1 ± 0.5m/min for 6 months (p>0.05). The impact of oral health on quality of life decreased with time after bariatric surgery (p= 0.029). CONCLUSION The lifestyle changes after bariatric surgery and these changes may increase the severity of pre-existing dental problems. However, these alterations in oral health did not influence the quality of life.

Impact of bariatric surgery on oral health conditions: 6-months cohort study

OBJECTIVES We evaluate oral health conditions before and after bariatric surgery. METHODS The sample was composed of 59 patients who had undergone Roux-en-Y gastric bypass (RYGB). Salivary flow, periodontal pocket depth and dental wear were evaluated before and after 6 months of surgery. Body mass index (BMI), C-reactive protein (CRP) and glucose levels were obtained from the patients medical files. A t-test was used for dependent samples. RESULTS The mean BMI decreased from 49.31 ± 8.76 to 35.52 ± 8.12 kg/m(2) in 6 months after surgery (P < 0.000). Before surgery, 67% of patients had high levels of CRP and 38% higher blood glucose levels and after surgery there were significant reductions in these levels (P < 0.001). Salivary flow ranged from 0.84 to 0.95 ml/min. There was increased prevalence of periodontal pockets (P = 0.022) and mean pocket depth increased to about 0.5 mm (P < 0.001). The percentage of surfaces with dental wear in dentine was significantly higher after bariatric surgery (P = 0.002), while dental wear in enamel decreased (P = 0.019). CONCLUSIONS Bariatric surgery may improve systemic conditions. However, it had a negative impact on oral health conditions because of an increase in periodontal disease and dental wear.

Altered plasma response to zinc and iron tolerance test after Roux-en-Y gastric bypass

BACKGROUND The duodenum and proximal jejunum are excluded after Roux-en-Y gastric bypass but these intestinal sites are where iron and zinc are most absorbed. Therefore, they are among the nutrients whose digestive and absorptive process can be impaired after surgery. The aim of the present study was to investigate the iron and zinc plasma response to a tolerance test before and after bariatric surgery. The study was performed at São Paulo University School of Medicine of Ribeirão Preto, Brazil. METHODS In a longitudinal paired study, 9 morbidly obese women (body mass index ≥40 kg/m(2)) underwent an iron and zinc tolerance test before and 3 months after surgery. The iron and zinc levels were determined at 0, 1, 2, 3, and 4 hours after a physiologic unique oral dose. The mineral concentrations in the plasma and 24-hour urine sample were assayed using an atomic absorption spectrophotometer. The anthropometric measurements and 3-day food record were also evaluated. A linear mixed model was used to compare the plasma concentration versus interval after the oral dose, before and after surgery. RESULTS The pre- and postoperative test results revealed a significantly lower plasma zinc response (P <.01) and a delayed response to iron intake after surgery. The total plasma iron concentration area, during the 4 hours, was not different after surgery (P >.05). The 24-hour urinary iron and zinc excretion did not differ between the pre- and postoperative phases. CONCLUSION The present data showed a compromised response to the zinc tolerance test after gastric bypass surgery, suggesting an impaired absorption of zinc. More attention must be devoted to zinc nutritional status after surgery.

Comparison between Henley jejunal interposition and Roux-en-Y anastomosis as concerns enterogastric biliary reflux levels

The amount of enterogastric biliary reflux was assessed in patients who previously underwent Henley operation (n = 8) or Roux-en-Y biliary diversion (n = 7) using the radiopharmaceutical 99mTechnetium-DISIDA. Two other groups were investigated: a control group consisting of patients with unoperated duodenal ulcer (n = 10) and a group of patients who underwent Billroth II gastrectomy (n = 7). The length of the interposed segment of jejunum ranged from 20 to 30 cm (median of 22.5 cm) in the Henley patients, and from 30 to 60 cm (median of 40 cm) in the Roux-en-Y group. In Henley patients, the percentage of administered 99mTechnetium-DISIDA that was recovered from the stomach (median of 0.92%) was lower (p < 0.01) than that obtained for Billroth II patients (median of 32.28%) and did not differ (p > 0.10) from that of the Roux-en-Y (median of 0.36%) and duodenal ulcer groups (median of 2.53%). These results indicate that Henley operation is as effective as Roux-en-Y diversion in promoting the reduction of the amount of enterogastric biliary reflux that follows Billroth II distal gastrectomy.

Routine abdominal drains after Roux-en-Y gastric bypass: a prospective evaluation of the inflammatory response

BACKGROUND Despite the extensive published data regarding the use of drains in surgery, it is still controversial. Most bariatric surgeons use drains as routinely. However, drains have sometimes have been shown to be unhelpful and even to increase the anastomotic leak rates. The purpose of the present study was to evaluate the peritoneal inflammatory response in the presence of a drain left in place until the seventh postoperative day after bariatric surgery. METHODS All patients who underwent open Roux-en-Y gastric bypass from February 2007 to August 2008 were prospectively evaluated. A 24F Blake drain was left in place for 7 days. The peritoneal effluent from the drain was collected for the determination of cytokine levels and for microbiologic analysis. RESULTS A total of 107 obese patients were studied. A marked increase in the levels of tumor necrosis factor-α and interleukin-1β was observed by the seventh postoperative day, even in patients without any abdominal complications. Bacterial contamination of the peritoneal effluent was also demonstrated. CONCLUSION The results of our study have shown that at 7 days after surgery, a marked peritoneal inflammatory response and bacterial contamination are present. These findings could have resulted from the use of the drain for 7 postoperative days.

Periodontal status and pathogenic bacteria after gastric bypass: a cohort study

AIM The aim this study was to evaluate the influence of gastric bypass surgery (GBS) on periodontal disease and quantify the periodontopathogenic bacteria in patients undergoing this surgery. MATERIAL AND METHODS This prospective study was composed of 50 patients who underwent bariatric surgery and the data collection was performed in three periods pre-operative, 6 (6M) and 12 months (12 M) postoperative. The oral clinical examination to assess periodontal disease; gingival fluid sample collection for quantification of the periodontopathogenic bacteria Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Prevotella intermedia using q-PCR; body mass index (BMI) and for collection of the individuals health-related data from medical files. RESULTS There was a significant reduction in serum C-reactive protein (CRP) and glucose levels after surgery. The mean probing pocket depth (PPD) and clinical attachment level (CAL) increased significantly in the postoperative period of 6 months (p = 0.001). In the same period, the amount of P. gingivalis increased (p = 0.028) and the other bacteria decreased slightly (p > 0.050). In the presence of P. gingivalis, T. forsythia, T. denticola and P. intermedia, a poor periodontal condition was observed. CONCLUSION The periodontal disease increased in severity and P. gingivalis increased after GBS. A systemic inflammation resolution due to bariatric surgery in obese subjects does not seem to affect the course of periodontal disease.

Alterações cronológicas do perfil dos pacientes e da modalidade de tratamento cirúrgico do megaesôfago chagásico

OBJECTIVE: To analize the changes in the profile of the patients with chagasic megaesophagus and treatment modalities by comparing two groups of patients in different time periods. METHODS: Two series of consecutive patients with chagasic megaesophagus treated surgically were analized in two different time periods, between 1955 and 1962 (n=147) and between 1988 and1998 (n=100). The age, duration of disphagia and the stage of the disease were correlated to the type of surgical procedure. The degree of megaesophagus was defined radiologically. RESULTS: There was a reduction in the number of patients, an increase in the median age and a reduction in the duration of disphagia in the second time period. During the first period, ressectional procedures were more common, while cardiomiotomy predominated in the second. CONCLUSIONS: The profile of the patients with chagasic megaesophagus, treated at the HCFMRP-USP, has changed along the years, the main change being earlier stages of the disease. Earlier medical assistance results in less aggressive surgical procedures with the perspective of better outcomes.