Renato Santos de Oliveira Filho

Desenhos de pesquisa

O presente estudo de revisao visa uniformizar a nomenclatura e os conceitos classificatorios existentes na literatura, relativos aos desenhos ou modelos de estudo cientifico mais comumente utilizados em pesquisas na area clinico-cirurgica geral. Procurou-se facilitar a elaboracao do delineamento de um projeto de pesquisa cientifica, visando sua aplicabilidade. Esta revisao tambem tem o intuito de auxiliar o cirurgiao-pesquisador a identificar qual foi o delineamento proposto em um artigo, assim como desenvolver um senso de critica metodologica mais apurada sobre o mesmo, alem de desmistificar a miscelânea conceitual existente na literatura.

Is intra-operative gamma probe detection really necessary for inguinal sentinel lymph node biopsy?

CONTEXT Sentinel node (SN) biopsy has changed the surgical treatment of malignant melanoma. The literature has emphasized the importance of gamma probe detection (GPD) of the SN. OBJECTIVE Our objective was to evaluate the efficacy of patent blue dye (PBD) and GPD for SN biopsy in different lymphatic basins. DESIGN Patients with cutaneous malignant melanoma in stages I and II were submitted to biopsy of the SN, identified by PBD and GPD, as part of a research project. SETTING Patients were seen at Hospital São Paulo by a multidisciplinary group (Plastic Surgery Tumor Branch, Nuclear Medicine and Pathology). PATIENTS 64 patients with localized malignant melanoma were studied. The median age was 46.5 years. The primary tumor was located in the neck, trunk or extremities. INTERVENTIONS Preoperative lymphoscintigraphy, lymphatic mapping with PBD and intraoperative GPD was performed on all patients. The SN was examined by conventional and immunohistochemical staining. If the SN was not found or contained micrometastases, only complete lymphadenectomy was performed. MAIN MEASUREMENTS The SN was identified by PBD if it was blue-stained, and by GPD if demonstrated activity five times greater than the adipose tissue of the neighborhood. RESULTS Seventy lymphatic basins were explored. Lymphoscintigraphy showed ambiguous drainage in 7 patients. GPD identified the SN in 68 basins (97%) and PBD in 53 (76%). PBD and GPD identified SN in 100% of the inguinal basins. For the remaining basins both techniques were complementary. A metastatic SN was found in 10 basins. Three patients with negative SN had recurrence (median follow-up = 11 months). CONCLUSION Although both GPD and PBD are useful and complementary, PBD alone identified the SN in 100% of the inguinal lymphatic basins.

A variation in the component separation technique that preserves linea semilunaris: a study in cadavers and a clinical case

The purpose of this study is to evaluate and compare the effect of the incision of the external oblique aponeurosis along the semilunaris in amount of tension present after the undermining of the anterior rectus sheaths. Forty fresh adult cadavers were studied and divided into two groups: group A (n=20) and group B (n=20). Traction indexes were compared in three situations: (1) before any aponeurotic undermining (similar on both groups); (2) after incision and undermining of the anterior rectus sheaths (similar on both groups) and (3) group A: after undermining of the external oblique muscles with the incision of their aponeurosis along the semilunaris and group B: undermining of a continuous layer of the anterior rectus sheaths and the external oblique aponeurosis, after release of the lateral aspect of the rectus sheaths. Significance of differences was assessed using non-parametric tests. There was a significant tension reduction after each stage of dissection in both supra- and infra-umbilical levels and on both groups. Comparisons between groups A and B did not show statistically significant differences in all sites and stages of the dissections. Therefore, both techniques showed similar aponeurotic tension reduction after each stage of the dissections in cadavers.

Influence of colloid particle profile on sentinel lymph node uptake

INTRODUCTION Particle size of colloids employed for sentinel lymph node (LN) detection is not well studied. This investigation aimed to correlate particle size and distribution of different products with LN uptake. METHODS All agents (colloidal tin, dextran, phytate and colloidal rhenium sulfide) were labeled with (99m)Tc according to manufacturers instructions. Sizing of particles was carried out on electron micrographs using Image Tool for Windows (Version 2.0). Biodistribution studies in main excretion organs as well as in popliteal LN were performed in male Wistar rats [30 and 90 min post injection (p.i.)]. The injected dose was 0.1 ml (37 MBq) in the footpad of the left posterior limb. Dynamic images (0-15 min p.i.) as well as static ones (30 and 90 min) were acquired in gamma camera. RESULTS Popliteal LN was clearly reached by all products. Nevertheless, particle size remarkably influenced node uptake. Colloidal rhenium sulfide, with the smallest diameter (5.1 x 10(-3)+/-3.9 x 10(-3) microm), permitted the best result [2.72+/-0.64 percent injected dose (%ID) at 90 min]. Phytate displayed small particles (<15 microm) with favorable uptake (1.02+/-0.14%ID). Dextran (21.4+/-12.8 microm) and colloidal tin (39.0+/-8.3 microm) were less effective (0.55+/-0.14 and 0.06+/-0.03%ID respectively). Particle distribution also tended to influence results. When asymmetric, it was associated with biphasic uptake which increased over time; conversely, symmetric distribution (colloidal tin) was consistent with a constant pattern. CONCLUSION The results are suggesting that particle size and symmetry may interfere with LN radiopharmaceutical uptake.

Vital dye is enough for inguinal sentinel lymph node biopsy in melanoma patients

PURPOSE The importance of gamma probe detection (GPD) combined with vital dye for sentinel node (SN) biopsy is well accepted. We evaluated the efficacy of patent blue dye (PBD) in identifying inguinal SN. METHODS Ninety-four cutaneous melanoma patients with inferior extremity lesions were submitted to SNB according to a established protocol. Patients were randomized in two groups: Blue group, where SN was identified by PPD and Probe group, where SN was identified by GPD. The median age was 44.2 years and median Breslow thickness was 2.1 mm. Preoperative lymphoscintigraphy, lymphatic mapping with PBD and intra-operative GPD was performed on all patients. Histological examination of SN consisted of hematoxylin-eosin and immunohistochemical staining. If micrometastases were present complete lymphadenectomy was performed. The SN was considered as identified by PBD if it was blue and identified by GPD if it demonstrated at least ten times greater radioactivity than background. RESULTS It was explored 94 inguinal lymphatic basins, 145 SN were excised (70 guided primarily by blue dye and 75 guided primarily by probe). All SN identified by preoperative lymphoscintigraphy were excised. In the Blue group PPD identified all SN and all of them were hot. In the Probe group all SN were identified by probe and were blue. The coincidence of PPD and GPD was 100%. CONCLUSION Patent blue dye is enough to identify superficial inguinal SN in cutaneous melanoma.

Relevance of micrometastases detected by reverse transcriptase-polymerase chain reaction for melanoma recurrence: systematic review and meta-analysis

CONTEXT Cutaneous melanoma presents significant morbidity and mortality. Nowadays, about 90% of them are diagnosed by clinical examination and most are localized melanomas. Sentinel node biopsy has brought about a new and interesting approach towards localized cutaneous melanoma. The meaning of micrometastases in sentinel nodes diagnosed by the reverse transcriptase-polymerase chain reaction is not well established. OBJECTIVE To define the real value of micrometastases diagnosed by the reverse transcriptases polymerase chain reaction in relation to melanoma recurrence. METHODS Systematic literature review and meta-analysis. The Cochrane Library, Medline, Embase and Lilacs were the databases searched. We used the following key words: sentinel node and melanoma; sentinel node and reverse transcriptase-polymerase chain reaction; melanoma and reverse transcriptase-polymerase chain reaction. Cohort studies enrolling localized cutaneous melanoma patients who underwent sentinel node biopsy were selected. Sentinel node evaluations included hematoxylin and eosin, immunohistochemistry and reverse transcriptase-polymerase chain reaction. RESULTS Out of the 1,542 studies evaluated, four were eligible. The four studies, when combined, were statistically homogeneous. The sample totaled 450 patients grouped as follows: 163 with a sentinel node negative to hematoxylin eosin and immunohistochemistry and positive to the reverse transcriptase-polymerase chain reaction; 192 with a sentinel node negative to hematoxylin eosin, immunohistochemistry and the reverse transcriptase-polymerse chain reaction and 95 patients with a sentinel node positive to hematoxylin eosin and/or immunohistochemistry. We analyzed the first two groups. The meta-analysis for the random model showed an increased effect from a positive reverse transcriptase-polymerase chain reaction on the recurrence rate. A similar result occurred in the meta-analysis for the fixed effect model. CONCLUSION Patients with a positive reverse transcriptase-polymerase chain reaction had a greater recurrence rate than those with a negative reverse transcriptase-polymerase chain reaction. This suggests an important role for the reverse transcriptase-polymerase chain reaction in sentinel node examinations. In view of the small sample, a clinical trial could better evaluate this question.

Auto-estima em pacientes com carcinomas de pele

BACKGROUND: To evaluate self-esteem among patients with skin cancer of the face and the neck area. METHODS: One hundred patients were studied, with ages ranging between 30 and 90 years old (median = 55 years old). There were 44 males and 56 females. We divided them in two groups. One group had fifty patients with skin cancers, equal or larger than 10mm in the greater axis, and the pathological status was confirmed by previous biopsy. The control group had 50 patients without skin cancer. Rosenberg/UNIFESP-EPMs Self-esteem Scale was used to evaluate self-esteem. Data were analyzed by Mann - Whitneys test and Kruskal Wallis test. RESULTS: There was no significant difference between the two groups in relation to age (p = 0.331), sex and education. The mean tumor size was 20.9 ± 2 mm. Skin cancer patients presented significantly lower self-esteem, with average score of 6.84 and 3.90 for the control group (p = 0.002). CONCLUSION: Patients with skin cancer of the head and neck presented lower self-esteem than individuals without cancer.

Parameters optimization defined by statistical analysis for cysteine-dextran radiolabeling with technetium tricarbonyl core

The objective of this study was the development of a statistical approach for radiolabeling optimization of cysteine-dextran conjugates with Tc-99m tricarbonyl core. This strategy has been applied to the labeling of 2-propylene-S-cysteine-dextran in the attempt to prepare a new class of tracers for sentinel lymph node detection, and can be extended to other radiopharmaceuticals for different targets. The statistical routine was based on three-level factorial design. Best labeling conditions were achieved. The specific activity reached was 5 MBq/μg.

Influence of calcium hydroxide addition to AH Plus sealer on its biocompatibility

OBJECTIVE The objective of this study was to determine whether the addition of 5% calcium hydroxide to AH Plus sealer improves its biocompatibility in subcutaneous connective tissue of rats. STUDY DESIGN Thirty female rats distributed into 3 groups of 10 animals each received subcutaneous dorsal implants of silicone tubes filled with AH Plus (Group 1), AH Plus containing 5% (wt/wt) calcium hydroxide (Group 2), or no material (Group 3: control). The animals were killed after 14 days and the subcutaneous tissue containing the tubes was removed and processed for histological analysis. Biocompatibility was assessed by evaluating the inflammatory response to the implants qualitatively and quantitatively. Data were analyzed statistically by the Wilcoxon and Kruskal-Wallis tests (alpha = 0.05). RESULTS The area adjacent to the implant was characterized by nonspecific chronic inflammation and was qualitatively similar in the 3 groups. Animals implanted with AH Plus/calcium hydroxide showed significantly less intense inflammatory response when compared with the animals implanted with AH Plus alone. CONCLUSION The addition of calcium hydroxide to AH Plus root canal sealer improved its histopathological behavior within 14 days of analysis, producing less severe inflammatory response and less cytotoxicity when implanted in the subcutaneous tissue of rats.

Sentinel lymph node biopsy in cutaneous melanoma

PURPOSE To assess the importance of sentinel lymph node biopsy in patients with cutaneous melanoma. METHODS Ninety consecutive non-randomized patients with stages I and II melanoma who underwent sentinel lymph node biopsy were followed up prospectively for six years. RESULTS Patients were followed up for a mean period of 30 months. Their mean age was 53.3 years, ranging from 12 to 83 years. Thirty patients were male (37.5%) and 50, female (62.5%). Sentinel lymph node was positive in 32.5% and negative in 67.5%. It was found that the thicker the tumor, the greater the incidence of positive sentinel lymph nodes. In the group of patients with positive sentinel lymph nodes, recurrence occurred in 43.5%, but in those with negative sentinel lymph nodes, in only 7%, what points out to the association of tumor recurrence and positive sentinel lymph nodes. There were no major postoperative complications. CONCLUSION Sentinel lymph node biopsy was demonstrated to be a safe method for selecting patients who need therapeutic lymphadenectomy.