Sublay repair results in superior mesh incorporation and histological fibrogenesis in comparison to onlay and primary suture in an experimental rat model

PURPOSE

To compare adhesion scores, repair strength and histological findings among sublay, onlay and primary repair incisional hernioplasty techniques. Surgical repairs were employed directly on healthy animals, without previous hernia induction, to avoid confounding factors related to hernia development.

METHODS

Forty Wistar rats were divided into four groups, control, simulation, onlay and sublay. After 42 days, adhesion intensity, tensile strength of the abdominal wall and anatomopathological histological substrate were compared.

RESULTS

SL group presented greater adhesion scores (p < 0.0001), higher tensiometric (p < 0.0001), and was characterized by more histiocytes, mononuclear cells, macrovacuolar granulomas and type I collagen on histological analysis. Pearson correlation between adhesions and tensiometry, and between tensiometry and neocollagenization showed a strong positive association (r = 0.8905 and 0.6757, respectively in SL group, p < 0.05).

CONCLUSION

Mesh positioning in sublay compartment was followed by increased adhesion development and provides a stronger mesh-tissue attachment, in addition, resulted in a different histological profile of the inflammation/repair substrate. The intensity of these findings was directly correlated, suggesting they could be the result of a common biological phenomenon. Our findings indicate that mesh placement following the retromuscular technique generates a superior repair response, and give clues to a better understanding of the superiority of sublay repair in achieving lower recurrence rates. Characterization of the cellular and molecular elements responsible for the superiority of this technique is in our view an essential prerequisite aiming for improvements in the therapeutic options for the treatment of this disease.

[Do diabetic patients benefit from bilateral internal mammary artery?]

INTRODUCTION

Bilateral internal mammary artery (BIMA) grafting has been associated with increased long term survival when compared to single IMA, but its benefit on diabetic patients remains controversial.

AIMS

To compare long-term survival following BIMA versus single internal mammary artery (SIMA) grafting between diabetic and non-diabetic patients.

METHODS

We retrospectively reviewed all the patients who underwent isolated CABG and received two or more grafts with at least one IMA graft between 2004 and 2013. Mean follow-up was 4 years and maximum 10. Kaplan-Meier analysis was used to compare long-term survival between BIMA and SIMA in both groups (diabetic vs. non-diabetic). Propensity score matching was used to adjust for treatment selection bias.

RESULTS

1259 out of 3045 eligible patients were diabetic. BIMA was associated with better long-term survival than SIMA on unadjusted analysis in both groups (cumulative survival of 87% vs. 70% in diabetic patients and 89% vs. 79% in non-diabetic patients, respectively). After propensity score matching, BIMA was associated with increased long-term survival in the non-diabetic cohort (n=1042, HR: 0.570 CI95%: 0.342-0.950), but there was no statistically significant difference in the diabetic cohort (n=850, HR: 0.774 CI95% 0.447-1.339). In-hospital mortality and sternal wound infection were low in matching cohorts irrespectively of the number of IMA grafts or diabetes status.

CONCLUSIONS

BIMA grafting appears to be safe for diabetic patients, despite the apparent lack of significant survival advantage.

[Bilateral Internal Mammary Artery Versus Single Internal Mammary Artery in Myocardial Revascularization Surgery. Propensity Score - Adjusted Survival Analysis]

BACKGROUND

Although arterial grafts are superior to venous grafts in terms of long-term patency, single internal mammary artery (SIMA) is still the preferred strategy in most cardiac surgical centres. Our main aim was to compare long- -term survival between BIMA and SIMA at our own tertiary care centre.

METHODS

Retrospective cohort including patients referred to Centro Hospitalar São João (CHSJ), from 2004 to 2011, who underwent isolated CABG and received two or more bypass with at least 1 IMA graft. Kaplan-Meier, Cox regression and propensity score matching 2:1 were used to compare long-term survival between BIMA and SIMA.

RESULTS

BIMA was performed in 696 (29.3%) out of 2329 eligible procedures. Mean follow-up time was 5.1 years (2-9.9 years). All-cause mortality was superior in patients with only one internal mammary artery - cumulative survival of 75% for SIMA vs 88% for BIMA. Because of discrepancy between groups regarding preoperative and surgical characteristics, we ran a propensity score matching which revealed BIMA as an independent predictor of survival (n=1510, 40.3% BIMA, HR: 0.648, 95% CI: 0.452-0.927).

CONCLUSION

BIMA is associated with significantly better long-term survival than SIMA in CABG. A higher sample size might clarify BIMA advantages, discriminating specific groups that might profit the most with this approach.

Development of a quartz tuning-fork-based force sensor for measurements in the tens of nanoNewton force range during nanomanipulation experiments

Understanding the mechanical properties of nanoscale systems requires new experimental and theoretical tools. In particular, force sensors compatible with nanomechanical testing experiments and with sensitivity in the nN range are required. Here, we report the development and testing of a tuning-fork-based force sensor for in situ nanomanipulation experiments inside a scanning electron microscope. The sensor uses a very simple design for the electronics and it allows the direct and quantitative force measurement in the 1-100 nN force range. The sensor response is initially calibrated against a nN range force standard, as, for example, a calibrated Atomic Force Microscopy cantilever; subsequently, applied force values can be directly derived using only the electric signals generated by the tuning fork. Using a homemade nanomanipulator, the quantitative force sensor has been used to analyze the mechanical deformation of multi-walled carbon nanotube bundles, where we analyzed forces in the 5-40 nN range, measured with an error bar of a few nN.

[Congenital hypothyroidism screening program: preliminary results]

OBJECTIVE

The authors report early results of a screening program for Congenital Hypothyroidism in Santa Catarina, Brazil.

METHODS

All the assays (82.709) analysed by Laboratório Central (LACEN) between July 1993 and December 1994 were studied. A blood sample was collected on filter paper for serum Thyroid Stimulating Hormone (TSH) measurement by fluoroimmunoassay, in triplicate. All children who had persistent abnormal TSH values (cord blood: TSH > 30 micro U/ml; from 2 to 7 days: >20 micro U/ml; older than 7 days: > 10 micro U/ml) were recalled for clinical evaluation.

RESULTS

Out of 82.709 infants aged from 0 to 60 days (40% of the deliveries in this period), 304 presented abnormal results of TSH and 34 were confirmed as Congenital Hypothyroidism. The mean age of beginning the treatment was 45 days of life.

CONCLUSIONS

The prevalence (1:2500) was higher than that observed in other countries, probably because some children had Transient Congenital Hypothyroidism. Nevertheless, sex prevalence was similar to that described in the literature. Clinical manifestations were inespecific which reinforces the importance of this kind of screening. Efforts have been done to improve the program in order to begin earlier treatment.

Antarctic Marine Flora: Uniquely Devoid of Kelps

The discovery of embryonic stages of the common large Antarctic brown seaweed Himantothallus has led to the conclusion that this plant, hitherto assigned equivocally to the Laminariales (kelps), is a member of the Desmarestiales. Moreover, field study of a large sample of Himantothallus and two other enigmatic brown algae, Phyllogigas and Phaeoglossum, has led to the merger of these three genera with the recognition of a single species, Himantothallus grandifolius. The correct placement of these kelp-like algae underscores the uniqueness of the Antarctic marine flora as the only cold-water flora without kelps.