Preliminary experience with umbilical stoma in transumbilical single-port colorectal surgery

BACKGROUND

The umbilicus, an embryological natural orifice, is increasingly used as the only access route during single-incision laparoscopic surgery (SILS) for colorectal disease. As a part of some of these procedures, a temporary, diverting ostomy could be exteriorized through the umbilicus itself. Theoretical advantages include better preservation of the abdominal wall and potentially superior cosmetic results. The aim of the present study was to evaluate our preliminary experience in SILS colorectal resection with umbilical stoma (u-stoma).

METHODS

We retrospectively reviewed all colorectal patients operated using SILS for benign or malignant disease at Paris Poissy Medical Center. Patients were selected for consideration of u-stoma with our stoma therapists.

RESULTS

Between January 2010 and December 2016, 234 patients underwent colorectal SILS procedures. In 74 patients (31.6%), an ileostomy (n = 41) or a colostomy (n = 33) was fashioned. Of these, 20 (27% of all ostomies) were umbilical stomas. The 20 u-stoma patients, 10 men and 10 women, received either a loop ileostomy (n = 14) or an end (n = 4) or loop (n = 2) colostomy. The mean age was 52 years (range 29-81 years). There was no mortality. Operative stoma-related morbidity occurred in only 5% of patients (n = 1: ileal torsion volvulus). Median follow-up after stoma formation was 30 months (range 12-59 months). Adjustment to the stoma and quality of life were satisfactory as estimated by both the patient and the stoma therapist. All stomas were reversed. At a median follow-up of 27.5 months (range 7-55 months) after stoma reversal, two patients had reoperation for incisional hernia.

CONCLUSION

This preliminary experience showed that u-stoma is a feasible and safe alternative to more conventional ostomy after SILS.

Cellular toxicity of TiO2-based nanofilaments

At present, nanofilaments are not exclusively based on carbon atoms but can be produced from many inorganic materials in the form of nanotubes and nanowires. It is essential to systematically assess the acute toxicity of these newly synthesized materials since it cannot be predicted from the known toxicity of the same material in another form. Here, the cellular toxicity of TiO2-based nanofilaments was studied in relation to their morphology and surface chemistry. These structures produced by hydrothermal treatment were titanate nanotubes and nanowires with a Na(x)TiO(2+delta) composition. The cytotoxic effect was mainly evaluated by MTT assays combined with direct cell counting and cytopathological analyses of the lung tumor cells. Our work clearly demonstrated that the presence of Na(x)TiO(2+delta) nanofilaments had a strong dose-dependent effect on cell proliferation and cell death. Nanofilament internalization and alterations in cell morphology were observed. Acid treatment performed to substitute Na(+) with H(+) in the Na(x)TiO(2+delta) nanofilaments strongly enhanced the cytotoxic action. This effect was attributed to structural imperfections, which are left by the atom diffusion during the substitution. On the basis of our findings, we conclude that TiO2-based nanofilaments are cytotoxic and thus precautions should be taken during their manipulation.

Alterations of the Wnt signaling pathway during the neoplastic progression of Barrett's esophagus

Aberrant activation of the Wnt signaling pathway has been reported during neoplastic progression in Barrett's esophagus (BE). However, mutations in APC and CTNNB1 genes were rarely observed. In this study, expression pattern of Wnt ligands, Frizzled receptors and APC, as well as the methylation status of the APC, SFRP1 and SFRP2 promoter genes were investigated in normal esophageal mucosa and in preneoplastic and neoplastic lesions of BE patients. Promoter methylation of APC was found in all BE samples and in 95% of esophageal adenocarcinomas (EAC). Full methylation of APC correlated with lack of expression. In EAC, nuclear translocation of beta-catenin was observed regardless of the expression of APC. WNT2 expression was higher in dysplasia and EAC than in BE, with 20/26 (77%) of the EAC showing high expression of WNT2. SFRP1 methylation occurred in all BE samples and in 96% of EAC, while SFRP2 was methylated in 73% of the normal squamous esophageal mucosa samples. In conclusion, (1) alterations of key regulators of the Wnt signaling are frequent in the pathogenesis of BE; (2) the APC and SFRP1 genes are inactivated by promoter methylation in BE; (3) the WNT2 gene is upregulated along the progression from low-grade dysplasia to EAC.

Cellular toxicity of carbon-based nanomaterials

The cellular toxicity of carbon-based nanomaterials was studied as a function of their aspect ratio and surface chemistry. These structures were multiwalled carbon nanotubes, carbon nanofibers, and carbon nanoparticles. Their toxicity was tested in vitro on lung tumor cells. Our work clearly indicated that these materials are toxic while the hazardous effect is size-dependent. Moreover, cytotoxicity is enhanced when the surface of the particles is functionalized after an acid treatment.

Methylation of APC, TIMP3, and TERT: a new predictive marker to distinguish Barrett's oesophagus patients at risk for malignant transformation

Barrett's associated oesophageal adenocarcinoma (EAC) is one of the most rapidly increasing malignancies in Western countries. Because of its poor prognosis, management of this disease through screening of Barrett's oesophagus (BE) patients and identification of those with a high risk of developing an adenocarcinoma seems a promising approach. Early molecular markers of malignant transformation might contribute to such screening approaches. Gene promoter methylation analysis was performed on normal, pre-neoplastic, and neoplastic lesions from BE patients. All lesions of interest were sampled by microdissection from formalin-fixed paraffin-embedded tissue sections. We found that, in 27 adenocarcinomas, APC, TIMP3, TERT, CDKN2A, and SFRP1 promoters were methylated in 93%, 65%, 64%, 48%, and 91%, respectively; in contrast MLH1, RASSF1, RARB, CDH1, and FHIT promoters were methylated in less than 5% of the tumours. In BE mucosa from patients who had progressed to adenocarcinoma (12 samples), APC, TIMP3, and TERT promoters were hypermethylated in 100%, 91%, and 92% of cases, whereas in BE mucosa from patients who had not progressed (16 samples) methylation was found only in 36%, 23%, and 17%, respectively. Furthermore, the epigenetic profile of BE with and without EAC differed significantly with, respectively, 81% and 26% of the PCR samples showing promoter hypermethylation for APC, TIMP3, and TERT (p < 0.0001). Promoter methylation of CDKN2A was infrequently detected in BE samples, while SFRP1 methylation was observed in all samples. Our results suggest that promoter methylation profiling of BE using multiple target genes including APC, TIMP3, and TERT might be used as a predictive marker for increased EAC risk.

[Psychological aspects of bone marrow donation in donor brothers and sisters in bone marrow transplantation]

It appears to be necessary to consider, during a bone marrow transplantation, brothers and sisters who are donors. These children face psychological difficulties, which are not always understood by medical staff and families who are mainly concerned with the health of the sick children. Systematic meetings with a hundred donors point out the distress experienced in these situations.