SUMMER Trial: mesh versus suture repair in small umbilical hernias in adults-a study protocol for a prospective randomized double-blind multicenter clinical trial

Background

Small umbilical hernia repair is one of the most common surgical performances in general surgery. Yet, a gold standard procedure for the repair is still lacking today. There is an increasing evidence that mesh could be advantageous compared to suture repair in lowering recurrence rates. An additional important question remains with regard to the optimal anatomical positioning of the mesh. We hypothesize that the use of an onlay mesh in small umbilical hernia defects can reduce recurrence rates without increasing the complications compared to a simple suture repair.

Methods

A prospective, national, multicenter, randomized, double-blind clinical trial comparing a standardized 4 × 4 cm onlay mesh to a conventional suture repair will be conducted. A total of 288 patients with a primary elective umbilical hernia ≤ 2 cm from 7 participating Swedish surgical centers will be enrolled. Intraoperative randomization will take place using a centralized web-based system resulting in total allocation concealment. Stratification will be done by surgical site and by defect size. Trial participants and follow-up clinical surgeons will be blinded to the assigned allocation. The primary outcome assessed will be postoperative recurrence at 1 and 3 years. Secondary outcomes assessed will be postoperative complications at 30 days and pain 1 year after surgery.

Discussion

Currently, there has been no randomized clinical trial comparing the recurrence rates between an onlay mesh repair and a simple suture repair for small umbilical hernia defects. How to best repair a small umbilical hernia continues to be debated. This trial design should allow for a good assessment of the differences in recurrence rate due to the large sample size and the adequate follow-up. Surgeons’ concerns surrounding optimal anatomical positioning and fear for larger required dissections are understandable. A small onlay mesh may become an easy and safe method of choice to reduce recurrence rates. Guidelines for small umbilical hernia repairs have stressed the need for reliable data to improve treatment recommendations. We can expect that this trial will have a direct implication on small umbilical hernia repair standards.

Trial registration

ClinicalTrials.gov NCT04231071. Registered on 31 January 2020. SUMMER Trial underwent external peer review as part of the funding process.

Epstein-Barr virus infection after adolescence and human herpesvirus 6A as risk factors for multiple sclerosis

BACKGROUND AND PURPOSE

Infections with human herpesvirus 6A (HHV-6A) and Epstein-Barr virus (EBV) have been linked to multiple sclerosis (MS) development. For EBV, late infection has been proposed as a risk factor, but serological support is lacking. The objective of this study was to investigate how age affects the EBV and HHV-6A associated risks of developing MS.

METHODS

In this nested case-control study, Swedish biobanks were accessed to find pre-symptomatically collected blood samples from 670 individuals who later developed relapsing MS and 670 matched controls. A bead-based multiplex assay was used to determine serological response against EBV and HHV-6A. Conditional logistic regression was used to calculate odds ratios and 95% confidence intervals.

RESULTS

Seropositivity against EBV exhibited a pattern where associations switched from a decreased risk of developing MS in the group below 20 years of age to an increased risk amongst individuals aged 20-29 and 30-39 years (p for trend 0.020). The age of transition was estimated to be 18.8 years. In contrast, HHV-6A was associated with increased MS risk in all age groups (total cohort odds ratio 2.1, 95% confidence interval 1.6-2.7).

CONCLUSIONS

This study suggests EBV infection after adolescence and age independent HHV-6A infection as risk factors for MS.

Polymorphisms in dopamine-associated genes and cognitive decline in Parkinson's disease

OBJECTIVES

Cognitive decline is common in Parkinson's disease (PD), but the underlying mechanisms for this complication are incompletely understood. Genotypes affecting dopamine transmission may be of importance. This study investigates whether genotypes associated with reduced prefrontal dopaminergic tone and/or reduced dopamine D2-receptor availability (Catechol-O-methyltransferase [COMT] Val158 Met genotype and DRD2 C957 T genotype) affect the development of cognitive deficits in PD.

MATERIALS AND METHODS

One hundred and 34 patients with idiopathic PD, participating in a regional, population-based study of incident parkinsonism, underwent genotyping. After extensive baseline investigations (including imaging and biomarker analyses), the patients were followed prospectively during 6-10 years with neuropsychological evaluations, covering six cognitive domains. Cognitive decline (defined as the incidence of either Parkinson's disease mild cognitive impairment [PD-MCI] or dementia [PDD], diagnosed according to published criteria and blinded to genotype) was studied as the primary outcome.

RESULTS

Both genotypes affected cognition, as shown by Cox proportional hazards models. While the COMT 158 Val/Val genotype conferred an increased risk of mild cognitive impairment in patients with normal cognition at baseline (hazard ratio: 2.13, P = .023), the DRD2 957 T/T genotype conferred an overall increased risk of PD dementia (hazard ratio: 3.22, P < .001). The poorer cognitive performance in DRD2 957 T/T carriers with PD occurred mainly in episodic memory and attention.

CONCLUSIONS

The results favor the hypothesis that dopamine deficiency in PD not only relate to mild cognitive deficits in frontostriatal functions, but also to a decline in memory and attention. This could indicate that dopamine deficiency impairs a wide network of brain areas.