P-EGS21 The impact of COVID-19 on operative difficulty and outcomes of laparoscopic cholecystectomy

Background

The COVID-19 pandemic resulted in substantial delays to surgery among patients with symptomatic gallstones due to cessation of elective surgical procedures. As this exposed patients to a longer period of time during which complications from gallstones could develop, we hypothesised that the operative difficulty and complication rate of laparoscopic cholecystectomy (LC) increased following the first wave of the pandemic.

Methods

This was a retrospective cohort study of patients receiving emergency or elective LC at a single NHS trust comprising three sites. We included patients undergoing surgery in the pre-pandemic period (July-September 2019) and after resumption of elective surgical services following the first wave of the pandemic (July-September 2020). We compared data on operative duration, length of hospital stay, complications (bile leak, bile duct injury and mortality) and need for subtotal cholecystectomy. Categorical data are reported as n(%) and were compared with Fisher’s exact test. Continuous data are reported as median with interquartile range and compared with Mann-Whitney U Test.

Results

220 patients were included; 106 in the pre-pandemic group and 114 in the pandemic group. There were no significant differences in median operative times between the pre-pandemic (91 (71-121 minutes) and post-first wave (86 (69-114) minutes) groups (p = 0.48).  The proportion of prolonged operations (over two hours) was similar in the pre-pandemic and pandemic groups (50% versus 46%, respectively, p = 0.59). Median length of hospital stay was 0 days for both groups (pre-pandemic 0 (0-1) days; pandemic 0 (0-1) days, p = 0.42)). There were no significant differences in the rates of bile leak, bile duct injury, mortality, or the conversion to subtotal cholecystectomy.

Conclusions

Interruption of elective surgery following the first wave of the COVID-19 pandemic did not result in a discernible change in the technical difficulty or complication rate of LC at our centre. Longer term studies are required to assess the effect of prolonged delays to surgery and the impact of subsequent waves of the pandemic.

Modulating myosin restores muscle function in a mouse model of nemaline myopathy

OBJECTIVE

Nemaline myopathy, one of the most common congenital myopathies, is associated with mutations in various genes including ACTA1. This disease is also characterized by various forms/degrees of muscle weakness, with most cases being severe and resulting in death in infancy. Recent findings have provided valuable insight into the underlying pathophysiological mechanisms. Mutations in ACTA1 directly disrupt binding interactions between actin and myosin, and consequently the intrinsic force-generating capacity of muscle fibers. ACTA1 mutations are also associated with variations in myofiber size, the mechanisms of which have been unclear. In the present study, we sought to test the hypotheses that the compromised functional and morphological attributes of skeletal muscles bearing ACTA1 mutations (1) would be directly due to the inefficient actomyosin complex and (2) could be restored by manipulating myosin expression.

METHODS

We used a knockin mouse model expressing the ACTA1 His40Tyr actin mutation found in human patients. We then performed in vivo intramuscular injections of recombinant adeno-associated viral vectors harboring a myosin transgene known to facilitate muscle contraction.

RESULTS

We observed that in the presence of the transgene, the intrinsic force-generating capacity was restored and myofiber size was normal.

INTERPRETATION

This demonstrates a direct link between disrupted attachment of myosin molecules to actin monomers and muscle fiber atrophy. These data also suggest that further therapeutic interventions should primarily target myosin dysfunction to alleviate the pathology of ACTA1-related nemaline myopathy. Ann Neurol 2016;79:717-725.