Traditional electrosurgery and a low thermal injury dissection device yield different outcomes following bilateral skin-sparing mastectomy: a case report

<p>Abstract</p> <p>Introduction</p> <p>Although a skin- and nipple-sparing mastectomy technique offers distinct cosmetic and reconstructive advantages over traditional methods, partial skin flap and nipple necrosis remain a significant source of post-operative morbidity. Prior work has suggested that collateral thermal damage resulting from electrocautery use during skin flap development is a potential source of this complication. This report describes the case of a smoker with recurrent ductal carcinoma <it>in situ </it>(DCIS) who experienced significant unilateral skin necrosis following bilateral skin-sparing mastectomy while participating in a clinical trial examining mastectomy outcomes with two different surgical devices. This unexpected complication has implications for the choice of dissection devices in procedures requiring skin flap preservation.</p> <p>Case presentation</p> <p>The patient was a 61-year-old Caucasian woman who was a smoker with recurrent DCIS of her right breast. As part of the clinical trial, each breast was randomized to either the standard of care treatment group (a scalpel and a traditional electrosurgical device) or treatment with a novel, low thermal injury dissection device, allowing for a direct, internally controlled comparison of surgical outcomes. Post-operative follow-up at six days was unremarkable for both operative sites. At 16 days post-surgery, the patient presented with a significant wound necrosis in the mastectomy site randomized to the control study group. Following debridement and closure, this site progressively healed over 10 weeks. The contralateral mastectomy, randomized to the alternative device, healed normally.</p> <p>Conclusion</p> <p>We hypothesize that thermal damage to the subcutaneous microvasculature during flap dissection may have contributed to this complication and that the use of a low thermal injury dissection device may be advantageous in select patients undergoing skin- and nipple-sparing mastectomy.</p

Transitions between explosive and effusive phases during the cataclysmic 2010 eruption of Merapi volcano, Java, Indonesia

Transitions between explosive and effusive activity are commonly observed during dome-forming eruptions and may be linked to factors such as magma influx, ascent rate and degassing. However, the interplay between these factors is complex and the resulting eruptive behaviour often unpredictable. This paper focuses on the driving forces behind the explosive and effusive activity during the well-documented 2010 eruption of Merapi, the volcano’s largest eruption since 1872. Time-controlled samples were collected from the 2010 deposits, linked to eruption stage and style of activity. These include scoria and pumice from the initial explosions, dense and scoriaceous dome samples formed via effusive activity, as well as scoria and pumice samples deposited during subplinian column collapse. Quantitative textural analysis of groundmass feldspar microlites, including measurements of areal number density, mean microlite size, crystal aspect ratio, groundmass crystallinity and crystal size distribution analysis, reveal that shallow pre- and syn-eruptive magmatic processes acted to govern the changing behaviour during the eruption. High-An (up to ∼80 mol% An) microlites from early erupted samples reveal that the eruption was likely preceded by an influx of hotter or more mafic magma. Transitions between explosive and effusive activity in 2010 were driven primarily by the dynamics of magma ascent in the conduit, with degassing and crystallisation acting via feedback mechanisms, resulting in cycles of effusive and explosive activity. Explosivity during the 2010 eruption was enhanced by the presence of a ‘plug’ of cooled magma within the shallow magma plumbing system, which acted to hinder degassing, leading to overpressure prior to initial explosive activity

Pre- and syn-eruptive degassing and crystallisation processes of the 2010 and 2006 eruptions of Merapi volcano, Indonesia

The 2010 eruption of Merapi (VEI 4) was the volcano’s largest since 1872. In contrast to the prolonged and effusive dome-forming eruptions typical of Merapi’s recent activity, the 2010 eruption began explosively, before a new dome was rapidly emplaced. This new dome was subsequently destroyed by explosions, generating pyroclastic density currents (PDCs), predominantly consisting of dark coloured, dense blocks of basaltic andesite dome lava. A shift towards open-vent conditions in the later stages of the eruption culminated in multiple explosions and the generation of PDCs with conspicuous grey scoria and white pumice clasts resulting from sub-plinian convective column collapse. This paper presents geochemical data for melt inclusions and their clinopyroxene hosts extracted from dense dome lava, grey scoria and white pumice generated during the peak of the 2010 eruption. These are compared with clinopyroxene-hosted melt inclusions from scoriaceous dome fragments from the prolonged dome-forming 2006 eruption, to elucidate any relationship between pre-eruptive degassing and crystallisation processes and eruptive style. Secondary ion mass spectrometry analysis of volatiles (H2O, CO2) and light lithophile elements (Li, B, Be) is augmented by electron microprobe analysis of major elements and volatiles (Cl, S, F) in melt inclusions and groundmass glass. Geobarometric analysis shows that the clinopyroxene phenocrysts crystallised at depths of up to 20 km, with the greatest calculated depths associated with phenocrysts from the white pumice. Based on their volatile contents, melt inclusions have re-equilibrated during shallower storage and/or ascent, at depths of ~0.6–9.7 km, where the Merapi magma system is interpreted to be highly interconnected and not formed of discrete magma reservoirs. Melt inclusions enriched in Li show uniform “buffered” Cl concentrations, indicating the presence of an exsolved brine phase. Boron-enriched inclusions also support the presence of a brine phase, which helped to stabilise B in the melt. Calculations based on S concentrations in melt inclusions and groundmass glass require a degassing melt volume of 0.36 km3 in order to produce the mass of SO2 emitted during the 2010 eruption. This volume is approximately an order of magnitude higher than the erupted magma (DRE) volume. The transition between the contrasting eruptive styles in 2010 and 2006 is linked to changes in magmatic flux and changes in degassing style, with the explosive activity in 2010 driven by an influx of deep magma, which overwhelmed the shallower magma system and ascended rapidly, accompanied by closed-system degassing