Perineal wound closure using gluteal turnover flap or primary closure after abdominoperineal resection for rectal cancer: study protocol of a randomised controlled multicentre trial (BIOPEX-2 study)

BACKGROUND: Abdominoperineal resection (APR) for rectal cancer is associated with high morbidity of the perineal wound, and controversy exists about the optimal closure technique. Primary perineal wound closure is still the standard of care in the Netherlands. Biological mesh closure did not improve wound healing in our previous randomised controlled trial (BIOPEX-study). It is suggested, based on meta-analysis of cohort studies, that filling of the perineal defect with well-vascularised tissue improves perineal wound healing. A gluteal turnover flap seems to be a promising method for this purpose, and with the advantage of not having a donor site scar. The aim of this study is to investigate whether a gluteal turnover flap improves the uncomplicated perineal wound healing after APR for rectal cancer. METHODS: Patients with primary or recurrent rectal cancer who are planned for APR will be considered eligible in this multicentre randomised controlled trial. Exclusion criteria are total exenteration, sacral resection above S4/S5, intersphincteric APR, biological mesh closure of the pelvic floor, collagen disorders, and severe systemic diseases. A total of 160 patients will be randomised between gluteal turnover flap (experimental arm) and primary closure (control arm). The total follow-up duration is 12 months, and outcome assessors and patients will be blinded for type of perineal wound closure. The primary outcome is the percentage of uncomplicated perineal wound healing on day 30, defined as a Southampton wound score of less than two. Secondary outcomes include time to perineal wound closure, incidence of perineal hernia, the number, duration and nature of the complications, re-interventions, quality of life and urogenital function. DISCUSSION: The uncomplicated perineal wound healing rate is expected to increase from 65 to 85% by using the gluteal turnover flap. With proven effectiveness, a quick implementation of this relatively simple surgical technique is expected to take place. TRIAL REGISTRATION: The trial was retrospectively registered at Clinicaltrials.gov NCT04004650 on July 2, 2019

Adult firefly abundance is linked to weather during the larval stage in the previous year

1. Much is known about the brief adult phase of fireflies. However, fireflies spend a relatively long developmental period under the soil surface. Climatic and soil conditions may directly affect the eggs, larvae, and pupae, and also affect them indirectly through predators, competitors, and prey items. Climatic conditions during the early life stages of this iconic species are therefore relevant to their hypothesised decline within the context of global warming. 2. Data on the abundance of fireflies were extracted from the publicly available citizen dataset across North America over a period of 9 years. The effects of weather in the 24 months before the observations of firefly abundance were documented based on 6761 observations. 3. Climatic conditions during both the larval and adult phases have a non‐linear effect on adult firefly abundance. Maximum winter and spring temperatures and mean precipitation in the 20‐month period before the observations had the greatest impact on the abundance of firefly adults. Low maximum soil moisture during the 5–19 months preceding the observations affected the adult abundance negatively, and high maximum soil moisture affected it positively. 4. After correcting the firefly abundance for these weather effects, it is estimated that the abundance of fireflies increased over the time period of this study. 5. This study suggests that early life climatic conditions have a small but significant impact on adult firefly abundance with a total R2 of 0.017

A map of the study area showing the proportion of boma attacks prior to and after installation of the flashlight technique.

<p>Empty circles (○) represent bomas where attacks had been reported before installation and none after installation. The partly filled circles (◔) represent bomas where attacks took place after flashlight installation. The stars (★) represent bomas of interview participants without flashlights.</p

Yearly mean distance of boma attack from the park boundary since the introduction of the flashlight technique south of NNP.

<p>Yearly mean distance of boma attack from the park boundary since the introduction of the flashlight technique south of NNP.</p

A drawing of a livestock boma with flashlights installed.

<p>The car battery is powered by a solar panel. The bulbs at the fence perimeter are connected through a wire from the flasher unit to flicker at night.</p

Mean number of attacks (±sd) by lions prior to and after installation of the LED flashlight technique based on 43 bomas with flashlights.

<p>Mean number of attacks (±sd) by lions prior to and after installation of the LED flashlight technique based on 43 bomas with flashlights.</p

Effectiveness of a LED flashlight technique in reducing livestock depredation by lions (<i>Panthera leo</i>) around Nairobi National Park, Kenya

<div><p>The global lion (<i>Panthera leo</i>) population decline is partly a result of retaliatory killing in response to livestock depredation. Nairobi National Park (NNP) is a small protected area in Kenya surrounded by a human-dominated landscape. Communities around the park use flashlights to deter lions from their livestock bomas. We investigated the response by lions to the installation of a LED flashlight technique during 2007–2016.We interviewed 80 owners of livestock bomas with flashlights (n = 43) and without (n = 37) flashlights in the surroundings of NNP and verified reported attacks on bomas against predation data over10 years. The frequency of attacks on bomas equipped with flashlights was significantly lower compared to bomas without flashlights. We also found that after flashlight installation at livestock bomas, lion attacks took place further away from the park edge, towards areas where bomas without flashlights were still present. With increased numbers of flashlight installations at bomas in recent years, we further noticed a shift from nocturnal to more diurnal predation incidences. Our study shows that the LED flashlight technique is effective in reducing nocturnal livestock predation at bomas by lions. Long term studies on the effects as well as expansion of this technique into other communities around NNP are recommended.</p></div

Mean number of nocturnal and diurnal boma attacks around NNP between 2007 and 2016 at different distances from the park boundary.

<p>Mean number of nocturnal and diurnal boma attacks around NNP between 2007 and 2016 at different distances from the park boundary.</p

Difference in the probability of lion attacks between the two categories of livestock bomas, (Yes = with Flashlight, No = without flashlight) between 2007 and 2016 based on GLMER model.

<p>Difference in the probability of lion attacks between the two categories of livestock bomas, (Yes = with Flashlight, No = without flashlight) between 2007 and 2016 based on GLMER model.</p