Comparison of emergency surgical cricothyroidotomy and percutaneous cricothyroidotomy by experienced airway providers in an obese,in vivo porcine hemorrhage airway model

Background: Emergency front-of-neck airway(eFONA) is a life-saving procedure in “cannot intubate, cannot oxygenate”(CICO). The fastest and most reliable method of eFONA has not been determined. We compared two of the most advocated approaches: surgical cricothyroidotomy and percutaneous cricothyroidotomy, in an obese, in vivo porcine hemorrhage model, designed to introduce real-time physiological feedback, relevant and high provider stress. The primary aim was to determine the fastest method to secure airway. Secondary aims were arterial saturation and partial pressure of oxygen, proxy survival and influence of experience.Methods: Twelve pigs [(60.3±4.1) kg] were anesthetized and exposed to 25%–35% total blood volume hemorrhage before extubation and randomization to Seldinger technique “percutaneous cricothyroidotomy”(n=6) or scalpelbougie-tube technique “surgical cricothyroidotomy”(n=6). Specialists in anesthesia and intensive care in a tertiary referral hospital performed the eFONA, simulating an actual CICO-situation.Results: In surgical cricothyroidotomy vs. percutaneous cricothyroidotomy, the median(interquartile range, IQR) times to secure airway were 109(IQR 71–130) s and 298(IQR 128–360) s(P=0.0152), arterial blood saturation(SaO2) were 74.7(IQR 46.6–84.2)% and 7.9(IQR 4.1–15.6)%(P=0.0167), PaO_(2) were 7.0(IQR 4.7–7.7) kPa and 2.0(IQR 1.1–2.9) kPa(P=0.0667), and times of cardiac arrest(proxy survival) were 137–233 s, 190(IQR 143–229) s, from CICO. All six animals survived surgical cricothyroidotomy, and two of six(33%) animals survived percutaneous cricothyroidotomy. Years in anesthesia, 13.5(IQR 7.5–21.3), did not influence time to secure airway.Conclusions: eFONA by surgical cricothyroidotomy was faster and had increased oxygenation and survival, when performed under stress by board certified anesthesiologists, and may be an indication of preferred method in situations with hemorrhage and CICO, in obese patients.

Porcine Breeding Management in a Large-scale Piggery with Microbial Fermentation Bed

[Objective] The behavior of eating, drinking, defecating and peeing of 1 500 pigs in a large-scale microbial fermentation bed-equipped piggery was observed. We hoped to find some simple indicators that could reflect the health status of swinery and to provide experience for the swinery performance management in large-scale microbial fermentation bed-equipped piggery. [Method] The body weight （BW）, daily BW gain, feed intake and other indicators of different-day-old pigs were recorded in details. Based on the recorded data, the models between BW, BW gain, average daily feed intake and feed/gain ratio and growth days （d） were established. In addition, the incidences of pox-like macula （dermatitis）, diarrhea （gastrointestinal disease）, cough （respiratory disease）, stiff pig （malnutrition）, conjunctivitis （eye disease） and foot inflection （trauma） among fattening pigs were also investigated. [Result] The BW range, average BW, daily BW gain, breeding days, daily feed intake range, average daily feed intake, staged feed intake, accumulated feed intake, feed/gain ratio and accumulated feed/gain ratio of different-day-old pigs were studied, respectively. Four dynamic models were established for the growth of pigs： （1） the BW （y）-age （x） mod- el： y=0.758 9x-19.883 （3=0.993 7）; （2） the BW gain （y）-age （x） model： y=1.039 5x05051 （F=0.885 4）; （3） the average daily feed intake （y）-age （x） model： y=0.023 5x-0.334 3 （F=0.991 7）; （4） the feed/gain ratio （y）-age （x） model： y=0.022x＋0.427 8 （P=0.988 5）. Based on these models, the corresponding theoretical growth value of pigs at different growth stage could be predicted. The main diseases occurred among the swinery in the large-scale microbial fermentation bed piggery included pox-like macula （dermatitis）, diarrhea （gastrointestinal disease）, cough （respiratory disease）, stiff pig （mal- nutrition）, conjunctivitis （eye disease） and foot inflection （trauma）. The deadly infec- tious diseases had been not found among the pigs. [Conclusion] When the actual BW, BW gain, average daily feed intake and feed/gain ratio were all lower than the theoretical values predicted by the models, the management should be enhanced. The average daily feed intake of 60 to 65-day-old pigs was lower than the theoretic value, indicating that the pigs could not adapt nicely to the fermentation bed at the very early stage. When the pigs grew up to 70 to 75 d old, the average daily feed intake was higher than the theoretical value, indicating that the pigs had adapted to the fermentation bed. In particularly, average daily feed intake of 75-day-old pigs was higher than the theoretical value by 21%. It was suggested the fermentation bed was conducive to the growth of pigs. Considering the occurrence of diseases among pigs, the overall incidence was relatively low. The incidence of each disease was all lower than 10% with little difficulty in treating. If the management of mattress was strength- ened, such as paying attention to feeding and keeping water clean, many diseases could heal by themselves.

Transit time ultrasound perivascular flow probe technology is superior to MR imaging on hepatic blood flow measurement in a porcine model

Background: The hepatic hemodynamics is an essential parameter in surgical planning as well as in various disease processes. The transit time ultrasound(TTUS) perivascular flow probe technology is widely used in clinical practice to evaluate the hepatic inflow, yet invasive. The phase-contrast-MRI(PC-MRI) is not invasive and potentially applicable in assessing the hepatic blood flow. In the present study, we compared the hepatic inflow rates using the PC-MRI and the TTUS probe, and evaluated their predictive value of post-hepatectomy adverse events. Methods: Eighteen large white pigs were anaesthetized for PC-MRI and approximately 75% hepatic resection was performed under a unified protocol. The blood flow was measured in the hepatic artery(Qha), the portal vein(Qpv), and the aorta above the celiac trunk(Qca) using PC-MRI, and was compared to the TTUS probe. The Bland-Altman method was conducted and a partial least squares regression(PLS) model was implemented. Results: The mean Qpv measured in PC-MRI was 0.55 ± 0.12 L/min, and in the TTUS probe was 0.74 ± 0.17 L/min. Qca was 1.40 ± 0.47 L/min in the PC-MRI and 2.00 ± 0.60 L/min in the TTUS probe. Qha was 0.17 ± 0.10 L/min in the PC-MRI, and 0.13 ± 0.06 L/min in the TTUS probe. The Bland-Altman method revealed that the estimated bias of Qca in the PC-MRI was 32%(95% CI:-49% to 15%); Qha 17%(95% CI:-15% to 51%); and Qpv 40%(95% CI:-62% to 18%). The TTUS probe had a higher weight in predicting adverse outcomes after 75% resection compared to the PC-MRI( β= 0.35 and 0.43 vs β = 0.22 and 0.07, for tissue changes and premature death, respectively). Conclusions: There is a tendency of the PC-MRI to underestimate the flow measured by the TTUS probes. The TTUS probe measures are more predictive of relevant post-hepatectomy outcomes.

Is laparoscopy equal to laparotomy in detecting and treating small bowel injuries in a porcine model?

AIM: To evaluate the safety and effectiveness of laparoscopy compared with laparotomy for diagnosing and treating small bowel injuries (SBIs) in a porcine model. METHODS: Twenty-eight female pigs were anesthetized and laid in the left recumbent position. The SBI model was established by shooting at the right lower quadrant of the abdomen. The pigs were then randomized into either the laparotomy group or the laparoscopy group. All pigs underwent routine exploratory laparotomy or laparoscopy to evaluate the abdominal injuries, particularly the types, sites, and numbers of SBIs. Traditional open surgery or therapeutic laparoscopy was then performed. All pigs were kept alive within the observational period (postoperative 72 h). The postoperative recovery of each pig was carefully observed. RESULTS: The vital signs of all pigs were stable within 1-2 h after shooting and none of the pigs died from gunshot wounds or SBIs immediately. The SBI model was successfully established in all pigs and definitively diagnosed with single or multiple SBIs either by exploratory laparotomy or laparoscopy. Compared with exploratory laparotomy, laparoscopy took a significantly longer time for diagnosis (41.27 ± 12.04 min vs 27.64 ± 13.32 min, P = 0.02), but the time for therapeutic laparoscopy was similar to that of open surgery. The length of incision was significantly reduced in the laparoscopy group compared with the laparotomy group (5.27 ± 1.86 cm vs 15.73 ± 1.06 cm, P < 0.01). In the final post-mortem examination 72 h after surgery, both laparotomy and laparoscopy offered a definitive diagnosis with no missed injuries. Postoperative complications occurred in four cases (three following laparotomy and one following laparoscopy, P = 0.326). The average recovery period for bowel function, vital appearance, and food re-intake after laparoscopy was 10.36 ± 4.72 h, 14.91 ± 3.14 h, and 15.00 ± 7.11 h, respectively. All of these were significantly shorter than after laparotomy (21.27 ± 10.17 h, P = 0.004; 27.82 ± 9.61 h, P < 0.001; and 24.55 ± 9.72 h, respectively, P = 0.016). CONCLUSION: Compared with laparotomy, laparoscopy offers equivalent efficacy for diagnosing and treating SBIs, and reduces postoperative complications as well as recovery period.

Porcine model characterizing various parameters assessing the outcome after acetaminophen intoxication induced acute liver failure

To investigate the changes of hemodynamic and laboratory parameters during the course of acute liver failure following acetaminophen overdose.METHODSEight pigs underwent a midline laparotomy following jejunal catheter placement for further acetaminophen intoxication and positioning of a portal vein Doppler flow-probe. Acute liver failure was realized by intrajejunal acetaminophen administration in six animals, two animals were sham operated. All animals were invasively monitored and received standardized intensive care support throughout the study. Portal blood flow, hemodynamic and ventilation parameters were continuously recorded. Laboratory parameters were analysed every eight hours. Liver biopsies were sampled every 24 h following intoxication and upon autopsy.RESULTSAcute liver failure (ALF) occurred after 28 ± 5 h resulted in multiple organ failure and death despite maximal support after further 21 ± 1 h (study end). Portal blood flow (baseline 1100 ± 156 mL/min) increased to a maximum flow of 1873 ± 175 mL/min at manifestation of ALF, which was significantly elevated (P < 0.01). Immediately after peaking, portal flow declined rapidly to 283 ± 135 mL/min at study end. Thrombocyte values (baseline 307 × 103/µL ± 34 × 103/µL) of intoxicated animals declined slowly to values of 145 × 103/µL ± 46 × 103/µL when liver failure occurred. Subsequent appearance of severe thrombocytopenia in liver failure resulted in values of 11 × 103/µL ± 3 × 103/µL preceding fatality within few hours which was significant (P > 0.01).CONCLUSIONDeclining portal blood flow and subsequent severe thrombocytopenia after acetaminophen intoxication precede fatality in a porcine acute liver failure model.

Gastrotomy closure with a new tissue anchoring device:A porcine survival study

AIM: To evaluate the feasibility, reproducibility and efficacy of a new tissue anchoring device in a porcine survival model. METHODS: Gastrotomies were performed using a needle-knife and balloon dilator in 10 female Yorkshire pigs weighing 30-35 kg. Gastric closure was attempted using a new tissue anchoring device. The tightness of the closure was confirmed by means of air insufflation and the ability to maintain gastric distension with stability in peritoneal pressure measured with a Veress needle. All animals were monitored daily for signs of peritonitis and sepsis over 14 d. During necropsy, the peritoneal cavity and the gastric access site were examined.RESULTS: Transgastric access, closure and 14 d survival was achieved in all pigs. The mean closure time was 18.1 ± 19.2 min and a mean of 2.1 ± 1 devices were used. Supplementary clips were necessary in 2 cases. The closure time was progressively reduced (24.8 ± 13.9 min in the first 5 pigs vs 11.4 ± 5.9 min in the last 5, P = NS). At necropsy, the gastric access site was correctly closed in all cases with all brace-bars present. One device was misplaced in the mesocolon. Minimal adhesions were observed in 3 pigs and signs of mild peritonitis and adhesions in one. CONCLUSIONS: The use of this new tissue anchoring device in porcine stomachs is feasible, reproducible and effective and requires a short learning curve.

Double-row repair of rotator cuff tears: Comparing tendon contact area between techniques

BACKGROUND In rotator cuff repair surgery,the double-row technique is widely performed.Studies have shown that with increased contact area and pressure between tendon and bone interface,better healing is promoted.AIM To assess the different suture configurations with the double-row technique and how this influences the contact area of the rotator cuff tendon to bone.METHODS This was a controlled laboratory study where identical tears were created in 24 fresh porcine shoulders over a 1.5 cm×2.5 cm infraspinatus insertion footprint.Double-row repair techniques,with 3 to 4-suture anchors in different configurations(2 medial,2 lateral vs 2 medial,1 lateral vs 1 medial,2 lateral),were employed for three control groups.Each group consisted of eight shoulders with identical repair configurations.Footprint contact areas of the repaired tendon against the tuberosity were determined using pressure sensitive Fujifilm placed between the tendon and tuberosity.RESULTS The mean contact area between tendon and insertion footprint from the imprinted Fujifilm was obtained using computer software.The contact area measured from a standard 4-suture anchor double row repair was 75.1±9.3 mm2,whereas areas obtained for the 2 lateral-1 medial and 2 medial-1 lateral anchor configurations were 72.9±5.2 mm2 and 75.0±4.9 mm2 respectively.No statistical significance was noted between the three groups.CONCLUSION In the technique of double-row repair,using a 3-suture anchor configuration may offer a non-inferior alternative to the standard 4-anchor construct in terms of efficacy.This may also result in overall cost reduction and shorter surgical time.

Assistant skill in gastric endoscopic submucosal dissection using a clutch cutter

BACKGROUND A clutch cutter is a scissor-type knife used in endoscopic submucosal dissection(ESD)for gastrointestinal tract tumors.The assistant during the ESD using a clutch cutter(ESD-C)needs to rotate the device and grasp the target tissue appropriately;therefore,the assistant’s skill may affect the technical outcomes of ESD-C.AIM To determine how assistant skill level affected the technical outcomes of gastric ESD-C using an ex vivo porcine training model.METHODS In this pilot study,mock lesions of 15-30 mm in diameter were created in the middle or lower third of the porcine stomach.A total of 32 ESD-C procedures were performed by 16 trainees.Each trainee operator performed two ESD-C procedures;one ESD-C was assisted by an expert(ESD-C-E),and the other was assisted by a non-expert(ESD-C-NE).The total procedure time of the ESD was set as the primary outcome,and en bloc resection rate,complete procedure rate,perforation rate,and each procedure time/speed for mucosal incision or submucosal dissection were set as the secondary outcomes.In addition,we investigated factors associated with the difficulty of ESD including incompletion of ESD procedure,a long procedure time(≥20 min)or intraoperative perforation.RESULTS The median total procedure time of the ESD-C-E was significantly shorter than that of the ESD-C-NE(12.9 min vs 21.9 min,P=0.001).The en bloc resection rate was 100%in both groups.Complete resection rates of the ESD-C-E and ESD-C-NE groups were 100%and 93.8%,respectively.No intraoperative perforation was observed in both groups.In the multivariate analysis,assistant skill was significantly associated with the difficulty of ESD,with the highest odds ratio of 16.5.CONCLUSION Assistance by an expert is an important factor when trainees perform ESD-C procedures.

Investigation of long-term implantation of BuMA stent in a porcine coronary model

Background Stent-based delivery of sirolimus has been shown to reduce neointimal hyperplasia significantly. However, the long-term effect of the polymer is thought to initiate and sustain an inflammatory response and contribute to the occurrence of late complications. Our study aimed to evaluate the efficacy and safety of the BuMA biodegradable drug-coated sirolimus-eluting stent （BSES） for inhibiting neointimal hyperplasia in a porcine coronary model. Methods Four types of stents were implanted at random in different coronary arteries of the same pig： BSES （n=24）, bare metal stent （BMS） （n=24）, biodegradable polymer coated stent without drug （PCS） （n=24） and only poly （n-butyl methacrylate） base layer coated stent （EGS） （n=23）. In total, 26 animals underwent successful random placement of 95 oversized stents in the coronary arteries. Coronary angiography was performed after 28 days, 90 days and 240 days of stent implantation. After 14 days, 28 days, 90 days and 240 days, 6 animals at each timepoint were sacrificed for histomorphologic analysis. Results The 28-day, 90-day and 240-day results of quantitative coronary angiography （QCA） showed reduction in luminal loss （LL） in the BSES group when compared with the BMS group; （0.20±0.35） mm vs. （0.82±0.51） mm （P=-0.035）, （0.20±0.30） mm vs. （0.93±0.51） mm （P=-0.013）, and （0.18±0.16） mm vs. （0.19±0.24） mm （P=0.889）, respectively. By 28-day, 90-day and 240-day histomorphomeric analysis results, there was also a corresponding significant reduction in neointimal tissue proliferation with similar injury scores of BSES compared with the BMS control; average neointimal area （0.90±0.49） mm2 vs. （2.16±1.29） mm2 （P=0.049）, （1.53±0.84） mm2 vs. （3.41±1.55） mm2 （P=-0.026）, and （2.43±0.95） mm2 vs. （3.12±1.16） mm2 （P=0.228）, respectively. High magnification histomorphologic examination revealed similar inflammation scores and endothelialization scores in both the BSES and BMS groups. Conclusions The BuMA biodegradable drug-coated sirolimus-eluting stents can significantly reduce neointimal hyperplasia and in-stent restenosis. Re-endothelialization of the BuMA stent is as good as that of the BMS in the porcine coronary model due to the reduced inflammation response to the BuMA stent.

Therapeutic silencing miR-146b-5p improves cardiac remodeling in a porcine model of myocardial infarction by modulating the wound reparative phenotype

Fibrotic remodeling is an adverse consequence of immune response-driven phenotypic modulation of cardiac cells following myocardial infarction(Ml).MicroRNA-146b(miR-146b)is an active regulator of immunomodulation,but its function in the cardiac inflammatory cascade and its clinical implication in fibrotic remodeling following Ml remain largely unknown.Herein,miR-146b-5p was found to be upregulated in the infarcted myocardium of mice and the serum of myocardial ischemia patients.Gain-and loss-of-function experiments demonstrated that miR-146b-5p was a hypoxia-induced regulator that governed the pro-fibrotic phenotype transition of cardiac cells.Overexpression of miR-146b-5p activated fibroblast proliferation,migration,and fibroblast-to-myofibroblast transition,impaired endothelial cell function and stress survival,and disturbed macrophage paracrine signaling.Interestingly,the opposite effects were observed when miR-146b-5p expression was inhibited.Luciferase assays and rescue studies demonstrated that the miR-146b-5p target genes mediating the above phenotypic modulations included interleukin 1 receptor associated kinase 1(IRAKI)and carcinoembryonic antigen related cell adhesion molecule 1(CEACAM1).Local delivery of a miR-146b-5p antagomir significantly reduced fibrosis and cell death,and upregulated capillary and reparative macrophages in the infarcted myocardium to restore cardiac remodeling and function in both mouse and porcine Ml models.Local inhibition of miR-146b-5p may represent a novel therapeutic approach to treat cardiac fibrotic remodeling and dysfunction following Ml.