Objective:To explore the value of using bipolar electrogram to guide target selection in patients with frequent premature ventricular contractions in the right ventricular outflow tract (RVOT-PVC).Methods:The clinical data of 115 patients with idiopathic and frequent RVOT-PVC from October 2018 to January June 2020 in Guangzhou First People′s Hospital were retrospectively analyzed. The number of PVCs in Holter 24 h before ablation was 19 802.6±4916.7, and the load was (20.3±5.0)%. The Johnson & Johnson Carto 3.0 system was used to guide RVOT-PVC radiofrequency ablation, and the morphological characteristics of the bipolar electrogram in the cavity of the successful ablation target were observed. According to whether the starting part of the bipolar electrogram of the distal ablation catheter showed a steep negative shape recorded by the Carto 3.0 system, the patients were divided into positive group and negative group. The differences in ablation success rate, effective discharge time, total ablation time and other indicators of the two groups were compared.Results:Steep negative wave was recorded in the initial part of the effective target site of 87 patients (75.7%). The ablation success rate of the patients was 95.4%(83/87) based on the excitation mapping and unipolar morphology combined with the above initial part of the bipolar electrogram. Compared with the negative group, the PVC disappeared faster in patients of positive group [(6.9±2.3)s vs (10.2±2.9)s, P<0.05] and the total ablation time was shorter [(187.5±35.7)s vs (267.3±54.1)s, P<0.05]. Ambulatory electrocardiogram (ECG) was rechecked at 3 months. At 3 months, there was 1 case recurrence in the positive group and 1 case recurrence in the negative group, and there was no significant difference in the long-term recurrence rate between the two groups ( P=0.422). Conclusions:On the basis of traditional mapping, the bipolar electrogram combined with the steep negative shape of the initial part can be used as an alternative RVOT-PVC ablation strategy.

Objective:To explore the effect of neurolysis and tendon transplantation in functional reconstruction of the upper limb with severe thermal crush injury.Methods:A retrospective case series study was conducted to analyze the clinical data of 12 patients with thermal crush injuries of the upper limb admitted to Changhai Hospital of Naval Medical University from January 2014 to December 2018. There were 9 males and 3 females, aged 22-54 years (mean, 38 years). The percentage of total body surface area (TBSA) burn ranged from 3% to 8% [(4.9±1.4)%], and wound depth was III degree. According to the damage condition of nerve/tendon and whether there was any dysfunction of the affected limb after wound healing, 12 patients received 2 to 4 times of neurolysis and tendon transplant-related surgeries, with an average surgery of 2.7 times. Among them, a total of 18 times of neurolysis were performed, including 7 times of radial neurolysis, 6 times of median nerve neurolysis and 5 times of ulnar neurolysis, and 14 times of tendon transplantation were done, including 6 times of anastomosis of superficial flexor tendon and long thumb extensor tendon, 5 times of tendon repair transplantation and 3 times of anastomosis of lateral wrist extensor tendon and long thumb extensor tendon. The time interval of each operation was 3-6 months [(4.5±1.0) months]. The Changhai pain ruler, disability of arm-shoulder-hand table (DASH) and joint activity assessment table were assessed before the first operation, 3 months and 6 months after the last operation.Results:All the patients were followed up for 6-12 months (mean, 9.2 months). The score of Changhai pain ruler in the affected limb improved from 3 (2, 3)points before surgery to 1 (0.5, 1)points 3 months after surgery and 1 (0, 1)points 6 months after surgery ( P<0.01). The score of DASH improved from (69.9±2.7) points before surgery to (35.1±1.7) points 3 months after surgery and (33.8±2.0) points 6 months after surgery ( P<0.01). The range of motion score was improved from (1.3±0.5) points before surgery to (2.4±0.5) points 3 months after surgery and (2.8±0.4) points 6 months after surgery ( P<0.01). Conclusion:Neurolysis and tendon transplantation in the treatment of severe thermal crush injuries of the upper limb can alleviate pain in the affected limbs, improve upper limb dysfunction, increase mobility of the palm and upper limb joints, and enhance the quality of life of the patients.

Objective: To study the antiseptic effect of compound lysostaphin disinfectant and its preventive effect on infection of artificial dermis after graft on full-thickness skin defect wound in rats. Methods: (1) Each one standard strain of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were selected. Each 20 clinical strains of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were collected from those isolated from wound exudates of burn patients hospitalized in our wards from January 2014 to December 2016 according to the random number table. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of compound lysostaphin disinfectant to above-mentioned strains were detected. The experiment was repeated 3 times. Compared with the corresponding standard strain, the clinical strain with higher MIC and/or MBC was considered as having decreased sensitivity to the disinfectant. The percentage of strains of each of the three kinds of bacteria with decreased sensitivity was calculated. (2) Artificial dermis pieces were soaked in compound lysostaphin disinfectant for 5 min, 1 h, 2 h, and 4 h, respectively, with 21 pieces at each time point. After standing for 0 (immediately), 12, 24, 36, 48, 60, 72 h (with 3 pieces at each time point), respectively, the diameters of their inhibition zones to standard strains of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were measured. The experiment was repeated 3 times. The shortest soaking time corresponding to the longest standing time, after which the disinfectant-soaked artificial dermis could form an effective inhibition zone (with diameter more than 7 mm), was the sufficient soaking time of the disinfectant to the artificial dermis. (3) Forty Sprague-Dawley rats were divided into post injury day (PID) 3, 7, 14, and 21 sampling groups according to the random number table, with 10 rats in each group. A full-thickness skin defect wound with a diameter of 20 mm was made on both sides of the spine on the back of each rat. Immediately after injury, the artificial dermis without any treatment was grafted on the wound on left side of the spine (hereinafter referred to as control wound), while the sufficiently soaked artificial dermis with compound lysostaphin disinfectant was grafted on the wound on right side of the spine (hereinafter referred to as disinfectant wound). On PID 3, 7, 14, and 21, the gross condition of wounds of all the surviving rats was observed, and the new infection rates of control wounds and disinfectant wounds were calculated. Then, the rats in the sampling group with corresponding time were killed, and the full-thickness wound tissue containing artificial dermis was collected for quantitative analysis of bacteria. Bacteria content of the uninfected control wounds and that of the uninfected disinfectant wounds were compared. Data were processed with chi-square test and Wilcoxon rank sum test. Results: (1) The MIC of compound lysostaphin disinfectant to standard strains of Staphylococcus aureus, Klebsiella pneumoniae, and Acinetobacter baumannii were 1/32, 1/32, and 1/512 of the original concentration of the disinfectant, respectively, and the MBC were 1/32, 1/16, and 1/512 of the original concentration of the disinfectant, respectively. The percentages of clinical strains of Klebsiella pneumoniae, Acinetobacter baumannii and Staphylococcus aureus with decreased sensitivity to compound lysostaphin disinfectant were 15% (3/20), 20% (4/20), and 10% (2/20), respectively. (2) After being soaked in compound lysostaphin disinfectant for 2 and 4 h, the longest standing time, after which the artificial dermis could form an effective inhibition zone against Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus, were 24, 36, and 48 h respectively, longer than 12, 24, and 24 h of soaking for 5 min and 24, 24, and 36 h of soaking for 1 h. The sufficient soaking time of compound lysostaphin disinfectant to artificial dermis was 2 h. (3) On PID 3, no infection symptom was observed in all the wounds, and so both the new infection rate of control wounds and that of disinfectant wounds were 0. The artificial dermis was transparent but not well connected with the wound. On PID 7, the new infection rate of control wounds was 20.00% (6/30), which was obviously higher than 3.33% (1/30) of disinfectant wounds, χ²=4.043, P<0.05. On the infected wound, a large amount of purulent exudates were observed, and the artificial dermis was not connected with the wound and degraded partially. On the uninfected wound, artificial dermis was transparent and had a partial connection with the wound. On PID 14 and 21, no new infected wound was observed, and so both the new infection rate of control wounds and that of disinfectant wounds were 0. There was no obvious improvement on the infected wounds. The collagen layers of artificial dermis in the uninfected wound established a good connection with the wound and were separating from the silica gel layer gradually. Infection occurred in 2, 3, 1 control wound (s) in PID 7, 14, and 21 sampling groups, respectively, and in 1 disinfectant wound in PID 14 sampling group. The bacteria content of the infected wounds tissue was 0.79×10⁶ to 7.22×10⁹ colony-forming unit (CFU)/g. The bacteria content of uninfected control wounds tissue in PID 3, 7, and 14 sampling groups were (3.43±1.88)×10^2, (2.37±0.43)×10^3, and (8.40±1.03)×10³ CFU/g, respectively, which were significantly higher than (0.33±0.12)×10^2, (0.43±0.17)×10^3, (2.16±0.52)×10³ CFU/g of uninfected disinfectant wounds tissue (Z=-3.780, -3.554, -3.334, P<0.05). The bacteria content of uninfected control wounds tissue and that of uninfected disinfectant wounds tissue in PID 21 sampling group were similar (Z=-0.490, P>0.05). Conclusions Compound lysostaphin disinfectant has quite strong antibacterial ability against Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus. Clinical strains of the three kinds of bacteria were highly sensitive to compound lysostaphin disinfectant. Saturation of absorption of compound lysostaphin disinfectant achieves in artificial dermis after 2 hours′ soaking. After 24, 36, and 48 hours′ standing, the soaked artificial dermis still has the antibacterial effect on Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus, respectively. The infection rate and the bacteria content of full-thickness skin defect wound in rats are all decreased when grafted with soaked artificial dermis.