Objective To investigate the changes of cerebral blood flow and the level of brain injury in a rat model of deep hypothermia low flow(DHLF).Methods Twelve SD rats aged 3 weeks were randomly divided into sham group and model group.Regional cerebral blood flow(rCBF)of all rats was measured continuously during the operation by laser Doppler flowmetry,and the changes of rCBF were measured before temperature decreased,when the temperature decreased to(21.0±0.5)℃,0-5 minutes,25-30 minutes,55-60 minutes,115-120 minutes during DHLF and 0-5 minutes after DHLF operation.Another 60 SD rats aged 3 weeks were randomly divided into sham group and model group.Six rats of each group were sacrificed at 1,6,24,72 hours and 7 days after DHLF operation to detect the pathological changes of the brain and the neuronal apoptosis by HE staining and TUNEL assay.The neurological deficit score(NDS)was recorded at 24,72 hours and 7 days after operation for evaluating the neurologic functional outcome.ResultsWhen the temperature was decreased to(21.0±0.5)℃,the levels of rCBF of sham group and model group were significantly decreased to(41.1±4.2)% and(40.7±3.4)% of the baseline value,and the rCBF level of model group was further decreased to(15.7±3.5)% of the baseline value 0-15 minutes during DHLF(P ＜ 0.01),with no obvious changes in all the time intervals during DHLF.Compared with the sham group,the scores of NDS of model group were significant lower at 24 and 72 hours after operation(P ＜ 0.05 or 0.01).Besides,a significant pathological change of the brain tissue and a increased percentage of TUNEL-positive staining cells were observed in model group at 6,24,72 hours and 7 days after operation(P ＜ 0.01).Conclusions Rat model of DHLF is an ideal and reliable model of brain injury,for it is similar to DHLF procedure of clinical cardiac operation.

Objective To study the surgical techniques and the clinical curative ettect of the reconstruction of adjacent large finger pulps with the modified sensate free proximal ulnar artery perforator flap.Methods From February,2013 to May,2016,20 fingers in 10 patients with adjacent large finger pulp defects crossing the DIP joint were reconstructed by the modified senate free proximal ulnar artery perforator flap.All the pulps of every patient were recovered by 1 flap in the first stage and the artificial syndactyly of two digits was divided in 7 weeks after the flap transfer in the second stage.In order to reconstruct the sensation of two pulps in each patient,firstly both of the proximal and distal ends of the cutaneous nerve in flaps were dissected and anastomosed with the most lateral and medial palmar digital nerves of two adjacent fingers respectively,which were divided into 2 groups.Secondly the cutaneous nerve in the middle part of flap was cut and the two ends were anastomosed with the other two palmar digital nerves in the second surgery.There were 8 fingers in 4 patients with the index and middle finger pulp defects,12 fingers in 6 patients with the middle and ring finger defects.The flap size was from 5.0 cm×3.5 cm to 5.5 cm×4.0 cm,and the perforator artery was anastomosed with the palmar digital artery in 6 cases and with the joint branch of digital artery in 4 cases.Results Nine flaps survived uneventfully except the venous congestion was found in 1 flap which was salvaged successfully by acupuncture bleeding.Also,no congestion or ischemia of all the 20 pulp flaps occurred right after releasing the artificial syndactyly.The time of followed-up was from 11 months to 32 months with the average of 17 months after the second surgery.The static two point discrimination of the 2 groups of the sensate pulp flap was (7.3 ± 1.2) mm and (8.6 ±2.4) mm respectively.There was no significant difference between groups (P ＞ 0.05).These 20 pulp flaps were also assessed by the Semmes-Weinstein monofilament test with the result of diminished light touch in 14 pulps and diminished protective touch in 6 pulps.The total active motion in all 20 fingers was (248.0±4.5) °.No patients suffered cold intolerance and local pain but 1 had hypersensitiveness in the pulp flap.Conclusion The modified sensate free proximal ulnar arte~ perforator flap is a practical alternative for the reconstruction of two large adjacent pulps with satisfactory functional and aesthetic outcomes.

Objective:To compare the clinical effecacy of artificial dermal regeneration matrix (as "artificial dermis" hereafter) and flap transfer in the treatment of soft tissue defects around interphalangeal joint.Methods:Through postoperative follow-up at outpatient clinic, a retrospective study was conducted on the clinical data of 60 patients who had soft tissue defects around the interphalangeal joints and received treatment in the Department of Hand Surgery, the Sixth Hospital of Ningbo from January 2018 to January 2022. According to applied surgical procedures, patients were divided into a flap transfer group (group A, n=30) and an artificial dermis group (group B, n=30). Group A included 19 males and 11 females aged 44.83 years ± 11.56 years including 5 patients with simple soft tissue defects, and 6 with soft tissue defects and fractures, 10 with soft tissue defects with tendon and (or) ligament injuries, 3 with soft tissue defects and vessel and (or) nerve injuries, and 6 with soft tissue defects and over 2 other types of compound injuries. The defect areas ranged from 2.5 cm×1.2 cm to 5.0 cm×1.6 cm. After emergency debridement and treatment for bone and tendon injuries, the patients in group A received transfers of free flap or transfers with adjacent digit flaps or island flaps. Postoperative functional exercise started from 1-6 weeks after surgery. Patients in group B included 17 males and 13 females, aged 44.70 years ± 11.20 years and there were 6 patients with simple soft tissue defects, 6 with soft tissue defects and fractures, 9 with soft tissue defects and tendon and (or) ligament injuries, 5 with soft tissue defects and vessel and (or) nerve injuries, and 4 with soft tissue defects and over 2 other types of compound injuries. The defect area ranged from 3.1 cm ×1.3 cm to 4.5 cm × 1.8 cm. Debridement and treatment of the bone and tendon injury in group B were the same as what in group A, but the patients in group B received artificial dermis coverage other than transfer of flap. After an artificial dermis had completely vascularised, a split-thickness skin graft was performed over the neo-dermis in the second phase surgery. Postoperative functional exercise started from 1-2 weeks after artificial dermis grafting surgery. The interval time of flap transfer or split-thickness skin grafting, survival rate of flap transfer or split-thickness skin grafting, Vancouver Scar Scale(VSS), TPD and total active movement(TAM) were compared between the 2 groups. The count data were analysed by Chi-square test. All measured data were analysed by independent sample t test or Mann-Whitney U test. P<0.05 indicates a statistically significant difference. Results:The interval time of flap transfer in group A and artificial dermis grafting in group B were 2.93 days ± 2.48 days and 19.87 days ± 3.35 days, respectively. There was a statistically significant difference between the 2 groups( P<0.05). All patients were entered in postoperative outpatient follow-up for 11-14 months(12.00 months ± 0.93 months). The appearance of flaps of some patients in group A was bloated with slightly limited digit movement. In group B, the digit movement was normal, without obvious scar hyperplasia in both of the recipient and donor sites. The survival rate of flap transfer or artificial dermis graft, TPD, VSS score and TAM score for group A and group B were 96.00% ± 9.32% and 98.17% ± 3.07%, respectively, 8.67 mm ± 2.01 mm and 9.50 mm ± 1.81 mm, 3.40 ± 1.07 and 3.17 ± 0.91 and 18.30 ± 1.97 and 18.93 ± 1.64, respectively. There were no significant differences between the 2 groups( P>0.05). Conclusion:In comparison with the transfer of flap, an artificial dermis is also effective and satisfactory in the treatment of soft tissue defects around the interphalangeal joint. Further large scale and multi-centre investigations are required.

Objective:To investigate the feasibility of reducing the radiation dose on coronary artery calcium score (CS) of virtual non-contrast (VNC) scanning in dual-layer spectral coronary CT angiography(CCTA).Methods:One hundred and twenty-two patients were examined on a dual-layer spectral detector CT scanner from March 2019 to August 2020. Volume CT dose index (CTDI vol), dose length product (DLP), effective dose ( E) were all evaluated for each patient. CS was calculated from both true non-contrast (TNC) and VNC images for left anterior descending (LAD), left circumflex (LCx), right coronary artery (RCA), and the total coronary artery (Total) by two radiologists independently. Pearson′s correlation coefficient was calculated for measuring the association between variables. The correction coefficients of each branch (λ LAD, λ LCx, and λ RCA) and the average correction coefficient (λ AVG) of the total coronary artery were obtained. The calibrated calcium score (CCS_VNC) was equal to λ multiplied by CS_VNC. The CS_TNC and CCS_VNC were compared using repeated oneway analysis of variance test. Correlation analyses for CS_TNC and CCS_VNC and agreement evaluation with Bland-Altman-Plots were performed. Results:The average effective doses in TNC, CCTA and total group were 0.69, 6.47 and 7.16 mSv, respectively. The effective dose was reduced by 10.6% and the scan time was reduced by 39% while using VNC images. There were significant differences among the CS_TNC and CS_VNC of LAD, LCx, RCA and Total ( t=6.75, 5.33, 4.99, 6.60, P< 0.05). Excellent correlations were observed between CS_VNC and CS_TNC ( R2 values were 0.929, 0.896, 0.958, and 0.918; λ values were 2.18, 1.18, 2.15, and 2.07, respectively). There were no significant statistically difference among the CS_TNC, CCS_VNC AVG, and CCS_VNC LAD/RCA of the LAD and RCA (all P> 0.05). The difference was statistically significant among the CS_TNC, CCS_VNC AVG, and CCS_VNC LCx of the LCx ( F=10.94, P<0.05). The paired comparison were performed in groups and the differences were statistically significant between the CS_TNC versus CCS_VNC AVGand CCS_VNC AVG versus CCS_VNC LCx ( t=3.31, 3.43, all P<0.05). There was no significant statistically difference between the CCS_VNC LCx and CCS_VNC AVG( P>0.05). Conclusions:It was feasible to accurately evaluate the CS_VNC from spectral data in comparison to TNC imaging, and to reduce the patient radiation dose and acquisition time.