Tracheostomy is to establish an artificial airway by making an opening at anterior tracheal wall. Due to the blossom of mechanical ventilation and intensive care unit after 1950s, tracheostomy is the most favorable surgical method to access airway at present. In addition to traditional surgical tracheostomy, percutaneous dilational tracheostomy have gained increasing popularity and become an alternative procedure because of its merits such as easier manipulation, shorter operative duration and less complications. This review summarized tracheostomy from definition, history and current status, anatomy and physiology, indications, contraindications, timing, complications and management. We also elaborate our understanding of current contraercy and give some suggestions based on our clinical experience.
Humans ; Intensive Care Units ; Respiration, Artificial ; Trachea ; surgery ; Tracheostomy ; methods

Objective To compare efficacy, time consumed and complications among cricothyroid membrane puncture guided tracheostomy ( CMPGT ) , surgical tracheostomy ( ST ) , surgical cricothyroidotomy ( SC) , and percutaneous tracheostomy using Griggs'guide wire dilating forceps ( GWDF) for the establishment of airway in urgent need of medical attention.Methods Twenty miniature swine were randomly ( random number) divided into four groups.The procedures of CMPGT, ST, SC and GWDF were carried out when patients'SpO2 ( oxygen saturation of blood ) declined to 80% by suspension of oxygen supply after general anesthesia. Procedure performed time, ventilation resumed time, SpO2 and electrocardiograph ( ECG) and arterial blood gases ( ABG) analysis including SaO2 , PaO2 , PaCO2 , blood pH, and heart rate, blood pressure were recorded.Fiberoptic bronchoscope was used to assess any damage to the tracheal wall.Complications were noted and scored in a two-month follow-up period.Results Airways were successfully established in all swine.The times consumed for SC, GWDF, CMPGT, and ST were (86 ±12) s, (165 ±63) s, (174 ±34) s, and (519 ±128) s, respectively, however a shorter time for ventilation resumed was found in CMPGT procedure (23 ±4) s, P<0.01.ECG showed that SpO2 and T-wave decreased and Q-T shortened after oxygen suspension and recovered to normal level rapidly after ventilation.There were significant differences in ECG and ABG between pre-and post-operative periods ( P<0.05) in all groups.Minimal intra-operative bleeding was found in two swine of each group.In ST group, moderate intra-operative bleeding was encountered in three swine.Three pigs were suffered from hypotension owing to prolonged hypoxemia.There was minimal postoperative bleeding occurred in one swine, thus leading to stoma infection.In SC group, moderate intra-operative bleeding was noticed in one swine. One miniature swine had slight injury at laryngeal cartilage resulting in difficult decannulation happened in one swine.and moderate tracheal wall injury occurred in one swine of GWDF group.The complication scores of CMPGT, GWDF, SC and ST were 3, 5, 9, and 19, respectively.Conclusions A shorter time for ventilation resumed with fewer complications was found in the procedure of CMPGT than that in the other methods.This animal study suggested that CMPGT was a time-saving and secure technique for emergency surgical airway establishment which has been practiced in human being as well.Key words:Surgical airway establishment, Cricothyroidotomy, Tracheostomy, Percutaneous dilational tracheostomy.

BACKGROUND:In 2001, Zuk et al found adipose-derived stem cels (ASCs) from the aspirate of liposuction for the first time, which launched a new era of stem cel research. In recent years, stem cels have been proved to widely exist in many tissues and organs. ASCs are always in the spotlight of plastic and reconstructive surgery, tissue engineering and regenerative medicine because of extensive sources and simple isolation.
OBJECTIVE: To review the fat tissue harvesting and ASCs isolation, purification, expansion, and cryopreservation, to discuss the main factors which influence the yield, proliferation capacity and differentiation potential of ASCs, and to predict the future research interests based on current issues.
METHODS:On September 10th, 2015, relevant articles were searched in PubMed using the folowing format: (adipose stem cels[Title]) OR (adipose-derived stem cels[Title]) OR (adipose-derived mesenchymal stem cels[Title]) and in SinoMed using the folowing format in Chinese: (“adipose-derived stem cels” [Title])or(“adipose-derived mesenchymal stem cels”[Title]). Finaly, 81 representative articles were included according to their titles and abstracts. In this review, we also introduced relevant experience about the aforementioned procedures from the Department of Plastic Surgery and Tissue Regeneration and Molecular Cel Engineering Lab of University of Texas, MD Anderson Cancer Center, USA.
RESULTS AND CONCLUSION:The widely dispersed fat tissues potentialy provide abundant stem cels for tissue engineering and regenerative medicine. Liposuction is a mini-invasive approach for harvesting fat tissues. Colagenase digestion is the major method for ASCs isolation due to its simplicity and high yield in basic research. However, clinical fat transplantation without ASCs isolation or non-colagenase isolation of stromal vascular fraction or ASCs is preferred. The phenotype, proliferation and differentiation capacity of ASCs may be affected by several factors during the fat tissue harvesting and ASCs isolation. Therefore, a standard protocol for ASCs isolation is needed.

Objective To compare cricothyroid membrane puncture directed tracheostomy (CMPDT) with conventional surgical tracheostomy (ST) and cricothyroidotomy (CT) and to evaluate the feasibility, efficacy and safety of this novel technique.Methods 15 minipigs were divided randomly into 3 groups, 5 in each.After general anesthesia, CMPDT, ST and CT were performed respectively according to the established techniques when SPO2 reached 80％ (T0).Procedure duration, ECG and arterial blood gas results were recorded.Complications were recorded and scored according to an established score scale by an observer blinded to the grouping.Results Airway was successfully established in all animals (15/15).ECG monitor showed T-wave decreased and Q-T shortened after seasing of oxygen supply and both recovered rapidly to normal levels after reoxygenation.There were no significant differences between 3 groups in HR,BP, SPO2, SaO2, PaO2, PaCO2 and pH at pre-apnea, TO or post-operation, but with significant intragroup variation in the parameters before and after operation.The time for CMPDT, ST and CT was (174 ±34) s,(619 ± 128) s and (86 ± 12) s respectively.Three of 5 minipigs in ST group experienced hypotension due to longer time of hypoxia.1 and one had minor bleeding and stoma infection after surgery.One of 5 animals in CT group had minor laryngeal cartilage injury leading to difficult decannulation, postoperative fiber bronchoscopy showed no subglottic stenosis.The complication scores were 13, 9, and 3 for ST, CT and CMPDT, respectively.Conclusions All 3 methods can provide with effective airway access with no significant differences in ventilation effect, however CMPDT has short recovery time for SpO2 and other vital signs with the lowest complication score.The animal experiment suggests that CMPDT is a fast, safe and effective surgical technique for emergency airway.

Objective:To investigate the effects of temperature-sensitive hydroxybutyl chitosan hydrogel on wound healing of full-thickness skin defect in rats.Methods:The experimental research method was used. Fifty-one no matter male or female Sprague-Dawley rats aged 7-10 weeks were selected, and two round full-thickness skin defect wounds with a diameter of 2 cm were created on the back of each rat at a distance about 1.0 cm to the spine. The rats were divided into temperature-sensitive hydrogel group, gel group, and blank control group according to the random number table, with 17 rats and 34 wounds in each group. Wounds of rats in the first two groups were applied respectively with 0.3 mL temperature-sensitive hydroxybutyl chitosan hydrogel and carboxymethyl chitosan hydrogel immediately after injury, and the wounds of rats in blank control group received no treatment. The wounds of rats in the three groups were all covered with vaseline oil gauze. The states of temperature-sensitive hydroxybutyl chitosan hydrogel in wounds of rats in temperature-sensitive hydrogel group and carboxymethyl chitosan hydrogel in wounds of rats in gel group were observed every day when the dressings were changed, and the difficulty of vaseline oil gauze removal was recorded. On the 3rd, 7th, 10th, 14th, and 21st day after injury, the wound healing of rats in the three groups was observed and the wound healing rates were calculated. On the 3rd, 7th, 10th, 14th, and 21st day after injury, tissue from 4 wounds of 2 rats in each group was collected for the following observation and detection. The infiltration of inflammatory cells, angiogenesis, and re-epithelialization were observed by hematoxylin eosin staining. The regeneration and remodeling of collagen fibers were observed by Masson staining, and the collagen volume fraction was calculated. The expressions of interleukin-6 (IL-6), transforming growth factor β 1 (TGF-β 1), and matrix metalloproteinase-1 (MMP-1) were detected by enzyme-linked immunosorbent assay method. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, and Bonferroni test. Results:The carboxymethyl chitosan gel in wounds of rats in gel group was liquid gel and could flow with the body position, while the temperature-sensitive hydroxybutyl chitosan hydrogel in wounds of rats in temperature-sensitive hydrogel group was solid gel and could not flow with the body position, and the distribution of the latter was more uniform. The vaseline oil gauzes were easily removed in wounds of rats in temperature-sensitive hydrogel group, while the vaseline oil gauzes were difficult to remove in the other two groups. On the 3rd, 7th, 10th, 14th, and 21st day after injury, the wound granulation tissue of rats grew well in temperature-sensitive hydrogel group and gel group, with no obvious infection, and two rats in blank control group died of wound infection on the 3rd and 5th day after injury. On the 7th, 10th, 14th, and 21st day after injury, the wound healing rates of rats in temperature-sensitive hydrogel group and gel group were significantly higher than that in blank control group ( P<0.01). On the 10th day after injury, the wound healing rate of rats in temperature-sensitive hydrogel group was significantly higher than that in gel group ( P<0.05). A large number of neutrophils and lymphocytes infiltrated into the wounds of rats in the three groups on the 3rd day after injury. The infiltration of inflammatory cells was gradually reduced and the wound healed gradually in rats of temperature-sensitive hydrogel group and gel group from the 7th to 21st day after injury, and the epidermis and dermis could be seen, without hair follicles and other skin appendages. The wounds of rats in blank control group did not heal completely on 21st day after injury. From the 3rd to 10th day after injury, the newly formed collagen fibers increased gradually in the wounds of rats in the three groups. On the 14th and 21st day after injury, the collagen fibers in the wounds of rats in temperature-sensitive hydrogel group and gel group were denser and more orderly than those in blank control group. On the 10th, 14th, and 21st day after injury, the collagen volume fraction of wounds of rats in temperature-sensitive hydrogel group and gel group was significantly higher than that in blank control group ( P<0.01). On the 14th day after injury, the collagen volume fraction of wounds of rats in temperature-sensitive hydrogel group was significantly higher than that in gel group ( P<0.01). On the 3rd, 7th, and 10th day after injury, the expressions of IL-6 in wounds of rats in temperature-sensitive hydrogel group were significantly higher than those in gel group and blank control group ( P<0.01), and the expressions of IL-6 in wounds of rats in gel group were significantly lower than those in blank control group ( P<0.01). On the 3rd, 7th, and 10th day after injury, the expressions of TGF-β 1 in wounds of rats in temperature-sensitive hydrogel group were significantly higher than those in gel group and blank control group ( P<0.01). The expressions of TGF-β 1 in wounds of rats in gel group were significantly lower than those in blank control group on the 3rd and 7th day after injury ( P<0.01), and the expression of TGF-β 1 in wounds of rats in gel group was significantly higher than that in blank control group on the 10th day after injury ( P<0.01). On the 14th day after injury, the expression of TGF-β 1 in wounds of rats in gel group was significantly higher than that in temperature-sensitive hydrogel group and blank control group ( P<0.01). On the 21st day after injury, the expression of TGF-β 1 in wounds of rats in temperature-sensitive hydrogel group was significantly lower than that in gel group and blank control group ( P<0.01), and the expression of TGF-β 1 in wounds of rats in gel group was significantly lower than that in blank control group ( P<0.01). On the 7th day after injury, the expression of MMP-1 in wounds of rats in gel group was significantly higher than that in temperature-sensitive hydrogel group and blank control group ( P<0.01). On the 10th, 14th, and 21st day after injury, the expressions of MMP-1 in wounds of rats in temperature-sensitive hydrogel group were significantly higher than those in gel group and blank control group ( P<0.01). On the 10th day after injury, the expression of MMP-1 in wounds of rats in gel group was significantly lower than that in blank control group ( P<0.01). On the 14th and 21st day after injury, the expressions of MMP-1 in wounds of rats in gel group were significantly higher than those in blank control group ( P<0.01). Conclusions:Temperature-sensitive hydroxybutyl chitosan hydrogel can promote the healing of full-thickness skin defect wounds in rats by increasing the expressions of IL-6, TGF-β 1, and MMP-1, regulating the wound healing environment, inhibiting inflammatory reaction, improving the strength of tissue repair, and promoting collagen synthesis or decomposition

Objective:To observe the effect of adipose tissue decellularized matrix hydrogel (DAT-gel) on the repair of sciatic nerve defect in rats.Methods:From April, 2019 to April, 2020, aseptic granular adipose tissue was collected from healthy adult women who underwent thigh or abdominal liposuction in the Department of Plastic Surgery, the First Medical Centre of the PLA General Hospital. Decellularisation and enzymatic digestion of adipose tissue were performed to prepare DAT-gel. Scanning electron microscope (SEM) was used to observe the ultrastructure of the hydrogel, and rheology was employed to test the gel dynamics and viscoelasticity of the hydrogel. A rat model of sciatic nerve defect was established and randomly divided into 3 groups: simple chitin catheter group (Chitin group), DAT-gel plus chitin catheter group (DAT-gel group) and autologous nerve reverse connection group (Autograft group) with 10 rats in each group. At the 12th week after surgery, the general view, function and morphology of the regenerated nerve were observed to evaluate the repairing status of the injured nerve. One-way analysis of variance (one-way ANOVA) was used for data analysis. If the difference between the groups was statistically significant, the Turkey method was further used for pairwise comparison. P<0.05 was considered as statistically significant. Results:The results of SEM showed that the DAT-gel had a three-dimensional structure in porous fibre network. The results of rheological test results showed that the complex viscosity of the hydrogel at 4 ℃ and 37 ℃ were 148.91 mPa·s and 801.29 mPa·s, respectively. DAT-gel underwent a sol-gel phase transition when the temperature had been increased. The results showed that DAT-gel had a good temperature-sensitive effect, and its critical point of sol-gel phase transition was similar to the internal temperature of rat. The results of animal experiments showed that the morphology and function of the regenerated nerve in the DAT-gel group were superior to Chitin group at 12 weeks after surgery, according to macroscopic view of the regenerated nerve, electrophysiology of the nerve, the morphology of the new axon and the target muscle, etc.. There was statistically significant between groups ( P<0.05). Conclusion:DAT-gel can significantly promote a repair of sciatic nerve defects in rats.

Objective:This study is to investigate the parameter settings and imaging effects of Micro-CT scanning externalmalignancies during operation and summarize the characteristics of Micro-CT images regarding external soft tissue and tumors.Methods:According to the inclusion criteria, patients with externalmalignancies admitted to the Department of Plastic and Reconstructive Surgery of the First Medical Center of the PLA General Hospital from October 2018 to January 2020 were collected. Through the surgical resection of tumors, the isolated tumor specimens were divided into appropriate sizes (length × width × thickness not exceeding 5 cm×3 cm×3 cm), placed on the Micro-CT scanning bed, and scanned with different parameters. (1) Scanning with different times: with the fixedscanning voltage (50 kV for sarcoma, 70 kV for other tumors), the same specimen was scanned with 4min and 14min protocols respectively. (2) Scanning with different voltages: with the fixed scanning time (4 min), the same specimen was scanned with 30, 50, 70, and 90 kV voltages respectively. After comparing the imaging results with different scanning times and different scanning voltages, the optimal scanning parameters for different tumors were obtained. (3) The regions of interest for radiology were taken from the specimens, and pathological HE stained slides were prepared. Digital slices were obtained by precice automatic digital slice scanning system. The slices were compared with Micro-CT corresponding cross-sectional images and the radiological characteristics of different tissues were recorded.Results:A total of 27 patients were included/incorporated into the study and there were 15 males and 12 females, aged from 33 to 82, with an average age of 63.9 years old, including 16 cases of skin squamous cell carcinoma, 2 cases of basal cell carcinoma, and 2 cases of extramammary Paget′s disease, 1 case of melanoma, 3 cases of cutaneous fibrosarcoma, 1 case of angiosarcoma, and 2 cases of liposarcoma. A total of 65 groups were compared between Micro-CT images and pathology slides. (1) Scanning time: both 4 min and 14 min scanning times can obtain clear images which can meet requirements for morphology observation and identification of margins of tumors. (2) Scanning voltage: as for squamous cell carcinoma, the quality of images obtained by the scanning voltage of 30 and 50 kV is poor, while by the voltage of 70 and 90 kV is high. As for sarcoma, the quality of images obtained by the scanning voltage of 30 kV is poor; by the voltage of 50 kV is high and the contrast between tumor and subcutaneous fat is low by the scanning voltage of 70 and 90 kV. (3) The radiological morphology of external tumors and surrounding tissues are similar with the pathology slides. The boundary between skin and subcutaneous tissue is clear and the hair follicles are clearly distinguishable. The radiological characteristics of tumors are related to the type of tumors and the density of tumors, including high-density shadows, thicker than normal skin, no hair follicles and some small calcification points. The boundary between squamous cell carcinoma or sarcoma and normal skin or subcutaneous can be distinguished. As for the tumors in the skin, such as basal cell carcinoma, extra-mammary Paget′s disease, etc. the imaging results are poor.Conclusions:The Micro-CT scanning parameters need to be set according to the type of the tumor. The scanning time has little effect on the evaluation of the tumor. It is recommended to choose the protocol of 4 min during operation. The recommended scanning voltage of squamous cell carcinoma is 70 kV and the voltage of sarcoma is 50 kV. Micro-CT can clearly imaging the skin structure of soft tissue specimens on the body surface; configuration is identifiable for tumors that invade beyond skin and have a large heterogeneity of density compared with surrounding tissues; for tumors that do not exceed the dermis, the imaging effect is not good.

Objective:To investigate the clinical effect of water-jet excision combined with skin graft in the treatment of giant congenital melanotic nevus.Methods:The patients with giant nevus who were admitted to the Department of Plastic Surgery, Chinese PLA General Hospital from January 2015 to May 2019 were retrospectively analyzed. All patients were treated by layer-by-layer cutting of giant nevus with water-jet, preserving the subcutaneous fascial layer and part of the dermis as much as possible, then following by skin graft transplantation. The patients visited the hospital 1-2 years after operation. The postoperative scar of skin graft area was scored by Patient and Observer Scar Assessment Scale (POSAS), and the satisfaction of skin graft area was evaluated by digital scoring method (1-10 points). The recurrence of nevus pigmentosus and implantation metastasis were observed. Descriptive method were used for statistical analysis.Results:A total of 7 children were included, 2 males and 5 females, aged 4 to 14 years. There were 3 cases on the trunk and 4 cases on the extremities. Giant nevi accounted for (7.4 ± 3.1)% of the body surface area. Then skin graft survived well after surgery in all 7 children. During the 1-year follow-up after operation, the POSAS score of skin graft scar showed that the sum of 1-3 points in the scores of scar pain, itching, hardness and thickness by the patients or their families was 6, 4, 4 and 5 cases, respectively, and the sum of 4-10 points in the pigmentation and irregularity was 5 and 5 cases, respectively. None of the 7 patients had functional limitation in the skin graft area; the physicians’, scores for vascularity, pigmentation, thickness, and flexibility of the scars in the skin graft area were low, with a sum of 6, 3, 4, and 4 for the number of cases with 1-3 points and 2 and 4 for the number of cases with 1-3 points and 4-6 points in the flatness score, respectively. The satisfaction of both doctors and patients (sum of 7-10 points) was 4 and 5 cases, respectively. 7 cases were reexamined 1 year after operation, with recurrence of 2 punctate nevus pigmentosus(less than 1 mm in diameter) in only one case. No implantation metastasis in the skin graft area of nevus pigmentosus happened.Conclusions:Water-jet excision combined with skin graft in the treatment of giant nevus is simple and only one procedure required. The donor site only needs to cut a split-thickness skin graft. The postoperative scar is not obvious and the skin elasticity is better. Patients were relatively satisfied with the postoperative effect. It is suitable for the resection of nevus pigmentosus in the trunk especially the nevus pigmentosus with good texture and lighter color but not for the lesion at articular area of limbs.

It is a common problem for all mentors to cultivate the capacity for scientific research of master degree candidates in plastic surgery under the current training program of "double-track in one" and "four-certificate in one". This study introduces the "COME" training mode that includes clinical study, off-hour, multiple modalities, and efficient feedback. This study elaborates the composition and method of this training mode, and compares the number and quality of published papers and thesis before and after its implementation. Results show that the "COME" training mode can significantly improve the capacity for scientific research of master degree candidates in plastic surgery.

Objective:This study is to investigate the parameter settings and imaging effects of Micro-CT scanning externalmalignancies during operation and summarize the characteristics of Micro-CT images regarding external soft tissue and tumors.Methods:According to the inclusion criteria, patients with externalmalignancies admitted to the Department of Plastic and Reconstructive Surgery of the First Medical Center of the PLA General Hospital from October 2018 to January 2020 were collected. Through the surgical resection of tumors, the isolated tumor specimens were divided into appropriate sizes (length × width × thickness not exceeding 5 cm×3 cm×3 cm), placed on the Micro-CT scanning bed, and scanned with different parameters. (1) Scanning with different times: with the fixedscanning voltage (50 kV for sarcoma, 70 kV for other tumors), the same specimen was scanned with 4min and 14min protocols respectively. (2) Scanning with different voltages: with the fixed scanning time (4 min), the same specimen was scanned with 30, 50, 70, and 90 kV voltages respectively. After comparing the imaging results with different scanning times and different scanning voltages, the optimal scanning parameters for different tumors were obtained. (3) The regions of interest for radiology were taken from the specimens, and pathological HE stained slides were prepared. Digital slices were obtained by precice automatic digital slice scanning system. The slices were compared with Micro-CT corresponding cross-sectional images and the radiological characteristics of different tissues were recorded.Results:A total of 27 patients were included/incorporated into the study and there were 15 males and 12 females, aged from 33 to 82, with an average age of 63.9 years old, including 16 cases of skin squamous cell carcinoma, 2 cases of basal cell carcinoma, and 2 cases of extramammary Paget′s disease, 1 case of melanoma, 3 cases of cutaneous fibrosarcoma, 1 case of angiosarcoma, and 2 cases of liposarcoma. A total of 65 groups were compared between Micro-CT images and pathology slides. (1) Scanning time: both 4 min and 14 min scanning times can obtain clear images which can meet requirements for morphology observation and identification of margins of tumors. (2) Scanning voltage: as for squamous cell carcinoma, the quality of images obtained by the scanning voltage of 30 and 50 kV is poor, while by the voltage of 70 and 90 kV is high. As for sarcoma, the quality of images obtained by the scanning voltage of 30 kV is poor; by the voltage of 50 kV is high and the contrast between tumor and subcutaneous fat is low by the scanning voltage of 70 and 90 kV. (3) The radiological morphology of external tumors and surrounding tissues are similar with the pathology slides. The boundary between skin and subcutaneous tissue is clear and the hair follicles are clearly distinguishable. The radiological characteristics of tumors are related to the type of tumors and the density of tumors, including high-density shadows, thicker than normal skin, no hair follicles and some small calcification points. The boundary between squamous cell carcinoma or sarcoma and normal skin or subcutaneous can be distinguished. As for the tumors in the skin, such as basal cell carcinoma, extra-mammary Paget′s disease, etc. the imaging results are poor.Conclusions:The Micro-CT scanning parameters need to be set according to the type of the tumor. The scanning time has little effect on the evaluation of the tumor. It is recommended to choose the protocol of 4 min during operation. The recommended scanning voltage of squamous cell carcinoma is 70 kV and the voltage of sarcoma is 50 kV. Micro-CT can clearly imaging the skin structure of soft tissue specimens on the body surface; configuration is identifiable for tumors that invade beyond skin and have a large heterogeneity of density compared with surrounding tissues; for tumors that do not exceed the dermis, the imaging effect is not good.