ObjectivesTo explore the statistical performance of different methods for meta-analysis of single rates with zero events so as to provide evidence for selecting meta-analysis methods in evidence-based research.MethodsThrough Monte-Carlo simulations, we evaluated the performance of various transformation and correction methods for meta-analysis of single rates with zero events, considering the point estimate bias, confidence interval coverage and width.ResultsWhen the overall event rate was above 30%, all methods showed good statistical performance. As the event rate dropped, log, logit, and arcsine transformations could still maintain good performance. However, when the event rate was less than 5%, only Freeman-Tukey transformation showed excellent performance.ConclusionsThe meta-analysis of single rate based on Freeman-Tukey transformation is robust, and should be recommended as the preferable choice of meta-analysis of single rate with zero events.
In order to compare the immunogenecity and biological properties of homologous tendon grafts after treatment from different methods of freezing, tendons from chickens received repeated freezing-thawing treatment or ultra-low-temperature treatment, and then, the post-treatment tendons were preserved in liquid nitrogen for 3 months before transplantation. The autogenous tendon transplantation was served as the control. It was found that in the group of repeated freezing-thawing treated tendons, the tendon cells all died and while in the ultra-low temperature treated tendons the active rate of tendon cells was 92.5% +/- 3.4%, and the histological observation showed that transplantation of frozen tendons would result in extensive infiltration of inflammatory cells in the grafted tendons and the peritendinous adhesion was serious than that of the autografts. The active flexion function, hydroxyproline levels and the biomechanical analysis showed no significant differences between the repeated freezing-thawing treated homografts and the ultra-low-temperature treated homografts, and that the autografts was definitely superior to the homografts. The conclusions were: (1) Transplantation of the homologous tendons from the two different methods of freezing could receive considerable success and there was no significant difference between them; (2) Transplantation of frozen homologous tendon graft might give successful result which was probably due to the preservation of the cellular activity of the tendon cells following freezing treatment and elimination of the antigen presenting cells in the tendon as well, and (3) Although the cellular components of the tendon were damaged and the antigenicity of the tendon was lowered, it did not necessarily mean that homologous tendon graft would always be successful in transplantation.
Objective To study the method and effect of free rectusabdominis muscle flaps with intermediate split thickness skin graft in repairing defects on legs and ankles.Methods From May 1998 to December 2002, 11 cases of defects on legs(2 cases) and on ankles( 9 cases) were repaired by use of unilateral free rectus abdominis flap with skin graft. The soft tissue defects were accompanied by osteomyelitis or the exposure of bone or tendon.The disease course was 1 month to 10 years. The defect size ranged 3 cm×4 cm to 8 cm×14 cm. The area ofrectus abdominis muscle flaps was 4 cm×6 cm to 8 cm×15 cm. Results All patients were followed up 6 months to 4 years after operation. All rectusabdominis flaps survived with good appearances and functions.The primary healing was achieved in 8 cases, intermediate split thickness skin graft necrosed in 3 cases and the wound healed after skin re-graft.Conclusion Free rectus abdominis flap is a proper option for repair of the soft tissue defects or irregular woundson legs and ankles. It has the advantages of abundant blood supply, b anti-infection ability, good compliance and satisfied appearance.
Objective To reveal the fibrillar network in vitreous and the effect of plasmin on this network.Methods 20 vitreous gels of freshly slaughtered pigs were divided into 2 groups, the gels in first group were digested by 3 Uplasmin (3 U/ml) at 37c for 24 hours respectively, the second group received the same PBS as control. After digestion, gels were fixed in neutral buffered formalin solution. Samples from vitreous base, cortex and the central region were observed by the technique of freeze etching electron microscopy.Results In vitreous collagen fibril network was in a three-dimensional array, collagen fibril density showed marked differences, central vitreous had the sparse fibril density, the cortex denser and the basal vitreous densest. After digestion by plasmin, the collagen fibrillar network was destructed.Conclusion Collagen fibrils in vitreous present spatial arrangement regularly, plasmin can lead to destruction of the fibrillar network.(Chin J Ocul Fundus Dis，2003，19：179-181)
OBJECTIVE: To investigate the clinical effect of free vascularized thoracoumbilical flap with reversal flow in repairing the soft tissue defect in leg with tibia exposure. METHODS: Forty-four casting mould specimens of leg arteries were studied firstly. Then 25 cases with soft tissue defect and tibia exposure in the proximal-middle segment of leg were adopted in this study. Among them, 18 cases had long distance thrombosis of the anterior tibial vessels or posterior tibial vessels due to traumatic lesion. The maximal size of defect was 28 cm x 11 cm and the minimal size of defect was 11 cm x 9 cm. In operation, the thoracoumbilical flap which was based on the inferior epigastric vessels was anastomosed to the distal end of the anterior tibial vessels or posterior tibial vessels. RESULTS: Anterior tibial artery, posterior tibial artery and fibular artery had rich communication branches in foot and ankle. All the flaps survived, the color and cosmetic result of them were good. CONCLUSION: The free vascularized thoracoumbilical flap with reversed flow is practical in repairing the soft tissue defect of leg with tibia exposure. Either the anterior tibial vessels or the posterior tibial vessels is normal, and the distal end of injured blood vessels is available, this technique can be adopted.
Abstract In order to have more selective sources of skin flaps to repair soft tissue defects, the prefabricated flap combining with skin expander was tried. Implanted the dorsal thoracic artery and vein with a muscle bundle of latissimus dorsi into the lateral thoracic wall subdermally andset a skin expander subcutaneously. Injected saline into the expander to inflate the flap gradually. In a month, an axial flap with the dorsal thoracic vesselswas prepared. the flap was transferred to the defect by vascular anastomosis technique. This method was applied in two cases, one to the left ankle, another to the left side of the neck. The sizes of the two flaps were 20cm×14cmand 22cm×15cm respectively. After operation, the flaps were alive completely. The advantages included selective source of vascular pedicle, thinpliable flap with enough blood supply, and direct closure of the donor site without skin graft.
ObjectiveTo prospective study the effectiveness and safety of multimodal analgesia (MA) in treatment of avascular necrosis of the femoral head with free vascularized fibular grafting (FVFG).MethodsSixty patients with avascular necrosis of the femoral head, who were scheduled to unilateral primary FVFG between February 2016 and December 2016 and met the selection criteria, were included in the study. All patients were allocated to two groups according to the method of random number table: MA group (n=30) and control group (n=30). There was no significant difference in gender, age, body mass index, side, duration and stage of avascular necrosis of the femoral head, preoperative visual analogue scale (VAS) scores under quiescent and active states, and range of motion (ROM) of hip flexion and abduction before operation (P>0.05). The patients in the MA group were treated with MA therapy, including oral administration of celecoxib before operation, local anesthetic wound infiltration during operation, and ice compression and oral administration of celecoxib after operation. The patients in control group were only treated with patient-controlled intravenous analgesia pump. The postoperative VAS scores under quiescent and active states, ROM of hip flexion and abduction, prescription of Tramadol and adverse reaction were recorded and compared.ResultsThe operations were completed successfully in both groups without obvious complications and adverse reaction. The Tramadol was used in 4 cases (13.3%) of MA group and in 11 cases (36.7%) of control group, but no significant difference was found between the two groups (χ2=4.356, P=0.072). The VAS scores under quiescent state at 6 and 24 hours postoperatively were significantly lower in MA group than in control group (P<0.05), while VAS scores under active state at 48 hours postoperatively and on the day of discharge were significantly lower in MA group than in control group (P<0.05). There was no significant difference in VAS score between two groups at other time points (P>0.05). The ROM of hip flexion in MA group was better than that in control group at 1 day postoperatively and the day of discharge (P<0.05), while no significant difference was found at 2 and 3 days postoperatively (P>0.05). The ROM of hip abduction in MA group was superior to the control group at 1, 2, and 3 days postoperatively and the day of discharge (P<0.05).ConclusionThe MA can effectively relieve the pain following FVFG and facilitate early functional exercises of the hip. The usage of opioids was also relatively fewer for MA protocol.
ObjectiveTo explore the effectiveness of free lobed perforator flaps in repairing of complex wounds of limbs. Methods Between January 2018 and January 2021, 10 patients with complex wounds of limbs were admitted. There were 7 males and 3 females, aged from 32 to 64 years, with an average age of 45 years. There were 4 cases of traffic accident injuries, 3 cases of machine strangulation injuries, 1 case of machine crush injury, and 2 cases of heavy object crush injuries. There were 5 cases of upper limb wounds and 5 cases of lower limb wounds. The size of wounds ranged from 11 cm×10 cm to 25 cm×18 cm. The wounds were repaired with tri-lobed flaps of the descending branch of the lateral femoral circumflex artery in 7 cases, four-lobed flaps in 2 cases, and with tri-lobed flaps of the descending branch of the lateral femoral circumflex artery combined with oblique branch in 1 case. The size of flaps ranged from 12.0 cm×10.5 cm to 28.0 cm×12.0 cm. The donor sites were sutured directly in 9 cases and repaired with superficial iliac circumflex artery perforator flap in 1 case. ResultsSinus formed at the edge of the flap in 1 patient, which healed after dressing change and drainage; other flaps survived well, and the wounds healed by first intention. The skin flap at donor site survived, and the incisions healed by first intention. All patients were followed up 6-24 months (mean, 11 months). All flaps had good appearance and function, and linear scars were left at the donor site without obvious complications. ConclusionFree lobed perforator flap is an alternative method to repair complex wounds of limbs with high safety, good effectiveness, and less complications.
Objective To evaluate the feasibility of preservation of arteriesby vitrification and the effectiveness of vitrified arteries as allografts. Methods Sixty rabbits were used in the research. Forty-eight femoral arteries wereharvested from 24 rabbits as the transplanted materials，and 24 femoral arteries were preserved by vitrification, 24 by freezing for 14 days，respectively. Theother 36 rabbits were used as the transplanted subjects，and were divided into three groups， 12 rabbits including 24 femoral arteries per group: Group A(fresharterial autografts), Group B(vitrified arterial allografts) and Group C(frozen arterial allografts). The morphologic changes of arterial grafts were observed macroscopically and histologically. The patent rate of arterial grafts were measured by angiography, and the rabbits were sacrificed on the 14th day, the 30th day, the 60th day and the 120th day after transplantation respectively. Arterial grafts were harvested to observe the morphological changes，and the immunological rejection was evaluated by measuring the ratio of tunica intima and tunica media. The results were compared between these groups. Results Before transplantation，theintegrated rate of Group B was 91.67%，which was significantly better than that of Group C（54.17%, Plt;0.01）. After transplantation, the accumulative patent rate of Group B was 87.50%，which was significantly better than that of Group C（66.67%, Plt;0.05）. There was statistically significant difference in the ratioof tunica intima and tunica media between Group B and Groups A, C（Plt;0.05）.Conclusion The above results show that vitrification does less damage to cells and tissues because of ice-free in the process of cryopreservation. So vitrification can be used to preserve arteries， and the arterial allografts preserved by vitrification are better than those preserved by freezing.
In order to understand the influence of the free tendon graft and the tendon transfer on their blood supply, histological and biochemical changes during healing following repair of the damaged tendon after the alteration of the nourishing environment, an experiment was carried on 36 New Zealand white rabbits. In the front paws of the rabbits, the free tendon graft was sutured in the tendon defect of flexor of the fourth toe and the flexor tendon of the third toe was transferred to the second toe to reconstr...