Comparison of outcomes between single- and multiple-perforator-based free perforator flaps: A systematic review and meta-analysis.

BACKGROUND: Perforator-based free perforator flaps have become an important tool for the reconstruction of tissue defects. The effect of the number of perforators on the outcomes of perforator flaps has been widely debated. This study aimed to compare the outcomes of single- and multiple-perforator-based free perforator flaps in free-flap reconstruction. METHODS: We searched PubMed, Web of Science, EMBASE, Chinese BioMedical Literature Database (CBM), Cochrane Library, and clinicaltrials.gov between January 2000 and June 2021 to identify studies that reported data on the outcomes of free perforator flaps. Two authors individually extracted data and performed quality assessment. Outcomes, including partial flap loss, total loss, fat necrosis, arterial insufficiency, venous insufficiency, hemorrhage and hematoma, wound dehiscence at recipient sites and donor site complications, were evaluated. RESULTS: Thirty-two studies with 2498 flaps were included in our analysis. No significant difference was found in the rates of partial loss and arterial insufficiency of flaps, hemorrhage and hematoma, wound dehiscence at recipient sites and donor site complications. However, the multiple-perforator group showed significantly lower rates of total loss (relative risk [RR] = 1.08, 95% confidence interval [CI]: 0.78-1.79, p = .754), fat necrosis (RR = 1.79, 95% [CI]: 1.36-2.36, p = .000) and venous insufficiency (RR = 1.72, 95% CI: 1.07-2.79, p = .026) than the single-perforator group. CONCLUSION: The rates of total loss, fat necrosis and venous insufficiency in the multiple-perforator group were lower than those in the single-perforator group. Hence, we recommend that multiple perforators be included in the free perforator flap when appropriate, to yield better clinical outcomes in reconstruction.

Risk Factors for Free Flap Outcomes: A Retrospective Study of 318 Free Flaps for Head and Neck Defect Reconstruction.

OBJECTIVES: This study was conducted to identify the risk factors for free flap outcomes in head and neck reconstruction. METHODS: A retrospective review of 318 free flaps were used for head and neck reconstructions in 317 patients over seven years. The patient characteristics, surgical data, and flap outcomes were recorded. The impact of risk factors related on the outcomes of free flaps were analyzed using single and multivariate analysis. RESULTS: For single factor analysis, 295 free flaps for the first reconstruction were included. Hypertension and the type of recipient vein are associated with venous thrombosis (P = .018, P = .047). Hypertension, type of free flap, recipient artery, and recipient vein were associated with the incidence of re-exploration (P = .009, P = .011, P = .017, P = .021). Hypertension had an obvious effect on the flap survival (P = .005). For multivariate analysis, hypertension (odds ratio = .166, 95% confidence interval: .043 - .636; P = .009) was a statistically significant risk factor for flap survival. For types of recipient artery and vein, selecting two venous anastomosis (one of IJVS and one of EJVS) had the minimum incidence of venous thrombosis (2.2%), and selecting facial artery, single vein (one of IJVS), and two veins (one of IJVS and one of EJVS) for anastomosis had lower incidence of re-exploration, which were 4.4%, 2.9%, and 6.0%, respectively (P < .05). CONCLUSIONS: Risk factors as hypertension, type of free flap, recipient artery and vein should be paid more attention in the free flaps for head and neck reconstructions. We believe proper measures will lead to better results in head and neck reconstruction.

Comparing donor site morbidity between radial and ulnar forearm free flaps: a meta-analysis.

The vascularised forearm free flap is a workhorse flap for the reconstruction of many types of soft tissue defects. However, the difference in donor-site morbidity between the radial forearm free flap (RFFF) and ulnar forearm free flap (UFFF) remains controversial. This study aimed to compare the donor-site outcomes of RFFF and UFFF. We searched PubMed, EMBASE, Web of Science, clinicaltrials.gov, Cochrane Library, and Chinese Biomedical Literature Database up to August 10, 2021, to identify studies on donor-site outcomes of RFFF versus UFFF in patients undergoing reconstructive surgery. Two authors individually extracted data and performed quality assessments of the selected articles. The overall morbidity and overall effect of individual complications of the donor site were analysed. In total, 288 cases from five studies were included in our analysis. The UFFF group was significantly superior to the RFFF group regarding overall morbidity and overall effect of individual complications of the donor site. The morbidity of UFFF donor sites was significantly lower than that of RFFF, and UFFF may be an ideal substitute for RFFF in reconstructive surgery. However, additional large-scale studies are necessary to confirm this finding.

Rapid analysis of piperazine ferulate tablets by optic-fiber sensing technology and the similarity of ultraviolet spectra.

A rapid analysis method of piperazine ferulate tablets by optic-fiber sensing technology with UV-vis absorption spectrum was established. Qualitative and quantitative data were obtained and compared by maximum and minimum wavelength, absorbance and contrast spectra. Similarity method was used to identify authenticity of drugs. The difference of contents measured by this method and UV determination method in China Pharmacopoeia showed no statistical significance (P>0.05), while the similarity can be used as a parameter to identify the authenticity of drugs.

[A three-dimensional finite element analysis for the biomechanical characteristics of orthodontic anchorage micro-implant].

PURPOSE: To establish a three-dimensional finite element model for orthodontic anchorage micro-implant,and to analyze the influence of different titled angles on the biomechanical characteristics of orthodontic anchorage implant-bone interface. METHODS: ANSYS(Analysis System)finite element analysis software was used to perform the finite element modeling of the micro-implant with 7 different tilted angles, including 30 degrees, 40 degrees, 50 degrees, 60 degrees, 70 degrees, 80 degrees and 90 degrees. A simulated orthodontic force, which was 200 grams, was loaded mesiodistally to the mathematical models. The stress and displacement distribution on the implant-bone interface were analyzed. RESULTS: As the titled angle increased, the Von-Mises stress at the cervix of the implants were 1.0792, 1.0104, 0.8848, 0.8181, 0.7583, 0.6339 and 0.5608MPa, while the displacement were 5.5513, 4.9900, 3.7419, 3.1264, 2.5874, 1.3624 and 0.8027microm CONCLUSION: The micro-implant can be safely loaded with 200 grams of mesiodistal orthodontic force. The increase of the titled angle can efficaciously enhance the ability,implicating that the implant can bear a mesiodistal orthodontic force, vertical angle should be chosen when the micro-implant is embedded. Supported by Natural Science Foundation of Liaoning Province (20042076).

[Effect of fluorided etching fluid on the shear bond strength and the deposition on the surface of enamel.].

PURPOSE: The aim of this study was to find the best concentration of fluorided etching acid in the dental clinic which had both the best shear bond strength and the maximal anti-caries effect. METHODS: 84 extracted human premolars were divided into four groups of 21 teeth each. The enamel of each group was conditioned with 35% phosphoric acid containing 0%, 1.23%, 2%, 3% NaF. The shear bond strength was tested by bond strength machine and the enamel morphology was observed by scanning electron microscopy at once, 1 week, 4 weeks, 12 weeks, 24 weeks after etching. The shear bond strength was statistically analyzed by SPSS10.0 software. RESULTS: The shear bond strength of the group whose acid containing 3% NaF was less than the others significantly (P<0.05); and there was no significant difference among the other groups (P>0.05). The amount of the deposition on the surface of enamel after etching was increased with the time after etching and the concentration of NaF increasing. CONCLUSIONS: 2% NaF added to 35% phosphoric acid has both the best bond strength and the best effect of preventing enamel from caries.