ABSTRACT
Objective: To explore the preoperative whole perforator evaluation and intraoperative eccentric design of anterolateral thigh flap (ALTF) based on superficial fascial perforators by modified computed tomography angiography (CTA), and the clinical effects were observed. Methods: A prospective observational study was adopted. Twelve patients with oral and maxillofacial tumors and 10 patients with open injury of the upper limb with large soft tissue defects were hospitalized in the Department of Hand & Microsurgery and Department of Oral & Maxillofacial Surgery of Affiliated Hospital of Binzhou Medical University from January 2021 to July 2022, with 12 males and 10 females, aged from 33 to 75 years, an average age of 56.6 years. The wounds of the patients with oral and maxillofacial tumors were reconstructed by ALTF after the extensive tumor resection and radical cervical lymph node dissection in the same stage; the wounds of the patients with skin and soft tissue defect on the upper limb were covered by ALTF in stage Ⅱ after debridement in stage Ⅰ. After debridement, the area of wound was 3.5 cm×3.5 cm-25.0 cm×10.0 cm and the area of the required flap area was 4.0 cm×4.0 cm-23.0 cm×13.0 cm. Modified CTA scan was performed on the donor site of ALTF before the operation, with the parameters of modified CTA being set to mainly reduce the tube voltage and tube current, and increase the contrast dose and the dual phase scan. The acquired image data were sent to GE AW 4.7 workstation and adopted the volume reconstruction function for visual reconstruction and evaluation of the whole perforator. The information of perforator and source artery was marked on the body surface before operation according to the above evaluation. During the operation, an eccentric flap centered on the visible superficial fascia whole perforator was designed and cut according to the desired flap area and shape. The donor sites of the flap were repaired by direct sutures or full-thickness skin grafts. The total radiation dose was compared between the modified CTA scan and the traditional CTA scan. The distribution of outlet point of perforator of double thighs, the length and direction of superficial fascia perforators based modified CTA were recorded. The type, number, and origin of the target perforator, distribution of of outlet point of perforator, and the diameter, course, and branch of the source artery observed before the operation were compared with those observed during the operation. The healing of donor site wound and the survival of flaps in recipient site were observed after operation. The texture and appearance of flap, oral and upper limb functions, and the functions of femoral donor sites were followed up. Results: The total radiation dose of modified CTA scan was lower than that of the traditional CTA scan. A total of 48 perforators of double thighs were observed, among which, 31 (64.6%) perforators went outward and downward, 9 (18.8%) perforators went inward and downward, 6 (12.5%) perforators went outward and upward, and 2 (4.2%) perforators went inward and upward, and the average length of superficial fascia perforators was 19.94 mm. The preoperative observed type, number, and source of the perforator, the distribution of the outlet point of the perforator, diameter, course, and branches of the source artery were basically consistent with the intraoperative exploration. The types of 15 septocutaneous (including musculoseptocutaneous) perforators and 10 musculocutaneous perforators observed before the operation was consistent with intraoperative exploration. The distance between the mark of the surface perforator point and the actual exit point of the perforator during operation was (0.38±0.11) mm. All flaps survived without vascular crisis. The donor site wounds of 5 cases of skin grafting and 17 cases of direct suturing wounds healed well. The postoperative follow-up was 2 months to 1 year, with an average of 8.2 months, the flaps were soft and slightly bloated; the function of diet and mouth closing was accessible in patients with oral and maxillofacial tumors, the speech function was mildly impaired in patients with tongue cancer, but they could complete basic oral communication; the wrist and elbow joints and forearm rotation function were not significantly limited in patients with upper limb soft tissue injuries; there was no obvious tightness in the donor sites, and the function of the hip and knee joints was not limited. Conclusions: The whole perforator and even the subcutaneous perforator of the donor site of ALTF can be evaluated by modified CTA, and the flap can be used in oral or maxillofacial reconstruction and repair of skin and soft tissue defects of upper limbs to achieve good results. By clarifying the type, number, and source of the perforator, the distribution of the outlet point of the perforator, diameter, course, and branches of the source artery before the operation, the eccentric design of the ALTF based on the superficial fascia perforator was realized. This study has strong guiding value.
Subject(s)
Female , Male , Humans , Middle Aged , Adult , Aged , Thigh , Computed Tomography Angiography , Prospective Studies , Subcutaneous Tissue , Tomography, X-Ray ComputedABSTRACT
In order to confirm the role that the 49th amino acid residue plays in enzymatic inactivity of Glutamine 49 phospholipase A2(Gln49-PLA2),site-directed mutagenesis of its 49th amino acid gene codon was conducted using PCR.Aspartic acid 49 phospholipase A2(Asp49-PLA2-Q49D-PLA2),the mutant of Gln49-PLA2 was expressed in E.coli with pET32a+ vector.The fusion protein,expressed as inclusion body,after being denatured,was on-column refolded and purified by immobilized metal affinity chromatography(IMAC),and then cleaved by Factor Xa.The mature Q49D-PLA2 mutant was obtained by Hitrap SP cation exchange and Superdex 75 gel filtration chromatography,with the recovery rate of 1.3%,and the specific activity of the mature Q49D-PLA2 mutant was 72 U/mg.It has been demonstrated that the 49th glutamine amino acid residue is the main reason in enzymatic inactivity of Gln49-PLA2 and the results are helpful for denatured protein refolding,especially in rich disulfide bonds conditions.