Application Of Digital Surgical Technique In Repairing Soft Tissue Defects Of Head And Neck With Anterolateral Thigh Flap

Objective: Femoral anterolateral skin flap,the lateral femoral circumflex artery blood supply mainly from descending branch and its perforators,needs to be in the process of preparation of perforators flap artery and through the muscle and fascia support skin intramuscular perforators out to serve as a flap preparation and vascular anastomosis,and between different individuals,even identical individuals around the lateral thigh perforators blood vessels on anatomy and morphology,there are various variations,This puts forward higher requirements for surgery and imaging,which increases the difficulty and operational risk of free vascular flap transplantation.Therefore,accurate preoperative positioning of perforator vessels for precise individualized design can improve the success rate of flap dissection and greatly reduce the risk of surgery.Computed Tomography Angiography(CTA)is a commonly used method for accurate clinical positioning.It is widely used in ALTF(ANTEROLATERAL FEMORAL FLAP),thoracolateral artery perforator Flap,peroneal artery perforator Flap and so on.However,there are also low spatial resolution,difficult identification of dynamic and static penetration branches,complex supporting hardware,poor visual 3D reconstruction results,and inability to accurately design and simulate peeling of the skin flap.Among them,how to carry out fine 3D visualization of CTA scan and how to locate the CTA image information to the donor skin more accurately? It is a difficult problem that needs to be solved at present.In recent years,CTA technology combined with CURA software has been used to study the vascular anatomy of skin flaps and preoperative skin flap design,with good feasibility.However,such studies are not yet mature,and there are few studies on the application of CTA technology combined with CURA software in the design and preparation of ALTF,and the feasibility needs to be further explored and improved.The aim of this study is to reconstruct the spiral strands by the combination of CTA technology and CURA digital software through the fine 3D reconstructionMethods: A total of 20 patients with head and neck tumor were selected from January 2020 to December 2020 in the Department of Otolaryngology,Head and Neck Surgery of the Affiliated Hospital of Southwest Medical University and the Department of Thyroid Head and Neck Maxillofacial Surgery of the Third People’s Hospital of Mianyang,who underwent ALTF reconstruction.All patients underwent free ALTF for reconstruction of the defect site,and were followed up for 1-12 months after surgery.Routine examinations were performed preoperatively,and CTA examination of the lower limbs was performed to locate the anterolateral thigh perforator branches.Computed Tomography and MRI were performed in the recipient region.Determine the scope of the lesion and the vascular condition of the affected area;Will seek perforators,delimit the CTA data preprocessing,rebuild the area,using CURA software to rebuild bone,blood vessels and skin,generate the 3 d visualization model of personalized free ALTF,using 3 d printing production ALTF wear vascular stationary positioning guide,fixed in operation the lateral thigh,eeg,the femoral anterolateral descending blood vessels and skin perforators,The skin flap was removed and anastomosed with the neck vessels(one artery and two veins).Routine nursing was given after surgery,and the repair of the skin flap was closely observed to strengthen drainage and promote wound healing.The obtained data were analyzed by SPSS 20.0 software.Results:(1)General information: The length of the vascular pedicle of the anterolateral thigh flap is between 7 cm and 14 cm,with an average of 9.9 cm,and the area range is(3 to 6 cm)×(4.5 to 13 cm).Obvious skin perforations were seen in all flaps.Anterolateral thigh flap was used to repair 20 cases of head and neck defects(including 5 cases of buccal mucosa repair,4 cases of tongue,3 cases of soft palate,2 cases of mouth floor,2 cases of gingiva,and 2cases of compound defect of tongue and mouth floor),1 case of hypopharynx,1 case of complex defect of cheek and gum).(2)Computed tomography angiography results: Twenty patients who underwent anterolateral thigh perforator flap repair were compared with the intraoperatively found perforators through computed tomography angiography images,and 41 perforators were found in 20 cases.Among the 41 perforators,38 on the right thigh and 3 on the left thigh(n=1),with an average of 2perforators on each thigh.The number and location distribution of perforators The number of perforators on each thigh of 20 patients ranged from 1 to 4.The most common is 2 perforators,accounting for 45.00%(n=9).The data is shown in Table 2.Most of the perforators are located on the sides of the AP line(the line between the anterior superior spine and the superior lateral angle of the bone),a total of 28,accounting for 70.0%.Seven penetrating branches were found at a radius of 3 cm around the midpoint of the AP line,and 2 penetrating branches were found at a distance of 3 to 5 cm around the midpoint of the AP line.The other penetrating branches were identified more than 5 cm away from the AP line.(3)Types and Trends of Wearing Supports: During the operation,it was found that the type of perforator had a musculocutaneous perforator that passed through the lateral femoral muscle long and tortuous,accounting for 80.5%(n=33).The incidence of skin perforation between muscles was 14.6%(n=6),and the septal space between the lateral platysma and rectus femoris was short.Finally,4.9%(n=2)of the perforators penetrated part of the diaphragm and the weak part of the lateral femoral muscle,which is called the perforator of the subcutaneous or semi-diaphragmatic skin.(4)Origin of piercing: During the operation,it was found that most of the anterolateral thigh perforation originated from the descending branch of the lateral femoral circumflex artery,accounting for 75.6%(n=31).The oblique branch was found in 21.9%(n=9)of the thigh before surgery,originating from the descending branch of the thigh.Only 2.5% of penetrating branches came from oblique branches(n=1).(5)The origin of perforators determined by CTA is consistent with the results determined during surgery: According to tumor resection and defect,20 patients actually used the anterolateral thigh perforator flap.19 flaps were harvested from the right thigh and 1 flap was harvested from the left thigh.The perforator information obtained by computed tomography angiography was compared with the intraoperative findings of 20 patients.Among the 20 patients,the origin of 20 cases of perforators determined by preoperative mapping was consistent with the results of intraoperative exploration.Except for the fact that the perforators of two patients actually originated from lateral branches,one of the patients was considered preoperatively It is from the descending branch.Harvest 41 perforator flaps on the anterolateral thigh.Among them,preoperative computed tomography angiography accurately located 41perforators(accounting for 100%).The source vessels of the 41 perforating branches used as the flap pedicles are the descending branch(n=31),oblique branch(n=9)and transverse branch(n=1)of the lateral circumflex femoral artery.Preoperative computed tomography blood vessels There was no significant difference between the angiographic results and the intraoperative findings(P>0.05).(6)Success rate and complications: Twenty patients were successfully operated with flaps to repair head and neck defects,and no cases of flap necrosis occurred.Postoperative anastomotic venous crisis occurred in 1 case.Re-operation found 1 venous thrombosis,another venous anastomosis was unobstructed,and the flap survived after anticoagulation,spasmolysis,and hyperbaric oxygen therapy.One patient had a partial dehiscence of the wound at the donor site after the operation,which healed after dressing change.There were no complications of lower limb motor and sensory dysfunction.Conclusion: Through the combination of CTA technology and CURA digital software,the lateral femoral circumflex artery,descending branch and its branches can be reconstructed in a refined three-dimensional reconstruction manner,and the stable three-dimensional visualization of the main perforating vessels relative to the surrounding bones,muscles and skin can be reconstructed Model;through the analysis of the three-dimensional visualization model,the precise marking is transferred to the patient’s body surface for positioning,and the design is reproduced on the patient’s body surface,so as to complete the personalized design of the anterolateral thigh flap.According to the defect marking the range of the flap,The extraction of the simulated skin flap reduces the surgical risk caused by the vascular variation of the skin flap,and greatly promotes the preparation of the free anterolateral thigh flap,which is conducive to the simplification of the surgical method and the promotion of the surgical style,and improves the head The success rate of neck tissue defect repair.