Prospective Comparison Of Forearm Free Flap Donor Site Morbidity And The Potential Solutions For Aesthetic Issues

Background: Microvascular free flaps surgery has become the gold standard for head and neck reconstruction after ablative surgery.Radial forearm free flap(RFFF)has been described as a workhorse and ideal for oral cavity reconstruction.It has many of the ideal prerequisites for resurfacing soft tissue defects.It is thin,has a consistent vascular pedicle,is supple,and has a feasible two-team approach.However,it has been criticized for being associated with significant donor site morbidity.This may be due to the fact that RFFF donor site defect cannot be closed primarily and needs to be covered with a skin graft harvested from an extra-operative site.This option creates an inevitable third operative area associated with additional complications,such as pain,delayed healing,infection,and poor aesthetic.Therefore,it would be of great improvement if we could use an alternative flap that shares all advantages of the RFFF,with less donor site morbidity,or if we can find a suitable method to reduce RFFF donor site morbidity and avoids the need for a third operative site to close RFFF donor site defect.Objectives: The current thesis aims to find an ulnar forearm free flap(UFFF)flap that shares all advantages of RFFF but is associated with less donor site morbidity.The specific aims can be divided into three parts.Each part has its objectives.Part one: This part aims to evaluate donor-site morbidity after UFFF on wrist movement,hand strength,and other complications at different time intervals compared with the preoperative baseline.Also,to investigate the anatomical features such as septocutaneous perforator distribution,pedicle length,diameter,flap thickness,harvesting time,and other operative difficulties.Part two: This part aims to provide an objective and subjective analysis of donor-site morbidity for patients undergoing free flap reconstruction with either RFFF or UFFF and evaluate changes in hand biomechanics for both groups at different time intervals.Additionally,the study seeks to assess morbidity’s impact on patient-reported quality of life(Qo L)outcomes resulting from these two reconstructive options.Part three: This part aims to find a suitable method to reduce the RFFF donor site troublesomely as well as quantitate the functional biomechanics outcomes of the hand after the closure of the RFFF donor site using either an ipsilateral triangular full-thickness skin graft(FTSG)harvested adjacent to the donor site defect or an abdominal split-thickness skin graft(STSG).Methods: The first part of the study is a prospective study that included all patients undergoing UFFF presenting to the Department of Oromaxillofacial-Head and Neck Surgery,School of Stomatology,China Medical University.Grip strength,pinch strength,wrist movement,sensation to light touch and temperature,and hand dexterity were assessed at different time intervals.Moreover,cosmetic results and quality of life were assessed using the Patient and Observer Scar Assessment Scale(POSAS)and Disability of Arm,Shoulder,and Hand(DASH)score.The second part of the study included all patients undergoing RFFF or UFFF harvest between October 2020 and January 2022.Grip strength,pinch strength,wrist range of movement,hand dexterity,and testing skin sensitivity were assessed with the appropriate scales perioperatively and at 1,3,6,and 12 months if possible.In addition,Patient and Observer Scar Assessment Scale(POSAS),Disability of Arm,Shoulder and Hand(DASH),University of Washington Quality of Life(UW-QOL),14-item Oral Health Impact Profile(OHIP-14),and Decision Regret Scale(DRS)questionnaire were used to evaluate the donor site scars and patients’ quality of life.The third part included a retrospective review of a prospective database of the patients who underwent reconstruction of the oral cavity with RFFF from March 2017 to August2021.The patients were divided into two groups based on donor site closure methods(FTSGs and STSGs).The outcomes were biomechanics evaluation of grip strength,pinch strength,and range of wrist movements.The subjective donor site morbidity,aesthetic,and overall functional results were also analyzed.Results: Part One: A total of 35 patients were enrolled.A significant reduction in grip strength for the donor’s hand was observed between preoperative and postoperative 1 and3 months(Mean difference;13.39 kg and 7 kg,respectively,P <0.001 for all).A similar trend was observed for pinch strength and range of motion except for ulnar abduction(P<0.05).Three months after surgery,a faster return to the baseline in thumb-index tip pinch,palmar flexion,and pronation.Six months after surgery,all biomechanical outcomes had returned to their preoperative baseline.None of the patients experienced significant changes in sensation to light touch,temperature,or numbness.The DASH score significantly increased by 3.37 points 6 months after surgery(P<0.001).Additionally,based on the POSAS score,patients expressed satisfaction with the appearance of the donor site.Part Two: Eighty patients(53 men and 27 women)underwent the transfer of RFFF and UFFF(40 patients for each group)to reconstruct intraoral defects following tumor extirpation.There were no significant differences between the two groups regarding sex,age,body mass index,smoking,drinking,comorbidities,or tumor sites,which made the two groups comparable.The harvesting time was significantly longer in the RFFF than in the UFFF(P= 0.011).There were no flap losses in the study.In the short-term analysis,a significant reduction in grip strength,fine motor skill strengths(tip pinch,key pinch,palmar pinch),and range of motion compared to the baseline was observed for RFFF.However,this significant improvement over time for all patients tested with no significant differences.None of the patients for both groups had any functional disturbance of grip strength,wrist motion,fine motor skills,and sensation to light touch at 1 year.Nine patients developed partial loss of the graft(RFFF= 6;UFFF= 3),which did not reach statistical significance.There was a significant difference between the two groups concerning early numbness favorably with the UFFF(p=0.040).Persistent numbness occurred in 3 cases in RFFF.Cold intolerance was significantly lower in UFFF(2.5 %)than in RFFF(22.5%)(p= 0.014).The mean DASH score increased 6 months after surgery in RFFF,but this difference wasn’t statistically significant between the two groups.However,the mean DASH score for both groups reduced at 12 months,and this reduction was statistically significant between the two groups favorable with UFFF.Further analysis showed that social function had the highest score within the RFFF group,and the activity-related pain part had the highest score within the UFFF group 12 months after surgery.A similar trend was observed for POSAS score,which reduced at 12 months compared to 6 months,significantly superior for UFFF.The UW-QOL score for appearance was significantly lower in the RFFF than in the UFFF(68.33 vs.77.27,respectively;P = 0.026).Additionally,the RFFF reported significant impairments with UW-Qo L Social Domain.The OHIP-14 for both groups(RFFF mean score 40.15,UFFF mean score 37.60)was similar.The DRS score between the RFFF and UFFF(36.26 ± 11.57 vs.27.36 ± 13.74,respectively),the UFFF group had less decisional regret(p = 0.005).Part Three: The study included 75 patients(51 male and 24 female).The patients were divided into the FTSG group(n=35)and the STSG group(n=40).There was no significant difference between the two groups concerning sex,age,tumor type,or length of hospital stay.A significant postoperative reduction in grip strength and wrist extension was observed when comparing the FTSG to STSG(mean difference =3.74 kg,2.5°,respectively),and the effect size index of Cohen’s d is considered a minimum.Changes in pinch strength and other ranges of motion were insignificant between groups.FTSG had a significantly shorter harvesting time than STSG(P = 0.041).Loss of the skin graft with delayed healing of the donor site occurred in 9 patients(four in FTSG,five in STSG).There was a significant difference in appearance favorably with FTSG(p=0.026).Cold intolerance was noticed in 6.7% for FTSG and 32.5% for STSG(p= 0.017).There was no significant difference between groups in subjective function,numbness,pain,hypertrophic scar,itching,and social stigma.Conclusion: 1)UFFF is a safe and reliable option for oral cavity reconstruction with minimum donor site morbidities,mainly when cosmesis is paramount.Furthermore,objective hand biomechanics ultimately returns to its preoperative state within 6 months after surgery.2)Objective biomechanical function limitations are reversible short-term effects after radial or ulnar forearm flap harvesting and do not restrict daily routine in the long term.Additionally,UFFF appears to be preferred over RFFF in terms of overall subjective complications of the donor site and patient Qo L.These results emphasize that the UFFF should be considered an alternative to the RFFF for reconstructing soft-tissue defects.3)Donor-site morbidity for closing RFFF defect is comparable between the ipsilateral triangle-shaped FTSG and STSG without increased risks of wound healing complications or decreased sensation.Compared with the STSG,the FTSG adds no additional surgical morbidity and has shown consistently positive results.