| BackgroundThe congenital microtia is one of the most common malformation in plastic surgery.More than half of microtia is not single and is often part of other congenital syndromes.Hemifacial microsomia(HFM),is the most common one and affects the development of facial bones,cartilage,and soft tissues such as muscles,nerves,and fat.Patients with severe microtia require ear reconstruction using the periauricular fascia,but the effect of HFM on periauricular fascia development is unknown.The commonly used periauricular fascia includes the posterior auricular fascia and the superficial temporal fascia,whose main supply vessels are the posterior auricular artery and the superficial temporal artery.The dysplasia of the above structures seriously threatens the safety of ear reconstruction surgery.ObjectiveFrom the perspective of clinical application,this study researches the following contents:1.To investigate the correlation between HFM and cartilage framework exposure after ear reconstruction;2.To investigate the effect of hemifacial microsomia on the development of periauricular fascia and its supplying blood vessels;3.To study the effect of HFM on the blood supply pattern in the hairless area of postauricular region;4.To investigate the effect of HFM on the blood perfusion of the posterior auricular fascia.Patients and methods1.The patients with congenital microtia who underwent ear reconstruction surgery in our center from March 2017 to December 2020 were retrospectively studied.The patients with cartilage exposure after ear reconstruction were screened,and the data of patients' gender,affected side,age and time of complication were analyzed to study the occurrence regularity of cartilage exposure in patients with microtia.In addition,according to the ratio of 1:1,accurate matching sampling was conducted for the patients with cartilage exposure in other patients without complications,and the OMENS classification of HFM in the two groups of patients was statistically analyzed,and the correlation between HFM and cartilage exposure was studied as a control.2.Unilateral congenital microtia patients with HFM were selected from our center for the first visit between October 2020 and January 2021.M-type ultrasound was used to detect the distribution of the superficial temporal artery and the farthest length of the parietal branch,and Doppler ultrasound was used to detect the thickness of the posterior ear fascia and the temporal parietal fascia,as well as the diameter of the trunk,parietal branch and frontal branch of the temporal parietal artery.3.Patients with microtia who visited our center for the first time from November 2020 to March 2021 were selected to record the OMENS classification of the patients,and the indocyanine green angiography was used to observe the blood perfusion pattern in the hairless area behind the ear and its correlation with HFM.4.Patients admitted to our center from November 2020 to March 2021,who underwent the second stage of ear reconstruction by expanded two-flap method,were classified by OMENS for the diagnosis of HFM.Indocyanine green angiography system was used to observe and measure the blood perfusion and vascular distribution of the posterior auricular fascia,and to explore the effect of HFM on the blood perfusion,vascular distribution and postoperative complications.Results1.A total of 2383 patients were included in this study,including 30 patients with cartilage exposure after ear reconstruction and 2353 patients in the non-cartilage exposure group.There were 1793 males(75.2%)and 590 females(24.8%),and the gender difference between the two groups was not statistically significant(P=0.807).The total age of the samples ranged from 5 to 52 years old,with a mean age of 10.26±5.27 years old,and the age difference between the two groups could be considered statistically significant(P<0.01).There were 1378 patients(57.8%)with congenital microtia on the right side,852 patients(35.8%)with congenital microtia on the left side,and 153 patients(6.4%)with congenital microtia on both sides.There was no significant difference between the two groups(P=0.294).The time of complications in the 30 patients with cartilage exposure ranged from 21 to 2787 days after ear reconstruction(mean 323±558.14 days).Based on gender(tolerance 0),age(tolerance 1)and side(tolerance 1),1:1 matching sampling was conducted between the cartilage exposure group and the non-cartilage exposure group,and 28 pairs were accurately matched and 2 pairs were fuzzy matched.The cartilage exposure group was called the case group,and the matched samples were the control group.According to the OMENS classification of the patient,the MacQuillan method was used to make the diagnosis of HFM.There were 27 HFM patients,including 15 in the case group and 12 in the control group,with an OR value of 1.5(95%CI:0.539-4.171).The OR value is greater than 1,indicating that hemifacial shortness is a risk factor for cartilage exposure after ear reconstruction,but it cannot be considered statistically significant at present.Wilcoxon signed rank test of two related samples was used to compare each subtype of OMENS classification between the two groups,and the differences in the severity of ocular malformation(P=0.026)and facial nerve dysplasia(P=0.042)between the two groups were statistically significant.2.A total of 47 congenital microtia patients with HFM were included,including 44 males(93.6%)and 3 females(6.4%).The ratio of right to left microtia was 2.9:1(35:12),with an age range of 6-21 years,with an average of 9.3±2.1 years.The accessible length of the temporoparietal artery was 12.06±2.39cm on the affected side and 14.06±2.00cm on the healthy side,and the difference was statistically significant(P=0.012).Among the 94 superficial temporal arteries,6 of the superficial temporal arteries were missing the top branch,11 of the superficial temporal arteries were missing the frontal branch,and 5 of the superficial temporal arteries were missing the bifurcation point below the zygomatic arch.The differences between the healthy side and the affected side could not be considered statistically significant.The mean distance between the bifurcation point of the anterior and posterior branches of the superficial temporal artery and the superior margin of the zygomatic arch was 2.56±0.57cm,the mean distance between the affected side and the healthy side was 2.67±0.72cm,and the mean distance between the healthy side and the anterior branch was 2.45±0.34cmm,which was considered statistically significant(P=0.031).The mean length of the longest branch of the superficial temporal artery from the superior margin of the zygomatic arch to the accessible end was 13.06±2.42cm,12.06±2.39cm on the affected side and 14.06±1.99cm on the healthy side(P=0.012).The mean diameter of the main trunk of the superficial temporal artery was 1.38±0.31mm,the mean diameter of the affected side was 1.38±0.31mm,the mean diameter of the healthy side was 1.39±0.31mm,P=0.286.The mean diameter of the parietal branch of the superficial temporal artery was 1.06±0.25mm,the mean diameter of the affected side was 1.08±0.27mm,and the mean diameter of the healthy side was 1.03±0.22mm,P=0.511.The mean diameter of the frontal branch of the superficial temporal artery was 1,14±0.32mm,the mean diameter of the affected side was 1.17±0.36mm,and the mean diameter of the healthy side was 1.10±0.29mm,P=0.067.The mean thickness of the posterior auricular fascia was 0.75±0.17mm,0.78±0.12mm,0.81±0.19mm,P=0.037.The mean thickness of the temporoparietal fascia was 0.59 ± 0.12mm,the mean thickness of the affected side was 0.59±0.12mm,the mean thickness of the healthy side was 0.6010.12mm,P=0.432.3.A total of 34 patients,19 males(55.9%)and 15 females(44.1%),were included in the study of the pattern of blood perfusion in the hairless area behind the lesser auricular side.The ratio of right to left was 1.8:1(22:12),and the age span ranged from 6 to 15 years,with an average of 8.1±3.7 years.There were 21 patients without HFM and 13 patients with HFM.In the 34 lateral hairless skin behind the ear,except for 1 patient whose posterior auricular blood supply was not obviously from behind the ear,the other 33 patients(33/34,97.1%)had posterior auricular blood supply from the root of remanent ear,and no obvious occipital artery branch was found within the hair line,and the difference between the two groups was not statistically significant(P=0.197).Thirty patients(30/34,88.2%)had significant enhancement at the root of the earlobe,and one auricular patient had significant enhancement at the location where the earlobe should have appeared,although there was no earlobe.The difference between the two groups was not statistically significant(P=0.562).There were 27 patients(27/34,79.4%)with significant upper ear vascularization,and the difference between the two groups was statistically significant(P=0.043).4.A total of 32 retroauricular fascia were included in this study,including 18 patients with non-HFM and 14 patients with HFM.The mean follow-up was 2.3(0.5-5.5)months.No serious surgical complications such as necrosis of skin flap and cartilage exposure were found.Twelve patients developed obvious postauricular pigmentation,and 5 patients suffered partial necrosis after suture removal.There was no statistically significant difference in complications between the two groups.The mean absolute and relative ICG perfusion values of all retroauricular fascia were 45.9±19.1 and 35.2%±14.9 respectively.The mean absolute perfusion value and relative perfusion value were 49.2±20.1 and 32.5%±15.6 in the non-HFM group.The mean absolute perfusion value and relative perfusion value of the group were 41.7±17.7 and 38.7%±14.2 respectively.The difference of absolute perfusion value between the HFM group and the non-HFM group was statistically significant(P=0.035).In terms of blood supply pattern,marginal type(10/18,55.6%)and vascular type(12/18,66.7%)were the most common in the non-hemifacial short group,while homogeneous type(8/14,57.1%)and mixed type(9/14,64.3%)were the most common in the non-HFM group,and there was a statistical difference between them(P<0.05).The difference between upper,middle and lower part perfusion could not be considered statistically significant.Conclusion1.It was found in this study that congenital microtia patients with HFM,especially those with orbit malformation and facial nerve dysplasia,were more likely to have severe complications of cartilage exposure after ear reconstruction surgery.This suggests that clinicians should be more careful in the selection of surgical methods and pay closer attention to patients when treating such patients.2.In this study,it was found that the length of the probable temporoparietal artery on the affected side of HFM was shorter than that on the healthy side,the bifurcation point of the superficial temporal artery was higher,and the thickness of the retroauricular fascia was thinner,suggesting that HFM may affect the development of the temporal parietal artery and retroauricular fascia.The dysplasia of blood vessels and fascia increases the difficulty and risk of ear reconstruction.In patients with HFM,ear reconstruction should be performed on the basis of safety,and the height and fineness of the reconstructed ear should be sacrificed if necessary.3.In this study,it was found that the upper ear vascularization of patients with HFM was worse than that of patients with non-HFM,suggesting that the postauricular fascia blood supply of patients with HFM might be worse.In addition,perfusion analysis of the soft tissue behind the ear on the affected side confirmed that the blood supply from the posterior ear of the patients with microtia originated from the root of remanent ear,and compared with the occipital artery,the blood supply from remanent ear in the hairless area was absolutely dominant.In addition,there are perforating branches of blood vessels behind the root of earlobe,which are obviously enhanced.However,there is still one case of variation,suggesting that the distribution of blood vessels behind the ear varies greatly between individuals.4.In this study,indocyanine green angiography(ICGA)was applied to research the retroauricular fascia for the first time.None of the 32 enrolled patients had any serious complications related to fascia,so it would be safe if the absolute perfusion value of retroauricular fascia is above 38.5(38.5-48.2,C.I.95%),and the relative perfusion value is not less than 28.6%(28.6%-35.3%,C.I.95%).According to the measurement results,it was found that the upper part of the posterior auricular fascia had the best blood supply,while the middle part had worse blood perfusion.This may be related to the joint supply of the upper part by the posterior auricular artery and the superficial temporal artery,but the difference could not be considered statistically significant at present.There were differences in blood perfusion and blood supply pattern between the posterior fascia of the HFM group and the non-HFM group,with fewer clear vessels visible in the HFM group(P<0.01),and the vessels in the non-HFM group were mostly distributed at the edge of fascia(P=0.017).In this study,the number of cases was small and the time span was short,so the sample size and follow-up time should be expanded in the future to evaluate the effect of hemifacial short on the retroauricular fascia more objectively and accurately. |
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