Factors Influencing The Appearance Of Intersegmental Plane In Segmentectomy By Dilatation-collapse Method

Objective:Segmentectomy as a surgical method for early lung cancer has been gradually popularized.The most commonly used method to determine the intersegmental plane is dilatation-collapse method.The waiting time for the intersegment plane to appear varies from several minutes to tens of minutes in the application of dilatation-collapse method,and the relevant influencing factors are not clear at present.We propose a dilatation-collapse method that only ligate the artery,which is called arterial-ligation-alone method.This study is aim to demonstrate the effectiveness of the formation of intersegment plane by arterial-ligation-alone method in anatomical segmentectomy and the factors affecting the formation speed.Methods:We retrospectively analyzed 163 patients who underwent anatomical segmentectomy from January,2019 to September,2020.All patients underwent anatomical segmentectomy and systematic lymph node dissection/sampling by arterial-ligation-alone method during the operation.According to the speed of intersegment plane,it was divided into fast group(<15min)and slow group(≥15min),and the factors affecting the formation speed of intersegment plane were analyzed.Results:Fast group(<15min)80 cases,slow group(>15min)83 cases.In 157 cases(96.3%),a clear intersegmental plane was obtained by arterial-ligation-alone method,and the intersegmental plane was consistent with preoperative 3D reconstruction.The average waiting time of intersegmental plane for the fast group was(11.6±1.81)min,and that of the slow group was(18.3±4.4)min.There was significant difference in age between fast group and slow group(P=0.029<0.05),52(47-61)and 56(49-67),respectively.Left side surgery was performed on 30 patients(37.5%)in the fast group and 47 patients(56.7%)in the slow group,respectively(P=0.014<0.05).The fast group was lower than the slow group in some indicators of lung function,which were as follows:VC MAX%pred(93.0± 10.9 VS 97.2±11.2,P=0.019),VC EX%pred(92.1 ± 10.7 VS 96.4± 11.5,P=0.015),TLCO SB%pred(82.2± 14.3 VS 87.2± 12.9,P=0.021),VC IN%pred,92.0(84.7～97.6)VS(88.8～102.2),94.6(P=0.028),FVC%pred,95.3(86.0～100.1)VS(92.7～104.2),97.9(P=0.014),the TLC-He%pred,92.7(87.1～102.9)VS 97.2(91.0～105.3),P=0.045),VA%pred,88.8(81.8～98.0)VS(88.7～101.4),93,8(P=0.035),the RV/TLC～He(%),39.58(36.03～43.40)VS(38.43～46.01),42.39(P=0.004).There was no significant difference between the fast and slow groups in other pulmonary function indicators,including maximal voluntary ventilation,expiratory reserve volume,forced expiratory volume in one second,maximal mid expiratory,inspiratory capacity,functional residual capacity.Lung 3D reconstruction showed that the total lung volume in fast group and slow group was 3756.1 ±839.3 and 4608.7±1160.6(P=0.002<0.05),respectively.The volume of target segment to be resected was 243.2(179.7～343.0)and 338.2(225.7～516.6)(P=0.021<0.05).This means that the larger the total lung volume and the target segmental volume,the longer the waiting time of intersegmental plane.The intraoperative partial pressure of arterial oxygen(PaO2)in the fast group(388.3±84.6)was also lower than that in the slow group(439.5±85.7)(P=0.025<0.05).The intraoperative PaCO2,heart rate and blood pressure had no significant effect on the intersegmental plane.A total of 10 patients(6.13%)developed pulmonary leakage after surgery,and no serious complications or postoperative death occurred in any of the patients.Conclusion:The arterial-ligation-alone method is a feasible method to determine the intersegmental plane in anatomical segmentectomy.However,the intersegmental plane appeared more quickly in younger patients,patients with poor preoperative pulmonary capacity,patients with small lung volume and small target segmental volume,and patients with lower arterial oxygen partial pressure after intraoperative pulmonary dilation.