Observation Of The Anatomical Types And Variation Of Pulmonary Segmentbronchus Based On Multi-slice Spiral CT Three Dimensional Reconstruction Technique

Objective:To investigate the anatomical types and variation of segmental bronchi based on CT three-dimensional reconstruction.Methods:It was a retrospective study.The imaging data of 615 patients who underwent chest thin-layer enhanced CT examination in the Department of Thoracic Surgery,the First Affiliated Hospital of Xinjiang Medical University from December 2019 to August 2022 were included,including 250 males and 365 females,aged 38 to 70 years（median age 58 years）.Among the 615 patients,there were 488 cases of lung cancer and 127 cases of tuberculosis and inflammation.CT examination showed that the lesions were located in the right lung in359 cases,including 205 cases in the right upper lobe,43 cases in the right middle lobe,and 111 cases in the right lower lobe.There were 256 cases of left lung,including 184cases of the left upper lobe and 72 cases of the left lower lobe.The bronchi and blood vessels of the affected lung were reconstructed according to the CT scan data of the patients.The anatomical types and anatomical variations of bronchi of each segment of the lung on the affected side were observed and counted.Results:There were 359 cases in the right lung:（1）The anatomical types of the right upper lobe bronchus were divided into three types:105 cases（29.2%）of two-branch type,233 cases（64.9%）of three-branch type,and 11 cases（3.1%）of four-branch type.Of the three-branch types,the B¹,B²,B³subtype was the most common anatomical type in the upper lobe of the right lung,with 215 cases（59.9%）.In addition,10 cases（2.8%）of rare anatomical variations were observed.（2）The anatomical types of the right middle lobe bronchus were divided into three types:two-branch type in 343 cases（95.5%）,three-branch type in 15 cases（4.2%）,and four-branch type in 1 case（0.3%）.Of the two-branch type,the B⁴,B⁵subtype（332 cases,92.5%）was the most common anatomical type of the right middle lobe bronchus.In addition,In 27 cases（7.5%）,the spatial relationship of the B⁴,B⁵type in the right middle lobe was similar to that of the B⁴,B⁵type in the left upper lobe.（3）The anatomical types of the superior segment of the right lower lobe bronchus were divided into three types:one-branch type（353 cases,98.3%）,two-branch type（5 cases,1.4%）,and three-branch type（1 case,0.3%）.The one-branch type was further divided into bifurcated subtype（248 cases,69.1%）and trifurcated subtype（105 cases,29.2%）.Among the bifurcated subtype,the B⁶b,B⁶a+c type（114 cases,31.8%）was the most common anatomical type of the superior segment of the right lower lobe bronchus.The mediobasal segmental bronchus of the right lower lobe was divided into six subtypes,of which the B⁷a type was the most common type（215 cases,59.9%）.The anatomical types of the ventrobasal,lateralbasal and dorsobasal segmental bronchus of the right lower lobe were divided into four types,of which the B⁸,B⁹+B¹⁰type was the most common type（261cases,72.7%）.The subsuperior segmental bronchus（B^*）was found in the right lower lobe in 124 cases（34.5%）.According to the number of B^*branches,114 cases（31.7%）were one-branch type and 10 cases（2.8%）were two-branch type.According to the origin site of B^*,the patients were divided into three subtypes,of which the B⁸,B^*+B⁹+B¹⁰type was the most common（88 cases,24.5%）.256 cases of left lung:（1）The anatomical types of the proper segment bronchus of the left upper lobe were divided into three types:165cases（64.4%）of the two-branch type,90 cases（35.2%）of the three-branch type,and 1case（0.4%）of the four-branch type.The two-branche type were divided into 8 subtypes,of which the(B¹⁺²a+b,B¹⁺²c),（B³a,B³b+c）type was the most common anatomical type in the proper segment of the left upper lobe bronchus（116 cases,45.3%）.The anatomical types of the lingual bronchus in the upper lobe of the left lung were divided into two types,249 cases（97.3%）of two-branch type and 7 cases（2.7%）of three-branch type.The two-branch type were divided into 4 subtypes,of which the B⁴,B⁵type was the most common anatomical type（182 cases,71.7%）.In addition,in 56 cases（21.9%）,the spatial relationship of the B⁴,B⁵type in the left upper lobe was similar to that B⁴,B⁵type in the right middle lobe.（2）The anatomical types of the superior segment bronchus of the left lower lobe were divided into three types:254 cases（99.2%）of one-branch type,1 case（0.4%）of two-branch type,and 1 case（0.4%）of three-branch type.The one-branch type was further divided into three subtypes:bifurcated type（164 cases,64.1%）,trifurcated type（89 cases,34.8%）and quadrvival type（1 case,0.4%）.Among the trifurcated subtype,the B⁶a,B⁶b,B⁶c type was the most common anatomical type in the superior segment of the left lower lobe of the lung（85 cases,33.2%）.The anatomical types of the ventrobasal,lateralbasal and dorsobasal segmental bronchus of the left lower lobe were divided into three types,of which the B⁸,B⁹+B¹⁰type was the most common（148 cases,57.8%）.In addition,a separate branch of B⁷from the basal trunk was observed in 19 cases（7.4%）.In addition,95 cases（37.1%）of B^*were observed in the lower lobe of the left lung.According to the number of B^*branches,there were 78 cases（30.5%）of one-branch type and 17 cases（6.6%）of two-branch type.There were five subtypes according to the B^*origin site,among which B⁸,B^*+B⁹+B¹⁰subtype was the most common in 52 cases（20.3%）.Conclusions:The anatomical types of segmental and subsegmental bronchi are complex and diverse,and there are rare anatomical variations.It is necessary to be fully familiar with the branch types of the corresponding bronchi before related operations to avoid misjudgment and accidental injury during operation.