| Objective The three-dimensional model of kidney was reconstructed by image segmentation and fusion of kidney CT scanning data collected from 30 normal persons and patients with kidney stones.To provide basic data for the etiology of kidney stones,the anatomical data related to the etiology of kidney stones were measured,and the differences between normal people and patients with kidney stones were compared and analyzed.Percutaneous nephrolithotomy PCNL virtual surgery was performed on the reconstructed three-dimensional model of renal calculi patients.The differences of puncture path,puncture point,puncture depth and channel selection between virtual surgery and these patients were compared.At the same time,the differences of hospital stay,operation time,operation effect,complications and post-operative bleeding between PCNL operation planned and simulated by preoperative virtual surgery planning and conventional PCNL operation without PCNL virtual surgery planning simulation were compared,so as to provide new ideas for improving the operation effect of PCNL and reducing complications.Materials and Methods Thirty patients with kidney stones and 30 normal persons were randomly selected as study group and control group.The study group selected patients with kidney stones who were treated in Liangxiang Hospital of Fangshan District from December 2017 to February 2019.The control group were normal persons who underwent physical examination in our hospital at the same time.After collecting the CT scan data of the two groups of patients,the three-dimensional modelofthe kidney was reconstructed by image segmentation and fusion.Relevant anatomical structure data(kidney length,kidney width,sinus length,sinus width,pelvis-ureter junction diameter,upper renal margin to spinous process length,inferior renal margin to spinous process length,hilum to spinous process length)weremeasured and compared between the two groups.According to the results of three-dimensional digital measurement and the reconstructed three-dimensional model,the operation planning and design of the puncture path,puncture point,puncture depth and channel selection for patients with renal calculi were carried out with PCNL simulation surgical instrument.The relationship between the renal structure and adjacent organs was familiarized with the operation simulation of virtual simulation surgery.The virtual operation included indwelling catheter and construction of adjacent organs.Vertical channel,lithotripsy process and indwelling fistula tube were used to perform real PCNL operation after virtual operation,and the puncture location,puncture channel and puncture depth were recorded to compare the coincidence between virtual operation and actual operation.GroupA was patients with renal calculi who underwent PCNL after virtual surgery.Group B was inquired about the patients with kidney stones who were hospitalized in our hospital for routine PCNL operation without virtual operation at the same time.The difference between group A and group B in real PCNL operation(operation time,intraoperative bleeding volume,postoperative hospitalization days,total hospitalization days,postoperative complications)were compared between two groups.All the subjects underwent spiral CT scanning of the kidney on an empty stomach with the position of supine position,and the scanning period consisted of four phases: plain scan,arterial scan,venous scan and pelvic excretion.The acquired CT image data of four phases were imported into three-dimensional image processing and editing software(MIMICS 16.0)to produce three-dimensional images,and the three-dimensional image model of kidney stones was formed by editing,image segmentation and three-dimensional reconstruction.Image segmentation technology mainly used threshold segmentation method and region growing method,image segmentation and three-dimensional reconstruction were automatically processed by software,but in order to make image data more accurate and close to reality,manual proofreading is also needed.The quality evaluation and control of the three-dimensional image were evaluated by two experienced urologists,and the validity of the reconstructed three-dimensional model was judged according to the evaluation criteria.Virtual simulation surgery wasaccomplished by 3D Studio Max software and FreeForm Modeling Plus(3D haptic design system).The reconstructed three-dimensional model could be enlarged and reduced.The location and size of the three-dimensional space of the kidney can also be observed by rotation.The internal structure of the kidney can be observed by transparency.The comparative data were analyzed by SPSS20.0.P < 0.05 showed significant difference,P < 0.01 showed extremely significant difference.Results 1.There were no significant differences in renal length,renal width,sinus length,sinus width,pelvis-ureter junction diameter,upper renal margin-spinous process longitudinal line distance,lower renal margin-spinous process longitudinal line distance and hilum-spinous process longitudinal line distance between patients with calculi and normal persons(P > 0.05).2.Multiparameter logistic regression analysis of renal anatomy in patients with renal calculi showed that there was no significant correlation between the length of kidney,the width of kidney,the length of renal sinus,the width of renal sinus,the diameter of the junction between renal pelvis and ureter,the distance between upper renal margin and spinous process,the distance between lower renal margin and spinous process,and the distance between renal hilum and spinous process(P > 0.05).3.A total of 30 sets of 64-slice CT images of kidney stones in four phases were collected,and a three-dimensional model of kidney stones were established in 30 patients.Among them,29 cases were valid and complete,and the validity was 96.7%.The reconstructed kidney model had a clear outline and can truly reflect the patient's physiological and anatomical morphology.Renal artery can clearly show the main trunk and fourth branch of renal artery,and renal vein can show the main trunk and reflux branch of renal vein.The shape and number of stones and the expansion degree of aggregate system can be visually displayed.At the same time,we can see the relationship between adjacent organs and kidneys.4.The puncture site was located at the upper pole of the kidney in 16 cases,at the middle level in 13 cases.The location of the puncture channel was above 12 ribs in 26 cases and below 12 ribs in 3 cases,with an average puncture depth of(6.51±0.94)cm.5.In virtual simulation surgery,16 cases were punctured in the upper calyx,13 in the middle calyx;26 cases were punctured in the 11 th rib,3 in the 12 th rib;29cases were single-channel;17 cases were punctured in the upper calyx,12 in the middle calyx;26 cases were punctured in the 11 th rib,3 in the 12 th rib;28 cases were single-channel and 1 case was double-channel.The coincidence of puncture path,puncture point and puncture passage between virtual simulation operation and actual operation was 96.6%(28/29),100%(29/29)and 96.6%(28/29),respectively.The average puncture depth in virtual simulation operation was(6.51± 0.94)cm,while the average puncture depth in actual operation was(7.05± 0.83)cm.The puncture path,puncture point,puncture passage and puncture depth between virtual operation and actual operation were 96.6%(28/29),respectively.There was no significant difference(P > 0.05).6.The average operation time of PCNL group(group A)was(75.13±25.69)minute,the average hospital stay was(14.30± 5.27)day,the average bleeding volume was(40.67± 59.38)ml,the hospital stay was(7.20± 1.75)day,the incidence of serious complications was 0%,while those of PCNL group(hereinafter referred to as group B)were average.The average operation time was(83.95 ±60.14)min,the average hospital stay was(16.54± 6.13)days,the average bleeding volume was(104.27±51.48)ml,the hospitalization time was(9.15± 2.24)days,the incidence of serious complications was 6.9%.There were no significant difference in hospitalization time and average operation time between the two groups(P > 0.05),but the average bleeding volume,the average operation time were not significantly different.Postoperative hospital stay,incidence of complications,were significantly different(P < 0.05).Conclusion 1.In patients with renal calculi,renal length,renal width,length of renal sinus,width of renal sinus,diameter of the junction between the renal pelvis and ureter,distance from the upper edge of the kidney to the longitudinal line of the spinous process,distance from the lower edge of the kidney to the longitudinal line of the spinous process,and distance from the hilum to the longitudinal line of the spinous process were not significantlycorrelated with the formation of renal calculi.2.Virtual surgery for renal calculi is in good agreement with the actual operation.Preoperative planning and Simulation of virtual surgery with reconstructed three-dimensional model of renal calculi can help to reduce the bleeding volume ofPCNL operation,improve the stone clearance rate,and reduce the hospital stay and the occurrence of serious complications. |
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