The Clinical Value And Anatomical Observation Of MSCT 3D Reconstruction Before Laparoscopic Radical Resection For The Left Colon Cancer

Research backgroundThe left half colon cancer refers to the tumors of splenic flexure of colon tumor, the tumors of descending colon and descending sigmoid junction. The left half colon cancer accounts for about 5% to 6% of all colorectal cancer. At present, the comprehensive treatment mainly treated with operation, the clinical reports about laparoscopic radical resection for the left colon cancer is less, Because part of the left colon easily lead to closed loop intestinal obstruction need emergency laparotomy, In addition, the difficulty of laparoscopic radical resection for the left colon cancer is big. There are several problems should be concerned mainly causes. Firstly, the splenic flexure of colon, which close to the lower pole of spleen, locates in high position. It meets intersection of different anatomical planes and adjacent to many other organs. This complex anatomy contributes difficult to separate the colon safely during laparoscopic procedure. Secondly, the blood supply of left half colon depends on branch vessels of inferior mesenteric artery (IMA) and middle colic artery (MCA). Variation of their anatomy and communication can partly affect the extent and site of lymph nodes and colon resection and incidence of anastomisis complications. In addition, the laparoscopic operation by using instruments tactile feedback the information provided and the judgment and estimation of the lesions in the two-dimensional picture, the lack of real tactility may not easy for positioning in the operation, particularly for complete cavity growth, small lesions, hardly identified neoplasm infiltration in serosa layer by eyes. Therefore, we observed the anatomy of the upper and lower mesenteric artery, the inferior mesenteric vein and adjacent case, tumor location and its blood vessels supplying by preoperative MSCT 3D reconstruction to forward-looking guidance for the laparoscopic radical resection for the left colon cancer, to improve the safety of operation.ObjectiveCollect the MSCT data of 32 patients, who underwent Laparoscopic radical resection for the left colon cancer and preoperative use MSCT scan the whole abdomen+dual-phase enhanced scan. Analyzed the CTA data and established image reconstruction model, according to its own three-dimensional CT reconstruction technique. Compared by multi-faceted and multi-angle observation of the anatomy of the upper and lower mesenteric artery, the inferior mesenteric vein and adjacent case, tumor location and its blood vessels, for Laparoscopic radical resection for the left colon cancer to provide certain anatomical and radiological reference, and finally to explore the clinical value of MSCT 3D reconstruction before surgical operation.Material and method1. ObjectCollected in our hospital from August 2012 to December 2014 who had underwent Laparoscopic radical resection for the left colon cancer in 32 patients, including 13 males and 19 females; Their mean age was (60.25±13.03) years, the mean body weight was (54.95±8.48) kg, the mean height was (158.56±10.91) cm, the mean BMI was (21.79±1.74), Preoperatively diagnosis confirmed the left colon malignant tumors by colonoscopy and pathology.Indications:the tumors of splenic flexure of colon tumor, the tumors of descending colon and descending sigmoid junction and before operation the patient must without radiotherapy or chemotherapy. Contraindications:Patients who had severe widespread or cardiopulmonary dysfunction, coagulation disorders, heavy abdominal adhesions after previous surgery, too large and advanced tumor and distant metastasis were excluded. The studies met the standards of medical ethics, and the patient will be asked to sign informed consent.2. EquipmentsIncluding laparoscopic special equipments, laparoscopic surgical instruments, Commonly used surgical equipments. The main equipment information was as follows:(1) CT scanner:Siemens Somatom Emotion 16-slice CT scanner (Siemens).(2) Double-syringe high-pressure injector:US medrad companies.(3)Image post processing workstation:Siemens Somatom Emotion 16-slice CT machine own Siemens syngo CT workstation.(4) Iopromide:300mgI/ml (Bayer healthcare).(5) Laparoscopic System (Japan Olympus Company)(6) Video recording system (Guangzhou Kang Medical Technology Co.).(7) Insufflations’system (Japan Olympus Company).(8) Energy Platform System (Li Kang heal force companies).3. CT scanning parameter and test methodRegular bowel preparation before the test, in this study all patients routinely scan the whole abdomen+dual-phase enhanced scan, the scanning range from the top of the diaphragm to the pubic symphysis, in each scan after deep inspiration breath hold a post. Using Siemens Somatom Emotion 16-slice CT machine, tube voltage:110kV, tube current:100-220mA (CareDose 4D), collimator 16.0mm×1.2mm, lap rotation time:0.6s, pitch:0.9, reconstruction thickness 1.5～8.0mm. Negative oral contrast agent prior to scanning, the forearm superficial vein micro pump into a non-ionic contrast agent:Iopromide 80～90ml, speed:3.5ml/s, using the diaphragm flat top threshold triggering aortic CT, CT threshold:120Hu, arterial scan delay time of 24～ 28s, portal venous phase scan delay time of 50～70s.4. Three dimensional reconstruction of CTThe complete images after scanning sent to the Siemens syngo CT workstation, used the soft tissue algorithm, the images were used 1.5mm thick volume rendering (VR), multiplanar reconstruction (MPR), maximum intensity projection (MIP) reconstruction of the main mesenteric vessels, that includes mesenteric artery (IMA) and its branches, colon artery (MCA) and its branches, the abdominal aorta (AA), the inferior mesenteric vein (IMV) and Major blood vessels involved in the abdominal cavity of the left colon. Three dimensional reconstruction of blood vessels to identify reference Knight Color Atlas of Human Anatomy, human anatomy and human anatomy atlas. All CTA images were evaluated and reached agreement by two senior doctors of Imaging Department. Observed the anatomical structure of vessels. Measured the distance from the root of the IMA to the abdominal aortic bifurcation point distance (D1) and the distance from the root to IMA issued the first branch(D2), measured the horizontal distance from the root of the IMA to IMV (D3), the location of tumor and the blood supply and adjacent conditions were observed.5. Surgical proceduresAll patients received general anesthesia tracheal intubation, the patient usually keep lithotomy position, head low enough height to 15-20°, tilt to the right 15～ 20°; The operator and the rotary mirror hand station is located in the right operation table, the first assistant station on the left of the table, you can adjust the position; 10mm tube is placed into the belly button edge for put into laparoscopic, right subclavian central line placed above and below the level of the navel 5cm two 5mm tubes, the outer edge of the left subclavian midline umbilical level 10mm tube placement, it can be used expand to 5 or 6cm to removing the specimen. Properly adjusting the position of the sleeve.abdominal exploration:pre-surgery CT tumor localization was observed after the completion of pneumoperitoneum, the specifically tumor location determined the scope of surgical resection and dissection. To observed the forming region by inferior mesenteric vessels and abdominal aorta and Iliac vessels. Open the left colon right peritoneum on abdominal aortic bifurcation into the Toldt’s fascial space. Reference the measured distance of D1 by preoperative reconstructed, free surface of the IMA root and lymph nodes were cleaning, Reference the measured distance of D2 by preoperative reconstructed, to revealed the anatomy of IMA, the left colic artery, sigmoid artery 1～2 branch at the root of IMA were cut off, Reference the measured distance of D3 by preoperative reconstructed exploration and cut off the inferior mesenteric vein. Cut off the left gastric colon ligament and the lienorenal ligament. Isolated and cut off the left branch of the MCA, MCV. For tumor blood supply artery was MCA, the lymphoid of MCA roots tissue should be cleaned. Resection of left colon in vitro. Transverse sigmoid colon end-to-end anastomosis and closed mesocolon hole; Pneumoperitoneum reconstruction after wound closure, Peritoneal lavage and drainage tube put into after abdominal closure. If you cannot control the complications or difficult to separate tumors, the surgeon should make an accurate judgment, taking into account the safety of the operation should be converted to laparotomy.6. Statistical AnalysisWe used SPSS 13.0 software for statistical analysis, measurement data using mean±standard deviation, measured the distance from the root of the IMA to aortic bifurcation point (D1),the distance from the root of the IMA to the first branch of IMA issued (D2), observed the horizontal distance from the root of IMA to the IMV (D3), The correlation analysis between D1, D2, D3, height, weight, BMI, The correlation coefficient is indicated by r, r using t test method, P< 0.01 shows the difference had statistical significance. Preoperative tumor localization and intraoperative observation of mutual comparison, consistency for Kappa test value in 0～1. Kappa= 0.75 both have good correlation; 0.75>Kappa= 0.4 they have general correlation, Kappa<0.4 they have poor correlation, P< 0.05 shows the difference had statistical significance.Results①Preoperative MSCT 3D reconstruction clearly shows the anatomic structure of the inferior mesenteric vessels:the IMA comes from the abdominal aorta, the IMA backbone slanting to the left, the branch of the IMA includes left colic artery, sigmoid artery and the superior rectal artery, they exist various types of variation. IMV is located in left the of IMA, its lower segment concomitant with IMA, The middle of the IMV concomitant with LCA, the terminal of the IMV leave for IMA.②Preoperative the average length of D1 was(4.21±0.63)cm measured by MSCT 3D reconstruction, D2 average length was(4.27±0.55)cm. D3 average length was(3.09±0.75)cm, The correlation analysis between D1, D2, D3, height, weight, BMI, the correlation coefficient is indicated by r, r using t test method, the results of P was greater than 0.01, the difference was not significant, no statistical significance, these suggesting that D1, D2, D3, height, weight, BMI are not correlated.③Preoperative MSCT 3D reconstruction can shows the location of the tumor and its blood supply,32 cases of malignant tumor collected by MSCT preoperative localization shows that there are 10 cases of splenic flexure of colon cancer,12 cases of descending colon,10 cases of descending-sigmoid junction colon cancer,we found in laparoscopic surgery:there are 10 cases of splenic flexure of colon cancer,12 cases of descending colon,10 cases of descending-sigmoid junction colon cancer,1 case of the transverse colon,1 case of the sigmoid colon,28 cases has same positioning with preoperative, the accuracy rate reaches 87.5%, K=0.818, P<0.05, showed that tumor preoperative localization and intraoperative observations are consistent.32 cases were completed under laparoscopy with no intraoperative injury or serious postoperative complications.Conclusions1. Before Laparoscopic radical resection of left colon cancer should done MSCT 3D reconstruction, it can provides certain anatomical and radiological reference for the schemes of preoperative and intraoperative operation.It is benefits to improve the safety of laparoscopic radical resection for the left colon cancer, and it has the prospective value of guidance.2. The key indicators of MSCT 3D reconstruction before Laparoscopic radical resection for the left colon cancer Includes:the anatomical structure of IMA; the length of D1, D2,D3; the location of the tumor and its blood supply.①Preoperative MSCT 3D reconstruction can accurately show the anatomical structure of IMA, Clearly mesenteric vascular for help reduce intraoperative injury, reduce surgical complications will help improve the safety of operation.②Preoperative MSCT 3D reconstruction measured the distance of D1 conduct separated upward prejudge length conducive intraoperative search for the root of the IMA; preoperative measured the distance of D2 to determine the location LCA guide IMA respective branches separated within a certain length; Preoperative measurement of the distance of D3 can determine the location of the IMV, helps protect the ureter and gonadal vessels, smooth entry into the Toldt’s compartment. D1, D2, D3 be measured can guide the laparoscopic operation.③ Preoperative MSCT 3D reconstruction can help localization judgment early and mid-cavity cancer, especially fully grown, small lesions, non-invasive serous appearance of normal colorectal tumor, reducing the risk of surgery.④Preoperative MSCT 3D reconstruction can clearly display the blood supply of the tumor,for the left colon in the splenic flexure, Supply artery of the tumor is MCA, the complete third station lymph node dissection should clean the root node, guarantees the cleaning scope of lymphoid tissue in the operation.