Objective To investigate the feasibility and clinical efficacy of total three-dimensional laparoscopic pancreatoduodenectomy. Methods The clinical data of 28 patients who underwent total three-dimensional laparoscopic...Objective To investigate the feasibility and clinical efficacy of total three-dimensional laparoscopic pancreatoduodenectomy. Methods The clinical data of 28 patients who underwent total three-dimensional laparoscopic pancreatoduodenectomy at the Second Hospital of Hebei Medical University from August 2015 to May 2016 were retrospectively analyzed. The surgical indications and method of performing total threedimensional laparoscopic pancreatoduodenectomy were similar to those of the patients who underwent two-dimensional laparoscopic pancreatoduodenectomy. All of the patients were followed up via outpatient reviews and telephone interviews through September 2016. Results In all 28 cases, total three-dimensional laparoscopic pancreatoduodenectomy was successfully performed with no conversion to laparotomy, intraoperative complications, or perioperative death. The mean operative time was 406 min(200–520 min) with a mean blood loss of 528 m L(200–1500 m L), a mean number of dissected lymph nodes of 11(6–16), a mean postoperative anus exhaust time of 4.4 d(2–8 d), and a mean length of stay of 16.9 d(9–23 d). There was a postoperative pancreatic fistula in 4 out of the 28 cases, with 3 cases of grade A and 1 case of grade B. Postoperatively, one patient with early-stage intra-abdominal hemorrhage improved after conservative symptomatic treatment, and two patients with gastroplegia were cured with conservative treatment. No complications occurred in the other patients. All of the cases underwent R0 resection with a negative surgical margin. All of the 28 patients were followed up for 6 to 12 months, with a median follow-up period of 9.2 months. During the follow-up period, there were no postoperative complications related to the procedures and no deaths; tumor recurrence was identified 9 months after the procedure using positron emission computed tomography(PECT) in one patient with pancreatic ductal adenocarcinoma.Conclusion Total three-dimensional laparoscopic pancreatoduodenectomy is safe and feasible for the treatment of periampullary carcinoma, with the advantage of favorable short-term outcomes.展开更多
Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate ...Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate chemistry. The results show that the calculated streak picture is in qualitative agreement with the picture recorded by a high speed streak camera from published literature. The three-dimensional flow field induced by a continuously rotating detonation was visualized and distinctive features of the rotating detonations were clearly depicted. Owing to the unconfined character of detonation wavelet, a deficit of detonation parameters was observed. Due to the effects of wall geometries, the strength of the outside detonation front is stronger than that of the inside portion. The detonation thus propagates with a constant circular velocity. Numerical simulation also shows three-dimensional rotating detonation structures, which display specific feature of the detonation- shock combined wave. Discrete burning gas pockets are formed due to instability of the discontinuity. It is believed that the present study could give an insight into the interest- ing properties of the continuously rotating detonation, and is thus beneficial to the design of continuous detonation propulsion systems.展开更多
A calculation scheme, which combines a horizontal upwind finite element method with vertical implicit differences, is used to establish a three-dimensional mathematical model of tidal motion and sediment transport in...A calculation scheme, which combines a horizontal upwind finite element method with vertical implicit differences, is used to establish a three-dimensional mathematical model of tidal motion and sediment transport in tidal current. Compared with those of the relative theoretical formula, the results are satisfactory. The model mentioned above has been applied to the water area of the Lianzhou Bay, Guangxi Province. On the basis of the analysis and comparison with the field data, it shows clearly that the model calculation results are reasonable.展开更多
AIM:To investigate whether computed tomography with 3D imaging(3DCT)can reduce the risks associated with laparoscopic surgery.METHODS:We performed a retrospective case-control study evaluating the efficacy of preopera...AIM:To investigate whether computed tomography with 3D imaging(3DCT)can reduce the risks associated with laparoscopic surgery.METHODS:We performed a retrospective case-control study evaluating the efficacy of preoperative 3DCT of the splenic vascular anatomy on surgical outcomes in patients undergoing laparoscopic spleen-preserving splenic hilar lymph node(LN)dissection for upper-or middle-third gastric cancer.The clinical records of 312patients with upper-or middle-third gastric cancer who underwent laparoscopic total gastrectomy with spleenpreserving splenic lymph node dissection in our hospital from January 2010 to June 2013 were collected,and the patients were divided into two groups(group 3DCT vs group NO-3DCT)depending on whether they underwent 3DCT or not.Clinicopathologic characteristics,operative and postoperative measures,the number of retrieved LNs,and complications were compared between these two groups.Patients were further compared regarding operative and postoperative measures,the number of retrieved LNs,and complications when subdivided by body mass index(≥23 and<23 kg/m2)and the number of operations performed by their surgeon(≤40 vs>40).RESULTS:The mean numbers of retrieved splenic hilar LNs were similar in patients in group 3DCT and group NO-3DCT(2.85±2.33 vs 2.48±2.18,P>0.05).The operation time and blood loss at the splenic hilum were lower in the patients in group 3DCT(P<0.05 each).The postoperative recovery time and complication rates were similar between the two groups(P>0.05 each).Subgroup analysis showed that the operation time at the splenic hilum in patients with a BMI≥23 kg/m2was significantly shorter in patients in group 3DCT than in group NO-3DCT(20.27±5.84 min vs 26.17±11.01 min,P=0.003).In patients with a BMI<23kg/m2,the overall operation time(171.8±26.32 min vs 188.09±52.63 min,P=0.028),operation time at the splenic hilum(19.39±5.46 min vs 23.74±9.56min,P=0.001),and blood loss at the splenic hilum(13.27±4.96 mL vs 17.98±8.12 mL,P=0.000)were significantly lower in patients in group 3DCT than in group NO-3DCT.After 40 operations,the operation time(18.63±4.40 min vs 23.85±7.92 min,P=0.000)and blood loss(13.10±4.17 mL vs 15.10±4.42 mL,P=0.005)at the splenic hilum were significantly lower in patients who underwent 3DCT,but there were no significant between-group differences prior to 40 operations.CONCLUSION:3DCT is critical for surgical guidance to reduce the risks of splenic LN dissection.This method may be important in safely facilitating laparoscopic spleen-preserving splenic LN dissection.展开更多
文摘Objective To investigate the feasibility and clinical efficacy of total three-dimensional laparoscopic pancreatoduodenectomy. Methods The clinical data of 28 patients who underwent total three-dimensional laparoscopic pancreatoduodenectomy at the Second Hospital of Hebei Medical University from August 2015 to May 2016 were retrospectively analyzed. The surgical indications and method of performing total threedimensional laparoscopic pancreatoduodenectomy were similar to those of the patients who underwent two-dimensional laparoscopic pancreatoduodenectomy. All of the patients were followed up via outpatient reviews and telephone interviews through September 2016. Results In all 28 cases, total three-dimensional laparoscopic pancreatoduodenectomy was successfully performed with no conversion to laparotomy, intraoperative complications, or perioperative death. The mean operative time was 406 min(200–520 min) with a mean blood loss of 528 m L(200–1500 m L), a mean number of dissected lymph nodes of 11(6–16), a mean postoperative anus exhaust time of 4.4 d(2–8 d), and a mean length of stay of 16.9 d(9–23 d). There was a postoperative pancreatic fistula in 4 out of the 28 cases, with 3 cases of grade A and 1 case of grade B. Postoperatively, one patient with early-stage intra-abdominal hemorrhage improved after conservative symptomatic treatment, and two patients with gastroplegia were cured with conservative treatment. No complications occurred in the other patients. All of the cases underwent R0 resection with a negative surgical margin. All of the 28 patients were followed up for 6 to 12 months, with a median follow-up period of 9.2 months. During the follow-up period, there were no postoperative complications related to the procedures and no deaths; tumor recurrence was identified 9 months after the procedure using positron emission computed tomography(PECT) in one patient with pancreatic ductal adenocarcinoma.Conclusion Total three-dimensional laparoscopic pancreatoduodenectomy is safe and feasible for the treatment of periampullary carcinoma, with the advantage of favorable short-term outcomes.
基金supported by the National Natural Science Foundation of China (10872096)the Open Fund of State Key Laboratory of Explosion Science and Technology, Beijing University of Science and Technology (KFJJ09-13)
文摘Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate chemistry. The results show that the calculated streak picture is in qualitative agreement with the picture recorded by a high speed streak camera from published literature. The three-dimensional flow field induced by a continuously rotating detonation was visualized and distinctive features of the rotating detonations were clearly depicted. Owing to the unconfined character of detonation wavelet, a deficit of detonation parameters was observed. Due to the effects of wall geometries, the strength of the outside detonation front is stronger than that of the inside portion. The detonation thus propagates with a constant circular velocity. Numerical simulation also shows three-dimensional rotating detonation structures, which display specific feature of the detonation- shock combined wave. Discrete burning gas pockets are formed due to instability of the discontinuity. It is believed that the present study could give an insight into the interest- ing properties of the continuously rotating detonation, and is thus beneficial to the design of continuous detonation propulsion systems.
文摘A calculation scheme, which combines a horizontal upwind finite element method with vertical implicit differences, is used to establish a three-dimensional mathematical model of tidal motion and sediment transport in tidal current. Compared with those of the relative theoretical formula, the results are satisfactory. The model mentioned above has been applied to the water area of the Lianzhou Bay, Guangxi Province. On the basis of the analysis and comparison with the field data, it shows clearly that the model calculation results are reasonable.
文摘AIM:To investigate whether computed tomography with 3D imaging(3DCT)can reduce the risks associated with laparoscopic surgery.METHODS:We performed a retrospective case-control study evaluating the efficacy of preoperative 3DCT of the splenic vascular anatomy on surgical outcomes in patients undergoing laparoscopic spleen-preserving splenic hilar lymph node(LN)dissection for upper-or middle-third gastric cancer.The clinical records of 312patients with upper-or middle-third gastric cancer who underwent laparoscopic total gastrectomy with spleenpreserving splenic lymph node dissection in our hospital from January 2010 to June 2013 were collected,and the patients were divided into two groups(group 3DCT vs group NO-3DCT)depending on whether they underwent 3DCT or not.Clinicopathologic characteristics,operative and postoperative measures,the number of retrieved LNs,and complications were compared between these two groups.Patients were further compared regarding operative and postoperative measures,the number of retrieved LNs,and complications when subdivided by body mass index(≥23 and<23 kg/m2)and the number of operations performed by their surgeon(≤40 vs>40).RESULTS:The mean numbers of retrieved splenic hilar LNs were similar in patients in group 3DCT and group NO-3DCT(2.85±2.33 vs 2.48±2.18,P>0.05).The operation time and blood loss at the splenic hilum were lower in the patients in group 3DCT(P<0.05 each).The postoperative recovery time and complication rates were similar between the two groups(P>0.05 each).Subgroup analysis showed that the operation time at the splenic hilum in patients with a BMI≥23 kg/m2was significantly shorter in patients in group 3DCT than in group NO-3DCT(20.27±5.84 min vs 26.17±11.01 min,P=0.003).In patients with a BMI<23kg/m2,the overall operation time(171.8±26.32 min vs 188.09±52.63 min,P=0.028),operation time at the splenic hilum(19.39±5.46 min vs 23.74±9.56min,P=0.001),and blood loss at the splenic hilum(13.27±4.96 mL vs 17.98±8.12 mL,P=0.000)were significantly lower in patients in group 3DCT than in group NO-3DCT.After 40 operations,the operation time(18.63±4.40 min vs 23.85±7.92 min,P=0.000)and blood loss(13.10±4.17 mL vs 15.10±4.42 mL,P=0.005)at the splenic hilum were significantly lower in patients who underwent 3DCT,but there were no significant between-group differences prior to 40 operations.CONCLUSION:3DCT is critical for surgical guidance to reduce the risks of splenic LN dissection.This method may be important in safely facilitating laparoscopic spleen-preserving splenic LN dissection.
