Objective:To analyze the clinical efficacy and learning curve of robotic-assisted Warshaw procedure using the da Vinci system.Methods:Clinical data of 91 consecutive patients with pancreatic body and tail lesions undergoing robotic-assisted Warshaw procedure at Qingdao University Affiliated Hospital from October 2021 to April 2023 were retrospectively analyzed, including 21 males and 70 females, aged (50.2±14.3) years. Patient characteristics, operative time, and intraoperative blood loss were recorded. The learning curve was constructed using cumulative sum (CUSUM) analysis, with case number on the x-axis and CUSUM values on the y-axis. Linear fitting was performed, and the model with the highest determination coefficient was selected as the optimal fitting model. The learning process was divided into two phases based on the inflection point of the CUSUM learning curve: the learning phase and the proficiency phase. Perioperative outcomes were compared between these two phases.Results:All 91 procedures were successfully completed using the da Vinci robotic system with R0 resection margins. There were no perioperative mortalities or reoperations due to postoperative splenic infarction. The operative time was (227.84±76.68) min. The optimal fitting equation for the CUSUM learning curve was: CUSUM=0.005 640X 3-1.501X 2+ 92.59X-183.1. The CUSUM learning curve showed an inflection point at case 39, dividing the learning process into the learning phase (cases 1-39) and proficiency phase (cases 40-91). Compared to the learning phase, the proficiency phase demonstrated significantly shorter operative time [(203.0±75.6) min vs. (260.9±65.5) min], less intraoperative blood loss [50.0 (20.0, 50.0) ml vs. 100.0 (50.0, 100.0) ml], and reduced postoperative drainage duration [(8.7±2.4) d vs. (10.8±3.2) d] (all P<0.05). Conclusion:The robotic-assisted Warshaw procedure feasible for patients with pancreatic body and tail lesions. Surgeons require approximately 39 cases to complete the learning curve and achieve proficiency in this procedure.

Objectives:To explore the efficacy of robotic-assisted retroperitoneal benign tumor resection and to analyze its learning curve.Methods:This is a retrospective case series study. The data of patients who underwent robotic-assisted retroperitoneal benign tumor resection from August 2015 to February 2023 at the Department of Retroperitoneal Tumor Surgery was analyzed retrospectively. There were 24 males and 45 females, with an age of (46.3±10.6) years (range: 19 to 76 years). The perioperative data, postoperative pathological results, and follow-up data were recorded. The cumulative sum (CUSUM) method was used to analyze the robotic system setup time and operative time to plot the learning curve. A linear regression model was applied to determine the best-fit curve, selecting the model with the highest R2 value. Based on the vertex of the learning curve for surgical time, the patients were divided into a learning group and a mastery group. The general data and perioperative conditions of the two groups were compared. Independent sample t-tests, Mann-Whitney U tests, and χ2 tests were used for comparisons. Results:All 69 patients successfully completed the surgery without intraoperative complications. The diameter of tumors was (49.7±18.6) mm (range: 16 to 131 mm). The setup time for the robotic surgical system was (35.3±9.8) minutes (range: 20 to 61 minutes); the surgical time was (169.2±36.5) minutes (range: 70 to 305 minutes); intraoperative blood loss ( M(IQR)) was 10.0 (15.0) ml (range: 2.0 to 200.0 ml). The tumors in 32 patients (46.4%) were adherent to major blood vessels. All patients were discharged without complications. The follow-up period lasted until February 2024, and no patients required reoperation, readmission, or died due to retroperitoneal benign tumors. There were no severe long-term complications, and no radiological evidence of tumor recurrence was found. The best-fit equation for the learning curve based on surgical time was CUSUM=0.010X3-1.648X2-68.573X-61.091, and the best-fit equation for the learning curve based on robotic system setup time was CUSUM=0.0018X3-0.285X2+10.460X+57.541 (where X represents the number of surgeries). The R2 values of 2 learning curve models were 0.953 and 0.957, respectively, and the fit model tests had P<0.05. The inflection point of the learning curve based on surgical time was the 28th case, which is considered the minimum number of surgeries required to achieve proficiency in robotic-assisted retroperitoneal benign tumor resection. Based on this, the patients were divided into a learning group (cases 1 to 28) and a mastery group (cases 29 to 69). The surgical time for the learning group was significantly longer than that of the mastery group ((194.7±30.0) minutes vs. (151.9±31.4) minutes, t=4.126, P<0.01). No statistically significant differences were found for other parameters (all P>0.05). Conclusions:Robotic-assisted retroperitoneal benign tumor resection is feasible. The minimum number of surgeries required to achieve proficiency in overcoming the learning curve is about 28 cases.

Objective:To analyze the clinical efficacy and learning curve of robotic-assisted Warshaw procedure using the da Vinci system.Methods:Clinical data of 91 consecutive patients with pancreatic body and tail lesions undergoing robotic-assisted Warshaw procedure at Qingdao University Affiliated Hospital from October 2021 to April 2023 were retrospectively analyzed, including 21 males and 70 females, aged (50.2±14.3) years. Patient characteristics, operative time, and intraoperative blood loss were recorded. The learning curve was constructed using cumulative sum (CUSUM) analysis, with case number on the x-axis and CUSUM values on the y-axis. Linear fitting was performed, and the model with the highest determination coefficient was selected as the optimal fitting model. The learning process was divided into two phases based on the inflection point of the CUSUM learning curve: the learning phase and the proficiency phase. Perioperative outcomes were compared between these two phases.Results:All 91 procedures were successfully completed using the da Vinci robotic system with R0 resection margins. There were no perioperative mortalities or reoperations due to postoperative splenic infarction. The operative time was (227.84±76.68) min. The optimal fitting equation for the CUSUM learning curve was: CUSUM=0.005 640X 3-1.501X 2+ 92.59X-183.1. The CUSUM learning curve showed an inflection point at case 39, dividing the learning process into the learning phase (cases 1-39) and proficiency phase (cases 40-91). Compared to the learning phase, the proficiency phase demonstrated significantly shorter operative time [(203.0±75.6) min vs. (260.9±65.5) min], less intraoperative blood loss [50.0 (20.0, 50.0) ml vs. 100.0 (50.0, 100.0) ml], and reduced postoperative drainage duration [(8.7±2.4) d vs. (10.8±3.2) d] (all P<0.05). Conclusion:The robotic-assisted Warshaw procedure feasible for patients with pancreatic body and tail lesions. Surgeons require approximately 39 cases to complete the learning curve and achieve proficiency in this procedure.

Objectives:To explore the efficacy of robotic-assisted retroperitoneal benign tumor resection and to analyze its learning curve.Methods:This is a retrospective case series study. The data of patients who underwent robotic-assisted retroperitoneal benign tumor resection from August 2015 to February 2023 at the Department of Retroperitoneal Tumor Surgery was analyzed retrospectively. There were 24 males and 45 females, with an age of (46.3±10.6) years (range: 19 to 76 years). The perioperative data, postoperative pathological results, and follow-up data were recorded. The cumulative sum (CUSUM) method was used to analyze the robotic system setup time and operative time to plot the learning curve. A linear regression model was applied to determine the best-fit curve, selecting the model with the highest R2 value. Based on the vertex of the learning curve for surgical time, the patients were divided into a learning group and a mastery group. The general data and perioperative conditions of the two groups were compared. Independent sample t-tests, Mann-Whitney U tests, and χ2 tests were used for comparisons. Results:All 69 patients successfully completed the surgery without intraoperative complications. The diameter of tumors was (49.7±18.6) mm (range: 16 to 131 mm). The setup time for the robotic surgical system was (35.3±9.8) minutes (range: 20 to 61 minutes); the surgical time was (169.2±36.5) minutes (range: 70 to 305 minutes); intraoperative blood loss ( M(IQR)) was 10.0 (15.0) ml (range: 2.0 to 200.0 ml). The tumors in 32 patients (46.4%) were adherent to major blood vessels. All patients were discharged without complications. The follow-up period lasted until February 2024, and no patients required reoperation, readmission, or died due to retroperitoneal benign tumors. There were no severe long-term complications, and no radiological evidence of tumor recurrence was found. The best-fit equation for the learning curve based on surgical time was CUSUM=0.010X3-1.648X2-68.573X-61.091, and the best-fit equation for the learning curve based on robotic system setup time was CUSUM=0.0018X3-0.285X2+10.460X+57.541 (where X represents the number of surgeries). The R2 values of 2 learning curve models were 0.953 and 0.957, respectively, and the fit model tests had P<0.05. The inflection point of the learning curve based on surgical time was the 28th case, which is considered the minimum number of surgeries required to achieve proficiency in robotic-assisted retroperitoneal benign tumor resection. Based on this, the patients were divided into a learning group (cases 1 to 28) and a mastery group (cases 29 to 69). The surgical time for the learning group was significantly longer than that of the mastery group ((194.7±30.0) minutes vs. (151.9±31.4) minutes, t=4.126, P<0.01). No statistically significant differences were found for other parameters (all P>0.05). Conclusions:Robotic-assisted retroperitoneal benign tumor resection is feasible. The minimum number of surgeries required to achieve proficiency in overcoming the learning curve is about 28 cases.

Objective: To clarify the clinicopathologic features of hepatocellular carcinoma (HCC) patients survived more than 10 years after radical hepatectomy. Methods: Two hundreds and fifty-two patients who underwent curative resection for HCC between January 1999 and March 2006 at Department of Hepatopancreatobiliary Surgery, Affiliated Hospital of Qingdao University were included.There were 217 male cases and 35 female cases aging from 17 to 82 years with median age of (53.8±10.5)years. Followed by March 31 2016, clinicopathologic factors in 10-year survivors and patients who died within 10 years were compared by χ² test, Kaplan-Meier survival analysis and Cox proportional hazards model and the prognostic factors affecting survival were identified. Results: All patients were followed-up for 4.0 to 205.7 months with median time of 53.4 months. The 10-year overall survival rate was 26%, there were 62 cases(26.2%) who survived for more than 10 years after initial hepatectomy. In survival >10-year group, the paitents with ALT<40 U/L, gamma-glutamyl transpeptidase<64 U/L, albumin≥35 g/L, without liver cirrhosis and portal hypertension, Child-Pugh grade A, no blood transfusion, AFP≤20 μg/L, tumor size ≤5.0 cm, single tumor, high differentiation, TNM stage Ⅰ and TACE negative after resection were more than the patients in survival <10-year group (P<0.05). In multivariate analysis, Child-Pugh grade A, the tumor size ≤5.0 cm and TACE negative after resection were favorable independent factors associated with 10-year survival (P<0.05). Conclusion Based on the results of the study, Child-Pugh grade A, tumor size ≤5.0 cm and TACE negative after resection at initial hepatectomy might be biologically favorable conditions for patients surviving more than 10 years.

Objective To study the prognosis of patients with huge hepatocellular carcinoma (HCC) after R0 resection.Methods 517 patients with primary HCC who underwent R0 resection from January 1997 to December 2008 at the Affiliated Hospital of Medical College Qingdao University were analyzed retrospectively.Results The 5-and 10-years overall survivals (OS) in patients with huge HCC (≥10 cm; n=69) and in patients with HCC ＜10 cm (n=448) were 24％,18％ and 49％,30％,respectively.The median OS was 23.0 and 58.0 month (P＜0.001,log rank test) ; and the median disease-free survivals (DFS) were 15.3 and 34.8 month (P＜0.001),respectively.The recurrence rate within the first year and the extrahepatic recurrence after resection in patients with huge HCC was significantly higher than in patients with HCC ＜10 cm (44.9％ vs.24.3％,P=0.022;32.7％ vs.16.0％,P=0.004).Independent poor prognostic factors of OS and DFS for patients with huge HCC after R0 resection were portal hypertension and vascular invasion.Preoperative transcatheter arterial chemoembolization (TACE) was an independent prognostic factor for better DFS.Conclusions Surgical resection for huge HCC is safe and feasible.For huge HCC after resection,portal hypertension and vascular invasion were poor prognostic factors.Preoperative TACE improved DFS after resection.

Objective To investigate the prognosis of patients with primary liver cancer in different pathological types after hepatectomy,and to analyze the effects of clinicopathological factors on the survival.Methods The clinical data of 567 patients with primary liver cancer who received hepatectomy at the Affiliated Hospital of Qingdao University from January 1997 to December 2008 were retrospectively analyzed.All patients were divided into hepatocellular carcinoma (HCC) group,cholangiocarcinoma (CC) group and combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC) group.The survival and risk factors of the patients were analyzed.All data were analyzed by using the chi-square test,t test,analysis of variance.The survival curve was drawn by the Kaplan-Meier method and the survival of the 3 groups was compared by the Log-rank test.The risk factors were analyzed by the one-way analysis of variance and COX regression model.Results The results of pathological examination confirmed that 92.9％ (527/567) patients were with HCC,4.6％ (26/576) with CC and 2.5％ (14/567)with cHCC-CC.The median cumulative survival time of patients with HCC was 48 months,which was significantly longer than 19 months of patients with CC and 14 months of patients with cHCC-CC (Log-rank value =4.354,8.847,P ＜ 0.05).The median tumor-free survival time of patients with HCC was 26 months,which was significantly longer than 9 months of patients with CC and 9 months of patients with cHCC-CC (Log-rank value =6.479,7.708,P ＜ 0.05).The tumor recurrence rate within 1 year of patients with HCC was 28.8％ (152/527),which was significantly lower than 57.7％ (15/26) of patients with CC or 9/14 of patients with cHCC-CC (F =17.046,P ＜ 0.05).No vascular thrombosis was detected in patients with CC,but the regional lymph node metastasis rate was 19.2％ (5/26),which was significantly higher than 2.8％ (15/527) of patients with HCC (x2 =19.082,P ＜ 0.05).Level of alpha-fetoprotein,TNM staging,tumor diameter,multiple foci,liver capsule invasion,satellite foci and lymph node metastasis were risk factors for the survivals of patients with primary liver cancer after hepateetomy (x2 =8.648,118.786,59.548,7.639,13.200,43.842,15.540,P ＜ 0.05).Vascular tumor thrombosis and Child-Pugh classification were the risk factors for the survivals of patients with HCC or cHCC-CC (x2 =70.446,6.230,P ＜ 0.05).TNM staging,tumor diameter,satellite foci and vascular tumor thrombusis were the independent risk factors for the survivals of patients with primary liver cancer (RR =1.420,1.050,1.513,1.899,P ＜ 0.05) ; TNM staging,tumor diameter and vascular tumor thrombosis were the independent risk factors for the survivals of patients with HCC (RR =1.432,1.888,1.052,P ＜ 0.05).TNM staging and tumor diameter were the independent risk factors for the survivals patients with CC (RR =1.473,1.503,P ＜ 0.05).Conclusion Although CC and cHCC-CC take small proportion in the primary liver cancer,the tumor recurrence rate is higher and the survival rate is lower when compared with patients with HCC.

Objective To analyze the factors that influence the survival condition during the first year after hepatectomy in patients with hepatocellular carcinoma (HCC). Methods Five hundred twentyeight HCC cases undergoing hepatectomy were included from January 1997 to December 2008.The factors and survival outcomes in these patients were analyzed. Results There were 302 patients dying during a medium follow-up of 35 months and 1-year cumulative survival was 85％.The causes of death during first year were tumor recurrence (78.1％,75/96) and liver dyscompensation ( 19.8％,19/96).By Cox regression analysis,tumor size ≥5 cm (P =0.047 ),vascular invasion ( P =0.018),histologic moderately and poorly differentiation ( P =0.001 ) and pathologically positive margin ( P =0.004 ) were significantly associated with tumor recurrence,and portal hypertension was an independent factor for patients dying from liver dysfunction ( P =0.001 ).Positive tumor margin was the most important factor associated with postoperative death within one year (59.3％,60/96). Conclusions During the first year after HCC resection,tumor recurrence and liver dysfunction are main factors influencing HCC patients' survival,nonR0 resection is the main factor causing tumor recurrence,and portal hypertension is an independent factor for patients dying of liver dyscompensation.

Objective To summarize the experience in the diagnosis and treatment of mucinous cystic neoplasms (MCN) of the pancreas. Methods The clinical data of 20 cases who were diagnosed as MCN of the pancreas in the affiliated hospital of Qingdao university from January, 2003 to June, 2008 were collected, data including clinical manifestations, pathological features, treatment and survival were analyzed retrospectively. Results The clinical manifestations mainly included abdominal pain or discomfort, nausea, vomiting; 11 patients had abdominal tenderness, 6 patients had palpable abdominal mass. All the patients underwent ultrasound and CT scan examinations, 13 patients were diagnosed as having benign MCN of the pancreas, 4 were serous cystadenoma, 3 were mucinous cystadenocarcinoma. The tumors were located in the body and tail of the pancreas, with a mean diameter of 4 - 14 cm. All the 20 cases received surgical treatment. The procedures mainly included pancreaticoduodenectomy and resection of pancreatic body and tail. Pathological examinations confirmed there were 10 patients with benign MCN of the pancreas, 3 were borderline mucinous cystadenomas and 7 mucinous cystadenocarcinomas. After a mean follow-up of 26 months, patients with benign MCN of the pancreas or borderline mucinous cystadenomas were still alive without recurrence, the three year survival of patients with mucinous cystadenocarcinomas was 50%. Conclusions MCN of the pancreas mainly occurred in female, and there was no specific clinical features, preoperative ultrasound and CT scan examinations could help to diagnose this disease. Surgical resection was the only effective method to cure MCN with good prognosis.

Objective To investigate the effect and safety of duct-to-mucosa anastomosis technique for pancreaticoduodenectomy(PD).Methods The clinical data,including pancreatic fistula and other complications,of 189 patients underwent PD with end-to-side pancreaticojejunostomy at our institution from Jan 2001 to Jan 2009 were analyzed retrospectively.The definition of pancreatic fistula was threefold increase over the serum amylase level 7 days after operation,and draining volume was more than 50 ml per day.Results Totally 177 Whipple procedures were performed,while 12 pylorus-preserving pancreateduodenectomy procedures were performed.Five patients developed pancreatic fistula with a incidence of 2.65%(5/189).In which 3 were mild Cases,who fully recovered after conservative management,and the other 2 cages were cured by surgical intervention.Other complications included 9 cases of wound infection(4.76%,9/189),11 cases of empty dysfunction(5.82%,11/189),5 Cases of delayed hemorrhage(2.65%,5/189),and 4 cases of intra-abdominal infection(2.12%,4/189),and 2 patients died due to severe intra-abdominal infection and acute pulmonary infarction.Conclusions Duet-to-mucesa anastomosis technique resembles physiological state with low incidence of pancreatic fistula and delayed anastomosis hemorrhage.It may be used for different kinds of anastomosis for pancreatic stump.