Targeted delivery of antibody bound to antigen is a precise drug delivery mode. It is regarded as one of the ideal targeted drug delivery modes due to its high specificity and affinity, which opens up a new way to successfully solve the problem of poor selectivity of chemotherapy drugs in antitumor therapy. Currently, the research on antibody drug conjugates(ADCs) that bind monoclonal antibodies to target antigens has become a research hotspot of molecular targeted therapy. This paper reviews the mechanism of action, targeting strategies and progress in the targeted delivery of ADCs, in order to provide reference for the clinical development of new ADCs.

Objective:To study the risk factors for duodenal injury caused by malposition of plastic bile duct stent for the treatment of biliary stricture.Methods:Data of 1 408 patients with biliary stricture (2 607 procedures of plastic stent placement) who received plastic stent placement in Hangzhou First People's Hospital from January 2017 to December 2021 were retrospectively analyzed and duodenal injury caused by bile duct stent malposition after placement was recorded. The patients were divided into two groups: the malposition injury group ( n=23 procedures) and the non-malposition injury group ( n=2 584 procedures). The differences in the baseline data and procedure-related condition between the malposition injury group and the non-malposition injury group were compared, and the independent risk factors for duodenal injury caused by bile duct plastic stent malposition were studied by using logistic regression analysis. Results:A total of 2 607 procedures of plastic stent placement were performed in 1 408 patients with biliary stricture, and 23 cases of duodenal injury were caused by stent malposition. Logistic regression analysis revealed that a history of gastrointestinal surgery ( OR=4.278, 95% CI: 1.332-13.737, P=0.015), a history of endoscopic sphincterotomy (EST) ( OR=8.128, 95% CI: 2.382-27.738, P=0.001), and high-level bile duct stenosis ( OR=4.457, 95% CI: 1.722-11.539, P=0.002), plastic stents with a length≥ 7 cm ( OR=4.701, 95% CI: 1.708-12.938, P=0.003) and Christmas tree-shaped stent ( OR=6.890, 95% CI: 1.540-30.830, P=0.012) were independent risk factors for duodenal injury caused by bile duct plastic stent malposition. Conclusion:High-level bile duct stenosis, the use of plastic stents with a length≥ 7 cm and Christmas tree-shaped stent, a history of gastrointestinal surgery, and a history of EST could increase the risk of duodenal injury caused by bile duct plastic stent malposition in patients with bile duct stenosis.

To evaluate the safety and clinical effectiveness of endoscopic retrograde cholangiopancreatography (ERCP) with biliary and pancreatic duct stenting combined with enucleation (En) for cystadenoma in pancreatic head, clinical data of patients with cystadenoma in pancreatic head treated by ERCP+En (ERCP+En group, n=11) or En (En group, n=12) at Hangzhou First People's Hospital from January 2020 to January 2023 were retrospectively analyzed. The general information, intraoperative condition, perioperative complications, hospital stay, and follow-up outcomes were compared between the two groups. No noteworthy difference in general information was observed between the two groups ( P>0.05). In the ERCP+En group, ERCP was successfully implanted into the biliary pancreatic duct stent, and hyperamylasemia occurred in 3 cases after ERCP, which improved after conservative treatment. No conversion to laparotomy or blood transfusion occurred during the En operation, and no serious complication occurred after EN operation in the two groups. There was 0 case and 3 cases of grade B/C postoperative pancreatic fistula in the ERCP+En group and the En group, respectively ( P=0.001). The median hospital stay was 11 days and 15 days, respectively, with statistical significance ( U=2.25, P=0.031). No noteworthy difference in median En time (145 min VS 155 min, U=0.03, P=0.952) or intraoperative blood loss (100 mL VS 120 mL, U=0.05, P=0.784) was observed between the two groups. During a median follow-up of 18 months, no recurrence happened in either group, and the ERCP+En group did not experience biliary pancreatic duct stenosis, while the En group experienced 2 pancreatic duct stenosis and 1 biliary duct stenosis. Endoscopic biliary and pancreatic duct stenting combined with En is an effective way to reduce postoperative pancreatic fistula and avoid long-term complications such as biliary and pancreatic duct stenosis for cystadenoma in pancreatic head.

Objective:To compare the fully covered self-expanding metal stents (FCSEMS) and multiple plastic stents (MPS) in the effectiveness, safety and cost-effectiveness for benign bile duct strictures.Methods:A single-center retrospective study was conducted to analyze the clinical data of 107 patients with benign biliary strictures who underwent FCSEMS or MPS implantation through endoscopic retrograde cholangiopancreatography (ERCP) in Hangzhou First People's Hospital from January 2013 to June 2019.There were 54 cases in group FCSEMS and 53 cases in group MPS. Benign biliary stricture was confirmed by computed tomography (CT), magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasonography. The primary index was the rate of stricture remission, and the secondary indices were the incidence of stricture recurrence, ERCP-related complications, the rate of stent migration, hospital stay and charges.Results:The median follow-up times were 10.0 (6.5, 18.0) months and 12.0 (9.0, 20.0) months in group FCSEMS and in group MPS respectively ( P>0.05). The rates of stricture remission in the two groups were 87.0% (47/54) and 83.0% (44/53), the incidences of stricture recurrence were 14.6% (6/41) and 23.5% (8/34), and the incidences of ERCP-related complications were 14.8% (8/54) and 11.9% (13/109), respectively. And the differences were not statistically significant (all P>0.05). But the stent migration rates of the two groups were 22.9% (11/54) and 2.8% (3/109) with significant difference ( P<0.001). Cost-effectiveness analysis showed that the median numbers of ERCP intervention in the two groups were 2 (2,2) times and 3 (2,4) times ( P<0.001), and the median hospital stays were 6.0 (4.0,11.0) days and 9.0 (6.5,16.0) days respectively ( P=0.009). The median hospitalization expenses of the two groups were 44 646 yuan and 51 355 yuan without significant difference ( P>0.05). Conclusion:The effectiveness, safety and cost of FCSEMS for benign bile duct stenosis are similar to those of MPS, but it reduces ERCP intervention and treatment cycles. Even with a certain migration rate, it can still be a first-line treatment approach.

Objective:To investigate the effects of modified radical prostatectomy via an extraperitoneal approach on urinary control and sexual function in patients with prostate cancer.Methods:Fifty-six patients with stable prostate cancer who received treatment in Deqing People's Hospital between March 2015 and March 2018 were included in this study. They were randomly divided into observation and control groups ( n = 28/group). The observation group was subjected to modified radical prostatectomy via an extraperitoneal approach. The control group underwent standard laparoscopic surgery. Clinical efficacy and the effects of modified radical prostatectomy via an extraperitoneal approach on urinary control and sexual function were compared between the two groups. Results:Amount of blood loss and postoperative drainage were (125.39 ± 11.12) mL and (65.39 ± 10.12) mL in the observation group, and (224.79 ± 14.01) mL and (104.79 ± 15.01) mL in the control group. There were no significant differences in amount of blood loss and postoperative drainage between the two groups ( t = 18.83, 15.67, both P < 0.05). At 1, 3 and 6 months after surgery, the percentage of patients who had urinary control recovery in the observation group was 53.57% (15/28), 78.57% (22/28), 98.21% (27/28), respectively, which were significantly higher than those in the control group [21.43% (6/28), 35.71% (10/28), 67.86% (19/28), χ2 = 4.12, 7.21, 5.01, all P < 0.05]. At 1, 3 and 6 months after surgery, the score of erectile function recovery in the observation group was (15.98 ± 0.28) points, (15.99 ± 0.72) points, and (18.91 ± 0.48) points, which were significantly higher than those in the control group [(17.11 ± 0.34) points, (13.11 ± 0.48) points, (13.41 ± 0.39) points, t = 3.01, 12.89, 15.78, all P < 0.05]. Conclusion:Modified radical prostatectomy via an extraperitoneal approach can improve postoperative urinary control and sexual dysfunction.

Objective:To evaluate the safety, efficacy and performance of disposable cholangiopancreatoscope in the diagnosis and treatment of bile duct diseases.Methods:A total of 20 subjects were selected and 16 subjects were enrolled in the prospective and exploratory clinical study which were performed in the Digestive Endoscope Center of Hangzhou First People's Hospital Affiliated to Zhejiang University School of Medicine from July 2021 to August 2021. The disposable cholangiopancreatoscope was used to diagnose bile duct diseases in routine endoscopic retrograde cholangiopancreatography. Biopsies were performed in cases where malignancy was considered. The use related indexes and performance indexes of the instruments were analyzed.Results:Among the 16 patients, there were 6 cases of biliary space-occupying lesions, 6 cases of biliary calculi, and 4 cases of benign biliary stricture before operation. The success rate of the disposable insertion was 100.00% (16/16), and the success rate of observation was 100.00% (16/16). Three biliary space-occupying lesions diagnosed as malignant tumor under cholangiopancreatoscope were confirmed by pathology after operation. Diagnosis of other patients was consistent with preoperative diagnose, so no biopsy was conducted. The rate of positive feedback from operators in directional control was 81.25% (13/16), the image failure rate was 18.75% (3/16), and the rate of positive feedback for image clarity was 93.75% (15/16). In terms of clinical performance, the imaging quality of excellence was 93.75% (15/16), the flexible degree of excellence was 81.25% (13/16), and other indexes were all 100.00% excellence. During the period, there were no instrument defects, pancreatitis, perforation, bleeding or other instrument-related adverse events.Conclusion:The effectiveness, safety and performance indexes of domestic disposable cholangiopancreatoscope have reached the standards of clinical application with high pixel, integration, and portability. It's worthy of clinical recommendation.

To evaluate the clinical efficacy and safety of Hot AXIOS, a novel luminal metal stent with a cautery system guided by endoscopic ultrasound, for the treatment of infected pancreatic necrosis (IPN), 5 cases of IPN treated with endoscopic ultrasound-guided Hot AXIOS placement in Hangzhou First People's Hospital from December 2021 to January 2022 were retrospectively analyzed. The results showed that all 5 cases successfully completed the treatment, with 8-21 minutes of the operation time. The symptoms of abdominal pain and bloating on the first day after operation were significantly relieved, and the abdominal CT showed that the walled-off necrosis was significantly reduced. After 2-9 times of direct endoscopic necrosectomy, supplemented by antibiotics, patient's temperature and blood inflammatory indexes returned to normal, the cavity was reduced and necrosis was removed. The Hot AXIOS stent was indwelled for 12-40 days and then removed. After 25-113 days of the follow-up, all patients survived without recurrence. Preliminary results suggest that endoscopic ultrasound-guided Hot AXIOS placement is safe and effective for the treatment of IPN.

Objective:To investigate the risk factors of duodenal papilla hemorrhage after endoscopic papillary balloon dilatation (EPBD) for choledocholithiasis.Methods:Clinical data of 411 cases of choledocholithiasis treated by EPBD in Hangzhou First People′s Hospital from January 2016 to December 2019 were analyzed retrospectively. Based on the development of hemorrhage after EPBD, patients were divided into the hemorrhage group and the non-hemorrhage group. The risk factors of hemorrhage after EPBD were analyzed by single and Logistic regression.Results:Among 411 patients who received EPBD, 29 patients had EPBD-related duodenal papilla hemorrhage and the overall incidence was 7.1%.Univariate analysis showed that there were significant differences between the hemorrhage group and the non-hemorrhage group in diameter≥1.2 cm of balloon dilation ( P=0.001), endoscopic sphincterotomy (EST) ( P=0.002)and the incision length of EST ( P<0.001). Logistic regression analysis showed that the incision length of EST ( OR=69.771, 95% CI: 7.544-645.296, P<0.001) was the independent risk factor for duodenal papilla hemorrhage after EPBD. Diameter≥1.2 cm of balloon dilation( OR=0.192, 95% CI: 0.071-0.524, P=0.001) was a protective factor. Conclusion:The incision length of EST is an independent risk factor of duodenal papilla hemorrhage after EPBD. Endoscopic papillary large balloon dilation is a protective factor for postoperative hemorrhage, which can reduce the incidence of bleeding.

Objective:To evaluate endoscopic nasobiliary drainage (ENBD) combined with nasojejunal tube feeding for elderly patients with severe acute cholangitis.Methods:Data of 43 elderly patients with severe acute cholangitis, who received ENBD combined with nasojejunal tube feeding from January 1, 2016 to May 31, 2018 at Affiliated Hangzhou First People′s Hospital, Zhejiang University School of Medicine were retrospectively analyzed and were included in the observation group, and 43 other patients who received ENBD combined with conventional therapy in the same period were included in the control group with the matching principle of 1∶1. Liver function indices (ALT and AST), nutritional status (Hb, TP and ALB) and inflammation indices (WBC, NEU% and CRP) of the two groups before the operation, 3 days and 7 days of nutritional support after the operation were compared. Adverse reactions (abdominal distention and diarrhea), mortality, hospitalization time and expenses of the two groups were also compared.Results:There were no significant differences in gender composition, mean age, preoperative APACHE-Ⅱ score, NRS2002 score, liver function index, nutritional index, or inflammatory index between the observation group and the control group ( P>0.05). The baseline data of the two groups were comparable. After 3 days of nutritional support, ALT, AST, TP were 21.0 (15.0, 35.5) U/L, 26.0 (21.0, 36.5) U/L, and 64.2±5.2 g/L, respectively in the observation group, and 47.0 (29.5, 82.5) U/L ( P<0.05), 47.0 (29.0, 75.0) U/L ( P<0.05), and 60.5±6.4 g/L ( P<0.05), respectively in the control group. The levels of other indicators were not statistically different at this time point ( P>0.05). At 7 days postoperative nutritional support, ALT, AST, TP, ALB and CRP of the observation group were 22.0 (14.0, 31.5) U/L, 26.0 (20.5, 38.5) U/L, 67.6±5.4 g/L, 34.6±3.7 g/L, and 28.0 (18.5, 35.5) mg/L, respectively, and 43.0 (18.0, 59.5) U/L ( P<0.01), 34.0 (24.0, 60.5) U/L ( P=0.02), 64.5±5.7 g/L ( P=0.01), 31.5±7.0 g/L ( P=0.02), and 34.0 (24.0, 66.5) mg/L ( P<0.05) in the control group. There were no significant differences in the levels of other indicators between the two groups at this time point ( P>0.05). In the observation group, the incidence of diarrhea, abdominal distension, mortality, hospitalization time and hospitalization expenses were 32.6% (14/43), 30.2% (13/43), 9.3% (4/43), 16.0±7.0 days and 40±10 thousand yuan, respectively, and in the control group, the above indicators were 4.7% (2/43) ( P<0.05), 7.0% (3/43) ( P<0.05), 11.6% (5/43) ( P=0.72), 19.3±3.7 days ( P<0.05)) and 53±23 thousand yuan ( P<0.05), respectively. Conclusion:For elderly patients with severe acute cholangitis, enteral nutrition with ENBD can effectively improve the nutritional status, reduce inflammatory reaction, the impact on liver function, and hospital costs, and shorten the hospitalization time, which is suitable for further clinical application.

To evaluate the value of endoscopic retrograde cholangiopancreatography(ERCP)and SpyGlass in the diagnosis of intraductal papillary mucinous neoplasm of the bile duct (IPMN-B). Data of patients who underwent ERCP and SpyGlass in Hangzhou First People′s Hospital from January 2016 to December 2019 were analyzed. ERCP and SpyGlass features, complications, clinicopathologic characteristics and prognosis were retrospectively analyzed.A total of 9 patients (5 benign lesions and 4 malignant lesions) were included.ERCP was successfully performed in 9 cases, while SpyGlass was technically successful in 8 cases. Endoscopy showed mucus outflow from the papilla in 5 cases, and the mucus was removed by the balloon of ERCP in 8 cases.ERCP showed bile duct diffuse dilatation and filling defects in all patients. SpyGlass found the mucus in the bile duct in all patients. SpyGlass showed lesion mucosa were fish-egg like without vascular images (Ⅱtype, 3 cases), fish-egg like with vascular images (Ⅲ type, 1 case), villous (Ⅳtype, 4 cases). SpyGlass defined extent of the lesion in 8 cases. SpyGlass found that the lesion involved the intra and extrahepatic bile ducts in one case. Therefore, liver transplantation was recommended to avoid surgical exploration. One type Ⅲ lesion underwent a direct biopsy. The pathology showed moderate dysplasia, which was consistent with the postoperative pathology. No complication occurred. ERCP combined with SpyGlass could clarify the scope of IPMN-B and provide basis for surgical options, which is safe and effective in IPMN-B diagnosis.