Safety and feasibility of a novel recanalization technique using guidewire puncture under cholangioscopy for complete biliary stricture after liver transplantation.

Cholangioscopy is reportedly useful for selective guidewire placement across difficult biliary strictures, but few methods are available for complete stricture of biliary anastomosis. This study aimed to propose a guidewire puncture technique to recanalize totally obstructed anastomosis and discuss its safety and feasibility. From January 2015 to December 2021, a total of 11 patients with complete biliary anastomotic stricture after liver transplantation were enrolled. These patients underwent peroral single operator cholangioscopy (SpyGlass), whereas two failed cases on SpyGlass finally underwent percutaneous transhepatic cholangioscopy (PTCS). The steps of the recanalization technique were as follows: the stricture was viewed carefully to detect the closure point (CP) of the scar endoscopically, then the CP was targeted by the hard tip of the guidewire and broke through under guidance of the cholangioscope and fluoroscope. Complete occlusions were confirmed by SpyGlass in all cases. A total of 13 hard-tip guidewire punctures were performed under cholangioscopy, and ten punctures were successful (technical success rate, 76.9% [10/13]). After recanalization of the occluded anastomosis, plastic stent or metallic stent was deployed in three and seven patients, respectively. No procedure-related complications occurred during or after the cholangioscopy-assisted guidewire puncture. After a mean follow-up of 12 months, stents had been removed in five patients. The other six patients were still receiving stent treatment. This study demonstrated that the guidewire puncture technique under cholangioscopy is safe and feasible for complete stricture of biliary anastomosis, and the success rate is satisfactory.

[Research Progress of Magnetically Anchored Abdominal Video System].

Magnetic anchoring technology provides a new development opportunity for current minimally invasive surgery. The magnetic anchoring abdominal video system based on this technology can effectively improve the operability and minimally invasiveness of single-port laparoscopic surgery. The development history of magnetically anchored abdominal video system was reviewed, and the design features and deficiencies of various types of magnetically anchored video devices were compared and analyzed. The evolution characteristics of the magnetic anchored video system are explained from minimally invasive and intelligent perspectives, and the challenges and opportunities of magnetic anchored video system are summarized and prospected.

Regional anticoagulation magnetic artificial blood vessels constructed by heparin-PLCL core-shell nanofibers for rapid deployment of veno-venous bypass.

Veno-venous bypass (VVB) is necessary for maintaining hemodynamic and internal environment stabilities in complex liver surgeries. However, the current VVB strategies require systematic anticoagulation and are time-consuming, leading to unexpected complications. This study aims to overcome these limitations by using a novel magnetic artificial blood vessel constructed with heparin-PLCL core-shell nanofibers. Coaxial electrospinning was used to fabricate core-shell nanofibers with heparin encapsulated into the core layer. The microstructure, physical and chemical properties, hemocompatibility, and heparin release behavior were characterized. The regional anticoagulation magnetic artificial vessel was constructed with these nanofibers and used to perform VVB in a rat liver transplantation model for in vivo evaluation. The core-shell nanofibers appeared smooth and uniform without apparent defects. Fluorescence and TEM images indicated that heparin was successfully encapsulated into the core layer. In addition, the in vitro heparin release test presented a two-phase release profile, burst release at day 1 and sustained release from days 2 to 14, which resulted in better hemocompatibility. The VVB could be rapidly deployed in 3.65 ± 0.83 min by the magnetic artificial vessel without systemic anticoagulation. Moreover, the novel device could reduce portal pressure and abdominal organ congestion, protect intestinal function, and increase the survival rate of liver transplantation with a long anhepatic phase from 0 to 65%. In summary, VVB can be rapidly deployed using regional anticoagulation magnetic artificial blood vessels without systemic anticoagulation, which is promising for improving patient outcomes after complex liver surgery.

Effects of water cooling on laser-induced thermal damage in rat hepatectomy.

PURPOSE: High-powered lasers are commonly used for tissue resection in surgeries, including liver resection, medically known as hepatectomy; however, such lasers inevitably induce thermal damage that causes postoperative complications. This study aims to explore the effects of water cooling and different laser output modes on laser-induced thermal damage during hepatectomy. METHODS: To avoid the influence of superposition, a 980-nm diode laser was used for a single-point hepatectomy. Eighteen Sprague-Dawley rats were used to explore the effects of water cooling and different laser output modes. A constant energy 10-J laser was used to cut the liver tissue with a power of 10 W and time of 1 second. The rats were randomly divided into six groups. The first three groups were assigned as test subjects for different laser output modes. Group 1 was operated with a continuous laser output for a duration of 1 second. Groups 2 and 3 were operated with a pulsed laser output for a duration of 1 second and a pulse width of 0.5 and 0.25 seconds, respectively. Groups 4, 5, and 6 were assigned for the water cooling test. Water cooling was performed based on the parameters of the first three groups. Medical saline (0.9% NaCl) was used for water cooling. The main observation indicators were resection efficiency and thermal damage, including the area of the thermal damage zone. Resection efficiency is calculated by dividing the resection area by the total thermal damage area. RESULTS: In the three water cooling groups, the area of the resection, carbonized, sub-boiling coagulated, and total thermal damage zones were 0.0677, 0.00, 1.7293, and 2.2982 mm2 in Group 4; 0.0465, 0.00, 1.3205, and 1.8414 mm2 in Group 5; and 0.0565, 0.00, 1.4301, and 1.9650 mm2 in Group 6, respectively. Compared with the first three groups, the water cooling groups exhibited significantly reduced thermal damage areas of in the carbonized, sub-boiling coagulated, and total thermal damage zones (p < 0.001 for all). In addition, there was no statistical difference in the resection area, vacuolated area, and resection efficiency. Furthermore, there was no statistical difference in the area of each thermal damage zone between the continuous and pulsed output groups. The resection efficiencies were 4.82%, 3.34%, 3.73%, 3.93%, 3.36%, and 3.01% in Groups 1 to 6, respectively. Moreover, there was no statistical difference (p > 0.05) in the resection efficiencies. CONCLUSION: Water cooling can reduce the total laser-induced thermal damage area and prevent tissue carbonization. Therefore, this cooling method can be used as a simple and safe strategy for controlling thermal damage during hepatectomy.

Remote-controlled cholangiography injection device: first clinical study in China.

BACKGROUND: X-ray cholangiography is of great value in the imaging of biliary tract diseases; however, occupational radiation exposure is unavoidable. Moreover, clinicians must manually inject the contrast dye, which may result in a relatively high incidence of adverse reactions due to unstable injection pressure. Thus, there is a need to develop a novel remote-controlled cholangiography injection device. METHODS: Patients with external biliary drainage requiring cholangiography were included. A remote-controlled injection device was developed with three major components: an injection pump, a pressure sensor, and a wireless remote-control panel. Image quality, adverse reactions, and radiation dose were evaluated. RESULTS: Different kinds of X-ray cholangiography were successfully and smoothly performed using this remote-controlled injection device in all patients. The incidence of adverse reactions in the device group was significantly lower than that in the manual group (4.17% vs. 13.9%, P = 0.001), and increasing the injection pressure increased the incidence of adverse reactions. In addition, the device helped operators avoid ionizing radiation completely. CONCLUSIONS: With good control of injection pressure (within 10 kPa), the remote-controlled cholangiography injection device could replace the need for the doctor to inject contrast agent with good security and effectivity. It is expected to be submitted for clinical application.

Telemedicine for Follow-up Management of Patients After Liver Transplantation: Cohort Study.

BACKGROUND: Technical capabilities for performing liver transplantation have developed rapidly; however, the lack of available livers has prompted the utilization of edge donor grafts, including those donated after circulatory death, older donors, and hepatic steatosis, thereby rendering it difficult to define optimal clinical outcomes. OBJECTIVE: We aimed to investigate the efficacy of telemedicine for follow-up management after liver transplantation. METHODS: To determine the efficacy of telemedicine for follow-up after liver transplantation, we performed a clinical observation cohort study to evaluate the rate of recovery, readmission rate within 30 days after discharge, mortality, and morbidity. Patients (n=110) who underwent liver transplantation (with livers from organ donation after citizen's death) were randomly assigned to receive either telemedicine-based follow-up management for 2 weeks in addition to the usual care or usual care follow-up only. Patients in the telemedicine group were given a robot free-of-charge for 2 weeks of follow-up. Using the robot, patients interacted daily, for approximately 20 minutes, with transplant specialists who assessed respiratory rate, electrocardiogram, blood pressure, oxygen saturation, and blood glucose level; asked patients about immunosuppressant medication use, diet, sleep, gastrointestinal function, exercise, and T-tube drainage; and recommended rehabilitation exercises. RESULTS: No differences were detected between patients in the telemedicine group (n=52) and those in the usual care group (n=50) regarding age (P=.17), the model for end-stage liver disease score (MELD, P=.14), operation time (P=.51), blood loss (P=.07), and transfusion volume (P=.13). The length and expenses of the initial hospitalization (P=.03 and P=.049) were lower in the telemedicine group than they were in the usual care follow-up group. The number of patients with MELD score ≥30 before liver transplantation was greater in the usual care follow-up group than that in the telemedicine group. Furthermore, the readmission rate within 30 days after discharge was markedly lower in the telemedicine group than in the usual care follow-up group (P=.02). The postoperative survival rates at 12 months in the telemedicine group and the usual care follow-up group were 94.2% and 90.0% (P=.65), respectively. Warning signs of complications were detected early and treated in time in the telemedicine group. Furthermore, no significant difference was detected in the long-term visit cumulative survival rate between the two groups (P=.50). CONCLUSIONS: Rapid recovery and markedly lower readmission rates within 30 days after discharge were evident for telemedicine follow-up management of patients post-liver transplantation, which might be due to high-efficiency in perioperative and follow-up management. Moreover, telemedicine follow-up management promotes the self-management and medication adherence, which improves patients' health-related quality of life and facilitates achieving optimal clinical outcomes in post-liver transplantation.

Recurrence of Non-functional Pancreatic Neuroendocrine Tumors After Curative Resection: A Tumor Burden-Based Prediction Model.

BACKGROUND: Patients can experience recurrence following curative-intent resection of non-functional pancreatic neuroendocrine tumors (NF-pNETs). We sought to develop a nomogram to risk stratify patients relative to recurrence following resection of NF-pNETs. METHODS: Patients who underwent curative-intent resection for NF-pNETs between 1997 and 2016 were identified from a multi-institutional database. The impact of clinicopathologic factors, including tumor burden score (TBS) (TBS2 = (maximum tumor diameter)2 + (number of tumors)2), was assessed relative to recurrence-free survival (RFS), and a nomogram was developed and internally validated. RESULTS: With a median follow-up of 31.0 months (IQR 11.3-56.6 months), 66 (15.8%) out of 416 patients in the cohort experienced tumor recurrence. Overall, 3-, 5-, and 10-year RFS following curative-intent resection was 83.2%, 74.0%, and 44.7%, respectively. Several factors were associated with risk of recurrence including tumor grade (referent G1: G2, HR 4.07, 95% CI 2.29-7.26, p < 0.001; G3, HR 10.83, 95% CI 3.72-31.53, p < 0.001), lymph node metastasis (LNM) (HR 4.71, 95% CI 2.69-8.26, p < 0.001), as well as TBS (referent low: medium, HR 4.36, 95% CI 2.06-9.24, p < 0.001; high, HR 6.04, 95% CI 2.96-12.31, p < 0.001). A weighted nomogram including tumor grade (G1 0, G2 54.19, G3 100), LNM (N0 0, N1 42.06), and TBS (low 0, medium 44.07, high 56.48) was developed. The discriminatory power of the nomogram was very good with a C-index of 0.75 (95% CI, 0.66-0.79) in the training cohort and 0.71 (95% CI, 0.65-0.75) in the validation cohort. In addition, the nomogram performed better than the current 8th edition of AJCC TNM staging system, which had a C-index of 0.67 (95% CI, 0.60-0.73). CONCLUSIONS: A nomogram that incorporated tumor grade, LNM, and TBS was established that had good discrimination and calibration. The nomogram may be an effective tool to stratify patients relative to recurrence risk following resection of NF-pNETs.

Number and Station of Lymph Node Metastasis After Curative-intent Resection of Intrahepatic Cholangiocarcinoma Impact Prognosis.

OBJECTIVES: To determine the prognostic implication of the number and station of LNM, and the minimal number of LNs needed for evaluation to accurately stage patients with intrahepatic cholangiocarcinoma (ICC). BACKGROUND: Impact of the number and station of LNM on long-term survival, and the minimal number of LNs needed for accurate staging of ICC patients remain poorly defined. METHODS: Data on patients who underwent curative-intent resection for ICC was collected from 15 high-volume centers worldwide. External validation was performed using the SEER registry. Primary outcomes included overall (OS), disease-specific, and recurrence-free survival. RESULTS: Among 603 patients who underwent curative-intent resection, median and 5-year OS were 30.6 months and 30.4%. Patients with 1 or 2 LNM had comparable worse OS versus patients with no nodal disease (median OS, 1 LNM 18.0, 2 LNM 20.0 vs no LNM 45.0 months, both P < 0.001), yet better OS versus patients with 3 or more LNM (median OS, 1-2 LNM 19.8 vs ≥3 LNM 16.0 months, P < 0.01). On multivariable analysis, a proposed new nodal staging with N1 (1-2 LNM) (Ref. N0, HR 2.40, P < 0.001) and N2 (≥3 LNM) [Ref. N0, hazard ratio (HR) 3.85, P < 0.001] categories were independently associated with incrementally worse OS. Patients with no nodal metastasis, 1-2 LNM and ≥3 LNM also had an increasingly worse disease-specific survival, and recurrence-free survival (both P < 0.05). Total number of LNs examined ≥6 had the greatest discriminatory power relative to OS among patients with 1-2 LNM, and patients with ≥3 LNM in both the multi-institutional (area under the curve 0.780) and SEER database (area under the curve 0.820) (n = 1036). Among patients who underwent an adequate regional lymphadenectomy (total number of LNs examined ≥6), LNM beyond the HDL was associated with worse OS versus LNM within the HDL only (median OS, 14.0 vs 24.0 months, HR 2.41, P = 0.003). CONCLUSION: Standard lymphadenectomy of at least 6 LNs is strongly recommended and should include examination beyond station 12 to have the greatest chance of accurate staging. The proposed new nodal staging of N0, N1, and N2 should be considered to stratify outcomes among patients after curative-intent resection of ICC.

New Nodal Staging for Primary Pancreatic Neuroendocrine Tumors: A Multi-institutional and National Data Analysis.

OBJECTIVE: To determine the prognostic role of metastatic lymph node (LN) number and the minimal number of LNs for optimal staging of patients with pancreatic neuroendocrine tumors (pNETs). BACKGROUND: Prognosis relative to number of LN metastasis (LNM), and minimal number of LNs needed to evaluate for accurate staging, have been poorly defined for pNETs. METHODS: Number of LNM and total number of LN evaluated (TNLE) were assessed relative to recurrence-free survival (RFS) and overall survival (OS) in a multi-institutional database. External validation was performed using Surveillance, Epidemiology and End Results (SEER) registry. RESULTS: Among 854 patients who underwent resection, 233 (27.3%) had at least 1 LNM. Patients with 1, 2, or 3 LNM had a comparable worse RFS versus patients with no nodal metastasis (5-year RFS, 1 LNM 65.6%, 2 LNM 68.2%, 3 LNM 63.2% vs 0 LNM 82.6%; all P < 0.001). In contrast, patients with ≥4 LNM (proposed N2) had a worse RFS versus patients who either had 1 to 3 LNM (proposed N1) or node-negative disease (5-year RFS, ≥4 LNM 43.5% vs 1-3 LNM 66.3%, 0 LNM 82.6%; all P < 0.05) [C-statistics area under the curve (AUC) 0.650]. TNLE ≥8 had the highest discriminatory power relative to RFS (AUC 0.713) and OS (AUC 0.726) among patients who had 1 to 3 LNM, and patients who had ≥4 LNM in the multi-institutional and SEER database (n = 2764). CONCLUSIONS: Regional lymphadenectomy of at least 8 lymph nodes was necessary to stage patients accurately. The proposed nodal staging of N0, N1, and N2 optimally staged patients.

Fedora-type magnetic compression anastomosis device for intestinal anastomosis.

BACKGROUND: Although previous studies have confirmed the feasibility of magnetic compression anastomosis (MCA), there is still a risk of long-term anastomotic stenosis. For traditional MCA devices, a large device is associated with great pressure, and eventually increased leakage. AIM: To develop a novel MCA device to simultaneously meet the requirements of pressure and size. METHODS: Traditional nummular MCA devices of all possible sizes were used to conduct ileac anastomosis in rats. The mean (± SD) circumference of the ileum was 13.34 ± 0.12 mm. Based on short- and long-term follow-up results, we determined the appropriate pressure range and minimum size. Thereafter, we introduced a novel "fedora-type" MCA device, which entailed the use of a nummular magnet with a larger sheet metal. RESULTS: With traditional MCA devices, the anastomoses experienced stenosis and even closure during the long-term follow-up when the anastomat was smaller than Φ5 mm. However, the risk of leakage increased when it was larger than Φ4 mm. On comparison of the different designs, it was found that the "fedora-type" MCA device should be composed of a Φ4-mm nummular magnet with a Φ6-mm sheet metal. CONCLUSION: The diameter of the MCA device should be greater than 120% of the enteric diameter. The novel "fedora-type" MCA device controls the pressure and optimizes the size.

Single Large Nodule (>5 cm) Prognosis in Hepatocellular Carcinoma: Kinship with Barcelona Clinic Liver Cancer (BCLC) Stage A or B?

BACKGROUND The aim of the present study was to evaluate the prognosis among patients with a single large hepatocellular carcinoma (HCC) >5 cm compared with other patients in Barcelona Clinic Liver Cancer (BCLC) stage A or stage B. MATERIAL AND METHODS Data on patients with BCLC stage A/B HCC were collected between 2008 and 2012. BCLC stage A was subclassified as A1 (single tumor, 2-5 cm, or 2-3 nodules £3 cm), or A2 (single tumor >5 cm). Overall survival (OS) was evaluated and compared. RESULTS Among 1005 patients with HCC, 455 were stage A1, 188 were stage A2, and 362 were stage B. The OS of stage A2 patients was significantly worse than that of stage A1 patients (median survival, 30.6 vs. 43.2 months, p5 cm had a comparable survival with BCLC stage B. HCC >5 cm should therefore be classified as an intermediate stage.

Surgical outcomes of patients with duodenal vs pancreatic neuroendocrine tumors following pancreatoduodenectomy.

BACKGROUND: To investigate the short- and long-term outcomes of patients undergoing pancreaticoduodenectomy (PD) for duodenal neuroendocrine tumors (dNETs) vs pancreatic neuroendocrine tumors (pNETs). METHOD: Patients undergoing PD for dNETs or pNETs between 1997 and 2016 were identified from a multi-institutional database. Overall survival (OS) and recurrence-free survival (RFS) were evaluated. RESULTS: Among 276 patients who underwent PD, 244 (88.4%) patients had a primary pNET, whereas 32 (11.6%) patients had a dNET. Following PD, postoperative morbidity and mortality were comparable. While the total number of lymph nodes examined was similar between the two groups (median, dNETs 15.0 vs pNETs 13.0; P= .648), patients with dNETs had a higher incidence of lymph node metastasis (LNM) (60.0% vs 38.2%; P = .022) and a larger number of metastatic nodes (median, 3.5 vs 2.0; P = .039). No differences in OS or RFS were noted among patients with dNETs vs pNETs in both unadjusted and adjusted analyses. Among patients who recurred after PD, patients with dNETs were more likely to recur early (within 2 years, 100% vs 49.2%; P = .029) and at an extrahepatic site (intrahepatic-only recurrence, 20.0% vs 54.1%; P = 0.142) vs patients with pNETs. CONCLUSIONS: Patients with dNETs and pNETs had a similar prognosis following PD. Data on differences in the incidence of LNM, as well as in recurrence time and patterns may help to inform the treatment of these patients.

A novel preoperative scoring system to predict technical difficulty in laparoscopic splenectomy for non-traumatic diseases.

BACKGROUND: Laparoscopic splenectomy (LS) has been proven to be a safe and advantageous procedure. To ensure that resections of appropriate difficulty are selected, an objective preoperative grading of difficulty is required. We aimed to develop a predictive difficulty grading of LS based on intraoperative complications. METHODS: A total of 272 non-traumatic patients who underwent LS were identified from a regional medical center. Patients were randomized into a training cohort (n = 222) and a validation cohort (n = 50). Data on demographics, medical and surgical history, operative and pathological characteristics, and postoperative outcome details were collected. Univariate and multivariate analyses of risk factors for intraoperative complications were performed to develop a difficulty scoring system. The Spearman correlation coefficient was used to evaluate the relationship between the difficulty grading score and intraoperative outcomes. Receiver operating characteristic (ROC) curve was used to evaluate the discriminatory power of this scoring system. RESULTS: Three preoperative factors (spleen weight, esophagogastric varices, and INR) had a significant effect on operative time, bleeding, and conversion to open surgery. We created a difficulty grading score with three levels of difficulty: low (≤ 4 points), medium (5-6 points), and high (≥ 7 points), based on the three preoperative parameters. The correlation was highly significant (P < 0.01) according to Spearman's correlation. The area under the ROC curve was 0.695 (95% CI 0.630-0.755). The external validation showed significant correlations with the present model, with an AUC of 0.725 (95% CI 0.580-0.842). The comparison between our difficulty score and the previous grading system in the 272-patient cohort presented a significant difference in the AUC (0.701, 95% CI 0.643-0.755 vs. 0.644, 95% CI 0.584-0.701, P = 0.0452). CONCLUSION: The present difficulty scoring system, based on preoperative factors, has good performance in predicting the risk of intraoperative complications of LS and could be helpful for enabling appropriate case selection with respect to the current experience of a surgeon.

Resection of pancreatic neuroendocrine tumors: defining patterns and time course of recurrence.

BACKGROUND: To define recurrence patterns and time course, as well as risk factors associated with recurrence following curative resection of pNETs. METHOD: Patients who underwent curative-intent resection for pNET between 1997 and 2016 were identified from the US Neuroendocrine Tumor Study Group. Data on baseline and tumor-specific characteristics, overall survival (OS), timing and first-site of recurrence, predictors and recurrence management were analyzed. RESULTS: Among 1020 patients, 154 (15.1%) patients developed recurrence. Among patients who experienced recurrence, 76 (49.4%) had liver-only recurrence, while 35 (22.7%) had pancreas-only recurrence. The proportion of liver-only recurrence increased from 54.3% within one-year after surgery to 61.5% from four-to-six years after surgery; whereas the proportion of pancreas-only recurrence decreased from 26.1% to 7.7% over these time periods. While liver-only recurrence was associated with tumor characteristics, pancreas-only recurrence was only associated with surgical margin status. Patients undergoing curative resection of recurrence had comparable OS with patients who had no recurrence (median OS, pancreas-only recurrence, 133.9 months; liver-only recurrence, not attained; no recurrence, 143.0 months, p = 0.499) CONCLUSIONS: Different recurrence patterns and timing course, as well as risk factors suggest biological heterogeneity of pNET recurrence. A personalized approach to postoperative surveillance and treatment of recurrence disease should be considered.

Magnetic compression anastomosis for the treatment of benign biliary strictures: a clinical study from China.

BACKGROUND: Magnetic compression anastomosis (MCA) is a revolutionary minimally invasive method to perform choledochocholedochostomy in patients with benign biliary stricture (BBS). We conducted MCA for the treatment of severe BBS that could not be treated by conventional methods. PATIENTS AND METHODS: Patients with BBSs that could not be treated using conventional treatments were included. All patients underwent percutaneous transhepatic biliary drainage (PTBD) before MCA, and underwent cholangiography via simultaneous PTBD and endoscopic retrograde cholangiopancreatography (ERCP). The MCA device consisted of a parent and a daughter magnet. The daughter magnet was delivered via the PTBD route to the proximal end of the obstruction, and the parent magnet was delivered via ERCP to the distal end of the obstruction. After recanalization, the MCA device was removed, and biliary stenting (or PTBD) was performed for at least 6 months. RESULTS: Of the 9 patients (age 49 ± 12.9 years), 6 had undergone orthotopic liver transplantation. MCA was successful in all 9 patients. The stricture length was 3 ± 1.7 mm, and recanalization occurred after 16.3 ± 13.2 days. Multiple plastic stents (4 patients), fully covered self-expandable metallic stents (4 patients), or PTBD (1 patient) was used after recanalization. Two mild adverse events occurred (cholangitis, 1 patient; biliary bleeding, 1 patient), but were resolved with conservative treatment. Stents were retrieved after > 6 months, and no stenosis occurred during 2-66 months of stent-free follow-up. CONCLUSION: The MCA technique is a revolutionary method for choledochocholedochostomy in patients with severe BBS unresponsive to conventional procedures.

Tumor burden score predicts tumor recurrence of non-functional pancreatic neuroendocrine tumors after curative resection.

BACKGROUND: To investigate the feasibility of Tumor Burden Score (TBS) to predict tumor recurrence following curative-intent resection of non-functional pancreatic neuroendocrine tumors (NF-pNETs). METHOD: The TBS cut-off values were determined by a statistical tool, X-tile. The influence of TBS on recurrence-free survival (RFS) was examined. RESULTS: Among 842 NF-pNETs patients, there was an incremental worsening of RFS as the TBS increased (5-year RFS, low, medium, and high TBS: 92.0%, 73.3%, and 59.3%, respectively; P < 0.001). TBS (AUC 0.74) out-performed both maximum tumor size (AUC 0.65) and number of tumors (AUC 0.5) to predict RFS (TBS vs. maximum tumor size, p = 0.05; TBS vs. number of tumors, p < 0.01). The impact of margin (low TBS: R0 80.4% vs. R1 71.9%, p = 0.01 vs. medium TBS: R0 55.8% vs. R1 37.5%, p = 0.67 vs. high TBS: R0 31.9% vs. R1 12.0%, p = 0.11) and nodal (5-year RFS, low TBS: N0 94.9% vs. N1 68.4%, p < 0.01 vs. medium TBS: N0 81.8% vs. N1 55.4%, p < 0.01 vs. high TBS: N0 58.0% vs. N1 54.2%, p = 0.15) status on 5-year RFS outcomes disappeared among patients who had higher TBS. CONCLUSIONS: TBS was strongly associated with risk of recurrence and outperformed both tumor size and number alone.

Magnetic Spiderman, a New Surgical Training Device: Study of Safety and Educational Value in a Liver Transplantation Surgical Training Program.

INTRODUCTION: Difficulties with liver transplantation (LT)-related surgical techniques are great challenges for young surgeons. Thus, young surgeons need to undergo systematic preclinical training. However, an optimal training system for LT is still lacking. This study aims to evaluate the safety and educational value of the Magnetic Spiderman (MS) during LT-related surgical techniques training, particularly during training for the preparation of the donor's liver and vascular reconstruction. METHODS: For the donor liver preparation training, the pulling force of the MS was measured using 16 porcine livers. Another 40 porcine livers were divided into two groups: MS group (used MS in the preparation of the liver) (n = 25) and manual group (took manual assistance in the preparation of the liver) (MA group, n = 15). In vascular reconstruction training, 25 pairs of porcine iliac veins were used to practice reconstruction. Five LT experts evaluated the MS for its use in LT-related surgical techniques training. RESULTS: During the donor liver preparation training, the number of assistants required in the MS group was significantly less than the number required in the MA group (0 vs. 1.8 ± 0.1; P < 0.001). However, the number of vasculature leaking points was similar between the two groups (0.2 ± 0.1 vs. 0.4 ± 0.2; P = 0.51). In vascular reconstruction training, the trainee alone could complete the vascular reconstruction training, with a reconstruction success rate of 80% (20/25). All five experts considered the MS a viable alternative to assistants, with the ability to facilitate single surgeon training for LT. Four out of five (80%) experts considered MS quite safe for surgery and effective at keeping the surgical field clear. CONCLUSION: MS can reduce the number of assistants to zero in LT-related techniques training without increasing the risk of the operation, thus facilitating training for LT.

A Training and Testing System for Performing Vascular Reconstruction In Vitro.

Manual vascular reconstruction training is essential for a beginner surgeon. However, an optimal training system for vascular reconstruction in vitro has yet to be developed. In this study, we introduce an in vitro training and testing system using a magnetic anchoring technique with which a trainee can practice manual vascular reconstruction individually. Additionally, this system can also be used to test the quality of the reconstruction. The described system includes a vascular reconstruction training machine, magnetic tractors, and a magnetic suture puller. In this manuscript, we detail an end-to-end vein anastomosis using porcine right and left iliac veins. To identify the potential damage caused by a magnetic suture puller on the suture, we created three groups with six segments of 4-0 polypropylene sutures each: a control group with no intervention on the polypropylene suture, a group in which the polypropylene suture is manually pulled with sterile gloves 20x, and a magnetic puller group in which the magnetic puller pulled the polypropylene suture 20x. These groups were tested by light microscopy and breaking strength tests, and the effect of reconstruction was assessed. In the light microscopy test, the control group was less likely to be damaged (p < 0.05) and the number of damaged points of the manual group and magnetic puller group were similar (p > 0.05). The results of the breaking strength test were compared across groups and no significant difference was observed (p > 0.05). The end-to-end anastomosis of the porcine iliac veins was successfully performed using this training system, and the reconstructed veins could undergo 2.0 kPa perfusion pressure. Using this training and testing system the trainee can practice manual vascular reconstruction in vitro individually with the aid of magnetic tractors and a magnetic suture puller, and the quality of the reconstruction can be tested.

Impact of tumor size and nodal status on recurrence of nonfunctional pancreatic neuroendocrine tumors ≤2 cm after curative resection: A multi-institutional study of 392 cases.

BACKGROUND: The current study sought to define the impact of lymph node metastasis (LNM) relative to tumor size on tumor recurrence after curative resection for nonfunctional pancreatic neuroendocrine tumors (NF-pNETs) ≤2 cm. METHODS: Patients who underwent curative resection for ≤2-cm NF-pNETs were identified from a multi-institutional database. Risk factors associated with tumor recurrence as well as LNM were identified. Recurrence-free survival (RFS) was compared among patients with or without LNM. RESULTS: A total of 392 ≤2-cm NF-pNETs patients were identified. Among the 328 patients who had lymph node dissection and evaluation, 42 (12.8%) patients had LNM. LNM was associated with tumor recurrence (hazard ratio, 3.06; P = .026) after surgery. RFS was worse among LNM vs no LNM patients (5-year RFS, 81.7% vs 94.1%; P = .019). Patients with tumors measuring 1.5-2 cm had a two-fold increase in the incidence of LNM vs patients with tumors <1.5 cm (17.9% vs 8.7%, odds ratio, 2.59; P = .022), as well as a higher risk of advanced tumor grade and higher Ki-67 levels (both P < .01). After curative resection, a total of 14 (8.0%) patients with a tumor of 1.5-2 cm and 10 (4.5%) patients with tumor <1.5 cm developed tumor recurrence. CONCLUSION: Surgical resection with lymphadenectomy should be considered for patients with NF-pNETs ≥1.5-2.0 cm.

Characterization of the PM2.5 concentration in surgical smoke in different tissues during hemihepatectomy and protective measures.

The characteristics of the PM2.5 concentration in surgical smoke produced by operating on different human tissues during hemihepatectomy were explored to provide a reference for protective measures. Our results showed that the highest concentration of PM2.5 produced by the electrosurgical knife was the liver tissue, followed by muscle, adipose, and vascular tissue. When the single-layer disposable medical mask, double-layer disposable medical mask, and surgical particulate respirator were used to cover the sampling port of the detector, the PM2.5 concentration for all tissue types could be reduced by approximately 40%, 55% and 75%, respectively. In the liver, the average concentration of PM2.5 produced by the ultrasonic scalpel was approximately twice that produced by the electrosurgical knife, suggesting that the air pollution around the chief surgeon caused by the ultrasonic scalpel is more serious than that caused by the electrosurgical knife. Much more protective work should be given for the liver-related surgery.