Recycled melanoma-secreted melanosomes regulate tumor-associated macrophage diversification.

Extracellular vesicles (EVs) are important mediators of communication between cells. Here, we reveal a new mode of intercellular communication by melanosomes, large EVs secreted by melanocytes for melanin transport. Unlike small EVs, which are disintegrated within the receiver cell, melanosomes stay intact within them, gain a unique protein signature, and can then be further transferred to another cell as "second-hand" EVs. We show that melanoma-secreted melanosomes passaged through epidermal keratinocytes or dermal fibroblasts can be further engulfed by resident macrophages. This process leads to macrophage polarization into pro-tumor or pro-immune cell infiltration phenotypes. Melanosomes that are transferred through fibroblasts can carry AKT1, which induces VEGF secretion from macrophages in an mTOR-dependent manner, promoting angiogenesis and metastasis in vivo. In melanoma patients, macrophages that are co-localized with AKT1 are correlated with disease aggressiveness, and immunotherapy non-responders are enriched in macrophages containing melanosome markers. Our findings suggest that interactions mediated by second-hand extracellular vesicles contribute to the formation of the metastatic niche, and that blocking the melanosome cues of macrophage diversification could be helpful in halting melanoma progression.

Surgical Intelligence can Lead to Higher Adoption of Best Practices in Minimally Invasive Surgery.

OBJECTIVE: To examine the use of surgical intelligence for automatically monitoring critical view of safety (CVS) in laparoscopic cholecystectomy (LC) in a real-world quality initiative. BACKGROUND: Surgical intelligence encompasses routine, AI-based capture and analysis of surgical video, and connection of derived data with patient and outcomes data. These capabilities are applied to continuously assess and improve surgical quality and efficiency in real-world settings. METHODS: LCs conducted at two general surgery departments between December 2022 and August 2023 were routinely captured by a surgical intelligence platform, which identified and continuously presented CVS adoption, surgery duration, complexity, and negative events. In March 2023, the departments launched a quality initiative aiming for 75% CVS adoption. RESULTS: 279 procedures were performed during the study. Adoption increased from 39.2% in the 3 pre-intervention months to 69.2% in the final 3 months (P < .001). Monthly adoption rose from 33.3% to 75.7%. Visualization of the cystic duct and artery accounted for most of the improvement; the other two components had high adoption throughout. Procedures with full CVS were shorter (P = .007) and had fewer events (P = .011) than those without. OR time decreased following intervention (P = .033). CONCLUSION: Surgical intelligence facilitated a steady increase in CVS adoption, reaching the goal within 6 months. Low initial adoption stemmed from a single CVS component, and increased adoption was associated with improved OR efficiency. Real-world use of surgical intelligence can uncover new insights, modify surgeon behavior, and support best practices to improve surgical quality and efficiency.

Implementation of artificial intelligence-based computer vision model in laparoscopic appendectomy: validation, reliability, and clinical correlation.

BACKGROUND: Application of artificial intelligence (AI) in general surgery is evolving. Real-world implementation of an AI-based computer-vision model in laparoscopic appendectomy (LA) is presented. We aimed to evaluate (1) its accuracy in complexity grading and safety adherence, (2) clinical correlation to outcomes. METHODS: A retrospective single-center study of 499 consecutive LA videos, captured and analyzed by 'Surgical Intelligence Platform,' Theator Inc. (9/2020-5/2022). Two expert surgeons viewed all videos and manually graded complexity and safety adherence. Automated annotations were compared to surgeons' assessments. Inter-surgeons' agreements were measured. Since 7/2021 videos were linked to patients' admission numbers. Data retrieval from medical records was performed (n = 365). Outcomes were compared between high and low complexity grades. RESULTS: Low and high complexity grades comprised 74.8 and 25.2% of 499 videos. Surgeons' agreements were high (76.9-94.4%, kappa 0.77/0.91; p < 0.001) for all annotated complexity grades. Surgeons' agreements were also high (96.0-99.8%, kappa 0.78/0.87; p < 0.001) for full safety adherence, whereas agreement was moderate in partial safety adherence and none (32.8-58.8%). Inter-surgeons' agreements were high for complexity grading (kappa 0.86, p < 0.001) and safety adherence (kappa 0.88, p < 0.001). Comparing high to low grade complexity, preoperative clinical features were similar, except larger appendix diameter on imaging (13.4 ± 4.4 vs. 10.5 ± 3.0 mm, p < 0.001). Intraoperative outcomes were significantly higher (p < 0.001), including time to achieve critical view of safety (29.6, IQR 19.1-41.6 vs. 13.7, IQR 8.5-21.1 min), operative duration (45.3, IQR 37.7-65.2 vs. 25.0, IQR 18.3-32.7 min), and intraoperative events (39.4% vs. 5.9%). Postoperative outcomes (7.4% vs. 9.2%) including surgical complications, mortality, and readmissions were comparable (p = 0.6), except length of stay (4, IQR 2-5.5 vs. 1, IQR 1-2 days; p < 0.001). CONCLUSION: The model accurately assesses complexity grading and full safety achievement. It can serve to predict operative time and intraoperative course, whereas no clinical correlation was found regarding postoperative outcomes. Further studies are needed.

Retrospective Analysis of Retroperitoneal-Abdominal-Pelvic Ganglioneuromas: An International Study by the Transatlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG).

OBJECTIVE: The Transatlantic Australasian Retroperitoneal Sarcoma Working Group conducted a retrospective study on the disease course and clinical management of ganglioneuromas. BACKGROUND: Ganglioneuromas are rare tumors derived from neural crest cells. Data on these tumors remain limited to case reports and single-institution case series. METHODS: Patients of all ages with pathologically confirmed primary retroperitoneal, intra-abdominal, and pelvic ganglioneuromas between January 1, 2000, and January 1, 2020, were included. We examined demographic, clinicopathologic, and radiologic characteristics, as well as clinical management. RESULTS: Overall, 328 patients from 29 institutions were included. The median age at diagnosis was 37 years with 59.1% of patients being female. Symptomatic presentation comprised 40.9% of cases, and tumors were often located in the extra-adrenal retroperitoneum (67.1%). At baseline, the median maximum tumor diameter was 7.2 cm. One hundred sixteen (35.4%) patients underwent active surveillance, whereas 212 (64.6%) patients underwent resection with 74.5% of operative cases achieving an R0/R1 resection. Serial tumor evaluations showed that malignant transformation to neuroblastoma was rare (0.9%, N=3). Tumors undergoing surveillance had a median follow-up of 1.9 years, with 92.2% of ganglioneuromas stable in size. With a median follow-up of 3.0 years for resected tumors, 84.4% of patients were disease free after resections, whereas recurrences were observed in 4 (1.9%) patients. CONCLUSIONS: Most ganglioneuromas have indolent disease courses and rarely transform to neuroblastoma. Thus, active surveillance may be appropriate for benign and asymptomatic tumors particularly when the risks of surgery outweigh the benefits. For symptomatic or growing tumors, resection may be curative.

PD-1 Blockade Combined with Heated Intraperitoneal Chemotherapy Improves Outcome in Experimental Peritoneal Metastases from Colonic Origin in a Murine Model.

BACKGROUND: Heated intraperitoneal chemotherapy (HIPEC) was shown to induce immunogenicity of peritoneal metastases from colorectal cancer (PM-CRC) by induction of immunogenic cell death. We aimed to explore whether the addition of a checkpoint inhibitor would augment the effect of HIPEC in an experimental murine model of PM-CRC. METHODS: PM-CRC was established in C57BL mice by intraperitoneal inoculation of MC38 colon cancer cells. HIPEC was administered using the closed technique with mitomycin C (MMC). Clinical and immunological parameters were compared between animals treated with HIPEC alone and those treated with HIPEC + anti-programmed death receptor-1 (aPD-1). RESULTS: MMC-based HIPEC increased the overall survival of animals compared with sham-treated animals (22.8; 95% confidence interval [CI] 21.14-24.53 vs. 18.9 days; 95% CI 17.6-20.3, p < 0.001). The extent of peritoneal disease as measured by the modified peritoneal carcinomatosis index was also reduced by HIPEC. This clinical benefit was accompanied by increased infiltration of CD8+, CD68+, and CD20+ cells into tumor metastases in HIPEC-treated animals compared with sham-treated animals. We identified heat shock protein (HSP) 90 as a potential immunogenic cell death protein whose expression is increased under HIPEC conditions (fold change: 2.37 ± 1.5 vs. 1 without HIPEC, p < 0.05). Combined HIPEC + PD-1 treatment ameliorated survival compared with HIPEC alone and sham treatment (24.66; 95% CI 20.13-29.2 vs. 19; 95% CI 15.85-22.14 and 14.33 days; 95% CI 9.6-19.04, respectively; p = 0.008). This clinical effect was accompanied by increased CD8+ tumor infiltration. CONCLUSIONS: HIPEC induced the expression of immunogenic cell death signals that can support an anti-tumor immune response. This response can be further exploited by a checkpoint inhibitor.

Lymph Node Metastases from Visceral Peritoneal Colorectal Metastases are Associated with Systemic Recurrence.

BACKGROUND: Visceral peritoneal colorectal metastases (VPCMs) may further metastasize to lymph nodes that drain those organs. The rate of lymph node metastases (LNMs) from VPCMs and their clinical and prognostic significance are unknown. METHODS: This study retrospectively analyzed the authors' institutional databases of 160 patients with peritoneal colorectal metastases who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Patients with LNM-VPCM (n = 12) were identified by pathologic reports, and both their short- and long-term outcomes were compared with those of patients without LNM-VPCM. RESULTS: The clinical presentation and primary tumor pathologic characteristics did not differ between the two groups. The patients with LNM-VPCM had a higher tumor burden (measured by the peritoneal carcinomatosis index [PCI]) and visible remnant disease compared with those who had no LNM-VPI (10 vs 5.5 [p = 0.03] vs 33.3% vs 6.8% [p = 0.007], respectively). The postoperative outcomes also were comparable. The patients with LNM-VPCM had a shorter overall survival (OS) than those without LNM-VPCM (median OS, 22.5 months; 95% confidence interval [CI], 15.1-29.9 months vs 40.1 months; 95% CI, 38.1-42 months; p = 0.02). However, only tumor grade and PCI were predictors of OS in the multivariate analysis (hazard ratio [HR], 2.33 [p = 0.001]; 1.77 [p = 0.03], respectively). The study showed that LNM-VPCM was associated with systemic but not peritoneal recurrence compared with non-LNM-VPCM (81.8% vs 51.6% for systemic recurrence, respectively; p = 0.05). CONCLUSION: The small distinct group of patients defined by LNM-VPCM were prone to systemic recurrence. Given its correlation with systemic recurrence, LNM-VPCM may indicate the need for adjuvant treatment.

Severe Postoperative Complications are Associated with Impaired Survival in Primary but not in Recurrent Retroperitoneal Sarcoma.

BACKGROUND: Retroperitoneal sarcoma (RPS) surgery entails multivisceral resection, which may cause postoperative complications. We assessed the effects of complications on survival to identify their predisposing factors in primary (PRPS) and recurrent (RRPS) RPS. METHODS: We retrospectively analyzed our institutional database. Severe postoperative complications (SC) were defined as Clavien-Dindo classification ≥ 3. Predisposing factors for complications were investigated, as was their effect on long-term outcomes. RESULTS: In total, 154 RPS resections (78 PRPS and 76 RRPS) performed between January 2008 and December 2018 were included. Neoadjuvant chemotherapy and multifocal tumors were more common in RRPS than PRPS (34.2% vs. 11.3%, P = 0.001 and 42.1% vs. 10.3%, P < 0.001, respectively). Although surgical extent in RRPS was limited compared with PRPS (weighted organ score 1 vs. 2, P = 0.01; transfusion requirement 23.6% vs. 35.8%, P = 0.04), SC and mortality rates were comparable. SC rates were 30.1% and 35.5% for PRPS and RRPS, respectively. NACT rate tended to be higher in PRPS patients with SC (20.8% vs. 7.4%, P = 0.09), whereas weighted organ score and transfusion requirement were increased in RRPS patients with SC (2 vs. 1, P = 0.01; 40.7% vs. 14.3%, P = 0.009, respectively). PRPS patients with SC had decreased overall survival (35 months, 95% confidence interval [CI] 12.2-57.7) compared with those without SC (90 months, 95% CI 71.4-108.5, P = 0.01). CONCLUSIONS: Postoperative complications are associated with impaired outcomes in PRPS but not in RRPS. The negative effects of complications on outcomes should be factored to perioperative management.

Innate inflammatory markers for predicting survival in retroperitoneal sarcoma.

INTRODUCTION: Existing prognostic tools for retroperitoneal sarcomas (RPS) utilize parameters that can be accurately determined only postoperatively. This study evaluated the application of the neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein (CRP) levels for predicting prognosis in primary RPS. MATERIALS AND METHODS: We retrospectively analyzed our database of patients with primary RPS operated between 2008 and 2018. The NLR was calculated from preoperative blood tests and its association with outcomes was determined. RESULTS: The NLR values of 78 suitable patients were analyzed. Patients were classified in the NLR-high group if the NLR was ≥2.1. High-grade tumors were more common in the NLR-high group (71.6% vs 48%, P = .02). NLR-high patients had impaired overall survival (OS) and progression-free survival (PFS) compared to NLR-low patients (median OS not reached vs 74 months 95% confidence interval [CI]: 21.6-126.4, P = .03; median PFS not reached vs 48 months 95% CI: 6.5-98.6, P = .06, respectively). Multivariate analysis showed statistical significance only for PFS but not for OS (hazard ratio [HR] = 4.1, P = .03; HR = 2.3, P = .3). Patients with low CRP levels had improved OS and PFS. CONCLUSIONS: The NLR may serve as a preoperative, easily derived marker for prognosis in RPS. Serum biomarkers may prove useful in these large and spatially heterogeneous tumors.

Intraperitoneal Invasion of Retroperitoneal Sarcomas: A Risk Factor for Dismal Prognosis.

INTRODUCTION: Retroperitoneal sarcomas (RPS) lie in the retroperitoneal space and are covered by a peritoneal layer. However, some RPS have an intraperitoneal component (IPC), which invades into the peritoneal cavity. The significance of such a clinical presentation is unknown. METHODS: We retrospectively analyzed our prospectively maintained institutional database of RPS, along with intraoperative photographs taken to document the primary tumor extent at laparotomy. The effects of IPC on overall survival (OS), local recurrence (LR), and distant metastasis (DM) were evaluated. RESULTS: IPC was present in 81 of 493 patients (16.4%). It was significantly associated with older age (64 vs. 59, p = 0.008), gender (67% vs. 33% males, p = 0.005), and multifocality (11.1% vs. 0.5%; p < 0.0001). IPC was not associated with size or any specific histology, while it showed a weak association with high malignancy grade (40.7% vs. 28.6% in G3 tumors; p = 0.076). At a median follow-up of 32 months IPC was associated with worse 5-year OS (54% vs. 74%, p < 0.001) and crude cumulative incidence (CCI) of LR (5-year CCI of LR: 38% vs. 19%, p = 0.001), but not to CCI of DM. However, multivariable models showed that IPC's effect on OS (HR: 1.52, 95% CI 0.92-2.49, p = 0.1) and LR (HR: 1.34, 95% CI 0.8-2.26, p = 0.27) could be sufficiently explained by other known risk factors. CONCLUSIONS: IPC is associated with increased LR and decreased survival. However, the effect of IPC on prognosis is predominantly related to other tumor characteristics already included in published nomograms. IPC should not be a contraindication to a proper surgical resection.

Completion surgery of residual disease after primary inadequate surgery of retroperitoneal sarcomas can salvage a selected subgroup of patients-A propensity score analysis.

BACKGROUND: Patients with retroperitoneal sarcoma (RPSs) who undergo primary inadequate surgery before referral to specialized sarcoma centers may be considered for completion surgery (CS). We wanted to compare the outcome of these patients to those who underwent primary adequate surgery (PAS) at a single referral institution. METHODS: We identified 34 patients who were referred for CS after primary inadequate surgery. Using a propensity score based on validated RPS outcome risk factors, we managed to match 28 patients to patients with PAS. RESULTS: Median time lag between the first and second operation in CS patients was 5 months (2-15). Surgical extent was similar among groups (median number of organs resected = 3; P = 0.08), and macroscopically complete excision was achieved in all patients. The rate of severe complications did not differ between the groups (1 of 28 vs 3 of 28, respectively; P = 0.35) and no perioperative mortality was documented. Median follow-up was 43.5 months. Patients in the CS group had similar local recurrence-free survival (mean, 92.1 ± 9.7 vs 99.8 ± 12.4; P = 0.85) and relapse-free survival (mean, 88.7 ± 9.8 vs 80.9 ± 12.3; P = 0.3) to those with PAS. CONCLUSIONS: CS has short- and long-term outcomes comparable to PAS. While primary surgery should always be carried out at a referral institution, some of the patients who undergo an initial incomplete resection at a non specialist center can still be offered a salvage procedure at a referral institution with comparable results.

European association for endoscopic surgery (EAES) consensus statement on single-incision endoscopic surgery.

BACKGROUND: Laparoscopic surgery changed the management of numerous surgical conditions. It was associated with many advantages over open surgery, such as decreased postoperative pain, faster recovery, shorter hospital stay and excellent cosmesis. Since two decades single-incision endoscopic surgery (SIES) was introduced to the surgical community. SIES could possibly result in even better postoperative outcomes than multi-port laparoscopic surgery, especially concerning cosmetic outcomes and pain. However, the single-incision surgical procedure is associated with quite some challenges. METHODS: An expert panel of surgeons has been selected and invited to participate in the preparation of the material for a consensus meeting on the topic SIES, which was held during the EAES congress in Frankfurt, June 16, 2017. The material presented during the consensus meeting was based on evidence identified through a systematic search of literature according to a pre-specified protocol. Three main topics with respect to SIES have been identified by the panel: (1) General, (2) Organ specific, (3) New development. Within each of these topics, subcategories have been defined. Evidence was graded according to the Oxford 2011 Levels of Evidence. Recommendations were made according to the GRADE criteria. RESULTS: In general, there is a lack of high level evidence and a lack of long-term follow-up in the field of single-incision endoscopic surgery. In selected patients, the single-incision approach seems to be safe and effective in terms of perioperative morbidity. Satisfaction with cosmesis has been established to be the main advantage of the single-incision approach. Less pain after single-incision approach compared to conventional laparoscopy seems to be considered an advantage, although it has not been consistently demonstrated across studies. CONCLUSIONS: Considering the increased direct costs (devices, instruments and operating time) of the SIES procedure and the prolonged learning curve, wider acceptance of the procedure should be supported only after demonstration of clear benefits.

Dose-Dependent Effect of Red Blood Cells Transfusion on Perioperative and Long-Term Outcomes in Peritoneal Surface Malignancies Treated with Cytoreduction and HIPEC.

BACKGROUND: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are associated with increased red blood cell transfusion (RBT) demand. Although the deleterious effects of RBT are documented in various settings, its effect in this setting is obscure. In this study, we evaluated the effects of different-grade RBT on the short- and long-term outcomes of CRS and HIPEC. METHODS: We analyzed 231 patients with diffuse malignant peritoneal mesothelioma (DMPM) and 273 patients with pseudomyxoma peritonei (PMP) operated in our unit. RBT was categorized according to the amount of packed red blood cell units (PRBCs) administered (0, 1-2, 3-5, > 6). The effects of RBT on long-term oncological outcomes [progression-free survival (PFS) and overall survival (OS)] were assessed by using multivariate analysis. RESULTS: Overall, 74% of the patients were transfused with a median of 2 PRBCs (range 0-37). Transfusion level correlated with operative time, surgical extent (as measured by the peritoneal carcinomatosis index), and age. Postoperatively, patients with major transfusion (> 6 PRBCs) had increased mortality rate (11.1%, p = 0.01) and length of hospital stay (31.2 ± 16.8 days, p = 0.01) compared with other levels of RBT. RBT was dose-dependently associated with oncological outcomes in both DMPM and PMP for both PFS [hazard ratio (HR) = 1.40, 95% confidence interval (CI) 1.12-1.74, p = 0.003; HR = 1.44, 95% CI 1.15-1.81, p = 0.001, respectively] and OS (HR = 1.57, 95% CI 1.21-2.03, p = 0.001; HR = 1.43, 95% CI 1.15-1.90, p = 0.01, respectively). CONCLUSIONS: Our data show a dose-dependent relationship between RBT and oncological outcomes. Further research to develop transfusion sparing protocols is needed in this extensive surgical procedure.

T-Helper 1 Immune Response in Metastatic Lymph Nodes of Pancreatic Ductal Adenocarcinoma: A Marker For Prolonged Survival.

BACKGROUND: Although lymph node (LN) metastases is considered a grave prognostic sign in pancreatic ductal adenocarcinoma (PDAC), patients with positive lymph nodes (PLN) constitute a heterogeneous group. Our purpose was to identify morphological and immune parameters in the primary tumor and in PLN of resected PDAC patients, which could further stratify these patients to different subgroups. METHODS: We retrospectively evaluated histological and immunohistochemical characteristics of 66 patients with PDAC who were operated at our institution. These were subsequently correlated to clinical outcome. RESULTS: Mean patient age and number of LN harvested was 65.5 ± 10.3 and 12.3 ± 6.5 years, respectively. Tumor size (T stage) and perineural invasion had no effect on clinical outcome. High-grade tumor was associated with decreased survival [overall survival (OS) = 19.6 ± 2.7 months for poorly differentiated PDAC vs. 31.2 ± 4 for well and moderately differentiated, p = 0.03]. Patients with ≥ 8 PLN had significantly worse outcome (OS = 7.3 ± 0.8 months for PLN ≥ 8 vs. OS = 30.1 ± 3.2 months for PLN < 8, p < 0.0001). T helper (Th) 1 immune response was measured both by its effector cells (CD8+) and expression of its main transcription factor, T-bet. CD8+ high patients had significantly increased OS compared with CD8+ low (OS = 36.8 ± 5.3 months for CD8 + high vs. OS = 24.3 ± 3.5 for CD8 + low, p = 0.03) Similarly, Th1 predominant immune response measured by T-bet expression was associated with improved OS compared with non-Th1 (OS = 32.8 ± 3.2 vs. OS = 19.5 ± 2.9, p < 0.0001). CONCLUSIONS: Our data indicate an association between Th1-type immune response and increased survival. Future research is needed to exploit Th1 immune response as a biological marker for immunotherapy.

Optimization of liposomal indocyanine green for imaging of the urinary pathways and a proof of concept in a pig model.

BACKGROUND: Iatrogenic ureteral injury is an increasing concern in the laparoscopic era, affecting both patient morbidity and costs. Current techniques enabling intraoperative ureteral identification require invasive procedures or radiations. Our aim was to develop a real-time, non-invasive, radiation-free method to visualize ureters, based on near-infrared (NIR) imaging. For this purpose, we interfered with the biliary excretion pathway of the indocyanine green (ICG) fluorophore by loading it into liposomes, enabling renal excretion. In this work, we studied various parameters influencing ureteral imaging. METHODS: Fluorescence intensity (FI) of various liposomal ICG sizes and doses were characterized in vitro and subsequently tested in vivo in mice and pigs. Quantification was performed by measuring FI in multiple points and applying the ureteral/retroperitoneum ratio (U/R). RESULTS: The optimal liposomal ICG loading dose was 20%, for the different liposomes' sizes tested (30, 60, 100 nm). Higher concentration of ICG decreased FI. In vivo, the optimal liposome size for ureteral imaging was 60 nm, which yielded a U/R of 5.2 ± 1.7 (p < 0.001 vs. free ICG). The optimal ICG dose was 8 mg/kg (U/R = 2.1 ± 0.4, p < 0.05 vs. 4 mg/kg). Only urine after liposomal ICG injection had a measurable FI, and not after free ICG injection. Using a NIR-optimized laparoscopic camera, ureters could be effectively imaged in pigs, from 10 min after injection and persisting for at least 90 min. Ureteral peristaltic waves could be clearly identified only after liposomal ICG injection. CONCLUSIONS: Optimization of liposomal ICG allowed to visualize enhanced ureters in animal models and seems a promising fluorophore engineering, which calls for further developments.

Intraoperative Localization of Rectal Tumors Using Liposomal Indocyanine Green.

BACKGROUND: Tumor localization may pose a significant challenge during minimally invasive rectal resection. Near-infrared (NIR) imaging can penetrate biological tissue and afford tumor localization from the external surface of the rectum. Our aim was to develop an NIR-based tool for rectal tumor imaging that can be administered intravenously. METHODS: We prepared indocyanine-green (ICG)-loaded liposomes by sonication. Liposomes were evaluated for their size and morphology. We then used an endoscopically induced rectal cancer in mice as a model for rectal cancer. After intravenous administration, tumors were evaluated for their fluorescence intensity. Tumor intensity was expressed in relation to the background signal, that is, tumor to background ratio (TBR). RESULTS: Liposomes in various sizes could be prepared by adjusting sonication time. We selected 100-nm-sized liposomes for further experiments. Transmission electron microscopy showed spherical particles and confirmed the size measurements. The liposomes could be lyophilized and then rehydrated again before use without compromising their structure or signal. Fluorescence intensity was kept for 24 hours after solubilization. Testing the optimal time course for rectal tumor imaging revealed that early time course (up to 3 hours) yielded nonspecific imaging, whereas after long time course (24 hours), a very weak signal remained in the tissue. The optimal time window for imaging was after 12 hours from injection, with TBR = 8.1 ± 3.6 ( P = .002). Free ICG could not achieve similar results. CONCLUSIONS: The liposomal ICG can be reproducibly prepared and kept in lyophilized form. Liposomal ICG could serve as a tool for intraoperative tumor localization.

Imaging the urinary pathways in mice by liposomal indocyanine green.

Intraoperative ureter identification can assist in the prevention of ureteral injury and consequently improve surgery outcomes. Our aim was to take advantage of the altered pharmacokinetics of liposomal indocyanine green (ICG), the only FDA-approved near-infrared (NIR) dye, for imaging of ureters during surgeries. ICG was passively adsorbed to liposomes. NIR whole mice body and isolated tissue imaging were used to study liposomal ICG properties vs. free ICG. In vivo, the urinary bladder could be clearly observed in most of the liposome-treated mice. Liposomal encapsulation of ICG enhanced ureteral emission up to 1.9 fold compared to free ICG (P<0.01). Increase in liposomal micropolarity and microviscosity and differential scanning calorimetry supported ICG localization within the liposomal bilayer. Our findings suggest that liposomal ICG could be utilized for ureteral imaging intra-operatively, thus potentially improving surgical outcomes. FROM THE CLINICAL EDITOR: Iatrogenic ureteral injury is a serious complication of abdominal surgery and intra-operative recognition of the ureters is usually the best method of injury prevention. In this article, the authors developed liposomal indocyanine green, which could be excreted via the urinary system and investigated its in-vivo use in mice.

Epithelial-to-mesenchymal transition (EMT) in intraductal papillary mucinous neoplasm (IPMN) is associated with high tumor grade and adverse outcomes.

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) is generally associated with increased tumor aggressiveness and poor prognosis. We evaluated EMT characteristics in intraductal papillary mucinous neoplasm (IPMN) tumor specimens and their potential role as biomarkers for malignancy, metastasis, and adverse patient outcomes. METHODS: IPMN surgical specimens were identified and reviewed by two gastrointestinal pathologists. Immunohistochemical analysis of E-cadherin, vimentin, and ZEB-1 was performed. Samples were linked to clinicopathologic and outcome data for these patients. Western blot test was used to evaluate ZEB-1 expression in IPMN samples; 846 human miRNAs were profiled, and EMT-related differentially expressed miRNAs were validated using quantitative real-time polymerase chain reaction. RESULTS: Fifty-eight IPMN specimens and five normal pancreatic tissue samples were immunohistochemically stained and scored. E-cadherin expression was significantly lower in malignant versus low-grade IPMN (p < 0.05). Vimentin expression was increased in malignant IPMN tumor samples (p < 0.05). EMT was associated with increased lymph node metastasis and decreased survival of malignant IPMN patients (p < 0.05). ZEB-1, an imperative EMT regulator, was exclusively expressed by malignant IPMN tumors. miRNA hierarchical clustering demonstrated grouping of two main IPMN subgroups: low-grade IPMN versus high-grade IPMN and carcinoma. Twenty-four miRNAs were differentially expressed (14 up-regulated, 10 down-regulated). The EMT-regulatory miRNAs, miR-200c and miR-141, were down-regulated (twofold and 1.8-fold decrease, respectively) in malignant versus low-grade IPMN (p < 0.05). CONCLUSIONS: EMT may play a role in IPMN tumorigenesis and metastasis. EMT molecular deregulations could be utilized as potential novel biomarkers for the identification of high-risk IPMN patients.

Technical Considerations in One Anastomosis Gastric Bypass-the Israeli Society of Metabolic and Bariatric Surgery Experience.

BACKGROUND: One anastomosis gastric bypass (OAGB) is gaining popularity worldwide due to its safety and effectiveness. OAGB is the most commonly performed metabolic bariatric surgery (MBS) in Israel. Israel is the only country where OAGB is the most prevalent MBS. Our aim is to address OAGB technical aspects using a national survey completed by members of the Israeli Society of Metabolic and Bariatric Surgery (ISMBS). MATERIALS AND METHODS: An online-survey composed of a 17-item-based questionnaire was sent to ISMBS members. All responses were collected and analyzed. RESULTS: A total of 47/64 (73.4%) ISMBS members participated in the survey. Most surgeons (74.5%) had > 10 years of MBS experience, and most (61.7%) performed > 100 MBS/year. The majority (78.7%) perform OAGB as their most common procedure. Most surgeons fashion a 10-15-cm pouch and use a 36-Fr bougie, (57.4% and 38.3%). Regarding bowel length measurement, 70% use visual estimation and 10.6% routinely measure total small bowel length (TSBL). The most common reasons for creating a longer biliopancreatic limb (BPL) were high body mass index (BMI) and revisional surgery (83.3% and 66%, respectively). In a primary procedure of a patient with a BMI = 40, most (76.6%) would create a 150-200-cm BPL. In patients with a BMI > 50 or revisional cases, most (70.2% and 68.0%) would create a 175-225-cm BPL. CONCLUSION: OAGB is the most prevalent MBS performed in Israel. This survey showed common preferences and variations among ISMBS members. Further studies are needed in order to standardize and build a consensus on OAGB technique.