Ensemble deep learning for the prediction of proficiency at a virtual simulator for robot-assisted surgery

BACKGROUND

Artificial intelligence (AI) has the potential to enhance patient safety in surgery, and all its aspects, including education and training, will derive considerable benefit from AI. In the present study, deep-learning models were used to predict the rates of proficiency acquisition in robot-assisted surgery (RAS), thereby providing surgical programs directors information on the levels of the innate ability of trainees to facilitate the implementation of flexible personalized training.

METHODS

176 medical students, without prior experience with surgical simulators, were trained to reach proficiency in five tasks on a virtual simulator for RAS. Ensemble deep neural networks (DNN) models were developed and compared with other ensemble AI algorithms, i.e., random forests and gradient boosted regression trees (GBRT).

RESULTS

DNN models achieved a higher accuracy than random forests and GBRT in predicting time to proficiency, 0.84 vs. 0.70 and 0.77, respectively (Peg board 2), 0.83 vs. 0.79 and 0.78 (Ring walk 2), 0.81 vs 0.81 and 0.80 (Match board 1), 0.79 vs. 0.75 and 0.71 (Ring and rail 2), and 0.87 vs. 0.86 and 0.84 (Thread the rings 2). Ensemble DNN models outperformed random forests and GBRT in predicting number of attempts to proficiency, with an accuracy of 0.87 vs. 0.86 and 0.83, respectively (Peg board 2), 0.89 vs. 0.88 and 0.89 (Ring walk 2), 0.91 vs. 0.89 and 0.89 (Match board 1), 0.89 vs. 0.87 and 0.83 (Ring and rail 2), and 0.96 vs. 0.94 and 0.94 (Thread the rings 2).

CONCLUSIONS

Ensemble DNN models can identify at an early stage the acquisition rates of surgical technical proficiency of trainees and identify those struggling to reach the required expected proficiency level.

Robot-assisted pancreatoduodenectomy with the da Vinci Xi: can the costs of advanced technology be offset by clinical advantages? A case-matched cost analysis versus open approach

BACKGROUND

Robot-assisted pancreatoduodenectomy (RPD) has shown some advantages over open pancreatoduodenectomy (OPD) but few studies have reported a cost analysis between the two techniques. We conducted a structured cost-analysis comparing pancreatoduodenectomy performed with the use of the da Vinci Xi, and the traditional open approach, and considering healthcare direct costs associated with the intervention and the short-term post-operative course.

MATERIALS AND METHODS

Twenty RPD and 194 OPD performed between January 2011 and December 2020 by the same operator at our high-volume multidisciplinary center for robot-assisted surgery and for pancreatic surgery, were retrospectively analyzed. Two comparable groups of 20 patients (Xi-RPD-group) and 40 patients (OPD-group) were obtained matching 1:2 the RPD-group with the OPD-group. Perioperative data and overall costs, including overall variable costs (OVCs) and fixed costs, were compared.

RESULTS

No difference was reported in mean operative time: 428 min for Xi-RPD-group versus 404 min for OPD, p = 0.212. The median overall length of hospital stay was significantly lower in the Xi-RPD-group: 10 days versus 16 days, p = 0.001. In the Xi-RPD-group, consumable costs were significantly higher (€6149.2 versus €1267.4, p < 0.001), while hospital stay costs were significantly lower: €5231.6 versus €8180 (p = 0.001). No significant differences were found in terms of OVCs: €13,483.4 in Xi-RPD-group versus €11,879.8 in OPD-group (p = 0.076).

CONCLUSIONS

Robot-assisted surgery is more expensive because of higher acquisition and maintenance costs. However, although RPD is associated to higher material costs, the advantages of the robotic system associated to lower hospital stay costs and the absence of difference in terms of personnel costs thanks to the similar operative time with respect to OPD, make the OVCs of the two techniques no longer different. Hence, the higher costs of advanced technology can be partially compensated by clinical advantages, particularly within a high-volume multidisciplinary center for both robot-assisted and pancreatic surgery. These preliminary data need confirmation by further studies.

"Depart from evil, and do good": Turning Axl from uncontrolled tumorigenic gene to biomarker for early detection of pancreatic cancer

Attempts to achieve early diagnosis are crucial to improve the outcome of patients with pancreatic ductal adenocarcinoma (PDAC). Here we present a critical evaluation of a recent study unraveling the potential of circulating AXL as a novel blood marker for early detection of PDAC and differential diagnosis from chronic pancreatitis (CP).

In Pancreatic Adenocarcinoma Alpha-Synuclein Increases and Marks Peri-Neural Infiltration

α-Synuclein (α-syn) is a protein involved in neuronal degeneration. However, the family of synucleins has recently been demonstrated to be involved in the mechanisms of oncogenesis by selectively accelerating cellular processes leading to cancer. Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal human cancers, with a specifically high neurotropism. The molecular bases of this biological behavior are currently poorly understood. Here, α-synuclein was analyzed concerning the protein expression in PDAC and the potential association with PDAC neurotropism. Tumor (PDAC) and extra-tumor (extra-PDAC) samples from 20 patients affected by PDAC following pancreatic resections were collected at the General Surgery Unit, University of Pisa. All patients were affected by moderately or poorly differentiated PDAC. The amount of α-syn was compared between tumor and extra-tumor specimen (sampled from non-affected neighboring pancreatic areas) by using in situ immuno-staining with peroxidase anti-α-syn immunohistochemistry, α-syn detection by using Western blotting, and electron microscopy by using α-syn-conjugated immuno-gold particles. All the methods consistently indicate that each PDAC sample possesses a higher amount of α-syn compared with extra-PDAC tissue. Moreover, the expression of α-syn was much higher in those PDAC samples from tumors with perineural infiltration compared with tumors without perineural infiltration.

The management of colorectal liver metastases amenable of surgical resection: How to shape treatment strategies according to clinical, radiological, pathological and molecular features

Metastatic colorectal cancer (mCRC) patients have poor chances of long term survival, being < 15% of them still alive after 5 years from diagnosis. Nonetheless, patients with colorectal liver metastases (CRLM) may be eligible for metastases resection thus being able to achieve long-term disease remission and survival. The likelihood for patients with CRLM of being or becoming eligible for liver metastasectomy is increasing, thanks to the evolution of surgical techniques, the availability of active systemic treatments and the widespread diffusion of experienced multidisciplinary boards to manage these patients. However, disease relapse after liver surgery is common and occurs in two-thirds of resected patients. Therefore, adequate radiological staging and risk stratification is crucial for the optimal selection of patients candidate to surgery in order to maximize the benefit-risk ratio of liver metastasectomy and to individualize the treatment strategy. Based on the multidimensional assessment, three possible approaches are available: upfront liver surgery followed by adjuvant chemotherapy, perioperative chemotherapy preceding and following liver surgery, and an upfront systemic treatment including chemotherapy plus a targeted agent, both chosen according to patients' and tumours' characteristics, then followed by liver surgery if indicated. In this review, we describe the most important factors impacting the therapeutic choices in patients with resectable and potentially resectable CRLM, and we discuss the most promising factors that may reshape the future decision-making process of these patients.

Variations in risk-adjusted outcomes following 4318 laparoscopic liver resections

Background/Purpose

Quality measures in surgery are important to establish appropriate levels of care and to develop improvement strategies. The purpose of this study was to provide risk‐adjusted outcome measures after laparoscopic liver resection (LLR).

Methods

Data from a prospective, multicenter database involving 4318 patients submitted to LLRs in 41 hospitals from an intention‐to‐treat approach (2014–2020) were used to analyze heterogeneity (I²) among centers and to develop a risk‐adjustment model on outcome measures through multivariable mixed‐effect models to account for confounding due to case‐mix.

Results

Involved hospitals operated on very different patients: the largest heterogeneity was observed for operating in the presence of previous abdominal surgery (I²:79.1%), in cirrhotic patients (I²:89.3%) suffering from hepatocellular carcinoma (I²:88.6%) or requiring associated intestinal resections (I²:82.8%) and in regard to technical complexity (I² for the most complex LLRs: 84.1%). These aspects determined substantial or large heterogeneity in overall morbidity (I²:84.9%), in prolonged in‐hospital stay (I²:86.9%) and in conversion rate (I²:73.4%). Major complication had medium heterogeneity (I²:46.5%). The heterogeneity of mortality was null. Risk‐adjustment accounted for all of this variability and the final risk‐standardized conversion rate was 8.9%, overall morbidity was 22.1%, major morbidity was 5.1% and prolonged in‐hospital stay was 26.0%. There were no outliers among the 41 participating centers. An online tool was provided.

Conclusions

A benchmark for LLRs including all eligible patients was provided, suggesting that surgeons can act accordingly in the interest of the patient, modifying their approach in relation to different indications and different experience, but finally providing the same quality of care.

Potential Role of Exosomes in the Chemoresistance to Gemcitabine and Nab-Paclitaxel in Pancreatic Cancer

In recent years, a growing number of studies have evaluated the role of exosomes in pancreatic ductal adenocarcinoma cancer (PDAC) demonstrating their involvement in a multitude of pathways, including the induction of chemoresistance. The aim of this review is to present an overview of the current knowledge on the role of exosomes in the resistance to gemcitabine and nab-paclitaxel, which are two of the most commonly used drugs for the treatment of PDAC patients. Exosomes are vesicular cargos that transport multiple miRNAs, mRNAs and proteins from one cell to another cell and some of these factors can influence specific determinants of gemcitabine activity, such as the nucleoside transporter hENT1, or multidrug resistance proteins involved in the resistance to paclitaxel. Additional mechanisms underlying exosome-mediated resistance include the modulation of apoptotic pathways, cellular metabolism, or the modulation of oncogenic miRNA, such as miR-21 and miR-155. The current status of studies on circulating exosomal miRNA and their possible role as biomarkers are also discussed. Finally, we integrated the preclinical data with emerging clinical evidence, showing how the study of exosomes could help to predict the resistance of individual tumors, and guide the clinicians in the selection of innovative therapeutic strategies to overcome drug resistance.

Identification of Recessively Inherited Genetic Variants Potentially Linked to Pancreatic Cancer Risk

Although 21 pancreatic cancer susceptibility loci have been identified in individuals of European ancestry through genome-wide association studies (GWASs), much of the heritability of pancreatic cancer risk remains unidentified. A recessive genetic model could be a powerful tool for identifying additional risk variants. To discover recessively inherited pancreatic cancer risk loci, we performed a re-analysis of the largest pancreatic cancer GWAS, the Pancreatic Cancer Cohort Consortium (PanScan) and the Pancreatic Cancer Case-Control Consortium (PanC4), including 8,769 cases and 7,055 controls of European ancestry. Six single nucleotide polymorphisms (SNPs) showed associations with pancreatic cancer risk according to a recessive model of inheritance. We replicated these variants in 3,212 cases and 3,470 controls collected from the PANcreatic Disease ReseArch (PANDoRA) consortium. The results of the meta-analyses confirmed that rs4626538 (7q32.2), rs7008921 (8p23.2) and rs147904962 (17q21.31) showed specific recessive effects (p<10-5) compared with the additive effects (p>10-3), although none of the six SNPs reached the conventional threshold for genome-wide significance (p < 5×10-8). Additional bioinformatic analysis explored the functional annotations of the SNPs and indicated a possible relationship between rs36018702 and expression of the BCL2L11 and BUB1 genes, which are known to be involved in pancreatic biology. Our findings, while not conclusive, indicate the importance of considering non-additive genetic models when performing GWAS analysis. The SNPs associated with pancreatic cancer in this study could be used for further meta-analysis for recessive association of SNPs and pancreatic cancer risk and might be a useful addiction to improve the performance of polygenic risk scores.

STARSurg Collaborative and COVIDSurg Collaborative . Death following pulmonary complications of surgery before and during the SARS-CoV-2 pandemic

BACKGROUND

This study aimed to determine the impact of pulmonary complications on death after surgery both before and during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic.

METHODS

This was a patient-level, comparative analysis of two, international prospective cohort studies: one before the pandemic (January-October 2019) and the second during the SARS-CoV-2 pandemic (local emergence of COVID-19 up to 19 April 2020). Both included patients undergoing elective resection of an intra-abdominal cancer with curative intent across five surgical oncology disciplines. Patient selection and rates of 30-day postoperative pulmonary complications were compared. The primary outcome was 30-day postoperative mortality. Mediation analysis using a natural-effects model was used to estimate the proportion of deaths during the pandemic attributable to SARS-CoV-2 infection.

RESULTS

This study included 7402 patients from 50 countries; 3031 (40.9 per cent) underwent surgery before and 4371 (59.1 per cent) during the pandemic. Overall, 4.3 per cent (187 of 4371) developed postoperative SARS-CoV-2 in the pandemic cohort. The pulmonary complication rate was similar (7.1 per cent (216 of 3031) versus 6.3 per cent (274 of 4371); P = 0.158) but the mortality rate was significantly higher (0.7 per cent (20 of 3031) versus 2.0 per cent (87 of 4371); P < 0.001) among patients who had surgery during the pandemic. The adjusted odds of death were higher during than before the pandemic (odds ratio (OR) 2.72, 95 per cent c.i. 1.58 to 4.67; P < 0.001). In mediation analysis, 54.8 per cent of excess postoperative deaths during the pandemic were estimated to be attributable to SARS-CoV-2 (OR 1.73, 1.40 to 2.13; P < 0.001).

CONCLUSION

Although providers may have selected patients with a lower risk profile for surgery during the pandemic, this did not mitigate the likelihood of death through SARS-CoV-2 infection. Care providers must act urgently to protect surgical patients from SARS-CoV-2 infection.

Detailing the ultrastructure's increase of prion protein in pancreatic adenocarcinoma

BACKGROUND

Recent evidences have shown a relationship between prion protein (PrPc) expression and pancreatic ductal adenocarcinoma (PDAC). Indeed, PrPc could be one of the markers explaining the aggressiveness of this tumor. However, studies investigating the specific compartmentalization of increased PrPc expression within PDAC cells are lacking, as well as a correlation between ultrastructural evidence, ultrastructural morphometry of PrPc protein and clinical data. These data, as well as the quantitative stoichiometry of this protein detected by immuno-gold, provide a significant advancement in understanding the biology of disease and the outcome of surgical resection.

AIM

To analyze quantitative stoichiometry and compartmentalization of PrPc in PDAC cells and to correlate its presence with prognostic data.

METHODS

Between June 2018 and December 2020, samples from pancreatic tissues of 45 patients treated with pancreatic resection for a preoperative suspicion of PDAC at our Institution were collected. When the frozen section excluded a PDAC diagnosis, or the nodules were too small for adequate sampling, patients were ruled out from the present study. Western blotting was used to detect, quantify and compare the expression of PrPc in PDAC and control tissues, such as those of non-affected neighboring pancreatic tissue of the same patient. To quantify the increase of PrPc and to detect the subcellular compartmentalization of PrPc within PDAC cells, immuno-gold stoichiometry within specific cell compartments was analyzed with electron microscopy. Finally, an analysis of quantitative PrPc expression according to prognostic data, such as cancer stage, recurrence of the disease at 12 mo after surgery and recurrence during adjuvant chemotherapy was made.

RESULTS

The amount of PrPc within specimen from 38 out of 45 patients was determined by semi-quantitative analysis by using Western blotting, which indicates that PrPc increases almost three-fold in tumor pancreatic tissue compared with healthy pancreatic regions [242.41 ± 28.36 optical density (OD) vs 95 ± 17.40 OD, P < 0.0001]. Quantitative morphometry carried out by using immuno-gold detection at transmission electron microscopy confirms an increased PrPc expression in PDAC ductal cells of all patients and allows to detect a specific compartmentalization of PrPc within tumor cells. In particular, the number of immuno-gold particles of PrPc was significantly higher in PDAC cells respect to controls, when considering the whole cell (19.8 ± 0.79 particles vs 9.44 ± 0.45, P < 0.0001). Remarkably, considering PDAC cells, the increase of PrPc was higher in the nucleus than cytosol of tumor cells, which indicates a shift in PrPc compartmentalization within tumor cells. In fact, the increase of immuno-gold within nuclear compartment exceeds at large the augment of PrPc which was detected in the cytosol (nucleus: 12.88 ± 0.59 particles vs 5.12 ± 0.32, P < 0.0001; cytosol: 7.74. ± 0.44 particles vs 4.3 ± 0.24, P < 0.0001). In order to analyze the prognostic impact of PrPc, we found a correlation between PrPc expression and cancer stage according to pathology results, with a significantly higher expression of PrPc for advanced stages. Moreover, 24 patients with a mean follow-up of 16.8 mo were considered. Immuno-blot analysis revealed a significantly higher expression of PrPc in patients with disease recurrence at 12 mo after radical surgery (360.71 ± 69.01 OD vs 170.23 ± 23.06 OD, P = 0.023), also in the subgroup of patients treated with adjuvant CT (368.36 ± 79.26 OD in the recurrence group vs 162.86 ± 24.16 OD, P = 0.028), which indicates a correlation with a higher chemo-resistance.

CONCLUSION

Expression of PrPc is significantly higher in PDAC cells compared with control, with the protein mainly placed in the nucleus. Preliminary clinical data confirm the correlation with a poorer prognosis.

CXCL12/SDF-1 in IgG4-Related Disease

Background: SDF-1/CXCL12 is a chemokine with pleiotropic functions in hematopoietic stem cell niche homeostasis, germinal center architecture, B cell maturation, neoangiogenesis, and fibrosis. Recently, the CXCL12/CXCR4/CXCR7 axis was associated with cancer metastasis and autoimmune diseases. The IgG4-related disease (IgG4-RD) is a pathological condition characterized by IgG4+ plasma cells infiltrating fibrotic lesions. The aim of this research is to investigate the relevance of SDF-1/CXCL12 in IgG4-RD. Materials and Methods: Peripheral blood samples were collected before therapy from a single-center cohort of 28 IgG4-RD patients, fulfilling the ACR-EULAR classification criteria. Clinical and serological data were obtained for each patient. In total, 14 healthy donors (NHS), 9 patients with pancreatic ductal adenocarcinoma (PDAC), and 9 with Sjogren syndrome (SSj) were recruited as controls and screened for circulating SDF-1/CXCL12 by ELISA. Moreover, paraffin-embedded pancreatic biopsies obtained from patients with IgG4-RD (n = 7), non-autoimmune pancreatitis (n = 3), PDAC (n = 5), and control tissues (n = 4) were analyzed to study the tissue expression and localization of SDF-1/CXCL12 and one of its receptors, CXCR4, and their potential relation with neutrophil extracellular traps (NETs). Results: IgG4-RD patients had higher serum levels of SDF-1/CXCL12 than normal controls (p = 0.0137). Cytokine levels did not differ between the IgG4-RD autoimmune pancreatitis (AIP) and retroperitoneal fibrosis nor between the single- and multiple-organ involvement. No correlation was seen with the IgG4-RD Responder Index, IgG4 levels, white blood cells, or inflammatory markers in the serum. When compared to SSj, the IgG4-RD AIP subgroup presents higher amounts of serum SDF-1/CXCL12 (p = 0.0275), while no differences are seen in comparison with PDAC. The expression of SDF-1/CXCL12 in the tissue was significantly higher in the IgG4-RD tissue than the normal pancreas, and the tissue with the high SDF-1/CXCL12 expression is characterized by the overall inflammatory cell infiltration, fibrosis, and high level of NETs. Conclusion: Modulating B cell development, neoangiogenesis and fibrosis, and SDF-1/CXCL12 may play a role in IgG4-RD. The higher levels observed in IgG4-RD, as compared to SSj, which closely mimics the disease, can be related to a different pattern of lesions, with prevalent fibrosis seen in IgG4-RD. Taken together, these findings suggest that drugs acting on the CXCL12/CXCR4/CXCR7 axis may affect IgG4-RD.

Machine learning risk prediction of mortality for patients undergoing surgery with perioperative SARS-CoV-2: the COVIDSurg mortality score

To support the global restart of elective surgery, data from an international prospective cohort study of 8492 patients (69 countries) was analysed using artificial intelligence (machine learning techniques) to develop a predictive score for mortality in surgical patients with SARS-CoV-2. We found that patient rather than operation factors were the best predictors and used these to create the COVIDsurg Mortality Score (https://covidsurgrisk.app). Our data demonstrates that it is safe to restart a wide range of surgical services for selected patients.

Effect of COVID-19 pandemic lockdowns on planned cancer surgery for 15 tumour types in 61 countries: an international, prospective, cohort study

BACKGROUND

Surgery is the main modality of cure for solid cancers and was prioritised to continue during COVID-19 outbreaks. This study aimed to identify immediate areas for system strengthening by comparing the delivery of elective cancer surgery during the COVID-19 pandemic in periods of lockdown versus light restriction.

METHODS

This international, prospective, cohort study enrolled 20 006 adult (≥18 years) patients from 466 hospitals in 61 countries with 15 cancer types, who had a decision for curative surgery during the COVID-19 pandemic and were followed up until the point of surgery or cessation of follow-up (Aug 31, 2020). Average national Oxford COVID-19 Stringency Index scores were calculated to define the government response to COVID-19 for each patient for the period they awaited surgery, and classified into light restrictions (index <20), moderate lockdowns (20-60), and full lockdowns (>60). The primary outcome was the non-operation rate (defined as the proportion of patients who did not undergo planned surgery). Cox proportional-hazards regression models were used to explore the associations between lockdowns and non-operation. Intervals from diagnosis to surgery were compared across COVID-19 government response index groups. This study was registered at ClinicalTrials.gov, NCT04384926.

FINDINGS

Of eligible patients awaiting surgery, 2003 (10·0%) of 20 006 did not receive surgery after a median follow-up of 23 weeks (IQR 16-30), all of whom had a COVID-19-related reason given for non-operation. Light restrictions were associated with a 0·6% non-operation rate (26 of 4521), moderate lockdowns with a 5·5% rate (201 of 3646; adjusted hazard ratio [HR] 0·81, 95% CI 0·77-0·84; p<0·0001), and full lockdowns with a 15·0% rate (1775 of 11 827; HR 0·51, 0·50-0·53; p<0·0001). In sensitivity analyses, including adjustment for SARS-CoV-2 case notification rates, moderate lockdowns (HR 0·84, 95% CI 0·80-0·88; p<0·001), and full lockdowns (0·57, 0·54-0·60; p<0·001), remained independently associated with non-operation. Surgery beyond 12 weeks from diagnosis in patients without neoadjuvant therapy increased during lockdowns (374 [9·1%] of 4521 in light restrictions, 317 [10·4%] of 3646 in moderate lockdowns, 2001 [23·8%] of 11 827 in full lockdowns), although there were no differences in resectability rates observed with longer delays.

INTERPRETATION

Cancer surgery systems worldwide were fragile to lockdowns, with one in seven patients who were in regions with full lockdowns not undergoing planned surgery and experiencing longer preoperative delays. Although short-term oncological outcomes were not compromised in those selected for surgery, delays and non-operations might lead to long-term reductions in survival. During current and future periods of societal restriction, the resilience of elective surgery systems requires strengthening, which might include protected elective surgical pathways and long-term investment in surge capacity for acute care during public health emergencies to protect elective staff and services.

FUNDING

National Institute for Health Research Global Health Research Unit, Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, Medtronic, Sarcoma UK, The Urology Foundation, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research.

Is minimally invasive liver surgery a reasonable option in recurrent HCC? A snapshot from the I Go MILS registry

Laparoscopic liver resection (LLR) for Hepatocellular carcinoma (HCC) is a safe procedure. Repeat surgery is more often required, and the role of minimally invasive liver surgery (MILS) is not yet clearly defined. The present study analyzes data compiled by the Italian Group of Minimally Invasive Liver Surgery (IGoMILS) on LLR. To compare repeated LLR with the first LLR for HCC is the primary endpoint. The secondary endpoint was to evaluate the outcome of repeat LLR in the case of primary open versus primary MILS surgery. The data cohort is divided into two groups. Group 1: first liver resection and Group 2: Repeat LLR. To compare the two groups a 3:1 Propensity Score Matching is performed to analyze open versus MILS primary resection. Fifty-two centers were involved in the present study, and 1054 patients were enrolled. 80 patients underwent to a repeat LLR. The type of resection was different, with more major resections in the group 1 before matching the two groups. After propensity score matching 3:1, each group consisted of 222 and 74 patients. No difference between the two groups was observed. In the subgroup analysis, in 44 patients the first resection was performed by an open approach. The other 36 patients were resected with a MILS approach. We found no difference between these two subgroups of patients. The present study in repeat MILS for HCC using the IGoMILS Registry has observed the feasibility and safety of the MILS procedure.

Genetic Polymorphisms Involved in Mitochondrial Metabolism and Pancreatic Cancer Risk

BACKGROUND

The mitochondrial metabolism has been associated with pancreatic ductal adenocarcinoma (PDAC) risk. Recent evidence also suggests the involvement of the genetic variability of the mitochondrial function in several traits involved in PDAC etiology. However, a systematic investigation of the genetic variability of mitochondrial genome (mtSNP) and of all the nuclear genes involved in its functioning (n-mtSNPs) has never been reported.

METHODS

We conducted a two-phase association study of mtSNPs and n-mtSNPs to assess their effect on PDAC risk. We analyzed 35,297 n-mtSNPs and 101 mtSNPs in up to 55,870 individuals (12,884 PDAC cases and 42,986 controls). In addition, we also conducted a gene-based analysis on 1,588 genes involved in mitochondrial metabolism using Multi-marker Analysis of GenoMic Annotation (MAGMA) software.

RESULTS

In the discovery phase, we identified 49 n-mtSNPs and no mtSNPs associated with PDAC risk (P < 0.05). In the second phase, none of the findings were replicated. In the gene-level analysis, we observed that three genes (TERT, SUGCT, and SURF1) involved in the mitochondrial metabolism showed an association below the Bonferroni-corrected threshold of statistical significance (P = 0.05/1588 = 3.1 × 10^-5).

CONCLUSIONS

Even though the mitochondrial metabolism might be involved in PDAC etiology, our results, obtained in a study with one of the largest sample sizes to date, show that neither n-mtSNPs nor mtSNPs are associated with PDAC risk.

IMPACT

This large case-control study does not support a role of the genetic variability of the mitochondrial function in PDAC risk.

Technical details for a robot-assisted hand-sewn esophago-gastric anastomosis during minimally invasive Ivor Lewis esophagectomy

Background

Minimally invasive Ivor Lewis esophagectomy (MIILE) provides better outcomes than open techniques, particularly in terms of post-operative recovery and pulmonary complications. However, in addition to requiring advanced technical skills, thoracoscopic access makes it hard to perform esophagogastric anastomosis safely, and the reported rates of anastomotic leak vary from 5 to 16%. Several minimally invasive esophago-gastric anastomotic techniques have been described, but to date strong evidence to support one technique over the others is still lacking. We herein report the technical details and preliminary results of a new robot-assisted hand-sewn esophago-gastric anastomosis technique.

Methods

From January 2018 to December 2020, 12 cases of laparoscopic/thoracoscopic Ivor Lewis esophagectomy with robot-assisted hand-sewn esophago-gastric anastomosis were performed. The gastric conduit was prepared and tailored taking care of vascularization with a complete resection of the gastric fundus. The anastomosis consisted of a robot-assisted, hand-sewn four layers of absorbable monofilament running barbed suture (V-lock). The posterior outer layer incorporated the gastric and esophageal staple lines.

Results

The post-operative course was uneventful in nine cases. Two patients developed chyloperitoneum, one patient a Sars-Cov-2 infection, and one patient a late anastomotic stricture. In all cases, there were no anastomotic leaks or delayed gastric conduit emptying. The median post-operative stay was 13 days (min 7, max 37 days); the longest in-hospital stay was recorded in patients who developed chyloperitoneum.

Conclusion

Despite the small series, we believe that our technique looks to be promising, safe, and reproducible. Some key points may be useful to guarantee a low complications rate after MIILE, particularly regarding anastomotic leaks and delayed emptying: the resection of the gastric fundus, the use of robot assistance, the incorporation of the staple lines in the posterior aspect of the anastomosis, and the use of barbed suture. Further cases are needed to validate the preliminary, but very encouraging, results.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08715-4.

Association of Genetic Variants Affecting microRNAs and Pancreatic Cancer Risk

Genetic factors play an important role in the susceptibility to pancreatic cancer (PC). However, established loci explain a small proportion of genetic heritability for PC; therefore, more progress is needed to find the missing ones. We aimed at identifying single nucleotide polymorphisms (SNPs) affecting PC risk through effects on micro-RNA (miRNA) function. We searched in silico the genome for SNPs in miRNA seed sequences or 3 prime untranslated regions (3'UTRs) of miRNA target genes. Genome-wide association data of PC cases and controls from the Pancreatic Cancer Cohort (PanScan) Consortium and the Pancreatic Cancer Case-Control (PanC4) Consortium were re-analyzed for discovery, and genotyping data from two additional consortia (PanGenEU and PANDoRA) were used for replication, for a total of 14,062 cases and 11,261 controls. None of the SNPs reached genome-wide significance in the meta-analysis, but for three of them the associations were in the same direction in all the study populations and showed lower value of p in the meta-analyses than in the discovery phase. Specifically, rs7985480 was consistently associated with PC risk (OR = 1.12, 95% CI 1.07-1.17, p = 3.03 × 10-6 in the meta-analysis). This SNP is in linkage disequilibrium (LD) with rs2274048, which modulates binding of various miRNAs to the 3'UTR of UCHL3, a gene involved in PC progression. In conclusion, our results expand the knowledge of the genetic PC risk through miRNA-related SNPs and show the usefulness of functional prioritization to identify genetic polymorphisms associated with PC risk.

SARS-CoV-2 infection and venous thromboembolism after surgery: an international prospective cohort study

SARS‐CoV‐2 has been associated with an increased rate of venous thromboembolism in critically ill patients. Since surgical patients are already at higher risk of venous thromboembolism than general populations, this study aimed to determine if patients with peri‐operative or prior SARS‐CoV‐2 were at further increased risk of venous thromboembolism. We conducted a planned sub‐study and analysis from an international, multicentre, prospective cohort study of elective and emergency patients undergoing surgery during October 2020. Patients from all surgical specialties were included. The primary outcome measure was venous thromboembolism (pulmonary embolism or deep vein thrombosis) within 30 days of surgery. SARS‐CoV‐2 diagnosis was defined as peri‐operative (7 days before to 30 days after surgery); recent (1–6 weeks before surgery); previous (≥7 weeks before surgery); or none. Information on prophylaxis regimens or pre‐operative anti‐coagulation for baseline comorbidities was not available. Postoperative venous thromboembolism rate was 0.5% (666/123,591) in patients without SARS‐CoV‐2; 2.2% (50/2317) in patients with peri‐operative SARS‐CoV‐2; 1.6% (15/953) in patients with recent SARS‐CoV‐2; and 1.0% (11/1148) in patients with previous SARS‐CoV‐2. After adjustment for confounding factors, patients with peri‐operative (adjusted odds ratio 1.5 (95%CI 1.1–2.0)) and recent SARS‐CoV‐2 (1.9 (95%CI 1.2–3.3)) remained at higher risk of venous thromboembolism, with a borderline finding in previous SARS‐CoV‐2 (1.7 (95%CI 0.9–3.0)). Overall, venous thromboembolism was independently associated with 30‐day mortality (5.4 (95%CI 4.3–6.7)). In patients with SARS‐CoV‐2, mortality without venous thromboembolism was 7.4% (319/4342) and with venous thromboembolism was 40.8% (31/76). Patients undergoing surgery with peri‐operative or recent SARS‐CoV‐2 appear to be at increased risk of postoperative venous thromboembolism compared with patients with no history of SARS‐CoV‐2 infection. Optimal venous thromboembolism prophylaxis and treatment are unknown in this cohort of patients, and these data should be interpreted accordingly.

Associations between pancreatic expression quantitative traits and risk of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal cancers. Its poor prognosis is predominantly due to the fact that most patients remain asymptomatic until the disease reaches an advanced stage, alongside the lack of early markers and screening strategies. A better understanding of PDAC risk factors is essential for the identification of groups at high risk in the population. Genome-wide association studies (GWAS) have been a powerful tool for detecting genetic variants associated with complex traits, including pancreatic cancer. By exploiting functional and GWAS data, we investigated the associations between polymorphisms affecting gene function in the pancreas (expression quantitative trait loci, eQTLs) and PDAC risk. In a two-phase approach, we analysed 13 713 PDAC cases and 43 784 controls and identified a genome-wide significant association between the A allele of the rs2035875 polymorphism and increased PDAC risk (P = 7.14 × 10-10). This allele is known to be associated with increased expression in the pancreas of the keratin genes KRT8 and KRT18, whose increased levels have been reported to correlate with various tumour cell characteristics. Additionally, the A allele of the rs789744 variant was associated with decreased risk of developing PDAC (P = 3.56 × 10-6). This single nucleotide polymorphism is situated in the SRGAP1 gene and the A allele is associated with higher expression of the gene, which in turn inactivates the cyclin-dependent protein 42 (CDC42) gene expression, thus decreasing the risk of PDAC. In conclusion, we present here a functional-based novel PDAC risk locus and an additional strong candidate supported by significant associations and plausible biological mechanisms.

Zebrafish Patient-Derived Xenografts Identify Chemo-Response in Pancreatic Ductal Adenocarcinoma Patients

Simple Summary

Treating the PDAC (pancreatic ductal adenocarcinoma) zPDXs (zebrafish patient-derived xenografts) with chemotherapy regimens commonly used, we performed a co-clinical trial testing the predictiveness of the model. We found that zPDX may predict patient outcomes, classifying them into responders (R) and non-responders (NR), reporting a statistically significant higher cancer recurrence rate at 1 year after surgery in the NR group: 66.7 versus 14.3%. Our zPDX model seems to be a promising tool for the stratification of PDAC patients. This is a crucial starting point for future study involving more patients to obtain a method to really personalize the oncological treatment of PDAC patients.

Abstract

It is increasingly evident the necessity of new predictive tools for the treatment of pancreatic ductal adenocarcinoma in a personalized manner. We present a co-clinical trial testing the predictiveness of zPDX (zebrafish patient-derived xenograft) for assessing if patients could benefit from a therapeutic strategy (ClinicalTrials.gov: XenoZ, NCT03668418). zPDX are generated xenografting tumor tissues in zebrafish embryos. zPDX were exposed to chemotherapy regimens commonly used. We considered a zPDX a responder (R) when a decrease ≥50% in the relative tumor area was reported; otherwise, we considered them a non-responder (NR). Patients were classified as Responder if their own zPDX was classified as an R for the chemotherapy scheme she/he received an adjuvant treatment; otherwise, we considered them a Non-Responder. We compared the cancer recurrence rate at 1 year after surgery and the disease-free survival (DFS) of patients of both groups. We reported a statistically significant higher recurrence rate in the Non-Responder group: 66.7% vs. 14.3% (p = 0.036), anticipating relapse/no relapse within 1 year after surgery in 12/16 patients. The mean DFS was longer in the R-group than the NR-group, even if not statistically significant: 19.2 months vs. 12.7 months, (p = 0.123). The proposed strategy could potentially improve preclinical evaluation of treatment modalities and may enable prospective therapeutic selection in everyday clinical practice.

Can Liquid Lenses Increase Depth of Field in Head Mounted Video See-Through Devices?

Wearable Video See-Through (VST) devices for Augmented Reality (AR) and for obtaining a Magnified View are taking hold in the medical and surgical fields. However, these devices are not yet usable in daily clinical practice, due to focusing problems and a limited depth of field. This study investigates the use of liquid-lens optics to create an autofocus system for wearable VST visors. The autofocus system is based on a Time of Flight (TOF) distance sensor and an active autofocus control system. The integrated autofocus system in the wearable VST viewers showed good potential in terms of providing rapid focus at various distances and a magnified view.

Organotypic-liver slide culture systems to explore the role of extracellular vesicles in pancreatic cancer metastatic behavior and guide new therapeutic approaches

Introduction: Recent studies suggested that extracellular vesicles (EVs) play a role both in the metastatic niche formation and in the progression of several tumors, including pancreatic cancer. In particular, the effects of EVs on metastasis should be studied in model systems that take into account both the tumor cells and the metastatic site/tumor microenvironment. Studies with labeled EVs or EV-secreting cells in ex vivo models will reflect the physiological and pathological functions of EVs. The organotypic-tissue slide culture systems can fulfill such a role.Areas covered: This review provides an overview of available organotypic-culture slide systems. We specifically focus on the assay system of liver culture-slides in combination with pancreatic tumors, which can be modulated to test the efficacy of new therapeutic approaches.Expert opinion: The intercellular exchange of EVs has emerged as a biologically relevant phenomenon to drive cancer metastasis. However, further models need to be developed to better elucidate the functional roles of EVs. The use of novel organotypic slide culture systems provides the opportunity to explore the role of EVs in the metastatic behavior of pancreatic cancer, decreasing the use of costly and cumbersome organoid or animal models.

Perioperative Nutritional Aspects in Total Pancreatectomy: A Comprehensive Review of the Literature

Total pancreatectomy (TP) is a highly invasive procedure often performed in patients affected by anorexia, malabsorption, cachexia, and malnutrition, which are risk factors for bad surgical outcome and even may cause enhanced toxicity to chemo-radiotherapy. The role of nutritional therapies and the association between nutritional aspects and the outcome of patients who have undergone TP is described in some studies. The aim of this comprehensive review is to summarize the available recent evidence about the influence of nutritional factors in TP. Preoperative nutritional and metabolic assessment, but also intra-operative and post-operative nutritional therapies and their consequences, are analyzed in order to identify the aspects that can influence the outcome of patients undergoing TP. The results of this review show that preoperative nutritional status, sarcopenia, BMI and serum albumin are prognostic factors both in TP for pancreatic cancer to support chemotherapy, prevent recurrence and prolong survival, and in TP with islet auto-transplantation for chronic pancreatitis to improve postoperative glycemic control and obtain better outcomes. When it is possible, enteral nutrition is always preferable to parenteral nutrition, with the aim to prevent or reduce cachexia. Nowadays, the nutritional consequences of TP, including diabetes control, are improved and become more manageable.

Prognostic impact of conservative surgery for pancreatic IPMNs

BACKGROUND

The extent of pancreatic resection for intraductal papillary mucinous neoplasms (IPMNs) remains an unresolved issue. The study aims at analyzing the prognostic impact of conservative surgery (CS) i.e. of pancreatoduodenectomy or distal pancreatectomy, versus total pancreatectomy (TP), for pancreatic IPMNs.

METHODS

We retrospectively analyzed and compared data of patients who had undergone pancreatic resection for IPMNs at our center between November 2007 and April 2019. Patients were divided into two main groups based on the extent of surgery: TP-group and CS-group. Subsequently, the perioperative and the long-term outcomes were compared. Moreover, a sub-group analysis of patients with IPMN alone and patients with malignant IPMN, based on preoperative indications to surgery and post-operative histopathological findings, was also performed.

RESULTS

Fifty-three patients were included in the TP-group and 73 in the CS-group. In 50 (39.7%) cases the frozen section changed the pre-operative surgical planning, with an extension of the pancreatic resection, in 43 (34.1%) cases up to a total pancreatectomy. Twenty-six patients (20.6%) with low-grade dysplasia at the frozen section underwent CS, while twenty (15.8%) underwent TP. Comparing these two sub-groups no differences were found in surgical IPMN recurrence, nor progression. The rate of overall postoperative complications was 56.6% in the TP-group and 57.5% in the CS-group (p = 0.940). Fifteen patients (20.5%) developed diabetes in the CS-group. None of the patients treated with CS developed a surgical IPMN recurrence or progression during the follow-up period. Comparing OS and DFS of the two groups, we did not find any statistically significant difference (p = 0.619 and 0.315).

CONCLUSION

A timely CS can be considered an appropriate and valid strategy in the surgical treatment of the majority of pancreatic IPMNs, as it can avoid the serious long-term metabolic consequences of TP in patients with a long-life expectancy. On the contrary, TP remains mandatory in case of PDAC or high-risk features involving the entire gland.

Technical feasibility and short-term outcomes of laparoscopic isolated caudate lobe resection: an IgoMILS (Italian Group of Minimally Invasive Liver Surgery) registry-based study

Background

Although isolated caudate lobe (CL) liver resection is not a contraindication for minimally invasive liver surgery (MILS), feasibility and safety of the procedure are still poorly investigated. To address this gap, we evaluate data on the Italian prospective maintained database on laparoscopic liver surgery (IgoMILS) and compare outcomes between MILS and open group.

Methods

Perioperative data of patients with malignancies, as colorectal liver metastases (CRLM), hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), non-colorectal liver metastases (NCRLM) and benign liver disease, were retrospectively analyzed. A propensity score matching (PSM) analysis was performed to balance the potential selection bias for MILS and open group.

Results

A total of 224 patients were included in the study, 47 and 177 patients underwent MILS and open isolated CL resection, respectively. The overall complication rate was comparable between the two groups; however, severe complication rate (Dindo–Clavien grade ≥ 3) was lower in the MILS group (0% versus 6.8%, P = ns). In-hospital mortality was 0% in both groups and mean hospital stay was significantly shorter in the MILS group (P = 0.01). After selection of 42 MILS and 43 open CL resections by PSM analysis, intraoperative and postoperative outcomes remained similar except for the hospital stay which was not significantly shorter in MILS group.

Conclusions

This multi-institutional cohort study shows that MILS CL resection is feasible and safe. The surgical procedure can be technically demanding compared to open resection, whereas good perioperative outcomes can be achieved in highly selected patients.

Focal adhesion kinase inhibition synergizes with nab-paclitaxel to target pancreatic ductal adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDAC) is a very lethal disease, with minimal therapeutic options. Aberrant tyrosine kinase activity influences tumor growth and is regulated by phosphorylation. We investigated phosphorylated kinases as target in PDAC.

Methods

Mass spectrometry-based phosphotyrosine proteomic analysis on PDAC cell lines was used to evaluate active kinases. Pathway analysis and inferred kinase activity analysis was performed to identify novel targets. Subsequently, we investigated targeting of focal adhesion kinase (FAK) in vitro with drug perturbations in combination with chemotherapeutics used against PDAC. Tyrosine phosphoproteomics upon treatment was performed to evaluate signaling. An orthotopic model of PDAC was used to evaluate the combination of defactinib with nab-paclitaxel.

Results

PDAC cell lines portrayed high activity of multiple receptor tyrosine kinases to various degree. The non-receptor kinase, FAK, was identified in all cell lines by our phosphotyrosine proteomic screen and pathway analysis. Targeting of this kinase with defactinib validated reduced phosphorylation profiles. Additionally, FAK inhibition had anti-proliferative and anti-migratory effects. Combination with (nab-)paclitaxel had a synergistic effect on cell proliferation in vitro and reduced tumor growth in vivo.

Conclusions

Our study shows high phosphorylation of several oncogenic receptor tyrosine kinases in PDAC cells and validated FAK inhibition as potential synergistic target with Nab-paclitaxel against this devastating disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01892-z.

Changes in surgicaL behaviOrs dUring the CoviD-19 pandemic. The SICE CLOUD19 Study

Background

The spread of the SARS-CoV2 virus, which causes COVID-19 disease, profoundly impacted the surgical community. Recommendations have been published to manage patients needing surgery during the COVID-19 pandemic. This survey, under the aegis of the Italian Society of Endoscopic Surgery, aims to analyze how Italian surgeons have changed their practice during the pandemic.

Methods

The authors designed an online survey that was circulated for completion to the Italian departments of general surgery registered in the Italian Ministry of Health database in December 2020. Questions were divided into three sections: hospital organization, screening policies, and safety profile of the surgical operation. The investigation periods were divided into the Italian pandemic phases I (March–May 2020), II (June–September 2020), and III (October–December 2020).

Results

Of 447 invited departments, 226 answered the survey. Most hospitals were treating both COVID-19-positive and -negative patients. The reduction in effective beds dedicated to surgical activity was significant, affecting 59% of the responding units. 12.4% of the respondents in phase I, 2.6% in phase II, and 7.7% in phase III reported that their surgical unit had been closed. 51.4%, 23.5%, and 47.8% of the respondents had at least one colleague reassigned to non-surgical COVID-19 activities during the three phases. There has been a reduction in elective (> 200 procedures: 2.1%, 20.6% and 9.9% in the three phases, respectively) and emergency (< 20 procedures: 43.3%, 27.1%, 36.5% in the three phases, respectively) surgical activity. The use of laparoscopy also had a setback in phase I (25.8% performed less than 20% of elective procedures through laparoscopy). 60.6% of the respondents used a smoke evacuation device during laparoscopy in phase I, 61.6% in phase II, and 64.2% in phase III. Almost all responders (82.8% vs. 93.2% vs. 92.7%) in each analyzed period did not modify or reduce the use of high-energy devices.

Conclusion

This survey offers three faithful snapshots of how the surgical community has reacted to the COVID-19 pandemic during its three phases. The significant reduction in surgical activity indicates that better health policies and more evidence-based guidelines are needed to make up for lost time and surgery not performed during the pandemic.

Supplementary Information

The online version of this article (10.1007/s13304-021-01010-w) contains supplementary material, which is available to authorized users.

Treatment of completely obstructed anastomosis after low rectal resection A trans-anal plus endoscopic trans-colostomy rendez-vous approach and a review of the literature

AIM

Completely obstructed anastomosis (COA) after low rectal resection (LRR) represents a rare entity difficult to manage. We herein summarize the available evidence from literature on the treatment of this condition and we report our particular experience in the management of a completely obstructed colon-anal anastomosis (CAA) with a trans-anal plus endoscopic trans-colostomy rendez-vous approach.

METHODS

The Pub-Med database was inquired from inception to October 2019 about the treatment of COA after LRR reported in English literature. Article selection was carried out according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) criteria. Moreover, clinical, radiological and surgical data of our case presentation were retrieved.

RESULTS

Ten articles involving twelve patients and concerning the management of COA were identified. All of them reported the treatment of completely obstructed colon-rectal anastomosis. As we didn't find any article reporting the treatment of completely obstructed CAA, we also described a case of its treatment. The patient was successfully treated at our institution using a rendez-vous approach with a simultaneous trans-colostomy endoscopy, associated to a trans-anal dilatation. This combined approach, thanks to trans-illumination and to the miniature passage of CO2 coming from above, permitted to identify the correct way to surgically establish a trans-anal lumen. The post-procedural course was uneventful.

CONCLUSIONS

The treatment of COA after LRR can be very demanding, particularly after CAA. Few data are reported in literature to define the best approach to treat these conditions. Our described rendez-vous technique can represent a valid choice, especially after CAA.

KEY WORDS

Colorectal anastomosis, Endoscopic treatment, Low-rectal resection.

A meta-analysis of DaVinci Si versus Xi in colorectal surgery

BACKGROUND

The aim of this meta-analysis was to evaluate whether adoption of DaVinci Xi^® had any impact upon intra- and postoperative metrics in colorectal surgery.

METHODS

The Pubmed, CINAHL, Cochrane Library and MEDLINE (Ovid) databases were systematically searched. Operating time as well as docking and surgeon console times were the primary endpoints. Conversion and postoperative complication rates were the secondary endpoints.

RESULTS

Six studies totaling 610 patients (320 Si and 290 Xi) were included. Total operating time [MD (95% CI) = 30.553 (15.071, 46.035); p < 0.001], docking time [MD (95% CI) = 4.178 (2.120, 6.235); p < 0.001] and surgeon console time [MD (95% CI) = 17.246 (-0.479, 34.971); p = 0.056] were longer in DaVinci Si^® as compared to DaVinci Xi^® . No significant difference was found in conversion (p = 0.816) and postoperative complication rates (p = 0.405).

CONCLUSION

This meta-analysis found that the adoption of DaVinci Xi^® was associated with significantly decreased total operating time as well as docking and surgeon console times. Conversion and complication rates were similar.

Genome-wide scan of long noncoding RNA single nucleotide polymorphisms and pancreatic cancer susceptibility

Pancreatic ductal adenocarcinoma (PDAC) is projected to become the second cancer-related cause of death by 2030. Identifying novel risk factors, including genetic risk loci, could be instrumental in risk stratification and implementation of prevention strategies. Long noncoding RNAs (lncRNAs) are involved in regulation of key biological processes, and the possible role of their genetic variability has been unexplored so far. Combining genome wide association studies and functional data, we investigated the genetic variability in all lncRNAs. We analyzed 9893 PDAC cases and 9969 controls and identified a genome-wide significant association between the rs7046076 SNP and risk of developing PDAC (P = 9.73 × 10^-9 ). This SNP is located in the NONHSAG053086.2 (lnc-SMC2-1) gene and the risk allele is predicted to disrupt the binding of the lncRNA with the micro-RNA (miRNA) hsa-mir-1256 that regulates several genes involved in cell cycle, such as CDKN2B. The CDKN2B region is pleiotropic and its genetic variants have been associated with several human diseases, possibly though an imperfect interaction between lncRNA and miRNA. We present a novel PDAC risk locus, supported by a genome-wide statistical significance and a plausible biological mechanism.

Minimally invasive distal pancreatectomy: a case-matched cost-analysis between robot-assisted surgery and direct manual laparoscopy

Background

Few studies have reported a structured cost analysis of robotic distal pancreatectomy (RDP), and none have compared the relative costs between the robotic-assisted surgery (RAS) and the direct manual laparoscopy (DML) in this setting. The aim of the present study is to address this issue by comparing surgical outcomes and costs of RDP and laparoscopic distal pancreatectomies (LDP).

Methods

Eighty-eight RDP and 47 LDP performed between January 2008 and January 2020 were retrospectively analyzed. Three comparable groups of 35 patients each (Si-RDP-group, Xi-RDP group, LDP-group) were obtained matching 1:1 the RDP-groups with the LDP-group. Overall costs, including overall variable costs (OVC) and fixed costs were compared using generalized linear regression model adjusting for covariates.

Results

The conversion rate was significantly lower in the Si-RDP-group and Xi-RDP-group: 2.9% and 0%, respectively, versus 14.3% in the LDP-group (p = 0.045). Although not statistically significant, the mean operative time was lower in Xi-RDP-group: 226 min versus 262 min for Si-RDP-group and 247 min for LDP-group. The overall post-operative complications rate and the length of hospital stay (LOS) were not significantly different between the three groups. In LDP-group, the LOS of converted cases was significantly longer: 15.6 versus 9.8 days (p = 0.039). Overall costs of LDP-group were significantly lower than RDP-groups, (p < 0.001). At multivariate analysis OVC resulted no longer statistically significantly different between LDP-group and Xi-RDP-group (p = 0.099), and between LDP-group and the RDP-groups when the spleen preservation was indicated (p = 0.115 and p = 0.261 for Si-RDP-group and Xi-RDP-group, respectively).

Conclusions

RAS is more expensive than DML for DP because of higher acquisition and maintenance costs. The flattening of these differences considering only the variable costs, in a high-volume multidisciplinary center for RAS, suggests a possible optimization of the costs in this setting. RAS might be particularly indicated for minimally invasive DP when the spleen preservation is scheduled.

Preoperative nasopharyngeal swab testing and postoperative pulmonary complications in patients undergoing elective surgery during the SARS-CoV-2 pandemic

BACKGROUND

Surgical services are preparing to scale up in areas affected by COVID-19. This study aimed to evaluate the association between preoperative SARS-CoV-2 testing and postoperative pulmonary complications in patients undergoing elective cancer surgery.

METHODS

This international cohort study included adult patients undergoing elective surgery for cancer in areas affected by SARS-CoV-2 up to 19 April 2020. Patients suspected of SARS-CoV-2 infection before operation were excluded. The primary outcome measure was postoperative pulmonary complications at 30 days after surgery. Preoperative testing strategies were adjusted for confounding using mixed-effects models.

RESULTS

Of 8784 patients (432 hospitals, 53 countries), 2303 patients (26.2 per cent) underwent preoperative testing: 1458 (16.6 per cent) had a swab test, 521 (5.9 per cent) CT only, and 324 (3.7 per cent) swab and CT. Pulmonary complications occurred in 3.9 per cent, whereas SARS-CoV-2 infection was confirmed in 2.6 per cent. After risk adjustment, having at least one negative preoperative nasopharyngeal swab test (adjusted odds ratio 0.68, 95 per cent confidence interval 0.68 to 0.98; P = 0.040) was associated with a lower rate of pulmonary complications. Swab testing was beneficial before major surgery and in areas with a high 14-day SARS-CoV-2 case notification rate, but not before minor surgery or in low-risk areas. To prevent one pulmonary complication, the number needed to swab test before major or minor surgery was 18 and 48 respectively in high-risk areas, and 73 and 387 in low-risk areas.

CONCLUSION

Preoperative nasopharyngeal swab testing was beneficial before major surgery and in high SARS-CoV-2 risk areas. There was no proven benefit of swab testing before minor surgery in low-risk areas.

The Role of Cellular Prion Protein in Promoting Stemness and Differentiation in Cancer

Simple Summary

Aside from its well-established role in prion disorders, in the last decades the significance of cellular prion protein (PrP^C) expression in human cancers has attracted great attention. An extensive body of work provided evidence that PrP^C contributes to tumorigenesis by regulating tumor growth, differentiation, and resistance to conventional therapies. In particular, PrP^C over-expression has been related to the acquisition of a malignant phenotype of cancer stem cells (CSCs) in a variety of solid tumors, encompassing pancreatic ductal adenocarcinoma, osteosarcoma, breast, gastric, and colorectal cancers, and primary brain tumors as well. According to consensus, increased levels of PrP^C endow CSCs with self-renewal, proliferative, migratory, and invasive capacities, along with increased resistance to anti-cancer agents. In addition, increasing evidence demonstrates that PrPc also participates in multi-protein complexes to modulate the oncogenic properties of CSCs, thus sustaining tumorigenesis. Therefore, strategies aimed at targeting PrP^C and/or PrP^C-organized complexes could be a promising approach for anti-cancer therapy.

Abstract

Cellular prion protein (PrP^C) is seminal to modulate a variety of baseline cell functions to grant homeostasis. The classic role of such a protein was defined as a chaperone-like molecule being able to rescue cell survival. Nonetheless, PrP^C also represents the precursor of the deleterious misfolded variant known as scrapie prion protein (PrP^Sc). This variant is detrimental in a variety of prion disorders. This multi-faceted role of PrP is greatly increased by recent findings showing how PrP^C in its folded conformation may foster tumor progression by acting at multiple levels. The present review focuses on such a cancer-promoting effect. The manuscript analyzes recent findings on the occurrence of PrP^C in various cancers and discusses the multiple effects, which sustain cancer progression. Within this frame, the effects of PrP^C on stemness and differentiation are discussed. A special emphasis is provided on the spreading of PrP^C and the epigenetic effects, which are induced in neighboring cells to activate cancer-related genes. These detrimental effects are further discussed in relation to the aberrancy of its physiological and beneficial role on cell homeostasis. A specific paragraph is dedicated to the role of PrP^C beyond its effects in the biology of cancer to represent a potential biomarker in the follow up of patients following surgical resection.

Ileo-colic intra-corporeal anastomosis during robotic right colectomy: a systematic literature review and meta-analysis of different techniques

PURPOSE

Robotic assistance could increase the rate of ileo-colic intra-corporeal anastomosis (ICA) during robotic right colectomy (RRC). However, although robotic ICA can be accomplished with several different technical variants, it is not clear whether some of these technical details should be preferred. An evaluation of the possible advantage of one respect to another would be useful.

METHODS

We conducted a systematic review of literature on technical details of robotic ileo-colic ICA, from which we performed a meta-analysis of clinical outcomes. The extracted data allowed a comparative analysis regarding the outcome of overall complication (OC), bleeding rate (BR) and leakage rate (LR), between (1) mechanical anastomosis with robotic stapler, versus laparoscopic stapler, versus totally hand-sewn anastomosis and (2) closure of enterocolotomy with manual double layer, versus single layer, versus stapled.

RESULTS

A total of 30 studies including 2066 patients were selected. Globally, the side-to-side, isoperistaltic anastomosis, realized with laparoscopic staplers, and double-layer closure for enterocolotomy, is the most common technique used. According to the meta-analysis, the use of robotic stapler was significantly associated with a reduction of the BR with respect to mechanical anastomosis with laparoscopic stapler or totally hand-sewn anastomosis. None of the other technical aspects significantly influenced the outcomes.

CONCLUSIONS

ICA fashioning during RRC can be accomplished with several technical variants without evidence of a clear superiority of anyone of these techniques. Although the use of robotic staplers could be associated with some benefits, further studies are necessary to draw conclusions.

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study

PURPOSE

As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway.

PATIENTS AND METHODS

This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation).

RESULTS

Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76).

CONCLUSION

Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks.

Omics Analysis of Educated Platelets in Cancer and Benign Disease of the Pancreas

Pancreatic ductal adenocarcinoma (PDAC) is traditionally associated with thrombocytosis/hypercoagulation and novel insights on platelet-PDAC "dangerous liaisons" are warranted. Here we performed an integrative omics study investigating the biological processes of mRNAs and expressed miRNAs, as well as proteins in PDAC blood platelets, using benign disease as a reference for inflammatory noise. Gene ontology mining revealed enrichment of RNA splicing, mRNA processing and translation initiation in miRNAs and proteins but depletion in RNA transcripts. Remarkably, correlation analyses revealed a negative regulation on SPARC transcription by isomiRs involved in cancer signaling, suggesting a specific "education" in PDAC platelets. Platelets of benign patients were enriched for non-templated additions of G nucleotides (#ntaG) miRNAs, while PDAC presented length variation on 3' (lv3p) as the most frequent modification on miRNAs. Additionally, we provided an actionable repertoire of PDAC and benign platelet-ome to be exploited for future studies. In conclusion, our data show that platelets change their biological repertoire in patients with PDAC, through dysregulation of miRNAs and splicing factors, supporting the presence of de novo protein machinery that can "educate" the platelet. These novel findings could be further exploited for innovative liquid biopsies platforms as well as possible therapeutic targets.

Somatostatin administration following pancreatoduodenectomy: a case-matched comparison according to surgical technique, body mass index, American Society of Anesthesiologists' score and Fistula Risk Score

PURPOSE

This study evaluated the controversial role of somatostatin after pancreatoduodenectomy (PD), stratifying patients for the main risk factors using the most recent postoperative pancreatic fistula (POPF) classification and including only patients who had undergone PD with the same technique of pancreatojejunostomy.

METHODS

Between November 2010 and February 2020, 218 PD procedures were carried out via personal modified pancreatojejunostomy (mPJ-PD). Somatostatin was routinely administered between 2010 and 2016, while from 2017, 97 mPJ-PD procedures without somatostatin (WS) were performed. The WS group was retrospectively compared with a control (C) group obtained with one-to-one case-control matching according to the body mass index, American Society of Anesthesiologists' score, and Fistula Risk Score (FRS).

RESULTS

A total of 144 patients (72 WS group versus 72 C group) were compared. In the WS group. 6 patients (8.3%) developed clinically relevant POPF, compared with 8 patients (11.1%) in the C group (p = 0.656). In addition, on analyzing the subgroup of high-risk patients according to the FRS, we did not note any significant differences in POPF occurrence. Furthermore, no marked differences in the morbidity or mortality were found. Digestive bleeding and diabetes onset rates were higher in the WS group than in the control group, but not significantly so.

CONCLUSIONS

The results of the present study confirm no benefit with the routine administration of somatostatin after PD to prevent POPF, even in high-risk patients. However, a possible role in the prevention of postoperative digestive bleeding and diabetes was observed.

Tissue microarray-chip featuring computerized immunophenotypical characterization more accurately subtypes ampullary adenocarcinoma than routine histology

BACKGROUND

Ampullary adenocarcinomas (AACs) are heterogeneous tumors currently classified into three important sub-classes (SC): Intestinal (INT), Pancreato-Biliary (PB) and Mixed-Type (MT). The different subgroups have similar clinical presentation and are treated by pancreatoduodenectomy with curative intent. However, they respond differently to chemotherapy and have different prognostic outcomes. The SC are often difficult to identify with conventional histology alone. The clinical outcome of all three remains unclear, particularly for MT.

AIM

To identify two main subtypes of AACs, using an immunohistochemical (IHC) score based on CDX2, CK7 and CK20.

METHODS

Tissue samples from 21 patients who had undergone resection of AAC were classified by HE histology and IHC expression of CDX2, CK7 and CK 20. An IHC score was obtained for each marker by counting the number of positive cells (0 = no stained cells; 1 < 25%; 2 < 50% and 3 > 50%) and their intensity (1 = weak; 2 = moderate and 3 = strong). A global score (GS) was then obtained by summation of the IHC scores of each marker. The MT tumors were grouped either with the INT or PB group based on the predominant immuno-molecular phenotype, obtaining only two AACs subtypes. The overall survival in INT and PB patients was obtained by Kaplan-Meier methods.

RESULTS

Histological parameters defined the AACs subtypes as follows: 15% INT, 45% PB and 40% MT. Using IHC expression and the GS, 75% and 25% of MT samples were assigned to either the INT or the PB group. The mean value of the GS was 9.5 (range 4-16). All INT samples had a GS above the average, distinct from the PB samples which had a GS score significantly below the average (P = 0.0011). The INT samples were identified by high expression of CDX2 and CK20, whereas PB samples exhibited high expression of CK7 and no expression of CK20 (P = 0.0008). The INT group had a statistically significant higher overall survival than in the PB group (85.7 mo vs 20.3 mo, HR: 8.39; 95%CI: 1.38 to 18.90; P = 0.0152).

CONCLUSION

The combination of histopathological and molecular criteria enables the classification of AACs into two clinically relevant histo-molecular phenotypes, which appear to represent distinct disorders with potentially significant changes to the current therapeutic strategies.

EAES Recommendations for Recovery Plan in Minimally Invasive Surgery Amid COVID-19 Pandemic

Background

COVID-19 pandemic presented an unexpected challenge for the surgical community in general and Minimally Invasive Surgery (MIS) specialists in particular. This document aims to summarize recent evidence and experts’ opinion and formulate recommendations to guide the surgical community on how to best organize the recovery plan for surgical activity across different sub-specialities after the COVID-19 pandemic.

Methods

Recommendations were developed through a Delphi process for establishment of expert consensus. Domain topics were formulated and subsequently subdivided into questions pertinent to different surgical specialities following the COVID-19 crisis. Sixty-five experts from 24 countries, representing the entire EAES board, were invited. Fifty clinicians and six engineers accepted the invitation and drafted statements based on specific key questions. Anonymous voting on the statements was performed until consensus was achieved, defined by at least 70% agreement.

Results

A total of 92 consensus statements were formulated with regard to safe resumption of surgery across eight domains, addressing general surgery, upper GI, lower GI, bariatrics, endocrine, HPB, abdominal wall and technology/research. The statements addressed elective and emergency services across all subspecialties with specific attention to the role of MIS during the recovery plan. Eighty-four of the statements were approved during the first round of Delphi voting (91.3%) and another 8 during the following round after substantial modification, resulting in a 100% consensus.

Conclusion

The recommendations formulated by the EAES board establish a framework for resumption of surgery following COVID-19 pandemic with particular focus on the role of MIS across surgical specialities. The statements have the potential for wide application in the clinical setting, education activities and research work across different healthcare systems.

Electronic supplementary material

The online version of this article (10.1007/s00464-020-08131-0) contains supplementary material, which is available to authorized users.

A Plea for Surgery in Pancreatic Metastases from Renal Cell Carcinoma: Indications and Outcome from a Multicenter Surgical Experience

BACKGROUND

Pancreatic metastases from renal-cell carcinoma (RCC-PMs) are rare. Surgery may play a role in improving overall (OS) and disease-free survival (DFS).

METHODS

Clinical-pathological features, surgery and follow-up data of patients with RCC-PMs operated on in three pancreatic surgical centers (2000-2019) were retrospectively evaluated.

RESULTS

Thirty-nine patients (21 male/18 female, averaging 65 years) were enrolled. RCC-PMs were metachronous in 36 patients (mean 94 months, up to 24 years after nephrectomy), multiple in 21 patients, and with a median size of 2.5 (range, 0.7-7.5) cm. All the patients underwent pancreatic surgery (33 standard resections, 6 limited resections). Fifteen patients had post-operative complications (morbidity 38.5%). The median DFS was 63 months, and 19 out of 36 patients showed a disease recurrence. The median OS was 134 months, and 13 out of 36 patients were alive with no evidence of disease. At univariate analysis, lymph node positivity (HR 5.1, 95% CI 1.5-18), multi-visceral resection (HR 3.4, 95% CI 1.1-10) and synchronous RCC-PMs (HR 13, 95% CI 3-55) were significantly associated with a short OS.

CONCLUSION

Surgery may allow a DFS up to 17 years in more than one third of patients, even after limited resections. Splenectomy and lymph node dissection are not mandatory.

Use of barbed suture without fashioning the "classical" Wirsung-jejunostomy in a modified end-to-side robotic pancreatojejunostomy

Background

The treatment of the pancreatic stump is a critical step of pancreatoduodenectomy (PD). Robot-assisted surgery (RAS) can facilitate minimally invasive challenging abdominal procedures, including pancreatojejunostomy. However, one of the major limitations of RAS stems from its lack of tactile feedback that can lead to pancreatic parenchyma laceration during knot tying or during traction on the suture. Moreover, a Wirsung-jejunostomy is not always easy to execute, especially in cases with small diameter duct. Herein, we describe and video-report the technical details of a robotic modified end-to-side invaginated robotic pancreatojejunostomy (RmPJ) with the use of barbed suture instead of the “classical” Wirsung-jejunostomy.

Methods

The RmPJ technique consists of a double layer of absorbable monofilament running barbed suture (3–0 V-Loc), the outer layer is used to invaginate the pancreatic stump. Thereafter, a small enterotomy is made in the jejunum exactly opposite to the location of the pancreatic duct for stent insertion (usually 5 Fr) inside the duct. The internal layer provides a second barbed running suture placed between the pancreatic capsule/parenchyma and the jejunal seromuscular layer.

Results

A total of 14 patients underwent robotic PD with RmPJ at our Institution. The mean console time was (281.36 ± 31.50 min), while the mean operative time for fashioning the RmPJ was 37.31 ± 7.80 min. Ten out of 14 patients were discharged within postoperative day 8. No clinically relevant pancreatic fistulas were encountered, while two patients developed biochemical leaks.

Conclusions

RmPJ is feasible and reproducible irrespective of pancreatic duct size and parenchyma, and can enhance the surgical workflow of this operation. Specifically, the use of barbed sutures allows the exploitation of the potential advantages of the RAS, while minimizing the negative effect caused by the main disadvantage of the robotic approach, its absence of tactile feedback, by ensuring uniform tension on the continuous suture lines used, especially during the reconstructive phase of the operation.

Electronic supplementary material

The online version of this article (10.1007/s00464-020-07991-w) contains supplementary material, which is available to authorized users.

The occurrence of prion protein in surgically resected pancreatic adenocarcinoma

BACKGROUND

Among the several new targets for the comprehension of the biology of pancreatic ductal adenocarcinoma (PDAC), Prion proteins (PrPc) deserve particular mention, since they share a marked neurotropism. Actually, PrPc could have also a role in tumorigenesis, as recently demonstrated. However, only few in vitro studies in cell cultures showed the occurrence of PrPc in PDAC cells. We aim to evaluate the presence of PrPc in vivo in PDAC tissues as a potential new biomarker.

METHODS

Samples from tumors of 23 patients undergone pancreatic resections from July 2018 to May 2020 at our institution were collected and analyzed. Immunohistochemistry and western blotting of PDAC tissues were compared with control tissues. Immunohistochemistry was used also to evaluate the localization of PrPc and of CD155, a tumoral stem-cell marker.

RESULTS

All cases were moderately differentiated PDAC, with perineural invasion (PNI) in 19/23 cases (83%). According to western-blot analysis, PrPc was markedly expressed in PDAC tissues (273.5 ± 44.63 OD) respect to controls (100 ± 28.35 OD, p = 0.0018). Immunohistochemistry confirmed these findings, with higher linear staining of PrPc in PDAC ducts (127.145 ± 7.56 μm vs 75.21 ± 5.01 μm, p < 0.0001). PrPc and CD155 exactly overlapped in ductal tumoral cells, highlighting the possible relationship of PrPc with cancer stemness. Finally, PrPc expression related with cancer stage and there was a potential correspondence with PNI.

CONCLUSIONS

Our work provides evidence for increased levels of PrPc in PDAC. This might contribute to cancer aggressiveness and provides a potentially new biomarker. Work is in progress to decipher clinical implications.

Renal cell carcinoma: The role of radical surgery on different patterns of local or distant recurrence

INTRODUCTION

With the increasing reliance on targeted therapies and immunotherapy, no standard management strategy is today available for the treatment of locally, distant, or both renal cell carcinoma (RCC) recurrences, and their surgical treatment seems to play a crucial role. We report the 20-year experience of our center evaluating the short- and long-term outcomes of patients undergone surgical resection of RCC recurrences, and the possible role of repeated surgical resections of RCC recurrences.

MATERIALS AND METHODS

From January 1999 to January 2019, 40 patients underwent surgical resection of isolated locally recurrent RCC (iLR-RCC-group), locally recurrent RCC associated with the presence of distant recurrence (LR-DR-RCC-group), and distant-only recurrent RCC (DR-RCC-group). Data regarding pre-, intra-, post-operative course, and follow-up, prospectively collected in an institutional database, were retrospectively analyzed and compared.

RESULTS

iLR-RCC-group was composed of 9 patients, LR-DR-RCC-group of 6 patients, and DR-RCC-group of 25 patients. The recurrence rate was 55.6% (5/9 patients) in iLR-RCC-group, 50% (3/6 patients) in LR-DR-RCC-group, and 44% (11/25) patients in DR-RCC-group, p = 0.830. 3/5 (60%) patients in iLR-RCC-group, 2/3 (66.7%) patients in LR-DR-RCC-group, and 7/11 (63.6%) patients in DR-RCC group underwent to almost one further local treatments of their recurrences, respectively (p = 0.981). No differences in the mean disease-free survival (p = 0.384), overall survival (OS) (p = 0.881), and cancer-specific survival (p = 0.265) were reported between the three groups. In DR-RCC-group, patients who underwent further local treatments of new recurrences presented a longer OS: 150.7 versus 66.5 months (p = 0.004).

CONCLUSIONS

A surgical resection of RCC recurrences should be always taken in consideration, also in metastatic patients and/or in those who have already undergone surgery of previous RCC recurrence, whenever radicality is still possible, because this approach may offer a potentially long survival.