Complications in Post-Liver Transplant Patients.

Liver transplantation (LT) is the treatment of choice for liver failure and selected cases of malignancies. Transplantation activity has increased over the years, and indications for LT have been widened, leading to organ shortage. To face this condition, a high selection of recipients with prioritizing systems and an enlargement of the donor pool were necessary. Several authors published their case series reporting the results obtained with the use of marginal donors, which seem to have progressively improved over the years. The introduction of in situ and ex situ machine perfusion, although still strongly debated, and better knowledge and treatment of the complications may have a role in achieving better results. With longer survival rates, a significant number of patients will suffer from long-term complications. An extensive review of the literature concerning short- and long-term outcomes is reported trying to highlight the most recent findings. The heterogeneity of the behaviors within the different centers is evident, leading to a difficult comparison of the results and making explicit the need to obtain more consent from experts.

Predicting Post-Hepatectomy Liver Failure in HCC Patients: A Review of Liver Function Assessment Based on Laboratory Tests Scores.

The assessment of liver function is crucial in predicting the risk of post-hepatectomy liver failure (PHLF) in patients undergoing liver resection, especially in cases of hepatocellular carcinoma (HCC) which is often associated with cirrhosis. There are currently no standardized criteria for predicting the risk of PHLF. Blood tests are often the first- and least invasive expensive method for assessing hepatic function. The Child-Pugh score (CP score) and the Model for End Stage Liver Disease (MELD) score are widely used tools for predicting PHLF, but they have some limitations. The CP score does not consider renal function, and the evaluation of ascites and encephalopathy is subjective. The MELD score can accurately predict outcomes in cirrhotic patients, but its predictive capabilities diminish in non-cirrhotic patients. The albumin-bilirubin score (ALBI) is based on serum bilirubin and albumin levels and allows the most accurate prediction of PHLF for HCC patients. However, this score does not consider liver cirrhosis or portal hypertension. To overcome this limitation, researchers suggest combining the ALBI score with platelet count, a surrogate marker of portal hypertension, into the platelet-albumin-bilirubin (PALBI) grade. Non-invasive markers of fibrosis, such as FIB-4 and APRI, are also available for predicting PHLF but they focus only on cirrhosis related aspects and are potentially incomplete in assessing the global liver function. To improve the predictive power of the PHLF of these models, it has been proposed to combine them into a new score, such as the ALBI-APRI score. In conclusion, blood test scores may be combined to achieve a better predictive value of PHLF. However, even if combined, they may not be sufficient to evaluate liver function and to predict PHLF; thus, the inclusion of dynamic and imaging tests such as liver volumetry and ICG r15 may be helpful to potentially improve the predictive capacity of these models.

A Comparison between Open and Minimally Invasive Techniques for the Resection of Colorectal Liver Metastasis.

The liver is the most common site of colorectal cancer metastasis. Liver surgery is a cornerstone in treatment, with progressive expansion of minimally invasive surgery (MIS). This study aims to compare short- and long-term outcomes of open surgery and MIS for the treatment of colorectal adenocarcinoma liver metastasis during the first three years of increasing caseload and implementation of MIS use in liver surgery. All patients treated between November 2018 and August 2021 at Careggi Teaching Hospital in Florence, Italy, were prospectively entered into a database and retrospectively reviewed. Fifty-one patients were resected (41 open, 10 MIS). Considering that patients with a significantly higher number of lesions underwent open surgery and operative results were similar, postoperative morbidity rate and length of hospital stay were significantly higher in the open group. No differences were found in the pathological specimen. The postoperative mortality rate was 2%. Mean overall survival and disease-free survival were 46 months (95% CI 42-50) and 22 months (95% CI 15.6-29), respectively. The use of minimally invasive techniques in liver surgery is safe and feasible if surgeons have adequate expertise. MIS and parenchymal sparing resections should be preferred whenever technically feasible.

Evaluating the best treatment for multifocal hepatocellular carcinoma: A propensity score-matched analysis.

BACKGROUND: Hepatocellular carcinoma (HCC) is a common tumour often diagnosed with a multifocal presentation. Patients with multifocal HCC represent a heterogeneous group. Although Trans-Arterial ChemoEmbolization (TACE) is the most frequently employed treatment for these patients, previous data suggested that liver resection (LR) could be a safe and effective procedure. AIM: To compare LR and TACE in patients with multifocal HCC in terms of procedure-related morbidity and oncologic outcomes. METHODS: All patients with multifocal HCC who underwent LR or TACE as the first procedure between May 2011 and March 2021 were enrolled. The decision to perform surgery or TACE was made after a multidisciplinary team evaluation. Only patients in Child-Pugh class A or B7 and stage B (according to the Barcelona Clinic Liver Cancer staging system, without severe portal hypertension, vascular invasion, or extrahepatic spread) were included in the final analysis. Propensity score matching was used to adjust the baseline differences between patients undergoing LR and the TACE group [number and diameter of lesions, presence of cirrhosis, alpha-fetoprotein (AFP) levels, and Model for End-Stage Liver Disease score]. The Kaplan-Meier method was used to estimate overall survival (OS) and disease-free survival (DFS). The outcomes of LR and TACE were compared using the log-rank test. RESULTS: After matching, 30 patients were eligible for the final analysis, 15 in each group. Morbidity rates were 42.9% and 40% for LR and TACE, respectively (P = 0.876). Median OS was not different in the LR and TACE groups (53 mo vs 18 mo, P = 0.312), while DFS was significantly longer with LR (19 mo vs 0 mo, P = 0.0001). Subgroup analysis showed that patients in the Italian Liver Cancer (ITA.LI.CA) B2 stage, with AFP levels lower than 400 ng/mL, less than 3 lesions, and lesions bigger than 41 mm, benefited more from LR in terms of DFS. Patients classified as ITA.LI.CA B3, with AFP levels higher than 400 ng/mL and with more than 3 lesions, appeared to receive more benefit from TACE in terms of OS. CONCLUSION: In a small cohort of patients with multifocal HCC, LR confers longer DFS compared with TACE, with similar OS and post-procedural morbidity.

Impact of microbiota-immunity axis in pancreatic cancer management.

The microbiota impact on human diseases is well-known, and a growing body of literature is providing evidence about the complex interplay between microbiota-immune system-human physiology/pathology, including cancers. Together with the defined risk factors (e.g., smoke habits, diet, diabetes, and obesity), the oral, gut, biliary, and intrapancreatic microbiota contribute to pancreatic cancer development through different pathways including the interaction with the immune system. Unfortunately, a great majority of the pancreatic cancer patients received a diagnosis in advanced stages not amenable to be radically treated and potentially cured. Given the poor pancreatic cancer prognosis, complete knowledge of these complicated relationships could help researchers better understand the disease pathogenesis and thus provide early potential non-invasive biomarkers, new therapeutic targets, and tools for risk stratification that might result in greater therapeutic possibilities and eventually in a better and longer patient survival.

The emerging role of immunotherapy in biliary tract cancer: a review of new evidence and predictive biomarkers.

Biliary tract cancers (BTCs) are frequently diagnosed in advanced stages and are highly lethal. Immunotherapy may play a role in the treatment of these patients. Promising results come from monotherapy or combination therapy studies in pretreated patients. In addition, several studies have demonstrated the safety and efficacy of immune checkpoint inhibitors (ICIs) in combination with chemotherapy in treatment-naive patients. Numerous biomarkers have been investigated to define their predictive role in response to ICIs. However, the full extent of the benefit of immunotherapies has not yet been fully established and, except for high microsatellite instability status, no other biomarkers were uniquely predictive of response to ICIs.

Gut microbiota and immune system in liver cancer: Promising therapeutic implication from development to treatment.

Liver cancer is a leading cause of death worldwide, and hepatocellular carcinoma (HCC) is the most frequent primary liver tumour, followed by cholangiocarcinoma. Notably, secondary tumours represent up to 90% of liver tumours. Chronic liver disease is a recognised risk factor for liver cancer development. Up to 90% of the patients with HCC and about 20% of those with cholangiocarcinoma have an underlying liver alteration. The gut microbiota-liver axis represents the bidirectional relationship between gut microbiota, its metabolites and the liver through the portal flow. The interplay between the immune system and gut microbiota is also well-known. Although primarily resulting from experiments in animal models and on HCC, growing evidence suggests a causal role for the gut microbiota in the development and progression of chronic liver pathologies and liver tumours. Despite the curative intent of "traditional" treatments, tumour recurrence remains high. Therefore, microbiota modulation is an appealing therapeutic target for liver cancer prevention and treatment. Furthermore, microbiota could represent a non-invasive biomarker for early liver cancer diagnosis. This review summarises the potential role of the microbiota and immune system in primary and secondary liver cancer development, focusing on the potential therapeutic implications.

A Wearable Sensor-Based Platform for Surgeon Posture Monitoring: A Tool to Prevent Musculoskeletal Disorders.

Surgeons are workers that are particularly prone to the development of musculoskeletal disorders. Recent advances in surgical interventions, such as laparoscopic procedures, have caused a worsening of the scenario, given the harmful static postures that have to be kept for long periods. In this paper, we present a sensor-based platform specifically aimed at monitoring the posture during actual surgical operations. The proposed system adopts a limited number of Inertial Measurement Units (IMUs) to obtain information about spine and neck angles across time. Such a system merges the reliability of sensor-based approaches and the validity of state-of-the-art scoring procedure, such as RULA. Specifically, three IMUs are used to estimate the flexion, lateral bending, and twisting angles of spine and neck. An ergonomic risk index is thus estimated in a time varying fashion borrowing relevant features from the RULA scoring system. The detailed functioning of the proposed systems is introduced, and the assessment results related to a real surgical procedure, consisting of a laparoscopy and mini-laparotomy sections, are shown and discussed. In the exemplary case study introduced, the surgeon kept a high score, indicating the need for an intervention on the working procedures, for a large time fraction. The system allows separately analyzing the contribution of spine and neck, also specifying the angle configuration. It is shown how the proposed approach can provide further information, as related to dynamical analysis, which could be used to enlarge the features taken into account by currently available approaches for ergonomic risk assessment. The proposed system could be adopted both for training purposes, as well as for alerting surgeons during actual surgical operations.

Multiple hepatocellular carcinoma: Long-term outcomes following resection beyond actual guidelines. An Italian multicentric retrospective study.

BACKGROUND: Hepatocellular carcinoma (HCC) is frequently diagnosed as multinodular. This study aims to assess prognostic factors for survival and identify patients with multiple HCC who may benefit from surgery beyond the Barcelona Clinic Liver Cancer classification indications. METHODS: This retrospective study included all the consecutive patients from 4 Italian tertiary centers receiving liver resection for naive multiple HCC between 1990 and 2012 to have a potential follow-up of 5 years. RESULTS: Included patients were 144. Ninety-day morbidity and mortality rates were 38.3% and 8.3%, respectively. The 5-year overall and disease-free survival rates were 33.3% and 19.1%, respectively. Tumor size <3 cm, bilirubin, Child-Pugh A, BCLC-A stage, being within "up-to-7" criteria, and minor resections resulted in prognostic factors. The Child-Pugh score resulted in an independent prognostic factor. CONCLUSIONS: Surgery may be related to good outcomes in selected patients with multiple HCC.

Evaluation of prognostic factors and clinicopathological patterns of recurrence after curative surgery for colorectal cancer.

BACKGROUND: Colorectal cancer is a common tumor with a quite high-related mortality. Despite the used curative treatments, patients will develop cancer recurrence in up to 50% of the cases and/or other primary neoplasms. Although most of the recurrences are discovered within 3 years from the first treatment, a small percentage is found after 5 years. The early detection of recurrence is crucial to allow further therapies improving patients' survival. Several follow-up programs have been developed but the optimal one is far from being established. AIM: To evaluation of potential prognostic factors for timing and patterns of recurrence in order to plan tailored follow-up programs. METHODS: Perioperative and long-term data of all consecutive patients surgically treated with curative intent, from January 2006 to June 2009, for colorectal adenocar-cinoma, were retrospectively reviewed to find potential prognostic factors associated with: (1) Recurrence incidence; (2) Incidence of an early (within 3 years from surgery) or late recurrence; and (3) Different sites of recurrence. In addition, the incidence of other primary neoplasms has been evaluated in a cohort of patients with a minimum potential follow-up of 10 years. RESULTS: Our study included 234 patients. The median follow-up period has been 119 ± 46.2 mo. The recurrence rate has been 25.6%. Patients with a higher chance to develop recurrence had also the following characteristics: Higher levels of preoperative glycemia and carcinoembryonic antigen, highest anaesthesiologists Score score, occlusion, received a complex operation performed with an open technique, after a longer hospital stay, and showed advanced tumors. The independent prognostic factors for recurrence were the hospital stay, N stage 2, and M stage 1 (multivariate analysis). Younger ages were significantly associated with an early recurrence onset. Patients that received intermediate colectomies or segmental resections, having an N stage 2 or American Joint Committee on Cancer stage 3 tumors were also associated with a higher risk of liver recurrence, while metastatic diseases at diagnosis were linked with local recurrence. Neoadjuvant treatments showed lung recurrence. Finally, bigger tumors and higher lymph node ratio were associated with peritoneal recurrence (marginally significant). Thirty patients developed a second malignancy during the follow-up time. CONCLUSION: Several prognostic factors should be considered for tailored follow-up programs, eventually, beyond 5 years from the first treatment.

Current management of intrahepatic cholangiocarcinoma: from resection to palliative treatments.

Background Intrahepatic cholangiocarcinoma (ICC) is the second most common liver primary tumour after hepatocellular carcinoma and represents 20% of all the cholangiocarcinomas. Its incidence is increasing and mortality rates are rising. Surgical resection is the only option to cure the disease, despite the high recurrence rates reported to be up to 80%. Intrahepatic recurrences may be still treated with curative intent in a small percentage of the patients. Unfortunately, due to lack of specific symptoms, most patients are diagnosed in a late stage of disease and often unsuitable for resection. Liver transplantation for ICC is still controversial. After the first published poor results, improving outcomes have been reported in highly selected cases, including locally advanced ICC treated with neoadjuvant chemotherapy, when successful in controlling tumour progression. Thus, liver transplantation should be considered a possible option within study protocols. When surgical management is not possible, palliative treatments include chemotherapy, radiotherapy and loco-regional treatments such as radiofrequency ablation, trans-arterial chemoembolization or radioembolization. Conclusions This update on the management of ICC focusses on surgical treatments. Known and potential prognostic factors are highlighted in order to assist in treatment selection.

Role of gut microbiota-immunity axis in patients undergoing surgery for colorectal cancer: Focus on short and long-term outcomes.

Human body is colonized by a huge amount of microorganisms mostly located in the gastrointestinal tract. These dynamic communities, the environment and their metabolites constitute the microbiota. Growing data suggests a causal role of a dysbiotic microbiota in several pathologies, such as metabolic and neurological disorders, immunity dysregulations and cancer, especially the well-studied colorectal cancer development. However, many were preclinical studies and a complete knowledge of the pathogenetic mechanisms in humans is still absent. The gut microbiota can exert direct or indirect effects in different phases of colorectal cancer genesis. For example, Fusobacterium nucleatum promotes cancer through cellular proliferation and some strains of Escherichia coli and Bacteroides fragilis produce genotoxins. However, dysbiosis may also cause a pro-inflammatory state and the stimulation of a Th17 response with IL-17 and IL-22 secretion that have a pro-oncogenic activity, as demonstrated for Fusobacterium nucleatum. Microbiota has a crucial role in several stages of postoperative course; dysbiosis in fact seems related with surgical site infections and Enterococcus faecalis (and other collagenase-producers microbes) are suggested as a cause of anastomotic leak. Consequently, unbalanced presence of some species, together with altered immune response may also have a prognostic role. Microbiota has also a substantial role in effectiveness of chemotherapy, chemoresistance and in the related side effects. In other words, a complete knowledge of the fine pathological mechanisms of gut microbiota may provide a wide range of new diagnostic tools other than therapeutic targets in the light of tailored medicine.

Inferior vena cava resection and reconstruction with a peritoneal patch for a leiomyosarcoma: A case report.

INTRODUCTION: Leiomyosarcomas (LMs) of the inferior vena cava (IVC) are very rare neoplasms seldom reported in the literature. The majority of patients does not present with specific abdominal pain and IVC LMs are used to become symptomatic with the increase of tumor volume. The role of chemotherapy or radiotherapy is not yet defined and surgical resection seems to be the only chance to improve survival rates. PRESENTATION OF CASE: We present a case of a 58-year-old female with a recent diagnosis of IVC LM who underwent surgery with a partial resection of the anterior wall of the vein using a lateral and partial vein clamping. The primary repair of the defect could result in stricture of the vein, so a parietal peritoneum patch was used for the vein reconstruction. The postoperative course was uneventful. DISCUSSION: Actual evidence suggests that vascular sarcomas have limited responsiveness to cytotoxic chemotherapy and chemoradiotherapy, so surgery is the treatment of choice. Major surgery entailing multivisceral and complex vascular resection is usually necessary to achieve negative margins and accurate vascular reconstruction techniques are mandatory to avoid serious circulatory complications. Different kinds of graft (biological or synthetics) are available for the reconstruction, with intrinsic advantages and limitations. The use of peritoneal patches seems a valid and cheap option for vascular reconstruction and it is gaining great attention in recent years. CONCLUSION: This case demonstrates that peritoneal graft could be a safe option to manage IVC defects in expert hands. A brief review of literature is also included.

Robotic enucleations of pancreatic benign or low-grade malignant tumors: preliminary results and comparison with robotic demolitive resections.

BACKGROUND: The incidental detection of benign to low-grade malignant small pancreatic neoplasms increased in the last decades. The surgical management of these patients is still under debate. The aim of this paper is to evaluate the safety and feasibility of robotic enucleations and to compare the outcomes with non-parenchymal sparing robotic resections. METHODS: The study included a total of 25 patients. Nine of them underwent a robotic enucleation (EN Group) and 16 patients received a robotic demolitive resection (DR Group). Perioperative and medium-term outcomes were compared between the two groups. RESULTS: Patients' baseline characteristics were similar in the two groups except for presence of symptoms and tumor size, due to the inclusion criteria. Operative time was significantly shorter and postoperative results were better for EN group, including a significant shorter hospitalization (5 vs. 8 days, p = 0.027), reduced pancreatic leaks (22% vs. 50%, p = 0.287) and a better preservation of glandular function (100% vs. 62.5%, p = 0.066). Mortality rate was zero in both groups, with all patients free from disease at a median follow-up of 18 months. CONCLUSIONS: The risks of under/overtreatment remain still unavoidable for benign to low-grade malignant small pancreatic neoplasms. Simple enucleation should be performed whenever oncological appropriate, to achieve the best postoperative outcomes. The adoption of robotic technique might widen the indications for parenchymal sparing, minimally invasive surgery.

Ultrasound-Guided Robotic Enucleation of Pancreatic Neuroendocrine Tumors.

BACKGROUND: Pancreatic neuroendocrine tumors (PanNETs) are relatively rare neoplasms with a low to mild malignant potential. They can be further divided into functioning and nonfunctioning, according to their secretive activity. Surgery is an optimal approach, but the classic open approach is challenging, with some patients having long hospitalization and potentially life-threatening complications. The robotic approach for PanNETs may represent an option to optimize their management. METHODS: We retrospectively reviewed our prospectively maintained databases from 2 high-volume Italian centers for pancreatic surgery. Demographics, pathological characteristics, perioperative outcome, and medium-term follow-up of patients who underwent robotic pancreatic enucleations were collected. RESULTS: Twelve patients with final diagnosis of PanNET were included. The mean age of the patients was 53.8 years (25-77). The median body mass index was 26 (24-29). Three lesions were functioning insulinomas, while the others were nonfunctioning tumors. No deaths occurred. Mild postoperative complications occurred, except for 1 grade B pancreatic fistula. The mean postoperative stay was 3.9 days (2-5). CONCLUSIONS: Our results confirm that robotic enucleation is a feasible and safe approach for the treatment of PanNETs, with short hospital stay and low incidence of morbidity.

Analysis of Prognostic Factors for Resected Synchronous and Metachronous Liver Metastases from Colorectal Cancer.

BACKGROUND: Surgical treatment is the cornerstone in the management of colorectal cancer (CRC) liver metastases. The aim of this study is to identify clinicopathological factors affecting disease-free (DFS) and overall survival (OS) in patients undergoing potentially curative liver resection for CRC metastasis. METHODS: All consecutive patients undergoing liver resection for first recurrence of CRC from February 2006 to February 2018 were included. Prognostic impact of factors related to the patient, primary and metastatic tumors, was retrospectively tested through univariate and multivariate analyses. RESULTS: Seventy patients were included in the study. Median postoperative follow-up was 37 months (range 1-119). Median DFS and OS were 15.2 and 62.7 months, and 5-year DFS and OS rates were 16% and 53%. In univariate analysis, timing of metastasis presentation/treatment (combined colorectal and liver resection, "bowel first" approach or metachronous presentation) (p < 0.0001), ASA score (p = 0.003), chemotherapy after liver surgery (p = 0.028), T stage (p = 0.021), number of resected liver lesions (p < 0.0001), and liver margin status (p = 0.032) was significantly associated with DFS while peritoneal resection at colorectal surgery (p = 0.026), ASA score (p = 0.036), extension of liver resection (p = 0.024), chemotherapy after liver surgery (p = 0.047), and positive nodes (p = 0.018) with OS. In multivariate analysis, timing of metastasis presentation/treatment, ASA score, and chemotherapy (before and after liver surgery) resulted significantly associated with DFS and timing of metastasis presentation/treatment, positive nodes, peritoneal resection at colorectal surgery, and surgical approach (open or minimally invasive) of colorectal resection with OS. CONCLUSIONS: Surgery may provide good DFS and OS rates for CRC liver metastasis. Patient selection for surgery and correct timing of intervention within a multidisciplinary approach may be improved by taking into account negative prognostic factors which stress the importance of systemic therapy.

Current Management of Pancreatic Neuroendocrine Tumors: From Demolitive Surgery to Observation.

Incidental diagnosis of pancreatic neuroendocrine tumors (PanNETs) greatly increased in the last years. In particular, more frequent diagnosis of small PanNETs leads to many challenging clinical decisions. These tumors are mostly indolent, although a percentage (up to 39%) may reveal an aggressive behaviour despite the small size. Therefore, there is still no unanimity about the best management of tumor smaller than 2 cm. The risks of under/overtreatment should be carefully evaluated with the patient and balanced with the potential morbidities related to surgery. The importance of the Ki-67 index as a prognostic factor is still debated as well. Whenever technically feasible, parenchyma-sparing surgeries lead to the best chance of organ preservation. Lymphadenectomy seems to be another important prognostic issue and, according to recent findings, should be performed in noninsulinoma patients. In the case of enucleation of the lesion, a lymph nodal sampling should always be considered. The relatively recent introduction of minimally invasive techniques (robotic) is a valuable option to deal with these tumors. The current management of PanNETs is analysed throughout the many available published guidelines and evidences with the aim of helping clinicians in the difficult decision-making process.

Comparing laparoscopic surgery with open surgery for long-term outcomes in patients with stage I to III colon cancer.

BACKGROUND: Although the short-term advantages of laparoscopy for colon cancer (CC) over open surgery have been clearly demonstrated, there is little evidence available concerning the long-term outcomes. This study aimed to compare the long-term results of laparoscopic surgery versus open surgery in a cohort of CC patients from a single center. METHODS: A series of 443 patients consecutively operated on for stage I to III CC between January 2006 and December 2013 were followed up. Patients were divided into two groups according to the surgical technique and were compared for disease-free survival (DFS) and overall survival (OS) before and after 1:1 propensity score matching. RESULTS: Due to exclusions and drop-outs, the statistical analysis of the study is based on 398 patients. Open surgery was performed in 133 patients, and laparoscopic surgery was performed in 265. After propensity score matching, two comparable groups of 89 patients each were obtained. The 5-year DFS was 64.3% and 78.2% for patients in the open and laparoscopic resection groups, respectively [hazard ratio (HR) 0.63, 95% confidence interval (CI) 0.33-1.19; P = 0.148]. A 5-year OS of 72.1% and 86.8% was observed in the open and laparoscopic resection groups, respectively (HR 0.43, 95%CI 0.20-0.94; P = 0.026). The multivariate survival analysis demonstrated better results of laparoscopy compared with open surgery for both DFS (HR 0.43, 95%CI 0.23-0.78; P = 0.004) and OS (HR 0.28, 95%CI 0.14-0.59; P < 0.001). CONCLUSIONS: Despite the limitations of a retrospective analysis, our study confirms better results for laparoscopic surgery in terms of DFS and OS compared with open surgery in CC treatment.

Pringle maneuver in robotic liver surgery: preliminary study.

BACKGROUND: Liver resection may be complicated by unpredictable intraoperative bleeding. Pringle's maneuver was the first attempt to control bleeding, but the main problem is the duration of ischemia. Robotic surgery thanks to the magnified view, three-dimensional visualization associated and fine movement allow to perform good parenchymal dissection and identification of vascular structure. Aim of study is to evaluate blood loss and the need to perform Pringle maneuver in patients underwent robotic liver resection. METHODS: Thirty-three patients underwent robotic liver resections were analyzed, 16 (48%) male and 17 (52%) female, with median age of 64 years. Seven (21%) patients had benign lesions and twenty-six (79%) malignant tumor. RESULTS: Seventeen (52%) patients had anatomical resections, while sixteen (48%) patients had non anatomical resection. Operative time was 270 minutes. Estimated blood loss was 100 mL and Pringle maneuver was carried out on seven patients. Median hospital stay was 4 days. CONCLUSIONS: Our results show that liver resections with robotic technique can be performed safely even without systematic Pringle maneuver.

Vasodilator activity of hydrogen sulfide (H2S) in human mesenteric arteries.

The role of endogenous H2S has been highlighted as a gaseous transmitter. The vascular smooth muscle inhibitory effects of H2S have been characterized in isolated aorta and mesenteric arteries in rats and mice. Our study was aimed at investigating the vascular effects of H2S on human isolated mesenteric arteries and examining the underlying mechanisms involved. All experiments were performed on rings (4-8mm long) of human mesenteric arteries obtained from patients undergoing abdominal surgery. Ethical approval was obtained from the Ethics Committee of the University Hospital of the University of Florence (app. N. 2015/0024947). The effect of NaHS, an H2S donor, was determined using noradrenaline pre-contracted human isolated mesenteric rings. NaHS evoked a concentration-dependent relaxation (EC50 57µM). In contrast, homocysteine, an endogenous precursor of H2S, failed to affect human isolated mesenteric rings. Vasorelaxant response to NaHS was reduced by endothelium removal, application of the nitric oxide synthase inhibitor L-NAME and ODQ inhibitor of cyclic GMP. SQ 22536, an adenylate-cyclase inhibitor, failed to block NaHS-induced vasorelaxation. Inhibition of endogenous prostanoid production by indomethacin significantly reduced NaHS induced vasorelaxation. The role of potassium channels was also examined: blockers of the Ca2+-dependent potassium channel, charybdotoxin and apamin, failed to have any influence on the relaxant response to NaHS on this vascular tissue. In summary, H2S induced relaxation of isolated rings of human mesenteric arteries. Endothelium-dependent related mechanisms with the stimulation of ATP-sensitive potassium channels represents important cellular mechanisms for H2S effect on human mesenteric arteries.