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N Sartori

Publications and source records attributed to N Sartori.

At least 19 recordsLinked to original sources

Role of unlabelled somatostatin analogues in the prevention of complications after elective pancreatic and peripancreatic surgery: a critical review.

Although studies on the use of the somatostatin analogues in the elective pancreatic surgery are mostly prospective, double blind and randomised, the results are contradictory and not univocally interpretable. Through the examination of all randomised perspective works published on this subject, a critical interpretation is attempted which may give relevant suggestions for further studies. A new clinical, randomised, double blind and multicentric prospective trial should take into proper consideration even the changes which have occurred in the care of the patients. Over the years a significant decrease of postoperative hospital stay and a deeper awareness of the medical expenses have been observed. Moreover, since the drug has a potential advantage on specific pancreatic complications, only these must be considered among the end points of the study and the population studied will be limited exclusively to patients who underwent resection of the pancreatic head or of the periampullar region because of neoplastic disease. Finally, the selection of the centres that enrol the patients must be considered, since the expertise of each operator or of the team, affects, as an independent variable, both morbidity and mortality.

Double-Blind Method↗

Pancreatic cystic tumors.

Cystic tumors of the pancreas are less frequent than other tumors in neoplastic pancreatic pathology, but in recent years the literature has reported an increasing number. After the first report by Becourt in 1830, cystic tumors were classified into 2 different types by Compagno and Oertel in 1978: benign tumors with glycogen-rich cells and mucinous cystic neoplasms with overt and latent malignancy. The WHO classification of exocrine tumors of the pancreas, published in 1996, is based on the histopathological features of the epithelial wall, which are the main factor in differential diagnosis with cystic lesions of the pancreas. Thanks to the knowledge acquired up to now, a surgical procedure is not always required because the therapeutic choice is conditioned by the correct classification of this heterogeneous group of tumors. Clinical signs are not really useful in the clinical work up, most patients have no symptoms and when clinical signs are present, they may help us to pinpoint the organ of origin but never to identify the type of pathology. In the last few years, the great improvement in imaging has enabled us not only to discriminate cystic from solid lesions, but also to identify the features of the lesions and label them preoperatively. More invasive diagnostic procedures such as fine needle aspiration and intracystic fluid tumor marker level are not really useful because they are not sensitive and the cystic wall can show different degrees of dysplasia and de-epithelialization. These are the reasons for sending the entire specimen to pathology. Good cooperation between surgeons, pathologists, radiologists and gastroenterologists is mandatory to increase the chances of making a proper diagnosis. Therefore, we must analyze all the information we have, such as age, sex, clinical history, location of the tumor and radiological features, in order to avoid the mistake of treating a cystic neoplasm as a benign lesion or as a pseudocyst, as described in the literature. Except for inoperable cases due to the critical condition of the patient or non-resectable lesions, surgical treatment differs with the diagnosis. Cystic tumors of the pancreas, therefore, are a heterogeneous group of tumors, with a real problem regarding differential diagnosis between neoplastic and inflammatory lesions. Even with a proper work up, some perplexity may remain about the nature of the lesion and in these cases the surgical procedure has a therapeutic value as well as playing a diagnostic role. The role of surgery is central in the treatment of these tumors because it could be curative when complete resection is possible. In this way, the lack of good therapeutic results with chemotherapy and radiotherapy force the surgeon to go ahead with the procedure. Intraductal papillary mucinous neoplasms represent a new and, from the epidemiological point of view, important chapter in the world of cystic tumors. The margin of resection is important and the surgeon has to be aware that in order to have a curative resection, total pancreatectomy is sometimes required. In the last few years the therapeutic approach has changed thanks to new knowledge of the biological behavior of these tumors. In fact, from a surgical approach in all cases, we are now discussing the possibility of a follow-up not only for asymptomatic serous cystadenomas but also for the little branch side intraductal papillary mucinous neoplasms (IPMNs) in critical patients. A follow-up could be planned even for solid pseudopapillary tumors but it seems risky to leave untreated big tumors in young patients without a certain diagnosis and with so few studies reported in the literature.

Cystadenocarcinoma, Serous↗

Use of a toxicokinetic model in the analysis of cancer mortality in relation to the estimated absorbed dose of dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD).

We performed an analysis of All cancer and Lung cancer mortality in relation to estimated absorbed dose of dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD) in the cohort of chemical workers at 12 US plants assembled by the US National Institute for Occupational Safety and Health (NIOSH) (n = 5172). Estimates of cumulative exposure to TCDD were based on a minimal physiologic toxicokinetic model (MPTK) that accounts for inter- and intra-individual variations in body mass index (BMI) over time. Population-level parameters related to liver elimination and background (input or concentration) of TCDD were estimated from separate data with repeated measures of serum TCDD (US Air Force Health Study). An occupational TCDD input parameter was estimated based on one-point-in-time TCDD data available for a subset (n = 253) of the NIOSH cohort. Model-based time-dependent cumulative dose estimates (area under the curve (AUC) of the lipid-adjusted serum TCDD concentration over time) were obtained for members of the full cohort with recorded body height and weight (n = 4049), as this information is required by the MPTK model to compute dose. Missing-value problems arose in the estimation of the occupational input parameter (n = 42) and in TCDD-dose calculation in the full cohort (n = 886) and they were handled with multiple imputation methods. Risk-regression analyses were based on Cox log-linear models including age at entry, year of entry and duration of employment as categorical covariates in addition to the logarithm of cumulative TCDD dose in ppt-years. Risk sets were stratified on birth cohort. Estimates of the unlagged exposure coefficient in these models were 0.1249 [95% confidence interval (CI) 0.0144, 0.2354] for All cancer and 0.2158 (95% CI 0.02376, 0.4078) for lung cancer. A 10-year lag produced an increase in the estimate for all cancer (0.1539, 95% CI 0.0387, 0.2691), whereas, the estimate for lung cancer was not affected much (0.2125, 95% CI 0.0138, 0.4112). At a dose level of 100 times the background the estimates obtained with a 10-year lag translate into a relative risk of 2.03 (95% CI 1.19-3.45) for all cancer and of 2.66 (95% CI 1.07-6.64) for lung cancer. Higher estimates of the exposure coefficients were obtained after imputation of missing values. This increase in risk seemed due to the inclusion of short-term workers, who may exhibit a higher mortality for reasons other than dioxin exposure.

Body Mass Index↗

Changes in pancreatic resection for chronic pancreatitis over 28 years in a single institution.

BACKGROUND: Because of advances in knowledge over recent years there is reason to believe that surgical attitudes towards patients with chronic pancreatitis may have changed. METHODS: Some 547 patients were treated surgically for chronic pancreatitis from 1971 to June 1998. Anastomoses were performed in 80 per cent (438 patients) and resections in 20 per cent (109 patients). Indications and type of operation were analysed, as were mortality and morbidity rates and long-term follow-up results, in patients undergoing resection both over the period as a whole and after dividing the series into two subperiods of 14 years. RESULTS: In the second 14-year period, there was a significant reduction in the percentage of resections compared with anastomoses (28 per cent (69 of 244 patients) versus 13 per cent (40 of 303); P < 0.0001), and a significant change in the type of resection with a substantial increase in resections of the head compared with those of the body and tail. Statistically significant reductions occurred in operating times, number of units of blood transfused (mean(s.d.) 4.7(3.6) versus 1.2(1.6) units; P = 0.0001) and mean hospital stay (18 versus 14 days for pylorus-preserving and 12 versus 8 days for left pancreatectomy with splenectomy; P < 0. 01); mortality and morbidity rates also tended to decrease, but not significantly. CONCLUSION: A different pattern has emerged over the years as regards both the type and number of resections performed.

Adolescent↗

Alcohol and smoking as risk factors in chronic pancreatitis and pancreatic cancer.

The aim of this study was to compare alcohol and smoking as risk factors in the development of chronic pancreatitis and pancreatic cancer. We considered only male subjects: (1) 630 patients with chronic pancreatitis who developed 12 pancreatic and 47 extrapancreatic cancers; (2) 69 patients with histologically well documented pancreatic cancer and no clinical history of chronic pancreatitis; and (3) 700 random controls taken from the Verona polling list and submitted to a complete medical check-up. Chronic pancreatitis subjects drink more than control subjects and more than subjects with pancreatic cancer without chronic pancreatitis (P<0.001). The percentage of smokers in the group with chronic pancreatitis is significantly higher than that in the control group [odds ratio (OR) 17.3; 95% CI 12.6-23.8; P<0.001] and in the group with pancreatic carcinomas but with no history of chronic pancreatitis (OR 5.3; 95% CI 3.0-9.4; P<0.001). In conclusion, our study shows that: (1) the risk of chronic pancreatitis correlates both with alcohol intake and with cigarette smoking with a trend indicating that the risk increases with increased alcohol intake and cigarette consumption; (2) alcohol and smoking are statistically independent risk factors for chronic pancreatitis; and (3) the risk of pancreatic cancer correlates positively with cigarette smoking but not with drinking.

Adenocarcinoma↗

Incidence of cancer in the course of chronic pancreatitis.

OBJECTIVE: Chronic pancreatitis patients appear to present an increased incidence of pancreatic cancer. The aim of the study was to compare the incidence of cancer, whether pancreatic or extrapancreatic, in our chronic pancreatitis cases with that in the population of our region. METHODS: We analyzed 715 cases of chronic pancreatitis with a median follow-up of 10 yr (7287 person-years); during this observation period they developed 61 neoplasms, 14 of which were pancreatic cancers. The cancer incidence rates were compared, after correction for age and gender, with those of a tumour registry. RESULTS: We documented a significant increase in incidence of both extrapancreatic (Standardized Incidence Ratio [SIR], 1.5; 95% confidence interval [CI], 1.1-2.0; p <0.003) and pancreatic cancer (SIR, 18.5; 95% CI, 10-30; p <0.0001) in chronic pancreatitis patients. Even when excluding from the analysis the four cases of pancreatic cancer that occurred within 4 yr of clinical onset of chronic pancreatitis, the SIR is 13.3 (95% CI, 6.4-24.5; p <0.0001). If we exclude these early-onset cancers, there would appear to be no increased risk of pancreatic cancer in nonsmokers, whereas in smokers this risk increases 15.6-fold. CONCLUSIONS: The risks of pancreatic and nonpancreatic cancers are increased in the course of chronic pancreatitis, the former being significantly higher than the latter. The very high incidence of pancreatic cancer in smokers probably suggests that, in addition to cigarette smoking, some other factor linked to chronic inflammation of the pancreas may be responsible for the increased risk.

Adult↗

Uncertainty in estimating exposure using a toxicokinetic model. The example of 2,3,7,8-tetrachlorodibenzo-p-dioxin.

This paper deals with sources of uncertainty in the use of a minimal physiological toxicokinetic model to obtain dose estimates for a dose-response analysis of cancer in an occupational cohort. Toxicokinetic models make it possible to construct exposure parameters that are more closely related to the individual dose than traditional measures of exposures to toxic agents. However, the process introduces a wide array of sources of uncertainty. Selecting a model structure to describe the kinetics of a toxic agent implies necessarily making simplifications and assumptions that influence the range of applicability of the model. Once a model has been selected, the value of certain model parameters (constants) must be assigned, for example, from anthropometric data. The question then arises of how sensitive the model predictions are to variations in the values of these constants. Other model parameters, typically those describing the kinetics of the agent, are next estimated from actual data. There may be limitations in the data concerning, for example, sparseness (too few observations per subject) or missing values. The methods used for parameter estimation carry their own set of assumptions that need to be appropriate to the situation at hand. In summary, the dioxin example is used to characterize the sources of uncertainty at different levels, such as model structure, methods and data used for parameter estimation, estimation of occupational exposure, and imputation of missing values in exposure indices derived from the kinetic model.

Environmental Exposure↗

Role of chemoembolization in synchronous liver metastases from pancreatic endocrine tumours.

Endocrine tumours of the pancreas, even in case of liver involvement, are generally characterized by a slower evolution and a better prognosis, if compared with ductal carcinoma. This fact gives reason to a radical surgical approach, whenever possible, and to the research of any effective adjuvant treatment. For this purpose, hepatic transarterial chemoembolization (TACE) has been proposed in recent years for the treatment of metastatic endocrine tumours. Out of 80 patients suffering from endocrine tumours of the pancreas, observed between January 1985 and December 1996, 28 (35%) presented liver metastases at the time of diagnosis. Twelve of these patients were submitted to palliative resection of pancreatic tumour and one or more cycles of TACE. Overall survival was 50% (6/12); median survival was 35.4 months (range 4-75). These results suggest that chemoembolization, combined with surgical resection of primary malignancy, appears to be able to control the disease for a certain time and to increase the survival rate.

Actuarial Analysis↗

Assessment and treatment of severe pancreatitis. Protease inhibitor.

From the theoretical point of view, antiproteolytic therapy would seem to be the rationale for acute pancreatitis management. Unfortunately, clinical human trials studying the role of antiproteases in the treatment of acute pancreatitis differ in several respects in terms of their basic design. As a consequence, any form of homogeneous analysis of the reported data as a whole is impossible. Considering the data emerging from a meta-analysis of five trials a rational use of antiproteases may result in a reduction of complications requiring surgery and of patient management costs only in selected cases, meaning by that severe and necrotic forms. As regards presumptive applications, over 400 patients were prospectively tested versus placebo in a double-blind trial with the aim of preventing acute pancreatitis after ERCP. The complication incidence was significantly lower among the pretreated patients; anyway, also in this field of protease inhibitor clinical application it is necessary to identify the patients with the greatest risk to develop post-ERCP acute pancreatitis. In conclusion, antiproteases can still play a role when given prophylactically or when used in the very early phases of the disease; moreover a 'multiple drugs approach' (including, for example, suitable antibiotics) seems to represent nowadays the most modern and rational treatment of acute pancreatitis.

Health Care Costs↗

Management of digestive tract fistulas. A review.

Digestive tract fistulas are a complex subject in terms both of classification and management. There is still a lack of firm epidemiological data regarding the their incidence, though the prognostic factors conditioning the prognosis of these patients are now well known. They are related mainly to the nutritional status of the patients and to the presence or otherwise of sepsis. Instrumental investigations should be aimed not merely at identifying the complication, but also at guiding clinicians in their choice of therapeutic management. According to the various situations arising, the treatment will be surgical, endoscopic or conservative medical. In the latter case, the clinician should establish first of all whether, as a result of the site of the fistula or the nutritional status, the patient requires total parenteral or enteral artificial nutrition, whenever possible. In those cases in which parenteral nutrition is indicated, the ideal drug with the best proven ability to shorten healing times and reduce the number of complications when used in combination with parenteral nutrition is naturally occurring somatostatin at the dose of 250 micrograms/h over 24 h. In all other cases, if the fistula is clinically important, its synthetic analogue, octreotide, should be the drug of choice and can be administered subcutaneously. The amount of octreotide administered ranges from 300 to 600 micrograms/day in 3 or 4 daily doses.

Digestive System Fistula↗

Cytoreductive surgery in advanced endocrine tumours of the pancreas.

Surgery still plays an important role even in advanced endocrine tumours of the pancreas, owing to their biological behaviour. Sometimes it is possible to attempt a radical approach, but more often only cytoreduction is feasible. In fact, when the malignancy is not completely resectable on account of vessel involvement or extensive liver metastases, surgical reduction of the tumour burden (debulking) can be proposed, aimed at improving the clinical conditions and survival of these patients. Forty-one patients suffering from advanced endocrine tumour of the pancreas were observed from 1985 to 1996. In 13 patients, the disease was locally advanced as far as concerns lymph node metastases and/or vessel involvement, while the other 28 patients presented liver metastases. In the former group, we performed 6 radical resections, in the latter we submitted 2 patients to radical resection and 12 patients to cytoreductive surgery, with complete removal of the pancreatic malignancy. The overall survival of the resected patients was 87% (7/8). Three patients (37.5%) are alive and free of disease, while the other 4 have subsequently developed liver metastases. One patient died with hepatic recurrence. Half the patients (6/12) undergoing cytoreductive surgery are alive, 3 with stable and 3 with progressive disease. The other 6 patients have died due to liver progression of the disease. As data in the literature concerning the role of debulking as regards the survival are conflicting, we have modified our surgical approach in patients with advanced disease. We perform cytoreductive surgery whenever complete removal of the pancreatic tumour is feasible. The rationale of this approach is to leave only a liver with residual disease, with a view to giving targeted adjuvant treatment.

Adolescent↗

Resection and radiochemotherapy of pancreatic cancer--the future?

BACKGROUND: To improve the surgical outcome after resection of pancreatic adenocarcinomas, multimodal treatment concepts need to be applied and improved. The controversies among those being pro and contra adjuvant treatment need an up-to-date review of the indications and results achievable with various treatment modalities. PATIENTS/METHODS: The literature regarding the indications and results of adjuvant/neoadjuvant therapies in pancreatic cancer was reviewed to provide a solid base for current recommendations and future developments. The biology of the disease in the spontaneous course, after surgery and during/after various palliative and adjuvant/neoadjuvant treatment modalities was focussed on, to characterise the disease for an optimally targeted treatment in conjunction with surgical removal of the tumour. The results of systemic and regional chemotherapy and radiotherapy, either alone or in combination, before, during and after surgery were critically analysed with respect to the oncological possibilities and pitfalls of each treatment method. RESULTS: In two randomised trials, one testing postoperative radiochemotherapy (GITSG), and one postoperative chemotherapy, the adjuvant treatment achieved a significant prolongation of the median survival time. The 5-year and 10-year survival rates were improved in the GITSG study. The EORTC-GITCCG trial could not confirm the benefit of adjuvant radiochemotherapy. This study had a different design than the GITSG trial. Several historical control studies supported the beneficial effect of postoperative radiochemotherapy. In three historical control trials using regional chemotherapy, one with intraoperative radiotherapy, the survival times were improved compared with surgery alone. Intraoperative or postoperative radiotherapy as single modalities might reduce local relapses, but a survival advantage is still debated. Preoperative neoadjuvant radiochemotherapy has several advantages (downstaging, devitalising margins and lymph node metastases, compatibility of treatment vs. postoperative radiochemotherapy), and does not seem to increase the postoperative morbidity. Several trials have confirmed the feasibility of this concept, but no survival advantage has yet been proven. Systemic and regional chemotherapy is able to downstage primarily nonresectable pancreatic cancers. CONCLUSIONS: Postoperative adjuvant radiochemotherapy with up-to-date protocols can be recommended for routine treatment, if the surgeon or the patient desires to improve the usually remote prognosis after surgery alone. For those being indecisive or against adjuvant therapy, the participation in trials, e.g. the ESPAC 1 and 2 studies, is strongly recommended. Regarding our own positive experience with adjuvant regional chemotherapy and in view of the postresectional progression pattern, we currently favour adjuvant radiochemotherapy, with the chemotherapy delivered regionally via the celiac axis. This concept will be tested against surgery alone in the ESPAC 2 trial. Neoadjuvant therapies have a great potential, but should be conducted within studies, such as pre-, intra-, or postoperative radiotherapy.

Adenocarcinoma↗

Long-term follow-up of patients with chronic pancreatitis in Italy.

BACKGROUND: We investigated the epidemiologic, clinical, and radiologic aspects of a mixed medicosurgical series of chronic pancreatitis patients observed at the University of Verona Centre for the Study of Pancreatic Diseases over the period 1971-1995. METHODS: Even though the pathogenesis of chronic pancreatitis has yet to be clarified and the classification is still debatable, the patients were subdivided in accordance with the Marseilles-Rome classification into those with alcoholic, obstructive, familial, and idiopathic forms of the disease. A total of 715 patients were analysed with a median follow-up period of 10 years (range, 1-25 years). RESULTS AND CONCLUSIONS: At the end of follow-up the dropout rate amounted to 7.1% (51 patients), and 176 patients (24.6%) had died. Data are reported about the type of chronic pancreatitis, sex, and age distribution at the onset of the disease, drinking and smoking habits before onset and during follow-up, and incidence of calcifications, pain, diabetes, steatorrhoea, and pseudocysts. Surgical aspects, survival curves, and causes of death are also analysed, and the most frequent concomitant diseases in chronic pancreatitis sufferers are discussed.

Adolescent↗

To what extent is surgery superior to endoscopic therapy in the management of chronic pancreatitis?

The surgeon was the only figure involved in the management of chronic pancreatitis patients unresponsive to medical treatment, until a few years ago. Nowadays, because of less invasive, endoscopy offers a seductive alternative to surgery. Up to now no clinical prospective and randomized data comparing the results of the two different approaches are available. Surgery seems to be the only solution for chronic pancreatitis with duodenal stenosis and the last chance of eliminating diagnostic uncertainty. Also in the case of biliary tract involvement surgery should be regarded as the procedure of choice, inasmuch as the stenosis is benign and generally long-lasting, and endoscopic treatment would have to be repeated several times; endoscopy, in this indication, should be reserved only for patients who present contraindicating surgery conditions (such as severe jaundice, colangitis etc.); the endoscopist should assess whether to insert a stent or a naso-biliary drainage tube referring the patient back to the surgeon once good clinical conditions have been restored. Endoscopy and surgery should be regarded not as adversaries in the management of chronic pancreatitis and its complications, but as complementary procedures in an integrated approach. The maximum degree of complementarity should be achieved in the management of pseudocysts and in cases presenting severe, incapacitating pain. In selected cases endoscopy can play a definitive role. The generally good surgical outcomes, moreover, should convince endoscopists not to insist with repeated, hazardous manoeuvres in cases of failure. Particularly interesting is the possibility of performing endoscopic sphincterotomy combined with extracorporeal shock-wave lithotripsy prior to surgical treatment in cases of chronic calcifying calcific pancreatitis. The crushing of the calculi and partial clearance of the duct have simplified surgery and complete clearance of the duct in those patients receiving such treatment in our experience.

Chronic Disease↗

Pancreatic cystic manifestations in von Hippel-Lindau disease.

CONCLUSION: In view of the frequent absence of symptoms related to pancreatic lesions, screening tests for VHL should always include assessment of the pancreas and, considering the frequency of polycystic manifestations, VHL should always be borne in mind in the differential diagnosis of multiple pancreatic cysts, especially when occurring in young patients and in the absence of a positive history of pancreatic disease. BACKGROUND: Von Hippel-Lindau disease (VHL) is a hereditary disease transmitted with an autosomal dominant character and characterized by hemangioblastomas of the central nervous system and retina, renal tumors and cysts, and pheochromocytoma. Pancreatic manifestations of VHL are reported in the literature with incidences ranging from 16 to 29% of cases and consist mainly in cystadenomas of the serous type and in multiple cystic lesions, often with complete replacement of the gland. METHODS AND RESULTS: We report five cases of VHL with a polycystic pancreas as the main or only manifestation, all devoid of symptoms related to involvement of the pancreas, who were referred to our Pancreatic Surgery center with diagnoses of multiple pancreatic pseudocysts of undefined origin.

Adult↗

The role of surgery in the major early complications of severe acute pancreatitis.

The early complications of severe acute pancreatitis may constitute a dramatic clinical dilemma in the first 2 weeks of the disease, when the surgical approach is made even more difficult by failure to define the precise extent of the necrotic component of the disease. Moreover, the surgical indication itself is not always based on clear guidelines to which the clinician can refer, and this is due to factors of two types: (i) the intrinsic complexity of the pancreatitis syndrome in its early toxic stages and (ii) the difficulty in understanding the relevant information reported in the literature in this connection, which is often incomplete and based on confused terminology. While the surgical indication is universally accepted in the case of infection of the necrotic tissue (an event, however, which is by no means frequent in the early stages of severe pancreatitis), the development of multi-organ failure despite adequate intensive care is a potential indication which not all specialists go along with, at least not as regards the ideal timing of the intervention. Other surgical indications which have emerged are evidence of complete rupture of the main pancreatic duct and the presence of very extensive sterile necrosis. As things stand at present, however, we are witnessing a general tendency to postpone surgery, since delayed surgery is associated with a lower incidence of complications than is the case with early surgery. If, as is known, the role of surgery is aimed mainly at the treatment of superinfections and severe multi-organ failures, targeted antibiotic prophylaxis and earlier, more complete anti-enzymatic therapy may, as suggested by a number of pilot studies, offer a promising alternative to invasive procedures which are sometimes risky, though indispensable, in an attempt to save patients who would otherwise have no chance of survival.

Acute Disease↗