Predicting the Risk of Morbidity by GLIM-Based Nutritional Assessment and Body Composition Analysis in Oncologic Abdominal Surgery in the Context of Enhanced Recovery Programs : The PHase Angle Value in Abdominal Surgery (PHAVAS) Study.

BACKGROUND: Preoperative nutritional status and body structure affect short-term prognosis in patients undergoing major oncologic surgery. Bioimpedance vectorial analysis (BIVA) is a reliable tool to assess body composition. Low BIVA-derived phase angle (PA) indicates a decline of cell membrane integrity and function. The aim was to study the association between perioperative PA variations and postoperative morbidity following major oncologic upper-GI surgery. PATIENTS AND METHODS: Between 2019 and 2022 we prospectively performed BIVA in patients undergoing surgical resection for pancreatic, hepatic, and gastric malignancies on the day before surgery and on postoperative day (POD) 1. Malnutrition was defined as per the Global Leadership Initiative on Malnutrition criteria. The PA variation (ΔPA) between POD1 and preoperatively was considered as a marker for morbidity. Uni and multivariable logistic regression models were applied. RESULTS: Overall, 542 patients with a mean age of 64.6 years were analyzed, 279 (51.5%) underwent pancreatic, 201 (37.1%) underwent hepatobiliary, and 62 (11.4%) underwent gastric resections. The prevalence of preoperative malnutrition was 16.6%. The overall morbidity rate was 53.3%, 59% in those with ΔPA < -0.5 versus 46% when ΔPA ≥ -0.5. Age [odds ratio (OR) 1.11; 95% confidence interval (CI) (1.00; 1.22)], pancreatic resections [OR 2.27; 95% CI (1.24; 4.18)], estimated blood loss (OR 1.20; 95% CI (1.03; 1.39)], malnutrition [OR 1.77; 95% CI (1.27; 2.45)], and ΔPA [OR 1.59; 95% CI (1.54; 1.65)] were independently associated with postoperative complications in the multivariate analysis. CONCLUSIONS: Patients with preoperative malnutrition were significantly more likely to develop postoperative morbidity. Moreover, a decrease in PA on POD1 was independently associated with a 13% increase in the absolute risk of complications. Whether proactive interventions may reduce the downward shift of PA and the complication rate need further investigation.

The clinical and economic impact of surgical site infections after distal pancreatectomy.

BACKGROUND: The present study aimed to evaluate surgical site infections' clinical and economic impact after distal pancreatectomy. METHODS: The study was a prospective, monocentric, observational study, including all adult patients who underwent distal pancreatectomy. According to the American Centers for Disease Control and Prevention definition, the surgical site infection assessment was prospectively performed by trained personnel. The Accordion Severity Grading System was used to evaluate the clinical burden of surgical site infection. The hospitalization's total costs were calculated using the hospital expenditure report, excluding the intraoperative costs. RESULTS: During the study period, 414 distal pancreatectomies were performed. The overall incidence of surgical site infection was 26% (106 patients). Surgical site infections were associated with a higher body mass index (P = .022, odds ratio 1.2), positive preoperative rectal swab for multidrug resistant bacteria (P = .010, odds ratio 4.2), and increased operative time (P = .037, odds ratio 1.1). Using the Accordion Severity Grading System, surgical site infections contributed significantly to the total clinical burden (25.5%) and prolonged hospitalization (P < .001). Furthermore, surgical site infection doubled the costs (12.915 vs 6.888 euros, P < .001). CONCLUSION: Surgical site infection has a high clinical burden, negatively impacting the postoperative course. The costs and length of stay proportionally increased with the surgical site infection severity, doubling the hospitalization expenses.

Evolving pancreatic cancer treatment: From diagnosis to healthcare management.

The prognosis of pancreatic ductal adenocarcinoma is still the worst among solid tumors. In this review, a panel of experts addressed the main unanswered questions about the clinical management of this disease, with the aim of providing practical decision support for physicians. On the basis of the evidence available from the literature, the main topics concerning pancreatic cancer are discussed: the diagnosis, as the need for a pathological characterization and the role for germ-line and somatic molecular profiling; the therapeutic management of resectable disease, as the role of upfront surgery or neoadjuvant chemotherapy, the post-operative restaging and the optimal timing foradjuvant chemotherapy, the management of the borderline resectable and locally advanced disease; the metastatic disease and the role of surgery for the management of patients with isolated metastasis and the use of biomarkers of metastatic potential; the role of supportive care and the healthcare management of pancreatic ductal adenocarcinoma.

Cost-effectiveness and quality of life analysis of laparoscopic and robotic distal pancreatectomy: a propensity score-matched study.

BACKGROUND: This study analyzed the Quality of Life (QoL) and cost-effectiveness of laparoscopic (LDP) versus robotic distal pancreatectomy (RDP). METHOD: All patients who underwent LDP or RDP from 2011 to 2017 and with a minimum postoperative follow-up of 12 months were included in the study. To minimize bias, a propensity score-matched analysis (1:2) was performed. Two different questionnaires (EORTC QLQ-C30 and EQ-5D) were completed by the patients. The mean differential cost and mean differential Quality Adjusted Life Years (QALY) were calculated and plotted on a cost-utility plane. RESULTS: The study population consisted of 152 patients. After having applied the propensity score matching, the final population included 103 patients divided into RDP group (n = 37, 36%) and LDP (n = 66, 64%). No differences were found between groups regarding the baseline, intraoperative, postoperative, and pathological variables (p > 0.05). The QoL analysis showed a significant improvement in the RDP group on the postoperative social function, nausea, vomiting, and financial status (p = 0.010, p = 0.050, and p = 0.030, respectively). As expected, the crude costs analysis confirmed that RDP was more expensive than LDP (12,053 Euros vs. 5519 Euros, p < 0.001). However, the robotic approach had a higher probability of being more cost-effective than the laparoscopic procedure when a willingness to pay of more than 4800 Euros/QALY was accepted. CONCLUSION: RDP was associated with QoL improvement in specific domains. Crude costs were higher relative to LDP. Cost-effectiveness threshold resulted to be 4800 euros/QALY. The increasing worldwide diffusion of the robotic technology, with easier access and possible cost reduction, could increase the sustainability of this procedure.

Decoding Grade B Pancreatic Fistula: A Clinical and Economical Analysis and Subclassification Proposal.

OBJECTIVE: The aim of this study was to describe characteristics and management approaches for grade B pancreatic fistula (B-POPF) and investigate whether it segregates into distinct subclasses. BACKGROUND: The 2016 ISGPS refined definition of B-POPF is predicated on various postoperative management approaches, ranging from prolonged drainage to interventional procedures, but the spectrum of clinical severity within this entity is yet undefined. METHODS: Pancreatectomies performed at 2 institutions from 2007 to 2016 were reviewed to identify B-POPFs and their treatment strategies. Subclassification of B-POPFs into 3 classes was modeled after the Fistula Accordion Severity Grading System (B1: prolonged drainage only; B2: pharmacologic management; B3: interventional procedures). Clinical and economic outcomes, unique from the ISGPS definition qualifiers, were analyzed across subclasses. RESULTS: B-POPF developed in 320 of 1949 patients (16.4%), and commonly required antibiotics (70.3%), prolonged drainage (67.8%), and enteral/parenteral nutrition (54.7%). Percutaneous drainage occurred in 79 patients (24.7%), always in combination with other strategies. Management of B-POPFs was widely heterogeneous with a median of 2 approaches/patient (range 1 to 6) and 38 various strategy combinations used. Subclasses B1-3 comprised 19.1%, 52.2%, and 28.8% of B-POPFs, respectively, and were associated with progressively worse clinical and economic outcomes. These results were confirmed by multivariable analysis adjusted for clinical and operative factors. Notably, distribution of the B-POPF subclasses was influenced by institution and type of resection (P < 0.001), while clinical/demographic predictors proved elusive. CONCLUSION: B-POPF is a heterogeneous entity, where 3 distinct subclasses with increasing clinical and economic burden can be identified. This classification framework has potential implications for accurate reporting, comparative research, and performance evaluation.

Number of Examined Lymph Nodes and Nodal Status Assessment in Distal Pancreatectomy for Body/Tail Ductal Adenocarcinoma.

OBJECTIVE: First, to assess the impact of the number of examined lymph nodes (ELNs) on staging and survival after distal pancreatectomy (DP) for pancreatic adenocarcinoma (PDAC). Second, to identify the minimum number of ELNs (MNELNs) ensuring an accurate detection of nodal involvement. Third, to reappraise the role of lymph node (LN) parameters, including N-status and lymph node ratio (LNR). BACKGROUND: In contrast with pancreatoduodenectomy, information on LN staging and the MNELN required in DP is lacking. METHODS: Patients undergoing DP for PDAC at 2 academic hospitals from 2000 through 2013 were retrospectively analyzed. The eighth edition of the American Joint Committee on Cancer staging system was used. The MNELN was estimated using the binomial probability law. Survival analyses were performed separately for node-negative and node-positive patients using univariable and multivariable models. RESULTS: The study population consisted of 240 patients. The median number of ELN was 21, significantly lower in node-negative patients as compared with node-positive patients (18.5 vs 24.0; P = 0.001). The proportion of node-positive patients increased with increasing numbers of ELNs, whereas LNR showed an inverse trend. The estimated MNELN was 20. The number of ELN (≥ or <20) was an independent prognostic factor only in node-negative patients [odds ratio (OR) 3.23 for ELN <20), suggesting a stage migration effect. In node-positive patients, N2-class, but not LNR, was a significant predictor of survival at multivariable analysis (OR 1.68). CONCLUSION: The number of ELN affects nodal staging in body/tail PDAC. At least 20 LNs are required for correct staging. N-status is superior to LNR in predicting survival of node-positive patients.

Chyle leak after pancreatic surgery: validation of the International Study Group of Pancreatic Surgery classification.

BACKGROUND: Chyle leak is an uncommon complication after pancreatic surgery. The chyle leak incidence, definition, diagnosis, and treatment had been reported heterogeneously so far. Recently a consensus definition and grading system was published by the International Study Group for Pancreatic Surgery. This study aims to evaluate the differences in the clinical and economic burden of chyle leak applying the new definition. METHODS: All data from patients who underwent pancreatic surgery for any disease from January 2014 to December 2016 were retrieved from the institutional prospective database. The 2017 International Study Group for Pancreatic Surgery definition and classification were applied. The classification was validated analyzing the differences in major complications, length of stay, and hospitalization costs. RESULTS: A total of 945 patients was the final population. A chyle leak was reported in 43 patients (4.5%). Grade A chyle leak occurred in 10 patients (23.3%), Grade B chyle leak in 31 patients (72.1%), and Grade C chyle leak in 2 patients (4.6%). Chyle leak occurred as unique postoperative complication in 29 cases (67.4%). The economic analysis showed that the average costs of the 3 grades were 2,806, 7,150 and 15,684 euros respectively (P < .001). Furthermore, the length of stay, the rates of septic events, and major complications were significantly different among the 3 grades (P = .008, P = .004, and P < .001, respectively). Of note, we did not find any intraoperative factor associated with chyle leak. CONCLUSION: The present study confirms the validity of the International Study Group for Pancreatic Surgery classification of chyle leak. The 3 grades of chyle leak proposed identify reliably clinical and economical differences among the chyle leak cases.

Quantitative Assessment of Pancreatic Texture Using a Durometer: A New Tool to Predict the Risk of Developing a Postoperative Fistula.

BACKGROUND: Pancreatic texture is one of the key predictors of postoperative pancreatic fistula (POPF) after pancreatoduodenectomy (PD). Currently, the "gold standard" for assessment of pancreatic texture is surgeon's subjective evaluation through manual palpation. AIM: To evaluate a new "durometer" that is able to assess quantitatively the pancreatic stiffness by measuring its elastic module (i.e., the resistance offered by the pancreatic stump when elastically deformed expressed in mPa). METHODS: Measurements were obtained from the pancreatic remnant during 138 consecutive PDs performed at the Department of General and Pancreatic Surgery-The Pancreas Institute, University of Verona Hospital Trust. Values were correlated to clinical features and, in particular, with the senior surgeon's evaluation of pancreatic texture (hard/soft). Sixteen beating-heart donors were used as a control group to assess the stiffness of a non-pathologic pancreas. Univariate analysis was performed for the assessment of POPF predictors. RESULTS: Durometry allowed segregating between non-pathologic, soft and hard pancreas according to surgeon's evaluation (mean values 111 vs. 196 vs. 366 mPa, p < 0.01). There were no significant differences in stiffness with regard to histology, BMI, and neoadjuvant therapy. Larger tumors (>20 mm) and male sex were associated with greater stiffness on univariate analysis. Pancreatic texture, pancreatic duct size, BMI, prior neoadjuvant therapy, and histology were predictors of POPF. Patients who developed POPF showed a lesser stiffness (178 vs. 261 mPa, p = 0.05). CONCLUSION: Assessment of pancreatic stiffness using a durometer correlated with the surgeon's evaluation of pancreatic texture. Measurement of pancreatic parenchymal stiffness is reliable and correlates with the development of POPF.

The influence of fellowship training on the practice of pancreatoduodenectomy.

BACKGROUND: There has been a proliferation of gastrointestinal surgical fellowships; however, little is known regarding their association with surgical volume and management approaches. METHODS: Surveys were distributed to members of GI surgical societies. Responses were evaluated to define relationships between fellowship training and surgical practice with pancreatoduodenectomy (PD). RESULTS: Surveys were completed by 889 surgeons, 84.1% of whom had completed fellowship training. Fellowship completion was associated with a primarily HPB or surgical oncology-focused practice (p < 0.001), and greater median annual PD volume (p = 0.030). Transplant and HPB fellowship-trained respondents were more likely to have high-volume (≥20) annual practice (p = 0.005 and 0.029, respectively). Regarding putative fistula mitigation strategies, HPB-trained surgeons were more likely to use stents, biologic sealants, and autologous tissue patches (p = 0.007, <0.001 and 0.001, respectively). Surgical oncology trainees reported greater autologous patch use (p = 0.003). HPB fellowship-trained surgeons were less likely to routinely use intraperitoneal drainage (p = 0.036) but more likely to utilize early (POD ≤ 3) drain amylase values to guide removal (p < 0.001). Finally, HPB fellowship-trained surgeons were more likely to use the Fistula Risk Score in their practice (29 vs. 21%, p = 0.008). CONCLUSION: Fellowship training correlated with significant differences in surgeon experience, operative approach, and use of available fistula mitigation strategies for PD.

Prognostication and response assessment in liver and pancreatic tumors: The new imaging.

Diffusion-weighted imaging (DWI), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and perfusion computed tomography (CT) are technical improvements of morphologic imaging that can evaluate functional properties of hepato-bilio-pancreatic tumors during conventional MRI or CT examinations. Nevertheless, the term "functional imaging" is commonly used to describe molecular imaging techniques, as positron emission tomography (PET) CT/MRI, which still represent the most widely used methods for the evaluation of functional properties of solid neoplasms; unlike PET or single photon emission computed tomography, functional imaging techniques applied to conventional MRI/CT examinations do not require the administration of radiolabeled drugs or specific equipments. Moreover, DWI and DCE-MRI can be performed during the same session, thus providing a comprehensive "one-step" morphological and functional evaluation of hepato-bilio-pancreatic tumors. Literature data reveal that functional imaging techniques could be proposed for the evaluation of these tumors before treatment, given that they may improve staging and predict prognosis or clinical outcome. Microscopic changes within neoplastic tissues induced by treatments can be detected and quantified with functional imaging, therefore these techniques could be used also for post-treatment assessment, even at an early stage. The aim of this editorial is to describe possible applications of new functional imaging techniques apart from molecular imaging to hepatic and pancreatic tumors through a review of up-to-date literature data, with a particular emphasis on pathological correlations, prognostic stratification and post-treatment monitoring.

Assessment of a complication risk score and study of complication profile in laparoscopic distal pancreatectomy.

OBJECTIVE: This study assessed the patient-specific risk for major postoperative morbidity in a series of 100 laparoscopic distal pancreatectomies (LDP). METHODS: A previously established complication risk score (CRS), identifying body mass index (BMI), estimated blood loss (EBL), and pancreatic specimen length as determinants of postoperative morbidity were examined against the observed outcomes. In addition, multivariate analyses were performed to investigate risk factors specific to our study population. RESULTS: The postoperative morbidity rate was 49 %, major complication accounted for 12 %, and clinically relevant pancreatic fistulae (PF) were 13 %. The incidence of any complications, major complications, any PF, and clinically relevant PF did not vary appreciably when the CRS increased. The multivariate analysis indicated that male sex and an EBL ≥150 mL were independent predictors of major morbidity and clinically relevant PF. CONCLUSION: In conclusion, the previously published CRS based on pre- and intraoperative factors was not able to predict the postoperative risk in our population. This is probably because risk scores may not be able to adjust for the case-mix (heterogeneity in baseline patient characteristics). According to our data, men and patients with EBL ≥150 mL are more likely to develop major postoperative complications after LDP.

Guidelines for time-to-event end-point definitions in trials for pancreatic cancer. Results of the DATECAN initiative (Definition for the Assessment of Time-to-event End-points in CANcer trials).

BACKGROUND: Using potential surrogate end-points for overall survival (OS) such as Disease-Free- (DFS) or Progression-Free Survival (PFS) is increasingly common in randomised controlled trials (RCTs). However, end-points are too often imprecisely defined which largely contributes to a lack of homogeneity across trials, hampering comparison between them. The aim of the DATECAN (Definition for the Assessment of Time-to-event End-points in CANcer trials)-Pancreas project is to provide guidelines for standardised definition of time-to-event end-points in RCTs for pancreatic cancer. METHODS: Time-to-event end-points currently used were identified from a literature review of pancreatic RCT trials (2006-2009). Academic research groups were contacted for participation in order to select clinicians and methodologists to participate in the pilot and scoring groups (>30 experts). A consensus was built after 2 rounds of the modified Delphi formal consensus approach with the Rand scoring methodology (range: 1-9). RESULTS: For pancreatic cancer, 14 time to event end-points and 25 distinct event types applied to two settings (detectable disease and/or no detectable disease) were considered relevant and included in the questionnaire sent to 52 selected experts. Thirty experts answered both scoring rounds. A total of 204 events distributed over the 14 end-points were scored. After the first round, consensus was reached for 25 items; after the second consensus was reached for 156 items; and after the face-to-face meeting for 203 items. CONCLUSION: The formal consensus approach reached the elaboration of guidelines for standardised definitions of time-to-event end-points allowing cross-comparison of RCTs in pancreatic cancer.

A grading system can predict clinical and economic outcomes of pancreatic fistula after pancreaticoduodenectomy: results in 755 consecutive patients.

AIM: Postoperative pancreatic fistula (POPF) has a wide range of clinical and economical implications due to the difference of the associated complications and management. The aim of this study is to verify the applicability of the International Study Group of Pancreatic Fistula (ISGPF) definition and its capability to predict hospital costs. METHODS: This is a retrospective study based on prospectively collected data of 755 patients who underwent pancreaticoduodenectomy in our institution between November 1996 and October 2006. A number of 147 patients (19.5%) have developed a POPF according to ISGPF definition. RESULTS: Grade A fistula, which has no clinical impact, occurred in 19% of all cases. Grade B occurred in 70.7% and was successfully managed with conservative therapy or mini-invasive procedures. Grade C (8.8%) was associated to severe clinical complications and required invasive therapy. Pulmonary complications were statistically higher in the groups B and C rather than the group A POPFs (p < 0.005; OR 8). Patients with carcinoma of the ampullary region had a higher incidence of POPF compared to ductal cancer, with a predominance of grade A (p = 0.036). Increasing fistula grades have higher hospital costs (€11,654, €25,698, and €59,492 for grades A, B, and C, respectively; p < 0.001). CONCLUSIONS: The development of a POPF does not always determine a substantial change of the postoperative management. Clinically relevant fistulas can be treated conservatively in most cases. Higher fistula severity corresponds to increased costs. The grading system proposed by the ISGPF allows a correct stratification of the complicated patients based on the real clinical and economic impact of the POPF.

Delayed gastric emptying after pylorus-preserving pancreaticoduodenectomy: validation of International Study Group of Pancreatic Surgery classification and analysis of risk factors.

OBJECTIVES: This study evaluates the incidence and clinical features and associated risk factors of delayed gastric emptying (DGE) after pancreaticoduodenectomy, employing the International Study Group of Pancreatic Surgery (ISGPS) consensus definition. METHODS: Demographic, pathological and surgical details for 260 consecutive patients who underwent pylorus-preserving pancreaticoduodenectomy at a single institution were analysed using univariate and multivariate models. RESULTS: Postoperative complications occurred in 108 (41.5%) and DGE was diagnosed in 36 (13.8%) of 260 patients. Among the 36 DGE patients, 16 had grade A, 18 grade B and two grade C DGE. Resumption of a solid diet (P < 0.001), time to passage of stool (P= 0.002) and hospital discharge (P < 0.001) occurred later in DGE patients. The need for total parenteral nutrition was significantly higher in DGE grade B/C patients (P < 0.001). In the univariate analysis, abdominal collections (P≤ 0.001), pancreatic fistula (PF) grades B and C (P < 0.001), biliary fistula (P= 0.002), pulmonary complications (P < 0.001) and sepsis (P= 0.002) were associated with DGE. Only abdominal collections (P= 0.009), PF grade B/C (P < 0.001) and sepsis (P= 0.024) were associated with clinically relevant DGE. In the multivariate analysis, PF grade B/C (P= 0.004) and biliary fistula (P= 0.039) were independent risk factors for DGE. CONCLUSIONS: The ISGPS classification and grading systems correlate well with the clinical course of DGE and are feasible for patient management. The principal risk factors for DGE seem to be pancreatic and biliary fistulas.

Early assessment of pancreatic infections and overall prognosis in severe acute pancreatitis by procalcitonin (PCT): a prospective international multicenter study.

BACKGROUND: Pancreatic infections and sepsis are major complications in severe acute pancreatitis (AP) with significant impact on management and outcome. We investigated the value of Procalcitonin (PCT) for identifying patients at risk to develop pancreatic infections in severe AP. METHODS: A total of 104 patients with predicted severe AP were enrolled in five European academic surgical centers within 96 hours of symptom onset. PCT was measured prospectively by a semi-automated immunoassay in each center, C-reactive protein (CRP) was routinely assessed. Both parameters were monitored over a maximum of 21 consecutive days and in weekly intervals thereafter. RESULTS: In contrast to CRP, PCT concentrations were significantly elevated in patients with pancreatic infections and associated multiorgan dysfunction syndrome (MODS) who all required surgery (n = 10) and in nonsurvivors (n = 8) early after onset of symptoms. PCT levels revealed only a moderate increase in patients with pancreatic infections in the absence of MODS (n = 7), all of whom were managed nonoperatively without mortality. A PCT value of > or =3.5 ng/mL on 2 consecutive days was superior to CRP > or =430 mg/L for the assessment of infected necrosis with MODS or nonsurvival as determined by ROC analysis with a sensitivity and specificity of 93% and 88% for PCT and 40% and 100% for CRP, respectively (P < 0.01). The single or combined prediction of the two major complications was already possible on the third and fourth day after onset of symptoms with a sensitivity and specificity of 79% and 93% for PCT > or =3.8 ng/mL compared with 36% and 97% for CRP > or =430 mg/L, respectively (P = 0.002). CONCLUSION: Monitoring of PCT allows early and reliable assessment of clinically relevant pancreatic infections and overall prognosis in AP. This single test parameter significantly contributes to an improved stratification of patients at risk to develop major complications.

What preoperative assessment is necessary for insulinomas? Calculating the degree of waste: analysis of 29 cases.

In patients affected with insulinomas the preoperative work-up is debated. The success rate of various localisation procedures seems considerably inferior in respect to intraoperative results. Aim of the study is to evaluate our personal experience with this dichotomy. Twenty nine patients with definitive diagnoses of primary hyperinsulinemia from 1985 until June of 2001 were selected. Sensitivity, diagnostic accuracy, positive predictive value and cost of ultrasound (US) (29 pts.), computerised tomography (CT) (29 pts.), magnetic resonance imaging (MRI) (16 pts.), selective angiography (18 pts) and intraoperative ultrasound (IOUS) (18 pts.) in the localisation of neoplasm were evaluated. The presence of neoplasm was verified at operation or at autopsy in 27 cases (93%). The sensitivity of US, CT, MRI and selective angiography was 52%, 44%, 57% and 82%, respectively, with a cost of non-diagnostic studies equal to 422 [symbol: see text]/patient with a comprehensive waste equal to 43.7% of resources utilised. The sensitivity of IOUS and visualisation or physical exam by the surgeon was 100%, 46% and 96%, respectively. In 2 cases where there was a recurrence of symptoms after surgery, the histological exam of the operative specimen did not have evidence of insulinoma tissue. Surgery with the help of IOUS, preceded by only one pre-op diagnostic imaging technique represents the best approach for establishing the diagnosis of and treating insulinomas.