Evaluation of Indocyanine Green Fluorescence Imaging for Intraoperative Identification of Liver Malignancy.

INTRODUCTION: There is early evidence that indocyanine green (ICG) fluorescence imaging has the ability to detect metastatic and primary malignancies in the liver that are too small to be identified by other methods. However, the rate of false positives and false negatives remains unknown. MATERIALS AND METHODS: This is a single institution prospective single-arm study. Patients with suspected hepatic or pancreatic malignancies were intravenously injected with ICG one to three days prior to their scheduled surgical therapy. At the beginning of the procedure, the liver was assessed with fluorescence imaging and all identified lesions were biopsied and evaluated. RESULTS: Twenty-three patients were enrolled from April 2015 through February 2016. Fifteen patients with confirmed malignancy had adequate fluorescence imaging evaluation of the liver; 10 with pancreatic primary malignancies and five with hepatic primaries. Fluorescence imaging was the only modality that identified nine concerning hepatic lesions, all of which were benign on pathology examination. Out of 11 malignant hepatic masses, six were visible on fluorescence imaging. Out of nine benign hepatic lesions, five were visible. No side effects or complications of the fluorescence imaging were encountered. The sensitivity for ICG fluorescence was 45.5%, the specificity 21.2%, the positive predictive value 25%, and the negative predictive value 40%. CONCLUSION: Intraoperative hepatic assessment with ICG fluorescence imaging to identify malignancy in the liver is feasible and safe. However, in this study the significant number of false positives limit the utility of the technique. Our preliminary data do not support its routine use for detection of malignancies in the liver.

Preoperative imaging characteristics predict poor survival and inadequate resection for left-sided pancreatic adenocarcinoma: a multi-institutional analysis.

BACKGROUND: Optimal treatment of pancreatic ductal adenocarcinoma of the neck, body and tail (PDAC-NBT) necessitates R0 surgical resection. Preoperative radiographic identification of patients likely to achieve successful oncologic resection remains difficult. This study seeks to identify preoperative imaging characteristics predictive of non-R0 resections or impaired survival for PDAC-NBT. METHODS: Patients at five high-volume centers who underwent resection for PDAC-NBT were retrospectively analyzed. The most immediate preoperative cross-sectional scan was assessed along with outcome measures of overall survival and margin status. RESULTS: 330 patients were treated between 2001 and 2016. Margin status included 247 R0 (78.2%), 67 R1 (21.2%), and 2 R2 (0.6%). A non-R0 resection predicted worse survival (p = 0.0002). On preoperative imaging, patients with tumors greater than 20 mm, tumor attenuation greater than 70 Hounsfield units, or who demonstrated pancreatic atrophy and/or calcifications also had worse survival (p = 0.010, p = 0.036, p = 0.025 respectively). Patients with tumors interfacing with the splenic artery or vein or extending posteriorly achieved fewer R0 resections (p = 0.0006, p = 0.0004, p = 0.001, respectively). CONCLUSION: Preoperative cross-sectional imaging can identify tumor characteristics associated with poor survival and non-R0 resection. Further investigation is needed to identify the appropriate surgical and treatment modifications necessary to clinically benefit this subset of patients.

Experiences of pressure to conform in postgraduate medical education.

BACKGROUND: Perception of pressure to conform prevents learners from actively participating in educational encounters. We expected that residents would report experiencing different amounts of pressure to conform in a variety of educational settings. METHODS: A total of 166 residents completed questionnaires about the frequency of conformity pressure they experience across 14 teaching and clinical settings. We examined many individual characteristics such as their age, sex, international student status, level of education, and tolerance of ambiguity; and situational characteristics such as residency program, type of learning session, status of group members, and type of rotation to determine when conformity pressure is most likely to occur. RESULTS: The majority of participants (89.8%) reported pressure to conform at least sometimes in at least one educational or clinical setting. Residents reported higher rates of conformity during informal, rather than formal, teaching sessions, p < .001. Also, pressure was greater when residents interacted with higher status group members, but not with the same or lower level status members, p < .001. Effect sizes were in the moderate range. CONCLUSIONS: The findings suggest that most residents do report feeling pressure to conform in their residency settings. This result is consistent with observations of medical students, nursing students, and clerks conforming in response to inaccurate information within experimental studies. Perception of pressure is associated with the setting rather than the trainee personal characteristics.

Regional Metastatic Behavior of Nonfunctional Pancreatic Neuroendocrine Tumors: Impact of Lymph Node Positivity on Survival.

OBJECTIVES: Literature addressing the significance of lymph node positivity in the management of nonfunctional pancreatic neuroendocrine tumors (PNETs) is conflicting. METHODS: The National Cancer Data Base was queried for patients who underwent surgical resection of nonfunctional PNETs between 1998 and 2011. Clinical data and overall survival were analyzed using χ and Cox proportional hazards regression. Multiple imputation was used as a comparative analysis because of the high number of patients missing data on tumor grade. RESULTS: Two thousand seven hundred thirty-five patients were identified. The overall incidence of lymph node metastasis was 51%. In the subset of patients with grade 1 tumors less than 1 cm, 24% had positive lymph nodes. Overall median survival for patients with negative lymph nodes was 11 years compared with 8 years for lymph node-positive patients (P < 0.001). On multivariate survival analysis, tumor grade, distant metastases, regional lymph node involvement, positive surgical margins, male sex, and older age were predictive of decreased overall survival. CONCLUSIONS: Lymph node positivity was associated with decreased overall survival. The incidence of lymph node involvement in resected low-grade tumors less than 1 cm is higher than previously reported. Patients selected for resection of PNETs should be offered lymphadenectomy for staging.

Novel Simulation Device for Targeting Tumors in Laparoscopic Ablation: A Learning Curve Study.

INTRODUCTION: A novel 3-dimensional (3D) guidance system was developed to aid accurate needle placement during ablation. METHODS: Five novices and 5 experienced hepatobiliary surgeons were recruited. Using an agar block with analog tumor, participants targeted under 4 conditions: in-line with the ultrasound plane using ultrasound, in-line using 3D guidance, 45° off-axis using ultrasound, and off-axis using 3D guidance. Time to target the tumor, number of withdrawals, and the National Aeronautics and Space Administration Task Load Index were collected. Initial and final parameters for each of the conditions were compared using a within-subjects paired t test. RESULTS: A significant reduction was seen in the number of required withdrawals in all situations when using the 3D guidance (0.75 vs 3.65 in-line and 0.25 vs 3.6 for off-axis). Mental workload was significantly lower when using 3D guidance compared with ultrasound both for novices (29.85 vs 41.03) and experts (31.98 vs 44.57), P < .001 for both. The only difference in targeting time between first and last attempt was in the novice group during off-axis targeting using 3D guidance (115 vs 32.6 seconds, P = .03). CONCLUSION: Though 3D guidance appeared to decrease time to target, this was not statistically significant likely as a result of lack of power in our trial. Three-dimensional guidance did reduce the number of required withdrawals, potentially decreasing complications, as well as mental workload after proficiency was achieved. Furthermore, novices without experience in ultrasound were able to learn targeting with the 3D guidance system at a faster pace than targeting with ultrasound alone.

Analysis of 340 Patients with Solid Pseudopapillary Tumors of the Pancreas: A Closer Look at Patients with Metastatic Disease.

INTRODUCTION: Current literature addressing the treatment of solid pseudopapillary neoplasms (SPNs) of the pancreas is limited, particularly for patients with distant metastases. We aimed to define predictive indicators of survival in a large series of patients and assess the outcome of patients with distant metastases. METHODS: The National Cancer Database was queried for patients diagnosed with SPNs of the pancreas between 1998 and 2011. Single predictor univariate analyses were performed on variables including demographics, tumor characteristics, and surgery outcomes, and multivariate Cox proportional hazards survival analysis was then completed with backward elimination. RESULTS: Overall, 340 patients were identified: 82% were female, median age was 39 years, and 84% had no comorbidities. Patients undergoing any type of surgical resection experienced long-term survival (85% 8-year survival). Patients undergoing surgical resection (n = 296) had superior survival (hazard ratio [HR] 21 for no surgery, p < 0.0001), as did patients treated at academic centers and those with private insurance (HR 3.9, p = 0.009; HR 4.9, p = 0.007). Sex, age, tumor size, presence of lymph node metastases, positive surgical margins, and presence of distant metastases were not significant predictors of survival in multivariate analysis. Of 24 patients with distant metastases, seven were treated surgically and experienced long-term survival similar to that of patients without metastases treated surgically (HR 2, p = 0.48). CONCLUSION: SPNs of the pancreas are rare neoplasms with excellent overall survival; however, in a low number of patients they metastasize. Of the few patients with metastatic disease selected for resection, most experienced long-term survival.

Validation of Fistula Risk Score calculator in diverse North American HPB practices.

BACKGROUND: Fistula Risk Score (FRS) is a previously developed tool to assess the risk of clinically relevant postoperative pancreatic fistula (CR-POPF) following pancreatoduodenectomy (PD). METHODS: Prospectively collected databases from 4 university affiliated and non-affiliated HPB centers in United States and Canada were used. The influence of individual baseline characteristics, FRS and FRS group on CR-POPF was assessed in univariate and multivariate analyses. FRS calculator performance was assessed using a C-statistic. RESULTS: 444 patients were identified. Pathology, soft pancreas texture and pancreatic duct size were associated with CR-POPF rates (p < 0.001 for each); EBL was not (p = 0.067). The negligible risk group consisted of 50 (11.3%) patients, low risk of 118 (26.6%), moderate 234 (52.7%) and high risk group of 42 (9.5%) patients. The overall rate of CR-POPF was 20%. Of the patients in the negligible risk group, 2% developed CR-POPF, 13.6% of the low risk, 23.1% moderate and 42.9% in the high risk group (p < 0.001). Overall C-statistic was 0.719. CONCLUSION: FRS is robust and able to stratify the risk of developing CR-POPF following PD in diverse North American academic and non-academic institutions. The FRS should be used in research and to guide clinical management of patients post PD in these institutions.

Effect of N-acetylcysteine on liver recovery after resection: A randomized clinical trial.

BACKGROUND AND OBJECTIVES: Liver failure following hepatic resection is a multifactorial complication. In experimental studies, infusion of N-acetylcysteine (NAC) can minimize hepatic parenchymal injury. METHODS: Patients undergoing liver resection were randomized to postoperative care with or without NAC. No blinding was performed. Overall complication rate was the primary outcome; liver failure, length of stay, and mortality were secondary outcomes. Due to safety concerns, a premature multivariate analysis was performed and included within the model randomization to NAC, preoperative ASA, extent of resection, and intraoperative vascular occlusion as factors. RESULTS: Two hundred and six patients were randomized (110 to conventional therapy; 96 to NAC). No significant differences were noted in overall complications (32.7% and 45.7%, P = 0.06) or hepatic failure (3.6% and 5.4%, P = 0.537) between treatment groups. There was significantly more delirium within the NAC group (2.7% and 9.8%, P < 0.05) that caused early trial termination. In multivariate analysis, only randomization to NAC (OR = 2.21, 95%CI = 1.16-4.19) and extensive resections (OR = 2.28, 95%CI = 1.22-4.29) were predictive of postoperative complications. CONCLUSIONS: Patients randomized to postoperative NAC received no benefit. There was a trend toward a higher rate of overall complications and a significantly higher rate of delirium in the NAC group. J. Surg. Oncol. 2016;114:446-450. © 2016 Wiley Periodicals, Inc.

Preoperative computed tomography scan to predict pancreatic fistula after distal pancreatectomy using gland and tumor characteristics.

BACKGROUND: Preoperative risk stratification for postoperative pancreatic fistula in patients undergoing distal pancreatectomy is needed. METHODS: Risk factors for postoperative pancreatic fistula in 220 consecutive patients undergoing distal pancreatectomy at 2 major institutions were recorded retrospectively. Gland density was measured on noncontrast computed tomography scans (n = 101), and histologic scoring of fat infiltration and fibrosis was performed by a pathologist (n = 120). RESULTS: Forty-two patients (21%) developed a clinically significant pancreatic fistula within 90 days of surgery. Fat infiltration was significantly associated with gland density (P = .0013), but density did not predict pancreatic fistula (P = .5). Recursive partitioning resulted in a decision tree that predicted fistula in this cohort with a misclassification rate less than 15% using gland fibrosis (histology), density (HU), margin thickness (cm), and pathologic diagnosis. CONCLUSIONS: This multicenter study shows that no single perioperative factor reliably predicts postoperative pancreatic fistula after distal pancreatectomy. A decision tree was constructed for risk stratification.

In search of the best reconstructive technique after pancreaticoduodenectomy: pancreaticojejunostomy versus pancreaticogastrostomy.

BACKGROUND: It has been suggested that pancreaticogastrostomy (PG) is a safer reconstruction than pancreaticojejunostomy (PJ), resulting in lower morbidity, including lower pancreatic leak rates and decreased postoperative mortality. We compared PJ and PG after pancreaticoduodenectomy (PD). METHODS: A randomized clinical trial was designed. It was stopped with 50% accrual. Patients underwent either PG or PJ reconstruction. The primary outcome was the pancreatic fistula rate, and the secondary outcomes were overall morbidity and mortality. We used the Student t, Mann-Whitney U and χ(2) tests for intention to treat analysis. The effect of randomization, American Society of Anesthesiologists score, soft pancreatic texture and use of pancreatic stent on overall complications and fistula rates was calculated using logistic regression. RESULTS: Our trial included 98 patients. The rate of pancreatic fistula formation was 18% in the PJ and 25% in the PG groups (p = 0.40). Postoperative complications occurred in 48% of patients in the PJ and 58% in the PG groups (p = 0.31). There were no significant predictors of overall complications in the multivariate analysis. Only soft pancreatic gland predicted the occurrence of pancreatic fistula (odds ratio 5.89, p = 0.003). CONCLUSION: There was no difference in the rates of pancreatic leak/fistula, overall complications or mortality between patients undergoing PG and and those undergoing PJ after PD.

CONTEXTE: Selon certains, la pancréatogastrostomie (PG) est une technique de reconstruction plus sécuritaire que la pancréatojéjunostomie (PJ) et entraîne une morbidité moindre, y compris un taux moins élevé de fuites pancréatiques et une mortalité postopératoire diminuée. Nous avons comparé la PJ et la PG post-pancréatoduodénectomie. MÉTHODES: Un essai clinique randomisé a été conçu et cessé à l'atteinte d'un taux de participation de 50 %. Les patients ont subi une reconstruction par PG ou par PJ. Le paramètre principal était le taux de fistules pancréatiques et les paramètres secondaires étaient la morbidité et la mortalité globales. Nous avons utilisé les tests t de Student, U de Mann­Whitney et du χ2 carré pour l'analyse en intention de traiter. Nous avons calculé l'effet de la randomisation, du score de l'American Society of Anesthesiologists, de la consistance molle du pancréas et du recours à l'endoprothèse pancréatique sur les complications globales et les taux de fistules à l'aide d'une analyse de régression logistique. RÉSULTANTS: Notre essai a regroupé 98 patients. Le taux de fistules pancréatiques a été de 18 % dans le groupe soumis à la PJ et de 25 % dans le groupe soumis à la PG (p = 0,40). Des complications postopératoires sont survenues chez 48 % des patients du groupe soumis à la PJ et chez 58 % du groupe soumis à la PG (p = 0,31). Aucun prédicteur significatif des complications globales n'est ressorti à l'analyse multivariée. Seule la consistance molle du pancréas a permis de prédire la survenue d'une fistule pancréatique (rapport des cotes 5,89, p = 0,003). CONCLUSION: Nous n'avons noté aucune différence quant aux taux de fuites ou de fistules pancréatiques, de complications globales ou de mortalité entre les patients soumis à la PG et à la PJ post-pancréatoduodénectomie.

The role of peri-hepatic drain placement in liver surgery: a prospective analysis.

BACKGROUND: The standard use of an intra-operative perihepatic drain (IPD) in liver surgery is controversial and mainly supported by retrospective data. The aim of this study was to evaluate the role of IPD in liver surgery. METHODS: All patients included in a previous, randomized trial were analysed to determine the association between IPD placement, post-operative complications (PC) and treatment. A multivariate analysis identified predictive factors of PC. RESULTS: One hundred and ninety-nine patients were included in the final analysis of which 114 (57%) had colorectal liver metastases. IPD (n = 87, 44%) was associated with pre-operative biliary instrumentation (P = 0.023), intra-operative bleeding (P < 0.011), Pringle's manoeuver(P < 0.001) and extent of resection (P = 0.001). Seventy-seven (39%) patients had a PC, which was associated with pre-operative biliary instrumentation (P = 0.048), extent of resection (P = 0.002) and a blood transfusion (P = 0.001). Patients with IPD had a higher rate of high-grade PC (25% versus 12%, P = 0.008). Nineteen patients (9.5%) developed a post-operative collection [IPD (n = 10, 11.5%) vs. no drains (n = 9, 8%), P = 0.470]. Seven (8%) patients treated with and 9(8%) without a IPD needed a second drain after surgery, P = 1. Resection of ≥3 segments was the only independent factor associated with PC [odds ratio (OR) = 2, P = 0.025, 95% confidence interval (CI) 1.1-3.7]. DISCUSSION: In spite of preferential IPD use in patients with more complex tumours/resections, IPD did not decrease the rate of PC, collections and the need for a percutaneous post-operative drain. IPD should be reserved for exceptional circumstances in liver surgery.

Neoadjuvant therapy for downstaging of locally advanced hilar cholangiocarcinoma: a systematic review.

BACKGROUND: Hilar cholangiocarcinoma is a rare but highly lethal type of cancer. A minority of patients present with resectable disease. Surgery remains the only treatment modality offering a chance of long-term survival. Unresectable patients are typically offered palliative treatment. The aim of this systematic review was to summarize the evidence for neoadjuvant therapy followed by surgical resection in patients presenting with hilar cholangiocarcinoma. METHODS: Cochrane databases, Medline, PubMed and EMBASE were systematically searched to identify articles describing neoadjuvant therapy and surgical resection or re-assessment of resectability in patients with hilar cholangiocarcinoma. Included were all articles with original research. Study selection and data extraction were performed separately by two reviewers using a standardized protocol. RESULTS: From 732 articles 8 full text articles and 2 abstracts met the inclusion criteria. The 2 abstracts and 1 full text article were case reports, 3 articles were retrospective and 4 were prospective studies (2 phase I and 2 phase II studies). Photodynamic therapy, chemotherapy and radiation therapy were used in various indications in populations that included patients with hilar cholangiocarcinoma, some of which were primarily unresectable. Overall quality of articles was limited. CONCLUSION: Current evidence suggests that neoadjuvant therapy in patients with unresectable hilar cholangiocarcinoma can be performed safely and in a selected group of patients can lead to subsequent surgical R0 resection. Surgical resection of downstaged patients should be assessed in properly designed phase II studies.

Negative-pressure wound therapy for critically ill adults with open abdominal wounds: a systematic review.

BACKGROUND: Open abdominal management with negative-pressure wound therapy (NPWT) is increasingly used for critically ill trauma and surgery patients. We sought to determine the comparative efficacy and safety of NPWT versus alternate temporary abdominal closure (TAC) techniques in critically ill adults with open abdominal wounds. METHODS: We conducted a systematic review of published and unpublished comparative studies. We searched MEDLINE, PubMed, EMBASE, Scopus, Web of Science, the Cochrane Database, the Center for Reviews and Dissemination, clinical trials registries, and bibliographies of included articles. Two authors independently abstracted data on study design, methodological quality, patient characteristics, and outcomes. RESULTS: Among 2,715 citations identified, 2 randomized controlled trials and 9 cohort studies (3 prospective/6 retrospective) met inclusion criteria. Methodological quality of included prospective studies was moderate. One randomized controlled trial observed an improved fascial closure rate (relative risk [RR], 2.4; 95% confidence interval [CI], 1.0-5.3) and length of hospital stay after addition of retention sutured sequential fascial closure to the Kinetic Concepts Inc. (KCI) vacuum-assisted closure (VAC). Another reported a trend toward enhanced fascial closure using the KCI VAC versus Barker's vacuum pack (RR, 2.6; 95% CI, 0.95-7.1). A prospective cohort study observed improved mortality (RR, 0.48; 95% CI, 0.25-0.92) and fascial closure (RR, 1.5; 95% CI, 1.1-2.0) for patients who received the ABThera versus Barker's vacuum pack. Another noted a reduced arterial lactate, intra-abdominal pressure, and hospital stay for those fitted with the KCI VAC versus Bogotá bag. Most included retrospective studies exhibited low methodological quality and reported no mortality or fascial closure benefit for NPWT. CONCLUSION: Limited prospective comparative data suggests that NPWT versus alternate TAC techniques may be linked with improved outcomes. However, the clinical heterogeneity and quality of available studies preclude definitive conclusions regarding the preferential use of NPWT over alternate TAC techniques. LEVEL OF EVIDENCE: Systematic review, level III.

Predicting in-hospital mortality in patients undergoing complex gastrointestinal surgery: determining the optimal risk adjustment method.

OBJECTIVE: To compare the performance of Charlson/Deyo, Elixhauser, Disease Staging, and All Patient Refined Diagnosis-Related Groups (APR-DRGs) algorithms for predicting in-hospital mortality after 3 types of major abdominal surgeries: gastric, hepatic, and pancreatic resections. DESIGN: Cross-sectional nationwide sample. SETTING: Nationwide Inpatient Sample from 2002 to 2007. PATIENTS: Adult patients (≥18 years) hospitalized with a primary or secondary procedure of gastric, hepatic, or pancreatic resection between 2002 and 2007. MAIN OUTCOME MEASURES: Predicting in-hospital mortality using the 4 comorbidity algorithms. Logistic regression analyses were used and C statistics were calculated to assess the performance of the indexes. Risk adjustment methods were then compared. RESULTS: In our study, we identified 46,395 gastric resections, 18,234 hepatic resections, and 15,443 pancreatic resections. Predicted in-hospital mortality rates according to the adjustment methods agreed for 43.8% to 74.6% of patients. In all types of resections, the APR-DRGs and Disease Staging algorithms predicted in-hospital mortality better than the Charlson/Deyo and Elixhauser indexes (P < .001). Compared with the Charlson/Deyo algorithm, the Elixhauser index was of higher accuracy in gastric resections (0.847 vs 0.792), hepatic resections (0.810 vs 0.757), and pancreatic resections (0.811 vs 0.741) (P < .001 for all comparisons). Higher accuracy of the Elixhauser algorithm compared with the Charlson/Deyo algorithm was not affected by diagnosis rank, multiple surgeries, or exclusion of transplant patients. CONCLUSIONS: Different comorbidity algorithms were validated in the surgical setting. The Disease Staging and APR-DRGs algorithms were highly accurate. For commonly used algorithms such as Charlson/Deyo and Elixhauser, the latter showed higher accuracy.