Tumor Size Combined With CA-19 Level Improves Prediction of Survival of Patients With Pancreatic Adenocarcinoma Undergoing Perioperative Chemotherapy and Resection

BACKGROUND AND OBJECTIVE

Five-year survival in pancreatic adenocarcinoma is less than 20%. While previous studies have postulated that a carbohydrate antigen 19-9 (CA19-9) threshold could predict outcome of resection, the role for CA19-9 in decision-making remains unclear. This study aims to assess whether CA19-9 levels combined with tumor size improve prediction of post-resection survival.

METHOD

A retrospective analysis was conducted on 109 patients with pancreatic adenocarcinoma who underwent perioperative chemotherapy followed by resection. The primary outcome of mortality was, divided into short (<1 year) or prolonged (>2 years). Univariate and multivariable analyses compared the tumor size-adjusted CA19-9 between the outcome groups.

RESULTS

Twenty-seven (24.78%) and eighty-two (75.23%) patients were in the short survival and prolonged-survival groups, respectively. The mean CA19-9 was significantly greater in the short vs prolonged group (P < .001). Analyzing CA19-9 level by tumor size, the association of high CA19-9 and short survival was significant for small (≤2 cm) and large tumor (>4 cm), but not for intermediate-size tumors (2-4 cm). Adjusting for preoperative variable did not change this association.

CONCLUSION

CA 19-9 in combination with tumor size better identifies patients with prolonged post-resection survival. This prediction is most accurate in patients with either small (≤2 cms) or large (>4 cms) tumors compared to intermediate-size tumors.

Intramucosal Extent as a Marker for Advanced Disease and Survival in Gallbladder Adenocarcinoma

BACKGROUND

Gallbladder cancer (GBC) is the most common biliary tract malignancy and has a poor prognosis. The clinical significance of focal vs diffuse GBC remains unclear.

METHODS

A retrospective review was conducted on all patients with non-metastatic GBC at a quaternary care center. Pathology was reviewed, and gallbladder cancer pattern was defined based on the extent of mucosal involvement; "diffuse" if the tumor was multicentric or "focal" if the tumor was only in a single location. Patients undergoing liver resection and portal lymphadenectomy were considered to have definitive surgery. The primary outcome was overall survival and assessed by Kaplan-Meier curves.

RESULTS

63 patients met study criteria with 32 (50.7%) having diffuse cancer. No difference was observed in utilization of definitive surgery between the groups (14 [43.8%] with focal and 12 [38.7%] with diffuse, P = .88). Lymphovascular invasion (P = .04) and higher nodal stage (P = .04) were more common with diffuse GBC. Median overall survival was significantly improved in those with focal cancer (5.1 vs 1.2 years, P = .02). Although not statistically significant, this difference in overall survival persisted in patients who underwent definitive surgery (4.3 vs 2.4 years, P = .70).

DISCUSSION

Patients with diffuse involvement of the gallbladder mucosa likely represent a subset with aggressive biology and worse overall survival compared to focal disease. These findings may aid surgeons in subsequent surgical and medical decision-making for patients with GBC.

Natural history and growth prediction model of pancreatic serous cystic neoplasms

OBJECTIVE

Serous cystic neoplasms (SCN) are benign pancreatic cystic neoplasms that may require resection based on local complications and rate of growth. We aimed to develop a predictive model for the growth curve of SCNs to aid in the clinical decision making of determining need for surgical resection.

METHODS

Utilizing a prospectively maintained pancreatic cyst database from a single institution, patients with SCNs were identified. Diagnosis confirmation included imaging, cyst aspiration, pathology, or expert opinion. Cyst size diameter was measured by radiology or surgery. Patients with interval imaging ≥3 months from diagnosis were included. Flexible restricted cubic splines were utilized for modeling of non-linearities in time and previous measurements. Model fitting and analysis were performed using R (V3.50, Vienna, Austria) with the rms package.

RESULTS

Among 203 eligible patients from 1998 to 2021, the mean initial cyst size was 31 mm (range 5-160 mm), with a mean follow-up of 72 months (range 3-266 months). The model effectively captured the non-linear relationship between cyst size and time, with both time and previous cyst size (not initial cyst size) significantly predicting current cyst growth (p < 0.01). The root mean square error for overall prediction was 10.74. Validation through bootstrapping demonstrated consistent performance, particularly for shorter follow-up intervals.

CONCLUSION

SCNs typically have a similar growth rate regardless of initial size. An accurate predictive model can be used to identify rapidly growing outliers that may warrant surgical intervention, and this free model (https://riskcalc.org/SerousCystadenomaSize/) can be incorporated in the electronic medical record.

Comparing oncologic and surgical outcomes of robotic and laparoscopic pancreatoduodenectomy in patients with pancreatic cancer: a propensity-matched analysis

INTRODUCTION

Minimally invasive Pancreatoduodenectomy (MIPD), or the Whipple procedure, is increasingly utilized. No study has compared laparoscopic (LPD) and robotic (RPD) approaches, and the impact of the learning curve on oncologic, technical, and post-operative outcomes remains relatively understudied.

METHODS

The National Cancer Database was queried for patients undergoing LPD or RPD from 2010 to 2020 with a diagnosis of pancreatic cancer. Outcomes were compared between approaches using propensity-score matching (PSM); the impact of annual center-level volume of MIPD was also assessed by dividing volume into quartiles.

RESULTS

A total of 3,342 patients were included. Most (n = 2,716, 81.3%) underwent LPD versus RPD (n = 626, 18.7%). There was a high rate (20.2%, n = 719) of positive margins. Mean length-of-stay (LOS) was 10.4 ± 8.9 days. Thirty-day mortality was 2.8% (n = 92) and ninety-day mortality was 5.7% (n = 189). PSM matched 625 pairs of patients receiving LPD or RPD. After PSM, there was no differences between groups based on age, sex, race, CCI, T-stage, neoadjuvant chemo/radiotherapy, or type of PD. After PSM, there was a higher rate of conversion to open (HR = 0.68, 95%CI = 0.50-0.92)., but there was no difference in LOS (HR = 1.00, 95%CI = 0.92-1.11), 30-day readmission (HR = 1.08, 95% CI = 0.68-1.71), 30-day (HR = 0.78, 95% CI = 0.39-1.56) or 90-day mortality (HR = 0.70, 95% CI = 0.42-1.16), ability to receive adjuvant therapy (HR = 1.15, 95% CI = 0.92-1.44), nodal harvest (HR = 1.01, 95%CI = 0.94-1.09) or positive margins (HR = 1.19, 95% CI = 0.89-1.59). Centers in lower quartiles of annual volume of MIPD demonstrated reduced nodal harvest (p = 0.005) and a higher rate of conversion to open (p = 0.038). Higher-volume centers had a shorter LOS (p = 0.012), higher rate of initiation of adjuvant therapy (p = 0.042), and, most strikingly, a reduction in 90-day mortality (p = 0.033).

CONCLUSION

LPD and RPD have similar surgical and oncologic outcomes, with a lower rate of conversion to open in the robotic cohort. The robotic technique does not appear to eliminate the "learning curve", with higher volume centers demonstrating improved outcomes, especially seen at minimum annual volume of 5 cases.

Impact of autotransfusion on recurrence of colorectal cancer liver metastasis: Long-term follow-up of patients undergoing curative intent hepatectomy

INTRODUCTION

Colorectal cancer liver metastasis (CRLM) occurs in upto 50% of cases and drives patient outcomes. Up-front liver resection is the treatment of choice in resectable cases. There is no consensus yet established as to the safety of intraoperative autotransfusion in liver resection for CRLM.

METHODS

Patients undergoing curative-intent hepatectomy for CRLM at a single quaternary-care institution from 1999 to 2016 were included. Demographics, surgical variables, Fong Clinical Risk Score (FCRS), use of intraoperative auto and/or allotransfusion, and survival data were analyzed. Propensity score matching (PSM) was performed accounting for allotransfusion, extent of hepatectomy, FCRS, and systemic treatment regimens.

RESULTS

Three-hundred sixteen patients were included. The median follow-up was 10.4 years (7.8-14.1 years). The median recurrence-free survival (RFS) and overall survival (OS) in all patients were 1.6 years (interquartile range: 0.63-6.6 years) and 4.4 years (2.1-8.7), respectively.  Before PSM, there was a significantly reduced RFS in the autotransfusion group (0.96 vs. 1.73 years, p = 0.20). There was no difference in OS (4.11 vs. 4.44 years, p = 0.118). Patients in groups of FCRS 0-2 and 3-5 both had reduced RFS when autotransfusion was used (p = 0.005). This reduction in RFS was further found when comparing autotransfusion versus no autotransfusion within the FCRS 0-2 group and within the FCRS 3-5 group (p = 0.027). On Cox-regression analysis, autotransfusion (hazard ratio = 1.423, 1.028-2.182, p = 0.015) remained predictive of RFS. After PSM, there were no differences in FCRS (p = 0.601), preoperative hemoglobin (p = 0.880), allotransfusion (p = 0.130), adjuvant chemotherapy (p = 1.000), immunotherapy (p = 0.172), tumor grade (p = 1.000), use of platinum-based chemotherapy (p = 0.548), or type of hepatic resection (p = 0.967). After matching, there was a higher rate of recurrence with autotransfusion (69.0% vs. 47.6%, p = 0.046). There was also a reduced time to recurrence in the autotransfusion group compared with the group without (p = 0.006). There was no difference in OS after PSM (p = 0.262).

CONCLUSION

Autotransfusion may adversely affect recurrence in liver resection for CRLM. Until further studies clarify this risk profile, the use of intraoperative autotransfusion should be critically assessed on a case-by-case basis only when other resuscitation options are not available.

ASMBS statement on metabolic and bariatric surgery for beneficiaries of Centers for Medicare and Medicaid Services with a review of the literature

This position statement is issued by the American Society for Metabolic and Bariatric. Surgery in response to inquiries made to the Society by patients, physicians, Society members, hospitals, health insurance payors, the media, and others regarding the access and outcomes of metabolic and bariatric surgery for beneficiaries of Centers for Medicare and Medicaid Services. This position statement is based on current clinical knowledge, expert opinion, and published peer-reviewed scientific evidence available at this time. The statement is not intended to be and should not be construed as stating or establishing a local, regional, or national standard of care. This statement will be revised in the future as additional evidence becomes available.

Neoadjuvant Gastric Score: How Response to Neoadjuvant Chemotherapy Affects Overall Survival and Adjuvant Benefit

INTRODUCTION

The Neoadjuvant Rectal score (NAR) was developed as a short-term surrogate for 5-year overall survival (OS) prediction in locally advanced rectal cancer on the basis of response to neoadjuvant therapy. We aim to assess whether this score can be repurposed for locally advanced gastric adenocarcinoma treated with neoadjuvant chemotherapy followed by surgical resection.

METHODS

Patients with gastric adenocarcinoma treated with neoadjuvant systemic therapy followed by surgical resection were extracted from the National Cancer Database. Neoadjuvant Gastric (NAG) scores were calculated, and patients were stratified into low-, intermediate-, and high-score categories, with low scores predicting longer survival. Patients were propensity-matched 1:1:1 between the groups for OS comparison. We also matched patients within each group 1:1 per receipt of adjuvant therapy and compared 5-year OS.

RESULTS

There were 2,970 patients identified. NAG classified patients into low- (n = 396, 13.3%), intermediate-(n = 756, 25.5%), and high (n = 1818, 61.2%) groups. After propensity matching, 5-year OS was significantly different between the matched groups (low-NAG 82%, intermediate-NAG 73%, and high-NAG 39%; p < 0.001). NAG score grouping also predicted OS benefit of adjuvant therapy; low- and intermediate-NAG patients had no OS benefit with adjuvant therapy (86% vs. 84%; p = 0.492, and 77% vs. 74%; p = 0.382, respectively), whereas patients with high-NAG score had a 5-year OS benefit with adjuvant therapy (39% vs. 29%; p = 0.024).

CONCLUSION

NAR score may be repurposed to generate a prognostic tool in gastric adenocarcinoma to predict 5-year OS and has the potential to guide decision-making regarding allocation of adjuvant therapy. Further studies should prospectively validate these findings to confirm clinical utility.

Comparing Outcomes of Minimally Invasive and Open Hepatectomy for Primary Liver Malignancies in Patients with Low-MELD Cirrhosis

INTRODUCTION

Cirrhotic patients with primary liver cancer may undergo curative-intent resection when selected appropriately. Patients with T1 tumors and low-MELD are generally referred for resection. We aim to evaluate whether minimally invasive hepatectomy (MIH) is associated with improved outcomes versus open hepatectomy (OH).

METHODS

NSQIP hepatectomy database 2014-2021 was used to select patients with T1 Hepatocellular Carcinoma (HCC) or Intra-hepatic Cholangiocarcionoma (IHCC) and low-MELD cirrhosis (MELD ≤ 10) who underwent partial hepatectomy. Propensity score matching was applied between OH and MIH patients, and 30-day postoperative outcomes were compared. Multivariable regression was used to identify predictors of post-hepatectomy liver failure (PHLF) in the selected population.

RESULTS

There were 922 patients: 494 (53.6%) OH, 372 (40.3%) MIH, and 56 (6.1%) began MIH converted to OH (analyzed with the OH cohort). We matched 354 pairs of patients with an adequate balance between the groups. MIH was associated with lower rates of bile leak (HR 0.37 [0.19-0.72)], PHLF (HR 0.36 [0.15-0.86]), collections requiring drainage (HR 0.30 [0.15-0.63]), postoperative transfusion (HR 0.36 [0.21-0.61]), major (HR 0.45 [0.27-0.77]), and overall morbidity (HR 0.44 [0.31-0.63]), and a two-day shorter median hospitalization (3 vs. 5 days; HR 0.61 [0.45-0.82]). No difference was noted in operative time, wound, respiratory, and septic complications, or mortality. Regression analysis identified ascites, prior portal vein embolization (PVE), additional hepatectomies, Pringle's maneuver, and OH (vs. MIH) as independent predictors of PHLF.

CONCLUSION

MIH for early-stage HCC/IHCC in low-MELD cirrhotic patients was associated with improved postoperative outcomes over OH. These findings suggest that MIH should be considered an acceptable approach in this population of patients.

Postoperative Day 1 Drain Amylase After Pancreatoduodenectomy: Optimal Level to Predict Pancreatic Fistula

INTRODUCTION

Drain amylase on day 1 (DA-D1) after pancreaticoduodendectomy (PD) to predict occurrence of postoperative pancreatic fistula (POPF) is controversial. In this study, we evaluate the optimal DA-D1 level to predict clinically relevant POPF (CR-POPF).

METHODS

The 2014-2020 NSQIP pancreatectomy-targeted database was queried for patients who underwent elective PD. Perioperative data was extracted to determine development of POPF and CR-POPF per International Study Group of Pancreatic Fistula guidelines. Receiver operative curve (ROC) and Youden's index were used to assess the performance and optimal cutoff for DA-D1 to predict CR-POPF. The DA-D1 value was confirmed with a multivariable logistic regression to determine hazard ratios (HR) for CR-POPF and conditional logistic regression by modified fistula risk score (mFRS) subgroups.

RESULTS

A total of 6,087 patients with complete perioperative data were included. Mean DA-D1 was 2,897 ± 8,636 U/L; median drain duration was 5 days. CR-POPF was documented in 544 (8.9%) patients. DA-D1 ROC for CR-POPF had area under the curve of 0.779 (95%CI 0.759-0.798). Youden's index for the CR-POPF ROC coordinates had 77.6% sensitivity and 66.3% specificity, corresponding to DA-D1 values ≥ 720U/L as an optimal cutoff. CR-POPF was higher for patients with DA-D1 ≥ 720U/L (HR 4.6; p = 0.001). Patients DA-D1 < 720U/L with a negligible, low, intermediate, and high mFRS had respectively 1%, 3%, 4%, and 7% rate of CR-POPF.

CONCLUSION

DA-D1 < 720U/L after elective PD is a clinically useful predictor of CR-POPF. For patients with negligible to intermediate FRS, surgeons should consider utilizing DA-D1 < 720 U/L for removal of a drain on the first postoperative day.

The role of minimally invasive surgery in resectable distal pancreatic adenocarcinoma

BACKGROUND

In distal pancreatectomy (DP) for pancreatic ductal adenocarcinoma (PDAC), we hypothesize that minimally invasive DP (MIDP) carries short-term benefits over ODP (ODP) in the absence of postoperative pancreatic fistula (POPF).

METHODS

NSQIP database was queried to select patients who underwent DP for PDAC with available report on POPF. The population was divided into No-POPF vs. POPF groups. In each group, propensity-score matching was applied to compare 30-day outcomes of ODP vs. MIDP.

RESULTS

There were 2,824 patients; 2,332 (82%) had No-POPF and 492 (21%) had POPF. In No-POPF patients, 921 pairs were matched between ODP and MIDP. MIDP patients had slightly longer operations (227 vs. 205 minutes; p < 0.001), but lower rates of surgical site complications (1% vs. 2.9%; p = 0.002), postoperative transfusion (7.1% vs. 11.0%; p = 0.003), overall morbidity (21.1% vs. 26.3%; p = 0.009), and one-day shorter median length of stay (LOS) (5 vs. 6 days; p = 0.001). In the POPF group, 172 pairs were matched. There was no difference in morbidity, mortality, reoperation, LOS, and home discharge. Similar conclusions were drawn in the intention-to-treat and per-protocol analyses.

CONCLUSION

POPF is common following DP for PDAC. In the absence of POPF, MIDP is associated with fewer postoperative morbidities and shorter LOS.

Evaluating approaches to diagnosis and management of idiopathic acute pancreatitis

INTRODUCTION

Idiopathic acute pancreatitis (IAP) is a diagnosis of exclusion; systematic work-up is challenging but essential. Recent advances suggest IAP results from micro-choledocholithiasis, and that laparoscopic cholecystectomy (LC) or endoscopic sphincterotomy (ES) may prevent recurrence.

METHODS

Patients diagnosed with IAP from 2015-21 were identified from discharge billing records. Acute pancreatitis was defined by the 2012 Atlanta classification. Complete workup was defined per Dutch and Japanese guidelines.

RESULTS

A total of 1499 patients were diagnosed with IAP; 455 screened positive for pancreatitis. Most (N = 256, 56.2%) were screened for hypertriglyceridemia, 182 (40.0%) for IgG-4, and 18 (4.0%) MRCP or EUS, leaving 434 (29.0%) patients with potentially idiopathic pancreatitis. Only 61 (14.0%) received LC and 16 (3.7%) ES. Overall, 40% (N = 172) had recurrent pancreatitis versus 46% (N = 28/61) following LC and 19% (N = 3/16) following ES. Forty-three percent had stones on pathology after LC; none developed recurrence.

CONCLUSION

Complete workup for IAP is necessary but was performed in <5% of cases. Patients who potentially had IAP and received LC were definitively treated 60% of the time. The high rate of stones on pathology further supports empiric LC in this population. A systematic approach to IAP is lacking. Interventions aimed at biliary-lithiasis to prevent recurrent IAP have merit.

American Society for Metabolic and Bariatric Surgery literature review on the effect of Roux-en-Y gastric bypass limb lengths on outcomes

This literature review is issued by the American Society for Metabolic and Bariatric Surgery regarding limb lengths in Roux-en-Y gastric bypass (RYGB) and their effect on metabolic and bariatric outcomes. Limbs in RYGB consist of the alimentary and biliopancreatic limbs and the common channel. Variation of limb lengths in primary RYGB and as a revisional option for weight recurrence after RYGB are described in this review.

Efficacy of endoscopic retrograde cholangiopancreatography in familial adenomatous polyposis patients after duodenectomy

Objectives

Familial adenomatous polyposis (FAP) patients with Spigelman stage IV polyposis should be considered for prophylactic duodenectomy. Post‐surgical pancreaticobiliary complications occur and may require management via endoscopic retrograde cholangiopancreatography (ERCP). We aimed to assess the success and adverse events of ERCP in FAP patients after pancreas‐sparing duodenectomy (PSD) and pancreaticoduodenectomy (PD).

Methods

A retrospective review of FAP patients who underwent ERCP after PSD or PD from 1992 to 2020 at a quaternary referral center was completed. The technical success of ERCP was defined as the ability to identify the anastomosis and cannulate the duct. Post‐procedural adverse events were defined by bleeding, perforation, pancreatitis, or cholangitis. Clinical outcomes included the need for surgical intervention and recurrent pancreatitis after ERCP were assessed.

Results

Of 84 FAP patients with duodenectomy, 12 patients with PSD and two patients with PD underwent 17 ERCPs for pancreatic indications and five for biliary indications. The technical success of ERCP in patients with PSD and a single neoampullary complex for pancreatic (n = 6) and biliary (n = 5) indications was 100% but for those with PD (n = 2) or PSD reconstruction with pancreatic divisum or separate anastomoses (n = 3), it was 0%. Surgical intervention was required in 50% of patients with technically failed ERCP after PSD (2/4) and PD (1/2). There were no adverse events.

Conclusions

ERCP is expected to be therapeutically successful for biliary complications following PSD. Assessment and potential therapy for pancreatitis post‐PSD are best in the setting of a single neo‐ampullary complex rather than in PD or PSD with pancreatic divisum.

A chronological review of 500 minimally invasive liver resections in a North American institution: overcoming stagnation and toward consolidation

BACKGROUND

Although interest in expanding the application of minimally invasive liver resection (MILR) is high the world over, most of the extensive experience in MILR has been reported from Far East Asia and Europe and its adoption in North America is limited. The aim of this study was to review the experience of MILR in a single North American institute over a 15-year period, highlighting both the obstacles encountered and strategies adopted to overcome the stagnation in its uptake.

METHODS

This study included 500 MILR cases between 2006 and 2020. Patient demographics, disease characteristics, surgical technique, and perioperative outcomes are summarized. The major hepatectomy rate and conversion rate were assessed according to case numbers (first 100, 101-300, and 301-500 cases) to assess chronological trends.

RESULTS

Of 500, 402 MILRs were done by pure laparoscopic (80.4%), 67 were hand assisted (13.4%), and 31 were robotic (6.2%). The majority (64%) of cases were performed for malignancy (n = 320; 100 Hepatocellular carcinoma, 153 Colorectal metastases, 27 Intrahepatic cholangiocarcinoma, and others, 40, 64%). A total of 71 cases were converted to open (14.2%). The annual case number gradually increased over the first few years; however, case numbers stayed around 30 between 2009 and 2017. In this period, despite accumulating MILR experience, open conversion rates increased despite no change in major hepatectomy rate. After this period of long-term stagnation, we introduced crucial changes in team composition and laparoscopic instrumentation. Our MILR case number and major hepatectomy rate thereafter increased significantly without increasing conversion or complication rates.

CONCLUSION

Our recovery from long-term stagnation by instituting key changes as detailed in this study could be used as a guidepost for programs that are contemplating transitioning their MILR program from minor to advanced resections. Establishing a formal MILR training model through proper mentorship/proctorship and building a dedicated MILR team would be imperative to this strategy.

Lessons learned and keys to success: Provider experiences during the implementation of virtual oncology tumor boards in the era of COVID-19

Background and Objectives

The COVID‐19 pandemic required rapid adaptation of multidisciplinary tumor board conferences to a virtual setting; however, there are little data describing the benefits and challenges of using such a platform.

Methods

An anonymous quality improvement survey was sent to participants of tumor board meetings at a large academic institution. Participants answered questions pertaining to the relative strengths and weaknesses of in‐person and virtual settings.

Results

A total of 335 responses (23.3% response rate) were recorded, and 253 met inclusion criteria. Respondents represented 25 different tumor board meetings, with colorectal, breast, and liver (18.6%, 17.0%, and 13.0%, respectively) being the most commonly attended. Virtual tumor boards were equivalent to in‐person across 9 of 10 domains queried, while a virtual format was preferred for participation in off‐site tumor boards. The lack of networking opportunities was ranked by physicians to be a significant challenge of the virtual format. Consistent leadership and organization, engaged participation of all attendees, and upgrading technology infrastructure were considered critical for success of virtual meetings.

Conclusions

The implementation of virtual tumor board meetings has been associated with numerous challenges. However, improving several key aspects can improve participant satisfaction and ensure excellent patient care.

Correlation between physical status measures and frailty score in patients undergoing pancreatic resection

BACKGROUND

This study aimed to assess the correlation between validated measures of physical status in a prehabilitation regimen with an established frailty score and analyze changes in these measures after completion of a directed prehabilitation program among patients undergoing elective pancreatic resection.

METHODS

Adult patients undergoing pancreatic resection from 2019-2021 were enrolled in a pilot prehabilitation program. Three validated measures of physical status were used: the 6-minute walk test, grip strength, and chair-stand test. The prehabilitation program comprised 7,500 steps, 30 grip strength exercises, and 100 chair-stand exercises daily. Patients' frailty score was calculated using the Modified Johns Hopkins Frailty score. Changes in physical status measures after prehabilitation and postoperative outcomes were compared.

RESULTS

Thirty-two patients with a median age of 69.0 years (interquartile range = 59.5-76.3 years) were included. Patients' median duration of participation was 21.5 days (interquartile range = 16-29 days). There was a negative correlation between increasing frailty score and baseline the 6-minute walk test (R² = 0.17) and chair-stand test (R² = 0.18). Patients' mean the 6-minute walk test decreased at the end of the prehabilitation program, while grip strength and chair-stand test were unchanged. When stratified by low or intermediate and high frailty scores, the differences in the 6-minute walk test and chair-stand test were unchanged. Hospital duration of stay, complications, and 90-day readmission rates were not different between frailty groups (P > .05).

CONCLUSION

Correlation of physical status measures with frailty score suggests only one of these measures is sufficient to estimate patients' preoperative physical status. A longer, more comprehensive prehabilitation program or an expedited operation are likely the best strategies to improve patient outcomes.

Factors that Minimize Curative Resection for Gallbladder Adenocarcinoma: an Analysis of Clinical Decision-Making and Survival

BACKGROUND

Gallbladder adenocarcinoma has a poor prognosis as it is often diagnosed incidentally, and patients have a high risk for residual and occult metastatic disease. Expert guidelines recommend definitive surgery for ≥T1b tumors; however, surgical management is inconsistent. This study evaluates the factors that affect the completion of radical resection with portal lymphadenectomy and its impact on survival.

METHODS

A retrospective review of patients who underwent surgery for gallbladder cancer from 2008 to 2017 at an academic institution was performed. Patients were analyzed based on whether they underwent definitive surgical resection. Patient factors and clinical decision-making were analyzed; overall survival was compared using Kaplan-Meier analysis.

RESULTS

Seventy-five patients with ≥T1b tumors were identified, of who 32 (42.7%) underwent definitive resection. Fifty-four (72%) patients had gallbladder cancer identified as an incidental diagnosis following laparoscopic cholecystectomy. Among patients who did not undergo definitive resection, the underlying factors were varied. Only 24 (55.8%) patients in the non-definitive resection group were seen by surgical oncology. Among patients who underwent re-operation for definitive resection, 12 (38.7%) were upstaged on final pathology. Of the 43 patients who did not undergo definitive resection, 4 (9.3%) had metastatic disease identified during attempted re-resection. Patients who underwent definitive resection had a significantly longer median overall survival compared to those who did not (4.3 v. 1.9 years, p = 0.02).

CONCLUSIONS

Patients undergoing definitive resection have a significantly improved survival, including as part of a re-operative strategy. Universal referral to a surgical specialist is a modifiable factor resulting in increased definitive resection rates.

Clinical Significance of Postoperative Antibiotic Treatment for Positive Islet Cultures After Total Pancreatectomy With Islet Autotransplantation

OBJECTIVES

Islet cultures are routinely performed in total pancreatectomy with islet autotransplantation (TPIAT), and the need for empiric antibiotic treatment based on culture results is unknown. We evaluated the effect of postoperative antibiotic treatment for positive islet cultures on clinical infection.

METHODS

Seventy-nine patients undergoing TPIAT were reviewed. Prophylactic perioperative ceftriaxone and metronidazole were administered, and transplanted islet preparations included ciprofloxacin. Postoperative antibiotics were not routinely given for positive cultures unless a clinical infection was suspected. The primary end point was 30-day infectious complications.

RESULTS

Fifty-one patients (65%) had a positive culture. Overall, 39 patients (87%) had organisms susceptible to our perioperative antibiotic regimen. There was no difference in the infectious complication rate between those with positive compared with negative cultures (16% vs 29%, P = 0.17). Patients with a positive culture had similar 30-day postoperative infectious complication rates whether receiving postoperative antibiotics (n = 7) or not (14% vs 16%, P = 0.91). Only 1 patient had a correlation of clinical and islet cultures.

CONCLUSIONS

Beyond prophylactic antibiotics, empiric antibiotic treatment for a positive culture is not warranted and provides a rationale for the abandonment of routine cultures in TPIAT.

Effect of pre-operative opioid exposure on surgical outcomes in elective laparoscopic cholecystectomy

BACKGROUND

The effects of varying levels of pre-operative opioids on post-operative outcomes following elective laparoscopic cholecystectomy is largely unknown.

METHODS

Patients who underwent elective laparoscopic cholecystectomy from 2012 to 2019 were reviewed and categorized by the number of outpatient opioid prescriptions received in the 90 days preceding surgery: none (Naïve), one (1 Rx), two (2 Rx), or three or more (Chronic). Operative time, hospital length of stay, and 30-day readmission rate were analyzed.

RESULTS

Of the 11911 patients identified, 2958 (24.8%) used opioids pre-operatively. Among patients with an overnight admission, the Naïve, 1 Rx, and 2 Rx cohorts had a shorter length of stay compared to the Chronic cohort. The Naïve group had the lowest 30-day readmission rate (5.0%) followed by the 1 Rx (5.9%), 2 Rx and Chronic groups (9.1% and 8.7%, respectively) (p < 0.001).

CONCLUSIONS

Prevalence of pre-operative opioid use is high and warrants surgeon assessment to minimize adverse post-operative outcomes.

Management of early hepatocellular carcinoma: results of the Delphi consensus process of the Americas Hepato-Pancreato-Biliary Association

BACKGROUND

There are many potential treatment options for patients with early stage hepatocellular carcinoma (HCC) and practice patterns vary widely. This project aimed to use a Delphi conference to generate consensus regarding the management of small resectable HCC.

METHODS

A base case was established with review by members of AHPBA Research Committee. The Delphi panel of experts reviewed the literature and scored clinical case statements to identify areas of agreement and disagreement. Following initial scoring, discussion was undertaken, questions were amended, and scoring was repeated. This cycle was repeated until no further likelihood of reaching consensus existed.

RESULTS

The panel achieved agreement or disagreement consensus regarding 27 statements. The overarching themes included that resection, ablation, transplantation, or any locoregional therapy as a bridge to transplant were all appropriate modalities for early or recurrent HCC. For larger lesions, consensus was reached that radiofrequency ablation and microwave ablation were not appropriate treatments.

CONCLUSION

Using a validated system for identifying consensus, an expert panel agreed that multiple treatment modalities are appropriate for early stage HCC. These consensus guidelines are intended to help guide physicians through treatment modalities for early HCC; however, clinical decisions should continue to be made on a patient-specific basis.

Long-Term Outcomes of Pancreas-Sparing Duodenectomy for Duodenal Polyposis in Familial Adenomatous Polyposis Syndrome

BACKGROUND

Pancreas-sparing duodenectomy (PSD) offers definitive therapy for duodenal polyposis associated with familial adenomatous polyposis (FAP). We reviewed the long-term complications of PSD and evaluated the incidence of high-grade dysplasia (HGD) and cancer in the remaining upper gastrointestinal tract.

METHODS

Forty-seven FAP patients with duodenal polyposis undergoing PSD from 1992 to 2019 were reviewed. Long-term was defined as > 30 days from PSD.

RESULTS

All patients were treated with an open technique, and 43 (91.5%) had Spigelman stage III or IV duodenal polyposis. Median follow-up was 107 months (IQR, 26-147). There was no 90-day mortality. Seven patients died at a median of 10.5 years (IQR, 5.4-13.3) after PSD, with one attributed to gastric cancer. Pancreatitis occurred in 10 patients (21.3%), and two required surgical intervention. Seven patients (14.9%) developed an incisional hernia, and all underwent definitive repair. Forty-one patients (87.2%) had postoperative surveillance endoscopy over a median follow-up of 111 months (IQR, 42-138). Three patients (6.4%) developed adenocarcinoma (two gastric, one jejunal), and four (8.5%) had adenomas with HGD (two gastric, two jejunal) with a median of 15 years (IQR, 9-16) from PSD. One patient with gastric adenocarcinoma and all patients with HGD or adenocarcinoma of the jejunum required surgical intervention.

CONCLUSION

PSD can be performed with a low but definable risk of long-term morbidity. Risk of gastric and jejunal carcinoma rarely occurs and was diagnosed decades after PSD. This demonstrates the need for lifelong endoscopic surveillance and educates us on the risk of carcinoma in the remaining gastrointestinal tract.

Case report: multiple gastrointestinal stroma tumors in the background of neurofibromatosis type 1

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal malignancies of the gastrointestinal tract. GISTs can occur in the background of neurofibromatosis 1 (NF-1), where chemotherapeutic treatment is not optimal and surgical intervention is the only management option. In this case report, we present a case involving a 61-year-old gentleman with NF-1. The patient presented with acute blood loss anemia that was initially controlled with embolization of a hyper-vascular mass abutting the distal jejunum. The patient was taken to the operating room for excision of the mass. All macroscopic disease was excised and the pathology noted GISTs. Surgical decision making is not clearly delineated in the literature for GISTs in patients with NF-1, where targeted therapy is not a treatment option. Resection of all disease should be considered, since NF-1 associated GISTs generally do not have harbor mutations that can be targeted.

Survival impact based on hepatic artery lymph node status in pancreatic adenocarcinoma: A study of patients receiving modern chemotherapy

BACKGROUND

Chemotherapy for pancreatic adenocarcinoma (PDAC) has significantly improved in recent years. While the involvement of the hepatic artery lymph node (HALN; station 8a lymph node) likely represents advanced disease, a comparison to patients with metastases on modern chemotherapy is lacking.

METHODS

Patients who underwent pancreatoduodenectomy with HALN sent for pathologic review at a single institution from 2003 to 2018 were reviewed. Patients who presented with liver-only metastases at the time of PDAC diagnosis (Stage IV) and received chemotherapy were identified. Multivariate Cox proportional hazards regression modeling was utilized and overall survival (OS) was estimated using Kaplan-Meier analysis.

RESULTS

Of the 112 patients with a HALN sent for analysis, 17 (15%) were positive and 13 (76%) received chemotherapy. Ninety-four stage IV patients were identified and were significantly more likely to have received a multiagent rather than single-agent chemotherapy regimen compared to HALN positive patients (79.8% vs. 38.5%, p < .001). Median OS was significantly longer in all patients who underwent surgical resection, regardless of HALN status, compared to stage IV patients.

CONCLUSIONS

Patients undergoing pancreatoduodenectomy with HALN positivity have significantly improved OS compared to patients with stage IV disease. HALN involvement does not significantly alter survival among resected patients and does not warrant preoperative endoscopic ultrasound-guided biopsy.

Can an Academic RVU Model Balance the Clinical and Research Challenges in Surgery?

OBJECTIVE

The purpose of this study is to identify perceptions of academic surgeons regarding academic productivity and assess its relationship to clinical productivity. We hypothesized that these perceptions would vary based on respondent characteristics including clinical activity and leadership roles.

DESIGN

This retrospective, survey-based study was performed from August 26, 2019 to September 26, 2019.

SETTING

The setting was academic surgical departments across the US.

PARTICIPANTS

The survey instrument was administered to faculty members of the Association of Program Directors in Surgery. A total of 105 academic surgeons responded.

RESULTS

Most respondents were Program Directors (59%) of general surgery programs. Of the participants, 30% identified as Professor, 36% as Associate Professor, and 15% as Assistant Professor. Respondents agreed that multiple academic pursuits or factors should count towards academic productivity including the following (in descending order): completing a first-authored manuscript (98.8%), completing a senior-authored manuscript (97.7%), chairing a national committee (94.1%), serving on a national committee (88.2%), completing a second-authored manuscript (88.0%), completing a first lecture (83.7%), completing a middle-authored manuscript (71.8%), completing a lecture (whether or not repeated) (70.9%), impact factor of journal (60.7%), and attendance at grand rounds (57.0%). Perspectives did not vary significantly based on surgeon demographics, clinical setting, or leadership role (p > 0.05).

CONCLUSIONS

Perceptions regarding what constitutes academic productivity and merit a reduction in clinical expectation are remarkably similar across multiple surgeon characteristics including demographics, academic title, leadership role, and practice environment.

Survival outcomes after surgical management of sporadic or familial adenomatous polyposis associated duodenal cancer

BACKGROUND

Duodenal cancer is the second most common cause of cancer death in familial adenomatous polyposis (FAP) patients. In this study, we compare oncologic outcomes between sporadic and FAP-associated duodenal cancer.

METHODS

In this retrospective study, all patients who underwent surgeries between 2000 and 2014 for either sporadic or FAP duodenal cancer were identified. The patients were grouped based on diagnoses and perioperative and survival outcomes were compared.

RESULTS

A total of 56 patients with duodenal cancer (43 sporadic, 13 FAP) who underwent surgery were identified. Pancreatoduodenectomy (PD) was the most common procedure performed. The overall median survival was 7.5 years (1 year: 92%; 5 years: 58.1%). FAP patients had earlier tumor, node, and metastasis stage, less margin involvement, less perineural, and angiolymphatic invasion but had a comparable survival to sporadic patients. The median survival for FAP duodenal cancer was 7.4 vs 9.6 years for sporadic (P = .97) with similar utilization of adjuvant chemotherapy. Although not statistically significant, PD had an improved median survival compared to segmental duodenal resection (SDR) (9.6 years for PD vs 3.6 years for SDR, P = .17). Non-periampullary location and presence of positive lymph nodes were significant predictors of mortality on multivariate analysis.

CONCLUSIONS

FAP duodenal cancer has no survival advantage compared to sporadic duodenal cancer despite an improved stage of resection with extraampullary lesions having a worse survival.

Comparison of pancreas-sparing duodenectomy (PSD) and pancreatoduodenectomy (PD) for the management of duodenal polyposis syndromes

BACKGROUND

Familial adenomatous polyposis affects primarily the colon but can also involve other locations within the gastrointestinal tract, including the duodenum. The aim of this study was to describe a single center experience with pancreas-sparing duodenectomy for familial adenomatous polyposis and to compare outcomes with pancreatoduodenectomy performed for duodenal polyp disease.

PATIENTS AND METHODS

A retrospective review of a prospectively maintained database identified patients who had undergone pancreas-sparing duodenectomy during the period 2001 to 2016. This population was matched 1:1 with a cohort of patients undergoing pancreatoduodenectomy for duodenal adenomas, both sporadic and familial, during the same time period. Baseline demographics and perioperative (short- and long-term) outcomes were compared.

RESULTS

A total of 88 patients were included; 44 in each group. The pancreas-sparing duodenectomy cohort was younger (52.6 vs 64.3 years; P < .001) and more patients had undergone prior colectomy (100% vs 32%; P < .001) or additional prior abdominal surgery (27% vs 9% (P < .001). Median operative times were greater for pancreatoduodenectomy (391 vs 460 min; P = .002). There was no difference in any of the early postoperative complications. There was 1 30-day mortality in the pancreatoduodenectomy group secondary to aspiration. Late acute pancreatitis was more common after pancreas-sparing duodenectomy (16% vs 0%; P = .012) and exocrine pancreatic insufficiency was more common after pancreatoduodenectomy (30% vs 11%; P = .034).

CONCLUSION

Pancreas-sparing duodenectomy is a reasonable option for duodenal cancer prophylaxis in familial adenomatous polyposis with high-risk features. The perioperative safety profile is comparable to pancreatoduodenectomy done for similar indications, and pancreas-sparing duodenectomy has a favorable long-term with a lesser incidence of exocrine impairment.

A unique case of xanthogranulomatous cholecystitis complicated by multiple liver abscesses and portal vein and hepatic artery thrombosis and occlusion

Xanthogranulomatous cholecystitis (XGC) is difficult to diagnose preoperatively because it often mimics gallbladder cancer. We present a case of a 64-year-old Caucasian male who presented with multiple intrahepatic abscesses, left portal vein and segmental right hepatic arterial thrombosis suspicious for extrahepatic cholangiocarcinoma who ultimately underwent an extended left hepatectomy and was noted to have XGC on final pathology. This case presents a new challenge in diagnosing XGC prior to final pathology results given the unique left portal vein, and later, right anterior portal vein thrombosis and occlusion. XGC should be in the differential diagnosis when diffuse gallbladder wall thickening is associated with involvement of biliary and vascular structures. While diagnosing these cases can be challenging, increased awareness of varied involvement of the liver and hilar structures associated with this diseases process may aid in the selection of the most appropriate surgical techniques.

Early Postoperative Outcomes of Primary Bariatric Surgery in Patients on Chronic Steroid or Immunosuppressive Therapy

BACKGROUND

Previous research suggests that patients on chronic steroids may be at an increased risk of postoperative morbidity after major surgery. We aimed to evaluate the prognostic impact of chronic use of steroid or immunosuppression on 30-day morbidity and mortality rates after primary bariatric surgery.

METHODS

From American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database, we identified patients who underwent primary bariatric surgery between 2005 and 2013. Logistic regression was used to determine the prognostic impact of chronic use of steroid or immunosuppression on the 30-day postoperative outcomes.

RESULTS

One thousand two hundred seventy seven steroid/immunosuppressant-dependent (SD) and 112,892 non-dependent (ND) patients were analyzed. SD patients had a higher baseline risk profile compared to ND patients. Thirty-day mortality rates for SD and ND patients were 0.55 and 0.11 %, respectively (P < 0.001) which corresponds to an adjusted odds ration (OR) of 6.85 (95 % confidence interval (CI) 1.95-24.12). SD patients had a higher 30-day major morbidity compared to ND patients (5.01 versus 2.54 %; P < 0.001, respectively). After adjustment, this translated into an OR of 2.21 (95 % CI 1.29-3.79). Among SD patients, there was no significant difference in 30-day major morbidity after gastric bypass compared to sleeve gastrectomy (OR = 0.36; 95 % CI 0.08-1.66).

CONCLUSIONS

Chronic and active use of steroid or immunosuppressant medications is a strong predictor of 30-day postoperative morbidity and mortality following primary bariatric surgery. Among the steroid/immunosuppressant users, complication rates were similar for gastric bypass and sleeve gastrectomy patients. Further studies are needed to help guide the management or discontinuation of such medications in the perioperative period.

Frailty predicts risk of life-threatening complications and mortality after pancreatic resections

BACKGROUND

To assess the effect of frailty on morbidity and mortality after partial pancreatectomy.

METHODS

A retrospective analysis of National Surgical Quality Improvement Project from 2005-2010 was conducted. A modified frailty index was created based on previously validated methodology. Patients were classified as nonfrail, low frailty, intermediate frailty, and frail. Outcomes of pancreatoduodenectomy and distal pancreatectomy were examined.

RESULTS

In the study, 13,020 patients were analyzed (8,729 pancreatoduodenectomy and 4,291 distal pancreatectomy). Among the pancreatoduodenectomy and distal pancreatectomy patients, frail patients regardless of the degree of frailty were older, more likely male, had a greater body mass index, lower serum albumin, and greater weight loss compared with the nonfrail patients (all P ≤ .05). Postoperatively, a stepwise increased risk of grade 4 complications (Clavien/Dindo) and mortality was noted from nonfrail to frail patients. Every 1-point increase in modified frailty index was associated with a significantly increased risk of grade 4 complications (∼2-6 times) and mortality (∼2-10 times) from low-frail to frail (adjusted for age, sex, body mass index, albumin, weight loss, and type of pancreatectomy). An abbreviated frailty index incorporating 8 variables was as predictive as the modified frailty index (P = .68).

CONCLUSION

An 11-point frailty index as measured in National Surgical Quality Improvement Project predicts serious complications and death after pancreatectomy. A modification of this index with 8 factors continues to have similar predictive ability. Consideration of frailty may be beneficial prior to the pancreatic surgeon and particularly in discussion of operative risk and selection of patients who might receive benefit from pre-operative optimization.

Quality of life comparing dor and toupet after heller myotomy for achalasia

Background:

Laparoscopic Heller cardiomyotomy (LHC) is standard therapy for achalasia. Traditionally, an antireflux procedure has accompanied the myotomy. This study was undertaken to compare quality-of-life outcomes between patients undergoing myotomy with Toupet versus Dor fundoplication. In addition, we investigated overall patient satisfaction after LHC in the treatment of achalasia.

Methods:

One hundred thirty-five patients who underwent LHC over a 13-year period were identified for inclusion. Symptoms queried included dysphagia, heartburn, and bloating using the Gastroesophageal Reflux Disease–Health-Related Quality of Life Scale and a second published scale for the assessment of gastroesophageal reflux disease and dysphagia symptoms. The patients' overall satisfaction after surgery was also rated. Data were compared on the basis of type of fundoplication. Symptom scores were analyzed using chi-square tests and Fisher's exact tests.

Results:

Sixty-three patients completed the survey (47%). There were no perioperative deaths or reoperations. The mean length of stay was 2.8 days. The mean operative time for LHC with Toupet fundoplication was 137.3 ± 30.91 minutes and for LHC with Dor fundoplication was 111.5 ± 32.44 minutes (P = .006). There was no difference with respect to the incidence or severity of postoperative heartburn, dysphagia, or bloating. Overall satisfaction with Toupet fundoplication was 87.5% and with Dor fundoplication was 93.8% (P > .999).

Conclusions:

LHC with either Toupet or Dor fundoplication gave excellent patient satisfaction. Postoperative symptoms of heartburn and dysphagia were equivalent when comparing LHC with either antireflux procedure. Dor and Toupet fundoplication were found to have equivalent outcomes in the short term. We prefer Dor to Toupet fundoplication because of its decreased need for extensive dissection and better mucosal protection.

Emergent Surgery Does Not Independently Predict 30-Day Mortality After Paraesophageal Hernia Repair: Results from the ACS NSQIP Database

AIM

Patients undergoing emergency surgery for paraesophageal hernia (PEH) repair have a higher adjusted mortality risk based on Nationwide Inpatient Sample (NIS). We sought to examine this relationship in the National Surgical Quality Improvement Program (NSQIP), which adjusts for patient-level risk factors, including factors contributing to patient frailty.

METHODS

This is a retrospective analysis of the NSQIP from 2009 through 2011. A modified frailty index was created based on previously validated methodology.

RESULTS

Of 3498 patients with PEH repair, 175 (5 %) underwent emergent surgery. Older age, lower BMI, chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), current dialysis, SIRS, and sepsis were significantly more common among emergent patients. These patients also had a poorer functional status, higher American Society of Anesthesiologists (ASA), and higher frailty scores and more likely to undergo open surgery. Postoperative complications were proportionally more common, and LOS was longer (8.5 vs. 3.4 days) among emergent patients (all p < 0.05). In univariate analysis, emergent patients demonstrated ten times greater mortality than the elective surgery group (8 vs. 0.8 %). On adjusted analysis, emergent surgery was no longer independently associated with mortality. Frailty score 2 or above and preoperative sepsis significantly predicted increased mortality while laparoscopic repair and BMI 25-50 and BMI ≥30 (vs. BMI <18.5) were significantly protective in the entire group of patients.

CONCLUSION

Increased mortality among patients undergoing emergent PEH repair may be related to severity of disease and other preoperative comorbid illness. Without an emergent indication, some of these patients likely would have been excluded as candidates for elective surgical intervention.

Failed Surgical Weight Loss Does Not Necessarily Mean Failed Metabolic Effects

The metabolic profile of patients after a failed surgical weight loss procedure is unknown. Long-term clinical outcomes of 31 obese diabetes patients with post-bariatric surgery excess weight loss of ≤25% were assessed. At a median follow-up of 6 years (range, 5-9 years) after surgery, remission and clinical improvement of diabetes occurred in seven (23%) and 13 (42%) patients, respectively. A long-term mean total weight loss of 7.0±4.7% and excess weight loss of 13.7±8.5% were associated with a mean reduction in fasting blood glucose level, from 158.9±66.7 to 128.4±35.3 mg/dL (P=0.03), and a significant decrease in diabetes medication requirements (P<0.001). A significant decrease in systolic blood pressure (11.1±23.4 mm Hg, P=0.01) and level of circulating triglycerides (35.7±73.4 mg/dL, P=0.04) was also observed after surgery. A modest surgical weight loss in the range of 5-10% of initial weight was associated with significant improvement in cardiometabolic risk factors of morbidly obese diabetes patients. The markedly improved glycemic control (65% remission or clinical improvement) may be partly explained by weight-independent antidiabetes mechanisms of certain bariatric surgical procedures.

Unravelling viral camouflage: approaches to the study and characterization of conformational epitopes

Antibodies are broadly used in clinical and basic research. Many of monoclonal antibodies are successfully adopted for therapeutic and diagnostic targeting of viral pathogens. Efficacy of antiviral neutralizing or protective antibodies depends on their ability to recognize epitopes interfering with viral infection. However, viruses are able to incessantly change their antigenic determinants to escape surveillance of humoral immune system and therefore the successful antiviral therapies require continuous development. Characterization of interactions of antibodies with prevalently conformational viral epitopes is important for understanding antibody mode of action and can help to identify conserved regions that may be exploited in designing new vaccines and virus neutralizing antibodies. In this article, we are reviewing techniques in use for characterization of conformational epitopes of monoclonal antibodies with focus on viruses.

A systematic review and meta-analysis of the efficacy of lixisenatide in the treatment of patients with type 2 diabetes

The aim of this study is to assess the efficacy and safety of lixisenatide for treating type 2 diabetes. A systematic search in electronic databases (up to October 2012) was conducted and the manufacturer was contacted regarding unpublished data. Randomized controlled trials (RCTs) were included if they provided information on at least one of the following outcomes: mortality, health-related quality of life, hypoglycaemic events, adverse events, change in HbA1c, body weight, blood pressure, gastric emptying, fasting plasma glucose or 2 h postprandial glucose (PPG). Twenty-six publications and 10 unpublished study reports, relating to 14 RCTs (6156 patients) were included. Eleven studies related to placebo comparisons; active comparators were in three studies. Compared to placebo, lixisenatide significantly reduced HbA1c (-0.52%; 95% CI: -0.64 to -0.39), bodyweight (-0.65 kg; 95% CI: -0.94 to -0.37) and 2-h PPG level (-4.58 mmol/l; 95% CI: -5.88 to -3.28). There were significantly more symptomatic hypoglycaemic events among lixisenatide compared to placebo-treated patients (log OR: 0.54; 95% CI: 0.32-0.75), but significantly fewer compared to other incretin mimetics. In comparison to exenatide and liraglutide, lixisenatide was more effective in reducing 2 h-PPG with a better adverse events profile, but it showed a lower reduction in HbA1c and body weight. Lixisenatide improves HbA1c levels and moderately reduces body weight compared to placebo and showed less frequent symptomatic hypoglycaemic and gastrointestinal events and an improvement in PPG control compared to other GLP-1 agonists. Firm conclusions regarding the performance of lixisenatide compared to other incretin mimetics, however, can not yet be drawn, due to limited data.