Publications by authors named "John Christein"
Background: Irreversible electroporation (IRE) has emerged as a viable consolidative therapy after induction chemotherapy, in which this combination has improved overall survival of locally advanced pancreatic cancer (LAPC). Optimal timing and patient selection for irreversible electroporation remains a clinically unmet need. The aim of this study was to investigate preoperative factors that may assist in predicting progression-free and overall survival following IRE.
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- Intraperitoneal drains are used after pancreatic surgery to reduce complications, especially in patients at risk for postoperative pancreatic fistulas (CR-POPF).
- A study analyzed data from over 4,000 cases to see whether using multiple drains is better than a single drain for reducing complications.
- Results showed that using one or two drains both help mitigate complications, but using no drains significantly increases the risk of problems and mortality, regardless of the patient's risk level.
Objectives: Although lumen-apposing metal stents (LAMS) are being increasingly used in lieu of plastic stents, the clinical approach to endoscopic management of pancreatic fluid collections (PFCs) is poorly standardized. We compared outcomes of approaches over two time intervals, initially using plastic stents and later integrating LAMS.
Methods: This was a retrospective, observational, before-after study of prospectively collected data on consecutive patients with symptomatic PFCs managed over two time periods.
Background: The association between intraoperative estimated blood loss and outcomes after pancreatoduodenectomy has, thus far, been rarely explored.
Methods: In total, 7,706 pancreatoduodenectomies performed at 18 international institutions composing the Pancreas Fistula Study Group were examined (2003-2020). High estimated blood loss (>700 mL) was defined as twice the median.
Background: Pancreatoduodenectomies at high risk for clinically relevant pancreatic fistula are uncommon, yet intimidating, situations. In such scenarios, the impact of individual surgeon experience on outcomes is poorly understood.
Methods: The fistula risk score was applied to identify high-risk patients (fistula risk score 7-10) from 7,706 pancreatoduodenectomies performed at 18 international institutions (2003-2020).
Objective: To investigate the role of intraoperative estimated blood loss (EBL) on development of clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreatoduodenectomy (PD).
Background: Minimizing EBL has been shown to decrease transfusions and provide better perioperative outcomes in PD. EBL is also felt to be influential on CR-POPF development.
Introduction: Ampullary adenocarcinoma (AAC) is a rare malignancy with great morphological heterogeneity, which complicates the prediction of survival and, therefore, clinical decision-making. The aim of this study was to develop and externally validate a prediction model for survival after resection of AAC.
Materials And Methods: An international multicenter cohort study was conducted, including patients who underwent pancreatoduodenectomy for AAC (2006-2017) from 27 centers in 10 countries spanning three continents.
Objective: This study aims to present a full spectrum of individual patient presentations of pancreatic fistula risk, and to define the utility of mitigation strategies amongst some of the most prevalent, and vulnerable scenarios surgeons encounter.
Background: The FRS has been utilized to identify technical strategies associated with reduced CR-POPF incidence across various risk strata. However, risk-stratification using the FRS has never been investigated with greater granularity.
Neuroendocrine tumor (NET) of the ampulla of Vater is a rare presentation of biliary obstruction. Here, we present a case of NET and discuss the current recommendations that necessitate different management and surgical treatment than other sites. A 56-year-old Caucasian female presented with 2 years of right upper quadrant pain.
View Article and Find Full Text PDFThere is an author's name misspelled in the published paper, Shyam Varadarajula should be Shyam Varadarajulu.
View Article and Find Full Text PDFImportance: Ampullary adenocarcinoma is a rare malignant neoplasm that arises within the duodenal ampullary complex. The role of adjuvant therapy (AT) in the treatment of ampullary adenocarcinoma has not been clearly defined.
Objective: To determine if long-term survival after curative-intent resection of ampullary adenocarcinoma may be improved by selection of patients for AT directed by histologic subtype.
Background: The optimal treatment and management of locally advanced pancreatic cancer (LAPC) remains unclear and controversial. This study aimed to report the initial outcomes of the AHPBA Registry and evaluate the reproducibility of existing evidence that the addition of Irreversible Electroporation (IRE), a nonthermal ablative treatment, confers survival benefits beyond standard therapeutic options for patients with LAPC.
Methods: From December 2015 to October 2017, patients with LAPC were treated with open-technique IRE following the AHPBA Registry Protocols.
Non-Hepatic Abdominal Surgery in Patients with Cirrhotic Liver Disease.
J Gastrointest Surg
March 2019
Cirrhotic liver disease is an important cause of peri-operative morbidity and mortality in general surgical patients. Early recognition and optimization of liver dysfunction is imperative before any elective surgery. Patients with MELD <12 or classified as Child A have a higher morbidity and mortality than matched controls without liver dysfunction, but are generally safe for elective procedures with appropriate patient education.
View Article and Find Full Text PDFCholangiocarcinoma (CCA) is a fatal disease with a 5-year survival of <30%. For a majority of patients, chemotherapy is the only therapeutic option, and virtually all patients relapse. Gemcitabine is the first-line agent for treatment of CCA.
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- This study aimed to identify a clinical risk score for pancreatic fistulas after distal pancreatectomy, a common complication that can lead to increased morbidity in patients.
- The analysis included data from 2,026 surgeries conducted by 52 surgeons over 15 years, revealing that factors such as age, obesity, and the absence of epidural anesthesia significantly increase the risk of developing clinically relevant pancreatic fistulas.
- Despite identifying these risk factors, the study concluded that a reliable predictive model for pancreatic fistula occurrence remains elusive, and certain mitigation strategies did not significantly impact the risk, except for intraoperative drainage which increased fistula rates but lessened their severity.
We present a cancer nanomedicine based on acidic pH targeted gold nanorods designed for multispectral optoacoustic tomography (MSOT). We have designed gold nanorods coated with mesoporous silica and subsequently capped with chitosan (CMGs). We have conjugated pH-sensitive variant 7 pHLIP peptide to the CMGs (V7-CMG) to provide targeting specificity to the acidic tumor microenvironment.
View Article and Find Full Text PDFObjective: The aim of this study was to identify the optimal fistula mitigation strategy following pancreaticoduodenectomy.
Background: The utility of technical strategies to prevent clinically relevant postoperative pancreatic fistula (CR-POPF) following pancreatoduodenectomy (PD) may vary by the circumstances of the anastomosis. The Fistula Risk Score (FRS) identifies a distinct high-risk cohort (FRS 7 to 10) that demonstrates substantially worse clinical outcomes.
Background: As payment models evolve, disease-specific risk stratification may impact patient selection and financial outcomes. This study sought to determine whether a validated clinical risk score for post-operative pancreatic fistula (POPF) could predict hospital costs, payments, and profit margins.
Methods: A multi-institutional cohort of 1193 patients undergoing pancreaticoduodenectomy (PD) were matched to an independent hospital where cost, in US$, and payment data existed.
Objective: To study the effect of disconnected pancreatic duct syndrome (DPDS) on endoscopic management of pancreatic fluid collections (PFCs).
Background: Data on the impact of DPDS in patients undergoing endoscopic treatment of PFCs are limited.
Methods: Retrospective study of patients undergoing endoscopic drainage of PFCs from 2003 to 2015.
Purpose: To conduct a telephone survey establishing pancreatic cancer survivors' level of interest in, preferences for, and perceived barriers and facilitators to participating in exercise and diet intervention programming. These data will inform the development of such interventions for newly-diagnosed patients.
Methods: Seventy-one survivors treated for resectable pancreatic adenocarcinoma from October 2011 to August 2014 were identified through an institutional cancer registry and contacted via telephone.
Background: Evidence suggests externalized trans-anastomotic stents may be beneficial as a fistula mitigation strategy for pancreatoduodenectomy (PD); however, previous studies have not been rigorously risk-adjusted.
Methods: From 2001 to 2015, PDs were performed at three institutions, with externalized stents placed at the surgeon's discretion. The Fistula Risk Score (FRS) and the Modified Accordion Severity Grading System were used to analyze occurrence and severity of clinically relevant postoperative pancreatic fistula (CR-POPF) across various risk scenarios.
Background: Pancreatic adenocarcinoma patients have low survival rates due to late-stage diagnosis and high rates of cancer recurrence even after surgical resection. It is important to understand the molecular characteristics associated with survival differences in pancreatic adenocarcinoma tumors that may inform patient care.
Results: RNA sequencing was performed for 51 patient tumor tissues extracted from patients undergoing surgical resection, and expression was associated with overall survival time from diagnosis.
Objective: This multicenter study sought to evaluate the accuracy of the American College of Surgeons National Surgical Quality Improvement Program's (ACS-NSQIP) surgical risk calculator for predicting outcomes after pancreatoduodenectomy (PD) and to determine whether incorporating other factors improves its predictive capacity.
Background: The ACS-NSQIP surgical risk calculator has been proposed as a decision-support tool to predict complication risk after various operations. Although it considers 21 preoperative factors, it does not include procedure-specific variables, which have demonstrated a strong predictive capacity for the most common and morbid complication after PD - clinically relevant pancreatic fistula (CR-POPF).
Objective: To evaluate surgical performance in pancreatoduodenectomy using clinically relevant postoperative pancreatic fistula (CR-POPF) occurrence as a quality indicator.
Background: Accurate assessment of surgeon and institutional performance requires (1) standardized definitions for the outcome of interest and (2) a comprehensive risk-adjustment process to control for differences in patient risk.
Methods: This multinational, retrospective study of 4301 pancreatoduodenectomies involved 55 surgeons at 15 institutions.