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Dive into the research topics where Ali Siddiqui is active.

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Featured researches published by Ali Siddiqui.


The New England Journal of Medicine | 2009

Radiofrequency Ablation in Barrett's Esophagus with Dysplasia

Nicholas J. Shaheen; Prateek Sharma; Bergein F. Overholt; Herbert C. Wolfsen; Richard E. Sampliner; Kenneth K. Wang; Joseph A. Galanko; Mary P. Bronner; John R. Goldblum; Ana E. Bennett; Blair A. Jobe; Glenn M. Eisen; M. Brian Fennerty; John G. Hunter; David E. Fleischer; Virender K. Sharma; Robert H. Hawes; Brenda J. Hoffman; Richard I. Rothstein; Stuart R. Gordon; Hiroshi Mashimo; Kenneth J. Chang; V. Raman Muthusamy; Steven A. Edmundowicz; Stuart J. Spechler; Ali Siddiqui; Rhonda F. Souza; Anthony Infantolino; Gary W. Falk; Michael B. Kimmey

BACKGROUND Barretts esophagus, a condition of intestinal metaplasia of the esophagus, is associated with an increased risk of esophageal adenocarcinoma. We assessed whether endoscopic radiofrequency ablation could eradicate dysplastic Barretts esophagus and decrease the rate of neoplastic progression. METHODS In a multicenter, sham-controlled trial, we randomly assigned 127 patients with dysplastic Barretts esophagus in a 2:1 ratio to receive either radiofrequency ablation (ablation group) or a sham procedure (control group). Randomization was stratified according to the grade of dysplasia and the length of Barretts esophagus. Primary outcomes at 12 months included the complete eradication of dysplasia and intestinal metaplasia. RESULTS In the intention-to-treat analyses, among patients with low-grade dysplasia, complete eradication of dysplasia occurred in 90.5% of those in the ablation group, as compared with 22.7% of those in the control group (P<0.001). Among patients with high-grade dysplasia, complete eradication occurred in 81.0% of those in the ablation group, as compared with 19.0% of those in the control group (P<0.001). Overall, 77.4% of patients in the ablation group had complete eradication of intestinal metaplasia, as compared with 2.3% of those in the control group (P<0.001). Patients in the ablation group had less disease progression (3.6% vs. 16.3%, P=0.03) and fewer cancers (1.2% vs. 9.3%, P=0.045). Patients reported having more chest pain after the ablation procedure than after the sham procedure. In the ablation group, one patient had upper gastrointestinal hemorrhage, and five patients (6.0%) had esophageal stricture. CONCLUSIONS In patients with dysplastic Barretts esophagus, radiofrequency ablation was associated with a high rate of complete eradication of both dysplasia and intestinal metaplasia and a reduced risk of disease progression. (ClinicalTrials.gov number, NCT00282672.)


Gastroenterology | 2011

Durability of Radiofrequency Ablation in Barrett's Esophagus With Dysplasia

Nicholas J. Shaheen; Bergein F. Overholt; Richard E. Sampliner; Herbert C. Wolfsen; Kenneth K. Wang; David E. Fleischer; Virender K. Sharma; Glenn M. Eisen; M. Brian Fennerty; John G. Hunter; Mary P. Bronner; John R. Goldblum; Ana E. Bennett; Hiroshi Mashimo; Richard I. Rothstein; Stuart R. Gordon; Steven A. Edmundowicz; Ryan D. Madanick; Anne F. Peery; V. Raman Muthusamy; Kenneth J. Chang; Michael B. Kimmey; Stuart J. Spechler; Ali Siddiqui; Rhonda F. Souza; Anthony Infantolino; John A. Dumot; Gary W. Falk; Joseph A. Galanko; Blair A. Jobe

BACKGROUND & AIMS Radiofrequency ablation (RFA) can eradicate dysplasia and intestinal metaplasia in patients with dysplastic Barretts esophagus (BE), and reduce rates of esophageal adenocarcinoma. We assessed long-term rates of eradication, durability of neosquamous epithelium, disease progression, and safety of RFA in patients with dysplastic BE. METHODS We performed a randomized trial of 127 subjects with dysplastic BE; after cross-over subjects were included, 119 received RFA. Subjects were followed for a mean time of 3.05 years; the study was extended to 5 years for patients with eradication of intestinal metaplasia at 2 years. Outcomes included eradication of dysplasia or intestinal metaplasia after 2 and 3 years, durability of response, disease progression, and adverse events. RESULTS After 2 years, 101 of 106 patients had complete eradication of all dysplasia (95%) and 99 of 106 had eradication of intestinal metaplasia (93%). After 2 years, among subjects with initial low-grade dysplasia, all dysplasia was eradicated in 51 of 52 (98%) and intestinal metaplasia was eradicated in 51 of 52 (98%); among subjects with initial high-grade dysplasia, all dysplasia was eradicated in 50 of 54 (93%) and intestinal metaplasia was eradicated in 48 of 54 (89%). After 3 years, dysplasia was eradicated in 55 of 56 of subjects (98%) and intestinal metaplasia was eradicated in 51 of 56 (91%). Kaplan-Meier analysis showed that dysplasia remained eradicated in >85% of patients and intestinal metaplasia in >75%, without maintenance RFA. Serious adverse events occurred in 4 of 119 subjects (3.4%); the rate of stricture was 7.6%. The rate of esophageal adenocarcinoma was 1 per 181 patient-years (0.55%/patient-years); there was no cancer-related morbidity or mortality. The annual rate of any neoplastic progression was 1 per 73 patient-years (1.37%/patient-years). CONCLUSIONS In subjects with dysplastic BE, RFA therapy has an acceptable safety profile, is durable, and is associated with a low rate of disease progression, for up to 3 years.


Gastrointestinal Endoscopy | 2009

Duration of the interval between the completion of bowel preparation and the start of colonoscopy predicts bowel- preparation quality

Ali Siddiqui; Kenneth Yang; Stuart J. Spechler; Byron Cryer; Raquel E. Davila; Daisha J. Cipher; William V. Harford

BACKGROUND Recent studies suggest that colonoscopies done in the morning have better-quality bowel preparations than those done in the afternoon. OBJECTIVE We aimed to determine how the duration of the interval between the end of the preparation and the start of the colonoscopy affects preparation quality. DESIGN We prospectively studied consecutive outpatients who had colonoscopies performed at our hospital within a 3-month period. The time of day when the colonoscopy started and the time interval from the last dose of preparation agent to the start of the colonoscopy were recorded. The endoscopist graded the quality of the preparation in the right side of the colon by using a 5-point visual scale. PATIENTS We studied 378 patients (96% men, mean age 62.2 years) who received preparations of polyethylene glycol electrolyte-based (PEG) and sodium phosphate (SP) solution (71%), oral PEG and magnesium citrate (23%), or SP alone (6%). RESULTS Compared with patients whose preparations were graded as 2/3/4 (fair/poor/inadequate), those whose preparations were graded as 0/1 (excellent/good) had a significantly shorter interval between the time of the last preparation agent dose and the start of the colonoscopy (P = .013). LIMITATIONS We used a nonvalidated scale to assess the quality of bowel preparation. CONCLUSIONS Bowel-preparation quality varies inversely with the duration of the interval between the last dose of the bowel-preparation agent and the start of colonoscopy. This interval appears to be a better predictor of bowel-preparation quality than the time of day when colonoscopy is performed.


Gastrointestinal Endoscopy | 2012

Targeted cyst wall puncture and aspiration during EUS-FNA increases the diagnostic yield of premalignant and malignant pancreatic cysts

Shih-Kuang S. Hong; David E. Loren; Jason N. Rogart; Ali Siddiqui; Jocelyn Sendecki; Marluce Bibbo; Robert M. Coben; Daniel P. Meckes; Thomas E. Kowalski

BACKGROUND Characterization of pancreatic cysts by using EUS-FNA includes chemical and cytologic analysis. OBJECTIVE To evaluate whether material obtained from FNA of the cyst wall increases diagnostic yield. DESIGN Prospective series. SETTING Tertiary referral center. PATIENTS Consecutive patients with pancreatic cysts referred for EUS-FNA between March 2010 and March 2011. INTERVENTION FNA was performed with aspiration of cyst fluid for carcinoembryonic antigen (CEA) and cytology, followed by cyst wall puncture (CWP). CWP is defined as puncturing the far wall of the cyst and moving the needle back and forth through the wall to sample the wall epithelium. MAIN OUTCOME MEASUREMENTS The diagnostic yield for mucinous cystic pancreatic neoplasms by CEA and cytology obtained from cyst fluid compared with cytology obtained from CWP. CEA ≥192 ng/mL was considered mucinous. RESULTS A total of 69 pancreatic cysts from 66 patients were included. Adequate amounts of fluid were aspirated for CEA, amylase, and cytology in 60 cysts (81%). Cellular material adequate for cytologic assessment from CWP was obtained in 56 cysts (81%). Ten (30%) of 33 cysts with CEA <192 ng/mL and negative results of cyst fluid cytology had a mucinous diagnosis from CWP; 6 of 9 (67%) cysts with an insufficient amount of fluid for CEA analysis and cyst fluid cytology had a mucinous diagnosis from CWP. Furthermore, 4 malignant cysts were independently diagnosed by CWP cytology. The incremental diagnostic yield of CWP for mucinous or malignant cysts was therefore 29% (20 of 69 cysts, P = .0001). An episode of pancreatitis (1.45%) occurred. LIMITATION Lack of surgical criterion standard. CONCLUSIONS CWP during EUS-FNA is a safe and effective technique for improving the diagnostic yield for premalignant and malignant pancreatic cysts.


Digestive Diseases and Sciences | 2005

Esophageal visceral sensitivity to bile salts in patients with functional heartburn and in healthy control subjects

Ali Siddiqui; Sheila Rodriguez-Stanley; Sattar Zubaidi; Philip B. Miner

Patients with nonerosive gastroesophageal reflux disease often have relatively low esophageal acid exposure and respond suboptimally to gastric acid suppression. In these patients, other constituents of gastric contents may induce esophageal symptoms. We have demonstrated that gastric contents can cause heartburn when the gastric pH > 4. (Aliment Pharm Ther 14:129–134, 2000). The aim of this study was to determine relative sensitivities to chenodeoxycholic and ursodeoxycholic acids, and 0.1 N HCl, administered as provocative perfusion tests. Patients with functional heartburn and healthy control subjects were evaluated. Patients underwent a modified Bernstein acid infusion test and esophageal Barostat balloon distention. Time and volume to pain were recorded. Barostat balloon distention was performed using our standard protocol. Stepwise distentions were performed and pain was recorded. Sensitivity to chenodeoxycholic acid (Cheno) and Ursodeoxycholic acid (Urso) were assessed similarly to the Bernstein test using 2 mM concentrations of each, followed immediately by 5 mM if no pain was reported with 2 mM. Volume of bile acid infusion and length of time until pain was induced were assessed and compared to the same endpoints for acid sensitivity. “Total” time and “total” volume to induce pain were calculated for Cheno and Urso. Least-squares means were generated and two-tailed t-tests and regression analyses were performed (P < 0.05 level of significance). Ten functional heartburn patients and six healthy controls were evaluated (3 M, 13 F; age range, 19 to 56 years). Since five of six controls had pain with acid infusion (hypersensitive), all subjects were analyzed as one group. Only three subjects (all controls) had no pain with infusion of 2 mM Cheno and received the follow-up infusion of 5 mM. These same three subjects tolerated the maximum infusion (150 ml and 15 min) of 5 mM Cheno. Nine subjects did not have pain with 2 mM Urso and received the follow-up infusion of 5 mM Urso (five functional heartburn, four controls). Significantly more subjects tolerated the maximum bile acid infusion of 2 mM Urso vs 2 mM Cheno (nine vs three; P < 0.05, Chi-square test). The pain threshold (volume and time) for Urso was significantly higher than that for Cheno and acid (P < 0.05), and the pain threshold for Cheno was significantly higher than that for acid (P < 0.05). Conclusions are as follows: (1) Bile acids differ in their ability to induce pain. (2) Changing bile acid composition by treatment with Urso may change symptom presentation and symptom severity in patients with bile acid-induced esophageal pain.


Gastrointestinal Endoscopy | 2012

Placement of fully covered self-expandable metal stents in patients with locally advanced esophageal cancer before neoadjuvant therapy

Ali Siddiqui; Avik Sarkar; Sara K. Beltz; Jason Lewis; David E. Loren; Thomas E. Kowalski; John C. Fang; Kristen Hilden; Douglas G. Adler

BACKGROUND Most patients with locally advanced esophageal cancer requiring neoadjuvant therapy have significant dysphagia. OBJECTIVE To report our experience in using a fully covered self-expandable metal stent (FCSEMS) to treat malignant dysphagia and for maintenance of nutritional support during neoadjuvant therapy. DESIGN Retrospective study. SETTING Two tertiary-care referral centers. PATIENTS This study involved 55 patients with locally advanced esophageal cancer (50 adenocarcinoma, 5 squamous cell carcinoma). Forty-three patients were men, and the mean age was 65.8 years. INTERVENTION EUS followed by FCSEMS placement. MAIN OUTCOME MEASUREMENTS Procedural success, dysphagia scores, patient weights, stent migration, and stent-related complications. RESULTS All stents were successfully placed. Tumors were located in the middle esophagus (n = 10) and distal esophagus (n = 45). The mean dysphagia score obtained at 1 week after stent placement had improved significantly from baseline (2.4 and 1, respectively; P < .001). Patients maintained their weights at 1 month follow-up when compared with baseline (153 and 149 pounds, respectively; P = .58). Immediate complications included chest discomfort in 13 patients; 2 patients required stent removal because of intractable pain. One patient had stent removal because of significant acid reflux. Stent migration occurred at some point in 17 of 55 patients (31%). There was a delayed perforation in 1 patient. Because of disease progression or the discovery of metastasis after neoadjuvant therapy, only 8 of 55 patients underwent curative surgery. LIMITATIONS Retrospective study. CONCLUSION Placement of FCSEMSs in patients with locally advanced esophageal cancer significantly improves dysphagia and allows for oral nutrition during neoadjuvant therapy. FCSEMSs appear to be effective for palliating dysphagia. Migration was not associated with injury or harm to the patient and usually represented a positive response to neoadjuvant therapy. Few patients undergoing stenting in this situation ultimately undergo surgery because of disease progression or poor operative candidacy.


International Seminars in Surgical Oncology | 2006

The role of endoscopic ultrasound in the evaluation of rectal cancer

Ali Siddiqui; Yomi J. Fayiga; Sergio Huerta

Accurate staging of rectal cancer is essential for selecting patients who can undergo sphincter-preserving surgery. It may also identify patients who could benefit from neoadjuvant therapy. Clinical staging is usually accomplished using a combination of physical examination, CT scanning, MRI and endoscopic ultrasound (EUS). Transrectal EUS is increasingly being used for locoregional staging of rectal cancer. The accuracy of EUS for the T staging of rectal carcinoma ranges from 80-95% compared with CT (65-75%) and MR imaging (75-85%). In comparison to CT, EUS can potentially upstage patients, making them eligible for neoadjuvant treatment. The accuracy to determine metastatic nodal involvement by EUS is approximately 70-75% compared with CT (55-65%) and MR imaging (60-70%). EUS guided FNA may be beneficial in patients who appear to have early T stage disease and suspicious peri-iliac lymphadenopathy to exclude metastatic disease.


The American Journal of the Medical Sciences | 2011

Metabolic Syndrome and Its Association With Colorectal Cancer: A Review

Ali Siddiqui; Biff F. Palmer

Currently, significant amount of epidemiologic evidence is present to suggest that metabolic syndrome increases the risk of developing colorectal cancer. This evidence is based on studies of the evaluate determinants of the metabolic syndrome (obesity), clinical consequences of metabolic syndrome (type 2 diabetes and hypertension) and serum component of metabolic syndrome (hypertriglyceridemia, hyperglycemia and low high-density lipoprotein cholesterol), as well as markers of hyperinsulinemia. Although the exact pathogenesis of this relationship is unknown, it seems that hyperinsulinemia may play a pivotal role in increasing CRC risk.


Digestive Diseases and Sciences | 2007

Expandable Polyester Silicon-Covered Stent for Malignant Esophageal Structures before Neoadjuvant Chemoradiation: A Pilot Study

Ali Siddiqui; David E. Loren; Robert Dudnick; Thomas E. Kowalski

Patients with resectable esophageal cancer often require placement of a surgical jejunostomy tube prior to receiving chemoradiation so as to maintain adequate nutrition due to their inability to swallow and eat. This study reports a single institutional experience with the Polyflex self-expanding silicone stent (Rüsch; Kernen. Germany) in patients with malignant stenosis receiving chemoradiation prior to esophagectomy. This was a retrospective, nonrandomized study of 6 patients who underwent Polyflex esophageal stent placement across a malignant stricture prior to receiving neoadjuvant chemoradiation. The study assessed procedural success, restoration of oral nutrition, migration, and removal of the Polyflex stent. The outcomes measured were the efficacy of treatment, stent-related complications, and changes in the nutritional status of the patient after stent placement. Stent placement was successful in 5 of 6 patients (83%). Restoration of oral nutrition after stent placement occurred in 5 of 5 patients (100%). Migration of the stent into the stomach occurred in 3 patients (60%) without occurrence of gastric outlet obstruction; there was no proximal migration. Stents were successfully removed endoscopically or at the time of esophagectomy. This early experience suggests that the removable silicone Polyflex stent is an effective alternative to a surgical jejunostomy tube for the management of malignant esophageal stenosis in patients for whom neoadjuvant chemoradiation is planned prior to esophagectomy.


Clinical Gastroenterology and Hepatology | 2012

Identification of Cholangiocarcinoma by Using the Spyglass Spyscope System for Peroral Cholangioscopy and Biopsy Collection

Ali Siddiqui; Vaibhav Mehendiratta; Whitney E. Jackson; David E. Loren; Thomas E. Kowalski; Mohamad A. Eloubeidi

BACKGROUND & AIMS It is a challenge to collect samples from bile duct strictures to diagnose patients with cholangiocarcinoma. We investigated the utility of the Spyglass Spyscope, a single-operator endoscope that is used to perform cholangiopancreatoscopy, to identify extrahepatic cholangiocarcinoma in patients who were not diagnosed with this disorder by endoscopic retrograde cholangiopancreatography (ERCP) cytology or endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) analyses. METHODS We conducted a retrospective analysis of data from 30 patients (median age, 67 years; 67% male) with indeterminate extrahepatic biliary strictures who were ultimately diagnosed with cholangiocarcinoma but had inconclusive results from initial biliary ductal brush cytology and EUS-FNA analyses. Patients then underwent cholangioscopy by using the Spyglass Spyscope and intraductal biopsy analysis. None of the patients had a definitive mass in abdominal imaging or EUS analyses. RESULTS The biliary stricture was located in the common bile duct in 13 patients and in the common hepatic duct in 17 patients. The Spyglass Spyscope system had 77% accuracy (23 of 30) in the diagnosis of malignancies that were inconclusive on the basis of ERCP-guided brush or EUS-FNA analyses. CONCLUSIONS The Spyglass Spyscope for cholangioscopy and biopsy collection identified malignancies with 77% accuracy in patients with suspected cholangiocarcinoma.

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Thomas E. Kowalski

Thomas Jefferson University

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David E. Loren

Thomas Jefferson University

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Sobia N. Laique

Thomas Jefferson University Hospital

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Jason Korenblit

Thomas Jefferson University Hospital

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