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Dive into the research topics where Shahin Ayazi is active.

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Featured researches published by Shahin Ayazi.


Annals of Surgery | 2007

Vagal-sparing esophagectomy: The ideal operation for intramucosal adenocarcinoma and Barrett with high-grade dysplasia

Christian G. Peyre; Steven R. DeMeester; Christian Rizzetto; Neeraj Bansal; Andrew Tang; Shahin Ayazi; Jessica M. Leers; John C. Lipham; Jeffrey A. Hagen; Tom R. DeMeester

Objective:Our aim was to compare outcome of vagal-sparing esophagectomy with transhiatal and en bloc esophagectomy in patients with intramucosal adenocarcinoma or high-grade dysplasia. Summary Background Data:Intramucosal adenocarcinoma and high grade dysplasia have a low likelihood of lymphatic or systemic metastases and esophagectomy is curative in most patients. However, traditional esophagectomy is associated with significant morbidity and altered gastrointestinal function. A vagal-sparing esophagectomy offers the advantages of complete disease removal with the potential for reduced morbidity and a better functional outcome. Method:Retrospective review of outcome in patients with intramucosal adenocarcinoma or high grade dysplasia that had a vagal-sparing (n = 49), transhiatal (n = 39) or en bloc (n = 21) esophagectomy. Results:The length of hospital stay and the incidence of major complications was significantly reduced with a vagal-sparing esophagectomy compared with a transhiatal or en bloc resection. Further, postvagotomy dumping and diarrhea symptoms were significantly less common, and weight was better maintained postoperatively with a vagal-sparing esophagectomy. Recurrent cancer has developed in only 1 patient. Conclusion:Survival with intramucosal adenocarcinoma or Barretts with high-grade dysplasia is independent of the type of resection. A vagal-sparing esophagectomy is associated with significantly less perioperative morbidity and a shorter hospital stay than a transhiatal or en bloc esophagectomy. Further, late morbidity including weight loss, dumping, and diarrhea are significantly less likely after a vagal-sparing approach. Consequently a vagal-sparing esophagectomy is the preferred procedure for patients with intramucosal adenocarcinoma or high grade dysplasia.


Journal of Gastrointestinal Surgery | 2009

Obesity and gastroesophageal reflux: quantifying the association between body mass index, esophageal acid exposure, and lower esophageal sphincter status in a large series of patients with reflux symptoms.

Shahin Ayazi; Jeffrey A. Hagen; Linda S. Chan; Steven R. DeMeester; Molly W. Lin; Ali Ayazi; Jessica M. Leers; Arzu Oezcelik; Farzaneh Banki; John C. Lipham; Tom R. DeMeester; Peter F. Crookes

IntroductionObesity and gastroesophageal reflux disease (GERD) are increasingly important health problems. Previous studies of the relationship between obesity and GERD focus on indirect manifestations of GERD. Little is known about the association between obesity and objectively measured esophageal acid exposure. The aim of this study is to quantify the relationship between body mass index (BMI) and 24-h esophageal pH measurements and the status of the lower esophageal sphincter (LES) in patients with reflux symptoms.MethodsData of 1,659 patients (50% male, mean age 51 ± 14) referred for assessment of GERD symptoms between 1998 and 2008 were analyzed. These subjects underwent 24-h pH monitoring off medication and esophageal manometry. The relationship of BMI to 24-h esophageal pH measurements and LES status was studied using linear regression and multiple regression analysis. The difference of each acid exposure component was also assessed among four BMI subgroups (underweight, normal weight, overweight, and obese) using analysis of variance and covariance.ResultsIncreasing BMI was positively correlated with increasing esophageal acid exposure (adjusted R2 = 0.13 for the composite pH score). The prevalence of a defective LES was higher in patients with higher BMI (p < 0.0001). Compared to patients with normal weight, obese patients are more than twice as likely to have a mechanically defective LES [OR = 2.12(1.63–2.75)].ConclusionAn increase in body mass index is associated with an increase in esophageal acid exposure, whether BMI was examined as a continuous or as a categorical variable; 13% of the variation in esophageal acid exposure may be attributable to variation in BMI.


Journal of Gastrointestinal Surgery | 2009

A New Technique for Measurement of Pharyngeal pH: Normal Values and Discriminating pH Threshold

Shahin Ayazi; John C. Lipham; Jeffrey A. Hagen; Andrew Tang; Jörg Zehetner; Jessica M. Leers; Arzu Oezcelik; Emmanuele Abate; Farzaneh Banki; Steven R. DeMeester; T. R. DeMeester

IntroductionIdentifying gastroesophageal reflux disease as the cause of respiratory and laryngeal complaints is difficult and depends largely on the measurements of increased acid exposure in the upper esophagus or ideally the pharynx. The current method of measuring pharyngeal pH environment is inaccurate and problematic due to artifacts. A newly designed pharyngeal pH probe to avoid these artifacts has been introduced. The aim of this study was to use this probe to measure the pharyngeal pH environment in normal subjects and establish pH thresholds to identify abnormality.MethodsAsymptomatic volunteers were studied to define the normal pharyngeal pH environment. All subjects underwent esophagram, esophageal manometry, upper and lower esophageal pH monitoring with a dual-channel pH catheter and pharyngeal pH monitoring with the new probe. Analyses were performed at 0.5 pH intervals between pH 4 and 6.5 to identify the best discriminating pH threshold and calculate a composite pH score to identify an abnormal pH environment.ResultsThe study population consisted of 55 normal subjects. The pattern of pharyngeal pH environment was significantly different in the upright and supine periods and required different thresholds. The calculated discriminatory pH threshold was 5.5 for upright and 5.0 for supine periods. The 95th percentile values for the composite score were 9.4 for upright and 6.8 for supine.ConclusionA new pharyngeal pH probe which detects aerosolized and liquid acid overcomes the artifacts that occur in measuring pharyngeal pH with existing catheters. Discriminating pH thresholds were selected and normal values defined to identify patients with an abnormal pharyngeal pH environment.


The Journal of Thoracic and Cardiovascular Surgery | 2011

Endoscopic resection and ablation versus esophagectomy for high-grade dysplasia and intramucosal adenocarcinoma

Jörg Zehetner; Steven R. DeMeester; Jeffrey A. Hagen; Shahin Ayazi; Florian Augustin; John C. Lipham; Tom R. DeMeester

BACKGROUND Esophagectomy has been the traditional therapy for high-grade dysplasia and intramucosal adenocarcinoma. New endoscopic approaches allow treatment of these lesions with esophageal preservation. The aim of this study was to compare the outcome of endoscopic therapy with esophagectomy for high-grade dysplasia and intramucosal cancer. METHODS A retrospective review was performed of all patients treated for high-grade dysplasia or intramucosal adenocarcinoma from 2001 to April 2010. RESULTS Endoscopic therapy was performed in 40 patients (high-grade dysplasia = 22, intramucosal cancer = 18) and esophagectomy in 61 patients (high-grade dysplasia = 13, intramucosal cancer = 48). Endotherapy consisted of 102 endoscopic resections and 79 mucosal ablations (median 3 interventions per patient). In the endotherapy group, intramucosal cancer was completely resected in all patients. At last assessment, 10 patients have been converted to intestinal metaplasia without dysplasia and 21 to no residual intestinal metaplasia. Five patients have follow-up biopsy procedures pending after recent ablation, and esophagectomy was performed in 3 patients for failed endotherapy. A laparoscopic Nissen fundoplication has been performed in 8 patients after eradication of intestinal metaplasia. Esophagectomy resected the mucosal disease with negative margins in all patients. Compared with esophagectomy, endotherapy was associated with significantly lower morbidity (39% vs 0; P < .0001) and similar survival (94% at 3 years in both groups; median follow-up 34 months after esophagectomy vs 17 months after endotherapy; P = .0026). CONCLUSIONS Endoscopic therapy for high-grade dysplasia or intramucosal cancer has lower morbidity than an esophagectomy and similar survival during short-term follow-up, but required multiple procedures in most patients. Both therapies are appropriate options, but preservation of the esophagus allows the option of a fundoplication for reflux control, perhaps further improving long-term quality of life.


Journal of The American College of Surgeons | 2010

Recurrence after Esophagectomy for Adenocarcinoma: Defining Optimal Follow-Up Intervals and Testing

Emmanuele Abate; Steven R. DeMeester; Joerg Zehetner; Arzu Oezcelik; Shahin Ayazi; Jesse L. Costales; Farzaneh Banki; John C. Lipham; Jeffrey A. Hagen; Tom R. DeMeester

BACKGROUND To determine the optimal follow-up strategy after esophagectomy for adenocarcinoma of the esophagus or gastroesophageal junction by evaluating the timing of recurrence and the method that first detected the recurrence. STUDY DESIGN Between 1991 and 2007, 590 patients had an esophagectomy for adenocarcinoma. Recurrence occurred in 233 (40%) and, of those, 174 had complete follow-up at our center with a protocol that consisted of an office visit with CT scans and laboratory studies every 3 months for 3 years, every 6 months for 2 years, and then annually. A subset of patients had PET annually. RESULTS Recurrence in the 174 patients with complete follow-up was systemic in 104 (60%), locoregional/nodal in 51 (30%), and both in 19 (10%). Recurrence was first suspected by symptoms and/or physical examination in 29 patients (17%), by CT scan in 105 (60%), PET in 32 (18%), and by elevated CEA in 8 (5%). Recurrence was detected at a median of 11 months (range 3 to 72 months) and occurred later after esophagectomy alone compared with patients who received neoadjuvant therapy (12 versus 8 months; p = 0.01), but the pattern of recurrence was similar. More than 90% of recurrences were detected within 2 years after neoadjuvant therapy, compared with 3 years after esophagectomy alone. Median survival after recurrence was 7 months and was significantly longer in patients treated for the recurrence (9 versus 3 months; p = 0.001). CONCLUSIONS Frequent early follow-up is appropriate after esophagectomy for adenocarcinoma because >90% of recurrences will occur by 3 years after esophagectomy alone and by 2 years following neoadjuvant therapy. Beyond these time periods, 2% to 3% of recurrences were detected each year, suggesting that annual follow-up is adequate. Survival after recurrence was improved with therapy, confirming the use of careful follow-up in these patients.


Journal of The American College of Surgeons | 2011

Laparoscopic versus Open Repair of Paraesophageal Hernia: The Second Decade

Jörg Zehetner; Steven R. DeMeester; Shahin Ayazi; Patrick Kilday; Florian Augustin; Jeffrey A. Hagen; John C. Lipham; Helen J. Sohn; Tom R. DeMeester

BACKGROUND A decade ago we reported that laparoscopic repair of paraesophageal hernia (PEH) had an objective recurrence rate of 42% compared with 15% after open repair. Since that report we have modified our laparoscopic technique. The aim of this study was to determine if these modifications have reduced the rate of objective hernia recurrence. STUDY DESIGN We retrospectively identified all patients that had primary repair of a PEH with ≥ 50% of the stomach in the chest from May 1998 to January 2010 with objective follow-up by videoesophagram. The finding of any size of hernia was considered to be recurrence. RESULTS There were 73 laparoscopic and 73 open PEH repairs that met the study criteria. There were no significant differences in gender, body mass index, or prevalence of a comorbid condition between groups. The median follow-up was similar (12 months laparoscopic versus 16 months open; p = 0.11). In the laparoscopic group, 84% of patients had absorbable mesh reinforcement of the crural closure and 40% had a Collis gastroplasty, compared with 32% and 26%, respectively, in the open group. A recurrent hernia was identified in 27 patients (18%), 9 after laparoscopic repair and 18 after open repair (p = 0.09). The median size of a recurrent hernia was 3 cm, and the incidence of recurrence increased yearly in those with serial follow-up with no early peak or late plateau. CONCLUSIONS In our first decade of laparoscopic PEH repair, no mesh crural reinforcement was used, and no patient had a Collis gastroplasty. Evolution in the technique of laparoscopic PEH repair during the subsequent decade has reduced the hernia recurrence rate to that seen with an open approach. Reduced morbidity and shorter hospital stay make laparoscopy the preferred approach, but continued efforts to reduce hernia recurrence are warranted.


Clinical Gastroenterology and Hepatology | 2009

Bravo Catheter-Free pH Monitoring: Normal Values, Concordance, Optimal Diagnostic Thresholds, and Accuracy

Shahin Ayazi; John C. Lipham; Giuseppe Portale; Christian G. Peyre; Christopher G. Streets; Jessica M. Leers; Steven R. DeMeester; Farzaneh Banki; Linda S. Chan; Jeffrey A. Hagen; Tom R. DeMeester

BACKGROUND & AIMS The Bravo pH capsule is a catheter-free intraesophageal pH monitoring system that avoids the discomfort of an indwelling catheter. The objectives of this study were as follows: (1) to obtain normal values for the first and second 24-hour recording periods using a Bravo capsule placed transnasally 5 cm above the upper border of the lower esophageal sphincter determined by manometry and to assess concordance between the 2 periods, (2) to determine the optimal discriminating threshold for identifying patients with gastroesophageal reflux disease (GERD), and (3) to validate this threshold and to identify the recording period with the greatest accuracy. METHODS Normal values for a manometrically positioned, transnasally inserted Bravo capsule were determined in 50 asymptomatic subjects. A test population of 50 subjects (25 asymptomatic, 25 with GERD) then was monitored to determine the best discriminating thresholds. The thresholds for the first, second, and combined (48-hour) recording periods then were validated in a separate group of 115 patients. RESULTS In asymptomatic subjects, the values measured using a manometrically positioned Bravo pH capsule were similar between the first and second 24-hour periods of recording. The highest level of accuracy with Bravo was observed when an abnormal composite pH score was obtained in the first or second 24-hour period of monitoring. CONCLUSIONS Normal values for esophageal acid exposure were defined for a manometrically positioned, transnasally inserted, Bravo pH capsule. An abnormal composite pH score, obtained in either the first or second 24-hour recording period, was the most accurate method of identifying patients with GERD.


The Journal of Thoracic and Cardiovascular Surgery | 2009

Clinical characteristics, biologic behavior, and survival after esophagectomy are similar for adenocarcinoma of the gastroesophageal junction and the distal esophagus

Jessica M. Leers; Steven R. DeMeester; Nadia Chan; Shahin Ayazi; Arzu Oezcelik; Emmanuele Abate; Farzaneh Banki; John C. Lipham; Jeffrey A. Hagen; Tom R. DeMeester

OBJECTIVE The Siewert classification system differentiates between adenocarcinoma of the gastroesophageal junction and that of the distal esophagus. The purpose of this study was to evaluate whether there were differences in the location and prevalence of lymph node metastases, type of recurrence, and survival with these tumors that warrant distinguishing between them in clinical practice. METHODS Records of all patients who underwent resection for adenocarcinoma of the distal esophagus or gastroesophageal junction from 1987 to 2007 were retrospectively reviewed. Based on the endoscopic location of the epicenter of the tumor in relation to the gastroesophageal junction, tumors were categorized in 301 patients as being of the distal esophagus and in 208 as being of the gastroesophageal junction. RESULTS There were no significant differences in age, sex, or body mass index between patients with adenocarcinoma of the distal esophagus or gastroesophageal junction. Patients with adenocarcinoma of the distal esophagus were more likely to have reflux symptoms (75% vs 53%, P < .0001) and peritumoral intestinal metaplasia (73% vs 51%, P < .0001) and be in a surveillance program (54% vs 9%, P = .0005) compared with patients with adenocarcinoma of the gastroesophageal junction. However, the prevalence and location of nodal metastases was similar, and in node-positive patients mediastinal node involvement was present in more than 40% of the patients in each group (distal esophageal adenocarcinoma, 47%; gastroesophageal junction adenocarcinoma, 41%). Survival was similar (5 years: distal esophageal adenocarcinoma, 45%; gastroesophageal junction adenocarcinoma, 38%; P = .14), as was the prevalence and type of recurrence. CONCLUSION The prevalence and distribution of lymph node metastases in patients with adenocarcinoma of the distal esophagus and gastroesophageal junction were similar, and after esophagectomy, there was no difference in overall survival or recurrence. Efforts to differentiate between these tumors are unnecessary, and both are effectively treated with esophagectomy.


Annals of Surgery | 2010

The impact of gastric distension on the lower esophageal sphincter and its exposure to acid gastric juice.

Shahin Ayazi; Anand P. Tamhankar; Steven R. DeMeester; Joerg Zehetner; Calvin Wu; John C. Lipham; Jeffrey A. Hagen; Tom R. DeMeester

Background and Aims:The lower esophageal sphincter (LES) in patients with gastroesophageal reflux disease often has a low resting pressure and a short abdominal length. The mechanism by which this occurs is unknown. We hypothesize that gastric distension causes progressive effacement of the abdominal portion of the LES, exposing it to acid injury resulting in mucosal and sphincter damage. Our aim was to assess in normal subjects the effect of gastric distension on the LES length and pressure and its exposure to acid gastric juice. Methods:Eleven asymptomatic volunteers had their LES length and pressure measured before and during gastric distension. The location of the pH step-up point (shift from gastric pH to a pH >4) was also measured before and after distension. Results:Progressive gastric distension with air resulted in progressive shortening of LES (R2 = 0.89, P < 0.0001). After infusion of 750 cc of air there was a significant reduction in the median LES length from 4 to 2.6 cm (P = 0.001). This change occurred in the abdominal length of the LES (2.6–1.4 cm [P = 0.001]) and not in the thoracic length. At rest the pH step-up point was 0.5 cm above the lower border of the LES and with distension moved a median of 1 cm cephalad within the LES. Simultaneously with the loss of length there was a reduction in LES pressure (27.4–23.4 mm Hg, P = 0.02). Conclusions:Gastric distension causes progressive shortening of the abdominal length of the LES and a reduction in its pressure. The process exposes the effaced mucosa and sphincter to acid gastric juice.


Annals of Surgery | 2010

Genetic variations in angiogenesis pathway genes predict tumor recurrence in localized adenocarcinoma of the esophagus.

Georg Lurje; Jessica M. Leers; Alexandra Pohl; Arzu Oezcelik; Wu Zhang; Shahin Ayazi; Thomas Winder; Yan Ning; Dongyun Yang; Nancy Klipfel; Parakrama Chandrasoma; Jeffrey A. Hagen; Steven R. DeMeester; Tom R. DeMeester; Heinz-Josef Lenz

Objective:The aim of this study was to determine whether the risk of systemic disease after esophagectomy could be predicted by angiogenesis-related gene polymorphisms. Summary Background Data:Systemic tumor recurrence after curative resection continues to impose a significant problem in the management of patients with localized esophageal adenocarcinoma (EA). The identification of molecular markers of prognosis will help to better define tumor stage, indicate disease progression, identify novel therapeutic targets, and monitor response to therapy. Proteinase-activated-receptor 1 (PAR-1) and epidermal growth factor (EGF) have been shown to mediate the regulation of local and early-onset angiogenesis, and in turn may impact the process of tumor growth and disease progression. Methods:We investigated tissue samples from 239 patients with localized EA treated with surgery alone. DNA was isolated from formalin-fixed paraffin-embedded normal esophageal tissue samples and polymorphisms were analyzed using polymerase chain reaction-restriction fragment length polymorphism and 5′-end [&ggr;-33P] ATP-labeled polymerase chain reaction methods. Results:PAR-1 −506 ins/del (adjusted P value = 0.011) and EGF +61 A>G (adjusted P value = 0.035) showed to be adverse prognostic markers, in both univariate and multivariable analyses. In combined analysis, grouping alleles into favorable versus nonfavorable alleles, high expression variants of PAR-1 −506 ins/del (any insertion allele) and EGF +61 A>G (A/A) were associated with a higher likelihood of developing tumor recurrence (adjusted P value <0.001). Conclusion:This study supports the role of functional PAR-1 and EGF polymorphisms as independent prognostic markers in localized EA and may therefore help to identify patient subgroups at high risk for tumor recurrence.

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Steven R. DeMeester

University of Southern California

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Jeffrey A. Hagen

University of Southern California

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John C. Lipham

University of Southern California

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Tom R. DeMeester

University of Southern California

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Arzu Oezcelik

University of Southern California

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Joerg Zehetner

University of Southern California

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Farzaneh Banki

University of Texas Health Science Center at Houston

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Emmanuele Abate

University of Southern California

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Jessica M. Leers

University of Southern California

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Helen J. Sohn

University of Southern California

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