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Dive into the research topics where Ahmed A. Messallam is active.

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Featured researches published by Ahmed A. Messallam.


Gastrointestinal Endoscopy | 2015

International multicenter experience with peroral endoscopic myotomy for the treatment of spastic esophageal disorders refractory to medical therapy (with video)

Mouen A. Khashab; Ahmed A. Messallam; Manabu Onimaru; Ezra N. Teitelbaum; Michael B. Ujiki; Matthew E. Gitelis; Rani J. Modayil; Eric S. Hungness; Stavros N. Stavropoulos; Mohamad H. El Zein; Hironari Shiwaku; Rastislav Kunda; Alessandro Repici; Hitomi Minami; Philip W. Chiu; Jeffrey L. Ponsky; Vivek Kumbhari; Payal Saxena; Amit Maydeo; Haruhiro Inoue

BACKGROUND Limited data exist on the use of peroral endoscopic myotomy (POEM) for therapy of spastic esophageal disorders (SEDs). OBJECTIVE To study the efficacy and safety of POEM for the treatment of patients with diffuse esophageal spasm, jackhammer esophagus, or type III (spastic) achalasia. DESIGN Retrospective study. SETTING International, multicenter, academic institutions. PATIENTS All patients who underwent POEM for treatment of SEDs refractory to medical therapy at 11 centers were included. INTERVENTIONS POEM. MAIN OUTCOME MEASUREMENTS Eckardt score and adverse events. RESULTS A total of 73 patients underwent POEM for treatment of SEDs (diffuse esophageal spasm 9, jackhammer esophagus 10, spastic achalasia 54). POEM was successfully completed in all patients, with a mean procedural time of 118 minutes. The mean length of the submucosal tunnel was 19 cm, and the mean myotomy length was 16 cm. A total of 8 adverse events (11%) occurred, with 5 rated as mild, 3 moderate, and 0 severe. The mean length of hospital stay was 3.4 days. There was a significant decrease in Eckardt scores after POEM (6.71 vs 1.13; P = .0001). Overall, clinical response was observed in 93% of patients during a mean follow-up of 234 days. Chest pain significantly improved in 87% of patients who reported chest pain before POEM. Repeat manometry after POEM was available in 44 patients and showed resolution of initial manometric abnormalities in all cases. LIMITATIONS Retrospective design and selection bias. CONCLUSION POEM offers a logical therapeutic modality for patients with SEDs refractory to medical therapy. Results from this international study suggest POEM as an effective and safe platform for these patients.


Endoscopy International Open | 2015

Peroral endoscopic myotomy (POEM) vs laparoscopic Heller myotomy (LHM) for the treatment of Type III achalasia in 75 patients: a multicenter comparative study.

Vivek Kumbhari; Alan H. Tieu; Manabu Onimaru; Mohammad H. El Zein; Ezra N. Teitelbaum; Michael B. Ujiki; Matthew E. Gitelis; Rani J. Modayil; Eric S. Hungness; Stavros N. Stavropoulos; Hiro Shiwaku; Rastislav Kunda; Philip W. Chiu; Payal Saxena; Ahmed A. Messallam; Haruhiro Inoue; Mouen A. Khashab

Background and study aims: Type III achalasia is characterized by rapidly propagating pressurization attributable to spastic contractions. Although laparoscopic Heller myotomy (LHM) is the current gold standard management for type III achalasia, peroral endoscopic myotomy (POEM) is conceivably superior because it allows for a longer myotomy. Our aims were to compare the efficacy and safety of POEM with LHM for type III achalasia patients. Patients and methods: A retrospective study of 49 patients who underwent POEM for type III achalasia across eight centers were compared to 26 patients who underwent LHM at a single institution. Procedural data were abstracted and pre- and post-procedural symptoms were recorded. Clinical response was defined by improvement of symptoms and decrease in Eckardt stage to ≤ 1. Secondary outcomes included length of myotomy, procedure duration, length of hospital stay, and rate of adverse events. Results: Clinical response was significantly more frequent in the POEM cohort (98.0 % vs 80.8 %; P = 0.01). POEM patients had significantly shorter mean procedure time than LHM patients (102 min vs 264 min; P < 0.01) despite longer length of myotomy (16 cm vs 8 cm; P < 0.01). There was no significant difference between POEM and LHM in the length of hospital stay (3.3 days vs 3.2 days; P = 0.68), respectively. Rate of adverse events was significantly less in the POEM group (6 % vs 27 %; P < 0.01). Conclusions: POEM allows for a longer myotomy than LHM, which may result in improved clinical outcomes. POEM appears to be an effective and safe alternative to LHM in patients with type III achalasia.


Endoscopy International Open | 2016

International multicenter comparative trial of transluminal EUS-guided biliary drainage via hepatogastrostomy vs. choledochoduodenostomy approaches

Mouen A. Khashab; Ahmed A. Messallam; I Peñas; Yousuke Nakai; Rani J. Modayil; Carlos De la Serna; Kazuo Hara; Mohamad H. El Zein; Stavros N. Stavropoulos; Manuel Perez-Miranda; Vivek Kumbhari; Saowanee Ngamruengphong; Vinay Dhir; Do Hyun Park

Background and study aims: Endoscopic ultrasound-guided biliary drainage (EUS-BD) can be performed entirely transgastrically (hepatogastrostomy/EUS-HG) or transduodenally (choledochoduodenostomy/EUS-CDS). It is unknown how both techniques compare. The aims of this study were to compare efficacy and safety of both techniques and identify predictors of adverse events. Patients and methods: Consecutive jaundiced patients with distal malignant biliary obstruction who underwent EUS-BD at multiple international centers were included. Technical/clinical success, adverse events, stent complications, and survival were assessed. Results: A total of 121 patients underwent EUS-BD (CDS 60, HG 61). Technical success was achieved in 112 (92.56 %) patients (EUS-CDS 93.3 %, EUS-HG 91.8 %, P = 0.75). Clinical success was attained in 85.5 % of patients who underwent EUS-CDS group as compared to 82.1 % of patients who underwent EUS-HG (P = 0.64). Adverse events occurred more commonly in the EUS-HG group (19.67 % vs. 13.3 %, P = 0.37). Both plastic stenting (OR 4.95, 95 %CI 1.41 – 17.38, P = 0.01) and use of non-coaxial electrocautery (OR 3.95, 95 %CI 1.16 – 13.40, P = 0.03) were independently associated with adverse events. Length of hospital stay was significantly shorter in the CDS group (5.6 days vs. 12.7 days, P < 0.001). Mean follow-up duration was 151 ± 159 days. The 1-year stent patency probability was greater in the EUS-CDS group [0.98 (95 %CI 0.76 – 0.96) vs 0.60 (95 %CI 0.35 – 0.78)] but overall patency was not significantly different. There was no difference in median survival times between the groups (P = 0.36) Conclusions: Both EUS-CDS and EUS-HG are effective and safe techniques for the treatment of distal biliary obstruction after failed ERCP. However, CDS is associated with shorter hospital stay, improved stent patency, and fewer procedure- and stent-related complications. Metallic stents should be placed whenever feasible and non-coaxial electrocautery should be avoided when possible as plastic stenting and non-coaxial electrocautery were independently associated with occurrence of adverse events.


Gastrointestinal Endoscopy | 2014

Resolution of walled-off pancreatic necrosis by EUS-guided drainage when using a fully covered through-the-scope self-expandable metal stent in a single procedure (with video)

Payal Saxena; Vikesh K. Singh; Ahmed A. Messallam; Ayesha Kamal; Atif Zaheer; Vivek Kumbhari; Anne Marie Lennon; Marcia I. Canto; Anthony N. Kalloo; Todd H. Baron; Mouen A. Khashab

BACKGROUND Walled-off pancreatic necrosis (WOPN) is effectively managed with percutaneous and endoscopic techniques such as direct endoscopic necrosectomy. However, they require repeat interventions and lengthy hospital stays. OBJECTIVE To evaluate a new platform to manage WOPNs by using a large-bore, through-the-scope, fully covered, self-expandable metal stent (FCSEMS) to overcome the need for repeat interventions and extended hospital stays. DESIGN Retrospective, single-center study. SETTING Academic tertiary care center. PATIENTS Five consecutive patients with symptomatic WOPN underwent EUS-guided drainage of WOPN by using a large-bore FCSEMSs. INTERVENTIONS EUS-guided transgastric drainage of WOPN by using a large-bore FCSEMS. Cross-sectional imaging was repeated at 6- to 8-week intervals. The FCSEMS was removed after WOPN resolution. MAIN OUTCOME MEASUREMENTS Clinical success, number of repeat interventions, and length of hospital stay. RESULTS Five patients (mean age 60 years) with WOPN (mean diameter, 12.3 cm; range 9.8-14.3 cm) underwent drainage with the described technique. Technical and clinical success was achieved in 100% of patients. Direct endoscopic necrosectomy was not required in any patient. The median number of endoscopic procedures was 1. The median length of hospital stay was 1 day. There were no adverse events. LIMITATIONS Small, retrospective study. CONCLUSIONS The described novel platform facilitates resolution of WOPN with a single procedure, avoiding the need for repeat interventions and lengthy hospital stays.


Endoscopy International Open | 2015

Comparison of EUS-guided tissue acquisition using two different 19-gauge core biopsy needles: a multicenter, prospective, randomized, and blinded study.

John M. DeWitt; Chang-Min Cho; Jingmei Lin; Mohammad Al-Haddad; Marcia I. Canto; Ashley Salamone; Ralph H. Hruban; Ahmed A. Messallam; Mouen A. Khashab

Background and study aims: The optimal core biopsy needle for endoscopic ultrasound (EUS) is unknown. The principle aim of this study is to compare outcomes of EUS-fine-needle biopsy (EUS-FNB) with a new 19-gauge EUS histology needle (ProCore, Cook Medical Inc., Winston-Salem, North Carolina, United States) to a conventional 19-gauge Tru-Cut biopsy (EUS-TCB) needle (19G, Quick-Core, Cook Medical Inc.). Patients and methods: Patients referred for EUS who require possible histologic biopsy were prospectively randomized to EUS-FNB or EUS-TCB. With the initial needle, ≤ 3 biopsies were obtained until either technical failure or an adequate core was obtained. Patients with suspected inadequate biopsies were crossed over to the other needle and similarly ≤ 3 passes were obtained until adequate cores or technical failure occurred. Technical success, diagnostic histology, accuracy and complication rates were evaluated. Results: Eighty-five patients (mean 58 years; 43 male) were randomized to FNB (n = 44) and TCB (n = 41) with seven patients excluded. Procedure indication, biopsy site, mass size, number of passes, puncture site, overall technical success and adverse events were similar between the two groups. FNB specimens had a higher prevalence of diagnostic histology (85 % vs. 57 %; P = 0.006), accuracy (88 % vs. 62 %; P = 0.02), mean total length (19.4 vs. 4.3 mm; P = 0.001), mean complete portal triads from liver biopsies (10.4 vs. 1.3; P = 0.0004) and required fewer crossover biopsies compared to those of TCB (2 % vs. 65 %; P = 0.0001). Overall technical success and complication rates were comparable. Conclusion: EUS-FNB using a 19-gauge FNB needle is superior to 19-gauge EUS-TCB needle.


Endoscopy | 2014

Deep enteroscopy with standard endoscopes using a novel through-the-scope balloon

Vivek Kumbhari; Andrew C. Storm; Mouen A. Khashab; Marcia I. Canto; Payal Saxena; Venkata S. Akshintala; Ahmed A. Messallam; Vikesh K. Singh; Anne Marie Lennon; Eun Ji Shin; Joanna K. Law; Patrick I. Okolo

BACKGROUND AND STUDY AIMS A new on-demand enteroscopy (ODE) device has been designed to allow deep enteroscopy using a standard adult colonoscope with the aid of a novel through-the-scope balloon. The aims of the current study were to establish the feasibility, efficacy, and safety of ODE in performing anterograde and retrograde enteroscopy. PATIENTS AND METHODS A retrospective, single-center study of 28 consecutive deep ODE procedures (11 anterograde and 17 retrograde) was performed. Diagnostic yield, therapeutic yield, technical success, procedure time, depth of maximal insertion (DMI), time to DMI, and adverse events were recorded. RESULTS The mean diagnostic and therapeutic yields were 45 % and 36 % for anterograde enteroscopy and 59 % and 47 % for retrograde enteroscopy, respectively. Technical success was achieved in 100 %. For anterograde enteroscopy, the mean total procedure time was 24 minutes, with a mean DMI of 1.2 m. For retrograde enteroscopy, the mean total procedure time was 31 minutes, with a mean DMI of 1.1 m. No adverse events were recorded. CONCLUSION Deep enteroscopy using a novel through-the-scope balloon and standard endoscope appeared to be feasible and safe, with rapid procedures times.


Surgical Endoscopy and Other Interventional Techniques | 2015

Iatrogenic pharyngoesophageal perforations treated with fully covered self-expandable metallic stents (with video)

Vivek Kumbhari; Alba A. Azola; Alan H. Tieu; Reetika Sachdeva; Payal Saxena; Ahmed A. Messallam; Mohamad H. El Zein; Patrick I. Okolo; Mouen A. Khashab

BackgroundIatrogenic pharyngoesophageal perforations are a rare but serious complication of endoscopy. Surgical and non-surgical approaches have been reported but result in a significant morbidity and extended hospital stay. Therefore, an unmet need exists for an alternative management technique. We demonstrate a new endoscopic approach for the management of iatrogenic pharyngoesophageal perforations through the use of esophageal fully covered self-expandable metallic stents (FCSEMS).Patients and methodsTwo patients who underwent flexible endoscopy each suffered a large iatrogenic perforation detected intraprocedurally. After emergency intubation, an esophageal FCSEMS was deployed in the hypopharynx and the patient admitted to the intensive care unit. On day 3, the patients underwent an esophagogastroduodenoscopy with stent removal.ResultsThere was complete closure of the perforations on day 3. The patients were extubated and subsequently tolerated a soft diet. The patients were discharged home on day 4.ConclusionsThe placement of a removable FCSEMS in the setting of an acutely diagnosed perforation may be a suitable minimally invasive approach for the management of iatrogenic pharyngoesophageal perforations.


Endoscopy | 2018

Stylet slow-pull versus standard suction for endoscopic ultrasound-guided fine-needle aspiration of solid pancreatic lesions: a multicenter randomized trial

Payal Saxena; Mohamad H. El Zein; Tyler Stevens; Ahmed Abdelgelil; Sepideh Besharati; Ahmed A. Messallam; Vivek Kumbhari; Alba Azola; Jennifer Brainard; Eun Ji Shin; Anne Marie Lennon; Marcia I. Canto; Vikesh K. Singh; Mouen A. Khashab

BACKGROUND AND STUDY AIM Standard endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) procedures involve use of no-suction or suction aspiration techniques. A new aspiration method, the stylet slow-pull technique, involves slow withdrawal of the needle stylet to create minimum negative pressure. The aim of this study was to compare the sensitivity of EUS-FNA using stylet slow-pull or suction techniques for malignant solid pancreatic lesions using a standard 22-gauge needle. PATIENTS AND METHODS Consecutive patients presenting for EUS-FNA of pancreatic mass lesions were randomized to the stylet slow-pull or suction techniques using a 22-gauge needle. Both techniques were standardized for each pass until an adequate specimen was obtained, as determined by rapid on-site cytology examination. Patients were crossed over to the alternative technique after four nondiagnostic passes. RESULTS Of 147 patients screened, 121 (mean age 64 ± 13.8 years) met inclusion criteria and were randomized to the stylet slow-pull technique (n = 61) or the suction technique (n = 60). Technical success rates were 96.7 % and 98.3 % in the slow-pull and suction groups, respectively (P > 0.99). The sensitivity for malignancy of EUS-FNA was 82 % in the slow-pull group and 69 % in the suction group (P = 0.10). The first-pass diagnostic rate (42.6 % vs. 38.3 %; P = 0.71), acquisition of core tissue (60.6 % vs. 46.7 %; P = 0.14), and the median (range) number of passes to diagnosis (2 1 2 3 vs. 1 1 2; P = 0.71) were similar in the slow-pull and suction groups, respectively. CONCLUSIONS The stylet slow-pull and suction techniques both offered high and comparable diagnostic sensitivity with a mean of 2 passes required for diagnosis of solid pancreatic lesions. The endosonographer may choose either technique during FNA.


Endoscopy | 2015

Intraoperative determination of the adequacy of myotomy length during peroral endoscopic myotomy (POEM): The double-endoscope transillumination for extent confirmation technique (DETECT)

Mouen A. Khashab; Vivek Kumbhari; Alba Azola; Mohamad H. El Zein; Ahmed A. Messallam; Ahmed Abdelgelil; Sepideh Besharati; Anthony N. Kalloo; Payal Saxena

BACKGROUND AND STUDY AIMS Precise identification of the gastroesophageal junction (GEJ) is a challenging prerequisite for adequate length of an esophageal myotomy. Multiple standard methods to identify the GEJ have been described; however, a more objective modality is needed to ensure effective peroral endoscopic myotomy (POEM). PATIENTS AND METHODS In the double-endoscope transillumination for extent confirmation technique (DETECT), an ultraslim gastroscope is passed to the most distal aspect of the submucosal tunnel created during POEM. A regular gastroscope is advanced into the stomach, and the visualization of transillumination from the ultraslim gastroscope enables identification of the extent of the submucosal tunnel. RESULTS A total of 10 patients underwent POEM with DETECT. Initial submucosal tunneling was performed based on a determination of the GEJ location via standard methods. DETECT indicated the tunnel extent to be inadequate in 50% of patients, and the tunnel was extended a further 1 to 2cm. The mean initial tunnel length was 15.4cm, with a mean initial myotomy length of 11.9cm. DETECT was performed in less than 10 minutes without complications. CONCLUSION DETECT is an objective method for determining the adequacy of the submucosal tunnel length during POEM.


Gastroenterology | 2014

Tu1978 LES Pressures Are Inversely Correlated to Esophagogastric Junction Diameter and Cross-Sectional Area in Achalasia

Shreya Raja; Mouen A. Khashab; John O. Clarke; Sameer Dhalla; Payal Saxena; Vivek Kumbhari; Alba Azola; Ahmed A. Messallam; Francis C. Okeke; Kristle Lynch; Bani Chander Roland; Monica Nandwani; Pankaj J. Pasricha; Ellen M. Stein

G A A b st ra ct s each method are shown in Table 1. Among these candidate methods, optimal discrimination from type I achalasia was achieved using the 4s-IRP method and receiver operating curve analysis revealed an optimal threshold %EGJR to be (<40%, sensitivity 100%, specificity 88%). The Figure shows %EGJR data using the 4s-IRP method for all patients compared to controls. As a single metric, the IRP exhibited superior discriminative performance to %EGJR among diagnoses. However, in certain instances, %EGJR was a useful secondary metric. Specifically, 100%(25 patients) of the Jackhammer group, a classification which may present with an elevated IRP and have an erroneous diagnosis of type III achalasia, fell within the normative range for percent EGJ relaxation. However, with low baseline EGJ pressure, %EGJR performed poorly in discriminating between patients with absent peristalsis(24/25 of whom had a collagen vascular disease or reflux disease) and type I achalasia. Conclusions: This study discounts the viability of the %EGJR metric as a stand-alone tool for assessing the adequacy of EGJ relaxation within the framework of the CC of motility disorders. However, there may be a supplementary role for this metric in identifying borderline cases of achalasia from mechanical causes of EGJ outflow obstruction and in differentiating Jackhammer cases from type III achalasia.

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Vivek Kumbhari

Johns Hopkins University

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Payal Saxena

Johns Hopkins University

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Alba Azola

Johns Hopkins University

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Alan H. Tieu

Johns Hopkins University

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