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Biomedical subjects

Manoop S Bhutani

Publications and source records attributed to Manoop S Bhutani.

At least 37 records · Page 2Linked to original sources

Therapeutic endoscopy and endoscopic ultrasound for gastrointestinal malignancies.

Gastrointestinal endoscopy and endoscopic ultrasound not only provide strategies to diagnose and stage malignancy, but also to administer palliative and definitive care. Options for anticancer therapy include endoscopic mucosal resection, photodynamic therapy, thermal therapy, self-expanding metal stents and recently, endoscopic ultrasound-guided therapy, such as intratumoral injection. This review summarizes the available endoscopic techniques with a discussion of indications and recent clinical data pertaining to gastrointestinal malignancy. This review will inform the reader of emerging treatment options and stress the importance of incorporating gastroenterologists into the multidisciplinary approach in the management of gastrointestinal cancers.

Endoscopy↗

Recent advances in cell biology, diagnosis, and therapy of gastrointestinal stromal tumor (GIST).

The understanding of mesenchymal neoplasms of the gastrointestinal tract has evolved dramatically over the last two decades since gastrointestinal stromal tumor (GIST) was described as the most common stromal tumor arising anywhere from the esophagus to the ano-rectum. Although morphologically similar to other benign and malignant smooth muscle and neural stromal neoplasms, GIST constitutes a distinct group of rare gastrointestinal tract tumors that originate from the interstitial cells of Cajal, regulators of gut peristalsis that normally express CD117, which is the product of the c-KIT proto-oncogene that encodes a tyrosine kinase receptor that regulates cellular proliferation in GISTs. Virtually all GISTs occur from mutations of the c-KIT oncogene and exhibit consistent expression of c-KIT (CD117), which is considered the most specific criterion for a diagnosis of GIST. Gastrointestinal stromal tumors vary in their behavior and several features have to be considered to assess their malignant potential. The advent of sophisticated imaging techniques for the evaluation and sampling of stromal tumors of the gastrointestinal tract has resulted in improved detection of GISTs. The identification of a novel tumor-specific target in c-KIT resulted in the development of a tyrosine kinase-inhibitor (imatinib mesylate) that provides an encouraging option for treating GISTs. This article reviews recent advances in the understanding of the cell biology, diagnosis, and therapy of GISTS.

Antineoplastic Agents↗

Lymph sampling and lymphangiography via EUS-guided transesophageal thoracic duct puncture in a swine model.

BACKGROUND: The thoracic duct plays an important role in fluid balance, lipid absorption, and transport of immunologically active cells. The thoracic duct is difficult to access but is readily identified by EUS. The present study assessed the feasibility of EUS identification and EUS-guided puncture of the thoracic duct in a swine model. METHODS: Transesophageal EUS-guided thoracic duct puncture was attempted in 3 animals under fluoroscopy. In two animals, the thoracic duct was identified by cutdown in the neck; in the third animal, EUS-guided puncture was performed under fluoroscopy alone. In one animal, the thoracic duct was opacified by injecting contrast medium. In the second animal, thoracic duct was injected with patent blue and contrast medium. OBSERVATIONS: Thoracic duct was identified and punctured successfully in all 3 animals. In the first animal, contrast medium containing lymph was aspirated. In the second animal, lymph containing patent blue was aspirated, and, in the third animal, successful puncture was confirmed by obtaining a lymphangiogram. CONCLUSIONS: This pilot study in an animal model demonstrates that transesophageal EUS-guided puncture of the thoracic duct is feasible and that the technique can be used for lymph sampling and/or lymphangiography.

Animals↗

Role of endoscopic ultrasonography in diseases of the extrahepatic biliary system.

Endoscopic ultrasonography (EUS) is one of the most recent advances in gastrointestinal endoscopy. Available EUS devices include echoendoscopes, such as radial scanning and linear array echoendoscopes, and catheter ultrasound probes. Endoscopic ultrasonography has various applications, such as staging of gastrointestinal malignancy, evaluation of submucosal tumors, and has grown to be an important modality in evaluating the pancreaticobiliary system. With regard to the biliary system, EUS is useful for the detection and staging of ampullary tumors, detection of microlithiasis and choledocholithiasis and evaluation of benign and malignant bile-duct strictures. Endoscopic ultrasonography may be used as an adjunct to transabdominal ultrasound for the detection and characterization of gallbladder polyps. In addition, EUS is helpful in the staging of gallbladder cancer as well as in diagnosing anomalous pancreaticobiliary junction with its associated pancreatobiliary diseases. The present paper reviews the current applications of EUS for imaging and intervention in diseases of the extrahepatic biliary system.

Ampulla of Vater↗

Quantitative analysis of endosonographic parenchymal echogenicity in patients with chronic pancreatitis.

BACKGROUND AND AIM: The aim of the study was to develop a method of quantitation of endoscopic ultrasonography (EUS) changes of chronic pancreatitis (CP). METHODS: Twenty-three patients with chronic pancreatitis by EUS were compared with nine normal subjects. Hyperechogenicity was evaluated as the size of the hyperechoic area that was over a threshold echogenicity level. Mean echo density was expressed using the average gray-scale value within the region of interest. The quantitative data were compared with the diagnosis using conventional EUS criteria. RESULTS: The size of the hyperechoic area over the threshold level was 0.86 +/- 0.67 mm2 (mean +/- SD) in the normal pancreas using EUS criteria. In chronic pancreatitis, the size of the hyperechoic area was 7.28 +/- 2.98 mm2 in patients with mild CP, 18.12 +/- 2.56 mm2 in patients with moderate CP, and 18.02 +/- 10.81 mm2 in patients with severe CP, respectively. These changes in hyperechoic size area were statistically significant in all patients having mild to severe CP when compared with normal controls. CONCLUSION: Computer analysis of EUS images may provide objective information for the diagnosis of CP and may be useful in quantitating the severity of disease and overcoming interobserver variability in analyzing individual echo features supporting the diagnosis of CP.

Aged↗

A descriptive analysis of EUS-FNA for mediastinal lymphadenopathy: an emphasis on clinical impact and false negative results.

OBJECTIVES: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been shown to accurately diagnose mediastinal lymph node pathology. We investigated the clinical impact of EUS-FNA in the management of patients with mediastinal lymphadenopathy, and determined the nature and clinical consequences of false negative results. METHODS: We analyzed a cohort of patients who were found to have mediastinal lymph nodes by EUS and underwent FNA. The diagnostic standard included FNA cytology, histopathology, and clinical follow-up. RESULTS: Sixty EUS-FNAs of mediastinal lymph nodes were performed on 59 patients (mean age 61 years old, 74.5% men) over a 24-month period. Prior to EUS, 20 (34%) patients had known malignancy. The most frequent indication for EUS was failed diagnosis by bronchoscopy (54%). EUS-FNA of lymph nodes showed malignant cells in 38%. The diagnostic accuracy of EUS-FNA was 84%. Among the 47 patients who were available for follow-up, EUS-FNA provided new information by changing the clinical diagnosis, and subsequently changed the management in 18 (38%) patients. The false negative rate was 20% (95% exact CI, 8.4-31.6%). Two of the 7 false negative cases received empiric chemoradiation without tissue diagnosis, and 4 received palliative treatment for advanced malignancy. CONCLUSION: The most common indication for EUS-FNA of the mediastinum in our institution is nondiagnostic transbronchial FNA. EUS-FNA is a valuable diagnostic method for sampling mediastinal lymph nodes and affecting management. False negative results do not appear to delay appropriate treatment or adversely affect clinical outcome.

Biopsy, Fine-Needle↗

Endoscopic sonographically guided fine-needle aspiration yield in submucosal tumors of the gastrointestinal tract.

OBJECTIVE: To study the yield of endoscopic ultrasonographically guided fine-needle aspiration cytologic examination in the diagnosis of submucosal masses. METHODS: From 1999 to 2003, 10 patients underwent ultrasonographically guided fine-needle aspiration for the cytologic diagnosis of submucosal masses in our institution. The endoscopic ultrasonography records and the cytology database were consulted, and the reports were analyzed, as were slide material and the technical aspects related to these procedures. All procedures were performed under conscious sedation and cardiorespiratory monitoring on an outpatient basis. Ten patients (4 men and 6 women; mean age, 60.8 years) were studied. RESULTS: Eight lesions were located in the stomach, and 2 were located in the esophagus, with a mean diameter of 3.3 cm. An experienced cytopathologist was present on-site during all procedures for assessment of adequacy and preliminary cytologic examination. Cytologic diagnoses were obtained in 8 cases as follows: 6 gastrointestinal stromal tumors, 1 organizing submucosal hematoma, and 1 low-grade mucosa-associated lymphoid tissue-associated lymphoma. Two cases consisted of scant gastric epithelium only and were considered nondiagnostic. The cytologic diagnoses guided further clinical treatment. CONCLUSIONS: Ultrasonographically guided fine-needle aspiration with cytopathologic analysis has a high accuracy rate (80%) for diagnosing submucosal lesions. These findings potentially affect clinical decision making.

Aged↗

Role of endoscopic ultrasonography in the diagnosis and treatment of cystic tumors of the pancreas.

Endoscopic ultrasound (EUS) allows high resolution imaging of the pancreas. EUS is a very useful technique for evaluating morphological features of a cystic tumors of the pancreas. These features include thick wall type, tumor protruding type, thick septal type, microcystic type, thin septal type and simple type. Malignant cystic lesions may present as a hypoechoic cystic/solid mass or as a complex cyst and are frequently associated with a dilated main pancreatic duct. There is some overlap between EUS appearances of non-neoplastic and neoplastic cystic pancreatic lesions. EUS guided FNA of cystic pancreatic lesions can play an important role in the differential diagnosis of these lesions and deciding about the need for surgery by evaluating cytology and tumor markers such as CEA in cyst fluid. There is some emerging data on EUS guided treatment of cystic pancreatic tumors by injection of alcohol.

Diagnosis, Differential↗

Role of para-esophageal collateral veins in patients with portal hypertension based on the results of endoscopic ultrasonography and liver scintigraphy analysis.

BACKGROUND AND AIMS: Para-esophageal collateral veins (para-ECV) are observed by endoscopic ultrasonography (EUS) in patients with portal hypertension. However, the role of para-ECV in the portal venous system is not clear. To verify the role of para-ECV in the portal venous system, we investigated the relationship between the development of para-ECV as determined by EUS, and the portal blood flow ratio (PBFR) as determined by liver scintigraphy using 99mTc-phytate. METHODS: Eighteen patients who did not have fundal gastric varices were studied before the start of and after the completion of all endoscopic sclerotherapy sessions for esophageal varices. EUS was performed to observe veins around the esophagus, para-ECV and perforating veins. To quantify the degree of development of para-ECV, the cross-sectional area of each para-ECV observed by EUS was measured. The sum total of these areas was used as an index of development of para-ECV. The PBFR was calculated by liver scintigraphy using 99mTc-phytate. The correlation between the sum total cross-sectional area of para-ECV and PBFR was examined. RESULTS: After all endoscopic injection sclerotherapy sessions, the total cross-sectional area of para-ECV was 29.32 (26.72) mm2 (mean (SD)) and the PBFR was 48.47 (17.87)% (mean (SD)). A significant correlation between them was noted after treatment (r = - 0.70, P < 0.01). Variceal recurrence was observed in three of the patients who had perforating veins connected with para-ECV, regardless of degree of the para-ECV. CONCLUSION: The para-ECV are collaterals, which reflect the portal blood flow after endoscopic sclerotherapy. para-ECV without perforating veins were considered to be important collaterals after treatment.

Aged↗

Differentiating pancreatic cancer from pseudotumorous chronic pancreatitis.

The differentiation between pancreatic carcinoma and pseudotumorous pancreatitis continues to be a challenge. Several diagnostic imaging and endoscopic modalities can assist in making the differentiation, but the accuracy of each method varies. Radiologic imaging techniques include transabdominal ultrasound, computed tomography, magnetic resonance imaging, magnetic resonance cholangiopancreatography, and positron emission tomography. Endoscopic techniques include endoscopic ultrasonography, intraductal ultrasonography, and endoscopic retrograde cholangiopancreatography with brush cytology of pancreatobiliary strictures, endoscopic forceps biopsy, and analysis of pancreatic juices for malignant cells. Tumor markers appear to be promising, but further studies are needed to define the role of these markers.

Biomarkers↗

Gastrointestinal endoscopic ultrasonography.

Although conventional endoscopy provides excellent visualization of gastrointestinal mucosa, it provides little information about intramural or nearby extramural lesions. The imaging of intraabdominal structures by conventional transabdominal ultrasound is degraded by ultrasound energy attenuation with distance. The provision of an ultrasound probe on a flexible gastrointestinal endoscope, to form an echoendoscope, provides excellent imaging of the gastrointestinal wall and of adjacent extramural structures. During the last two decades, endoscopic ultrasound, using an echoendoscope, has revolutionized the diagnosis and treatment of gastrointestinal diseases that affect the submucosa, deep bowel wall, and adjacent extramural structures. This article reviews the role of endoscopic ultrasound in the diagnosis and treatment of gastrointestinal disease, including standard and promising new applications, as well as standard and emerging new technology.

Endoscopes↗

Pyloric injection of botulinum toxin for treatment of diabetic gastroparesis.

BACKGROUND: Diabetic gastroparesis is a common clinical problem. The pathophysiology includes prolonged pyloric contractions that may cause functional resistance to gastric outflow. Botulinum toxin was injected into the pyloric sphincter in an attempt to decrease pyloric resistance and improve gastric emptying. METHODS: Six patients with diabetic gastroparesis and an abnormal solid phase gastric emptying study underwent upper endoscopy during which 100 units of botulinum toxin were injected into the pyloric sphincter. Gastric emptying studies were obtained at 48 hours and 6 weeks after injection. Patients were questioned about symptoms of gastroparesis, and a symptom score was obtained at baseline and at 2 weeks and 6 weeks after injection. OBSERVATIONS: There was a mean improvement in the subjective symptom score at 2 weeks of 55% (range 14% to 80%). This improvement was maintained at 6 weeks. There was a 52% improvement in gastric emptying at 2 and 6 weeks. CONCLUSION: Pyloric injection of botulinum toxin can improve symptoms and gastric emptying in patients with diabetic gastroparesis. Further evaluation of pyloric injection of botulinum toxin as a treatment for diabetic gastroparesis is warranted.

Aged↗

Role of endoscopic ultrasound (EUS) and EUS-guided fine needle aspiration in the diagnosis and treatment of cystic lesions of the pancreas.

INTRODUCTION AND AIMS: Cystic neoplasms of the pancreas may be inadvertently treated as benign pseudocysts in clinical practice, often without the use of cytology, cyst tumor markers, or histopathology. We assessed the utility of EUS-guided fine-needle aspiration (EUS-FNA) to assist in the diagnosis and management of pancreatic cysts. METHODOLOGY: All patients who had pancreatic cysts detected by EUS over a 24-month period were analyzed. Preoperative diagnosis was derived from an algorithm combining clinical history and endosonographic features. In selected cases, EUS-FNA was performed and cyst fluid aspirates were analyzed. Surgical specimens served as diagnostic standard. RESULTS: A total of 43 patients with pancreatic cysts underwent 45 EUS examinations. Surgical specimens were obtained from 9 patients (mucinous cystadenocarcinoma, 3; adenocarcinoma, 3; pancreatic endocrine tumor, 2; and benign cyst, 1); diagnostic EUS correctly predicted malignant cysts in 8/9 (88.9%). One case inaccurately interpreted by EUS as cystic neoplasm turned out to be a benign cyst on resection. Twenty-one patients underwent EUS-FNA. The cytologic interpretation was adenocarcinoma in 9.5% (2/21); suspicious for malignancy or atypical cells in 19.0% (4/21); benign in 66.6% (14/21); and insufficient cells in 4.8% (1/21). CONCLUSION: The information gathered from clinical history and EUS, complemented by fluid analysis after EUS-guided FNA, predicts neoplastic pancreatic cysts and assists in decision-making for medical or surgical approach.

Algorithms↗