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Biomedical subjects

Patrick R Pfau

Publications and source records attributed to Patrick R Pfau.

16 recordsLinked to original sources
PubMed2006

Screening for colorectal neoplasia with CT colonography: initial experience from the 1st year of coverage by third-party payers.

PURPOSE: To evaluate our experience in the 1st year of computed tomographic (CT) colonography screening since the initiation of local third-party payer coverage. MATERIALS AND METHODS: This HIPAA-compliant study was approved by the institutional review board, and informed consent was waived. Over a 1-year period that ended on April 27, 2005, 1110 consecutive adults (585 women, 525 men; mean age, 58.1 years) underwent primary CT colonography screening. More than 99% were covered by managed care agreements. CT colonographic interpretation was performed with primary three-dimensional polyp detection, and the final results were issued within 2 hours. Patients with large (> or =10-mm) polyps were referred for same-day optical colonoscopy, and patients with medium-sized (6-9-mm) lesions had the option of immediate optical colonoscopy or short-term CT colonography surveillance. RESULTS: Large colorectal polyps were identified at CT colonography in 43 (3.9%) of 1110 patients. Medium-sized lesions were identified in 77 (6.9%) patients, 31 (40%) of whom chose optical colonoscopy and 46 (60%) of whom chose CT colonography surveillance. Concordant lesions were identified in 65 of 71 patients who underwent subsequent optical colonoscopy (positive predictive value, 91.5%). Sixty-one (86%) of 71 optical colonoscopic procedures were performed on the same day as CT colonography, thereby avoiding the need for repeat bowel preparation. The actual endoscopic referral rate for positive findings at CT colonography was 6.4% (71 of 1110 patients). The demand for CT colonography screening from primary care physicians and their patients increased throughout the study period. CONCLUSION: As a primary colorectal screening tool, CT colonography covered by third-party payers has an acceptably low endoscopic referral rate and a high concordance of positive findings at optical colonoscopy.

Chi-Square Distribution↗
PubMed2006

Comparison of the effect of non-ionic and ionic contrast agents on pancreatic histology in a canine model.

CONTEXT: Pancreatitis is the most frequent complication of endoscopic retrograde cholangiopancreatography. Controversy exists whether low osmolarity non-ionic contrast agents lessen the rate of pancreatitis and pancreatic injury. To evaluate we used a canine model to compare pancreatography performed with ionic and non-ionic contrast. DESIGN: Dogs were anesthetized and underwent open transduodenal cannulation of the main pancreatic duct under fluoroscopic control until complete acinarization was achieved to maximize injury. Three dogs received diatrozate, an ionic contrast agent with osmolarity of 1,415 mosM and three dogs were injected with omnipaque a non-ionic agent with osmolarity of 672 mosM. MAIN OUTCOME MEASURES: Serial amylase and white cell counts were followed for 48 hours at which time dogs were sacrificed. Each pancreas was then examined for evidence of pancreatitis and cellular injury with both light and electron microscopy. RESULTS: All animals developed significant hyperamylasemia and elevated white blood cell counts, without significant difference in the mean peak amylase (10,721 U/L vs. 9,367 U/L, P=0.876) or white cell counts (25.8 k/mL vs. 24.1 k/mL, P=0.586) between the ionic and non-ionic contrast groups. Light microscopy showed no evidence of pancreatitis in either group of dogs. Electron microscopy showed cellular injury of the ductal cells in two dogs injected with non-ionic contrast. CONCLUSION: In a pancreatic canine model, low osmolarity, non-ionic contrast does not appear to lessen cellular injury.

Amylases↗
PubMed2006

EUS characteristics of Nissen fundoplication: normal appearance and mechanisms of failure.

BACKGROUND: In patients who develop symptoms after Nissen fundoplication, the precise mechanism of failure can be difficult to determine. Current testing modalities do not demonstrate sufficient anatomic detail to definitively determine the mechanism. This observational study establishes that EUS can determine fundoplication integrity and hiatal anatomic relationships after Nissen fundoplication. METHODS: EUS was performed on the native esophagogastric junction and after Nissen fundoplication in two swine. The EUS characteristics of a properly performed fundoplication were determined. Subsequently, complications of Nissen fundoplication were created, and EUS was performed on each. The EUS criteria of each mechanism of failure were defined. RESULTS: EUS provided sufficient axial resolution to distinguish the esophagus, the fundoplication, and the surrounding hiatal structures within a single image. US of the native esophagogastric junction discerned the length of intra-abdominal esophagus, esophagogastric junction, crura, and anterior hiatus, and, thus, the point of entry into the abdominal cavity. EUS of Nissen fundoplication revealed a 5-layered pattern in a 360 degree configuration. These layers represent the following: (1) the esophageal wall, (2) the space between the esophagus and the fundoplication, (3) the inner gastric wall of the fundoplication, (4) the gastric lumen, and (5) the outer gastric wall of the fundoplication. A slipped repair was identified by the presence of an echogenic gastric serosa within the fundoplication. A tight fundoplication results in attenuation of the gastric walls, thickening of the esophageal wall, and loss of the 5-layer pattern secondary to obliteration of the potential spaces of the gastric lumen. Dehiscence of the fundoplication was evidenced by a less than 360 degree 5-layer pattern. CONCLUSIONS: EUS of hiatal anatomic relationships is feasible and provides detailed information regarding the integrity and the position of a Nissen fundoplication. EUS may enable a precise determination of the anatomic causes of failure after antireflux surgery.

Animals↗
PubMed2005

Transgastric laparoscopic resection of a giant esophageal lipoma.

We present an unusual case of a giant, pedunculated esophageal lipoma originating in the mid-esophagus ball-valving through the gastroesophageal junction resulting in intermittent obstruction and hemorrhage. Endoscopic ultrasonography revealed a 1 cm in diameter vessel in the stalk of the polyp, and endoscopic resection was not performed. Transgastric laparoscopic resection with endoscopic guidance was successfully performed using 2 balloon-tipped laparoscopic trocars inserted laparoscopically into the gastric lumen through separate gastrotomies. Intraoperative esophagoscopy confirmed proper port placement and the exact location of the mass. Under direct visualization, a Snowden-Pencer grasper was used to pull the polyp down into the stomach and an Endo-GIA blue articulating stapler was used to transect its stalk. The polyp was retrieved via an endopouch placed through the intragastric laparoscopic port. We conclude that transgastric laparoscopy should be considered for the resection of a variety of pedunculated esophageal lesions when the use of standard endoscopic techniques is not possible.

Digestive System Surgical Procedures↗
PubMed2004

Success and shortcomings of a clinical care pathway in the management of acute nonvariceal upper gastrointestinal bleeding.

OBJECTIVES: Acute nonvariceal upper gastrointestinal (GI) bleeding is the most common medical emergency encountered by gastroenterologists resulting in high patient morbidity and cost. We sought to establish if a GI bleeding clinical care pathway could improve the quality and cost effectiveness of inpatient medical care. METHODS: A disease management program for acute upper GI bleeding was established. Length of stay, time to endoscopy, utilization of potentially unnecessary radiological tests, acid suppression, and cost of care were compared between patients pre- and postinitiation of GI bleeding pathway guidelines. RESULTS: The instituted GI bleeding management program significantly reduced the use of intravenous H2-blockade from 65.3% to 47.7% (p = 0.002). The use of radiological tests, time to endoscopy, and length of hospital of stay were unchanged. There was a trend toward a reduction in total cost and variable direct cost per patient admitted with acute upper GI bleeding, from $5,381 to $4,627 and from $2,269 to $1,952, respectively. CONCLUSION: A clinical care pathway may affect the management of acute upper GI bleeding and reduce costs. However, there are significant limitations and barriers to the overall effectiveness of such a pathway in actual clinical practice.

Acute Disease↗
PubMed2004

Endoscopic management of biliary complications after adult living donor liver transplantation.

OBJECTIVES: Biliary complications and their treatment in adult cadaveric liver transplantation (CLT) are well described. However, biliary complications and their management in living donor liver transplantation (LDLT) are not well characterized. We assessed the role of endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis and management of biliary complications following LDLT. METHODS: We performed a retrospective cohort analysis of all LDLT recipients with duct-to-duct anastomoses (n = 15). Specific data included referral for ERCP, diagnosis, and therapy. Comparisons were made to a 260 CLT recipient cohort. RESULTS: Greater percentage of LDLT recipients underwent ERCP (73%) compared to CLT recipients (25%; p= 0.001). Biliary complications diagnosed by ERCP in LDLT recipients consisted of bile leaks and strictures, and were more frequent than in CLT recipients (leaks: 53%vs 12%; p= 0.001; strictures: 27%vs 5%; p= 0.01). Most leaks occurred at T-tube sites (LDLT: 87%; CLT: 65%). Diagnosis and therapy of leaks required a median of 2 ERCP procedures in both groups. Bile leaks were successfully treated endoscopically in 100% and 84% of LDLT and CLT recipients, respectively (p= 0.56). Most biliary strictures were anastomotic (LDLT: 100%; CLT: 64%). Strictures were diagnosed and treated with a median of 1.5 and 2 ERCP procedures in the LDLT and CLT groups, respectively. The duration of endoscopic therapy was a median of 10 and 14 wk, and success rates were 75% and 62% (p= 1.0) in LDLT and CLT groups, respectively. CONCLUSIONS: LDLT is associated with increased biliary complications as compared to CLT. ERCP is useful for diagnosis, can successfully treat most LDLT-related biliary complications, and should be attempted prior to more invasive interventions.

Adolescent↗
PubMed2003

Criteria for the diagnosis of dysplasia by endoscopic optical coherence tomography.

BACKGROUND: Endoscopic optical coherence tomography provides images of the GI mucosa and submucosa in microscopic detail. It is unknown whether endoscopic optical coherence tomography can reliably detect dysplasia. Colon polyps were used as a model to determine whether dysplasia in GI tissue has characteristic optical coherence tomography imaging features. METHODS: Endoscopic optical coherence tomography images of colon polyps and normal colon tissue were obtained at colonoscopy. In real time, endoscopists compared tissue organization and light scattering for polyps and normal mucosa with endoscopic optical coherence tomography. Imaged polyps were removed and evaluated histopathologically. Organization and light scattering, as assessed by endoscopic optical coherence tomography at colonoscopy, were compared for adenomas versus hyperplastic polyps. A computer program also quantified and compared the degree of light scattering for hyperplastic polyps and adenomas. RESULTS: A total of 44 polyps were imaged in 24 patients (30 adenomas, 14 hyperplastic polyps). Endoscopic optical coherence tomography images of adenomas had significantly less structure (p = 0.0005) and scattered light to a lesser degree than hyperplastic polyps (p = 0.0007). Hyperplastic polyps were significantly closer in organization (p = 0.0003) and light scattering (p = 0.0006) to normal mucosa as compared with adenomas. By digital image analysis, the light-scattering property of hyperplastic polyps was closer to normal mucosa compared with adenomas (14.86 vs. 45.81; p = 0.0001). CONCLUSIONS: Real-time endoscopic optical coherence tomography imaging differentiated adenomas, hyperplastic polyps, and normal colon tissue. By using the colon adenoma as a model, the endoscopic optical coherence tomography characteristics of dysplasia are loss of tissue organization and reduced light scattering.

Adenoma↗
PubMed2002

Accuracy of a narrow-diameter battery-powered endoscope in sedated and unsedated patients.

BACKGROUND: Esophagoscopy with a portable battery-powered endoscope could provide a safe, inexpensive, and minimally invasive way to screen for Barrett's esophagus or esophageal varices. The use of such an instrument in an unsedated fashion has not been previously evaluated. METHODS: Patients referred for an EGD were recruited to undergo an additional examination with the battery-powered endoscope before EGD. In phase 1, (n = 42) patients received conscious sedation before the battery-powered endoscopic examination. In phase 2, (n = 56) patients were not sedated and were given the option of a peroral (n = 43) or transnasal (n = 13) endoscopy. Examiners were blinded to patient history and procedure indications. Esophageal findings, ease of intubation, optical quality, and patient comfort for the battery-powered endoscope and standard EGD were recorded by the endoscopist. RESULTS: Ninety-eight patients (60 men, 38 women, mean age 53 years) were recruited. The sensitivity for detecting Barrett's esophagus, esophageal tumors, and esophageal varices was 54.5%, 66.7%, and 80%, respectively. Ease of intubation and patient comfort as perceived by the endoscopist were not significantly different between the battery-powered endoscope and EGD. Optical quality was ranked as less than 4 (on a 5-point scale with 5 = standard EGD and 1 = poor) in 42% of battery-powered endoscopic examinations. There were no complications. CONCLUSION: The accuracy of esophageal examination with a 3.1-mm endoscope is substantially inferior to standard EGD. Thus, the battery-powered endoscope would not be useful for screening patients for Barrett's esophagus or varices unless improvements in optical quality and visualization are made.

Adult↗
PubMed2002

Patient tolerance and acceptance of unsedated ultrathin esophagoscopy.

BACKGROUND: Unsedated endoscopy has not gained wide acceptance in the United States. Factors that may predict tolerance and acceptance of unsedated endoscopy are ill defined. METHODS: Outpatients referred for standard EGD were recruited to undergo unsedated ultrathin esophagoscopy (UUE) with a new 3.1-mm battery-powered esophagoscope before sedated EGD. They rated preprocedure and postprocedure anxiety levels with the Profile of Mood States Tension/Anxiety subscale (POMS-SF T/A). They also rated symptoms and overall acceptability and listed procedural preference between EGD and UUE. Patients who refused UUE noted a reason for refusal and also completed the anxiety questionnaire. RESULTS: Fifty-two of 98 patients recruited agreed to participate, and underwent both UUE and EGD. Patients who refused UUE were significantly more anxious (mean anxiety score, 8.2 vs. 4.5, p < 0.005). Participants reported no significant difference between preprocedural (4.6 vs. 5.3) or postprocedural (3.5 vs. 2.6) anxiety for UUE versus standard EGD. After undergoing both procedures, only 46% stated they would prefer UUE to EGD in the future. Patients who chose the peroral approach were more likely to prefer UUE than those who chose the transnasal approach (58% vs. 23%, p = 0.02). CONCLUSIONS: Patient acceptance of unsedated endoscopy even with an ultrathin instrument is limited. Anxiety assessment by the POMS-SF T/A can identify patients willing to undergo UUE. Patients who choose transoral UUE may be more willing to repeat the procedure.

Adult↗
PubMed2002

Endoscopic retrograde cholangiopancreatography in children and adolescents.

OBJECTIVES: Endoscopic retrograde cholangiopancreatography (ERCP) is becoming a more frequently used diagnostic and therapeutic tool in children. We sought to determine the indications, feasibility, safety, and effect on patient management of ERCP in pediatric patients of varying age. METHODS: All ERCPs performed during a 4-year period in patients aged 18 years or less at an academic hospital were retrospectively reviewed. The indications, type of anesthesia administered, type of duodenoscope used, diagnostic findings, therapeutic interventions, complication rate, and effect on management were compared between children (age 0-12 years) and adolescents (age 13-18 years). RESULTS: A total of 53 procedures were performed in 43 patients whose median age was 13.5 years. ERCP was successful in 50 of 53 cases (94%) with a complication rate of 6%. Endoscopic therapy was provided in 24 of 53 cases (45%). Compared with adolescents (n = 28), children (n = 25) were more likely to receive general anesthesia (96% vs. 29%; P < 0.001) and undergo ERCP with a pediatric duodenoscope (0% vs. 40%). ERCP affected management in 73% of cases, equally in both groups. CONCLUSION: ERCP is a successful and safe diagnostic and therapeutic modality in a variety of pancreatobiliary disorders that directly affects management in children of all ages.

Adolescent↗
PubMedDate not supplied

A novel use of endoscopic clips in the treatment planning for radiation therapy (XRT) of esophageal cancer.

GOAL: To determine if the placement of metal endoclips improves radiotherapy (XRT) planning for esophageal cancer. BACKGROUND: XRT is an important modality in the treatment and palliation of esophageal cancer. Accurate simulation of the radiation field ensures optimal therapy while limiting toxicity. STUDY: Patients with esophageal carcinoma underwent EGD and endoscopic mucosal clip placement at the proximal and distal margins of the tumor. At XRT simulation the radiation oncologist simulated the field based on barium study, CT scan, and endoscopy report. A second radiation oncologist then assessed the ease of identification of the clips/margins of the tumor, shift in the field isocenter, and change in the radiation field width and length because of the metal clips. RESULTS: Seven patients with cancer of the esophagus had endoscopic clips placed followed by XRT simulation. The clips could be identified in all 7 patients. Simulation with the use of clips caused a shift in the field isocenter with a mean longitudinal shift (y-axis) of 3.5 cm (range, 1-6 cm) and a mean lateral shift (x-axis) of 0.33 cm (range, 0-1 cm). CONCLUSIONS: Endoscopically placed mucosal metal clips can aid field simulation when planning radiation therapy in patients with esophageal cancer.

Aged↗