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Biomedical subjects

David L Carr-Locke

Publications and source records attributed to David L Carr-Locke.

14 recordsLinked to original sources
PubMed2003

Late genitourinary and gastrointestinal toxicity after magnetic resonance image-guided prostate brachytherapy with or without neoadjuvant external beam radiation therapy.

BACKGROUND: This study was designed to estimate the rates of late genitourinary (GU) and rectal toxicity after magnetic resonance image (MRI)-guided prostate brachytherapy exclusively or in conjunction with external beam radiation therapy (EBRT). METHODS: Between November 1997 and April 2002, 201 patients with category T1C prostate carcinoma (according to the 2002 American Joint Committee on Cancer staging criteria), prostate specific antigen levels < 10 ng/mL, and biopsy Gleason score 3 + 4 disease were treated with MRI-guided brachytherapy exclusively or in conjunction with EBRT. The MRI-guided technique was designed to spare the urethra based on delivery of the prescription dose to the peripheral zone exclusively. The Kaplan-Meier method was used to estimate rates of freedom from late GU and rectal toxicity. Comparisons were made using a log-rank test. RESULTS: At a median follow-up of 2.8 years (range, 0.5-5.0 years), the 4-year estimates of rectal bleeding requiring coagulation for patients who underwent implantation therapy, compared with patients who received combined-modality therapy, were 8% versus 30%, respectively (log-rank P value = 0.0001). Although erectile dysfunction was common (range, 82-93%), with the use of sildenafil citrate (Viagra), it was estimated that at least two-thirds of patients had erectile function comparable to or superior to baseline function, independent of whether they received monotherapy or combined-modality therapy (P = 0.46). The 4-year estimate of freedom from radiation cystitis was 100% versus 95% (P = 0.01) for patients who received monotherapy and patients who received combined-modality therapy, respectively. No urethral strictures were observed, and no patients underwent postimplantation transurethral resection of the prostate. CONCLUSIONS: In the current study, rectal bleeding after MRI-guided prostate brachymonotherapy was infrequent, and urethral and bladder toxicity is reported to be rare and may be attributed to the urethral-sparing technique of the MRI-guided approach.

Aged↗
PubMed2003

Biliary pancreatitis.

Gallstone-induced acute pancreatitis is a prevalent condition that is associated with an unacceptably high mortality rate. Early endoscopic intervention, including endoscopic retrograde cholangiopancreatography and endoscopic sphincterotomy within 24 to 72 h of hospital admission, can be used to remove stones in the common bile duct (CBD) and establish biliary drainage. Anecdotal evidence of its effectiveness led to formal testing in randomized clinical trials. Although the design and results of the four published studies have varied, the overall conclusion is that early endoscopic therapy reduces morbidity and mortality in patients with acute biliary pancreatitis. Benefits are especially apparent in patients who satisfy generally accepted criteria for severe pancreatitis. The author's practice is to undertake endoscopic retrograde cholangiopancreatography in patients with severe or worsening pancreatitis, or in patients with jaundice, cholangitis or dilation of the CBD. Endoscopic sphincterotomy is performed in patients with CBD stones or in patients with biliary pancreatitis and cholelithiasis who are not candidates for cholecystectomy. The roles of newer diagnostic modalities, including magnetic resonance cholangiopancreatography and endoscopic ultrasonography, are not yet clear.

Acute Disease↗
PubMed2002

NAD(P)H and collagen as in vivo quantitative fluorescent biomarkers of epithelial precancerous changes.

During the development of neoplasia, epithelial tissues undergo biochemical and structural changes that can manifest in tissue fluorescence. There have been several reports on different in vivo fluorescence characteristics between normal and precancerous (dysplastic) tissues. However, it has been difficult to identify and quantify the origins of these changes, mainly because of distortions introduced in measured tissue fluorescence spectra by tissue scattering and absorption. Such distortions can be removed by combining information in simultaneously measured fluorescence and reflectance spectra. Thus, we can recover the intrinsic (undistorted) tissue fluorescence. In this report, we show that extraction of the intrinsic fluorescence allows us: (a) to determine the fluorescence spectra of NAD(P)H and collagen in an in vivo environment, and (b) to use these NAD(P)H and collagen spectra to describe, quantitatively, diagnostically significant biochemical changes between normal and dysplastic tissues. Specifically, by analyzing intrinsic fluorescence of human epithelial tissue as it becomes deoxygenated in vivo, we can resolve the fluorescence spectra of NAD(P)H and collagen, two of the major tissue fluorophores. This is important because fluorescence depends on the local environment of the chromophore. Then, we extract the intrinsic fluorescence spectra of sites from 35 patients with suspected cervical lesions and 7 patients with Barrett's esophagus and describe them accurately as a linear combination of NAD(P)H and collagen contributions. In both tissue cases, we find that low collagen and high NAD(P)H fluorescence characterizes the high-grade dysplastic lesions when compared with nondysplastic tissues. These data present evidence for the presence of detectable levels of NAD(P)H fluorescence in human epithelial tissues in an in vivo setting and demonstrate that NAD(P)H and collagen may be used as quantitative fluorescence biomarkers for in vivo detection of dysplasia in the cervix and the esophagus.

Barrett Esophagus↗
PubMed2002

The role of ERCP and pancreatoscopy in cystic and intraductal tumors.

ERCP and pancreatoscopy may establish a diagnosis of IPMT and differentiate it from a pseudocyst or cystic neoplasm of the pancreas. These techniques may also assess risk of malignancy, extent of disease, allow tissue sampling, and provide therapeutic intervention.

Adenocarcinoma, Mucinous↗
PubMed2002

Virtual colonoscopy for the detection of colorectal polyps and cancers in a Chinese population.

AIM: The aim of this study is to assess the sensitivity of virtual colonoscopy in detecting colorectal polyps and cancers in a Chinese population. METHODS: Seventy-one consecutive Chinese patients (38 men and 33 women) referred for diagnostic colonoscopy were recruited. Patients received a routine bowel preparation in the morning followed by a helical abdominal computed tomography (CT) scan with air insufflation of the colon. The CT images were then processed by using surface-rendered software and interpreted by a single radiologist who was blinded to the clinical information. Colonoscopy was performed in the same afternoon without knowledge of the radiology results. All polyps and cancers were proven histologically. RESULTS: Five colorectal cancers were diagnosed and all were detected by virtual colonoscopy. The sensitivity and specificity of virtual colonoscopy for the detection of patients with polyps of all sizes, and patients with polyps >/=10 mm were 59, 92, 88 and 100%, respectively. The procedure was well tolerated by all patients. CONCLUSIONS: This study was carried out in a real clinical setting without a preselection of cases. Virtual colonoscopy was satisfactory for the detection of polyps greater than 10 mm, and for the diagnosis of cancer, and it is also a promising imaging modality for colorectal neoplasm detection in a Chinese population.

Colonic Polyps↗
PubMed2002

"Tannenbaum" Teflon stents versus traditional polyethylene stents for treatment of malignant biliary stricture.

BACKGROUND: Premature stent clogging is the major limitation with plastic stents used in the treatment of malignant biliary structures. A pilot study suggested improved duration of patency of the Tannenbaum stent compared with polyethylene stents. The aim of this prospective, multicenter randomized trial was to compare the Tannenbaum Teflon stent with a conventional polyethylene endoprosthesis (Cotton-Leung biliary stent set) for the treatment of malignant biliary strictures. METHODS: Patients over age 18 years with symptoms caused by nonhilar malignant biliary strictures were enrolled. Patients were randomized to receive a 10F Tannenbaum or polyethylene stent after a guidewire was passed beyond the stricture. One hundred six patients (mean age 72 years and 71 years, respectively) were enrolled (54 Tannenbaum, mean age 72 years; 52 polyethylene, mean age 71 years). RESULTS: Tannenbaum and polyethylene stent placement was successful in, respectively, 100% and 96% of procedures without complications. The mean (SD) 90-day stent patency of the Tannenbaum stent was 67% (7%) compared with 73% (7%) for the polyethylene stents. CONCLUSIONS: The present study demonstrated no difference in ease of implantation or stent patency between Tannenbaum and polyethylene stents.

Aged↗
PubMed2002

High-resolution chromoendoscopy for classifying colonic polyps: a multicenter study.

BACKGROUND: Chromoendoscopy may reliably separate adenomatous from nonadenomatous polyps. The aim of this multicenter trial was to determine the accuracy of high-resolution chromoendoscopy for the determination of colonic polyp histology. METHODS: This multicenter trial included 4 academic centers and a primary care practice. In 299 patients referred for routine colonoscopy or sigmoidoscopy, 520 polyps 10 mm in size were sprayed with indigo carmine dye. Using a high-resolution endoscope, the endoscopist predicted the histology of each polyp based on its surface characteristics. Hyperplastic polyps had a "pitted" surface pattern of orderly arranged "dots" that resembled surrounding normal mucosa. Adenomatous polyps had at least one surface "groove" or "sulcus." Each polyp was subsequently resected for histopathologic evaluation. RESULTS: The resected polyps were comprised by 193 adenomas (37%), 225 hyperplastic polyps (43%), and 102 "other" types (20%). Forty polyps (7.7%) could not be classified by high resolution chromoendoscopy with indigo carmine dye. For the remaining polyps, the sensitivity, specificity, and negative predictive value of indigo carmine dye staining for adenomatous polyps were, respectively, 82%, 82%, and 88%. The results were consistent among the academic centers and the primary care practice. CONCLUSIONS: High-resolution chromoendoscopy with indigo carmine dye demonstrates morphologic detail of diminutive colorectal polyps that can reliably be used to separate adenomatous from nonadenomatous polyps.

Adenoma↗
PubMed2002

Pancreatic stent placement for duct disruption.

BACKGROUND: The aim of this study was to identify predictors of outcome after pancreatic duct stent placement for duct disruption. METHODS: Patients were identified from endoscopy databases. Disruption was defined by extravasation of contrast from the pancreatic duct during endoscopic retrograde pancreatography. Data collected included demographic information, imaging studies, management before and outcome after stent placement. Success was defined as resolution of the disruption clinically, on radiologic imaging, and/or at endoscopic retrograde pancreatography. RESULTS: Forty-three patients (23 women, 20 men; mean age 57 years, [SD] 15.2 years) were studied. The etiology of pancreatic duct disruption was acute pancreatitis in 24, chronic pancreatitis in 9, operative injury in 7, and trauma in 3 patients. In 25 patients there was resolution of the disruption, whereas stent therapy was unsuccessful in 16 and the outcome was indeterminate in 2 patients. On univariate analysis, stent positioned to bridge the disruption (p = 0.04) and longer duration of stent therapy (p = 0.002) were associated with a successful outcome. Female gender (p = 0.05) and acute pancreatitis (p = 0.05) were associated with a lack of success. On multivariate analysis, only the bridging stent position remained correlated to outcome. Complications occurred in 4 patients. CONCLUSIONS: A bridging stent is associated with a successful outcome after pancreatic duct stent placement for duct disruption.

Acute Disease↗
PubMed2002

Risk factors for complications after performance of ERCP.

BACKGROUND: ERCP has become widely available for the diagnosis and treatment of benign and malignant pancreaticobiliary diseases. In this prospective study, the overall complication rate and risk factors for diagnostic and therapeutic ERCP were identified. METHODS: Data were collected prospectively on patient characteristics and endoscopic techniques from 1223 ERCPs performed at a single referral center and entered into a database. Univariate and multivariate analyses were used to identify risk factors for ERCP-associated complications. RESULTS: Of 1223 ERCPs performed, 554 (45.3%) were diagnostic and 667 (54.7%) therapeutic. The overall complication rate was 11.2%. Post-ERCP pancreatitis was the most common (7.2%) and in 93% of cases was self-limiting, requiring only conservative treatment. Bleeding occurred in 10 patients (0.8%) and was related to a therapeutic procedure in all cases. Nine patients had cholangitis develop, most cases being secondary to incomplete drainage. There was one perforation (0.08%). All other complications totaled 1.5%. Variables derived from cannulation technique associated with an increased risk for post-ERCP pancreatitis were precut access papillotomy (20%), multiple cannulation attempts (14.9%), sphincterotome use to achieve cannulation (13.1%), pancreatic duct manipulation (13%), multiple pancreatic injections (12.3%), guidewire use to achieve cannulation (10.2%), and the extent of pancreatic duct opacification (10%). Patient characteristics associated with an increased risk of pancreatitis were sphincter of Oddi dysfunction (21.7%) documented by manometry, previous ERCP-related pancreatitis (19%), and recurrent pancreatitis (16.2%). Pain during the procedure was an important indicator of an increased risk of post-ERCP pancreatitis (27%). Independent risk factors for post-ERCP pancreatitis were identified as a history of recurrent pancreatitis, previous ERCP-related pancreatitis, multiple cannulation attempts, pancreatic brush cytology, and pain during the procedure. CONCLUSIONS: The most frequent ERCP-related complication was pancreatitis, which was mild in the majority of patients. The frequency of post-ERCP pancreatitis was similar for both diagnostic and therapeutic procedures. Bleeding was rare and mostly associated with sphincterotomy. Other complications such as cholangitis and perforation were rare. Specific patient- and technique-related characteristics that can increase the risk of post-ERCP complications were identified.

Adolescent↗
PubMedDate not supplied

Benign nonampullary duodenal neoplasms.

Benign duodenal neoplasms (BDNs) are uncommon, and their optimal management remains undefined. We analyzed all cases of BDN treated at our institution during a 10-year period (January 1990 through January 2000). Data are expressed as median (range). Sixty-two patients were treated for BDNs. The results of histologic examination of their lesions were as follows: 36 adenomas, eight Brunner's gland tumors, 10 inflammatory polyps, two hamartomas, and six others. Forty-seven patients were treated nonoperatively, and 15 patients underwent surgery. Lesion characteristics leading to surgical intervention included large polyp diameter and submucosal penetration detected on endoscopic ultrasound imaging. There were no treatment-related deaths. Major morbidity occurred in 2% of patients who underwent endoscopic resection and in 33% of patients who underwent surgery (P = 0.002). Among patients treated for adenomas, seven (19.4%) had a recurrence at a median of 12 (4 to 48) months. Most BDNs can be managed with minimal morbidity using endoscopic techniques. Systematic follow-up of patients treated for adenomas is required.

Adenoma↗