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Biomedical subjects

David H Harpole

Publications and source records attributed to David H Harpole.

30 records · Page 2Linked to original sources
PubMed2004

Prospective randomized study evaluating a biodegradable polymeric sealant for sealing intraoperative air leaks that occur during pulmonary resection.

BACKGROUND: To evaluate the safety and effectiveness of a new biodegradable polymeric sealant to close intraoperative air leaks after pulmonary resection. METHODS: In a multicenter prospective randomized trial, 161 patients with a median age of 67 years old (range 18-85 years old), were randomized in a 2:1 ratio to receive sealant or control for at least one significant air leak (> or = 2.0 mm in size) after pulmonary resection. In the sealant group, all significant air leaks underwent attempted repair by standard methods (sutures, staples, or cautery) prior to the application of sealant. The control group underwent only standard methods. Blood was analyzed for immunologic response. Patients were followed up 1 month after surgery. RESULTS: Intraoperative air leaks were sealed in 77% of the sealant group compared with 16% in the control group (p < 0.001). The sealant group had significantly fewer patients with postoperative air leaks compared with the control group (65% vs 86%, p = 0.005). Median length of hospitalization was 6 days (range, 3-23 days) for the sealant group compared with 7 days (range 4-38 days) for controls (p = 0.028). There was no difference in mortality, morbidity, duration of chest tubes, or immune responses between the two groups. CONCLUSIONS: This study demonstrates the effectiveness of a biodegradable polymer when used as an adjunct to standard closure methods for sealing significant intraoperative air leaks that develop from pulmonary surgery. Use of the sealant led to a reduction in postoperative air leaks, which may have decreased the length of hospitalization.

Adolescent↗
PubMed2004

Reducing hospital morbidity and mortality following esophagectomy.

BACKGROUND: Esophagogastrectomy (EG) is a formidable operation with significant morbidity and mortality rates. Risk factor analyses have been performed, but few studies have produced strategies that have improved operative results. This study was performed in order to identify prognostic variables that might be used to develop a strategy for optimizing outcomes after EG. METHODS: The records of all patients (n = 379) who underwent EG patients at a tertiary medical center between 1996 and 2002 were retrospectively reviewed. Thirty-day morbidity and mortality were determined, and multivariable logistical regression analysis assessed the effect of preoperative and postoperative variables on early mortality. RESULTS: Operations included Ivor Lewis (n = 179), transhiatal (n = 130), and other approaches (n = 70). Operative mortality was 5.8%; 64% experienced complications, including respiratory complications (28.5%), anastamotic strictures (25%), and leak (14%). Increasing age, anastomotic leak, Charlson comorbidity index 3, worse swallowing scores, and pneumonia were associated with increased risk of mortality by univariate analysis. However, only age (p = 0.002) and pneumonia (p = 0.0008) were independently associated with mortality by multivariable analysis. Pneumonia was associated with a 20% incidence of death. Patients with pneumonia had significantly worse deglutition and anastomotic integrity on barium esophagogram compared with patients without pneumonia (p < 0.001, Mann-Whitney rank sum test). CONCLUSIONS: Morbidity and mortality of EG are significant, but most complications, including anastomotic leak, are not independent predictors of mortality. The most important complication after EG is pneumonia. Strategies to decrease postoperative mortality should include careful assessment of swallowing abnormalities and predisposition to aspiration by cineradiography or fiberoptic endoscopy. After EG, acceptable pharyngeal function and airway protection should be verified before resuming oral intake.

Adenocarcinoma↗
PubMed2004

Thoracoscopic sympathectomy in the management of vasomotor disturbances and complex regional pain syndrome of the hand.

Complex regional pain syndrome, vasospastic disorders, and hyperhidrosis are chronic and debilitating upper extremity problems. Twenty-nine consecutive patients treated with thoracoscopic sympathectomy are presented. Diagnoses included complex regional pain syndrome, hyperhidrosis, Buerger's disease, Raynaud's disease, and peripheral vascular disease. All patients with hyperhidrosis had complete symptom resolution. Patients with Buerger's and Raynaud's disease had excellent/good results. Six patients with complex regional pain syndrome had excellent or good relief; the remaining six patients had varying degrees of recurrence. A statistically significant association was noted between duration of complex regional pain syndrome prior to sympathectomy and outcome. Thoracoscopic sympathectomy is an effective treatment for hyperhidrosis and vasospastic disorders. Although the results for complex regional pain syndrome are not uniformly excellent, this technique offers promise in the treatment of this difficult problem.

Adolescent↗
PubMed2003

Results of the American College of Surgeons Oncology Group Z0050 trial: the utility of positron emission tomography in staging potentially operable non-small cell lung cancer.

OBJECTIVES: The American College of Surgeons Oncology Group undertook a trial to ascertain whether positron emission tomography with 18F-fluorodeoxyglucose could detect lesions that would preclude pulmonary resection in a group of patients with documented or suspected non-small cell lung cancer found to be surgical candidates by routine staging procedures. METHODS: A total of 303 eligible patients registered from 22 institutions underwent positron emission tomography after routine staging (computed tomography of chest and upper abdomen, bone scintigraphy, and brain imaging) had deemed their tumors resectable. Positive findings required confirmatory procedures. RESULTS: Positron emission tomography was significantly better than computed tomography for the detection of N1 and N2/N3 disease (42% vs 13%, P =.0177, and 58% vs 32%, P =.0041, respectively). The negative predictive value of positron emission tomography for mediastinal node disease was 87%. Unsuspected metastatic disease or second primary malignancy was identified in 18 of 287 patients (6.3%). Distant metastatic disease indicated in 19 of 287 patients (6.6%) was subsequently shown to be benign. By correctly identifying advanced disease (stages IIIA, IIIB, and IV) or benign lesions, positron emission tomography potentially avoided unnecessary thoracotomy in 1 of 5 patients. CONCLUSIONS: In patients with suspected or proven non-small cell lung cancer considered resectable by standard staging procedures, positron emission tomography can prevent nontherapeutic thoracotomy in a significant number of cases. Use of positron emission tomography for mediastinal staging should not be relied on as a sole staging modality, and positive findings should be confirmed by mediastinoscopy. Metastatic disease, especially a single site, identified by positron emission tomography requires further confirmatory evaluation.

Adult↗
PubMed2003

Outcomes after esophagectomy: a ten-year prospective cohort.

BACKGROUND: The Department of Veterans Affairs National Surgical Quality Improvement Program is a unique resource to prospectively analyze surgical outcomes from a cross-section of surgical services nationally. We used this database to assess risk factors for morbidity and mortality after esophagectomy in Veterans Affairs Medical Centers from 1991 to 2001. METHODS: A total of 1,777 patients underwent an esophagectomy at 109 Veterans Affairs hospitals with complete in-hospital and 30-day outcomes recorded. Bivariate and multivariable analyses were completed. RESULTS: Thirty-day mortality was 9.8% (174/1,777) and the incidence of one or more of 20 predefined complications was 49.5% (880/1,777). The most frequent postoperative complications were pneumonia in 21% (380/1,777), respiratory failure in 16% (288/1,777), and ventilator support more than 48 hours in 22% (387/1,777). Preoperative predictors of mortality based on multivariable analysis included neoadjuvant therapy, blood urea nitrogen level of more than 40 mg/dL, alkaline phosphatase level of more than 125 U/L, diabetes mellitus, alcohol abuse, decreased functional status, ascites, and increasing age. Preoperative factors impacting morbidity were increasing age, dyspnea, diabetes mellitus, chronic obstructive pulmonary disease, alkaline phosphatase level of more than 125 U/L, lower serum albumin concentration, increased complexity score, and decreased functional status. Intraoperative risk factors for mortality included the need for transfusion; intraoperative risk factors for morbidity included the need for transfusion and longer operative time. CONCLUSIONS: These data constitute the largest prospective outcomes cohort in the literature and document a near 50% morbidity rate and 10% mortality rate after esophagectomy. Data from this study can be used to better stratify patients before esophagectomy.

Age Factors↗
PubMed2003

Measurement of chemoresistance markers in patients with stage III non-small cell lung cancer: a novel approach for patient selection.

BACKGROUND: The long-term survival of patients with stage III non-small cell lung cancer treated with a combination of chemotherapy and radiation is 10% to 20%. Survival could potentially be increased and toxicity limited if one could identify patients most likely to respond to a particular treatment regimen. This project prospectively evaluated a panel of potential immunohistochemical markers of chemoresistance in a population of patients with pathology-confirmed stage III non-small cell lung cancer in order to determine the prognostic value of each marker in relation to response to chemotherapy or survival. METHODS: Immunohistochemical staining was performed on histologically positive mediastinal nodal specimens obtained from 59 patients (mean age, 62 years; range, 41 to 79 years) without evidence of distant metastatic disease treated with navelbine-based chemotherapy and external beam radiation therapy between 1996 and 2001. Included were markers for apoptosis (p53, bcl-2), drug efflux/degradation (MDR, GST-pi), growth factors (EGFr, Her2-neu), and mismatch repair (hMLH1, hMSH2). After chemotherapy, patients underwent radiologic evaluation for response measured by standard criteria. RESULTS: After a median 41 months of follow-up (range, 17 to 55 months), 43 patients had recurrent disease and 38 of these patients were dead of cancer (median cancer-free survival of 10 months and overall survival of 18 months). Patients who demonstrated a complete or partial response (n = 38) had a significantly improved survival (p = 0.002) compared with those with stable or progressive cancer (n = 21). Multivariable Cox step-wise regression analysis of marker expression associated overexpression of p53 and low expression of hMSH2 with poor treatment response and cancer death. CONCLUSIONS: These preliminary data suggest that marker expression may allow the separation of patients into low- and high-risk groups with respect to survival after combined navelbine-based chemotherapy and XRT. This could represent a novel method of selecting patients for a particular treatment regimen if these data are reproduced in a larger prospective trial.

Aged↗
PubMed2003

A comparative analysis of positron emission tomography and mediastinoscopy in staging non-small cell lung cancer.

OBJECTIVES: Positron emission tomography has been demonstrated to improve the detection of distant metastases in patients with lung cancer. This study compares the efficacy of PET to mediastinoscopy in mediastinal staging of patients with non-small cell lung cancer. METHODS: Between May 1995 and May 2000, positron emission tomography was performed on 1988 patients with known or suspected non-small cell lung cancer at Duke University Medical Center. Cervical mediastinoscopy was subsequently performed in patients without demonstrable evidence of distant metastases. The efficacy of mediastinal staging was analyzed by comparing the prospective results of positron emission tomography with the histopathologic results of mediastinoscopy by nodal station. RESULTS: In this study 202 patients with non-small cell lung cancer (116 of whom were male) underwent mediastinoscopy after positron emission tomography. Of the 65 patients with positive results of positron emission tomography, only 29 patients had positive results of mediastinoscopy in the corresponding nodal station. Of the 137 patients with negative results of positron emission tomography, 16 patients were demonstrated to have N2 or N3 disease. The sensitivity, specificity, positive and negative predictive values, and accuracy for positron emission tomography were 64.4%, 77.1%, 44.6%, 88.3%, and 74.3%, respectively. Histologic findings in patients with non-small cell lung cancer and false-positive results of mediastinal positron emission tomography included granulomatous inflammation, sinus histiocytosis, and silicosis. CONCLUSIONS: Positron emission tomography neither confirms nor excludes involvement of the mediastinum in patients with non-small cell lung cancer. Cervical mediastinoscopy with lymph node biopsy remains the criterion standard for mediastinal staging.

Adult↗
PubMed2003

Predictive value of the EphA2 receptor tyrosine kinase in lung cancer recurrence and survival.

PURPOSE: Underestimation of disease severity is a major problem confronting the successful clinical management of non-small cell lung cancer. Recent advances in molecular biological substaging may provide an opportunity to identify those patients with the most aggressive forms of the disease, but there is a continuing need for accurate markers of disease relapse and survival. EXPERIMENTAL DESIGN: In our present study, immunohistochemical analyses of a retrospective database of pathologic specimens were used to demonstrate that the EphA2 receptor kinase is frequently overexpressed in NSCLC. RESULTS: Initial presentation with high levels of EphA2 predicts subsequent survival, overall relapse, and site of relapse. Specifically, high levels of EphA2 in the primary tumor predict brain metastases, whereas low levels of EphA2 relate to disease-free survival or contralateral lung metastasis. CONCLUSIONS: These data suggest that EphA2 may provide a molecular marker to identify and predict patients who have isolated brain metastases. Moreover, the high levels of EphA2 in lung cancer may provide an opportunity for therapeutic targeting.

Biomarkers, Tumor↗
PubMed2002

Impact of computed tomography-positron emission tomography fusion in staging patients with thoracic malignancies.

BACKGROUND: Positron emission tomography (PET) has been demonstrated to improve staging in patients with thoracic malignancies. This study evaluates the ability of a new imaging technique to improve the spatial resolution and accuracy of PET. METHODS: Patients with known or suspected malignancy (n = 21) who were referred for a dedicated PET scan were also evaluated with a new camera-based PET system, which uniquely allows simultaneous computed tomography (CT) and fusion of the camera-based PET images with the CT images. The dedicated PET scan was obtained 1 hour after intravenous injection of fluorodeoxyglucose. The camera-based PET imaging was fused with the CT images at approximately 2 hours after injection. The camera-based PET and CT-PET fusion images were read independently and blindly by 2 experienced observers and the presence and location of abnormalities was compared with dedicated PET scans. RESULTS: Dedicated PET identified 18 sites in the chest as abnormal. The CT-PET fusion was superior to the camera-based PET alone, concordant with the dedicated PET in 16 of 21 patients compared with 13 of 21 by camera-based PET. The lesions missed by the camera-based PET were less than 1 cm in diameter. Fused CT-PET images provided superior anatomic localization and spatial resolution compared with dedicated PET and camera-based PET. CONCLUSIONS: CT-PET fusion images were more accurate than camera-based PET alone. CT-PET fusion improves the spatial resolution compared with dedicated PET and may improve the availability and efficacy of staging of patients with thoracic malignancies.

Humans↗
PubMed2002

Molecular staging of lung and esophageal cancer.

In both esophageal and NSCLC, the TNM stage at diagnosis remains the most important determinant of survival. Significant research to investigate the biology of NSCLC and esophageal carcinoma is ongoing, and the roles of proto-oncogenes, tumor suppressor genes, angiogenic factors, extracellular matrix proteases, and adhesion molecules are being elucidated. While evidence is accumulating that various markers are involved in NSCLC and esophageal tumor virulence, the current studies are compromised by small sample sizes, heterogeneous populations, and variations in techniques. Large prospective studies with homogenous groups designed to evaluate the role of these various markers should clarify their potential involvement in NSCLC and esophageal cancer. Identification of occult micrometastases in lymph nodes and bone marrow using immunohistochemical techniques and rt-PCR is intriguing. These techniques are promising as a method to more accurately stage patients, and therefore to predict outcomes and to determine therapies. Perhaps the most promising area of research is the development of novel drugs whose mechanism of action targets the pathways of various molecular markers. Molecular biologic substaging offers an opportunity to individualize a chemotherapeutic regimen based on the molecular profile of the tumor, thus providing the potential for improved outcomes with less morbidity in patients with both NSCLC and esophageal cancer.

Carcinoma, Non-Small-Cell Lung↗
PubMed2002

Intraoperative techniques to prevent air leaks.

Persistent air leaks prolong chest tube duration and hospital stay after lung surgery. Air leaks also may lead to life-threatening empyemas. Preventing postoperative air leaks and BPFs is the best treatment for air-leak complications. Meticulous closure of parenchymal, pleural, and bronchial defects is the mainstay of air-leak control. The reinforcement of parenchymal suture and staple lines, pleural apposition, and well-vascularized tissue-flap coverage of bronchial suture and staple lines further reduce the incidence of prolonged air leaks and BPFs.

Animals↗